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Sample records for tendon corrosion-inhibitor leakage

  1. Predicting the Performance of Organic Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    David A. Winkler

    2017-12-01

    Full Text Available The withdrawal of effective but toxic corrosion inhibitors has provided an impetus for the discovery of new, benign organic compounds to fill that role. Concurrently, developments in the high-throughput synthesis of organic compounds, the establishment of large libraries of available chemicals, accelerated corrosion inhibition testing technologies, and the increased capability of machine learning methods have made discovery of new corrosion inhibitors much faster and cheaper than it used to be. We summarize these technical developments in the corrosion inhibition field and describe how data-driven machine learning methods can generate models linking molecular properties to corrosion inhibition that can be used to predict the performance of materials not yet synthesized or tested. We briefly summarize the literature on quantitative structure–property relationships models of small organic molecule corrosion inhibitors. The success of these models provides a paradigm for rapid discovery of novel, effective corrosion inhibitors for a range of metals and alloys in diverse environments.

  2. Emerging Corrosion Inhibitors for Interfacial Coating

    Directory of Open Access Journals (Sweden)

    Mona Taghavikish

    2017-12-01

    Full Text Available Corrosion is a deterioration of a metal due to reaction with environment. The use of corrosion inhibitors is one of the most effective ways of protecting metal surfaces against corrosion. Their effectiveness is related to the chemical composition, their molecular structures and affinities for adsorption on the metal surface. This review focuses on the potential of ionic liquid, polyionic liquid (PIL and graphene as promising corrosion inhibitors in emerging coatings due to their remarkable properties and various embedment or fabrication strategies. The review begins with a precise description of the synthesis, characterization and structure-property-performance relationship of such inhibitors for anti-corrosion coatings. It establishes a platform for the formation of new generation of PIL based coatings and shows that PIL corrosion inhibitors with various heteroatoms in different form can be employed for corrosion protection with higher barrier properties and protection of metal surface. However, such study is still in its infancy and there is significant scope to further develop new structures of PIL based corrosion inhibitors and coatings and study their behaviour in protection of metals. Besides, it is identified that the combination of ionic liquid, PIL and graphene could possibly contribute to the development of the ultimate corrosion inhibitor based coating.

  3. Development of green vapour corrosion inhibitor

    Science.gov (United States)

    Asmara, Y. P.; Suraj, V.; Siregar, J. P.; Kurniawan, T.; Bachtiar, D.; Mohamed, N. M. Z. N.

    2017-10-01

    Corrosion control using inhibitor is an effective method to protect carbon steel from corrosion. Due to environmental toxicity of chemical inorganic corrosion inhibitors (synthetic), green inhibitors are potentially to develop. In atmospheric conditions, green vapour corrosion inhibitors are the best solutions to replace the uses of inorganic corrosion inhibitors. This research used chemical acid extraction from the key lime (citrus aurantiifolia) leaves and seeds. They are used as the main ingredients to produce this effective green corrosion inhibitor. The experiments investigated effects of corrosion inhibition on corrosion rate of low carbon steel in 3% NaCl solution using both fog salt chamber and electrochemical cell. Using salt fog chamber to represent atmospheric conditions, and corrosion rates are evaluated visually and calculated using weight loss methods. Corrosion rate on electrochemical cell were calculated using linear polarization resistance (LPR) methods. All of the experiments were set in natural conditions at pH 7. Using weight loss for three days exposure time, the efficiency of the inhibitor reached 82.39%.

  4. Corrosion inhibitor and method of use

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D.A.; Holifield, P.K.; Looney, J.R.; McDougall, L.A.

    1991-03-26

    This paper discusses a corrosion inhibitor formulation capable of dispersion in aqueous well treating acids. It comprises from 1 to 25 wt % of a metal salt wherein the metal thereof is selected from the group consisting of Cu{sup +}, Sn, Zn, and a Group IIA metal having an atomic number from 12 to 56, a Group IVA metal having an atomic number of 22 or 40, a Group IIIB metal having an atomic number from 13 to 49, a Group VIA metal having an atomic number from 24 to 74, and a Group VB metal having an atomic number from 33 to 83; and mixtures thereof; from 3 to 50 wt% of a quaternary ammonium compound capable of forming a complex with the metal salt; sufficient amount of a highly polar aprotic solvent to dissolve the metal salt and the quaternary ammonium compounds, the concentration of the polar aprotic solvent being between 20 to 90 wt %; and from 1 to 15% of an organic amine dispersant for dispersing the complex of the quaternary ammonium compound and the metal salt in the sell treating acid, the wt % being based on the formulation. This patent also describes a method of acidizing a subterranean formation by injecting a well treating acid solution down pipe into the well. It comprises preparing the corrosion inhibitor formulation of claim 1; dispersing the formulation in the well treating acid solution to provide the solution with at least 0.08 wt % of the metal salt based on the combined weight of the well treating acid and formulation, and injecting the well treating acid solution containing the corrosion inhibitor formulation through the pipe into the formation.

  5. Dual Use Corrosion Inhibitor and Penetrant for Anomaly Detection in Neutron/X Radiography

    Science.gov (United States)

    Hall, Phillip B. (Inventor); Novak, Howard L. (Inventor)

    2004-01-01

    A dual purpose corrosion inhibitor and penetrant composition sensitive to radiography interrogation is provided. The corrosion inhibitor mitigates or eliminates corrosion on the surface of a substrate upon which the corrosion inhibitor is applied. In addition, the corrosion inhibitor provides for the attenuation of a signal used during radiography interrogation thereby providing for detection of anomalies on the surface of the substrate.

  6. Application of response surface methodology method in designing corrosion inhibitor

    Science.gov (United States)

    Asmara, Y. P.; Athirah; Siregar, J. P.; Kurniawan, T.; Bachtiar, D.

    2017-10-01

    In oil and gas pipelines and offshore structure, inhibitors have been considered to be the first choice to reduce corrosion rate. There are many corrosion inhibitor compositions available in the market. To produce the best corrosion inhibitor requires many experimental data which is not efficient. These experiments used response surface methodology (RSM) to select corrosion inhibitor compositions. The experiments investigated effects of corrosion inhibition on corrosion rate of low carbon steel in 3% NaCl solution with different concentrations of selected main inhibitor compositions which are ethyl acetate (EA), ethylene glycol (EG) and sodium benzoate (SB). Corrosion rate were calculated using linear polarization resistance (LPR). All of the experiments were set in natural conditions at pH 7. MINITAB® version 15 was used for data analysis. It is shown that a quadratic model is a representative model can predict best corrosion inhibitor composition comprehensibly.

  7. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  8. Investigating longevity of corrosion inhibitors and performance of deicer products under storage or after pavement application.

    Science.gov (United States)

    2011-06-01

    This study evaluated the longevity of corrosion inhibitors and the performance of inhibited deicer products under storage or after pavement application. No significant degradation of corrosion inhibitor or loss of chlorides was seen during the months...

  9. Release of cerium dibutylphosphate corrosion inhibitors from highly filled epoxy coating systems

    NARCIS (Netherlands)

    Soestbergen, M. van; Baukh, V.; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

    2014-01-01

    Carcinogenic chromates are phased out as corrosion inhibitors in organic coatings, and are replaced by benign alternatives. Cerium-based compounds are excellent corrosion inhibitors in an aqueous environment. However, whether they are effective as corrosion inhibitor in an organic coating also

  10. 21 CFR 178.3300 - Corrosion inhibitors used for steel or tinplate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Corrosion inhibitors used for steel or tinplate... AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3300 Corrosion inhibitors used for steel or tinplate. Corrosion inhibitors may be safely used for steel or tinplate intended for use in, or...

  11. An interesting and efficient green corrosion inhibitor for aluminium ...

    African Journals Online (AJOL)

    An interesting and efficient green corrosion inhibitor for aluminium from extracts of Moringa oleifera in acidic solution. ... The environmentally friendly inhibitor could find possible applications in metal surface anodizing and surface coating in industries. Keywords: Moringa oleifera, Aluminium, Hydrochloric acid, Langmuir ...

  12. phytochemicals as green corrosion inhibitors in various corrosive ...

    African Journals Online (AJOL)

    Mgina

    replace toxic inhibitors used for mitigation of corrosion of various metals and alloys in aqueous solutions. Plants represent a class of ... structures causing economic consequences in terms of repair, replacement, product ... Buchweishaija – Physicochemicals as green corrosion inhibitors … 78 rather complex molecular ...

  13. Phytochemicals as Green Corrosion Inhibitors in Various Corrosive ...

    African Journals Online (AJOL)

    There is an intensive effort underway to develop new plant origin corrosion inhibitors for metal subjected to various environmental conditions. These efforts have been motivated by the desire to replace toxic inhibitors used for mitigation of corrosion of various metals and alloys in aqueous solutions. Plants represent a class ...

  14. Cashew nut shell liquid as an alternative corrosion inhibitor for ...

    African Journals Online (AJOL)

    Cashew Nut Shell Liquid (CNSL) has been tested as a corrosion inhibitor for carbon steel in 3% aqueous NaCl solution (pH 6) saturated with carbon dioxide gas at 30°C under static conditions using ac-impedance and potentiodynamic polarisation techniques. It was found that CNSL reduces the extent of the ...

  15. Use of Silica Tubes as Nanocontainers for Corrosion Inhibitor Storage

    Directory of Open Access Journals (Sweden)

    Cesia Ávila-Gonzalez

    2011-01-01

    Full Text Available A new alkyd paint anticorrosion smart coating was developed by using silica nanoparticles as corrosion inhibitor nanocontainers. Silica particles were mixed with the paint at different concentrations to study their performance and ensure their free transportation to the damaged metal. The filling up of silica particles was done preparing three solutions: distilled water, acetone, and a mixture of both, with Fe(NO33 and silica particles immersed in each of the solutions to adsorb the inhibitor. Acetone solution was the best alternative determined by weight gain analysis made with the inhibitor adsorbed in silica nanocontainers. Steel samples were painted with inhibitor silica nanocontainer coatings and immersed in an aqueous solution of 3% sodium chloride. Polarization curves and electrochemical noise techniques were used to evaluate the corrosion inhibitor system behavior. Good performance was obtained in comparison with samples without inhibitor nanocontainer coating.

  16. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  17. Novel Synthesis of Vegetable Oil Derived Corrosion Inhibitors

    OpenAIRE

    Paul Rostron; Sonia Kasshanna

    2015-01-01

    Two different naturally occurring vegetable oils, Cress seed oil, and Linseed oil were chemically modified via novel one pot synthesis to produce fatty acid derived amides. These were characterized by their ability to prevent corrosion of carbon steel in vigorously stirred, aerated seawater, one of the most corrosive naturally occurring environments. Corrosion inhibitor efficiencies of up to 99.6% or a corrosion rate reduction factor of 250 in this medium is reported. The one pot synthetic st...

  18. Natural compounds as corrosion inhibitors for highly cycled systems

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. [Corrosion Research Lab., Aligarh (India)

    1999-11-01

    Strict environmental legislations have led to the development of green inhibitors in recent years. In continuation of the authors` research work on development of green inhibitors, they have investigated the aqueous extracts of three plants namely: Azadirachta indica, Punica Granatum and Momordica charantia as corrosion inhibitors for mild steel in 3% NaCl using weight loss and electrochemical methods. All the investigated compounds exhibited excellent corrosion inhibition properties comparable to that of HEDP. Azadirachta showed better scale inhibition effect than HEDP.

  19. Corrosion inhibitor mechanisms on reinforcing steel in Portland cement pastes

    Science.gov (United States)

    Martin, Farrel James

    2001-07-01

    The mechanisms of corrosion inhibitor interaction with reinforcing steel are investigated in the present work, with particular emphasis on effects associated with corrosion inhibitors admixed into Portland cement paste. The principal objective in reinforcing steel corrosion inhibition for Portland cement concrete is observed to be preservation of the naturally passive steel surface condition established by the alkaline environment. Introduction of chloride ions to the steel surface accelerates damage to the passive film. Excessive damage to the passive film leads to loss of passivity and a destabilization of conditions that facilitate repair of the passive film. Passive film preservation in presence of chloride ions is achieved either through stabilization of the passive film or by modification of the chemical environment near the steel surface. Availability of inhibitors to the steel surface and their tendency to stabilize passive film defects are observed to be of critical importance. Availability of admixed corrosion inhibitors to the passive film is affected by binding of inhibitors during cement paste hydration. It is determined that pore solution concentrations of inorganic admixed inhibitors tend to be lower than the admixed concentration, while pore solution concentrations of organic admixed inhibitors tend to be higher than the admixed concentration. A fundamental difference of inhibitor function is observed between film-forming and defect stabilizing corrosion inhibitors. Experiments are conducted using coupons of reinforcing steel that are exposed to environments simulating chloride-contaminated Portland cement concrete. A study of the steel/cement paste interface is also performed, and compounds forming at this interface are identified using X-Ray diffraction.

  20. Sulphonamides as corrosion inhibitor: Experimental and DFT studies

    Science.gov (United States)

    Obayes, Hasan R.; Al-Amiery, Ahmed A.; Alwan, Ghadah H.; Abdullah, Thamer Adnan; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2017-06-01

    Inhibitors are synthetic and natural molecules have various functional groups like double or triple bonds and heteroatoms; N, O or S, which permit adsorption onto the MS (metal surface). These inhibitors have the ability to adsorb onto the MS and block the active site that was reducing the corrosion rate. Inhibition efficiencies of the investigated compounds: Sulfacetamide (SAM), Sulfamerazine (SMR), Sulfapyridine (SPY) and Sulfathiazole (STI), as inhibitors in corrosive solution were evaluated based on weight loss technique. Nitro and Amino groups were chosen for the study of the substituted reaction of four corrosion inhibitor compounds: SAM, SMR, SPY and STI, theoretically utilizing the thickness capacities hypothesis DFT (density functions theory) method with the level [rB3LYP/6-311G(d,p)]. Our research demonstrated that the nitration of studied molecules lead to a diminishing in inhibition efficiencies, group lead to an increase in inhibition efficiency. Compared with corrosion inhibitor molecules these results gave a significant improvement in inhibition efficiency for corrosion inhibitor molecules.

  1. Bonding-Compatible Corrosion Inhibitor for Rinsing Metals

    Science.gov (United States)

    Saunders, C. R.; Wurth, L. A.; Radar, A.

    2005-01-01

    A corrosion-inhibiting mixture of compounds has been developed for addition to the water used to rinse metal parts that have been cleaned with aqueous solutions in preparation for adhesive bonding of the metals to rubber and rubber-like materials. Prior to the development of this corrosion inhibitor, the parts (made, variously, of D6AC steel and 7075-T73 aluminum) were rinsed by deionized water, which caused corrosion in some places on the steel parts especially in such occluded places as sealing surfaces and threaded blind holes. An integral part of the particular cleaning process is the deposition of a thin layer of silicates and silane primers that increase the strength of the adhesive bond. The corrosion inhibitor is formulated, not only to inhibit corrosion of both D6AC steel and 7075- T73 aluminum, but also to either increase or at least not reduce the strength of the adhesive bond to be formed subsequently. The corrosion inhibitor is a mixture of sodium silicate and sodium tetraborate. The sodium silicate functions as both a corrosion inhibitor and a bond-strength promoter in association with the silane primers. The sodium tetraborate buffers the rinse solution at the optimum pH and functions as a secondary corrosion inhibitor for the steel. For a given application, the concentrations of sodium silicate and sodium tetraborate must be chosen in a compromise among the needs to inhibit corrosion of steel, inhibit corrosion of aluminum, and minimize cosmetic staining of both steel and aluminum. Concentrations of sodium silicate in excess of 150 parts of silicon per million parts of solution (ppm Si) have been determined to enhance inhibition of corrosion; unfortunately, because of the alkalinity of sodium silicate, even a small concentration can raise the pH of the rinse solution to such a level that aluminum becomes corroded despite the inhibiting effect. The pH of a solution that contains a high concentration of sodium silicate can be decreased by adding

  2. Investigation of Corrosion Inhibitors by Nuclear Quadrupole Resonance Relaxometry Method

    Directory of Open Access Journals (Sweden)

    Nikolay Sinyavsky

    2015-12-01

    Full Text Available The changes taking place with the corrosion-resistant coating, but not the state of the surface subjected to corrosion are investigated in this paper in contrast to traditional approaches. We used the method of nitrogen relaxometry NQR and multi-exponential inversion of decay of longitudinal and transverse components of the nuclear magnetization is applied for the first time for this purpose. The results of experimental studies of changes in the distributions of spin-spin and spin-lattice relaxation of crystallite powder of sodium nitrite and urotropin, the mixture of which is used as a corrosion inhibitor of ferrous metals are considered.

  3. Research on the corrosion inhibitors of zinc in hydrochloric acid

    Science.gov (United States)

    Sun, C. X.; Chen, Y. M.; Xu, H. W.; Huang, C. S.; Zhang, M.; Wu, J. Y.; Chen, M.; Xue, M.

    2017-06-01

    Three organic compounds were tested as zinc corrosion inhibitors in hydrochloric acid: cetyltrimethyl ammonium bromide (CTAB), nicotini acid, bromohexadecyl pyridine. The static coupon test results indicate that CTAB and bromohexadecyl pyridine offer the best zinc corrosion protection, while nicotinic acid accelerates zinc corrosion. The polarization results indicate that CTAB, nicotinic acid and bromohexadecyl pyridine induce a positive shift in the E0 of zinc in hydrochloric acid. A complex of CTAB and bromohexadecyl pyridine inhibits the corrosion of zinc in hydrochloric acid. SEM results indicate that the CTAB and bromohexadecyl pyridine formed a uniform and compact membrane on the surface of zinc that subsequently protects the zinc from effective corrosion.

  4. Chromenopyridin derivatives as environmentally benign corrosion inhibitors for N80

    Directory of Open Access Journals (Sweden)

    K.R. Ansari

    2017-02-01

    Full Text Available This research work was to investigate the corrosion inhibition performance of two newly synthesized chromenopyridine derivatives namely 2,4-diamino-5-(phenylthio-5H-chromeno[2,3-b]pyridine-3-carbonitrile (PPC-1 and 2,4-diamino-5-phenoxy-5H-chromeno[2,3-b]pyridine-3-carbonitrile (PPC-2 as potential environmentally friendly corrosion inhibitors for N80 steel in 15% hydrochloric acid (HCl. Various techniques like gravimetric, electrochemical impedance spectroscopy (EIS, Tafel polarizations, scanning electron microscope (SEM and atomic force microscopy (AFM have been used. The inhibition efficiencies given by PPC-1 and PPC-2 at 200 mg L−1 are 92.4% and 82.1% respectively. Tafel polarization revealed that both inhibitors are cathodic in nature. Langmuir adsorption isotherm was found to be the best fit. The experimental result was further supported by quantum chemical study.

  5. Evaluation of two corrosion inhibitors using two surface application methods for reinforced concrete structures.

    Science.gov (United States)

    2004-01-01

    This study investigated the use of penetrating corrosion inhibitors to extend the life of existing reinforced concrete bridge decks. The use of assisted (vacuum/pressure injection) and unassisted (diffusion) treatment methods and two inhibitors were ...

  6. Schiff bases as corrosion inhibitor for aluminium in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Safak, Serpil [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Duran, Berrin, E-mail: bduran@ogu.edu.tr [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Yurt, Aysel [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Tuerkoglu, Guelsen [Anadolu University, Faculty of Science, Department of Chemistry, 26470 Eskisehir (Turkey)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Three Schiff bases have been tested as possible corrosion inhibitors for aluminium. Black-Right-Pointing-Pointer Corrosion tests have been performed via EIS and Tafel polarisation methods. Black-Right-Pointing-Pointer Experimental inhibition efficiencies were correlated with quantum chemical parameters. - Abstract: Three Schiff bases named 1,5-bis[2-(2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D1), 1,5-bis[2-(5-chloro-2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D2) and 1,5-bis[2-(5-bromo-2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D3) were synthesized and their inhibitive capabilities on the aluminium corrosion in 0.1 M HCl were investigated by means of electrochemical impedance spectroscopy, Tafel polarisation and scanning electron microscopy techniques. Results showed that, compounds under study exhibit inhibitor properties and adsorption of these compounds was found to accord with Temkin adsorption isotherm. Polarisation curves indicated that the studied Schiff bases were cathodic inhibitor and the effectiveness of these inhibitors decreased in the order of D3 > D2 > D1. Quantum chemical calculations were performed to provide further insight into the inhibition efficiencies determined experimentally.

  7. Pipeline corrosion prevention by pH stabilization or corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Nyborg, Rolf [Institute for Energy Technology, Oslo (Norway)

    2009-07-01

    In many offshore oil and gas projects the pipeline costs are a considerable part of the investment and can become prohibitively high if the corrosivity of the fluid necessitates the use of corrosion resistant alloys instead of carbon steel. Development of more robust and reliable methods for internal corrosion control can increase the application range of carbon steel and therefore have a large economic impact. Corrosion control of carbon steel pipelines has traditionally often been managed by the use of corrosion inhibitors. The pH stabilization technique has been successfully used for corrosion control of several large wet gas pipelines in the last years. This method has advantages over film forming corrosion inhibitors when no or little formation water is produced. The use of corrosion inhibitors in multiphase pipelines implies several challenges which are not fully accounted for in traditional corrosion inhibitor testing procedures. Specialized test procedures have been developed to take account for the presence of emulsions dispersions and sand and clay particles in corrosion inhibitor testing. (author)

  8. Study on tea leaves extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

    Science.gov (United States)

    Hamdan, A. B.; Suryanto; Haider, F. I.

    2018-01-01

    Corrosion inhibitor from extraction of plant has been considered as the most preferable and most chosen technique to prevent corrosion of metal in acidic medium because of the environmental friendly factor. In this study, black tea leaves extraction was tested as corrosion inhibitor for mild steel in 0.1M of hydrochloric acid (HCl) with the absence and presence of corrosion inhibitor. The efficiency and effectiveness of black tea as corrosion inhibitor was tested by using corrosion weight loss measurement experiment was carried out with varies parameters which with different concentration of black tea extract solution. The extraction of black tea solution was done by using aqueous solvent method. The FT-IR result shows that black tea extract containing compounds such as catechin, caffeine and tannins that act as anti-corrosive reagents and responsible to enhance the effectiveness of black tea extract as corrosion inhibitor by forming the hydrophobic thin film through absorption process. As a result of weight loss measurement, it shows that loss in weight of mild steel reduces as the concentration of inhibitor increases. The surface analysis was done on the mild steel samples by using SEM.

  9. pH Sensitive Microcapsules for Delivery of Corrosion Inhibitors

    Science.gov (United States)

    Li, Wenyan; Calle, Luz M.

    2006-01-01

    A considerable number of corrosion problems can be solved by coatings. However, even the best protective coatings can fail by allowing the slow diffusion of oxygen and moisture to the metal surface. Corrosion accelerates when a coating delaminates. Often, the problems start when microscopic nicks or pits on the surface develop during manufacturing or through wear and tear. This problem can be solved by the incorporation of a self-healing function into the coating. Several new concepts are currently under development to incorporate this function into a coating. Conductive polymers, nanoparticles, and microcapsules are used to release corrosion-inhibiting ions at a defect site. The objective of this investigation is to develop a smart coating for the early detection and inhibition of corrosion. The dual function of this new smart coating system is performed by pH-triggered release microcapsules. The microcapsules can be used to deliver healing agents to terminate the corrosion process at its early stage or as corrosion indicators by releasing dyes at the localized corrosion sites. The dyes can be color dyes or fluorescent dyes, with or without pH sensitivity. Microcapsules were formed through the interfacial polymerization process. The average size of the microcapsules can be adjusted from 1 to 100 micron by adjusting the emulsion formula and the microcapsule forming conditions. A typical microcapsule size is around 10 microns with a narrow size distribution. The pH sensitivity of the microcapsule can also be controlled by adjusting the emulsion formula and the polymerization reaction time. Both corrosion indicator (pH indicator) and corrosion inhibitor containing microcapsules were formed and incorporated into paint systems. Test panels of selected steels and aluminum alloys were painted using these paints. Testing of compatibility between the microcapsule system and different paint systems are in progress. Initial experiments with the microcapsule containing paint

  10. Vapour phase corrosion inhibitors from South African renewable resources and their evaluation

    CSIR Research Space (South Africa)

    Vuorinen, E

    2006-02-01

    Full Text Available A vapour-phase corrosion inhibitor (VCI) needs to be a volatile compound or a mixture of compounds. It reaches the surfaces that need to be protected from corrosion via the vapour phase and forms a relatively stable bond at the interface...

  11. costus afer leave extract as nontoxic corrosion inhibitor for mild steel ...

    African Journals Online (AJOL)

    users

    2013-05-06

    May 6, 2013 ... inhibitors is an important task in the protection of metals from corrosion. Till now the majority of metal corrosion inhibitors used is toxic for humans and the environment. The choice of the present inhibitors is based on the following considerations: Investigation of Costus afer. Leaves Extract shows that it is:.

  12. Corrosion protection performance of corrosion inhibitors and epoxy-coated reinforcing steel in a simulated concrete pore water solution.

    Science.gov (United States)

    1998-06-01

    We used a simulated concrete pore water solution to evaluate the corrosion protection performance of concrete corrosion-inhibiting admixtures and epoxy-coated reinforcing bars (ECR). We evaluated three commercial corrosion inhibitors, ECR from three ...

  13. Mathematical model for galvanic corrosion of steel–copper couple in petroleum waste water in presence of friendly corrosion inhibitor

    National Research Council Canada - National Science Library

    Khadom, Anees A; Abod, Baker M

    2017-01-01

    Galvanic corrosion of steel–copper couple in saline petroleum wastewater in the absence and presence of curcuma extract as corrosion inhibitor was studied as a function of temperature, velocity, and inhibitor concentration...

  14. Determining the Chemical Composition of Corrosion Inhibitor/Metal Interfaces with XPS: Minimizing Post Immersion Oxidation.

    Science.gov (United States)

    Walczak, Monika S; Morales-Gil, Perla; Belashehr, Turia; Kousar, Kiran; Arellanes Lozada, Paulina; Lindsay, Robert

    2017-03-15

    An approach for acquiring more reliable X-ray photoelectron spectroscopy data from corrosion inhibitor/metal interfaces is described. More specifically, the focus is on metallic substrates immersed in acidic solutions containing organic corrosion inhibitors, as these systems can be particularly sensitive to oxidation following removal from solution. To minimize the likelihood of such degradation, samples are removed from solution within a glove box purged with inert gas, either N2 or Ar. The glove box is directly attached to the load-lock of the ultra-high vacuum X-ray photoelectron spectroscopy instrument, avoiding any exposure to the ambient laboratory atmosphere, and thus reducing the possibility of post immersion substrate oxidation. On this basis, one can be more certain that the X-ray photoelectron spectroscopy features observed are likely to be representative of the in situ submerged scenario, e.g. the oxidation state of the metal is not modified.

  15. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil [School of Applied Physic, Faculty Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2014-09-03

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  16. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Science.gov (United States)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil

    2014-09-01

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  17. Standard guide for evaluating and qualifying oilfield and refinery corrosion inhibitors in the laboratory

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This guide covers some generally accepted laboratory methodologies that are used for evaluating corrosion inhibitors for oilfield and refinery applications in well defined flow conditions. 1.2 This guide does not cover detailed calculations and methods, but rather covers a range of approaches which have found application in inhibitor evaluation. 1.3 Only those methodologies that have found wide acceptance in inhibitor evaluation are considered in this guide. 1.4 This guide is intended to assist in the selection of methodologies that can be used for evaluating corrosion inhibitors. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

  18. Fatty Amides from Crude Rice Bran Oil as Green Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    E. Reyes-Dorantes

    2017-01-01

    Full Text Available Due to its high oil content, this research proposes the use of an agroindustrial byproduct (rice bran as a sustainable option for the synthesis of corrosion inhibitors. From the crude rice bran oil, the synthesis of fatty amide-type corrosion inhibitors was carried out. The corrosion inhibitory capacity of the fatty amides was evaluated on an API X-70 steel using electrochemical techniques such as real-time corrosion monitoring and potentiodynamic polarization curves. As a corrosive medium, a CO2-saturated solution (3.5% NaCl was used at three temperatures (30, 50, and 70°C and different concentrations of inhibitor (0, 5, 10, 25, 50, and 100 ppm. The results demonstrate that the sustainable use of agroindustrial byproducts is a good alternative to the synthesis of environmentally friendly inhibitors with high corrosion inhibition efficiencies.

  19. The Effect of Concentration of Lawsonia inermis as a Corrosion Inhibitor for Aluminum Alloy in Seawater

    Directory of Open Access Journals (Sweden)

    F. Zulkifli

    2017-01-01

    Full Text Available Lawsonia inermis also known as henna was studied as a corrosion inhibitor for aluminum alloy in seawater. The inhibitor has been characterized by optical study via Fourier transform infrared spectroscopy (FTIR. The FTIR proves the existence of hydroxyl and carbonyl functional groups in Lawsonia inermis. Aluminum alloy 5083 immersed in seawater in the absence and presence of Lawsonia inermis was tested using electrochemistry method, namely, electrochemical impedance spectroscopy (EIS and potentiodynamic polarization (PP. EIS and PP measurements suggest that the addition of Lawsonia inermis has caused the adsorption of inhibitor on the aluminum surface. The adsorption behavior of the inhibitor follow Langmuir adsorption model where the value of free energy of adsorption, -ΔG, is less than 40 kJ/mol indicates that it is a physical adsorption. Finally, it was inferred that Lawsonia inermis has a real potential to act as a corrosion inhibitor for aluminum alloy in seawater.

  20. Study of low cost eco-friendly compounds as corrosion inhibitors for cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Farooqi, I.H.; Hussain, A.; Saini, P.A. [AMU, Aligarh (India). Dept. of Civil Engineering; Quraishi, M.A. [AMU, Aligarh (India). Dept. of Applied Chemistry

    1999-07-01

    Attempts are made to utilize the aqueous extracts of natural compounds, namely cordia latifolia and curcumin, as corrosion inhibitors for mild steel in cooling systems, and their inhibition efficiencies are compared with that of Hydroxyethylidene 1-1 diphosphonic acid (HEDP). HEDP is also blended with aqueous extracts of natural compounds so as to improve their inhibition efficiency. The blowdown of the cooling system is also analysed for environmental factors. (author)

  1. Corrosion-Inhibitor Efficiency Control: Comparison by Means of Different Portable Corrosion Rate Meters

    OpenAIRE

    Martinez Sierra, Isabel; Andrade Perdrix, Maria del Carmen; Rebolledo Ramos, Nuria; Luo, L.; De Schutter, G.

    2010-01-01

    Corrosion-inhibiting substances have been applied to suppress corrosion mainly on bare steel, but when corrosion is progressing, suppression can be achieved if anodic and cathodic reactions are avoided, which is not an easy objective, particularly if the bare metal is surrounded by concrete. In the present article, several corrosion inhibitors are studied to identify their inhibition efficiency in concrete. The percentage of reduction of the corrosion rate without and with inhibitor is named ...

  2. Extract of Combretum micranthum as corrosion inhibitor for Al – Si ...

    African Journals Online (AJOL)

    The leaf extract of Combretum micranthum (CM) was tested as green corrosion inhibitor for Al-Si-Mg alloy in 3.5wt% NaCl solution using gravimetric and linear polarization methods at 300C, 500C and 700C, from 1, 2, 3, 4, 5 hours of exposure time with concentration of the extract 0, 0.2, 0.4, 0.6, 0.8 and 1.0 v/v respectively.

  3. Ginger extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

    Science.gov (United States)

    Fidrusli, A.; Suryanto; Mahmood, M.

    2018-01-01

    Ginger extract as corrosion inhibitor from natural resources was studied to prevent corrosion of mild steel in acid media. Ginger rhizome was extracted to produce green corrosion inhibitor (G-1) while ginger powder bought at supermarket was also extract to form green corrosion inhibitor (G-2). Effectiveness of inhibitor in preventing corrosion process of mild steel was studied in 1.0 M of hydrochloric acid. The experiment of weight loss method and polarization technique were conducted to measure corrosion rate and inhibition efficiency of mild steel in solution containing 1.0 M of hydrochloric acid with various concentration of inhibitor at room temperature. The results showed that, the rate of corrosion dropped from 8.09 mmpy in solution containing no inhibitor to 0.72 mmpy in solution containing 150g/l inhibitor while inhibition efficiency up to 91% was obtained. The polarization curve in polarization experiments shows that the inhibition efficiency is 86% with high concentration of inhibitor. The adsorption of ginger extract on the surface of mild steel was observed by using optical microscope and the characterization analysis was done by using pH measurement method. When high concentration of green inhibitor in the acid solution is used, the pH at the surface of steel is increasing.

  4. Development of Ecofriendly Corrosion Inhibitors for Application in Acidization of Petroleum Oil Well

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2013-01-01

    Full Text Available In the present investigation the protective ability of 1-(2-aminoethyl-2-octadecylimidazoline (AEODI and 1-(2-octadecylamidoethyl-2-octadecylimidazoline (ODAEODI as corrosion inhibitors for N80 steel in 15% hydrochloric acid has been studied, which may find application as ecofriendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentration of synthesized inhibitors AEODI and ODAEODI was added to test solution (15% HCl, and corrosion inhibition of N80 steel was tested by weight loss, potentiodynamic polarization, and AC impedance measurements. Influence of temperature (298 to 323 K on the inhibition behaviour was studied. Surface studies were performed by using SEM. It was found that both the inhibitors were effective inhibitors, and their inhibition efficiency was significantly increased with increasing their concentration. Polarization curves revealed that the used inhibitors represent mixed-type inhibitors. The adsorption of used inhibitors led to a reduction in the double-layer capacitance and an increase in the charge transfer resistance. The adsorption of used compounds was found to obey Langmuir isotherm. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

  5. Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, Benjamin Pieter; Calle, Luz M.

    2015-01-01

    This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

  6. Standard practice for evaluating and qualifying oil field and refinery corrosion inhibitors using rotating cage

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers a generally accepted procedure to use the rotating cage (RC) for evaluating corrosion inhibitors for oil field and refinery applications. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. Electrochemical investigation of thiourea as corrosion inhibitor for copper in acidic solution

    Science.gov (United States)

    Wu, Jintian; Wang, Lingling; Liu, Peidong; Liu, Yuanjie; Chen, Bei; Tao, Zhihua; He, Wei

    2017-04-01

    The thiourea as a copper corrosion inhibitor in the base electrolyte (containing 0.54M H2SO4 and 0.88M CuSO4) was investigated using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The research results suggest that the inhibition efficiency depends on the concentration of the thiourea. The slopes of the cathodic and anodic Tafel lines are approximately constant and independent on the inhibitor concentration. Potentiodynamic polarization curves showed that thiourea acts as the mixed-up inhibitor. The results obtained from EIS measurements are in good agreement with that obtained from potentiodynamic polarization.

  8. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

    2014-12-01

    Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

  9. Biogenic corrosion inhibitor on mild steel protection in concentrated HCl medium.

    Science.gov (United States)

    Krishnan, Muthukumar; Subramanian, Harinee; Dahms, Hans-Uwe; Sivanandham, Vignesh; Seeni, Palanichamy; Gopalan, Subramanian; Mahalingam, Ashok; Rathinam, Arthur James

    2018-02-08

    Turbinaria ornata (TO) extract was tested as green corrosion inhibitor on mild steel (MS) coupons in conc. HCl medium with an efficiency of 100% at 25 g l -1 during 5 min exposure. Antibacterial efficacy performed against 16 S rDNA identified marine biofilming bacteria (MBB) and human pathogenic bacteria (HPB). Maximum inhibition growth was 16 mm on MBB observed in Bacillus megaterium (MBF14 - AB894827) and 20 mm on HPB in Escherichia coli (B5 - NCIM 2931). Similarly, minimum of 10 mm on MBB witnessed in Pseudomonas sp., (MBF9 - AB894829). Toxicity studies proved 50.0% LC 50 at 500 μg ml -1 in 24 hrs, whereas Balanus amphitrite resulted in 100% mortality within 12 hrs. Results including weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy, FT-IR and GC-MS confirm 10-Octadecaonic acid as a major corrosion inhibitor from T. ornata and is discovered as a novel antifoulant. Anticorrosion formulation will become available soon.

  10. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  11. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Science.gov (United States)

    Nava, N.; Likhanova, N. V.; Olivares-Xometl, O.; Flores, E. A.; Lijanova, I. V.

    2011-11-01

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission 57Fe Mössbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ( α-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  12. Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Abboud Y.

    2013-09-01

    Full Text Available Leave of Punica granatum extract (LPGE as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spectroscopy. Further examination using X-ray diffraction confirms the role of LPGE as an effective corrosion inhibitor for mild steel in acid media.

  13. Semiempirical Theoretical Studies of 1,3-Benzodioxole Derivatives as Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Omnia A. A. El-Shamy

    2017-01-01

    Full Text Available The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR. Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital EHOMO, the energy of the lowest unoccupied molecular orbital ELUMO, energy gap ΔEg, dipole moment μ, and Mulliken charge on the atom. QSAR approach is applied to elucidate some important parameters as the hydrophobicity (Log P, surface area (S.A, polarization (P, and hydration energy (EHyd.

  14. Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

    2007-02-15

    The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

  15. A novel imidazoline derivative as corrosion inhibitor for P110 carbon steel in hydrochloric acid environment

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2015-09-01

    Full Text Available A novel imidazoline derivative, 2-methyl-4-phenyl-1-tosyl-4, 5-dihydro-1H-imidazole (IMI, was prepared and investigated as corrosion inhibitor for P110 carbon steel in 1.0 M HCl solution by weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS tests. The inhibition efficiency increased with the rising concentration of IMI inhibitor. The test results and fitting data indicated that the IMI behaved as a mixed-type inhibitor and obeys the Langmuir adsorption isotherm. Scanning electron microscopy (SEM was carried out to investigate the surface of carbon steel specimens, showing great protection from aggressive solution. Finally, inhibition mechanism of IMI on metal surface was further discussed.

  16. Marjoram Extract as Corrosion Inhibitor for Dissolution of Zinc in 1.0 M HCl

    Directory of Open Access Journals (Sweden)

    M. Sobhi

    2013-01-01

    Full Text Available In this study, water marjoram (Origanum marjorana L. extract was evaluated as corrosion inhibitor for zinc in 1.0 M HCl solution. The polarization measurements showed that this inhibitor is acting as mixed inhibitors for both anodic and cathodic reactions. The results showed that the inhibition efficiency was increased by increasing the inhibitor doses and reached the maximum at 500 ppm. The adsorption of marjoram extract on zinc surface was found to obey Langmuir type isotherm. The efficiency obtained from the impedance measurements was in good agreement with those obtained from the gravimetrical, thermometric, and polarization techniques which prove the validity of these tolls in the measurements of the tested inhibitor.

  17. Thiosemicarbazide and thiocarbohydrazide functionalized chitosan as ecofriendly corrosion inhibitors for carbon steel in hydrochloric acid solution.

    Science.gov (United States)

    Chauhan, Dheeraj Singh; Ansari, K R; Sorour, A A; Quraishi, M A; Lgaz, H; Salghi, R

    2017-10-10

    Organically functionalized chitosan macromolecules namely Chitosan-Thiosemicarbazide (CS-TS) and Chitosan-Thiocarbohydrazide (CS-TCH) were synthesized and evaluated as new corrosion inhibitors for mild steel corrosion in 1M HCl. The FTIR and (1)H NMR studies confirmed the formation of the derivatives. The corrosion tests were performed using weight loss method, electrochemical measurements, surface morphology (AFM), quantum chemical investigation and molecular dynamics simulation methods. The maximum efficiency of 92% was obtained at a concentration as low as 200mgL(-1). The inhibitors were found to obey Langmuir adsorption isotherm and exhibited both physical and chemical adsorption. Electrochemical impedance spectroscopy (EIS) results showed an increase in polarization resistance which supported the adsorption of inhibitors on the mild steel surface. Tafel data showed a mixed type behavior with cathodic predominance. The data of quantum chemical calculations and molecular dynamics simulation supported the experimental findings. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste.

    Science.gov (United States)

    Hussein, Mohamed H M; El-Hady, Mohamed F; Shehata, Hassan A H; Hegazy, Mohammad A; Hefni, Hassan H H

    2013-03-01

    Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa. Chitosan was modified to 2-N,N-diethylbenzene ammonium chloride N-oxoethyl chitosan (compound I), and 12-ammonium chloride N-oxododecan chitosan (compound II) as soluble water derivatives. The corrosion inhibition efficiency for carbon steel of compound (I) in 1 M HCl at varying temperature is higher than for chitosan and compound (II). However, the antibacterial activity of chitosan for Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans is higher than for its derivatives, and the minimum inhibition concentration and minimum bacterial concentration of chitosan and its derivatives were carried out with the same strain.

  19. Adsorption and performance of the 2-mercaptobenzimidazole as a carbon steel corrosion inhibitor in EDTA solutions

    Energy Technology Data Exchange (ETDEWEB)

    Calderón, J.A., E-mail: andres.calderon@udea.edu.co [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Vásquez, F.A. [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Carreño, J.A. [Laboratório de H2S, CO2 e Corrosividade, Instituto Nacional De Tecnologia (INT), Av. Venezuela, 82 – Térreo, Anexo 01, Sala 101A, Saúde, Rio de Janeiro, RJ (Brazil)

    2017-01-01

    This study presents a thermodynamic analysis of the adsorption and anti-corrosion performance of 2-mercaptobenzimidazole (2-MBI) on carbon steel in EDTA-Na2 solutions. The adsorption of the inhibitor on the metal surface was studied as a function of the concentration of the inhibiting species and the temperature of the system. The corrosion inhibition efficiency was studied by electrochemical impedance spectroscopy and mass loss tests. The results show that the adsorption of the inhibitor onto the metal surface behaves according to the Langmuir model, following an endothermic process. The inhibitor is chemically adsorbed onto the carbon steel surface. The efficiency of corrosion inhibition was above 93%, which was confirmed by both mass loss tests and the electrochemical impedance technique. The good performance of the corrosion inhibitor was maintained up to 24 h after the inhibitor was added to the corrosive EDTA-Na2 solutions. When the ratio of the volume of solution/exposed area was reduced, a decrease in the area covered by the inhibitor was observed. The best cost/benefit ratio for the corrosion protection of carbon steel was obtained when the number of moles of the inhibitor per surface area was maintained at 2.68 mmol cm{sup −2}. - Highlights: • Adsorption of the inhibitor on the metal surface is confirmed by thermodynamic data. • Adsorption of the inhibitor onto the metal behaves according to the Langmuir model. • Endothermic adsorption process indicates that the inhibitor is chemically adsorbed. • The efficiency of corrosion inhibition was above 93%. • The good performance of the corrosion inhibitor was maintained up to 24 h.

  20. Achilles Tendonitis

    Science.gov (United States)

    ... You Treat Achilles Tendonitis? en español Tendinitis de Aquiles Kim didn't do much over the summer ... Achilles Tendonitis and Who Gets It? Your Achilles tendon is located at the back of your foot, ...

  1. The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

    Science.gov (United States)

    Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

    2013-01-01

    The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).

  2. Synergistic effects of additives to benzotriazole solutions applied as corrosion inhibitors to archaeological copper and copper alloy artefacts.

    OpenAIRE

    Golfomitsou, S.

    2006-01-01

    Benzotriazole (BTA) is a corrosion inhibitor extensively used for the stabilisation of active corrosion of archaeological copper and copper alloys. However, BTA often fails to effectively retard corrosion when applied on heavily corroded artefacts. Although there are numerous studies about its mode of action on clean copper, there is no comprehensive understanding about the way it is bonded to corroded copper. This thesis aimed to understand and compare BTA and its mode of action on clean and...

  3. The effect of corrosion inhibitors on microbial communities associated with corrosion in a model flow cell system.

    Science.gov (United States)

    Duncan, Kathleen E; Perez-Ibarra, Beatriz Monica; Jenneman, Gary; Harris, Jennifer Busch; Webb, Robert; Sublette, Kerry

    2014-01-01

    A model flow cell system was designed to investigate pitting corrosion in pipelines associated with microbial communities. A microbial inoculum producing copious amounts of H₂S was enriched from an oil pipeline biofilm sample. Reservoirs containing a nutrient solution and the microbial inoculum were pumped continuously through six flow cells containing mild steel corrosion coupons. Two cells received corrosion inhibitor "A", two received corrosion inhibitor "B", and two ("untreated") received no additional chemicals. Coupons were removed after 1 month and analyzed for corrosion profiles and biofilm microbial communities. Coupons from replicate cells showed a high degree of similarity in pitting parameters and in microbial community profiles, as determined by 16S rRNA gene sequence libraries but differed with treatment regimen, suggesting that the corrosion inhibitors differentially affected microbial species. Viable microbial biomass values were more than 10-fold higher for coupons from flow cells treated with corrosion inhibitors than for coupons from untreated flow cells. The total number of pits >10 mils diameter and maximum pitting rate were significantly correlated with each other and the total number of pits with the estimated abundance of sequences classified as Desulfomicrobium. The maximum pitting rate was significantly correlated with the sum of the estimated abundance of Desulfomicrobium plus Clostridiales, and with the sum of the estimated abundance of Desulfomicrobium plus Betaproteobacteria. The lack of significant correlation with the estimated abundance of Deltaproteobacteria suggests not all Deltaproteobacteria species contribute equally to microbiologically influenced corrosion (MIC) and that it is not sufficient to target one bacterial group when monitoring for MIC.

  4. Bio-testing integral toxicity of corrosion inhibitors, biocides and oil hydrocarbons in oil-and gas-processing industry

    Energy Technology Data Exchange (ETDEWEB)

    Chugunov, V.A.; Kholodenko, V.P.; Irkhina, I.A.; Fomchenkov, V.M.; Novikov, I.A. [State Research Center for Applied Microbiology, Obolensk, Moscow (Russian Federation)

    2004-07-01

    In recent years bioassays have been widely used for assessing levels of contamination of the environment. This is due to the fact that test-organisms provide a general response to toxicants present in samples. Based on microorganisms as test objects, it is possible to develop cheap, sensitive and rapid assays to identify environmental xenobiotics and toxicants. The objective of the research was to develop different microbiological assays for assessing integral toxicity of water environments polluted with corrosion inhibitors, biocides and hydrocarbons in oil- and gas-processing industry. Bio-luminescent, electro-orientational, osmo-optic and microorganism reducing activity assays were used for express evaluation of integral toxicity. They are found to determine promptly integral toxicity of water environments containing various pollutants (oil, oil products, corrosion inhibitors, biocides). Results conclude that the assays may be used for analyzing integral toxicity of water polluted with hydrocarbons, as well as for monitoring of water changes as a result of biodegradation of pollutants by microorganisms and their associations. Using a kit of different assays, it is also possible to evaluate ecological safety of biocides, corrosion inhibitors, and their compositions. Bioassays used as a kit are more effective than each assay individually, allowing one to get complete characterization of a reaction of bacterial test organisms to different environments. (authors)

  5. Application of carbohydrate polymers as corrosion inhibitors for metal substrates in different media: A review.

    Science.gov (United States)

    Umoren, Saviour A; Eduok, Ubong M

    2016-04-20

    Naturally occurring polysaccharides are biopolymers existing as products of biochemical processes in living systems. A wide variety of them have been employed for various material applications; as binders, coatings, drug delivery, corrosion inhibitors etc. This review describes the application of some green and benign carbohydrate biopolymers and their derivatives for inhibition of metal corrosion. Their modes and mechanisms of protection have also been described as directly related to their macromolecular weights, chemical composition and their unique molecular and electronic structures. For instance, cellulose and chitosan possess free amine and hydroxyl groups capable of metal ion chelation and their lone pairs of electrons are readily utilized for coordinate bonding at the metal/solution interface. Some of the carbohydrate polymers reviewed in this work are either pure or modified forms; their grafted systems and nanoparticle composites with multitude potentials for metal protection applications have also been highlighted. Few inhibitors grafted to introduce more compact structures with polar groups capable of increasing the total energy of the surface have also been mentioned. Exudate gums, carboxymethyl and hydroxyethyl cellulose, starch, pectin and pectates, substituted/modified chitosans, carrageenan, dextrin/cyclodextrins and alginates have been elaborately reviewed, including the effects of halide additives on their anticorrosion performances. Aspects of computational/theoretical approach to corrosion monitoring have been recommended for future studies. This non-experimental approach to corrosion could foster a better understanding of the corrosion inhibition processes by correlating actual inhibition mechanisms with molecular structures of these carbohydrate polymers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Amino acids as corrosion inhibitors for copper in acidic medium: Experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Milošev Ingrid

    2013-01-01

    Full Text Available Experimental electrochemical methods combined with quantum chemical calculations and molecular dynamics simulations were used to investigate the possibility of use various amino acids as “green” corrosion inhibitors for copper in 0.5 M HCl solution. Among eleven amino acids studied, cysteine achieved the highest inhibitor effectiveness reaching 52% at 10 mM concentration. Other amino acids reached achieved effectiveness less than 25%, some of them even acted as corrosion accelerators. Based on the experimental results, theoretical calculations and simulations were focused on cysteine and alanine. The electronic and reactivity parameters of their protonated forms in electrical double layer were evaluated by density functional calculations. In addition, molecular dynamic simulations were introduced to follow the adsorption behaviour of these two amino acids at the Cu(111 surface in the electrolyte solution. The results indicate that the orientation of both molecules is nearly parallel to the surface except of ammonium group which is directed away from the surface. Therefore, as the orientation of the cysteine and alanine molecules at the surface is similar, thiol functional group is responsible for superior inhibition efficiency of cysteine.

  7. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-01-01

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

  8. Safe corrosion inhibitor for treating cooling water on heat power engineering plants

    Science.gov (United States)

    Nikolaeva, L. A.; Khasanova, D. I.; Mukhutdinova, E. R.; Safin, D. Kh.; Sharifullin, I. G.

    2017-08-01

    Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08-0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.

  9. Antifungal drugs as corrosion inhibitors for aluminium in 0.1 M HCl

    Energy Technology Data Exchange (ETDEWEB)

    Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria); Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)

    2009-08-15

    The inhibitive capabilities of Clotrimazole (CTM) and Fluconazole (FLC), two antifungal drugs, on the electrochemical corrosion of aluminium in 0.1 M HCl solution has been studied using weight loss measurements at 30 and 50 deg. C. The results indicate that both compound act as inhibitors in the acidic corrodent. At constant acid concentration, the inhibition efficiency (%I) increased with increase in the concentration of the inhibitors. Increase in temperature increased the corrosion rate in the absence and presence of the inhibitors but decreased the inhibition efficiency. CTM and FLC adsorbed on the surface of aluminium according to the Langmuir adsorption isotherm model at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameter obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. The reactivity of these compounds was analyzed through theoretical calculations based on AM1 semi-empirical method to explain the different efficiencies of these compounds as corrosion inhibitors. CTM was found to be a better inhibitor than FLC.

  10. Synthesis and Application of Phenyl Nitrone Derivatives as Acidic and Microbial Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Shijun Chen

    2015-01-01

    Full Text Available Nitrone has drawn great attention due to its wide applications as a 1,3-dipole in heterocyclic compounds synthesis and the bioactivities. With the special structure, nitrone can also be used as ligand in inorganic chemistry. Based on the current research, the nitrones are anticipated to be effective inhibitors against acidic and microbial corrosion. The aim of this work is to investigate the inhibitory action of nitrones. In this work, a series of phenyl nitrone derivatives (PN was synthesized and used as acidic and microbial corrosion inhibitors. The results indicate that several compounds show moderate to high inhibition efficiency (IE in 3% HCl. Accompanied with HMTA or BOZ, the IEs greatly increase, and the highest efficiency of 98.5% was obtained by using PN4 + BOZ. Investigation of the antibacterial activity against oilfield microorganism shows that the nitrone derivatives can inhibit SRB, IB, and TGB with moderate to high efficiency under 1,000 mg/L, which makes them potential to be used as bifunctional oilfield chemicals.

  11. Corrosion of X65 Pipeline Steel Under Deposit and Effect of Corrosion Inhibitor

    Directory of Open Access Journals (Sweden)

    XU Yun-ze

    2016-10-01

    Full Text Available Effect of the deposit on the electrochemical parameters of X65 pipeline steel in oxygen contained sodium chloride solution was studied by EIS and PDS methods. The galvanic corrosion behavior under deposit and effect of different concentration of corrosion inhibitor PBTCA were studied by electrical resistance (ER method combined with ZRA. The results show that the corrosion potential of X65 steel shifts negatively as SiO2 covering its surface and the corrosion rate becomes lower. When the galvanic couple specimen with deposit is electrically connected with the specimen without deposit, anodic polarization occurs on X65 steel under deposit and the galvanic current density decreases from 120μA/cm2 to 50μA/cm2 and keeps stable. As 5×10-5, 8×10-5 and 3×10-4 PBTCA were introduced into the solution, the galvanic current density reaches the highest 1300μA/cm2 and then decreases to 610μA/cm2 keeping stable around 610μA/cm2, corrosion rate of X65 steel under deposit reaches 6.11mm/a. PBTCA accelerates the corrosion of X65 steel under deposit in oxygen contained solution. Through the investigation on the surface of the specimens, serious local corrosion occurs on the X65 steel surface under deposit.

  12. A Study on Corrosion Inhibitor for Mild Steel in Ethanol Fuel Blend.

    Science.gov (United States)

    Vu, Nguyen Si Hoai; Hien, Pham Van; Man, Tran Van; Hanh Thu, Vu Thi; Tri, Mai Dinh; Nam, Nguyen Dang

    2017-12-31

    The main aim of this study is to investigate Aganonerion polymorphum leaf-ethyl acetate extract (APL-EAE) and its inhibiting effect for steel in ethanol fuel blend. The immersion test, electrochemical and surface analysis techniques were successfully carried out in this research. Scanning electron microscope images indicated that the ethanol fuel blend induced pitting corrosion of steel. Remarkably, the surface of the sample containing 1000 ppm APL-EAE is smoother than the others submerged in different conditions. The electrochemical impedance spectroscopy result shows that APL-EAE has formed a good protective layer, preventing corrosive factors from hitting the steel surface. The potentiodynamic polarization data argue that the corrosion inhibition efficiency was strengthened with the increase of APL-EAE concentration. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated less intensity of Fe peaks, higher intensity of C 1s peak and the appearance of organic peaks (N 1s , P 2p , O 1s ) from specimens with and without APL-EAE addition. Therefore, the results suggest the formation of the protective film on steel surface and affirm that APL-EAE has served as an effective corrosion inhibitor for steel in ethanol fuel blend.

  13. The efficiency of a corrosion inhibitor on steel in a simulated concrete environment

    Energy Technology Data Exchange (ETDEWEB)

    Gartner, Nina; Kosec, Tadeja, E-mail: tadeja.kosec@zag.si; Legat, Andraž

    2016-12-01

    The aim of the present work was to characterize the efficiency of a corrosion inhibitor on steel in a simulated concrete pore solution. Laboratory measurements were performed at various chloride and inhibitor concentrations in order to simulate different applications of the inhibitor when used for the protection or rehabilitation of steel reinforcement in concrete. Two electrochemical techniques, i.e. potentiodynamic polarization scans and electrochemical impedance spectroscopy, were used for this study. The exposed surfaces of the steel specimens were subsequently investigated by Raman spectroscopy and scanning electron microscopy. It was found that the inhibitor can efficiently retard the corrosion of steel in a simulated concrete pore solution at concentrations of the inhibitor >2.0% and of chlorides <0.3% at a pH 10.5. On the other hand, when these conditions are not fulfilled, localized corrosion was observed. The results of the Raman and SEM/EDS analysis showed various morphologies of corrosion products and different types of corrosion attack depending on the pH of the pore solution, and the applied concentrations of the chlorides and the inhibitor. - Highlights: • Electrochemical studies performed at various Cl{sup −} and inhibitor concentrations. • Exposed steel surfaces investigated by Raman spectroscopy and SEM. • Cl{sup −}/inhibitor ratio is important parameter for the inhibitor's efficiency. • The corrosion can re-occur if the concentration of the inhibitor is reduced. • Different corrosion behaviour and oxides in the presence of inhibitor and/or Cl{sup −}.

  14. Tendon Injuries

    Science.gov (United States)

    ... What OT Can Do: Video For Professionals Ethics Tendon Injuries When a person experiences a tendon injury in the hand that affects the ability ... plan. What can a person with a hand tendon injury do? Implement a home exercise program recommended ...

  15. Standard practice for evaluating and qualifying oil field and refinery corrosion inhibitors using the rotating cylinder electrode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers a generally accepted procedure to use the rotating cylinder electrode (RCE) for evaluating corrosion inhibitors for oil field and refinery applications in defined flow conditions. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  16. Emblica Officinalis (Indian Gooseberry Leaves Extract as Corrosion Inhibitor for Mild Steel in 1N HCl Medium

    Directory of Open Access Journals (Sweden)

    R. Saratha

    2010-01-01

    Full Text Available Corrosion inhibition efficiency of acid extract of dry Emblica officinalis leaves for mild steel in 1N HCl medium is investigated in the present study. Experimental methods include weight loss, potentiodynamic polarization and impedance studies. The results indicate Emblica officinalis leaves to be a good corrosion inhibitor of a mixed type and having efficiency of 87.9% at 2% v/v inhibitor concentration. Corrosion inhibition may be due to the spontaneous physical adsorption of the plant constituents on the mild steel surface. Experimental data fitted the Langmuir, Temkin, Freundlich and Flory-Huggins adsorption isotherms.

  17. Mathematical model for galvanic corrosion of steel–copper couple in petroleum waste water in presence of friendly corrosion inhibitor

    Directory of Open Access Journals (Sweden)

    Anees A. Khadom

    2017-02-01

    Full Text Available Galvanic corrosion of steel–copper couple in saline petroleum wastewater in the absence and presence of curcuma extract as corrosion inhibitor was studied as a function of temperature, velocity, and inhibitor concentration. The electrochemical polarization technique was used to evaluate the corrosion parameters. Corrosion currents densities increase with temperature and velocity, while it decreases with inhibitor concentrations. In this investigation, a theoretical model equation was used to analyze the shape of polarization curves. Microsoft Excel program was used to find the galvanic current and galvanic potential. Theoretical results agreed with experimental one.

  18. Pomegranate (Punica granatum Peel Extract as a Green Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Habib Ashassi-Sorkhabi

    2015-01-01

    Full Text Available The inhibition effect of pomegranate peel extract (PPE on the corrosion of mild steel in hydrochloric acid (HCl solution was investigated. The polarization, mass loss, and electrochemical impendence techniques were used to evaluate the corrosion inhibition performance of the pomegranate peel extract. The results revealed that PPE acts as a corrosion inhibitor in HCl solution. The inhibition efficiency increased with the increase of extract concentration. The inhibition action was attributed to the adsorption of the chemical compounds present in the extract solution, on mild steel surface.

  19. Adsorption behavior of caffeine as a green corrosion inhibitor for copper

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fernando Silvio de [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Giacomelli, Cristiano [Departamento de Quimica, Universidade Federal de Santa Maria, Av. Roraima 1000, 97119-900, Santa Maria, RS (Brazil); Goncalves, Reinaldo Simoes [Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Spinelli, Almir, E-mail: almir.spinelli@ufsc.br [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil)

    2012-12-01

    protective barrier. Black-Right-Pointing-Pointer This corrosion inhibitor covers up to 72% of the total active surface of copper.

  20. Synthesis and Characterization of Oligomer 4-Vinylpyridine as A Corrosion Inhibitor for Mild Steel in CO2 Saturated Brine Solution

    Directory of Open Access Journals (Sweden)

    Ilim Ilim

    2016-08-01

    Full Text Available In this work, the oligomer of 4-vinylpyridine designated as O(4-VP was synthesized by hydrogen peroxide initiated chain growth polymerization and characterized in terms of molecular weight and structure by matrix assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF MS. The oligomer was tested as corrosion inhibitor of mild steel in brine solution saturated with carbon dioxide, with the main purpose to investigate the effect of inhibitor concentrations and temperatures on the inhibition activity defined in terms of corrosion rate and percent of protection. The inhibition tests were carried out using the methods of weight loss (WL and linear polarization (LP. Characterization using MALDI-TOF MS revealed that the oligomer has the mass (m/z in the range 200-2400, which corresponds to chain length of 2-22 repeating units. The results of corrosion rate measurements show that the corrosion rate with the use of oligomer is significantly lower than that without inhibitor, demonstrating that the oligomer functioned as effective corrosion inhibitor, while the 4-vinyl pyridine monomer was found to promote the corrosion. It was also found that the protection by the oligomer increased with increasing temperature and it was predicted the oligomer was chemically adsorbed by the surface of the metal.

  1. An investigation of the effect of migratory type corrosion inhibitor on mechanical properties of zeolite-based novel geopolymers

    Science.gov (United States)

    Auqui, Nestor Ulloa; Baykara, Haci; Rigail, Andres; Cornejo, Mauricio H.; Villalba, Jose Luis

    2017-10-01

    The effects of migratory type corrosion inhibitor and curing time on the thermal stability and mechanical properties of Ecuadorian natural zeolite-based geopolymers were evaluated. Geopolymer samples were prepared by alkali activation of the natural zeolite by 8 M NaOH solution and calcium hydroxide Ca(OH)2 1-3 wt%, with an activator/binder ratio of 0.6. The geopolymer samples cured for 24 h at 40 °C and then for 6 days more at room temperature showed the compressive strength values in a range of 3-5,5 MPa. Mineralogical analysis of natural zeolite obtained by XRD is as follows: Mordenite (∼67%), quartz (∼27%) and amorphous (∼6%). SEM-EDS micrographs analysis of geopolymers revealed the presence of Na and Ca which proves the incorporation of the activators, NaOH and Ca(OH)2. The compressive strength values obtained indicate that the use of alkali activation of natural zeolites is an effective method for the synthesis of geopolymers. The mechanical properties of geopolymers were slightly but not adversely affected by the addition of the migratory corrosion inhibitor, MCI-2005 NS. These results will be used in future research on geopolymer concrete with embedded reinforcing steel.

  2. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    Science.gov (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-14

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  3. The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    El Bribri, A. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Tabyaoui, M., E-mail: hamidtabyaoui@yahoo.fr [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Laboratoire des Matériaux, Nanoparticules et Environnement, Université Mohamed V Agdal, Faculté des Sciences, 4 Av. Ibn Battouta, B.P. 1014 RP, M-10000 Rabat (Morocco); Tabyaoui, B. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); El Attari, H.; Bentiss, F. [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2013-08-15

    Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔG{sub ads}{sup o} value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm.

  4. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-01-01

    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  5. Experimental and DFT Studies on the Behavior of Caffeine as Effective Corrosion Inhibitor of Copper in 1M HNO3

    Directory of Open Access Journals (Sweden)

    Victorien Kouakou

    2016-04-01

    Full Text Available Caffeine was tested as copper corrosion inhibitor in 1M HNO3 using mass loss technique at 308-328K and theoretical studies based on quantum chemistry. The inhibition efficiency is concentration and temperature dependent: Caffeine showed an inhibition efficiency of 78% at 5mM for T =328K. The thermodynamic adsorption parameters ( were determined and analyzed. They revealed a spontaneous adsorption process and a strong interaction between Caffeine and the metal surface. Adsorption isotherms including Langmuir, Temkin and El-Awady were tested. It was found that Caffeine adsorbs on copper according to the modified Langmuir adsorption isotherm. The Dubinin Raduskevitch model was used to distinguish between chemisorption and physisorption. Activation parameters ( were also determined and discussed. Furthermore, the quantum chemical properties/descriptors most relevant to the potential action of the molecule as corrosion inhibitor such as highest occupied molecular energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, energy gap(∆E, dipole moment ( and charges on heteroatoms were calculated using DFT at B3LYP level with 6-31+G (d and LanL2DZ basis sets. Fukui indices were also determined and discussed. The theoretical results are consistent with the experimental data reported. DOI: http://dx.doi.org/10.17807/orbital.v8i2.804 

  6. Wet-gas transport in the Mediterranean Sea. Selection of a combined kinetic hydrate/corrosion inhibitor system

    Energy Technology Data Exchange (ETDEWEB)

    Zettlitzer, M. [RWE Dea AG, Wietze (Germany); Rozengard, N.; Koeckritz, V. [Technical Univ. Freiberg (Germany); Malt, E. [RWE Dea AG (Egypt)

    2007-09-13

    Raw gas will be collected on a platform in the centre of the field. Due to volume and weight constraints, condensing fluids will not be separated from the gas on the platform so that the raw gas will be transported in three-phase mode (gas, water, and condensate) via a 33 km long pipeline to a gas treatment plant. Under the calculated pipeline pressure of about 100 barg, hydrate formation is - according to the outcome of thermodynamic simulations - to be expected at temperatures of 19 C and below while the pipeline may cool down to about 15 C in winter conditions. Due to logistical, environmental and economic reasons, RWE Dea decided to inhibit hydrate formation with kinetic hydrate inhibitors (KHI). As the gas also contains carbon dioxide, certain corrosivity was forecasted and addition of a corrosion inhibitor turned out to be necessary. Laboratory tests were carried out to confirm the feasibility of the concept and to define the required dosage of KHI. Service companies were contacted and several kinetic hydrate and corrosion inhibitors were screened. Experiments with the different chemicals were performed at the University of Freiberg in a high-pressure cell at the pipeline pressure of 100 barg. Hydrate formation was detected by continuous pressure registration during temperature changes and by observation through a glass window. In order to preselect the chemicals, first tests were performed with pure methane. These tests also served for calibration of the equipment with literature data and especially as an indication for the minimum chemical concentration required. A second test series was performed with synthetic gas in a composition close to that of the field gas under consideration in order to verify the results obtained with methane. Finally, the optimum kinetic hydrate inhibitor was identified as well as the required dosage concentration. Compatibility of KHI and corrosion inhibitor was experimentally proven. A further set of kinetic inhibitor tests with

  7. The use of morinda citrifolia as a green corrosion inhibitor for low carbon steel in 3.5% NaCl solution

    Science.gov (United States)

    Kusumastuti, Rahayu; Pramana, Rakhmad Indra; Soedarsono, Johny W.

    2017-03-01

    The effect and mechanism of green corrosion inhibitor of Morinda Citrifolia (Noni) toward low carbon steel material has been researched. The general background is to develop the cheap and eco-friendly corrosion inhibitor based on components taken from tropical plants that grow +in Indonesia. This research aims to determine the effectiveness of the use of the extracts of noni as green corrosion inhibitor of carbon steel material in aggressive environment. The medium applied for this experiment is 3.5% natrium chloride solution. The variation of the concentration and immersion time duration has been applied as the experimental parameters. All the work was done at room temperature. The corrosion rate was measured by electrochemical polarization method with CMS 600-Gamry instruments and weight loss. The adsorption of inhibitor into the metal surface, which induced bonding formation after immersion was observed by using FTIR method. Inhibition mechanism was observed by polarization curves and fitted by the Langmuir adsorption models. The experimental results show that the higher concentration of inhibitor increasing the inhibition effect. The optimum inhibition is obtained at 3 ppm noni fruit extract, after immersion for about 288 hours. The corrosion rates obtained was 1.385 mpy, with the inhibitor efficiency of 76.92%. The monolayer film is formed coating the surface material as a result of mixed type corrosion inhibitor behavior of Noni. It can be concluded that this green inhibitor is effective to be used for low carbon steel material.

  8. Lithium salts as leachable corrosion inhibitors and potential replacement for hexavalent chromium in organic coatings for the protection of aluminum alloys

    NARCIS (Netherlands)

    Visser, P; Liu, Y; Terryn, H.A.; Mol, J.M.C.

    2016-01-01

    Lithium salts are being investigated as leachable corrosion inhibitor and potential replacement for hexavalent chromium in organic coatings. Model coatings loaded with lithium carbonate or lithium oxalate demonstrated active corrosion inhibition and the formation of a protective layer in a

  9. Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

    Directory of Open Access Journals (Sweden)

    J. P. Flores-De los Ríos

    2015-01-01

    Full Text Available The effect of Opuntia ficus-indica (Nopal as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60°C. Results indicated the inhibition efficiency increases with increasing extract concentration and decreases with the temperature, and the inhibitor acted as a cathodic-type inhibitor which is physically absorbed onto the steel surface. In fact, the adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm, indicating monolayer adsorption. The presence of heteroatoms such as C, N, and O and OH groups were responsible for the corrosion inhibition.

  10. Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

    2015-09-01

    The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

  11. Synthesis of some novel non ionic surfactants based on tolyltriazole and evaluation their performance as corrosion inhibitors for carbon steel

    Directory of Open Access Journals (Sweden)

    M.A. Migahed

    2013-06-01

    Full Text Available Five new synthesized non ionic surfactants (I–V were synthesized and characterized using FTIR and NMR spectroscopic methods. Performance of the synthesized compounds as corrosion inhibitors for X- 65 type carbon steel in oil wells formation water was investigated by various techniques such as weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. It was found that the percentage inhibition efficiency (η% increases by increasing the inhibitor concentration until the critical micelle concentration (CMC is reached. Also, the results showed enhancement in inhibition efficiencies with increasing both molecular size of the surfactant and the degree of ethoxylation. Potentiodynamic polarization curves indicated that the inhibitors under investigation act as mixed type. The data obtained from electrochemical impedance spectroscopy (EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Finally, the nature of the protective film formed on carbon steel surface was analyzed by SEM and EDX techniques.

  12. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  13. Experimental and theoretical studies of xanthan gum and its graft co-polymer as corrosion inhibitor for mild steel in 15% HCl

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Amrita; Pal, Sagar; Udayabhanu, G., E-mail: g_udayabhanu@hotmail.com

    2015-10-30

    Highlights: • Xanthan gum and its graft co-polymer used as corrosion inhibitors for mild steel in 15% HCl. • Electrochemical and weight loss studies give comparable corrosion rates. • Both the inhibitors are mixed type in nature. • Modified graft co-polymer is a more effective corrosion inhibitor. • Theoretical calculations taking monomer units of the polymer support the experimental results. - Abstract: Xanthan gum (XG) and its graft co-polymer have been investigated as corrosion inhibitors for mild steel in 15% HCl. Gravimetric analysis, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were employed for investigating the effectiveness of these inhibitors. Results indicate that both the inhibitors are of mixed type and follow Langmuir adsorption isotherm. Scanning electron microscopy (SEM) study also confirmed the protection of the metal surface by XG and xanthan gum-graft-poly(acrylamide) (XG-g-PAM). Theoretical calculations using Density Functional Theory (DFT) were used to establish the correlation between the structure and corrosion protection efficiencies.

  14. Ceria nanoparticles vis-à-vis cerium nitrate as corrosion inhibitors for silica-alumina hybrid sol-gel coating

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmi, R.V. [Surface Engineering Division, Council of Scientific and Industrial Research – National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bengaluru 560017 (India); Aruna, S.T., E-mail: staruna194@gmail.com [Surface Engineering Division, Council of Scientific and Industrial Research – National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bengaluru 560017 (India); Sampath, S. [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru 560012 (India)

    2017-01-30

    Highlights: • Corrosion protection efficiency comparison of ceria nanoparticles and cerium nitrate. • Silica-alumina hybrid coating exhibited good barrier protection. • Detailed XPS study confirm the hybrid structure and presence of Ce species in coating. • Loss of cerium ions not prevalent in ceria doped coating unlike that of cerium nitrate. • Ceria increased the coating integrity, corrosion inhibition and barrier protection. - Abstract: The present work provides a comparative study on the corrosion protection efficiency of defect free sol-gel hybrid coating containing ceria nanoparticles and cerium nitrate ions as corrosion inhibitors. Less explored organically modified alumina-silica hybrid sol-gel coatings are synthesized from 3-glycidoxypropyltrimethoxysilane and aluminium-tri-sec-butoxide. The microemulsion derived nanoparticles and the hybrid coatings are characterized and compared with coatings containing cerium nitrate. Corrosion inhibiting capability is assessed using electrochemical impedance spectroscopy. Scanning Kelvin probe measurements are also conducted on the coatings for identifying the apparent corrosion prone regions. Detailed X-ray photoelectron spectroscopy (XPS) analysis is carried out to comprehend the bonding and corrosion protection rendered by the hybrid coatings.

  15. The Effect of Two Amine-Based Corrosion Inhibitors in Improving the Corrosion Resistance of Carbon Steel in Sea Water

    Science.gov (United States)

    Rihan, Rihan; Shawabkeh, Reyad; Al-Bakr, Nawaf

    2014-03-01

    This study investigates the effect of two amine-based corrosion inhibitors in reducing the corrosion rate (CR) of 1018 carbon steel in formulated sea water. For discussion purposes, the two inhibitors are named Inhibitor A (belongs to the alkyl pyridine benzyl chloride quaternary family of inhibitors) and Inhibitor B (belongs to the alkyl amines family of inhibitors). The two inhibitors are routinely considered for applications by Saudi Aramco, the world's largest oil producing and processing company, for reducing its corrosion problems in carbon steel pipelines carrying oil and gas. The experimental apparatus was a circulating flow loop system inside an autoclave. The experimental work was performed at pH 8.2, 55 °C, and 1000 rpm. The inhibitors were evaluated at three different concentrations of 5, 10, and 15 ppm. The CR was determined using the weight loss method and electrochemical methods such potentiodynamic sweep and linear polarization resistance. The experimental results indicate that Inhibitor B reduced the CR more than that of Inhibitor A.

  16. Complexes of Imidazole with Poly(ethylene glycol) as a Corrosion Inhibitor for Carbon Steel in Sulphuric Acid

    Science.gov (United States)

    Salimi, Saeed; Nasr-Esfahani, Mojtaba; Umoren, Saviour A.; Saebnoori, Ehsan

    2015-12-01

    The inhibiting action of polyethylene glycol and imidazole (PEG/IMZ)) complexes prepared by a simple deprotonation procedure on carbon steel corrosion in 0.5 mol/L sulphuric acid was evaluated using the weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques complemented by surface analysis using scanning electron microscopy. The inhibiting effect of the PEG/IMZ complexes on carbon steel corrosion was compared with the non-complex forms. Results obtained show that PEG/IMZ complex is a very effective corrosion inhibitor of carbon steel in the acid environment. The inhibition efficiency increased with the increase in the temperature and also with increasing percentage of imidazole in the complex. Corrosion inhibition occurs by virtue of adsorption of PEG/IMZ complexes on the steel surface which was found to follow the Temkin adsorption isotherm model. The PEG/IMZ complexes function as a mixed-type inhibitor. Results from all the methods employed are in a reasonably good agreement.

  17. Corrosion inhibitor storage and release property of TiO{sub 2} nanotube powder synthesized by rapid breakdown anodization method

    Energy Technology Data Exchange (ETDEWEB)

    Arunchandran, C.; Ramya, S.; George, R.P. [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Kamachi Mudali, U., E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► TiO{sub 2} nanotube powders were synthesized by rapid breakdown anodization method. ► Benzotriazole was loaded into the TiO{sub 2} nanotube powders. ► Low pH induced release of benzotriazole from TiO{sub 2} nanotube powders was proved. -- Abstract: Titanium dioxide (TiO{sub 2}) is one of the most studied substances in material science due to its versatile properties and diverse applications. In this study titanium dioxide nanotube powder were synthesized by rapid breakdown anodization (RBA) method. The synthesis involved potentiostatic anodization of titanium foil in 0.1 M HClO{sub 4} electrolyte under an applied voltage of 20 V and rapid stirring. The morphology and the phase of titanium dioxide nanotube powder were studied using field emission scanning electron microscopy, laser Raman spectroscopy and high resolution transmission electron microscopy. Benzotriazole was chosen as model inhibitor to evaluate TiO{sub 2} nanotube powder's corrosion inhibitor loading and releasing properties. The storage and release properties of TiO{sub 2} nanotube powder were studied using UV–visible spectroscopy and thermogravimetric analysis.

  18. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Energy Technology Data Exchange (ETDEWEB)

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  19. 1-Butyl-1-methylpyrrolidinium chloride as an effective corrosion inhibitor for stainless steel current collectors in magnesium chloride complex electrolytes

    Science.gov (United States)

    Ha, Jung Hoon; Cho, Jae-Hyun; Kim, Jong Hak; Cho, Byung Won; Oh, Si Hyoung

    2017-07-01

    Corrosion of current collectors is one of the most significant issues to tackle in rechargeable magnesium batteries where chloride-abundant electrolytes are commonly used since it can affect the electrochemical performance and the safety of battery system seriously. Here we investigate 1-butyl-1-methylpyrrolidinium chloride ionic liquid as an effective corrosion inhibitor of the current collector in an electrolyte containing magnesium chloride complex. We find that adding just 0.2 wt.% ionic liquid increases the anodic stability of common current collectors by 0.1-0.3 V while maintaining the coulombic efficiencies for Mg deposition and stripping at over 98%. In particular, analytical studies of the passive film formed on 316L stainless steel show that the inhibitor efficiently prevents the formation of corrosion pits and preserves the protective property of the passive film upon repeated anodic scans. Furthermore, the inhibitor enables almost 100% efficiencies in the full cell cycling with Mo6S8 cathode, reflecting higher anodic stability of the current collectors in the electrolyte containing the inhibitor. We propose that the formation of an adsorbed layer of the ionic liquid as a plausible corrosion inhibition mechanism.

  20. Effect of storage time and natural corrosion inhibitor on carbohydrate and carboxylic acids content in canned tomato puree.

    Science.gov (United States)

    Grassino, A Nincevic; Grabaric, Z; De Sio, F; Cacace, D; Pezzani, A; Squitieri, G

    2012-06-01

    In this research compositional changes of tinplate-canned tomato purées, with or without the addition of essential onion oil were investigated. The study was focused on the analyses of carbohydrates and carboxylic acids in two groups of canned samples (with or without nitrates) to determine whether their chemical composition was affected with storage time. The measurements were performed by high performance liquid chromatography, during six months of storage. The contents of glucose, fructose and two major organic acids, citric and malic, were found in the concentration range 1.77-1.97%, 1.86-2.09%, 0.60-0.75% and 0.23-0.30%, respectively, in all canned samples. Compared to carbohydrates and organic acids, amino acids were found in minor quantities, among them, as most abundant ones were glutamic acid, arginine, aspartic and γ-amino butyric acids. The results show that contents of carbohydrates and carboxylic acids are significantly affected by the change of storage time in majority of analyzed samples. The results also indicated that the influence of essential onion oil on composition of canned tomato purée is within the range of changes due to storage time measured for all other types of cans. Therefore the addition of essential onion oil as natural efficient corrosion inhibitor, as it was found in our previous work, can be recommended for canned tomato purée.

  1. Achilles Tendon Rupture

    Science.gov (United States)

    ... Achilles tendon rupture. Obesity. Excess weight puts more strain on the tendon. Prevention To reduce your chance of developing Achilles tendon problems, follow these tips: Stretch and strengthen calf muscles. Stretch your calf until you feel a noticeable ...

  2. Posterior Tibial Tendon Dysfunction

    Science.gov (United States)

    .org Posterior Tibial Tendon Dysfunction Page ( 1 ) Posterior tibial tendon dysfunction is one of the most common problems of the foot and ankle. It occurs when the posterior tibial tendon becomes inflamed or torn. As a result, the ...

  3. Achilles tendon repair

    Science.gov (United States)

    Achilles tendon rupture-surgery; Percutaneous Achilles tendon rupture repair ... To fix your torn Achilles tendon, the surgeon will: Make a cut down the back of your heel Make several small cuts rather than one large ...

  4. Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Buchweishaija, Joseph

    1997-12-31

    Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

  5. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat (Indonesia)

    2015-09-30

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

  6. A Study of N,N-Diethylammonium O,O′-Di(p-methoxyphenyldithiophosphate as New Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Chuan Lai

    2016-01-01

    Full Text Available N,N-Diethylammonium O,O′-di(p-methoxyphenyldithiophosphate (EAPP as a new corrosion inhibitor was synthesized in the present work. The corrosion inhibition of EAPP in hydrochloric acid for carbon steel was evaluated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy, weight loss measurements, and scanning electron microscopy. The results indicate that the EAPP is mixed type inhibitor, and the adsorption of EAPP on carbon steel surface obeys Langmuir isotherm. In addition, the inhibition efficiency increases with increasing the concentration of inhibitor and decreases with increasing the hydrochloric acid concentration, temperature, and storage time.

  7. Flexor tendon nutrition.

    Science.gov (United States)

    Manske, P R; Lesker, P A

    1985-02-01

    The concepts regarding nutrient pathways to flexor tendons within the digital sheath are reviewed. Historically, both diffusion and perfusion have been considered significant pathways to the flexor tendon. Theories of tendon healing and adhesion formation, as well as techniques employed by the surgeon in the repair of tendons, are based on these concepts.

  8. Iliopsoas Tendon Reformation after Psoas Tendon Release

    Directory of Open Access Journals (Sweden)

    K. Garala

    2013-01-01

    Full Text Available Internal snapping hip syndrome, or psoas tendonitis, is a recognised cause of nonarthritic hip pain. The majority of patients are treated conservatively; however, occasionally patients require surgical intervention. The two surgical options for iliopsoas tendinopathy are step lengthening of the iliopsoas tendon or releasing the tendon at the lesser trochanter. Although unusual, refractory snapping usually occurs soon after tenotomy. We report a case of a 47-year-old active female with internal snapping and pain following an open psoas tenotomy. Postoperatively she was symptom free for 13 years. An MRI arthrogram revealed reformation of a pseudo iliopsoas tendon reinserting into the lesser trochanter. The pain and snapping resolved after repeat iliopsoas tendon release. Reformation of tendons is an uncommon sequela of tenotomies. However the lack of long-term studies makes it difficult to calculate prevalence rates. Tendon reformation should be included in the differential diagnosis of failed tenotomy procedures after a period of symptom relief.

  9. Peroneal tendon disorders

    OpenAIRE

    Davda, Kinner; Malhotra, Karan; O'Donnell, Paul; Singh, Dishan; Cullen, Nicholas

    2017-01-01

    Pathological abnormality of the peroneal tendons is an under-appreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries. Enclosed within the lateral compartment of the leg, the peroneal tendons are the primary evertors of the foot and function as lateral ankle stabilisers. Pathology of the tendons falls into three broad categories: tendinitis and tenosynovitis, tendon subluxation and dislocation, and tendon splits and ...

  10. Endoscopic adhesiolysis for extensive tibialis posterior tendon and Achilles tendon adhesions following compound tendon rupture

    OpenAIRE

    Lui, Tun Hing

    2013-01-01

    Tendon adhesion is one of the most common causes of disability following tendon surgery. A case of extensive peritendinous adhesions of the Achilles tendon and tibialis posterior tendon after compound rupture of the tendons was reported. This was managed by endoscopic adhesiolysis of both tendons. The endoscopic approach allows early postoperative mobilisation which can relieve the tendon adhesion.

  11. The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, Carlos A. [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)], E-mail: gorc74@yahoo.com; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)

    2008-12-01

    The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

  12. DETERMINATION OF CORROSION INHIBITOR CRITERIA FOR TYPE III/IIIA TANKS DURING SALT DISSOLUTION OPERATIONS INTERIM REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Counts, K; Bruce Wiersma, B; John Mickalonis, J

    2007-12-31

    Preparation of high level waste for vitrification involves in part the dissolution of salt cake from the carbon steel storage tanks. During dissolution, a point is reached in which the corrosion inhibitors, hydroxide and nitrite, are diluted below established guidelines, and nitrate stress corrosion cracking (SCC) is possible. Because the addition of inhibitors may be counterproductive to process efficiency and waste minimization, corrosion testing was initiated to revisit and possibly revise the guidelines for inhibitor limits. The bases for the work summarized in this status report are results from previously-completed phases of study. In the first two phases of study, several reduced-inhibitor levels were tested in HLW simulants with nitrate concentrations ranging from 4.5 M to 8.5 M. The first two phases of work determined, among other things, the reduced-inhibitor levels and solution chemistries in which heat-treated and non-heat-treated A537 carbon steel is susceptible to SCC, crevice corrosion, and pitting. The work covered in this current task both builds on and verifies the conclusions of the previous work. The current work involves testing of low levels of inhibitors in HLW simulants with 5.5 M to 8.5 M nitrate concentrations. Stressed U-bend specimens, both polarized and non-polarized, were tested. Non-polarized U-bend testing is ongoing, with the U-bends currently in test for 100 days. The purpose of the testing is to determine SCC susceptibility in the vapor space (VS) and liquid air interface (LAI) regions of the HLW tanks under conditions expected during salt dissolution, and also to verify previous accelerated testing. The simulated wastes being tested have nitrate concentrations of 5.5 M and 8.5 M and inhibitor levels of 0.01 M/0.01 M hydroxide/nitrite and 0.1 M/ 0.1 M hydroxide/nitrite. The open circuit potential measurements being monitored and the corrosion morphology of the U-bends are in agreement with results and observations of previous

  13. Diseases of the tendons and tendon sheaths.

    Science.gov (United States)

    Steiner, Adrian; Anderson, David E; Desrochers, André

    2014-03-01

    Contracted flexor tendon leading to flexural deformity is a common congenital defect in cattle. Arthrogryposis is a congenital syndrome of persistent joint contracture that occurs frequently in Europe as a consequence of Schmallenberg virus infection of the dam. Spastic paresis has a hereditary component, and affected cattle should not be used for breeding purposes. The most common tendon avulsion involves the deep digital flexor tendon. Tendon disruptions may be successfully managed by tenorrhaphy and external coaptation or by external coaptation alone. Medical management alone is unlikely to be effective for purulent tenosynovitis. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Peroneal Tendon Injuries

    Science.gov (United States)

    ... the type of peroneal tendon injury. Options include: Immobilization. A cast or splint may be used to ... arthritis, gout, tendonitis, fracture, nerve compression (tarsal tunnel syndrome), infection and... Founded in 1942, the American College ...

  15. Chronic Achilles Tendon Rupture

    Science.gov (United States)

    Maffulli, Nicola; Via, Alessio Giai; Oliva, Francesco

    2017-01-01

    Background: The Achilles tendon, the largest and strongest tendon in the human body, is nevertheless one of the tendons which most commonly undergoes a complete subcutaneous tear. Achilles tendon ruptures are especially common in middle aged men who occasionally participate in sport. Even though Achilles tendon ruptures are frequent, up to 25% of acute injuries are misdiagnosed, and present as chronic injuries. Methods: This is a review article about diagnosis and management of chronic Achilles tendon ruptures. Minimally invasive Achilles tendon reconstruction is discussed. Results: The optimal surgical procedure is still debated, however, less invasive peroneus brevis reconstruction technique and free hamstring autograft provide good functional results. Conclusion: The management of chronic ruptures is more demanding than acute tears, because of the retraction of the tendon ends, and the gap makes primary repair impossible. Wound complications and infections are frequent after open procedures. Minimally invasive treatments provide good functional results and lower complications rate. PMID:29081863

  16. Biologics for tendon repair☆

    Science.gov (United States)

    Docheva, Denitsa; Müller, Sebastian A.; Majewski, Martin; Evans, Christopher H.

    2015-01-01

    Tendon injuries are common and present a clinical challenge to orthopedic surgery mainly because these injuries often respond poorly to treatment and require prolonged rehabilitation. Therapeutic options used to repair ruptured tendons have consisted of suture, autografts, allografts, and synthetic prostheses. To date, none of these alternatives has provided a successful long-term solution, and often the restored tendons do not recover their complete strength and functionality. Unfortunately, our understanding of tendon biology lags far behind that of other musculoskeletal tissues, thus impeding the development of new treatment options for tendon conditions. Hence, in this review, after introducing the clinical significance of tendon diseases and the present understanding of tendon biology, we describe and critically assess the current strategies for enhancing tendon repair by biological means. These consist mainly of applying growth factors, stem cells, natural biomaterials and genes, alone or in combination, to the site of tendon damage. A deeper understanding of how tendon tissue and cells operate, combined with practical applications of modern molecular and cellular tools could provide the long awaited breakthrough in designing effective tendon-specific therapeutics and overall improvement of tendon disease management. PMID:25446135

  17. The water soluble composite poly(vinylpyrrolidone–methylaniline: A new class of corrosion inhibitors of mild steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    R. Karthikaiselvi

    2017-02-01

    Full Text Available In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1 M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy. SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

  18. Efficient Complex Surfactants from the Type of Fatty Acids as Corrosion Inhibitors for Mild Steel C1018 in CO{sub 2}-Environments

    Energy Technology Data Exchange (ETDEWEB)

    Abbasov, Vagif M.; Abd Ellatee, Hany M.; Aliyeva, Leylufer I.; Ismayilov, Ismayil T.; Qasimov, Elmar E.; Narmin, Mamedova M. [National Academy of Sciences of Azerbaijan, Baku (Azerbaijan)

    2013-02-15

    The efficiency of three complex surfactants based on sunflower oil and nitrogen containing compounds as corrosion inhibitors for mild steel in CO{sub 2}-saturated 1% NaCl solution, has been determined by weight loss and LPR corrosion rate measurements. These compounds inhibit corrosion even at very low concentrations. The inhibition process was attributed to the formation of an adsorbed film on the metal surface that protects the metal against corrosive media. The inhibition efficiency increases with increasing the concentration of the studied inhibitors. Maximum inhibition efficiency of the surfactants is observed at concentrations around its critical micellar concentration (CMC). Adsorption of complex surfactants on the mild steel surface is in agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Energy dispersive X-ray fluorescence microscopy (EDRF) observations of the electrode surface confirmed the existence of such an adsorbed film.

  19. Novel naphthenate surfactants based on petroleum acids and nitrogenous bases as corrosion inhibitors for C1018-type mild steel in CO2-saturated brine

    Directory of Open Access Journals (Sweden)

    Hany M. Abd El-Lateef

    2015-06-01

    Full Text Available The efficiency of two natural naphthenate surfactants (Naphthenic-dimethylamine and Naphthenic-diethylamine complexes, as corrosion inhibitors for mild steel in CO2-saturated 1% NaCl solution, has been determined by linear polarization resistance corrosion rate and potentiodynamic polarization measurements. These compounds inhibit corrosion even at very low concentrations (25 ppm, and Naphthenic-diethylamine complex is the best inhibitor giving maximum inhibition efficiency (99.76 at 100 ppm. Polarization curves indicate that, the two investigated compounds are mixed inhibitors, affecting both cathodic and anodic corrosion currents. Adsorption of naphthenate surfactants on the mild steel surface is in good agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Energy dispersive X-ray fluorescence microscopy (EDRF and scanning electron microscope (SEM observations confirmed the existence of such an adsorbed film on the mild steel surface.

  20. Thiomorpholin-4-ylmethyl-phosphonic acid and morpholin-4-methyl-phosphonic acid as corrosion inhibitors for carbon steel in natural seawater

    Energy Technology Data Exchange (ETDEWEB)

    Amar, H. [Corrodys, Centre de Corrosion Marine et Biologique, 55 rue de Beuzeville, BP 9, 50120 Equeurdreville-Hainneville (France)], E-mail: h.amar@corrodys.com; Braisaz, T. [Corrodys, Centre de Corrosion Marine et Biologique, 55 rue de Beuzeville, BP 9, 50120 Equeurdreville-Hainneville (France); Villemin, D.; Moreau, B. [Ecole Nationale Superieure d' Ingenieurs de Caen, UMR 6507 CNRS, Bd Marechal Juin, 14050 Caen Cedex (France)

    2008-07-15

    Electrochemical techniques have been used for investigating the inhibition of carbon steel by thiomorpholin-4-ylmethyl-phosphonic acid (TMPA) and morpholin-4-methyl-phosphonic acid (MPA) in natural seawater. The free corrosion potential was observed to the shift in noble direction which indicated that the phosphonic acids tested inhibit the corrosion of carbon steel in seawater. Potentiodynamic polarization curve shows clearly the fact that the addition of these molecules is associated with corrosion current density decrease and a corresponding reduction of the corrosion rate. The phosphonic acids tested as corrosion inhibitors of carbon steel in natural seawater are effective even with small concentration. Fourier transform infrared spectroscopy was used to obtain information on bonding mechanism between the metallic surface and the inhibitors. The morphology of the metal surface in the uninhibited and inhibited solution was examined using the scanning electron microscope coupled with an energy dispersive X-ray analysis system.

  1. Non toxic biodegradable cationic gemini surfactants as novel corrosion inhibitor for mild steel in hydrochloric acid medium and synergistic effect of sodium salicylate: Experimental and theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Mobin, Mohammad, E-mail: drmmobin@hotmail.com; Aslam, Ruby; Aslam, Jeenat

    2017-04-15

    Two biodegradable, non toxic cationic gemini surfactants having ester linkage in the spacer namely, C{sub m}H{sub 2m+1}(CH{sub 3}){sub 2}N{sup +}(CH{sub 2}COOCH{sub 2}){sub 2}N{sup +}(CH{sub 3}){sub 2}C{sub m}H{sub 2m+1}.2Cl{sup -} (m-E2-m, m = 12, 14), were synthesized and characterized using elemental analysis, FT-IR and {sup 1}H-NMR. The corrosion inhibition performance of synthesized compounds separately and in combination with sodium salicylate (SS), along with the nature and stability of inhibitive film, for mild steel (MS) in 1 M HCl solution at 30–60 °C was evaluated using weight loss, potentiodynamic polarization, EIS, UV–visible spectroscopy, FTIR, SEM/EDAX, TGA and quantum chemical calculations. Results of the studies confirm m-E2-m as effective corrosion inhibitor for MS in HCl; the inhibition effect being synergistically strengthened in presence of SS. The synthesized compounds act as mixed type inhibitor and adsorb on MS surface in accordance with Langmuir adsorption isotherm. Experimentally measured inhibition efficiencies are correlated with the molecular parameters obtained using PM6 semi-empirical method. Empirical results are in good agreement with the theoretical predictions. - Graphical abstract: (a) Optimized geometry of studied inhibitors by PM6 method with (b) HOMO and (c) LUMO orbital occupation. - Highlights: • Environment friendly gemini surfactants were studied as corrosion inhibitor for MS. • Studied compounds act as good inhibitor for MS corrosion in 1 M HCl at 30–60 °C. • η of inhibitors is synergistically increased in presence of sodium salicylate. • The synthesized cationic gemini surfactants act as mixed-type inhibitor. • Experimentally obtained results are in good agreement with theoretical results.

  2. Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes; Avaliacao da potencialidade de aditivos como inibidores de corrosao do aco carbono CA-50 usado como armadura de estruturas de concreto

    Energy Technology Data Exchange (ETDEWEB)

    Mennucci, Marina Martins

    2006-07-01

    In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

  3. FIBRILLINS IN TENDON

    Directory of Open Access Journals (Sweden)

    Betti Giusti

    2016-10-01

    Full Text Available Tendons among connective tissue, mainly collagen, contain also elastic fibres made of fibrillin 1, fibrillin 2 and elastin that are broadly distributed in tendons and represent 1-2% of the dried mass of the tendon. Only in the last years, studies on structure and function of elastic fibres in tendons have been performed. Aim of this review is to revise data on the organization of elastic fibres in tendons, in particular fibrillin structure and function, and on the clinical manifestations associated to alterations of elastic fibres in tendons. Indeed, microfibrils may contribute to tendon mechanics; therefore, their alterations may cause joint hypermobility and contractures which have been found to be clinical features in patients with Marfan syndrome and Beals syndrome. The two diseases are caused by mutations in genes FBN1 and FBN2 encoding fibrillin 1 and fibrillin 2, respectively.

  4. Tendon functional extracellular matrix.

    Science.gov (United States)

    Screen, Hazel R C; Berk, David E; Kadler, Karl E; Ramirez, Francesco; Young, Marian F

    2015-06-01

    This article is one of a series, summarizing views expressed at the Orthopaedic Research Society New Frontiers in Tendon Research Conference. This particular article reviews the three workshops held under the "Functional Extracellular Matrix" stream. The workshops focused on the roles of the tendon extracellular matrix, such as performing the mechanical functions of tendon, creating the local cell environment, and providing cellular cues. Tendon is a complex network of matrix and cells, and its biological functions are influenced by widely varying extrinsic and intrinsic factors such as age, nutrition, exercise levels, and biomechanics. Consequently, tendon adapts dynamically during development, aging, and injury. The workshop discussions identified research directions associated with understanding cell-matrix interactions to be of prime importance for developing novel strategies to target tendon healing or repair. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  5. Percutaneous Achilles Tendon Lengthening

    Science.gov (United States)

    ... Ligament Reconstruction Lateral Ankle Stabilization Mosaicplasty for Osteochondral Lesions of the Talus Peroneus Longus to Achilles Tendon Transfer Pilon Fracture Surgery Posterior Ankle Endoscopy or ...

  6. Tendon and ligament imaging

    Science.gov (United States)

    Hodgson, R J; O'Connor, P J; Grainger, A J

    2012-01-01

    MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease. PMID:22553301

  7. Accidental Bowel Leakage

    Science.gov (United States)

    ... I do to help treat accidental bowel leakage? Kegel exercises strengthen the muscles that surround the openings ... bowels that may cause cramping, diarrhea, or constipation. Kegel Exercises: Pelvic muscle exercises that assist in bladder ...

  8. Tendon lengthening and transfer.

    Science.gov (United States)

    Fitoussi, F; Bachy, M

    2015-02-01

    Tendon lengthening and transfer are usually indicated for certain neuromuscular disorders, peripheral or central nerve injury, congenital disorder or direct traumatic or degenerative musculotendinous lesion. In musculotendinous lengthening, technique depends on muscle anatomy, degree of correction required, and the need to avoid excessive loss of force. Lengthening within the muscle or aponeurosis is stable. In the tendon, however, it may provide greater gain but is not stable and requires postoperative immobilization to avoid excessive lengthening. Tendon transfer consists in displacing a muscle's tendon insertion in order to restore function. The muscle to be transferred is chosen according to strength, architecture and course, contraction timing, intended direction, synergy and the joint moment arm to be restored. Functions to be restored have to be prioritized, and alternatives to transfer should be identified. The principles of tendon transfer require preoperative assessment of the quality of the tissue through which the transfer is to pass and of the suppleness of the joints concerned. During the procedure, transfer tension should be optimized and the neurovascular bundle should be protected. The method of fixation, whether tendon-to-bone or tendon-to-tendon suture, should be planned according to local conditions and the surgeon's experience. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Langmuir adsorption isotherm analysis on the addition of Myrmecodia Pendans extract as a corrosion inhibitor with a variety of corrosive media

    Science.gov (United States)

    Pradityana, Atria; Sulistijono, Subowo, Suhariyanto, Subiyanto, Hari; Rusdiyana, Liza

    2017-05-01

    In this study, the corrosion process was done by potentiodynamic polarization method on API 5L Grade B. Variations corrosion media used were NaCl 3,5%, HCl 1 M and H2SO4 1 M. Organic Inhibitors used are plant Myrmecodia Pendans, while the concentration of the extract used were 100-500 mg / L (multiples of 100 mg / L). In this study, the mechanism of adsorption equation model used is Langmuir. This study aims to determine appropriate corrosive media followed the Langmuir adsorption isotherm when added to extracts of Myrmecodia Pendans as a corrosion inhibitor. The value of free energy of the system have obtained from the adsorption isotherm models. With the known value of free energy, it can be seen whether the adsorption occurs in physics or chemistry. This relates to the surface protective layer formed on the surface adsorption extract. The results showed that the corrosion in 3.5% NaCl solution that follows the Langmuir method.

  10. Assessment of cytotoxic and cytogenetic effects of a 1,2,5-thiadiazole derivative on CHO-K1 cells. Its application as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, C.A. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Mirifico, M.V. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina); Morales, M.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Reigosa, M.A. [IMBICE (Instituto Multidisciplinario de Biologia Celular), CICPBA, CONICET, Calle 526 entre 10 y 11, 1900 La Plata (Argentina); Mele, M. Fernandez Lorenzo de, E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina)

    2009-10-30

    This work focuses on the possible use of phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (TDZ) as a harmless corrosion inhibitor. TDZ range-dose providing minimum adverse effects to the environment and human health, with satisfactory corrosion-inhibiting properties was evaluated. Cytotoxicity and genotoxicity of TDZ at 0.57-12.50 {mu}M concentration range were tested by neutral red, chromosomal aberrations, mitotic index, and colony formation assays. Results showed a significant increase of chromatid-type aberrations for the highest concentration of TDZ assayed (12.50 {mu}M). Additionally, a reduction in the proliferative rate for lower concentrations was detected by the MI assay. We concluded that TDZ should be used at concentrations lower than 1.16 {mu}M. Corrosion assays performed showed good inhibition effect (ca. 50%) at low (0.65 {mu}M) TDZ concentration. Consequently, our results indicated that TDZ induced a time- and dose-dependent genotoxic and cytotoxic response on CHO-K1 cells. Short assays should be complemented with long exposure tests to simulate chronic contact with TDZ since lower threshold levels may be found for shorter exposures and a wrong safety range could be determined.

  11. Tendon Gradient Mineralization for Tendon to Bone Interface Integration

    Science.gov (United States)

    Qu, Jin; Thoreson, Andrew R.; Chen, Qingshan; An, Kai-Nan; Amadio, Peter C.; Zhao, Chunfeng

    2014-01-01

    Tendon-to-bone integration is a great challenge for tendon or ligament reconstruction regardless of use of autograft or allograft tendons. We mineralized the tendon, thus transforming the tendon-to-bone into a “bone-to-bone” interface for healing. Sixty dog flexor digitorum profundus (FDP) tendons were divided randomly into 5 groups: 1) normal FDP tendon, 2) CaP (Non-extraction and mineralization without fetuin), 3) CaPEXT (Extraction by Na2HPO4 and mineralization without fetuin), 4) CaPFetuin (Non-extraction and mineralization with fetuin), and 5) CaPEXTFetuin (Extraction and mineralization with fetuin). The calcium and phosphate content significantly increased in tendons treated with combination of extraction and fetuin compared to the other treatments. Histology also revealed a dense mineral deposition throughout the tendon outer layers and penetrated into the tendon to a depth of 200 μm in a graded manner. Compressive moduli were significantly lower in the four mineralized groups compared with normal control group. No significant differences in maximum failure strength or stiffness were found in the suture pull-out test among all groups. Mineralization of tendon alters the interface from tendon to bone into mineralized tendon to bone, which may facilitate tendon-to-bone junction healing following tendon or ligament reconstruction. PMID:23939935

  12. Peroneal tendon disorders.

    Science.gov (United States)

    Davda, Kinner; Malhotra, Karan; O'Donnell, Paul; Singh, Dishan; Cullen, Nicholas

    2017-06-01

    Pathological abnormality of the peroneal tendons is an under-appreciated source of lateral hindfoot pain and dysfunction that can be difficult to distinguish from lateral ankle ligament injuries.Enclosed within the lateral compartment of the leg, the peroneal tendons are the primary evertors of the foot and function as lateral ankle stabilisers.Pathology of the tendons falls into three broad categories: tendinitis and tenosynovitis, tendon subluxation and dislocation, and tendon splits and tears. These can be associated with ankle instability, hindfoot deformity and anomalous anatomy such as a low lying peroneus brevis or peroneus quartus.A thorough clinical examination should include an assessment of foot type (cavus or planovalgus), palpation of the peronei in the retromalleolar groove on resisted ankle dorsiflexion and eversion as well as testing of lateral ankle ligaments.Imaging including radiographs, ultrasound and MRI will help determine the diagnosis. Treatment recommendations for these disorders are primarily based on case series and expert opinion.The aim of this review is to summarise the current understanding of the anatomy and diagnostic evaluation of the peroneal tendons, and to present both conservative and operative management options of peroneal tendon lesions. Cite this article: EFORT Open Rev 2017;2:281-292. DOI: 10.1302/2058-5241.2.160047.

  13. How Obesity Affects Tendons?

    Science.gov (United States)

    Abate, Michele; Salini, Vincenzo; Andia, Isabel

    Several epidemiological and clinical observations have definitely demonstrated that obesity has harmful effects on tendons. The pathogenesis of tendon damage is multi-factorial. In addition to overload, attributable to the increased body weight, which significantly affects load-bearing tendons, systemic factors play a relevant role. Several bioactive peptides (chemerin, leptin, adiponectin and others) are released by adipocytes, and influence tendon structure by means of negative activities on mesenchymal cells. The ensuing systemic state of chronic, sub-clinic, low-grade inflammation can damage tendon structure. Metabolic disorders (diabetes, impaired glucose tolerance, and dislipidemia), frequently associated with visceral adiposity, are concurrent pathogenetic factors. Indeed, high glucose levels increase the formation of Advanced Glycation End-products, which in turn form stable covalent cross-links within collagen fibers, modifying their structure and functionality.Sport activities, so useful for preventing important cardiovascular complications, may be detrimental for tendons if they are submitted to intense acute or chronic overload. Therefore, two caution rules are mandatory: first, to engage in personalized soft training program, and secondly to follow regular check-up for tendon pathology.

  14. Adequacy of palmaris longus and plantaris tendons for tendon grafting.

    Science.gov (United States)

    Jakubietz, Michael G; Jakubietz, Danni F; Gruenert, Joerg G; Zahn, Robert; Meffert, Rainer H; Jakubietz, Rafael G

    2011-04-01

    The reconstruction of tendon defects is challenging. The palmaris longus and plantaris tendon are generally considered best for tendon grafting. Only a few studies have examined whether these tendons, when present, meet criteria for successful grafting. The purpose of this study was to evaluate these tendons in regard to adequacy as tendon grafts. To evaluate adequacy for grafting, the palmaris longus and plantaris tendons were harvested from 92 arms and legs of 46 cadavers. Macroscopic evaluation and measurements concerning presence, length, and diameter of the tendons were obtained. Criteria for adequacy were a minimum length of 15 cm with diameter of 3 mm or, alternatively, 30 cm with a diameter of 1.5 mm. The palmaris longus tendon was present bilaterally in 36 cases and was absent bilaterally in 4 cases. The plantaris tendon was present bilaterally in 38 cases and absent bilaterally in 4 cases. In 29 cadavers, the palmaris longus tendon did not meet the criteria to be used as a tendon graft. Only in 8 cases were the tendons satisfactory for grafting bilaterally. The plantaris tendon met criteria for grafting in 20 cases bilaterally. In 17 cases, the tendons were considered inadequate bilaterally. Despite their presence, the palmaris longus and plantaris tendons are adequate for grafting less often than previously thought. In less than 50%, the tendons, although present, would serve as useful grafts. Our findings underscore the importance of choosing a second donor site before surgery in case the primarily selected tendon is not found to be suitable. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  15. Tendon Transfers for Tetraplegia.

    Science.gov (United States)

    Bednar, Michael S

    2016-08-01

    It is estimated that 65% to 75% of patients with cervical spinal cord injuries could benefit from upper extremity tendon transfer surgery. The goals of surgery are to restore elbow extension, as well as hand pinch, grasp, and release. Patients who have defined goals, actively participate in therapy, and understand expected outcomes, appear to have the highest satisfaction following tendon transfer procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. History of flexor tendon repair.

    Science.gov (United States)

    Manske, Paul R

    2005-05-01

    The first issue of Hand Clinics published 20 years ago was devoted to flexor tendon injuries. This was most appropriate, because no subject in hand surgery has sparked more interest or discussion. That inaugural issue included excellent presentations on the basic science of tendon injuries (anatomy, biomechanics, nutrition, healing, adhesions) and the clinical practice of tendon repair. Of interest, there was no presentation on the fascinating history of flexor tendon surgery. It is most appropriate, therefore, that this current update of the flexor tendon begins with a historical review of the evolution of flexor tendon repair.

  17. Tendon transfer or tendon graft for ruptured finger extensor tendons in rheumatoid hands.

    Science.gov (United States)

    Chung, U S; Kim, J H; Seo, W S; Lee, K H

    2010-05-01

    We evaluated the clinical outcome of tendon reconstruction using tendon graft or tendon transfer and the parameters related to clinical outcome in 51 wrists of 46 patients with rheumatoid arthritis with finger extensor tendon ruptures. At a mean follow-up of 5.6 years, the mean metacarpophalangeal (MP) joint extension lag was 8 degrees (range, 0-45) and the mean visual analogue satisfaction scale was 74 (range, 10-100). Clinical outcome did not differ significantly between tendon grafting and tendon transfer. The MP joint extension lag correlated with the patient's satisfaction score, but the pulp-to-palm distance did not correlate with patient satisfaction. We conclude that both tendon grafting and tendon transfer are reliable reconstruction methods for ruptured finger extensor tendons in rheumatoid hands.

  18. [Achilles tendon rupture].

    Science.gov (United States)

    Thermann, H; Hüfner, T; Tscherne, H

    2000-03-01

    The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques.

  19. Steroid injections - tendon, bursa, joint

    Science.gov (United States)

    ... gov/ency/article/007678.htm Steroid injections - tendon, bursa, joint To use the sharing features on this ... can be injected into a joint, tendon, or bursa. Description Your health care provider inserts a small ...

  20. Tendon Driven Finger Actuation System

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); hide

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  1. Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

    Directory of Open Access Journals (Sweden)

    Masego Dibetsoe

    2015-08-01

    Full Text Available The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1, 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine (Pc2, 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3 and 29H,31H-phthalocyanine (Pc4, and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1, 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2 and 2,3-naphthalocyanine (nP3 were investigated on the corrosion of aluminium (Al in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR. Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I− ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR

  2. Clinical aspects of tendon healing

    NARCIS (Netherlands)

    J.C.H.M. van der Meulen (Jacques)

    1974-01-01

    textabstractWe know that healing of a tendon wound takes place by an invasion of fibreblasts from the surrounding tissues; the tendon itself has no intrinsic healing capacity. lt was Potenza (1962) who proved that a traumatic suture of the tendons within their sheath is followed by disintegration of

  3. Leakage resilient password systems

    CERN Document Server

    Li, Yingjiu; Deng, Robert H

    2015-01-01

    This book investigates tradeoff between security and usability in designing leakage resilient password systems (LRP) and introduces two practical LRP systems named Cover Pad and ShadowKey. It demonstrates that existing LRP systems are subject to both brute force attacks and statistical attacks and that these attacks cannot be effectively mitigated without sacrificing the usability of LRP systems. Quantitative analysis proves that a secure LRP system in practical settings imposes a considerable amount of cognitive workload unless certain secure channels are involved. The book introduces a secur

  4. corrosion inhibitor for carbon steels

    African Journals Online (AJOL)

    potentiodynamic polarisation techniques. It was found that. CNSL reduces the extent of the electrochemical processes taking place on carbon steel undergoing corrosion. The corrosion rate of the carbon steel was reduced by over 92 % when only 300 ppm of CNSL was applied. This indicates that. CNSL is a potential ...

  5. Tensammetric Studies on Corrosion Inhibitors

    Indian Academy of Sciences (India)

    The extent of polarization follows the same order as corrosion inhibition data. Both sodium nitrite and dicyclohexylamine nitrite polarise to the same extent, cyclohexylamine to a lesser extent and morpholine to a still lesser extent. (c) Corrosion inhibition data.-The period for which complete protection is given by the different ...

  6. Agricultural Polymers as Corrosion Inhibitors

    Science.gov (United States)

    Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...

  7. Sex Hormones and Tendon

    DEFF Research Database (Denmark)

    Hansen, Mette; Kjaer, Michael

    2016-01-01

    The risk of overuse and traumatic tendon and ligament injuries differ between women and men. Part of this gender difference in injury risk is probably explained by sex hormonal differences which are specifically distinct during the sexual maturation in the teenage years and during young adulthood....... The effects of the separate sex hormones are not fully elucidated. However, in women, the presence of estrogen in contrast to very low estrogen levels may be beneficial during regular loading of the tissue or during recovering after an injury, as estrogen can enhance tendon collagen synthesis rate. Yet...

  8. Open Achilles tendon lacerations.

    Science.gov (United States)

    Said, M Nader; Al Ateeq Al Dosari, Mohamed; Al Subaii, Nasser; Kawas, Alaa; Al Mas, Ali; Al Ser, Yaser; Abuodeh, Yousef; Shakil, Malik; Habash, Ali; Mukhter, Khalid

    2015-04-01

    In contrast to closed Achilles tendon ruptures, open injuries are rarely reported in the literature. This paper provides information about open Achilles tendon wounds that are eventually seen in the Middle East. The reporting unit, Hamad Medical Corporation, is one of the biggest trauma centers in the Gulf area and the major health provider in Qatar. This is a retrospective study including patients admitted and operated for open Achilles tendon injuries between January 2011 and December 2013. Two hundred and five cases of open Achilles tendon lacerations were operated in Hamad General Hospital in this period. Forty-eight cases showed partial injuries, and the remaining are complete tendons cut. In the same period, fifty-one closed ruptured Achilles tendons were operated in the same trauma unit. In the majority of cases, the open injury resulted from a slip in the floor-leveled traditional toilette seats. Local damage to the toilette seats resulted in sharp edges causing the laceration of the heel if the patient was slipping over the wet floor. This occurrence is the cause in the vast majority of the cases. Wounds were located 1-5 cm proximal to tendon insertion. Standard treatment principles were applied. This included thorough irrigation in the emergency room, intravenous antibiotics, surgical debridement and primary repair within 24 h. Patients were kept in the hospital 1-7 days for intravenous antibiotics and possible dressing changes. Postoperatively below knee slabs were applied in the majority of patients and were kept for about 4 weeks followed by gradual weight bearing and range of motion exercises. Outpatients follow up in 1-2 weeks. Further follow-up visits at around 2-, 4-, 8- and 12-week intervals until complete wound healing and satisfactory rehabilitation outcome. Sixteen cases needed a second procedure. A high incidence of Achilles tendon open injuries is reported. This seems to be related to partially damaged floor-level toilettes in the

  9. Achilles tendon rupture - aftercare

    Science.gov (United States)

    ... will cover your foot and go to your knee. Your toes will be pointing downward. The cast will be changed every 2 to 3 weeks to help stretch your tendon. If you have a leg brace, splint, or boot, it will keep you from ...

  10. Tendon injuries of the hand

    Science.gov (United States)

    Schöffl, Volker; Heid, Andreas; Küpper, Thomas

    2012-01-01

    Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients. Most injuries are open injuries to the flexor or extensor tendons, but less frequent injuries, e.g., damage to the functional system tendon sheath and pulley or dull avulsions, also need to be considered. After clinical examination, ultrasound and magnetic resonance imaging have proved to be important diagnostic tools. Tendon injuries mostly require surgical repair, dull avulsions of the distal phalanges extensor tendon can receive conservative therapy. Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair. In the postoperative course of flexor tendon injuries, the principle of early passive movement is important to trigger an “intrinsic” tendon healing to guarantee a good outcome. Many substances were evaluated to see if they improved tendon healing; however, little evidence was found. Nevertheless, hyaluronic acid may improve intrinsic tendon healing. PMID:22720265

  11. Miscellaneous conditions of tendons, tendon sheaths, and ligaments.

    Science.gov (United States)

    Dyson, S J; Dik, K J

    1995-08-01

    The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (fibularis tertius) and ligaments injuries of the back.

  12. MRI of the Achilles tendon

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M.; Lienemann, A.; Hahn, D.; Lissner, J.; Boehm, P.

    1987-06-01

    The Achilles tendon and preachillar space of 30 patients was studied by MRI. A surface coil (Helmholtz' principle) was applied and all patients were examined with a superconducting magnet operating at 1.0 Tesla field strength. The purpose of the study was to illustrate pathological changes of the tendon and the surrounding soft tissue. In 3 cases MRI diagnosed a total rupture of the Achilles tendon. Furthermore, the strain of the tendon and side effects of an inflammatory process could be demonstrated. The use of a surface coil yields a high resolution of the normal anatomy of the region and of the pathological changes of the tendon and the surrounding soft tissue structures. The advantages of MRI for Achilles tendon diagnostics against competitive modalities are 1) excellent soft tissue contrast, 2) multiplanar imaging, 3) as well as exact delineation and visualisation of the lesion.

  13. Multifamily Envelope Leakage Model

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, Omari [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Griffiths, Dianne [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  14. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  15. Duct Leakage Repeatability Testing

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  16. Wide-Awake Primary Flexor Tendon Repair, Tenolysis, and Tendon Transfer

    OpenAIRE

    Tang, Jin Bo

    2015-01-01

    Tendon surgery is unique because it should ensure tendon gliding after surgery. Tendon surgery now can be performed under local anesthesia without tourniquet, by injecting epinephrine mixed with lidocaine, to achieve vasoconstriction in the area of surgery. This method allows the tendon to move actively during surgery to test tendon function intraoperatively and to ensure the tendon is properly repaired before leaving the operating table. I applied this method to primary flexor tendon repair ...

  17. Gastrocnemius tendon length and strain are different when assessed using straight or curved tendon model

    OpenAIRE

    Stosic, Jelena; Finni Juutinen, Taija

    2011-01-01

    The present study investigated the effects of tendon curvature on measurements of tendon length using 3D-kinematic analysis. Curved and straight tendon models were employed for assessing medial gastrocnemius tendon length and strain during hopping (N = 8). Tendon curvature was identified using small reflective markers placed on the skin surface along the length of the tendon and a sum of vectors between the markers from the calcaneous up to the marker at the origin of tendon was calculated. T...

  18. Novel methods for tendon investigations

    DEFF Research Database (Denmark)

    Kjær, Michael; Langberg, Henning; Bojsen-Møller, J.

    2008-01-01

    Purpose. Tendon structures have been studied for decades, but over the last decade, methodological development and renewed interest for metabolic, circulatory and tissue protein turnover in tendon tissue has resulted in a rising amount of investigations. Method. This paper will detail the various...

  19. Ultrasound-guided tendon fenestration.

    Science.gov (United States)

    Chiavaras, Mary M; Jacobson, Jon A

    2013-02-01

    A potential treatment for chronic tendinosis or tendinopathy is percutaneous ultrasound-guided tendon fenestration, also termed dry needling or tenotomy. This procedure involves gently passing a needle through the abnormal tendon multiple times to change a chronic degenerative process into an acute condition that is more likely to heal. This article reviews the literature on tendon fenestration and describes the technical aspects of this procedure including postprocedural considerations. Although peer-reviewed literature on this topic is limited, studies to date have shown that ultrasound-guided tendon fenestration can improve patient symptoms. Several other percutaneous treatments for tendinopathy that include prolotherapy, autologous whole-blood injection, and autologous platelet-rich plasma injection are often performed in conjunction with fenestration. It is currently unknown if these other percutaneous procedures have any benefit over ultrasound-guided tendon fenestration alone. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  20. Rectus Femoris Tendon Calcification

    Science.gov (United States)

    Zini, Raul; Panascì, Manlio; Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Denaro, Vincenzo

    2014-01-01

    Background: Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach. Purpose: To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment. Study Design: Case series; Level of evidence, 4. Methods: Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used. Results: One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05). Conclusion: Arthroscopic excision of

  1. Biceps Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Daniel M Polvino

    2018-01-01

    Full Text Available History of present illness: A 55-year-old male presented to the emergency department with a chief complaint of right arm pain. Five days prior to arrival, he attempted to lift himself up on his van and experienced what he described as a “rubber band snapping” in his right arm. He reported severe pain at the time that persisted but lessened in severity. Additionally, he reported increasing bruising over the proximal right arm. He had no history of prior right arm or shoulder injury. Significant findings: Physical exam was significant for ecchymosis and mild swelling of the right bicep. When the right arm was flexed at the elbow, a prominent mass was visible and palpable over the right bicep. Right upper extremity strength was 4/5 with flexion at the elbow. Discussion: The biceps brachii muscle is comprised of a long and short head, which share a common attachment at the bicipital tuberosity on the radius. The short head originates from the coracoid process of the scapula and the long head originates from the supraglenoid tubercle.1 Biceps tendon rupture has been found to occur at a rate of 0.53/100,000 over five years, and is three times more likely to occur in men than women.2 Risk factors for biceps tendon rupture include male sex, old age, increased body mass index, smoking, and pre-existing shoulder pathology.3,4 Diagnosis of biceps tendon rupture is typically a clinical diagnosis utilizing inspection and palpation as well as special testing such as the Speed’s and/or Yergason’s tests. Ultrasound may be used to aid in diagnosis; in full-thickness tears, ultrasound was found to have a sensitivity of 88% and a specificity of 98%. However, in partial thickness tears ultrasound has a sensitivity of 27% and a specificity of 100%.5 Often considered the gold standard in diagnosis, MRI has been found to have a sensitivity of only 67% and specificity of 98% in detecting complete tears6. Treatment initially consists of rest, ice, compression

  2. [Pathophysiology of overuse tendon injury].

    Science.gov (United States)

    Kannus, P; Paavola, M; Paakkala, T; Parkkari, J; Järvinen, T; Järvinen, M

    2002-10-01

    Overuse tendon injury is one of the most common injuries in sports. The etiology as well as the pathophysiological mechanisms leading to tendinopathy are of crucial medical importance. At the moment intrinsic and extrinsic factors are assumed as mechanisms of overuse tendon injury. Except for the acute, extrinsic trauma, the chronic overuse tendon injury is a multifactorial process. There are many other factors, such as local hypoxia, less of nutrition, impaired metabolism and local inflammatory that may also contribute to the development of tissue damage. The exact interaction of these factors cannot be explained entirely at the moment. Further studies will be necessary in order to get more information.

  3. Ultrasonographic assessment of flexor tendon mobilization: Effect of different protocols on tendon excursion

    NARCIS (Netherlands)

    J.-W.H. Korstanje (Jan-Wiebe); J. Soeters (Johannes); A.R. Schreuders (Ton); P.C. Amadio (Peter ); S.E.R. Hovius (Steven); H.J. Stam (Henk); R.W. Selles (Ruud)

    2012-01-01

    textabstractBackground: Different mobilization protocols have been proposed for rehabilitation after hand flexor tendon repair to provide tendon excursion sufficient to prevent adhesions. Several cadaver studies have shown that the position of the neighboring fingers influences tendon excursions of

  4. Carbon leakage and green growth

    NARCIS (Netherlands)

    Altaghlibi, M.

    2017-01-01

    This dissertation consists of four chapters. A general introduction to the problem of carbon leakage and the necessity of sustainable development is furnished in the first chapter. In chapter 2, we investigate the conditions under which a donor country is motivated to give unconditional mitigation

  5. Practical Leakage-Resilient Symmetric Cryptography

    DEFF Research Database (Denmark)

    Faust, Sebastian; Pietrzak, Krzysztof; Schipper, Joachim

    2012-01-01

    Leakage resilient cryptography attempts to incorporate side-channel leakage into the black-box security model and designs cryptographic schemes that are provably secure within it. Informally, a scheme is leakage-resilient if it remains secure even if an adversary learns a bounded amount of arbitr......Leakage resilient cryptography attempts to incorporate side-channel leakage into the black-box security model and designs cryptographic schemes that are provably secure within it. Informally, a scheme is leakage-resilient if it remains secure even if an adversary learns a bounded amount...

  6. The tendon approximator device in traumatic injuries.

    Science.gov (United States)

    Forootan, Kamal S; Karimi, Hamid; Forootan, Nazilla-Sadat S

    2015-01-01

    Precise and tension-free approximation of two tendon endings is the key predictor of outcomes following tendon lacerations and repairs. We evaluate the efficacy of a new tendon approximator device in tendon laceration repairs. In a comparative study, we used our new tendon approximator device in 99 consecutive patients with laceration of 266 tendons who attend a university hospital and evaluated the operative time to repair the tendons, surgeons' satisfaction as well as patient's outcomes in a long-term follow-up. Data were compared with the data of control patients undergoing tendon repair by conventional method. Totally 266 tendons were repaired by approximator device and 199 tendons by conventional technique. 78.7% of patients in first group were male and 21.2% were female. In approximator group 38% of patients had secondary repair of cut tendons and 62% had primary repair. Patients were followed for a mean period of 3years (14-60 months). Time required for repair of each tendon was significantly reduced with the approximator device (2 min vs. 5.5 min, ptendon repair were identical in the two groups and were not significantly different. 1% of tendons in group A and 1.2% in group B had rupture that was not significantly different. The new nerve approximator device is cheap, feasible to use and reduces the time of tendon repair with sustained outcomes comparable to the conventional methods.

  7. On the fail-safe design of tendon-driven manipulators with redundant tendons

    Energy Technology Data Exchange (ETDEWEB)

    Sheu, Jinn Biau; Liu, Tyng; Lee, Jyh Jone [National Taiwan University, Taipei (China)

    2012-06-15

    A tendon-driven manipulator having redundant tendons may possess more flexibility in operation, such as optimizing the performance of tendons, reducing the burden of each tendon, and providing fail-safe features. The purpose of this paper is to investigate the design of tendon-driven manipulators with a fail-safe feature, that is, to synthesize a system that may still remain controllable as any of the tendons have broken down or malfunctioned. Characteristics of tendon-driven manipulators are briefly discussed. Criteria for tendon-driven manipulators with redundant tendons and fail-safe feature are then established. Subsequently, constraints for such system are derived from the structure of tendon-driven manipulator. Associated with the criteria, manipulators can remain controllable when any of the tendons fails to function. Finally, a geometric method for determining the structure is developed. Examples of two-DOF and three-DOF tendondriven manipulators are demonstrated.

  8. Histopathological findings in chronic tendon disorders.

    Science.gov (United States)

    Järvinen, M; Józsa, L; Kannus, P; Järvinen, T L; Kvist, M; Leadbetter, W

    1997-04-01

    Tendon injuries and other tendon disorders represent a common diagnostic and therapeutic challenge in sports medicine, resulting in chronic and long-lasting problems. Tissue degeneration is a common finding in many sports-related tendon complaints. In the great majority of spontaneous tendon ruptures, chronic degenerative changes are seen at the rupture site of the tendon (1). Systemic diseases and diseases specifically deteriorating the normal structure of the tendon (i.e. foreign bodies, and metabolic, inherited and infectious tendon diseases) are only rarely the cause of tendon pathology. Inherited diseases, such as various hereditary diseases with disturbed collagen metabolism and characteristic pathological structural alterations (Ehlers-Danlos syndrome, Marfani syndrome, homocystinuria (ochronosis)), represent approximately 1% of the causes of chronic tendon complaints (2), whereas foreign bodies are somewhat more common and are found in less than 10% of all chronic tendon problems (1). Rheumatoid arthritis and sarcoidosis are typical systemic diseases that cause chronic inflammation in tendon and peritendinous tissues. Altogether, these 'specific' disorders represented less than 2% of the pathological alterations found in the histological analysis of more than 1000 spontaneously ruptured tendons (1, 3, 4). In this material, degenerative changes were seen in a great majority of the tendons, indicating that a spontaneous tendon rupture is a typical clinical end-state manifestation of a degenerative process in the tendon tissue. The role of overuse in the pathogenesis of chronic tendon injuries and disorders is not completely understood. It has been speculated that when tendon is overused it becomes fatigued and loses its basal reparative ability, the repetitive microtraumatic processes thus overwhelming the ability of the tendon cells to repair the fiber damage. The intensive repetitive activity, which often is eccentric by nature, may lead to cumulative

  9. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions

    Directory of Open Access Journals (Sweden)

    Thabo Peme

    2015-09-01

    Full Text Available The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS, Amaranth (AM, Allura Red (AR, Tartrazine (TZ and Fast Green (FG, for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I− ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  10. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

    Science.gov (United States)

    Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-09-02

    The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  11. Issues behind Competitiveness and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the vulnerability of heavy industry to carbon leakage and competitiveness loss. It reviews the existing literature on competitiveness and carbon leakage under uneven climate policies. It also suggests a statistical method to track carbon leakage, and applies this methodology to Phase I of the EU emissions trading scheme, for various industrial activities: iron and steel, cement, aluminium and refineries. Finally, it reviews measures to mitigate carbon leakage, as discussed in Australia, Canada, Europe, New Zealand and the US.

  12. 16 CFR 1507.5 - Pyrotechnic leakage.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Pyrotechnic leakage. 1507.5 Section 1507.5... FIREWORKS DEVICES § 1507.5 Pyrotechnic leakage. The pyrotechnic chamber in fireworks devices shall be sealed in a manner that prevents leakage of the pyrotechnic composition during shipping, handling, and...

  13. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  14. Acute calcific tendinitis simulating tendon sheath infection.

    Science.gov (United States)

    Omololu, B; Alonge, T O; Ogunlade, S O

    2001-01-01

    Tendon sheath infection has catastrophic consequences if not diagnosed. We present acute calcific tendinitis, a simulator of tendon sheath infection with a good prognosis in a 14 year old athletic tennis player.

  15. Basic mechanisms of tendon fatigue damage

    OpenAIRE

    Neviaser, Andrew; Andarawis-Puri, Nelly; Flatow, Evan

    2012-01-01

    Pathologic processes intrinsic and extrinsic to the tendons have been proposed as the underlying cause of rotator cuff disease, but the precise etiology is not known. Tear formation is, in part, attributable to the accumulation of subrupture tendon fatigue damage. We review the molecular, mechanical, and structural changes induced in tendons subjected to controlled amounts of fatigue loading in an animal model of early tendinopathy. The distinct tendon responses to low and moderate levels of ...

  16. MRI of normal achilles tendon

    Energy Technology Data Exchange (ETDEWEB)

    Rollandi, G.A. [Institute of Radiology, Univ. of Genoa (Italy); Bertolotto, M. [Institute of Radiology, Univ. of Genoa (Italy); Perrone, R. [Institute of Radiology, Univ. of Genoa (Italy); Garlaschi, G. [Institute of Radiology, Univ. of Genoa (Italy); Derchi, L.E. [Institute of Radiology, Univ. of Genoa (Italy)

    1995-12-01

    To investigate the normal internal structure of tendons 11 volunteers without clinical evidence of tendinopathy were examined using conventional spin-echo T1-, T2- and proton-density weighted sequences. The Achilles tendon was chosen because of its high frequency of injury in athletic activity, large size, superficial position and because it is oriented nearly parallel to the static magnetic field, therefore minimizing the ``magic angle phenomenon``. The tendons exhibited areas of slighly increased signal in four T1-weighted and in all but one proton-density-weighted scans. No intratendinous signal was detected in T2-weighted images. The possible origin of these findings is discussed. We conclude that the knowledge of these normal signals may be useful to avoid incorrectly diagnosing as pathological. (orig.). With 2 figs.

  17. Achilles tendon reflex measuring system

    Science.gov (United States)

    Szebeszczyk, Janina; Straszecka, Joanna

    1995-06-01

    The examination of Achilles tendon reflex is widely used as a simple, noninvasive clinical test in diagnosis and pharmacological therapy monitoring in such diseases as: hypothyroidism, hyperthyroidism, diabetic neuropathy, the lower limbs obstructive angiopathies and intermittent claudication. Presented Achilles tendon reflect measuring system is based on the piezoresistive sensor connected with the cylinder-piston system. To determinate the moment of Achilles tendon stimulation a detecting circuit was used. The outputs of the measuring system are connected to the PC-based data acquisition board. Experimental results showed that the measurement accuracy and repeatability is good enough for diagnostics and therapy monitoring purposes. A user friendly, easy-to-operate measurement system fulfills all the requirements related to recording, presentation and storing of the patients' reflexograms.

  18. Midportion Achilles tendinosis and the plantaris tendon.

    Science.gov (United States)

    Alfredson, Håkan

    2011-10-01

    When re-operating patients with midportion Achilles tendinosis, having had a poor effect of ultrasound (US) and Doppler-guided scraping, the author found the involvement of the plantaris tendon to be a likely reason for the poor result. The aim of this study was to investigate the occurrence of a plantaris tendon in close relation to the Achilles tendon in consecutive patients with midportion Achilles tendinosis undergoing treatment with US and Doppler-guided scraping. This study includes 73 consecutive tendons with chronic painful midportion Achilles tendinosis, where US+Doppler examination showed thickening, irregular tendon structure, hypo-echoic regions, and localised high blood flow outside and inside the ventral Achilles midportion. The tendons were treated with US+Doppler-guided scraping, via a medial incision. If there was a plantaris tendon located in close relation to the medial Achilles, it was extirpated. An invaginated, or 'close by located', enlarged plantaris tendon was found in 58 of 73 (80%) tendons. Preliminary clinical results of the combined procedure, US + Doppler-guided surgical scraping and extirpation of the plantaris tendon, are very promising. A thickened plantaris tendon located in close relation to the medial Achilles seems common in patients with chronic painful midportion tendinosis. The role of the plantaris tendon in midportion Achilles tendinosis needs to be further evaluated and should be kept in mind when treating this condition.

  19. Heel pain and Achilles tendonitis -- aftercare

    Science.gov (United States)

    ... About Your Injury The Achilles tendon connects your calf muscles to your heel bone. Together, they help ... running or jumping. Do activities that do not strain the tendon, such as ... and strengthen the muscles and tendon. Range of motion exercises will help ...

  20. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  1. Chronic Achilles tendon rupture reconstructed using hamstring tendon autograft.

    Science.gov (United States)

    Ellison, Philip; Mason, Lyndon William; Molloy, Andrew

    2016-03-01

    Chronic rupture of the Achilles tendon (delayed diagnosis of more than 4 weeks) can result in retraction of the tendon and inadequate healing. Direct repair may not be possible and augmentation methods are challenging when the defect exceeds 5-6 cm, especially if the distal stump is grossly tendinopathic. We describe our method of Achilles tendon reconstruction with ipsilateral semitendinosis autograft and interference screw fixation in a patient with chronic rupture, a 9 cm defect and gross distal tendinopathy. Patient reported outcome measures consistently demonstrated improved health status at 12 months post surgery: MOXFQ-Index 38-25, EQ5D-5L 18-9, EQ VAS 70-90 and VISA-A 1-64. The patient was back to full daily function, could single leg heel raise and was gradually returning to sport. No complications or adverse events were recorded. Reconstruction of chronic tears of the Achilles tendon with large defects and gross tendinopathy using an ipsilateral semitendinosis autograft and interference screw fixation can achieve satisfactory improvements in patient reported outcomes up to 1 year post-surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Nutrition of flexor tendons in monkeys.

    Science.gov (United States)

    Manske, P R; Bridwell, K; Whiteside, L A; Lesker, P A

    1978-10-01

    The hydrogen washout technique was used to investigate the role of synovial diffusion versus vascular perfusion in the nutrition of monkey flexor tendons within the digital sheath. There was no significant difference in the uptake and washout of hydrogen tracer by tendons in contact with synovium but detached from the surrounding vasculature, compared to control tendons. However, there was insignificant uptake of tracer by tendons with intact vasculature, but separated from synovium. Synovial diffusion is a primary nutrient pathway of monkey flexor tendons within the digital sheath.

  3. Can PRP effectively treat injured tendons?

    Science.gov (United States)

    Wang, James H-C

    2014-01-01

    PRP is widely used to treat tendon and other tissue injuries in orthopaedics and sports medicine; however, the efficacy of PRP treatment on injured tendons is highly controversial. In this commentary, I reason that there are many PRP- and patient-related factors that influence the outcomes of PRP treatment on injured tendons. Therefore, more basic science studies are needed to understand the mechanism of PRP on injured tendons. Finally, I suggest that better understanding of the PRP action mechanism will lead to better use of PRP for the effective treatment of tendon injuries in clinics.

  4. Bioreactor Design for Tendon/Ligament Engineering

    Science.gov (United States)

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake

    2013-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments. PMID:23072472

  5. Transcription factor EGR1 directs tendon differentiation and promotes tendon repair

    Science.gov (United States)

    Guerquin, Marie-Justine; Charvet, Benjamin; Nourissat, Geoffroy; Havis, Emmanuelle; Ronsin, Olivier; Bonnin, Marie-Ange; Ruggiu, Mathilde; Olivera-Martinez, Isabel; Robert, Nicolas; Lu, Yinhui; Kadler, Karl E.; Baumberger, Tristan; Doursounian, Levon; Berenbaum, Francis; Duprez, Delphine

    2013-01-01

    Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen. Here, we investigated the function of the zinc finger transcription factor EGR1 in tendon formation, healing, and repair using rodent animal models and mesenchymal stem cells (MSCs). Adult tendons of Egr1–/– mice displayed a deficiency in the expression of tendon genes, including Scx, Col1a1, and Col1a2, and were mechanically weaker compared with their WT littermates. EGR1 was recruited to the Col1a1 and Col2a1 promoters in postnatal mouse tendons in vivo. Egr1 was required for the normal gene response following tendon injury in a mouse model of Achilles tendon healing. Forced Egr1 expression programmed MSCs toward the tendon lineage and promoted the formation of in vitro–engineered tendons from MSCs. The application of EGR1-producing MSCs increased the formation of tendon-like tissues in a rat model of Achilles tendon injury. We provide evidence that the ability of EGR1 to promote tendon differentiation is partially mediated by TGF-β2. This study demonstrates EGR1 involvement in adult tendon formation, healing, and repair and identifies Egr1 as a putative target in tendon repair strategies. PMID:23863709

  6. Functionally Distinct Tendons From Elastin Haploinsufficient Mice Exhibit Mild Stiffening and Tendon-Specific Structural Alteration.

    Science.gov (United States)

    Eekhoff, Jeremy D; Fang, Fei; Kahan, Lindsey G; Espinosa, Gabriela; Cocciolone, Austin J; Wagenseil, Jessica E; Mecham, Robert P; Lake, Spencer P

    2017-11-01

    Elastic fibers are present in low quantities in tendon, where they are located both within fascicles near tenocytes and more broadly in the interfascicular matrix (IFM). While elastic fibers have long been known to be significant in the mechanics of elastin-rich tissue (i.e., vasculature, skin, lungs), recent studies have suggested a mechanical role for elastic fibers in tendons that is dependent on specific tendon function. However, the exact contribution of elastin to properties of different types of tendons (e.g., positional, energy-storing) remains unknown. Therefore, this study purposed to evaluate the role of elastin in the mechanical properties and collagen alignment of functionally distinct supraspinatus tendons (SSTs) and Achilles tendons (ATs) from elastin haploinsufficient (HET) and wild type (WT) mice. Despite the significant decrease in elastin in HET tendons, a slight increase in linear stiffness of both tendons was the only significant mechanical effect of elastin haploinsufficiency. Additionally, there were significant changes in collagen nanostructure and subtle alteration to collagen alignment in the AT but not the SST. Hence, elastin may play only a minor role in tendon mechanical properties. Alternatively, larger changes to tendon mechanics may have been mitigated by developmental compensation of HET tendons and/or the role of elastic fibers may be less prominent in smaller mouse tendons compared to the larger bovine and human tendons evaluated in previous studies. Further research will be necessary to fully elucidate the influence of various elastic fiber components on structure-function relationships in functionally distinct tendons.

  7. Multiple extensor tendons reconstruction with hamstring tendon grafts and flap coverage for severe dorsal hand injuries.

    Science.gov (United States)

    Ozbaydar, M; Orman, O; Ozel, O; Altan, E

    2017-10-10

    Treatment of patients with traumatic loss of skin and multiple extensor tendons on the dorsum of the hand is a challenge. The aim of this study was to assess the outcome after reconstruction of soft tissues and multiple extensor tendons in patients who suffered traumatic loss of skin and multiple extensor tendons. Ten patients were enrolled in the study. These patients underwent single-stage reconstruction with autogenous hamstring tendon grafts for multiple extensor tendon defects and fasciocutaneous flaps for coverage of dorsal hand defects. In total, 25 tendons (2 tendons in 5 patients and 3 tendons in 5 patients) were reconstructed. The semitendinosus tendon was used in all patients and the gracilis tendon was added in five patients for tendon reconstruction. Total tendon length requiring reconstruction was between 9cm and 31cm. Free anterolateral thigh flaps were used in six patients and reverse pedicled forearm flaps were used in four patients. According to Miller's scoring system, 8 fingers had excellent results, 12 fingers had good results and 5 fingers had fair results at the final follow-up. Hamstring tendons can be used satisfactorily for primary reconstruction of multiple digital extensor tendons due to their availability and compatibility, with a fasciocutaneous flap. IV. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  8. Hyperuricemic PRP in Tendon Cells

    Directory of Open Access Journals (Sweden)

    I. Andia

    2014-01-01

    Full Text Available Platelet-rich plasma (PRP is injected within tendons to stimulate healing. Metabolic alterations such as the metabolic syndrome, diabetes, or hyperuricemia could hinder the therapeutic effect of PRP. We hypothesise that tendon cells sense high levels of uric acid and this could modify their response to PRP. Tendon cells were treated with allogeneic PRPs for 96 hours. Hyperuricemic PRP did not hinder the proliferative actions of PRP. The gene expression pattern of inflammatory molecules in response to PRP showed absence of IL-1b and COX1 and modest expression of IL6, IL8, COX2, and TGF-b1. IL8 and IL6 proteins were secreted by tendon cells treated with PRP. The synthesis of IL6 and IL8 proteins induced by PRP is decreased significantly in the presence of hyperuricemia (P = 0.017 and P = 0.012, resp.. Concerning extracellular matrix, PRP-treated tendon cells displayed high type-1 collagen, moderate type-3 collagen, decorin, and hyaluronan synthase-2 expression and modest expression of scleraxis. Hyperuricemia modified the expression pattern of extracellular matrix proteins, upregulating COL1 (P = 0.036 and COMP (P = 0.012 and downregulating HAS2 (P = 0.012. Positive correlations between TGF-b1 and type-1 collagen (R = 0.905, P = 0.002 and aggrecan (R = 0.833, P = 0.010 and negative correlations between TGF-b1 and IL6 synthesis (R = −0.857, P = 0.007 and COX2 (R = −0.810, P = 0.015 were found.

  9. Leakage, entrepreneurship, and satisfaction in hospitality

    OpenAIRE

    Galdón Salvador, José Luis; Garrigós Simón, Fernando José; Gil Pechuán, Ignacio

    2013-01-01

    This is an Accepted Manuscript of an article published by Taylor & Francis in The Service Industries Journal on 2013, available online:http://www.tandfonline.com/10.1080/02642069.2013.740464 Tourism is a very important tool for economic development. However, its economic effects are mainly conditioned by the level of leakage. This work defines leakage, provides an original evaluation of the entrepreneurial environment in showing that it is the one with the lowest level of leakage, and crea...

  10. Improving stopping construction to minimize leakage.

    Science.gov (United States)

    Grau, Roy H; Mazzella, Andrew L; Martikainen, Anu L

    2012-07-01

    The proper sealing of stoppings is an important step in reducing leakage from the intake to the return airways. Leakage and the subsequent loss of ventilation resulting from improperly sealed stoppings can lead to unhealthy and unsafe working conditions. The research presented in this paper investigates the total leakage of a stopping, including air leakage through the stopping, at the stopping perimeter, and through the coalbed. The study also examines sealing considerations for stoppings that are constructed under roof control screen, the effects that wooden wedges had on inhibiting efficient application of polyurethane foam sealant, and airflow leakage through the surrounding coal. The work involved building a stopping in a dead end room of the NIOSH Safety Research Coal Mine and then pressurising the room using compressed air. Stopping leakage was evaluated by measuring air pressure loss in the enclosed room due to the air leakage. Part of the research utilises a diluted soap solution that was applied to the stopping and the surrounding coal to detect air leakage signified by bubble formations. The results show that stopping leakage can be minimised with proper sealing.

  11. Mechanical properties of the human Achilles tendon, in vivo

    DEFF Research Database (Denmark)

    Kongsgaard, M; Nielsen, C H; Hegnsvad, S

    2011-01-01

    Ultrasonography has been widely applied for in vivo measurements of tendon mechanical properties. Assessments of human Achilles tendon mechanical properties have received great interest. Achilles tendon injuries predominantly occur in the tendon region between the Achilles-soleus myotendinous...... Achilles tendon in vivo by the use of ultrasonography and 2) assess the between-day reproducibility of these measurements....

  12. [Diagnosis of flexor tendon injuries of the hand].

    Science.gov (United States)

    Hahn, P; Unglaub, F; Spies, C K

    2015-10-01

    Open or closed flexor tendon injuries may be caused by a variety of circumstances. Loss of function based on flexor tendon injuries is quite often missed. Therefore, a precise knowledge of the anatomy, the biomechanical behaviour of tendons and the intrinsic hand muscles enables the clinician to examine flexor tendon injuries adequately. This article focuses on relevant clinical tests for flexor tendon injuries.

  13. Tendon healing in vivo. An experimental model.

    Science.gov (United States)

    Abrahamsson, S O; Lundborg, G; Lohmander, L S

    1989-01-01

    Flexor tendon segments were incubated in a diffusion chamber in the subcutis of rabbits. Tendons incubated up to 6 weeks in the diffusion chamber showed proliferating and migrating cells from the epitenon cell layer as well as viable endotenon cells. Explants frozen in liquid nitrogen prior to incubation showed no signs of extrinsic cell contamination and remained non-viable indicating that no cell penetration occurred through the Millipore filter and that cell division seen in non-frozen and incubated tendons was an expression of intrinsic cellular proliferative capacity of the tendon. In tendon segments incubated in chambers for three weeks, collagen synthesis was reduced by 50% and the rate of cell proliferation measured as 3H-thymidine incorporation, was 15 times that of native tendons. Frozen and incubated tendons showed only traces of remaining matrix synthesis or cell proliferation. With this experimental model we have histologically and biochemically shown that tendons may survive and heal while the nutrition exclusively could be based on diffusion and the tendons have an intrinsic capacity of healing. The described model enables further studies on tendon healing and its regulation.

  14. Ipsilateral free semitendinosus tendon graft transfer for reconstruction of chronic tears of the Achilles tendon

    Directory of Open Access Journals (Sweden)

    Gougoulias Nikolaos

    2008-07-01

    Full Text Available Abstract Background Many techniques have been developed for the reconstruction of the Achilles tendon in chronic tears. In presence of a large gap (greater than 6 centimetres, tendon augmentation is required. Methods We present our method of minimally invasive semitendinosus reconstruction for the Achilles tendon using one para-midline and one midline incision. Results The first incision is a 5 cm longitudinal incision, made 2 cm proximal and just medial to the palpable end of the residual tendon. The second incision is 3 cm long and is also longitudinal but is 2 cm distal and in the midline to the distal end of the tendon rupture. The distal and proximal Achilles tendon stumps are mobilised. After trying to reduce the gap of the ruptured Achilles tendon, if the gap produced is greater than 6 cm despite maximal plantar flexion of the ankle and traction on the Achilles tendon stumps, the ipsilateral semitendinosus tendon is harvested. The semitendinosus tendon is passed through small incisions in the substance of the proximal stump of the Achilles tendon, and it is sutured to the Achilles tendon. It is then passed beneath the intact skin bridge into the distal incision, and passed from medial to lateral through a transverse tenotomy in the distal stump. With the ankle in maximal plantar flexion, the semitendinosus tendon is sutured to the Achilles tendon at each entry and exit point Conclusion This minimally invasive technique allows reconstruction of the Achilles tendon using the tendon of semitendinosus preserving skin integrity over the site most prone to wound breakdown, and can be especially used to reconstruct the Achilles tendon in the presence of large gap (greater than 6 centimetres.

  15. Collagen Structure of Tendon Relates to Function

    Directory of Open Access Journals (Sweden)

    Marco Franchi

    2007-01-01

    Full Text Available A tendon is a tough band of fibrous connective tissue that connects muscle to bone, designed to transmit forces and withstand tension during muscle contraction. Tendon may be surrounded by different structures: 1 fibrous sheaths or retinaculae; 2 reflection pulleys; 3 synovial sheaths; 4 peritendon sheaths; 5 tendon bursae. Tendons contain a few cells, mostly represented by tenoblasts along with endothelial cells and some chondrocytes; b proteoglycans (PGs, mainly decorin and hyaluronan, and c collagen, mostly type I. Tendon is a good example of a high ordered extracellular matrix in which collagen molecules assemble into filamentous collagen fibrils (formed by microfibrils which aggregate to form collagen fibers, the main structural components. It represents a multihierarchical structure as it contains collagen molecules arranged in fibrils then grouped in fibril bundles, fascicles and fiber bundles that are almost parallel to the long axis of the tendon, named as primary, secondary and tertiary bundles. Collagen fibrils in tendons show prevalently large diameter, a D-period of about 67 nm and appear built of collagen molecules lying at a slight angle (< 5°. Under polarized light microscopy the collagen fiber bundles appear crimped with alternative dark and light transverse bands. In recent studies tendon crimps observed via SEM and TEM show that the single collagen fibrils suddenly changing their direction contain knots. These knots of collagen fibrils inside each tendon crimp have been termed “fibrillar crimps”, and even if they show different aspects they all may fulfil the same functional role. As integral component of musculoskeletal system, the tendon acts to transmit muscle forces to the skeletal system. There is no complete understanding of the mechanisms in transmitting/absorbing tensional forces within the tendon; however it seems likely that a flattening of tendon crimps may occur at a first stage of tendon stretching

  16. Forest Carbon Leakage Quantification Methods and Their Suitability for Assessing Leakage in REDD

    Directory of Open Access Journals (Sweden)

    Sabine Henders

    2012-01-01

    Full Text Available This paper assesses quantification methods for carbon leakage from forestry activities for their suitability in leakage accounting in a future Reducing Emissions from Deforestation and Forest Degradation (REDD mechanism. To that end, we first conducted a literature review to identify specific pre-requisites for leakage assessment in REDD. We then analyzed a total of 34 quantification methods for leakage emissions from the Clean Development Mechanism (CDM, the Verified Carbon Standard (VCS, the Climate Action Reserve (CAR, the CarbonFix Standard (CFS, and from scientific literature sources. We screened these methods for the leakage aspects they address in terms of leakage type, tools used for quantification and the geographical scale covered. Results show that leakage methods can be grouped into nine main methodological approaches, six of which could fulfill the recommended REDD leakage requirements if approaches for primary and secondary leakage are combined. The majority of methods assessed, address either primary or secondary leakage; the former mostly on a local or regional and the latter on national scale. The VCS is found to be the only carbon accounting standard at present to fulfill all leakage quantification requisites in REDD. However, a lack of accounting methods was identified for international leakage, which was addressed by only two methods, both from scientific literature.

  17. Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration☆

    Science.gov (United States)

    Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

    2012-01-01

    Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7–21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

  18. Biceps tendon disorders in athletes.

    Science.gov (United States)

    Eakin, C L; Faber, K J; Hawkins, R J; Hovis, W D

    1999-01-01

    It has been proposed that the long head of the biceps functions as a humeral head depressor and stabilizer. In addition, in many overhead sports, the biceps helps to accelerate and decelerate the arm. With improper training or fatigue, inordinate stresses can be placed on the biceps as it attempts to compensate for other muscles. This can lead to attrition and failure, either within the tendon substance or at its origin. Bicipital problems in athletes usually occur in conjunction with other types of shoulder disorders, such as rotator cuff impingement and glenohumeral instability, making determination of the role and degree of biceps involvement difficult. Conditions affecting the biceps tendon in athletes can be generally classified as degeneration, instability, and disorders of the origin. Because of the close association of biceps lesions with other abnormalities, a thorough evaluation of the shoulder with a suspected biceps disorder is essential. Treatment of bicipital problems in athletes must often be accompanied by treatment of associated shoulder conditions.

  19. Nutrient pathways of flexor tendons in primates.

    Science.gov (United States)

    Manske, P R; Lesker, P A

    1982-09-01

    The perfusion and diffusion pathways to the flexor profundus tendons of 40 monkeys were investigated by measuring the uptake of tritiated proline by various tendon segments. In the absence of all vascular connections, the process of diffusion provides nutrients to all areas of flexor tendon and in this study the process of diffusion was greater. The distal segment of tendon was observed to be profused most rapidly. The proximal tendon segment is perfused from both the muscular-tendinous junction and the vinculum longus; vincular segment perfusion is via the vinculum longus vessels alone; central segment perfusion is shared by the vinculum longus and vinculum brevis vasculature. The distal segment uptake is by both the process of diffusion or vinculum brevis perfusion. The osseous attachment at the distal phalanx contributes little to tendon nutrition.

  20. Nutrient pathways of flexor tendons in primates

    Energy Technology Data Exchange (ETDEWEB)

    Manske, P.R.; Lesker, P.A.

    1982-09-01

    The perfusion and diffusion pathways to the flexor profundus tendons of 40 monkeys were investigated by measuring the uptake of tritiated proline by various tendon segments. In the absence of all vascular connections, the process of diffusion provides nutrients to all areas of flexor tendon and in this study the process of diffusion was greater. The distal segment of tendon was observed to be profused most rapidly. The proximal tendon segment is perfused from both the muscular-tendinous junction and the vinculum longus; vincular segment perfusion is via the vinculum longus vessels alone; central segment perfusion is shared by the vinculum longus and vinculum brevis vasculature. The distal segment uptake is by both the process of diffusion or vinculum brevis perfusion. The osseous attachment at the distal phalanx contributes little to tendon nutrition.

  1. Tendon Force Transmission at the Nanoscale

    DEFF Research Database (Denmark)

    Svensson, René

    2013-01-01

    of connective tissue function that are poorly understood. One such aspect is the microscopic mechanisms of force transmission through tendons over macroscopic distances. Force transmission is at the heart of tendon function, but the large range of scales in the hierarchical structure of tendons has made...... it difficult to tackle. The tendon hierarchy ranges from molecules (2 nm) over fibrils (200 nm), fibers (2 μm) and fascicles (200 μm) to tendons (10 mm), and to derive the mechanisms of force transmission it is necessary to know the mechanical behavior at each hierarchical level. The aim of the present work...... was to elucidate the mechanisms of force transmission in tendons primarily by investigating the mechanical behavior at the hierarchical level of collagen fibrils. To do so we have developed an atomic force microscopy (AFM) method for tensile testing of native collagen fibrils. The thesis contains five papers...

  2. Achilles tendon rupture in badminton.

    Science.gov (United States)

    Kaalund, S; Lass, P; Høgsaa, B; Nøhr, M

    1989-01-01

    The typical badminton player with an Achilles tendon rupture is 36 years old and, despite limbering up, is injured at the rear line in a sudden forward movement. He resumes work within three months and has a slight lack of dorsiflexion in the ankle as the main complication. Most patients resume badminton within one year, but some finish their sports career, mainly due to fear of a new injury. The investigation discusses predisposing factors and prophylactic measures. PMID:2605439

  3. Investigating tendon mineralisation in the avian hindlimb: a model for tendon ageing, injury and disease

    Science.gov (United States)

    Agabalyan, Natacha A; Evans, Darrell J R; Stanley, Rachael L

    2013-01-01

    Mineralisation of the tendon tissue has been described in various models of injury, ageing and disease. Often resulting in painful and debilitating conditions, the processes underlying this mechanism are poorly understood. To elucidate the progression from healthy tendon to mineralised tendon, an appropriate model is required. In this study, we describe the spontaneous and non-pathological ossification and calcification of tendons of the hindlimb of the domestic chicken (Gallus gallus domesticus). The appearance of the ossified avian tendon has been described previously, although there have been no studies investigating the developmental processes and underlying mechanisms leading to the ossified avian tendon. The tissue and cells from three tendons – the ossifying extensor and flexor digitorum longus tendons and the non-ossifying Achilles tendon – were analysed for markers of ageing and mineralisation using histology, immunohistochemistry, cytochemistry and molecular analysis. Histologically, the adult tissue showed a loss of healthy tendon crimp morphology as well as markers of calcium deposits and mineralisation. The tissue showed a lowered expression of collagens inherent to the tendon extracellular matrix and presented proteins expressed by bone. The cells from the ossified tendons showed a chondrogenic and osteogenic phenotype as well as tenogenic phenotype and expressed the same markers of ossification and calcification as the tissue. A molecular analysis of the gene expression of the cells confirmed these results. Tendon ossification within the ossified avian tendon seems to be the result of an endochondral process driven by its cells, although the roles of the different cell populations have yet to be elucidated. Understanding the role of the tenocyte within this tissue and the process behind tendon ossification may help us prevent or treat ossification that occurs in injured, ageing or diseased tendon. PMID:23826786

  4. Quadriceps tendon allografts as an alternative to Achilles tendon allografts: a biomechanical comparison.

    Science.gov (United States)

    Mabe, Isaac; Hunter, Shawn

    2014-12-01

    Quadriceps tendon with a patellar bone block may be a viable alternative to Achilles tendon for anterior cruciate ligament reconstruction (ACL-R) if it is, at a minimum, a biomechanically equivalent graft. The objective of this study was to directly compare the biomechanical properties of quadriceps tendon and Achilles tendon allografts. Quadriceps and Achilles tendon pairs from nine research-consented donors were tested. All specimens were processed to reduce bioburden and terminally sterilized by gamma irradiation. Specimens were subjected to a three phase uniaxial tension test performed in a custom environmental chamber to maintain the specimens at a physiologic temperature (37 ± 2 °C) and misted with a 0.9 % NaCl solution. There were no statistical differences in seven of eight structural and mechanical between the two tendon types. Quadriceps tendons exhibited a significantly higher displacement at maximum load and significantly lower stiffness than Achilles tendons. The results of this study indicated a biomechanical equivalence of aseptically processed, terminally sterilized quadriceps tendon grafts with bone block to Achilles tendon grafts with bone block. The significantly higher displacement at maximum load, and lower stiffness observed for quadriceps tendons may be related to the failure mode. Achilles tendons had a higher bone avulsion rate than quadriceps tendons (86 % compared to 12 %, respectively). This was likely due to observed differences in bone block density between the two tendon types. This research supports the use of quadriceps tendon allografts in lieu of Achilles tendon allografts for ACL-R.

  5. Radiofrequency radiation leakage from microwave ovens.

    Science.gov (United States)

    Lahham, Adnan; Sharabati, Afifeh

    2013-12-01

    This work presents data on the amount of radiation leakage from 117 microwave ovens in domestic and restaurant use in the West Bank, Palestine. The study of leakage is based on the measurements of radiation emissions from the oven in real-life conditions by using a frequency selective field strength measuring system. The power density from individual ovens was measured at a distance of 1 m and at the height of centre of door screen. The tested ovens were of different types, models with operating powers between 1000 and 1600 W and ages ranging from 1 month to >20 y, including 16 ovens with unknown ages. The amount of radiation leakage at a distance of 1 m was found to vary from 0.43 to 16.4 μW cm(-2) with an average value equalling 3.64 μW cm(-2). Leakages from all tested microwave ovens except for seven ovens (∼6 % of the total) were below 10 μW cm(-2). The highest radiation leakage from any tested oven was ∼16.4 μW cm(-2), and found in two cases only. In no case did the leakage exceed the limit of 1 mW cm(-2) recommended by the ICNIRP for 2.45-GHz radiofrequency. This study confirms a linear correlation between the amount of leakage and both oven age and operating power, with a stronger dependence of leakage on age.

  6. Predicting Envelope Leakage in Attached Dwellings

    Energy Technology Data Exchange (ETDEWEB)

    Faakye, O.; Arena, L.; Griffiths, D.

    2013-07-01

    The most common method for measuring air leakage is to use a single blower door to pressurize and/or depressurize the test unit. In detached housing, the test unit is the entire home and the single blower door measures air leakage to the outside. In attached housing, this 'single unit', 'total', or 'solo' test method measures both the air leakage between adjacent units through common surfaces as well air leakage to the outside. Measuring and minimizing this total leakage is recommended to avoid indoor air quality issues between units, reduce energy losses to the outside, reduce pressure differentials between units, and control stack effect. However, two significant limitations of the total leakage measurement in attached housing are: for retrofit work, if total leakage is assumed to be all to the outside, the energy benefits of air sealing can be significantly over predicted; for new construction, the total leakage values may result in failing to meet an energy-based house tightness program criterion. The scope of this research is to investigate an approach for developing a viable simplified algorithm that can be used by contractors to assess energy efficiency program qualification and/or compliance based upon solo test results.

  7. The roentgenographic findings of achilles tendon rupture

    Energy Technology Data Exchange (ETDEWEB)

    Seouk, Kang Hyo; Keun, Rho Yong [Shilla General Hospital, Seoul (Korea, Republic of)

    1999-03-01

    To evaluate the diagnostic value of a lateral view of the ankles in Achilles tendon rupture. We performed a retrospective analysis of the roentgenographic findings of 15 patients with surgically proven Achilles tendon rupture. Four groups of 15 patients(normal, ankle sprain, medial lateral malleolar fracture, and calcaneal fracture) were analysed as reference groups. Plain radiographs were reviewed with regard to Kager's triangle, Arner's sign, Toygar's angle, ill defined radiolucent shadow through the Achilles tendon, sharpness of the anterior margin of Achilles tendon, and meniscoid smooth margin of the posterior skin surface of the ankle. Kager's triangle was deformed and disappeared after rupture of the Achilles tendon in nine patients(60%) with operative verification of the rupture, six patients(40%) had a positive Arner's sign, while none had a diminished Toygars angle. In 13 patients(87%) with a ruptured Achilles tendon, the thickness of this was nonuniform compared with the reference group. The anterior margin of the Achilles tendon became serrated and indistinct in 14 patients(93%) in whom this was ruptured. An abnormal ill defined radiolucent shadow through the Achilles tendon was noted in nine patient(60%), and nonparallelism between the anterior margin of the Achilles tendon and posterior skin surface of the ankle was detected in 11 patients(73%). The posterior skin surface of the ankle had a nodular surface margin in 13 patients(87%). A deformed Kager's triangle and Achilles tendon, and an abnormal ill defined radiolucent shadow through the Achilles tendon in a lateral view of the ankles are important findings for the diagnesis of in diagnosing achilles tendon rupture.

  8. Experimental evaluation of clinical colon anastomotic leakage

    DEFF Research Database (Denmark)

    Pommergaard, Hans-Christian

    2014-01-01

    UNLABELLED: Colorectal anastomotic leakage remains a frequent and serious complication in gastrointestinal surgery. Patient and procedure related risk factors for anastomotic leakage have been identified. However, the responsible pathophysiological mechanisms are still unknown. Among these......, whereas the eight-suture control anastomoses had a 0% leakage rate. Furthermore, the use of absorbable suture together with voluntarily ingested Temgesic in chocolate spread as analgesic regimen were feasible. This model may be used to test the leakage reducing potential of coating materials. STUDY 3...... has been improved and is now thoroughly validated. If used by researchers worldwide, comparison of results is possible. Pure ischemia/anoxia may be too simple an approach to create a clinical leakage model. Thus, future models could focus on multiple risk factors. Conclusively, large-scale clinical...

  9. [Microstructure of tendon and its clinical significance].

    Science.gov (United States)

    Yan, J G

    1990-08-01

    Superficial and internal-structure of human and rat tendons were investigated under scanning electronic microscopy. Histologically, there are many pores on the synovium, under which a layer of network of fiber bands wraps the tendon. The synovial fluid propulsion system includes: Synovium----pores----network of fiber bands----space of tendon bands----space of tendon fibers. The synovial fluid is propelled through the above structure. The function of the network structure is like a sponge, it has the function of nutrition, absorption of heat, and lubrication.

  10. Tendon sheath fibroma in the thigh.

    Science.gov (United States)

    Moretti, Vincent M; Ashana, Adedayo O; de la Cruz, Michael; Lackman, Richard D

    2012-04-01

    Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patient's lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patient's tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men. Copyright 2012, SLACK Incorporated.

  11. Simulation of tendon energy storage in pedaling

    DEFF Research Database (Denmark)

    Rasmussen, John; Damsgaard, Michael; Christensen, Søren Tørholm

    2001-01-01

    system is based on inverse dynamics, where the redundancy problem is solved by a minimum fatigue criterion guaranteeing maximuminter-muscular collaboration. The tendons are assumed to be linearly elastic. It is concluded that tendon elasticity is responsible for metabolic power loss......The role of elastic energy stored in tendons during pedaling is investigated by means of numerical simulation using the AnyBody body modeling system. The loss of metabolic energy due to tendon elasticity is computed and compared to the mechanical work involved in the process. The AnyBody simulation...

  12. Early diagnosis of tendon pathologies with sonoelastography

    Directory of Open Access Journals (Sweden)

    Zeynep ilerisoy Yakut

    2015-04-01

    RESULTS: Achilles tendon thicknesses measured at three segments (proximal, middle ,distal. did not show any statistically significant difference in both painless and symptomatic side. Proximal part of achilles tendon's elasticity did not show any difference in both side (p=0.31. In middle and distal segment , the elasticity was statistically different in symptomatic side than normal side p=0.005 and p=0.001 respectively. CONCLUSION: Sonoelastographic examination of Achilles tendons in patients with FMF suffering from talalgia may be useful for determining early dejenerative changes in tendons either in the absence of B-mode ultrasound findings. [TAF Prev Med Bull 2015; 14(2.000: 75-80

  13. Corrosion inhibitor testing in archaeological conservation

    Directory of Open Access Journals (Sweden)

    Robert Faltermeier

    1997-11-01

    Full Text Available Metal objects from archaeological contexts often suffer serious damage by corrosion. Various methods for inhibiting corrosion have been developed, but their effects need to be evaluated. Here new research is described on how treatments to inhibit the corrosion of copper and copper-alloy artefacts may be tested.

  14. Ampicillin potentials as Corrosion Inhibitor: fukui function ...

    African Journals Online (AJOL)

    Inhibition and adsorption potentials of ampicillin for the corrosion of mild steel in solutions of HCl have been investigated using empirical and computational approach. The experimental study was carried out using gravimetric and Fourier transform infrared spectroscopy methods of monitoring corrosion while the ...

  15. Polarized Neutron Reflectometry of Nickel Corrosion Inhibitors.

    Science.gov (United States)

    Wood, Mary H; Welbourn, Rebecca J L; Zarbakhsh, Ali; Gutfreund, Philipp; Clarke, Stuart M

    2015-06-30

    Polarized neutron reflectometry has been used to investigate the detailed adsorption behavior and corrosion inhibition mechanism of two surfactants on a nickel surface under acidic conditions. Both the corrosion of the nickel surface and the structure of the adsorbed surfactant layer could be monitored in situ by the use of different solvent contrasts. Layer thicknesses and roughnesses were evaluated over a range of pH values, showing distinctly the superior corrosion inhibition of one negatively charged surfactant (sodium dodecyl sulfate) compared to a positively charged example (dodecyl trimethylammonium bromide) due to its stronger binding interaction with the surface. It was found that adequate corrosion inhibition occurs at significantly less than full surface coverage.

  16. Climate Policy and Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This report explores the effects of the EU emissions trading scheme on the aluminium sector (i.e. competitiveness loss and carbon leakage). With its very high electricity intensity, primary aluminium stands out in the heavy industry picture: a sector whose emissions are not capped in the present EU ETS, European aluminium smelters still stand to lose profit margins and, possibly, market shares, as electricity prices increase following CO2 caps on generators' emissions - the famous pass-through of CO2 prices into electricity prices. The analysis includes a method of quantification of this issue, based on two indicators: profit margins and trade flows. As the EU is at the forefront of such policy, the paper provides policy messages to all countries on how trade exposed energy-intensive industries can be 'moved' by carbon constraint. This also is a contentious topic in Australia, Japan, New Zealand, and the US, where ambitious climate policies -- including cap-and-trade systems -- are currently debated.

  17. Comparison of the Achilles tendon moment arms determined using the tendon excursion and three?dimensional methods

    OpenAIRE

    Hashizume, Satoru; Fukutani, Atsuki; Kusumoto, Kazuki; Kurihara, Toshiyuki; Yanagiya, Toshio

    2016-01-01

    Abstract The moment arm of muscle?tendon force is a key parameter for calculating muscle and tendon properties. The tendon excursion method was used for determining the Achilles tendon moment arm (ATMA). However, the accuracy of this method remains unclear. This study aimed to investigate the magnitude of error introduced in determining the ATMA using the tendon excursion method by comparing it with the reference three?dimensional (3D) method. The tendon excursion method determined the ATMA a...

  18. Tendon mineralization is accelerated bilaterally and creep of contralateral tendons is increased after unilateral needle injury of murine achilles tendons.

    Science.gov (United States)

    O'Brien, Etienne John Ogilvy; Shrive, Nigel G; Rosvold, Joshua M; Thornton, Gail M; Frank, Cyril B; Hart, David A

    2013-10-01

    Heterotopic mineralization may result in tendon weakness, but effects on other biomechanical responses have not been reported. We used a needle injury, which accelerates spontaneous mineralization of murine Achilles tendons, to test two hypotheses: that injured tendons would demonstrate altered biomechanical responses; and that unilateral injury would accelerate mineralization bilaterally. Mice underwent left hind (LH) injury (I; n = 11) and were euthanized after 20 weeks along with non-injured controls (C; n = 9). All hind limbs were examined by micro computed tomography followed by biomechanical testing (I = 7 and C = 6). No differences were found in the biomechanical responses of injured tendons compared with controls. However, the right hind (RH) tendons contralateral to the LH injury exhibited greater static creep strain and total creep strain compared with those LH tendons (p ≤ 0.045) and RH tendons from controls (p ≤ 0.043). RH limb lesions of injured mice were three times larger compared with controls (p = 0.030). Therefore, despite extensive mineralization, changes to the responses we measured were limited or absent 20 weeks postinjury. These results also suggest that bilateral occurrence should be considered where tendon mineralization is identified clinically. This experimental system may be useful to study the mechanisms of bilateral new bone formation in tendinopathy and other conditions. Copyright © 2013 Orthopaedic Research Society.

  19. Masticatory muscle tendon-aponeurosis hyperplasia exhibits heterotopic calcification in tendons.

    Science.gov (United States)

    Sato, T; Hori, N; Nakamoto, N; Akita, M; Yoda, T

    2014-05-01

    Masticatory muscle tendon-aponeurosis hyperplasia is a new disease entity associated with limited mouth opening. In this study, we analyzed the microstructural characteristics of muscles and tendons in masticatory muscle tendon-aponeurosis hyperplasia by electron microscopy and energy-dispersive X-ray analysis to determine the elemental composition. Histological analysis was performed to detect the calcification. Transmission electron microscopy and scanning electron microscopy were conducted to clarify the microstructural characteristics of muscles and tendons. Energy-dispersive X-ray microanalysis was performed to identify the distribution of elements. Mineralized nodules were observed in tendon tissues of masticatory muscle tendon-aponeurosis hyperplasia as compared with facial deformity. Electron microscopy revealed that the muscle and tendon tissues in masticatory muscle tendon-aponeurosis hyperplasia showed degenerative changes and distinctive histological findings as compared with tissues in facial deformity. We found that Ca, P, and Si were detected only in masticatory muscle tendon-aponeurosis hyperplasia. We demonstrated that masticatory muscle tendon-aponeurosis hyperplasia exhibits heterotopic calcification in tendon tissues. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Single-stage reconstruction of flexor tendons with vascularized tendon transfers.

    Science.gov (United States)

    Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C

    2015-03-01

    The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established. © The Author(s) 2014.

  1. Flexor tendon physiology: tendon nutrition and cellular activity in injury and repair.

    Science.gov (United States)

    Gelberman, R H

    1985-01-01

    Scientific studies of the past 20 years have done much to redefine the mechanisms by which flexor tendons heal. Several points have become increasingly clear: Flexor tendons are nourished to a greater extent by synovial fluid diffusion than vascular perfusion. Tendon cells are capable of proliferating, producing collagen, and reconstructing their own gliding surface in the absence of adhesion ingrowth. The key to a successful outcome after flexor tendon repair appears to be an early restoration of tendon continuity, reconstruction of the sheath, if possible, and early passive mobilization. This complex stimulates the tendon's intrinsic repair potential, which is contained within the cells of the tendon itself but appears to be expressed only under ideal experimental and clinical situations.

  2. From Tendon Injury to Collagen-based Tendon Regeneration: Overview and Recent Advances.

    Science.gov (United States)

    Rieu, Clement; Picaut, Lise; Mosser, Gervaise; Trichet, Lea

    2017-01-01

    Tendon injury is a clinical, societal and economical issue. Moreover, tendon repair represents an important clinical challenge, partly due to the mechanical constraints that occur at the junctions with muscle and bone. Several strategies have been developed for tendon repair. In this review, we first assess the importance of tendon injuries from different sites and their causes. After a short overview of tendon three-dimensional organization, the complexity of the perfect repair quest is presented ranging from current clinical procedures to new engineering scaffolds. We then sum up tendon engineering requirements and focus on new collagen-based scaffolds, which raise promising prospects to mimic and repair tendon. In particular, we survey quantitatively a large panel of techniques to produce these scaffolds, detailing their principle and recent improvements. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Leakage-Resilient Circuits without Computational Assumptions

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2012-01-01

    into the model and to construct schemes that are provably secure within them. We design a general compiler that transforms any cryptographic scheme, e.g., a block-cipher, into a functionally equivalent scheme which is resilient to any continual leakage provided that the following three requirements are satisfied......: (i) in each observation the leakage is bounded, (ii) different parts of the computation leak independently, and (iii) the randomness that is used for certain operations comes from a simple (non-uniform) distribution. In contrast to earlier work on leakage resilient circuit compilers, which relied...

  4. The pathology of flexor tendon repair.

    Science.gov (United States)

    Matthews, P

    1979-10-01

    This paper discusses the problems of failure after tendon repair. For a long time the subject has been dominated by the problem of adhesion formation. Recent work has shown that this is not inevitable, and consideration of other factors, particularly the nutrition of tendon tissue is leading to the possibilities of other methods of treatment.

  5. Flexor tendon specimens in organ cultures.

    Science.gov (United States)

    Rank, F; Eiken, O; Bergenholtz, A; Lundborg, G; Erkel, L J

    1980-01-01

    The healing process of sectioned and subsequently sutured rabbit tendon segments was studied over a period of 3 weeks, using an organ culture technique. In one series, the tendon specimens were exposed to a chemically defined culture medium for nutrition. In two control series, the specimens were kept in the synovial cavity of the knee joint for varying periods of time, before being transferred to the culture medium. The tendons remained viable in the medium. The superficial tendon cells demonstrated the morphological characteristics of fibroblasts, but cellular fibroplasia could not be detected. The two control series subjected to synovia prior to transfer into the culture medium showed superficial repair similar to the findings in previous studies on healing capacity of tendon nourished by synovia. The investigation supports the hypothesis that superficial tendon cells are fibroblasts with a potential for repair and that synovia is an efficient nutrient medium. Thus, the beneficial effects on repair exercised by the tendon sheath function should be utilized in flexor tendon surgery.

  6. [Spontaneous achilles tendon rupture in granulomatous vasculitis].

    Science.gov (United States)

    Benthien, Jan Philipp; Delling, G; Rüther, W

    2003-08-01

    A 66-year old patient sustained a non-traumatic rupture of her left achilles tendon. She suffered from Sjögren's syndrome which occurred in conjunction with a systemic vasculitis, and recurrent episcleritis. The combination of Sjögren's syndrome and systemic vasculitis is well known. Subsequently, she was treated with high-dose systemic steroids over a period of 2 years. In order to reduce the amount of steroids due to preexisting severe osteoporosis and thoracic vertebral fractures, her medication was changed to cyclophosphamide shortly before her injury. Intraoperatively, a granuloma was discovered at the site of the rupture. This granuloma had infiltrated most of the achilles tendon at this site and virtually replaced viable tendon tissue. Originally, the rupture was supposedly due to the high dose steroids. This theory had to be revised according to the intraoperative findings. Following excision of the granuloma and operative treatment of the achilles tendon rupture, the continuity of the tendon could be completely restored. A MRI scan 3 months after the procedure demonstrated a completely healed Achilles tendon. Spontaneous achilles tendon rupture due to a granuloma in patients with vasculitis seems to be a rare event. However, tendon ruptures in combination with systemic lupus erythematodes have been described. Mostly, these events are attributed to long term application of steroids. Spontaneous rupture in combination with high dose treatment of steroids seems to be an underestimated problem.

  7. Recent advances in flexor tendon repair

    NARCIS (Netherlands)

    J.C.H.M. van der Meulen (Jacques)

    1971-01-01

    markdownabstractThe prognosis for restoration of good function after the treatment of a tendon lesion in 'no-man's land' is influenced by a number of factors which may be summarized as follows: - The nature of the injury. - The amplitude of the tendon excursion. - The motility of the

  8. Ultrasonographic assessment of the equine palmar tendons.

    Science.gov (United States)

    Padaliya, N R; Ranpariya, J J; Kumar, Dharmendra; Javia, C B; Barvalia, D R

    2015-02-01

    The present study was conducted to evaluate the equine palmar tendon by ultrasonography (USG) in standing the position. USG of palmar tendons was performed in 40 adult horses using linear transducer having frequency of 10-18 MHz (e-soate, My Lab FIVE) and L52 linear array transducer (Titan, SonoSite) with frequencies ranging from 8 to 10 MHz. Palmar tendon was divided into 7 levels from distal to accessory carpal bone up to ergot in transverse scanning and 3 levels in longitudinal scanning. The USG evaluation was very useful for diagnosis of affections of the conditions such as chronic bowed tendon, suspensory ligament desmitis, carpal sheath tenosynovitis and digital sheath effusions. The mean cross-sectional area (cm(2)) of affected tendons was significantly increased in affected than normal tendons. The echogenicity was also found reduced in affected tendons and ligaments along with disorganization of fiber alignment depending on the severity of lesion and injury. USG proved ideal diagnostic tool for diagnosis and post-treatment healing assessment of tendon injuries in horses.

  9. MANAGEMENT OF OPEN ACHILLES TENDON INJURY: PRIMARY ...

    African Journals Online (AJOL)

    is attributable to increase in both competitive and recreational sports. In most of the literature written on Achilles tendon injuries there were rarely any information about open Achilles tendon lacerations. In ... Methods: This was a prospective study that took place at the Plastic Surgery Unit of Irrua Specialist. Teaching Hospital ...

  10. Instructive materials for tendon and ligament augmentation

    NARCIS (Netherlands)

    Ribeiro Pereira Simões Crispim, João Francisco

    2016-01-01

    Tendons and ligaments (T/L) are the connective tissue that connect muscles to bone and bone to bone, respectively. The main function of tendons is to translate muscle contractions into join motion and consequently generate movement. Ligaments function to stabilize joints and guide them during their

  11. Bilateral synchronous rupture of the quadriceps tendon.

    LENUS (Irish Health Repository)

    Ellanti, P

    2012-09-01

    Bilateral simultaneous rupture of the quadriceps tendon is a rare entity. They are often associated with degenerative changes of the tendons and predisposing conditions such as diabetes or excessive steroid use. They most commonly tend to occur in patients of 40 years of age or older.

  12. Tendon xanthomas : Not always familial hypercholesterolemia

    NARCIS (Netherlands)

    Koopal, Charlotte; Visseren, Frank L J; Marais, A David; Westerink, Jan; Spiering, Wilko

    2016-01-01

    Tendon xanthoma are most commonly associated with Familial Hypercholesterolemia, but the differential diagnosis includes sitosterolemia and cerebrotendinous xanthomatosis (CTX). The case presented here is of a 48-year old male with large tendon xanthomas attributable to CTX. CTX is a rare, recessive

  13. Rupture of Achilles Tendon : Usefulness of Ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Hyeon; Ki, Won Woo; Yoon, Kwon Ha; Kim, Song Mun; Shin, Myeong Jin [Ulsan Medical College, Ulsan (Korea, Republic of); Kwon, Soon Tae [Chungnam University College of Medicine, Daejeon (Korea, Republic of)

    1996-06-15

    To differentiate a complete rupture of Achilles tendon from an incomplete one which is important because its treatment is quite different. And it is necessary to know the exact site of the rupture preoperatively. Fifteen cases of fourteen patients which were diagnosed as Achilles tendon rupture by ultrasonography and surgery were reviewed. We compared sonographic rupture site with surgical findings. Ultrasonographic criteria for differentiation of complete and incomplete rupture was defined as follows : the discreteness, which means the proximal intervening hypoechogenicity to the interface echogenicity of distal margin of ruptured tendon : the slant sign, which represents the interface of ruptured distal margin which was seen over the 3/4 of the thickness of the tendon without intervening low echogeneicity : the invagination sign, which means the echogenic invagination from Kager triangle into posterior aspect of Achilles tendon over the half thickness of the tendon. The sites of complete tendon rupture were exactly corresponded to surgical finding in four cases of ten complete ruptures. And the discrepancy between sonographic and surgical findings in the site of complete rupture was 1.2 {+-} 0.4 cm in six cases. Three of ten complete ruptures showed the discreteness sign, all of ten showed the slant sign and two of ten showed the invagination sign. It is helpful to differentiate a complete from incomplete rupture of the Achilles tendon and to localize the site of the complete rupture with the ultrasonographic evaluation

  14. Tendon Vasculature in Health and Disease

    Science.gov (United States)

    Tempfer, Herbert; Traweger, Andreas

    2015-01-01

    Tendons represent a bradytrophic tissue which is poorly vascularized and, compared to bone or skin, heal poorly. Usually, a vascularized connective scar tissue with inferior functional properties forms at the injury site. Whether the increased vascularization is the root cause of tissue impairments such as loss of collagen fiber orientation, ectopic formation of bone, fat or cartilage, or is a consequence of these pathological changes remains unclear. This review provides an overview of the role of tendon vasculature in healthy and chronically diseased tendon tissue as well as its relevance for tendon repair. Further, the nature and the role of perivascular tendon stem/progenitor cells residing in the vascular niche will be discussed and compared to multipotent stromal cells in other tissues. PMID:26635616

  15. Simultaneous bilateral patellar tendon rupture without

    Directory of Open Access Journals (Sweden)

    LU Hua-ding

    2012-04-01

    Full Text Available 【Abstract】There is a dearth of case reports de-scribing simultaneous bilateral patellar tendon ruptures in the medical literature. These ruptures are often associated with systemic disorders such as lupus erythematosus or chronic steroid use. The author describes a case of a 24-year-old man who sustained traumatic bilateral patellar ten-don ruptures without any history of systemic disease or steroidal medication. We repaired and reattached the rup-tured tendons to the patella and augmented our procedure with allogeneic tendon followed by wire loop reinforcement. One year after operation, the patient regained a satisfactory range of motion of both knees with good quadriceps strength and no extensor lag. The recurrent microtrauma from a history of intense sports activity and a high body mass index may have played an important role in this trauma event. Key words: Patella; Patellar ligament; Rupture; Ten-don injuries; Knee

  16. Thompson Test in Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Spencer Albertson

    2016-07-01

    Full Text Available HPI: A 26-year old male presented to the emergency department after experiencing the acute onset of left ankle pain while playing basketball. Upon jumping, he felt a “pop” in his left posterior ankle, followed by pain and difficulty ambulating. His exam was notable for a defect at the left Achilles tendon on palpation. The practitioner performed a Thompson test, which was positive (abnormal on the left. Significant Findings: The left Achilles tendon had a defect on palpation, while the right Achilles tendon was intact. When squeezing the right (unaffected calf, the ankle spontaneously plantar flexed, indicating a negative (normal Thompson test. Upon squeeze of the left (affected calf, the ankle did not plantar flex, signifying a positive (abnormal Thompson test. The diagnosis of left Achilles tendon rupture was confirmed intraoperatively one week later. Discussion: The Achilles tendon (also: calcaneal tendon or heel cord is derived from the medial and lateral heads of the gastrocnemius muscle, as well as the soleus muscle. Rupture of the Achilles tendon most commonly occurs in the distal tendon, approximately 2-6 cm from its attachment to the calcaneal tuberosity, in an area of hypovascularity known as the “watershed” or “critical” zone.1-3 The Thompson test (also: Simmonds-Thompson test, described by Simmonds in 1957 and Thompson in 1962, is done while the patient is in the prone position, with feet hanging over the end of a table/gurney, or with the patient kneeling on a stool or chair.4-5 Squeezing the calf of an unaffected limb will cause the ankle to plantar flex, but squeezing the calf of a limb with an Achilles tendon rupture will cause no motion. The sensitivity of the Thompson’s test for the diagnosis of a complete Achilles tendon rupture is 96-100% and the specificity is 93-100%, but data is limited.6-8

  17. [Clinical application of peroneal muscles tendon transposition in repair of Achilles tendon rupture].

    Science.gov (United States)

    Jin, Rihao; Jin, Yu; Fang, Xiulin

    2006-07-01

    To discuss applied anatomy, biomechanics and surgical procedures of long peroneal muscles tendon transposition in repair of occlusive achilles tendon rupture. The blood supply and the morphology of long peroneal muscles tendon were observed in the lower extremity of 50 sides adult specimens and the mechanical tests which stretch load on the tendon were carried out. The methods were designed on the basis of the anatomical characteristics and morphology. Ten patients suffering occlusive Achilles tendon rupture were treated by using long peroneal muscles tendon transposition from March 2001 to July 2004. Among 10 patients, there were 7 males and 3 females, aging 32 to 54 years including 6 cases of jump injury, 2 cases of bruise, 1 case of step vacancy and 1 case of spontaneity injury. The interval between injury and surgery was 6 hours to 7 days in 7 fresh rupture and 21 days to 3 months in 3 old rupture. All cases belonged to occlusive Achilles tendon rupture (8 cases of complete rupture and 2 cases of incomplete rupture). The origin of long peroneal muscles was proximal tibia and fibular head, the end of them was base of first metatarsal bones and medial cuboid. The length of tendon was 13.5 +/- 2.5 cm. The width of origin tendon was 0.9 +/- 0.2 cm and the thickness was 0.3 +/- 0.1 cm; the width on apex of lateral malleolus was 0.7 +/- 0.1 cm and the thickness was 0.4 +/- 0.1 cm, the width on head of cuboid was 0.7 +/- 0.1 cm and the thickness was 0.3 +/- 0.1 cm. The long peroneal muscles tendon had abundant blood supply. The results of mechanical test showed that the biggest load was 2,292.4 +/- 617.3 N on tendon calcaneus, 1,020.4 +/- 175.4 N on long peroneal muscles tendon, 752.0 +/- 165.4 N on peroneus brevis tendon and 938.2 +/- 216.7 N on tibialis posterior tendon. Ten cases of occlusive Achilles tendon rupture achieved healing by first intention and were followed up 18-24 months. No Achilles tendon re-rupture, necrosis of skin or other complications occurred

  18. Carbon leakage from a Nordic perspective

    Energy Technology Data Exchange (ETDEWEB)

    Naess-Schmidt, S.; Hansen, Martin Bo; Sand Kirk, J. [Copenhagen Economics, Copenhagen (Denmark)

    2012-02-15

    Carbon pricing is generally considered a highly effective tool in reducing carbon emissions. Putting a price on carbon provides incentives for users and producers of fossil fuels to reduce consumption and develop low carbon products and processes. However, pursuing an ambitious climate policy can lead to carbon leakage, which refers to a situation where unilateral or regional climate change policy drives the relocation of industry investments and installations, and associated emissions, to third countries. This report by Copenhagen Economics has been commissioned by the Nordic Council of Ministers to give an overview of the industries at risk of carbon leakage in the Nordic countries, and estimate the expected extent of carbon leakage from unilateral climate policies in the Nordic countries. The report also assesses available policy options that may reduce the risk of carbon leakage, such as exemptions from energy tax and exemptions from quota obligations under green certificate schemes. The key drivers of carbon leakage are identified, which include energy intensity, product differentiation, transportation costs and capital intensity. The analysis suggests that industries such as paper and pulp, iron and steel, aluminium, cement, pharmaceuticals, chemicals, and fertilizers are most at risk of carbon leakage in the Nordic manufacturing sector. (Author)

  19. Studies in flexor tendon reconstruction: biomolecular modulation of tendon repair and tissue engineering.

    Science.gov (United States)

    Chang, James

    2012-03-01

    The Andrew J. Weiland Medal is presented each year by the American Society for Surgery of the Hand and the American Foundation for Surgery of the Hand for a body of work related to hand surgery research. This essay, awarded the Weiland Medal in 2011, focuses on the clinical need for flexor tendon reconstruction and on investigations into flexor tendon biology. Reconstruction of the upper extremity is limited by 2 major problems after injury or degeneration of the flexor tendons. First, adhesions formed after flexor tendon repair can cause decreased postoperative range of motion and hand function. Second, tendon losses can result from trauma and degenerative diseases, necessitating additional tendon graft material. Tendon adhesions are even more prevalent after tendon grafting; therefore these 2 problems are interrelated and lead to considerable disability. The total costs in terms of disability and inability to return to work are enormous. In this essay, published work from the past 12 years in our basic science laboratory is summarized and presented with the common theme of using molecular techniques to understand the cellular process of flexor tendon wound healing and to create substances and materials to improve tendon repair and regeneration. These are efforts to address 2 interrelated and clinically relevant problems that all hand surgeons face in their practice. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  20. Is higher serum cholesterol associated with altered tendon structure or tendon pain? A systematic review.

    Science.gov (United States)

    Tilley, Benjamin J; Cook, Jill L; Docking, Sean I; Gaida, James E

    2015-12-01

    Tendon pain occurs in individuals with extreme cholesterol levels (familial hypercholesterolaemia). It is unclear whether the association with tendon pain is strong with less extreme elevations of cholesterol. To determine whether lipid levels are associated with abnormal tendon structure or the presence of tendon pain. We conducted a systematic review and meta-analysis. Relevant articles were found through an electronic search of 6 medical databases-MEDLINE, Cochrane, AMED, EMBASE, Web of Science and Scopus. We included all case-control or cross-sectional studies with data describing (1) lipid levels or use of lipid-lowering drugs and (2) tendon structure or tendon pain. 17 studies (2612 participants) were eligible for inclusion in the review. People with altered tendon structure or tendon pain had significantly higher total cholesterol, low-density lipoprotein cholesterol and triglycerides, as well as lower high-density lipoprotein cholesterol; with mean difference values of 0.66, 1.00, 0.33, and -0.19 mmol/L, respectively. The results of this review indicate that a relationship exists between an individual's lipid profile and tendon health. However, further longitudinal studies are required to determine whether a cause and effect relationship exists between tendon structure and lipid levels. This could lead to advancement in the understanding of the pathoaetiology and thus treatment of tendinopathy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. Elastographic characteristics of the metacarpal tendons in horses without clinical evidence of tendon injury.

    Science.gov (United States)

    Lustgarten, Meghann; Redding, W Rich; Labens, Raphael; Morgan, Michel; Davis, Weston; Seiler, Gabriela S

    2014-01-01

    Tendon and ligament injuries are common causes of impaired performance in equine athletes. Gray-scale ultrasonography is the current standard method for diagnosing and monitoring these injuries, however this modality only provides morphologic information. Elastography is an ultrasound technique that allows detection and measurement of tissue strain, and may provide valuable mechanical information about equine tendon and ligament injuries. The purpose of this study was to determine the feasibility, reproducibility, and repeatability of elastography; and to describe elastographic characteristics of metacarpal tendons in sound horses. Nineteen legs for 17 clinically sound horses without evidence of musculoskeletal pathology were included. Elastographic images of the superficial and deep digital flexor tendons and the branches of the suspensory ligament (tendon of the interosseous muscle) were described quantitatively and qualitatively. There was no statistically significant difference between operators (P = 0.86) nor within operators (P = 0.93). For qualitative assessments, reproducibility (0.46) was moderate and repeatability (0.78) was good. Similar to human Achilles tendons, equine tendons were classified as predominantly hard using elastography. There was no statistically significant difference in stiffness of the flexor tendons (P = 0.96). No significant difference in stiffness was found with altered leg position during standing (P = 0.84) and while nonweight bearing (P = 0.61). The flexor tendons were softer when imaged in longitudinal versus transverse planes (P tendons and ligaments of the distal forelimb in horses. © 2013 American College of Veterinary Radiology.

  2. Minimally invasive, endoscopic Achilles tendon reconstruction using semitendinosus and gracilis tendons with Endobutton stabilization.

    Science.gov (United States)

    Piontek, Tomasz; Bąkowski, Paweł; Ciemniewska-Gorzela, Kinga; Grygorowicz, Monika

    2016-06-03

    Plantaris tendon, peronus brevis tendon and flexor hallucis longus tendon augmentation, commonly used in Achilles tendon rupture, often lead to weakening of injured foot and they require the immobilization after the surgery. It is essential to develop the technique, which gives no such limitation and allows for immediate functional improvement. We present our method of minimally invasive, endoscopic Achilles tendon reconstruction using semitendinosus and gracilis tendons with Endobutton stabilization. Posterolateral and posteromedial portals were made approximately 3 cm above the posterosuperior part of the calcaneus to clean the area of the Achilles tendon endoscopically. Then the hamstrings are harvested and prepared for the "Endobutton" system. A midline incision of the skin is performed approximately 1 cm above the posterosuperior part of the calcaneus to approach to the posterosuperior part of the calcaneus. Then under fluoroscopy the calcaneus was drilled through using K-wire. The distal end of the graft equipped with an Endobutton loop was entered into the drilled tunnel in the calcaneus. Later, 8 consecutive skin incisions are performed. Proximal ends of the graft were brought out through the native Achilles tendon reaching medial and lateral skin incisions. The final step was to transfer and tie the graft ends through the most proximal skin incision. This minimally invasive, endoscopic technique allows reconstruction of the Achilles tendon using semitendinosus and gracilis tendons with Endobutton stabilization and can be used in so-called "difficult", resistant cases as a "salvage procedure".

  3. Serial superficial digital flexor tendon biopsies for diagnosing and monitoring collagenase-induced tendonitis in horses

    Directory of Open Access Journals (Sweden)

    José C. de Lacerda Neto

    2013-06-01

    Full Text Available The purpose of this investigation was to demonstrate the feasibility of a biopsy technique by performing serial evaluations of tissue samples of the forelimb superficial digital flexor tendon (SDFT in healthy horses and in horses subjected to superficial digital flexor tendonitis induction. Eight adult horses were evaluated in two different phases (P, control (P1 and tendonitis-induced (P2. At P1, the horses were subjected to five SDFT biopsies of the left forelimb, with 24 hours (h of interval. Clinical and ultrasonographic (US examinations were performed immediately before the tendonitis induction, 24 and 48 h after the procedure. The biopsied tendon tissues were analyzed through histology. P2 evaluations were carried out three months later, when the same horses were subjected to tendonitis induction by injection of bacterial collagenase into the right forelimb SDFT. P2 clinical and US evaluations, and SDFT biopsies were performed before, and after injury induction at the following time intervals: after 24, 48, 72 and 96 h, and after 15, 30, 60, 90, 120 and 150 days. The biopsy technique has proven to be easy and quick to perform and yielded good tendon samples for histological evaluation. At P1 the horses did not show signs of localised inflammation, pain or lameness, neither SDFT US alterations after biopsies, showing that the biopsy procedure per se did not risk tendon integrity. Therefore, this procedure is feasible for routine tendon histological evaluations. The P2 findings demonstrate a relation between the US and histology evaluations concerning induced tendonitis evolution. However, the clinical signs of tendonitis poorly reflected the microscopic tissue condition, indicating that clinical presentation is not a reliable parameter for monitoring injury development. The presented method of biopsying SDFT tissue in horses enables the serial collection of material for histological analysis causing no clinical signs and tendon damage seen

  4. The effect of glucocorticoids on tendon cell viability in human tendon explants

    Science.gov (United States)

    Lui, Wai Ting; Chuen Fu, Sai; Man Lee, Kwong

    2009-01-01

    Background and purpose Previous studies on the culture of human tenocytes have shown that dexamethasone and triamcino-lone reduce cell viability, suppress cell proliferation, and reduce collagen synthesis. However, such cell cultures lack the extracellular matrix and three-dimensional structure of normal tendons, which affects their response to stimuli. We established a human tendon explant culture system and tested the effects of dexamethasone and triamcinolone on cell viability. Methods Primary human tendon explant cultures were prepared from healthy hamstring tendons. Tendon strips were harvested from hamstring tendons and cultured in 24-well plates in Dulbecco’s modification of Eagle’s Medium (DMEM) supplemented with 2% fetal calf serum. The tendon explants were treated with 0 μM (control), 10 μM, or 100 μM dexamethasone sodium phosphate or 0 μM (control), 10 μM, or 100 μM triamcinolone acetonide in DMEM for 96 h. Cell viability was measured by Alamar blue assay before and after glucocorticoid treatment. Results Incubation with 10 μM and 100 μM dexamethasone reduced cell viability in human tendon explants by 35% and 45%, respectively, as compared to a 6% increase in the controls (p = 0.01, mixed-effects ANOVA). Triamcinolone at 10 μM and 100 μM reduced cell viability by 33% and 36%, respectively, as compared to a 9% increase in the controls (p = 0.07, mixed-effects ANOVA). Interpretation Human tendon explant cultures can be used to study the effects of glucocorticoids on human tendon. Dexamethasone and triamcinolone suppress the cell viability of human tendon in its natural 3-dimensional environment with matrix anchorage. Human tendon explant cultures provide a species-specific model for further investigation of the effects of glucocorticoids on the metabolism of the extracellular matrix of human tendon, and on its mechanical properties. PMID:19421908

  5. Blood flow and clearance in tendons. Studies with dogs.

    Science.gov (United States)

    Hooper, G; Davies, R; Tothill, P

    1984-05-01

    Blood flow in intact tendons in dogs was measured using 57Co-labelled microspheres and compared with the simultaneous clearance of a diffusible radionuclide, 85Sr, by the same tendons. Clearance was significantly greater than flow in all tendons, indicating that diffusion from surrounding tissues may be important in the nutrition of normal tendons.

  6. [Experimental study of allogenic tendon with sheath grafting in chicken].

    Science.gov (United States)

    Zhang, Y L; Wang, S L; Gao, X S

    2001-03-01

    To investigate availability of deep freeze stored allogenic tendon with sheath grafting in repairing the tendon and sheath defect in the II area of flexor digitorum tendon. Sixty chickens with tendon and sheath defect were divided into 2 groups randomly, group A was treated with allogenic grafting and group B was treated with autogenic grafting, these two groups were divided into two subgroups respectively, they were, group A1 allogenic tendon with whole sheath grafting, group A2 allogenic tendon with partial sheath grafting, group B1 autogenic tendon with whole sheath grafting and group B2 autogenic tendon with whole sheath grafting. All the allogenic grafts were treated by deep freeze. Histomorphological study, histoimmunological study and slipping function of the grafts were measured after operation. In group A1 and B1, the local reaction was sever, the nutrition of tendon graft was barricaded by the whole sheath resulting in adhesion, degeneration and necrosis. In group A2 and B2, the tendon graft healed well and little adhesion existed between tendon and sheath. The results showed that there were significant differences between tendon grafting with whole sheath and tendon grafting with partial sheath. Deep freeze store can reduce the immunogenicity of allogenic tendon with sheath. Allogenic tendon with partial sheath grafting can be used as a new biological material for repairing the tendon and sheath defect.

  7. Achilles tendon: US diagnosis of pathologic conditions. Work in progress

    Energy Technology Data Exchange (ETDEWEB)

    Blei, C.L.; Nirschl, R.P.; Grant, E.G.

    1986-06-01

    Twenty-three patients were prospectively examined with ultra-sound (US) for acute or recurrent Achilles tendon symptoms. Three types of pathologic conditions of the Achilles tendon were found: tendinitis/tenosynovitis, acute tendon trauma, and postoperative changes. US appears to enable differentiation of these conditions and to contribute to the diagnosis of a broad range of Achilles tendon disorders.

  8. Micromechanical properties and collagen composition of ruptured human achilles tendon

    DEFF Research Database (Denmark)

    Hansen, Philip; Kovanen, Vuokko; Hölmich, Per

    2013-01-01

    The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive.......The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive....

  9. Hamstring tendons insertion - an anatomical study

    Directory of Open Access Journals (Sweden)

    Cristiano Antonio Grassi

    2013-09-01

    Full Text Available OBJECTIVE: To study the anatomy of the hamstring tendons insertion and anatomical rela-tionships. METHODS: Ten cadaver knees with medial and anterior intact structures were selected. The dissection was performed from anteromedial access to exposure of the insertion of the flexor tendons (FT, tibial plateau (TP and tibial tuberosity (TT. A needle of 40 × 12 and a caliper were used to measure the distance of the tibial plateau of the knee flexor tendons insertion at 15 mm from the medial border of the patellar tendon and tibial tuberosity to the insertion of the flexor tendons of the knee. The angle between tibial plateau and the insertion of the flexor tendons of the knee (A-TP-FT was calculated using Image Pro Plus software. RESULTS: The mean distance TP-FT was 41 ± 4.6 mm. The distance between the TT-FT was 6.88 ± 1 mm. The (A-TP-FT was 20.3 ± 4.9°. CONCLUSION: In the anterior tibial flexor tendons are about 40 mm from the plateau with an average of 20°.

  10. Sex differences in tendon structure and function.

    Science.gov (United States)

    Sarver, Dylan C; Kharaz, Yalda Ashraf; Sugg, Kristoffer B; Gumucio, Jonathan P; Comerford, Eithne; Mendias, Christopher L

    2017-10-01

    Tendons play a critical role in the transmission of forces between muscles and bones, and chronic tendon injuries and diseases are among the leading causes of musculoskeletal disability. Little is known about sex-based differences in tendon structure and function. Our objective was to evaluate the mechanical properties, biochemical composition, transcriptome, and cellular activity of plantarflexor tendons from 4 month old male and female C57BL/6 mice using in vitro biomechanics, mass spectrometry-based proteomics, genome-wide expression profiling, and cell culture techniques. While the Achilles tendons of male mice were approximately 6% larger than female mice (p differences in mechanical properties (p > 0.05) of plantaris tendons were observed. Mass spectrometry proteomics analysis revealed no significant difference between sexes in the abundance of major extracellular matrix (ECM) proteins such as collagen types I (p = 0.30) and III (p = 0.68), but female mice had approximately twofold elevations (p differed by only 1%. In vitro, neither the sex of the serum that fibroblasts were cultured in, nor the sex of the ECM in which they were embedded, had profound effects on the expression of collagen and cell proliferation genes. Our results indicate that while male mice expectedly had larger tendons, male and female tendons have very similar mechanical properties and biochemical composition, with small increases in some ECM proteins and proteoglycans evident in female tendons. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2117-2126, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  11. Fibroma of the tendon sheath of the long head of the biceps tendon

    Energy Technology Data Exchange (ETDEWEB)

    Maeseneer, Michel de; Shahabpour, Maryam [Universitair Ziekenhuis Brussel, Department of Radiology, Brussels (Belgium); Isacker, Tom van [Sint-Lucas Hospital, Department of Orthopedic Surgery, Brugge (Belgium); Lenchik, Leon [Wake Forest School of Medicine, Department of Radiology, Winston Salem, NC (United States); Caillie, Marie-Astrid van [Sint-Lucas Hospital, Department of Pathology, Brugge (Belgium)

    2014-03-15

    Fibroma of the tendon sheath is a benign tumor that is less common than giant cell tumor of the tendon sheath. Both tumors may present as a painless, slowly enlarging mass. Radiological findings may be similar for both tumors. Histologically, fibroma of the tendon sheath lacks the hemosiderin-laden macrophages that are typical for giant cell tumor of the tendon sheath. We report on a 49-year-old woman with fibroma of the tendon sheath of the long head of the biceps tendon. In our case, on MR images, we observed band-like hypointense areas centrally in the tumor, mild patchy contrast enhancement, and most importantly, no decrease of signal intensity on gradient echo images. These characteristics reflected histological findings. (orig.)

  12. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakage...

  13. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

    OpenAIRE

    Wei Yee Leong; Daniel Gheorghiu; Janardhan Rao

    2013-01-01

    Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR) in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body bui...

  14. Assessment of Postoperative Tendon Quality in Patients With Achilles Tendon Rupture Using Diffusion Tensor Imaging and Tendon Fiber Tracking.

    Science.gov (United States)

    Sarman, Hakan; Atmaca, Halil; Cakir, Ozgur; Muezzinoglu, Umit Sefa; Anik, Yonca; Memisoglu, Kaya; Baran, Tuncay; Isik, Cengiz

    2015-01-01

    Although pre- and postoperative imaging of Achilles tendon rupture (ATR) has been well documented, radiographic evaluations of postoperative intratendinous healing and microstructure are still lacking. Diffusion tensor imaging (DTI) is an innovative technique that offers a noninvasive method for describing the microstructure characteristics and organization of tissues. DTI was used in the present study for quantitative assessment of fiber continuity postoperatively in patients with acute ATR. The data from 16 patients with ATR from 2005 to 2012 were retrospectively analyzed. The microstructure of ART was evaluated using tendon fiber tracking, tendon continuity, fractional anisotropy, and apparent diffusion coefficient values by way of DTI. The distal and proximal portions were measured separately in both the ruptured and the healthy extremities of each patient. The mean patient age was 41.56 ± 8.49 (range 26 to 56) years. The median duration of follow-up was 21 (range 6 to 80) months. The tendon fractional anisotropy values of the ruptured Achilles tendon were significantly lower statistically than those of the normal side (p = .001). However, none of the differences between the 2 groups with respect to the distal and proximal apparent diffusion coefficient were statistically significant (p = .358 and p = .899, respectively). In addition, the fractional anisotropy and apparent diffusion coefficient measurements were not significantly different in the proximal and distal regions of the ruptured tendons compared with the healthy tendons. The present study used DTI and fiber tracking to demonstrate the radiologic properties of postoperative Achilles tendons with respect to trajectory and tendinous fiber continuity. Quantifying DTI and fiber tractography offers an innovative and effective tool that might be able to detect microstructural abnormalities not appreciable using conventional radiologic techniques. Copyright © 2015 American College of Foot and Ankle

  15. A Biomechanical Study of a Novel Asymmetric 6-Strand Flexor Tendon Repair Using Porcine Tendons.

    Science.gov (United States)

    Wong, Yoke Rung; Tay, Shian Chao

    2018-01-01

    This study evaluated the biomechanical performance of a novel asymmetric 6-strand flexor tendon repair technique without locking loops. Twenty porcine flexor tendons were equally repaired by using the asymmetric technique and compared with the modified Lim-Tsai repair technique. The ultimate tensile strength, load to 1-mm gap force, stiffness, and mechanism of failure were measured. The asymmetric repair technique had significantly higher tensile strength (63.3 ± 3.7 N) than the modified Lim-Tsai repairs (46.7 ± 8.3 N). A novel flexor tendon repair technique with improved biomechanical performance may be available for use in flexor tendon repairs.

  16. Transcription factor EGR1 directs tendon differentiation and promotes tendon repair

    National Research Council Canada - National Science Library

    Guerquin, Marie-Justine; Charvet, Benjamin; Nourissat, Geoffroy; Havis, Emmanuelle; Ronsin, Olivier; Bonnin, Marie-Ange; Ruggiu, Mathilde; Olivera-Martinez, Isabel; Robert, Nicolas; Lu, Yinhui; Kadler, Karl E; Baumberger, Tristan; Doursounian, Levon; Berenbaum, Francis; Duprez, Delphine

    2013-01-01

    Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen...

  17. Multi-Layer Electrospun Membrane Mimicking Tendon Sheath for Prevention of Tendon Adhesions

    Directory of Open Access Journals (Sweden)

    Shichao Jiang

    2015-03-01

    Full Text Available Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid-polyethylene glycol (PELA electrospun fibrous membrane as the outer layer, hyaluronic acid (HA gel as middle layer, and PELA electrospun fibrous membrane as the inner layer was designed. The anti-adhesion efficacy of this multi-layer membrane was compared with a single-layer use in rabbit flexor digitorum profundus tendon model. The surface morphology showed that both PELA fibers and celecoxib-loaded PELA fibers in multi-layer membrane were uniform in size, randomly arrayed, very porous, and smooth without beads. Multi-layer membrane group had fewer peritendinous adhesions and better gliding than the PELA membrane group and control group in gross and histological observation. The similar mechanical characteristic and collagen expression of tendon repair site in the three groups indicated that the multi-layer membrane did not impair tendon healing. Taken together, our results demonstrated that such a biomimetic multi-layer sheath could be used as a potential strategy in clinics for promoting tendon gliding and preventing adhesion without poor tendon healing.

  18. Determination of leakage areas in nuclear piping

    Energy Technology Data Exchange (ETDEWEB)

    Keim, E. [Siemens/KWU, Erlangen (Germany)

    1997-04-01

    For the design and operation of nuclear power plants the Leak-Before-Break (LBB) behavior of a piping component has to be shown. This means that the length of a crack resulting in a leak is smaller than the critical crack length and that the leak is safely detectable by a suitable monitoring system. The LBB-concept of Siemens/KWU is based on computer codes for the evaluation of critical crack lengths, crack openings, leakage areas and leakage rates, developed by Siemens/KWU. In the experience with the leak rate program is described while this paper deals with the computation of crack openings and leakage areas of longitudinal and circumferential cracks by means of fracture mechanics. The leakage areas are determined by the integration of the crack openings along the crack front, considering plasticity and geometrical effects. They are evaluated with respect to minimum values for the design of leak detection systems, and maximum values for controlling jet and reaction forces. By means of fracture mechanics LBB for subcritical cracks has to be shown and the calculation of leakage areas is the basis for quantitatively determining the discharge rate of leaking subcritical through-wall cracks. The analytical approach and its validation will be presented for two examples of complex structures. The first one is a pipe branch containing a circumferential crack and the second one is a pipe bend with a longitudinal crack.

  19. Traumatic tibialis anterior tendon rupture: treatment with a two-stage silicone tube and an interposition hamstring tendons graft protocol.

    Science.gov (United States)

    Kontogeorgakos, Vasileios; Koutalos, Antonios; Hantes, Michael; Manoudis, Gregory; Badras, Leonidas; Malizos, Konstantinos

    2015-03-01

    A novel technique for managing ruptured tibialis anterior tendon complicated by infection and tendon substance loss in a young adult is described. A two-stage reconstruction technique with a silicon tube and tendon autograft was performed. At first, after local control of the infection, scar excision and placement of a silicone tube was performed. Ten weeks later, ipsilateral hamstrings tendons were harvested and bridged the 7 cm tendon gap. Eighteen months later, the patient has excellent clinical and functional outcome.

  20. Converting round tendons to flat tendon constructs: Does the preparation process have an influence on the structural properties?

    Science.gov (United States)

    Domnick, C; Herbort, M; Raschke, M J; Schliemann, B; Siebold, R; Śmigielski, R; Fink, C

    2017-05-01

    The structural properties of hamstring tendon grafts were evaluated in a porcine model, after processing it to a flat shape, to better replace or augment anatomic flat structures (e.g. ACL, MPFL or MCL). In this biomechanical study, porcine flexor tendons were used which have a comparable shape to semitendinosus and gracilis tendons. One part of the tendon was prepared to a flat tendon construct by splitting the tendon longitudinally with a knife to half of the diameter of the tendon. The semi-split tendon was scratched out to a flat shape. The other matched part was tested in its original round shape. The tendons (n = 40) have been fixed in a uniaxial testing machine (Zwick/Roell) by cryo-clamps after preparing the fixed ends by 2-0 polyester sutures (2-0 Ethibond(®) EXCEL, Ethicon, Somerville, NJ). In every specimen, there was a free 60-mm tendon part between both clamps. The tendons have been loaded to failure to evaluate typical biomechanical parameters such as stiffness, yield load and maximum load. No statistically significant differences (n.s.) regarding stiffness, yield load and maximum load between natively round and processed flat tendons could be detected. A prepared flat-shaped tendon does not show any different structural properties compared with an original round tendon. Therefore, a flat tendon seems to be a biomechanical stable graft option for anatomic reconstruction or augmentation of injured natively flat-shaped structures such as MCL, MPFL or ACL.

  1. Position Control of Tendon-Driven Fingers

    Science.gov (United States)

    Abdallah, Muhammad E.; Platt, Robert, Jr.; Hargrave, B.; Pementer, Frank

    2011-01-01

    Conventionally, tendon-driven manipulators implement some force control scheme based on tension feedback. This feedback allows the system to ensure that the tendons are maintained taut with proper levels of tensioning at all times. Occasionally, whether it is due to the lack of tension feedback or the inability to implement sufficiently high stiffnesses, a position control scheme is needed. This work compares three position controllers for tendon-driven manipulators. A new controller is introduced that achieves the best overall performance with regards to speed, accuracy, and transient behavior. To compensate for the lack of tension feedback, the controller nominally maintains the internal tension on the tendons by implementing a two-tier architecture with a range-space constraint. These control laws are validated experimentally on the Robonaut-2 humanoid hand. I

  2. PERONEAL TENDON LESIONS IN ATHLETES (REVIEW)

    National Research Council Canada - National Science Library

    E. E. Achkasov; A. P. Sereda; A. D. Repetyuk

    2016-01-01

    .... Peroneal tendons pathology is not the major but the underestimated cause of pain in lateral and hindfoot as well as of foot dysfunction which is difficult to distinguish from lesions of lateral...

  3. Terminology for Achilles tendon related disorders

    NARCIS (Netherlands)

    van Dijk, C. N.; van Sterkenburg, M. N.; Wiegerinck, J. I.; Karlsson, J.; Maffulli, N.

    2011-01-01

    The terminology of Achilles tendon pathology has become inconsistent and confusing throughout the years. For proper research, assessment and treatment, a uniform and clear terminology is necessary. A new terminology is proposed; the definitions hereof encompass the anatomic location, symptoms,

  4. Is sonoelastography of value in assessing tendons?

    Science.gov (United States)

    Klauser, Andrea S; Faschingbauer, Ralph; Jaschke, Werner R

    2010-09-01

    Sonoelastography is a newly introduced ultrasound technique that evaluates tissue elasticity and thus provides additional information to that offered by conventional ultrasound images. In the musculoskeletal field, sonoelastography can help improve estimation of tendon stiffness. In this article, the principles and future developments of sonoelastography are discussed using the strongest and thickest tendon of the human body, the Achilles tendon, for illustrative purposes. Preliminary findings of sonoelastography in healthy and pathological Achilles tendons, technical considerations, examination technique and several limitations are addressed. The usefulness of elastography can be expected to increase rapidly in the musculoskeletal field, as soon as we learn to interpret elastographic artifacts as well as to take advantage of the new information provided by sonoelastography. Thieme Medical Publishers.

  5. Jumper's Knee (Patellar Tendonitis) (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee (Patellar Tendonitis) KidsHealth / For Parents / Jumper's Knee (Patellar ... prevent continued damage to the knee. How the Knee Works To understand how jumper's knee happens, it ...

  6. Achilles tendon assessed with sonoelastography: histologic agreement

    National Research Council Canada - National Science Library

    Klauser, Andrea S; Miyamoto, Hideaki; Tamegger, Mario; Faschingbauer, Ralph; Moriggl, Bernhard; Klima, Guenther; Feuchtner, Gudrun M; Kastlunger, Martin; Jaschke, Werner R

    2013-01-01

    ...) and sonoelastography of the Achilles tendon with findings at histologic assessment. This study was conducted with the approval of the institutional review boards, and all cadavers were in legal custody of the study institution...

  7. Early diagnosis of tendon pathologies with sonoelastography

    OpenAIRE

    Zeynep ilerisoy Yakut; Torel Ogur; sukran Erten; Deniz Delibas; Meltem Yildirim; Halil Arslan; Mehmet Gumus

    2015-01-01

    AIM : Sonoelastography (SE) is a new ultrasound-based imaging technique that provides information on tissue elasticity and stiffness. Strain sonoelastography is the most commonly used technique that allows real-time visualisation of the tissue. In this study, we searched the efficacy of SE for assessing Achilles tendon abnormalities in patients with familial mediterranean fever (FMF) suffering from talalgia. METHODS: Achilles tendons of 18 FMF patients suffering from unilateral talala...

  8. Suitable long tendon technologies and practices

    CSIR Research Space (South Africa)

    Altounyan, P

    2001-10-01

    Full Text Available to improve safety in coal mines. In order to improve safety in South African coal mining operations it is essential that rock engineering and support practices be improved in the light of available international knowledge and best practice... and Practices 2 1. The introduction of safer and more effective long tendon support systems. 2. The development of an industry wide guidance documents for each long tendon support type to be used. 3. The identification of appropriate laboratory...

  9. Quantifying Information Leakage of Randomized Protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Wasowski, Andrzej; Legay, Axel

    2013-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model and analyze the information leakage of deterministic and probabilistic systems. We show that this method generalizes the lattice...... of information approach and is a natural framework for modeling refined attackers capable to observe the internal behavior of the system. We also use our method to obtain an algorithm for the computation of channel capacity from our Markovian models. Finally, we show how to use the method to analyze timed...

  10. Quantifying information leakage of randomized protocols

    DEFF Research Database (Denmark)

    Biondi, Fabrizio; Legay, Axel; Malacaria, Pasquale

    2015-01-01

    The quantification of information leakage provides a quantitative evaluation of the security of a system. We propose the usage of Markovian processes to model deterministic and probabilistic systems. By using a methodology generalizing the lattice of information approach we model refined attackers...... capable to observe the internal behavior of the system, and quantify the information leakage of such systems. We also use our method to obtain an algorithm for the computation of channel capacity from our Markovian models. Finally, we show how to use the method to analyze timed and non-timed attacks...

  11. Leakage current measurement in transformerless PV inverters

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Sera, Dezso; Mathe, Laszlo

    2012-01-01

    Photovoltaic (PV) installations have seen a huge increase during the last couple of years. Transformerless PV inverters are gaining more share of the total inverter market, due to their high conversion efficiency, small weight and size. Nevertheless safety should have an important role in case...... to be used in commercial PV inverters for the measurement of leakage and fault ground currents. The German VDE0126–1–1 standard gives the limit for fault and leakage ground currents and all grid connected PV inverters have to comply with these limits and disconnect from the grid in case of a fault....

  12. Tendon rupture associated with excessive smartphone gaming.

    Science.gov (United States)

    Gilman, Luke; Cage, Dori N; Horn, Adam; Bishop, Frank; Klam, Warren P; Doan, Andrew P

    2015-06-01

    Excessive use of smartphones has been associated with injuries. A 29-year-old, right hand-dominant man presented with chronic left thumb pain and loss of active motion from playing a Match-3 puzzle video game on his smartphone all day for 6 to 8 weeks. On physical examination, the left extensor pollicis longus tendon was not palpable, and no tendon motion was noted with wrist tenodesis. The thumb metacarpophalangeal range of motion was 10° to 80°, and thumb interphalangeal range of motion was 30° to 70°. The clinical diagnosis was rupture of the left extensor pollicis longus tendon. The patient subsequently underwent an extensor indicis proprius (1 of 2 tendons that extend the index finger) to extensor pollicis longus tendon transfer. During surgery, rupture of the extensor pollicis longus tendon was seen between the metacarpophalangeal and wrist joints. The potential for video games to reduce pain perception raises clinical and social considerations about excessive use, abuse, and addiction. Future research should consider whether pain reduction is a reason some individuals play video games excessively, manifest addiction, or sustain injuries associated with video gaming.

  13. TREATMENT OF OLD ACHILLES TENDON RUPTURES

    Directory of Open Access Journals (Sweden)

    N. A. Koryshkov

    2012-01-01

    Full Text Available From 1998 to 2010 32 patients (14 men, 18 women, aged 15-65 years, underwent surgical treatment for old Achilles tendon rupture. In all cases correct diagnosis was made not earlier than 1 month after injury. The importance of clinical Thompson test and sonographic examination for diagnosis of Achilles tendon rupture is underlined. For the restoration of Achilles tendon V-Y plasty was used. Surgery was performed in a period of 1 to 13 months in patients with subcutaneous Achilles tendon ruptures. Follow-up results of patients in the postoperative period ranged from 6 months to 10 years (mean follow-up 1 year 7 months. Date of observation in the postoperative period ranged from 6 months to 19 years. Marginal necrosis wound occurred in 3 (10% patients, re-rupture of the Achilles tendon to tendon suture zone - in one patient, even in one patient on day 14 became infected. Violations of the foot innervation were no detected.

  14. Triceps tendon rupture: repair and rehabilitation.

    Science.gov (United States)

    Kocialkowski, Cezary; Carter, Rebecca; Peach, Chris

    2018-01-01

    Triceps tendon ruptures are rare injuries and are frequently missed on initial presentation to the emergency department. In cases of complete rupture, surgical repair is recommended but no guidelines exist on the optimum reconstructive technique or rehabilitation. We present a surgical technique and rehabilitation programme for the management of these injuries. A midline posterior incision is performed, the ruptured triceps tendon is identified and mobilized, and the tendon footprint is prepared. The tendon is then repaired using bone suture anchors, with a parachute technique, and held in 40° of flexion. The rehabilitation programme is divided into five phases, over a period of 12 weeks. Range of movement is gradually increased in a brace for the first 6 weeks. Rehabilitation is gradually increase in intensity, progressing from isometric extension exercises to weight-resisted exercises, and finally plyometrics and throwing exercises. Our surgical technique provides a solid tendon repair without the need for further metalwork removal. The graduated rehabilitation programme also helps to protect the integrity of the repair at the same time as enabling patients to gradually increase the strength of the triceps tendon and ultimately return to sport activities.

  15. Arthroscopic quadriceps tendon repair: two case reports.

    Science.gov (United States)

    Saito, Hidetomo; Shimada, Yoichi; Yamamura, Toshiaki; Yamada, Shin; Sato, Takahiro; Nozaka, Koji; Kijima, Hiroaki; Saito, Kimio

    2015-01-01

    Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation). Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA) Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury.

  16. Arthroscopic Quadriceps Tendon Repair: Two Case Reports

    Directory of Open Access Journals (Sweden)

    Hidetomo Saito

    2015-01-01

    Full Text Available Recently, although some studies of open repair of the tendon of the quadriceps femoris have been published, there have been no reports in the literature on primary arthroscopic repair. In our present study, we present two cases of quadriceps tendon injury arthroscopically repaired with excellent results. Case 1 involved a 68-year-old man who was injured while shifting his weight to prevent a fall. MRI showed complete rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using both suture anchor and pull-out suture fixation methods via bone tunnels (hereafter, pull-out fixation. Two years after surgery, retearing was not observed on MRI and both Japan Orthopedic Association (JOA Knee and Lysholm scores had recovered to 100. Case 2 involved a 50-year-old man who was also injured when shifting his weight to prevent a fall. MRI showed incomplete superficial rupture at the insertion of the patella of the quadriceps tendon. The rupture was arthroscopically repaired using pull-out fixation of six strand sutures. One year after surgery, MRI revealed a healed tendon and his JOA and Lysholm scores were 95 and 100, respectively. Thus, arthroscopic repair may be a useful surgical method for repairing quadriceps tendon injury.

  17. [Treatment of unrecent patellar tendon tear with semitendinous and gracilis tendons].

    Science.gov (United States)

    Estrada-Malacón, C A; García-Estrada, G A

    2011-01-01

    The patellar tendon lesion is very important due to the role of this tendon on the conformation of the extensor mechanism of the quadriceps. When the terminal end of this mechanism is injured, the extensor function of the knee is completely lost and thus the functional capability of the involved limb is completely disrupted.

  18. Local trauma in human patellar tendon leads to widespread changes in the tendon gene expression

    DEFF Research Database (Denmark)

    Heinemeier, Katja Maria; Lorentzen, Marc P; Kildevang Jensen, Jacob

    2016-01-01

    of Insulin-like growth factor-I, connective tissue growth factor, scleraxis, decorin, fibromodulin, tenascin-C, tenomodulin, VEGFa, CD68, IL-6, MMP12 and MMP13. In conclusion, a moderate trauma to a healthy human tendon (e.g. biopsy sampling) results in a widespread up-regulation of tendon cell activity...

  19. Three-dimensional muscle-tendon geometry after rectus femoris tendon transfer.

    Science.gov (United States)

    Asakawa, Deanna S; Blemker, Silvia S; Rab, George T; Bagley, Anita; Delp, Scott L

    2004-02-01

    Rectus femoris tendon transfer is performed in patients with cerebral palsy to improve knee flexion during walking. This procedure involves detachment of the muscle from its insertion into the quadriceps tendon and reattachment to one of the knee flexor muscles. The purpose of the present study was to evaluate the muscle-tendon geometry and to assess the formation of scar tissue between the rectus femoris and adjacent structures. Magnetic resonance images of the lower extremities were acquired from five subjects after bilateral rectus femoris tendon transfer. A three-dimensional computer model of the musculoskeletal geometry of each of the ten limbs was created from these images. The three-dimensional paths of the rectus femoris muscles after transfer demonstrated that the muscle does not follow a straight course from its origin to its new insertion. The typical muscle-tendon path included an angular deviation; this deviation was sharp (>35 degrees ) in seven extremities. In addition, scar tissue between the transferred rectus femoris and the underlying muscles was visible on the magnetic resonance images. The angular deviations in the rectus femoris muscle-tendon path and the presence of scar tissue between the rectus femoris and the underlying muscles suggest that the beneficial effects of rectus femoris tendon transfer are derived from reducing the effects of the rectus femoris muscle as a knee extensor rather than from converting the muscle to a knee flexor. These findings clarify our understanding of the mechanism by which rectus femoris tendon transfer improves knee flexion.

  20. Mechanical Properties of Human Patellar Tendon at the Hierarchical levels of Tendon and Fibril

    DEFF Research Database (Denmark)

    Svensson, Rene Brüggebusch; Hansen, Philip; Hassenkam, Tue

    2012-01-01

    that of tendon supports that fibrillar rather than interfibrillar properties govern sub-failure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition...

  1. Effect of estrogen on tendon collagen synthesis, tendon structural characteristics, and biomechanical properties in postmenopausal women

    DEFF Research Database (Denmark)

    Hansen, M.; Kongsgaard, M; Holm, Lars

    2009-01-01

    therapy (ERT, n = 10) were studied at rest and in response to one-legged resistance exercise. Synthesis of tendon collagen was determined by stable isotope incorporation [fractional synthesis rate (FSR)] and microdialysis technique (NH(2)-terminal propeptide of type I collagen synthesis). Tendon area...

  2. Mechanical properties of the human Achilles tendon, in vivo

    DEFF Research Database (Denmark)

    Kongsgaard, M; Nielsen, C H; Hegnsvad, S

    2011-01-01

    Ultrasonography has been widely applied for in vivo measurements of tendon mechanical properties. Assessments of human Achilles tendon mechanical properties have received great interest. Achilles tendon injuries predominantly occur in the tendon region between the Achilles-soleus myotendinous...... junction and Achilles-calcaneus osteotendinous junction i.e. in the free Achilles tendon. However, there has been no adequate ultrasound based method for quantifying the mechanical properties of the free human Achilles tendon. This study aimed to: 1) examine the mechanical properties of the free human...

  3. Flexor tendon tissue engineering: acellularization of human flexor tendons with preservation of biomechanical properties and biocompatibility.

    Science.gov (United States)

    Pridgen, Brian C; Woon, Colin Y L; Kim, Maxwell; Thorfinn, Johan; Lindsey, Derek; Pham, Hung; Chang, James

    2011-08-01

    Acellular human tendons are a candidate scaffold for tissue engineering flexor tendons of the hand. This study compared acellularization methods and their compatibility with allogeneic human cells. Human flexor tendons were pretreated with 0.1% ethylenediaminetetracetic acid (EDTA) for 4  h followed by 24  h treatments of 1% Triton X-100, 1% tri(n-butyl)phosphate, or 0.1% or 1% sodium dodecyl sulfate (SDS) in 0.1% EDTA. Outcomes were assessed histologically by hematoxylin and eosin and SYTO green fluorescent nucleic acid stains and biochemically by a QIAGEN DNeasy kit, Sircol collagen assay, and 1,9 dimethylmethylene blue glycosaminoglycan assay. Mechanical data were collected using a Materials Testing System to pull to failure tendons acellularized with 0.1% SDS. Acellularized tendons were re-seeded in a suspension of human dermal fibroblasts. Attachment of viable cells to acellularized tendon was assessed biochemically by a cell viability assay and histologically by a live/dead stain. Data are reported as mean±standard deviation. Compared with the DNA content of fresh tendons (551±212  ng DNA/mg tendon), only SDS treatments significantly decreased DNA content (1% SDS [202.8±37.4  ng DNA/mg dry weight tendon]; 0.1% SDS [189±104  ng DNA/mg tendon]). These findings were confirmed by histology. There was no decrease in glycosaminoglycans or collagen following acellularization with SDS. There was no difference in the ultimate tensile stress (55.3±19.2 [fresh] vs. 51.5±6.9 [0.1% SDS] MPa). Re-seeded tendons demonstrated attachment of viable cells to the tendon surface using a viability assay and histology. Human flexor tendons were acellularized with 0.1% SDS in 0.1% EDTA for 24  h with preservation of mechanical properties. Preservation of collagen and glycoaminoglycans and re-seeding with human cells suggest that this scaffold is biocompatible. This will provide a promising scaffold for future human flexor tendon tissue engineering studies to

  4. The effect of decellularized matrices on human tendon stem/progenitor cell differentiation and tendon repair.

    Science.gov (United States)

    Yin, Zi; Chen, Xiao; Zhu, Ting; Hu, Jia-jie; Song, Hai-xin; Shen, Wei-liang; Jiang, Liu-yun; Heng, Boon Chin; Ji, Jun-feng; Ouyang, Hong-Wei

    2013-12-01

    It is reported that decellularized collagen matrices derived from dermal skin and bone have been clinically used for tendon repair. However, the varying biological and physical properties of matrices originating from different tissues may influence the differentiation of tendon stem cells, which has not been systematically evaluated. In this study, the effects of collagenous matrices derived from different tissues (tendon, bone and dermis) on the cell differentiation of human tendon stem/progenitor cells (hTSPCs) were investigated, in the context of tendon repair. It was found that all three matrices supported the adhesion and proliferation of hTSPCs despite differences in topography. Interestingly, tendon-derived decellularized matrix promoted the tendinous phenotype in hTSPCs and inhibited their osteogenesis, even under osteogenic induction conditions, through modulation of the teno- and osteolineage-specific transcription factors Scleraxis and Runx2. Bone-derived decellularized matrix robustly induced osteogenic differentiation of hTSPCs, whereas dermal skin-derived collagen matrix had no apparent effect on hTSPC differentiation. Based on the specific biological function of the tendon-derived decellularized matrix, a tissue-engineered tendon comprising TSPCs and tendon-derived matrix was successfully fabricated for Achilles tendon reconstruction. Implantation of this cell-scaffold construct led to a more mature structure (histology score: 4.08 ± 0.61 vs. 8.51 ± 1.66), larger collagen fibrils (52.2 ± 1.6 nm vs. 47.5 ± 2.8 nm) and stronger mechanical properties (stiffness: 21.68 ± 7.1 Nm m(-1) vs.13.2 ± 5.9 Nm m(-1)) of repaired tendons compared to the control group. The results suggest that stem cells promote the rate of repair of Achilles tendon in the presence of a tendinous matrix. This study thus highlights the potential of decellularized matrix for future tissue engineering applications, as well as developing a practical strategy for functional tendon

  5. Leakage Resilient Secure Two-Party Computation

    DEFF Research Database (Denmark)

    Damgård, Ivan Bjerre; Hazay, Carmit; Patra, Arpita

    2012-01-01

    Definitions.} We formalize the notion of secure two-party computation in the presence of leakage and introduce security definitions in the {\\em ideal/real framework}. Our formalization induces two types of adversarial attacks. We further study the feasibility of our definitions in the computational setting...

  6. Protection of window glass from acoustic leakage

    OpenAIRE

    Lych, Sergij; Rakobovchuk, Volodymyr

    2013-01-01

    In a survey was presented an analysis of the most common glass samples on the Ukrainian market on their protection level against leakage of acoustic information. The glass samples were studied by means of roentgen analysis, and the impact of elemental composition of glass according to a laser beam reflection factor was defined.

  7. Pressure Gauges Monitor Leakage Past Seals

    Science.gov (United States)

    Smith, Steven A.

    1990-01-01

    Method devised to measure leakage of gas past each of two sets of primary and secondary seals into common volume from which aggregate flow measured. Although method applicable only to specific combination of flow configuration and thermal conditions, it serves as example of more general approach involving use of statistical analysis to extract additional information from measurements.

  8. Local administration of Trolox, a vitamin E analog, reduced tendon adhesion in a chicken model of flexor digitorum profundus tendon injury

    OpenAIRE

    Lee, Yuk Wa; Fu, Sai Chuen; Mok, Tsui Yu; Chan, Kai Ming; Hung, Leung Kim

    2016-01-01

    Background: Hand flexor tendon injuries are compromised with tendon adhesion. Tendon adhesion forms between flexor tendon and tendon sheath, reduces the range of motion of fingers, and affects their function. Oxidative stress is increased in flexor tendon after injury and might play a role in tendon adhesion formation. Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a water-soluble analog of vitamin E, is antioxidative. Trolox reduced oxidative stress and the expression of fi...

  9. Management of acute Achilles tendon rupture with tendon-bundle technique.

    Science.gov (United States)

    Li, Chun-Guang; Li, Bing; Yang, Yun-Feng

    2017-02-01

    Objective * These authors contributed equally to this work. To explore tendon-bundle technique for treating Achilles tendon rupture with no defects. Methods Patients with full unilateral Achilles tendon rupture with no defects were included. The Achilles tendon medial edge surgical repair approach was used, revealing horsetail-like rupture bundles. Tendon bundles were anatomically realigned and repaired end-to-end using 5-0 sutures. Patients were followed-up for 1 year, and assessed for differences between the repaired versus healthy limb. Results Out of 24 patients (18 male, 6 female; aged 19-56 years) at 1 year following surgery, mean American Orthopaedic Foot and Ankle Society score was 92.4 ± 5.9; mean differences between the surgically repaired versus contralateral side in dorsiflexion and plantarflexion angle were 3.5 ± 2.3° and 5.6 ± 3.2°, respectively; mean difference in calf circumference between the two sides was 0.9 ± 0.5 cm; and mean increase in Achilles tendon width versus the healthy side was 0.8 ± 0.2 cm. By 1 year post-surgery, there were no significant between-side differences in dorsiflexion and plantarflexion angle, or calf circumference. Conclusions Tendon-bundle surgery resulted in good ankle function restoration and low complication rates. Tendon-bundle surgery may reduce blood supply destruction and maximally preserve Achilles tendon length, and may be effective for treating Achilles tendon rupture with no defects.

  10. MR imaging in chronic Achilles tendon disorder

    Energy Technology Data Exchange (ETDEWEB)

    Movin, T.; Rolf, C. [Section for Sports Medicine, Dept. of Orthopedic Surgery, Huddinge Univ. Hospital (Sweden); Kristoffersen-Wiberg, M.; Aspelin, P. [Dept. of Diagnostic Radiology, Karolinska Inst., Huddinge Univ. Hospital (Sweden)

    1998-03-01

    Objectives: The primary objective was to compare 4 imaging sequences (T1-weighted, T2-weighted, proton density, and T1-weighted with gadolinium contrast agent enhancement) with regard to intratendinous signal abnormality in patients with achillodynia. The secondary objective was to relate the images to the clinical symptoms and histopathological findings. Material and Methods: Twenty patients (16 men, 4 women, median age 40 years) with chronic achillodynia participated in the study. The symptoms prohibited activity and clinical examination revealed swelling and tenderness 1.5-6 cm proximal to the Achilles tendon insertion. Of the 20 patients: 5 had bilateral achillodynia, 4 had had previous contralateral Achilles tendon disorder, and 11 had never had symptoms in the contralateral tendon region. These 11 tendons served as controls for comparison. MR imaging was performed on a superconductive 1.5 T unit. Both Achilles tendons were examined (n=40) at the same time, and multiple sagittal and transversal images were obtained. The corresponding sections on these images were visually graded according to both extension and level of MR signal intensity. Tissue was obtained for microscopic examination from the most symptomatic side in all patients (n=20). Results: T1-weighted images following gadolinium contrast medium enhancement proved to be the best method by which to visualize intratendinous signal abnormality. This sequence revealed signal abnormality in 24/25 symptomatic tendons and in 1/11 control tendons. Histopathological examination showed an increased noncollagenous extracellular matrix and altered fiber structure in the lesions corresponding to the contrast-enhanced areas. (orig./MG).

  11. Minimum Leakage/Low Cost Duct Connections

    Energy Technology Data Exchange (ETDEWEB)

    John Proctor

    2003-08-01

    Leaky and disconnected joints in HVAC air distribution systems are extremely widespread. The average efficiency of duct systems in homes in the US is approximately 55% with approximately 60% of the loss due to duct leakage. Beyond the energy and emissions penalties caused by these leaks, leaky systems have detrimental comfort, health, and safety effects. The health and safety effects include the delivery of combustion products into the homes due to leakage induced depressurization. Current duct installation practice does not attempt to address the problem. This project developed a prototype Professionally Engineered Duct System that will virtually eliminate air leakage and that can be applied in new and replacement installations at the same labor cost as current designs. It uses snap-together duct fittings that will not come apart, can be applied to all types of duct systems, and cannot be separated without exceptional force. its use would require minimal changes to current installation practice. The research team developed the prototype through a multi-step process beginning with a functional analysis of duct connections. This was followed by identifying duct sealing and attachment methods offering potential to meet design objectives, evaluating the designs in terms of function and economic feasibility, and building and testing the most promising design option. Two versions of this design were developed through a test, revise, retest process. One application was to a rigid sheet metal duct, the other was to a helix core flex duct. The process produced a sheet metal application with 1/20th the leakage of a standard connection and a flex duct application with 1/10th the leakage of a standard connection. A patent search has found that the design will not infringe on existing patents and is patentable.

  12. Energetic ion leakage from foreshock transient cores

    Science.gov (United States)

    Liu, Terry Z.; Angelopoulos, Vassilis; Hietala, Heli

    2017-07-01

    Earth's foreshock is filled with backstreaming particles that can interact with the ambient solar wind and its discontinuities to form foreshock transients. Many foreshock transients have a core with low dynamic pressure that can significantly perturb the bow shock and the magnetosphere-ionosphere system. Foreshock transients have also been recently recognized as sites of particle acceleration, which may be important for seeding the parent shock with energetic particles. A relevant step of this seeding would be energetic ion leakage into the surrounding foreshock environment. On the other hand, such leakage would also suppress the energetic particle flux contrast across foreshock transients' boundaries masking their perceived contribution to ion energization. To further examine this hypothesis of ion leakage, we report on multipoint case studies of three foreshock transient events selected from a large database. The cases were selected to exemplify, in increasing complexity, the nature and consequences of energetic ion leakage. Ion energy dispersion, observed upstream and/or downstream of the foreshock transients, is explained with a simple, ballistic model of ions leaking from the foreshock transients. Larger energies are required for leaked ions to reach the spacecraft as the distance between the transient and spacecraft increases. Our model, which explains well the observed ion energy dispersion and velocity distributions, can also be used to reveal the shape of the foreshock transients in three dimensions. Our results suggest that ion leakage from foreshock transient cores needs to be accounted for both in statistical studies and in global models of ion acceleration under quasi-parallel foreshock conditions.

  13. Discrepancy between fluoroscopic arthrography and magnetic resonance arthrography in patients with arthroscopically confirmed supraspinatus tendon tears: The additional benefit of cine fluoroscopic arthrography images

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Seok; Lee, Young Han; Suh, Jin Suck [Dept. Radiology, Research Institute of Radiological Science, Medical Convergence Research Institute, and Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    To determine the additional diagnostic benefits of fluoroscopic arthrography (FA) in patients with full-thickness supraspinatus tendon (SST) tears by comparing FA images with magnetic resonance arthrography (MRA) images. This study included FA and MRA images of 53 patients who were confirmed to have full-thickness SST tears by arthroscopy. In the FA analysis, the presence of contrast leakage into the subacromial-subdeltoid bursa was recorded. In the MRA analysis, contrast leakage, retraction of a torn tendon, width and length of the tear, and supraspinatus atrophy were evaluated. Patients were divided into the concordant group or the discordant group based on the presence of contrast leakage to compare the characteristics of SST tears. We used Fisher's exact test and two-sample t-test for the comparison. Of the 53 patients, 34 were included in the concordant group and 19 were included in the discordant group. In the concordant group, the grades of retraction were higher than those in the discordant group; the width and length of the tears were larger. Muscle atrophy was more severe in the concordant group. A full-thickness SST tear did not always exhibit contrast leakage on FA, particularly small SST tears or tears with low-grade retraction. FA can provide diagnostic information regarding the severity of full-thickness SST tears by itself.

  14. Direct Repair of Chronic Achilles Tendon Ruptures Using Scar Tissue Located Between the Tendon Stumps.

    Science.gov (United States)

    Yasuda, Toshito; Shima, Hiroaki; Mori, Katsunori; Kizawa, Momoko; Neo, Masashi

    2016-07-20

    Several surgical procedures for chronically ruptured Achilles tendons have been reported. Resection of the interposed scar tissue located between the tendon stumps and reconstruction using normal autologous tissue have been well described. We developed a direct repair procedure that uses scar tissue, which obviates the need to use normal autologous tissue. Thirty consecutive patients with Achilles tendon ruptures with a delay in diagnosis of >4 weeks underwent removal of a section of scar and healing tissue with direct primary suture of the ends of the tendon without the use of allograft or autograft. Patients were followed for a mean time of 33 months. Preoperative and postoperative clinical outcomes were measured with the Achilles Tendon Total Rupture Score (ATRS) and the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. In addition, the patients underwent preoperative and postoperative functional measurements and magnetic resonance imaging. Lastly, we evaluated the histology of the interposed healing tissue. The mean AOFAS scores were 82.8 points preoperatively and 98.1 points postoperatively. The mean postoperative ATRS was 92.0 points. At the time of the latest follow-up, none of the patients had experienced tendon reruptures or difficulties in walking or climbing stairs, and all except 2 patients could perform a single-limb heel rise. All athletes had returned to their pre-injury level of sports participation. Preoperative T2-weighted magnetic resonance imaging showed that 22 Achilles tendons were thickened with diffuse intratendinous high-signal alterations, and 8 Achilles tendons were thinned. Postoperative T2-weighted magnetic resonance imaging findings included fusiform-shaped tendon thickening and homogeneous low-signal alterations of the tendons in all patients. Histologically, the interposed scar tissue consisted of dense collagen fibers. Shortening of the tissue between the 2 tendon ends that included healing scar and direct

  15. Distal tendinosis of the tibialis anterior tendon.

    Science.gov (United States)

    Beischer, Andrew D; Beamond, Ben M; Jowett, Andrew J L; O'Sullivan, Richard

    2009-11-01

    Disorders of the tibialis anterior (TA) tendon have infrequently been reported but spontaneous rupture of this tendon is well recognized. The clinical presentation of tendinosis without rupture of the distal TA has not previously been reported and is the basis of this paper. A study of 29 patients diagnosed with distal TA tendinosis was undertaken. Data collected included, patient demographics, weight, height, pain profile and examination findings. All patients underwent MRI of the symptomatic foot. Operative findings of those patients undergoing surgery for this condition were collected. Twenty-nine patients (32 feet) were included in the study group. Their mean age was 62 years and 27 patients were female. Twenty-one patients were overweight. The usual presenting symptom was burning medial midfoot pain that was often reported to be worst at night. Swelling over the TA tendon was frequently observed. On MRI the TA was thickened in all patients. Longitudinal split tears were observed in 19 feet. Chondral thinning and/or osteophyte formation at the first tarsometatarsal or medial naviculocuneiform joints was observed in 11 feet. Eleven feet underwent surgery. Universally the TA tendon was macroscopically thickened and had lost its normal fibrillary appearance. Longitudinal split tears were observed in eight tendons. Pathology was typical of a degenerative tendinosis. Distal TA tendinosis is a condition that seems to predominantly affect overweight elderly women. It often presents with nocturnal burning medial midfoot pain.

  16. No Telescoping Effect with Dual Tendon Vibration.

    Directory of Open Access Journals (Sweden)

    Valeria Bellan

    Full Text Available The tendon vibration illusion has been extensively used to manipulate the perceived position of one's own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration on both 'upward-downward' and 'towards-away from the elbow' planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a 'telescoping' effect. Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow, but no evidence of a contraction of the perceived arm length.

  17. Animal Models for Tendon Repair Experiments: A Comparison of Pig, Sheep and Human Deep Flexor Tendons in Zone II.

    Science.gov (United States)

    Peltz, Tim Sebastian; Hoffman, Stuart William; Scougall, Peter James; Gianoutsos, Mark Peter; Savage, Robert; Oliver, Rema Antoinette; Walsh, William Robert

    2017-09-01

    This laboratory study compared pig, sheep and human deep flexor tendons in regards to their biomechanical comparability. To investigate the relevant biomechanical properties for tendon repair experiments, the tendons resistance to cheese-wiring (suture drag/splitting) was assessed. Cheese-wiring of a suture through a tendon is an essential factor for repair gapping and failure in a tendon repair. Biomechanical testing showed that forces required to pulling a uniform suture loop through sheep or pig tendons in Zone II were higher than in human tendons. At time point zero of testing these differences did not reach statistical significance, but differences became more pronounced when forces were measured beyond initial cheese-wiring (2 mm, 5 mm and 10 mm). The stronger resistance to cheese-wiring was more pronounced in the pig tendons. Also regarding size and histology, sheep tendons were more comparable to human tendons than pig tendons. Differences in tendon bio-properties should be kept in mind when comparing and interpreting the results of laboratory tendon experiments.

  18. Robot Arm with Tendon Connector Plate and Linear Actuator

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Millerman, Alexander (Inventor)

    2014-01-01

    A robotic system includes a tendon-driven end effector, a linear actuator, a flexible tendon, and a plate assembly. The linear actuator assembly has a servo motor and a drive mechanism, the latter of which translates linearly with respect to a drive axis of the servo motor in response to output torque from the servo motor. The tendon connects to the end effector and drive mechanism. The plate assembly is disposed between the linear actuator assembly and the tendon-driven end effector and includes first and second plates. The first plate has a first side that defines a boss with a center opening. The second plate defines an accurate through-slot having tendon guide channels. The first plate defines a through passage for the tendon between the center opening and a second side of the first plate. A looped end of the flexible tendon is received within the tendon guide channels.

  19. Sex Differences in Outcome After an Acute Achilles Tendon Rupture

    National Research Council Canada - National Science Library

    Grävare Silbernagel, Karin; Brorsson, Annelie; Olsson, Nicklas; Eriksson, Bengt I; Karlsson, Jon; Nilsson-Helander, Katarina

    2015-01-01

    Background: Tendon healing differs between the sexes. Comparisons in outcome between the sexes after an Achilles tendon rupture are often not possible because of the small cohort (<20%) of women. Purpose...

  20. 21 CFR 888.3025 - Passive tendon prosthesis.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a... flexor tendon of the hand. The device is implanted for a period of 2 to 6 months to aid growth of a new...

  1. Healing of AchiIIes Tendon lnjury : Ultrasonographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hyoen [Chungang University College of Medicine, Seoul (Korea, Republic of)

    1995-06-15

    To evaluate the ultrasonographic findings of ruptured Achilles tendon after healing by surgical or conservative treatment. Ultrasonography of Achilles tendon was performed in 15 patients with Achilles tendon injury that was believed to be cured after surgical or conservative treatment. We used 7MHz liner transducer. Ultrasonographic characteristics of the affected tendon were compared with those of the opposite healthy tendon in terms of echogenicity and thickness of tendon, contour disruption, and surrounding fluid collection. The thickness of the affected Achilles tendon was significantly greater than that of the healthy tendon(P<0.001). Ultrasonographic findings included focal hylpoechogenicity(4), diffusehypoechogenicity(9), isoecho-genicity(2) and focal sonolucent area(6). Ultrasonographic findings of healed Achilles are diffuse increase in thickness and diffuse or focal decrease in echogenicity in the avsence of surrounding fluid collection or hematoma

  2. Tendon Mineralization Is Progressive and Associated with Deterioration of Tendon Biomechanical Properties, and Requires BMP-Smad Signaling in the Mouse Achilles Tendon Injury Model

    Science.gov (United States)

    Zhang, Kairui; Asai, Shuji; Hast, Michael W.; Liu, Min; Usami, Yu; Iwamoto, Masahiro; Soslowsky, Louis J.; Enomoto-Iwamoto, Motomi

    2016-01-01

    Ectopic tendon mineralization can develop following tendon rupture or trauma surgery. The pathogenesis of ectopic tendon mineralization and its clinical impact have not been fully elucidated yet. In this study, we utilized a mouse Achilles tendon injury model to determine whether ectopic tendon mineralization alters the biomechanical properties of the tendon and whether BMP signaling is involved in this condition. A complete transverse incision was made at the midpoint of the right Achilles tendon in 8-week-old CD1 mice and the gap was left open. Ectopic cartilaginous mass formation was found in the injured tendon by 4 weeks post-surgery and ectopic mineralization was detected at 8–10 weeks post-surgery. Ectopic mineralization grew over time and volume of the mineralized materials of 25-weeks samples was about 2.5 fold bigger than that of 10-weeks samples, indicating that injury-induced ectopic tendon mineralization is progressive. In vitro mechanical testing showed that max force, max stress and mid-substance modulus in the 25-weeks samples were significantly lower than the 10-weeks samples. We observed substantial increases in expression of bone morphogenetic protein family genes in injured tendons 1 week post-surgery. Immunohistochemical analysis showed that phosphorylation of both Smad1 and Smad3 were highly increased in injured tendons as early as 1 week post-injury and remained high in ectopic chondrogenic lesions 4 weeks post-injury. Treatment with the BMP receptor kinase inhibitor (LDN193189) significantly inhibited injury-induced tendon mineralization. These findings indicate that injury-induced ectopic tendon mineralization is progressive, involves BMP signaling and associated with deterioration of tendon biomechanical properties. PMID:26825318

  3. Compensatory muscle activation caused by tendon lengthening post Achilles tendon rupture

    Science.gov (United States)

    Suydam, Stephen M.; Buchanan, Thomas S.; Manal, Kurt; Silbernagel, Karin Gravare

    2013-01-01

    Purpose The purpose of this study was to establish a relationship between the lengthening of the Achilles tendon post rupture and surgical repair to muscle activation patterns during walking in order to serve as a reference for post-surgical assessment. Method The Achilles tendon lengths were collected from 4 patients with an Achilles tendon rupture 6 and 12 month post-surgery along with 5 healthy controls via ultrasound. EMG was collected from the triceps surae muscles and tibialis anterior during over-ground walking. Results Achilles lengths at 6 and 12 months post-surgery were significantly longer (p Achilles tendon rupture; no side to side difference was found in the healthy controls. The triceps surae muscles’ activations were fair to moderately correlated to the Achilles lengths (0.38 Achilles tendon length and iEMG from the triceps surae muscles indicate that loss of function is primarily caused by anatomical changes in the tendon and the appearance of muscle weakness is due to a lack of force transmission capability. This study indicates that when aiming for full return of function and strength an important treatment goal appears to be to minimize tendon elongation. Level of evidence Prognostic prospective case series. Level IV. PMID:23609529

  4. Acute partial rupture of the common extensor tendon

    OpenAIRE

    Kachrimanis, G.; Papadopoulou, O.

    2010-01-01

    Rupture of the common extensor tendon is the most common acute tendon injury of the elbow. The authors describe a case of a patient with a clinical history of tendinopathy caused by functional overload of the common extensor tendon, treated also with infiltrations of steroids, and subsequent partial rupture of the tendon during sport activity. The diagnosis was made clinically and at ultrasound (US) examination; US follow-up after some time showed the healing of the lesion. This case confirms...

  5. Calcaneal tendon: imaging findings; Tendao calcaneo: avaliacao por imagem

    Energy Technology Data Exchange (ETDEWEB)

    Montandon, Cristiano; Fonseca, Cristiano Rezio; Montandon Junior, Marcelo Eustaquio [Colegio Brasileiro de Radiologia e Diagnostico por Imagem, Sao Paulo, SP (Brazil)]. E-mail: crismontandon@hotmail.com; Lobo, Leonardo Valadares; Ribeiro, Flavia Aparecida de Souza; Teixeira, Kim-Ir-Sen Santos [Goias Univ., Goiania, GO (Brazil). Hospital de Clinicas. Dept. de Diagnostico por Imagem e Anatomia Patologica

    2003-12-01

    We reviewed the radiological and clinical features of 23 patients with calcaneal tendon diseases, who were submitted to ultrasound or magnetic resonance imaging. The objective of this study was to characterize the lesions for a precise diagnosis of calcaneal tendon injuries. A wide range of calcaneal tendon diseases include degenerative lesions, inflammation of the peritendinous tissue such as peritendinitis and bursitis, and rupture. Imaging methods are essential in the diagnosis, treatment and follow-up of calcaneal tendon diseases. (author)

  6. MRI in flexor tendon rupture after collagenase injection

    Energy Technology Data Exchange (ETDEWEB)

    Khurana, Shruti [Lady Hardinge Medical College, New Delhi (India); Wadhwa, Vibhor [University of Arkansas for Medical Sciences, Little Rock, AR (United States); Chhabra, Avneesh [UT Southwestern Medical Center, Dallas, TX (United States); Johns Hopkins University, Baltimore, MD (United States); Amirlak, Bardia [UT Southwestern Medical Center, Dallas, TX (United States)

    2017-02-15

    Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture. (orig.)

  7. p38 MAPK signaling in postnatal tendon growth and remodeling.

    Directory of Open Access Journals (Sweden)

    Andrew J Schwartz

    Full Text Available Tendon is a dynamic tissue whose structure and function is influenced by mechanical loading, but little is known about the fundamental mechanisms that regulate tendon growth and remodeling in vivo. Data from cultured tendon fibroblasts indicated that the p38 MAPK pathway plays an important role in tendon fibroblast proliferation and collagen synthesis in vitro. To gain greater insight into the mechanisms of tendon growth, and explore the role of p38 MAPK signaling in this process, we tested the hypotheses that inducing plantaris tendon growth through the ablation of the synergist Achilles tendon would result in rapid expansion of a neotendon matrix surrounding the original tendon, and that treatment with the p38 MAPK inhibitor SB203580 would prevent this growth. Rats were treated with vehicle or SB203580, and subjected to synergist ablation by bilateral tenectomy of the Achilles tendon. Changes in histological and biochemical properties of plantaris tendons were analyzed 3, 7, or 28 days after overload, and comparisons were made to non-overloaded animals. By 28 days after overload, tendon mass had increased by 30% compared to non-overloaded samples, and cross-sectional area (CSA increased by around 50%, with most of the change occurring in the neotendon. The expansion in CSA initially occurred through the synthesis of a hyaluronic acid rich matrix that was progressively replaced with mature collagen. Pericytes were present in areas of active tendon growth, but never in the original tendon ECM. Inhibition of p38 MAPK resulted in a profound decrease in IL6 expression, and had a modest effect on the expression of other ECM and cell proliferation genes, but had a negligible impact on overall tendon growth. The combined results from this study provided novel insights into tendon mechanobiology, and suggest that p38 MAPK signaling does not appear to be necessary for tendon growth in vivo.

  8. Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

    Science.gov (United States)

    Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Docking, Sean; Purdam, Craig; Cook, Jill

    2016-01-01

    Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal

  9. Structural tendon changes in patients with acromegaly: assessment of Achilles tendon with sonoelastography.

    Science.gov (United States)

    Onal, Eda Demil; Ipek, Ali; Evranos, Berna; Idilman, Ilkay Sedakat; Cakir, Bekir; Ersoy, Reyhan

    2016-03-01

    To describe the sonoelastographic appearance of the Achilles tendon in acromegalic patients and to determine whether the blood concentrations of growth hormone (GH) and insulin-like growth factor (IGF-1) are associated with the various sonographic elasticity types of Achilles tendons. Eighty-four Achilles tendons of 42 acromegaly patients and 84 Achilles tendons of 42 healthy volunteers were assessed with sonoelastography. The tendons were classified into two main types according to the elasticity features: type 1 blue/green (hard tissue) and type 2 yellow/red within green (intermediate-soft tissue). Two subtypes of these types were also defined. According to the definition, the elasticity of the tissue was in a spectrum ranging from hard to soft as the type progressed from 1a to 2b. The mean thickness of Achilles tendons in patients with acromegaly was significantly higher compared with healthy Achilles tendons (5.1+/-0.7 mm vs. 4.4+/-0.5, pAchilles tendons (5.5+/-0.8 mm vs. 4.8+/-0.5 mm in inactive disease, p=0.003). A significantly higher proportion of acromegaly patients had type 2 sonoelastographic appearance of the Achilles tendon (124/252 third; 49.2% vs. 81/252 third; 32.1%, p=0.0001). Activity status of acromegaly and GH/IGF-I levels were similar in patients with different types of elasticity (p>0.05). Sonoelastography revealed structural changes in the tendinous tissue of patients with acromegaly, but it was not sensitive enough to reflect changes in the serum levels of GH/IGF-1.

  10. Subscapularis tendon avulsions and biceps tendon dislocations. A series of forty five patients; Lesions isolees du tendon subscapularis et malpositions internes du tendon long biceps

    Energy Technology Data Exchange (ETDEWEB)

    Bernageau, J. [Hopital Lariboisiere, 75 - Paris (France); Goutallier, D. [Hopital Henri-Mondor, 94 - Creteil (France)

    1997-12-01

    Our series consists of 45 lesions of the subscapularis tendon investigated by arthrography and CT arthrography. Arthrography demonstrated opacification of the sub-acromial bursa in 24 % of cases, internal malposition of the long head of biceps in 46 % of cases and direct signs of a lesion of the subscapularis tendon in 91 % of cases. CT arthrography showed incomplete transverse avulsion in 18 % of cases and complete transverse avulsion in 82 % of cases. The biceps was dislocated in 35 % of cases, and subluxated in 11 % of cases. The subscapularis muscle was infiltrated by fat in 46 % of cases. Isolated lesions of the subscapularis can be difficult to diagnose clinically and are more frequent than generally thought. CT arthrography must therefore be requested at the slightest doubt, as the intraoperative search for a lesion of the subscapularis tendon is sometimes difficult. (authors)

  11. Lateral force transmission between human tendon fascicles

    DEFF Research Database (Denmark)

    Haraldsson, Bjarki T; Aagaard, Per; Qvortrup, Klaus

    2008-01-01

    Whether adjacent collagen fascicles transmit force in parallel is unknown. The purpose of the present study was to examine the magnitude of lateral force transmission between adjacent collagen fascicles from the human patellar and Achilles tendon. From each sample two adjacent strands of fascicles...... was transversally cut while the other fascicle and the fascicular membrane were kept intact. Cycle 3: both fascicles were cut in opposite ends while the fascicular membrane was left intact. A decline in peak force of 45% and 55% from cycle 1 to cycle 2, and 93% and 92% from cycle 2 to cycle 3 was observed...... in the patellar and Achilles tendon fascicles, respectively. A decline in stiffness of 39% and 60% from cycle 1 to cycle 2, and of 93% and 100% from cycle 2 to cycle 3 was observed in the patellar and Achilles tendon fascicles, respectively. The present data demonstrate that lateral force transmission between...

  12. Achilles tendon rupture; assessment of nonoperative treatment

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner

    2014-01-01

    to be clarified, particularly the role of weight-bearing during early rehabilitation. Also, there is a need for a clinically applicable and accurate measurement to detect patients in risk of developing Achilles tendon elongation. PURPOSE: The aim of this PhD thesis was to evaluate non-operative treatment of acute......BACKGROUND: Acute Achilles tendon rupture is a frequent and potentially disabling injury. Over the past decade a change in treatment of acute Achilles tendon rupture away from operative towards non-operative treatment has taken place. However, the optimal non-operative treatment protocol remains.......3 mm), inter-rater reliability (ICC 0.97, SEM 3.3 mm and MDC 9.3 mm) and validity (measurement error 2%). CONCLUSION: Treatment algorithms across Scandinavia showed considerable variation, though operative treatment and controlled early weight-bearing was the preferred treatment in Denmark, Norway...

  13. PERONEAL TENDON LESIONS IN ATHLETES (REVIEW

    Directory of Open Access Journals (Sweden)

    E. E. Achkasov

    2016-01-01

    Full Text Available The authors analyzed scientific literature in respect of various issues in treatment of athletes with peroneal muscles lesions starting from 1987 till 2016. Key search and publications selection was made in PubMed and russian national electronic scientific library eLIBRARY. Peroneal tendons pathology is not the major but the underestimated cause of pain in lateral and hindfoot as well as of foot dysfunction which is difficult to distinguish from lesions of lateral ligaments of the ankle joint. Untreated lesions of peroneal tendons can result in chronic ankle pain and significant functional disorders. The purpose of the present paper is to improve the current comprehension of anatomy, to identify factors contributing to pathology, to perform diagnostic evaluation of peroneal tendons and to review current treatment options of such lesions.

  14. Triple Achilles Tendon Rupture: Case Report.

    Science.gov (United States)

    Saxena, Amol; Hofer, Deann

    2017-11-16

    We present a case report with 1-year follow-up data of a 57-year-old male soccer referee who had sustained an acute triple Achilles tendon rupture injury during a game. His triple Achilles tendon rupture consisted of a rupture of the proximal watershed region, a rupture of the main body (mid-watershed area), and an avulsion-type rupture of insertional calcific tendinosis. The patient was treated surgically with primary repair of the tendon, including tenodesis with anchors. Postoperative treatment included non-weightbearing for 4 weeks and protected weightbearing until 10 weeks postoperative, followed by formal physical therapy, which incorporated an "antigravity" treadmill. The patient was able to return to full activity after 26 weeks, including running and refereeing, without limitations. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  15. A Simulation Model for Extensor Tendon Repair

    Directory of Open Access Journals (Sweden)

    Elizabeth Aronstam

    2017-07-01

    Full Text Available Audience: This simulation model is designed for use by emergency medicine residents. Although we have instituted this at the PGY-2 level of our residency curriculum, it is appropriate for any level of emergency medicine residency training. It might also be adapted for use for a variety of other learners, such as practicing emergency physicians, orthopedic surgery residents, or hand surgery trainees. Introduction: Tendon injuries commonly present to the emergency department, so it is essential that emergency physicians be competent in evaluating such injuries. Indeed, extensor tendon repair is included as an ACGME Emergency Medicine Milestone (Milestone 13, Wound Management, Level 5 – “Performs advanced wound repairs, such as tendon repairs…”.1 However, emergency medicine residents may have limited opportunity to develop these skills due to a lack of patients, competition from other trainees, or preexisting referral patterns. Simulation may provide an alternative means to effectively teach these skills in such settings. Previously described tendon repair simulation models that were designed for surgical trainees have used rubber worms4, licorice5, feeding tubes, catheters6,7, drinking straws8, microfoam tape9, sheep forelimbs10 and cadavers.11 These models all suffer a variety of limitations, including high cost, lack of ready availability, or lack of realism. Objectives: We sought to develop an extensor tendon repair simulation model for emergency medicine residents, designed to meet ACGME Emergency Medicine Milestone 13, Level 5. We wished this model to be simple, inexpensive, and realistic. Methods: The learner responsible content/educational handout component of our innovation teaches residents about emergency department extensor tendon repair, and includes: 1 relevant anatomy 2 indications and contraindications for emergency department extensor tendon repair 3 physical exam findings 4 tendon suture techniques and 5 aftercare. During

  16. Primary flexor tendon repair: surgical techniques based on the anatomy and biology of the flexor tendon system.

    Science.gov (United States)

    Tonkin, M A

    1991-01-01

    The anatomy, biology and bio-mechanics of the flexor tendon system demand a precise approach to flexor tendon repair. Within the fibroosseous canal, the synovial fluid and a complex intratendinous vascular network provide nutrition for intrinsic flexor tendon healing. Retention of the synovial sheath theoretically maintains an enclosed tendon/tendon sheat environment in which the tendon repair is bathed in synovial fluid, and may glide within a smooth tunnel. The preservation of the intricate double tendon inter-relationship and the annular pulley system is vital to the efficiency of finger flexion. This review details surgical and postoperative techniques aimed at restoring the normal anatomy and providing optimal conditions for the return of flexor tendon function.

  17. MicroRNA29a Treatment Improves Early Tendon Injury.

    Science.gov (United States)

    Watts, Ashlee E; Millar, Neal L; Platt, Josh; Kitson, Susan M; Akbar, Moeed; Rech, Raquel; Griffin, Jay; Pool, Roy; Hughes, Tom; McInnes, Iain B; Gilchrist, Derek S

    2017-10-04

    Tendon injuries (tendinopathies) are common in human and equine athletes and characterized by dysregulated collagen matrix, resulting in tendon damage. We have previously demonstrated a functional role for microRNA29a (miR29a) as a post-transcriptional regulator of collagen 3 expression in murine and human tendon injury. Given the translational potential, we designed a randomized, blinded trial to evaluate the potential of a miR29a replacement therapy as a therapeutic option to treat tendinopathy in an equine model that closely mimics human disease. Tendon injury was induced in the superficial digital flexor tendon (SDFT) of 17 horses. Tendon lesions were treated 1 week later with an intralesional injection of miR29a or placebo. miR29a treatment reduced collagen 3 transcript levels at week 2, with no significant changes in collagen 1. The relative lesion cross-sectional area was significantly lower in miR29a tendons compared to control tendons. Histology scores were significantly better for miR29a-treated tendons compared to control tendons. These data support the mechanism of microRNA-mediated modulation of early pathophysiologic events that facilitate tissue remodeling in the tendon after injury and provides a strong proof of principle that a locally delivered miR29a therapy improves early tendon healing. Copyright © 2017 The American Society of Gene and Cell Therapy. All rights reserved.

  18. Management of open achilles tendon injury: Primary repair and ...

    African Journals Online (AJOL)

    Background: Achilles tendon injuries have progressive increase worldwide in the last few decades. This is attributable to increase in both competitive and recreational sports. In most of the literature written on Achilles tendon injuries there were rarely any information about open Achilles tendon lacerations. In fact, Achilles ...

  19. Bilateral spontaneous rupture of flexor digitorum profundus tendons.

    LENUS (Irish Health Repository)

    O'Sullivan, S T

    2012-02-03

    Spontaneous tendon rupture is an unusual condition usually associated with underlying disease processes such as rheumatoid arthritis, chronic renal failure or bony abnormalities of the hand. We report a case of spontaneous, non-concurrent bilateral rupture of flexor profundus tendons in an otherwise healthy individual. Treatment was successful and consisted of a two-stage reconstruction of the ruptured tendon.

  20. Measurement of tendon reflexes by surface electromyography in normal subjects

    NARCIS (Netherlands)

    Stam, J.; van Crevel, H.

    1989-01-01

    A simple method for measuring the tendon reflexes was developed. A manually operated, electronic reflex hammer was applied that enabled measurement of the strength of tendon taps. Reflex responses were recorded by surface electromyography. Stimulus-response relations and latencies of tendon reflexes

  1. Semitendinosus Tendon for Solitary Use in Anterior Cruciate ...

    African Journals Online (AJOL)

    for reconstruction of the anterior cruciate ligament requires adequate tendon length (>28 cm) and four strand construct diameter (>8 mm). This study sought to determine the dimensions of the semitendinosus tendon graft among Kenyans. Methods: Forty pairs of ST tendons were harvested from formalin fixed cadavers by ...

  2. Region-specific mechanical properties of the human patella tendon

    DEFF Research Database (Denmark)

    Haraldsson, B T; Aagaard, P; Krogsgaard, M

    2004-01-01

    The present study investigated the mechanical properties of tendon fascicles from the anterior and posterior human patellar tendon. Collagen fascicles from the anterior and posterior human patellar tendon in healthy young men (mean +/- SD, 29.0 +/- 4.6 yr, n = 6) were tested in a mechanical rig. ...

  3. Painful Snapping Hip Owing to Bifid Iliopsoas Tendon and ...

    African Journals Online (AJOL)

    A case of internal snapping hip owing to a bifid iliopsoas tendon is described with a concurrent labral tear in a young active female. The labral tear was identified on magnetic resonance imaging, and the snapping bifid tendon on dynamic ultrasound. The patient was administered bupivicaine and steroid around the tendon ...

  4. Posterior tibial tendon dysfunction by bone imprisonment | Zejjari ...

    African Journals Online (AJOL)

    The radiological assessment finds imprisonment of posterior tibial tendon in the internal retromalleolar bony canal. The patient received a release of the tendon with resection of the bony canal in full. The posterior tibial tendon showed longitudinal laceration was sutured and the internal retromalleolar canal was closed.

  5. Using the zebrafish to understand tendon development and repair.

    Science.gov (United States)

    Chen, J W; Galloway, J L

    2017-01-01

    Tendons are important components of our musculoskeletal system. Injuries to these tissues are very common, resulting from occupational-related injuries, sports-related trauma, and age-related degeneration. Unfortunately, there are few treatment options, and current therapies rarely restore injured tendons to their original function. An improved understanding of the pathways regulating their development and repair would have significant impact in stimulating the formulation of regenerative-based approaches for tendon injury. The zebrafish provides an ideal system in which to perform genetic and chemical screens to identify new pathways involved in tendon biology. Until recently, there had been few descriptions of tendons and ligaments in the zebrafish and their similarity to mammalian tendon tissues. In this chapter, we describe the development of the zebrafish tendon and ligament tissues in the context of their gene expression, structure, and interactions with neighboring musculoskeletal tissues. We highlight the similarities with tendon development in higher vertebrates, showing that the craniofacial tendons and ligaments in zebrafish morphologically, molecularly, and structurally resemble mammalian tendons and ligaments from embryonic to adult stages. We detail methods for fluorescent in situ hybridization and immunohistochemistry as an assay to examine morphological changes in the zebrafish musculoskeleton. Staining assays such as these could provide the foundation for screen-based approaches to identify new regulators of tendon development, morphogenesis, and repair. These discoveries would provide new targets and pathways to study in the context of regenerative medicine-based approaches to improve tendon healing. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dickerhoff, Darryl J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  7. Techniques for Leakage Power Reduction in Nanoscale Circuits: A Survey

    DEFF Research Database (Denmark)

    Liu, Wei

    This report surveys progress in the field of designing low power especially low leakage CMOS circuits in deep submicron era. The leakage mechanism and various recently proposed run time leakage reduction techniques are presented. Two designs from Cadence and Sony respectively, which can represent...... current industrial application of these techniques, are also illustrated....

  8. 49 CFR 192.706 - Transmission lines: Leakage surveys.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Transmission lines: Leakage surveys. 192.706... Transmission lines: Leakage surveys. Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line which...

  9. Ultrasound diagnostics of muscle and tendon injuries

    Directory of Open Access Journals (Sweden)

    Stević Ruža

    2009-01-01

    Full Text Available Introduction. Sonography is a useful technique for the investigation of a number of musculoskeletal disorders. The most common indication for ultrasonography of muscles and tendons is the diagnosis of traumatic lesions, distinguishing them from other disorders and follow-up of healing process. Objective. The purpose of this paper is to show the importance of ultrasound in the diagnosis of muscle and tendon injuries. Methods. The study included 170 patients (148 male and 22 female, mean age 29.6 years (range 14-60 years. All examinations were performed by linear transducer of 7.5-10 MHz, with longitudinal and transverse scanning. Ultrasound examination followed physical examination. Results. Traumatic lesions of muscles were diagnosed in 113 patients (66.7% and tendon injuries in 57 cases (33.2%. The muscle changes detected by ultrasonography were the following: 70 (61.9% partial and two (1.76% complete ruptures, 22 (19.46% haematoma, 9 (7.96% strains grade I, 4 fibroses and 4 ossifying myositis 4 (3.5%, respectively. Complications of muscle injuries were diagnosed in two cases, a muscular hernia and an arteriovenous fistula. Among tendon injuries, 21 (33.8% ruptures and 36 (66.1% tendinitis were diagnosed. Accompanying effusion in the bursa of patients with tendon injuries was found in 9 cases. Conclusion. Ultrasonography allowed visualization and objective assessment of the type and the extent of traumatic pathomorphological changes of muscles and tendons. Such diagnostic possibilities of ultrasonography are especially important in the choice of appropriate therapy.

  10. 3DHZETRN: Neutron leakage in finite objects

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-11-01

    The 3DHZETRN formalism was recently developed as an extension to HZETRN with an emphasis on 3D corrections for neutrons and light ions. Comparisons to Monte Carlo (MC) simulations were used to verify the 3DHZETRN methodology in slab and spherical geometry, and it was shown that 3DHZETRN agrees with MC codes to the degree that various MC codes agree among themselves. One limitation of such comparisons is that all of the codes (3DHZETRN and three MC codes) utilize different nuclear models/databases; additionally, using a common nuclear model is impractical due to the complexity of the software. It is therefore difficult to ascertain if observed discrepancies are caused by transport code approximations or nuclear model differences. In particular, an important simplification in the 3DHZETRN formalism assumes that neutron production cross sections can be represented as the sum of forward and isotropic components, where the forward component is subsequently solved within the straight-ahead approximation. In the present report, previous transport model results in specific geometries are combined with additional results in related geometries to study neutron leakage using the Webber 1956 solar particle event as a source boundary condition. A ratio is defined to quantify the fractional neutron leakage at a point in a finite object relative to a semi-infinite slab geometry. Using the leakage ratio removes some of the dependence on the magnitude of the neutron production and clarifies the effects of angular scattering and absorption with regard to differences between the models. Discussion is given regarding observed differences between the MC codes and conclusions drawn about the need for further code development. Although the current version of 3DHZETRN is reasonably accurate compared to MC simulations, this study shows that improved leakage estimates can be obtained by replacing the isotropic/straight-ahead approximation with more detailed descriptions.

  11. Control of Leakage in the Triaxial Test

    Science.gov (United States)

    1964-03-01

    ON MEMBRANES APPENDIX F DATA FOR OSMOSIS TSSTS ON NATURAL RUBBER MEMBRANES APPENDIX G DATA FOR BINDING LEAKAGE TESTS APPENDIX H DATA FOR...Fraction of Sucrose Required to Prevent Flow due to Hydraulic Pressure and/or Mole Fraction Differences. :• ’ ’ : XV Figures in Appendices A-l... osmosis . Osmosis or osmotic pressure differences are caused by differences in the mole fraction of ions or molecules across a barrier. (The

  12. Spontaneous Achilles tendon rupture in alkaptonuria

    Science.gov (United States)

    Alajoulin, Omar A.; Alsbou, Mohammed S.; Ja’afreh, Somayya O.; Kalbouneh, Heba M.

    2015-01-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  13. [Comprehensive treatment in Achilles tendon rupture].

    Science.gov (United States)

    Matus-Jiménez, Juan; Avalos, Cecilia Henríquez

    2007-01-01

    Due to incapacity caused by calcaneal tendon injuries for the reintegration of patients back to their daily activities and/or sparts it is necessary to decrease the time of reinstatement of patients. At present these times have improved by a good surgical technique and an early rehabilitation, and the patient is returned quickly as he sees less disability. It is proposed in this paper a type of surgical treatment and an early rehabilitation program, which have shortened the time of disability and incorporation to their daily activities and sports to eight weeks in 10 patients with Achilles tendon plasty.

  14. Lubricin in human achilles tendon: The evidence of intratendinous sliding motion and shear force in achilles tendon.

    Science.gov (United States)

    Sun, Yu-Long; Wei, Zhuang; Zhao, Chunfeng; Jay, Gregory D; Schmid, Thomas M; Amadio, Peter C; An, Kai-Nan

    2015-06-01

    Achilles tendon is one of the most commonly injured tendons. Mechanical force is regarded as a major causative factor. However, the biomechanics of Achilles tendon and mechanical mechanism of the injuries are unclear. Lubricin expresses at regions exposed to sliding motion and shear force in a number of tissues. This study investigated the distribution and concentration of lubricin in human Achilles tendons for better understanding the biomechanics of Achilles tendon. Achilles tendons were harvested from nine cadavers. Lubricin was extracted from various locations proximal to the calcaneal insertion and quantified with ELISA. The distribution of lubricin was investigated with immunohistochemistry. Lubricin was mainly identified at the interfaces of tendon fascicles, especially in the mid-portion of the tendon. The concentration of lubricin in Achilles tendons varied by individual and the distance from its calcaneal insertion. The distal portion of the tendon had a higher concentration of lubricin than the proximal regions of the tendon. This study suggests the presence of intratendinous sliding motion of fascicles and shear force at interfaces of fascicles in human Achilles tendon. Shear force could be an important mechanical factor for the development of Achilles tendinopathy and rupture. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Alopecia associated with unexpected leakage from electron cone

    Energy Technology Data Exchange (ETDEWEB)

    Wen, B.C.; Pennington, E.C.; Hussey, D.H.; Jani, S.K.

    1989-06-01

    Excessive irradiation due to unexpected leakage was found on a patient receiving electron beam therapy. The cause of this leakage was analyzed and the amount of leakage was measured for different electron beam energies. The highest leakage occurred with a 6 x 6 cm cone using a 12 MeV electron beam. The leakage dose measured along the side of the cone could be as great as 40%. Until the cones are modified or redesigned, it is advised that all patient setups be carefully reviewed to assure that no significant patient areas are in the side scatter region.

  16. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture.

    Science.gov (United States)

    Leong, Wei Yee; Gheorghiu, Daniel; Rao, Janardhan

    2013-01-01

    There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR) in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient.

  17. Human Achilles tendon glycation and function in diabetes

    DEFF Research Database (Denmark)

    Couppé, Christian; Svensson, Rene Brüggebusch; Madsen, Mads Kongsgaard

    2016-01-01

    Diabetic patients have an increased risk of foot ulcers, and glycation of collagen may increase tissue stiffness. We hypothesized that the level of glycemic control (glycation) may affect Achilles tendon stiffness, which can influence gait pattern. We therefore investigated the relationship between...... collagen glycation, Achilles tendon stiffness parameters and plantar pressure in poorly (n = 22) and well (n = 22) controlled diabetic patients, including healthy age matched (45-70 yrs) controls (n = 11). There were no differences in any of outcome parameters (collagen cross-linking or tendon stiffness...... concentrations (55%, P Achilles tendon material stiffness was higher in DB (54%, P Achilles tendon material stiffness and skin connective...

  18. Anatomic, Vascular, and Mechanical Overview of the Achilles Tendon.

    Science.gov (United States)

    Dayton, Paul

    2017-04-01

    The Achilles tendon is the strongest and thickest tendon in the body and is subjected to unique forces during the activities of living. A variety of pathologic processes have been identified causing clinical symptoms in patients of all ages. A detailed understanding of Achilles anatomy is necessary to understand the pathologic process that are seen in the tendon. As with all medical topics and conditions, our understanding is evolving as new research sheds light on pathologic processes involved with the Achilles tendon. This article reviews the anatomic, histologic, hemodynamic, and mechanical properties of the Achilles tendon and associated muscle structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Debridement and Functional Rehabilitation for Achilles Tendon Infection Following Tendon Repair.

    Science.gov (United States)

    Bae, Seung Hwan; Lee, Ho-Seong; Seo, Sang Gyo; Kim, Sang Woo; Gwak, Heui-Chul; Bae, Su-Young

    2016-07-20

    An infected Achilles tendon after tendon repair is particularly difficult to treat because of the poor vascularity of the tendon as well as the thin surrounding soft tissue. For treatment of an infected Achilles tendon following tendon repair, we first focused on complete debridement and then promoted fibrous scar healing of the Achilles tendon using functional treatment. We retrospectively reviewed all of the medical records of 15 tertiary referral patients with postoperative infection of the Achilles tendon occurring between 2007 and 2012. The mean follow-up time was 33 months (range, 22 to 97 months). The infected tissue and the necrotic tendon were debrided, and the ankle was placed in a short leg splint for 2 weeks. The splint was then replaced with an ankle brace for the next 4 weeks. Partial weight-bearing was allowed immediately, and full weight-bearing was allowed at 2 weeks postoperatively. We assessed and recorded the physical parameters such as the range of motion, calf circumference, ability to perform a single-limb heel rise, patient satisfaction, and Arner-Lindholm scale. Laboratory tests, postoperative ultrasonography, and isokinetic plantar flexion power tests were also performed. At a mean time of 17 days (range, 8 to 30 days) after debridement, infection signs such as discharge from the wound, redness, and local warmth resolved. The wound had healed and the stitches were removed at a mean of 17 days following the wound repair. At the time of the latest follow-up, there were no signs of active infection. Achilles tendon continuity recovered in all patients by fibrous scar healing. Compared with the contralateral side, there was no difference in the ankle range of motion in 8 patients. According to the Arner-Lindholm scale, 9 of the 15 results were excellent and 6 were good. Ten patients were able to perform a single-limb heel rise. Eleven of 15 patients returned to their pre-injury recreational activities. Diffuse homogeneous echotexture of the

  20. Achilles Tendon Rupture: Avoiding Tendon Lengthening during Surgical Repair and Rehabilitation

    Science.gov (United States)

    Maquirriain, Javier

    2011-01-01

    Achilles tendon rupture is a serious injury for which the best treatment is still controversial. Its primary goal should be to restore normal length and tension, thus obtaining an optimal function. Tendon elongation correlates significantly with clinical outcome; lengthening is an important cause of morbidity and may produce permanent functional impairment. In this article, we review all factors that may influence the repair, including the type of surgical technique, suture material, and rehabilitation program, among many others. PMID:21966048

  1. The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model.

    Science.gov (United States)

    Li, Shengkun; Ma, Kui; Li, Hong; Jiang, Jia; Chen, Shiyi

    2016-01-01

    The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET) artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA) is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired with PET were assigned to PET group; the other eight rabbits repaired with PET along with injection of HE were assigned to HA-PET group. All rabbits were sacrificed at 4 and 8 weeks postoperatively for biomechanical and histological examination. The HA-PET group revealed higher biomechanical property compared with the PET group. Histologically, more collagen tissues grew into the HA-PET group compared with PET group. In conclusion, application of sodium hyaluronate can improve the healing of Achilles tendon reconstruction with polyethylene terephthalate artificial ligament.

  2. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Wei Yee Leong

    2013-07-01

    Full Text Available Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. Conclusion: The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient. Keywords: Quadriceps tendon rupture; Achilles tendon rupture; Bilateral.

  3. The "turtleneck" pulley plasty for finger flexor tendon repair.

    Science.gov (United States)

    Goubier, Jean-Noel; Lafosse, Thibault; Teboul, Frédéric

    2014-03-01

    Injuries to the flexor tendons are frequent. Even when correctly treated, they can cause a loss of mobility of the digits secondary to postoperative adhesions. Further, conflicts between the tendon suture and the pulleys can limit the range of motion of the tendon and the flexion of the fingers. We propose a new pulley plasty that permits immediate retraining and avoids conflict with the tendon suture. Ten patients underwent surgery for a tendon injury in zone II, with no lesions of the associated pedicles. The tendons were repaired by a 4-strand stitch technique associated with a continuous peritendinous suture. Pulley plasty was systematically performed on A2, A4, or both. Eight patients recovered a satisfactory range of motion with a finger to palm distance of pulleys was necessary. This plasty technique is simple to carry out, reliable, and reproducible. Because it facilitates tendon repair and reinforces the existing pulleys, it permits immediate retraining and controlled active mobilization.

  4. A posterior tibial tendon skipping rope

    NARCIS (Netherlands)

    van Sterkenburg, M. N.; Haverkamp, D.; van Dijk, C. N.; Kerkhoffs, G. M. M. J.

    2010-01-01

    This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord

  5. Engaging Stem Cells for Customized Tendon Regeneration

    Directory of Open Access Journals (Sweden)

    Hatim Thaker

    2012-01-01

    Full Text Available The need for a consistent therapeutic approach to tendon injury repair is long overdue. Patients with tendon microtears or full ruptures are eligible for a wide range of invasive and non invasive interventions, often subjectively decided by the physician. Surgery produces the best outcomes, and while studies have been conducted to optimize graft constructs and to track outcomes, the data from these studies have been inconclusive on the whole. What has been established is a clear understanding of healthy tendon architecture and the inherent process of healing. With this knowledge, tissue regeneration efforts have achieved immense progress in scaffold design, cell line selection, and, more recently, the appropriate use of cytokines and growth factors. This paper evaluates the plasticity of bone-marrow-derived stem cells and the elasticity of recently developed biomaterials towards tendon regeneration efforts. Mesenchymal stem cells (MSCs, hematopoietic progenitor cells, and poly(1,8-octanediol co-citrate scaffolds (POC are discussed in the context of established grafting strategies. With POC scaffolds to cradle the growth of MSCs and hematopoietic progenitor cells, developing a fibroelastic network guided by cytokines and growth factors may contribute towards consistent graft constructs, enhanced functionality, and better patient outcomes.

  6. Can Shockwave Therapy Improve Tendon Metabolism?

    NARCIS (Netherlands)

    Zwerver, Johannes; Waugh, Charlotte; van der Worp, Henk; Scott, Alex; Ackermann, PW; Hart, DA

    2016-01-01

    Shockwave treatments are commonly used in the management of tendon injuries and there is increasing evidence for its clinical effectiveness. There is a paucity of fundamental (in vivo) studies investigating the biological action of shockwave therapy. Destruction of calcifications, pain relief and

  7. Palmar and digital flexor tendon pulleys.

    Science.gov (United States)

    Doyle, J R

    2001-02-01

    Retinacular structures, called pulleys, maintain the flexor tendons of the hand in constant relationship to the joint axes and promote economy and efficiency in finger flexion. This system is composed of the transverse carpal ligament, the palmar aponeurosis pulley, and the digital flexor pulley system. Of these three components, the digital pulleys are the most critical to finger flexion. In their normal state, these pulley components are ideal in all aspects including configuration and location, which accomodates a 260 degrees arc of motion without impingement and with minimum friction while at the same time using muscle tendon excursion that is well within the natural range of the muscle. An absent pulley results in an increased moment arm and requires increased tendon excursion to produce the same arc of motion. Because muscle excursion is not a limitless factor and is directly proportional to muscle fiber length, the effectiveness of tendon excursion is dependent on maintenance of the critical relationship between pulleys and the adjacent joints. Preservation and reconstruction of this system is based on knowledge of the anatomy and an understanding of the relative functional significance of each component of the system.

  8. Achilles Tendon Repair, A Modified Technique

    Directory of Open Access Journals (Sweden)

    Sohrab Keyhani

    2013-12-01

    Full Text Available   Background: Wound complications following open repair for acute Achilles tendon ruptures (AATR remain the subject of significant debate. The aim of this study is to investigate the effects of covering repaired AATR using well-nourished connective tissues (paratenon and deep fascia to avoid complications after open repair.   Methods: In this case series study, open repair was performed for 32 active young patients with AATR. After the tendon was repaired, the deep fascia and paratenon was used to cover the Achilles tendon. Patients were followed for two years and any wound complication was recorded. During the last visit, the American Orthopedic Foot and Ankle Society (AOFAS ankle-hind foot score was completed for all patients. Calf circumference and ankle range of motion were measured and compared with the contralateral side. Patients were asked about returning to previous sports activities and limitations with footwear. Results: Only, one patient developed deep wound infection (3%. None of the patients had any discomfort around the operation area, limitation with footwear, sural nerve injury, re-rupture, and skin adhesion. The AOFAS score averaged 92.5±6. Two patients (7% were unable to return to previous sports activities because of moderate pain in heavy physical exercises. The calf circumference and ankle ROM were similar between healthy and operated sides. Conclusion: The present study showed that fascial envelope for full covering of the repaired Achilles tendon may help to prevent the occurrence of wound complications.

  9. Mineral distributions at the developing tendon enthesis.

    Directory of Open Access Journals (Sweden)

    Andrea G Schwartz

    Full Text Available Tendon attaches to bone across a functionally graded interface, "the enthesis". A gradient of mineral content is believed to play an important role for dissipation of stress concentrations at mature fibrocartilaginous interfaces. Surgical repair of injured tendon to bone often fails, suggesting that the enthesis does not regenerate in a healing setting. Understanding the development and the micro/nano-meter structure of this unique interface may provide novel insights for the improvement of repair strategies. This study monitored the development of transitional tissue at the murine supraspinatus tendon enthesis, which begins postnatally and is completed by postnatal day 28. The micrometer-scale distribution of mineral across the developing enthesis was studied by X-ray micro-computed tomography and Raman microprobe spectroscopy. Analyzed regions were identified and further studied by histomorphometry. The nanometer-scale distribution of mineral and collagen fibrils at the developing interface was studied using transmission electron microscopy (TEM. A zone (∼20 µm exhibiting a gradient in mineral relative to collagen was detected at the leading edge of the hard-soft tissue interface as early as postnatal day 7. Nanocharacterization by TEM suggested that this mineral gradient arose from intrinsic surface roughness on the scale of tens of nanometers at the mineralized front. Microcomputed tomography measurements indicated increases in bone mineral density with time. Raman spectroscopy measurements revealed that the mineral-to-collagen ratio on the mineralized side of the interface was constant throughout postnatal development. An increase in the carbonate concentration of the apatite mineral phase over time suggested possible matrix remodeling during postnatal development. Comparison of Raman-based observations of localized mineral content with histomorphological features indicated that development of the graded mineralized interface is linked

  10. Turkey model for flexor tendon research: in vitro comparison of human, canine, turkey, and chicken tendons.

    Science.gov (United States)

    Kadar, Assaf; Thoreson, Andrew R; Reisdorf, Ramona L; Amadio, Peter C; Moran, Steven L; Zhao, Chunfeng

    2017-08-01

    Flexor tendon injuries are one of the most common hand injuries and remain clinically challenging for functional restoration. Canine and chicken have been the most commonly used animal models for flexor tendon-related research but possess several disadvantages. The purpose of this study was to explore a potential turkey model for flexor tendon research. The third digit from human cadaveric hands, canine forepaws, turkey foot, and chicken foot were used for this study. Six digits in each of four species were studied in detail, comparing anatomy of the flexor apparatus, joint range of motioņ tendon excursion, tendon cross-sectional area, work of flexion, gliding resistance at the level of the A2 pulley, modulus of elasticity, suture retention strength, and histology across species. Anatomically, the third digit in the four species displayed structural similarities; however, the tendon cross-sectional area of the turkey and human were similar and larger than canine and chicken. Furthermore, the turkey digit resembles the human's finger with the lack of webbing between digits, similar vascularization, tendon excursion, work of flexion, gliding resistance, mechanical properties, and suture holding strength. More importantly, human and turkey tendons were most similar in histological appearance. Turkey flexor tendons have many properties that are comparable to human flexor tendons which would provide a clinically relevant, economical, nonhuman companion large animal model for flexor tendon research. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Lyman Continuum Leakage in the Local Universe

    Science.gov (United States)

    Leitherer, Claus; Hernandez, Svea; Lee, Janice; Oey, Sally

    2015-08-01

    Star-forming galaxies are viable candidates for providing the ionizing photon supply accounting for the reionization of the early universe. However, direct determination of the fraction of ionizing photons that can escape the optically thick galaxy ISM is challenging. I will discuss Lyman continuum observations of a sample of massive young star clusters in local galaxies which take advantage of a new capability of HST's Cosmic Origins Spectrograph. The derived photon leakages are compared to values found at high redshift and discussed in the context of cosmological models.

  12. EVA Suit Microbial Leakage Investigation Project

    Science.gov (United States)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  13. Analysis of U.S. residential air leakage database

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Wanyu R.; Price, Phillip N.; Sohn, Michael D.; Gadgil, Ashok J.

    2003-07-01

    The air leakage of a building envelope can be determined from fan pressurization measurements with a blower door. More than 70,000 air leakage measurements have been compiled into a database. In addition to air leakage, the database includes other important characteristics of the dwellings tested, such as floor area, year built, and location. There are also data for some houses on the presence of heating ducts, and floor/basement construction type. The purpose of this work is to identify house characteristics that can be used to predict air leakage. We found that the distribution of leakage normalized with floor area of the house is roughly lognormal. Year built and floor area are the two most significant factors to consider when predicting air leakage: older and smaller houses tend to have higher normalized leakage areas compared to newer and larger ones. Results from multiple linear regression of normalized leakage with respect to these two factors are presented for three types of houses: low-income, energy-efficient, and conventional. We demonstrate a method of using the regression model in conjunction with housing characteristics published by the US Census Bureau to derive a distribution that describes the air leakage of the single-family detached housing stock. Comparison of our estimates with published datasets of air exchange rates suggests that the regression model generates accurate estimates of air leakage distribution.

  14. Effect of tendon tensioning: an in vitro study in porcine extensor tendons.

    Science.gov (United States)

    Figueroa, David; Calvo, Rafael; Vaisman, Alex; Meleán, Patricio; Figueroa, Francisco

    2010-06-01

    Graft tensioning is a controversial issue in anterior cruciate ligament reconstruction (ACLR) that has not achieved consensus between peers. The purpose of this study is to determine if after tensioning tendon length and resistance to maximal load changes. We performed an in vitro study with 50 porcine extensors tendons. The first group (P=25) was tensioned with 80 N (19.97 lb) for 10 min, using an ACL graft preparation board. The second group (C=25) was used as control and was not tensioned. The average initial (groups P and C) and post tensioning tendon length (group C) were measured; the average initial and post tensioning tendon diameter were measured as well. All samples were fixated in a tube-clamp system connected to a tension sensor. The samples were stressed with continuous and progressive tension until ultimate failure at maximum load (UFML) occurs. The initial mean length was: P before tensioning=13.4 mm+/-1.4 mm (range 10.5-16.5); P after tensioning=13.8 mm+/-1.4 mm (range 11.5-16.5); C=13 mm+/-1.35 mm (p=0.005). The mean diameter was: P=5.6 mm (4.5-6); C=5.5 mm (range 4.5-6) (p>0.05). The UFML was: P=189.7 N (114-336); C=229.9 N (143-365) (p=0.029). Tendon tensioning with 80 N for 10 min produced 3% average elongation. These could be beneficial in ACLR since tendon tensioning decreases elongation of the graft after fixation. Regardless, tendon tensioning is not innocuous since it diminishes their resistance when continuously stressed until complete failure occurs.

  15. Chronic Achilles Tendon Rupture Reconstructed With Achilles Tendon Allograft and Xenograft Combination.

    Science.gov (United States)

    Hollawell, Shane; Baione, William

    2015-01-01

    More than 20% of acute Achilles tendon injuries are misdiagnosed, leading to chronic or neglected ruptures. Some controversy exists regarding how to best manage an acute Achilles tendon rupture. However, a general consensus has been reached that chronic rupture with ≥3 cm of separation is associated with functional morbidity and, therefore, should be managed operatively. It has been demonstrated that the functional outcomes of surgically treated Achilles ruptures are superior to the nonoperative outcomes in a chronic setting. In the present report, we reviewed 4 patients with chronic Achilles tendon ruptures that were successfully treated with an Achilles tendon interposition allograft and simultaneous augmentation with a xenograft. The median duration of rupture was 11 (range 8 to 16) weeks, the median gap between the proximal and distal segments of the tendon was 4.75 (range 3.5 to 6) cm, and the patients were able to return pain-free to all preinjury activities at a median of 14.5 (range 13.8 to 15.5) weeks, without the need for tendon transfer, lengthening, or additional intervention. The median duration of follow up was 37.25 (range 15.25 to 51.5) months, at which point the mean Foot and Ankle Outcomes Instrument core scale score was 97 ± 1 (mean normative score 53 ± 1), and the Foot and Ankle Outcomes Instrument shoe comfort core scale score was 100 ± 0 (mean normative score 59 ± 0). The combined Achilles allograft plus xenograft augmentation technique appears to be a reasonable option for the surgical treatment of chronic Achilles tendon rupture. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Biomembrane Permeabilization: Statistics of Individual Leakage Events Harmonize the Interpretation of Vesicle Leakage

    Czech Academy of Sciences Publication Activity Database

    Braun, S.; Pokorná, Šárka; Šachl, Radek; Hof, Martin; Heerklotz, H.; Hoernke, M.

    2018-01-01

    Roč. 12, č. 1 (2018), s. 813-819 ISSN 1936-0851 R&D Projects: GA ČR GA17-03160S Institutional support: RVO:61388955 Keywords : leakage * dye release * pore Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 13.942, year: 2016

  17. Decellularized and Engineered Tendons as Biological Substitutes: A Critical Review

    Directory of Open Access Journals (Sweden)

    Arianna B. Lovati

    2016-01-01

    Full Text Available Tendon ruptures are a great burden in clinics. Finding a proper graft material as a substitute for tendon repair is one of the main challenges in orthopaedics, for which the requirement of a biological scaffold would be different for each clinical application. Among biological scaffolds, the use of decellularized tendon-derived matrix increasingly represents an interesting approach to treat tendon ruptures. We analyzed in vitro and in vivo studies focused on the development of efficient protocols for the decellularization and for the cell reseeding of the tendon matrix to obtain medical devices for tendon substitution. Our review considered also the proper tendon source and preclinical animal models with the aim of entering into clinical trials. The results highlight a wide panorama in terms of allogenic or xenogeneic tendon sources, specimen dimensions, physical or chemical decellularization techniques, and the cell type variety for reseeding from terminally differentiated to undifferentiated mesenchymal stem cells and their static or dynamic culture employed to generate implantable constructs tested in different animal models. We try to identify the most efficient approach to achieve an optimal biological scaffold for biomechanics and intrinsic properties, resembling the native tendon and being applicable in clinics in the near future, with particular attention to the Achilles tendon substitution.

  18. Shear Wave Measurements for Evaluation of Tendon Diseases.

    Science.gov (United States)

    Yeh, Chia-Lun; Kuo, Po-Ling; Gennisson, Jean-Luc; Brum, Javier; Tanter, Mickael; Li, Pai-Chi

    2016-11-01

    This paper investigated the feasibility of using supersonic shear wave measurements to quantitatively differentiate normal and damaged tendons based on their mechanical properties. Five freshly harvested porcine tendons excised from pig legs were used. Tendon damage was induced by incubating the tendons with a 1% w/v collagenase solution. Values of shear modulus were derived both by a time-of-flight (TOF) approach and a transverse isotropic plate model (TI-model). The results show that as the preload applied to the tendon increased from 0 to 3 N, the mean shear modulus derived based on the TOF approach, the TI-model, and Young's modulus estimated from mechanical testing increased from 14.6 to 89.9 kPa, 53.9 to 348 kPa, and from 1.45 to 10.36 MPa, respectively, in untreated tendons, and from 8.4 to 67 kPa, 28 to 258 kPa, and from 0.93 to 7.2 MPa in collagenase-treated tendons. Both the TOF approach and the TI-model correlated well with the changes in Young's modulus. Although there is bias on the estimation of shear modulus using the TOF approach, it still provides statistical significance to differentiate normal and damaged tendons. Our data indicate that supersonic shear wave imaging is a valuable imaging technique to assess tendon stiffness dynamics and characterize normal and collagenase-damaged tendons.

  19. [MR imaging of the Achilles tendon: evaluation of criteria for the differentiation of asymptomatic and symptomatic tendons].

    Science.gov (United States)

    Weber, C; Wedegärtner, U; Maas, L C; Buchert, R; Adam, G; Maas, R

    2011-07-01

    The purpose of this study was to develop quantitative and qualitative MRI criteria to differentiate between healthy and pathological Achilles tendons. 364 Achilles tendons were examined on a 1.5 T MRI scanner. 264 patients had Achilles tendon complaints, 100 asymptomatic Achilles tendons served as a control. T 1-weighted, T 2-weighted and a STIR sequence were performed in sagittal and axial orientation. Images were evaluated in consensus by two radiologists. Quantitative and qualitative criteria were assessed. A Mann-Whitney-U-Test and a regression analysis were used for statistical analysis. There were statistically significant differences between the patients with disorders and the control group concerning the depth (12.0 mm and 6.3 mm, p tendon, the area of the tendon cross section (1.60 mm (2) and 061 mm (2), p tendon depth (A4), length of bursa (A5) and area of tendon (F). The measurement of the Achilles tendon and the binary-logistic regression analysis allow differentiation between normal and pathological Achilles tendons. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Proximal tendon-prosthesis junction for active tendon implants of the hand: a biomechanical comparison of 2 techniques.

    Science.gov (United States)

    Thompson, Matthew J; Owen, John R; McDowell, Charles L; Wayne, Jennifer S

    2015-01-01

    To study the biomechanical characteristics (percent stretch, stiffness, and ultimate load) of 2 tendon-prosthesis techniques used to connect the proximal tendon stump to silicone active tendon implants used in reconstruction of flexor tendons. We evaluated percent stretch following cyclic loading and at failure, stiffness during load to failure, and ultimate load of 16 tendon-prosthesis junctions using cadaveric canine flexor digitorum profundus tendons to re-create 2 junction techniques: the tendon loop (TL) and the polyester weave (PW). The TL junction showed greater percent stretch at a static load of 2 N, following 500 cycles of loading between 2 N and 50 N, and at peak load. The PW junction displayed greater stiffness from 50 to 150 N during load to failure. Both junctions failed at a mean ultimate load greater than 220 N. The described proximal junction techniques for active tendon implants were strong enough to resist early active motion in the immediate postoperative period without significant elongation. The PW technique displayed greater stiffness and ultimate load compared with the TL. Data on tendon-prosthesis characteristics of these 2 methods may aid the surgeon in choosing which junction technique to use, during surgical tensioning decisions, and in considering activity protocols after surgery. These data may also serve as a baseline for further investigations regarding active tendon implants. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  1. Increased unilateral tendon stiffness and its effect on gait 2-6 years after Achilles tendon rupture.

    Science.gov (United States)

    Agres, A N; Duda, G N; Gehlen, T J; Arampatzis, A; Taylor, W R; Manegold, S

    2015-12-01

    Achilles tendon rupture (ATR) alters tissue composition, which may affect long-term tendon mechanics and ankle function during movement. However, a relationship between Achilles tendon (AT) properties and ankle joint function during gait remains unclear. The primary hypotheses were that (a) post-ATR tendon stiffness and length differ from the noninjured contralateral side and that (b) intra-patient asymmetries in AT properties correlate to ankle function asymmetries during gait, determined by ankle angles and moments. Ultrasonography and dynamometry were used to assess AT tendon stiffness, strain, elongation, and rest length in both limbs of 20 ATR patients 2-6 years after repair. Three-dimensional ankle angles and moments were determined using gait analysis. Injured tendons exhibited increased stiffness, rest length, and altered kinematics, with higher dorsiflexion and eversion, and lower plantarflexion and inversion. Intra-patient tendon stiffness and tendon length ratios were negatively correlated to intra-patient ratios of the maximum plantarflexion moment and maximum dorsiflexion angle, respectively. These results suggest that after surgical ATR repair, higher AT stiffness, but not a longer AT, may contribute to deficits in plantarflexion moment generation. These data further support the claim that post-ATR tendon regeneration results in the production of a tissue that is functionally different than noninjured tendon. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. A ganglion of the patellar tendon in patellar tendon-lateral femoral condyle friction syndrome.

    Science.gov (United States)

    Touraine, Sébastien; Lagadec, Matthieu; Petrover, David; Genah, Idan; Parlier-Cuau, Caroline; Bousson, Valérie; Laredo, Jean-Denis

    2013-09-01

    Intratendinous ganglia are rare. We report the case of a sedentary woman with chronic mechanical anterolateral pain of the knee and an extensive ganglion of the patellar tendon as indicated on magnetic resonance (MR) and ultrasound (US) examinations. There was evidence of a high-riding patella, patellar malalignment and patellar tendon-lateral femoral condyle friction syndrome with significantly close contact between the patellar tendon and the lateral facet of the femoral trochlea. The ultrasound-guided aspiration of the ganglion enabled a localized injection of an anti-inflammatory drug (cortivazol) and the cytopathological examination of the fluid, which confirmed the diagnosis. Clinical improvement was maintained with knee rehabilitation and was satisfactory at follow-up after 1 year. To our knowledge, we report the first case of a ganglion of the patellar tendon subsequent to patellar tendon-lateral femoral condyle friction syndrome. We found that this case was illustrative of mucoid degeneration in connective tissue due to chronic repetitive microtraumas. Additionally, this case provided the opportunity to discuss the management of this condition in a sedentary individual with a high-riding patella and patellar malalignment.

  3. Augmented Repair of Acute Achilles Tendon Rupture Using an Allograft Tendon Weaving Technique.

    Science.gov (United States)

    Huang, Xiaowei; Huang, Gan; Ji, Ying; Ao, Rong guang; Yu, Baoqing; Zhu, Ya Long

    2015-01-01

    Achilles tendon rupture is a common injury, especially in those who are physically active. Although open surgery is a widely used option for the treatment of acute Achilles tendon rupture, the optimal treatment is still disputed. In our study, 59 patients with unilateral, closed, acute rupture of the Achilles tendon were treated by open surgery using an allograft weave to augment the repair. All the surgeries were performed within 1 to 4 days after injury. The mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score was recorded as 91.20 (range 88 to 95), 95.34 (range 92 to 98), and 98.27 (range 97 to 99) at the 3-, 6-, and 12-month follow-up visit, respectively. At the final follow-up visit, the mean difference between the mid-calf circumference of the injured and uninjured legs was 0.19 (range -0.03 to 1.50) cm (p = .43). At the final follow-up visit, the mean difference between the vertical distances from the plantar surface of the heel to the ground for the injured and uninjured lower extremities was 0.44 (range -0.03 to 0.5) cm (p = .17). Augmented repair using the allograft tendon weaving technique provided satisfactory tendon strength and functional outcomes and a timely return to the patients' activities. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Fibrocartilage associated with human tendons and their pulleys.

    Science.gov (United States)

    Benjamin, M; Qin, S; Ralphs, J R

    1995-12-01

    The presence of fibrocartilage in tendons that wrap around bony or fibrous pulleys is well known. It is an adaptation to resisting compression or shear, but the extent to which the structure of most human tendons is modified where they contact pulleys is less clear, for there has been no single comprehensive survey of a large number of sites. Less is known of the structure of the corresponding pulleys. In the present study, 38 regions of tendons that wrap around bony pulleys or pass beneath fibrous retinacula have been studied in routine histology sections taken from each of 2 or 3 elderly dissecting room cadavers. Most of the corresponding pulleys have also been examined. Fibrocartilage was present in 22 of the 38 tendon sites and it was most conspicuous where the tendons pressed predominantly against bone rather than retinacula and where they showed a large change in direction. Fibrocartilage was more characteristic of tendons at the ankle than the wrist, probably because the long axis of the foot is at right angles to that of the leg. There was considerable variation in the structure of tendon fibrocartilage. The most fibrocartilaginous tendons had oval or round cells embedded in a highly metachromatic matrix with interwoven or spiralling collagen fibres. At other sites, fibrocartilage cells were arranged in rows between parallel collagen fibres. The differences probably relate to differences in development. A single tendon could be modified at successive points along its length and fibrocartilage could be present in the endotenon and epitenon as well as in the tendon itself. Pathological changes seen in 'wrap around' tendons were fragmentation and partial delamination of the compressed surface, chondrocyte clustering, fatty infiltration and bone formation. Three types of pulleys were described for tendons--bony prominences and grooves, fibrous retinacula and synovial joints. The extent of cartilaginous differentiation on the periosteum of bony pulleys

  5. Transformerless photovoltaic inverters with leakage current and pulsating power elimination

    DEFF Research Database (Denmark)

    Tang, Yi; Yao, Wenli; Wang, H.

    2015-01-01

    This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV-to-ground parasi......This paper presents a transformerless inverter topology, which is capable of simultaneously solving leakage current and pulsating power issues in grid-connected photovoltaic (PV) systems. Without adding any additional components to the system, the leakage current caused by the PV...

  6. Bifurcated intraarticular long head of biceps tendon

    Directory of Open Access Journals (Sweden)

    Vivek Pandey

    2014-01-01

    Full Text Available Though rare, many anomalous origins of long head of the biceps tendon (LHBT have been reported in the literature. Anatomic variations commonly explained are a third humeral head, anomalous insertion, congenital absence and adherence to the rotator cuff. We report a rare case who underwent shoulder arthroscopy with impingement symptoms where in LHBT was found to be bifurcated with a part attached to superior labrum and the other part to the posterior capsule of joint. Furthermore, intraarticular portion of LHBT was adherent to the undersurface of the supraspinatus tendon. Awareness of such an anatomical aberration during the shoulder arthroscopy is of great importance as it can potentially avoid unnecessary confusion and surgery.

  7. Motor responses to experimental Achilles tendon pain

    DEFF Research Database (Denmark)

    Henriksen, Marius; Aaboe, Jens; Graven-Nielsen, Thomas

    2011-01-01

    different days separated by 1 week, three-dimensional ground reaction forces, ankle joint kinematics and surface electromyography (EMG) of the lower leg muscles were recorded during one-legged full weight-bearing ankle plantar (concentric) and dorsal (eccentric) flexion exercises. Measurements were done...... before, during and after either experimental Achilles tendon pain or a non-painful control condition. Pain was induced by intratendinous injections of hypertonic saline with isotonic saline injections as control. Joint kinematics, ground reaction force frequency contents and average EMG amplitudes were...... calculated. Results Compared with the control condition experimental Achilles tendon pain reduced the EMG activity in agonistic, synergistic and antagonistic muscles, and increased the ground reaction force frequency content around 10 Hz, during both eccentric and concentric movement phases. Conclusions...

  8. [Animal experiment study of healing of the sutured flexor tendon].

    Science.gov (United States)

    Martini, A K; Blimke, B

    1992-01-01

    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. Effect of aging and exercise on the tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Heinemeier, Katja Maria; Couppé, Christian

    2016-01-01

    in humans, which likely reflects synthesis at the very periphery of the tendon rather than the core. Average collagen fibril diameter is largely unaffected by exercise, while there can be some hypertrophy of the whole tendon. In addition, it seems that resistance training can yield increased stiffness......Here, we review the literature on how tendons respond and adapt to ageing and exercise. With respect to aging, there are considerable changes early in life, but this seems to be maturation rather than aging per se. In vitro data indicate that aging is associated with a decreased potential for cell...... proliferation and a reduction in the number of stem/progenitor-like cells. Further, there is persuasive evidence that turnover in the core of the tendon after maturity is very slow or absent. Tendon fibril diameter, collagen content, and whole tendon size appear to be largely unchanged with aging, while...

  10. Congenital extensor tendon dislocation causing pseudotriggering of the little finger

    Directory of Open Access Journals (Sweden)

    Meriç Çırpar

    2017-10-01

    Full Text Available The main complaints in extensor tendon dislocations are pain, swelling, sense of discomfort, snapping and difficulty in writing and forceful flexion. However, congenital extensor tendon subluxations may present with triggering of the fingers due to tendon dislocations. Unnecessary A1 pulley release may be performed for pseudotriggerring with unsuccessful results. Here, we report an unusual case of congenital extensor tendon subluxation of multiple digits with triggering of the left little finger and aim to attract notice to pseudotriggering of the digits due to tendon dislocations. An extensor hood reconstruction performed by an extensor digitorum communis tendon slip which is passed beneath the deep intermetacarpal ligament is a successful choice of treatment for these patients.

  11. [Suture techniques and material in surgery of flexor tendons].

    Science.gov (United States)

    Pillukat, T; Fuhrmann, R; Windolf, J; van Schoonhoven, J

    2017-03-01

    Adhesions and scar formation between flexor tendons and the surrounding tissue are only contemporarily avoidable by movement of flexor tendons. Concepts with active follow-up protocols are more favorable than passive mobilization. The main risks of flexor tendon repair are rupture of the tendon suture, insidious gap formation and resistance to tendon gliding within the tendon sheath. Currently, there is no consensus with respect to the optimal suture technique or suture material. Nevertheless, there are some principles worth paying attention to, such as using stronger suture material, blocking stitches, suture techniques with four or more strands as well as circular running sutures. A technically acceptable compromise, even for the less experienced, is currently the four-strand suture combined with a circular running suture. It maintains sufficient stability for active motion follow-up protocols without resistance.

  12. The Achilles tendon: fundamental properties and mechanisms governing healing

    Science.gov (United States)

    Freedman, Benjamin R.; Gordon, Joshua A.; Soslowsky, Louis J.

    2014-01-01

    Summary This review highlights recent research on Achilles tendon healing, and comments on the current clinical controversy surrounding the diagnosis and treatment of injury. The processes of Achilles tendon healing, as demonstrated through changes in its structure, composition, and biomechanics, are reviewed. Finally, a review of tendon developmental biology and mechano transductive pathways is completed to recognize recent efforts to augment injured Achilles tendons, and to suggest potential future strategies for therapeutic intervention and functional tissue engineering. Despite an abundance of clinical evidence suggesting that current treatments and rehabilitation strategies for Achilles tendon ruptures are equivocal, significant questions remain to fully elucidate the basic science mechanisms governing Achilles tendon injury, healing, treatment, and rehabilitation. PMID:25332943

  13. Biceps femoris tendon injuries sustained while playing hockey

    OpenAIRE

    Watura, Christopher; Harries, William

    2011-01-01

    A 42-year-old female nurse presented in March 2008 with a left proximal hamstring tendon injury sustained while playing hockey. At surgery, the proximal biceps femoris tendon and semitendonosus were found to be ruptured and were repaired. The patient made a good recovery but sustained a further hockey injury in January 2010 involving a complete tear and rupture of the biceps femoris tendon distally. This was managed conservatively and the patient was able to return to playing hockey 10 months...

  14. Hamstring Tendon Regeneration After Harvesting: A Systematic Review.

    Science.gov (United States)

    Suijkerbuijk, Mathijs A M; Reijman, Max; Lodewijks, Susanne J M; Punt, Jorien; Meuffels, Duncan E

    2015-10-01

    Hamstring tendons are often used as autografts for anterior cruciate ligament (ACL) reconstruction. However, no systematic review has been performed describing consequences such as hamstring tendon regeneration rate and determinants of hamstring tendon regeneration. To summarize the current literature regarding hamstring tendon rate regeneration, the time course of regeneration, and determinants of hamstring regeneration. Systematic review. A search was performed in the Embase, Medline (OvidSP), Web of Science, Cochrane, PubMed, and Google Scholar databases up to June 2014 to identify relevant articles. A study was eligible if it met the following inclusion criteria: tendons were harvested, regeneration at harvest site was assessed, population size was at least 10 human subjects, full-text article was available, and the study design was either a randomized controlled trial, prospective cohort study, retrospective cohort study, or case control study. A risk of bias assessment of the eligible articles was determined. Data describing hamstring tendon regeneration rates were pooled per time period. A total of 18 publications met the inclusion criteria. The mean regeneration rate for the semitendinosus and gracilis tendons was, in all cases, 70% or higher. More than 1 year after harvesting, 79% (median [IQR], 80 [75.5-90]) of the semitendinosus tendons and 72% (median [IQR], 80 [61-88.5]) of the gracilis tendons were regenerated. No significant differences in regeneration rate could be found considering patient sex, age, height, weight, or duration of immobilization. Results did not clearly show whether absence of regeneration disadvantages the subsequent hamstring function. Five studies measured the regeneration rate at different moments in time. Hamstring tendons regenerated in the majority of patients after ACL reconstruction. The majority of the hamstring tendon regeneration was found to occur between 1 month and 1 year after harvest. No significant determinants for

  15. Inflammation activation and resolution in human tendon disease

    OpenAIRE

    Dakin, Stephanie G; Martinez, Fernando O; Yapp, Clarence; Wells, Graham; Oppermann, Udo; Dean, Benjamin JF; Smith, Richard DJ; Wheway, Kim; Watkins, Bridget; Roche, Lucy; Carr, Andrew J

    2015-01-01

    Improved understanding of the role of inflammation in tendon disease is required to facilitate therapeutic target discovery. We studied supraspinatus tendons from patients experiencing pain before and after surgical subacromial decompression treatment. Tendons were classified as having early, intermediate or advanced disease and inflammation was characterized through activation of pathways mediated by Interferon, NF-κB, glucocorticoid receptor and STAT-6. Inflammation signatures revealed expr...

  16. Isolated tear of the plantaris tendon: ultrasound and MRI appearance

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Stefano [CIM, Cabinet Imagerie Medicale, Geneva (Switzerland); Sailly, Matthieu [CIM, Cabinet Imagerie Medicale, Geneva (Switzerland); Health Center, ASPIRE, Doha (Qatar); Molini, Lucio [Ospedale Galliera, Struttura complessa di Radiodiagnostica, Genova (Italy)

    2011-07-15

    We report a retrospective analysis of the ultrasound and magnetic resonance imaging appearance of five patients with isolated plantaris tendon tears. Both imaging techniques allowed detection of the tear, assessment of its severity and of its location. Compared with magnetic resonance imaging, ultrasound resulted in a less expensive and time-consuming evaluation. Isolated plantaris tendon tears can clinically mimic Achilles tendon tears or thrombophlebitis. Unlike these conditions, plantaris tear has a benign outcome and does not need surgical treatment or anticoagulation. (orig.)

  17. Development of leakage monitoring system using radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. C.; Lee, D. S. [Seoil College, Seoul (Korea); Cho, Y. S. [Konyang University, Nonsan (Korea); Shin, S. K. [Sungkyunkwan Univ., Seoul (Korea)

    2000-04-01

    This study is to development the potable neutron back-scattering gauge for leakage and detecting liquid interface of an oil and liquid tank, using a radioisotopes. For this purpose, small sized, light weight potable gauge is to be designed as to develope neutron shielding mechanism, low power supply circuit, high voltage circuit, measurement circuit, and operating handle etc. The user will be able to set the duration of the time interval, the scale, the high voltage, the threshold, the channel window, the selection whether the data storage or not, the selection whether the scale, high voltage, threshold and window fix or not at any time. The counted pulse will be displayed with the numerical value and the line bar. The gauge will be able to connect to an IBM compatible PC via a serial port, power will be supplied by internal battery. 9 refs., 28 figs., 10 tabs. (Author)

  18. Markovian Processes for Quantitative Information Leakage

    DEFF Research Database (Denmark)

    Biondi, Fabrizio

    Quantification of information leakage is a successful approach for evaluating the security of a system. It models the system to be analyzed as a channel with the secret as the input and an output as observable by the attacker as the output, and applies information theory to quantify the amount...... of information transmitted through such channel, thus effectively quantifying how many bits of the secret can be inferred by the attacker by analyzing the system’s output. Channels are usually encoded as matrices of conditional probabilities, known as channel matrices. Such matrices grow exponentially...... in the size of the secret and observables, are cumbersome to compute and store, encode both the behavior of the system and assumptions about the attacker, and assume an input-output behavior of the system. For these reasons we propose to model the systemattacker scenario with Markovian models. We show...

  19. Fluid leakage near the percolation threshold

    Science.gov (United States)

    Dapp, Wolf B.; Müser, Martin H.

    2016-02-01

    Percolation is a concept widely used in many fields of research and refers to the propagation of substances through porous media (e.g., coffee filtering), or the behaviour of complex networks (e.g., spreading of diseases). Percolation theory asserts that most percolative processes are universal, that is, the emergent powerlaws only depend on the general, statistical features of the macroscopic system, but not on specific details of the random realisation. In contrast, our computer simulations of the leakage through a seal—applying common assumptions of elasticity, contact mechanics, and fluid dynamics—show that the critical behaviour (how the flow ceases near the sealing point) solely depends on the microscopic details of the last constriction. It appears fundamentally impossible to accurately predict from statistical properties of the surfaces alone how strongly we have to tighten a water tap to make it stop dripping and also how it starts dripping once we loosen it again.

  20. Use of the semitendinosus tendon for foot and ankle tendon reconstructions,

    Directory of Open Access Journals (Sweden)

    Frederico Lutti Guerra de Aguiar Zink

    2014-10-01

    Full Text Available Objective:To demonstrate the results obtained from foot and ankle tendon reconstructions using the tendon of the semitendinosus muscle. The clinical results, the patient's degree of satisfaction and complications in the graft donor and recipient areas were evaluated.Methods:This was a retrospective study in which the medical files of 38 patients who underwent this surgical procedure between 2006 and 2010 were surveyed. The functional results from this technique, the complications in the donor and recipient areas and the patients' degree of satisfaction were evaluated.Results:Three patients presented complications in the recipient area (skin necrosis; one patient showed complications in the donor area (pain and insensitivity; and all patients had satisfactory functional results, with complete range of motion.Conclusion:The semitendinosus muscle is a good option for treatments for foot and ankle tendon injuries.

  1. The histology of tendon attachments to bone in man.

    OpenAIRE

    Benjamin, M.; Evans, E. J.; Copp, L

    1986-01-01

    Based on a parallel study of a wide range of human tendons from embalmed dissecting room subjects and from a study of dried bones, an explanation is offered for the well known similarity in gross appearance between the markings left by certain tendons (e.g. those of the rotator cuff) and by articular surfaces on dried bones. Epiphyseal tendons leave markings on bones that look like those left by articular surfaces. These tendons have a prominent zone of fibrocartilage at their attachment site...

  2. Biology and augmentation of tendon-bone insertion repair

    Directory of Open Access Journals (Sweden)

    Lui PPY

    2010-08-01

    Full Text Available Abstract Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis" which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be paid to augment tendon to bone insertion (TBI healing. Apart from surgical fixation, biological and biophysical interventions have been studied aiming at regeneration of TBI healing complex, especially the regeneration of interpositioned fibrocartilage and new bone at the healing junction. This paper described the biology and the factors influencing TBI healing using patella-patellar tendon (PPT healing and tendon graft to bone tunnel healing in ACL reconstruction as examples. Recent development in the improvement of TBI healing and directions for future studies were also reviewed and discussed.

  3. Asymmetrical Achilles tendon ossification and rare rear heel pain

    Directory of Open Access Journals (Sweden)

    Md Abu Bakar Siddiq

    2017-03-01

    Full Text Available Achilles tendon ossification is not a frequent association of posterior heel pain in pain physicians’ daily practice. The condition has been reportedly common following rear heel trauma (repetitive heel stress injury, surgery (club foot surgery; however, some endocrino-metabolic, haematological disorders can also contribute to Achilles tendon ossification. Shape of ossified tendon mass varies from discrete (single/multiple to extensive variety; and as per literature review, in bilateral cases they are alike. To be intriguing, here in this write-up, we demonstrate asymmetrical (in terms of clinical features and radioimaging findings, bilateral Achilles tendon ossification in a 70-year-old retired farmer, first time in literature.

  4. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration.

    Science.gov (United States)

    Youngstrom, Daniel W; Barrett, Jennifer G

    2016-01-01

    Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS) possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems.

  5. Engineering Tendon: Scaffolds, Bioreactors, and Models of Regeneration

    Directory of Open Access Journals (Sweden)

    Daniel W. Youngstrom

    2016-01-01

    Full Text Available Tendons bridge muscle and bone, translating forces to the skeleton and increasing the safety and efficiency of locomotion. When tendons fail or degenerate, there are no effective pharmacological interventions. The lack of available options to treat damaged tendons has created a need to better understand and improve the repair process, particularly when suitable autologous donor tissue is unavailable for transplantation. Cells within tendon dynamically react to loading conditions and undergo phenotypic changes in response to mechanobiological stimuli. Tenocytes respond to ultrastructural topography and mechanical deformation via a complex set of behaviors involving force-sensitive membrane receptor activity, changes in cytoskeletal contractility, and transcriptional regulation. Effective ex vivo model systems are needed to emulate the native environment of a tissue and to translate cell-matrix forces with high fidelity. While early bioreactor designs have greatly expanded our knowledge of mechanotransduction, traditional scaffolds do not fully model the topography, composition, and mechanical properties of native tendon. Decellularized tendon is an ideal scaffold for cultivating replacement tissue and modeling tendon regeneration. Decellularized tendon scaffolds (DTS possess high clinical relevance, faithfully translate forces to the cellular scale, and have bulk material properties that match natural tissue. This review summarizes progress in tendon tissue engineering, with a focus on DTS and bioreactor systems.

  6. Nanoparticles for tendon healing and regeneration: literature review.

    Directory of Open Access Journals (Sweden)

    Paolo Domenico Parchi

    2016-08-01

    Full Text Available Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial and anti-inflammatory properties to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration

  7. A novel postoperative immobilization model for murine Achilles tendon sutures.

    Science.gov (United States)

    Shibuya, Yoichiro; Takayama, Yuzo; Kushige, Hiroko; Jacinto, Sandra; Sekido, Mitsuru; Kida, Yasuyuki S

    2016-08-01

    The body's motion and function are all in part effected by a vital tissue, the tendon. Tendon injury often results in limited functioning after postoperative procedures and even for a long time after rehabilitation. Although numerous studies have reported surgical procedures using animal models which have contributed to both basic and clinical research, modeling of tendon sutures or postoperative immobilizations has not been performed on small experimental animals, such as mice. In this study we have developed an easy Achilles tendon suture and postoperative ankle fixation model in a mouse. Right Achilles tendons were incised and 10-0 nylons were passed through the proximal and distal ends using a modified Kessler method. Subsequently, the right ankle was immobilized in a plantarflexed position with novel splints, which were made from readily available extension tubes. Restriction of the tendon using handmade splints reduced swelling, as opposed to fixating with the usual plaster of Paris. Using this method, the usage of the right Achilles tendons began on postoperative days 13.5 ± 4.6, which indicated healing within two weeks. Therefore our simple short-term murine Achilles tendon suture procedure is useful for studying immediate tendon repair mechanisms in various models, including genetically-modified mice. © The Author(s) 2015.

  8. Tendon progenitor cells in injured tendons have strong chondrogenic potential: the CD105-negative subpopulation induces chondrogenic degeneration.

    Science.gov (United States)

    Asai, Shuji; Otsuru, Satoru; Candela, Maria Elena; Cantley, Leslie; Uchibe, Kenta; Hofmann, Ted J; Zhang, Kairui; Wapner, Keith L; Soslowsky, Louis J; Horwitz, Edwin M; Enomoto-Iwamoto, Motomi

    2014-12-01

    To study the cellular mechanism of the tendon repair process, we used a mouse Achilles tendon injury model to focus on the cells recruited to the injured site. The cells isolated from injured tendon 1 week after the surgery and uninjured tendons contained the connective tissue progenitor populations as determined by colony-forming capacity, cell surface markers, and multipotency. When the injured tendon-derived progenitor cells (inTPCs) were transplanted into injured Achilles tendons, they were not only integrated in the regenerating area expressing tenogenic phenotype but also trans-differentiated into chondrogenic cells in the degenerative lesion that underwent ectopic endochondral ossification. Surprisingly, the micromass culture of the inTPCs rapidly underwent chondrogenic differentiation even in the absence of exogenous bone morphogenetic proteins or TGFβs. The cells isolated from human ruptured tendon tissues also showed connective tissue progenitor properties and exhibited stronger chondrogenic ability than bone marrow stromal cells. The mouse inTPCs contained two subpopulations one positive and one negative for CD105, a coreceptor of the TGFβ superfamily. The CD105-negative cells showed superior chondrogenic potential in vitro and induced larger chondroid degenerative lesions in mice as compared to the CD105-positive cells. These findings indicate that tendon progenitor cells are recruited to the injured site of tendons and have a strong chondrogenic potential and that the CD105-negative population of these cells would be the cause for chondroid degeneration in injured tendons. The newly identified cells recruited to the injured tendon may provide novel targets to develop therapeutic strategies to facilitate tendon repair. © 2014 AlphaMed Press.

  9. In vivo passive mechanical behaviour of muscle fascicles and tendons in human gastrocnemius muscle-tendon units.

    Science.gov (United States)

    Herbert, Robert D; Clarke, Jillian; Kwah, Li Khim; Diong, Joanna; Martin, Josh; Clarke, Elizabeth C; Bilston, Lynne E; Gandevia, Simon C

    2011-11-01

    Ultrasound imaging was used to measure the length of muscle fascicles in human gastrocnemius muscles while the muscle was passively lengthened and shortened by moving the ankle. In some subjects the muscle belly 'buckled' at short lengths. When the gastrocnemius muscle-tendon unit was passively lengthened from its shortest in vivo length by dorsiflexing the ankle, increases in muscle-tendon length were not initially accompanied by increases in muscle fascicle lengths (fascicle length remained constant), indicating muscle fascicles were slack at short muscle-tendon lengths. The muscle-tendon length at which slack is taken up differs among fascicles: some fascicles begin to lengthen at very short muscle-tendon lengths whereas other fascicles remain slack over a large range of muscle-tendon lengths. This suggests muscle fascicles are progressively 'recruited' and contribute sequentially to muscle-tendon stiffness during passive lengthening of the muscle-tendon unit. Even above their slack lengths muscle fascicles contribute only a small part (tendon length. The contribution of muscle fascicles to muscle-tendon length increases with muscle length. The novelty of this work is that it reveals a previously unrecognised phenomenon (buckling at short lengths), posits a new mechanism of passive mechanical properties of muscle (recruitment of muscle fascicles), and confirms with high-resolution measurements that the passive compliance of human gastrocnemius muscle-tendon units is due largely to the tendon. It would be interesting to investigate if adaptations of passive properties of muscles are associated with changes in the distribution of muscle lengths at which fascicles fall slack.

  10. The promoting effect of pentadecapeptide BPC 157 on tendon healing involves tendon outgrowth, cell survival, and cell migration.

    Science.gov (United States)

    Chang, Chung-Hsun; Tsai, Wen-Chung; Lin, Miao-Sui; Hsu, Ya-Hui; Pang, Jong-Hwei Su

    2011-03-01

    Pentadecapeptide BPC 157, composed of 15 amino acids, is a partial sequence of body protection compound (BPC) that is discovered in and isolated from human gastric juice. Experimentally it has been demonstrated to accelerate the healing of many different wounds, including transected rat Achilles tendon. This study was designed to investigate the potential mechanism of BPC 157 to enhance healing of injured tendon. The outgrowth of tendon fibroblasts from tendon explants cultured with or without BPC 157 was examined. Results showed that BPC 157 significantly accelerated the outgrowth of tendon explants. Cell proliferation of cultured tendon fibroblasts derived from rat Achilles tendon was not directly affected by BPC 157 as evaluated by MTT assay. However, the survival of BPC 157-treated cells was significantly increased under the H(2)O(2) stress. BPC 157 markedly increased the in vitro migration of tendon fibroblasts in a dose-dependent manner as revealed by transwell filter migration assay. BPC 157 also dose dependently accelerated the spreading of tendon fibroblasts on culture dishes. The F-actin formation as detected by FITC-phalloidin staining was induced in BPC 157-treated fibroblasts. The protein expression and activation of FAK and paxillin were determined by Western blot analysis, and the phosphorylation levels of both FAK and paxillin were dose dependently increased by BPC 157 while the total amounts of protein was unaltered. In conclusion, BPC 157 promotes the ex vivo outgrowth of tendon fibroblasts from tendon explants, cell survival under stress, and the in vitro migration of tendon fibroblasts, which is likely mediated by the activation of the FAK-paxillin pathway.

  11. The Effect of Phospholipids (Surfactant on Adhesion and Biomechanical Properties of Tendon: A Rat Achilles Tendon Repair Model

    Directory of Open Access Journals (Sweden)

    T. Kursat Dabak

    2015-01-01

    Full Text Available Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p0.008. Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon.

  12. Time-Dependent Alterations of MMPs, TIMPs and Tendon Structure in Human Achilles Tendons after Acute Rupture.

    Science.gov (United States)

    Minkwitz, Susann; Schmock, Aysha; Kurtoglu, Alper; Tsitsilonis, Serafeim; Manegold, Sebastian; Wildemann, Britt; Klatte-Schulz, Franka

    2017-10-20

    A balance between matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) is required to maintain tendon homeostasis. Variation in this balance over time might impact on the success of tendon healing. This study aimed to analyze structural changes and the expression profile of MMPs and TIMPs in human Achilles tendons at different time-points after rupture. Biopsies from 37 patients with acute Achilles tendon rupture were taken at surgery and grouped according to time after rupture: early (2-4 days), middle (5-6 days), and late (≥7 days), and intact Achilles tendons served as control. The histological score increased from the early to the late time-point after rupture, indicating the progression towards a more degenerative status. In comparison to intact tendons, qRT-PCR analysis revealed a significantly increased expression of MMP-1, -2, -13, TIMP-1, COL1A1, and COL3A1 in ruptured tendons, whereas TIMP-3 decreased. Comparing the changes over time post rupture, the expression of MMP-9, -13, and COL1A1 significantly increased, whereas MMP-3 and -10 expression decreased. TIMP expression was not significantly altered over time. MMP staining by immunohistochemistry was positive in the ruptured tendons exemplarily analyzed from early and late time-points. The study demonstrates a pivotal contribution of all investigated MMPs and TIMP-1, but a minor role of TIMP-2, -3, and -4, in the early human tendon healing process.

  13. Time-Dependent Alterations of MMPs, TIMPs and Tendon Structure in Human Achilles Tendons after Acute Rupture

    Science.gov (United States)

    Minkwitz, Susann; Schmock, Aysha; Kurtoglu, Alper; Tsitsilonis, Serafeim; Manegold, Sebastian; Klatte-Schulz, Franka

    2017-01-01

    A balance between matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) is required to maintain tendon homeostasis. Variation in this balance over time might impact on the success of tendon healing. This study aimed to analyze structural changes and the expression profile of MMPs and TIMPs in human Achilles tendons at different time-points after rupture. Biopsies from 37 patients with acute Achilles tendon rupture were taken at surgery and grouped according to time after rupture: early (2–4 days), middle (5–6 days), and late (≥7 days), and intact Achilles tendons served as control. The histological score increased from the early to the late time-point after rupture, indicating the progression towards a more degenerative status. In comparison to intact tendons, qRT-PCR analysis revealed a significantly increased expression of MMP-1, -2, -13, TIMP-1, COL1A1, and COL3A1 in ruptured tendons, whereas TIMP-3 decreased. Comparing the changes over time post rupture, the expression of MMP-9, -13, and COL1A1 significantly increased, whereas MMP-3 and -10 expression decreased. TIMP expression was not significantly altered over time. MMP staining by immunohistochemistry was positive in the ruptured tendons exemplarily analyzed from early and late time-points. The study demonstrates a pivotal contribution of all investigated MMPs and TIMP-1, but a minor role of TIMP-2, -3, and -4, in the early human tendon healing process. PMID:29053586

  14. An observed 20-year time series of Agulhas leakage

    NARCIS (Netherlands)

    Le Bars, D.; Durgadoo, J. V.; Dijkstra, H. A.; Biastoch, A.; De Ruijter, W. P M

    2014-01-01

    We provide a time series of Agulhas leakage anomalies over the last 20-years from satellite altimetry. Until now, measuring the interannual variability of Indo-Atlantic exchange has been the major barrier in the investigation of the dynamics and large scale impact of Agulhas leakage. We compute the

  15. Leakage-Resilient Cryptography from the Inner-Product Extractor

    DEFF Research Database (Denmark)

    Dziembowski, Stefan; Faust, Sebastian

    2011-01-01

    We present a generic method to secure various widely-used cryptosystems against arbitrary side-channel leakage, as long as the leakage adheres three restrictions: first, it is bounded per observation but in total can be arbitrary large. Second, memory parts leak independently, and, third, the ran...

  16. Contrast media for radiological examination in gastrointestinal tract leakage

    NARCIS (Netherlands)

    A.Z. Ginai (Abida)

    1987-01-01

    textabstractThe aim of this investigation has been to find a safe and suitable contrast medium for radiological evaluation of the gastrointestinal tract in cases where leakage outside the GIT can be suspected. Leakage outside the gastro-intestinal tract lumen can occur in many ways eg.,

  17. Macrophage migration inhibitory factor induces vascular leakage via autophagy

    Directory of Open Access Journals (Sweden)

    Hong-Ru Chen

    2015-01-01

    Full Text Available Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF, we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA, a ROS scavenger (NAC or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

  18. Late anastomotic leakage in colorectal surgery : a significant problem

    NARCIS (Netherlands)

    Morks, A. N.; Ploeg, R. J.; Hofker, H. Sijbrand; Wiggers, T.; Havenga, K.

    Aim Reported incidence rates of colorectal anastomotic leakage (AL) vary between 2.5 and 20%. There is little information on late anastomotic leakage (LAL). The aim of this study was to determine the incidence of LAL after colorectal resection. Method All patients undergoing colorectal resection

  19. Continuous leakage measurement during hyperthermic isolated limb perfusion

    NARCIS (Netherlands)

    Daryanani, D; Komdeur, R; Ter Veen, J; Nijhuis, PH; Piers, DA; Hoekstra, HJ

    Background: Continuous measurement of perfusate leakage into the systemic circulation is of the utmost importance and can be performed with the help of radioactive tracers. The purpose of this study was to assess changes in the perfusion leakage rate between two periods: 1977-1990 and 1991-2000, and

  20. Science to Practice: Quantitative US Elastography Can Be Used to Quantify Mechanical and Histologic Tendon Healing in a Rabbit Model of Achilles Tendon Transection.

    Science.gov (United States)

    Lee, Kenneth S; Martin, Jack; Thelen, Darryl

    2017-05-01

    Compression-based ultrasonographic (US) elastography is associated with time-dependent mechanical and histologic changes of the healing tendon in a transected rabbit model of the Achilles tendon. This finding will lead to continued development of quantitative US, which can be used to objectively assess a diseased or healing tendon. With advances in the method used, clinical translation of tendon elastography may enable clinicians to diagnose tendon damage and track healing, which should improve both treatment and outcome.

  1. Insulator Contamination Forecasting Based on Fractal Analysis of Leakage Current

    Directory of Open Access Journals (Sweden)

    Bing Luo

    2012-07-01

    Full Text Available In this paper, an artificial pollution test is carried out to study the leakage current of porcelain insulators. Fractal theory is adopted to extract the characteristics hidden in leakage current waveforms. Fractal dimensions of the leakage current for the security, forecast and danger zones are analyzed under four types of degrees of contamination. The mean value and the standard deviation of the fractal dimension in the forecast zone are calculated to characterize the differences. The analysis reveals large differences in the fractal dimension of leakage current under different contamination discharge stages and degrees. The experimental and calculation results suggest that the fractal dimension of a leakage current waveform can be used as a new indicator of the discharge process and contamination degree of insulators. The results provide new methods and valid indicators for forecasting contamination flashovers.

  2. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  3. The development of zebrafish tendon and ligament progenitors

    Science.gov (United States)

    Chen, Jessica W.; Galloway, Jenna L.

    2014-01-01

    Despite the importance of tendons and ligaments for transmitting movement and providing stability to the musculoskeletal system, their development is considerably less well understood than that of the tissues they serve to connect. Zebrafish have been widely used to address questions in muscle and skeletal development, yet few studies describe their tendon and ligament tissues. We have analyzed in zebrafish the expression of several genes known to be enriched in mammalian tendons and ligaments, including scleraxis (scx), collagen 1a2 (col1a2) and tenomodulin (tnmd), or in the tendon-like myosepta of the zebrafish (xirp2a). Co-expression studies with muscle and cartilage markers demonstrate the presence of scxa, col1a2 and tnmd at sites between the developing muscle and cartilage, and xirp2a at the myotendinous junctions. We determined that the zebrafish craniofacial tendon and ligament progenitors are neural crest derived, as in mammals. Cranial and fin tendon progenitors can be induced in the absence of differentiated muscle or cartilage, although neighboring muscle and cartilage are required for tendon cell maintenance and organization, respectively. By contrast, myoseptal scxa expression requires muscle for its initiation. Together, these data suggest a conserved role for muscle in tendon development. Based on the similarities in gene expression, morphology, collagen ultrastructural arrangement and developmental regulation with that of mammalian tendons, we conclude that the zebrafish tendon populations are homologous to their force-transmitting counterparts in higher vertebrates. Within this context, the zebrafish model can be used to provide new avenues for studying tendon biology in a vertebrate genetic system. PMID:24803652

  4. Air leakage in refrigerated vans: report of confirmation tests conducted with the prototype air leakage test set

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    The objective of the work described was to evaluate the utility of the Prototype Air Leakage Test Set constructed for the United States Department of Energy under this contract, and to compare the air leakage data obtained by use of the Test Set to that obtained by use of three different, existing test equipments at three manufacturers of trailers and containers.

  5. Human flexor tendon tissue engineering: decellularization of human flexor tendons reduces immunogenicity in vivo.

    Science.gov (United States)

    Raghavan, Shyam S; Woon, Colin Y L; Kraus, Armin; Megerle, Kai; Choi, Matthew S S; Pridgen, Brian C; Pham, Hung; Chang, James

    2012-04-01

    In mutilating hand injuries, tissue engineered tendon grafts may provide a reconstructive solution. We have previously described a method to decellularize cadaveric human flexor tendons while preserving mechanical properties and biocompatibility. The purpose of this study is to evaluate the immunogenicity and strength of these grafts when implanted into an immunocompetent rat model. Cadaveric human flexor tendons were divided into two groups. Group 1 was untreated, and Group 2 was decellularized by treatment with sodium dodecyl sulfate (SDS), ethylenediaminetetraacetic acid (EDTA), and peracetic acid (PAA). Both groups were then analyzed for the presence of major histocompatibility complexes by immunohistochemistry (IHC). Pair-matched tendons from each group were then placed into the dorsal subcutaneous tissue and anchored to the spinal ligaments of Wistar rats for 2 or 4 weeks, and harvested. The infiltration of B-cells and macrophages was determined using IHC. The explants where then subjected to mechanical testing to determine the ultimate tensile stress (UTS) and elastic modulus (EM). Statistical analysis was performed using a paired Student's t-test. The decellularization protocol successfully removed cells and MHC-1 complexes. At 2 weeks after implantation, there was increased infiltration of B-cells in Group 1 (untreated) compared with Group 2 (acellular), both in the capsule and tendon substance. There was improved ultimate tensile stress (UTS, 42.7 ± 8.3 vs. 22.8 ± 7.8 MPa, ptendons that were decellularized. At 4 weeks, there was continued B-cell infiltration in Group 1 (untreated) compared with Group 2 (acellular). There was no appreciable difference in macrophage infiltration at both time points. At 4 weeks Group 2 (acellular) demonstrated persistently greater UTS (40.5 ± 9.1 vs. 14.6 ± 4.2 MPa, ptendons that were decellularized with SDS, EDTA, and PAA resulted in removal of cellular antigens and a decreased immune response when placed into Wistar

  6. Minimally invasive reconstruction of chronic achilles tendon ruptures using the ipsilateral free semitendinosus tendon graft and interference screw fixation.

    Science.gov (United States)

    Maffulli, Nicola; Loppini, Mattia; Longo, Umile Giuseppe; Maffulli, Gayle D; Denaro, Vincenzo

    2013-05-01

    Achilles tendon ruptures represent more than 40% of all tendon ruptures requiring surgical management. About 20% of acute Achilles tendon tears are not diagnosed at the time of injury and become chronic, necessitating more complicated management than fresh injuries. Several techniques for the reconstruction of chronic tears of the Achilles tendon have been described, but the superiority of one technique over the others has not been demonstrated. Mini-invasive reconstruction of the Achilles tendon, with a gap lesion larger than 6 cm, using the ipsilateral free semitendinosus tendon graft will result in improvement of the overall function with a low rate of complications. Case series; Level of evidence, 4. Between 2008 and 2010, the authors prospectively enrolled 28 consecutive patients (21 men and 7 women; median age, 46 years) with chronic closed ruptures of the Achilles tendon who had undergone reconstruction with a free semitendinosus tendon graft. They assessed the Achilles tendon Total Rupture Score (ATRS), maximum calf circumference, and isometric plantarflexion strength before surgery and at the last follow-up. Outcome of surgery and rate of complications were also recorded. The median follow-up after surgery was 31.4 months. The overall result of surgery was excellent/good in 26 (93%) of 28 patients. The ATRS improved from 42 (range, 29-55) to 86 (range, 78-95) (P tendon, with a gap lesion larger than 6 cm, using the ipsilateral free semitendinosus tendon graft provides a significant improvement of symptoms and function, although calf circumference and ankle plantarflexion strength do not recover fully.

  7. Bilateral simultaneous spontaneous rupture of the quadriceps tendons

    African Journals Online (AJOL)

    simultaneous rupture of the quadriceps tendons. The injury occurs most often in elderly people and delay in the diagnosis is not uncommon. Early operative repair is recommended. By using a metal wire passing through a transverse hole in the superior pole of the patella and through the tendon proximal to the repair site, ...

  8. Rehabilitation of tendon problems in patients with diabetes mellitus

    NARCIS (Netherlands)

    Rees, Jonathan; Gaida, Jamie E.; Silbernagel, Karin Grävare; Zwerver, Johannes; Anthony, Joseph S.; Scott, Alex; Ackermann, PW; Hart, DA

    2016-01-01

    Exercise is crucial in the management of diabetes mellitus and its associated complications. However, individuals with diabetes have a heightened risk of musculoskeletal problems, including tendon pathologies. Diabetes has a significant impact on the function of tendons due to the accumulation of

  9. Intratendinous Ganglion of the Extensor Tendon of the Hand.

    Science.gov (United States)

    Lee, Hyun-Joo; Kim, Poong-Taek; Chang, Hyo-Won

    2015-01-01

    Ganglion is a common benign lesion that usually arises adjacent to the joints or tendons of the hand. However, an intratendinous ganglion is a rare condition. We report two cases of intratendinous ganglion of the extensor tendon of the hand which were treated with excision.

  10. Surgical management of acute quadriceps tendon rupture (a case ...

    African Journals Online (AJOL)

    Surgical repair is realized in emergency to completely restore the extension. We report a case of a patient who has sustained of complete quadriceps tendon tear after a long period of tendon weakening by statin therapy, hypertension and diabetes. The repair has consisted on end-to-end Krackow sutures associated with ...

  11. Reliability of the clinical and electromyographic examination of tendon reflexes

    NARCIS (Netherlands)

    Stam, J.; van Crevel, H.

    1990-01-01

    The reliability of clinical examination of the tendon reflexes was examined by studying inter-observer agreement. Twenty patients were examined by three neurologists. The briskness of the tendon reflexes in arms and legs was scored on a nine-point scale. In 28% of the 160 examined reflexes the

  12. Avulsion of subscapularis muscle tendon leading to recurrent ...

    African Journals Online (AJOL)

    Key words: sho~~lder, recurrent dislocation, subscapularis tendon avulsion. Fifteen patients, ten ... The dislocation was found to be due to a complete tear of the subscapularis tendon (12 patients) and partial tears in three patients, without fracture of the lesser tuberosity ... Exercises to strengthen the internal rotator muscles ...

  13. Tendon needling for treatment of tendinopathy: A systematic review.

    Science.gov (United States)

    Krey, David; Borchers, James; McCamey, Kendra

    2015-02-01

    To summarize the best available evidence to determine if tendon needling is an effective treatment for tendinopathy. Data source. Medline and Cochrane Databases through November 2013. Utilizing the search terms tendinopathy, needle, needling, tenotomy, dry needling, needling tendon, needle fenestration, and tendon fenestration, 17 articles were identified through our systematic literature search. Of these, 4 studies met the inclusion criteria. Four independent reviewers reviewed the articles. The study results and generated conclusions were agreed upon. The studies that were included in this review suggest that tendon needling improves patient reported outcomes in patients with tendinopathy. In 2 studies evaluating tendon needling in lateral epicondylosis, one showed an improvement in a subjective visual analogue scale score of 34% (significant change > 25%) from baseline at 6 months. The other showed an improvement of 56.1% in a visual analogue scale score from baseline. In 1 study evaluating tendon needling in addition to eccentric therapy for Achilles tendinosis, the subjective Victorian Institute of Sport Assessment-Achilles (VISA-A) score improved by 19.9 (significant change > 10) (95% CI, 13.6-26.2) from baseline. In 1 study evaluating tendon needling in rotator cuff tendinosis, the subjective shoulder pain and disability index showed statistical significant improvement from baseline at 6 months (P < 0.05). The evidence suggests that tendon needling improves patient-reported outcome measures in patients with tendinopathy. There is a trend that shows that the addition of autologous blood products may further improve theses outcomes.

  14. Case Report:Triceps Tendon Avulsion: A Rare Injury | Sharma ...

    African Journals Online (AJOL)

    Background: Triceps tendon avulsion is one of the rare tendinous injuries. Such injuries can easily be missed, and should be kept as a differential diagnosis in all patients who present with pain and swelling at the back of the elbow after a traumatic event. Case Details: We present a case of triceps tendon avulsion which ...

  15. Rare causes of closed rupture of the flexor tendon

    NARCIS (Netherlands)

    Stenekes, Martin W.; Ruttermann, Mike; Werker, Paul M. N.

    Closed injuries to the flexor tendon are relatively rare. We present three rare causes of closed injury to the flexor tendon. Early recognition and adequate treatment by a specialised hand surgeon are crucial for the prognosis of such cases. Delayed diagnosis and treatment often require secondary

  16. Development of Mechanical Anchor for CFRP Tendons Using Integrated Sleeve

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Bennitz, Anders; Täljsten, Björn

    2010-01-01

    A durable and very efficient external strengthening system is achieved if steel tendons for post-tensioning applications can be replaced with CFRP (Carbon Fibre Reinforced Polymer) tendons and if reliable anchorage systems are developed,. This paper presents a newly developed and simple-to-use tw...

  17. Closed rupture of the thumb flexor tendon pulleys.

    Science.gov (United States)

    Wilson, S M; Roulot, E; Le Viet, D

    2005-12-01

    Closed flexor tendon pulley ruptures are relatively rare injuries. All previously reported cases have been in the long finger pulleys. To our knowledge, there has not been a case of closed thumb flexor tendon pulley rupture reported in the literature. This paper presents two cases of this pathology and discusses appropriate treatment of it.

  18. Tendon Cell Behavior and Matrix Remodeling in Degenerative Tendinopathy

    NARCIS (Netherlands)

    M. de Mos (Marieke)

    2009-01-01

    textabstractTendon injuries are common in human athletes [1-4]. Furthermore, such injuries are also prevalent in the ageing sedentary population [5-7]. In recent decades, the incidence of tendon injuries has risen due to both an increase in an elderly population and a rise in participation

  19. Painful snapping hip owing to bifid iliopsoas tendon and concurrent ...

    African Journals Online (AJOL)

    2015-05-22

    May 22, 2015 ... A case of internal snapping hip owing to a bifid iliopsoas tendon is described with a concurrent labral tear in a young active female. The labral tear was identified on magnetic resonance imaging, and the snapping bifid tendon on dynamic ultrasound. The patient was administered bupivicaine and steroid ...

  20. Surgical Strategy for the Chronic Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Yangjing Lin

    2016-01-01

    Full Text Available Background. Chronic Achilles tendon rupture is usually misdiagnosed and treated improperly. This study aims to better understand the treatment of chronic Achilles tendon rupture. Methods. Patients who were not able to perform a single-limb heel rise were chosen. Pre- and postoperative magnetic resonance imaging (MRI were conducted. By evaluating the presence or absence of Achilles tendon stumps and the gap length of rupture, V-Y advancement, gastrocnemius fascial turndown flap, or flexor halluces longus tendon transfer were selected for tendon repair. The function of ankle and foot was assessed by American Orthopaedic Foot & Ankle Society (AOFAS ankle-hindfoot scores and Achilles Tendon Total Rupture Score (ATRS. Results. Twenty-nine patients were followed up. One patient had superficial incision infection, which was healed after debridement and oral antibiotics. Three months postoperatively, MRI showed some signs of inflammation, which disappeared at one or two years postoperatively. All patients were able to perform a single-limb heel rise. Mean AOFAS scores and ATRS scores were increased at the latest follow-up. Conclusion. Surgical options can be determined by evaluating the presence of the Achilles tendon stumps and the gap length, which can avoid using the nearby tendon and yield satisfactory functional results.

  1. Surgical Strategy for the Chronic Achilles Tendon Rupture

    Science.gov (United States)

    Yang, Liu; Yin, Li

    2016-01-01

    Background. Chronic Achilles tendon rupture is usually misdiagnosed and treated improperly. This study aims to better understand the treatment of chronic Achilles tendon rupture. Methods. Patients who were not able to perform a single-limb heel rise were chosen. Pre- and postoperative magnetic resonance imaging (MRI) were conducted. By evaluating the presence or absence of Achilles tendon stumps and the gap length of rupture, V-Y advancement, gastrocnemius fascial turndown flap, or flexor halluces longus tendon transfer were selected for tendon repair. The function of ankle and foot was assessed by American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores and Achilles Tendon Total Rupture Score (ATRS). Results. Twenty-nine patients were followed up. One patient had superficial incision infection, which was healed after debridement and oral antibiotics. Three months postoperatively, MRI showed some signs of inflammation, which disappeared at one or two years postoperatively. All patients were able to perform a single-limb heel rise. Mean AOFAS scores and ATRS scores were increased at the latest follow-up. Conclusion. Surgical options can be determined by evaluating the presence of the Achilles tendon stumps and the gap length, which can avoid using the nearby tendon and yield satisfactory functional results. PMID:27847806

  2. Isolated limb perfusion with cytostatic drug leakage.

    Science.gov (United States)

    Zarazua, M; Paredes, P; Gahete-Santiago, F; Rull, R; Blasi, A; Balust, J

    2017-07-25

    Isolated limb perfusion is the treatment of stage III melanoma with in-transit metastasis. This technique allows the administration of cytostatics at an effective concentration and temperature, which could not be administered systemically because of their toxicity. The toxicity due to leakage of the chemotherapy agent from the limb into the systemic circulation is the most serious short-term complication, and is manifested by a systemic inflammatory response syndrome in the immediate post-intervention period. Early detection of this complication and its peri-operative management requires a multidisciplinary approach, in which the anaesthesiologist plays a key role. A case of isolated lower limb perfusion is reported in which the procedure had to be interrupted due to the passage of tumour necrosis factor into the systemic circulation, with severe intra-operative haemodynamic repercussions. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Quantum Speed Limits for Leakage and Decoherence.

    Science.gov (United States)

    Marvian, Iman; Lidar, Daniel A

    2015-11-20

    We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.

  4. Insulin Antagonizes Thrombin-Induced Microvessel Leakage.

    Science.gov (United States)

    Liu, Yan; Chen, Xue Lian; Wang, Lei; Martins-Green, Manuela

    2017-01-01

    Sustained increase in microvessel permeability results in cell and tissue damage. To date, it has not been possible to safely and specifically block increased microvessel permeability in vivo. We showed that insulin stimulates angiogenesis and that the new microvessels are associated with more αSMA-producing cells, suggesting greater stability. In this study, we show that local injection of insulin under the skin of mice significantly inhibits thrombin-induced microvessel permeability and that insulin improves the barrier function of primary human endothelial cells under conditions that mimic endothelium in vivo. These findings indicate that insulin antagonizes thrombin-induced microvessel permeability. At the cell and molecular levels, we show that insulin interferes with thrombin-induced VE-cadherin signaling by decreasing the ability of thrombin to induce VE-cadherin translocation to the cytoskeleton/nuclear compartment, leading to microvessel leakage. Simultaneously, the rapid activation of Src by insulin followed by the activation of Rac1, a small GTPase involved in cytoskeletal reorganization, leads to the maintenance of endothelial barrier, short-circuiting the slower thrombin-induced Src-RhoA signaling that leads to endothelial permeability. This novel mechanism by which insulin inhibits thrombin-induced permeability provides support for the use of insulin treatment in pathological conditions that involve blood-barrier dysfunction, especially as resuscitation treatment methods for extensive burns, sepsis, and other severe pathological conditions. © 2017 S. Karger AG, Basel.

  5. Modeling colorant leakage techniques: application to endodontics.

    Science.gov (United States)

    Romieu, Olivier J; Zimányi, László; Warszyński, Piotr; Levallois, Bernard; Cuisinier, Frédéric J; de Périère, Dominique Deville; Jacquot, Bruno

    2010-09-01

    Our aim was to improve the comprehension of in vitro tracer leakage studies and to determine in which conditions such studies can be reliable. We aimed to develop different theoretical models to describe either an initially dry or a wet interface (slit) between sealer and dentin. Equations based on physical laws were derived to model theoretically in vitro tracer penetration. For the dry interfaces, atmospheric, hydrostatic, tracer gravimetric, capillary and internal air pressures were considered as the underlying forces that control tracer penetration. For wet interfaces, the laws of diffusion were used to model colorant penetration. In both cases penetration is influenced by the width of the interface and by the size of the colorant. Calculations for dry conditions have shown that penetration is quick, mainly driven by the capillary pressure, and the penetration increases as the width of the interface diminishes. Dentinal tubules and the extent of their interconnection modify the penetration depth. For wet conditions, tracer size is the main factor controlling the penetration length and speed (the bigger the tracer, the slower the penetration). Our model calculations demonstrate that tracer penetration studies have to be performed under strict experimental conditions. Dry and wet interfaces are two extreme cases with very different tracer penetration modes. In vitro colorant penetration tests should be performed in both of these conditions avoiding cases where the slit contains both air and water. Theses models can be adapted to other dental situations as well. Copyright 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Thermal image analysis for detecting facemask leakage

    Science.gov (United States)

    Dowdall, Jonathan B.; Pavlidis, Ioannis T.; Levine, James

    2005-03-01

    Due to the modern advent of near ubiquitous accessibility to rapid international transportation the epidemiologic trends of highly communicable diseases can be devastating. With the recent emergence of diseases matching this pattern, such as Severe Acute Respiratory Syndrome (SARS), an area of overt concern has been the transmission of infection through respiratory droplets. Approved facemasks are typically effective physical barriers for preventing the spread of viruses through droplets, but breaches in a mask"s integrity can lead to an elevated risk of exposure and subsequent infection. Quality control mechanisms in place during the manufacturing process insure that masks are defect free when leaving the factory, but there remains little to detect damage caused by transportation or during usage. A system that could monitor masks in real-time while they were in use would facilitate a more secure environment for treatment and screening. To fulfill this necessity, we have devised a touchless method to detect mask breaches in real-time by utilizing the emissive properties of the mask in the thermal infrared spectrum. Specifically, we use a specialized thermal imaging system to detect minute air leakage in masks based on the principles of heat transfer and thermodynamics. The advantage of this passive modality is that thermal imaging does not require contact with the subject and can provide instant visualization and analysis. These capabilities can prove invaluable for protecting personnel in scenarios with elevated levels of transmission risk such as hospital clinics, border check points, and airports.

  7. Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts.

    Science.gov (United States)

    Buescu, Cristian Tudor; Onutu, Adela Hilda; Lucaciu, Dan Osvald; Todor, Adrian

    2017-03-01

    The objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft. A total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test. Supplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group. The use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft. Level I Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  8. Do Dietary Factors Influence Tendon Metabolism?

    Science.gov (United States)

    Scott, Alex; Nordin, Cara

    There is very little direct research to conclusively prove the relevance of diet in primary tendinopathies, however it seems prudent to ask whether our current knowledge about the impact of nutrition on collagen metabolism could be useful in assessing, preventing, or treating tendinopathy. The objective of this chapter is to discuss the potential impact (negative or positive) that nutrition may have on the metabolism of tendons by summarizing the related research. The chapter briefly discusses the roles that specific vitamins, amino acids, lipids, and antioxidants have in various processes of the body that may be directly or indirectly related to tenocyte metabolism.

  9. Achilles tendon rupture; assessment of nonoperative treatment

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner

    2014-01-01

    to be clarified, particularly the role of weight-bearing during early rehabilitation. Also, there is a need for a clinically applicable and accurate measurement to detect patients in risk of developing Achilles tendon elongation. PURPOSE: The aim of this PhD thesis was to evaluate non-operative treatment of acute...... I found surgery to be the preferred treatment in 83% of departments in Denmark, 92% in Norway, 65% in Sweden, and 30% in Finland (p up except from a better health......-related quality of life in the weight-bearing group (p=0.009). Compared to the unaffected limb, the affected limb had decreased stiffness (77%, p

  10. Nonoperative, dynamic treatment of acute achilles tendon rupture

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner; Bencke, Jesper; Lauridsen, Hanne Bloch

    2015-01-01

    ° dorsiflexion, the stiffness during slow stretching, and the maximal strength were measured in both limbs. The stiffness of the plantar flexor muscle-tendon complex in the terminal part of dorsiflexion was significantly increased (p = .024) in the non-weightbearing group at 12 months. The peak passive torque......Acute Achilles tendon rupture alters the biomechanical properties of the plantar flexor muscle-tendon complex that can affect functional performance and the risk of repeat injury. The purpose of the present study was to compare the biomechanical properties of the plantar flexor muscle......-tendon complex in patients randomized to early weightbearing or non-weightbearing in the nonoperative treatment of Achilles tendon rupture. A total of 60 patients were randomized to full weightbearing from day 1 of treatment or non-weightbearing for 6 weeks. After 6 and 12 months, the peak passive torque at 20...

  11. Fibroma of the flexor hallucis longus tendon sheath.

    Science.gov (United States)

    Kim, Sang Wha; Lee, So Young; Jung, Sung-No; Sohn, Won Il; Kwon, Ho

    2012-01-01

    Fibroma of tendon sheath is a rare benign tumor that usually occurs in upper extremities. It is mostly asymptomatic and grows slowly within the tendons or tendon sheaths. Histopathologic findings show well-demarcated nodules consisting of haphazardly arranged fibroblast-like spindle cells, which are embedded in a dense, collagenous matrix. We present a patient with fibroma of the tendon sheath on the flexor hallucis longus tendon, which was in an unusual location and has never been reported. The lesion was completely excised and showed no evidence of recurrence after 2 years of follow-up. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Use of fluroquinolone and risk of Achilles tendon rupture

    DEFF Research Database (Denmark)

    Sode, Jacob; Obel, Niels; Hallas, Jesper

    2007-01-01

    OBJECTIVE: Several case-control studies have reported that the use of fluoroquinolone increases the risk of rupture of the Achilles tendon. Our aim was to estimate this risk by means of a population-based cohort approach. SETTING: Data on Achilles tendon ruptures and fluoroquinolone use were...... retrieved from three population-based databases that include information on residents of Funen County (population: 470,000) in primary and secondary care during the period 1991-1999. A study cohort of all 28,262 first-time users of fluoroquinolone and all incident cases of Achilles tendon ruptures were...... identified. MAIN OUTCOME MEASURES: The incidence rate of Achilles tendon ruptures among users and non-users of fluoroquinolones and the standardised incidence rate ratio associating fluoroquinolon use with Achilles tendon rupture were the main outcome measures. RESULTS: Between 1991 and 2002 the incidence...

  13. System and Method for Tensioning a Robotically Actuated Tendon

    Science.gov (United States)

    Reiland, Matthew J. (Inventor); Diftler, Myron A. (Inventor)

    2013-01-01

    A tendon tensioning system includes a tendon having a proximal end and a distal end, an actuator, and a motor controller. The actuator may include a drive screw and a motor, and may be coupled with the proximal end of the tendon and configured to apply a tension through the tendon in response to an electrical current. The motor controller may be electrically coupled with the actuator, and configured to provide an electrical current having a first amplitude to the actuator until a stall tension is achieved through the tendon; provide a pulse current to the actuator following the achievement of the stall tension, where the amplitude of the pulse current is greater than the first amplitude, and return the motor to a steady state holding current following the conclusion of the pulse current.

  14. Specialisation of extracellular matrix for function in tendons and ligaments

    Science.gov (United States)

    Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.

    2013-01-01

    Summary Tendons and ligaments are similar structures in terms of their composition, organisation and mechanical properties. The distinction between them stems from their anatomical location; tendons form a link between muscle and bone while ligaments link bones to bones. A range of overlapping functions can be assigned to tendon and ligaments and each structure has specific mechanical properties which appear to be suited for particular in vivo function. The extracellular matrix in tendon and ligament varies in accordance with function, providing appropriate mechanical properties. The most useful framework in which to consider extracellular matrix differences therefore is that of function rather than anatomical location. In this review we discuss what is known about the relationship between functional requirements, structural properties from molecular to gross level, cellular gene expression and matrix turnover. The relevance of this information is considered by reviewing clinical aspects of tendon and ligament repair and reconstructive procedures. PMID:23885341

  15. Ossification of the Achilles tendon: imaging abnormalities in 12 patients

    Energy Technology Data Exchange (ETDEWEB)

    Yu, J.S. [Dept. of Radiology, Veterans Administration Medical Center, San Diego, CA (United States); Witte, D. [Dept. of Radiology, Veterans Administration Medical Center, San Diego, CA (United States); Resnick, D. [Dept. of Radiology, Veterans Administration Medical Center, San Diego, CA (United States); Pogue, W. [Dept. of Radiology, AMI Valley Medical Center, El Cajon, CA (United States)

    1994-02-01

    Ossification of the Achilles tendon is a rare clinical entity that is characterized by the presence of an ossific mass contained within the fibrocartilaginous substance of the tendon. Because the radiographic features of this condition have not been documented entirely and the magnetic resonance (MR) imaging findings have not been determined, a review of 16 affected tendons in 12 patients was performed in an attempt to characterize the imaging abnormalities associated with this process. MR imaging was performed in three Achilles tendons which demonstrated thickening of the tendons at the level of the ossifications and a lack of intratendinous signal abnormalities compatible with acute tendinitis. Signal intensity similar to that of bone marrow was present in the ossifications. (orig.)

  16. Patellar tendon ossification after partial patellectomy: a case report

    Directory of Open Access Journals (Sweden)

    Guven Melih

    2010-02-01

    Full Text Available Abstract Introduction Patellar tendon ossification is a rare pathology that may be seen as a complication after sleeve fractures of the tibial tuberosity, total patellectomy during arthroplasty, intramedullary nailing of tibial fractures, anterior cruciate ligament reconstruction with patellar tendon autograft and knee injury without fracture. However, its occurrence after partial patellectomy surgery has never been reported in the literature. Case presentation We present the case of a 35-year-old Turkish man with a comminuted inferior patellar pole fracture that was treated with partial patellectomy. During the follow-up period, his patellar tendon healed with ossification and then ruptured from the inferior attachment to the tibial tubercle. The ossification was excised and the tendon was subsequently repaired. Conclusion To the best of our knowledge, this is the first report of patellar tendon ossification occurring after partial patellectomy. Orthopaedic surgeons are thus cautioned to be conscious of this rare complication after partial patellectomy.

  17. Validation of a novel ultrasound measurement of achilles tendon length

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner; Riecke, Anja Falk; Boesen, Anders

    2014-01-01

    PURPOSE: A clinically applicable and accurate method for measuring Achilles tendon length is needed to investigate the influence of elongation of the Achilles tendon after acute rupture. The purpose of this study was to develop and validate an ultrasonographic (US) length measurement...... of the Achilles tendon-aponeurosis complex. METHODS: Both legs of 19 non-injured subjects were examined by magnetic resonance imaging (MRI) and US. The length from calcaneus to the medial head of m. Gastrocnemius was measured by three independent US examiners. Repeated US measurements were performed and compared...... to be further assessed in the setting of acute Achilles tendon rupture. CLINICAL RELEVANCE: This new ultrasound measurement might allow for length measurement of ruptured Achilles tendons in the acute and chronic state after rupture. LEVEL OF EVIDENCE: II....

  18. Different Achilles Tendon Pathologies Show Distinct Histological and Molecular Characteristics

    Directory of Open Access Journals (Sweden)

    Franka Klatte-Schulz

    2018-01-01

    Full Text Available Reasons for the development of chronic tendon pathologies are still under debate and more basic knowledge is needed about the different diseases. The aim of the present study was therefore to characterize different acute and chronic Achilles tendon disorders. Achilles tendon samples from patients with chronic tendinopathy (n = 7, chronic ruptures (n = 6, acute ruptures (n = 13, and intact tendons (n = 4 were analyzed. The histological score investigating pathological changes was significantly increased in tendinopathy and chronic ruptures compared to acute ruptures. Inflammatory infiltration was detected by immunohistochemistry in all tendon pathology groups, but was significantly lower in tendinopathy compared to chronic ruptures. Quantitative real-time PCR (qRT-PCR analysis revealed significantly altered expression of genes related to collagens and matrix modeling/remodeling (matrix metalloproteinases, tissue inhibitors of metalloproteinases in tendinopathy and chronic ruptures compared to intact tendons and/or acute ruptures. In all three tendon pathology groups markers of inflammation (interleukin (IL 1β, tumor necrosis factor α, IL6, IL10, IL33, soluble ST2, transforming growth factor β1, cyclooxygenase 2, inflammatory cells (cluster of differentaition (CD 3, CD68, CD80, CD206, fat metabolism (fatty acid binding protein 4, peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, adiponectin, and innervation (protein gene product 9.5, growth associated protein 43, macrophage migration inhibitory factor were detectable, but only in acute ruptures significantly regulated compared to intact tendons. The study gives an insight into structural and molecular changes of pathological processes in tendons and might be used to identify targets for future therapy of tendon pathologies.

  19. Muscle-tendon glucose uptake in Achilles tendon rupture and tendinopathy before and after eccentric rehabilitation: Comparative case reports.

    Science.gov (United States)

    Masood, Tahir; Kalliokoski, Kari; Bojsen-Møller, Jens; Finni, Taija

    2016-09-01

    Achilles tendon rupture (ATR) is the most common tendon rupture injury. The consequences of ATR on metabolic activity of the Achilles tendon and ankle plantarflexors are unknown. Furthermore, the effects of eccentric rehabilitation on metabolic activity patterns of Achilles tendon and ankle plantarflexors in ATR patients have not been reported thus far. We present a case study demonstrating glucose uptake (GU) in the Achilles tendon, the triceps surae, and the flexor hallucis longus of a post-surgical ATR patient before and after a 5-month eccentric rehabilitation. At baseline, three months post-surgery, all muscles and Achilles tendon displayed much higher GU in the ATR patient compared to a healthy individual despite lower plantarflexion force. After the rehabilitation, plantarflexion force increased in the operated leg while muscle GU was considerably reduced. The triceps surae muscles showed similar values to the healthy control. When compared to the healthy or a matched patient with Achilles tendon pain after 12 weeks of rehabilitation, Achilles tendon GU levels of ATR patient remained greater after the rehabilitation. Past studies have shown a shift in the metabolic fuel utilization towards glycolysis due to immobilization. Further research, combined with immuno-histological investigation, is needed to fully understand the mechanism behind excessive glucose uptake in ATR cases. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Quadriceps Tendon Rupture and Contralateral Patella Tendon Avulsion Post Primary Bilateral Total Knee Arthroplasty: A Case Report

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2016-07-01

    Full Text Available Background: Extensor mechanism failure secondary to knee replacement could be due to tibial tubercle avulsion, Patellar tendon rupture, patellar fracture or quadriceps tendon rupture. An incidence of Patella tendon rupture of 0.17% and Quadriceps tendon rupture of around 0.1% has been reported after Total knee arthroplasty. These are considered a devastating complication that substantially affects the clinical results and are challenging situations to treat with surgery being the mainstay of the treatment. Case Description: We report here an interesting case of a patellar tendon rupture of one knee and Quadriceps tendon rupture of the contralateral knee following simultaneous bilateral knee replacement in a case of inflammatory arthritis patient. End to end repair for Quadriceps tear and augmentation with Autologous Hamstring tendon graft was done for Patella tendon rupture. OUTCOME: Patient was followed up for a period of 1 year and there was no Extension lag with a flexion of 100 degrees in both the knees. DISCUSSION: The key learning points and important aspects of diagnosing these injuries early and the management techniques are described in this unique case of bilateral extensor mechanism disruption following knee replacements.

  1. Combined flexor hallucis longus tendon transfer and gastrocnemius recession for reconstruction of gapped chronic achilles tendon ruptures.

    Science.gov (United States)

    Elgohary, Hatem Elsayed Ahmed; Elmoghazy, Nabil A; Abd Ellatif, Mohammed Serry

    2016-12-01

    The aim of this study was to assess the functional outcomes after a combined FHL transfer and a gastrocnemius recession for treatment of chronic ruptures of Achilles tendon with a gap and to investigate the patient's satisfaction about the great toe function after transfer. 19 patients with chronic rupture of the Achilles tendon with a gap were treated with a flexor halluces longus tendon transfer combined with a gastrocnemius recession, Clinical diagnosis depends on the presence of gap in the tendon on examination, inability of tip toe walking on the affected side and positive calf-squeeze test, MRI was used to confirm the clinical diagnosis. American Orthopedic Foot & Ankle Society hind foot score was used for assessment of the results. The AOFAS score improved significantly from a mean of 65 preoperatively to 94 at the last follow up (ptendon weaved through the stump of the Achilles tendon and those with trans osseous tunnels, the mean AOFAS score at the last follow up was 94.2, 93.8 respectively, no patient complained of big toe dysfunction. Management of chronic rupture of the Achilles tendon with a gap with flexor halluces longus tendon transfer combined with a gastrocnemius recession is a safe and reliable method with a significantly improved functional outcome, muscle advancement through gastrocnemius recession decreases the length of the gap without affecting the muscle function, flexor halluces longus tendon transfer doesn't harm the big toe function. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Junction leakage measurements with micro four-point probes

    DEFF Research Database (Denmark)

    Lin, Rong; Petersen, Dirch Hjorth; Wang, Fei

    2012-01-01

    We present a new, preparation-free method for measuring the leakage current density on ultra-shallow junctions. The junction leakage is found by making a series of four-point sheet resistance measurements on blanket wafers with variable electrode spacings. The leakage current density is calculated...... using a fit of the measured four-point resistances to an analytical two-sheet model. The validity of the approximation involved in the two-sheet model is verified by a comparison to finite element model calculations....

  3. Endoscopic-assisted achilles tendon reconstruction with free hamstring tendon autograft for chronic rupture of achilles tendon: clinical and isokinetic evaluation.

    Science.gov (United States)

    El Shazly, Ossama; Abou El Soud, Maged M; El Mikkawy, Dalia M E; El Ganzoury, Ibrahim; Ibrahim, Ayman Mohamed

    2014-05-01

    To evaluate the clinical and functional outcome of endoscopic-assisted reconstruction of chronic ruptures of the Achilles tendon using free hamstring tendon autograft. We present a case series of 15 patients who had chronic ruptures of the Achilles tendon (>6 weeks earlier) and underwent endoscopic-assisted reconstruction with a free hamstring autograft. The graft loop was passed through and fixed to the proximal stump of the tendon. The graft was then passed through suture to the distal stump and finally inserted into a tunnel in the anterior calcaneus to the Achilles tendon insertion and fixed with an bioabsorbable interference screw. The mean follow-up period was 27 months (SD, 3 months; range, 24 to 33 months). All patients underwent magnetic resonance imaging preoperatively, immediately postoperatively, and at follow-up 2 years postoperatively. All patients were functionally evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) score for the hindfoot preoperatively and postoperatively. Calf muscle power was evaluated by isokinetic strength testing at 2 years' follow-up. The mean size of the gap on preoperative magnetic resonance imaging was 49 mm (SD, 9 mm). The mean preoperative AOFAS score was 32.6 (SD, 7.5). There was a statistically significant improvement in the postoperative AOFAS score after 2 years to 90.8 (SD, 3.54) (P Achilles tendon reconstruction with free hamstring tendon autograft for chronic ruptures of the Achilles tendon showed good to excellent results in all patients. Isokinetic testing showed a nonsignificant deficit between the involved and uninvolved sides at 2 years' follow-up. Level IV, therapeutic cases series. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  4. Surgical Treatment for Failure of Repair of Patellar and Quadriceps Tendon Rupture With Ipsilateral Hamstring Tendon Graft.

    Science.gov (United States)

    Maffulli, Nicola; Papalia, Rocco; Torre, Guglielmo; Denaro, Vincenzo

    2017-03-01

    Tears of the patellar and quadriceps tendon are common in the active population, especially in athletes. At present, several techniques for surgical repair and reconstruction are available. When reruptures occur, a reconstruction is mandatory. In the present paper, we describe a surgical technique for patellar and quadriceps tendon reconstruction using ipsilateral hamstring autograft. After routine hamstring tendon harvesting, the tendon ends are prepared using a whip stitch. A transverse tunnel is drilled in the midportion of the patella, the hamstring graft is passed through the patella, and firmly secured to the patellar tunnel openings with sutures. The details of the technique are fully described. Autologous ipsilateral hamstring tendon grafts provide a secure sound means to manage these challenging injuries.

  5. Tissue engineering of flexor tendons: the effect of a tissue bioreactor on adipoderived stem cell-seeded and fibroblast-seeded tendon constructs.

    Science.gov (United States)

    Angelidis, Ioannis K; Thorfinn, Johan; Connolly, Ian D; Lindsey, Derek; Pham, Hung M; Chang, James

    2010-09-01

    Tissue-engineered flexor tendons could eventually be used for reconstruction of large tendon defects. The goal of this project was to examine the effect of a tissue bioreactor on the biomechanical properties of tendon constructs seeded with adipoderived stem cells (ASCs) and fibroblasts (Fs). Rabbit rear paw flexor tendons were acellularized and seeded with ASCs or Fs. A custom bioreactor applied a cyclic mechanical load of 1.25 N at 1 cycle/minute for 5 days onto the tendon constructs. Three additional groups were used as controls: fresh tendons and tendons reseeded with either ASCs or Fs that were not exposed to the bioreactor treatment and were left in stationary incubation for 5 days. We compared the ultimate tensile stress (UTS) and elastic modulus (EM) of bioreactor-treated tendons with the unloaded control tendons and fresh tendons. Comparison across groups was assessed using one-way analysis of variance with the significance level set at ptendons that were exposed to cyclic load were significantly higher than those of unloaded control tendons. Acellularized tendon constructs that were reseeded with ASCs and exposed to a cyclic load had a UTS of 66.76 MPa and an EM of 906.68 MPa; their unloaded equivalents had a UTS of 47.90 MPa and an EM of 715.57 MPa. Similar trends were found in the fibroblast-seeded tendon constructs that were exposed to the bioreactor treatment. The bioreactor-treated tendons approached the UTS and EM values of fresh tendons. Histologically, we found that cells reoriented themselves parallel to the direction of strain in response to cyclic strain. The application of cyclic strain on seeded tendon constructs that were treated with the bioreactor helped achieve a UTS and an EM comparable with those of fresh tendons. Bioreactor pretreatment and alternative cell lines, such as ASCs and Fs, might therefore contribute to the in vitro production of strong tendon material. Copyright 2010. Published by Elsevier Inc.

  6. Ruptures of the distal biceps tendon.

    Science.gov (United States)

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon.

  7. The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model

    Directory of Open Access Journals (Sweden)

    Shengkun Li

    2016-01-01

    Full Text Available The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired with PET were assigned to PET group; the other eight rabbits repaired with PET along with injection of HE were assigned to HA-PET group. All rabbits were sacrificed at 4 and 8 weeks postoperatively for biomechanical and histological examination. The HA-PET group revealed higher biomechanical property compared with the PET group. Histologically, more collagen tissues grew into the HA-PET group compared with PET group. In conclusion, application of sodium hyaluronate can improve the healing of Achilles tendon reconstruction with polyethylene terephthalate artificial ligament.

  8. Suture materials and suture techniques used in tendon repair.

    Science.gov (United States)

    Ketchum, L D

    1985-02-01

    Immediately after a tendon repair, the tendon contributes nothing to the strength of repair. During that time, the suture itself and suture technique are the sole contributors to the strength of repair. Although stainless steel is the strongest material that can be used at the time of repair, it has serious disadvantages. It is difficult to work with and makes a bulky knot. Conversely, all absorbable sutures become too weak too soon to be of value. At this time, nonabsorbable, synthetic fibers that are relatively strong, such as Supramid or prolene, are the most desirable materials available. Regarding suture techniques, the lateral trap and end-weave techniques produce the strongest repairs; however, the end-weave technique can only be used with tendon grafts and the lateral trap, though it can be used for end-to-end primary repairs. It is too bulky for use in the fingers and hand but is ideal for the forearm and wrist. In the hand and fingers, the strongest repair techniques available are the Bunnell, Kessler, and Mason-Allen; however, the Bunnell stitch is more strangulating to the microcirculation of the tendon than the latter two stitches; thus, it contributes to tendomalacia and gap formation. The simplest and least traumatic suture technique, though weakest at first, will allow tendon healing to proceed more rapidly. If such a repair is protected from tension by splinting the wrist and metacarpophalangeal joints in flexion during healing (while allowing controlled passive motion of the finger joints), there will be a rapid increase in tensile strength of the tendon juncture with minimal gap formation, as the repaired hand is progressively stressed up until about 90 days postrepair. At that point, strength plateaus and maximum stress can be applied to the repaired tendon. Somewhere between three and six weeks post-tendon repair, the suture material and technique become secondary to tendon healing as the primary provider of tensile strength to the tendon wound

  9. Fetal development of the pulley for muscle insertion tendons: A review and new findings related to the tensor tympani tendon.

    Science.gov (United States)

    Rodríguez-Vázquez, Jose Francisco; Honkura, Yohei; Katori, Yukio; Murakami, Gen; Abe, Hiroshi

    2017-01-01

    The existence of hard tissue pulleys that act to change the direction of a muscle insertion tendon is well known in the human body. These include (1) the trochlea for the extraocular obliquus superior muscle, (2) the pterygoid hamulus for the tensor veli palatini muscle, (3) the deep sulcus on the plantar aspect of the cuboid bone for the peroneus longus tendon, (4) the lesser sciatic notch for the obturator internus muscle, and (5) the bony trochleariformis process for the tensor tympani muscle tendon. In addition, (6) the stapedius muscle tendon shows a lesser or greater angulation at the pyramidal eminence of the temporal bone. Our recent studies have shown that the development of pulleys Nos. 1 and 2 can be explained by a change in the topographical relationship between the pulley and the tendon, that of pulley No. 3 by the rapidly growing calcaneus pushing the tendon, and that of pulley No. 4 by migration of the insertion along the sciatic nerve and gluteus medius tendon. Therefore, in Nos. 1-4, an initially direct tendon curves secondarily and obtains an attachment to the pulley. In case No. 6, the terminal part of the stapedius tendon originates secondarily from the interzone mesenchymal tissue of the incudostapedial joint. In the case of pulley No. 5, we newly demonstrated that its initial phase of development was similar to No. 6, but the tensor tympani tendon achieved a right-angled turn under guidance by a specific fibrous tissue and it migrated along the growing malleus manubrium. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Influence of neglecting the curved path of the Achilles tendon on Achilles tendon length change at various ranges of motion

    Science.gov (United States)

    Fukutani, Atsuki; Hashizume, Satoru; Kusumoto, Kazuki; Kurihara, Toshiyuki

    2014-01-01

    Abstract Achilles tendon length has been measured using a straight‐line model. However, this model is associated with a greater measurement error compared with a curved‐line model. Therefore, we examined the influence of neglecting the curved path of the Achilles tendon on its length change at various ranges of motion. Ten male subjects participated in this study. First, the location of the Achilles tendon was confirmed by using ultrasonography, and markers were attached on the skin over the Achilles tendon path. Then, the three‐dimensional coordinates of each marker at dorsiflexion (DF) 15°, plantarflexion (PF) 0°, PF15°, and PF30° were obtained. Achilles tendon length in the curved‐line model was calculated as the sum of the distances among each marker. On the other hand, Achilles tendon length in the straight‐line model was calculated as the straight distance between the two most proximal and distal markers projected onto the sagittal plane. The difference of the Achilles tendon length change between curved‐line and straight‐line models was calculated by subtracting the Achilles tendon length change obtained in curved‐line model from that obtained in straight‐line model with three different ranges of motion (i.e., PF0°, PF15°, and PF30° from DF15°, respectively). As a result, the difference in Achilles tendon length change between the two models increased significantly as the range of motion increased. In conclusion, neglecting the curved path of the Achilles tendon induces substantial overestimation of its length change when the extent of ankle joint angle change is large. PMID:25303951

  11. Patellar tendon strain is increased at the site of the jumper's knee lesion during knee flexion and tendon loading: results and cadaveric testing of a computational model.

    Science.gov (United States)

    Lavagnino, Michael; Arnoczky, Steven P; Elvin, Niell; Dodds, Julie

    2008-11-01

    Patellar tendinopathy (jumper's knee) is characterized by localized tenderness of the patellar tendon at its origin on the inferior pole of the patella and a characteristic increase in signal intensity on magnetic resonance imaging at this location. However, it is unclear why the lesion typically occurs in this area of the patellar tendon as surface strain gauge studies of the patellar tendon through the range of motion have produced conflicting results. The predicted patellar tendon strains that occur as a result of the tendon loads and patella-patellar tendon angles (PPTAs) experienced during a jump landing will be significantly increased in the area of the patellar tendon associated with patellar tendinopathy. Descriptive laboratory study. A 2-dimensional, computational, finite element model of the patella-patellar tendon complex was developed using anatomic measurements taken from lateral radiographs of a normal knee. The patella was modeled with plane strain rigid elements, and the patellar tendon was modeled with 8-node plane strain elements with neo-Hookean material properties. A tie constraint was used to join the patellar tendon and patella. Patella-patellar tendon angles corresponding to knee flexion angles between 0 degrees and 60 degrees and patellar tendon strains ranging from 5% to 15% were used as input variables into the computational model. To determine if the location of increased strain predicted by the computational model could produce isolated tendon fascicle damage in that same area, 5 human cadaveric patella-patellar tendon-tibia specimens were loaded under conditions predicted by the model to significantly increase localized tendon strain. Pre- and posttesting ultrasound images of the patella-patellar tendon specimens were obtained to document the location of any injured fascicles. Localized tendon strain at the classic location of the jumper's knee lesion was found to increase in association with an increase in the magnitude of applied

  12. Characterization of subretinal fluid leakage in central serous chorioretinopathy

    DEFF Research Database (Denmark)

    Pryds, Anders; Sander, Birgit; Larsen, Michael

    2010-01-01

    The purpose of the study was to determine which category of hydrodynamic phenomena the smokestack in central serous chorioretinopathy (CSC) most likely belongs to: leakage by diffusion or bulk flow....

  13. Low-leakage modular regenerators for gas-turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Kluka, J.A. [Pratt and Whitney, Middletown, CT (United States); Wilson, D.G. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Mechanical Engineering

    1998-04-01

    One of the significant problems plaguing regenerator designs is seal leakage resulting in a reduction of thermal efficiency. This paper describes the preliminary design and analysis of a new regenerative heat-exchanger concept, called a modular regenerator, that promises to provide improved seal-leakage performance. The modular regenerator concept consists of a ceramic-honeycomb matrix discretized into rectangular blocks, called modules. Separating the matrix into modules substantially reduces the transverse sealing lengths and substantially increases the longitudinal sealing lengths as compared with typical rotary designs. Potential applications can range from small gas-turbine engines for automotive applications to large stationary gas turbines for industrial power generation. Descriptions of two types of modular regenerators are presented including sealing concepts. Results of seal leakage analysis for typical modular regenerators sized for a small gas-turbine engine (120 kW) predict leakage rates under one percent for most seal-clearance heights.

  14. Understanding instrumental Stokes leakage in Murchison Widefield Array polarimetry

    National Research Council Canada - National Science Library

    Sutinjo, A; O'Sullivan, J; Lenc, E; Wayth, R. B; Padhi, S; Hall, P; Tingay, S. J

    2015-01-01

    ...” with the Murchison Widefield Array (MWA) as an example. A long‐standing issue that has been seen here is significant instrumental Stokes leakage after calibration, particularly in Stokes Q at high frequencies...

  15. An Investigation of Leakage Current and Partial Discharge For

    Directory of Open Access Journals (Sweden)

    Arkan A. Hussain

    2013-05-01

    Full Text Available High voltage insulators used in various overhead forms are exposed to leakage current and partial discharge.This work deals with different structure forms of insulator, such as (pin post, clamp top and tie top. These structures are applied in different tests, as covered and stripped states. The leakage current for these forms were measured by raising the insulator voltage to (5.25, 6.35, 7.57 kV for covered and stripped state. Partial discharges were determined in covered and stripped state of these insulator forms using (straight and balanced detection method.Pin post insulators have a leakage current and electric field larger than both clamp top and tie top. The clamp top and tie top insulator show almost the same value of leakage current measurements.The stripped conductors always produce large partial discharge than covered conductor.

  16. Low-frequency measurement of leakage in enclosures

    Science.gov (United States)

    Sherman, Max; Modera, Mark

    1986-07-01

    A wide variety of enclosed structures either require or cannot entirely prevent leakage from their interior space to the outside. Existing methods for measuring such leakage have important disadvantages. We have developed a device and technique that permits leakage areas to be measured from within or without the enclosure without causing unacceptable disturbance. The apparatus uses low-frequency (1 Hz) acoustic monopoles to generate an internal pressure signal which is then analyzed synchronously to provide a measurement of leakage area. We have successfully applied this technique to measuring air tightness in residential houses, and believe it can be easily adapted for use in field, laboratory, or classroom applications. We are currently evaluating why the values we obtained were, on average, 14% lower than those obtained through conventional methods and we are investigating the apparent inability of the device, as presently designed, to measure large leaks.

  17. Leakage Flow Influence on SHF pump model performances

    National Research Council Canada - National Science Library

    Dupont, Patrick; Bayeul-Lainé, Annie-Claude; Dazin, Antoine; Bois, Gérard; Roussette, Olivier; Si, Qiaorui

    2015-01-01

    This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations...

  18. Leakage Flow Influence on SHF pump model performances

    National Research Council Canada - National Science Library

    Dupont, Patrick; Bayeul-Lainé, Annie-Claude; Dazin, Antoine; Bois, Gérard; Roussette, Olivier; Si, Qiaorui

    2015-01-01

    This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations...

  19. Tendon healing: an experimental model in the dog.

    Science.gov (United States)

    McDowell, C L; Snyder, D M

    1977-03-01

    Based upon the studies of the healing process in dogs in which profundus tendons were severed partially by a method in which the cut surfaces remained in contact and the area of division was in an undamaged area of the sheath, it was shown that healing of the tendon took place without evidence of vascular contribution from the sheath. Vascular loop patterns, similar to those seen in synovial lining of joints or on either side of the growth plate of growing bone, were found on the surface of the tendons in the area of mesotenon reflection, the osseotendinous junctions, where the vinculum joined the tendon, and in various areas of the tendon sheath. No other vessels were found. A theory for nutrition of the tendon is proposed analagous to that postulated for maintenance of cartilage, first with the formation of synovial fluid by the vascular loop system and then a diffusion phase dependent upon the repetitive loading and unloading of the tissue to force the fluid into the system of canaliculi in the tendon.

  20. Quantification of regional blood flow to canine flexor tendons

    Energy Technology Data Exchange (ETDEWEB)

    Weidman, K.A.; Simonet, W.T.; Wood, M.B.; Cooney, W.P.; Ilstrup, D.M.

    1984-01-01

    Although the blood supply and the microcirculation of flexor tendons have been studied and defined extensively using qualitative methods, the quantitative assessment of blood flow has been lacking because of the limitations of the available experimental techniques. The authors studied the regional blood supply to the flexor tendons of dogs by the technique of radionuclide-labeled microspheres. Seven adult mongrel dogs were used. Microsphere injection and tissue-counting techniques previously used for other tissues were applied. Samples of proximal, isthmus, and distal portions of the profundus and superficialis flexor tendons were harvested from each digital unit of available limbs from each dog. Mean (+/- SE) flows (ml/100 g dry tissue/min) were proximal profundus 1.78 +/- 0.60 and superficialis 7.10 +/- 1.50. The differences were significant. The study suggests that regional variation in blood flow to canine digital flexor tendons exists, so that a single value for blood flow to these tendons is not relevant. Furthermore, the study supports the concept of dual (vascular and synovial) nutrition to the digital flexor tendons in dogs. These observations may have implications regarding tendon repair techniques.

  1. Quantification of regional blood flow to canine flexor tendons.

    Science.gov (United States)

    Weidman, K A; Simonet, W T; Wood, M B; Cooney, W P; Ilstrup, D M

    1984-01-01

    Although the blood supply and the microcirculation of flexor tendons have been studied and defined extensively using qualitative methods, the quantitative assessment of blood flow has been lacking because of the limitations of the available experimental techniques. We studied the regional blood supply to the flexor tendons of dogs by the technique of radionuclide-labeled microspheres. Seven adult mongrel dogs were used. Microsphere injection and tissue-counting techniques previously used for other tissues were applied. Samples of proximal, isthmus, and distal portions of the profundus and superficialis flexor tendons were harvested from each digital unit of available limbs from each dog. Mean (+/- SE) flows (ml/100 g dry tissue/min) were proximal profundus 1.78 +/- 0.60 and superficialis 7.10 +/- 1.50. The differences were significant (p less than 0.01). The study suggests that regional variation in blood flow to canine digital flexor tendons exists, so that a single value for blood flow to these tendons is not relevant. Furthermore, the study supports the concept of dual (vascular and synovial) nutrition to the digital flexor tendons in dogs. These observations may have implications regarding tendon repair techniques.

  2. Anatomical repair of zone 1 flexor tendon injuries.

    Science.gov (United States)

    Teo, T C; Dionyssiou, Dimitrios; Armenio, Andrea; Ng, Darren; Skillman, Joanna

    2009-02-01

    Repair and rehabilitation of the flexor digitorum profundus tendon in zone I may be demanding. The aim of the authors' study was to assess a new technique for reinsertion of the distal flexor digitorum profundus tendon. The authors' series consisted of 18 patients who required primary (n = 10) or secondary (n = 8) repair of the flexor digitorum profundus tendon in zone I. A half-Bruner incision was extended into the distal volar skin to expose the insertion site. Two drill holes were made through the base of the distal phalanx obliquely from the insertion of the profundus tendon in a dorsolateral direction. A modified Kessler suture was passed through the tendon and then through these holes and tied anteriorly, providing transosseous, internal fixation. Range of movement was assessed according to Moiemen's categories. Fourteen patients had excellent or good results, two patients had fair results, and one patient had a poor result. One patient failed to complete physiotherapy and was lost to follow-up. No tendon rupture was documented during a mean follow-up period of 8 months. The authors' technique anchors the flexor digitorum profundus tendon or the graft in an anatomical position on the distal phalanx, without the need for external sutures or additional incisions. Furthermore, this is accomplished with minimal morbidity to the surrounding highly specialized tissue. The authors' results compare favorably with those of other techniques in the literature.

  3. Endoscopy-assisted percutaneous repair of acute Achilles tendon tears.

    Science.gov (United States)

    Chiu, Chih-Hao; Yeh, Wen-Lin; Tsai, Min-Chien; Chang, Shih-Sheng; Hsu, Kuo-Yao; Chan, Yi-Sheng

    2013-08-01

    We developed a technique for endoscopy-assisted percutaneous repair of acute Achilles tendon tears. Nineteen patients with acute Achilles tendon tears were prospectively recruited into the study. All patients (18 male, 1 female) had sports-related injuries. Preoperative diagnosis was made from patient history, physical examination, and sonography. The average patient age was 38.7 years, and follow-up averaged 24 months. All patients received endoscopy-assisted percutaneous Achilles tendon repair with modified Bunnell sutures passed by bird beak and No. 5 Ethibond under direct visualization using 4.0-mm arthroscopy. Results were evaluated by physical examination, sonography, and magnetic resonance imaging (MRI). All 19 patients achieved tendon healing. All patients were evaluated by sonography, and the tendons of 16 patients were imaged using MRI to evaluate the extent of healing. Final dorsiflexion was 16 degrees and plantar flexion 26 degrees, and 95% of the patients (18/19) returned to their previous level of sporting activity. One patient developed a superficial infection, and 2 patients had postoperative sural nerve injury with numbness for 1 month. There were no other major complications. Endoscopy-assisted percutaneous repair of the Achilles tendon allowed good tendon healing and return to sports at 6 months. Sural nerve injury during surgery was a potential complication of this procedure. Level IV, retrospective case series.

  4. Tendon shift in hallux valgus: observations at MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eustace, S. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Williamson, D. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Wilson, M. [Department of Orthopedics, Brigham and Womens Hospital, Boston, Massachusetts (United States); O`Byrne, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Bussolari, L. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Thomas, M. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Stephens, M. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Stack, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Weissman, B. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States)

    1996-08-01

    Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. Results. There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. Conclusion. Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity. (orig.). With 4 figs., 1 tab.

  5. Automating the Classification of Field Leakage Current Waveforms

    OpenAIRE

    D. Pylarinos; K. Siderakis; Pyrgioti, E.; E. Thalassinakis; I. Vitellas

    2011-01-01

    Leakage current monitoring is widely employed to investigate the performance of high voltage insulators and the development of surface activity. Field measurements offer an exact view of experienced activity and insulators’ performance, which are strongly correlated to local conditions. The required long term monitoring however, results to the accumulation of vast amounts of data. Therefore, an identification system for the classification of field leakage current waveforms rises as a ne...

  6. Expedient methods of respiratory protection. II. Leakage tests. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, D.W.; Hinds, W.C.; Price, J.M.; Weker, R.; Yee, H.S.

    1983-07-01

    The following readily-available materials were tested on a manikin connected to a breathing simulator to determine the fraction of an approximately 2-..mu..m-diameter aerosol that would leak around the seal of the materials to the manikin's face: cotton/polyester shirt material, cotton handkerchief material, toweling (a wash cloth), a surgical mask (Johnson and Johnson Co., model HRI 8137), and a NIOSH-approved disposable face mask (3M, model number 8710). The leakage tests were performed to supplement the measurements of penetration through the materials, conducted as the first phase of this investigation. The leakage tests were performed with the materials held on to the face by three methods, leakage fractions being determined from comparisons with the penetration of the same aerosol for the materials fully taped to the face. At a breathing rate of 37 liters per minute, mean leakages ranged from 0.0 percent to 63 percent. Mean penetrations exclusive of leakage ranged from 0.6 percent to 39 percent. Use of nylon hosiery material (panty hose) to hold the handkerchief material or the disposable face mask to the face was found to be very effective in preventing leakage. Such a combination could be expected to reduce leakage around the handkerchief to about ten percent or less in practice, and around the mask to less than one percent, offering substantial protection from accidentally generated aerosols. The reduction in leakage around the mask provided by the hosiery material suggests the adaptation and use of such an approach in regular industrial hygiene practice. The third and final phase of this investigation is underway, in which the penetration of the materials by particles with diameters between 0.05 and 0.5 ..mu..m is being measured and the effectiveness of the methods for dose reduction in the presence of radioactive aerosols is being modeled.

  7. The histology of tendon attachments to bone in man.

    Science.gov (United States)

    Benjamin, M; Evans, E J; Copp, L

    1986-12-01

    Based on a parallel study of a wide range of human tendons from embalmed dissecting room subjects and from a study of dried bones, an explanation is offered for the well known similarity in gross appearance between the markings left by certain tendons (e.g. those of the rotator cuff) and by articular surfaces on dried bones. Epiphyseal tendons leave markings on bones that look like those left by articular surfaces. These tendons have a prominent zone of fibrocartilage at their attachment site and the deepest part of this is calcified, just as the deepest part of articular hyaline cartilage is calcified. After maceration of the soft tissues, the calcified (fibro) cartilage is left attached to the bone at articular surfaces and at the sites of tendon attachment. In all cases, the tissues separate at the basophilic tidemark between the calcified and uncalcified regions. This tidemark is smooth where there is much overlying uncalcified (fibro) cartilage and it is the smoothness that gives the typical appearance of the dried bone. Blood vessels do not generally traverse the tendon fibrocartilage plugs. Hence the areas are devoid of vascular foramina. The functional significance of tendon fibrocartilage is discussed with particular reference to supraspinatus. It is suggested that the uncalcified fibrocartilage ensures that the tendon fibres do not bend, splay out or become compressed at a hard tissue interface, and are thereby offered some protection from wear and tear. It is also suggested that the fibrocartilage plug of supraspinatus prevents the tendon from rubbing on the head of the humerus.

  8. Early Passive Movement in flexor tendon injuries of the hand.

    Science.gov (United States)

    Quadlbauer, S; Pezzei, Ch; Jurkowitsch, J; Reb, P; Beer, T; Leixnering, M

    2016-02-01

    Flexor tendon injuries are underestimated considering their anatomical function in the hand. According to the publications of Kleinert, Verdan and Kessler, primary suturing of the flexor tendon combined with immediate postoperative physiotherapy in terms of "Early Passive Movement" became the standard form of therapy following acute flexor tendon injuries of the hand. In a study between 2007 and 2009, a total of 115 flexor tendon injuries were analysed retrospectively. All patients were treated using a two-strand repair technique according to Zechner. They received physiotherapy from the first postoperative day according to the Viennese flexor tendon rehabilitation protocol. For statistical purposes, the factors: age, gender, range of motion (ROM), follow up interval, affected flexor tendon and zone were analysed. The time between injury and surgery was also determined, classified into groups and included in the study. On the basis of the range of motion AROM, the Buck-Gramcko and modified Strickland Score was calculated. The mean follow-up interval was 7 months. Using the Buck-Gramcko and Strickland Score an "excellent" overall result was achieved. Complications occurred in 3.5 %, one secondary rupture (0.9 %), two tendon adhaesions requiring tenolysis (1.7 %) and one case of infection (0.9 %). The time interval between injury and operation, gender, affected zone, flexor tendon and affected finger nerve had no influence on the Buck-Gramcko and Strickland Score. Using Zechner's core suture technique as the primary treatment, combined with immediate postoperative physiotherapy in terms of "Early Passive Movement" according to the Viennese flexor tendon rehabilitation programme, an excellent clinical outcome and low complication rate was acchieved. IV: case series.

  9. Energy Efficient High-Pressure Turbine Leakage Technology Report

    Science.gov (United States)

    Gardner, W. B.

    1980-01-01

    The leakage test program was one of such supporting technology programs structured to provide guidance to the Energy Efficient Engine High Pressure Turbine Component Design Effort. Leakage reduction techniques were identified and evaluated. Test models were used to simulate component leak paths and to evaluate leakage reduction techniques. These models simulated the blade/disk attachment, the vane inner platform attachment, and the vane outer platform attachment combined with the blade outer airseal. Disk blade attachment testing indicated that leakage in this area could be reduced to very low levels by paying careful attention to the tolerances along the contact surface between the blade vibration damper and the blade platform contact surface. The aim of feather seal testing was to achieve a goal for an effective leakage gap of one mil (.001 inch) per inch of feather seal length. Results indicated that effective gaps even below the goal level were achievable by (1) maintaining close tolerances between feather seals and their slots to minimize end gaps and limit seal rotation, (2) avoiding feather seal overlap, and (3) minimizing feather seal intersections. W seals were shown to be effective leakage control devices. Wire rope, in its present state of development, was shown not to be an effective sealing concept for application to the component design.

  10. [Conservative therapy in the treatment of cervical chylous leakage].

    Science.gov (United States)

    Wu, Gao-song; Huang, Li-li; Tu, Shun-gui; Liu, Yan-yan; Liu, Jie; Yan, Qun; Yi, Ji-lin; Zou, Sheng-quan

    2009-05-01

    To explore and evaluate the combined conservative managements in the treatment of cervical chylous leakage. Thirty nine cases of cervical chylous leakage from June 1992 to June 2008 were retrospectively analyzed in this hospital. All of the 39 cases were cured by treating with conservative individualized therapy, including the applying of diet with high calorie, high protein and low fat and fatty food should only contains medium-chain triglycerides, total parenteral nutrition, keep the balance of hydrogen and electrolyte and correct hypoproteinemia, local pressure dressing, high persistent vacuum drainage (-50 approximately -80 kPa) and/or somatostatin analogue. All the cases of chylous leakage happened 2nd to 5th days after the operation. Among the 39 cases, 7 were high flow (drainage>or=500 ml/d) chylous leakage, the amount of drainage reached as high as 1440 ml per day. The time of chylous leakage closure was 3 approximately 12 days, and the mean time was 7 days. No one experienced re-operation, wound hydrops or wound infection. The conservative individualized therapy may play a key role in the treatment of cervical chylous leakage.

  11. International Market Leakage from China’s Forestry Policies

    Directory of Open Access Journals (Sweden)

    Xin Hu

    2014-11-01

    Full Text Available Carbon leakage can be a problem when seeking to reduce carbon emissions through forest policy. International market leakage is mainly caused by supply and demand imbalances in the timber market. This paper selects China, which is implementing forestry policy changes, as the research object. We begin by offering a brief analysis of China’s forestry policy changes, such as the logging quota and Six Key Forestry Programs to determine whether those policies affect timber supply. Second, through the use of three shock variables, carbon leakage is simulated under different scenarios by the Global Trade Analysis Project (GTAP model. The results reveal that the magnitude of leakage caused by implementing China’s forestry policies is between 79.7% and 88.8% with carbon leakage mainly displaced to Russia, Southeast Asia, and the EU. Two effective scenarios for reducing market leakage are presented: forest tenure reform and fast growing forest projects to improve domestic timber production, and raising tariffs on timber imports to reduce imports.

  12. Acute alcohol intoxication-induced microvascular leakage.

    Science.gov (United States)

    Doggett, Travis M; Breslin, Jerome W

    2014-09-01

    Alcohol intoxication can increase inflammation and worsen injury, yet the mechanisms involved are not clear. We investigated whether acute alcohol intoxication increases microvascular permeability and investigated potential signaling mechanisms in endothelial cells that may be involved. Conscious rats received a 2.5 g/kg alcohol bolus via gastric catheters to produce acute intoxication. Microvascular leakage of intravenously administered fluorescein isothiocyanate (FITC)-conjugated albumin (FITC-albumin) from the mesenteric microcirculation was assessed by intravital microscopy. Endothelial-specific mechanisms were studied using cultured endothelial cell monolayers. Transendothelial electrical resistance (TER) served as an index of barrier function, before and after treatment with alcohol or its metabolite acetaldehyde. Pharmacologic agents were used to test the roles of alcohol metabolism, oxidative stress, p38 mitogen-activated protein kinase (MAPK), myosin light-chain kinase (MLCK), rho kinase (ROCK), and exchange protein activated by cAMP (Epac). VE-cadherin localization was investigated to assess junctional integrity. Rac1 and RhoA activation was assessed by ELISA assays. Alcohol significantly increased FITC-albumin extravasation from the mesenteric microcirculation. Alcohol also significantly decreased TER and disrupted VE-cadherin organization at junctions. Acetaldehyde significantly decreased TER, but inhibition of alcohol dehydrogenase or application of a superoxide dismutase mimetic failed to prevent alcohol-induced decreases in TER. Inhibition of p38 MAPK, but not MLCK or ROCK, significantly attenuated the alcohol-induced barrier dysfunction. Alcohol rapidly decreased GTP-bound Rac1 but not RhoA during the drop in TER. Activation of Epac increased TER, but did not prevent alcohol from decreasing TER. However, activation of Epac after initiation of alcohol-induced barrier dysfunction quickly resolved TER to baseline levels. Our results suggest that

  13. Copper Ion as a New Leakage Tracer

    Science.gov (United States)

    Modaresi, J; Baharizade, M; Shareghi, A; Ahmadi, M; Daneshkazemi, A

    2013-01-01

    Statement of Problem: Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal. Purpose: Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method. Materials and Method: The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope. Results: The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods. Conclusion: Based on our results, there was no significant correlation between the dye

  14. The role of proximal pulleys in preventing tendon bowstringing: pulley rupture and tendon bowstringing.

    Science.gov (United States)

    Leeflang, S; Coert, J H

    2014-06-01

    The aim of this study was to investigate factors that contribute to tendon bowstringing at the proximal phalanx. We hypothesised that: (1) a partial rupture of the A2 pulley leads to significant bowstringing, (2) the location of the A2 rupture, starting proximally or distally, influences bowstringing, (3) an additional A3 pulley rupture causes a significant increase in bowstringing following a complete A2 pulley rupture and (4) the skin and tendon sheath may prevent bowstringing in A2 and A3 pulley ruptures. Index, middle and ring fingers of eight freshly frozen cadaver arms were used. A loading device pulled with 100 N force was attached to the flexor digitorum profundus (FDP). The flexor digitorum superficialis (FDS) was preloaded with 5 N. Bowstringing was measured and quantified by the size of the area between the FDP tendon and the proximal phalanx over a distance of 5 mm with ultrasonography (US). US images showed that already a 30% excision of the A2 pulley resulted in significant bowstringing. In addition, a partial distal incision of the A2 pulley showed significantly more bowstringing compared to a partial proximal incision. Additional A3 pulley incision and excision of the proximal tendon sheath did not increase bowstringing. Subsequently, removing the skin did increase the bowstringing significantly. A partial A2 pulley rupture causes a significant bowstringing. A partial rupture of the A2 pulley at the distal rim of the A2 pulley resulted in more bowstringing than a partial rupture at the proximal rim. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Methods of Assessing Human Tendon Metabolism and Tissue Properties in Response to Changes in Mechanical Loading

    DEFF Research Database (Denmark)

    Heinemeier, Katja M; Kjaer, Michael; Magnusson, S Peter

    2016-01-01

    In recent years a number of methodological developments have improved the opportunities to study human tendon. Microdialysis enables sampling of interstitial fluid in the peritendon tissue, while sampling of human tendon biopsies allows direct analysis of tendon tissue for gene- and protein......)), and tendon mechanical properties (ultrasonography combined with force measurement during movement). Finally, 3D cell cultures of human tendon cells provide the opportunity to investigate cell-matrix interactions in response to various interventions....

  16. Endoscopic Resection of Gouty Tophus of the Patellar Tendon

    OpenAIRE

    Lui, Tun Hing

    2015-01-01

    Tophaceous deposition of tendon can result in spontaneous patellar tendon rupture. Surgical therapy may be needed to control symptoms and prevent tendon rupture. Open debridement of the lesion requires a lengthy incision over the lesion; this may result in symptomatic scar adhesion of the patellar tendon or an unhealed wound with persistent tophaceous discharge. Moreover, the other part of the patellar tendon cannot be examined through the incision. We describe a technique for endoscopic rese...

  17. Giant cell tumour of extensor tendon sheath: Preventing recurrence

    Directory of Open Access Journals (Sweden)

    S S Shirol

    2012-01-01

    Full Text Available Giant Cell Tumour of tendon sheath is relatively rare tumour with an overall incidence of around 1 in 50,000 individuals. Marginal excision of giant cell tumour of the tendon sheath is the treatment of choice. It is also the commonest hand lesion to recur after excision. The incidence of local recurrence is high, ranging from 9-44%. Here we present a case report of a giant cell tumour of extensor tendon sheath in hand which was successfully treated with special emphasis on ways of prevention of recurrence.

  18. Adductor longus tendon rupture mistaken for incarcerated inguinal hernia.

    Science.gov (United States)

    Aerts, Bas R J; Plaisier, Peter W; Jakma, Tijs S C

    2014-03-01

    An incarcerated inguinal hernia is a common diagnosis, since the risk of an inguinal hernia incarcerating or strangulating is around 0.3-3%. An acute rupture of the adductor longus tendon is rarely seen and mostly affects (semi-) professional sportsmen. We present a case of a patient with an assumed incarcerated inguinal hernia which turned out to be a proximal adductor longus tendon rupture. If patients without a history of inguinal hernia present themselves with acute groin pain after suddenly exorotating the upper leg, a rupture of the adductor longus tendon should be considered. Both surgical and non-surgical treatment can be performed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Gender Differences in Outcome After an Acute Achilles Tendon Rupture

    OpenAIRE

    Silbernagel, Karin Gravare; Nilsson-Helander, Katarin; Olsson, Nicklas; Brorsson, Annelie; Eriksson, Bengt I; Karlsson, Jon

    2014-01-01

    Objectives: There is an indication in the literature that there is a difference in tendon healing between genders. However comparisons in outcome are often not possible due to the small sample size of women with an acute Achilles tendon rupture. In most studies on patients with Achilles tendon rupture the women only account for less then 20% of the patients. The objective of this study was to evaluate if there are any differences in outcome between genders when combining the data from two lar...

  20. Tendon collagen synthesis declines with immobilization in elderly humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

    2017-01-01

    -80 yr) were randomly assigned to NSAIDs (ibuprofen 1,200 mg/day; Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 wk and retrained for 6 wk. Tendon collagen protein synthesis, mechanical properties, size, expression of genes related to collagen turnover and remodeling, and signal...... intensity (from magnetic resonance imaging) were investigated. Tendon collagen synthesis decreased (P ... immobilization in both groups, whereas scleraxis mRNA decreased with inactivity in the Plc group only (P collagen protein synthesis decreased after 2 wk of immobilization, whereas tendon stiffness and modulus were only marginally reduced, and NSAIDs had no influence upon this...

  1. Ultrasound-based testing of tendon mechanical properties

    DEFF Research Database (Denmark)

    Seynnes, O R; Bojsen-Møller, J.; Albracht, K

    2015-01-01

    In the past 20 years, the use of ultrasound-based methods has become a standard approach to measure tendon mechanical properties in vivo. Yet the multitude of methodological approaches adopted by various research groups probably contribute to the large variability of reported values. The technique......, or signal synchronization; and 2) in physiological considerations related to the viscoelastic behavior or length measurements of tendons. Hence, the purpose of the present review is to assess and discuss the physiological and technical aspects connected to in vivo testing of tendon mechanical properties...

  2. Fibrocartilage associated with human tendons and their pulleys.

    OpenAIRE

    Benjamin, M; Qin, S; Ralphs, J R

    1995-01-01

    The presence of fibrocartilage in tendons that wrap around bony or fibrous pulleys is well known. It is an adaptation to resisting compression or shear, but the extent to which the structure of most human tendons is modified where they contact pulleys is less clear, for there has been no single comprehensive survey of a large number of sites. Less is known of the structure of the corresponding pulleys. In the present study, 38 regions of tendons that wrap around bony pulleys or pass beneath f...

  3. Tendon biomechanics and mechanobiology - a mini-review of basic concepts and recent advancements

    Science.gov (United States)

    Wang, James H-C.; Guo, Qianping; Li, Bin

    2011-01-01

    Due to their unique hierarchical structure and composition, tendons possess characteristic biomechanical properties, including high mechanical strength and viscoelasticity, which enable them to carry and transmit mechanical loads (muscular forces) effectively. Tendons are also mechano-responsive by adaptively changing their structure and function in response to altered mechanical loading conditions. In general, mechanical loading at physiological levels is beneficial to tendons, but excessive loading or disuse of tendons is detrimental. This mechano-adaptability is due to the cells present in tendons. Tendon fibroblasts (tenocytes) are the dominant tendon cells responsible for tendon homeostasis and repair. Tendon stem cells (TSCs), which were recently discovered, also play a vital role in tendon maintenance and repair by virtue of their ability to self-renew and differentiate into tenocytes. TSCs may also be responsible for chronic tendon injury, or tendinopathy, by undergoing aberrant differentiation into non-tenocytes in response to excessive mechanical loading. Thus, it is necessary to devise optimal rehabilitation protocols in order to enhance tendon healing while reducing scar tissue formation and tendon adhesions. Moreover, along with scaffolds that can mimic tendon matrix environments and platelet-rich plasma (PRP), which serves as a source of growth factors, TSCs may be the optimal cell type for enhancing repair of injured tendons. PMID:21925835

  4. Radial forearm flap plus Flexor Carpi Radialis tendon in Achilles tendon reconstruction: Surgical technique, functional results, and gait analysis.

    Science.gov (United States)

    Innocenti, Marco; Tani, Massimiliano; Carulli, Christian; Ghezzi, Serena; Raspanti, Andrea; Menichini, Giulio

    2015-11-01

    Wound dehiscence, infection, and necrosis of tendon and overlying skin are severe complications after open repairs of Achilles tendon. A simultaneous reconstruction should be provided in a single stage operation. We evaluated the outcomes of one of the possible options: the radial forearm free flap with Flexor Carpi Radialis (FCR) tendon. Between 2006 and 2014, six patients affected by infection and necrosis after Achilles tendon open repair underwent multi-tissutal reconstruction by a composite radial forearm free flap including a vascularized FCR tendon. The mean skin and tendon defect was respectively 9.8 cm × 4.7 cm and 6.5 cm. After reconstruction, patients underwent clinical examination, including the Achilles Tendon Total Rupture Score (ATRS) questionnaire, DASH score, MRI study, and a computer-assisted gait analysis. All flaps survived and no complications were recorded. Full weightbearing was allowed within 2 months after surgery. The mean follow-up was 36.2 months (range 12-96). MRI showed an optimal reconstruction of the tendon. Range of motion was minimally reduced if compared to the contralateral side. Gait analysis showed the recovery of a nearly symmetrical stance phase, time to heel off, and step length of the gate. ATRS and DASH score improved to a mean value of 85.2 (range 83-88) and 8.0 (range 3-15) respectively. This procedure provided an anatomical reconstruction of the Achilles tendon and skin achieving good and objective functional results; donor site morbidity was limited to the sacrifice of the radial artery, which, in our opinion, is a minor drawback if compared to the quality of the results. © 2015 Wiley Periodicals, Inc.

  5. The high variability of the chiasma plantare and the long flexor tendons: Anatomical aspects of tendon transfer in foot surgery.

    Science.gov (United States)

    Pretterklieber, Bettina

    2017-05-01

    As tendon transfer of the flexor hallucis longus (FHL) and the flexor digitorum longus (FDL) is an established procedure, exact knowledge of the formation of the chiasma plantare is of great interest. Although the quadratus plantae (QP) appears to play a major role, it has been rarely addressed in previous studies. The aim of the present study was to reinvestigate the formation of the chiasma plantare and the composition of the long flexor tendons in order to clarify the inexact and partly contradictory descriptions published from 1865 onward. The chiasma plantare and the long flexor tendons in both feet of 50 formalin-fixed specimens of body donors (25 men and women) were analyzed by gross anatomical dissection. It was composed of one (3%), two (69%) or three layers (28%) which were variably established by the tendinous and muscular fibers of the FHL, the FDL and the QP. In 61% the FHL gave one or more slips to the FDL, and in 39% there was a bidirectional interconnection between the two tendons. The slip from the FHL to the FDL largely reinforces the second (45%), or the second and third tendon (46%). Thus, the FHL is involved in the first tendon in all cases, in the second one in 97% of cases, and in the third tendon in about one half of cases (53%). In all instances, the FDL contributes to the third to fourth, in 98% the second, and in at least 39% to the first tendon. The QP reinforces the second to fourth tendon in nearly all cases, the fifth in about one half of cases, and even the first tendon in 14% of cases. In addition, the individual composition of the five long flexor tendons arising from the chiasma plantare was analyzed in detail. Special emphasis was placed on the evaluation of side and sex differences as well as individual symmetry. Furthermore, biomechanical, developmental and phylogenetic aspects were outlined. In terms of the outcome of this study, the FHL appears to be the better donor for tendon transfer to restore lost function, but

  6. Calcific Tendonitis of the Rotator Cuff: An Unusual Case

    Directory of Open Access Journals (Sweden)

    Yasuhiro Mitsui

    2012-01-01

    Full Text Available Few case reports have described the surgical treatment of calcifying tendonitis of the subscapularis tendon. We present a case of symptomatic diffuse calcifying tendonitis involving the subscapularis and infraspinatus insertions that was difficult to detect arthroscopically. The patient was treated with arthroscopic incision of the tendinous insertions thorough removal of the calcific deposits and subsequent repair using a suture-anchor technique. Two years after the surgical procedure, the patient was completely pain-free and attained full range of motion. Radiographic evaluation performed 2 years after the procedure revealed no calcific deposits. We conclude that the combination of incision of the subscapularis and infraspinatus insertions, complete removal of the calcific deposits, and subsequent suture-anchor repair in an all-arthroscopic manner can lead to an excellent clinical outcome without compromising the functional integrity of the rotator cuff tendons.

  7. Protect Your Tendons: Preventing the Pain of Tendinitis

    Science.gov (United States)

    ... steroid injections, or give you a splint or brace. Then gentle exercises can help strengthen the tendon. ... Q&A About Bursitis and Tendinitis Sports Injuries Knee Problems Tendinitis: NIH Health Information NIH Office of ...

  8. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    Directory of Open Access Journals (Sweden)

    Engin Cetinkaya

    2015-01-01

    Conclusion: We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy.

  9. The Flexor Tendon Pulley System and Rock Climbing

    National Research Council Canada - National Science Library

    Crowley, Timothy

    Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers...

  10. The tendon-to-bone attachment: Unification through disarray

    Science.gov (United States)

    Genin, Guy M.; Thomopoulos, Stavros

    2017-06-01

    High-resolution imaging, composition analysis and mechanical testing reveal a disordered transitional material within the Achilles tendon-to-bone attachment, structured as a fibrous network to enable force transfer and maximize structural integrity.

  11. Tendon and ligament adaptation to exercise, immobilization, and remobilization.

    Science.gov (United States)

    Wren, T A; Beaupré, G S; Carter, D R

    2000-01-01

    This study provides a theoretical and computational basis for understanding and predicting how tendons and ligaments adapt to exercise, immobilization, and remobilization. In a previous study, we introduced a model that described the growth and development of tendons and ligaments. In this study, we use the same model to predict changes in the cross-sectional area, modulus, and strength of tendons and ligaments due to increased or decreased loading. The model predictions are consistent with the results of experimental exercise and immobilization studies performed by other investigators. These results suggest that the same fundamental principles guide both development and adaptation. A basic understanding of these principles can contribute both to prevention of tendon and ligament injuries and to more effective rehabilitation when injury does occur.

  12. Adrenergic control of tendon jerk reflexes in man.

    Science.gov (United States)

    Phillips, S J; Richens, A; Shand, D G

    1973-03-01

    1. Tendon jerk responses and H reflexes were recorded from conscious human volunteers before and after intravenous injection of methylamphetamine, thymoxamine and propranolol, and during intravenous infusion of noradrenaline.2. Methylamphetamine produced a significant increase in the amplitude of the tendon jerk, whereas noradrenaline had no effect in doses which caused a greater pressor response than methylamphetamine.3. Thymoxamine produced a dose-related reduction in the tendon jerk.4. Propranolol had no significant effect on the jerk.5. None of these drugs significantly affected the H reflex.6. It is suggested that central adrenoceptors, possibly alpha in type, exist in man, and that stimulation of these receptors facilitates tendon jerk reflexes by an action on the fusimotor system.

  13. Achilles tendon rupture as a result of oral steroid therapy.

    Science.gov (United States)

    Hersh, Bryan L; Heath, Nicholas S

    2002-06-01

    Spontaneous Achilles tendon rupture associated with long-term oral steroid use is not uncommon, particularly in older patients who use these drugs daily to treat systemic diseases. Rupture often results in a large defect, which complicates surgical repair. The authors review Achilles tendon rupture associated with systemic and local steroid use and present a case of rupture due to chronic oral steroid use in a patient with Addison's disease.

  14. Tendon Cell Behavior and Matrix Remodeling in Degenerative Tendinopathy

    OpenAIRE

    Mos, Marieke

    2009-01-01

    textabstractTendon injuries are common in human athletes [1-4]. Furthermore, such injuries are also prevalent in the ageing sedentary population [5-7]. In recent decades, the incidence of tendon injuries has risen due to both an increase in an elderly population and a rise in participation in recreational and competitive sporting activities. In the general population the lifetime cumulative incidence of Achilles tendinopathy is 5.9 % among sedentary people and 50 % among elite endurance athle...

  15. Molecular basis for elastic energy storage in mineralized tendon.

    Science.gov (United States)

    Silver, F H; Freeman, J W; Horvath, I; Landis, W J

    2001-01-01

    Animals store elastic energy in leg and foot tendons during locomotion. In the turkey, much of the locomotive force generated by the gastrocnemius muscle is stored as elastic energy during tendon deformation. Little energy storage occurs within the muscle. During growth of some avians, including the turkey, leg tendons mineralize in the portions distal to the attached muscle and show increased tensile strength and modulus as a result. The purpose of this study is to test the hypothesis that the degree of elastic energy storage in mineralizing turkey tendon is directly related to the tendon mineral content. To test this hypothesis, the stress-strain behavior of tendons was separated into elastic and viscous components. Both the elastic spring constant and the elastic energy stored, calculated up to a strain of 20%, were found to be proportional to tendon mineral content. It is concluded that mineralization is an efficient means for increasing the amount of elastic energy storage that is required for increased load-bearing ability needed for locomotion of adult birds. Examination of molecular models of the hole region, where mineralization is initiated within the collagen fibril, leads to the hypothesis that elastic energy is stored in the tendon by direct stretching of the flexible regions. Flexible regions within the collagen molecule fall within the positively stained bands of the collagen D period. It is proposed that mineralization increases the stored elastic energy by preventing flexible regions within the positively stained bands from stretching. These observations suggest that mineralization begins in the hole region due to the large number of charged amino acid residues found in the d and e bands.

  16. Bilateral Achilles tendon rupture: a report on two cases.

    Science.gov (United States)

    Orava, S; Hurme, M; Leppilahti, J

    1996-10-01

    Two cases of traumatic bilateral Achilles tendon rupture are reported. One of the patients was a healthy middle-aged man, who had been an active national-level gymnast 20 years earlier. He had not suffered any complaints of Achilles tendons before. The ruptures occurred when, after a sauna, he showed his guests a vault forwards, which he had been able to perform easily. This time the landing took place on the toes, causing a high peak stretch to the calf muscles and Achilles tendons. The total rupture of both Achilles tendons was treated surgically, with an excellent result 2 days after the trauma. End-to-end suturation and a fascial flap plasty were made on both sides. No macroscopic degeneration could be detected on the rupture sites. He was allowed to walk freely 6 weeks after the surgery. The second case was a 54-year-old woman, who had suffered from Achilles tendinitis and peritendinitis for 2 years. Both tendons had been surgically treated, and severe adhesions and local degenerative changes had been found. The tendon rupture occurred when she injured her left ankle while getting out of the car. Two days later she fell at home, because of the weakness of the left side, and consequently the right Achilles tendon was injured. She was treated conservatively for 10 days, before the surgery was performed. Both tendons were ruptured and an extensive degeneration of the area was observed. The right side suffered from a rerupture, which was again treated surgically. After surgery the recovery was slow, but the final result 3 years later was moderate. Neither of the patients had any systemic diseases.

  17. The flexor tendon pulley system and rock climbing.

    Science.gov (United States)

    Crowley, Timothy P

    2012-06-01

    Rock climbing has increased in popularity over the past two decades. Closed traumatic rupture of the finger flexor tendon pulleys is rare among the general population but is seen much more commonly in rock climbers. This article reviews the anatomy and biomechanics of the finger flexor tendon pulleys, how they may be injured in rock climbing and how these injuries are best diagnosed and managed.

  18. Investigation of Corrosion Inhibitors by Nuclear Quadrupole Resonance Relaxometry Method

    OpenAIRE

    Nikolay Sinyavsky; Ivan Mershiev; Irina Korneva

    2015-01-01

    The changes taking place with the corrosion-resistant coating, but not the state of the surface subjected to corrosion are investigated in this paper in contrast to traditional approaches. We used the method of nitrogen relaxometry NQR and multi-exponential inversion of decay of longitudinal and transverse components of the nuclear magnetization is applied for the first time for this purpose. The results of experimental studies of changes in the distributions of spin-spin and spin-lattice rel...

  19. The study of henna leaves extract as green corrosion inhibitor

    African Journals Online (AJOL)

    Chaudhari H.G and Vashi R.T

    2016-05-01

    May 1, 2016 ... oil and gas industries [1-4]. Generally lower molecular ... The extract of plant leaves also known as green inhibitors such as Newbouldia leavis [6], Carica Papaya and Camellia ... In order to study the adsorption of henna leaves extract, on mild steel surface, best agreement was obtained with Langmuir ...

  20. Gossipium hirsutum L. extract as green corrosion inhibitor for ...

    African Journals Online (AJOL)

    Inhibitive effect of Gossipium hirsutum L. leaves extract on the acid corrosion of aluminum in 1 M HCl solution was studied by weight loss technique. The extract at optimum concentration inhibited the corrosion of aluminum, with about 92% inhibition efficiency and the inhibition efficiency increased with increasing ...