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Sample records for synthesis tendon structural

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

    DEFF Research Database (Denmark)

    Hansen, Mette; Kongsgaard, Mads; Holm, Lars

    2009-01-01

    and fibril characteristics were determined by MRI and transmission electron microscopy, whereas tendon biomechanical properties were measured during isometric maximal voluntary contraction by ultrasound recording. Tendon FSR was markedly higher in ERT users (P

  2. From mechanical loading to collagen synthesis, structural changes and function in human tendon

    DEFF Research Database (Denmark)

    Kjær, Michael; Langberg, Henning; Heinemeier, Katja

    2009-01-01

    The adaptive response of connective tissue to loading requires increased synthesis and turnover of matrix proteins, with special emphasis on collagen. Collagen formation and degradation in the tendon increases with both acute and chronic loading, and data suggest that a gender difference exists...

  3. 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

  4. Local administration of insulin-like growth factor-I (IGF-I) stimulates tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Hansen, Mette; Boesen, Anders; Holm, Lars

    2013-01-01

    Collagen is the predominant structural protein in tendons and ligaments, and can be controlled by hormonal changes. In animals, injections of insulin-like growth factor I (IGF-I) has been shown to increase collagen synthesis in tendons and ligaments and to improve structural tissue healing......, but the effect of local IGF-I administration on tendon collagen synthesis in human has not been studied. The purpose of this study was to study whether local injections of IGF-I would have a stimulating effect on tendon collagen synthesis. Twelve healthy nonsmoking men [age 62 ± 1 years (mean ± SEM), BMI 27 ± 1......] participated. Two injections of either human recombinant IGF-I (0.1 mL Increlex©) or saline (control) into each patellar tendon were performed 24-h apart, respectively. Tendon collagen fractional synthesis rate (FSR) was measured by stable isotope technique in the hours after the second injection...

  5. 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  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 tendons 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.

  6. Tendon collagen synthesis declines with immobilization in elderly humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

    2017-01-01

    NSAID treatment would affect the tendon adaptations during such periods. Thus we studied human patellar tendon protein synthesis and mechanical properties during immobilization and subsequent rehabilitating resistance training and the influence of NSAIDs upon these parameters. Nineteen men (range 60......-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, and NSAIDs did not influence this. Matrix metalloproteinase-2 mRNA tended to increase (P

  7. 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.

  8. 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.

  9. FRP tendon anchorage in post-tensioned concrete structures

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Täljsten, Björn; Bennitz, Anders

    2008-01-01

    Strengthening of building structures by the use of various external post-tensioning steel tendon systems, is known to be a very efficient method. However, FRP as material in external post-tensioning projects has been investigated during the last decade. The advantages for this material are the high...... effective Young´s modulus and the high stress capacity in the linear elastic range of the material. The use of external tendons increases the requirements on the anchorage systems. This is in particular important when using un-bonded tendon systems, where the anchorage and deviators are the only force...... transfer points. The demand for high capacity anchorage tendons is fulfilled for steel tendons, but no competitive mechanical anchor has yet been developed for FRP tendon. A new small, reliable and more user friendly anchor has to be developed, before FRP tendons can be utilized with all of its capacity...

  10. Insulin-like growth factor I enhances collagen synthesis in engineered human tendon tissue

    DEFF Research Database (Denmark)

    Herchenhan, Andreas; Bayer, Monika L.; Eliasson, Pernilla

    2015-01-01

    OBJECTIVE: Isolated human tendon cells form 3D tendon constructs that demonstrate collagen fibrillogenesis and feature structural similarities to tendon when cultured under tensile load. The exact role of circulating growth factors for collagen formation in tendon is sparsely examined. We investi...

  11. Numerical models for prestressing tendons in containment structures

    International Nuclear Information System (INIS)

    Kwak, Hyo-Gyoung; Kim, Jae Hong

    2006-01-01

    Two modified stress-strain relations for bonded and unbonded internal tendons are proposed. The proposed relations can simulate the post-cracking behavior and tension stiffening effect in prestressed concrete containment structures. In the case of the bonded tendon, tensile forces between adjacent cracks are transmitted from a bonded tendon to concrete by bond forces. Therefore, the constitutive law of a bonded tendon stiffened by grout needs to be determined from the bond-slip relationship. On the other hand, a stress increase beyond the effective prestress in an unbonded tendon is not section-dependent but member-dependent. It means that the tendon stress unequivocally represents a uniform distribution along the length when the friction loss is excluded. Thus, using a strain reduction factor, the modified stress-strain curve of an unbonded tendon is derived by successive iterations. In advance, the prediction of cracking behavior and ultimate resisting capacity of prestressed concrete containment structures using the introduced numerical models are succeeded, and the need for the consideration of many influencing factors such as the tension stiffening effect, plastic hinge length and modification of stress-strain relation of tendon is emphasized. Finally, the developed numerical models are applied to prestressed concrete containment structures to verify the efficiency and applicability in simulating the structural behavior with bonded and/or unbonded tendons

  12. GH receptor blocker administration and muscle-tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Nielsen, Rie H; Doessing, Simon; Goto, K.

    2011-01-01

    , but the effect of local IGF-I administration on tendon collagen synthesis in human has not been studied. The purpose of this study was to study whether local injections of IGF-I would have a stimulating effect on tendon collagen synthesis. Twelve healthy nonsmoking men [age 62 ± 1 years (mean ± SEM), BMI 27 ± 1.......05). In conclusion, local IGF-I administration can directly enhance tendon collagen synthesis both within and around the human tendon tissue....

  13. GH receptor blocker administration and muscle-tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Nielsen, Rie Harboe; Doessing, Simon; Goto, Kazushige

    2011-01-01

    The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans.......The growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis stimulates collagen synthesis in tendon and skeletal muscle, but no studies have investigated the effect of reducing IGF-I on collagen synthesis in healthy humans....

  14. Structure of retracted tendons after staged repair following continuous traction.

    Science.gov (United States)

    Farshad, Mazda; Gerber, Christian; Snedeker, Jess G; Frauenfelder, Thomas; Meyer, Dominik C

    2011-12-01

    The effect of staged repair involving continuous re-lengthening of the retracted musculotendinous unit after rotator cuff tear is not known. We quantified changes in chronically retracted tendons undergoing no repair or a staged repair involving an initial re-lengthening of the musculotendinous unit by traction in a sheep model of massive rotator cuff tear. Infraspinatus tendons of 12 sheep were released and allowed to retract for 4 months. Repair was performed after the retracted musculotendinous unit had been progressively returned to its original length through continuous traction in 8 sheep (group I). In the other 4 sheep (group II) traction was not successful and the tendons remained retracted. Tendon structure was assessed macroscopically, by MRI, histology, and TEM. Normalized to their contralateral controls, at sacrifice, tendon thickness was unchanged in group I (116%, n.s) and increased in group II (129%, P Retracted musculotendinous units have deteriorated tendons, characterized by increased collagen fiber crimp, and ultrastructural collagen fibril atrophy and disorganization. Continuous traction may arrest and partially restore degenerative changes in retracted tendon. The findings of this study might contribute to new approaches for the treatment of chronic "irreparable" rotator cuff tears.

  15. Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis

    DEFF Research Database (Denmark)

    Doessing, Simon; Heinemeier, Katja; Holm, Lars

    2010-01-01

    matrix collagen synthesis in skeletal muscle and tendon, but without any effect upon myofibrillar protein synthesis. The results suggest that GH is more important in strengthening the matrix tissue than for muscle cell hypertrophy in adult human musculotendinous tissue.......In skeletal muscle and tendon the extracellular matrix confers important tensile properties and is crucially important for tissue regeneration after injury. Musculoskeletal tissue adaptation is influenced by mechanical loading, which modulates the availability of growth factors, including growth...... young individuals. rhGH administration caused an increase in serum GH, serum IGF-I, and IGF-I mRNA expression in tendon and muscle. Tendon collagen I mRNA expression and tendon collagen protein synthesis increased by 3.9-fold and 1.3-fold, respectively (P muscle collagen I m...

  16. 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.

  17. 77 FR 69508 - Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons

    Science.gov (United States)

    2012-11-19

    ... NUCLEAR REGULATORY COMMISSION [NRC-2011-0096] Inservice Inspection of Prestressed Concrete... (RG) 1.90, ``Inservice Inspection of Prestressed Concrete Containment Structures with Grouted Tendons... appropriate surveillance program for prestressed concrete containment structures with grouted tendons...

  18. Structured white light scanning of rabbit Achilles tendon.

    Science.gov (United States)

    Hayes, Alex; Easton, Katrina; Devanaboyina, Pavan Teja; Wu, Jian-Ping; Kirk, Thomas Brett; Lloyd, David

    2016-11-07

    The cross-sectional area (CSA) of a material is used to calculate stress under load. The mechanical behaviour of soft tissue is of clinical interest in the management of injury; however, measuring CSA of soft tissue is challenging as samples are geometrically irregular and may deform during measurement. This study presents a simple method, using structured light scanning (SLS), to acquire a 3D model of rabbit Achilles tendon in vitro for measuring CSA of a tendon. The Artec Spider™ 3D scanner uses structured light and stereophotogrammetry technologies to acquire shape data and reconstruct a 3D model of an object. In this study, the 3D scanner was integrated with a custom mechanical rig, permitting 360-degree acquisition of the morphology of six New Zealand White rabbit Achilles tendons. The reconstructed 3D model was then used to measure CSA of the tendon. SLS, together with callipers and micro-CT, was used to measure CSA of objects with a regular or complex shape, such as a drill flute and human cervical vertebra, for validating the accuracy and repeatability of the technique. CSA of six tendons was measured with a coefficient of variation of less than 2%. The mean CSA was 9.9±1.0mm 2 , comparable with those reported by other researchers. Scanning of phantoms demonstrated similar results to μCT. The technique developed in this study offers a simple and accurate method for effectively measuring CSA of soft tissue such as tendons. This allows for localised calculation of stress along the length, assisting in the understanding of the function, injury mechanisms and rehabilitation of tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. A reinforcement system and a method of reinforcing a structure with a tendon

    DEFF Research Database (Denmark)

    2016-01-01

    A reinforcement system for anchoring tendons for structural reinforcing a structure such as a concrete structure, said reinforcement system comprises at least one anchor and at least one tendon, said anchor is adapted to fix said tendon in and/or outside said structure, wherein said reinforcement...... system comprises a ductility element, which is positioned in structural connection between said tendon and said anchor, said ductility element comprising weakened deformation zones being deformable so that the length of the ductility is increased or decreased in an axial direction along the length...... of said tendon....

  20. Calf Endurance and Achilles Tendon Structure in Classical Ballet Dancers.

    Science.gov (United States)

    Zellers, Jennifer A; van Ostrand, Katrina; Silbernagel, Karin Grävare

    2017-06-15

    Optimal lower leg function is critical for ballet dancers to meet their occupational requirements. Achilles tendon injury is particularly detrimental to ballet dancers. While standardized measures have been validated and incorporated into clinical practice for use in people with Achilles tendon injury, normative ranges specific to the dancer population have not been described. The purpose of this pilot study was to observe the performance of pre-professional ballet students and professional ballet dancers on a well-established test battery for lower leg functional performance as well as ultra-sonographic evaluation of the structure of their Achilles tendons. The dancers in this study had significantly shorter Achilles tendons than non-dancers (p = 0.016). Dancers demonstrated significantly higher maximum heel-rise height on the heel-rise test for calf endurance (p < 0.001) but performed significantly less work than non-dancers (p = 0.014). The results of this study support the use of the heel-rise test as a tool for screening and to guide rehabilitation.

  1. Local administration of growth hormone stimulates tendon collagen synthesis in elderly men

    DEFF Research Database (Denmark)

    Vestergaard, P; Jørgensen, J.O.L.; Olesen, J.L.

    2012-01-01

    Tendon collagen content and circulating growth hormone (GH) are reduced in elderly. In a placebo-controlled, double-blinded study, we examined if local injections of rhGH enhance collagen synthesis in healthy elderly men (61 ± 1 yr). Two injections of rhGH or saline (control) were injected into e...

  2. Coordinated collagen and muscle protein synthesis in human patella tendon and quadriceps muscle after exercise

    DEFF Research Database (Denmark)

    Miller, Benjamin F; Olesen, Jens L; Hansen, Mette

    2005-01-01

    We hypothesized that an acute bout of strenuous, non-damaging exercise would increase rates of protein synthesis of collagen in tendon and skeletal muscle but these would be less than those of muscle myofibrillar and sarcoplasmic proteins. Two groups (n = 8 and 6) of healthy young men were studie...

  3. Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats.

    Directory of Open Access Journals (Sweden)

    Diego Pulzatto Cury

    Full Text Available Tendons are transition tissues that transfer the contractile forces generated by the muscles to the bones, allowing movement. The region where the tendon attaches to the bone is called bone-tendon junction or enthesis and may be classified as fibrous or fibrocartilaginous. This study aims to analyze the collagen fibers and the cells present in the bone-tendon junction using light microscopy and ultrastructural techniques as scanning electron microscopy and transmission electron microscopy. Forty male Wistar rats were used in the experiment, being 20 adult rats at 4 months-old and 20 elderly rats at 20 months-old. The hind limbs of the rats were removed, dissected and prepared to light microscopy, transmission electron microscopy and scanning electron microscopy. The aging process showed changes in the collagen fibrils, with a predominance of type III fibers in the elderly group, in addition to a decrease in the amount of the fibrocartilage cells, fewer and shorter cytoplasmic processes and a decreased synthetic capacity due to degradation of the organelles involved in synthesis.

  4. The Tendon Structure Returns to Asymptomatic Values in Nonoperatively Treated Achilles Tendinopathy but Is Not Associated With Symptoms: A Prospective Study

    NARCIS (Netherlands)

    de Jonge, Suzan; Tol, Johannes L.; Weir, Adam; Waarsing, Jan H.; Verhaar, Jan A. N.; de Vos, Robert-Jan

    2015-01-01

    Background: Tendinopathy is characterized by alterations in the tendon structure, but there are conflicting results on the potential of tendon structure normalization and no large studies on the quantified, ultrasonographic tendon structure and its association with symptoms. Purpose: To determine

  5. High voltage pulsed current in collagen realignment, synthesis, and angiogenesis after Achilles tendon partial rupture

    Directory of Open Access Journals (Sweden)

    Érika P. Rampazo

    2016-01-01

    Full Text Available ABSTRACT Objective To verify the efficacy of high voltage pulsed current in collagen realignment and synthesis and in angiogenesis after the partial rupturing of the Achilles tendon in rats. Method Forty male Wistar rats were randomized into four groups of 10 animals each: sham, cathodic stimulation, anodic stimulation, and alternating stimulation. Their Achilles tendons were submitted to direct trauma by a free-falling metal bar. Then, the treatment was administered for six consecutive days after the injury. In the simulation group, the electrodes were positioned on the animal, but the device remained off for 30 minutes. The other groups used a frequency of 120 pps, sensory threshold, and the corresponding polarity. On the seventh day, the tendons were removed and sent for histological slide preparation for birefringence and Picrosirius Red analysis and for blood vessel quantification. Results No significant difference was observed among the groups regarding collagen realignment (types I or III collagen or quantity of blood vessels. Conclusion High voltage pulsed current for six consecutive days was not effective in collagen realignment, synthesis, or angiogenesis after the partial rupturing of the Achilles tendon in rats.

  6. Effect of administration of oral contraceptives in vivo on collagen synthesis in tendon and muscle connective tissue in young women

    DEFF Research Database (Denmark)

    Hansen, M; Miller, B F; Holm, Lars

    2009-01-01

    Women are at greater risk than men for certain kinds of diseases and injuries, which may at least partly be caused by sex hormonal differences. We aimed to test the influence of estradiol in vivo on collagen synthesis in tendon, bone, and muscle. Two groups of young, healthy women similar in age...... concentrations of estradiol and progesterone (control, n = 12). Subjects performed 1 h of one-legged kicking exercise. The next day collagen fractional synthesis rates (FSR) in tendon and muscle connective tissue were measured after a flooding dose of [(13)C]proline followed by biopsies from the patellar tendon...

  7. The structural and mechanical properties of the Achilles tendon 2 years after surgical repair

    NARCIS (Netherlands)

    Geremia, J.M.; Bobbert, M.F.; Casa Nova, M.; Ott, R.D.; De Aguiar Lemos, F.; De Oliveira Lupion, R.; Frasson, V.B.

    2015-01-01

    Background Acute ruptures of the Achilles tendon affect the tendon's structural and mechanical properties. The long-term effects of surgical repair on these properties remain unclear. Purpose To evaluate effects of early mobilization versus traditional immobilization rehabilitation programs 2 years

  8. Effect of prostaglandin E2 injection on the structural properties of the rat patellar tendon

    Directory of Open Access Journals (Sweden)

    Ferry Scott T

    2012-01-01

    Full Text Available Abstract Background Increased tendon production of the inflammatory mediator prostaglandin E2 (PGE2 has been suggested to be a potential etiologic agent in the development of tendinopathy. Repeated injection of PGE2 into tendon has been proposed as a potential animal model for studying treatments for tendinopathy. In contrast, nonsteroidal anti-inflammatory drugs (NSAIDs which inhibit PGE2 production and are commonly prescribed in treating tendinopathy have been shown to impair the healing of tendon after acute injury in animal models. The contradictory literature suggests the need to better define the functional effects of PGE2 on tendon. Our objective was to characterize the effects of PGE2 injection on the biomechanical and biochemical properties of tendon and the activity of the animals. Our hypothesis was that weekly PGE2 injection to the rat patellar tendon would lead to inferior biomechanical properties. Methods Forty rats were divided equally into four groups. Three groups were followed for 4 weeks with the following peritendinous injection procedures: No injection (control, 4 weekly injections of saline (saline, 4 weekly injections of 800 ng PGE2 (PGE2-4 wks. The fourth group received 4 weekly injections of 800 ng PGE2 initially and was followed for a total of 8 weeks. All animals were injected bilaterally. The main outcome measurements included: the structural and material properties of the patellar tendon under tensile loading to failure, tendon collagen content, and weekly animal activity scores. Results The ultimate load of PGE2-4 wks tendons at 4 weeks was significantly greater than control or saline group tendons. The stiffness and elastic modulus of the PGE2 injected tendons at 8 weeks was significantly greater than the control or saline tendons. No differences in animal activity, collagen content, or mean fibril diameter were observed between groups. Conclusions Four weekly peritendinous injections of PGE2 to the rat patellar

  9. Increase in tendon protein synthesis in response to insulin-like growth factor-I is preserved in elderly men

    DEFF Research Database (Denmark)

    Nielsen, Rie Harboe; Holm, Lars; Malmgaard-Clausen, Nikolaj Mølkjær

    2014-01-01

    Insulin-like growth factor-I (IGF-I) is known to be an anabolic factor in tendon, and the systemic levels are reduced with aging. However, it is uncertain how tendon fibroblasts are involved in tendon aging and how aging cells respond to IGF-I. The purpose of this study was to investigate...... the in vivo IGF-I stimulation of tendon protein synthesis in elderly compared with young men. We injected IGF-I in the patellar tendons of young (n = 11, 20-30 yr of age) and old (n = 11, 66-75 yr of age) men, and the acute fractional synthesis rate (FSR) of tendon protein was measured with the stable isotope...... technique and compared with the contralateral side (injected with saline as control). We found that tendons injected with IGF-I had significantly higher protein FSR compared with controls (old group: 0.018 ± 0.015 vs. 0.008 ± 0.008, young group: 0.016 ± 0.009 vs. 0.009 ± 0.006%/h, mean ± SE, P

  10. Structural integrity is decreased in both Achilles tendons in people with unilateral Achilles tendinopathy.

    Science.gov (United States)

    Docking, Sean I; Rosengarten, Samuel D; Daffy, John; Cook, Jill

    2015-07-01

    A high proportion of Achilles tendinopathy patients develop bilateral symptoms with human and animal studies showing bilateral histological changes associated with overuse/pathology in one tendon. The current study examined changes in tendon structure, assessed semi-quantitatively using ultrasound tissue characterisation, in both the symptomatic and asymptomatic tendon in unilateral Achilles tendinopathy patients in comparison to individuals with no history of tendinopathy. Cross-sectional case-control study. Participants with Achilles tendinopathy (n=21), with varying severity and length of clinical symptoms, and six participants with no history of tendinopathy were recruited. Tendons were scanned using ultrasound tissue characterisation, which captures contiguous transverse ultrasound images every 0.2mm and renders a 3-dimensional image. Ultrasound tissue characterisation quantifies tendon structure by measuring the stability of echopattern over contiguous transverse images. Four echo-types were discriminated and expressed as a percentage. Antero-posterior diameter of all tendons was measured. Significant differences were observed in the proportion of normal tendon structure between all three groups (ptendinopathy. Future studies need to investigate whether these changes increase the risk of developing symptoms. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. The influence of physical activity during youth on structural and functional properties of the Achilles tendon

    DEFF Research Database (Denmark)

    Lenskjold, A; Kongsgaard, M; Larsen, J O

    2015-01-01

    Achilles tendinopathy is a highly prevalent sports injury. Animal studies show a growth response in tendons in response to loading in the immature phase but not after puberty maturation. The aim of this investigation was to examine the structural and material properties in long distance runners w...... did not appreciably influence the mechanical, structural, or biochemical properties of the Achilles tendon in adult long distance runners.......Achilles tendinopathy is a highly prevalent sports injury. Animal studies show a growth response in tendons in response to loading in the immature phase but not after puberty maturation. The aim of this investigation was to examine the structural and material properties in long distance runners who...... were either physically active (HAY) or inactive (LAY) in young age. Twelve men in HAY group and eight men in LAY group participated. Structural, functional, and biochemical properties of Achilles tendon were estimated from magnetic resonance imaging, ultrasound video recordings, mechanical tests...

  12. Are Sport-Specific Profiles of Tendon Stiffness and Cross-Sectional Area Determined by Structural or Functional Integrity?

    Directory of Open Access Journals (Sweden)

    Hans-Peter Wiesinger

    Full Text Available The present study aimed to determine whether distinct sets of tendon properties are seen in athletes engaged in sports with contrasting requirements for tendon function and structural integrity. Patellar and Achilles tendon morphology and force-deformation relation were measured by combining ultrasonography, electromyography and dynamometry in elite ski jumpers, distance runners, water polo players and sedentary individuals. Tendon cross-sectional area normalized to body mass2/3 was smaller in water polo players than in other athletes (patellar and Achilles tendon; -28 to -24% or controls (patellar tendon only; -9%. In contrast, the normalized cross-sectional area was larger in runners (patellar tendon only; +26% and ski jumpers (patellar and Achilles tendon; +21% and +13%, respectively than in controls. Tendon stiffness normalized to body mass2/3 only differed in ski jumpers, compared to controls (patellar and Achilles tendon; +11% and +27%, respectively and to water polo players (Achilles tendon only; +23%. Tendon size appears as an adjusting variable to changes in loading volume and/or intensity, possibly to preserve ultimate strength or fatigue resistance. However, uncoupled morphological and mechanical properties indicate that functional requirements may also influence tendon adaptations.

  13. Structure and component alteration of rabbit Achilles tendon in tissue culture.

    Science.gov (United States)

    Hosaka, Yoshinao; Ueda, Hiromi; Yamasaki, Tadatsugu; Suzuki, Daisuke; Matsuda, Naoya; Takehana, Kazushige

    2005-12-01

    The aim of this study was to investigate alterations of cultured tendon tissues to determine whether tissue culture is a useful method for biological analyses of the tendon. Tendon tissues for tissue culture were isolated from Achilles tendons of rabbits. The tendon segments were placed one segment per well and incubated in growth medium consisting of Dullbecco's modified Eagle's medium supplemented with 5% fetal bovine serum at 37 degrees C in a humidified atmosphere with 5% CO(2) for various periods. The alignment of collagen fibrils was preserved for 48 h, but tendon structure has disintegrated at 96 h. Alcian blue staining and gelatine zymography revealed that proteoglycan markedly diminished and that matrix metalloproteinase (MMPs) activity was upregulated sharply at 72 and 96 h. The ratio of collagen fibrils with large diameter had increased and the mean diameter and mass average diameter value had reached maximum at 48 h. The values then decreased and mean diameters at 72 and 96 h were significantly different from that at 48 h. At 96 h, the ratio of collagen fibrils with small diameters had increased and collagen fibrils with large diameters had disappeared. These findings indicate that structural alteration is possible to be induced by disintegration of collagen fibrils and disappearance of glycosaminoglycans from extracellular matrix (ECM), subsequent of upregulation of MMPs activity. Although the study period is limited, the tissue culture method is available for investigating cell-ECM interaction in tendons.

  14. Coordinated development of muscles and tendon-like structures: early interactions in the Drosophila leg

    Directory of Open Access Journals (Sweden)

    cedric esoler

    2016-02-01

    Full Text Available The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates during the early steps of leg development, we affect the spatial localisation of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes.

  15. Synthesis, characterization and histomorphometric analysis of cellular response to a new elastic DegraPol® polymer for rabbit Achilles tendon rupture repair.

    Science.gov (United States)

    Buschmann, Johanna; Calcagni, Maurizio; Bürgisser, Gabriella Meier; Bonavoglia, Eliana; Neuenschwander, Peter; Milleret, Vincent; Giovanoli, Pietro

    2015-05-01

    Tendon rupture repair is a surgical field where improvements are still required due to problems such as repeat ruptures, adhesion formation and joint stiffness. In the current study, a reversibly expandable and contractible electrospun tube based on a biocompatible and biodegradable polymer was implanted around a transected and conventionally sutured rabbit Achilles tendon. The material used was DegraPol® (DP), a polyester urethane. To make DP softer, more elastic and surgeon-friendly, the synthesis protocol was slightly modified. Material properties of conventional and new DP film electrospun meshes are presented. At 12 weeks post-surgery, tenocyte and tenoblast density, nuclei and width, collagen fibre structure and inflammation levels were analyzed histomorphometrically. Additionally, a comprehensive histological scoring system by Stoll et al. (2011) was used to compare healing outcomes. Results showed that there were no adverse reactions of the tendon tissue following the implant. No differences were found whether the DP tube was applied or not for both traditional and new DP materials. As a result, the new DP material was shown to be an excellent carrier for delivery of growth factors, stem cells and other agents responsible for tendon healing. Copyright © 2015 John Wiley & Sons, Ltd.

  16. p38 MAPK Signaling in Postnatal Tendon Growth and Remodeling

    Science.gov (United States)

    Schwartz, Andrew J.; Sarver, Dylan C.; Sugg, Kristoffer B.; Dzierzawski, Justin T.; Gumucio, Jonathan P.; Mendias, Christopher L.

    2015-01-01

    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. PMID:25768932

  17. 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.

  18. Evidence of structurally continuous collagen fibrils in tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias

    2017-01-01

    favor continuity. This study initially set out to trace the full length of individual fibrils in adult human tendons, using serial block face-scanning electron microscopy. But even with this advanced technique the required length could not be covered. Instead a statistical approach was used on a large...... volume of fibrils in shorter image stacks. Only a single end was observed after tracking 67.5 mm of combined fibril lengths, in support of fibril continuity. To shed more light on this observation, the full length of a short tendon (mouse stapedius, 125 μm) was investigated and continuity of individual...... fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. STATEMENT OF SIGNIFICANCE: Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen...

  19. Nonlinear ultrasonic guided waves for stress monitoring in prestressing tendons for post-tensioned concrete structures

    Science.gov (United States)

    Bartoli, Ivan; Nucera, Claudio; Srivastava, Ankit; Salamone, Salvatore; Phillips, Robert; Lanza di Scalea, Francesco; Coccia, Stefano; Sikorsky, Charles S.

    2009-03-01

    Many bridges, including 90% of the California inventory, are post-tensioned box-girders concrete structures. Prestressing tendons are the main load-carrying components of these and other post-tensioned structures. Despite their criticality, much research is needed to develop and deploy techniques able to provide real-time information on the level of prestress in order to detect dangerous stress losses. In collaboration with Caltrans, UCSD is investigating the combination of ultrasonic guided waves and embedded sensors to provide both prestress level monitoring and defect detection capabilities in concrete-embedded PS tendons. This paper presents a technique based on nonlinear ultrasonic guided waves in the 100 kHz - 2 MHz range for monitoring prestress levels in 7-wire PS tendons. The technique relies on the fact that an axial stress on the tendon generates a proportional radial stress between adjacent wires (interwire stress). In turn, the interwire stress modulates nonlinear effects in ultrasonic wave propagation through both the presence of finite strains and the interwire contact. The nonlinear ultrasonic behavior of the tendon under changing levels of prestress is monitored by tracking higher-order harmonics at (nω) arising under a fundamental guided-wave excitation at (ω). Experimental results will be presented to identify (a) ranges of fundamental excitations at (ω) producing maximum nonlinear response, and (b) optimum lay-out of the transmitting and the receiving transducers within the test tendons. Compared to alternative methods based on linear ultrasonic features, the proposed nonlinear ultrasonic technique appears more sensitive to prestress levels and more robust against changing excitation power at the transmitting transducer or changing transducer/tendon bond conditions.

  20. Experimental diabetes induces structural, inflammatory and vascular changes of Achilles tendons.

    Directory of Open Access Journals (Sweden)

    Rodrigo R de Oliveira

    Full Text Available This study aims to demonstrate how the state of chronic hyperglycemia from experimental Diabetes Mellitus can influence the homeostatic imbalance of tendons and, consequently, lead to the characteristics of tendinopathy. Twenty animals were randomly divided into two experimental groups: control group, consisting of healthy rats and diabetic group constituted by rats induced to Diabetes Mellitus I. After twenty-four days of the induction of Diabetes type I, the Achilles tendon were removed for morphological evaluation, cellularity, number and cross-sectional area of blood vessel, immunohistochemistry for Collagen type I, VEGF and NF-κB nuclear localization sequence (NLS and nitrate and nitrite level. The Achilles tendon thickness (µm/100g of diabetic animals was significantly increased and, similarly, an increase was observed in the density of fibrocytes and mast cells in the tendons of the diabetic group. The average number of blood vessels per field, in peritendinous tissue, was statistically higher in the diabetic group 3.39 (2.98 vessels/field when compared to the control group 0.89 (1.68 vessels/field p = 0.001 and in the intratendinous region, it was observed that blood vessels were extremely rare in the control group 0.035 (0.18 vessels/field and were often present in the tendons of the diabetic group 0.89 (0.99 vessels/field. The immunohistochemistry analysis identified higher density of type 1 collagen and increased expression of VEGF as well as increased immunostaining for NFκB p50 NLS in the nucleus in Achilles tendon of the diabetic group when compared to the control group. Higher levels of nitrite/nitrate were observed in the experimental group induced to diabetes. We conclude that experimental DM induces notable structural, inflammatory and vascular changes in the Achilles tendon which are compatible with the process of chronic tendinopathy.

  1. Ultrasonographic tissue characterisation of human Achilles tendons: quantification of tendon structure through a novel non-invasive approach

    NARCIS (Netherlands)

    J.T.M. van Schie (Hans); R.J. de Vos (Robert-Jan); S. de Jonge (Suzan); E.M. Bakker (Erwin); M.P. Heijboer (Rien); J.A.N. Verhaar (Jan); J.L. Tol (Johannes); H.H. Weinans (Harrie)

    2009-01-01

    textabstractOBJECTIVE: To asses if three-dimensional imaging of the Achilles tendon by Ultrasonographic Tissue Characterisation (UTC) can differentiate between symptomatic and asymptomatic tendons. DESIGN: Case-control study. SETTING: Sports medical department of The Hague medical centre. PATIENTS:

  2. Structure relates to elastic recoil and functional role in quadriceps tendon and patellar ligament.

    Science.gov (United States)

    Franchi, Marco; Quaranta, Marilisa; Macciocca, Maria; De Pasquale, Viviana; Ottani, Vittoria; Ruggeri, Alessandro

    2009-04-01

    Tendons and ligaments have similar but slightly different structure and composition. Crimps of tendons and ligaments are morphological structures related to the elastic functional properties of these connective tissues. Aim of this study was to investigate the morphological arrangement of collagen fibres, fibrils and crimping pattern of suprapatellar (rectus femoris tendon-RFT and vastus intermedius tendon-VIT) and infrapatellar connective tissues (patellar ligament-PL) to relate their structural aspects to their common function role of leg extension. RFT, VIT and PL were removed from knees of Sprague-Dawley rats and light and electron microscopy (TEM and SEM) performed. Sagittal sections showed that collagen array and crimping pattern were similar in RFT and PL but differed from VIT. Morphometric analysis confirmed that crimp number was about the same in RFT and PL (5.4+/-1.4 and 6.1+/-2.8 respectively), but it was almost three times higher in VIT (14.5+/-4.7). Similarly crimp top angle in RFT and PL (141.5+/-15.0 degrees and 146.2+/-12.2 degrees respectively) was significantly higher than in VIT (122.3+/-14.8 degrees ) and the crimp base length was more than twice as wide in RFT (75.5+/-22.6microm) and PL (72.3+/-28.9microm) than in VIT (36+/-14.1microm). The smaller, fewer and most crimped crimps in VIT show that this tendon has a greater elastic recoil and responds to higher forces as among quadriceps muscles the vastus intermedius belly contributes the most during knee extension. By contrast, RFT acting as a "stopper" tendon also plays a ligament role by limiting an excessive flexion of the joint during postural rest position of the knee.

  3. Health monitoring of prestressing tendons in post-tensioned concrete structures

    Science.gov (United States)

    Salamone, Salvatore; Bartoli, Ivan; Nucera, Claudio; Phillips, Robert; Lanza di Scalea, Francesco

    2011-04-01

    Currently 90% of bridges built in California are post-tensioned box-girder. In such structures the steel tendons are the main load-carrying components. The loss of prestress, as well as the presence of defects or the tendon breakage, can be catastrophic for the entire structure. Unfortunately, today there is no well-established method for the monitoring of prestressing (PS) tendons that can provide simultaneous information related to the presence of defects and the level of prestress in a continuous, real time manner. If such a monitoring system were available, considerable savings would be achieved in bridge maintenance since repairs would be implemented in a timely manner without traffic disruptions. This paper presents a health monitoring system for PS tendons in post-tensioned structures of interest to Caltrans. Such a system uses ultrasonic guided waves and embedded sensors to provide simultaneously and in real time, (a) measurements of the level of applied prestress, and (b) defect detection at early grow stages. The proposed PS measurement technique exploits the sensitivity of ultrasonic waves to the inter-wire contact developing in a multi-wire strand as a function of prestress level. In particular the nonlinear ultrasonic behavior of the tendon under changing levels of prestress is monitored by tracking higher-order harmonics at (nω) arising under a fundamental guided-wave excitation at (ω). Moreover this paper also present real-time damage detection and location in post-tensioned bridge joints using Acoustic Emission techniques. Experimental tests on large-scale single-tendon PT joint specimens, subjected to multiple load cycles, will be presented to validate the monitoring of PS loads (through nonlinear ultrasonic probing) and the monitoring of damage progression and location (through acoustic emission techniques). Issues and potential for the use of such techniques to monitor post-tensioned bridges in the field will be discussed.

  4. No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy

    NARCIS (Netherlands)

    de Vos, R. J.; Weir, A.; Tol, J. L.; Verhaar, J. A. N.; Weinans, H.; van Schie, H. T. M.

    2011-01-01

    To assess whether a platelet-rich plasma (PRP) injection leads to an enhanced tendon structure and neovascularisation, measured with ultrasonographic techniques, in chronic midportion Achilles tendinopathy. Double-blind, randomised, placebo-controlled clinical trial. Sports medical department of The

  5. Effect of cyclic training model on terminal structure of rabbit Achilles tendon: an experimental study

    Directory of Open Access Journals (Sweden)

    Chang-lin HUANG

    2012-05-01

    Full Text Available Objective  To observe the effect of cyclic training on histomorphology of the terminal structure of rabbit Achilles tendon, and explore its preventive effect on training-based enthesiopathy. Methods  Seventy-two Japanese white rabbits were randomly assigned to four groups: control group, jumping group, running group and cyclic training group, 18 for each. Three rabbits of each group were sacrificed at the 2nd, 3rd, 4th, 6th, 8th and 10th week. The terminal insertion tissues of bilateral Achilles tendons were harvested from these rabbits for observing the pathomorphological changes under light microscope, and pathological scoring and statistical analysis were carried out. Results  Light microscopy showed that the tendon fibers and fibrocartilage in the Achilles tendon insertion region were severely damaged in the jumping group, and though the tendon fibers were damaged severely, the injury to the fibrocartilage was comparatively less serious in the running group. The injuries to the tendon fibers and fibrocartilage were milder in the cyclic training group than in the jumping group and running group. In the 2nd, 3rd, 4th, 6th and 8th week, the histopathology score of insertion of Achilles tendon was 1.17±0.12, 2.19±0.15, 3.23±0.20, 4.66±0.16, 4.71±0.18, 4.63±0.13 respectively in the jumping group, and 1.16±0.13, 1.15±0.14, 2.18±0.12, 2.99±0.15, 3.98±0.16, 4.01±0.12 respectively in the running group. Increase in pathological score appeared earlier in the jumping group than in the running group, and a significant increase began at the 3rd week. The difference in pathological score between the two groups originated mainly from the changes in the tidemark. In the 2nd, 3rd, 4th, 6th, 8th and 10th week, the pathological score of Achilles tendon insertion was 1.13±0.14, 1.16±0.17, 1.15±0.13, 2.18±0.13, 2.17±0.12, 2.92±0.11 respectively in the cyclic training group, and they showed no significant changes as compared with control

  6. Changes in skeletal muscle and tendon structure and function following genetic inactivation of myostatin in rats.

    Science.gov (United States)

    Mendias, Christopher L; Lynch, Evan B; Gumucio, Jonathan P; Flood, Michael D; Rittman, Danielle S; Van Pelt, Douglas W; Roche, Stuart M; Davis, Carol S

    2015-04-15

    Myostatin is a negative regulator of skeletal muscle and tendon mass. Myostatin deficiency has been well studied in mice, but limited data are available on how myostatin regulates the structure and function of muscles and tendons of larger animals. We hypothesized that, in comparison to wild-type (MSTN(+/+) ) rats, rats in which zinc finger nucleases were used to genetically inactivate myostatin (MSTN(Δ/Δ) ) would exhibit an increase in muscle mass and total force production, a reduction in specific force, an accumulation of type II fibres and a decrease and stiffening of connective tissue. Overall, the muscle and tendon phenotype of myostatin-deficient rats was markedly different from that of myostatin-deficient mice, which have impaired contractility and pathological changes to fibres and their extracellular matrix. Extensor digitorum longus and soleus muscles of MSTN(Δ/Δ) rats demonstrated 20-33% increases in mass, 35-45% increases in fibre number, 20-57% increases in isometric force and no differences in specific force. The insulin-like growth factor-1 pathway was activated to a greater extent in MSTN(Δ/Δ) muscles, but no substantial differences in atrophy-related genes were observed. Tendons of MSTN(Δ/Δ) rats had a 20% reduction in peak strain, with no differences in mass, peak stress or stiffness. The general morphology and gene expression patterns were similar between tendons of both genotypes. This large rodent model of myostatin deficiency did not have the negative consequences to muscle fibres and extracellular matrix observed in mouse models, and suggests that the greatest impact of myostatin in the regulation of muscle mass may not be to induce atrophy directly, but rather to block hypertrophy signalling. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  7. Leg tendon glands in male bumblebees ( Bombus terrestris): structure, secretion chemistry, and possible functions

    Science.gov (United States)

    Jarau, Stefan; Žáček, Petr; Šobotník, Jan; Vrkoslav, Vladimír; Hadravová, Romana; Coppée, Audrey; Vašíčková, Soňa; Jiroš, Pavel; Valterová, Irena

    2012-12-01

    Among the large number of exocrine glands described in bees, the tarsal glands were thought to be the source of footprint scent marks. However, recent studies showed that the compounds used for marking by stingless bees are secreted by leg tendon instead of tarsal glands. Here, we report on the structure of leg tendon glands in males of Bombus terrestris, together with a description of the chemical composition of their secretions and respective changes of both during the males' lives. The ultrastructure of leg tendon glands shows that the secretory cells are located in three independent regions, separated from each other by unmodified epidermal cells: in the femur, tibia, and basitarsus. Due to the common site of secretion release, the organ is considered a single secretory gland. The secretion of the leg tendon glands of B. terrestris males differs in its composition from those of workers and queens, in particular by (1) having larger proportions of compounds with longer chain lengths, which we identified as wax esters; and (2) by the lack of certain hydrocarbons (especially long chain dienes). Other differences consist in the distribution of double bond positions in the unsaturated hydrocarbons that are predominantly located at position 9 in males but distributed at seven to nine different positions in the female castes. Double bond positions may change chemical and physical properties of a molecule, which can be recognized by the insects and, thus, may serve to convey specific information. The function of male-specific compounds identified from their tendon glands remains elusive, but several possibilities are discussed.

  8. Clinical improvements are not explained by changes in tendon structure on UTC following an exercise program for patellar tendinopathy.

    Science.gov (United States)

    van Ark, Mathijs; Rio, Ebonie; Cook, Jill; van den Akker-Scheek, Inge; Gaida, James E; Zwerver, Johannes; Docking, Sean

    2018-04-11

    The aim of this study was to investigate the effects of a 4-week in-season exercise program of isometric or isotonic exercises on tendon structure and dimensions as quantified by Ultrasound Tissue Characterization (UTC). Randomized clinical trial. Volleyball and basketball players (16-31 years, n=29) with clinically diagnosed patellar tendinopathy were randomized to a 4-week isometric or isotonic exercise program. The programs were designed to decrease patellar tendon pain. A baseline and 4-week UTC scan was used to evaluate change in tendon structure. No significant change in tendon structure or dimensions on UTC was detected after the exercise program, despite patellar tendinopathy symptoms improving. The percentage and mean cross-sectional area (mCSA) of aligned fibrillar structure (echo-types I+II) (Z=-0.414,p=0.679) as well as disorganized structure (echo-types III + IV) (Z=-0.370,p=0.711) did not change over the 4-week exercise program. Change in tendon structure and dimensions on UTC did not differ significantly between the groups. Structural properties and dimensions of the patellar tendon on UTC did not change after a 4-week isometric or isotonic exercise program for athletes with patellar tendinopathy in-season, despite an improvement of symptoms. It seems that structural improvements are not required for a positive clinical outcome.

  9. Increasing platelet concentrations in leukocyte-reduced platelet-rich plasma decrease collagen gene synthesis in tendons.

    Science.gov (United States)

    Boswell, Stacie G; Schnabel, Lauren V; Mohammed, Hussni O; Sundman, Emily A; Minas, Tom; Fortier, Lisa A

    2014-01-01

    Platelet-rich plasma (PRP) is used for the treatment of tendinopathy. There are numerous PRP preparations, and the optimal combination of platelets and leukocytes is not known. Within leukocyte-reduced PRP (lrPRP), there is a plateau effect of platelet concentration, with increasing platelet concentrations being detrimental to extracellular matrix synthesis. Controlled laboratory study. Different formulations of lrPRP with respect to the platelet:leukocyte ratio were generated from venous blood of 8 horses. Explants of the superficial digital flexor tendon were cultured in lrPRP products for 96 hours. Platelet-derived growth factor-BB (PDGF-BB), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and interleukin-1β (IL-1β) concentrations were determined in the media by enzyme-linked immunosorbent assay. Gene expression in tendon tissue for collagen type I and III (COL1A1 and COL3A1, respectively), matrix metalloproteinase-3 and -13 (MMP-3 and MMP-13, respectively), cartilage oligomeric matrix protein (COMP), and IL-1β was determined. Data were divided into 3 groups of lrPRP based on the ratio of platelets:leukocytes and evaluated to determine the effect of platelet concentration. Complete blood counts verified leukocyte reduction and platelet enrichment in all PRP preparations. In the lrPRP preparation, the anabolic growth factors PDGF-BB and TGF-β1 were increased with increasing platelet concentrations, and the catabolic cytokine IL-1β was decreased with increasing platelet concentrations. Increasing the platelet concentration resulted in a significant reduction in COL1A1 and COL3A1 synthesis in tendons. Increasing the platelet concentration within lrPRP preparations results in the delivery of more anabolic growth factors and less proinflammatory cytokines, but the biological effect on tendons is diminished metabolism as indicated by a decrease in the synthesis of both COL1A1 and COL3A1. Together, this information suggests that

  10. 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.

  11. Chronic alterations in growth hormone/insulin-like growth factor-I signaling lead to changes in mouse tendon structure

    DEFF Research Database (Denmark)

    Nielsen, R H; Clausen, N M; Schjerling, P

    2014-01-01

    RNA expression (targets: GAPDH, RPLP0, IGF-IEa, IGF-IR, COL1A1, COL3A1, TGF-β1, TGF-β2, TGF-β3, versican, scleraxis, tenascin C, fibronectin, fibromodulin, decorin) in the Achilles tendon, and the mRNA expression was also measured in calf muscle (same targets as tendon plus IGF-IEb, IGF-IEc). We found that GHR......The growth hormone/insulin-like growth factor-I (GH/IGF-I) axis is an important stimulator of collagen synthesis in connective tissue, but the effect of chronically altered GH/IGF-I levels on connective tissue of the muscle-tendon unit is not known. We studied three groups of mice; 1) giant......-/- mice had significantly lower collagen fibril volume fraction in Achilles tendon, as well as decreased mRNA expression of IGF-I isoforms and collagen types I and III in muscle compared to CTRL. In contrast, the mRNA expression of IGF-I isoforms and collagens in bGH mice was generally high in both tendon...

  12. Structural and mechanical multi-scale characterization of white New-Zealand rabbit Achilles tendon.

    Science.gov (United States)

    Kahn, Cyril J F; Dumas, Dominique; Arab-Tehrany, Elmira; Marie, Vanessa; Tran, Nguyen; Wang, Xiong; Cleymand, Franck

    2013-10-01

    Multi-scale characterization of structures and mechanical behavior of biological tissues are of huge importance in order to evaluate the quality of a biological tissue and/or to provide bio-inspired scaffold for functional tissue engineering. Indeed, the more information on main biological tissue structures we get, the more relevant we will be to design new functional prostheses for regenerative medicine or to accurately evaluate tissues. From this perspective, we have investigated the structures and their mechanical properties from nanoscopic to macroscopic scale of fresh ex-vivo white New-Zealand rabbit Achilles tendon using second harmonic generation (SHG) microscopy, atomic force microscopy (AFM) and tensile tests to provide a "simple" model whose parameters are relevant of its micro or nano structure. Thus, collagen fiber's crimping was identified then measured from SHG images as a plane sine wave with 28.4 ± 5.8 μm of amplitude and 141 ± 41 μm of wavelength. Young's moduli of fibrils (3.0 GPa) and amorphous phases (223 MPa) were obtained using TH-AFM. From these investigations, a non-linear Zener model linking a statistical Weibull's distribution of taut fibers under traction to crimp fibers were developed. This model showed that for small strain (tendon observations under static or dynamic solicitations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Effect of cyclic training model on terminal structure of rabbit Achilles tendon: an experimental study

    OpenAIRE

    Chang-lin HUANG; Wang GAO; Tao HUANG; Zhen-hai GUO

    2012-01-01

    Objective  To observe the effect of cyclic training on histomorphology of the terminal structure of rabbit Achilles tendon, and explore its preventive effect on training-based enthesiopathy. Methods  Seventy-two Japanese white rabbits were randomly assigned to four groups: control group, jumping group, running group and cyclic training group, 18 for each. Three rabbits of each group were sacrificed at the 2nd, 3rd, 4th, 6th, 8th and 10th week. The terminal insertion tissues of bilateral Achil...

  14. 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...... has also been linked to a reduced responsiveness to relaxin. The present chapter will focus on sex difference in tendon injury risk, tendon morphology and tendon collagen turnover, but also on the specific effects of estrogen and androgens....

  15. Extracellular matrix adaptation of tendon and skeletal muscle to exercise

    DEFF Research Database (Denmark)

    Kjaer, Michael; Magnusson, Peter; Krogsgaard, Michael

    2006-01-01

    The extracellular matrix (ECM) of connective tissues enables linking to other tissues, and plays a key role in force transmission and tissue structure maintenance in tendons, ligaments, bone and muscle. ECM turnover is influenced by physical activity, and both collagen synthesis and metalloprotease......-beta and IL-6 is enhanced following exercise. For tendons, metabolic activity (e.g. detected by positron emission tomography scanning), circulatory responses (e.g. as measured by near-infrared spectroscopy and dye dilution) and collagen turnover are markedly increased after exercise. Tendon blood flow...... is regulated by cyclooxygenase-2 (COX-2)-mediated pathways, and glucose uptake is regulated by specific pathways in tendons that differ from those in skeletal muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as to some degree of net collagen synthesis...

  16. Structural Sizing Methodology for the Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) System

    Science.gov (United States)

    Jones, Thomas C.; Dorsey, John T.; Doggett, William R.

    2015-01-01

    The Tendon-Actuated Lightweight In-Space MANipulator (TALISMAN) is a versatile long-reach robotic manipulator that is currently being tested at NASA Langley Research Center. TALISMAN is designed to be highly mass-efficient and multi-mission capable, with applications including asteroid retrieval and manipulation, in-space servicing, and astronaut and payload positioning. The manipulator uses a modular, periodic, tension-compression design that lends itself well to analytical modeling. Given the versatility of application for TALISMAN, a structural sizing methodology was developed that could rapidly assess mass and configuration sensitivities for any specified operating work space, applied loads and mission requirements. This methodology allows the systematic sizing of the key structural members of TALISMAN, which include the truss arm links, the spreaders and the tension elements. This paper summarizes the detailed analytical derivations and methodology that support the structural sizing approach and provides results from some recent TALISMAN designs developed for current and proposed mission architectures.

  17. Structural synthesis of parallel robots

    CERN Document Server

    Gogu, Grigore

    This book represents the fifth part of a larger work dedicated to the structural synthesis of parallel robots. The originality of this work resides in the fact that it combines new formulae for mobility, connectivity, redundancy and overconstraints with evolutionary morphology in a unified structural synthesis approach that yields interesting and innovative solutions for parallel robotic manipulators.  This is the first book on robotics that presents solutions for coupled, decoupled, uncoupled, fully-isotropic and maximally regular robotic manipulators with Schönflies motions systematically generated by using the structural synthesis approach proposed in Part 1.  Overconstrained non-redundant/overactuated/redundantly actuated solutions with simple/complex limbs are proposed. Many solutions are presented here for the first time in the literature. The author had to make a difficult and challenging choice between protecting these solutions through patents and releasing them directly into the public domain. T...

  18. Achilles tendon and sports

    International Nuclear Information System (INIS)

    Ulreich, N.; Kainberger, F.; Huber, W.; Nehrer, S.

    2002-01-01

    Because of the rising popularity of recreational sports activities achillodynia is an often associated symptom with running, soccer and athletics. Therefore radiologist are frequently asked to image this tendon. The origin of the damage of the Achilles tendon is explained by numerous hypothesis, mainly a decreased perfusion and a mechanical irritation that lead to degeneration of the tendon. High-resolution technics such as sonography and magnetic resonance imaging show alterations in the structure of the tendon which can be graduated and classified. Manifestations like tendinosis, achillobursitis, rupture and Haglunds disease can summarized as the tendon overuse syndrom. A rupture of a tendon is mostly the result of a degeneration of the collagenfibres. The task of the radiologist is to acquire the intrinsic factors for a potential rupture. (orig.) [de

  19. 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

  20. Detonation-synthesis nanodiamonds: synthesis, structure, properties and applications

    International Nuclear Information System (INIS)

    Dolmatov, Valerii Yu

    2007-01-01

    The review outlines the theoretical foundations and industrial implementations of modern detonation synthesis of nanodiamonds and chemical purification of the nanodiamonds thus obtained. The structure, key properties and promising fields of application of detonation-synthesis nanodiamonds are considered.

  1. SYNTHESIS, STRUCTURE AND PHOTOLUMINESCENCE OF ...

    African Journals Online (AJOL)

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    dimensional supramolecular framework. ... The growing interest in the field of the crystal engineering of inorganic-organic hybrid materials .... Synthesis, structure and photoluminescence of (HgCl3)n(C6NO2H6)n(C6NO2H5)n nH2O. Bull. Chem.

  2. The roles of TGF-beta1 gene transfer on collagen formation during Achilles tendon healing.

    Science.gov (United States)

    Hou, Yu; Mao, ZeBing; Wei, XueLei; Lin, Lin; Chen, LianXu; Wang, HaiJun; Fu, Xin; Zhang, JiYing; Yu, ChangLong

    2009-05-29

    Collagen content and cross-linking are believed to be major determinants of tendon structural integrity and function. The current study aimed to investigate the effects of transforming growth factor (TGF)-beta1 on the collagen content and cross-linking of Achilles tendons, and on the histological and biomechanical changes occurring during Achilles tendon healing in rabbits. Bone marrow-derived mesenchymal stem cells (BMSCs) transfected with the TGF-beta1 gene were surgically implanted into experimentally injured Achilles tendons. Collagen proteins were identified by immunohistochemical staining and fiber bundle accumulation was revealed by Sirius red staining. Achilles tendons treated with TGF-beta1-transfected BMSCs showed higher concentrations of collagen I protein, more rapid matrix remodeling, and larger fiber bundles. Thus TGF-beta1 can promote mechanical strength in healing Achilles tendons by regulating collagen synthesis, cross-link formation, and matrix remodeling.

  3. synthesis and structures

    Indian Academy of Sciences (India)

    Priya Saxena

    2017-08-29

    Aug 29, 2017 ... complexes as well as for biological applications.16–24. Of particular mention here are the nickel and palladium complexes of ..... tion and indexing were performed with CrysAlisPro software suite.42 WinGX module was used to perform all the cal- culations.43 The structures were solved by direct methods.

  4. New imaging methods for non-invasive assessment of mechanical, structural and biochemical properties of Human Achilles tendon: a mini review

    Directory of Open Access Journals (Sweden)

    Alexandre Fouré

    2016-07-01

    Full Text Available The mechanical properties of tendon play a fundamental role to passively transmit forces from muscle to bone, withstand sudden stretches and act as a mechanical buffer allowing the muscle to work more efficiently. The use of non-invasive imaging methods for the assessment of human tendon’s mechanical, structural and biochemical properties in vivo is relatively young in sports medicine, clinical practice and basic science. Non-invasive assessment of the tendon properties may enhance the diagnosis of tendon injury and the characterization of recovery treatments. While ultrasonographic imaging is the most popular tool to assess the tendon’s structural and, indirectly, mechanical properties, ultrasonographic elastography and ultra-high field magnetic resonance imaging (UHF MRI have recently emerged as potentially powerful techniques to explore tendon tissues. This paper highlights some methodological cautions associated with conventional ultrasonography and perspectives for in vivo human Achilles tendon assessment using ultrasonographic elastography and UHF MRI.

  5. Does aerobic exercise training promote changes in structural and biomechanical properties of the tendons in experimental animals? A systematic review.

    Science.gov (United States)

    Bezerra, M A; Lemos, A; Lira, K D S; Silveira, P V C; Coutinho, M P G; E Moraes, S R A

    2012-12-01

    To develop a systematic review to evaluate, through the best scientific evidence available, the effectiveness of aerobic exercise in improving the biomechanical characteristics of tendons in experimental animals. Two independent assessors conducted a systematic search in the databases Medline/PUBMED and Lilacs/BIREME, using the following descriptors of Mesh in animal models. The ultimate load of traction and the elastic modulus tendon were used as primary outcomes and transverse section area, ultimate stress and tendon strain as secondary outcomes. The assessment of risk of bias in the studies was carried out using the following methodological components: light/dark cycle, temperature, nutrition, housing, research undertaken in conjunction with an ethics committee, randomization, adaptation of the animals to the training and preparation for the mechanical test. Eight studies, comprising 384 animals, were selected; it was not possible to combine them into one meta-analysis due to the heterogeneity of the samples. There was a trend to increasing ultimate load without changes in the other outcomes studied. Only one study met more than 80% of the quality criteria. Physical training performed in a structured way with imposition of overloads seems to be able to promote changes in tendon structure of experimental models by increasing the ultimate load supported. However, the results of the influence of exercise on the elastic modulus parameters, strain, transverse section area and ultimate stress, remain controversial and inconclusive. Such a conclusion must be evaluated with reservation as there was low methodological control in the studies included in this review.

  6. [Posterior tibial tendon dysfunction: what other structures are involved in the development of acquired adult flat foot?].

    Science.gov (United States)

    Herráiz Hidalgo, L; Carrascoso Arranz, J; Recio Rodríguez, M; Jiménez de la Peña, M; Cano Alonso, R; Álvarez Moreno, E; Martínez de Vega Fernández, V

    2014-01-01

    To evaluate the association of posterior tibial tendon dysfunction and lesions of diverse ankle structures diagnosed at MRI with radiologic signs of flat foot. We retrospectively compared 29 patients that had posterior tibial tendon dysfunction (all 29 studied with MRI and 21 also studied with weight-bearing plain-film X-rays) with a control group of 28 patients randomly selected from among all patients who underwent MRI and weight-bearing plain-film X-rays for other ankle problems. In the MRI studies, we analyzed whether a calcaneal spur, talar beak, plantar fasciitis, calcaneal bone edema, Achilles' tendinopathy, spring ligament injury, tarsal sinus disease, and tarsal coalition were present. In the weight-bearing plain-film X-rays, we analyzed the angle of Costa-Bertani and radiologic signs of flat foot. To analyze the differences between groups, we used Fisher's exact test for the MRI findings and for the presence of flat foot and analysis of variance for the angle of Costa-Bertani. Calcaneal spurs, talar beaks, tarsal sinus disease, and spring ligament injury were significantly more common in the group with posterior tibial tendon dysfunction (P<.05). Radiologic signs of flat foot and anomalous values for the angle of Costa-Bertani were also significantly more common in the group with posterior tibial tendon dysfunction (P<.001). We corroborate the association between posterior tibial tendon dysfunction and lesions to the structures analyzed and radiologic signs of flat foot. Knowledge of this association can be useful in reaching an accurate diagnosis. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  7. Analysis of initial prestress force of spatial tendon prestressed concrete containment structures

    International Nuclear Information System (INIS)

    Shiau, H.-S.

    1975-01-01

    A theoretical investigation is presented of the initial stage of prestressed tendon and prestressed concrete before and after jacking force of tendon anchorage released. A method is developed that is applicable to any kind of spatial tendon considering frictional loss due to length and curvature effects. A triple integral equation of one independent variable and jacking force is derived to represent an exact solution of tendon force along the whole tendon which may have reverse curvatures. In order to analyze the stress response of concrete due to this prestress force by using existing finite element computer program or any other kind of computer program, a systematic method is suggested to obtain tendon force components, which are represented by a series of equations of one independent variable, in any coordinate system as external force applied on the concrete. The resulting systems of the equations are then solved by numerical mathematic and computer techniques. Two numerical examples are represented. The first example is, dome prestress analysis of containment building by the proposed method and Kalnins' computer program for shell of revolution. Results are discussed. The second example is picked from prestress analysis for personnel air lock of containment building by using proposed method and FELAP finite element Computer program. It includes two different tendon arrangements around the opening. The results of these two different arrangements are compared and discussed

  8. Tendon protein synthesis rate in classic Ehlers-Danlos patients can be stimulated with insulin-like growth factor-I

    DEFF Research Database (Denmark)

    Nielsen, Rie Harboe; Holm, Lars; Jensen, Jacob Kildevang

    2014-01-01

    The classic form of Ehlers-Danlos syndrome (cEDS) is an inherited connective tissue disorder, where mutations in type V collagen-encoding genes result in abnormal collagen fibrils. Thus the cEDS patients have pathological connective tissue morphology and low stiffness, but the rate of connective...... was measured with the stable isotope technique using a flood-primed continuous infusion over 6 h. After the infusion one skin biopsy and two tendon biopsies (one from each patellar tendon) were obtained. We found similar baseline FSR values in skin and tendon in the cEDS patients and controls [skin: 0.005 ± 0.......002 (cEDS) and 0.007 ± 0.002 (CTRL); tendon: 0.008 ± 0.001 (cEDS) and 0.009 ± 0.002 (CTRL) %/h, mean ± SE]. IGF-I injections significantly increased FSR values in cEDS patients but not in controls (delta values: cEDS 0.007 ± 0.002, CTRL 0.001 ± 0.001%/h). In conclusion, baseline protein synthesis rates...

  9. Synthesis, development, characterization and effectiveness of bovine pure platelet gel-collagen-polydioxanone bioactive graft on tendon healing

    Science.gov (United States)

    Moshiri, Ali; Oryan, Ahmad; Meimandi-Parizi, Abdolhamid

    2015-01-01

    Bovine platelet gel (BPG) is an accessible and cost-effective source of growth factors which may have a value in tendon regenerative medicine. We produced a collagen implant (CI) as a tendon proper, covered it with polydioxanone (PDS) sheath to simulate paratenon and finally embedded the BPG as an active source of growth factor within the bioimplant to test whether BPG would be able to accelerate and enhance tendon regeneration and repair. After in vitro characterization of the bioactive grafts, the grafts were implanted in rabbit large tendon defect model. Untreated tendons and tendons treated with either CI or CI-PDS were served as controls for the CI-PDS-BPG. The animals were investigated clinically, ultrasonographically and haematologically for 120 days. After euthanasia, dry matter content, water uptake and delivery characteristics and also gross morphological, histopathological and scanning electron microscopic features of the healing tendons were assessed. In vitro, the activated platelets in the scaffold, released their growth factors significantly more than the controls. BPG also increased cell viability, and enhanced cellular differentiation, maturation and proliferation inside the CI-PDS compared with the controls. In vivo, the BPG modulated inflammation, increased quality and rate of fibroplasia and produced a remodelled tendon that had significantly higher collagen content and superior collagen fibril and fibre differentiation than controls. Treatment also significantly improved tendon water uptake and delivery characteristics, animals’ serum PDGF level, CI-PDS biocompatibility and biodegradability and reduced peritendinous adhesions, muscle fibrosis and atrophy. BPG was effective on tendon healing and CI-PDS-BPG may be a valuable bioscaffold in tendon reconstructive surgery. PMID:25702535

  10. Injury patterns and the role of tendons in protecting neurovascular structures in wrist injuries.

    Science.gov (United States)

    Lee, Chul Hyung; Cha, Soo Min; Shin, Hyun Dae

    2016-06-01

    The purpose of this study was to evaluate the anatomical features of injured structures, investigate the protection provided by the specific tendon of each corresponding important neurovascular structure (radial artery, median nerve, and ulnar nerve/artery) and to compare the results among the three categories of wrist injuries. This study included 114 patients who underwent primary repair for damaged wrist structures; 40 patients sustained accidental damage without intention (group 1), 40 had self-inflicted damage (group 2), and 34 patients had a stab or penetrating wound caused by a sharp instrument during a conflict or violent event involving another person (group 3). The basic demographic factors, distribution pattern, area, and depth of the injured structures were investigated and compared. The barrier roles of the flexor carpi radialis (FCR) for the radial artery, palmaris longus (PL) for the median nerve, and flexor carpi ulnaris (FCU) for the ulnar nerve were estimated. In group 1, FCU injury was the most common single-structure injury. In group 2, PL±median nerve injuries were the most common. Multiple-structure injuries involving more than five structures occurred more frequently in group 3 than in the other groups. FCU±ulnar nerve injuries were more common in group 3 than in the other groups. Radial-side structures were injured most frequently in group 3, and central-side injuries occurred most frequently in groups 1 and 2. Superficial- and middle-layer injuries occurred at similar frequencies among the three groups. Particularly, deep-layer injuries were most weakly related to group 2 injuries. The barrier effects of the FCR, PL, and FCU were confirmed, respectively. Wrist soft tissue injuries showed particular patterns of injured structures and depths according to the injury mechanism. These patterns included features such as single-structure injuries and the locations and depths of multiple-structure injuries with or without neurovascular injuries

  11. Effect of anti-inflammatory medication on the running-induced rise in patella tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Christensen, Britt; Dandanell, Sune; Kjaer, Michael

    2011-01-01

    NSAIDs are widely used in the treatment of inflammatory diseases as well as of tendon diseases associated with pain in sports and labor. However, the effect of NSAID intake, and thus blockade of PGE(2) production, on the tendon tissue adaptation is unknown. The purpose of the present study was to...

  12. Structural Evolution of Nonoperatively Treated High-Grade Partial-Thickness Tears of the Supraspinatus Tendon.

    Science.gov (United States)

    Kong, Bong Young; Cho, Minjoon; Lee, Hwa Ryeong; Choi, Young Eun; Kim, Sae Hoon

    2018-01-01

    High-grade partial-thickness rotator cuff tears (hPTRCTs) are frequently encountered in the shoulder. However, little information is available on the prevalence or timing of tear progression. Purpose/Hypothesis: The purpose was to prospectively evaluate the structural progression of hPTRCTs with a minimum follow-up of 1 year using magnetic resonance imaging (MRI). The hypothesis was that a substantial portion of hPTRCT patients would experience tear progression or evolution to a full-thickness rotator cuff tear. Case series; Level of evidence, 4. Between May 2010 and December 2015, 362 patients were diagnosed with hPTRCT (tear involvement >50% of the mediolateral length of the footprint) of the supraspinatus and were treated nonoperatively. Among these patients, 81 underwent follow-up MRI at least 1 year after initial presentation, and these patients were included in the final analysis. Initial and follow-up MRIs were used to determine whether tears had improved, had not changed, or had progressed. A change in tear involvement of >20% was defined as a significant change. Patients were categorized as follows: (1) a decrease in tear involvement of >20% (improved), (2) an increase or decrease of ≤20% (no change), or (3) an increase in tear involvement of >20% (progressed). Demographic data and morphologic data were analyzed to identify variables related to tear progression. Among them, severity of tendinosis was graded using MRIs: grade 1 (mild tendinosis), mild focal increase in tendon signal; grade 2 (moderate tendinosis), moderate focal increase in tendon signal; and grade 3 (marked tendinosis), marked generalized increase in tendon signal. At initial diagnosis, 23 were articular-side (28%) and 58 were bursal-side (72%) hPTRCTs. The study cohort was composed of 51 women and 30 men, and the mean patient age was 62.3 years (range, 41-77 years). Follow-up MRI was performed at a mean 19.9 ± 10.9 months (range, 12-52 months). A significant change in tear involvement

  13. Effect of acute resistance exercise and sex on human patellar tendon structural and regulatory mRNA expression

    DEFF Research Database (Denmark)

    Sullivan, B.E.; Carroll, C.C.; Jemiolo, B.

    2009-01-01

    -2, MMP-9, MMP-3, and TIMP-1 at rest and after RE. Patellar tendon biopsy samples were taken from six individuals (3 men and 3 women) before and 4 h after a bout of RE and from a another six individuals (3 men and 3 women) before and 24 h after RE. Resting mRNA expression was used for sex comparisons...... (6 men and 6 women). Collagen type I, collagen type III, and MMP-2 were downregulated (P 0.05) 24 h after RE. All other genes remained unchanged (P > 0.05) after RE. Women had higher resting mRNA expression (P ... = 0.08) toward lower resting expression of MMP-3 than men. All other genes were not influenced (P > 0.05) by sex. Acute RE appears to stimulate a change in collagen type I, collagen type III, and MMP-2 gene regulation in the human patellar tendon. Sex influences the structural and regulatory m...

  14. DOES AEROBIC EXERCISE TRAINING PROMOTE CHANGES IN STRUCTURAL AND BIOMECHANICAL PROPERTIES OF THE TENDONS IN EXPERIMENTAL ANIMALS? A SYSTEMATIC REVIEW

    Directory of Open Access Journals (Sweden)

    Márcio A. Bezerra

    2012-11-01

    Full Text Available To develop a systematic review to evaluate, through the best scientific evidence available, the effectiveness of aerobic exercise in improving the biomechanical characteristics of tendons in experimental animals. Two independent assessors conducted a systematic search in the databases Medline/PUBMED and Lilacs/BIREME, using the following descriptors of Mesh in animal models. The ultimate load of traction and the elastic modulus tendon were used as primary outcomes and transverse section area, ultimate stress and tendon strain as secondary outcomes. The assessment of risk of bias in the studies was carried out using the following methodological components: light/dark cycle, temperature, nutrition, housing, research undertaken in conjunction with an ethics committee, randomization, adaptation of the animals to the training and preparation for the mechanical test. Eight studies, comprising 384 animals, were selected; it was not possible to combine them into one meta-analysis due to the heterogeneity of the samples. There was a trend to increasing ultimate load without changes in the other outcomes studied. Only one study met more than 80% of the quality criteria. Physical training performed in a structured way with imposition of overloads seems to be able to promote changes in tendon structure of experimental models by increasing the ultimate load supported. However, the results of the influence of exercise on the elastic modulus parameters, strain, transverse section area and ultimate stress, remain controversial and inconclusive. Such a conclusion must be evaluated with reservation as there was low methodological control in the studies included in this review.

  15. Computed Tomography Assessment of Peroneal Tendon Displacement and Posteromedial Structure Entrapment in Pilon Fractures.

    Science.gov (United States)

    Fokin, Alex; Huntley, Samuel R; Summers, Spencer H; Lawrie, Charles M; Miranda, Alejandro D; Caban-Martinez, Alberto J; Steinlauf, Steven D

    2016-11-01

    To determine the proportion of (1) peroneal tendon displacement (PTD) and posteromedial structure entrapment (PMSE) cases in a sample of pilon fractures, (2) missed diagnoses of PTD and PMSE on computed tomography (CT) by radiologists and attending orthopaedic trauma surgeons, and PTD and PMSE cases by (3) OTA/AO classification, and (4) fibular fracture. Retrospective cohort review. Regional level 1 Trauma Center. Two hundred patients treated between July 2008 and November 2014. Axial and reconstructed CT images were used in bone and soft tissue windows to identify PTD and PMSE. Medical charts were reviewed to identify OTA/AO fracture classification, the presence of concomitant fibular fracture, whether radiologist CT interpretation noted PTD or PMSE, and whether attending orthopaedic trauma surgeons' operative notes mentioned recognition of and management of PTD or PMSE. From the retrospective review of CT, PTD was identified in 11.0% and PMSE in 19.0% of all pilon fractures. Of the 22 patients with PTD, 59.1% sustained a concomitant fibular fracture and 90.9% sustained a 43-C fracture. Patients with PTD sustained more 43-C fractures (90.9% vs. 62.9%) but significantly fewer fibular fractures (59.1% vs. 80.3%; P = 0.023) than patients without PTD. Of the 38 patients with PMSE, 81.6% sustained a fibular fracture and 86.8% sustained a 43-C fracture. PMSE was more common in patients with 43-C fractures (86.8% vs. 61.1%). The final preoperative radiologist CT interpretation commented on PTD and PMSE in 50.0% of cases. Higher energy pilon fractures (43-C) are associated with higher incidence of PMSE and PTD. Concomitant fibula fracture may play a protective role in PTD in the setting of pilon fractures. Both attending radiologists and attending orthopaedic trauma surgeons frequently fail to recognize the diagnoses of PTD and PMSE. Prognostic level III. See Instructions for Authors for a complete description of levels of evidence.

  16. Ultrasound assessment for grading structural tendon changes in supraspinatus tendinopathy: an inter-rater reliability study

    DEFF Research Database (Denmark)

    Ingwersen, Kim Gordon; Hjarbæk, John; Eshøj, Henrik

    2016-01-01

    (24 patients) were included for assessing inter-rater reliability of measurements of fibrillar disruption, neovascularity, as well as the number and total length of calcifications and tendon thickness. Linear weighted κ, intraclass correlation (ICC), SEM, limits of agreement (LOA) and minimal...

  17. Leg tendon glands in male bumblebees (Bombus terrestris): structure, secretion chemistry, and possible functions

    Czech Academy of Sciences Publication Activity Database

    Jarau, S.; Žáček, Petr; Šobotník, Jan; Vrkoslav, Vladimír; Hadravová, Romana; Coppée, Audrey; Vašíčková, Soňa; Jiroš, Pavel; Valterová, Irena

    2012-01-01

    Roč. 99, č. 12 (2012), s. 1039-1049 ISSN 0028-1042 R&D Projects: GA TA ČR TA01020969 Institutional support: RVO:61388963 Keywords : bumblebee * hydrocarbons * leg tendon gland s * sex specific secretion * wax esters Subject RIV: CC - Organic Chemistry Impact factor: 2.144, year: 2012

  18. Effect of PNF stretching training on the properties of human muscle and tendon structures.

    Science.gov (United States)

    Konrad, A; Gad, M; Tilp, M

    2015-06-01

    The purpose of this study was to investigate the influence of a 6-week proprioceptive neuromuscular facilitation (PNF) stretching training program on the various parameters of the human gastrocnemius medialis muscle and the Achilles tendon. Therefore, 49 volunteers were randomly assigned into PNF stretching and control groups. Before and after the stretching intervention, we determined the maximum dorsiflexion range of motion (RoM) with the corresponding fascicle length and pennation angle. Passive resistive torque (PRT) and maximum voluntary contraction (MVC) of the musculo-articular complex were measured with a dynamometer. Muscle-tendon junction (MTJ) displacement allowed us to determine the length changes in tendon and muscle, and hence to calculate stiffness. Mean RoM increased from 31.1 ± 7.2° to 33.1 ± 7.2° (P = 0.02), stiffness of the tendon decreased significantly in both active (from 21.1 ± 8.0 to 18.1 ± 5.5 N/mm) and passive (from 12.1 ± 4.9 to 9.6 ± 3.2 N/mm) conditions, and the pennation angle increased from 18.5 ± 1.8° to 19.5 ± 2.1° (P = 0.01) at the neutral ankle position (90°), only in the intervention group, whereas MVC and PRT values remained unchanged. We conclude that a 6-week PNF stretching training program increases RoM and decreases tendon stiffness, despite no change in PRT. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. 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...... modern investigative techniques available to study tendons. Results. There are a variety of investigative methods available to study the correlations between mechanics and biology in tendons. Conclusion. The available methodologies not only allow for potential insight into physiological...... and pathophysiological mechanisms in tendon tissue, but also, to some extent, allow for more elaborate studies of the intact human tendon. Read More: http://informahealthcare.com/doi/full/10.1080/09638280701785403...

  20. 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

  1. Synthesis, spectroscopic characterization and electronic structure of ...

    Indian Academy of Sciences (India)

    Unknown

    Copper(I) carbene complex; carbene complex synthesis; Cu(I)–carbene electronic structure. 1. Introduction. Metal carbene complexes are arguably the most ver- satile organometallic reagents that have been devel- oped for organic synthesis.1 Different reactions of these complexes have been reported since their dis-.

  2. Achilles Tendonitis

    Science.gov (United States)

    ... that you use crutches or wear a walking boot to keep weight off your foot. I ce: ... 2014 More on this topic for: Teens Jumper's Knee Proximal Biceps Tendonitis Safety Tips: Basketball Safety Tips: ...

  3. Influence of muscle-tendon unit structure on rate of force development during the squat, countermovement, and drop jumps.

    Science.gov (United States)

    Earp, Jacob E; Kraemer, William J; Cormie, Prue; Volek, Jeffery S; Maresh, Carl M; Joseph, Michael; Newton, Robert U

    2011-02-01

    Previous research has highlighted the importance of muscle and tendon structure to stretch shortening cycle performance. However, the relationships between muscle and tendon structure to performance are highly dependent on the speed and intensity of the movement. The purpose of this study was to determine if muscle and tendon structure is associated with the rate of force development (RFD) throughout static squat jump (SJ), countermovement jump (CMJ), and drop jump (DJ; 30-cm height). Twenty-five strength- and power-trained men participated in the study. Using ultrasonography, vastus lateralis (VL) and gastrocnemius (GAS) pennation (PEN) and fascicle length (FL), and Achilles tendon (AT) thickness and length were measured. Subjects then performed SJ, CMJ, and DJ, during which RFD was calculated over time 5 distinct time intervals. During CMJs, early RFD could be predicted between 0 and 10 milliseconds by both GAS-FL (r² = 0.213, β = 0.461) and AT-length (r² = 0.191, β = 20.438). Between 10 and 30 milliseconds GAS-FL was a significant predictor of CMJ-RFD (r² = 0.218, β = 0.476). During DJ, initial RFD (0-10 milliseconds) could be significantly predicted by GAS-FL (r² = 0.185, β = 20.434), VL-PEN (r² = 0.189, β = 0.435), and GAS-PEN (r² = 0.188, β = 0.434). These findings suggest that longer ATs may have increased elasticity, which can decrease initial RFD during CMJ; thus, their use in talent identification is not recommended. The GAS fascicle length had an intensity-dependent relationship with RFD, serving to positively predict RFD during early CMJs and an inverse predictor during early DJs. During DDJs, subjects with greater PEN were better able to redirected initial impact forces. Although both strength and plyometric training have been shown to increase FL, only heavy strength training has been shown to increase PEN. Thus, when a high eccentric load or multiple jumps are required, heavy strength training might be used to elicit muscular adaptations

  4. No donor age effect of human serum on collagen synthesis signaling and cell proliferation of human tendon fibroblasts

    DEFF Research Database (Denmark)

    Bayer, Monika L; Schjerling, Peter; Biskup, Edyta

    2012-01-01

    and elderly donors, and we found no difference in collagen expression when cells were subjected to human serum from elderly versus young donors. In addition, tendon cell proliferation was similar when culture medium was supplemented with serum of different donor age. These findings suggest that factors...... was to investigate whether human serum from elderly donors would have an inhibiting effect on the expression of collagen and collagen-related genes as well as on cell proliferative capacity in tendon cells from young individuals. There was no difference in systemic TGF-ß1 levels in serum obtained from young...... such as the cell intrinsic capacity or the tissue-specific environment rather than systemic circulating factors are important for functional capacity throughout life in human tendon cells....

  5. 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.

  6. Diagnostic value of tendon thickness and structure in the sonographic diagnosis of supraspinatus tendinopathy: room for a two-step approach

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Carlos Frederico, E-mail: carlos_arend@hotmail.com; Arend, Ana Amalia, E-mail: ana.amalia.arend@hotmail.com; Rodrigues da Silva, Tiago, E-mail: rumoabali@hotmail.com

    2014-06-15

    Objective: The aim of our study was to systematically compare different methodologies to establish an evidence-based approach based on tendon thickness and structure for sonographic diagnosis of supraspinatus tendinopathy when compared to MRI. Methods: US was obtained from 164 symptomatic patients with supraspinatus tendinopathy detected at MRI and 42 asymptomatic controls with normal MRI. Diagnostic yield was calculated for either maximal supraspinatus tendon thickness (MSTT) and tendon structure as isolated criteria and using different combinations of parallel and sequential testing at US. Chi-squared tests were performed to assess sensitivity, specificity, and accuracy of different diagnostic approaches. Results: Mean MSTT was 6.68 mm in symptomatic patients and 5.61 mm in asymptomatic controls (P < .05). When used as an isolated criterion, MSTT > 6.0 mm provided best results for accuracy (93.7%) when compared to other measurements of tendon thickness. Also as an isolated criterion, abnormal tendon structure (ATS) yielded 93.2% accuracy for diagnosis. The best overall yield was obtained by both parallel and sequential testing using either MSTT > 6.0 mm or ATS as diagnostic criteria at no particular order, which provided 99.0% accuracy, 100% sensitivity, and 95.2% specificity. Among these parallel and sequential tests that provided best overall yield, additional analysis revealed that sequential testing first evaluating tendon structure required assessment of 258 criteria (vs. 261 for sequential testing first evaluating tendon thickness and 412 for parallel testing) and demanded a mean of 16.1 s to assess diagnostic criteria and reach the diagnosis (vs. 43.3 s for sequential testing first evaluating tendon thickness and 47.4 s for parallel testing). Conclusions: We found that using either MSTT > 6.0 mm or ATS as diagnostic criteria for both parallel and sequential testing provides the best overall yield for sonographic diagnosis of supraspinatus tendinopathy when

  7. Peroneal Tendon Injuries

    Science.gov (United States)

    ... of peroneal tendon injuries are tendonitis, tears and subluxation. Tendonitis is an inflammation of one or both ... An increase in the height of the arch Subluxation means one or both tendons have slipped out ...

  8. The vascularization of human flexor tendons within the digital synovial sheath region--structureal and functional aspects.

    Science.gov (United States)

    Lundborg, G; Myrhage, R; Rydevik, B

    1977-11-01

    The intrinsic vascularization of human flexor tendons within the digital sheath region was studied on fresh amputation specimens with the aid of angiographic and histochemical techniques. In the flexor digitorum profundus tendon, three separate vascular systems of various origin and with no or very little communication could be verified. In the flexor digitorum superficialis tendon, two such systems were observed. The volar surface of both tendons is more or less devoid of vessels. Moreover, at the proximal interphalangeal joint level, the flexor digitorum profundus tendon has a volar avascular zone, constituting about 1 mm, i.e., about one-third to one-fourth of the thickness of the tendon. It is assumed that the synovial fluid is of importance for the nutrition of the tendons and that therefore the synovial sheath should be preserved as much as possible.

  9. IONOTHERMAL SYNTHESIS, STRUCTURES AND SUPRAMOLE

    African Journals Online (AJOL)

    Preferred Customer

    2Department of Chemistry, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal. (Received October 14 ... The principal feature of ionothermal synthesis is that the ionic liquids (ILs) act as both the “designed” green solvents ... purification except [EMI]Br. [EMI]Br was synthesized from the reaction of ethylbromide with.

  10. Pes Anserinus Structural Framework and Constituting Tendons Are Grossly Aberrant in Nigerian Population

    Directory of Open Access Journals (Sweden)

    J. O. Ashaolu

    2015-01-01

    Full Text Available We evaluated the morphological framework of the pes anserinus in both knees of ten Nigerian cadavers and we observed high degree of variability in its morphology and location. The pes anserinus inserted specifically on the superior half of the media border of the tibia, as far inferiorly as 124.44 mm to the tibial tuberosity (prolonged insertion. The insertion was also joined to the part of tibia close to the tibia tuberosity (90% and to the fascia cruris (10%. The initial insertion point of the pes anserinus was always found at the level of the tibia tuberosity. We found out that accessory bands of sartorius, gracilis, or semitendinosus were part of the pes anserinus in 95% of all occasions studied whereas the combined occurrence of monotendinosus sartorius, gracilis, and semitendinosus tendons was found in only 5% of all occasions. The pes anserinus did not conform to the layered pattern and the tendons of sartorius, gracilis, or semitendinosus were short. The inferior prolongation of the pes anserinus connotes extended surface area of attachment to support the mechanical pull from the hamstring muscles. This information will be useful in precise location and grafting of the pes anserinus.

  11. Structured synthesis of MEMS using evolutionary approaches

    DEFF Research Database (Denmark)

    Fan, Zhun; Wang, Jiachuan; Achiche, Sofiane

    2008-01-01

    In this paper, we discuss the hierarchy that is involved in a typical MEMS design and how evolutionary approaches can be used to automate the hierarchical synthesis process for MEMS. The paper first introduces the flow of a structured MEMS design process and emphasizes that system-level lumped...... the integrated design automation idea using these evolutionary approaches....

  12. Synthesis, spectroscopy and supramolecular structures of two ...

    Indian Academy of Sciences (India)

    TECS

    2007-05-16

    May 16, 2007 ... Indian Academy of Sciences. 243. #. Dedicated to Prof. Dr. Werner Weisweiler on the occasion of his 69th birthday. *For correspondence. Synthesis, spectroscopy and supramolecular structures of two magnesium 4-nitrobenzoate complexes. #. BIKSHANDARKOIL R SRINIVASAN,. 1,. * JYOTI V SAWANT,.

  13. Hydrothermal synthesis, crystal structure and luminescence property ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 12. Hydrothermal synthesis, crystal structure and luminescence property of a three dimensional Sm(III) coordination polymer with 2,5-pyridinedicarboxylic acid. Kranthi Kumar Gangu Anima S Dadhich Saratchandra Babu Mukkamala. Volume 127 Issue 12 ...

  14. Synthesis, crystal structure, thermal analysis and dielectric

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 39; Issue 5. Synthesis, crystal structure, thermal analysis and dielectric properties of two mixed trichlorocadmiates (II).

  15. Synthesis, properties and supramolecular structure of ...

    Indian Academy of Sciences (India)

    Synthesis, properties and supramolecular structure of piperazinediium thiosulfate monohydrate. +. BIKSHANDARKOIL R SRINIVASANa*, ASHISH R NAIKa. , SUNDER N DHURIa. ,. CHRISTIAN NÄTHERb and WOLFGANG BENSCHb. aDepartment of Chemistry, Goa University, Goa 403 206, India. bInstitut für ...

  16. [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.

  17. Synthesis and structures of metal chalcogenide precursors

    Science.gov (United States)

    Hepp, Aloysius F.; Duraj, Stan A.; Eckles, William E.; Andras, Maria T.

    1990-01-01

    The reactivity of early transition metal sandwich complexes with sulfur-rich molecules such as dithiocarboxylic acids was studied. Researchers recently initiated work on precursors to CuInSe2 and related chalcopyrite semiconductors. Th every high radiation tolerance and the high absorption coefficient of CuInSe2 makes this material extremely attractive for lightweight space solar cells. Their general approach in early transition metal chemistry, the reaction of low-valent metal complexes or metal powders with sulfur and selenium rich compounds, was extended to the synthesis of chalcopyrite precursors. Here, the researchers describe synthesis, structures, and and routes to single molecule precursors to metal chalcogenides.

  18. 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.

  19. Experimental evaluation of multiscale tendon mechanics.

    Science.gov (United States)

    Fang, Fei; Lake, Spencer P

    2017-07-01

    Tendon's primary function is a mechanical link between muscle and bone. The hierarchical structure of tendon and specific compositional constituents are believed to be critical for proper mechanical function. With increased appreciation for tendon importance and the development of various technological advances, this review paper summarizes recent experimental approaches that have been used to study multiscale tendon mechanics, includes an overview of studies that have evaluated the role of specific tissue constituents, and also proposes challenges/opportunities facing tendon study. Tendon has been demonstrated to have specific structural characteristics (e.g., multi-level hierarchy, crimp pattern, helix) and complex mechanical properties (e.g., non-linearity, anisotropy, viscoelasticity). Physical mechanisms including uncrimping, fiber sliding, and collagen reorganization have been shown to govern tendon mechanical responses under both static and dynamic loading. Several tendon constituents with relatively small quantities have been suggested to play a role in its mechanics, although some results are conflicting. Further research should be performed to understand the interplay and communication of tendon mechanical properties across levels of the hierarchical structure, and further show how each of these components contribute to tendon mechanics. The studies summarized and discussed in this review have helped elucidate important aspects of multiscale tendon mechanics, which is a prerequisite for analyzing stress/strain transfer between multiple scales and identifying key principles of mechanotransduction. This information could further facilitate interpreting the functional diversity of tendons from different species, different locations, and even different developmental stages, and then better understand and identify fundamental concepts related to tendon degeneration, disease, and healing. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

  20. SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURES ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    The V atoms in the complexes are in octahedral coordination. Thermal stabilities of the complexes have also been studied. KEY WORDS: Oxovanadium complex, Aroylhydrazone ligand, Crystal structure, X-ray diffraction, Thermal property. INTRODUCTION. Coordination chemistry of vanadium has attracted considerable ...

  1. SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURE ...

    African Journals Online (AJOL)

    Preferred Customer

    Cg1, Cg2 and Cg3 are the centroids of Mo1-O2-C8-N2-N1, C9-C14 and. C1-C6 benzene rings. Figure 1. Molecular structure of the complex at 30% probability displacement. IR spectra. The hydrazone ligands showed stretching bands attributed to C=O, C=N, C–OH and NH at. 1656, 1637, 1155 and 1237, and 3211 cm–1, ...

  2. Hamstring tendons insertion - an anatomical study

    OpenAIRE

    Cristiano Antonio Grassi; Vagner Messias Fruheling; Joao Caetano Abdo; Marcio Fernando Aparecido de Moura; Mario Namba; Joao Luiz Vieira da Silva; Luiz Antonio Munhoz da Cunha; Ana Paula Gebert de Oliveira Franco; Isabel Ziesemer Costa; Edmar Stieven Filho

    2013-01-01

    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 ...

  3. Microstructural stress relaxation mechanics in functionally different tendons.

    Science.gov (United States)

    Screen, H R C; Toorani, S; Shelton, J C

    2013-01-01

    Tendons experience widely varying loading conditions in vivo. They may be categorised by their function as either positional tendons, which are used for intricate movements and experience lower stress, or as energy storage tendons which act as highly stressed springs during locomotion. Structural and compositional differences between tendons are thought to enable an optimisation of their properties to suit their functional environment. However, little is known about structure-function relationships in tendon. This study adopts porcine flexor and extensor tendon fascicles as examples of high stress and low stress tendons, comparing their mechanical behaviour at the micro-level in order to understand their stress relaxation response. Stress-relaxation was shown to occur predominantly through sliding between collagen fibres. However, in the more highly stressed flexor tendon fascicles, more fibre reorganisation was evident when the tissue was exposed to low strains. By contrast, the low load extensor tendon fascicles appears to have less capacity for fibre reorganisation or shearing than the energy storage tendon, relying more heavily on fibril level relaxation. The extensor fascicles were also unable to sustain loads without rapid and complete stress relaxation. These findings highlight the need to optimise tendon repair solutions for specific tendons, and match tendon properties when using grafts in tendon repairs. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  4. DOES AEROBIC EXERCISE TRAINING PROMOTE CHANGES IN STRUCTURAL AND BIOMECHANICAL PROPERTIES OF THE TENDONS IN EXPERIMENTAL ANIMALS? A SYSTEMATIC REVIEW

    OpenAIRE

    Márcio A. Bezerra; Kamilla D.S. Lira; Patrícia V. C. Silveira; Marcos P.G. Coutinho; Andrea Lemos; Silvia R. A. Moraes

    2012-01-01

    To develop a systematic review to evaluate, through the best scientific evidence available, the effectiveness of aerobic exercise in improving the biomechanical characteristics of tendons in experimental animals. Two independent assessors conducted a systematic search in the databases Medline/PUBMED and Lilacs/BIREME, using the following descriptors of Mesh in animal models. The ultimate load of traction and the elastic modulus tendon were used as primary outcomes and transverse section area,...

  5. Synthesis, structural and electrical characterizations of thermally ...

    African Journals Online (AJOL)

    Synthesis, structural and electrical characterizations of thermally evaporated Cu 2 SnS 3 thin films. ... The surface profilometer shows that the deposited films are rough. The XRD spectra identified the ... The electrical resistivity of the deposited Cu2SnS3 film is 2.55 x 10-3 Ωcm. The conductivity is in the order of 103 Ω-1cm-1.

  6. The early effects of sustained platelet-derived growth factor administration on the functional and structural properties of repaired intrasynovial flexor tendons: an in vivo biomechanic study at 3 weeks in canines.

    Science.gov (United States)

    Gelberman, Richard H; Thomopoulos, Stavros; Sakiyama-Elbert, Shelly E; Das, Rosalina; Silva, Matthew J

    2007-03-01

    A bioactive fibrin-based delivery system was used to provide sustained administration of platelet-derived growth factor (PDGF-BB) in a clinically relevant model of intrasynovial flexor tendon repair. We hypothesized that PDGF-BB administered in this manner would improve the sutured tendon's functional and structural properties 3 weeks after repair. A delivery system consisting of 30 microL of fibrin matrix, peptide, heparin, and 100 ng of PDGF-BB was incorporated into the repair sites of randomly selected medial or lateral forepaw flexor digitorum profundus tendons of 8 adult mongrel dogs. The remaining forepaw flexor digitorum profundus tendons were repaired without the growth-factor and fibrin-based delivery system and served as controls. The surgically treated forelimbs were treated with controlled passive motion rehabilitation. The animals were killed at 3 weeks, at which time the tendons were tested for range of motion with a motion analysis system and for tensile properties with a materials testing machine. Proximal interphalangeal joint and distal interphalangeal joint rotation values were significantly higher for the PDGF-BB-treated tendons compared with the repair-alone tendons. Excursion values were also significantly higher in the PDGF-BB-treated tendons. There were no significant differences in tensile properties when comparing PDGF-BB-treated with repair-alone tendons. The functional properties of repaired intrasynovial flexor tendons were significantly improved with the sustained administration of PDGF-BB. The failure to achieve improvements in ultimate load, stiffness, and strain in the experimental group may have been due to suboptimal PDGF-BB dosage or suboptimal release kinetics.

  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. Tendon Force Transmission at the Nanoscale

    DEFF Research Database (Denmark)

    Svensson, René

    2013-01-01

    The subject of this study is connective tissues, in particular tendon. Connective tissues consist of an extracellular matrix made of the protein collagen, which is responsible for the mechanical integrity of the body. While connective tissues may appear simple, there are still many aspects...... 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...

  9. 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...

  10. Marine Nucleosides: Structure, Bioactivity, Synthesis and Biosynthesis

    Directory of Open Access Journals (Sweden)

    Ri-Ming Huang

    2014-12-01

    Full Text Available Nucleosides are glycosylamines that structurally form part of nucleotide molecules, the building block of DNA and RNA. Both nucleosides and nucleotides are vital components of all living cells and involved in several key biological processes. Some of these nucleosides have been obtained from a variety of marine resources. Because of the biological importance of these compounds, this review covers 68 marine originated nucleosides and their synthetic analogs published up to June 2014. The review will focus on the structures, bioactivities, synthesis and biosynthetic processes of these compounds.

  11. 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.

  12. 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.

  13. 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.

  14. Structure, bioactivity, and synthesis of methylated flavonoids.

    Science.gov (United States)

    Wen, Lingrong; Jiang, Yueming; Yang, Jiali; Zhao, Yupeng; Tian, Miaomiao; Yang, Bao

    2017-06-01

    Methylated flavonoids are an important type of natural flavonoid derivative with potentially multiple health benefits; among other things, they have improved bioavailability compared with flavonoid precursors. Flavonoids have been documented to have broad bioactivities, such as anticancer, immunomodulation, and antioxidant activities, that can be elevated, to a certain extent, by methylation. Understanding the structure, bioactivity, and bioavailability of methylated flavonoids, therefore, is an interesting topic with broad potential applications. Though methylated flavonoids are widely present in plants, their levels are usually low. Because developing efficient techniques to produce these chemicals would likely be beneficial, we provide an overview of their chemical and biological synthesis. © 2017 New York Academy of Sciences.

  15. Synthesis of Structures Related to Antifreeze Glycoproteins

    OpenAIRE

    Fyrner, Timmy

    2005-01-01

    In this thesis, synthesis of structures related to antifreeze glycoproteins (AFGPs) are presented. Synthetic routes to a protected carbohydrate derivative, 2,3,4,6-tetra-O-benzyl-β-galactopyranosyl-(1→3)-2-deoxy-2-azido-4,6-di-O-benzyl-β-D-thio-1-galactopyranoside, and a tBu-Ala-Thr-Ala-Fmoc tripeptide, are described. These compounds are meant to be used in the assembly of AFGPs and analogues thereof. A Gal-GlcN disaccharide was synthesized via glycosylation between the donor, bromo-2-O-benzo...

  16. 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.

  17. Wall grid structure for interior scene synthesis

    KAUST Repository

    Xu, Wenzhuo

    2015-02-01

    We present a system for automatically synthesizing a diverse set of semantically valid, and well-arranged 3D interior scenes for a given empty room shape. Unlike existing work on layout synthesis, that typically knows potentially needed 3D models and optimizes their location through cost functions, our technique performs the retrieval and placement of 3D models by discovering the relationships between the room space and the models\\' categories. This is enabled by a new analytical structure, called Wall Grid Structure, which jointly considers the categories and locations of 3D models. Our technique greatly reduces the amount of user intervention and provides users with suggestions and inspirations. We demonstrate the applicability of our approach on three types of scenarios: conference rooms, living rooms and bedrooms.

  18. Metabolic activity and collagen turnover in human tendon in response to physical activity

    DEFF Research Database (Denmark)

    Kjaer, M; Langberg, H; Miller, B F

    2005-01-01

    Connective tissue of the human tendon plays an important role in force transmission. The extracellular matrix turnover of tendon is influenced by physical activity. Blood flow, oxygen demand, and the level of collagen synthesis and matrix metalloproteinases increase with mechanical loading. Gene...... of overuse tendon injuries occurring during sport, work or leisure-related activities....

  19. Extensor Tendon Injuries

    Science.gov (United States)

    ... Media Find a Hand Surgeon Home Anatomy Extensor Tendon Injuries Email to a friend * required fields From * ... to straighten one or more joints. Common Extensor Tendon Injuries Mallet Finger refers to a drooping end- ...

  20. Flexor Tendon Injuries

    Science.gov (United States)

    ... Media Find a Hand Surgeon Home Anatomy Flexor Tendon Injuries Email to a friend * required fields From * ... move the fingers through cord-like extensions called tendons, which connect the muscles to bone. The flexor ...

  1. Percutaneous Achilles Tendon Lengthening

    Science.gov (United States)

    ... All Site Content AOFAS / FootCareMD / Treatments Percutaneous Achilles Tendon Lengthening Page Content ​ Pre-operative incision markings along ... What is the goal of a percutaneous Achilles tendon lengthening? The goal of this procedure is to ...

  2. Calcaneal tendon: imaging findings

    International Nuclear Information System (INIS)

    Montandon, Cristiano; Fonseca, Cristiano Rezio; Montandon Junior, Marcelo Eustaquio; Lobo, Leonardo Valadares; Ribeiro, Flavia Aparecida de Souza; Teixeira, Kim-Ir-Sen Santos

    2003-01-01

    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)

  3. THE ROLE OF DETRAINING IN TENDON MECHANOBIOLOGY

    Directory of Open Access Journals (Sweden)

    Antonio eFrizziero

    2016-02-01

    Full Text Available Introduction: Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, there is a paucity of data examining the impact that cessation of training may have on tendon. In practice, we do not fully understand how tendons respond to a period of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined.Materials and methods: A descriptive systematic literature review was conducted by searching three databases (PubMed, Scopus and Web of Knowledge on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com was used to delete duplicate articles.Results: An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70. 15 publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and whole articles were then reviewed to detect if they met inclusion criteria.Conclusions: The revised literature comprised 4 clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g. after an injury, physical activity

  4. The Role of Detraining in Tendon Mechanobiology.

    Science.gov (United States)

    Frizziero, Antonio; Salamanna, Francesca; Della Bella, Elena; Vittadini, Filippo; Gasparre, Giuseppe; Nicoli Aldini, Nicolò; Masiero, Stefano; Fini, Milena

    2016-01-01

    Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, few data evaluated the importance that cessation of training might have on tendon. Basically, we do not fully understand how tendons react to a phase of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined. A descriptive systematic literature review was carried out by searching three databases (PubMed, Scopus and Web of Knowledge) on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com) was adopted to remove duplicate articles. An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70). Fifteen publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and complete articles were after that reviewed to evaluate if they met inclusion criteria. The revised literature comprised four clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g., after an injury), physical activity should be taken with caution, following a targeted rehabilitation

  5. 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.

  6. 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

  7. 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...... 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...... adjacent collagen fascicles in human tendons is small or negligible, suggesting that tendon fascicles largely act as independent structures and that force transmission principally takes place within the individual fascicles....

  8. Flexor digitorum profundus tendon anatomy in the forearm

    Directory of Open Access Journals (Sweden)

    Teoman Dogan

    2012-04-01

    Methods: We used 11 forearms belonging to cadavers and fixed with formaldehyde. The forearms numbered 1, 2, 8, 9, 10, 11 were the left and right arms of the same cadavers. Those numbered 3, 4, 5, 6, 7 belonged to different cadavers. Dissections were made by using the atraumatic surgical technique. The tendons were studied to identify the structure and number of the fibers forming them. Results: The presence of a large common tendon was found in 10 of the 11 forearms. In 4 of these, the common tendon included the tendons of all four fingers. While the common tendon included 3 fingers in four forearms, it only included tendons belonging to 2 fingers in two forearms. It was not possible in one forearm to separate the common tendon into its fibers. In another forearm, tendons belonging to each digit were separate and independent starting at the muscle-tendon junction to the attachment points. Conclusion: The majority of the cadaver forearms used in the study displayed a single large FDP tendon in the zone between the muscle-tendon joint to the carpal tunnel entry prior to being distributed into each index. This anatomical feature should be considered in choosing materials and surgical technique for Zone V FDP tendon injuries, as well as in planning the rehabilitation process. [Hand Microsurg 2012; 1(1.000: 25-29

  9. Effect of aging and exercise on the tendon

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... glycation-derived cross-links increase substantially. Mechanically, aging appears to be associated with a reduction in modulus and strength. With respect to exercise, tendon cells respond by producing growth factors, and there is some support for a loading-induced increase in tendon collagen synthesis...

  10. Structural adaptations of rat lateral gastrocnemius muscle-tendon complex to a chronic stretching program and their quantification based on ultrasound biomicroscopy and optical microscopic images.

    Science.gov (United States)

    Peixinho, Carolina Carneiro; Martins, Natália Santos Fonseca; de Oliveira, Liliam Fernandes; Machado, João Carlos

    2014-01-01

    A chronic regimen of flexibility training can increase range of motion, with the increase mechanisms believed to be a change in the muscle material properties or in the neural components associated with this type of training. This study followed chronic structural adaptations of lateral gastrocnemius muscle of rats submitted to stretching training (3 times a week during 8weeks), based on muscle architecture measurements including pennation angle, muscle thickness and tendon length obtained from ultrasound biomicroscopic images, in vivo. Fiber length and sarcomere number per 100μm were determined in 3 fibers of each muscle (ex vivo and in vitro, respectively), using conventional optical microscopy. Stretching training resulted in a significant pennation angle reduction of the stretched leg after 12 sessions (25%, P=0.002 to 0.024). Muscle thickness and tendon length presented no significant changes. Fiber length presented a significant increase for the stretched leg (8.5%, P=0.00006), with the simultaneous increase in sarcomere length (5%, P=0.041) since the stretched muscles presented less sarcomeres per 100μm. A stretching protocol with characteristics similar to those applied in humans was sufficient to modify muscle architecture of rats with absence of a sarcomerogenesis process. The results indicate that structural adaptations take place in skeletal muscle tissue submitted to moderate-intensity stretching training. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Synthesis, structures and theoretical investigation of

    Science.gov (United States)

    Weigend; Wirth; Ahlrichs; Fenske

    2000-02-04

    The silylated derivative of thiophosphoric acid (S)P(SSiMe3)3 is used as a convenient starting compound for the synthesis of multinuclear Cu and Au cluster complexes. (S)P(SSiMe3)3 reacts with CuCI/PPh3 and [AuCClPPh3] to give the following compounds: [Cu4(P2S6)(PPh3)4] (1), [Cu6(P2S6)Cl2-(PPh3)6] (2) and [Au4(P2S6)(PPh3)4](3). According to X-ray structure determination, these compounds contain P2S6(4-) ions, in which S atoms act as ligands for Cu+ and Au+ ions. Although 1 and 3 have the same stoichiometry, bonding of the metal ions to the P2S6 skeleton displays small but remarkable differences. Au is twofold coordinated, whereas Cu shows a threefold coordination. Ab initio calculations have been carried out to rationalise these structural differences. The theoretical treatment of the corresponding Ag compound indicates the latter to be less stable.

  12. Drug Development of the Antimalarial Agent Artemisinin: Total Synthesis, Analog Synthesis, and Structure-Activity Relationship Studies

    Science.gov (United States)

    1990-08-15

    jHoluenesulfonyl hydrazide in tetrahydrofuran (THF), solvolysis of the ketal group and subsequent hydrazone formation was observed. Under base...ARTEMISININ: TOTAL SYNTHESIS , ANALOG SYNTHESIS , AND STRUCTURE-ACTIVITY RELATIONSHIP STUDIES mc Mitchell A. Avery, Ph.D. SRI International...Antimalarial Agent Artemisinin: Total Synthesis , Analog Synthesis and Structure-Activity Relationship Studies 12 PERSONAL AUTHOR(S) Mitchell A

  13. Retrofibular osteochondroma with peroneal tendon subluxation.

    Science.gov (United States)

    Tsang, Jung Yin; Bhosale, Abhijit; Pillai, Anand

    2015-03-01

    Osteochondroma of the bone can cause a range of complications involving tendons, joints and neurovascular structures. Distal fibular osteochondroma and non-traumatic peroneal tendon subluxation are both rare. In this case report, we describe an unusual case of distal retrofibular osteochondroma in a 36-year old male causing peroneal tendon subluxation. He presented with pain and instability around his ankle, but with no history of trauma. He successfully underwent osteochondroma excision, peroneal groove deepening and a Brostrom-Gould type reconstruction for the lateral ankle ligament insufficiency. Complete resolution of the symptoms of instability and subluxation was noted upon 6-month follow up. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Ultrasonography for the diagnosis of diseases of the tendon and tendon sheath of the biceps brachii muscle.

    Science.gov (United States)

    Kramer, M; Gerwing, M; Sheppard, C; Schimke, E

    2001-01-01

    To describe the ultrasonographic appearance of the normal and diseased biceps brachii tendon and its tendon sheath in dogs. A prospective clinical study. One hundred twenty client-owned dogs. In the first part of the study, the ultrasonographic appearance of the normal biceps brachii muscle and the surrounding soft tissue was determined in 27 healthy dogs. Standard views were described and established. In the second part, 120 dogs with suspected pathology of the biceps brachii muscle were examined ultrasonographically. Fifty-five of these dogs had no sonographic changes, and 65 dogs had sonographically detectable pathologic changes of the tendon or the tendon sheath or both. The mean age of the affected dogs was 3.7 years. The ratio of males to females was 1.95:1. Sedation or anesthesia of the dogs was required because of the extreme movements of the leg necessary for the examination. To achieve a perpendicular view of the tendon and the tendon sheath, the area of the shoulder joint was rotated outward and abducted as far as possible. Examination of the muscle-tendon apparatus of the biceps brachii muscle was divided into 4 main sections. Linear transducers (7.5-10 MHz) allowed the soft tissue structures to be easily visualized with ultrasonography. Pathologic changes of the tendon and tendon sheath were visualized sonographically by using high-frequency linear probes. Partial or complete tendon rupture, medial luxation of the tendon, corpora libera in the tendon sheath, and tenosynovitis were clearly shown. High-frequency ultrasonography using linear transducers allows the examiner to accurately define the pathologic changes in the region of the biceps brachii tendon in dogs. The use of sonography for diagnosis of disease processes of the tendon and tendon sheath of the biceps brachii muscle complements clinical and radiographic examination findings.

  15. Plantar tendons of the foot: MR imaging and US.

    Science.gov (United States)

    Donovan, Andrea; Rosenberg, Zehava Sadka; Bencardino, Jenny T; Velez, Zoraida Restrepo; Blonder, David B; Ciavarra, Gina A; Adler, Ronald Steven

    2013-01-01

    Tendon disorders along the plantar aspect of the foot may lead to significant symptoms but are often clinically misdiagnosed. Familiarity with the normal anatomy of the plantar tendons and its appearance at magnetic resonance (MR) imaging and ultrasonography (US) is essential for recognizing plantar tendon disorders. At MR imaging, the course of the plantar tendons is optimally visualized with dedicated imaging of the midfoot and forefoot. This imaging should include short-axis images obtained perpendicular to the long axis of the metatarsal shafts, which allows true cross-sectional evaluation of the plantar tendons. Normal plantar tendons appear as low-signal-intensity structures with all MR sequences. At US, accurate evaluation of the tendons requires that the ultrasound beam be perpendicular to the tendon. The normal tendon appears as a compact linear band of echogenic tissue that contains a fine, mixed hypoechoic and hyperechoic internal fibrillar pattern. Tendon injuries can be grouped into six major categories: tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, and instability (subluxation or dislocation) and can be well assessed with both MR imaging and US. The radiologist plays an important role in the diagnosis of plantar tendon disorders, and recognizing their imaging appearances at MR imaging and US is essential.

  16. Synthesis, structure and low temperature study of electric transport ...

    Indian Academy of Sciences (India)

    Synthesis, structure and low temperature study of electric transport and magnetic properties of GdSr2MnCrO7. Devinder ... Keywords. Chemical synthesis; X-ray diffraction; electrical properties; magnetic properties. Abstract. The layered perovskite oxide, GdSr2MnCrO7, has been prepared by the standard ceramic method.

  17. Halogenated Symmetrical Tetraazapentacenes: Synthesis, Structures, and Properties.

    Science.gov (United States)

    Engelhart, Jens U; Paulus, Fabian; Schaffroth, Manuel; Vasilenko, Vladislav; Tverskoy, Olena; Rominger, Frank; Bunz, Uwe H F

    2016-02-05

    We herein describe the synthesis and property evaluation of several brominated and chlorinated tetraazapentacenes. The targets were obtained by thermal condensation of 2,5-dihydroxyquinone with 4,5-dichloro-, 2,6-dichloro-, and 4,5-dibromo-1,2-phenylenediamine, followed by oxidation with hot acidic dichromate. Double alkynylation, reductive deoxygenation, and subsequent oxidation using MnO2 furnishes the target compounds. Absorption spectra, electrochemistry, and single crystal structures of the targets are reported. The 1,4,8,11-tetrachlorotetraazapentacene (1,4,8,11-tetrachloroquinoxalino[2,3-b]phenazine) carrying its chlorine atoms in the peri-positions packs in a herringbone type arrangement, while the isomer (2,3,9,10-tetrachloroquinoxalino[2,3-b]phenazine, with the chlorine atoms in the east and west positions) packs in one-dimensional stacks. In all cases, the reduction potentials and the calculated LUMO-positions are decreased by the introduction of the halogen atoms.

  18. Organoactinide chemistry: synthesis, structure, and solution dynamics

    International Nuclear Information System (INIS)

    Brennan, J.G.

    1985-12-01

    This thesis considers three aspects of organoactinide chemistry. In chapter one, a bidentate phosphine ligand was used to kinetically stabilize complexes of the type Cp 2 MX 2 . Ligand redistribution processes are present throughout the synthetic work, as has often been observed in uranium cyclopentadienyl chemistry. The effects of covalent M-L bonding on the solution and solid state properties of U(III) coordination complexes are considered. In particular, the nature of the more subtle interaction between the metal and the neutral ligand are examined. Using relative basicity data obtained in solution, and solid state structural data (and supplemented by gas phase photoelectron measurements), it is demonstrated that the more electron rich U(III) centers engage in significant U → L π-donation. Trivalent uranium is shown to be capable of acting either as a one- or two-electron reducing agent toward a wide variety of unsaturated organic and inorganic molecules, generating molecular classes unobtainable via traditional synthetic approaches, as well as offering an alternative synthetic approach to molecules accessible via metathesis reactions. Ligand redistribution processes are again observed, but given the information concerning ligand lability, this reactivity pattern is applied to the synthesis of pure materials inaccessible from redox chemistry. 214 refs., 33 figs., 10 tabs

  19. 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

  20. 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.

  1. 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°.

  2. 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.

  3. 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

    expression as well as protein synthesis rate. Further the (14)C bomb-pulse method has provided data on long-term tissue turnover in human tendon. Non-invasive techniques allow measurement of tendon metabolism (positron emission tomography (PET)), tendon morphology (magnetic resonance imaging (MRI......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....

  4. Synthesis and crystal structure of a wheel-shaped supramolecular ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 5. Synthesis and crystal structure of a wheel-shaped supramolecular coordination complex. Deepak Gupta Palanisamy Rajakannu Bhaskaran Shankar Firasat Hussain Malaichamy Sathiyendiran. Special issue on Chemical Crystallography Volume 126 ...

  5. 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.

  6. Percutaneous tenotomy: development of a novel, percutaneous, ultrasound-guided needle-cutting technique for division of tendons and other connective tissue structures

    International Nuclear Information System (INIS)

    Hopkins, James; Sampson, Matthew

    2014-01-01

    A variety of surgical procedures derive therapeutic benefit from the division of retinacular, ligamentous or tendinous structures. Examples include carpal tunnel release for median nerve impingement, annular pulley release for trigger finger and tendon division for spastic muscular contractures. Here, using an animal cadaveric model, we describe the first steps in determining the feasibility of a novel, percutaneous, ultrasound-guided needle-cutting technique to achieve the same ends. The technique we describe involves the creation of an effective needle tenotomy device via a simple modification to an 18G coaxial, beveled needle. The technique holds promise for the development of a minimally invasive alternative approach that utilises readily available technology and equipment with minimisation of morbidity and cost associated with open procedures.

  7. Achilles tendon repair

    Science.gov (United States)

    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 cut After that, the surgeon will: Bring the ends of your tendon together Sew the ends together Stitch the wound closed

  8. Ionothermal synthesis and structural characterization of [Cu ...

    Indian Academy of Sciences (India)

    bSchool of Chemistry and Chemical Engineering, Harbin Normal University, No. 1 Shida Road Limin development Zone, Harbin 150025, P. R. China e-mail: caiqinghai@yahoo.com. MS received 29 December 2014; revised 2 April 2015; accepted 3 April 2015. Abstract. The ionothermal synthesis and spectroscopic, thermal ...

  9. Superheavy nuclei – cold synthesis and structure

    Indian Academy of Sciences (India)

    Abstract. The quantum mechanical fragmentation theory (QMFT), given for the cold synthesis of new and superheavy elements, is reviewed and the use of radioactive nuclear beams (RNB) and targets (RNT) is discussed. The QMFT is a complete theory of cold nuclear phenomena, namely, the cold fission, cold fusion and ...

  10. Superheavy nuclei–cold synthesis and structure

    Indian Academy of Sciences (India)

    The quantum mechanical fragmentation theory (QMFT), given for the cold synthesis of new and superheavy elements, is reviewed and the use of radioactive nuclear beams (RNB) and targets (RNT) is discussed. The QMFT is a complete theory of cold nuclear phenomena, namely, the cold fission, cold fusion and cluster ...

  11. Long bicipital tendon of the shoulder: normal anatomy and pathologic findings on MR imaging.

    Science.gov (United States)

    Erickson, S J; Fitzgerald, S W; Quinn, S F; Carrera, G F; Black, K P; Lawson, T L

    1992-05-01

    The tendon of the long head of the biceps muscle (long bicipital tendon) has a complex course from its muscle belly to its insertion onto the supraglenoid tubercle/glenoid labrum. It is stabilized by numerous tendinous and ligamentous structures and is, in turn, partly responsible for maintenance of normal glenohumeral function. In this report we describe the anatomy of this tendon, correlating high-resolution MR images with cryomicrotome sections. We illustrate typical MR findings in pathologic conditions affecting the long bicipital tendon sheath, the substance of the tendon, and finally the tendon position.

  12. 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

  13. The initiation of embryonic-like collagen fibrillogenesis by adult human tendon fibroblasts when cultured under tension

    DEFF Research Database (Denmark)

    Bayer, Monika L; Yeung, Chin-Yan C; Kadler, Karl E

    2010-01-01

    Tendon fibroblasts synthesize collagen and form fibrils during embryonic development, but to what extent mature fibroblasts are able to recapitulate embryonic development and develop normal tendon structure is unknown. The present study examined the capability of mature human tendon fibroblasts......, and fibroblasts stained positive for integrin alpha(5). Finally, the presence of cell extensions into the extracellular space with membrane-enclosed fibrils in fibripositors indicated characteristics of embryonic tendon. We conclude that mature human tendon fibroblasts retain an intrinsic capability to perform...... collagen fibrillogenesis similar to that of developing tendon, which implies that the hormonal/mechanical milieu, rather than intrinsic cellular function, inhibits regenerative potential in mature tendon....

  14. Comparison of transforming growth factor beta expression in healthy and diseased human tendon.

    Science.gov (United States)

    Goodier, Henry C J; Carr, Andrew J; Snelling, Sarah J B; Roche, Lucy; Wheway, Kim; Watkins, Bridget; Dakin, Stephanie G

    2016-02-17

    Diseased tendons are characterised by fibrotic scar tissue, which adversely affects tendon structure and function and increases the likelihood of re-injury. The mechanisms and expression profiles of fibrosis in diseased tendon is understudied compared to pulmonary and renal tissues, where transforming growth factor (TGF)β and its associated superfamily are known to be key drivers of fibrosis and modulate extracellular matrix homeostasis. We hypothesised that differential expression of TGFβ superfamily members would exist between samples of human rotator cuff tendons with established disease compared to healthy control tendons. Healthy and diseased rotator cuff tendons were collected from patients presenting to an orthopaedic referral centre. Diseased tendinopathic (intact) and healthy rotator cuff tendons were collected via ultrasound-guided biopsy and torn tendons were collected during routine surgical debridement. Immunohistochemistry and quantitative real-time polymerase chain reaction were used to investigate the protein and gene expression profiles of TGFβ superfamily members in these healthy and diseased tendons. TGFβ superfamily members were dysregulated in diseased compared to healthy tendons. Specifically, TGFβ-1, TGFβ receptor (R)1 and TGFβ R2 proteins were reduced (p tendons. At the mRNA level, TGFβ R1 was significantly reduced in samples of diseased tendons, whereas TGFβ R2 was increased (p tendon disease. We propose that downregulation of TGFβ pathways in established tendon disease may be a protective response to limit disease-associated fibrosis. The disruption of the TGFβ axis with disease suggests associated downstream pathways may be important for maintaining healthy tendon homeostasis. The findings from our study suggest that patients with established tendon disease would be unlikely to benefit from therapeutic TGFβ blockade, which has been investigated as a treatment strategy in several animal models. Future studies should investigate

  15. Tendons Arrangement Effects on Reinforced Concrete Frames

    Directory of Open Access Journals (Sweden)

    Ayad B. Bahnam

    2013-05-01

    Full Text Available  The tendons arrangement effects on the response of reinforced concrete frame experiencing blast loads is investigated in this paper. The structure is modeled using nonlinear finite elements employing a bilinear hysteretic model. So that elements are used so that yielding of the structures could be accurately modeled and captured. The frame is analyzed using a non-linear, elastic-plastic finite element program written in code MATLAB. Six tendon architectures were investigated. A single tendon was placed between different floors and its effects investigated. From the obtained results, the ideal case which causes a reduction in the maximum displacement and the amount of permanent deflection without increase in the maximum structural shear forces greatly is obtained.

  16. 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; Gaida, Jamie; Docking, Sean; Purdam, Craig; Cook, Jill

    2016-02-01

    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

  17. 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.

  18. 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.

  19. Distal biceps tendon rupture.

    Science.gov (United States)

    Savvidou, Olga D; Papagelopoulos, Panayiotis J; Mavrogenis, Andreas F; Partsinevelos, Antonios A; Karadimas, Evangelos J; Korres, Demetrios S

    2004-09-01

    The authors report a rupture of the distal tendon of biceps brachii in a 42-year-old athlete. Magnetic resonance imaging confirmed the injury. Early surgical repair was performed by reinsertion of the tendon on the radial tuberosity according to modified Boyd-Anderson technique. Indomethacin was administered prophylactically. No complications were noted. At the latest follow-up, the patient had full elbow range of motion and participated successfully in athletic activities and job.

  20. Hydrothermal synthesis, structure and characterization of new ...

    Indian Academy of Sciences (India)

    Unknown

    Keywords. Hydrothermal; crystal structure; solid electrolyte; iron (III) pyrophosphate. 1. Introduction ... tion, structure and electrical conductivity and the higher values of ..... type cavity structure. Acknowledgements. The authors would like to express their thanks to DST,. New Delhi, for financial assistance under the projects.

  1. Obesity/Type II diabetes alters macrophage polarization resulting in a fibrotic tendon healing response.

    Directory of Open Access Journals (Sweden)

    Jessica E Ackerman

    Full Text Available Type II Diabetes (T2DM dramatically impairs the tendon healing response, resulting in decreased collagen organization and mechanics relative to non-diabetic tendons. Despite this burden, there remains a paucity of information regarding the mechanisms that govern impaired healing of diabetic tendons. Mice were placed on either a high fat diet (T2DM or low fat diet (lean and underwent flexor tendon transection and repair surgery. Healing was assessed via mechanical testing, histology and changes in gene expression associated with collagen synthesis, matrix remodeling, and macrophage polarization. Obese/diabetic tendons healed with increased scar formation and impaired mechanical properties. Consistent with this, prolonged and excess expression of extracellular matrix (ECM components were observed in obese/T2DM tendons. Macrophages are involved in both inflammatory and matrix deposition processes during healing. Obese/T2DM tendons healed with increased expression of markers of pro-inflammatory M1 macrophages, and elevated and prolonged expression of M2 macrophages markers that are involved in ECM deposition. Here we demonstrate that tendons from obese/diabetic mice heal with increased scar formation and increased M2 polarization, identifying excess M2 macrophage activity and matrix synthesis as a potential mechanism of the fibrotic healing phenotype observed in T2DM tendons, and as such a potential target to improve tendon healing in T2DM.

  2. 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.

  3. 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.

  4. Chlorosulfolipids: Structure, synthesis, and biological relevance

    OpenAIRE

    Bedke, D. Karl; Vanderwal, Christopher D.

    2010-01-01

    Chlorosulfolipids have been isolated from freshwater algae and from toxic mussels. They appear to have a structural role in algal membranes and have been implicated in Diarrhetic Shellfish Poisoning. Further fascinating aspects of these compounds include their stereochemically complex polychlorinated structures and the resulting strong conformational biases, and their poorly understood (yet surely compelling) biosynthesis. Discussions of each of these topics and of efforts in structural and s...

  5. Synthesis, structure, redox and spectra of green iridium complexes ...

    Indian Academy of Sciences (India)

    TECS

    3. *For correspondence. Synthesis, structure, redox and spectra of green iridium complexes of tridentate azo-aromatic ligands. MANASHI PANDA,a CHAYAN DAS,a CHEN-HSIUNG HUNGb and. SREEBRATA ... Mn(II)7 and Fe(II)8 but also produces stable anionic ..... the EPR of the oxidized complexes were not suc- cessful ...

  6. Synthesis and structure refinement of layered double hydroxides of ...

    Indian Academy of Sciences (India)

    Administrator

    )-oxygen bond in this compound as opposed to the Co–Ga hydroxide. These observations are supported by IR spectra. Keywords. Layered double hydroxide; Rietveld refinement; urea hydrolysis. 1. Introduction. The synthesis, structure and properties of layered double hydroxides (LDHs) have been widely studied in recent.

  7. Abstract: Synthesis, structure and density functional theory (DFT ...

    Indian Academy of Sciences (India)

    Ruthenium Complexes of Chelating Amido-functionalized N-heterocyclic Carbene Ligands: Synthesis, Structure and DFT Studies. Sachin Kumar,† Anantha Narayanan,† Mitta Nageswar Rao,† Mobin M. Shaikh§ and Prasenjit Ghosh*,†. †Department of Chemistry and. §National Single Crystal X-ray Diffraction Facility,.

  8. Synthesis, structure and applications of [cis-dioxomolybdenum (VI ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 123; Issue 2. Synthesis, structure and applications of [cis-dioxomolybdenum(VI)-(ONO)] type complexes. Rajan Deepan Chakravarthy Dillip Kumar Chand. Volume 123 Issue 2 March 2011 pp 187-199 ... http://www.ias.ac.in/article/fulltext/jcsc/123/02/0187-0199 ...

  9. Synthesis, crystal structure and catecholase activity of a Ni (II ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 6. Synthesis, crystal structure and catecholase activity of a Ni(II) complex derived from a tetradentate Schiff base ligand. Pradipta Kumar Basu Merry Mitra Amrita Ghosh Latibuddin Thander Chia -Her Lin Rajarshi Ghosh. Rapid Communications Volume 126 ...

  10. Synthesis, characterization, X-ray crystal structure, electrochemical ...

    Indian Academy of Sciences (India)

    DOI 10.1007/s12039-015-0978-8. Synthesis, characterization, X-ray crystal structure, electrochemical evaluation and anti-cancer studies of a mixed ligand Cu(II) complex of (E)-N -((2-hydroxynaphthalen-1-yl)methylene)acetohydrazide. IRAN SHEIKHSHOAIEa, S YOUSEF EBRAHIMIPOURa,∗, MAHDIEH SHEIKHSHOAIEa,.

  11. Synthesis, structure and applications of [cis-dioxomolybdenum (VI ...

    Indian Academy of Sciences (India)

    Oxo-molybdenum chemistry is of great interest since such units are found in the active sites of a majority of molybdo-enzymes. In order to mimic the biological systems, a number of oxo-molybdenum complexes have been synthesised and studied. This review describes synthesis, structure and applications of ...

  12. Synthesis, structure and luminescence properties of phosphates A1 ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 1. Synthesis, structure and luminescence properties of phosphates A 1 − 3 x Eu x Zr 2 (PO 4 ) 3 (A—alkali metal). ANTON KANUNOV BENOIT GLORIEUX ALBINA ORLOVA ELENA BOROVIKOVA GALINA ZAVEDEEVA. Volume 40 Issue 1 February 2017 pp 7- ...

  13. Synthesis and crystal structure of a wheel-shaped supramolecular ...

    Indian Academy of Sciences (India)

    Synthesis and crystal structure of a wheel-shaped supramolecular coordination complex. DEEPAK GUPTA, PALANISAMY RAJAKANNU, BHASKARAN SHANKAR,. FIRASAT HUSSAIN and MALAICHAMY SATHIYENDIRAN. ∗. Department of Chemistry, University of Delhi, Delhi 110 007, India e-mail: mvdiran@yahoo.com; ...

  14. Accuracy of MRI technique in measuring tendon cross-sectional area

    DEFF Research Database (Denmark)

    Couppé, Christian; Svensson, R. B.; Elbrønd (Bibs), Vibeke Sødring

    2014-01-01

    Magnetic resonance imaging (MRI) has commonly been applied to determine tendon cross-sectional area (CSA) and length either to measure structural changes or to normalize mechanical measurements to stress and strain. The ability to reproduce CSA measurements on MRI images has been reported......, but the accuracy in relation to actual tendon dimensions has never been investigated. The purpose of this study was to compare tendon CSA measured by MRI with that measured in vitro with the mould casting technique. The knee of a horse was MRI-scanned with 1.5 and 3 tesla, and two examiners measured the patellar...... tendon CSA. Thereafter, the patellar tendon of the horse was completely dissected and embedded in an alginate cast. The CSA of the embedded tendon was measured directly by optical imaging of the cast impression. 1.5 tesla grey tendon CSA and 3 tesla grey tendon CSA were 16.5% and 13.2% lower than...

  15. Synthesis, crystal structure, thermal analysis and dielectric ...

    Indian Academy of Sciences (India)

    In both the materials, the crystal structure has been determined by X-ray single crystal analysis at room temperature (293 K). The compound structures consist of K + (or NH 4 + ) cations and double chains of CdCl 6 octahedra sharing one edge extending along b -axis. The mixture of KA + /NH 4 + cations are located ...

  16. Hydrothermal synthesis, structure and characterization of new ...

    Indian Academy of Sciences (India)

    Unknown

    The structure has tunnel-type cavities and are congenial for ion transportation through them. The compound exhibits moderate thermal stability. Keywords. Hydrothermal; crystal structure; solid electrolyte; iron (III) pyrophosphate. 1. Introduction. NASICON and related compounds belong to the well known family of solid ...

  17. Synthesis, crystal structures, spectroscopic characterization and in ...

    Indian Academy of Sciences (India)

    Both the complexes were structurally characterized by single crystal XRD. The crystal structure of complex 1 displays a distorted square pyramidal geometry in which Schiff base is coordinated to the Cu(II) ion via ONO-donor in the axial mode, whereas, the chelating diamine displays axial and equatorial mode of binding via ...

  18. Bioinspired synthesis of new silica structures.

    Science.gov (United States)

    Patwardhan, Siddharth V; Mukherjee, Niloy; Steintz-Kannan, Miriam; Clarson, Stephen J

    2003-05-21

    Silicon and oxygen are the two most abundant elements in the Earth's crust but despite the vast scientific literature on crystalline and amorphous silica, new chemistries, structures and applications continue to be discovered for compounds formed from these elements--thus we present here for the first time the formation of new amorphous silica structures that were uniquely synthesized by a bioinspired synthetic system.

  19. [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.

  20. The effect of acute exercise on collagen turnover in human tendons

    DEFF Research Database (Denmark)

    Mørch, Lina Steinrud; Pingel, Jessica; Boesen, Mikael

    2013-01-01

    and compared to values obtained by 72-h post-exercise. Power Doppler was used to monitor alterations in intratendinous blood flow velocity of the Achilles tendon and MRI used to quantitate changes in tendon cross-section area. Acute loading resulted in an increased collagen synthesis 72 h after the run in both...

  1. Metabolic activity and collagen turnover in human tendon in response to physical activity

    DEFF Research Database (Denmark)

    Kjaer, M; Langberg, H; Miller, B F

    2005-01-01

    Connective tissue of the human tendon plays an important role in force transmission. The extracellular matrix turnover of tendon is influenced by physical activity. Blood flow, oxygen demand, and the level of collagen synthesis and matrix metalloproteinases increase with mechanical loading. Gene ...

  2. Constrained saccharides: a review of structure, biology, and synthesis.

    Science.gov (United States)

    Rodriguez, Jacob; O'Neill, Sloane; Walczak, Maciej A

    2018-03-01

    Review primarily covers from 1995-2018Carbohydrate function, recognized in a multitude of biological processes, provides a precedent for developing carbohydrate surrogates that mimic the structure and function of bioactive compounds. In order to constrain highly flexible oligosaccharides, synthetic tethering techniques like those exemplified by stapled peptides are utilized to varying degrees of success. Naturally occurring constrained carbohydrates, however, exist with noteworthy cytotoxic and chemosensitizing properties. This review highlights the structure, biology, and synthesis of this intriguing class of molecules.

  3. Synthesis, crystal structure, theoretical study and luminescence ...

    Indian Academy of Sciences (India)

    phenanthroline) has been synthesized and characterized by elemental analysis, infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray single crystal analysis and fluorescent analysis. Its crystal structure is monoclinic with space group 2/ and ...

  4. 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.

  5. Synthesis and structure of cerium nitrosocarbonylcyanmethanid complex

    International Nuclear Information System (INIS)

    Gerasimenko, H.; Scopenko, V.V.; Kapshuk, A.A.

    1998-01-01

    Full text: The complex compound [CeL 4 Dy 2 ]Na*2Ac (where L- nitrosocarbonylcyanmethanid, Dy -- dipyridile, Ac - acetone) were synthesised by interaction of cerium chloride and sodium nitrosocarbonylcyanmethanid from acetone solution. After two hours of mixing the dipyridil solution in acetone was added for complex stabilization. After filtration solution was put to desiccator for crystallisation. The complex was studied using IR- and UV-spectroscopy. The structure of the complex was determined using X-ray structure analysis. It was found that the structure of the complex belongs to orthorhombic Pna2(1) syngony with the unit cell parameters 17.010, 16.280 and 16.340Angstroms, respectively. It was found that cerium in the compound was eight co-ordinated. Four nitroso ligands were co-ordinated by bidentate bridge method and two dipyridiles by bidentate-cycle method

  6. Endoscopic Management of Gluteus Medius Tendon Tears.

    Science.gov (United States)

    Thaunat, Mathieu; Noël, Eric; Nové-Josserand, Laurent; Murphy, Colin G; Sbiyaa, Mouhcine; Sonnery-Cottet, Bertrand

    2016-03-01

    Tears in the gluteus medius and minimus tendons have been recognized as an important cause of recalcitrant greater trochanteric pain syndrome. Because of the frequency of partial-thickness undersurface tears, this relatively unknown pathology is often misdiagnosed and left untreated. Surgery is indicated in case of 4 associated conditions: (i) Failure of conservative treatment with duration of symptoms >6 months; (ii) magnetic resonance imaging showing a tendon tear; (iii) positive ultrasound-guided infiltration test; and (iv) the absence of an evolved fatty degeneration or atrophy of the gluteus medius and minimus muscle. Endoscopic repair of partial or full-thickness tears, with systematic resection of the bony structures implicated in the impingement, and a complete bursectomy appear to give satisfactory results, although these results remain to be confirmed by clinical studies with longer follow-up. The degree of tendon degeneration may compromise the tissue left for reattachment, raising concerns over its healing capacity, durability, and ultimate strength of the repair.

  7. Synthesis, characterization and crystal structure of a ...

    African Journals Online (AJOL)

    The Mo atom in the complex is in octahedral coordination. Thermal stability of the complex has also been studied. KEY WORDS: Molybdenum complex, Hydrazone ligand, Crystal structure, X-ray diffraction, Thermal property. Bull. Chem. Soc. Ethiop. 2014, 28(3), 409-414. DOI: http://dx.doi.org/10.4314/bcse.v28i3.10 ...

  8. Synthesis, molecular structure, spectroscopic investigations and ...

    Indian Academy of Sciences (India)

    MS received 29 December 2015; revised 9 April 2016; accepted 25 May 2016 ... B, open form blue. Scheme 1. Structures and Photochromic reaction of the title compound. 2. Experimental. 2.1 Materials and measurements. The mid-IR spectra were obtained in the ... segment is put between two parallel Au(111) surfaces,.

  9. Synthesis, crystal structure, thermal analysis and dielectric ...

    Indian Academy of Sciences (India)

    [13] Perry C H and Lowdes R P 1969 J. Chem. Phys. 51 3648. [14] Sheldrick G M 1997 SHELXS9, Program for the Refinement of Crystal Structures (Germany: University of Gottingen). [15] Loukil M, Kabadou A, Salles Ph and Ben Salah A 2004 Chem. Phys. 300 247. [16] Rolies M M and De Ranter C J 1978 Acta Crystallogr.

  10. Synthesis, crystal structure, theoretical study and luminescence ...

    Indian Academy of Sciences (India)

    performed on complex 1 to rationalize its experimental absorption spectra. Complex 1 exhibits luminescence in EtOH ... potential applications in biological systems like, devel- opment of structural and functional models for ... to react with [WOnS4−n] (n = 0-2).11,12 These reactions result in the formation of a large number of ...

  11. 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

  12. Synthesis, crystal structure, thermal analysis and dielectric ...

    Indian Academy of Sciences (India)

    2.2 X-ray structure determination. Two transparent parallelepipedic crystals with dimensions,. 0.20 × 0.12 × 0.04 and 0.26 × 0.14 × 0.12, were chosen from the preparation. The intensity data were collected on. An APEX II diffractometer with graphite–crystal monochro- mated MoKα radiation (0.71073 Å). Lorentz and polariz-.

  13. Synthesis and structure of vanillin azomethines

    Directory of Open Access Journals (Sweden)

    Jasmina M. Jovanović

    2009-10-01

    Full Text Available Vanillin is most prominent as the principal flavor and aroma compound in vanilla. Vanillin has been used as a chemical intermediate in the production of pharmaceuticals and other fine chemicals.The two intermediates, assigned as intermediates I and II, were prepared by using vanillin and 1-butylbromide or 2-chloroacetic acid, respectively. The condensation of intermediates with 2,3- -diaminopyridine gave azomethines. Their structure was established by using elemental microanalysis, as well as UV/Vis, FTIR and 1H-NMR spectra. Synthesized compounds were tested for their antifungal activity against Candida albicans, Candida lipolytica and Sacharomyces cerevisiae.

  14. Experimental studies in chickens on the initial nutrition of tendon grafts.

    Science.gov (United States)

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

    1979-11-01

    A study of nutrition of various tendon graft preparations in adult chickens (up to 2 weeks after grafting), using tritiated proline and a trichloracetic acid extraction technique which separated the free and metabolized amino acid fractions, suggests that diffusion of nutrients is an important process in the initial nutrition of tendon grafts, that tendon grafts are metabolically active and viable structures, that adhesions which are frequently associated with tendon grafts do not appear to be essential to the nutrition of grafts, and that tendon grafts within fibrous pseudosheaths are nourished as effectively as grafts within synovial sheaths.

  15. Tendon material properties vary and are interdependent among turkey hindlimb muscles

    Science.gov (United States)

    Matson, Andrew; Konow, Nicolai; Miller, Samuel; Konow, Pernille P.; Roberts, Thomas J.

    2012-01-01

    SUMMARY The material properties of a tendon affect its ability to store and return elastic energy, resist damage, provide mechanical feedback and amplify or attenuate muscle power. While the structural properties of a tendon are known to respond to a variety of stimuli, the extent to which material properties vary among individual muscles remains unclear. We studied the tendons of six different muscles in the hindlimb of Eastern wild turkeys to determine whether there was variation in elastic modulus, ultimate tensile strength and resilience. A hydraulic testing machine was used to measure tendon force during quasi-static lengthening, and a stress–strain curve was constructed. There was substantial variation in tendon material properties among different muscles. Average elastic modulus differed significantly between some tendons, and values for the six different tendons varied nearly twofold, from 829±140 to 1479±106 MPa. Tendons were stretched to failure, and the stress at failure, or ultimate tensile stress, was taken as a lower-limit estimate of tendon strength. Breaking tests for four of the tendons revealed significant variation in ultimate tensile stress, ranging from 66.83±14.34 to 112.37±9.39 MPa. Resilience, or the fraction of energy returned in cyclic length changes was generally high, and one of the four tendons tested was significantly different in resilience from the other tendons (range: 90.65±0.83 to 94.02±0.71%). An analysis of correlation between material properties revealed a positive relationship between ultimate tensile strength and elastic modulus (r2=0.79). Specifically, stiffer tendons were stronger, and we suggest that this correlation results from a constrained value of breaking strain, which did not vary significantly among tendons. This finding suggests an interdependence of material properties that may have a structural basis and may explain some adaptive responses observed in studies of tendon plasticity. PMID:22771746

  16. Synthesis, structure, and properties of azatriangulenium salts

    DEFF Research Database (Denmark)

    Laursen, B.W.; Krebs, Frederik C

    2001-01-01

    A general synthetic route to novel nitrogen-bridged heterocyclic carbenium ions of the acridinium and triangulenium type has been developed and investigated. The synthetic method is based on nucleophilic aromatic substitution (SNAr) on the tris(2,6-dimethoxyphenyl)carbenium ion (1) with primary...... amines and, by virtue of its stepwise and irreversible nature, provides a powerful tool for the preparation of a wide variety of new heterocyclic carbenium salts. Several derivatives of the three new oxygen- and/or nitrogen-bridged triangulenium salts, azadioxa- (6), diazaoxa- (7......), and triazatriangulenium (4), have been synthesized and their physicochemical properties have been investigated. Crystal structures for compounds 2 b-PF6: 2d-PF6, 4b-BF4, 4c-BF4, 6e-BF4, and 8 are reported. The different packing modes found for the triazatriagulenium salts are discussed in relation to the electrostatic...

  17. Synthesis, crystal structures, hydrogen bonding graph-sets and ...

    African Journals Online (AJOL)

    Synthesis, crystal structures, hydrogen bonding graph-sets and theoretical studies of nickel (+II) co-ordinations with pyridine-2,6-dicarboxamide oxime. ... which crystallized in the monoclinic space group C2/c with a = 14.915(2), b = 0.895(2), c = 8.205(1) Å, β = 114.69(1), and Z = 4. The complex consists of discrete cations ...

  18. Structure of FD-895 revealed through total synthesis.

    Science.gov (United States)

    Villa, Reymundo; Mandel, Alexander L; Jones, Brian D; La Clair, James J; Burkart, Michael D

    2012-11-02

    The total synthesis of FD-895 was completed through a strategy that featured the use of a tandem esterification ring-closing metathesis (RCM) process to construct the 12-membered macrolide and a modified Stille coupling to append the side chain. These studies combined with detailed analysis of all four possible C16-C17 stereoisomers were used to confirm the structure of FD-895 and identify an analog with an enhanced subnanomolar bioactivity.

  19. 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 moving your foot. ...

  20. triceps tendon avulsion

    African Journals Online (AJOL)

    GB

    2014-01-01

    Jan 1, 2014 ... trauma. Systemic causes such as chronic renal failure, steriod use, diabetes mellitus, hyperparathyroidism, rheumatoid arthritis, osteogensis imperfecta and local causes like local steriod injection, olecranon bursitis and attritional changes due to degenerative arthritis are associated with tendon weakening.

  1. 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.

  2. Evaluation of the equine digital flexor tendon sheath using diagnostic ultrasound and contrast radiography

    International Nuclear Information System (INIS)

    Redding, W.R.

    1994-01-01

    This study was designed to evaluate the normal anatomy of the digital flexor tendon sheath using contrast radiography and diagnostic ultrasound. Iodinated contrast medium was injected into eight cadaver limbs and the limbs immediately frozen. Lateromedial and dorsopalmar/plantar radiographs were made. These limps were then cut transversely and proximal to distal radiographs of each slab were made. This cross sectional contrast methodology allowed the visualization of the relative size and shape of the superficial and deep digital flexor tendons as well as the potential space taken by effusions of the digital flexor tendon sheath. The second part of the study used twelve live animals with normal digital flexor tendon sheaths. Ultrasonographic measurement of the structures of the digital flexor tendon sheath at each level were compiled. This documented the ability of diagnostic ultrasound to image: 1) the superficial and deep digital flexor tendons, 2) the proximal and distal ring of the manica flexoria, 3) the straight and oblique sesamoidean ligaments, and 4) the mesotendinous attachments to the superficial and deep flexor tendons. Iodinated contrast medium was then injected into the digital flexor tendon sheath and the ultrasonography repeated. These images were compared with those obtained from contrast radiography and prosections of twenty normal limbs. The iodinated contrast medium enhanced sonographic imaging of the structures of the digital tendon sheath, particularly the abaxial borders of the superficial digital flexor tendon branches and the mesotendinous attachments to the superficial and deep digital flexor tendons

  3. Neuromuscular and muscle-tendon system adaptations to isotonic and isokinetic eccentric exercise.

    Science.gov (United States)

    Guilhem, G; Cornu, C; Guével, A

    2010-06-01

    To present the properties of an eccentric contraction and compare neuromuscular and muscle-tendon system adaptations induced by isotonic and isokinetic eccentric trainings. An eccentric muscle contraction is characterized by the production of muscle force associated to a lengthening of the muscle-tendon system. This muscle solicitation can cause micro lesions followed by a regeneration process of the muscle-tendon system. Eccentric exercise is commonly used in functional rehabilitation for its positive effect on collagen synthesis but also for resistance training to increase muscle strength and muscle mass in athletes. Indeed, eccentric training stimulates muscle hypertrophy, increases the fascicle pennation angle, fascicles length and neural activation, thus inducing greater strength gains than concentric or isometric training programs. Eccentric exercise is commonly performed either against a constant external load (isotonic) or at constant velocity (isokinetic), inducing different mechanical constraints. These different mechanical constraints could induce structural and neural adaptive strategies specific to each type of exercise. The literature tends to show that isotonic mode leads to a greater strength gain than isokinetic mode. This observation could be explained by a greater neuromuscular activation after IT training. However, the specific muscle adaptations induced by each mode remain difficult to determine due to the lack of standardized, comparative studies. 2010 Elsevier Masson SAS. All rights reserved.

  4. Metal Oxide Nano structures: Synthesis, Properties, and Applications

    International Nuclear Information System (INIS)

    Xu, L. H.; Patil, D. S.; Yang, J.; Xiao, J.

    2015-01-01

    In recent years, nano structured materials have attracted wide attention due to their fascinating optical and electrical properties, which make these materials potentially suitable for applications in electronics, optics, photonics, and sensors. Some metal oxides show a wide variety of morphologies such as nano wires, nano rods, nano tubes, nano rings, and nano belts. Synthesis and investigation of these metal-oxide nano structures are beneficial not only for understanding the fundamental phenomena in low dimensional systems, but also for developing new-generation nano devices with high performance.

  5. Structure, Chemical Synthesis, and Biosynthesis of Prodiginine Natural Products.

    Science.gov (United States)

    Hu, Dennis X; Withall, David M; Challis, Gregory L; Thomson, Regan J

    2016-07-27

    The prodiginine family of bacterial alkaloids is a diverse set of heterocyclic natural products that have likely been known to man since antiquity. In more recent times, these alkaloids have been discovered to span a wide range of chemical structures that possess a number of interesting biological activities. This review provides a comprehensive overview of research undertaken toward the isolation and structural elucidation of the prodiginine family of natural products. Additionally, research toward chemical synthesis of the prodiginine alkaloids over the last several decades is extensively reviewed. Finally, the current, evidence-based understanding of the various biosynthetic pathways employed by bacteria to produce prodiginine alkaloids is summarized.

  6. Characterization structural and morphology ZSM-5 zeolite by hydrothermal synthesis

    International Nuclear Information System (INIS)

    Silva, V.J.; Crispim, A.C.; Queiroz, M.B.; Laborde, H.M.; Rodrigues, M.G.F.; Menezes, R.R.

    2009-01-01

    Solid acids are catalytic materials commonly used in the chemical industry. Among these zeolites are the most important business processes including water treatment, gas separation, and cracking long hydrocarbon chains to produce high octane gasoline. Its synthesis, characterization and applications have been widely studied. The objective this study was to synthesize the ZSM-5 zeolite for future use in separation processes and catalysis. The zeolite ZSM-5 was prepared by hydrothermal synthesis at 170°C, using silica, deionized water and the director of structures (TPABr - tetrapropylammonium bromide). The materials were characterized by X ray diffraction (XRD), scanning electron microscopy (SEM) and semiquantitative chemical analysis by X ray fluorescence (XRF). According to the XRD was possible to observe the formation of ZSM-5 zeolite, with peaks intense and well defined. The SEM showed the formation of individual particles, clean, rounded shapes. (author)

  7. [Questions concerning two-stage reconstruction of injured flexor tendons. III. Ultrastructure of the tenosynovium in the pseudo-tendon sheath created by using a silicone rod].

    Science.gov (United States)

    Salamon, A; Bíró, V; Vámhidy, L; Trombitás, K; Józsa, L

    1993-01-01

    Authors have investigated the ultrastructure of the pseudo tendon sheath, formed with silicon rod and man. They have observed a superficial structure, resembling the normal tendon sheath in scanning electron microscopic examination. With transmission electron microscopy phagocyte "A" type and secretion "B" type synovial cells were found. Authors state that the newly formed tenosynovium has an important role in the nutrition of the tendon graft and the prevention of adhesions.

  8. In vitro tendon tissue development from human fibroblasts demonstrates collagen fibril diameter growth associated with a rise in mechanical strength

    DEFF Research Database (Denmark)

    Herchenhan, Andreas; Bayer, Monika L; Svensson, René B

    2013-01-01

    Collagen-rich tendons and ligaments are important for joint stability and force transmission, but the capacity to form new tendon is poorly understood. In the present study, we investigated mechanical strength, fibril size, and structure during development of tendon-like tissue from adult human...

  9. The initiation of embryonic-like collagen fibrillogenesis by adult human tendon fibroblasts when cultured under tension

    DEFF Research Database (Denmark)

    Bayer, Monika L; Yeung, Chin-Yan C; Kadler, Karl E

    2010-01-01

    Tendon fibroblasts synthesize collagen and form fibrils during embryonic development, but to what extent mature fibroblasts are able to recapitulate embryonic development and develop normal tendon structure is unknown. The present study examined the capability of mature human tendon fibroblasts t...

  10. 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.

  11. Suture materials and suture techniques used in tendon repair.

    Science.gov (United States)

    Ketchum, L D

    1985-02-01

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

  12. Effects of training, immobilization and remobilization on tendons.

    Science.gov (United States)

    Kannus, P; Józsa, L; Natri, A; Järvinen, M

    1997-04-01

    Since a tendon is a living tissue, it is not a surprise that tendon shows the capacity to adapt its structure and mechanical properties to the functional demands of the entire muscle-tendon unit. However, compared with muscle, the experimental knowledge of the effects of strength or endurance-type training on tendon tissue is scarce and clinical human experiments are completely lacking (1). Research should, however, be able to improve the true understanding of the biomechanical, functional, morphological and biochemical changes that occur in tendons due to training and physical activity, since understanding of the basic physiology of a tissue is the key to understanding its pathological processes (1, 2). Compared with muscle tissue, the metabolic turnover of tendon tissue is many times slower due to poorer vascularity and circulation (1, 3). The adaptive responses of tendons to training are therefore also slower than those in muscles, but they may finally be considerable if the time frame is long enough (3, 4).

  13. Simultaneous bilateral patellar tendon rupture ?

    OpenAIRE

    Moura, Diogo Lino; Marques, Jos? Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2016-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a s...

  14. Effect of adipose-derived nucleated cell fractions on tendon repair in horses with collagenase-induced tendinitis.

    Science.gov (United States)

    Nixon, Alan J; Dahlgren, Linda A; Haupt, Jennifer L; Yeager, Amy E; Ward, Daniel L

    2008-07-01

    To assess the potential of adipose-derived nucleated cell (ADNC) fractions to improve tendon repair in horses with collagenase-induced tendinitis. 8 horses. Collagenase was used to induce tendinitis in the superficial digital flexor tendon of 1 forelimb in each horse. Four horses were treated by injection of autogenous ADNC fractions, and 4 control horses were injected with PBS solution. Healing was compared by weekly ultrasonographic evaluation. Horses were euthanatized at 6 weeks. Gross and histologic evaluation of tendon structure, fiber alignment, and collagen typing were used to define tendon architecture. Biochemical and molecular analyses of collagen, DNA, and proteoglycan and gene expression of collagen type I and type III, decorin, cartilage oligomeric matrix protein (COMP), and insulin-like growth factor-I were performed. Ultrasonography revealed no difference in rate or quality of repair between groups. Histologic evaluation revealed a significant improvement in tendon fiber architecture; reductions in vascularity, inflammatory cell infiltrate, and collagen type III formation; and improvements in tendon fiber density and alignment in ADNC-treated tendons. Repair sites did not differ in DNA, proteoglycan, or total collagen content. Gene expression of collagen type I and type III in treated and control tendons were similar. Gene expression of COMP was significantly increased in ADNC-injected tendons. ADNC injection improved tendon organization in treated tendons. Although biochemical and molecular differences were less profound, tendons appeared architecturally improved after ADNC injection, which was corroborated by improved tendon COMP expression. Use of ADNC in horses with tendinitis appears warranted.

  15. Synthesis of carbon nano structures by plasma discharge

    International Nuclear Information System (INIS)

    Jimenez L, M.L.

    2007-01-01

    Due to the great quantity of applications of carbon neocarcinostatin (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, one has seen the necessity to generate new synthesis processes of these materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither impurities. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arc discharge, in a gas mixture He-CH 4 with 34% at.Ni/10.32%at.Y like catalyst; to a frequency of 42 k Hz and low power (300 W). This method benefits the agglomeration of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the type of obtained NEC and by X-ray diffraction analysis and Raman spectroscopy to determine the purity of the samples. The NFC are relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of the plasma using the Swan band to determine the temperature. (Author)

  16. The extended evolutionary synthesis: its structure, assumptions and predictions.

    Science.gov (United States)

    Laland, Kevin N; Uller, Tobias; Feldman, Marcus W; Sterelny, Kim; Müller, Gerd B; Moczek, Armin; Jablonka, Eva; Odling-Smee, John

    2015-08-22

    Scientific activities take place within the structured sets of ideas and assumptions that define a field and its practices. The conceptual framework of evolutionary biology emerged with the Modern Synthesis in the early twentieth century and has since expanded into a highly successful research program to explore the processes of diversification and adaptation. Nonetheless, the ability of that framework satisfactorily to accommodate the rapid advances in developmental biology, genomics and ecology has been questioned. We review some of these arguments, focusing on literatures (evo-devo, developmental plasticity, inclusive inheritance and niche construction) whose implications for evolution can be interpreted in two ways—one that preserves the internal structure of contemporary evolutionary theory and one that points towards an alternative conceptual framework. The latter, which we label the 'extended evolutionary synthesis' (EES), retains the fundaments of evolutionary theory, but differs in its emphasis on the role of constructive processes in development and evolution, and reciprocal portrayals of causation. In the EES, developmental processes, operating through developmental bias, inclusive inheritance and niche construction, share responsibility for the direction and rate of evolution, the origin of character variation and organism-environment complementarity. We spell out the structure, core assumptions and novel predictions of the EES, and show how it can be deployed to stimulate and advance research in those fields that study or use evolutionary biology. © 2015 The Author(s).

  17. The extended evolutionary synthesis: its structure, assumptions and predictions

    Science.gov (United States)

    Laland, Kevin N.; Uller, Tobias; Feldman, Marcus W.; Sterelny, Kim; Müller, Gerd B.; Moczek, Armin; Jablonka, Eva; Odling-Smee, John

    2015-01-01

    Scientific activities take place within the structured sets of ideas and assumptions that define a field and its practices. The conceptual framework of evolutionary biology emerged with the Modern Synthesis in the early twentieth century and has since expanded into a highly successful research program to explore the processes of diversification and adaptation. Nonetheless, the ability of that framework satisfactorily to accommodate the rapid advances in developmental biology, genomics and ecology has been questioned. We review some of these arguments, focusing on literatures (evo-devo, developmental plasticity, inclusive inheritance and niche construction) whose implications for evolution can be interpreted in two ways—one that preserves the internal structure of contemporary evolutionary theory and one that points towards an alternative conceptual framework. The latter, which we label the ‘extended evolutionary synthesis' (EES), retains the fundaments of evolutionary theory, but differs in its emphasis on the role of constructive processes in development and evolution, and reciprocal portrayals of causation. In the EES, developmental processes, operating through developmental bias, inclusive inheritance and niche construction, share responsibility for the direction and rate of evolution, the origin of character variation and organism–environment complementarity. We spell out the structure, core assumptions and novel predictions of the EES, and show how it can be deployed to stimulate and advance research in those fields that study or use evolutionary biology. PMID:26246559

  18. Achilles tendon injuries in athletes.

    Science.gov (United States)

    Kvist, M

    1994-09-01

    Two-thirds of Achilles tendon injuries in competitive athletes are paratenonitis and one-fifth are insertional complaints (bursitis and insertion tendinitis). The remaining afflictions consist of pain syndromes of the myotendineal junction and tendinopathies. The majority of Achilles tendon injuries from sport occur in males, mainly because of their higher rates of participation in sport, but also with tendinopathies a gender difference is probably indicated. Athletes in running sports have a high incidence of Achilles tendon overuse injuries. About 75% of total and the majority of partial tendon ruptures are related to sports activities usually involving abrupt repetitive jumping and sprinting movements. Mechanical factors and a sedentary lifestyle play a role in the pathology of these injuries. Achilles tendon overuse injuries occur at a higher rate in older athletes than most other typical overuse injuries. Recreational athletes with a complete Achilles tendon rupture are about 15 years younger than those with other spontaneous tendon ruptures. Following surgery, about 70 to 90% of athletes have a successful comeback after Achilles tendon injury. Surgery is required in about 25% of athletes with Achilles tendon overuse injuries and the frequency of surgery increases with patient age and duration of symptoms as well as occurrence of tendinopathic changes. However, about 20% of injured athletes require a re-operation for Achilles tendon overuse injuries, and about 3 to 5% are compelled to abandon their sports career because of these injuries. Myotendineal junction pain should be treated conservatively. Partial Achilles tendon ruptures are primarily treated conservatively, although the best treatment method of chronic partial rupture seems to be surgery. Complete Achilles tendon ruptures of athletes are treated surgically, because this increases the likelihood of athletes reaching preinjury activity levels and minimises the risk of re-ruptures. Marked forefoot

  19. A General Chemistry Experiment Incorporating Synthesis and Structural Determination

    Science.gov (United States)

    van Ryswyk, Hal

    1997-07-01

    An experiment for the general chemistry laboratory is described wherein gas chromatography-mass spectroscopy (GC-MS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) are used to characterize the products of a series of microscale reactions on vanillin. A single sophisticated instrument can be incorporated into the laboratory given sufficient attention to the use of sampling accessories and software macros. Synthetic experiments coupled with modern instrumental techniques can be used in the general chemistry laboratory to illustrate the concepts of synthesis, structure, bonding, and spectroscopy.

  20. Synthesis and Structural Analysis of Polyester Prodrugs of Norfloxacin

    Directory of Open Access Journals (Sweden)

    Waclaw Kolodziejski

    2008-01-01

    Full Text Available Two-, three- and four-arm, star-shaped poly(ε-caprolactone andpoly(D,L-lactide homopolymers, and copolymers of ε-caprolactone with D,L-lactide weresynthesized via ring-opening polymerization of cyclic esters in the presence of glycerol,penthaerythritol and poly(ethylene glycol as initiators and stannous octoate as a catalyst.Thus obtained oligomers were successfully used in the synthesis of novel macromolecularprodrugs of norfloxacin. The structures of the polymers and prodrugs were elucidated bymeans of MALDI-TOF MS, NMR and IR studies.

  1. Synthesis of resorcinolic lipids bearing structural similarities to cytosporone A

    Directory of Open Access Journals (Sweden)

    Edson dos Anjos dos Santos

    2009-01-01

    Full Text Available Inspired by the structure and biological activities of resorcinolic lipids and, particularly cytosporone A- a potent inhibitor of plantule germination and growth, we have performed the synthesis of the analogs 3-heptyl-3-hydroxy-5,7-dimethoxy-2-benzofuran-1(3H-one (1 and 3-heptyl-3-hydroxy-4,6-dimethoxy-2-benzofuran-1(3H-one (2. The intermediates and products were submitted to allelopathic test using Lactuca sativa L. seeds. Target compound 1 showed an inhibitory effect on germination and growth of hypocotyl and radicle in milimolar range.

  2. Synthesis of resorcinolic lipids bearing structural similarities to cytosporone A

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Edson dos Anjos dos; Beatriz, Adilson; Lima, Denis Pires de [Universidade Federal Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Centro de Ciencias Exatas e Tecnologia. Dept. de Quimica], e-mail: dlima@nin.ufms.br; Marques, Maria Rita; Leite, Carla Braga [Universidade Federal Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Centro de Ciencias Biologicas. Dept. de Morfofisiologia

    2009-07-01

    Inspired by the structure and biological activities of resorcinolic lipids and, particularly cytosporone A- a potent inhibitor of plantule germination and growth, we have performed the synthesis of the analogs 3-heptyl-3-hydroxy-5,7-dimethoxy-2-benzofuran-1(3H)-one (1) and 3-heptyl-3-hydroxy-4,6-dimethoxy-2-benzofuran-1(3H)-one (2). The intermediates and products were submitted to allelopathic test using Lactuca sativa L. seeds. Target compound 1 showed an inhibitory effect on germination and growth of hypocotyl and radicle in millimolar range. (author)

  3. Repair of Achilles tendon defect with autologous ASCs engineered tendon in a rabbit model.

    Science.gov (United States)

    Deng, Dan; Wang, Wenbo; Wang, Bin; Zhang, Peihua; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin; Liu, Wei

    2014-10-01

    Adipose derived stem cells (ASCs) are an important cell source for tissue regeneration and have been demonstrated the potential of tenogenic differentiation in vitro. This study explored the feasibility of using ASCs for engineered tendon repair in vivo in a rabbit Achilles tendon model. Total 30 rabbits were involved in this study. A composite tendon scaffold composed of an inner part of polyglycolic acid (PGA) unwoven fibers and an outer part of a net knitted with PGA/PLA (polylactic acid) fibers was used to provide mechanical strength. Autologous ASCs were harvested from nuchal subcutaneous adipose tissues and in vitro expanded. The expanded ASCs were harvested and resuspended in culture medium and evenly seeded onto the scaffold in the experimental group, whereas cell-free scaffolds served as the control group. The constructs of both groups were cultured inside a bioreactor under dynamic stretch for 5 weeks. In each of 30 rabbits, a 2 cm defect was created on right side of Achilles tendon followed by the transplantation of a 3 cm cell-seeded scaffold in the experimental group of 15 rabbits, or by the transplantation of a 3 cm cell-free scaffold in the control group of 15 rabbits. Animals were sacrificed at 12, 21 and 45 weeks post-surgery for gross view, histology, and mechanical analysis. The results showed that short term in vitro culture enabled ASCs to produce matrix on the PGA fibers and the constructs showed tensile strength around 50 MPa in both groups (p > 0.05). With the increase of implantation time, cell-seeded constructs gradually form neo-tendon and became more mature at 45 weeks with histological structure similar to that of native tendon and with the presence of bipolar pattern and D-periodic structure of formed collagen fibrils. Additionally, both collagen fibril diameters and tensile strength increased continuously with significant difference among different time points (p tendon tissue with fibril structure observable only at 45 weeks

  4. Disorders of the long head of the biceps tendon.

    Science.gov (United States)

    Sethi, N; Wright, R; Yamaguchi, K

    1999-01-01

    Without a clear understanding of the functional role of the biceps tendon, treatment recommendations have been a subject of controversy. An objective review of the available information would suggest that some humeral head stability may be imparted through the tendon. However, the magnitude of this function is likely to be small and possibly insignificant. In contrast, the symptomatic significance of the long head of the biceps is less controversial, and it has become increasingly recognized as an important source of persistent shoulder pain when not specifically addressed. When present, persistent pain from the long head of the biceps is likely to have more negative functional consequences than loss of the tendon itself. Given these concerns, evaluation and treatment of patients with long head of the biceps disorders should be individualized, based on the likelihood that biceps-related pain will resolve. Although not universally accepted, we recommend tenodesis of the long head of the biceps in those cases in which there are either chronic inflammatory or structural changes, which would make it unlikely that the pain would resolve. These clinical situations in which tenodesis would be required include greater than 25% partial thickness tearing of the tendon, chronic atrophic changes of the tendon, any luxation of the biceps tendon from the bicipital groove, any disruption of associated bony or ligamentous anatomy of the bicipital groove that would make autotenodesis likely (i.e., 4-part fracture), and any significant reduction or atrophy of the size of the tendon that is more than 25% of the normal tendon width. Relative indications for biceps tenodesis also include biceps disease in the context of a failed decompression for rotator cuff tendinitis. It should be emphasized that routine tenodesis is not recommended during operative treatment for the rotator cuff. Rather, we avoid tenodesis whenever it is believed that inflammatory changes to the biceps tendon are

  5. Achilles tendon of wistar rats treated with laser therapy and eccentric exercise

    Directory of Open Access Journals (Sweden)

    Maria Verônica de Souza

    2015-10-01

    as a healthy tendon. On the other hand, it also does not influence negatively the structure and function of the Achilles tendon.

  6. Structural Sizing of the EDIN0620 Body Components Using the APAS Structural Synthesis Computer Program

    Science.gov (United States)

    Nolte, W. E.

    1976-01-01

    The use of a structural synthesis computer program to design components for a heavy lift launch vehicle is defined. A loads program was used to determine the vehicle shears, bending moments, and axial loads at two design loading conditions. A comparison was made between results from the structures program and the results of a weight estimating program which used historical data in determining component weights.

  7. Synthesis of Carbon nano structures by plasma discharge

    International Nuclear Information System (INIS)

    Jimenez L, M.L.

    2007-01-01

    Due to the great quantity of applications of the carbon nano structures (NEC) in diverse areas like: synthesis of super-resistant materials, hydrogen storage, nano sensors generation and nano catalysts, it has seen the necessity to generate new processes of synthesis of this materials as well as to already improve those existent. The present work has as objective to optimize the NEC synthesis process by means of the electric arc method which uses alternating current to high frequencies (HF), obtaining relatively clean products; that is to say, it hardly presents amorphous material neither sludges. They stand out the obtaining of carbon nano fibers (NFC) by means of a luminescent-arch discharge, in a gas mixture of He-CH 4 with 34% at. Ni/10.32% at.Y like catalyst; at a frequency of 42 kHz and low power (300 W). This method benefits the amass of the particles in both electrodes due to the high frequencies. The time of duration of the process oscillates between 5 and 20 minutes. The obtained product was characterized by scanning electron microscopy (MEB), transmission electron microscopy (MET) to determine the NEC type obtained and by X-ray diffraction analysis and Raman spectroscopy for determining the purity of the samples. The NFC is relatively free of amorphous coal. The surface and structural analysis indicates that the fibers have a half diameter of 80 nm. It is also made, a study by optical emission spectroscopy of plasma using the Swan band for determining the temperature. (Author)

  8. Synthesis, structure and biological properties of active spirohydantoin derivatives

    Directory of Open Access Journals (Sweden)

    Lazić Anita M.

    2016-01-01

    Full Text Available Spirohidantoins represent an pharmacologically important class of heterocycles since many derivatives have been recognized that display interesting activities against a wide range of biological targets. First synthesis of cycloalkanespiro-5-hydantoins was performed by Bucherer and Lieb 1934 by the reaction of cycloalkanone, potassium cyanide and ammonium-carbonate at reflux in a mixture of ethanol and water. QSAR (Quantitative Structure-Activity Relationship studies showed that a wide range of biological activities of spirohydantoin derivatives strongly depend upon their structure. This paper describes different methods of synthesis of spirohydantoin derivatives, their physico-chemical properties and biological activity. It emphasizes the importance of cycloalkanespiro-5-hydantoins with anticonvulsant, antiproliferative, antipsychotic, antimicrobial and antiinflammatory properties as well as their importance in the treatment of diabetes. Numerous spirohydantoin compounds exhibit physiological activity such as serotonin and fibrinogen antagonist, inhibitors of the glycine binding site of the NMDA receptor also, antagonist of leukocyte cell adhesion, acting as allosteric inhibitors of the protein-protein interactions. Some spirohydantoin derivatives have been identified as antitumor agents. Their activity depends on the substituent presented at position N-3 of the hydantoin ring and increases in order alkene > ester > ether. Besides that, compounds that contain two electron withdrawing groups (e.g. fluorine or chlorine on the third and fourth position of the phenyl ring are better antitumor agents than compounds with a single electron withdrawing group. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  9. 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 ...

  10. Synthesis, Structure, and Properties of Refractory Hard-Metal Borides

    Science.gov (United States)

    Lech, Andrew Thomas

    As the limits of what can be achieved with conventional hard compounds, such as tungsten carbide, are nearing reach, super-hard materials are an area of increasing industrial interest. The refractory hard metal borides, such as ReB2 and WB4, offer an increasingly attractive alternative to diamond and cubic boron nitride as a next-generation tool material. In this Thesis, a thorough discussion is made of the progress achieved by our laboratory towards understanding the synthesis, structure, and properties of these extremely hard compounds. Particular emphasis is placed on structural manipulation, solid solution formation, and the unique crystallographic manifestations of what might also be called "super-hard metals".

  11. CT of peroneal tendon injury in patients with calcaneal fractures

    International Nuclear Information System (INIS)

    Rosenberg, Z.S.; Feldman, F.; Singson, R.D.

    1986-01-01

    Injury to the peroneal tendons is a major complication of intraarticular calcaneal fractures. Heretofore, the injury has been difficult to diagnose by routine imaging modalities. However, CT studies of 24 intraarticular calcaneal fractures revealed evidence of peroneal tendon injury in 22 cases. The pathologic conditions included lateral displacement, subluxation, dislocation, and impingement on the tendons by bony fragments, hematomas, and scar tissue. Patients studied 6-12 months after injury had CT evidence consistent with clinical symptoms of peroneal tenosynovitis. Since peroneal tendon injury is surgically correctable, it should be differentiated from other known and more obvious complications, of calcaneal fractures. CT therefore serves as a valuable, noninvasive tool in evaluating these otherwise nonvisualized soft tissue structures in the immediate posttraumatic period as well as during long-term follow up

  12. A Scalable Synthesis Pathway to Nanoporous Metal Structures.

    Science.gov (United States)

    Coaty, Christopher; Zhou, Hongyao; Liu, Haodong; Liu, Ping

    2018-01-23

    A variety of nanoporous transition metals, Fe, Co, Au, Cu, and others, have been readily formed by a scalable, room-temperature synthesis process. Metal halide compounds are reacted with organolithium reductants in a nonpolar solvent to form metal/lithium halide nanocomposites. The lithium halide is then dissolved out of the nanocomposite with a common organic solvent, leaving behind a continuous, three-dimensional network of metal filaments that form a nanoporous structure. This approach is applicable to both noble metals (Cu, Au, Ag) and less-noble transition metals (Co, Fe, Ni). The microstructures of these nanoporous transition metals are tunable, as controlling the formation of the metal structure in the nanocomposite dictates the final metal structure. Microscopy studies and nitrogen adsorption analysis show these materials form pores ranging from 2 to 50 nm with specific surface areas from 1.0 m 2 /g to 160 m 2 /g. Our analysis also shows that pore size, pore volume, and filament size of the nanoporous metal networks depend on the mobility of target metal and the amount of lithium halide produced by the conversion reaction. Further, it has been demonstrated that hybrid nanoporous structures of two or more metals could be synthesized by performing the same process on mixtures of precursor compounds. Metals (e.g., Co and Cu) have been found to stabilize each other in nanoporous forms, resulting in smaller pore sizes and higher surface areas than each element in their pure forms. This scalable and versatile synthesis pathway greatly expands our access to additional compositions and microstructures of nanoporous metals.

  13. Biomimetic synthesis of ordered silica structures mediated by block copolypeptides.

    Science.gov (United States)

    Cha, J N; Stucky, G D; Morse, D E; Deming, T J

    2000-01-20

    In biological systems such as diatoms and sponges, the formation of solid silica structures with precisely controlled morphologies is directed by proteins and polysaccharides and occurs in water at neutral pH and ambient temperature. Laboratory methods, in contrast, have to rely on extreme pH conditions and/or surfactants to induce the condensation of silica precursors into specific morphologies or patterned structures. This contrast in processing conditions and the growing demand for benign synthesis methods that minimize adverse environmental effects have spurred much interest in biomimetic approaches in materials science. The recent demonstration that silicatein-a protein found in the silica spicules of the sponge Tethya aurantia--can hydrolyse and condense the precursor molecule tetraethoxysilane to form silica structures with controlled shapes at ambient conditions seems particularly promising in this context. Here we describe synthetic cysteine-lysine block copolypeptides that mimic the properties of silicatein: the copolypeptides self-assemble into structured aggregates that hydrolyse tetraethoxysilane while simultaneously directing the formation of ordered silica morphologies. We find that oxidation of the cysteine sulphydryl groups, which is known to affect the assembly of the block copolypeptide, allows us to produce different structures: hard silica spheres and well-defined columns of amorphous silica are produced using the fully reduced and the oxidized forms of the copolymer, respectively.

  14. Achillodynia. Radiological imaging of acute and chronic overuse injuries of the Achilles tendon

    International Nuclear Information System (INIS)

    Syha, R.; Springer, F.; Grosse, U.; Tuebingen Univ.; Ketelsen, D.; Kramer, U.; Horger, M.; Ipach, I.; Schick, F.

    2013-01-01

    In the past decades the incidence of acute and chronic disorders of the Achilles tendon associated with sport-induced overuse has steadily increased. Besides acute complete or partial ruptures, achillodynia (Achilles tendon pain syndrome), which is often associated with tendon degeneration, represents the most challenging entity regarding clinical diagnostics and therapy. Therefore, the use of imaging techniques to differentiate tendon disorders and even characterize structure alterations is of growing interest. This review article discusses the potential of different imaging techniques with respect to the diagnosis of acute and chronic tendon disorders. In this context, the most commonly used imaging techniques are magnetic resonance imaging (MRI), B-mode ultrasound, and color-coded Doppler ultrasound (US). These modalities allow the detection of acute tendon ruptures and advanced chronic tendon disorders. However, the main disadvantages are still the low capabilities in the detection of early-stage degeneration and difficulties in the assessment of treatment responses during follow-up examinations. Furthermore, differentiation between chronic partial ruptures and degeneration remains challenging. The automatic contour detection and texture analysis may allow a more objective and quantitative interpretation, which might be helpful in the monitoring of tendon diseases during follow-up examinations. Other techniques to quantify tendon-specific MR properties, e.g. based on ultrashort echo time (UTE) sequences, also seem to have great potential with respect to the precise detection of degenerative tendon disorders and their differentiation at a very early stage. (orig.)

  15. Mechanoreceptors of the Achilles tendon: a histomorphological study in pigs with clinical significance for humans.

    Science.gov (United States)

    Kapetanakis, Stylianos; Gkasdaris, Grigorios; Daneva, Eleni; Givissis, Panagiotis; Papathanasiou, Jannis; Xanthos, Theodoros

    2017-01-01

    Tendons contain neurosensory elements called mechanoreceptors which contribute to the neuromuscular system as sources of reflex signals. The literature is lacking in histological assessment of mechanoreceptors of the Achilles tendon in piglets and our aim was to indicate their types, location and quantity. The study was performed using histological tissue samples from the Achilles tendon of ten healthy pigs, five left, five right, six males, four females. The samples were taken up to 12 hours after death. Immediately after removal, the tendons were placed in the laboratory where sections were taken and examined microscopically. The tendons were stained with the gold chloride method. The results showed that Golgi tendon organs, free nerve endings and Pacinian-like corpuscles were found in the Achilles tendon of pigs. Most structures were near the osteotendinous and myotendinous junctions, away from the middle portion of the tendon. As shown in other studies and similarly in ours, mechanoreceptors tend to be close to the distant thirds and not in the middle third of the tendon. This study could have clinical application on human Achilles tendon and its repair after damage. IV.

  16. Experimental study of the effects of helium-neon laser radiation on repair of injured tendon

    Science.gov (United States)

    Xu, Yong-Qing; Li, Zhu-Yi; Weng, Long-Jiang; An, Mei; Li, Kai-Yun; Chen, Shao-Rong; Wang, Jian-Xin; Lu, Yu

    1993-03-01

    in the treatment group (p < 0.05). The experimental results demonstrate helium-neon laser radiation had significant effects on anti-inflammation, detumescence, progressive hematoma absorbing, inhibiting the tendon extrinsic healing, reducing tendon adhesions, improving the tendon intrinsic healing, i.e., stimulating epitenon and endotenon cells proliferation and migrating into the gap, stimulating collagen synthesis in the tendon gap, and enhancing the late remodeling of fibrous peritendonous adhesion.

  17. Proximal phalanx and flexor digitorum longus tendon biomechanics in flexor to extensor tendon transfer.

    Science.gov (United States)

    DiPaolo, Zachary J; Ross, Matthew S; Laughlin, Richard T; Gould, Greg; Flower, Katie; Kiger, Lorrie; Markert, Ronald J

    2015-05-01

    for approximately 20% to 30% of the total volume of bone. Half of the bones fractured with forces between 100 and 200 N, and the majority of bones with a diameter of less than 6 mm fractured with a force of less than 100 N. The average proximal phalanx and FDL tendon size both showed an overall decrease from the second to the fourth digit, albeit not symmetrically. The proximal phalanx diameter appeared to be the most important factor in determining the strength of the structure. Iatrogenic fracture may occur in proximal phalanges with a diameter of bone less than 6 mm, as there may not be adequate bone strength remaining to withstand postoperative forces. © The Author(s) 2015.

  18. Facile synthesis of gold nanomaterials with unusual crystal structures.

    Science.gov (United States)

    Fan, Zhanxi; Huang, Xiao; Chen, Ye; Huang, Wei; Zhang, Hua

    2017-11-01

    Gold (Au) nanomaterials have attracted wide research attention, owing to their high chemical stability, promising catalytic properties, excellent biocompatibility, unique electronic structure and outstanding localized surface plasmon resonance (LSPR) absorption properties; all of which are closely related to their size and shape. Recently, crystal-phase-controlled synthesis of noble metal nanomaterials has emerged as a promising strategy to tune their physicochemical properties. This protocol describes the detailed experimental procedures for the crystal-phase-controlled syntheses of Au nanomaterials with unusual crystal structures under mild conditions. Briefly, pure hexagonal close-packed (hcp) Au square sheets (AuSSs) with a thickness of ∼2.4 nm are synthesized using a graphene-oxide-assisted method in which HAuCl 4 is reduced by oleylamine in a mixture of hexane and ethanol. By using pure hexane as the solvent, well-dispersed ultrathin hcp/face-centered cubic (fcc) Au nanowires with a diameter of ∼1.6 nm on graphene oxide can be obtained. Meanwhile, hcp/fcc Au square-like plates with a side length of 200-400 nm are prepared via the secondary growth of Au on the hcp AuSSs. Remarkably, hexagonal (4H) Au nanoribbons with a thickness of 2.0-6.0 nm can be synthesized with a one-pot colloidal method in which HAuCl 4 is reduced by oleylamine in a mixed solvent of hexane and 1,2-dichloropropane. It takes 17-37 h for the synthesis of these Au nanomaterials with unusual crystal structures. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) are used to characterize the resultant Au nanomaterials, which could have many promising applications, such as biosensing, near-IR photothermal therapy, catalysis and surface-enhanced Raman scattering (SERS).

  19. Non-linear finite element model to assess the effect of tendon forces on the foot-ankle complex.

    Science.gov (United States)

    Morales-Orcajo, Enrique; Souza, Thales R; Bayod, Javier; Barbosa de Las Casas, Estevam

    2017-11-01

    A three-dimensional foot finite element model with actual geometry and non-linear behavior of tendons is presented. The model is intended for analysis of the lower limb tendon forces effect in the inner foot structure. The geometry of the model was obtained from computational tomographies and magnetic resonance images. Tendon tissue was characterized with the first order Ogden material model based on experimental data from human foot tendons. Kinetic data was employed to set the load conditions. After model validation, a force sensitivity study of the five major foot extrinsic tendons was conducted to evaluate the function of each tendon. A synergic work of the inversion-eversion tendons was predicted. Pulling from a peroneus or tibialis tendon stressed the antagonist tendons while reducing the stress in the agonist. Similar paired action was predicted for the Achilles tendon with the tibialis anterior. This behavior explains the complex control motion performed by the foot. Furthermore, the stress state at the plantar fascia, the talocrural joint cartilage, the plantar soft tissue and the tendons were estimated in the early and late midstance phase of walking. These estimations will help in the understanding of the functional role of the extrinsic muscle-tendon-units in foot pronation-supination. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  20. Synthesis and crystal structure of chromium-bearing anhydrous wadsleyite

    Science.gov (United States)

    Sirotkina, E. A.; Bindi, L.; Bobrov, A. V.; Aksenov, S. M.; Irifune, T.

    2018-04-01

    A chromium-bearing wadsleyite (Cr- Wad) was synthesized in the model system Mg2SiO4-MgCr2O4 at 14 GPa and 1600 °C and studied from the chemical and structural point of views. Microprobe data gave the formula Mg1.930Cr0.120Si0.945O4, on the basis of 4 oxygen atoms. The crystal structure has been studied by single-crystal X-ray diffraction. The orthorhombic unit-cell parameters are: a = 5.6909(5) Å, b = 11.4640(10) Å, c = 8.2406(9) Å, V = 537.62(9) Å3, Z = 8. The structure, space group Imma, was refined to R 1 = 5.99% in anisotropic approximation using 1135 reflections with F o > 4σ( F o) and 43 parameters. Chromium was found to substitute for both Mg at the octahedral sites and Si at the tetrahedral site, according to the reaction VIMg2+ + IVSi4+ = VICr3+ + IVCr3+. On the whole, the structural topology is nearly identical to that of pure wadsleyite. The successful synthesis of Cr- Wad may be important for the thermobarometry of mantle phase associations.

  1. In vivo Evaluation of Patellar Tendon Stiffness in Individuals with Patellofemoral Pain Syndrome

    Directory of Open Access Journals (Sweden)

    Hsin-Yi Liu

    2008-01-01

    Full Text Available The objective of this study was to utilise an ultrasonic technique to assess the effect of patellofemoral pain syndrome (PFPS on the mechanical properties of the patellar tendon. Seven subjects with PFPS and seven matched control subjects volunteered to participate in this study. Subjects were asked to perform isometric maximal voluntary contractions of the knee extensors while their knee extension torque was monitored and the displacement of the patellar tendon was recorded with an ultrasonic system. Our results showed significantly lower tendon stiffness (by ∼30% in the PFPS subjects. Although tendon secant modulus was lower by 34% in the PFPS subjects, the difference was not statistically significant. Therefore, we conclude that the ultrasonic technique was able to detect a decrease in the structural stiffness of the patellar tendon associated with PFPS. The decrease in tendon stiffness was moderately correlated with the length of symptoms in these individuals.

  2. Mechanical Loading Improves Tendon-Bone Healing in a Rabbit Anterior Cruciate Ligament Reconstruction Model by Promoting Proliferation and Matrix Formation of Mesenchymal Stem Cells and Tendon Cells

    Directory of Open Access Journals (Sweden)

    Fanglong Song

    2017-02-01

    Full Text Available Background/Aims: This study investigated the effect of mechanical stress on tendon-bone healing in a rabbit anterior cruciate ligament (ACL reconstruction model as well as cell proliferation and matrix formation in co-culture of bone-marrow mesenchymal stem cells (BMSCs and tendon cells (TCs. Methods: The effect of continuous passive motion (CPM therapy on tendon-bone healing in a rabbit ACL reconstruction model was evaluated by histological analysis, biomechanical testing and gene expressions at the tendon-bone interface. Furthermore, the effect of mechanical stretch on cell proliferation and matrix synthesis in BMSC/TC co-culture was also examined. Results: Postoperative CPM therapy significantly enhanced tendon-bone healing, as evidenced by increased amount of fibrocartilage, elevated ultimate load to failure levels, and up-regulated gene expressions of Collagen I, alkaline phosphatase, osteopontin, Tenascin C and tenomodulin at the tendon-bone junction. In addition, BMSC/TC co-culture treated with mechanical stretch showed a higher rate of cell proliferation and enhanced expressions of Collagen I, Collagen III, alkaline phosphatase, osteopontin, Tenascin C and tenomodulin than that of controls. Conclusion: These results demonstrated that proliferation and differentiation of local precursor cells could be enhanced by mechanical stimulation, which results in enhanced regenerative potential of BMSCs and TCs in tendon-bone healing.

  3. Synthesis and structural studies of copper sulfide nanocrystals

    Directory of Open Access Journals (Sweden)

    Peter A. Ajibade

    Full Text Available We report the synthesis and structural studies of copper sulfide nanocrystals from copper(II dithiocarbamate single molecule precursors. The optical studies of the as-prepared copper sulfide nanoparticles were carried out using UV–Visible and photoluminescence spectroscopy. The absorption spectra show absorption band edges at 287 nm and exhibit considerable blue shift that could be ascribed to the quantum confinement effects as a result of the small crystallite sizes of the nanoparticles and the photoluminescence spectra show emission curves that are red shifted with respect to the absorption band edges. The structural studies were carried out using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The XRD patterns revealed the formation of hexagonal structure of covellite CuS with estimated crystallite sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microsphere on the surfaces and EDS spectra confirmed the presence of CuS nanoparticles. Keywords: CuS, Dithiocarbamate, Nanoparticles, Electron microscopy, AFM

  4. Rapamycin Attenuates Age-associated Changes in Tibialis Anterior Tendon Viscoelastic Properties

    Science.gov (United States)

    Zaseck, Lauren Wood; Miller, Richard A.

    2016-01-01

    Rapamycin extends mouse life span, but the extent to which rapamycin prevents aging-associated changes in specific tissues remains unclear. Stiffness increases and collagen turnover decreases in mouse tendon with aging; thus, our aim was to determine the effect of long-term rapamycin treatment on the mechanical and structural properties of tendons from old mice. Tendons were harvested from female UM-HET3 mice maintained on a standard chow diet for 4 (adult) or 22 (old) months or fed chow containing polymer-encapsulated rapamycin (eRAPA) from 9 to 22 months of age (old RAPA). Stiffness was twofold higher for tendons of old compared with adult mice, but in old RAPA mice, tendon stiffness was maintained at a value not different from that of adults. Additionally, expression of collagen decreased, expression of matrix metalloproteinase-8 increased, and total hydroxyproline content trended toward decreased levels in tendons of old eRAPA-fed mice compared with controls. Finally, age-associated calcification of Achilles tendons and accompanying elevations in expression of chondrocyte and osteoblast markers were all lower in old eRAPA-fed mice. These results suggest that long-term administration of rapamycin alters the molecular pathways responsible for aging of tendon extracellular matrix, resulting in tissue that is structurally and mechanically similar to tendons in adult mice. PMID:26809496

  5. Observation of tendon repair in animal model using second-harmonic-generation microscopy

    Science.gov (United States)

    Hase, Eiji; Minamikawa, Takeo; Sato, Katsuya; Takahashi, Mitsuhiko; Yasui, Takashi

    2016-03-01

    Tendon rupture is a trauma difficult to recover the condition before injury. In previous researches, tensile test and staining method have been widely used to elucidate the mechanism of the repair process from the viewpoints of the mechanical property and the histological findings. However, since both methods are destructive and invasive, it is difficult to obtain both of them for the same sample. If both the mechanical property and the histological findings can be obtained from the same sample, one may obtain new findings regarding mechanisms of tendon repairing process. In this paper, we used second-harmonic-generation (SHG) microscopy, showing high selectivity and good image contrast to collagen molecules as well as high spatial resolution, optical three-dimensional sectioning, deep penetration, and without additional staining. Since SHG light intensity sensitively reflects the structural maturity of collagen molecule and its aggregates, it will be a good indicator for the repairing degree of the ruptured tendon. From comparison of SHG images between the 4-weeks-repaired tendon and the sound tendon in the animal model, we confirmed that SHG light intensity of the repaired tendon was significantly lower than that of the sound tendon, indicating that the collagen structure in the repaired tendon is still immature. Furthermore, we performed both SHG imaging and the tensile test for the same sample, and confirmed a correlation between them. This result shows a potential of SHG light for an indicator of the histological and mechanical recovery of the ruptured tendon.

  6. [Experimental study on co-culture of human fibroblasts on decellularized Achilles tendon].

    Science.gov (United States)

    Wang, Zhibing; Zhang, Xia; Guo, Xinyu; Qin, Chuan

    2013-07-01

    To investigate the preparation of decellularized Achilles tendons and the effect of co-culture of human fibroblasts on the scaffold so as to provide a scaffold for the tissue engineered ligament reconstruction. Achilles tendons of both hind limbs were harvested from 10 male New Zealand white rabbits (5-month-old; weighing, 4-5 kg). The Achilles tendons were decellularized using trypsin, Triton X-100, and sodium dodecyl sulfate (SDS), and then gross observation, histological examination, and scanning electron microscope (SEM) observation were performed; the human fibroblasts were seeded on the decellularized Achilles tendon, and then cytocompatibility was tested using the cell counting kit 8 method at 1, 3, 5, 7, and 9 days after co-culture. At 4 weeks after co-culture, SEM, HE staining, and biomechanical test were performed for observing cell-scaffold composite, and a comparison was made with before and after decellularization. After decellularization, the tendons had integrated aponeurosis and enlarged volume with soft texture and good toughness; there was no loose connective tissue and tendon cells between tendon bundles, the collagen fibers arranged loosely with three-dimensional network structure and more pores between tendon bundles; and it had good cytocompatibility. At 4 weeks after co-culture, cells migrated into the pores, and three-dimensional network structure disappeared. By biomechanical test, the tensile strength and Young's elastic modulus of the decellularized Achilles tendon group decreased significantly when compared with normal Achilles tendons group and cell-scaffold composite group (P Achilles tendons group and cell-scaffold composite group (P > 0.05). There was no significant difference in elongation at break among 3 groups (P > 0.05). The decellularized Achilles tendon is biocompatible to fibroblasts. It is suit for the scaffold for tissue engineered ligament reconstruction.

  7. Early stage fatigue damage occurs in bovine tendon fascicles in the absence of changes in mechanics at either the gross or micro-structural level.

    Science.gov (United States)

    Shepherd, Jennifer H; Riley, Graham P; Screen, Hazel R C

    2014-10-01

    Many tendon injuries are believed to result from repetitive motion or overuse, leading to the accumulation of micro-damage over time. In vitro fatigue loading can be used to characterise damage during repeated use and investigate how this may relate to the aetiology of tendinopathy. This study considered the effect of fatigue loading on fascicles from two functionally distinct bovine tendons: the digital extensor and deep digital flexor. Micro-scale extension mechanisms were investigated in fascicles before or after a period of cyclic creep loading, comparing two different measurement techniques - the displacement of a photo-bleached grid and the use of nuclei as fiducial markers. Whilst visual damage was clearly identified after only 300 cycles of creep loading, these visual changes did not affect either gross fascicle mechanics or fascicle microstructural extension mechanisms over the 900 fatigue cycles investigated. However, significantly greater fibre sliding was measured when observing grid deformation rather than the analysis of nuclei movement. Measurement of microstructural extension with both techniques was localised and this may explain the absence of change in microstructural deformation in response to fatigue loading. Alternatively, the data may demonstrate that fascicles can withstand a degree of matrix disruption with no impact on mechanics. Whilst use of a photo-bleached grid to directly measure the collagen is the best indicator of matrix deformation, nuclei tracking may provide a better measure of the strain perceived directly by the cells. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Synthesis, Structure, Stability and Redispersion of Gold-based Nanoparticles

    Science.gov (United States)

    Tiruvalam, Ram Chandra

    Nanoscale gold has been shown to possess an intriguing combination of unexpected optical, photochemical and catalytic properties. The ability to control the size, shape, morphology, composition and dispersion of gold-based nanostructures is key to optimizing their performance for nanotechnology applications. The advanced electron microscopy studies described in this thesis analyze three important aspects of gold and gold-palladium alloy nanoparticles: namely, (i) the ability to synthesize gold nanoparticles of controlled size and shape in an aqueous medium; (ii) the colloidal preparation of designer gold-palladium alloys for selective oxidation catalysis; and (iii) the ability to disperse gold as finely and homogeneously as possible on a metal oxide or carbon support. The ability to exploit the nanoscale properties of gold for various engineering applications often depends on our ability to control size and shape of the nanoscale entity by careful manipulation of the synthesis parameters. We have explored an aqueous based synthesis route, using oleylamine as both a reductant and surfactant, for preparing gold nanostructures. By systematically varying synthesis parameters such as oleylamine concentration, reaction temperature, and aging time it is possible to identify processing regimens that generate Au nanostructures having either pseudo-spherical, faceted polyhedral, nanostar or wire shaped morphologies. Furthermore, by quenching the reaction partway through it is possible to create a class of metastable Au-containing structures such as nanocubes, nanoboxes and nanowires. Possible formation mechanisms for these gold based nano-objects are discussed. There is a growing interest in using supported bimetallic AuPd alloy nanoparticles for selective oxidation reactions. In this study, a systematic series of size controlled AuPd bimetallic particles have been prepared by colloidal synthesis methods. Particles having random alloy structures, as well as `designer

  9. 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

  10. Simultaneous bilateral patellar tendon rupture.

    Science.gov (United States)

    Moura, Diogo Lino; Marques, José Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2017-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  11. Simultaneous bilateral patellar tendon rupture

    Directory of Open Access Journals (Sweden)

    Diogo Lino Moura

    Full Text Available ABSTRACT Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  12. [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.

  13. Testing of large prestressing tendon end anchorage regions

    International Nuclear Information System (INIS)

    Johnson, T.E.

    1976-01-01

    Tests were performed on concrete end anchorage regions for prestressing tendons with ultimate strengths of approximately 8,900 kN. One test structure simulated a full scale concrete containment buttress and the other two test specimens were concrete blocks. The behavior of the test structure and specimens, when subjected to loading, was monitored by strain gages and dial gages. The testing illustrated that all of the amounts of reinforcing tested should be acceptable for the end anchor zones of large tendons presently used in prestressed concrete containment structures. (author)

  14. 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

  15. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    Science.gov (United States)

    van Ark, M; Docking, S I; van den Akker-Scheek, I; Rudavsky, A; Rio, E; Zwerver, J; Cook, J L

    2016-02-01

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. A cyamella causing popliteal tendonitis

    OpenAIRE

    Rehmatullah, N; McNair, R; Sanchez-Ballester, J

    2014-01-01

    A 64-year-old man presented with intermittent but progressive lateral-sided knee pain. Symptoms mimicked those of a lateral meniscal tear. Magnetic resonance imaging revealed a cyamella associated with popliteal tendonitis and an intact lateral meniscus.

  17. Tendon overuse syndrome: imaging diagnosis

    International Nuclear Information System (INIS)

    Huber, W.; Nehrer, S.; Muellner, T.; Kainberger, F.; Ulreich, N.; Bernhard, C.; Imhof, H.

    2001-01-01

    Injuries of muscles and tendons occur commonly during various sporting activities and in most cases the athletes feel such an accident to be sudden and unavoidable. The rupture of a tendon, however, has to be considered in many cases as the final stage of a long-standing progressive degeneration of collagen fibers. This process con be described as 'tendon overuse syndrome (TOS)'. Diagnostic imaging modalities, especially sonography and MRI, are suitable to detect and analyse the different stages of this syndrome and the degree of morphological abnormalities. The first stage is painful functional derangement, followed by tendovaginitis, peritendinitis, or bursitis. The third stage is tendinosis resulting from biomechanical or ischaemic injury of tendon fibers which may eventually be followed by partial or complete rupture. Regional or individual specifications of these four stages may occur at anatomically predisposing sites, so-called critical zones, or during periods of specific proneness, the vulnerable phases. (author)

  18. Steroid injections - tendon, bursa, joint

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007678.htm Steroid injections - tendon, bursa, joint To use the sharing features on this page, please enable JavaScript. A steroid injection is a shot of medicine used to ...

  19. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    NARCIS (Netherlands)

    van Ark, M.; Docking, S.I.; van den Akker-Scheek, I.; Rudavsky, A.; Rio, E.; Zwerver, J.; Cook, J.L.

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The

  20. Characteristics at haematoxylin and eosin staining of ruptures of the long head of the biceps tendon.

    Science.gov (United States)

    Longo, U G; Franceschi, F; Ruzzini, L; Rabitti, C; Morini, S; Maffulli, N; Denaro, V

    2009-08-01

    To examine the relative prevalence of histological changes that have been found to be associated with the process of tendinopathy in lesions of the tendon of the long head of the biceps brachii and to evaluate the reliability of histopathological evaluation of tendon tissue in lesions of the tendon of the long head of the biceps. Tendon samples were taken from 51 patients (31 men, 20 women; mean age 63.2 years) who underwent arthroscopic release of the long head of the biceps tendon because of refractory biceps tendinopathy and from 5 male patients who died of cardiovascular events (mean age 69.6 years). Histological examination was performed using haematoxylin and eosin staining of sections, which were interpreted using a semiquantitative grading scale assessing fibre structure and arrangement, rounding of the nuclei, regional variations in cellularity, increased vascularity, decreased collagen staining and hyalinisation. The mean (SD) pathological sum score of ruptured tendons was greater than that of control tendons (15.76 (3.11) vs 3.4 (1.9), pruptured tendons; all the variables were significantly different (Mann-Whitney U test 0.05, pbiceps, even at an advanced age and ruptured tendons of the long head of the biceps are clearly part of two distinct populations.

  1. In vivo engineering of a functional tendon sheath in a hen model.

    Science.gov (United States)

    Xu, Liang; Cao, Dejun; Liu, Wei; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin

    2010-05-01

    Repair of injured tendon sheath remains a major challenge and this study explored the possibility of in vivo reconstruction of a tendon sheath with tendon sheath derived cells and polyglycolic acid (PGA) fibers in a Leghorn hen model. Total 55 Leghorn hens with a 1cm tendon sheath defect created in the left middle toe of each animal were randomly assigned into: (1) experimental group (n=19) that received a cell-PGA construct; (2) scaffold control group (n=18) that received a cell-free PGA scaffold; (3) blank control group (n=18) with the defect untreated. Tendon sheath cells were isolated, in vitro expanded, and seeded onto PGA scaffolds. After in vitro culture for 7 days, the constructs were in vivo implanted to repair the sheath defects. Alcian blue staining confirmed the ability of cultured cells to produce specific matrices containing acidic carboxyl mucopolysaccharide (mainly hyaluronic acid). In addition, the engineered sheath formed a relatively mature structure at 12 weeks post-surgery, which was similar to that of native counterpart, including a smooth inner surface, a well-developed sheath histological structure with a clear space between the tendon and the engineered sheath. More importantly, Work of Flexion assay revealed that the tendons needed less power consumption to glide inside the engineered sheath when compared to the tendons which were surrounded by scar-repaired tissues, indicating that the engineered sheaths had gained the function to a certain extent of preventing tendon adhesion. Taken together, these results suggest that tendon sheaths that are functionally and structurally similar to native sheaths are possible to be engineered in vivo using tendon sheath cells and PGA scaffolds. Copyright 2010 Elsevier Ltd. All rights reserved.

  2. The role of sonography in differentiating full versus partial distal biceps tendon tears: correlation with surgical findings.

    Science.gov (United States)

    Lobo, Lucas Da Gama; Fessell, David P; Miller, Bruce S; Kelly, Aine; Lee, Jee Young; Brandon, Catherine; Jacobson, Jon A

    2013-01-01

    The purpose of this study was to determine the accuracy of ultrasound for distinguishing complete rupture of the distal biceps tendon versus partial tear and versus a normal biceps tendon. Surgical findings were used as the reference standard in cases of tear. Clinical follow-up was used to assess the normal tendons. The study population consisted of 45 consecutive elbow ultrasound cases with surgical confirmation and six cases of a clinically normal distal biceps tendon that underwent elbow ultrasound for suspicion of injury to a structure other than the biceps tendon. Cases underwent consensus review by two fellowship-trained musculoskeletal radiologists. Tendons were classified as normal biceps tendon, partial tear, or complete tear. The presence or absence of posterior acoustic shadowing at the distal biceps tendon was also assessed. The ultrasound findings were then compared with the surgical findings and clinical follow-up. Ultrasound showed 95% sensitivity, 71% specificity, and 91% accuracy for the diagnosis of complete versus partial distal biceps tendon tears. Posterior acoustic shadowing at the distal biceps had sensitivity of 97% and accuracy of 91% for indicating complete tear versus partial tear and sensitivity of 97%, specificity of 100%, and accuracy of 98% for indicating complete tear versus normal tendon. Ultrasound can play a role in the diagnosis of elbow injuries when a distal biceps brachii tendon tear is suspected.

  3. 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.

  4. Structuration, space and time: the reconstruction of Anthony Giddens’ «structure-agency» synthesis theory

    Directory of Open Access Journals (Sweden)

    A. D. Osypchuk

    2014-10-01

    Full Text Available The article presents a theoretical and analytical reconstruction of A.Giddens’ Structuration theory as an attempt of ‘structure-agency’ synthesis in sociology. The concept of structuration is introduced by Giddens to solve the problem of duality of structure and agency where the former is defined as rules and resources. Structuration can’t be understood without reference to Giddens’ use of ‘time-space’ concept and related locality and regionalization concepts. Article analyses in details which theoretical and methodological possibilities and limitations comes out of defining structuration as constant flux of conducts in time-space, especially in regard to snapshots of previous conditions of system or structure and memories about them. The article also deals with the concepts of presence, locality, and regionalization that are the result of critical development of time geography approach and are based on combining time and space into one inseparable dimension. The main types and modes of regionalization are reviewed. It is emphasized that through regionalization, locality, and forms of presence and of routine practices Giddens defines not only social institutions but also social system. There is a brief theoretical and methodological discussion of correlation between social structure and social system and of the potential application of Structuration theory to analysis of social change.

  5. Ligand-protected gold clusters: the structure, synthesis and applications

    Science.gov (United States)

    Pichugina, D. A.; Kuz'menko, N. E.; Shestakov, A. F.

    2015-11-01

    Modern concepts of the structure and properties of atomic gold clusters protected by thiolate, selenolate, phosphine and phenylacetylene ligands are analyzed. Within the framework of the superatom theory, the 'divide and protect' approach and the structure rule, the stability and composition of a cluster are determined by the structure of the cluster core, the type of ligands and the total number of valence electrons. Methods of selective synthesis of gold clusters in solution and on the surface of inorganic composites based, in particular, on the reaction of Aun with RS, RSe, PhC≡C, Hal ligands or functional groups of proteins, on stabilization of clusters in cavities of the α-, β and γ-cyclodextrin molecules (Au15 and Au25) and on anchorage to a support surface (Au25/SiO2, Au20/C, Au10/FeOx) are reviewed. Problems in this field are also discussed. Among the methods for cluster structure prediction, particular attention is given to the theoretical approaches based on the density functional theory (DFT). The structures of a number of synthesized clusters are described using the results obtained by X-ray diffraction analysis and DFT calculations. A possible mechanism of formation of the SR(AuSR)n 'staple' units in the cluster shell is proposed. The structure and properties of bimetallic clusters MxAunLm (M=Pd, Pt, Ag, Cu) are discussed. The Pd or Pt atom is located at the centre of the cluster, whereas Ag and Cu atoms form bimetallic compounds in which the heteroatom is located on the surface of the cluster core or in the 'staple' units. The optical properties, fluorescence and luminescence of ligand-protected gold clusters originate from the quantum effects of the Au atoms in the cluster core and in the oligomeric SR(AuSR)x units in the cluster shell. Homogeneous and heterogeneous reactions catalyzed by atomic gold clusters are discussed in the context of the reaction mechanism and the nature of the active sites. The bibliography includes 345 references.

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

    OpenAIRE

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

    2015-01-01

    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, curre...

  7. Achilles tendon and sports; Die Achillessehne im Sport

    Energy Technology Data Exchange (ETDEWEB)

    Ulreich, N.; Kainberger, F. [Univ.-Klinik fuer Radiodiagnostik Wien (Austria); Huber, W.; Nehrer, S. [Univ.-Klinik fuer Orthopaedie Wien (Austria)

    2002-10-01

    Because of the rising popularity of recreational sports activities achillodynia is an often associated symptom with running, soccer and athletics. Therefore radiologist are frequently asked to image this tendon. The origin of the damage of the Achilles tendon is explained by numerous hypothesis, mainly a decreased perfusion and a mechanical irritation that lead to degeneration of the tendon. High-resolution technics such as sonography and magnetic resonance imaging show alterations in the structure of the tendon which can be graduated and classified. Manifestations like tendinosis, achillobursitis, rupture and Haglunds disease can summarized as the tendon overuse syndrom. A rupture of a tendon is mostly the result of a degeneration of the collagenfibres. The task of the radiologist is to acquire the intrinsic factors for a potential rupture. (orig.) [German] Aufgrund des starken Anstiegs des Freizeitsportes sind Achillodynien ein besonders mit Laufsport, Fussball und Leichtathletik assoziiertes Symptom und die Indikation zur radiologischen Abklaerung wird oft gestellt. Die Entstehung von Sehnenschaeden wird durch eine Reihe von Hypothesen erklaert, wobei eine gestoerte Gewebeperfusion und eine mechanische Irritation als Hauptursachen angesehen werden, die zur Degeneration des Sehnengewebes und des umgebenden Gleitlagers fuehren. Sie koennen aufgrund sonographischer und MR-tomographischer Zeichen meist klar klassifiziert und graduiert werden, wobei hochaufloesende Techniken eine wesentliche Voraussetzung fuer die subtile Analyse der Sehnenstruktur darstellen. Die einzelnen klinischen Erscheinungsformen wie Tendinose, Achillobursitis, Haglund-Ferse und Sehnenruptur koennen unter dem Begriff des ''Sehnenueberlastungssyndroms'' (Tendon overuse syndrome) subsummiert werden. Rupturen der Achillessehne treten so gut wie immer bei bereits vorgeschaedigtem Kollagenfasergewebe auf, und der radiologischen Diagnostik kommt wesentliche Bedeutung dabei zu

  8. Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

    Science.gov (United States)

    Rolf, Christer G; Fu, Sai-Chuen; Hopkins, Chelsea; Luan, Ju; Ip, Margaret; Yung, Shu-Hang; Friman, Göran; Qin, Ling; Chan, Kai-Ming

    2017-07-01

    The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria. Bacteria are present in ruptured ATs but not in healthy tendons. Cross-sectional study; Level of evidence, 3. Patients with spontaneous AT ruptures and patients undergoing anterior cruciate ligament (ACL) reconstruction were recruited for this study. During AT surgical repair, excised tendinopathic tissue was collected, and healthy tendon samples were obtained as controls from hamstring tendon grafts used in ACL reconstruction. Half of every sample was reserved for DNA extraction and the other half for histology. Polymerase chain reaction (PCR) was conducted using 16S rRNA gene universal primers, and the PCR products were sequenced for the identification of bacterial species. A histological examination was performed to compare tendinopathic changes in the case and control samples. Five of 20 AT rupture samples were positive for the presence of bacterial DNA, while none of the 23 hamstring tendon samples were positive. Sterile operating and experimental conditions and tests on samples, controlling for harvesting and processing procedures, ruled out the chance of postoperative bacterial contamination. The species identified predominantly belonged to the Staphylococcus genus. AT rupture samples exhibited histopathological features characteristic of tendinopathy, and most healthy hamstring tendon samples displayed normal tendon features. There were no apparent differences in histopathology between the bacterial DNA-positive and bacterial DNA-negative AT rupture samples. The authors have demonstrated the presence of bacterial DNA in ruptured AT samples. It may suggest the potential involvement of bacteria

  9. Genetic Factors in Tendon Injury: A Systematic Review of the Literature.

    Science.gov (United States)

    Vaughn, Natalie H; Stepanyan, Hayk; Gallo, Robert A; Dhawan, Aman

    2017-08-01

    Tendon injury such as tendinopathy or rupture is common and has multiple etiologies, including both intrinsic and extrinsic factors. The genetic influence on susceptibility to tendon injury is not well understood. To analyze the published literature regarding genetic factors associated with tendon injury. Systematic review; Level of evidence, 3. A systematic review of published literature was performed in concordance with the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines to identify current evidence for genetic predisposition to tendon injury. PubMed, Ovid, and ScienceDirect databases were searched. Studies were included for review if they specifically addressed genetic factors and tendon injuries in humans. Reviews, animal studies, or studies evaluating the influence of posttranscription factors and modifications (eg, proteins) were excluded. Overall, 460 studies were available for initial review. After application of inclusion and exclusion criteria, 11 articles were ultimately included for qualitative synthesis. Upon screening of references of these 11 articles, an additional 15 studies were included in the final review, for a total of 26 studies. The genetic factors with the strongest evidence of association with tendon injury were those involving type V collagen A1, tenascin-C, matrix metalloproteinase-3, and estrogen-related receptor beta. The published literature is limited to relatively homogenous populations, with only level 3 and level 4 data. Additional research is needed to make further conclusions about the genetic factors involved in tendon injury.

  10. Synthesis, X-ray crystal structure, DNA binding and Nuclease activity ...

    Indian Academy of Sciences (India)

    s12039-016-1125-x. Synthesis, X-ray crystal structure, DNA binding and Nuclease activity of lanthanide(III) complexes of 2-benzoylpyridine acetylhydrazone. KARREDDULA RAJA, AKKILI SUSEELAMMA and KATREDDI HUSSAIN REDDY. ∗.

  11. Anti-inflammatory management for tendon injuries - friends or foes?

    Directory of Open Access Journals (Sweden)

    Chan Kai-Ming

    2009-10-01

    Full Text Available Abstract Acute and chronic tendon injuries are very common among athletes and in sedentary population. Most physicians prescribe anti-inflammatory managements to relieve the worst symptoms of swelling and pain, including non-steroidal anti-inflammatory drugs, corticosteroids and physical therapies. However, experimental research shows that pro-inflammatory mediators such as prostaglandins may play important regulatory roles in tendon healing. Noticeably nearly all cases of chronic tendon injuries we treat as specialists have received non-steroidal anti-inflammatory drugs by their physician, suggesting that there might be a potential interaction in some of these cases turning a mild inflammatory tendon injury into chronic tendinopathy in predisposed individuals. We are aware of the fact that non-steroidal anti-inflammatory drugs and corticosteroids may well have a positive effect on the pain control in the clinical situation whilst negatively affect the structural healing. It follows that a comprehensive evaluation of anti-inflammatory management for tendon injuries is needed and any such data would have profound clinical and health economic importance.

  12. MRI of tibialis anterior tendon rupture

    International Nuclear Information System (INIS)

    Gallo, Robert A.; DeMeo, Patrick J.; Kolman, Brett H.; Daffner, Richard H.; Sciulli, Robert L.; Roberts, Catherine C.

    2004-01-01

    Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58-67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of the tendon, and excess fluid in the tendon sheath. One patient demonstrated a partial tear showing an attenuated tendon with increased surrounding fluid. Although rupture of the tibialis anterior tendon is a rarely reported entity, MRI is a useful modality in the definitive detection and characterization of tibialis anterior tendon ruptures. (orig.)

  13. Suitable long tendon technologies and practices

    CSIR Research Space (South Africa)

    Altounyan, P

    2001-10-01

    Full Text Available effective long tendon support systems suitable in South African coalmines. Appropriate test procedures for the evaluation of the performance of long tendon systems were also determined and are detailed in this report....

  14. Using Combustion Synthesis to Reinforce Berms and Other Regolith Structures

    Science.gov (United States)

    Rodriquez, Gary

    2013-01-01

    The Moonraker Excavator and other tools under development for use on the Moon, Mars, and asteroids will be employed to construct a number of civil engineering projects and to mine the soil. Mounds of loose soil will be subject to the local transport mechanisms plus artificial mechanisms such as blast effects from landers and erosion from surface vehicles. Some of these structures will require some permanence, with a minimum of maintenance and upkeep. Combustion Synthesis (CS) is a family of processes and techniques whereby chemistry is used to transform materials, often creating flame in a hard vacuum. CS can be used to stabilize civil engineering works such as berms, habitat shielding, ramps, pads, roadways, and the like. The method is to unroll thin sheets of CS fabric between layers of regolith and then fire the fabric, creating a continuous sheet of crusty material to be interposed among layers of loose regolith. The combination of low-energy processes, ISRU (in situ resource utilization) excavator, and CS fabrics, seems compelling as a general method for establishing structures of some permanence and utility, especially in the role of robotic missions as precursors to manned exploration and settlement. In robotic precursory missions, excavator/ mobility ensembles mine the Lunar surface, erect constructions of soil, and dispense sheets of CS fabrics that are covered with layers of soil, fired, and then again covered with layers of soil, iterating until the desired dimensions and forms are achieved. At the base of each berm, for example, is a shallow trench lined with CS fabric, fired and filled, mounded, and then covered and fired, iteratively to provide a footing against lateral shear. A larger trench is host to a habitat module, backfilled, covered with fabric, covered with soil, and fired. Covering the applied CS fabric with layers of soil before firing allows the resulting matrix to incorporate soil both above and below the fabric ply into the fused layer

  15. Faster Movement Speed Results in Greater Tendon Strain during the Loaded Squat Exercise.

    Science.gov (United States)

    Earp, Jacob E; Newton, Robert U; Cormie, Prue; Blazevich, Anthony J

    2016-01-01

    Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT), and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture, and force platform recordings. Peak LT, FT, and RFDT were greater in JS than TS (p < 0.05), however no differences were observed between VS and TS. Thus, moving at faster speeds resulted in both greater tendon stress and strain despite an increased RFDT, as would be predicted of an elastic, but not a viscous, structure. Temporal comparisons showed that LT was greater in TS than JS during the early eccentric phase (10-14% movement duration) where peak RFDT occurred, demonstrating that the tendon's viscous properties predominated during initial eccentric loading. However, during the concentric phase (61-70 and 76-83% movement duration) differing FT and similar RFDT between conditions allowed for the tendon's elastic properties to predominate such that peak tendon strain was greater in JS than TS. Based on our current understanding, there may be an additional mechanical stimulus for tendon adaptation when performing large range-of-motion isoinertial exercises at faster movement speeds.

  16. Faster Movement Speed Results in Greater Tendon Strain during the Loaded Squat Exercise

    Science.gov (United States)

    Earp, Jacob E.; Newton, Robert U.; Cormie, Prue; Blazevich, Anthony J.

    2016-01-01

    Introduction: Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Methods: Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT), and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture, and force platform recordings. Results: Peak LT, FT, and RFDT were greater in JS than TS (p < 0.05), however no differences were observed between VS and TS. Thus, moving at faster speeds resulted in both greater tendon stress and strain despite an increased RFDT, as would be predicted of an elastic, but not a viscous, structure. Temporal comparisons showed that LT was greater in TS than JS during the early eccentric phase (10–14% movement duration) where peak RFDT occurred, demonstrating that the tendon's viscous properties predominated during initial eccentric loading. However, during the concentric phase (61–70 and 76–83% movement duration) differing FT and similar RFDT between conditions allowed for the tendon's elastic properties to predominate such that peak tendon strain was greater in JS than TS. Conclusions: Based on our current understanding, there may be an additional mechanical stimulus for tendon adaptation when performing large range-of-motion isoinertial exercises at faster movement speeds. PMID:27630574

  17. Structural archetypes in nickel(II) hybrid vanadates. Towards a directed hydrothermal synthesis

    International Nuclear Information System (INIS)

    Luis, R. Fernandez de; Urtiaga, M.K.; Mesa, J.L.; Rojo, T.; Arriortua, M.I.

    2009-01-01

    In the present work, we relate the modifications of the initial synthesis parameters (pH value, stoichiometry and concentration) with the different structural archetypes obtained in the {Ni/Bpy/VO} and {Ni/Bpe/VO} systems (4,4'-bipyridine (Bpy), 1,2-di(4-pyridyl) ethylene (Bpe)). The vanadium coordination is partially controlled by the hydrothermal synthesis conditions, and the final crystal structures depend on the synergetic interaction between the metal-organic subnets and the vanadium oxide subunits.

  18. Total synthesis, structure, and oral absorption of a thiazole cyclic peptide, sanguinamide A

    DEFF Research Database (Denmark)

    Nielsen, Daniel S; Hoang, Huy N; Lohman, Rink-Jan

    2012-01-01

    The first total synthesis and three-dimensional solution structure are reported for sanguinamide A, a thiazole-containing cyclic peptide from the sea slug H. sanguineus. Solution phase fragment synthesis, solid phase fragment assembly, and solution macrocyclization were combined to give (1) in 10......% yield. Spectral properties were identical for the natural product, requiring revision of its structure from (2) to (1). Intramolecular transannular hydrogen bonds help to bury polar atoms, which enables oral absorption from the gut....

  19. A bipyridyl thorium metallocene: synthesis, structure and reactivity.

    Science.gov (United States)

    Ren, Wenshan; Song, Haibin; Zi, Guofu; Walter, Marc D

    2012-05-21

    The synthesis, structure and reactivity of a new bipy thorium metallocene have been studied. The reduction of the thorium chloride metallocene [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)ThCl(2) (1) with potassium graphite in the presence of 2,2'-bipyridine gives the purple bipy metallocene [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)Th(bipy) (2) in good yield. Complex 2 has been fully characterized by various spectroscopic techniques, elemental analysis and X-ray diffraction analysis. Complex 2 reacts cleanly with trityl chloride, silver halides and diphenyl diselenide, leading to the halide metallocenes [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)ThX(2) (X = Cl (1), Br (3), I (4)) and [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)Th(F)(μ-F)(3)Th[η(5)-1,3-(Me(3)C)(2)C(5)H(3)](F)(bipy) (5), and selenido metallocene [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)Th(SePh)(2) (6), in good conversions. In addition, 2 cleaves the C[double bond, length as m-dash]S bond of CS(2) to give the sulfido complex, [η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)ThS (7), which further undergoes an irreversible dimerization or nucleophilic addition with CS(2), leading to the dimeric sulfido complex {[η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)Th}(μ-S)(2) (8) and dimeric trithiocarbonate complex {[η(5)-1,3-(Me(3)C)(2)C(5)H(3)](2)Th}(μ-CS(3))(2) (10) in good yields, respectively.

  20. A New Method for Modeling Spatial Prestressing Tendons

    Science.gov (United States)

    Li, Yi; Wang, Yuqian; Liu, Gao

    2010-05-01

    As a standard simulation procedure for curved lines and curved surfaces, spline has been widely used in the domain of computer-aided design. This paper presents a simple but relatively accurate procedure for the description of prestressing tendons. Cubic splines instead of conventional parabolic ones are introduced to obtain the characteristic parameters of the curved tendon profiles. The direct internal load method is adopted to obtain the equivalent load and loss of tendon force. In comparison with the traditional methods, Cubic splines needs less parameter for pre-processor and leads to higher accuracy in calculation. The direct internal load method can demonstrate the regularity of prestressing force acting on the structure, which modifies the prevalent equivalent load method. The results of the analysis presented in this paper indicate that the proposed method turns out to be convenient and reasonably accurate in the analysis of prestressed concrete bridges.

  1. Pathophysiology of overuse tendon injury

    International Nuclear Information System (INIS)

    Kannus, P.; Paavola, M.; Paakkala, T.; Parkkari, J.; Jaervinen, T.; Jaervinen, M.

    2002-01-01

    Overuse tendon injury is one of the most common injuries in sports.The etiology as well as the pathophysilogical 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. (orig.) [de

  2. 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.

  3. Rerouting extensor pollicis longus tendon transfer.

    Science.gov (United States)

    Colantoni Woodside, Julie; Bindra, Randip R

    2015-04-01

    Following radial nerve palsy, loss of the extensor pollicis longus (EPL), abductor pollicis longus and extensor pollicis brevis tendons results in loss of thumb extension and radial abduction. Multiple tendon transfers are described to address the loss of thumb extension following radial palsy utilizing the palmaris longus or flexor digitorum sublimis transferred to the EPL tendon. Owing to its ulnar vector of pull, the EPL tendon is a secondary adductor of the thumb, and in order to mitigate the tendency for thumb adduction, the EPL tendon is divided at the wrist and brought subcutaneously to the radial side of the wrist for repair to the donor tendon to improve the line of pull for the donor tendon. We describe the use of a technique to reroute the EPL tendon through the first compartment in a retrograde fashion prior to repair with the donor tendon on the radial side of the wrist. The use of the first dorsal compartment provides a pulley to maintain the position of the transfer and to prevent potential bowstringing of the tendon as wrist flexion and thumb extension are attempted. because the repair is performed proximal to the extensor retinaculum, the donor tendon length is not compromised. Because the tendon is redirected through the first dorsal compartment and inserts into the distal phalanx, a single transfer attempts to restores both thumb extension and radial abduction. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  4. Synthesis, structure and electronic structure of a new polymorph of CaGe2

    International Nuclear Information System (INIS)

    Tobash, Paul H.; Bobev, Svilen

    2007-01-01

    Reported are the flux synthesis, the crystal structure determination, the properties and the band structure calculations of a new polymorph of CaGe 2 , which crystallizes with the hexagonal space group P6 3 mc (no. 186) with cell parameters of a=3.9966(9) and c=10.211(4)A (Z=2; Pearson's code hP6). The structure can be viewed as puckered layers of three-bonded germanium atoms, ∼ 2 [Ge 2 ] 2- , which are stacked along the direction of the c-axis in an ABAB-fashion. The germanium polyanionic layers are separated by the Ca cations. As such, this structure is closely related to the structure of the other CaGe 2 polymorph, which crystallizes with the rhombohedral CaSi 2 type in the R3-bar m space group (No. 166), where the ∼ 2 [Ge 2 ] 2- layers are arranged in an AA'BB'CC'-fashion, and are also interspaced by Ca 2+ cations. LMTO calculations suggest that in spite of the formal closed-shell configuration for all atoms and the apparent adherence to the Zintl rules for electron counting, i.e., Ca 2+ [3b-Ge 1- ] 2 ), the phase will be a poor metal due to a small Ca-3d-Ge-4p band overlap. Magnetic susceptibility measurements as a function of the temperature indicate that the new CaGe 2 polymorph exhibits weak, temperature independent, Pauli-paramagnetism

  5. Tendon development and musculoskeletal assembly: emerging roles for the extracellular matrix

    Science.gov (United States)

    Subramanian, Arul; Schilling, Thomas F.

    2015-01-01

    Tendons and ligaments are extracellular matrix (ECM)-rich structures that interconnect muscles and bones. Recent work has shown how tendon fibroblasts (tenocytes) interact with muscles via the ECM to establish connectivity and strengthen attachments under tension. Similarly, ECM-dependent interactions between tenocytes and cartilage/bone ensure that tendon-bone attachments form with the appropriate strength for the force required. Recent studies have also established a close lineal relationship between tenocytes and skeletal progenitors, highlighting the fact that defects in signals modulated by the ECM can alter the balance between these fates, as occurs in calcifying tendinopathies associated with aging. The dynamic fine-tuning of tendon ECM composition and assembly thus gives rise to the remarkable characteristics of this unique tissue type. Here, we provide an overview of the functions of the ECM in tendon formation and maturation that attempts to integrate findings from developmental genetics with those of matrix biology. PMID:26672092

  6. Improved Achilles tendon healing by early mechanical loading in a rabbit model.

    Science.gov (United States)

    Wang, Jihong; Jiang, Dianming; Wen, Shuzheng; Jing, Shangfei; Fan, Dongsheng; Hao, Zengtao; Han, Chaoqian

    2015-01-01

    To investigate the structure and the attachment strength of a healing tendon-bone interface and the role of mechanical loading in tendon healing. Sixty rabbits underwent unilateral detachment and repair of the Achilles tendon. Thirty animals were immobilized (Group A), and the others wereallowed loadingimmediately postoperatively (Group B). Animals were sacrificed at 4 weeks and evaluated for histological and biomechanical testing. Statistical analysis was performed with an independent t test with significance set at P = 0.05. The ultimate stress was greater in group B (4.598 ± 1.321 N/mm(2)) compared with the control group (3.388 ± 0.994 N/mm(2)) (P tendon-to-bone interface with a larger area of chondrocytes was found in group B (P tendon-to-bone interface.

  7. Synthesis and structure of bis(β-dibenzoyl methanato -O,O') (aquo-O ...

    Indian Academy of Sciences (India)

    Synthesis and structure of bis(β-dibenzoyl methanato -O,O') (aquo-O) dioxouranium (VI) compound ... Keywords. β-diketonates; uranyl ion; adduct compound; crystal structure; hydrogen bonding. 1. Introduction. Structural studies on uranyl ... crystalline product obtained was filtered, washed with ether and dried. The crystal ...

  8. In vitro tendon tissue development from human fibroblasts demonstrates collagen fibril diameter growth associated with a rise in mechanical strength.

    Science.gov (United States)

    Herchenhan, Andreas; Bayer, Monika L; Svensson, René B; Magnusson, S Peter; Kjaer, Michael

    2013-01-01

    Collagen-rich tendons and ligaments are important for joint stability and force transmission, but the capacity to form new tendon is poorly understood. In the present study, we investigated mechanical strength, fibril size, and structure during development of tendon-like tissue from adult human tenocytes (termed tendon constructs) in vitro over 5 weeks in 3D tissue culture. The constructs displayed large elongated tendon cells aligned along the tendon axis together with collagen fibrils that increased in diameter by 50% from day 14 to 35, which approaches that observed in adult human tendon in vivo. The increase in diameter was accompanied by a 5-fold increase in mechanical strength (0.9±0.1 MPa to 4.9±0.6 MPa) and Young's modulus (5.8±0.9 MPa to 32.3±4.2 MPa), while the maximal strain at failure (16%) remained constant throughout the 5-week culture period. The present study demonstrates that 3D tendon constructs can be formed by isolated human tendon fibroblasts, and when these constructs are subjected to static self-generated tension, the fibrils will grow in size and strength approaching that of adult human tendon in vivo. Copyright © 2012 Wiley Periodicals, Inc.

  9. The role of bone sialoprotein in the tendon-bone insertion.

    Science.gov (United States)

    Marinovich, Ryan; Soenjaya, Yohannes; Wallace, Gregory Q; Zuskov, Andre; Dunkman, Andrew; Foster, Brian L; Ao, Min; Bartman, Kevin; Lam, Vida; Rizkalla, Amin; Beier, Frank; Somerman, Martha J; Holdsworth, David W; Soslowsky, Louis J; Lagugné-Labarthet, François; Goldberg, Harvey A

    2016-01-01

    Tendons/ligaments insert into bone via a transitional structure, the enthesis, which is susceptible to injury and difficult to repair. Fibrocartilaginous entheses contain fibrocartilage in their transitional zone, part of which is mineralized. Mineral-associated proteins within this zone have not been adequately characterized. Members of the Small Integrin Binding Ligand N-linked Glycoprotein (SIBLING) family are acidic phosphoproteins expressed in mineralized tissues. Here we show that two SIBLING proteins, bone sialoprotein (BSP) and osteopontin (OPN), are present in the mouse enthesis. Histological analyses indicate that the calcified zone of the quadriceps tendon enthesis is longer in Bsp(-/-) mice, however no difference is apparent in the supraspinatus tendon enthesis. In an analysis of mineral content within the calcified zone, micro-CT and Raman spectroscopy reveal that the mineral content in the calcified fibrocartilage of the quadriceps tendon enthesis are similar between wild type and Bsp(-/-) mice. Mechanical testing of the patellar tendon shows that while the tendons fail under similar loads, the Bsp(-/-) patellar tendon is 7.5% larger in cross sectional area than wild type tendons, resulting in a 16.5% reduction in failure stress. However, Picrosirius Red staining shows no difference in collagen organization. Data collected here indicate that BSP is present in the calcified fibrocartilage of murine entheses and suggest that BSP plays a regulatory role in this structure, influencing the growth of the calcified fibrocartilage in addition to the weakening of the tendon mechanical properties. Based on the phenotype of the Bsp(-/-) mouse enthesis, and the known in vitro functional properties of the protein, BSP may be a useful therapeutic molecule in the reattachment of tendons and ligaments to bone. Copyright © 2016 International Society of Matrix Biology. All rights reserved.

  10. Local Synthesis of Carbon Nanotubes in Silicon Microsystems: The Effect of Temperature Distribution on Growth Structure

    Directory of Open Access Journals (Sweden)

    Knut E. Aasmundtveit

    2013-07-01

    Full Text Available Local synthesis and direct integration of carbon nanotubes (CNTs into microsystems is a promising method for producing CNT-based devices in a single step, low-cost, and wafer-level, CMOS/MEMS-compatible process. In this report, the structure of the locally grown CNTs are studied by transmission imaging in scanning electron microscopy—S(TEM. The characterization is performed directly on the microsystem, without any post-synthesis processing required. The results show an effect of temperature on the structure of CNTs: high temperature favors thin and regular structures, whereas low temperature favors “bamboo-like” structures.

  11. Intrinsic flexor-tendon repair. A morphological study in vitro.

    Science.gov (United States)

    Manske, P R; Gelberman, R H; Vande Berg, J S; Lesker, P A

    1984-03-01

    Rabbit flexor tendons with a 90 per cent mid-section transverse laceration demonstrated the intrinsic capacity to participate in the repair process in the absence of extrinsic cell sources and without the benefit of nutrition from a circulating blood supply or the influence of synovial fluid. Two cellular processes were involved in the in vitro repair process: (1) phagocytosis occurred by differentiation of fibroblasts from the epitenon--the cells migrated into the repair site and removed cellular debris and collagen fragments, and (2) collagen synthesis occurred primarily within the endotenon cells. The results of this experimental study support the concept that flexor tendons have the intrinsic capacity to phagocytize old collagen and synthesize new collagen fibrils. Consequently, clinical attempts to prevent or control the peripheral adhesions appear valid, since these adhesions do not appear to be an essential component of the repair process.

  12. Tendon Length, Calf Muscle Atrophy, and Strength Deficit After Acute Achilles Tendon Rupture: Long-Term Follow-up of Patients in a Previous Study.

    Science.gov (United States)

    Heikkinen, Juuso; Lantto, Iikka; Piilonen, Juuso; Flinkkilä, Tapio; Ohtonen, Pasi; Siira, Pertti; Laine, Vesa; Niinimäki, Jaakko; Pajala, Ari; Leppilahti, Juhana

    2017-09-20

    In this prospective study, we used magnetic resonance imaging (MRI) to assess long-term Achilles tendon length, calf muscle volume, and muscle fatty degeneration after surgery for acute Achilles tendon rupture. From 1998 to 2001, 60 patients at our center underwent surgery for acute Achilles tendon rupture followed by early functional postoperative rehabilitation. Fifty-five patients were reexamined after a minimum duration of follow-up of 13 years (mean, 14 years), and 52 of them were included in the present study. Outcome measures included Achilles tendon length, calf muscle volume, and fatty degeneration measured with MRI of both the affected and the uninjured leg. The isokinetic plantar flexion strength of both calves was measured and was correlated with the structural findings. The Achilles tendon was, on average, 12 mm (95% confidence interval [CI] = 8.6 to 15.6 mm; p muscles were 63 cm (13%; p muscle atrophy. Increased Achilles tendon length is associated with smaller calf muscle volumes and persistent plantar flexion strength deficits after surgical repair of Achilles tendon rupture. Strength deficits and muscle volume deficits are partly compensated for by FHL hypertrophy, but 11% to 13% deficits in soleus and gastrocnemius muscle volumes and 12% to 18% deficits in plantar flexion strength persist even after long-term follow-up. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

  13. The clinical effect of tendon repair for tendon spontaneous rupture after corticosteroid injection in hands

    Science.gov (United States)

    Lu, Hui; Yang, Hu; Shen, Hui; Ye, Ganmin; Lin, Xiang-Jin

    2016-01-01

    Abstract Corticosteroid injections for hand tendinitis can lead to a rare significant complication of tendon spontaneous rupture. However, only sporadic cases were reported in the literature before. This study was designed to gauge the clinical effect of tendon repair in patients of tendon spontaneous rupture after corticosteroid injection and analyze our experience. This was a retrospective observational study of 13 patients (8 women and 5 men) operated between July 2011 and December 2015 for tendon spontaneous rupture after corticosteroid injection. Demographic data, clinical features, imaging data, and surgical treatments were carefully reviewed. The average age was 52.308 ± 15.381 years (range 29–71). The average injection times were 2.538 ± 1.664 times (range 1–6). The average rupture time (after last injection) was 10.923 ± 9.500 weeks (range 3–32). Nine patients were treated by tendon suture (69% of cases), and 4 patients were treated by tendon grafting (31% of cases). All patients received follow-up in our outpatient clinic. The sites of the tendon rupture (15 tendons of 13 patients had involved) include extensor pollicis longus (6 tendons, 40% of cases), extensor digiti quinti and extensor digiti minimi (4 tendons, 27% of cases), ring finger of extensor digitorum communis (3 tendons, 20% of cases), and middle finger of extensor digitorum communis (2 tendons, 13% of cases). Two patients who had tendon adhesion (15% of cases) were treated by tendon release. One patient who had tendon rerupture (8% of cases) was treated by tendon grafting. No patient had complications of infections, vascular, or nerve injury. Tendon spontaneous rupture is a serious complication after corticosteroid injection for tendinitis. Rigid standard of corticosteroid injection is very important. Magnetic resonance imaging was contributory to preoperative assess tendon defect and can be used to monitor healing quality of tendons during the follow-up. PMID:27741145

  14. 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.

  15. Green synthesis and structural control of metal and mineral nanostructures

    DEFF Research Database (Denmark)

    Engelbrekt, Christian

    nanomaterials. In the first approach, time-resolved chronopotentiometry, pH, conductivity and turbidity, and ultraviolet-visible light spectroscopy were employed to follow the green synthesis of gold nanoparticles. Several distinct phases were observed with all techniques providing a broad picture....... Detailed crystallographic characterization was obtained by combining X-ray diffraction and infrared spectroscopy. The synthesis of CuO was further optimized and the flat, rod-shaped nanostructures applied as heterogeneous catalysts for oxidative dehydrogenation reactions. High activity and good reusability...

  16. Release of tensile strain on engineered human tendon tissue disturbs cell adhesions, changes matrix architecture, and induces an inflammatory phenotype

    DEFF Research Database (Denmark)

    Bayer, Monika L; Schjerling, Peter; Herchenhan, Andreas

    2014-01-01

    Mechanical loading of tendon cells results in an upregulation of mechanotransduction signaling pathways, cell-matrix adhesion and collagen synthesis, but whether unloading removes these responses is unclear. We investigated the response to tension release, with regard to matrix proteins, pro...... were upregulated. Stimulation with the cytokine TGF-β1 had distinct effects on some tendon-related genes in both tensioned and de-tensioned tissue. These findings indicate an important role of mechanical loading for cellular and matrix responses in tendon, including that loss of tension leads...

  17. Smart Tendon Actuated Flexible Actuator

    Directory of Open Access Journals (Sweden)

    Md. Masum Billah

    2015-01-01

    Full Text Available We investigate the kinematic feasibility of a tendon-based flexible parallel platform actuator. Much of the research on tendon-driven Stewart platforms is devoted either to the completely restrained positioning mechanism (CRPM or to one particular type of the incompletely restrained positioning mechanism (IRPM where the external force is provided by the gravitational pull on the platform such as in cable-suspended Stewart platforms. An IRPM-based platform is proposed which uses the external force provided by a compliant member. The compliant central column allows the configuration to achieve n DOFs with n tendons. In particular, this investigation focuses on the angular deflection of the upper platform with respect to the lower platform. The application here is aimed at developing a linkable module that can be connected to one another so as to form a “snake robot” of sorts. Since locomotion takes precedence over positioning in this application, a 3-DOF Stewart platform is adopted. For an arbitrary angular displace of the end-effector, the corresponding length of each tendon can be determined through inverse kinematics. Mathematical singularities are investigated using the traditional analytical method of defining the Jacobian.

  18. 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

    2017-12-01

    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.

  19. 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

  20. Total synthesis based on the originally claimed structure of mucosin.

    Science.gov (United States)

    Gallantree-Smith, Harrison C; Antonsen, Simen G; Görbitz, Carl H; Hansen, Trond V; Nolsøe, Jens M J; Stenstrøm, Yngve H

    2016-09-28

    The first total synthesis aimed at the naturally occurring eicosanoid bicycle mucosin is reported. A practical route has been devised allowing the issues relating to the previous assignment of stereochemistry to be examined. X-ray crystallography was performed on a late stage intermediate to pinpoint the topological relationship displayed by the featured bicyclo[4.3.0]non-3-ene scaffold.

  1. Synthesis, characterization and crystal structure of new nickel ...

    Indian Academy of Sciences (India)

    School of Chemistry, University College of Science, University of Tehran, Tehran, Iran. Email: alnema@khayam.ut.ac.ir ... nation polymers and coordination complexes, is a suit- able building block for supramolecular ..... Kianpour G, Salavati-Niasari M and Emadi H 2013. Precipitation synthesis and characterization of cobalt.

  2. Synthesis and structure of copper(II) complexes: Potential cyanide ...

    Indian Academy of Sciences (India)

    ing the oxidase models. The necessity to make progress in developing copper oxidase models requires synthesis of appropriate copper complexes to rationalize the func- tions of such oxidases unequivocally.46–52 Therefore, to study the coordination chemistry of Cu(II) incorpo- rating the new azo ligands,53 HLa and HLb, ...

  3. Synthesis, characterization, crystal structure and DNA-binding study ...

    Indian Academy of Sciences (India)

    BOLIN

    SYNOPSIS. Synthesis and characterization of four mononuclear eight coordinated cadmium(II) complexes with newly explored carboxamide derivatives and study of interaction with calf-thymus DNA are reported. The results suggest that neutral complexes 2a and 2b bind to DNA in an intercalative mode. On the other hand, ...

  4. synthesis and structural studies of first row transition metal ...

    African Journals Online (AJOL)

    a

    deals with the synthesis and characterization of NBHQO and its complexes with chromium(III), manganese(II), iron(III), cobalt(II), nickel(II) and copper(II). EXPERIMENTAL. All the chemicals used were either of AR or chemically pure grade. Mass spectra were recorded on a Perkin-Elmer Hitachi-6L spectrometer and 1H NMR ...

  5. Synthesis, structural characterization and biological activity of a ...

    Indian Academy of Sciences (India)

    3.1 Synthesis and formulation. Schiff base ligand H2L was synthesized by 1:1 conden- sation of O-aminophenol and O-vanillin in dehydrated alcohol. 1 was prepared using reaction among Zn(II) salt and the ligand in methanol. Coordination geo- metry of 1 was determined by different spectroscopic characterization.

  6. Ultrasound elasticity imaging of human posterior tibial tendon

    Science.gov (United States)

    Gao, Liang

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, it could be used to quantify the severity of tendonosis and help determine the appropriate treatment. Ultrasound elasticity imaging (UEI) is a real-time, noninvasive technique to objectively measure mechanical properties in soft tissue. It consists of acquiring a sequence of ultrasound frames and applying speckle tracking to estimate displacement and strain at each pixel. The goals of my dissertation were to 1) use acoustic simulations to investigate the performance of UEI during tendon deformation with different geometries; 2) develop and validate UEI as a potentially noninvasive technique for quantifying tendon mechanical properties in human cadaver experiments; 3) design a platform for UEI to measure mechanical properties of the PTT in vivo and determine whether there are detectable and quantifiable differences between healthy and diseased tendons. First, ultrasound simulations of tendon deformation were performed using an acoustic modeling program. The effects of different tendon geometries (cylinder and curved cylinder) on the performance of UEI were investigated. Modeling results indicated that UEI accurately estimated the strain in the cylinder geometry, but underestimated in the curved cylinder. The simulation also predicted that the out-of-the-plane motion of the PTT would cause a non-uniform strain pattern within incompressible homogeneous isotropic material. However, to average within a small region of interest determined by principal component analysis (PCA

  7. Tissue-Engineered Tendon for Enthesis Regeneration in a Rat Rotator Cuff Model

    Directory of Open Access Journals (Sweden)

    Michael J. Smietana

    2017-06-01

    Full Text Available Healing of rotator cuff (RC injuries with current suture or augmented scaffold techniques fails to regenerate the enthesis and instead forms a weaker fibrovascular scar that is prone to subsequent failure. Regeneration of the enthesis is the key to improving clinical outcomes for RC injuries. We hypothesized that the utilization of our tissue-engineered tendon to repair either an acute or a chronic full-thickness supraspinatus tear would regenerate a functional enthesis and return the biomechanics of the tendon back to that found in native tissue. Engineered tendons were fabricated from bone marrow-derived mesenchymal stem cells utilizing our well-described fabrication technology. Forty-three rats underwent unilateral detachment of the supraspinatus tendon followed by acute (immediate or chronic (4 weeks retracted repair by using either our engineered tendon or a trans-osseous suture technique. Animals were sacrificed at 8 weeks. Biomechanical and histological analyses of the regenerated enthesis and tendon were performed. Statistical analysis was performed by using a one-way analysis of variance with significance set at p < 0.05. Acute repairs using engineered tendon had improved enthesis structure and lower biomechanical failures compared with suture repairs. Chronic repairs with engineered tendon had a more native-like enthesis with increased fibrocartilage formation, reduced scar formation, and lower biomechanical failure compared with suture repair. Thus, the utilization of our tissue-engineered tendon showed improve enthesis regeneration and improved function in chronic RC repairs compared with suture repair. Clinical Significance: Our engineered tendon construct shows promise as a clinically relevant method for repair of RC injuries.

  8. Tendon response to pharmaco-mechanical stimulation of the chronically retracted rotator cuff in sheep.

    Science.gov (United States)

    Wieser, Karl; Farshad, Mazda; Meyer, Dominik C; Conze, Philipp; von Rechenberg, Brigitte; Gerber, Christian

    2015-02-01

    Chronic tearing of tendons is associated with molecular and structural alterations causing biomechanical changes, which compromise musculotendinous function and become limiting factors for tendon repair. This study investigated the histological response of chronically retracted sheep rotator cuff tendons to mechanical and pharmacological stimulation in view of tendon repair. Sixteen weeks after experimental release of the infraspinatus tendon in 20 sheep, the retracted musculotendinous unit was subjected to continuous traction either with [anabolic steroids (nandrolone) group/insulin-like growth factor (IGF) group] or without (control group) additional pharmacological treatment during 6 weeks. A new degeneration score for tendinous tissues (DSTT), based on established knowledge on histological changes associated with tendon degeneration, was used for histological analysis at the time of tendon release, at the beginning of continuous re-lengthening and at repair in all animals. The DSTT score (inter-observer correlation: r = 0.83), quantifiably representing tendon degeneration, improved from 15.5 (SD 1.3) points before to 9.8 (SD 3.8) points after re-lengthening. It improved in a qualitatively and quantitatively similar fashion if pharmacological stimulation was added. The nandrolone group improved from 13.7 (SD 1.6) to 9.8 (SD 1.9) and the IGF group from 13.3 (SD 3.6) to 8.8 (SD 1.8) points. Mechanical stimulation significantly reduced tissue degeneration. However, the addition of a pharmacological stimulation with anabolic steroids or IGF had neither a measurable positive nor negative effect on the degenerative process. Therefore, this investigation does neither support the additional pharmacological use of the anabolic steroid nandrolone or of IGF decanoate for restoration of tendon degeneration, nor otherwise provide evidence for additional tendon damage, if those substances are used to alter the muscular metabolism.

  9. Sound Synthesis and Musical Composition by Physical Modelling of Self-Sustained Oscillating Structures

    OpenAIRE

    Poyer, François; Cadoz, Claude

    2007-01-01

    Paper 3 - Audio Synthesis (Oral Presentations); International audience; In this paper, we present the first results of a study that is carried out with the sound synthesis and musical creation environment GENESIS on self-sustained oscillating structures models. Based on the mass-interaction CORDIS-ANIMA physical modelling formalism, GENESIS has got the noteworthy property that it allows to work both on sound itself and on musical composition in a single coherent environment. By taking as a st...

  10. Synthesis and Structural Studies of Nanocrystalline Cd 0.3 Zn 0.7 Fe ...

    African Journals Online (AJOL)

    Synthesis and Structural Studies of Nanocrystalline Cd 0.3 Zn 0.7 Fe 2 O 4. ... South African Journal of Chemistry ... The synthesis of Cd0.3Zn0.7Fe2O4 nanoparticles has been achieved by a simple thermal decomposition method from the inorganic precursor, Cdd0.3Zn0.7Fe2(cin)3(N2H4)2, which was obtained by a novel ...

  11. MWW-type titanosilicate synthesis, structural modification and catalytic applications to green oxidations

    CERN Document Server

    Wu, Peng; Xu, Le; Liu, Yueming; He, Mingyuan

    2013-01-01

    This book provides a comprehensive review of a new generation of selective oxidation titanosilicate catalysts with the MWW topology (Ti-MWW) based on the research achievements of the past 12 years. It gives an overview of the synthesis, structure modification and catalytic properties of Ti-MWW. Ti-MWW can readily be prepared by means of direct hydrothermal synthesis with crystallization-supporting agents, using dual-structure-directing agents and a dry-gel conversion technique. It also can be post-synthesized through unique reversible structure transformation and liquid-phase isomorphous subst

  12. Merremoside D: de novo synthesis of the purported structure, NMR analysis, and comparison of spectral data.

    Science.gov (United States)

    Sharif, Ehesan U; Wang, Hua-Yu Leo; Akhmedov, Novruz G; O'Doherty, George A

    2014-01-17

    The first synthesis of the purported structure of Merremoside D has been achieved in 22 longest linear steps. The de novo asymmetric synthesis relied on the use of asymmetric catalysis to selectively install all 21 stereocenters in the final compounds from commercially available achiral starting materials. Adiabatic gradient 2D NMR techniques (gHSQCAD, gHMBCAD, gH2BCAD, gHSQCTOXYAD, ROESYAD) were used to completely assign the structure of synthetic Merremoside D. Comparison of our assignments with the limited NMR data reported for natural Merremoside D allows for the tentative confirmation of its structure.

  13. Plasma platelet-rich autogenous healing tendon of the gastrocnemius muscle in rabbits

    Directory of Open Access Journals (Sweden)

    Duvaldo Eurides

    2015-04-01

    Full Text Available Tendon lesions may involve the partial or total section of the common calcaneal tendon and cause postural changes of the member. This study evaluated, after 45 and 90 postoperative days (PO, the repair of the tendon of gastrocnemius muscle of rabbits with topical application of autologous platelet concentrate. Twelve adult rabbits were divided into two groups (n = 6 undergoing cardiac puncture and collection of 10 ml of blood to obtain platelet rich-plasma (PRP. Animals of both groups had a transverse tenotomy in the middle third of the lateral belly of the gastrocnemius tendon and muscle that was approximated with modified Kessler suture and nylon thread. In the animals of the treated group it was applied the average of 490.644 platelets / uL of PRP, per animal over the tendon synthesis. The treated group showed a higher amount of collagen fibers than the control one, and at 90 PO days the intensity of collagen was higher than at 45 days with more fibroblasts in the control than in treated one. The administration of plasma autogenous platelet concentrate in the repair of the gastrocnemius tendon of rabbits stimulates and organizes the repair process and causes early production of collagen fibers.

  14. Test of measuring frictional loss of tendons for PCCVs and others

    International Nuclear Information System (INIS)

    Igaki, Tsutomu; Kondo, Shigeru; Tadano, Naonori.

    1981-01-01

    Kansai Electric Power Co., Inc., has carried out the experimental research on large capacity tendons in order to introduce the prestressing structurally required for PCCVs since 1978. This experimental research is concerned with large circular cylinder structures using the large capacity tendons of unbonded type, and aimed at clarifying the problems concerning their design and construction. Through the experiment of prestressing the partial models of full size with the tendons of 1000 t class, the basic experiment on materials, the investigations of concrete placing and tendon arrangement, and the measurement before and after prestressing were carried out, and the studies on the loss of tension the soundness of anchoring part, and the capability of construction were made. The specimens were a rectangular block with 14 tendons, a circular cylinder of two-buttress type with 3 tendons, a U-type specimen simulating the vertical section and a C-type specimen simulating the horizontal section. It seems advantageous to decrease the number of buttresses in view of workability and economy when large capacity tendons are used, and it was confirmed that two-buttress construction did not cause problem at all. It was judged that the anchoring part was sufficiently safe. Concerning the friction during tensioning, the effectiveness rate was estimated. (Kako, I.)

  15. In-vitro tensile testing machine for vibration study of fresh rabbit Achilles tendon

    Science.gov (United States)

    Revel, Gian M.; Scalise, Alessandro; Scalise, Lorenzo; Pianosi, Antonella

    2001-10-01

    A lot of people, overall athletic one suffer from tendinitis or complete rupture of the Achilles tendon. This structure becomes inflamed and damaged mainly from a variety of mechanical forces and sometimes due to metabolic problems, such as diabetes or arthritis. Over the past three decades extensive studies have been performed on the structural and mechanical properties of Achilles tendon trying to explain the constitutive equations to describe and foresee tendon behavior. Among the various mechanical parameters, the vibrational behavior is also of interest. Several investigations are performed in order to study how the Achilles tendon vibrations influence the response of the muscle proprioception and human posture. The present article describes how in vitro tensile experiments can be performed, taking into account the need to simulate physiological condition of Achilles tendon and thus approaching some opened problems in the design of the experimental set-up. A new system for evaluating tendon vibrations by non contact techniques is proposed. Preliminary simple elongation tests are made extracting the main mechanical parameters: stress and strain at different fixed stretches, in order to characterize the tissue. Finally, a vibration study is made at each pretensioned tendon level evaluating the oscillating curves caused by a small hammer.

  16. Synthesis, structure and photocatalytic properties of β-ZrMo2O8

    Indian Academy of Sciences (India)

    Administrator

    Synthesis, structure and photocatalytic properties of β-ZrMo2O8. PRANGYA PARIMITA SAHOO, S SUMITHRA, GIRIDHAR MADRAS and. T N GURU ROW*. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India. Abstract. Monoclinic ZrMo2O8 was synthesized via solid state method ...

  17. Solvent-free synthesis of nanosized hierarchical sodalite zeolite with a multi-hollow polycrystalline structure

    KAUST Repository

    Zeng, Shangjing

    2016-08-03

    A solvent-free route is developed for preparing nanoscale sodalite zeolite with a multi-hollow structure. Furthermore, the synthesis of nanosized hollow sodalite polycrystalline aggregates with a mesoporous structure and high crystallinity is investigated by adding an organosilane surfactant as a mesopore-generating agent.

  18. Synthesis, structural and ferromagnetic properties of La1–x Kx ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Synthesis, structural and ferromagnetic properties of La1–KMnO3 (0.0≤ 0.25) phases by solution combustion method ... Structural parameters were determined by the Rietveld refinement method using powder XRD data. Parent ... The ratio of the Mn3+/Mn4+ was determined by the iodometric titration.

  19. Methodology in structural determination and synthesis of insect pheromone

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Lin

    1991-01-01

    Full Text Available By means of ethereal washing of insect pheromone glands of female moths, GC-MS detection along with microchemical reactions and electroantennogram (EAG survey, six economically important insect species were targeted for pheromone identification. The discovery of a natural pheromone inhibitor, chemo-selectivity and species isolation by pheromone will be described. The modified triple bond migration and triethylamine liganded vinyl cuprate were applied for achiral pheromone synthesis in double bond formation. Some optically active pheromones and their stereoisomers were synthesized through chiral pool or asymmetric synthesis. Some examples of chiral recognition of insects towards their chiral pheromones will be discussed. A CaH2 and silica gel catalyzed Sharpless Expoxidation Reaction was found in shortening the reaction time.

  20. New data structures and algorithms for logic synthesis and verification

    CERN Document Server

    Amaru, Luca Gaetano

    2017-01-01

    This book introduces new logic primitives for electronic design automation tools. The author approaches fundamental EDA problems from a different, unconventional perspective, in order to demonstrate the key role of rethinking EDA solutions in overcoming technological limitations of present and future technologies. The author discusses techniques that improve the efficiency of logic representation, manipulation and optimization tasks by taking advantage of majority and biconditional logic primitives. Readers will be enabled to accelerate formal methods by studying core properties of logic circuits and developing new frameworks for logic reasoning engines. · Provides a comprehensive, theoretical study on majority and biconditional logic for logic synthesis; · Updates the current scenario in synthesis and verification – especially in light of emerging technologies; · Demonstrates applications to CMOS technology and emerging technologies.

  1. 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....

  2. The synthesis and structure of new vinylogous carbamates of sparteine

    Science.gov (United States)

    Włodarczak, Jacek; Wysocka, Waleria; Katrusiak, Andrzej

    2010-05-01

    Synthesis of new ( E)-(-)-[2-methyl ( 2), ethyl ( 3), isopropyl ( 4), benzyl ( 5) and phenyl ( 6)] carbonylmethylideno-17-oxosparteine by the Eschenmoser coupling reaction has been described. Stereochemistry of these compounds has been determined by 13C and 1H NMR and that of compound 2 additionally by X-ray analysis. The Haasnoot equation has been used to determine the HCCH dihedral angle in ( E)-(-)-2-methyl-(methylcarbonylomethylideno)-17-oxosparteine on the basis of NMR spectroscopy.

  3. Organized Mesoporous Alumina: Synthesis, Structure and Potential in Catalysis

    Czech Academy of Sciences Publication Activity Database

    Čejka, Jiří

    2003-01-01

    Roč. 254, - (2003), s. 327-338 ISSN 0926-860X R&D Projects: GA AV ČR IAA4040001; GA ČR GA104/02/0571; GA MŠk ME 404 Institutional research plan: CEZ:AV0Z4040901 Keywords : organized mesoporous alumina * mesoporous molecular sieves * synthesis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.825, year: 2003

  4. Cellular and Molecular Factors Influencing Tendon Repair.

    Science.gov (United States)

    Durgam, Sushmitha; Stewart, Matthew

    2017-08-01

    Tendons are complex connective tissues that transmit tensile forces between muscles and tendons. Tendon injuries are among the most common orthopedic problems with long-term disability as a frequent consequence due to prolonged healing time. Furthermore, the repair tissue is of inferior quality, predisposing patients to high rates of recurrence following initial injury. Coordinated cellular processes and biological factors under the influence of mechanical loading are involved in tendon healing and our understanding of these events lags behind other musculoskeletal tissues. Tendons are relatively hypocellular and hypovascular, with little or no intrinsic regenerative capacity. Studies have documented fatty degeneration, chondrogenic dysplasia, and ectopic ossification within tendon repair tissue. The underlying pathogenesis for these metaplastic changes that compromise the quality of tendon repair tissue is poorly understood. The purpose of this review is to compile literature reporting molecular processes that regulate/control the phenotype of cells responsible for abnormal matrix deposition at repair site. In addition, recent studies reporting the interplay of mechanotransduction and cellular responses during tendon repair are summarized. Identifying the links between cellular, biological, and mechanical parameters involved in tendon repair is paramount to develop successful therapies for tendon healing.

  5. 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.

  6. The effect of estrogen on tendon and ligament metabolism and function.

    Science.gov (United States)

    Leblanc, D R; Schneider, M; Angele, P; Vollmer, G; Docheva, D

    2017-09-01

    Tendons and ligaments are crucial structures inside the musculoskeletal system. Still many issues in the treatment of tendon diseases and injuries have yet not been resolved sufficiently. In particular, the role of estrogen-like compound (ELC) in tendon biology has received until now little attention in modern research, despite ELC being a well-studied and important factor in the physiology of other parts of the musculoskeletal system. In this review we attempt to summarize the available information on this topic and to determine many open questions in this field. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  7. Structure sensitivity of Cu and CuZn catalysts relevant to industrial methanol synthesis

    Science.gov (United States)

    van den Berg, Roy; Prieto, Gonzalo; Korpershoek, Gerda; van der Wal, Lars I.; van Bunningen, Arnoldus J.; Lægsgaard-Jørgensen, Susanne; de Jongh, Petra E.; de Jong, Krijn P.

    2016-01-01

    For decades it has been debated whether the conversion of synthesis gas to methanol over copper catalysts is sensitive or insensitive to the structure of the copper surface. Here we have systematically investigated the effect of the copper particle size in the range where changes in surface structure occur, that is, below 10 nm, for catalysts with and without zinc promotor at industrially relevant conditions for methanol synthesis. Regardless of the presence or absence of a zinc promotor in the form of zinc oxide or zinc silicate, the surface-specific activity decreases significantly for copper particles smaller than 8 nm, thus revealing structure sensitivity. In view of recent theoretical studies we propose that the methanol synthesis reaction takes place at copper surface sites with a unique configuration of atoms such as step-edge sites, which smaller particles cannot accommodate. PMID:27703166

  8. 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

    2012-12-15

    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.

  9. 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

  10. Synthesis and structure of two-dimensional transition-metal dichalcogenides

    KAUST Repository

    Shi, Yumeng

    2015-07-13

    Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) exhibit unique electrical, optical, thermal, and mechanical properties, which enable them to be used as building blocks in compact and lightweight integrated electronic systems. The controllable and reliable synthesis of atomically thin TMDCs is essential for their practical application. Recent progress in large-area synthesis of monolayer TMDCs paves the way for practical production of various 2D TMDC layers. The intrinsic optical and electrical properties of monolayer TMDCs can be defined by stoichiometry during synthesis. By manipulating the lattice structure or layer stacking manner, it is possible to create atomically thin van der Waals materials with unique and unexplored physical properties. In this article, we review recent developments in the synthesis of TMDC monolayers, alloys, and heterostructures, which shine light on the design of novel TMDCs with desired functional properties.

  11. Synthesis of computational structures for analog signal processing

    CERN Document Server

    Popa, Cosmin Radu

    2011-01-01

    Presents the most important classes of computational structures for analog signal processing, including differential or multiplier structures, squaring or square-rooting circuits, exponential or Euclidean distance structures and active resistor circuitsIntroduces the original concept of the multifunctional circuit, an active structure that is able to implement, starting from the same circuit core, a multitude of continuous mathematical functionsCovers mathematical analysis, design and implementation of a multitude of function generator structures

  12. Investigating mechanisms of tendon damage by measuring multi-scale recovery following tensile loading.

    Science.gov (United States)

    Lee, Andrea H; Szczesny, Spencer E; Santare, Michael H; Elliott, Dawn M

    2017-07-15

    Tendon pathology is associated with damage. While tendon damage is likely initiated by mechanical loading, little is known about the specific etiology. Damage is defined as an irreversible change in the microstructure that alters the macroscopic mechanical parameters. In tendon, the link between mechanical loading and microstructural damage, resulting in macroscopic changes, is not fully elucidated. In addition, tendon damage at the macroscale has been proposed to initiate when tendon is loaded beyond a strain threshold, yet the metrics to define the damage threshold are not determined. We conducted multi-scale mechanical testing to investigate the mechanism of tendon damage by simultaneously quantifying macroscale mechanical and microstructural changes. At the microscale, we observe full recovery of the fibril strain and only partial recovery of the interfibrillar sliding, indicating that the damage initiates at the interfibrillar structures. We show that non-recoverable sliding is a mechanism for tendon damage and is responsible for the macroscale decreased linear modulus and elongated toe-region observed at the fascicle-level, and these macroscale properties are appropriate metrics that reflect tendon damage. We concluded that the inflection point of the stress-strain curve represents the damage threshold and, therefore, may be a useful parameter for future studies. Establishing the mechanism of damage at multiple length scales can improve prevention and rehabilitation strategies for tendon pathology. Tendon pathology is associated with mechanically induced damage. Damage, as defined in engineering, is an irreversible change in microstructure that alters the macroscopic mechanical properties. Although microstructural damage and changes to macroscale mechanics are likely, this link to microstructural change was not yet established. We conducted multiscale mechanical testing to investigate the mechanism of tendon damage by simultaneously quantifying macroscale

  13. 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.

  14. Achilles tendon rupture in athletes.

    Science.gov (United States)

    Deangelis, Joseph P; Wilson, Kristina M; Cox, Charles L; Diamond, Alex B; Thomson, A Brian

    2009-01-01

    Achilles tendon ruptures commonly affect middle-aged athletes and can result in considerable functional impairment. While the cause is multifactorial, the greatest risk is present for athletes involved in sports that involve sudden acceleration and deceleration. A thorough history and physical examination can accurately yield a diagnosis, but when question remains, magnetic resonance imaging is superior to ultrasound-guided evaluation. The best evidence available suggests that operative treatment has a lower rate of rerupture, a higher rate of return to the same level of sport participation, and a higher complication rate, if an open technique is used. Percutaneous methods of fixation have lower complication rates without an increase in the rate of rerupture when compared with open methods. Augmentation of an Achilles tendon repair has demonstrated no clinical benefit. Rehabilitation with early mobilization leads to improved patient-reported outcomes.

  15. 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.

  16. 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.

  17. Structural archetypes in nickel(II) hybrid vanadates. Towards a directed hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Luis, R. Fernandez de; Urtiaga, M.K. [Dpto. Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Mesa, J.L.; Rojo, T. [Dpto. Quimica Inorganica, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco UPV/EHU, Apdo. 644, 48080 Bilbao (Spain); Arriortua, M.I. [Dpto. Mineralogia y Petrologia, Facultad de Ciencia y Tecnologia, Universidad del Pais Vasco/UPV/EHU, Apdo. 644, 48080 Bilbao (Spain)], E-mail: maribel.arriortua@ehu.es

    2009-07-01

    In the present work, we relate the modifications of the initial synthesis parameters (pH value, stoichiometry and concentration) with the different structural archetypes obtained in the {l_brace}Ni/Bpy/VO{r_brace} and {l_brace}Ni/Bpe/VO{r_brace} systems (4,4'-bipyridine (Bpy), 1,2-di(4-pyridyl) ethylene (Bpe)). The vanadium coordination is partially controlled by the hydrothermal synthesis conditions, and the final crystal structures depend on the synergetic interaction between the metal-organic subnets and the vanadium oxide subunits.

  18. Medial hamstring tendon regeneration following harvest for anterior cruciate ligament reconstruction: fact, myth, and clinical implication.

    Science.gov (United States)

    Carofino, Brad; Fulkerson, John

    2005-10-01

    It has been demonstrated that the medial hamstring tendons regenerate in the majority of patients following their harvest for anterior cruciate ligament reconstruction. The anatomy and morphology of these regenerated tendons have been radiographically and surgically documented. The neotendons originate within the appropriate muscle belly but display an altered insertion anatomy. Their histological composition is largely tendinous but has regions that resemble scar tissue. Concordantly, an animal model indicates that the neotendon has decreased mechanical strength, which has implications for tendon re-harvest. The regenerated tendons do restore a muscle tendon complex that is able to generate force; however, strength testing indicates that the function of the hamstring muscles is altered by harvest and regeneration. The most significant strength deficits are present in deep knee flexion and internal rotation of the tibia, whereas the peak torque of knee flexion is minimally affected. Additional harvest of the gracilis tendon results in greater deficits. The current literature indicates that hamstring tendon regeneration does indeed occur, but with structural and functional alterations.

  19. Prestressed Containments - Prestress losses and the effects of re-tensioning tendons

    International Nuclear Information System (INIS)

    Lundqvist, P.; Edin, M.; Persson, P.; Frisk, A.

    2015-01-01

    In Sweden the design of nuclear reactor containments, the structure which encloses the reactor vessel, is that of a concrete cylinder prestressed both horizontally and vertically. The main purpose of the containment is to prevent any radioactive discharge to the environment in case of e.g. an internal accident mainly through the induced compressive forces from the prestressing system. Since the tendon forces decrease with time due to long-term mechanism in the materials the remaining tendon forces are measured at regular intervals. In this paper the results from these measurements in the Swedish nuclear power plant Forsmark are presented. In addition, the losses in the cylinder walls were calculated using the models in Eurocode 2, which were modified based on the climatic conditions inside the reactor building. The results from the tendon force measurements showed that the prestress losses are low, between 5 % and 10 %, i.e. the margin to the lowest acceptable limit is currently sufficient. The effects of increasing the tendon forces were also investigated. Results from subsequent measurements on tendons where the tendon forces have been increased indicate that the development of the prestress losses may increase significantly when the tendon forces are increased to levels exceeding those of the original tensioning. The calculated prestress losses were in relatively good agreement with the measured losses, generally, the models somewhat overestimated the measured losses. (authors)

  20. The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

    Directory of Open Access Journals (Sweden)

    Yue Song

    Full Text Available To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation.A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses and radiofrequency ablation (power control mode protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks.When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

  1. The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

    Science.gov (United States)

    Song, Yue; Zheng, Jingjing; Yan, Mingwei; Ding, Weidong; Xu, Kui; Fan, Qingyu; Li, Zhao

    2015-01-01

    To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation. A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses) and radiofrequency ablation (power control mode) protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time. Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks. When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

  2. Snapping wrist due to multiple accessory tendon of first extensor compartment.

    Science.gov (United States)

    Subramaniyam, S Dhiyaneswaran; Purushothaman, Rajesh; Zacharia, Balaji

    2018-01-01

    Snapping phenomena result from the sudden impingement between anatomical and/or heterotopical structures with subsequent abrupt movement and noise. Snaps are variously perceived by patients, from mild discomfort to significant pain requiring surgical management. snapping syndrome occurs at various site like hip, knee, shoulder and wrist. There are many cadaveric studies shows accessory tendon in first extensor compartment of wrist. We present a 19 year old male presents catching sensation and occasional radial side wrist pain for 6 months. Finkelstein test was negative. Radiograph showed small bony projection over the radial styloid. MRI wrist was reported as normal but retrospective analysis of image shows multiple tendons. Intraopertively we found multiple accessory tendon of extensor pollicis brevis which is causing snapping. Fibrous tunnel release with tenotomy of few accessory tendons done. On table patients catching sensation was assessed and found to be relieved. Patient is not having snapping on his follow up visit and able to carry out his daily activity without difficulties. There are various causes for snapping wrist syndrome. Multiple accessory tendon can also cause snapping as shown in this case report. Moreover am presenting this case to highlight the diagnostic failure with non dynamic radiological investigation and to consider multiple accessory tendon as differential diagnosis for snapping wrist syndrome. Also suggest dynamic study could be a better choice of investigation to diagnosis snapping syndrome. First compartment tunnel release with few accessory tendon slip tenotomy gives good result. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  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. Repair of chronic distal biceps brachii tendon rupture using free autogenous semitendinosus tendon.

    Science.gov (United States)

    Hang, D W; Bach, B R; Bojchuk, J

    1996-02-01

    Distal biceps brachii tendon ruptures occur much less frequently than do their proximal counterparts. Distal tendon ruptures usually are associated with considerable function deficits and may require surgical treatment. Repair of chronic distal biceps brachii ruptures are extremely unusual. A free autogenous semitendinosus tendon graft was used to reconstruct the distal biceps tendon by reattaching the graft to the radial tuberosity via a 2-incision technique in a patient with symptoms and a chronic injury.

  5. Field Evaluation of the System Identification Approach for Tension Estimation of External Tendons

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Noh

    2015-01-01

    Full Text Available Various types of external tendons are considered to verify the applicability of tension estimation method based on the finite element model with system identification technique. The proposed method is applied to estimate the tension of benchmark numerical example, model structure, and field structure. The numerical and experimental results show that the existing methods such as taut string theory and linear regression method show large error in the estimated tension when the condition of external tendon is different with the basic assumption used during the derivation of relationship between tension and natural frequency. However, the proposed method gives reasonable results for all of the considered external tendons in this study. Furthermore, the proposed method can evaluate the accuracy of estimated tension indirectly by comparing the measured and calculated natural frequencies. Therefore, the proposed method can be effectively used for field application of various types of external tendons.

  6. Tendon Based Full Size Biped Humanoid Robot Walking Platform Design

    Science.gov (United States)

    Kuo, Chung-Hsien; Chiou, Kuo-Wei

    Actuators and gear trains of most biped humanoid robots are divergently allocated on the links of two legs. Disadvantages of such a mechanical design are complicated wiring of power cord and sensing/ control signal bundles and imprecise kinetics models of mixed link-and-actuator structures. Based on these drawbacks, this paper proposes a tendon-driven mechanism to develop a lower body structure of a full-size biped humanoid robot. The actuators are compacted as an actuator module, and they are placed at a distal site. A 12 degree-of-freedom mechanical structure is proposed with 100 cm in height and 45 kg in weight. The gait planning module is simulated and evaluated using the Matlab software. At the same time, an ARM7 based controller is developed to automatically generate walking patterns as well as to control the motors. Finally, a tendon-driven biped humanoid robot prototype is realized for practical waling control in the future.

  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. Staged tendon grafts and soft tissue coverage

    Directory of Open Access Journals (Sweden)

    David Elliot

    2011-01-01

    Full Text Available The objective of the two-staged flexor tendon method is to improve the predictability of final results in difficult problems dealing with tendon reconstruction. This article reviews the evolution and benefits of this procedure. It also considers the use of the technique to help deal with problems requiring pulley and skin reconstruction simultaneously with re-constituting the flexor tendon system.

  9. The roentgenographic findings of achilles tendon rupture

    International Nuclear Information System (INIS)

    Seouk, Kang Hyo; Keun, Rho Yong

    1999-01-01

    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

  10. Synthesis, structure and properties of decakis(phenylthio)corannulene.

    Science.gov (United States)

    Baldridge, Kim K; Hardcastle, Kenneth I; Seiders, T Jon; Siegel, Jay S

    2010-01-07

    Decakis(phenylthio)corannulene has been prepared from decachlorocorannulene by direct nucleophilic substitution; electronic structure properties and the X-ray crystal structure were determined and compared to predictions made by ab initio quantum chemical calculations.

  11. Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms

    International Nuclear Information System (INIS)

    Nunes, D.; Vilarigues, M.; Correia, J.B.; Carvalho, P.A.

    2012-01-01

    The present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles.

  12. Synthesis, structure and Hirshfeld surface analysis, vibrational and ...

    Indian Academy of Sciences (India)

    2.2 Crystal data and structure determination. For the structural study we chose a crystal with the dimen- sions of 0.31 × 0.28 × 0.19 mm3. The single crystal was fixed on a Bruker APEXII CCD four-circle diffractometer;. MoKα radiation (λ = 0.71073 Ε) was used in order to study its structural analysis. The crystal structure has ...

  13. Tendon exhibits complex poroelastic behavior at the nanoscale as revealed by high-frequency AFM-based rheology.

    Science.gov (United States)

    Connizzo, Brianne K; Grodzinsky, Alan J

    2017-03-21

    Tendons transmit load from muscle to bone by utilizing their unique static and viscoelastic tensile properties. These properties are highly dependent on the composition and structure of the tissue matrix, including the collagen I hierarchy, proteoglycans, and water. While the role of matrix constituents in the tensile response has been studied, their role in compression, particularly in matrix pressurization via regulation of fluid flow, is not well understood. Injured or diseased tendons and tendon regions that naturally experience compression are known to have alterations in glycosaminoglycan content, which could modulate fluid flow and ultimately mechanical function. While recent theoretical studies have predicted tendon mechanics using poroelastic theory, no experimental data have directly demonstrated such behavior. In this study, we use high-bandwidth AFM-based rheology to determine the dynamic response of tendons to compressive loading at the nanoscale and to determine the presence of poroelastic behavior. Tendons are found to have significant characteristic dynamic relaxation behavior occurring at both low and high frequencies. Classic poroelastic behavior is observed, although we hypothesize that the full dynamic response is caused by a combination of flow-dependent poroelasticity as well as flow-independent viscoelasticity. Tendons also demonstrate regional dependence in their dynamic response, particularly near the junction of tendon and bone, suggesting that the structural and compositional heterogeneity in tendon may be responsible for regional poroelastic behavior. Overall, these experiments provide the foundation for understanding fluid-flow-dependent poroelastic mechanics of tendon, and the methodology is valuable for assessing changes in tendon matrix compressive behavior at the nanoscale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Synthesis, crystal structure and Thermogravimetry of ortho-phthalic ...

    Indian Academy of Sciences (India)

    The unit cell structure of the complex is shown in figure 3. The structure shows that the butoxy group from the ligand is lost during the formation of the complex and phthalic acid acts as a bridging ligand in the com- plex. Each Cu(II) ion is coordinated with four phtha- late ligands completing an octahedral structure with six.

  15. Synthesis, structure and luminescence properties of phosphates A1 ...

    Indian Academy of Sciences (India)

    rule and the localization of this cation in the structure, which is in agreement with the structural characterization. It appears that europium ... 1. Introduction. Atom isomorphism in complex crystalline compounds with ..... isotropic approx- imation of basis atom positions in the structures of phosphates Na0.7Eu0.1Zr2(PO4)3 and.

  16. Synthesis and crystal structure of a wheel-shaped supramolecular ...

    Indian Academy of Sciences (India)

    elucidation of the structure of the final product. The details of the structural parameters and the non-covalent ... tra for 1 and the bulk product were recorded on a. Bruker AMX-400 FT-NMR spectrometer. ICPMS was .... certed fashion to complete the ring structure (figure 2).6. Examples of metal-based trigonal-prisms were ...

  17. Simulation of tendon energy storage in pedaling

    DEFF Research Database (Denmark)

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

    2001-01-01

    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...... 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...

  18. Synthesis and characterization of Al-TON zeolite using a dialkylimizadolium as structure-directing agent

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Christian Wittee; Pergher, Sibele Berenice Castella, E-mail: chriswittee@gmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Villarroel-Rocha, Jhonny [Laboratorio de Solidos Porosos, Instituto de Fisica Aplicada, Universidad Nacional de San Luis, Chacabuco, San Luis (Argentina); Silva, Bernardo Araldi Da; Mignoni, Marcelo Luis [Universidade Regional Integrada, Erechim, RS (Brazil)

    2016-11-15

    In this work, the synthesis of zeolites using 1-butyl-3-methylimidazolium chloride [C{sub 4}MI]Cl as a structure-directing agent was investigated. The organic cation shows effectiveness and selectivity for the syntheses of TON zeolites under different reaction conditions compared to the traditional structure directing agent, 1,8-diaminooctane. The 1-butyl-3-methylimidazolium cation lead to highly crystalline materials and its role as OSDA in our synthesis conditions has been confirmed by characterization techniques. ICP-OES confirms the presence of Al in the samples and {sup 27}Al MAS NMR analysis indicated that aluminum atoms were incorporated in tetrahedral coordination. Scanning electron microscopy indicated that changing the crystallization condition (static or stirring), zeolites with different crystal size were obtained, which consequently affects the textural properties of the zeolites. Moreover, varying some synthesis parameters MFI zeolite can also be obtained. (author)

  19. Lineage tracing of resident tendon progenitor cells during growth and natural healing.

    Directory of Open Access Journals (Sweden)

    Nathaniel A Dyment

    Full Text Available Unlike during embryogenesis, the identity of tissue resident progenitor cells that contribute to postnatal tendon growth and natural healing is poorly characterized. Therefore, we utilized 1 an inducible Cre driven by alpha smooth muscle actin (SMACreERT2, that identifies mesenchymal progenitors, 2 a constitutively active Cre driven by growth and differentiation factor 5 (GDF5Cre, a critical regulator of joint condensation, in combination with 3 an Ai9 Cre reporter to permanently label SMA9 and GDF5-9 populations and their progeny. In growing mice, SMA9+ cells were found in peritendinous structures and scleraxis-positive (ScxGFP+ cells within the tendon midsubstance and myotendinous junction. The progenitors within the tendon midsubstance were transiently labeled as they displayed a 4-fold expansion from day 2 to day 21 but reduced to baseline levels by day 70. SMA9+ cells were not found within tendon entheses or ligaments in the knee, suggesting a different origin. In contrast to the SMA9 population, GDF5-9+ cells extended from the bone through the enthesis and into a portion of the tendon midsubstance. GDF5-9+ cells were also found throughout the length of the ligaments, indicating a significant variation in the progenitors that contribute to tendons and ligaments. Following tendon injury, SMA9+ paratenon cells were the main contributors to the healing response. SMA9+ cells extended over the defect space at 1 week and differentiated into ScxGFP+ cells at 2 weeks, which coincided with increased collagen signal in the paratenon bridge. Thus, SMA9-labeled cells represent a unique progenitor source that contributes to the tendon midsubstance, paratenon, and myotendinous junction during growth and natural healing, while GDF5 progenitors contribute to tendon enthesis and ligament development. Understanding the mechanisms that regulate the expansion and differentiation of these progenitors may prove crucial to improving future repair strategies.

  20. Sonoelastography shows that Achilles tendons with insertional tendinopathy are harder than asymptomatic tendons.

    Science.gov (United States)

    Zhang, Qi; Cai, Yehua; Hua, Yinghui; Shi, Jun; Wang, Yuanyuan; Wang, Yi

    2017-06-01

    To seek differences of Achilles tendon hardness between insertional tendinopathy (IT) and asymptomatic controls by using computer-assisted quantification on axial-strain sonoelastography (ASE). The study consisted of 37 non-athletic patients presenting with Achilles tendon pain in one or two tendons. Both tendons were examined clinically. Among the 74 tendons, 16 were diagnosed and categorized into an IT group and 29 into an asymptomatic group. The remaining 29 tendons were excluded due to non-insertional tendinopathy, ruptures, previous surgery or mixed disorders. The tendons in the IT and asymptomatic groups were examined with both ASE and conventional ultrasound. Computer-assisted quantification on ASE was conducted to extract parameters of tendon hardness, including the 20th percentile (H20), median (H50) and skewness (Hsk) of the hardness within tendon, as well as the ratio of the mean hardness within tendon to that outside tendon (Hratio). The H20 (p = 0.003), H50 (p = 0.004) and Hratio (p = 0.002) were larger and Hsk (p = 0.001) was smaller at distal thirds of IT tendons than those of asymptomatic tendons. For differentiation between two groups, the Hsk achieved the best value (0.815) of area under the receiver operating characteristic curve, with a sensitivity of 81.3 %, a specificity of 86.2 % and an accuracy of 84.4 %. Computer-assisted quantification on ASE shows that IT tendons are harder than asymptomatic tendons. It might act as a potentially useful technique for identification and risk stratification of IT patients and thus be valuable in day-by-day clinical practice for monitoring IT progression and for evaluating therapeutic effects. III.

  1. Synthesis and structural characterization of manganese olivine lithium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Herrera Robles, Joel O. [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Fuentes Cobas, Luis E. [Centro de Investigación en Materiales Avanzados CIMAV, Complejo Industrial, M. Cervantes 120, Chihuahua C.P. 31109 (Mexico); Díaz de la Torre, Sebastián [Instituto Politécnico Nacional, Centro de Investigación e Innovación Tecnológica CIITEC, Azcapotzalco, México, D.F. C.P. 02250 (Mexico); Camacho Montes, Héctor, E-mail: hcamacho@uacj.mx [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Elizalde Galindo, José T.; García Casillas, Perla E.; Rodríguez González, Claudia A. [Basic Science Department, IIT, Universidad Autónoma de Ciudad Juárez, Av. del Charro 460 norte Cd. Juárez, Chih. C.P. 32310 (Mexico); Álvarez Contreras, Lorena [Centro de Investigación en Materiales Avanzados CIMAV, Complejo Industrial, M. Cervantes 120, Chihuahua C.P. 31109 (Mexico)

    2015-09-15

    Highlights: • LiMnPO{sub 4} was obtained by sol gel method and crystallization in reducing atmosphere. • Magnetic and electric properties are reported for LiMnPO{sub 4}. • Electrochemical properties are also found and enhanced by adding carbon. • SEM and HRTEM show the submicron powder nature. • The multifunctional behavior of LiMnPO{sub 4} is experimentally demonstrated. - Abstract: The manganese olivine lithium phosphate is a multifunctional material. If carbon is added to form a composite LiMnPO{sub 4}–C, electrochemical properties can be enhanced, making this material a good candidate for battery cathode. High magnetic susceptibility is reported for this compound at room temperature. In this work, the magnetic response was measured through a Field Cooling/Zero Field Cooling technique at temperature below 100 K. Weak ferroelectric properties at room temperature were measured. Even though, the promising applications and the interesting properties of this system, the attention received in the literature is relatively low. The synthesis of this material is difficult because of the rapid manganese oxidation and the need of a reducing atmosphere. In fact, only few authors report the synthesis of the pure phase. In the present work, nanostructured LiMnPO{sub 4} is obtained by sol gel chemical method and according to X-ray diffraction patterns, pure LiMnPO{sub 4} is obtained after calcination in a reducing atmosphere (10% H{sub 2} – 90% Ar). Nanostructured LiMnPO{sub 4} is a material with very interesting properties that deserves attentions.

  2. Stop Flow Lithography Synthesis and Characterization of Structured Microparticles

    Directory of Open Access Journals (Sweden)

    David Baah

    2014-01-01

    Full Text Available In this study, the synthesis of nonspherical composite particles of poly(ethylene glycol diacrylate (PEG-DA/SiO2 and PEG-DA/Al2O3 with single or multiple vias and the corresponding inorganic particles of SiO2 and Al2O3 synthesized using the Stop Flow Lithography (SFL method is reported. Precursor suspensions of PEG-DA, 2-hydroxy-2-methylpropiophenone, and SiO2 or Al2O3 nanoparticles were prepared. The precursor suspension flows through a microfluidic device mounted on an upright microscope and is polymerized in an automated process. A patterned photomask with transparent geometric features masks UV light to synthesize the particles. Composite particles with vias were synthesized and corresponding inorganic SiO2 and Al2O3 particles were obtained through polymer burn-off and sintering of the composites. The synthesis of porous inorganic particles of SiO2 and Al2O3 with vias and overall dimensions in the range of ~35–90 µm was achieved. BET specific surface area measurements for single via inorganic particles were 56–69 m2/g for SiO2 particles and 73–81 m2/g for Al2O3 particles. Surface areas as high as 114 m2/g were measured for multivia cubic SiO2 particles. The findings suggest that, with optimization, the particles should have applications in areas where high surface area is important such as catalysis and sieving.

  3. Controlled Synthesis of Ultralong Carbon Nanotubes with Perfect Structures and Extraordinary Properties.

    Science.gov (United States)

    Zhang, Rufan; Zhang, Yingying; Wei, Fei

    2017-02-21

    Carbon nanotubes (CNTs) have drawn intensive research interest in the past 25 years due to their excellent properties and wide applications. Ultralong CNTs refers to the horizontally aligned CNT arrays which are usually grown on flat substrates, parallel with each other with large intertube distances. They usually have perfect structures, excellent properties, and lengths up to centimeters, even decimeters. Ultralong CNTs are promising candidates as building blocks for transparent displays, nanoelectronics, superstrong tethers, aeronautics and aerospace materials, etc. The controlled synthesis of ultralong CNTs with perfect structures is the key to fully exploit the extraordinary properties of CNTs. CNTs are typical one-dimensional single-crystal nanomaterials. It has always been a great challenge how to grow macroscale single-crystals with no defects. Thus, the synthesis of ultralong CNTs with no defect is of significant importance from both fundamental and industrial aspects. In this Account, we focus on our progress on the controlled synthesis of ultralong CNTs with perfect structures and excellent properties. A deep understanding of the CNT growth mechanism is the first step for the controlled synthesis of ultralong CNTs with high quality. We first introduce the growth mechanism for ultralong CNTs and the main factor affecting their structures. We then discuss the strategies to control the defects in the as-grown ultralong CNTs. With these approaches, ultralong high-quality CNTs with different structures can be obtained. By completely eliminating the factors which may induce defects in the CNT walls, ultralong CNTs with perfect structures can be obtained. Their chiral indices keep unchanged for several centimeters long along the axial direction of the CNTs. The defect-free structures render the ultralong CNTs with excellent electrical, mechanical and thermal properties. The as-grown ultralong CNTs exhibit superhigh mechanical strength (>100 GPa) and their

  4. 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.

  5. Synthesis and structural studies of half-sandwich Cp* rhodium and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 129; Issue 5. Synthesis and structural studies of half-sandwich Cp* rhodium and Cp* iridium complexes featuring mono, bi and tetradentate nitrogen and oxygen donor ligands. NARASINGA RAO PALEPU WERNER KAMINSKY MOHAN RAO KOLLIPARA. Regular ...

  6. [3.3]Dithia-bridged cyclophanes featuring a thienothiophene ring : synthesis, structures and conformational analysis

    NARCIS (Netherlands)

    Mashraqui, Sabir H.; Sanghvikar, Yogesh; Ghadhigaonkar, Shailesh; Kumar, Sukeerthi; Meetsma, Auke; Dau, Elise Tran Huu

    2009-01-01

    The synthesis of [3.3]dithia-bridgedcyclophanes 7, 9 and 11 incorporating a fused heterocycle, thieno[2,3-b] thiophene is described. The structures are established by H-1 NMR analysis and, in the case of 11, also by single crystal X-ray crystallography. Conformational analysis by variable

  7. Synthesis, Structure and Antioxidant Activity of Cyclohexene-Fused Selenuranes and Related Derivatives

    Directory of Open Access Journals (Sweden)

    Poonam Rajesh Prasad

    2015-07-01

    Full Text Available Synthesis, structure and antioxidant activity of new cyclohexene-fused spiroselenuranes and a spirotellurane is reported. Oxidation reactions of bis(o-formylcyclohex- 1-eneselenide/bis(2-hydroxymethylcyclohex-1-eneselenide provide the corresponding spiroselenuranes. The glutathione peroxidase-like activity of the newly synthesized compounds has been evaluated.

  8. Synthesis of PbTe nanocubes, worm-like structures and ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 36; Issue 5. Synthesis of PbTe nanocubes, worm-like structures and nanoparticles by simple thermal evaporation method. L Kungumadevi ... Sathyamoorthy1. PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore 641 029, India ...

  9. Synthesis, molecular structures and ESI-mass studies of copper (I ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 10. Synthesis, molecular structures and ESI-mass studies of copper(I) complexes with ligands incorporating N, S and P donor atoms. Tarlok S Lobana Arvinder Kaur Rohit Sharma Madhu Bala Amanpreet K Jassal Courtney E Duff Jerry P Jasinski. Volume ...

  10. Seeking Polymeric Prodrugs of Norfloxacin. Part 2. Synthesis and Structural Analysis of Polyurethane Conjugates

    Directory of Open Access Journals (Sweden)

    Waclaw Kolodziejski

    2010-02-01

    Full Text Available Oligo(ε-caprolactone and oligolactide were synthesized via ring-opening polymerization of cyclic esters in the presence of creatinine as initiators. Thus obtained oligomers were successfully used in the synthesis of novel polyurethane conjugates of norfloxacin. The structures of the polymers and conjugates were elucidated by means of MALDI-TOF MS, NMR and IR studies.

  11. Synthesis, crystal structure and photo luminescent property of a 3D ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 125; Issue 3. Synthesis, crystal structure and photo luminescent property of a 3D metal-organic hybrid of Cd(II) constructed by two different bridging carboxylate. Biswajit Bhattacharya Rajdip Dey Debajyoti Ghoshal. Volume 125 Issue 3 May 2013 pp 661-666 ...

  12. Aircraft interior noise prediction using a structural-acoustic analogy in NASTRAN modal synthesis

    Science.gov (United States)

    Grosveld, Ferdinand W.; Sullivan, Brenda M.; Marulo, Francesco

    1988-01-01

    The noise induced inside a cylindrical fuselage model by shaker excitation is investigated theoretically and experimentally. The NASTRAN modal-synthesis program is used in the theoretical analysis, and the predictions are compared with experimental measurements in extensive graphs. Good general agreement is obtained, but the need for further refinements to account for acoustic-cavity damping and structural-acoustic interaction is indicated.

  13. Synthesis, structural and dielectric properties of 0.8 PMN–0.2 PT ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 5. Synthesis, structural and dielectric ... S A BAND2. Department of Physics, J D College Of Engineering and Management (JDCOEM), Nagpur 441501, India; Department of Physics, Yeshwantrao Chavan College of Engineering, Nagpur 441110, India ...

  14. Synthesis, X-ray structure and N–H…O interactions in 1,3-diphenyl ...

    Indian Academy of Sciences (India)

    The synthesis, X-ray structure and role of intermolecular interactions have been studied in case of 1,3-diphenyl-urea, owing to its medicinal importance. The compound crystallizes in orthorhombic crystal system (space group, 21) with unit cell parameters, = 9.118(3), = 10.558(2), = 11.780(3) Å and = 4.

  15. Synthesis and molecular structure of chiral metallo-based sterically overcrowded alkenes

    NARCIS (Netherlands)

    Wiel, Matthijs K.J. ter; Meetsma, Auke; Feringa, Bernard

    2002-01-01

    A four step synthesis of pyridyl-2-yl-thioxanthen-9-ylidene-isoquinolines is described. The corresponding palladium complexes are the first examples of a novel class of chiral, metallo-based, sterically overcrowded alkenes. The crystal and molecular structure of the palladium dichloride complex

  16. Synthesis, X-ray structure and N–H…O interactions in 1,3-diphenyl ...

    Indian Academy of Sciences (India)

    Unknown

    the synthesis and structural investigations of 1,3-diphenyl- urea have been undertaken. The title compound has been expected to be an excellent potential tyrosine phosphatase inhibitor and sickle-cell anemia treatment drug. 2. Experimental. A mixture of phenylisocyanate, 1⋅07 g (0⋅01 mole), aniline,. 0⋅94 g (0⋅01 mole) ...

  17. Synthesis and crystal structure determination of YCo Fe O 3 (= 0 ...

    Indian Academy of Sciences (India)

    The results on synthesis, crystal structure determination and calculation of crystallochemical parameters of YCo1−FeO3 ( = 0, 0.33, 0.5, 0.67 and 1) perovskites are presented in this work. The compounds within this series were synthesized by solution combustion method using two different fuels: urea and citric acid.

  18. Tubular duplex alpha-cyclodextrin triply bridged with disulfide bonds: synthesis, crystal structure and inclusion complexes

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Lucie; Buděšínský, Miloš; Císařová, I.; Kraus, Tomáš

    -, č. 24 (2009), s. 3557-3559 ISSN 1359-7345 R&D Projects: GA AV ČR IAA400550810; GA ČR GA203/06/1550; GA MŠk OC 172 Institutional research plan: CEZ:AV0Z40550506 Keywords : cyclodextrines * synthesis * crystal structure Subject RIV: CC - Organic Chemistry Impact factor: 5.504, year: 2009

  19. Fixation of CO2 in air: Synthesis and crystal structure of a µ3-CO3 ...

    Indian Academy of Sciences (India)

    Unknown

    *For correspondence. Fixation of CO2 in air: Synthesis and crystal structure of a. µ3-CO3-bridged tricopper(II) compound. JHUMPA MUKHERJEEa, V BALAMURUGANa, MANINDER SINGH HUNDALb and. RABINDRANATH MUKHERJEEa,*. aDepartment of Chemistry, Indian Institute of Technology, Kanpur 208 016, India.

  20. SYNTHESIS AND STRUCTURAL ANALYSES OF BIS(2-OXO-2,3 ...

    African Journals Online (AJOL)

    SYNTHESIS AND STRUCTURAL ANALYSES OF BIS(2-OXO-2,3-. DIHYDROPYRIMIDIN-1-IUM) TETRACHLORO ZINCATE (II). [H2pymo][ZnCl4] AND BIS(PYRIMIDIN-2-OLATE) ZINC(II). [Zn(PYMO)2]. Mukhtar A. Kurawa. Department of Pure and Industrial Chemistry, Bayero University Kano. P. M. B. 3011 Kano Nigeria.

  1. Synthesis, structure analysis, anti-bacterial and in vitro anti-cancer ...

    Indian Academy of Sciences (India)

    DOI 10.1007/s12039-015-0824-z. Synthesis, structure analysis, anti-bacterial and in vitro anti-cancer activity of new Schiff base and its copper complex derived from sulfamethoxazole. I RAMA∗ and R SELVAMEENA. PG and Research Department of Chemistry, Seethalakshmi Ramaswami College,. Tiruchirappalli 620 002 ...

  2. In silico structure-based design and synthesis of novel anti-RSV compounds

    NARCIS (Netherlands)

    Cancellieri, Michela; Bassetto, Marcella; Widjaja, Ivy; van Kuppeveld, Frank; de Haan, Cornelis A M; Brancale, Andrea; de Haan, C.A.M.

    2015-01-01

    Respiratory syncytial virus (RSV) is the major cause for respiratory tract disease in infants and young children. Currently, no licensed vaccine or a selective antiviral drug against RSV infections are available. Here, we describe a structure-based drug design approach that led to the synthesis of a

  3. Synthesis and structure of D3h-symmetric triptycene trimaleimide

    NARCIS (Netherlands)

    Zonta, C.; De Lucchi, O.; Linden, Anthony; Lutz, M.

    2010-01-01

    A new D3h symmetric triptycene derivative has been synthesized with the aim of obtaining molecules that are able to assemble into porous structures, and can be used in the development of new ligands. The synthesis involves a Diels-Alder reaction as the key step, followed by an oxidation and the

  4. Origami-inspired active structures: a synthesis and review

    International Nuclear Information System (INIS)

    Peraza-Hernandez, Edwin A; Hartl, Darren J; Malak Jr, Richard J; Lagoudas, Dimitris C

    2014-01-01

    Origami, the ancient art of paper folding, has inspired the design of engineering devices and structures for decades. The underlying principles of origami are very general, which has led to applications ranging from cardboard containers to deployable space structures. More recently, researchers have become interested in the use of active materials (i.e., those that convert various forms of energy into mechanical work) to effect the desired folding behavior. When used in a suitable geometry, active materials allow engineers to create self-folding structures. Such structures are capable of performing folding and/or unfolding operations without being kinematically manipulated by external forces or moments. This is advantageous for many applications including space systems, underwater robotics, small scale devices, and self-assembling systems. This article is a survey and analysis of prior work on active self-folding structures as well as methods and tools available for the design of folding structures in general and self-folding structures in particular. The goal is to provide researchers and practitioners with a systematic view of the state-of-the-art in this important and evolving area. Unifying structural principles for active self-folding structures are identified and used as a basis for a quantitative and qualitative comparison of numerous classes of active materials. Design considerations specific to folded structures are examined, including the issues of crease pattern identification and fold kinematics. Although few tools have been created with active materials in mind, many of them are useful in the overall design process for active self-folding structures. Finally, the article concludes with a discussion of open questions for the field of origami-inspired engineering. (topical review)

  5. Synthesis, crystal structure and Thermogravimetry of ortho-phthalic ...

    Indian Academy of Sciences (India)

    Abstract. Coordination polymer of Cu(II) bridged by o-phthalic acid alone is not known. The reaction of. CuCl2.2H2O with (2-butoxycarbonyl)benzoic acid yielded three dimensional coordination polymer bridged by o-phthalic acid. X-ray crystal structure shows structure with monoclinic P21/c space group. o-Phthalic acid.

  6. Synthesis, structure and thermoelectric properties of La1 ...

    Indian Academy of Sciences (India)

    Structural parameters for all the compounds were confirmed by the Rietveld refinement method usingpowder X-ray diffraction (XRD) data and exhibit the rhombhohedral crystal structure with space group R-3c (No. 167). Thescanning electron microscopy study reveals that the particles are spherical in shape and sizes, in the ...

  7. Synthesis, reactivity and structural studies of carboranyl thioethers and disulfides

    Czech Academy of Sciences Publication Activity Database

    Laromaine, A.; Teixidor, F.; Kivekäs, R.; Sillanpää, R.; Benakki, R.; Grüner, Bohumír; Vinas, C.

    -, č. 10 (2005), s. 1785-1795 ISSN 1477-9226 Grant - others:Generalitat de Catalunya(ES) 2001/SGR/0033 Keywords : molecular structure * crystal structure * closo-carboranes Subject RIV: CA - Inorganic Chemistry Impact factor: 3.003, year: 2005

  8. Synthesis, structure and Hirshfeld surface analysis, vibrational and ...

    Indian Academy of Sciences (India)

    Hirshfeld surface analysis for visually analysing intermolecular interactions in crystal structures employing molecular surfacecontours and 2D fingerprint plots has been used to scrutinize molecular shapes. The vibration properties of this structure were studied by IR spectroscopy and Raman scattering. Vibration spectra ...

  9. Solid state synthesis and structural refinement of polycrystalline La ...

    Indian Academy of Sciences (India)

    Perovskite structure based ceramic precursors have a characteristic property of substitution in the ``A" site of the ABO3 structure. This makes them a potential material for nuclear waste management in synthetic rock (SYNROC) technology. In order to simulate the mechanism of rare earth fixation in perovskite, La ...

  10. Synthesis of nano structures for use as toxic gas adsorbents

    International Nuclear Information System (INIS)

    Velazquez P, S.; Pacheco S, J.; Estrada M, N.; Vasquez N, C.; Garcia R, M.; Garduno A, M.; Torres R, C.; Garcia G, J.; Pacheco P, M.; Valdivia B, R.; Ramos F, F.; Cruz A, A.; Duran G, M.; Hidalgo P, M.

    2008-01-01

    The work described here is the study of adsorption of nitrogen oxides by carbon nano structures and its implementation in a plasma reactor used to treat toxic gases. By placing a bed of carbon nano structures to the plasma reactor outlet obtained and increase in the efficiency of degradation. (Author)

  11. Synthesis, crystal structure, optical and electrochemical properties of ...

    Indian Academy of Sciences (India)

    Its molecular geometry in the ground state has also been calculated using density functional theory (DFT) at the B3LYP/6-31G∗∗ level and compared with its crystal structure. Results show that the optimized geometry can well reproduce the crystal structure. Furthermore, both absorption and emission spectra of 1 and 2 ...

  12. Bureaucratic Structure in Schools: A Refinement and Synthesis in Measurement.

    Science.gov (United States)

    Sousa, David A.; Hoy, Wayne K.

    1981-01-01

    Compares two methods of measuring bureaucratic structure, Hall's organizational inventory and the University of Aston (England) approach, and tests them using data from 55 public high schools in New Jersey. Factor analysis reveals four underlying dimensions of school structure, including organizational control, rational specialization, system…

  13. Synthesis, Structure and Hirshfeld surface analysis, vibrational and ...

    Indian Academy of Sciences (India)

    3

    lead to the formation of a three-dimensional architecture. Hirshfeld surface analysis for visually analyzing intermolecular interactions in crystal structures employing molecular surface contours and 2D fingerprint plots have been used to scrutinize molecular shapes. The vibration properties of this structure were studied by IR ...

  14. 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.

  15. Tensile strength of a weave tendon suture using tendons of different sizes.

    Science.gov (United States)

    Mazurek, Tomasz; Strankowski, Michał; Ceynowa, Marcin; Rocławski, Marek

    2011-05-01

    This study compared the maximum load, stress, elongation at failure and the mode of failure of three kinds of tendons most frequently used for tendon grafting and tendon transfers, using the Pulvertaft weave suture. Sixty tendons were used from fresh human cadaver upper and lower extremities. The performed repairs included: 9 specimens of flexor digitorum superficialis or profundus tendon with flexor digitorum superficialis or profundus tendon (thick-thick suture), 10 specimens of flexor digitorum superficialis or profundus tendon with palmaris longus tendon (thick-medium thin suture), and 10 specimens of flexor digitorum superficialis or profundus tendon with plantaris tendon (thick-thin suture). Material testing machine was used to test repairs to failure. The mean maximum load at failure increased with the thickness of donor tendon. For the thick-thick specimen, the maximum load at failure was 125 newtons (N), for the thick-medium thin specimen it was 86,8N, and for the thick-thin it was 65,2N. These differences were all statistically significant. The active rehabilitation protocol is possible only with thick-thick connections used, the strength of the thick-medium thin connection is on the border of indications for the active rehabilitation protocol, and the thick-thin connection strength is sufficient only for the passive rehabilitation protocol. Copyright © 2010. Published by Elsevier Ltd.

  16. 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.

  17. 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

    OpenAIRE

    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 w...

  18. 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.

  19. Mechanical properties and collagen cross-linking of the patellar tendon in old and young men

    DEFF Research Database (Denmark)

    Couppé, C; Hansen, P; Kongsgaard, M

    2009-01-01

    were higher in OM than in YM (73 +/- 13 vs. 11 +/- 2 mmol/mol; P appreciably influence the dimensions or mechanical properties of the human patellar tendon in vivo. Collagen concentration was reduced, whereas both enzymatic......Age-related loss in muscle mass and strength impairs daily life function in the elderly. However, it remains unknown whether tendon properties also deteriorate with age. Cross-linking of collagen molecules provides structural integrity to the tendon fibrils and has been shown to change with age...... in animals but has never been examined in humans in vivo. In this study, we examined the mechanical properties and pyridinoline and pentosidine cross-link and collagen concentrations of the patellar tendon in vivo in old (OM) and young men (YM). Seven OM (67 +/- 3 years, 86 +/- 10 kg) and 10 YM (27 +/- 2...

  20. Multilayered polycaprolactone/gelatin fiber-hydrogel composite for tendon tissue engineering.

    Science.gov (United States)

    Yang, Guang; Lin, Hang; Rothrauff, Benjamin B; Yu, Shuting; Tuan, Rocky S

    2016-04-15

    Regeneration of injured tendon and ligament (T&L) remains a clinical challenge due to their poor intrinsic healing capacity. Tissue engineering provides a promising alternative treatment approach to facilitate T&L healing and regeneration. Successful tendon tissue engineering requires the use of three-dimensional (3D) biomimetic scaffolds that possess the physical and biochemical features of native tendon tissue. We report here the development and characterization of a novel composite scaffold fabricated by co-electrospinning of poly-ε-caprolactone (PCL) and methacrylated gelatin (mGLT). We found that photocrosslinking retained mGLT, resulted in a uniform distribution of mGLT throughout the depth of scaffold and also preserved scaffold mechanical strength. Moreover, photocrosslinking was able to integrate stacked scaffold sheets to form multilayered constructs that mimic the structure of native tendon tissues. Importantly, cells impregnated into the constructs remained responsive to topographical cues and exogenous tenogenic factors, such as TGF-β3. The excellent biocompatibility and highly integrated structure of the scaffold developed in this study will allow the creation of a more advanced tendon graft that possesses the architecture and cell phenotype of native tendon tissues. The clinical challenges in tendon repair have spurred the development of tendon tissue engineering approaches to create functional tissue replacements. In this study, we have developed a novel composite scaffold as a tendon graft consisting of aligned poly-ε-caprolactone (PCL) microfibers and methacrylated gelatin (mGLT). Cell seeding and photocrosslinking between scaffold layers can be performed simultaneously to create cell impregnated multilayered constructs. This cell-scaffold construct combines the advantages of PCL nanofibrous scaffolds and photocrosslinked gelatin hydrogels to mimic the structure, mechanical anisotropy, and cell phenotype of native tendon tissue. The scaffold

  1. Synthesis and crystal structure of trans-[Ni(pyzdcH)M 2 (H 2 O) 2 ...

    African Journals Online (AJOL)

    Synthesis and crystal structure of trans-[Ni(pyzdcH)M 2 (H 2 O) 2 ] based on pyrazine-2,3-dicarboxylic acid. ... Bulletin of the Chemical Society of Ethiopia ... The determined structure of the title compound C24H20Ni2N8O20 consists of the mononuclear trans-[Ni(pyzdc)2(H2O)2], (pyzdc = pyrazine-2,3- dicarboxylate).

  2. Synthesis of gold nanoparticles with different atomistic structural characteristics

    International Nuclear Information System (INIS)

    Esparza, R.; Rosas, G.; Lopez Fuentes, M.; Sanchez Ramirez, J.F.; Pal, U.; Ascencio, J.A.; Perez, R.

    2007-01-01

    A chemical reduction method was used to produce nanometric gold particles. Depending on the concentration of the main reactant compound different nanometric sizes and consequently different atomic structural configurations of the particles are obtained. Insights on the structural nature of the gold nanoparticles are obtained through a comparison between digitally-processed experimental high-resolution electron microscopy images and theoretically-simulated images obtained with a multislice approach of the dynamical theory of electron diffraction. Quantum molecular mechanical calculations, based on density functional theory, are carried out to explain the relationships between the stability of the gold nanoparticles, the atomic structural configurations and the size of nanoparticles

  3. 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.

  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. Tendon balancing in hallux valgus surgery.

    Science.gov (United States)

    Van Elst, C; Van Riet, A; Vandeputte, G

    2016-09-01

    Recurrent valgus of the hallux after hallux valgus surgery is an unpleasant complication. A possible cause is the imbalance and maltracking of particularly the extensor hallucis longus (EHL) and less frequently the flexor hallucis longus (FHL) or extensor hallucis brevis (EHB) tendon of the hallux. In patients with a tight achilles tendon, the EHL tendon can be recruited to aid dorsiflexion of the foot, creating imbalance. The literature on this subject is very scarce. In 10 patients with severe hallux valgus, a perioperative evaluation after performing the osteotomies and capsular closure showed tight extensor or flexor tendons of the hallux with residual valgus maltracking. A balancing of the tendons was performed with a -realignment -lengthening procedure. A good clinical result was obtained in all patients. No adverse effects were seen after tendon balancing. Strength in all tendons was at least 3+, except in one patient with multiple sclerosis. No weaknesses or -difficulties during walking were reported. Tendon balancing could play a role in prevention of hallux valgus recurrences and can be performed without loss of strength or compromising of walking ability.

  7. 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

  8. Synthesis, structure and Hirshfeld surface analysis, vibrational and ...

    Indian Academy of Sciences (India)

    dimensional architecture. Hirshfeld surface analysis for visually analysing intermolecular interactions in crystal structures employing molecular sur- face contours and 2D fingerprint plots has been used to scrutinize molecular shapes. The vibration ...

  9. Synthesis and molecular structure of manganese complexes with ...

    Indian Academy of Sciences (India)

    Administrator

    Manganese-dioxygen complexes are assumed to play significant roles in physiologically important enzymatic reactions including superoxide dismutation, decomposition of hydrogen peroxide and dioxygen evolution from water catalysed by manganese containing proteins 1. Accordingly, the characterization of structurally ...

  10. "Chameleon" Macromolecules: Synthesis, Structures and Applications of Stimulus Responsive Polymers

    NARCIS (Netherlands)

    Sui, Xiaofeng

    2012-01-01

    This thesis describes the preparation and characterization of addressable responsive polymer structures and their versatile applications. Stimuli responsive polymer chains including temperature responsive poly(N-isopropylacrylamide), PNIPAM, pH responsive poly(methacrylic acid), PMAA and redox

  11. Carbothermal synthesis of ZnO nanocomb structure

    International Nuclear Information System (INIS)

    Lim, Y.S.; Park, J.W.; Hong, S.-T.; Kim, J.

    2006-01-01

    A study on the formation and characterization of ZnO nanocomb structure is presented. ZnO nanocomb was synthesized by the carbothermal reduction process with carbon black powder as a carbon source. As well as nanocomb, ZnO tetrapod and flower-like structures were also obtained in this experiment. When conventional graphite was used for a comparative study, no ZnO nanostructure could be achieved at the same experimental condition. The result shows that carbon source with large surface area more efficiently provides Zn (g) by the enhanced solid-solid reaction between C (s) and ZnO (s) source materials. The resulting ZnO structures were characterized with an X-ray diffractometer (XRD), a scanning electron microscopy (SEM), and a transmission electron microscopy (TEM), and the formation mechanism of nanocomb structure was discussed

  12. Synthesis, characterization, x-ray structure and antimicrobial activity ...

    African Journals Online (AJOL)

    Purpose: To synthesize thiosemicarbazide and determine its antimicrobial properties. Methods: Pyridine-based thiosemicarbazide was synthesized, characterized and evaluated for antimicrobial activity. The structure of the synthesized compound was established by spectral analysis, namely, Fourier transform infrared ...

  13. Synthesis, crystal structures and luminescence properties of two metal carboxyphosphonates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chaonan; Feng, Pingjing; Li, Jintang, E-mail: leejt@xmu.edu.cn; Luo, Xuetao

    2017-05-15

    Two metal carboxyphosphonates, [Co{sub 2}(OOCC{sub 5}H{sub 3}NPO{sub 3}){sub 2·}(H{sub 2}O){sub 3}] (Compound1) and Zn{sub 3}[OOCC{sub 6}H{sub 3}CH(OH)PO{sub 3}]{sub 2·}2H{sub 2}O (Compound2) were successfully synthesized under the hydrothermal reactions. In compound 1, two (Co1-NO{sub 5}) octahedra link the (CPO{sub 3}) by sharing the corner, which link the two (Co2-O{sub 6}) octahedra. From a-axis the six clusters form the layer. Each layer is linked through hydrogen bond. In compound 2, the (Zn-O{sub 4}) tetrahedron and (CPO{sub 3}) tetrahedron are corner-shared, which arrange in line. From a-axis, each line forms the columnar. The thermal and luminescence properties of these compounds were investigated. - Graphical abstract: The synthesis conditions of the two compounds and the crystal morphology. Compound 1 shows the layer and the compound 2 shows the pillared-layer. - Highlights: • Two new carboxyphosphonate ligands have been prepared. • Using the two ligands, two metal carboxyphosphonates have been synthesized. • The two MOFs may be candidates for fluorescent materials.

  14. Hand tendon involvement in rheumatoid arthritis: an ultrasound study.

    Science.gov (United States)

    Filippucci, Emilio; Gabba, Alessandra; Di Geso, Luca; Girolimetti, Rita; Salaffi, Fausto; Grassi, Walter

    2012-06-01

    To assess the prevalence and the distribution of tendon involvement in the hands and wrists of patients with rheumatoid arthritis (RA) describing in detail the ultrasound (US) morphostructural and vascular tendon abnormalities. Ninety consecutive RA patients were included in the study. The following tendons were scanned bilaterally: flexor pollicis longus tendon, flexor digitorum superficialis, and profundus tendons of the II to the V fingers (at both finger and carpal tunnel levels), flexor carpi radialis tendon, and extensor tendons of the 6 compartments on the dorsal aspect of the wrist. The presence of US findings indicative of tenosynovitis and tendon damage was investigated. Tenosynovitis was found in at least 1 anatomic site of 44 (48.8%) of 90 patients. Tendon damage was found in at least 1 anatomic site of 39 (43.3%) of 90 patients. The focal tendon echotexture derangement was found in 294 of 5400 (5.4%) tendons, the partial and complete tears in 14 (0.3%), and in 3 (0.06%) tendons, respectively. The most frequently involved tendons were the flexor tendons of the II, III, and IV fingers and the extensor carpi ulnaris tendon. The present study provides evidence in favor of the ability of US to reveal a relatively high frequency of tendon involvement at the hand and wrist level in RA patients. These data can both facilitate US examinations in daily clinical practice and direct further investigations in the US assessment of tendon involvement in RA. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Therapeutic potential of mesenchymal stem cells to treat Achilles tendon injuries.

    Science.gov (United States)

    Vieira, M H C; Oliveira, R J; Eça, L P M; Pereira, I S O; Hermeto, L C; Matuo, R; Fernandes, W S; Silva, R A; Antoniolli, A C M B

    2014-12-12

    Rupture of the Achilles tendon diminishes quality of life. The gold-standard therapy is a surgical suture, but this presents complications, including wound formation and inflammation. These complications spurred evaluation of the therapeutic potential of mesenchymal stem cells (MSCs) from adipose tissue. New Zealand rabbits were divided into 6 groups (three treatments with two time points each) evaluated at either 14 or 28 days after surgery: cross section of the Achilles tendon (CSAT); CSAT + Suture; and CSAT + MSC. A comparison between all groups at both time points showed a statistically significant increase in capillaries and in the structural organization of collagen in the healed tendon in the CSAT + Suture and CSAT + MSC groups at the 14-day assessment. Comparison between the two time points within the same group showed a statistically significant decrease in the inflammatory process and an increase in the structural organization of collagen in the CSAT and CSAT + MSC groups. A study of the genomic integrity of the cells suggested a linear correlation between an increase of injuries and culture time. Thus, MSC transplantation is a good alternative for treatment of Achilles tendon ruptures because it may be conducted without surgery and tendon suture and, therefore, has no risk of adverse effects resulting from the surgical wound or inflammation caused by nonabsorbable sutures. Furthermore, this alternative treatment exhibits a better capacity for wound healing and maintaining the original tendon architecture, depending on the arrangement of the collagen fibers, and has important therapeutic potential.

  16. Effects of plyometric and isometric training on muscle and tendon stiffness in vivo.

    Science.gov (United States)

    Kubo, Keitaro; Ishigaki, Tomonobu; Ikebukuro, Toshihiro

    2017-08-01

    The purpose of this study was to compare the effects of plyometric and isometric training on tendon properties during ramp and ballistic contractions and muscle stiffness under passive and active conditions. Eleven subjects completed 12 weeks (3 days/week) of a unilateral training program for the plantar flexors. They performed plyometric training on one side (PLY) and isometric training on the other side (ISO). Active muscle stiffness in the medial gastrocnemius muscle was calculated according to changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions. Passive muscle stiffness was also calculated from estimated passive muscle force and fascicle length during slow passive stretching. Stiffness and hysteresis of tendon structures were measured using ultrasonography during ramp and ballistic contractions. Passive muscle stiffness and tendon hysteresis did not change for PLY or ISO Active muscle stiffness significantly increased for PLY, but not for ISO Tendon stiffness during ramp and ballistic contractions increased significantly for ISO, but not for PLY In addition, tendon elongation values at force production levels beyond 100 N during ballistic contractions increased for PLY These results suggest that plyometric training (but not isometric training) enhances the extensibility of tendon structures during ballistic contractions and active muscle stiffness during fast stretching, and these changes may be related to improved performances during stretch-shortening cycle exercises. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  17. Effects of flunixin meglumine on experimental tendon wound healing: A histopathological and mechanical study in rabbits

    Directory of Open Access Journals (Sweden)

    Mehdi Behfar

    2014-12-01

    Full Text Available Tendons are frequently targets of injury in sports and work. Whether nonsteroidal anti-inflammatory drugs (NSAIDs have beneficial effects on tendon healing is still a matter of debate. This study was conducted to evaluate effects of flunixin meglumine (FM on tendon healing after experimentally induced acute trauma. Twenty eight adult male New Zealand White rabbits were subjected to complete transection of deep digital flexor tendons followed by suture placement. Treatment group received intramuscular injection of FM for three days, and controls received placebo. Subsequently, cast immobilization was continued for two weeks. Animals were sacrificed four weeks after surgery and tissue samples were taken. The histological evaluations revealed improved structural characteristics of neotendon formation including fibrillar linearity, fibrillar continuity and neovascularization in treatment group compared to those of controls (p 0.05. Mechanical evaluation revealed significant increase in load-related material properties including ultimate load, yield load, energy absorption and ultimate stress in treatment group compared to those of control group (p 0.05. The present study showed that intramuscular injection of FM resulted in improved structural and mechanical properties of tendon repairs and it could be an effective treatment for acute tendon injuries like severance and laceration.

  18. 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

  19. 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

  20. Achillodynia. Radiological imaging of acute and chronic overuse injuries of the Achilles tendon; Achillodynie. Radiologische Bildgebung bei akuten und chronischen Ueberlastungsschaeden der Achillessehne

    Energy Technology Data Exchange (ETDEWEB)

    Syha, R.; Springer, F.; Grosse, U. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology; Tuebingen Univ. (Germany). Section on Experimental Radiology; Ketelsen, D.; Kramer, U.; Horger, M. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology; Ipach, I. [University Hospital Tuebingen (Germany). Orthopaedic Surgery; Schick, F. [Tuebingen Univ. (Germany). Section on Experimental Radiology

    2013-11-15

    In the past decades the incidence of acute and chronic disorders of the Achilles tendon associated with sport-induced overuse has steadily increased. Besides acute complete or partial ruptures, achillodynia (Achilles tendon pain syndrome), which is often associated with tendon degeneration, represents the most challenging entity regarding clinical diagnostics and therapy. Therefore, the use of imaging techniques to differentiate tendon disorders and even characterize structure alterations is of growing interest. This review article discusses the potential of different imaging techniques with respect to the diagnosis of acute and chronic tendon disorders. In this context, the most commonly used imaging techniques are magnetic resonance imaging (MRI), B-mode ultrasound, and color-coded Doppler ultrasound (US). These modalities allow the detection of acute tendon ruptures and advanced chronic tendon disorders. However, the main disadvantages are still the low capabilities in the detection of early-stage degeneration and difficulties in the assessment of treatment responses during follow-up examinations. Furthermore, differentiation between chronic partial ruptures and degeneration remains challenging. The automatic contour detection and texture analysis may allow a more objective and quantitative interpretation, which might be helpful in the monitoring of tendon diseases during follow-up examinations. Other techniques to quantify tendon-specific MR properties, e.g. based on ultrashort echo time (UTE) sequences, also seem to have great potential with respect to the precise detection of degenerative tendon disorders and their differentiation at a very early stage. (orig.)

  1. In vivo microdialysis and immunohistochemical analyses of tendon tissue demonstrated high amounts of free glutamate and glutamate NMDAR1 receptors, but no signs of inflammation, in Jumper's knee.

    Science.gov (United States)

    Alfredson, H; Forsgren, S; Thorsen, K; Lorentzon, R

    2001-09-01

    This investigation describes, to our knowledge, the first experiment where the microdialysis technique was used to study certain metabolic events in human patellar tendons in combination with immunohistochemical analyses of tendon biopsies. In five patients (four men and one woman) with a long duration (range 12-36 months) of pain symptoms from Jumper's knee (localized tenderness in the patellar tendon verified as tendon changes with ultrasonography or MRI), and in five controls (four men and one woman) with normal patellar tendons, a standard microdialysis catheter was inserted into the patellar tendon under local anestesia. The local concentrations of glutamate (excitatory neurotransmitter) and prostaglandin E2 (PGE2) were registered under resting conditions. Samplings were done every 15 min during a 2 h period. In all individuals (patients and controls) biopsies were taken for immunohistochemical analyses. The results showed that it was possible to detect and measure the concentrations of glutamate and PGE2 in the patellar tendon with the use of microdialysis technique. There were significantly higher concentrations of free glutamate, but not PGE2, in tendons with tendinosis compared to normal tendons. In the biopsies, there were no inflammatory cell infiltrates, but, for the first time, it was shown that there was immunoreaction for the glutamate receptor NMDAR1 in association with nerve structures in human patellar tendons. These findings altogether indicate that glutamate might be involved in painful Jumper's knee, and further emphasizes that there is no chemical inflammation (normal PGE2 levels) in this chronic condition.

  2. Structural diversity and chemical synthesis of peroxide and peroxide-derived polyketide metabolites from marine sponges.

    Science.gov (United States)

    Norris, Matthew D; Perkins, Michael V

    2016-07-28

    Covering: up to early 2016Marine sponges are widely known as a rich source of natural products, especially of polyketide origin, with a wealth of chemical diversity. Within this vast collection, peroxide and peroxide-derived secondary metabolites have attracted significant interest in the fields of natural product isolation and chemical synthesis for their structural distinction and promising in vitro antimicrobial and anticancer properties. In this review, peroxide and peroxide-derived polyketide metabolites isolated from marine sponges in the past 35 years are summarised. Efforts toward their synthesis are detailed with a focus on methods that utilise or attempt to elucidate the complex biosynthetic interrelationships of these compounds beyond enzymatic polyketide synthesis. Recent isolations, advances in synthetic methodology and theories of biogenesis are highlighted and critically evaluated.

  3. Analysis study on change of tendon behavior during pressurization process of Pre-stressed Concrete Containment Vessel

    International Nuclear Information System (INIS)

    Kashiwase, Takako; Nagasaka, Hideo

    1999-01-01

    NUPEC has been planning the ultimate strength test of Pre-stressed Concrete Containment Vessel (PCCV). The test model is 1/4 uniform scale model of Japan actual PCCV. It involves an equipment hatch, several penetrations and liner with T-anchors. The ancillary test for the PCCV test was conducted, in which friction coefficient of hoop tendon was evaluated by tensile force distribution using the same tendon as that of 1/4 PCCV model. Tendon will be in plastic region under internal pressure above 3.5 times design pressure (Pd) and surface characteristic of tendon and the resultant friction coefficient will be changed. In the present paper, tendon friction coefficient in the plastic region was obtained by evaluating plastic region data of tendon in the ancillary test. The validity of the obtained friction coefficient was confirmed by the tendon elongation data. In addition to the formally developed elastic region friction coefficient, the obtained plastic region correlation was incorporated into ABAQUS Ver. 5.6. The effect of tendon tensile force distribution change on structural behavior up to 3.8 Pd was evaluated. (author)

  4. 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

  5. Synthesis, crystal structure and biological activity of novel diester cyclophanes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengfei; Yang, Bingqin; Fang, Xianwen; Cheng, Zhao; Yang, Meipan, E-mail: yangbq@nwu.edu.cn [Department of Chemistry, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Northwest University, Shaanxi (China)

    2012-10-15

    A series of novel diester cyclophanes was synthesized by esterification of 1,2-benzenedicarbonyl chloride with eight different diols under high dilution conditions. The structures of the compounds were verified by elemental analysis, {sup 1}H nuclear magnetic resonance (NMR), IR spectroscopy and high resolution mass spectrometry (HRMS). The crystal structures of two compounds were characterized by single crystal X-ray diffractometry (XRD). All the new cyclophanes were evaluated for biological activities and the results showed that some of these compounds have low antibacterial or antifungal activities (author)

  6. Synthesis, structure and electrical properties of the thallium ruthenate pyrochlores

    International Nuclear Information System (INIS)

    Kanno, Ryoji; Haung, Jinfan; Sleight, A.W.

    1993-01-01

    The thallium ruthenate pyrochlores, Tl 2 Ru 2 O 7-δ , were synthesized and their structures were determined by neutron diffraction measurements. The low-temperature (LT) and high-temperature (HT) phases were obtained at reaction temperatures of 500 and 900degC, respectively. Neutron diffraction measurements indicated the compositions of Tl 2 Ru 2 O 7 and Tl 2 Ru 2 O 6.71 for the HT phase and the LT phase, respectively. Electrical resistivity measurements showed metallic property for the HT phase and semiconducting property for the LT phase. The relationship between the electrical properties and the structural changes is discussed. (author)

  7. An approach to analyzing synthesis, structure and properties of bismuth titanate ceramics

    Directory of Open Access Journals (Sweden)

    Lazarević Z.

    2005-01-01

    Full Text Available The family of bismuth titanate, Bi4Ti3O12 (BIT layered-structured ferroelectrics materials is attractive from the viewpoint of their application as electronic materials such as dielectrics, piezoelectrics and pyroelectrics, because they are characterized by good stability of piezoelectric properties, a high Curie temperature and a good resistance vs temperature. Bismuth titanate (Bi4Ti3O12 powders can be prepared using different methods, depending if the creation will be film coating or ceramics. The structure and properties of bismuth titanate materials show a significance dependence on the applied synthesis method. In this review paper, we made an attempt to give an approach to analyzing the structure, synthesis methods and properties of bismuth titanate ferroelectrics materials. .

  8. Structural higher education reform - design and evaluation: synthesis report

    NARCIS (Netherlands)

    File, Jonathan M.; Huisman, Jeroen; de Boer, Harry F.; Seeber, Marco; Vukasovic, Martina; Westerheijden, Donald F.

    2016-01-01

    This study analyses how different types of system-level (or ‘landscape’) structural reforms in higher education have been designed and implemented in selected higher education systems. In the 12 case studies that form the core of the project, the researchers examine reforms aimed at: - Increasing

  9. Efficient synthesis and molecular structure of 2-hydroxyisophthaldehyde

    NARCIS (Netherlands)

    Zondervan, C; van den Beuken, E.K; Kooijman, H.; Spek, A.L.; Feringa, B.L.

    1997-01-01

    A new highly effective procedure has been developed for the preparation of 2-hydroxyisophthaldehyde from 2,6-dimethylphenol. The X-ray crystal structure shows infinite chains of molecules joined by hydrogen bonds. (C) 1997 Published by Elsevier Science Ltd.

  10. Synthesis of PbTe nanocubes, worm-like structures

    Indian Academy of Sciences (India)

    ... the optical bandgap energies of 1.61, 1.23 and 1.01 eV, respectively. Photoconductivity measurement shows that the prepared nanocrystalline PbTe thin films of different morphology exhibits good response. This structure induced change in optical properties may have potential applications in optoelectronics devices.

  11. short communication synthesis and crystal structure of a polymeric

    African Journals Online (AJOL)

    Preferred Customer

    Cg1 is the centroid of C1-C2-C3-C4-C5-C6. IR spectra of the complex. The infrared spectrum of the complex was consistent with the structure as determined by X-ray diffraction. Features corresponding to benzene ring puckering exist in the region between 820 and 600 cm-1. Asymmetric and symmetric C–O stretching.

  12. Synthesis and structural characterization of CsNiP crystal

    Indian Academy of Sciences (India)

    Unknown

    Fluck and Issleib 1965). However, studies of these alka- line metal phosphides gained momentum since last three decades (Johnson and Jeitschlo 1972; Barz et al 1983;. Muller et al 1983; Schnering et al 1999). In recent years, structural data of phosphides also were reported (Shan- non 1976; Jeitschlo and Braun 1977; ...

  13. Synthesis, crystal structure determination of two-dimensional ...

    Indian Academy of Sciences (India)

    The structure consists of 4-c uninodal net where Point symbol for Ag (I) ion and net is (44.62) with sql type topology. X-ray diffraction analysis and Hirshfeld surface analysis give rise to comparable results but in Hirshfeld surface analysis, twothird times more close contacts are obtained. The fingerprint plots demonstrate that ...

  14. Pyrene appended bile acid conjugates: Synthesis and a structure ...

    Indian Academy of Sciences (India)

    us to connect the existing gelator motifs into hybrid structures and study their gelation properties in solu- tion. We envisioned that by adding a pyrene moiety ...... seen with the simplest pyrene molecule 1-pyrene car- boxylic acid (19) or its mixture with 1-aminopyrene. (20) (prepared by heating the 1:1 mixture of the amine.

  15. Synthesis and Structure of Environmentally Relevant Perfluorinated Sulfonamides

    OpenAIRE

    Lehmler, Hans-Joachim; Rama Rao, V.V.V.N.S.; Nauduri, Dhananjaya; Vargo, John D.; Parkin, Sean

    2007-01-01

    Alkylated perfluorooctanesulfonamides are compounds of environmental concern. To make these compounds available for environmental and toxicological studies, a series of N-alkylated perfluorooctanesulfonamides and structurally related compounds were synthesized by reaction of the corresponding perfluoroalkanesulfonyl fluoride with a suitable primary or secondary amine. Perfluoroalkanesulfonamidoethanols were obtained from the N-alkyl perfluoroalkanesulfonamides either by direct alkylation with...

  16. Synthesis, structure, thermal, transport and magnetic properties of VN ceramics

    Czech Academy of Sciences Publication Activity Database

    Huber, Š.; Jankovský, O.; Sedmidubský, D.; Luxa, J.; Klimová, K.; Hejtmánek, Jiří; Sofer, Z.

    2016-01-01

    Roč. 42, č. 16 (2016), s. 18779-18784 ISSN 0272-8842 R&D Projects: GA ČR GA13-20507S Institutional support: RVO:68378271 Keywords : vanadium mononitride * phase transition * electronic structure * heat capacity * transport properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.986, year: 2016

  17. Synthesis, Crystal structure and Characterization of a New Oxalate ...

    Indian Academy of Sciences (India)

    O, N–H...O hydrogen bonds which connect ionic entities and water molecules and also by π–π stack- ing interactions between the rings of 3,5-dimethylpyrazole cations. Hence, both coordinated and uncoordinated water molecules play an important role in the hydrogen-bonding system and stabilize the structure. Keywords.

  18. Synthesis, characterization and crystal structure of new nickel ...

    Indian Academy of Sciences (India)

    ductive, luminescent, magnetic, porous, chiral or nonlinear optical materials. The most useful strategy to construct such materials is to employ appropriate bridging ..... C and 8 h were nanoparticles with size of 35–45 nm and confirmed by TEM. Further increase in thermal decomposition time led to nanosheet-like structures.

  19. Synthesis, characterization and crystal structure of new nickel ...

    Indian Academy of Sciences (India)

    Abstract. A novel nickel molybdenum complex with the 2,6-pyridine dicarboxylic acid ligand was successfully synthesized and characterized by thermogravimetric analysis and single crystal X-ray crystallography. The single-crystal X-ray data revealed that the structure is a hydrated 1-D polymer with two different Ni sites.

  20. Solid state synthesis and structural refinement of polycrystalline ...

    Indian Academy of Sciences (India)

    Unknown

    Step analysis data has been used to determine the structure of solid solution of lanthanum substituted calcium titanate. The SEM and EDAX analyses also confirm that the. CaTiO3 can act as a host for lanthanum. X-ray data has been interpreted using CRYSFIRE and POWDERCELL softwares. The h, k, l values for different ...

  1. Synthesis and structural characterization of a calcium coordination ...

    Indian Academy of Sciences (India)

    pounds showed a Ca:water ratio of 1:3 or less. A recent study based on the analysis of the crystal structures of 131 Ca-carboxylates has shown that the coordina- tion number of calcium ranges from three to ten, with octacoordination being the most favoured.5 Due to the larger ionic radius of 106 pm for Ca2+, the carboxy-.

  2. Synthesis, characterization, X-ray structure, optical properties and ...

    Indian Academy of Sciences (India)

    ESMA LAMERA

    Also, the values of dipole moment μ, the average polarizability ¯α, and the first static hyperpolarizability (β0) were computed. The theoretical and experimental results confirm the NLO behavior of both compounds. Keywords. Condensed phthalazine; DFT calculations; spectroscopic analysis; X-ray structure; NLO. 1.

  3. Synthesis, structure and thermoelectric properties of La1 ...

    Indian Academy of Sciences (India)

    2017-12-07

    Dec 7, 2017 ... All the heat treatments were limited to below 1123 K, in order to retain the. Na stoichiometry. Structural ... Nitrate–citrate gel combustion method; perovskite; monovalent ions doping; semiconductor; thermoelectric. 1. Introduction ... electricity by Terasaki et al [3] on NaCo2O4 single crystal in. 1997, there has ...

  4. Structural evolution of ZTA composites during synthesis and processing

    Czech Academy of Sciences Publication Activity Database

    Exare, C.; Kiat, J. M.; Guiblin, N.; Porcher, F.; Petříček, Václav

    2015-01-01

    Roč. 35, č. 4 (2015), s. 1273-1283 ISSN 0955-2219 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : ceramic s * alumina–zirconia composites * structural properties * strain effect * size effect Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.933, year: 2015

  5. Synthesis and Spectroscopic, Thermal and Crystal Structure Studies ...

    African Journals Online (AJOL)

    NICO

    The salt undergoes melting followed by decomposition to give gaseous products. KEYWORDS. Hydrazine, succinic acid, hydrazinium hydrogensuccinate, crystal structure, thermal studies. 1. Introduction. Dibasic acids are known to form N2H5HA, (N2H5)2A and. N2H5HA.H2A type salts (H2A = dibasic acid) with hydrazine.

  6. Nidovirus replication structures : hijacking membranes to support viral RNA synthesis

    NARCIS (Netherlands)

    Knoops, Kèvin

    2011-01-01

    Positive-stranded RNA viruses replicate in the cytoplasm of host cells and their replication complexes are associated with modified cell membranes. We investigated the structure of the nidovirus-induced membrane modifications and found that nidoviruses transform the endoplasmic reticulum into a

  7. Synthesis, crystal structure and characterization of new biologically ...

    Indian Academy of Sciences (India)

    Sulfonamide; Cu(II) complexes; crystal structure; oxidative DNA cleavage; cytotoxic activity. 1. Introduction. The continuous demand for new ... between the base stacks of double-stranded DNA, thus showing cytotoxic effects on several ... proteins.11,12 The toxicity of Cu(II) complexes seems to be lower than classic cancer ...

  8. Synthesis, Characterization, Crystal Structure and Keto-enol Kinetics

    African Journals Online (AJOL)

    A crystal structure determination of Hbth (orthorhombic, Pbca, Z=8, R=0.0290) shows asymmetrical enolization on the side of the phenyl group. The preferred enol isomer of β-diketones containing more than one aromatic moiety that crystallizes in the solid state is determined by the resonance driving force stabilization of the ...

  9. Synthesis and structural study of platinum group metal complexes ...

    Indian Academy of Sciences (India)

    )Cl]2, [CpRu(PPh3)2Cl] and [Cp∗M(-Cl)Cl]2, respectively, in the presence of NH4PF6. They were characterized by the following techniques viz. IR, NMR, mass spectrometry and UV-visible spectroscopy. The molecular structures of [2] and [7] ...

  10. Synthesis and crystal structure of trinuclear potassium(I) complex ...

    African Journals Online (AJOL)

    A furazan-based trinuclear potassium(I) complex derived from the oxy-bridged bis(gem-dinitro)furazan (OBNF) and triaminoguanidinium (TGA) units was synthesized and characterized by elemental analyses, nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. The single crystal X-ray structure of the ...

  11. Potassium and magnesium succinatouranilates – Synthesis and crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, S.A., E-mail: serg.alex.novikov@gmail.com [Samara National Research University, 443086 Samara (Russian Federation); Grigoriev, M.S. [Frumkin Institute of Physical Chemistry and Electrochemistry RAS, 119071 Moscow (Russian Federation); Serezhkina, L.B.; Serezhkin, V.N. [Samara National Research University, 443086 Samara (Russian Federation)

    2017-04-15

    Single crystal X-ray diffraction has been applied to determine the structures of two new uranyl coordination polymers: K{sub 2}[(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}] (1) and [Mg(H{sub 2}O){sub 6}] [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]·2H{sub 2}O (2), where C{sub 4}H{sub 4}O{sub 4}{sup 2-} is succinate anion. Crystals of 1 and 2 contain polymeric complex anions [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]{sup 2-} with the same A{sub 2}Q{sup 02}{sub 3} crystallochemical formula (A=UO{sub 2}{sup 2+}, Q{sup 02}=C{sub 4}O{sub 4}H{sub 4}{sup 2-}), and have layered (1) or chain (2) structure. It has been found, that conformation of succinate ions is one of the factors, which affects the structure of [(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]{sup 2-} anions. IR spectra of these new compounds are in good agreement with crystallographic data. Topological analysis of the uranium dicarboxylates with A{sub 2}Q{sup 02}{sub 3} crystallochemical formula has shown the presence of five isomers which differ from each other in coordination sequences and / or dimensionality. - Graphical abstract: Crystal structures of two new uranium(VI) coordination polymers with succinate linkers, namely K{sub 2}[(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}] (1) and [Mg(H{sub 2}O){sub 6}][(UO{sub 2}){sub 2}(C{sub 4}H{sub 4}O{sub 4}){sub 3}]·2H{sub 2}O (2), were determined by single-crystal XRD. Crystals of studied compounds are based on 2D or 1D structural units with the same composition and crystallochemical formula. Topological isomerism in A{sub 2}Q{sup 02}{sub 3} crystallochemical group and conformations of succinate anions in uranyl complexes are under discussion. - Highlights: • Two new uranium coordination polymers were synthesized. • Their structural units have the same composition and crystallochemical formula. • In spite the same composition and CCF dimensionality of units is different. • Structural features of uranyl CPs

  12. Synthesis and structure of cage-like mesoporous silica using different precursors

    International Nuclear Information System (INIS)

    Fantini, M.C.A.; Kanagussuko, C.F.; Zilioti, G.J.M.; Martins, T.S.

    2011-01-01

    Research highlights: → FDU-1 mesoporous silica was made with TEOS, Na 2 Si 3 O 7 and a new template Vorasurf 504. → The synthesis temperature of 15 deg. C improved the ordered porous structure. → HBr solution induced ordered pores, larger surface area and lattice parameter. - Abstract: In this work the synthesis of cubic, FDU-1 type, ordered mesoporous silica (OMS) was developed from two types of silicon source, tetraethyl orthosilicate (TEOS) and a less expensive compound, sodium silicate (Na 2 Si 3 O 7 ), in the presence of a new triblock copolymer template Vorasurf 504 (EO 38 BO 46 EO 38 ). For both silicon precursors the synthesis temperature was evaluated. For TEOS the effect of polymer dissolution in methanol and the acid solution (HCl and HBr) on the material structure was analyzed. For Na 2 Si 3 O 7 the influence of the polymer mass and the hydrothermal treatment time were the explored experimental parameters. The samples were examined by Small Angle X-ray Scattering (SAXS) and Nitrogen Sorption. For both precursors the decrease on the synthesis temperature from ambient, -25 deg. C, to -15 deg. C improved the ordered porous structure. For TEOS, the SAXS results showed that there is an optimum amount of hydrophobic methanol that contributed to dissolve the polymer but did not provoke structural disorder. The less electronegative Br - ions, when compared to Cl - , induced a more ordered porous structure, higher surface areas and larger lattice parameters. For Na 2 Si 3 O 7 the increase on the hydrothermal treatment time as well as the use of an optimized amount of polymer promoted a better ordered porous structure.

  13. 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.

  14. 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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

    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

  16. 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.

  17. 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.

  18. [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.

  19. 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....

  20. Osmotic pressure induced tensile forces in tendon collagen

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J.; Fratzl, Peter

    2015-01-01

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  1. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  2. Synthesis, Structure, and Fluorescence of a Novel Cadmium Compound

    Science.gov (United States)

    Yao, Zhong-Liang; Chen, Wen-Tong

    2017-12-01

    A novel cadmium compound, [(CdI3)2(μ2-I)]2(Me2-4,4'-H2bipy)3 (1) (Me = methyl; 4,4'-bipy = 4,4'-bipyridine) with the Me2-4,4'-H2bipy moiety generated in situ, has been prepared through a solvothermal reaction and structurally characterized by X-ray single crystal diffraction analysis. Compound 1 is characterized by an isolated structural motif, consisting of [(CdI3)2(μ2-I)]3- anions and Me2-4,4'-H2bipy2+ cations. The [(CdI3)2(μ2-I)]3- anions and Me2-4,4'-H2bipy2+ cations interconnect together via C-H···I hydrogen-bonding interactions to complete a three-dimensional (3D) supramolecular network. Solid state fluorescent spectrum reveals an emission band in the violet region.

  3. Synthesis of -aryl--lactones and relationship: Structure ...

    Indian Academy of Sciences (India)

    The biological tests allowed to find some relationships between the structure and biological activity of the compounds studied. -Ethyl--lactones 7a–c, 8a–c and unsaturated lactones 9a–c, 10a-c were usually stronger antifeedants than their parent iodolactones 5a–c and 6a–c. trans-Iodolactones 6a–c were more active ...

  4. synthesis and crystal structure of trinuclear potassium(i)

    African Journals Online (AJOL)

    DCC = distance between ring centroids; α perpendicular distance of Cg(I) from ring J;. Cg ring O7N5C4C5N6, O16N11C8C9N12 and O1 thesis and crystal structure of trinuclear potassium(I) complex. Bull. Chem. Soc. Ethiop. 2017, 31(2) anions, and connects with five adjacent OBNF2– anions through seven n bonds ...

  5. Synthesis, characterization, x-ray structure and antimicrobial activity ...

    African Journals Online (AJOL)

    intermolecular N3—H1N1•••O1 hydrogen bonds. (Table 2), resulting in the formation of zigzag layers lying parallel to (100) (Fig. 2b). The existence of π•••π interactions involving the centroid of the N4/C9-C13 pyridine ring (π•••π distance = 3.5108(18) Å) further stabilize the molecular packing. The structure of compound 2.

  6. Synthesis, crystal structure and properties of magnesium and ...

    Indian Academy of Sciences (India)

    2015-04-01

    Apr 1, 2015 ... 2.3 X-ray crystal structure determination. Single crystal X-ray analysis of compounds 1 and 2 was done at the Sophisticated Analytical Instrument. Table 1. Crystal data and selected refinement results for (1) and (2). Empirical formula. C16H30MgO14 (1). C16H16CaO7 (2). Formula weight (g mol−1). 470.71.

  7. Synthesis and crystal structure of [chlorobis (triphenylphospino)(p ...

    Indian Academy of Sciences (India)

    The structure of complex 3 was confirmed by X-ray crystallography. It has been found to crystallize in the triclinic system with space group P-1 and unit cell parameters: a = 10.207(5) Å, b = 13.027(5) Å, c = 16.269(5) Å, = 100.054(5)°, = 99.228(5)° and = 97.234(5)°. This complex has distorted tetrahedral geometry with ...

  8. Synthesis, structural and optical properties of nanoparticles (Al, V ...

    Indian Academy of Sciences (India)

    and aluminium as co-doping element of ZnO nanopowder on structural and optoelectronic properties have been reported. 2. Experimental. 2.1 Sample preparation. Zn0.89Al0.01V0.1O nanocrystals were prepared by the sol–gel method using 16 g of zinc acetate dehydrate as precursor in a 112 ml of methanol. After 10 min ...

  9. Synthesis, structural and property studies of bismuth containing perovskites

    OpenAIRE

    Chen, Wei-tin

    2009-01-01

    Several bismuth-containing transition metal perovskites that are of interest as potential multiferroic materials have been synthesised and studied. These materials have been structurally characterised and their physical properties have been examined at varying temperatures and pressures. The new series of substituted bismuth ferrite perovskites BixCa1-xFeO3, where x = 0.4 - 1.0, has been prepared. A disordered cubic phase (x = 0.4 - 0.67) and the coexistence of rhombohedral ...

  10. Synthesis and crystal structure of [chlorobis(triphenylphospino) (p ...

    Indian Academy of Sciences (India)

    X-ray Structure of new copper(I)-thiosemicarbazone complex. 187. Table 1. Crystallographic data of complex 3. Empirical Formula. C44H38Cl2CuN3P2S. Formula Weight. 837.21. Temperature (K). 293(2). Wavelength (Å). 0.71073. Crystal system. Triclinic. Crystal size (mm). 0.3 x 0.2 x 0.2. Space group. P-1. Z, calculated. 2.

  11. Synthesis and crystal structure of a trihydrate of dinuclear ...

    African Journals Online (AJOL)

    A new compound, [Cd2(C7H6N2)3(C6H4O2N)4]·3H2O (1), has been prepared under mild hydrothermal conditions and structurally characterized by single crystal X-ray diffraction. The two cadmium(II) ions are bridged by a carboxyl group from one 2-pyridinecarboxylate ligand. The thermal gravimetry (TG) data indicate ...

  12. The synthesis and structural characterization of novel transition metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, W.J. Jr.

    1992-09-01

    High purity KMF[sub 6] and K[sub 2]MF[sub 6] salts (M = Mo,Re, Ru, Os, Ir, Pt) are obtained from reduction hexafluorides. A rhombohedral unit cell is observed for KReF[sub 6]. Fluoride ion capture by Lewis acids from the hexafluorometallate (IV) salts affords high purity tetrafluorides for M = Mo, Re, Ru, Os, and Pd. The structure of RuF[sub 4] is determined from X-ray synchrotron and neutron powder data. Unit cells based on theorthorhombic PdF[sub 4] type cell are derived from X-ray powder data for ReF[sub 4] and OsF[sub 4]. Fluoride ion capture from KAgF[sub 4] provides the thermally unstable trifluoride as a bright, red, diamagnetic solid. The structure solution of AgF[sub 3] and redetermination of the AuF[sub 3] structure from X-ray synchrotron and neutron powder data demonstrate that the two are isostnictural. Thermal decomposition product of AgF[sub 3] is the mixed valence compound Ag[sup II]Ag[sub 2][sup III]F[sub 8]. Several new salts containing the (Ag - F)[sub n][sup n+] chain cation are prepared. The first linear (Ag - F)[sub n][sup n+] chain is observed in AgF[sup +]BF[sub 4 [sup [minus

  13. Solid state synthesis and structural characterization of zinc titanates

    Energy Technology Data Exchange (ETDEWEB)

    Ayed, Sarra, E-mail: ayedsarra1@gmail.com [Laboratory of Composite Ceramic and Polymer Materials, Scientific Faculty of Sfax (Tunisia); Abdelkefi, Helmi; Khemakhem, Hamadi [Laboratory of Ferroelectric Materials, Scientific Faculty of Sfax (Tunisia); Matoussi, Adel [Laboratory of Composite Ceramic and Polymer Materials, Scientific Faculty of Sfax (Tunisia)

    2016-08-25

    Zinc titanate composite materials were synthesized via solid state sintering process using high-purity metal oxide powders (purity ∼99.99%). The titanium incorporation into ZnO matrix was investigated by X-ray diffraction which revealed the coexistence of spinel Zn{sub 2}TiO{sub 4} and hexagonal ZnTiO{sub 3} with the ZnO wurtzite structures. No reflection peaks of rutile TiO{sub 2} phase were detected. The IR spectroscopy and Raman scattering spectroscopy were used to characterize the structural and chemical properties of the ZnO/TiO{sub 2} composites. The IR bands and vibrational modes of all crystalline phases were detected. The effect of TiO{sub 2} doping rates (x = 3, 5 and 7 wt%) on bands shifting, Raman intensity and structural quality was discussed. - Highlights: • Zinc titanates materials were synthesized via solid state sintering process. • XRD measurements reveal the formation of Zn{sub 2}TiO{sub 4}, hexagonal ZnTiO{sub 3} and ZnO phases. • IR analysis provokes the presence of Ti−O stretching vibration bands. • Raman study provokes the appearance of new zinc titanates vibrational peaks. • The TiO{sub 2} effect into ZnO is sensed by the shift and intensity changes of peaks.

  14. Uranium complexes with macrosyclic polyethers. Synthesis and structural chemical analysis

    International Nuclear Information System (INIS)

    Elbasyouny, A.

    1983-01-01

    This dissertation reports about studies on the chemical coordination behaviour of uranium of oxidation stages IV and VI with regard to twelve different macrocyclic ligands. For the preparation of the complexes, for every system a different method has been developed. The elementary analysis of the various complexes including the uranium had been done by X-ray fluorescence analysis, and the structural characterization proceeded via vibrational, uv-vis and emission spectroscopy as well as 1 H-NMR and 13 C-spin-lattice relaxation time studies. Conformational analysis of the polyethers used allowed the structural changes in the complexes to be observed. The structural analysis of the hydrous uranium VI crown ether complexes yielded information of characteristic features of these types of complexes. The first coordination sphere of the uranyl ion with covalently bonded anion remains unchanged. As to the water content, there is a certain range. Depending upon the solvent used, the complexes have two or four H 2 O molecules per formula unit. (orig./EF) [de

  15. High-field MR imaging of the tendons

    International Nuclear Information System (INIS)

    Beltran, J.; Burk, J.M.; Herman, L.J.; Mosure, J.C.

    1987-01-01

    MR imaging was used to investigate normal anatomy and pathologic conditions of the tendons. Tendons of experimental animals, cadaver joints, normal volunteers, and patients with suspected tendon pathology were studied. Tendon anatomy is easily identified because of the hypointensity of the tendons contrasting with the hyperintendensity of the surrounding fat. Pathologic conditions including posttraumatic and postsurgical tendon rupture, peritendinous scarring, tendinitis, and tenosynovitis are well seen with MR imaging. A detailed study of normal and abnormal tendon anatomy of the finger, wrist, shoulder, knee, and ankle is displayed, including MR images, gross specimens, and line drawings

  16. The composite anterolateral thigh flap for achilles tendon and soft tissue defect reconstruction with tendon repair by fascia with double or triple folding technique.

    Science.gov (United States)

    Youn, Seung Ki; Kim, Sang Wha; Kim, Youn Hwan; Hwang, Kyu Tae

    2015-11-01

    Rupture of the Achilles tendon is usually managed by surgical intervention. Recurrent tendon ruptures, segmental tendon defects, and overlying soft tissue defects render reconstructive procedures challenging. In this report, we present double or triple folding technique of the anterolateral thigh (ALT) free flap, and report the clinical outcomes of the reconstruction of combined defects, including the Achilles tendon and overlying soft tissue. From 2008 to 2013, 7 patients underwent reconstruction of combined Achilles tendon and soft tissue defects. The sizes of the soft tissue defects ranged from 9 × 5 to 12 × 5 cm(2) . Combined defects were reconstructed with ALT free flap including the vastus lateralis fascia and rectus femoris fascia, using a double or triple folding technique. The ALT free flap covered the soft tissue defect and the fascia was folded two or three times into a tendon-like structure. Three patients had full-layer defects of the Achilles tendon, and four patients had partial defects over half the layer. The dimension of the skin paddle of the ALT flap was 12 × 6 to 16 × 8 cm(2), and the dimension of the fascia was 12 × 8 to 16 × 10 cm(2). All the donor sites were closed primarily. All the flaps survived completely without complication. The mean follow-up period was 14.9 months. All patients were able to stand and ambulate. The double or triple folding technique of the ALT free flap represents simple, economical use of tissue, with minimal donor site morbidity. Thus, this technique may be useful and versatile reconstructive option for combined defects. © 2015 Wiley Periodicals, Inc.

  17. [MR imaging of flexor tendon and pulley system of the fingers: normal anatomy and injury].

    Science.gov (United States)

    Bai, R J; Zhan, H L; Liu, Y; Zhang, H; Qian, Z H; Ye, W; Li, Y X

    2017-09-05

    Objective: To explore the magnetic resonance imaging (MRI) features of the anatomy and injuries of flexor tendon and pulley system of the fingers. Methods: Clinical and imaging data of 20 healthy volunteers without injuries and 36 patients from Beijing Jishuitan Hospital with flexor tendon and pulley system injuries in the fingers between March 2013 and March 2016 were retrospectively analyzed. All subjects underwent magnetic resonance imaging (MRI) examination. The MRI findings of patients were compared with healthy volunteers. In addition, imaging findings of patients were compared with the surgical results and confirmed by double-blinded method. Results: Twenty volunteers without flexor tendon and pulley system injures showed homogeneous hypointensity on both T1-weighted and Proton Density-weighted images with fat saturation (PD-FS). There were 36 patients with finger injures, including 21 cases of flexor tendon injury, 10 cases of pulley system injury, 5 cases of compound injury, which demonstrated unclear signal, discontinuity on T1-weighted images and heterogeneously increased signal intensity of the involved structures on PD-FS images. Edema was detected in the soft tissues surrounding the injured sites. Conclusions: MRI is an accurate method for evaluation of the anatomy and pathologic conditions of flexor tendon and pulley system of the fingers and a useful tool for diagnosis and treatment of flexor tendon and pulley system injuries.

  18. Shortened stapedius tendon: a rare cause of conductive hearing loss.

    Science.gov (United States)

    Zawawi, F; Varshney, R; Schloss, M D

    2014-01-01

    Anomalies of the stapedius tendon have been reported to cause conductive hearing loss; in theory, such anomalies limit the movement of the stapes. To demonstrate a rare cause of conductive hearing loss resulting from anomaly of the stapedius tendon and to compare the clinical findings of this patient to other stapedius tendon anomalies reported in the literature. Case report of a single case of shortened stapedius tendon and a review of the English literature on stapedius tendon anomalies. This is a case report of a 15-year-old boy with shortened stapedius tendon causing unilateral hearing loss, accompanied by a review of the literature. Contrary to other reported cases, this patient did not have an ossified tendon, but rather an extremely short tendon. The boy regained normal hearing following excision of the stapedius tendon. A shortened stapedius tendon is a very rare diagnosis, yet it should be considered as a possible cause of conductive hearing loss.

  19. Inhibiting NF-κB-inducing kinase (NIK): discovery, structure-based design, synthesis, structure-activity relationship, and co-crystal structures.

    Science.gov (United States)

    Li, Kexue; McGee, Lawrence R; Fisher, Ben; Sudom, Athena; Liu, Jinsong; Rubenstein, Steven M; Anwer, Mohmed K; Cushing, Timothy D; Shin, Youngsook; Ayres, Merrill; Lee, Fei; Eksterowicz, John; Faulder, Paul; Waszkowycz, Bohdan; Plotnikova, Olga; Farrelly, Ellyn; Xiao, Shou-Hua; Chen, Guoqing; Wang, Zhulun

    2013-03-01

    The discovery, structure-based design, synthesis, and optimization of NIK inhibitors are described. Our work began with an HTS hit, imidazopyridinyl pyrimidinamine 1. We utilized homology modeling and conformational analysis to optimize the indole scaffold leading to the discovery of novel and potent conformationally constrained inhibitors such as compounds 25 and 28. Compounds 25 and 31 were co-crystallized with NIK kinase domain to provide structural insights. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Synthesis, reactivity, and electronic structure of molecular uranium nitrides

    OpenAIRE

    Cleaves, Peter A.

    2016-01-01

    The study of metal-ligand multiple bonding offers insight into the electronic structure and bond of metal systems. Until recently, for uranium, such systems were limited to uranyl, and terminal chalcogenide, imide and carbene complexes. In 2012, this was extended to nitrides with the first preparation of a uranium–nitride (U≡N) species isolable under standard conditions, namely [U(TrenTIPS)(N)][Na(12C4)2] (52), which is prepared by the two-electron reduction of sodium azide with a trivalent u...

  1. Topology Synthesis of Structures Using Parameter Relaxation and Geometric Refinement

    Science.gov (United States)

    Hull, P. V.; Tinker, M. L.

    2007-01-01

    Typically, structural topology optimization problems undergo relaxation of certain design parameters to allow the existence of intermediate variable optimum topologies. Relaxation permits the use of a variety of gradient-based search techniques and has been shown to guarantee the existence of optimal solutions and eliminate mesh dependencies. This Technical Publication (TP) will demonstrate the application of relaxation to a control point discretization of the design workspace for the structural topology optimization process. The control point parameterization with subdivision has been offered as an alternative to the traditional method of discretized finite element design domain. The principle of relaxation demonstrates the increased utility of the control point parameterization. One of the significant results of the relaxation process offered in this TP is that direct manufacturability of the optimized design will be maintained without the need for designer intervention or translation. In addition, it will be shown that relaxation of certain parameters may extend the range of problems that can be addressed; e.g., in permitting limited out-of-plane motion to be included in a path generation problem.

  2. Synthesis and Crystal Structures of N-Substituted Pyrazolines

    Directory of Open Access Journals (Sweden)

    Balladka Kunhanna Sarojini

    2013-02-01

    Full Text Available Four pyrazole compounds, 3-(4-fluorophenyl-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (1, 5-(4-bromophenyl-3-(4-fluorophenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (2, 1-[5-(4-chlorophenyl-3-(4-fluorophenyl-4,5-dihydro-1H-pyrazol-1-yl]ethanone (3 and 1-[3-(4-fluorophenyl-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]propan-1-one (4, have been prepared by condensing chalcones with hydrazine hydrate in the presence of aliphatic acids, namely formic acid, acetic acid and propionic acid. The structures were characterized by X-ray single crystal structure determination. The dihedral angles formed between the pyrazole and the fluoro-substituted rings are 4.64(7° in 1, 5.3(4° in 2 and 4.89(6° in 3. In 4, the corresponding angles for molecules A and molecules B are 10.53(10° and 9.78(10°, respectively.

  3. Synthesis and structural characterization of actinide oxalate compounds

    International Nuclear Information System (INIS)

    Tamain, C.

    2011-01-01

    Oxalic acid is a well-known reagent to recover actinides thanks to the very low solubility of An(IV) and An(III) oxalate compounds in acidic solution. Therefore, considering mixed-oxide fuel or considering minor actinides incorporation in ceramic fuel materials for transmutation, oxalic co-conversion is convenient to synthesize mixed oxalate compounds, precursors of oxide solid solutions. As the existing oxalate single crystal syntheses are not adaptable to the actinide-oxalate chemistry or to their manipulation constrains in gloves box, several original crystal growth methods were developed. They were first validate and optimized on lanthanides and uranium before the application to transuranium elements. The advanced investigations allow to better understand the syntheses and to define optimized chemical conditions to promote crystal growth. These new crystal growth methods were then applied to a large number of mixed An1(IV)-An2(III) or An1(IV)-An2(IV) systems and lead to the formation of the first original mixed An1(IV)-An2(III) and An1(IV)-An2(IV) oxalate single crystals. Finally thanks to the first thorough structural characterizations of these compounds, single crystal X-ray diffraction, EXAFS or micro-RAMAN, the particularly weak oxalate-actinide compounds structural database is enriched, which is essential for future studied nuclear fuel cycles. (author) [fr

  4. (Biodegradable Ionomeric Polyurethanes Based on Xanthan: Synthesis, Properties, and Structure

    Directory of Open Access Journals (Sweden)

    T. V. Travinskaya

    2017-01-01

    Full Text Available New (biodegradable environmentally friendly film-forming ionomeric polyurethanes (IPU based on renewable biotechnological polysaccharide xanthan (Xa have been obtained. The influence of the component composition on the colloidal-chemical and physic-mechanical properties of IPU/Xa and based films, as well as the change of their properties under the influence of environmental factors, have been studied. The results of IR-, PMS-, DMA-, and X-ray scattering study indicate that incorporation of Xa into the polyurethane chain initiates the formation of a new polymer structure different from the structure of the pure IPU (matrix: an amorphous polymer-polymer microdomain has occurred as a result of the chemical interaction of Xa and IPU. It predetermines the degradation of the IPU/Xa films as a whole, unlike the mixed polymer systems, and plays a key role in the improvement of material performance. The results of acid, alkaline hydrolysis, and incubation into the soil indicate the increase of the intensity of degradation processes occurring in the IPU/Xa in comparison with the pure IPU. It has been shown that the introduction of Xa not only imparts the biodegradability property to polyurethane, but also improves the mechanical properties.

  5. 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

    Low cellular activity and slow tissue turnover in human tendon may prolong resolution of tendinopathy. This may be stimulated by moderate localized traumas such as needle penetrations, but whether this results in a widespread cellular response in tendons is unknown. In an initial hypothesis......-generating study, a trauma-induced tendon cell activity (increased total RNA and collagen I mRNA) was observed after repeated patellar tendon biopsies in young men. In a subsequent controlled study, 25 young men were treated with two 0.8 mm diameter needle penetrations (n=13, needle-group (NG)) or one 2.1 mm...... diameter needle biopsy (n=12, biopsy-group (BG)) in one patellar tendon. Four weeks later biopsies were taken from treated (5 mm lateral from trauma site) and contralateral tendons for analyses of RNA content (ribogreen assay), DNA content (PCR based), and gene expression for relevant target genes (Real...

  6. Mechanical properties of human patellar tendon at the hierarchical levels of tendon and fibril

    DEFF Research Database (Denmark)

    Svensson, René B; Hansen, Philip; Hassenkam, Tue

    2012-01-01

    's modulus was 2.0 ± 0.5 GPa, and the toe region reached 3.3 ± 1.9% strain in whole patellar tendons. Based on dry cross-sectional area, the Young's modulus of isolated collagen fibrils was 2.8 ± 0.3 GPa, and the toe region reached 0.86 ± 0.08% strain. The measured fibril modulus was insufficient to account...... distinct collagen fibrils would display similar mechanical properties. Human patellar tendons (n = 5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon, and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young...... for the modulus of the tendon in vivo when fibril content in the tendon was accounted for. Thus, our original hypothesis was not supported, although the in vitro fibril modulus corresponded well with reported in vitro tendon values. This correspondence together with the fibril modulus not being greater than...

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

    International Nuclear Information System (INIS)

    Maeseneer, Michel de; Shahabpour, Maryam; Isacker, Tom van; Lenchik, Leon; Caillie, Marie-Astrid van

    2014-01-01

    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.)

  8. 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.)

  9. Tendon variations of extensor digitorum and abductor pollicis longus muscles

    OpenAIRE

    Kocabiyik N; Tatar I; Yalcin B; Yazar F; Ozan H

    2009-01-01

    Tendon variations of extensor digitorum and abductor pollicis longus muscles were observed in a 65-year-old male formalin fixed cadaver, during the dissections for second year medical students at the Gulhane Military Medical Academy Anatomy Dissection Laboratory. In the right forearm, the extensor digitorum muscle had a tripled tendon for the 3rd finger and a doubled tendon for the ring finger. The extensor digiti minimi muscle also had a doubled tendon. There was also a communicating tendon ...

  10. Transosseous-Equivalent Repair for Distal Patellar Tendon Avulsion

    OpenAIRE

    Galos, David K.; Konda, Sanjit R.; Kaplan, Daniel J.; Ryan, William E.; Alaia, Michael J.

    2016-01-01

    Extensor mechanism disruptions are relatively uncommon injuries involving injury to the quadriceps tendon, patella, or patellar tendon. Patellar tendon avulsions from the tibial tubercle in adults are rare; as such, little technical information has been written regarding surgical management of this injury in the adult. Transosseous-equivalent repairs have been described in the management of several types of tendon ruptures, including rotator cuff and distal triceps tendon ruptures, but not pr...

  11. Simulating Cellulose Structure, Properties, Thermodynamics, Synthesis, and Deconstruction with Atomistic and Coarse-Grain Models

    Energy Technology Data Exchange (ETDEWEB)

    Crowley, M. F.; Matthews, J.; Beckham, G.; Bomble, Y.; Hynninen, A. P.; Ciesielski, P. F.

    2012-01-01

    Cellulose is still a mysterious polymer in many ways: structure of microfibrils, thermodynamics of synthesis and degradation, and interactions with other plant cell wall components. Our aim is to uncover the details and mechanisms of cellulose digestion and synthesis. We report the details of the structure of cellulose 1-beta under several temperature conditions and report here the results of these studies and connections to experimental measurements and the measurement in-silico the free energy of decrystallization of several morphologies of cellulose. In spatially large modeling, we show the most recent work of mapping atomistic and coarse-grain models into tomographic images of cellulose and extreme coarse-grain modeling of interactions of large cellulase complexes with microfibrils. We discuss the difficulties of modeling cellulose and suggest future work both experimental and theoretical to increase our understanding of cellulose and our ability to use it as a raw material for fuels and materials.

  12. Some structural aspects that are relevant for synthesis of planetary gear trains

    Energy Technology Data Exchange (ETDEWEB)

    Rajasri, I. [Pathfinder Engineering College, Hanamkonda (India); Gupta, A.V.S.S.K.S. [JNTU, Hyderabad (India); Rao, Y.V.D. [BITS-Pilani. Dept. of Mechanical Engineering, Hyderabad (India)

    2012-07-01

    Gear Trains are typically used in various mechanisms including wind turbines and robots to transmit specified motion and/or torque between two or more shafts and wind turbines need drives and overdrives that amplify the speed of turbine shaft and provide high speed at generator shaft. Planetary gear trains (PGT) are compact, easy to build and operate. Therefore PGTs are most suitable for such drives including over drives. Graph theory used in synthesis of the PGTs is also useful to identify various possible structural aspects of the PGTs. Generation of PGTs is followed by the test for isomorphism in PGTs generated. In this context various structural aspects relevant for the synthesis of PGTs is described. (Author)

  13. The synthesis and structural characterization of novel transition metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, Jr., William Jack [Univ. of California, Berkeley, CA (United States)

    1992-09-01

    High purity KMF6 and K2MF6 salts (M = Mo,Re, Ru, Os, Ir, Pt) are obtained from reduction hexafluorides. A rhombohedral unit cell is observed for KReF6. Fluoride ion capture by Lewis acids from the hexafluorometallate (IV) salts affords high purity tetrafluorides for M = Mo, Re, Ru, Os, and Pd. The structure of RuF4 is determined from X-ray synchrotron and neutron powder data. Unit cells based on theorthorhombic PdF4 type cell are derived from X-ray powder data for ReF4 and OsF4. Fluoride ion capture from KAgF4 provides the thermally unstable trifluoride as a bright, red, diamagnetic solid. The structure solution of AgF3 and redetermination of the AuF3 structure from X-ray synchrotron and neutron powder data demonstrate that the two are isostnictural. Thermal decomposition product of AgF3 is the mixed valence compound AgIIAg2IIIF8. Several new salts containing the (Ag - F)$n+\\atop{n}$ chain cation are prepared. The first linear (Ag - F)$n+\\atop{n}$ chain is observed in AgF+BF4- which crystallizes in a tetragonal unit. AgFAuF4 has a triclinic unit cell and is isostructural with CuFAuF4. AgFAuF6 has an orthorhombic unit cell and appears to be isostructural with AgFAsF6. A second mixed valence silver fluoride, AgIIAgIIIF5, is prepared, which magnetic measurements indicate is probably an AgF+ salt. Magnetic data for all of the AgF+ salts exhibit low magnitude, temperature independent paramagnetism characteristic of metallic systems. Cationic AG(II) in acidic AHF solutions is a powerful oxidizer, capable of oxidizing Xe to Xe(II) and O2 to O2+. Reactions with C6F6 and C3F6 suggest an electron capture

  14. Synthesis and applications of novel silver nanoparticle structures

    Science.gov (United States)

    Dukes, Kyle

    The field of nanotechnology is rapidly expanding across disciplines as each new development is realized. New exciting technologies are being driven by advances in the application of nanotechnology; including biochemical, optical, and semiconductors research. This thesis will focus on the use of silver nanoparticles as optical labels on cells, methods of forming different small structures of silver nanoparticles, as well as the use of silver nanoparticles in the development of a photovoltaic cell. Silver nanoparticles have been modified with self-assembled monolayers of hydroxyl-terminated long chain thiols and encapsulated with a silica shell. The resulting core-shell nanoparticles were used as optical labels for cell analysis using flow cytometry and microscopy. The excitation of plasmon resonances in nanoparticles results in strong depolarized scattering of visible light permitting detection at the single nanoparticle level. The nanoparticles were modified with neutravidin via epoxide-azide coupling chemistry and biotinylated antibodies targeting cell surface receptors were bound to the nanoparticle surface. The nanoparticle labels exhibited long-term stability under physiological conditions without aggregation or silver ion leaching. Labeled cells exhibited two orders of magnitude enhancement of the scattering intensity compared to unlabeled cells. Dimers of silver nanoparticles have been fabricated by first immobilizing a monolayer of single silver nanoparticles onto poly(4-vinylpyridine) covered glass slides. The monolayer was then exposed to adenine, which has two amines which will bind to silver. The nanoparticle monolayer, now modified with adenine, is exposed to a second suspension of nanoparticles which will bind with the amine modified monolayer. Finally, a thin silica shell is formed about the structure via solgel chemistry to prevent dissolution or aggregation upon sonication/striping. Circular arrays of silver nanoparticels are developed using a

  15. Finite Element Analysis of Grouting Compactness Monitoring in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers.

    Science.gov (United States)

    Jiang, Tianyong; Zheng, Junbo; Huo, Linsheng; Song, Gangbing

    2017-09-29

    With the development of the post-tensioning technique, prestressed concrete structures have been widely used in civil engineering. To ensure the long-term effectiveness of the prestressed tendon, the grouting quality of the tendon duct is one of the important factors. However, it is still a challenge to monitor the grouting quality of post-tensioning tendon ducts, due to the invisibility of the grouting. The authors' previous work proposed a real-time method that employed a stress wave-based active sensing approach with piezoceramic transducers to monitor the grouting compactness of a Post-Tensioning Tendon Duct (PTTD). To further understand the piezoceramic induced stress wave propagation in the PTTD with different grouting levels, this paper develops a two-dimensional finite element model for monitoring the grouting compactness of the tendon duct with a piezoceramic transducer. A smart aggregate (SA) developed to utilize one Lead Zirconate Titanate (PZT) transducer with marble protection is installed in the center location of the tendon duct as an actuator. Two PZT patches are bonded on the bottom and top surface of the tendon duct as the sensors. The analysis results show that the finite element analysis results are in good agreement with the experimental results, which demonstrates that the finite element analysis is feasible and reliable. For the top half of the specimen, not much stress wave could be detected before the full grouting level, except for negligible signals that may propagate through the walls of the tendon duct. When the tendon duct grouting is at 100%, the stress wave propagates to the top of the specimen, and the displacements are symmetric in both left-right and top-bottom directions before the stress waves reach the boundary. The proposed two-dimensional finite element model has the potential to be implemented to simulate the stress wave propagation principle for monitoring grouting compaction of the post-tensioning tendon duct.

  16. Finite Element Analysis of Grouting Compactness Monitoring in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers

    Directory of Open Access Journals (Sweden)

    Tianyong Jiang

    2017-09-01

    Full Text Available With the development of the post-tensioning technique, prestressed concrete structures have been widely used in civil engineering. To ensure the long-term effectiveness of the prestressed tendon, the grouting quality of the tendon duct is one of the important factors. However, it is still a challenge to monitor the grouting quality of post-tensioning tendon ducts, due to the invisibility of the grouting. The authors’ previous work proposed a real-time method that employed a stress wave-based active sensing approach with piezoceramic transducers to monitor the grouting compactness of a Post-Tensioning Tendon Duct (PTTD. To further understand the piezoceramic induced stress wave propagation in the PTTD with different grouting levels, this paper develops a two-dimensional finite element model for monitoring the grouting compactness of the tendon duct with a piezoceramic transducer. A smart aggregate (SA developed to utilize one Lead Zirconate Titanate (PZT transducer with marble protection is installed in the center location of the tendon duct as an actuator. Two PZT patches are bonded on the bottom and top surface of the tendon duct as the sensors. The analysis results show that the finite element analysis results are in good agreement with the experimental results, which demonstrates that the finite element analysis is feasible and reliable. For the top half of the specimen, not much stress wave could be detected before the full grouting level, except for negligible signals that may propagate through the walls of the tendon duct. When the tendon duct grouting is at 100%, the stress wave propagates to the top of the specimen, and the displacements are symmetric in both left-right and top-bottom directions before the stress waves reach the boundary. The proposed two-dimensional finite element model has the potential to be implemented to simulate the stress wave propagation principle for monitoring grouting compaction of the post-tensioning tendon

  17. One-Dimensional SnO2 Nano structures: Synthesis and Applications

    International Nuclear Information System (INIS)

    Pan, J.; Shen, H.; Mathur, S.; Pan, J.

    2012-01-01

    Nano scale semiconducting materials such as quantum dots (0-dimensional) and one-dimensional (1D) structures, like nano wires, nano belts, and nano tubes, have gained tremendous attention within the past decade. Among the variety of 1D nano structures, tin oxide (SnO 2 ) semiconducting nano structures are particularly interesting because of their promising applications in optoelectronic and electronic devices due to both good conductivity and transparence in the visible region. This article provides a comprehensive review of the recent research activities that focus on the rational synthesis and unique applications of 1D SnO 2 nano structures and their optical and electrical properties. We begin with the rational design and synthesis of 1D SnO 2 nano structures, such as nano tubes, nano wires, nano belts, and some heterogeneous nano structures, and then highlight a range of applications (e.g., gas sensor, lithium-ion batteries, and nano photonics) associated with them. Finally, the review is concluded with some perspectives with respect to future research on 1D SnO 2 nano structures

  18. One dimensional aluminum nitride nanostructures: synthesis, structural, and luminescence properties.

    Science.gov (United States)

    Mousavi, S H; Gharavi, M A; Haratizadeh, H; Kitai, A; de Oliveira, P W

    2011-09-01

    Aluminum nitride (AIN) is a direct bandgap semiconductor with a bandgap about 6.1 eV at room temperature, the largest among semiconductors. This paper emphasizes experimental results of the growth and optical properties of AIN nanostructures by direct nitridation. The nitridation process was performed by chemical vapor deposition method with nitrogen (N2) gas flow. AIN nanostructures were analyzed by scanning electron microscope (SEM) equipped with energy-dispersive X-ray (EDX) spectroscope and photoluminescence (PL) spectroscopy. AIN nanowires with different widths from ultrathin to thick were synthesized with this method. All of the samples had high purity without presence of any other material in EDX spectrum. The PL spectra were obtained by a 325-nm helium-cadmium (He-Cd) laser as the excitation source showing high-intensity light emitting visible wavelengths for these structures at room temperature.

  19. Synthesis and Structural Characterization of ZnS Quantum Dots

    International Nuclear Information System (INIS)

    Selim, H.; Khalil, M.M.H.; Al-Kotb, M.S.; Kotkata, M.F.; Amer, H.H.

    2013-01-01

    Zinc sulfide QDs have been synthesized via a simple reaction of Zn (CH 3 COO) 2 and Na 2 S in the presence of sodium dodecyl sulphate (SDS) acting as an anionic capping material. The structure as well as characterization of the synthesized materials has been studied by XRD, EDX, SEM, TEM, TGA and FT-IR spectroscopy. Analysis of the obtained results revealed products of zinc blende ZnS nanoparticles with an average size of 5.3±0.2 nm in diameter distributed spherically and uniformly. The UV-visible absorption spectrum of the synthesized ZnS nanoparticles reflects an energy gap of 4.30 eV

  20. SYNTHESIS, CHARACTERIZATION AND CRYSTAL STRUCTURE OF BIS-(2-HYDROXYBENZALDEHYDEDIAMINOGUANIZONE

    Directory of Open Access Journals (Sweden)

    Diana Dragancea, Vladimir B. Arion, Sergiu Shova

    2008-12-01

    Full Text Available The new ligand, bis(2-hydroxybenzaldehydediaminoguanizone (1 has been synthesized and characterized by elemental analysis, IR and 1H NMR spectroscopies. The crystal structure of the compound was determined by X-ray diffraction. The ligand C15H15N5O2·C2H5OH crystallizes in the monoclinic space group P21/c with unit cell parameters a = 8.9102(3, b = 10.0357(3, c = 19.7618(6 Å, β = 98.385(2°, Z = 4, V = 1748.21(9 Å3, R1 = 0.040. The amino form of the ligand adopts a planar conformation stabilized by two intramolecular hydrogen bonds of the type O–H···N, in which the H atoms of the central amino group are directed to the lone-pair regions of the azomethine nitrogen atoms.