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Sample records for damage-dependent woven bone

  1. Microfibrous {beta}-TCP/collagen scaffolds mimic woven bone in structure and composition

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Bo; Deng Xuliang, E-mail: yangxp@mail.buct.edu.c [Department of VIP Dental Service, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2010-12-15

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate ({beta}-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure {beta}-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the {beta}-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  2. Microfibrous β-TCP/collagen scaffolds mimic woven bone in structure and composition

    International Nuclear Information System (INIS)

    Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping; Wang Bo; Deng Xuliang

    2010-01-01

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate (β-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure β-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the β-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  3. Elastic properties of woven bone: effect of mineral content and collagen fibrils orientation.

    Science.gov (United States)

    García-Rodríguez, J; Martínez-Reina, J

    2017-02-01

    Woven bone is a type of tissue that forms mainly during fracture healing or fetal bone development. Its microstructure can be modeled as a composite with a matrix of mineral (hydroxyapatite) and inclusions of collagen fibrils with a more or less random orientation. In the present study, its elastic properties were estimated as a function of composition (degree of mineralization) and fibril orientation. A self-consistent homogenization scheme considering randomness of inclusions' orientation was used for this purpose. Lacuno-canalicular porosity in the form of periodically distributed void inclusions was also considered. Assuming collagen fibrils to be uniformly oriented in all directions led to an isotropic tissue with a Young's modulus [Formula: see text] GPa, which is of the same order of magnitude as that of woven bone in fracture calluses. By contrast, assuming fibrils to have a preferential orientation resulted in a Young's modulus in the preferential direction of 9-16 GPa depending on the mineral content of the tissue. These results are consistent with experimental evidence for woven bone in foetuses, where collagen fibrils are aligned to a certain extent.

  4. Human DPSCs fabricate vascularized woven bone tissue: A new tool in bone tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Paino, F.; Noce, M.L.; Giuliani, A.; de Rosa, A.; Mazzoni, F.; Laino, L.; Amler, Evžen; Papaccio, G.; Desiderio, V.; Tirino, V.

    2017-01-01

    Roč. 131, č. 8 (2017), s. 699-713 ISSN 0143-5221 Institutional support: RVO:68378041 Keywords : bone differentiation * bone regeneration * bone tissue engineering Subject RIV: FP - Other Medical Disciplines OBOR OECD: Orthopaedics Impact factor: 4.936, year: 2016

  5. Subchondral chitosan/blood implant-guided bone plate resorption and woven bone repair is coupled to hyaline cartilage regeneration from microdrill holes in aged rabbit knees.

    Science.gov (United States)

    Guzmán-Morales, J; Lafantaisie-Favreau, C-H; Chen, G; Hoemann, C D

    2014-02-01

    Little is known of how to routinely elicit hyaline cartilage repair tissue in middle-aged patients. We tested the hypothesis that in skeletally aged rabbit knees, microdrill holes can be stimulated to remodel the bone plate and induce a more integrated, voluminous and hyaline cartilage repair tissue when treated by subchondral chitosan/blood implants. New Zealand White rabbits (13 or 32 months old, N = 7) received two 1.5 mm diameter, 2 mm depth drill holes in each knee, either left to bleed as surgical controls or press-fit with a 10 kDa (distal hole: 10K) or 40 kDa (proximal hole: 40K) chitosan/blood implant with fluorescent chitosan tracer. Post-operative knee effusion was documented. Repair tissues at day 0 (N = 1) and day 70 post-surgery (N = 6) were analyzed by micro-computed tomography, and by histological scoring and histomorphometry (SafO, Col-2, and Col-1) at day 70. All chitosan implants were completely cleared after 70 days, without increasing transient post-operative knee effusion compared to controls. Proximal control holes had worse osteochondral repair than distal holes. Both implant formulations induced bone remodeling and improved lateral integration of the bone plate at the hole edge. The 40K implant inhibited further bone repair inside 50% of the proximal holes, while the 10K implant specifically induced a "wound bloom" reaction, characterized by decreased bone plate density in a limited zone beyond the initial hole edge, and increased woven bone (WB) plate repair inside the initial hole (P = 0.016), which was accompanied by a more voluminous and hyaline cartilage repair (P holes with a biodegradable subchondral implant that elicits bone plate resorption followed by anabolic WB repair within a 70-day repair period. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  6. Phase I/II Trial of Autologous Bone Marrow Stem Cell Transplantation with a Three-Dimensional Woven-Fabric Scaffold for Periodontitis

    Directory of Open Access Journals (Sweden)

    Shunsuke Baba

    2016-01-01

    Full Text Available Regenerative medicine is emerging as a promising option, but the potential of autologous stem cells has not been investigated well in clinical settings of periodontal treatment. In this clinical study, we evaluated the safety and efficacy of a new regenerative therapy based on the surgical implantation of autologous mesenchymal stem cells (MSCs with a biodegradable three-dimensional (3D woven-fabric composite scaffold and platelet-rich plasma (PRP. Ten patients with periodontitis, who required a surgical procedure for intrabony defects, were enrolled in phase I/II trial. Once MSCs were implanted in each periodontal intrabony defect, the patients were monitored during 36 months for a medical exam including laboratory tests of blood and urine samples, changes in clinical attachment level, pocket depth, and linear bone growth (LBG. All three parameters improved significantly during the entire follow-up period (p<0.0001, leading to an average LBG of 4.7 mm after 36 months. Clinical mobility measured by Periotest showed a decreasing trend after the surgery. No clinical safety problems attributable to the investigational MSCs were identified. This clinical trial suggests that the stem cell therapy using MSCs-PRP/3D woven-fabric composite scaffold may constitute a novel safe and effective regenerative treatment option for periodontitis.

  7. Preparation of a non-woven poly(ε-caprolactone) fabric with partially embedded apatite surface for bone tissue engineering applications by partial surface melting of poly(ε-caprolactone) fibers.

    Science.gov (United States)

    Kim, In Ae; Rhee, Sang-Hoon

    2017-07-01

    This article describes a novel method for the preparation of a biodegradable non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface designed for application as a scaffold material for bone tissue engineering. The non-woven poly(ε-caprolactone) fabric was generated by the electro-spinning technique and then apatite was coated in simulated body fluid after coating the PVA solution containing CaCl 2 ·2H 2 O. The apatite crystals were partially embedded or fully embedded into the thermoplastic poly(ε-caprolactone) fibers by controlling the degree of poly(ε-caprolactone) fiber surface melting in a convection oven. Identical apatite-coated poly(ε-caprolactone) fabric that did not undergo heat-treatment was used as a control. The features of the embedded apatite crystals were evaluated by FE-SEM, AFM, EDS, and XRD. The adhesion strengths of the coated apatite layers and the tensile strengths of the apatite coated fabrics with and without heat-treatment were assessed by the tape-test and a universal testing machine, respectively. The degree of water absorbance was assessed by adding a DMEM droplet onto the fabrics. Moreover, cell penetrability was assessed by seeding preosteoblastic MC3T3-E1 cells onto the fabrics and observing the degrees of cell penetration after 1 and 4 weeks by staining nuclei with DAPI. The non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface showed good water absorbance, cell penetrability, higher apatite adhesion strength, and higher tensile strength compared with the control fabric. These results show that the non-woven poly(ε-caprolactone) fabric with a partially embedded apatite surface is a potential candidate scaffold for bone tissue engineering due to its strong apatite adhesion strength and excellent cell penetrability. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1973-1983, 2017. © 2017 Wiley Periodicals, Inc.

  8. Influence of Fibre Architecture on Impact Damage Tolerance in 3D Woven Composites

    Science.gov (United States)

    Potluri, P.; Hogg, P.; Arshad, M.; Jetavat, D.; Jamshidi, P.

    2012-10-01

    3D woven composites, due to the presence of through-thickness fibre-bridging, have the potential to improve damage tolerance and at the same time to reduce the manufacturing costs. However, ability to withstand damage depends on weave topology as well as geometry of individual tows. There is an extensive literature on damage tolerance of 2D prepreg laminates but limited work is reported on the damage tolerance of 3D weaves. In view of the recent interest in 3D woven composites from aerospace as well as non-aerospace sectors, this paper aims to provide an understanding of the impact damage resistance as well as damage tolerance of 3D woven composites. Four different 3D woven architectures, orthogonal, angle interlocked, layer-to-layer and modified layer-to-layer structures, have been produced under identical weaving conditions. Two additional structures, Unidirectional (UD) cross-ply and 2D plain weave, have been developed for comparison with 3D weaves. All the four 3D woven laminates have similar order of magnitude of damage area and damage width, but significantly lower than UD and 2D woven laminates. Damage Resistance, calculated as impact energy per unit damage area, has been shown to be significantly higher for 3D woven laminates. Rate of change of CAI strength with impact energy appears to be similar for all four 3D woven laminates as well as UD laminate; 2D woven laminate has higher rate of degradation with respect to impact energy. Undamaged compression strength has been shown to be a function of average tow waviness angle. Additionally, 3D weaves exhibit a critical damage size; below this size there is no appreciable reduction in compression strength. 3D woven laminates have also exhibited a degree of plasticity during compression whereas UD laminates fail instantly. The experimental work reported in this paper forms a foundation for systematic development of computational models for 3D woven architectures for damage tolerance.

  9. Tablet-woven and tabby-woven braids from the Czech late medieval archaeological findings

    Czech Academy of Sciences Publication Activity Database

    Březinová, Helena

    2010-01-01

    Roč. 23, - (2010), s. 47-51 ISSN 0860-0007 Institutional research plan: CEZ:AV0Z80020508 Keywords : textile fragments * tablet -woven braids * tabby-woven braids * late medieval Subject RIV: AC - Archeology, Anthropology, Ethnology

  10. Computational modelling of buckling of woven fabrics

    CSIR Research Space (South Africa)

    Anandjiwala, RD

    2006-02-01

    Full Text Available for reducing unit production cost is critically important if garment industries in developed countries are keen to improve their competitiveness vis-à-vis low labour cost countries. The mechanics of the buckling behaviour of woven fabric started... of woven fabric. INTRODUCTION The buckling, bending and drape behaviours of a woven fabric influence its performance during actual use and during the process of making-up into the end product. These properties are important, particularly when the fabric...

  11. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    GROSU Marian C

    2015-05-01

    Full Text Available A coated material is a composite structure that consists of at least two components: base material and coating layer. The purpose of coating is to provide special properties to base material, with potential to be applied in EMI shielding and diverse smart technical fields. This paper reports the results of a study about some physical and magnetic properties of coated woven fabrics made from cotton yarns with fineness of 17 metric count. For this aim, a plain woven fabric was coated with a solution hard magnetic polymer based. As hard magnetic powder, barium hexaferrite (BaFe12O19 was selected. The plain woven fabric used as base has been coated with five solutions having different amounts of hard magnetic powder (15% - 45% in order to obtain five different magnetic woven fabrics. A comparison of physical properties regarding weight (g/m2, thickness (mm, degree of charging (% and magnetic properties of magnetic woven samples were presented. Saturation magnetizing (emu/g, residual magnetizing (emu/g and coercive force (kA/m of pure hard magnetic powder and woven fabrics have been studied as hysteresis characteristics. The magnetic properties of the woven fabrics depend on the mass percentage of magnetic powder from coating solution. Also, the residual magnetism and coercive field of woven fabrics represents only a part of bulk barium hexafferite residual magnetism and coercive field.

  12. DRAPING SIMULATION OF WOVEN FABRICS

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, William [General Motors LLC; Jin, Xiaoshi [ESI Group NA; Zhu, Jiang [Optimal CAE; Wathen, Terrence [General Motors LLC; Doroudian2, Mark [ESI Group NA; Aitharaju, Venkat [General Motors LLC

    2016-09-07

    Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process, where the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the yarns may change significantly compared to the initial orientations. Accurate prediction of the yarn orientations after molding is important for evaluating the structural performance of the final part. This paper presents a systematic investigation of the angle changes during the preform operation for carbon fiber twill and satin weave fabrics. Preforming experiments were conducted using a truncated pyramid mold geometry designed and fabricated at the General Motors Research Laboratories. Predicted results for the yarn orientations were compared with experimental results and good agreement was observed

  13. Laminate mechanics for balanced woven fabrics

    NARCIS (Netherlands)

    Akkerman, Remko

    2006-01-01

    Laminate mechanics equations are presented for composites with balanced woven fabric reinforcements. It is shown that mimicking these textile composites with equivalent transversely isotropic (‘unidirectional’) layers requires disputable manipulations. Various micromechanics predictions of textile

  14. Carbon nanotube woven textile photodetector

    Science.gov (United States)

    Zubair, Ahmed; Wang, Xuan; Mirri, Francesca; Tsentalovich, Dmitri E.; Fujimura, Naoki; Suzuki, Daichi; Soundarapandian, Karuppasamy P.; Kawano, Yukio; Pasquali, Matteo; Kono, Junichiro

    2018-01-01

    The increasing interest in mobile and wearable technology demands the enhancement of functionality of clothing through incorporation of sophisticated architectures of multifunctional materials. Flexible electronic and photonic devices based on organic materials have made impressive progress over the past decade, but higher performance, simpler fabrication, and most importantly, compatibility with woven technology are desired. Here we report on the development of a weaved, substrateless, and polarization-sensitive photodetector based on doping-engineered fibers of highly aligned carbon nanotubes. This room-temperature-operating, self-powered detector responds to radiation in an ultrabroad spectral range, from the ultraviolet to the terahertz, through the photothermoelectric effect, with a low noise-equivalent power (a few nW/Hz 1 /2) throughout the range and with a Z T -factor value that is twice as large as that of previously reported carbon nanotube-based photothermoelectric photodetectors. Particularly, we fabricated a ˜1 -m-long device consisting of tens of p+-p- junctions and weaved it into a shirt. This device demonstrated a collective photoresponse of the series-connected junctions under global illumination. The performance of the device did not show any sign of deterioration through 200 bending tests with a bending radius smaller than 100 μ m as well as standard washing and ironing cycles. This unconventional photodetector will find applications in wearable technology that require detection of electromagnetic radiation.

  15. 77 FR 32938 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2012-06-04

    ... ribbons subject to the order include all narrow woven fabrics, tapes, and labels that fall within this... the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and apparel tapes, cut-to... 1994 U.S.C.C.A.N. 4040, 4198-99. Furthermore, ``affirmative evidence of bad faith on the part of a...

  16. 75 FR 11908 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-03-12

    ...)] Narrow Woven Ribbons With Woven Selvedge From China and Taiwan AGENCY: United States International Trade...(b) of the Act (19 U.S.C. 1673d(b)) to determine whether an industry in the United States is materially injured or threatened with material injury, or the establishment of an industry in the United...

  17. 75 FR 53711 - Narrow Woven Ribbons With Woven Selvedge From China and Taiwan

    Science.gov (United States)

    2010-09-01

    ... Woven Ribbons With Woven Selvedge From China and Taiwan Determinations On the basis of the record \\1... U.S.C. 1673d(b)) (the Act), that an industry in the United States is threatened with material injury... (19 U.S.C. 1673d(b)), that an industry in the United States is threatened with material injury by...

  18. 49 CFR 178.518 - Standards for woven plastic bags.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for woven plastic bags. 178.518 Section... PACKAGINGS Non-bulk Performance-Oriented Packaging Standards § 178.518 Standards for woven plastic bags. (a) The following are identification codes for woven plastic bags: (1) 5H1 for an unlined or non-coated...

  19. Processing and Characterization of Liquid-Phase Sintered NiTi Woven Structures

    Science.gov (United States)

    Erdeniz, Dinc; Weidinger, Ryan P.; Sharp, Keith W.; Dunand, David C.

    2018-03-01

    Porous NiTi is of interest for bone implants because of its unique combination of biocompatibility (encouraging osseointegration), high strength (to prevent fracture), low stiffness (to reduce stress shielding), and shape memory or superelasticity (to deploy an implant). A promising method for creating NiTi structures with regular open channels is via 3D weaving of NiTi wires. This paper presents a processing method to bond woven NiTi wire structures at contact points between wires to achieve structural integrity: (i) a slurry consisting of a blend of NiTi and Nb powders is deposited on the surface of the NiTi wires after the weaving operation; (ii) the powders are melted to create a eutectic liquid phase which collects at contact points; and (iii) the liquid is solidified and binds the NiTi woven structures. The bonded NiTi wire structures exhibited lower transformation temperatures compared to the as-woven NiTi wires because of Nb diffusion into the NiTi wires. A bonded woven sample was deformed in bending and showed near-complete recovery up to 6% strain and recovered nearly half of the deformation up to 19% strain.

  20. Woven fabric composites: Can we peel it?

    NARCIS (Netherlands)

    Sacchetti, Francisco; Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Villegas, I. Fernandez

    2016-01-01

    The present work focuses on the applicability of the mandrel peel test to quantify the fracture toughness of woven fabric Carbon/PEEK composites. For this purpose, the mandrel peel test was compared to the standardized DCB test. Unstable crack propagation (stick-slip) was observed in both testing

  1. Non-Wovens as Sound Reducers

    Science.gov (United States)

    Belakova, D.; Seile, A.; Kukle, S.; Plamus, T.

    2018-04-01

    Within the present study, the effect of hemp (40 wt%) and polyactide (60 wt%), non-woven surface density, thickness and number of fibre web layers on the sound absorption coefficient and the sound transmission loss in the frequency range from 50 to 5000 Hz is analysed. The sound insulation properties of the experimental samples have been determined, compared to the ones in practical use, and the possible use of material has been defined. Non-woven materials are ideally suited for use in acoustic insulation products because the arrangement of fibres produces a porous material structure, which leads to a greater interaction between sound waves and fibre structure. Of all the tested samples (A, B and D), the non-woven variant B exceeded the surface density of sample A by 1.22 times and 1.15 times that of sample D. By placing non-wovens one above the other in 2 layers, it is possible to increase the absorption coefficient of the material, which depending on the frequency corresponds to C, D, and E sound absorption classes. Sample A demonstrates the best sound absorption of all the three samples in the frequency range from 250 to 2000 Hz. In the test frequency range from 50 to 5000 Hz, the sound transmission loss varies from 0.76 (Sample D at 63 Hz) to 3.90 (Sample B at 5000 Hz).

  2. Numerical Tools for Composite Woven Fabric Preforming

    Directory of Open Access Journals (Sweden)

    Abel Cherouat

    2013-01-01

    Full Text Available An important step in the manufacturing processes of thin composite components is the layingup of the reinforcement onto the mould surface. The prediction of the angular distortion of the reinforcement during draping and the changes in fibre orientation are essential for the understanding of the manufacture process and the evaluation of the mechanical properties of the composite structures. This paper presents an optimization-based method for the simulation of the forming processes of woven fabric reinforced composites. Two different approaches are proposed for the simulation of the draping of woven fabric onto complex geometries: geometrical and mechanical approaches. The geometrical approach is based on a fishnet model. It is well adapted to predimensioning fabrics and to give a suitable quantification of the resulting flat patterns. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Some numerical simulations of the forming process are proposed and compared with the experimental results in order to demonstrate the efficiency of our approaches.

  3. 78 FR 29703 - Narrow Woven Ribbons With Woven Selvedge From Taiwan: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-05-21

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-844] Narrow Woven Ribbons With... AGENCY: Import Administration, International Trade Administration, Department of Commerce. SUMMARY: The..., International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution Avenue NW...

  4. From mindtools to social mindtools: collaborative writing with Woven Stories

    CSIR Research Space (South Africa)

    Nuutinen, J

    2010-09-01

    Full Text Available . We present the concept of Woven Stories and use it as an example of an effective social mindtool. We also describe a case study in which Woven Stories software was used as an online debating forum. This case study reveals the potential inherent...

  5. 75 FR 41804 - Notice of Final Determination of Sales at Less Than Fair Value: Narrow Woven Ribbons with Woven...

    Science.gov (United States)

    2010-07-19

    ... unaffiliated supplier informed the Department that it did not produce NWR but merely purchased and resold it... or set such as when packaged with other products, including but not limited to gift bags, gift boxes... ribbons with woven selvedge attached to and forming the handle of a gift bag; (7) cut-edge narrow woven...

  6. 3D ultrasound characterization of woven composites

    Science.gov (United States)

    Tayong, Rostand B.; Mienczakowski, Martin J.; Smith, Robert A.

    2018-04-01

    Recent studies on the Non-Destructive Testing (NDT) of composites for the aerospace industry have led to an understanding of ultrasonic propagation in these materials [1]. Techniques for enhanced ultrasonic imaging of the internal structure of composite laminates containing unidirectional fibers have been proposed and tested in a laboratory environment. For the automotive industry, textile composites are often preferred and widely used. The reason for this is that these types of composites offer good mechanical performance, with resistance to delamination and reduced manufacturing costs. In this study, two models are developed and shown to be suitable to characterize the woven specimen. The first model is a 1D analytical model that makes simplified assumptions and the second is a 3D time-domain Finite Element (FE) model developed [2] for advanced understanding of the woven composite response to an ultrasonic excitation. For each of the proposed models, three parameters are defined and used to analyze the structure behavior. They are the instantaneous amplitude, instantaneous phase and instantaneous frequency. These parameters are employed to track the in-plane fiber orientation and the ply-interface location and for the sentencing of features. Three different specimens with the following weave type: 3D orthogonal, 2D plain and Multilayer stitching were considered and scanned (using a focused ultrasonic transducer) to validate the proposed models. As a preliminary study, the work only focuses on the Orthogonal weave specimen. The results obtained from experimental, analytical and FE modeling, B-scan and C-scan are compared, discussed and presented in terms of the above defined parameters.

  7. Woven hybrid composites: Tensile and flexural properties of oil palm-woven jute fibres based epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Jawaid, M. [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abdul Khalil, H.P.S., E-mail: akhalilhps@gmail.com [School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang (Malaysia); Abu Bakar, A. [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2011-06-15

    Highlights: {yields} Woven hybrid composites show good tensile and flexural properties. {yields} Hybridization with 20% woven jute gives rise to sufficient modulus to composites. {yields} Layering pattern affect mechanical properties of hybrid composites. {yields} Statistical analysis shows that there is significant difference between composites. - Abstract: In this research, tensile and flexural performance of tri layer oil palm empty fruit bunches (EFB)/woven jute (Jw) fibre reinforced epoxy hybrid composites subjected to layering pattern has been experimentally investigated. Sandwich composites were fabricated by hand lay-up technique in a mould and cured with 105 deg. C temperatures for 1 h by using hot press. Pure EFB and woven jute composites were also fabricate for comparison purpose. Results showed that tensile and flexural properties of pure EFB composite can be improved by hybridization with woven jute fibre as extreme woven jute fibre mat. It was found that tensile and flexural properties of hybrid composite is higher than that of EFB composite but less than woven jute composite. Statistical analysis of composites done by ANOVA-one way, it showed significant differences between the results obtained. The fracture surface morphology of the tensile samples of the hybrid composites was performed by using scanning electron microscopy.

  8. Woven hybrid composites: Tensile and flexural properties of oil palm-woven jute fibres based epoxy composites

    International Nuclear Information System (INIS)

    Jawaid, M.; Abdul Khalil, H.P.S.; Abu Bakar, A.

    2011-01-01

    Highlights: → Woven hybrid composites show good tensile and flexural properties. → Hybridization with 20% woven jute gives rise to sufficient modulus to composites. → Layering pattern affect mechanical properties of hybrid composites. → Statistical analysis shows that there is significant difference between composites. - Abstract: In this research, tensile and flexural performance of tri layer oil palm empty fruit bunches (EFB)/woven jute (Jw) fibre reinforced epoxy hybrid composites subjected to layering pattern has been experimentally investigated. Sandwich composites were fabricated by hand lay-up technique in a mould and cured with 105 deg. C temperatures for 1 h by using hot press. Pure EFB and woven jute composites were also fabricate for comparison purpose. Results showed that tensile and flexural properties of pure EFB composite can be improved by hybridization with woven jute fibre as extreme woven jute fibre mat. It was found that tensile and flexural properties of hybrid composite is higher than that of EFB composite but less than woven jute composite. Statistical analysis of composites done by ANOVA-one way, it showed significant differences between the results obtained. The fracture surface morphology of the tensile samples of the hybrid composites was performed by using scanning electron microscopy.

  9. Evaluation on mechanical properties of woven aloevera and sisal ...

    Indian Academy of Sciences (India)

    Administrator

    behaviour of this composite is observed to be more effec- tive.5 The fibre .... been made to study the mechanical properties of woven aloevera and ... In each case, minimum of ... tions in automotive components, structures and consumer goods.

  10. Geometrical Modeling of Woven Fabrics Weavability-Limit New Relationships

    Directory of Open Access Journals (Sweden)

    Dalal Mohamed

    2017-03-01

    Full Text Available The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet. Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modified as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fiber materiel, all yarns etc…. The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties.

  11. Recent advancements in mechanical characterisation of 3D woven composites

    Science.gov (United States)

    Saleh, Mohamed Nasr; Soutis, Constantinos

    2017-12-01

    Three dimensional (3D) woven composites have attracted the interest of academia and industry thanks to their damage tolerance characteristics and automated fabric manufacturing. Although much research has been conducted to investigate their out-of-plane "through thickness" properties, still their in-plane properties are not fully understood and rely on extensive experimentation. To date, the literature lacks an inclusive summary of the mechanical characterisation for 3D woven composites. Therefore, the objective of this paper is to provide a comprehensive review of the available research studies on 3D woven composites mechanical characterisation, with less emphasis on the out-of-plane response, but an in-depth review of the in-plane response "un-notched vs. notched". The paper highlights the knowledge gap in the literature of 3D woven composites, suggesting opportunities for future research in this field and a room for improvement in utilising Non-Destructive Techniques (NDT), such as Digital Image Correlation (DIC), Acoustic Emission (AE) and X-ray Computed Tomography (CT), for observing damage initiation and evolution in 3D woven composites that could be used to calibrate and evaluate analytical and numerical models.

  12. Interlaminar fracture in woven carbon/epoxy laminates

    Directory of Open Access Journals (Sweden)

    Paulo N.B. Reis

    2014-10-01

    Full Text Available This paper describes an experimental study developed to characterize the mode I and mode II fracture toughness of carbon/epoxy woven composites, using DCB and ENF tests, respectively. The laminates were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of them with the same orientation (0/90º. Significant instantaneous delaminations were observed particularly for the DCB specimen, which were responsible for an oscillatory behaviour of GI versus crack length. The maximum values obtained for GIC and GIIC were 281 and 1800 J/m2, respectively.

  13. Rethinking the nature of fibrolamellar bone: an integrative biological revision of sauropod plexiform bone formation.

    Science.gov (United States)

    Stein, Koen; Prondvai, Edina

    2014-02-01

    We present novel findings on sauropod bone histology that cast doubt on general palaeohistological concepts concerning the true nature of woven bone in primary cortical bone and its role in the rapid growth and giant body sizes of sauropod dinosaurs. By preparing and investigating longitudinal thin sections of sauropod long bones, of which transverse thin sections were published previously, we found that the amount of woven bone in the primary complex has been largely overestimated. Using comparative cellular and light-extinction characteristics in the two section planes, we revealed that the majority of the bony lamina consists of longitudinally organized primary bone, whereas woven bone is usually represented only by a layer a few cells thin in the laminae. Previous arguments on sauropod biology, which have been based on the overestimated amount, misinterpreted formation process and misjudged role of woven bone in the plexiform bone formation of sauropod dinosaurs, are thereby rejected. To explain the observed pattern in fossil bones, we review the most recent advances in bone biology concerning bone formation processes at the cellular and tissue levels. Differentiation between static and dynamic osteogenesis (SO and DO) and the revealed characteristics of SO- versus DO-derived bone tissues shed light on several questions raised by our palaeohistological results and permit identification of these bone tissues in fossils with high confidence. By presenting the methods generally used for investigating fossil bones, we show that the major cause of overestimation of the amount of woven bone in previous palaeohistological studies is the almost exclusive usage of transverse sections. In these sections, cells and crystallites of the longitudinally organized primary bone are cut transversely, thus cells appear rounded and crystallites remain dark under crossed plane polarizers, thereby giving the false impression of woven bone. In order to avoid further confusion in

  14. 78 FR 26614 - Narrow Woven Ribbon With Woven Selvedge From the People's Republic of China: Rescission of...

    Science.gov (United States)

    2013-05-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-952] Narrow Woven Ribbon With...; 2011-2012 AGENCY: Import Administration, International Trade Administration, Department of Commerce... Administration, International Trade Administration, U.S. Department of Commerce, 14th Street and Constitution...

  15. 75 FR 41808 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Final Determination...

    Science.gov (United States)

    2010-07-19

    ... Ribbon Company, Inc. (``Petitioner''); Yama; and Yangzhou Bestpak Gifts & Crafts Co., Ltd. (``Bestpak... liquid petroleum gas from the supplier to Yama's factory.\\10\\ \\10\\ See Final Analysis Memorandum for Yama... limited to gift bags, gift boxes and/ or other types of ribbon. Narrow woven ribbons subject to the...

  16. 77 FR 47363 - Narrow Woven Ribbons With Woven Selvedge From the People's Republic of China: Preliminary Results...

    Science.gov (United States)

    2012-08-08

    ... fabrics, tapes, and labels that fall within this written description of the scope of the antidumping duty... of a kind used for the manufacture of typewriter or printer ribbons; (5) Narrow woven labels and..., ``affirmative evidence of bad faith on the part of a respondent is not required before the Department may make...

  17. 75 FR 56982 - Narrow Woven Ribbons With Woven Selvedge From Taiwan and the People's Republic of China: Amended...

    Science.gov (United States)

    2010-09-17

    ...: Margin Exporter or producer (percent) Taiwan Roung Shu Industry Corporation 4.37 All Others 4.37 Margin... Ribbons With Woven Selvedge From Taiwan and the People's Republic of China: Amended Antidumping Duty...: Notice of amended antidumping duty orders. FOR FURTHER INFORMATION CONTACT: Holly Phelps (Taiwan), AD/CVD...

  18. Debonding characteristics of adhesively bonded woven Kevlar composites

    Science.gov (United States)

    Mall, S.; Johnson, W. S.

    1988-01-01

    The fatigue damage mechanism of an adhesively bonded joint between fabric reinforced composite adherends was investigated with cracked-lap-shear specimens. Two bonded systems were studied: fabric Kevlar 49/5208 epoxy adherends bonded together with either EC 3445 or FM-300 adhesive. For each bonded system, two specimen geometries were tested. In all specimens tested, fatigue damage occurred in the form of cyclic debonding; however, the woven Kevlar specimens gave significantly slower debond growth rates and higher fracture toughness than previously found in the nonwoven adherend specimens. The surfaces for the woven adherends were not smooth; rather, they had regular crests (high spots) and troughs (low spots) due to the weave pattern. Radiographs of the specimens and examination of their failure surfaces revealed that fiber bridging occurred between the crests of the two adherends in the debonded region. The observed improvements in debond growth resistance and static fracture toughness are attributed to this bridging.

  19. A Wear Geometry Model of Plain Woven Fabric Composites

    Directory of Open Access Journals (Sweden)

    Gu Dapeng

    2014-09-01

    Full Text Available The paper g describes a model meant for analysis of the wear geometry of plain woven fabric composites. The referred model consists of a mathematical description of plain woven fabric based on Peirce’s model coupled with a stratified method for the solution of the wear geometry. The evolutions of the wear area ratio of weft yarn, warp yarn and matrix resin on the worn surface are simulated by MatLab software in combination of warp and weft yarn diameters, warp and weft yarn-to-yarn distances, fabric structure phases (SPs. By comparing theoretical and experimental results from the PTFE/Kevlar fabric wear experiment, it can be concluded that the model can present a trend of the component area ratio variations along with the thickness of fabric, but has a inherently large error in quantitative analysis as an idealized model.

  20. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    OpenAIRE

    A.E. Ismail; M.A. Che Abdul Aziz

    2015-01-01

    This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that...

  1. Mechanical properties of woven banana fibre reinforced epoxy composites

    International Nuclear Information System (INIS)

    Sapuan, S.M.; Leenie, A.; Harimi, M.; Beng, Y.K.

    2006-01-01

    In this paper, the experiments of tensile and flexural (three-point bending) tests were carried out using natural fibre with composite materials (Musaceae/epoxy). Three samples prepared from woven banana fibre composites of different geometries were used in this research. From the results obtained, it was found that the maximum value of stress in x-direction is 14.14 MN/m 2 , meanwhile the maximum value of stress in y-direction is 3.398 MN/m 2 . For the Young's modulus, the value of 0.976 GN/m 2 in x-direction and 0.863 GN/m 2 in y-direction were computed. As for the case of three-point bending (flexural), the maximum load applied is 36.25 N to get the deflection of woven banana fibre specimen beam of 0.5 mm. The maximum stress and Young's modulus in x-direction was recorded to be 26.181 MN/m 2 and 2.685 GN/m 2 , respectively. Statistical analysis using ANOVA-one way has showed that the differences of results obtained from those three samples are not significant, which confirm a very stable mechanical behaviour of the composites under different tests. This shows the importance of this product and allows many researchers to develop an adequate system for producing a good quality of woven banana fibre composite which maybe used for household utilities

  2. Fatigue life prediction in woven carbon fabric polyester composites

    International Nuclear Information System (INIS)

    Khan, Z.; Al-Sulaiman, F.S.; Farooqi, J.K.

    1999-01-01

    An analytical model, based on stiffness degradation during fatigue loading, which has been used for fatigue life predictions in the Fiber Reinforced Plastics (FRP), is employed to examine its validity to the fatigue life predictions in the Woven Fabric Reinforced Plastics. The rate of stiffness degradation (dE/dN) has been obtained from the constant amplitude fatigue testing of 8-ply coupons made from prepreg plain-weave woven carbon-carbon fabric having a polyester resin as the matrix material. The test coupons had three different ply stacking sequences, namely, the unidirectional (0)8,and two off axis plied (0,0,+45,-45)s, and (+45,-45,0,0)s orientations. The estimated fatigue lives obtained from the damage rate function dD/dN, which in turn was a function of the stiffness degradation rate dE/dN, were compared with the experimentally observed fatigue life data. It is shown that the stiffness degradation model provides reasonably good correlation between the analytically determined fatigue lives and the experimentally observed fatigue for the plain-weave woven Carbon-Carbon Fabric Reinforced Plastic Composites. (author)

  3. CREASING BEHAVIOR OF SOME WOVEN MATERIALS MADE FROM COMBED YARNS TYPE

    OpenAIRE

    HRISTIAN Liliana; BORDEIANU Demetra Lacramioara; OSTAFE Maria Magdalena; BŐHM-RÉVÉSZ Gabriela

    2017-01-01

    The paper analyses the behavior to creasing of some woven materials made from yarns type wool used for ready-made clothes. Factors like fibrous composition, properties of constituent fibers, wovens structure parameters, mechanical properties of warp and weft yarns and finishing treatments that influenced the recovery capacity from crease/folding were investigated experimentally through several tests which revealed their importance in the process. The creasing of woven materials made from c...

  4. Tensile Behavior Analysis on Different Structures of 3D Glass Woven Perform for Fibre Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Mazhar Hussain Peerzada

    2013-01-01

    Full Text Available Three common 3D (Three Dimensional Glass woven structures were studied to analyze the tensile behavior. Each type of strand (Warp, weft and binder of 3D woven structure was studied in detail. Crimp percentage of those strands was measured by crimp meter. Standard size samples of each 3D woven structure were cut in warp and weft direction and were stretched by Instron Tensile testing computerized machine. Results reveal that hybrid possesses lowest crimp in core strands and higher strength in warp as well as weft direction. Layer to layer woven structure appeared with lower strength and higher strain value due to highest crimp percentage in core strands.

  5. Mechanical properties of woven banana fibre reinforced epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Sapuan, S.M. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)]. E-mail: sapuan@eng.upm.my; Leenie, A. [Department of Mechanical and Manufacturing Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Harimi, M. [School of Engineering and Information Technology, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah (Malaysia); Beng, Y.K. [School of Engineering and Information Technology, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah (Malaysia)

    2006-07-01

    In this paper, the experiments of tensile and flexural (three-point bending) tests were carried out using natural fibre with composite materials (Musaceae/epoxy). Three samples prepared from woven banana fibre composites of different geometries were used in this research. From the results obtained, it was found that the maximum value of stress in x-direction is 14.14 MN/m{sup 2}, meanwhile the maximum value of stress in y-direction is 3.398 MN/m{sup 2}. For the Young's modulus, the value of 0.976 GN/m{sup 2} in x-direction and 0.863 GN/m{sup 2} in y-direction were computed. As for the case of three-point bending (flexural), the maximum load applied is 36.25 N to get the deflection of woven banana fibre specimen beam of 0.5 mm. The maximum stress and Young's modulus in x-direction was recorded to be 26.181 MN/m{sup 2} and 2.685 GN/m{sup 2}, respectively. Statistical analysis using ANOVA-one way has showed that the differences of results obtained from those three samples are not significant, which confirm a very stable mechanical behaviour of the composites under different tests. This shows the importance of this product and allows many researchers to develop an adequate system for producing a good quality of woven banana fibre composite which maybe used for household utilities.

  6. Influence of flock coating on bending rigidity of woven fabrics

    Science.gov (United States)

    Ozdemir, O.; Kesimci, M. O.

    2017-10-01

    This work presents the preliminary results of our efforts that focused on the effect of the flock coating on the bending rigidity of woven fabrics. For this objective, a laboratory scale flocking unit is designed and flocked samples of controlled flock density are produced. Bending rigidity of the samples with different flock densities are measured on both flocked and unflocked sides. It is shown that the bending rigidity depends on both flock density and whether the side to be measured is flocked or not. Adhesive layer thickness on the bending rigidity is shown to be dramatic. And at higher basis weights, flock density gets less effective on bending rigidity.

  7. 75 FR 46911 - Certain Woven Electric Blankets from the People's Republic of China: Amended Final Determination...

    Science.gov (United States)

    2010-08-04

    ... Blankets from the People's Republic of China: Amended Final Determination of Sales at Less Than Fair Value... than fair value (``LTFV'') in the antidumping investigation of certain woven electric blankets (``woven... From the People's Republic of China: Final Determination of Sales at Less Than Fair Value, 75 FR 38459...

  8. Dual-skinned polyamide/poly(vinylidene fluoride)/cellulose acetate membranes with embedded woven

    KAUST Repository

    Phuoc, Duong; Nunes, Suzana Pereira; Chung, Tai-Shung

    2016-01-01

    strength, (iii) a strong woven fabric, and (iv) fouling resistant porous cellulose acetate (CA) layer. The PA layer rejects solutes of the draw solution. The PVDF/woven fabric/CA (PVDF/CA) integrated layer performs as a mechanical support with unique

  9. Medical effects of poly-ethylene terephthalate (PET) non-woven ...

    African Journals Online (AJOL)

    In this study, bamboo activated charcoal was mixed with acrylic resin in various proportions and deposited on poly-ethylene terephthalate (PET) non-woven fabrics. A series of characterizations were carried out to estimate the performances of PET non-woven fabrics such as far infrared ray emission, heat retention, negative ...

  10. Woven Coronary Artery Disease Successfully Managed with Percutaneous Coronary Intervention: A New Case Report

    Directory of Open Access Journals (Sweden)

    Yakup Alsancak

    2015-01-01

    Full Text Available Woven coronary artery is relatively rare and can be complicated in both acute and chronic phases. A few case reports have been published until now. Herein we report a case with right woven coronary artery managed with drug-eluted stent implantation without complication.

  11. Comparative Study of the Properties of some Non-Woven Diapers ...

    African Journals Online (AJOL)

    ABSTRACT: The properties of locally made non-woven diapers were studied. Four locally made non-woven absorbent pads samples namely; Always ultra absorbent pad (sample A), Dr. Brown absorbent pad (sample B),. Everyday ultra thin normal absorbent pad (sample C), and Enjoy leto absorbent pad (sample D) were ...

  12. Spatial and temporal variations of the callus mechanical properties during bone transport

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Macias, J.; Reina-Romo, E.; Pajares, A.; Miranda, P.; Dominguez, J.

    2016-07-01

    Nanoindentation allows obtaining the elastic modulus and the hardness of materials point by point. This technique has been used to assess the mechanical propeties of the callus during fracture healing. However, as fas as the authors know, the evaluation of mechanical properties by this technique of the distraction and the docking-site calluses generated during bone transport have not been reported yet. Therefore, the aim of this work is using nanoindentation to assess the spatial and temporal variation of the elastic modulus of the woven bone generated during bone transport. Nanoindentation measurements were carried out using 6 samples from sheep sacrificed at different stages of the bone transport experiments. The results obtained show an important heterogeneity of the elastic modulus of the woven bone without spatial trends. In the case of temporal variation, a clear increase of the mean elastic modulus with time after surgery was observed (from 7±2GPa 35 days after surgery to 14±2GPa 525 days after surgery in the distraction callus and a similar increase in the docking site callus). Comparison with the evolution of the elastic modulus in the woven bone generated during fracture healing shows that mechanical properties increase slower in the case of the woven bone generated during bone transport. (Author)

  13. Mechanical Testing of Carbon Based Woven Thermal Protection Materials

    Science.gov (United States)

    Pham, John; Agrawal, Parul; Arnold, James O.; Peterson, Keith; Venkatapathy, Ethiraj

    2013-01-01

    Three Dimensional Woven thermal protection system (TPS) materials are one of the enabling technologies for mechanically deployable hypersonic decelerator systems. These materials have been shown capable of serving a dual purpose as TPS and as structural load bearing members during entry and descent operations. In order to ensure successful structural performance, it is important to characterize the mechanical properties of these materials prior to and post exposure to entry-like heating conditions. This research focuses on the changes in load bearing capacity of woven TPS materials after being subjected to arcjet simulations of entry heating. Preliminary testing of arcjet tested materials [1] has shown a mechanical degradation. However, their residual strength is significantly more than the requirements for a mission to Venus [2]. A systematic investigation at the macro and microstructural scales is reported here to explore the potential causes of this degradation. The effects of heating on the sizing (an epoxy resin coating used to reduce friction and wear during fiber handling) are discussed as one of the possible causes for the decrease in mechanical properties. This investigation also provides valuable guidelines for margin policies for future mechanically deployable entry systems.

  14. In vivo testing of a biodegradable woven fabric made of bioactive glass fibers and PLGA80--a pilot study in the rabbit.

    Science.gov (United States)

    Alm, Jessica J; Frantzén, Janek P A; Moritz, Niko; Lankinen, Petteri; Tukiainen, Mikko; Kellomäki, Minna; Aro, Hannu T

    2010-05-01

    The purpose of this study was to perform an intra-animal comparison of biodegradable woven fabrics made of bioactive glass (BG) fibers and poly(L-lactide-co-glycolide) 80/20 copolymer (PLGA(80)) fibers or PLGA(80) fibers alone, in surgical stabilization of bone graft. The BG fibers (BG 1-98) were aimed to enhance bone growth at site of bone grafting, whereas the PLGA component was intended to provide structural strength and flexibility to the fabric. Bone formation was analyzed qualitatively by histology and quantitatively by peripheral quantitative computed tomography (pQCT) at 12 weeks. The surgical handling properties of the control PLGA(80) fabric were more favorable. Both fabrics were integrated with the cortical bone surfaces, but BG fibers showed almost complete resorption. There were no signs of adverse local tissue reactions. As a proof of material integration and induced new bone formation, there was a significant increase in bone volume of the operated femurs compared with the contralateral intact bone (25% with BG/PLGA(80) fabric, p < 0.001 and 28% with the control PLGA(80) fabric, p = 0.006). This study failed to demonstrate the previously seen positive effect of BG 1-98 on osteogenesis, probably due to the changed resorption properties of BG in the form of fibers. Therefore, the feasibility and safety of BG as fibers needs to be reevaluated before use in clinical applications. (c) 2010 Wiley Periodicals, Inc.

  15. An insight in to Paget′s disease of bone

    Directory of Open Access Journals (Sweden)

    Robin Sabharwal

    2014-01-01

    Full Text Available Paget′s disease of bone (PDB is a common disorder which may affect one or many bones. Although many patients are asymptomatic, a variety of symptoms and complications may occur. PDB is a focal disorder of bone turnover characterized by excessive bone resorption coupled with bone formation. PDB begins with a period of increased osteoclastic activity and bone resorption, followed by increased osteoblast production of woven bone that is poorly mineralized. In the final phase of the disease process, dense cortical and trabecular bone deposition predominates, but the bone is sclerotic and poorly organized and lacks the structural integrity and strength of normal bone. This article briefly reviews the etiopathogenesis, clinical radiographic and histological features of Paget′s disease.

  16. Evolutionary patterns of bone histology and bone compactness in xenarthran mammal long bones.

    Science.gov (United States)

    Straehl, Fiona R; Scheyer, Torsten M; Forasiepi, Analía M; MacPhee, Ross D; Sánchez-Villagra, Marcelo R

    2013-01-01

    Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua), with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness.

  17. Evolutionary patterns of bone histology and bone compactness in xenarthran mammal long bones.

    Directory of Open Access Journals (Sweden)

    Fiona R Straehl

    Full Text Available Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua, with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness.

  18. Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

    Directory of Open Access Journals (Sweden)

    Chunhui Xiang

    2016-04-01

    Full Text Available Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats.

  19. Investigation of Circular Woven Composite Preforms for Composite Pipes

    Directory of Open Access Journals (Sweden)

    Amid Hooman

    2016-06-01

    Full Text Available The main traditional technique for commercial manufacturing of composite pipes is filament winding in which the winding angle and the discontinuity of the structure (caused by starting and ending points of the winding process are two important matters of concern. In the present study, circular woven fabric with its orthogonal net-shaped continuous structure was produced from polyester yarns. Fabric was wet with epoxy and hand lay-up was used to manufacture the composite pipes. Composite pipes were subjected to internal hydrostatic pressure and their burst strength was recorded. In addition, tensile strength of flat laminas was assessed in the warp and weft directions. We estimated and analysed the failure strength of composite pipes using Tresca’s failure criterion and Finite Element (FE modeling. The experimental burst strength was almost 23% more than the FE model and 77% more than the theoretical estimate.

  20. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    Directory of Open Access Journals (Sweden)

    A.E. Ismail

    2015-12-01

    Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

  1. Creep Burst Testing of a Woven Inflatable Module

    Science.gov (United States)

    Selig, Molly M.; Valle, Gerard D.; James, George H.; Oliveras, Ovidio M.; Jones, Thomas C.; Doggett, William R.

    2015-01-01

    A woven Vectran inflatable module 88 inches in diameter and 10 feet long was tested at the NASA Johnson Space Center until failure from creep. The module was pressurized pneumatically to an internal pressure of 145 psig, and was held at pressure until burst. The external environment remained at standard atmospheric temperature and pressure. The module burst occurred after 49 minutes at the target pressure. The test article pressure and temperature were monitored, and video footage of the burst was captured at 60 FPS. Photogrammetry was used to obtain strain measurements of some of the webbing. Accelerometers on the test article measured the dynamic response. This paper discusses the test article, test setup, predictions, observations, photogrammetry technique and strain results, structural dynamics methods and quick-look results, and a comparison of the module level creep behavior to the strap level creep behavior.

  2. Basalt woven fiber reinforced vinylester composites: Flexural and electrical properties

    International Nuclear Information System (INIS)

    Carmisciano, Salvatore; Rosa, Igor Maria De; Sarasini, Fabrizio; Tamburrano, Alessio; Valente, Marco

    2011-01-01

    A preliminary comparative study of basalt and E-glass woven fabric reinforced composites was performed. The fabrics were characterized by the same weave pattern and the laminates tested by the same fiber volume fraction. Results of the flexural and interlaminar characterization are reported. Basalt fiber composites showed higher flexural modulus and apparent interlaminar shear strength (ILSS) in comparison with E-glass ones but also a lower flexural strength and similar electrical properties. With this fiber volume fraction, scanning electron microscopy (SEM) analysis of the fractured surfaces enabled a better understanding both of the failure modes involved and of points of concern. Nevertheless, the results of this study seem promising in view of a full exploitation of basalt fibers as reinforcement in polymer matrix composites (PMCs).

  3. Fatigue damage mechanism and strength of woven laminates

    International Nuclear Information System (INIS)

    Xiao, J.; Bathias, C.

    1993-01-01

    The apparent secant stiffness changes with the cyclic number for both unnotched and notched woven laminated specimens (two orthotropic and one quasi-isotropic) during tensile fatigue test at a fixed ratio of maximum fatigue load to UTS were observed. The observable damage initiation and evolution as a function of the cyclic number were directly measured at the notched specimen surface with a video-camera system. The fatigue strengths of the unnotched and notched specimens were determined. The results show that the normalized apparent secant stiffness change curves as a function of cyclic numbers can be divided into three stages. For the first and the second stages in notched specimens and for total life of unnotched specimens, the damage has not been evidently observed and certainly verified with the traditional experimental methods such as radiography and microscopy although many acoustic emission signals can be obtained. The last stage for the notched specimens (N/Nf>0.4, the secant stiffness decreases fast) corresponds to the initiation and evolution of the observable damages. The fatigue strength of these woven composite laminates is dominated by the third stage during which the observable damage develops along the specimen ligament until fracture. During the third stage, a critical dimension at the specimen ligament and a life threshold can be found beyond which a final catastrophic fracture will immediately occur. The quasi-isotropic laminate is of a fatigue strength lower than the two orthotropic laminates of which the fatigue strengths are approaching to each other. The fatigue life is also influenced by the stacking sequences. (orig.)

  4. Physical properties of recycled PET non-woven fabrics for buildings

    Science.gov (United States)

    Üstün Çetin, S.; Tayyar, A. E.

    2017-10-01

    Recycled fibers have been commonly used in non-woven production technology for engineering applications such as textile engineering and civil engineering. Nonwovens including recycled fibers can be utilized in insulation, roofing and floor separation applications. In this study, physical performance properties such as drape, bending resistance, tensile strength, and breaking elongation values of non-woven fabrics consisting of v-PET (virgin) and r-PET (recycled) fibers in five different blend ratios are examined comparatively. The test results indicated that r-PET can be used in non-wovens for civil engineering applications such as insulation, roofing and floor separation fulfilling the acceptable quality level values.

  5. The Effect of Customized Woven and Stacked Layer Orientation on Tensile and Flexural Properties of Woven Kenaf Fibre Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    A. Hamdan

    2016-01-01

    Full Text Available The synthetic fibres have created some issues including risk of inhalation during fabrication process, renewability, biodegradability, and recyclability in composites industry. The usage of biocomposites as a replacement to synthetic fibres is beginning to be widespread. However, it is noted that lesser attention has been devoted to evaluating the mechanical properties of woven kenaf composites at various woven and stacked layer orientation. Thus, the research objective is to identify the effect of woven and stacked layer orientation on tensile and flexural properties of kenaf composites. Two types of fibre orientation are employed; type A contains a higher yarn density and type B contains a low yarn density. The tensile and flexural tests are conducted to analyze the mechanical properties of woven kenaf fibre composites and compare them to random chopped kenaf composites. The fracture interface between fibre and matrix epoxy is further investigated via scanning electron microscope. Type A kenaf improved up to 199% and 177% as compared to random chopped kenaf for flexural strength and tensile strength, respectively. Scanning electron microscopy analysis shows that resin matrix is properly induced into kenaf fibre gap hence giving additional strength to woven kenaf as compared to random chopped kenaf.

  6. Viscoelastic and thermal properties of woven sisal fabric reinforced natural rubber biocomposites

    CSIR Research Space (South Africa)

    John, MJ

    2009-01-01

    Full Text Available This study explores the dynamic mechanical behavior of woven sisal fabric reinforced natural rubber composites. The influence of chemical modification on the viscoelastic properties has also been determined. Moreover, the effect of frequency...

  7. Calibration of 3D Woven Preform Design Code for CMC Materials, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Mechanical and thermal performance of CMC components benefit from low part count, integrally fabricated designs of 3D woven reinforcement. The advantages of these...

  8. Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

    Science.gov (United States)

    Suhaily, M.; Hassan, C. H. Che; Jaharah, A. G.; Azmi, H.; Afifah, M. A.; Khairusshima, M. K. Nor

    2018-04-01

    In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites.

  9. Integration of Complex Geometry, 3D Woven Preforms via Innovative Stitching Technique, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Thick, 3D woven carbon/phenolic composites offer potential improvement over legacy thermal protection systems (TPS) for re-entry vehicle heat shield applications....

  10. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  11. Woven type smart soft composite beam with in-plane shape retention

    International Nuclear Information System (INIS)

    Wu, Renzhe; Han, Min-Woo; Lee, Gil-Yong; Ahn, Sung-Hoon

    2013-01-01

    Shape memory alloy (SMA) wire embedded composites (SMAECs) are widely used as morphing structures in small-size and high-output systems. However, conventional SMAECs cannot keep deformed shapes without additional energy. In this paper, a new kind of smart structure named the woven type smart soft composite (SSC) beam is introduced, which is not only capable of morphing, but also maintaining its deformed shape without additional energy. The woven type SSC beam consists of two parts: woven wires and matrix. The selected woven wires are nitinol (Ni–Ti) SMA wires and glass fibers, while the matrix part is polydimethylsiloxane (PDMS). In order to evaluate the performance of the woven type SSC beam in areas such as in-plane deformation, blocking force and repeatability, a beam-shape specimen is prepared of size 100 mm (length) × 8 mm (width) ×3 mm (thickness). The fabricated SSC beam achieved 21 mm deformation and 16 mm shape retention. Blocking force was measured using a dynamometer, and was about 60 mN. In the repeatability test, it recovered almost the same position when its cooling time was 90 s more. Consequently, the woven type SSC beam can be applied to bio-mimicking, soft morphing actuators, consuming less energy than traditional SMAECs. (paper)

  12. Automatic measurement for dimensional changes of woven fabrics based on texture

    Science.gov (United States)

    Liu, Jihong; Jiang, Hongxia; Liu, X.; Chai, Zhilei

    2014-01-01

    Dimensional change or shrinkage is an important functional attribute of woven fabrics that affects their basic function and price in the market. This paper presents a machine vision system that evaluates the shrinkage of woven fabrics by analyzing the change of fabric construction. The proposed measurement method has three features. (i) There will be no stain of shrinkage markers on the fabric specimen compared to the existing measurement method. (ii) The system can be used on fabric with reduced area. (iii) The system can be installed and used as a laboratory or industrial application system. The method processed can process the image of the fabric and is divided into four steps: acquiring a relative image from the sample of the woven fabric, obtaining a gray image and then the segmentation of the warp and weft from the fabric based on fast Fourier transform and inverse fast Fourier transform, calculation of the distance of the warp or weft sets by gray projection method and character shrinkage of the woven fabric by the average distance, coefficient of variation of distance and so on. Experimental results on virtual and physical woven fabrics indicated that the method provided could obtain the shrinkage information of woven fabric in detail. The method was programmed by Matlab software, and a graphical user interface was built by Delphi. The program has potential for practical use in the textile industry.

  13. Composites structures for bone tissue reconstruction

    International Nuclear Information System (INIS)

    Neto, W.; Santos, João; Avérous, L.; Schlatter, G.; Bretas, Rosario

    2015-01-01

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth

  14. Composites structures for bone tissue reconstruction

    Science.gov (United States)

    Neto, W.; Santos, João.; Avérous, L.; Schlatter, G.; Bretas, Rosario.

    2015-05-01

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

  15. Damage in woven CFRP laminates subjected to low velocity impacts

    International Nuclear Information System (INIS)

    Ullah, H; Abdel-Wahab, A A; Harland, A R; Silberschmidt, V V

    2012-01-01

    Carbon fabric-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution in these materials affects both their in-service properties and performance that can deteriorate with time. These processes need adequate means of analysis and investigation, the major approaches being experimental characterisation and non-destructive examination of internal damage in composite laminates. This research deals with a deformation behaviour and damage in woven composite laminates due to low-velocity dynamic out-of-plane bending. Experimental tests are carried out to characterise the behaviour of such laminates under large-deflection dynamic bending in un-notched specimens in Izod tests using a Resil Impactor. A series of low-velocity impact tests is carried out at various levels of impact energy to assess the energy absorbed and force-time response of CFRP laminates. X-ray micro computed tomography (micro-CT) is used to investigate material damage modes in the impacted specimens. X-ray tomographs revealed that through-thickness matrix cracking, inter-ply delamination and intra-ply delamination, such as tow debonding and fabric fracture, were the prominent damage modes.

  16. Damage in woven CFRP laminates under impact loading

    Science.gov (United States)

    Ullah, H.; Harland, A. R.; Silberschmidt, V. V.

    2012-08-01

    Carbon fibre-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution affects both in-service properties and performance of CFRP that can deteriorate with time. These failure modes need adequate means of analysis and investigation, the major approaches being experimental characterisation and numerical simulations. This research deals with a deformation behaviour and damage in composite laminates due to dynamic bending. Experimental tests are carried out to characterise the behaviour of a woven CFRP material under large-deflection dynamic bending in impact tests carried out to obtain the force-time and absorbed energy profiles for CFRP laminates. Damage in the impacted laminates is analysed using optical microscopy. Numerical simulations are performed to study the deformation behaviour and damage in CFRP for cases of large-deflection bending based on three-dimensional finite-element models implemented in the commercial code Abaqus/Explicit. Multiple layers of bilinear cohesive-zone elements are employed to model the initiation and progression of inter-ply delamination observed in the microscopy studies. The obtained results of simulations show good agreement with experimental data.

  17. Antibacterial properties of modified biodegradable PHB non-woven fabric.

    Science.gov (United States)

    Slepička, P; Malá, Z; Rimpelová, S; Švorčík, V

    2016-08-01

    The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles

    International Nuclear Information System (INIS)

    Degoutin, S; Jimenez, M; Casetta, M; Bellayer, S; Chai, F; Blanchemain, N; Neut, C; Kacem, I; Traisnel, M; Martel, B

    2012-01-01

    The aim of this work is to prepare non-woven polypropylene (PP) textile functionalized with bioactive molecules in order to improve its anticoagulation and antibacterial properties. This paper describes the optimization of the grafting process of acrylic acid (AA) on low-pressure cold-plasma pre-activated PP, the characterization of the modified substrates and the effect of these modifications on the in vitro biological response towards cells. Then, the immobilization of gentamicin (aminoglycoside antibiotic) and heparin (anticoagulation agent) has been carried out on the grafted samples by either ionic interactions or covalent linkages. Their bioactivity has been investigated and related to the nature of their interactions with the substrate. For gentamicin-immobilized AA-grafted samples, an inhibition radius and a reduction of 99% of the adhesion of Escherichia coli have been observed when gentamicin was linked by ionic interactions, allowing the release of the antibiotic. By contrast, for heparin-immobilized AA-grafted PP samples, a strong increase of the anticoagulant effect up to 35 min has been highlighted when heparin was covalently bonded on the substrate, by contact with the blood drop. (paper)

  19. ABSORBENCY CHARACTERISTICS OF PESHTAMALS: TRADITIONAL TURKISH WOVEN CLOTHES

    Directory of Open Access Journals (Sweden)

    KESKIN Reyhan

    2014-05-01

    Full Text Available Absorbency of textiles is defined as the ability of taking in a fluid in the manner of a sponge. Absorbency is required for comfort properties in so me clothes such as sportswear and underwear clothing, for drying properties in napkins, towels and bathrobes, for health concerns in some medical textiles such as bandages, gauze and absorbent cotton, and for cleaning properties in washclothes and mops. In this study five different fabric samples (three woven 100% cotton fabrics A, B and P respectively at plain, twill, and peshtamal weaving patterns and two 100% cotton terry towels T1 and T2 were tested. The absorbency properties of the samples were evaluated according to the droplet test, sinking time test and wicking height tests (pottasium chromate test. Peshtamal samples showed better absorbency results than plain and twill weaves and lower but close results to towel samples according to the droplet test, sinking time test and wicking height tests. The absorbency properties of peshtamals showed results close to towel samples. The void content of peshtamals is higher than plain and twill samples but closer and lower than towel samples. The good absorbency results of peshtamals might be due to the void content of peshtamals which is higher than plain and twill samples but closer and lower than towel samples. Peshtamals which are good in absorbency and light in weight might be used widespreadly in daily life for their high absorbency, and on travel for weight saving purposes.

  20. Woven TPS Enabling Missions Beyond Heritage Carbon Phenolic

    Science.gov (United States)

    Stackpoole, Margaret M.; Venkatapathy, Ethiraj; Feldman, Jay D.

    2013-01-01

    NASAs Office of the Chief Technologist (OCT) Game Changing Division recently funded an effort to advance a Woven TPS (WTPS) concept. WTPS is a new approach to producing TPS architectures that uses precisely engineered 3D weaving techniques to customize material characteristics needed to meet specific missions requirements for protecting space vehicles from the intense heating generated during atmospheric entry. Using WTPS, sustainable, scalable, mission-optimized TPS solutions can be achieved with relatively low life cycle costs compared with the high costs and long development schedules currently associated with material development and certification. WTPS leverages the mature state-of-the-art weaving technology that has evolved from the textile industry to design TPS materials with tailorable performance. Currently, missions anticipated encountering heat fluxes in the range of 1500 4000 Wcm2 and pressures greater than 1.5 atm are limited to using fully dense Carbon Phenolic. However, fully dense carbon phenolic is only mass efficient at higher heat fluxes g(reater than 4000 Wcm2), and current mission designs suffer this mass inefficiency for lack of an alternative mid-density TPS. WTPS not only bridges this mid-density TPS gap but also offers a replacement for carbon phenolic, which itself requires a significant and costly redevelopment effort to re-establish its capability for use in the high heat flux missions recently prioritized in the NRC Decadal survey, including probe missions to Venus, Saturn and Neptune. This presentation will overview the WTPS concept and present some results from initial testing completed comparing WTPS architectures to heritage carbon phenolic.

  1. Ballistic Impact Response of Woven Hybrid Coir/Kevlar Laminated Composites

    Directory of Open Access Journals (Sweden)

    Azrin Hani A.R

    2016-01-01

    Full Text Available The effects of different laminated hybrid composites stacking configuration subjected to ballistic impact were investigated. The hybrid composites consist of woven coir (C and woven Kevlar (K layers laminated together. The samples of woven coir were prepared using handloom device. The composites were produced by stacking the laminated woven coir and Kevlar alternately with the presence of the binder. The samples were tested under ballistic impact with different stacking configuration. The results obtained had successfully achieved the National Institute of Justice (NIJ standard level IIA with energy absorption of 435.6 kJ and 412.2 kJ under the projectile speed of between 330 m/s and 321 m/s respectively. Samples that having Kevlar layer at the front face and woven coir layer as back face achieved partial penetration during projectile impact. This orientation is proven to have good impact energy absorption and able to stop projectile at the second panel of the composites.

  2. Load transfer in bovine plexiform bone determined by synchrotron x-ray diffraction

    International Nuclear Information System (INIS)

    Akhtar, R.; Daymond, M.; Almer, J.; Mummery, P.; The Univ. of Manchester; Queen's Univ.

    2008-01-01

    High-energy synchrotron x-ray diffraction (XRD) has been used to quantify load transfer in bovine plexiform bone. By using both wide-angle and small-angle XRD, strains in the mineral as well as the collagen phase of bone were measured as a function of applied compressive stress. We suggest that a greater proportion of the load is borne by the more mineralized woven bone than the lamellar bone as the applied stress increases. With a further increase in stress, load is shed back to the lamellar regions until macroscopic failure occurs. The reported data fit well with reported mechanisms of microdamage accumulation in bovine plexiform bone

  3. [Osteoclasts and early bone remodeling after orthodontic micro-implant placement].

    Science.gov (United States)

    Zhang, Wei; Guo, Jia-jia; Zhu, Wen-qian; Tang, Guo-hua

    2013-08-01

    To observe the incidence of osteoclasts during early bone remodeling after orthodontic micro-implant placement. Twenty New Zealand rabbits were randomly allotted into 4 groups. One micro-implant was implanted proximal to the epiphyseal plate of the tibia. Animals were sacrificed on day 3, 7, 14 and 28 (n=5). The sequence of histological changes around the micro-implants were evaluated by hematoxylin and eosin (HE) staining. Osteoclasts were identified by TRAP staining. The differences of the number of the osteoclasts among each time point were analyzed by one way ANOVA with SPSS 19.0 software package. After 3 days of implantation, a large number of erythrocytes, inflammatory cells, mesenchymal cells and bone debris were seen at the implant bone interfaces. Few osteoclasts were observed. On day 7, granular woven bone was formed and some osteoclasts were found in the Howship's lacunae. New bone formation and mineralization were apparent on day 14. Meanwhile, large amounts of osteoclasts were found in the latticed woven bone. On day 28, woven trabeculae with lamellate structures connected to lamellar bone and fewer osteoclasts were identified. Semi-quantitative analysis showed that the number of the osteoclasts was at peak on day 14. There were significant differences among each time point (Pmicro-implant insertion.

  4. 77 FR 31182 - Final Withdrawal of Regulations Pertaining to Imports of Cotton Woven Fabric and Short Supply...

    Science.gov (United States)

    2012-05-25

    ... Woven Fabric and Short Supply Procedures AGENCY: Import Administration, International Trade... final rule withdrawing regulations pertaining to imports of cotton woven fabric and short supply..., and the short supply voluntary restraints have not affected U.S. trade for over 19 years. The removal...

  5. Studies on the chemical resistance and mechanical properties of natural polyalthia cerasoides woven fabric/glass hybridized epoxy composites

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2015-01-01

    Full Text Available In the present work, natural Polyalthiacerasoide woven fabrics were extracted from the bark of the tree and using these woven fabrics/glass fibre as reinforcements and epoxy as matrix the hybrid composites were prepared by the hand lay-up technique...

  6. The twenty-four/four hour ratio (T/F ratio) of Tc-99m MDP uptake in patients with bone metastases and degenerative changes

    International Nuclear Information System (INIS)

    Israel, O.; Kleinhaus, U.; Keren, R.; Frankel, A.; Front, D.

    1984-01-01

    Normal and metastatic bone differ in their histological structure. Normal bone is mainly lamellar while metastatic bone formation is made in a large part out of new woven bone. The woven bone has a much larger surface area than the more stable lamellar bone and it is lined with metabolically active osteoblasts. The crystalline structures in the woven bone are smaller and have a larger surface area available for absorption. Uptake of bone seeking radiopharmaceuticals continues in new woven bone longer than in the lamellar bone. Bone scintigraphy was performed in 89 patients at four hours and 24 hours using a digital camera. The lesion to non lesion (L/N) ratio was determined using the camera computer. The T/F ratio was calculated: T/F=((L/N)-24)/((L/N)-4). Three groups were investigated. In 15 patients with metastatic bone carcinoma, T/F ratio was 1.46 +- 0.4. In 47 patients with degenerative joint disease the T/F ratio was 1.05 +- 0.06. In 27 patients with treated metastatic bone carcinoma the T/F ratio was 1.12 +- 0.13. The T/F ratio is significantly (p<0.001) different in patients with metastases compared to patients with benign degenerative disease. Chemotherapeutic and hormonal treatment cause significant (p<0.001) reduction in the T/F ratio. The T/F ratio may have a potential in differentiating degenerative from neoplastic diseases and in the evaluation of patients with bone metastases undergoing treatment

  7. The Layer of Kevlar Angle-interlock Woven Fabric Effect on the Tensile Properties of Composite Materials

    Science.gov (United States)

    Xie, Wan-Chen; Guo, Xu-Yi; Yan, Tao; Zhang, Shang-Yong

    2017-09-01

    This article is based on the structure of three-dimensional angle-interlock longitudinal.The 3-layer, 5-layer, 7-layer and 9-layer of angle-interlock 3D fabrics are woven on sample weaving machine respectively with the 1500D Kevlar fiber twist filament produced by United States DuPont. At the same time, Kevlar plain weave fabric is woven, and three, five, seven and nine layers’ fabric are to be compared. In the process of VARTM composite technology, epoxy resin is matrix material, acetone is diluent, triethylene tetramine is curing agent and the five different fabrics are the reinforced materials respectively. Finally, eight different three-dimensional woven fabric composites were prepared. In this paper, the tensile properties of eight kinds of three-dimensional woven fabric composites were tested respectively.Finally, it is concluded that the five-layer angle-interlock woven fabric prepared by Kevlar fiber shows the best tensile property.

  8. Bone tumors

    International Nuclear Information System (INIS)

    Unni, K.K.

    1988-01-01

    This book contains the proceedings on bone tumors. Topics covered include: Bone tumor imaging: Contribution of CT and MRI, staging of bone tumors, perind cell tumors of bone, and metastatic bone disease

  9. Celecoxib does not significantly delay bone healing in a rat femoral osteotomy model: a bone histomorphometry study

    Directory of Open Access Journals (Sweden)

    Iwamoto J

    2011-12-01

    Full Text Available Jun Iwamoto1, Azusa Seki2, Yoshihiro Sato3, Hideo Matsumoto11Institute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, Japan; 2Hamri Co, Ltd, Tokyo, Japan; 3Department of Neurology, Mitate Hospital, Fukuoka, JapanBackground and objective: The objective of the present study was to determine whether celecoxib, a cyclo-oxygenase-2 inhibitor, would delay bone healing in a rat femoral osteotomy model by examining bone histomorphometry parameters.Methods: Twenty-one 6-week-old female Sprague-Dawley rats underwent a unilateral osteotomy of the femoral diaphysis followed by intramedullary wire fixation; the rats were then divided into three groups: the vehicle administration group (control, n = 8, the vitamin K2 administration (menatetrenone 30 mg/kg orally, five times a week group (positive control, n = 5, and the celecoxib administration (4 mg/kg orally, five times a week group (n = 8. After 6 weeks of treatment, the wires were removed, and a bone histomorphometric analysis was performed on the bone tissue inside the callus. The lamellar area relative to the bone area was significantly higher and the total area and woven area relative to the bone area were significantly lower in the vitamin K2 group than in the vehicle group. However, none of the structural parameters, such as the callus and bone area relative to the total area, lamellar and woven areas relative to the bone area, or the formative and resorptive parameters such as osteoclast surface, number of osteoclasts, osteoblast surface, osteoid surface, eroded surface, and bone formation rate per bone surface differed significantly between the vehicle and celecoxib groups.Conclusion: The present study implies that celecoxib may not significantly delay bone healing in a rat femoral osteotomy model based on the results of a bone histomorphometric analysis.Keywords: femoral osteotomy, bone healing, callus, rat, celecoxib

  10. Studies on the mechanical properties of woven jute fabric reinforced poly(l-lactic acid composites

    Directory of Open Access Journals (Sweden)

    G.M. Arifuzzaman Khan

    2016-01-01

    Full Text Available Development of ecofriendly biocomposites to replace non-biodegradable synthetic fiber composites is the main objective of this study. To highlight the biocomposites as a perfect replacement, the plain woven jute fabric (WJF reinforced poly(l-lactic acid (PLLA composites were prepared by the hot press molding method. The influence of woven structure and direction on the mechanical properties i.e. tensile, flexural and impact properties was investigated. The average tensile strength (TS, tensile modulus (TM, flexural strength (FS, flexural modulus (FM, and impact strength (IS of untreated woven jute composite (in warp direction were improved about 103%, 211%, 95.2%, 42.4% and 85.9%, respectively and strain at maximum tensile stress for composite samples was enhanced by 11.7%. It was also found that the strengths and modulus of composites in warp direction are higher than those in weft direction. WJF composites in warp and weft directions presented superior mechanical properties than non-woven jute fabric (NWJF composites. Chemical treatment of jute fabric through benzoylation showed a positive effect on the properties of composites. Morphological studies by SEM demonstrated that better adhesion between the treated fabric and PLLA was achieved.

  11. ROLE OF RESOURCE-BASED ENTREPRENEURSHIP DEVELOPMENT TO INCREASE COMPETITIVENESS OF TRADITIONALLY WOVEN SARONG CREATIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Zakiyah Z.

    2017-07-01

    Full Text Available The objectives of the study were to describe position of traditionally woven sarong creative industry in Donggala in business competition based on both internal aspects (strength and weakness and external ones (opportunity and threats, and role of resource-based entrepreneurship development to improve competitiveness of the traditionally woven sarong creative industry in Donggala. In order to meet the objectives, the study used SWOT and Moderating Regression Analysis (MRA. The findings showed that the strength of the Donggala woven sarong industry was the sarong had indigenous Central Sulawesi pattern, it was part of the rural society and was traditionally made. The weaknesses were the sarong pattern and design had yet been touched by modern technology, its color faded away easily during laundry and it was only sold in the local areas. The opportunities were the sarong may become alternative souvenir from Central Sulawesi and development of creative economy was widely discussed recently. The threat was there were various types and patterns of sarong in the market; and entrepreneurship was moderating variables between resource-based strategy and competitiveness of Donggala woven sarong creative industry; the level of significance was 0.001 and the R-Square was 0.803.

  12. 78 FR 12716 - Laminated Woven Sacks From the People's Republic of China: Negative Final Determination of...

    Science.gov (United States)

    2013-02-25

    ... visible, although, they are produced using only two inks and a screen. Petitioners contend that such graphics would normally be printed using three inks printed in register at three different print stations...-circumvention inquiry is laminated woven sacks produced with two ink colors printed in register and a screening...

  13. The effect of z-binding yarns on the electrical properties of 3D woven composites

    KAUST Repository

    Saleh, Mohamed Nasr; Yudhanto, Arief; Lubineau, Gilles; Soutis, Constantinos

    2017-01-01

    Electrical resistance monitoring (ERM) has been used to study the effect of the z-binding yarns on the initial electrical resistance (ER) and its change of three architectures of 3D woven carbon fibre composites namely (orthogonal “ORT”, layer

  14. A meso-scale model to study the compressive strength of woven carbon fiber reinforced plastics

    NARCIS (Netherlands)

    Schormans, J.M.J.; Remmers, J.J.C.; Wilson, W.; Deshpande, V.S.

    2016-01-01

    Modeling kink-band formation in woven composites using a detailed micro-model is numerically expensive. In order to reduce the computational resources, a method to homogenize fiber-tows is proposed which uses a rules of mixture approach. The method is tested by comparing the stiffness and

  15. Characterising the loading direction sensitivity of 3D woven composites: Effect of z-binder architecture

    KAUST Repository

    Saleh, Mohamed Nasr; Yudhanto, Arief; Potluri, Prasad; Lubineau, Gilles; Soutis, Constantinos

    2016-01-01

    Three different architectures of 3D carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) were tested in quasi-static uniaxial tension. Mechanical tests (tensile in on-axis of warp and weft directions as well

  16. Strengthening the Fabric of Government: A Description of WOVEN (Women's Ohio Volunteer Employment Network).

    Science.gov (United States)

    Miller, Mary E.

    WOVEN (Women's Ohio Volunteer Employment Network), is directed at changing the low representation of women in decision making positions in public service. Women comprise more than a third of the work force in the State of Ohio; yet they have typically held the low level, low paying jobs. A 1973 status report on women in State government revealed…

  17. 78 FR 6069 - Laminated Woven Sacks From the People's Republic of China: Preliminary Results of Antidumping...

    Science.gov (United States)

    2013-01-29

    ... the People's Republic of China: Preliminary Results of Antidumping Duty Administrative Review; 2011... antidumping duty order on laminated woven sacks (``sacks'') from the People's Republic of China (``PRC''). The period of review (``POR'') is August 1, 2011, through July 31, 2012. The review covers one exporter of...

  18. STRESS - STRAIN CURVE ANALYSIS OF WOVEN FABRICS MAD E FROM COMBED YARNS TYPE WOOL

    Directory of Open Access Journals (Sweden)

    VÎLCU Adrian

    2014-05-01

    Full Text Available The paper analyses the tensile behavior of woven fabrics made from 45%Wool + 55% PES used for garments. Analysis of fabric behavior during wearing has shown that these are submitted to simple and repeated uni-axial or bi-axial tensile strains. The level of these strains is often within the elastic limit, rarely going over yielding. Therefore the designer must be able to evaluate the mechanical behavior of such fabrics in order to control the fabric behavior in the garment. This evaluation is carried out based on the tensile testing, using certain indexes specific to the stress-strain curve. The paper considers an experimental matrix based on woven fabrics of different yarn counts, different or equal yarn count for warp and weft systems and different structures. The fabrics were tested using a testing machine and the results were then compared in order to determine the fabrics’ tensile behavior and the factors of influence that affect it.From the point of view of tensile testing, the woven materials having twill weave are preferable because this type of structure is characterized by higher durability and better yarn stability in the fabric. In practice, the woven material must exhibit an optimum behavior to repeated strains, flexions and abrasions during wearing process. The analysis of fabrics tensile properties studied by investigation of stress-strain diagrams reveals that the main factors influencing the tensile strength are: yarns fineness, technological density of those two systems of yarns and the weaving type.

  19. CREASING BEHAVIOR OF SOME WOVEN MATERIALS MADE FROM COMBED YARNS TYPE

    Directory of Open Access Journals (Sweden)

    HRISTIAN Liliana

    2017-05-01

    Full Text Available The paper analyses the behavior to creasing of some woven materials made from yarns type wool used for ready-made clothes. Factors like fibrous composition, properties of constituent fibers, wovens structure parameters, mechanical properties of warp and weft yarns and finishing treatments that influenced the recovery capacity from crease/folding were investigated experimentally through several tests which revealed their importance in the process. The creasing of woven materials made from combed yarns type wool used for ready-clothes is an undesired deformation effect with temporary or permanent character, which is caused by a composed strain of bending and compression during utilization, processing or maintenance. It is manifested by the appearance of wrinkles, folds or stripes on the surface of wovens materials, thus diminishing their qualitative appearance and also their practical value. Creasing is the result of irreversible changes created through the reciprocal sliding of structural fiber components when exposed to a bending strain. Creasing is specific to oriented structures with high crystallinity (cellulosic fibers. The sliding appears because of hydrogen bond breaking which can, however, reform easy in other positions conferring a permanent character to creasing.Functional apparel will be subjected to a wide range of end uses such that a garment will be affected by intern (fibres, yarn fineness warp/weft, fabric density, thickness, fabric count and external factors (external environment - exposure to sunlight, wind, rain, cold weather conditions, fabric/human body interaction. These factors affect the performance and behaviour of functional.

  20. Direct Cost of Reprocessing Cotton-woven Surgical Drapes: a Case Study

    Directory of Open Access Journals (Sweden)

    Mariana Fexina Tomé

    Full Text Available OBJECTIVE Identify the direct cost of reprocessing double and single cotton-woven drapes of the surgical LAP package. METHOD A quantitative, exploratory and descriptive case study, performed at a teaching hospital. The direct cost of reprocessing cotton-woven surgical drapes was calculated by multiplying the time spent by professionals involved in reprocessing the unit with the direct cost of labor, adding to the cost of materials. The Brazilian currency (R$ originally used for the calculations was converted to US currency at the rate of US$0.42/R$. RESULTS The average total cost for surgical LAP package was US$9.72, with the predominance being in the cost of materials (US$8.70 or 89.65%. It is noteworthy that the average total cost of materials was mostly impacted by the cost of the cotton-woven drapes (US$7.99 or 91.90%. CONCLUSION The knowledge gained will subsidize discussions about replacing reusable cotton-woven surgical drapes for disposable ones, favoring arguments regarding the advantages and disadvantages of this possibility considering human resources, materials, as well as structural, environmental and financial resources.

  1. Preparation and Characterization of Polypropylene Non-woven Fabrics Prepared by Melt-blown Spinning for Filtration Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Konghee; Park, Mira; Kim, Hakyong [Chonbuk National Univ., Jeonju (Korea, Republic of); Jin, Fanlong; Park, Soojin [Inha Univ., Incheon (Korea, Republic of)

    2014-06-15

    PP non-woven fabrics were prepared by melt-blown spinning, followed by heat and plasma treatments. After heat treatment, the PP non-woven fabrics displayed decreased water flux, increased tensile strength, decreased elongation, and an average pore size of 0.7 μm. The hydrophilicity of the PP non-woven fabrics was improved by plasma treatment. The water flux of the PP non-woven fabrics increased about two fold after the plasma treatment. The particle removal efficiency was determined to be 97.2-99.4% for 1-3 μm sized particles, demonstrating a high particle removal efficiency. Polypropylene (PP) non-woven fabrics have been widely used as filtration membranes in wastewater purification with industrial applications due to their low cost, good mechanical strength, and high thermal and chemical stability. The membrane fouling behavior depends strongly on the physical and mechanical properties of the membrane, including pore size, porosity, morphology, and hydrophilicity. In general, PP non-woven fabrics have poor hydrophilicity; this has limited their application in the biomedical field. It is therefore necessary to develop PP non-woven fabrics with improved surface hydrophilicity to increase the scope of their use. Plasma treatment, an environmentally friendly alternative to traditional chemical activation, only changes the uppermost atomic layers of a membrane surface without affecting the bulk properties of the polymer.

  2. Numerical study of the heat transfer in wound woven wire matrix of a Stirling regenerator

    International Nuclear Information System (INIS)

    Costa, S.C.; Barrutia, Harritz; Esnaola, Jon Ander; Tutar, Mustafa

    2014-01-01

    Highlights: • A correlation equation to characterize regenerator heat transfer is proposed. • Proposed correlation can be used as a effective tool to optimize the heat transfer. • Thermal efficiency can be maximized by optimizing Stirling regenerator heat transfer. • The wound woven wire matrix provides lower Nusselt numbers compared to stacked. • The developed correlation can be used for Reynolds number range from 4 to 400. - Abstract: Nusselt number correlation equations are numerically derived by characterizing the heat transfer phenomena through porous medium of both stacked and wound woven wire matrices of a Stirling engine regenerator over a specified range of Reynolds number, diameter and porosity. A finite volume method (FVM) based numerical approach is proposed and validated against well known experimentally obtained empirical correlations for a random stacking woven wire matrix, the most widely used due to fabrication issues, for Reynolds number up to 400. The results show that the numerically derived correlation equation corresponds well with the experimentally obtained correlations with less than 6% deviation with the exception of low Reynolds numbers. Once the numerical approach is validated, the study is further extended to characterize the heat transfer in a wound woven wire matrix model for a diameter range from 0.08 to 0.11 mm and a porosity range from 0.60 to 0.68 within the same Reynolds number range. Thus, the new correlation equations are numerically derived for different flow configurations of the Stirling engine regenerator. It is believed that the developed correlations can be applied with confidence as a cost effective solution to characterize and hence to optimize stacked and wound woven wire Stirling regenerator in the above specified ranges

  3. The Improvement of the Resistance to Candida albicans and Trichophyton interdigitale of Some Woven Fabrics Based on Cotton

    Science.gov (United States)

    Stelescu, Maria Daniela; Manaila, Elena; Nicula, Gheorghe; Iordache, Ovidiu; Dinca, Laurentiu Christian; Berechet, Mariana-Daniela; Vamesu, Mariana; Gurau, Dana

    2014-01-01

    This paper presents the improvement of the antimicrobial character of woven fabrics based on cotton. The woven fabrics were cleaned in oxygen plasma and treated by padding with silver chloride and titanium dioxide particles. The existence of silver and titanium on woven fabrics was evidenced by electronic microscope images (SEM, EDAX) and by flame atomic absorption spectrophotometry. The antimicrobial tests were performed with two fungi: Candida albicans and Trichophyton interdigitale. The obtained antimicrobial effect was considerably higher compared to the raw fabrics. Treatment of dyed fabrics with a colloidal solution based on silver chloride and titanium dioxide particles does not considerably influence colour resistance of dyes. PMID:25276112

  4. The mechanism of uptake of bone-seeking isotopes by skeletal metastases

    International Nuclear Information System (INIS)

    Galasko, C.S.B.

    1977-01-01

    Although skeletal scintigraphy has become accepted as an extremely useful method of examining the skeleton, particularly for the early detection of skeletal metastases and the assessment of their response to therapy, the underlying pathological changes which allow this use of isotopes are not well understood. This study was undertaken in man and in the experimental animal in an attempt to explain the underlying mechanism for skeletal scintigraphy. Autopsy specimens indicated that tumour invasion of bone, with the possible exception of lymphomata, is associated with a significant increase in new bone production, shown by an increase in the amount of osteoid tissue and particularly immature woven bone. The animal experiments indicated that there are two mechanisms for this new bone formation. These different mechanisms may explain the different radiographic appearances. Irrespective of the mechanism of production, this new bone had a markedly increased avidity for bone-seeking isotopes. When the tumour was successfully irradiated the bone lost its osteoblastic reaction, and the production of immature new bone ceased as did the increased uptake of bone-seeking isotopes. Investigation of the vascularity of the lesion showed that there was an increase in small vessels in the neighbourhood of the tumour. The results of the study suggest that the uptake of isotope occurs in two phases. During the first phase, which occurs very rapidly, large amounts of isotope accumulate in the extracellular fluid following the increased vascularity. In the second slower phase, the isotope is gradually concentrated by the reactive immature new woven bone. (author)

  5. Functionalisation of polypropylene non-woven fabrics (NWFs): Functionalisation by oxyfluorination as a first step for graft polymerisation

    CSIR Research Space (South Africa)

    Vargha, V

    2011-10-01

    Full Text Available Surface oxyfluorination had been carried out on polypropylene non-woven fabric (PP NWF) samples of different morphologies and pore sizes. The modified surfaces were characterised by Attenuated Total Reflectance Fourier Transform InfraRed (ATR...

  6. Effect of storage conditions on graft of polypropylene non-woven fabric induced by electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Young; Jeun, Joon Pyo; Kang, Phil Hyun [Radiation Research Dvision for Industry and Environment, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

    2015-05-15

    In this study, we fabricated effect of storage conditions on graft of polypropylene (PP) non-woven fabric induced by electron beam. The electron beam irradiations on PP non-woven fabric were carried out over a range of irradiation doses from 25 to 100 kGy to make free radicals on fabric surface. The radical measurement was established by electron spin resonance (ESR) for confirming the changes of the alkyl radical and peroxy radical according to effect of storage time, storage temperature and atmosphere. It was observed that the free radicals were increased with irradiation dose and decreased with storage time due to the continuous oxidation. However, the radical extinction was significantly delayed due to reduced mobility of radicals at extremely low temperature. The degree of graft based on the analysis of ESR was investigated. The conditions of graft reaction were set at a temperature: 60 degrees Celcius, reaction time: 6 hours and styrene monomer concentration: 20 wt%.

  7. Ballistic Impact Resistance of Plain Woven Kenaf/Aramid Reinforced Polyvinyl Butyral Laminated Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2016-07-01

    Full Text Available Traditionally, the helmet shell has been used to provide protection against head injuries and fatalities caused by ballistic threats. In this study, because of the high cost of aramid fibres and the necessity for environmentally friendly alternatives, a portion of aramid was replaced with plain woven kenaf fibre, with different arrangements and thicknesses, without jeopardising the requirements demanded by U.S. Army helmet specifications. Furthermore, novel helmets were produced and tested to reduce the dependency on the ballistic resistance components. Their use could lead to helmets that are less costly and more easily available than conventional helmet armour. The hybrid materials subjected to ballistic tests were composed of 19 layers and were fabricated by the hot press technique using different numbers and configurations of plain woven kenaf and aramid layers. In the case of ballistic performance tests, a positive effect was found for the hybridisation of kenaf and aramid laminated composites.

  8. Notched Strength of Woven Fabric Kenaf Composites with Different Fiber Orientations

    Directory of Open Access Journals (Sweden)

    Ahmad Hilton

    2017-01-01

    Full Text Available The awareness of implementing sustainable materials in construction industry is gaining good attention among engineers worldwide. Kenaf fibers are local renewable materials to combine with epoxy polymers matrix in producing lightweight composite materials which may replace imported synthetic fiber composites especially in developing countries. Other benefits of using kenaf fiber composites are relatively cheap, less abrasive and less hazardous during fabrication handling. Current study investigates parametric study on notched strength of woven fabric kenaf composite plates with different fiber orientations and circular hole sizes. Stress concentration occurred at the notch edge promotes to micro-damage events such as matrix cracking and fiber fracture as remote tensile loading applied. Current study showed that 0° fiber orientation gives optimum notched strength, plates with larger fiber tilting than 0° are associated with further strength reduction. Kenaf fibers give an alternative to material designers to opt woven fabric kenaf composites in low and medium load bearing applications.

  9. Notched Strength of Woven Fabric Kenaf Composite Plates with Different Stacking Sequences and Hole Sizes

    Directory of Open Access Journals (Sweden)

    Hans Romayne Anders

    2016-01-01

    Full Text Available Advantages of using kenaf fibres over synthetic fibres in composites manufacturing are relatively cheap, less abrasive and hazardous during handling, and renewable materials. Current work investigates parametric effects on notched strength of woven fabric kenaf polymer composites plates with variation of lay-up types, notch sizes and plate thickness. Testing coupons are prepared using hand lay-up technique and circular notch were drilled prior to mechanical testing. Stress concentration at the notch edge promotes micro-damage event as tensile loading was applied leading to crack initiation and propagations across the plate width. It is suggested that woven fabric kenaf polymer composites are potentially used in low and medium load bearing applications.

  10. Multi Length Scale Finite Element Design Framework for Advanced Woven Fabrics

    Science.gov (United States)

    Erol, Galip Ozan

    Woven fabrics are integral parts of many engineering applications spanning from personal protective garments to surgical scaffolds. They provide a wide range of opportunities in designing advanced structures because of their high tenacity, flexibility, high strength-to-weight ratios and versatility. These advantages result from their inherent multi scale nature where the filaments are bundled together to create yarns while the yarns are arranged into different weave architectures. Their highly versatile nature opens up potential for a wide range of mechanical properties which can be adjusted based on the application. While woven fabrics are viable options for design of various engineering systems, being able to understand the underlying mechanisms of the deformation and associated highly nonlinear mechanical response is important and necessary. However, the multiscale nature and relationships between these scales make the design process involving woven fabrics a challenging task. The objective of this work is to develop a multiscale numerical design framework using experimentally validated mesoscopic and macroscopic length scale approaches by identifying important deformation mechanisms and recognizing the nonlinear mechanical response of woven fabrics. This framework is exercised by developing mesoscopic length scale constitutive models to investigate plain weave fabric response under a wide range of loading conditions. A hyperelastic transversely isotropic yarn material model with transverse material nonlinearity is developed for woven yarns (commonly used in personal protection garments). The material properties/parameters are determined through an inverse method where unit cell finite element simulations are coupled with experiments. The developed yarn material model is validated by simulating full scale uniaxial tensile, bias extension and indentation experiments, and comparing to experimentally observed mechanical response and deformation mechanisms. Moreover

  11. Precipitation Coating of Monazite on Woven Ceramic Fibers: 1. Feasibility (Postprint)

    Science.gov (United States)

    2007-02-01

    08 Aug 2006. Paper contains color . 14. ABSTRACT Monazite coatings were deposited on woven cloths and tows of NextelTM 610 fibers by heterogeneous...by dissolving concentrated phosphoric acid ( Fish - er Scientific Co., Pittsburgh, PA) or a combination of lantha- num nitrate (Aldrich Chemical Co...Boccaccini, P. Karapappas, J. M. Marijuan, and C. Kaya, ‘‘ TiO2 Coat- ings on Silicon Carbide Fiber Substrates by Electrophoretic Deposition,’’ J.Mater. Sci

  12. Effects of Crimped Fiber Paths on Mixed Mode Delamination Behaviors in Woven Fabric Composites

    Science.gov (United States)

    2016-09-01

    of several fabric weave styles and crimp gradients on the damage tolerance and energy absorption capacities in 20-ply Kevlar / epoxy composite...Styles and Crimp Gradients on Woven Kevlar Epoxy Composites,” Experimental Mechanics, vol. 56, no. 4, pp. 617–635, 2016. 12. ABAQUS, Ver. 6.10...mismatched element sizes between interface surfaces. Benzeggagh and Kenane3 conducted experimental tests and fractography on 6-mm-thick E-glass/ epoxy

  13. The Effect Of Weave Construction On Tear Strength Of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Eryuruk Selin Hanife

    2015-09-01

    Full Text Available The tear strength of a woven fabric is very important, since it is more closely related to serviceability of the fabric. Tearing strength of the fabrics depend on the mobility of the yarn within the fabric structure. In this study, the tearing strength of four types of fabrics warp rib, weft rib, ripstop and plain weave were analysed, which were produced in different densities and with filament and texturised polyester yarns.

  14. Long-term follow-up of aneurysms treated electively with woven stent-assisted coiling.

    Science.gov (United States)

    Cheung, Nicholas K; Chiu, Albert Hy; Cheung, Andrew K; Wenderoth, Jason D

    2017-12-15

    Preliminary short-term results for stent-assisted coil embolization (SACE) using woven/braided stents have been promising. However, evidence supporting mid- to long-term efficacy and durability is lacking. To report the long-term results for the durability of elective intracranial aneurysms treated with woven stents. Between May 2012 and May 2015, 98 consecutive patients with 103 aneurysms underwent elective woven SACE across three Australian neurovascular centres. All patients had immediate, 6- and 18-month clinical and radiological follow-up. Radiological assessment was performed with modified Raymond-Roy occlusion scores based on angiography results, while clinical assessment was based on the modified Rankin Scale. Six-month follow-up was available in 100 aneurysms, and an 18-month follow-up in 97 aneurysms. Total occlusion rates of 82% were achieved at inception, 82% at 6 months, and 90% at 18 months. Satisfactory occlusion with small neck remnants was present in 17% at inception, 16% at 6 months, and 9% at 18 months. Good neurological outcomes were achieved in 95% at 18 months. Intraprocedural thromboembolic events were recorded in 3% and delayed events in 1% (all in patients taking clopidogrel). Aneurysm recurrence occurred in one patient (1%). Technical complications occurred in 5%. The total complication rate was 10%. Woven SACE is safe, efficacious, and durable at long-term 18-month follow-up, with very low recurrence and re-treatment rates. Preliminary results appear better than those for traditional laser-cut stents. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  15. Improved Strength and Toughness of Carbon Woven Fabric Composites with Functionalized MWCNTs

    Directory of Open Access Journals (Sweden)

    Eslam Soliman

    2014-06-01

    Full Text Available This investigation examines the role of carboxyl functionalized multi-walled carbon nanotubes (COOH-MWCNTs in the on- and off-axis flexure and the shear responses of thin carbon woven fabric composite plates. The chemically functionalized COOH-MWCNTs were used to fabricate epoxy nanocomposites and, subsequently, carbon woven fabric plates to be tested on flexure and shear. In addition to the neat epoxy, three loadings of COOH-MWCNTs were examined: 0.5 wt%, 1.0 wt% and 1.5 wt% of epoxy. While no significant statistical difference in the flexure response of the on-axis specimens was observed, significant increases in the flexure strength, modulus and toughness of the off-axis specimens were observed. The average increase in flexure strength and flexure modulus with the addition of 1.5 wt% COOH-MWCNTs improved by 28% and 19%, respectively. Finite element modeling is used to demonstrate fiber domination in on-axis flexure behavior and matrix domination in off-axis flexure behavior. Furthermore, the 1.5 wt% COOH-MWCNTs increased the toughness of carbon woven composites tested on shear by 33%. Microstructural investigation using Fourier Transform Infrared Spectroscopy (FTIR proves the existence of chemical bonds between the COOH-MWCNTs and the epoxy matrix.

  16. Study of the internal confinement of concrete reinforced (in civil engineering) with woven reinforcement

    Science.gov (United States)

    Dalal, M.; Goumairi, O.; El Malik, A.

    2017-10-01

    Concrete is generally the most used material in the field of construction. Despite its extensive use in structures, it represents some drawbacks related to its properties including its low tensile strength and low ductility. To solve this problem, the use of steel reinforcement in concrete structures is possible. Another possibility is the introduction of different types of continuous fibre / staple in the concrete, such as steel fibres or synthetic fibres, to obtain ″Concretes bundles″. Many types of fibre concrete, which have been developed and for many of them, the gain provided by the fibre was rather low and no significant improvement in tensile strength was really reaching. By cons, the ductility was higher than that of ordinary concrete. The objective of this study is to examine concrete reinforcement by inserting reinforcements woven polyester. These are either woven bidirectional (2D) or three-dimensional woven (3D). So we will report the properties of each type of reinforcement and the influence of the method of weaving on the strength reinforcements and on the strength of concrete in which they are incorporated. Such influence should contribute to improving the sustainability and enhancement of reinforcement

  17. Effect of stacking angles on mechanical properties and damage propagation of plain woven carbon fiber laminates

    Science.gov (United States)

    Zhuang, Weimin; Ao, Wenhong

    2018-03-01

    Damage propagation induced failure is a predominant damage mechanism. This study is aimed at assessing the damage state and damage propagation induced failure with different stacking angles, of woven carbon fiber/epoxy laminates subjected to quasi-static tensile and bending load. Different stages of damage processing and damage behavior under the bending load are investigated by Scanning Electron Microscopy (SEM). The woven carbon fiber/epoxy laminates which are stacked at six different angles (0°, 15°, 30°, 45°, 60°, 75°) with eight plies have been analyzed: [0]8, [15]8, [30]8, [45]8, [60]8, [75]8. Three-point bending test and quasi-static tensile test are used in validating the woven carbon fiber/epoxy laminates’ mechanical properties. Furthermore, the damage propagation and failure modes observed under flexural loading is correlated with flexural force and load-displacement behaviour respectively for the laminates. The experimental results have indicated that [45]8 laminate exhibits the best flexural performance in terms of energy absorption duo to its pseudo-ductile behaviour but the tensile strength and flexural strength drastically decreased compared to [0]8 laminate. Finally, SEM micrographs of specimens and fracture surfaces are used to reveal the different types of damage of the laminates with different stacking angles.

  18. 3D-WOVEN FIBER-REINFORCED COMPOSITE FOR CAD/CAM DENTAL APPLICATION.

    Science.gov (United States)

    Petersen, Richard; Liu, Perng-Ru

    2016-05-01

    Three-dimensional (3D)-woven noncrimp fiber-reinforced composite (FRC) was tested for mechanical properties in the two principal directions of the main XY plane and compared to different Computer-Aided-Design/Computer-Aided-Machining (CAD/CAM) Dental Materials. The Dental Materials included ceramic with Vitablock Mark II®, ProCAD®, InCeram® Spinel, InCeram® Alumina and InCeram® Zirconia in addition to a resin-based 3M Corp. Paradigm® particulate-filled composite. Alternate material controls included Coors 300 Alumina Ceramic and a tungsten carbide 22% cobalt cermet. The 3D-woven FRC was vacuum assisted resin transfer molding processed as a one-depth-thickness ~19-mm preform with a vinyl-ester resin and cut into blocks similar to the commercial CAD/CAM Dental Materials. Mechanical test samples prepared for a flexural three-point span length of 10.0 mm were sectioned for minimum-depth cuts to compare machinability and fracture resistance between groups. 3D-woven FRC improved mechanical properties with significant statistical differences over all CAD/CAM Dental Materials and Coors Alumina Ceramic for flexural strength (p<0.001), resilience (p<0.05), work of fracture (p<0.001), strain energy release (p<0.05), critical stress intensity factor (p<0.001) and strain (p<0.001).

  19. Geometrical analysis of woven fabric microstructure based on micron-resolution computed tomography data

    Science.gov (United States)

    Krieger, Helga; Seide, Gunnar; Gries, Thomas; Stapleton, Scott E.

    2018-04-01

    The global mechanical properties of textiles such as elasticity and strength, as well as transport properties such as permeability depend strongly on the microstructure of the textile. Textiles are heterogeneous structures with highly anisotropic material properties, including local fiber orientation and local fiber volume fraction. In this paper, an algorithm is presented to generate a virtual 3D-model of a woven fabric architecture with information about the local fiber orientation and the local fiber volume fraction. The geometric data of the woven fabric impregnated with resin was obtained by micron-resolution computed tomography (μCT). The volumetric μCT-scan was discretized into cells and the microstructure of each cell was analyzed and homogenized. Furthermore, the discretized data was used to calculate the local permeability tensors of each cell. An example application of the analyzed data is the simulation of the resin flow through a woven fabric based on the determined local permeability tensors and on Darcy's law. The presented algorithm is an automated and robust method of going from μCT-scans to structural or flow models.

  20. The effect of z-binding yarns on the electrical properties of 3D woven composites

    KAUST Repository

    Saleh, Mohamed Nasr

    2017-09-28

    Electrical resistance monitoring (ERM) has been used to study the effect of the z-binding yarns on the initial electrical resistance (ER) and its change of three architectures of 3D woven carbon fibre composites namely (orthogonal “ORT”, layer-to-layer “LTL” and angle interlock “AI”) when tested in tension. Specimens are loaded in on-axis “warp” and off-axis “45°” directions. In-situ ERM is achieved using the four-probe technique. Monotonic and cyclic “load/unload” tests are performed to investigate the effect of piezo-resistivity and residual plasticity on resistance variation. The resistance increase for the off-axis loaded specimens (∼90%) is found to be higher than that of their on-axis counterparts (∼20%). In the case of cyclic testing, the resistance increase upon unloading is irreversible which suggests permanent damage presence not piezo-resistive effect. At the moment, it is difficult to obtain a direct correlation between resistance variation and damage in 3D woven composites due to the complexity of the conduction path along the three orthogonal directions, however this study demonstrates the potential of using ERM for damage detection in 3D woven carbon fibre-based composites and highlights the challenges that need to be overcome to establish ERM as a Structural Health Monitoring (SHM) technique for such material systems.

  1. Investigating the Potential of Using Off-Axis 3D Woven Composites in Composite Joints’ Applications

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-09-26

    The effect of circular notch has been evaluated for three different architectures of three-dimensional (3D) carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) through open-hole quasi-static tension and double-lap bearing strength tests in the off-axis (45°) direction. Damage characterisation is monitored using Digital Image correlation (DIC) for open-hole testing and X-ray Computed Tomography (CT) for double-lap bearing strength test. The off-axis notched 3D woven composites exhibits minor reduction (less than 10 %) of the notched strength compared to the un-notched strength. DIC strain contour clearly show stress/strain localisation regions around the hole periphery and stress/strain redistribution away from the whole due to the z-binder existence, especially for ORT architecture. Up to 50 % bearing strain, no significant difference in the bearing stress/bearing strain response is observed. However when ORT architecture was loaded up to failure, it demonstrates higher strain to failure (~140 %) followed by AI (~105 %) and lastly LTL (~85 %). X-ray CT scans reveal the effect of the z-binder architecture on damage evolution and delamination resistance. The study suggests that off-axis loaded 3D woven composites, especially ORT architecture, has a great potential of overcoming the current challenges facing composite laminates when used in composite joints’ applications. © 2016 The Author(s)

  2. Investigating the Potential of Using Off-Axis 3D Woven Composites in Composite Joints’ Applications

    KAUST Repository

    Saleh, Mohamed Nasr; Wang, Ying; Yudhanto, Arief; Joesbury, Adam; Potluri, Prasad; Lubineau, Gilles; Soutis, Constantinos

    2016-01-01

    The effect of circular notch has been evaluated for three different architectures of three-dimensional (3D) carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) through open-hole quasi-static tension and double-lap bearing strength tests in the off-axis (45°) direction. Damage characterisation is monitored using Digital Image correlation (DIC) for open-hole testing and X-ray Computed Tomography (CT) for double-lap bearing strength test. The off-axis notched 3D woven composites exhibits minor reduction (less than 10 %) of the notched strength compared to the un-notched strength. DIC strain contour clearly show stress/strain localisation regions around the hole periphery and stress/strain redistribution away from the whole due to the z-binder existence, especially for ORT architecture. Up to 50 % bearing strain, no significant difference in the bearing stress/bearing strain response is observed. However when ORT architecture was loaded up to failure, it demonstrates higher strain to failure (~140 %) followed by AI (~105 %) and lastly LTL (~85 %). X-ray CT scans reveal the effect of the z-binder architecture on damage evolution and delamination resistance. The study suggests that off-axis loaded 3D woven composites, especially ORT architecture, has a great potential of overcoming the current challenges facing composite laminates when used in composite joints’ applications. © 2016 The Author(s)

  3. Characterising the loading direction sensitivity of 3D woven composites: Effect of z-binder architecture

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-08-29

    Three different architectures of 3D carbon fibre woven composites (orthogonal, ORT; layer-to-layer, LTL; angle interlock, AI) were tested in quasi-static uniaxial tension. Mechanical tests (tensile in on-axis of warp and weft directions as well as 45 degrees off-axis) were carried out with the aim to study the loading direction sensitivity of these 3D woven composites. The z-binder architecture (the through-thickness reinforcement) has an effect on void content, directional fibre volume fraction, mechanical properties (on-axis and off-axis), failure mechanisms, energy absorption and fibre rotation angle in off-axis tested specimens. Out of all the examined architectures, 3D orthogonal woven composites (ORT) demonstrated a superior behaviour, especially when they were tested in 45 degrees off-axis direction, indicated by high strain to failure (similar to 23%) and high translaminar energy absorption (similar to 40 MJ/m(3)). The z-binder yarns in ORT architecture suppress the localised damage and allow larger fibre rotation during the fibre

  4. The effect of platelet rich plasma from bone marrow aspirate with added bone morphogenetic protein-2 on the Achilles tendon-bone junction in rabbits.

    Science.gov (United States)

    Kim, Hak Jun; Nam, Hyok-Woo; Hur, Chang-Yong; Park, Misu; Yang, Hee Seok; Kim, Byung-Soo; Park, Jung-Ho

    2011-12-01

    To determine if exogenously injected bone marrow derived platelet-rich plasma (PRP) plus bone morphogenetic protein (BMP)-2 could accelerate the healing of bone-tendon junction injuries and increase the junction holding strength during the early regeneration period. A direct injury model of the bone-tendon junction was made using an Achilles tendon-calcaneus bone junction in a rabbit. In the PRP/BMP-2/fibrin group, 0.05 mL of bone marrow derived PRP and 100 ng/mL of BMP-2 both incorporated into 0.1 mL of fibrin glue were injected into Achilles tendon-calcaneus bone junctions. The effect of the intervention was tested by comparing the results of an intervention group to a control group. The results of biomechanical testing, and histological and gross analyses were compared between the 2 groups at the following time points after surgery: 2 weeks, 4 weeks, and 8 weeks. Histologic examinations showed that woven bone developed in tendon-bone junctions at 2 weeks after surgery in the PRP/BMP-2/fibrin group. Mechanical test results showed no significant difference between the PRP/BMP-2/fibrin and control groups at 2 and 4 weeks after surgery, but the mean maximal load in the PRP/BMP-2/fibrin group was significantly higher than in the control group (p rabbit model of tendon-bone junction injury.

  5. Effect of cisplatin on bone transport osteogenesis in dogs.

    Science.gov (United States)

    Ehrhart, Nicole; Eurell, Jo Ann C; Tommasini, Matteo; Constable, Peter D; Johnson, Ann L; Feretti, Antonio

    2002-05-01

    To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis. 10 skeletally mature hounds. Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups. Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups. Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.

  6. Vertically aligned TiO2 nanorods-woven carbon fiber for reinforcement of both mechanical and anti-wear properties in resin composite

    Science.gov (United States)

    Fei, Jie; Zhang, Chao; Luo, Dan; Cui, Yali; Li, Hejun; Lu, Zhaoqing; Huang, Jianfeng

    2018-03-01

    A series of TiO2 nanorods were successfully grown on woven carbon fiber by hydrothermal method to reinforce the resin composite. The TiO2 nanorods improved the mechanical interlocking among woven carbon fibers and resin matrix, resulting in better fibers/resin interfacial bonding. Compared with desized-woven carbon fiber, the uniform TiO2 nanorods array resulted in an improvement of 84.3% and 73.9% in the tensile and flexural strength of the composite. However, the disorderly TiO2 nanorods on woven carbon fiber leaded to an insignificant promotion of the mechanical strength. The enhanced performance of well-proportioned TiO2 nanorods-woven carbon fiber was also reflected in the nearly 56% decrease of wear rate, comparing to traditional woven carbon fiber reinforced composite.

  7. Effects of Weave Styles and Crimp Gradients on Damage Tolerance and Energy-Absorption Capacities of Woven Kevlar/Epoxy Composites

    Science.gov (United States)

    2015-09-01

    Capacities of Woven Kevlar /Epoxy Composites Paul V. Cavallaro Ranges, Engineering, and Analysis Department NEWPORT Naval Undersea Warfare Center Division...the Kevlar woven fabrics and technical data and to Core Composites Inc. for fabricating the composite laminates. Reviewed and Approved: 1...Effects of Weave Styles and Crimp Gradients on Damage Tolerance and Energy-Absorption Capacities of Woven Kevlar /Epoxy Composites 5a. CONTRACT NUMBER 5b

  8. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  9. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  10. Comparison of xenogenic bone bioimplant and calcium phosphate granules on experimental femoral bone defect healing in rabbits

    Directory of Open Access Journals (Sweden)

    GH Mousavi

    2012-05-01

    Full Text Available Rebuilding and renovation of lost bone whether because of physiologic or pathologic factors was one of the surgeons’ motivations from the past. Osteogenesis of decalcified bone induced by growth factors contained in it. This study is to assay probability effect of decalcified bone and calcium phosphate granules on osteogenesis which is made in experimental flaw and it is as a laboratory pattern in rabbit femur.This experimental study is made on 15 male rabbits. Animals were divided randomly into 3 groups (control and treatments.After induction of general anesthesia, 2 holes in size of 2 mm in diameter was made using a dental bit in femur width to medullary channel. After surgery, the control group left untreated and decalcified bones was placed in group 2 and calcium phosphate granules were placed in group 3. Histopathological and histomorphometrical studies for evaluation of bone healing were carried out in experimental rats, which were euthanized after 45 days of the experiment using hematoxylin-eosin (H&E staining method.In control group, defect seemed to be filled with woven bone and bone marrow spaces and in spite of a poor osteogenic activity. In calcium phosphate group, young bone trabeculas increased in number and bone trabeculas more organized. Histomorphometric results, observed that calcium phosphate granules has significant effect on bone healing than decalcified and control groups.

  11. Pretreatment of Woven Jute FRP Composite and Its Use in Strengthening of Reinforced Concrete Beams in Flexure

    Directory of Open Access Journals (Sweden)

    Tara Sen

    2013-01-01

    Full Text Available Environmental awareness motivates researchers worldwide to perform studies of natural fibre reinforced polymer composites, as they come with many advantages and are primarily sustainable. The present study aims at evaluating the mechanical characteristics of natural woven jute fibre reinforced polymer (FRP composite subjected to three different pretreatments, alkali, benzyl chloride, and lastly heat treatment. It was concluded that heat treatment is one of the most suitable treatment methods for enhancing mechanical properties of jute FRP. Durability studies on Jute FRP pertaining to some common environmental conditions were also carried out such as effect of normal water and thermal aging on the tensile strength of jute FRP followed by fire flow test. The heat treated woven jute FRP composites were subsequently used for flexural strengthening of reinforced concrete beams in full and strip wrapping configurations. The study includes the effect of flexural strengthening provided by woven jute FRP, study of different failure modes, load deflection behavior, effect on the first crack load, and ultimate flexural strength of concrete beams strengthened using woven jute FRP subjected to bending loads. The study concludes that woven jute FRP is a suitable material which can be used for flexural upgradation of reinforced concrete beams.

  12. Simulation of Degraded Properties of 2D plain Woven C/SiC Composites under Preloading Oxidation Atmosphere

    Science.gov (United States)

    Chen, Xihui; Sun, Zhigang; Sun, Jianfen; Song, Yingdong

    2017-12-01

    In this paper, a numerical model which incorporates the oxidation damage model and the finite element model of 2D plain woven composites is presented for simulation of the oxidation behaviors of 2D plain woven C/SiC composite under preloading oxidation atmosphere. The equal proportional reduction method is firstly proposed to calculate the residual moduli and strength of unidirectional C/SiC composite. The multi-scale method is developed to simulate the residual elastic moduli and strength of 2D plain woven C/SiC composite. The multi-scale method is able to accurately predict the residual elastic modulus and strength of the composite. Besides, the simulated residual elastic moduli and strength of 2D plain woven C/SiC composites under preloading oxidation atmosphere show good agreements with experimental results. Furthermore, the preload, oxidation time, temperature and fiber volume fractions of the composite are investigated to show their influences upon the residual elastic modulus and strength of 2D plain woven C/SiC composites.

  13. Effect of layering sequence and chemical treatment on the mechanical properties of woven kenaf–aramid hybrid laminated composites

    International Nuclear Information System (INIS)

    Yahaya, R.; Sapuan, S.M.; Jawaid, M.; Leman, Z.; Zainudin, E.S.

    2015-01-01

    Highlights: • The mechanical properties of woven kenaf/Kevlar hybrid composites were analysed. • The layering sequences affect the mechanical properties of hybrid composites. • Treated kenaf improves the mechanical properties of hybrid composites. - Abstract: This work aims to evaluate the effect of layering sequence and chemical treatment on mechanical properties of woven kenaf–Kevlar composites. Woven kenaf–aramid hybrid laminated composites fabricated through hand lay-up techniques by arranging woven kenaf and Kevlar fabrics in different layering sequences and by using treated kenaf mat. To evaluate the effect of chemical treatment on hybrid composites, the woven kenaf mat was treated with 6% sodium hydroxide (NaOH) diluted solution and compared mechanical properties with untreated kenaf hybrid composites. Results shows that the tensile properties of hybrid composites improved in 3-layer composites compared to 4-layer composites. Hybrid composite with Kevlar as outer layers display a better mechanical properties as compared to other hybrid composites. Tensile and flexural properties of treated hybrid composites are better than non-treated hybrid composites. The fractured surface of hybrid composites was investigated by scanning electron microscopy. This study is a part of exploration of potential application of the hybrid composite in high velocity impact application

  14. Comparison of Failure Modes in 2-D and 3-D Woven Carbon Phenolic Systems

    Science.gov (United States)

    Rossman, Grant A.; Stackpoole, Mairead; Feldman, Jay; Venkatapathy, Ethiraj; Braun, Robert D.

    2013-01-01

    NASA Ames Research Center is developing Woven Thermal Protection System (WTPS) materials as a new class of heatshields for entry vehicles (Stackpoole). Currently, there are few options for ablative entry heatshield materials, none of which is ideally suited to the planetary probe missions currently of interest to NASA. While carbon phenolic was successfully used for the missions Pioneer Venus and Galileo (to Jupiter), the heritage constituents are no longer available. An alternate carbon phenolic would need to be qualified for probe missions, which is most efficient at heat fluxes greater than those currently of interest. Additional TPS materials such as Avcoat and PICA are not sufficiently robust for the heat fluxes required. As a result, there is a large TPS gap between the materials efficient at very high conditions (carbon phenolic) and those that are effective at low-moderate conditions (all others). Development of 3D Woven TPS is intended to fill this gap, targeting mid-density weaves that could with withstand mid-range heat fluxes between 1100 W/sq cm and 8000 W/sq cm (Venkatapathy (2012). Preliminary experimental studies have been performed to show the feasibility of WTPS as a future mid-range TPS material. One study performed in the mARC Jet Facility at NASA Ames Research Center characterized the performance of a 3D Woven TPS sample and compared it to 2D carbon phenolic samples at ply angles of 0deg, 23.5deg, and 90deg. Each sample contained similar compositions of phenolic and carbon fiber volume fractions for experimental consistency. The goal of this study was to compare the performance of the TPS materials by evaluating resulting recession and failure modes. After exposing both samples to similar heat flux and pressure conditions, the 2D carbon phenolic laminate was shown to experience significant delamination between layers and further pocketing underneath separated layers. The 3D Woven TPS sample did not experience the delamination or pocketing

  15. Dual-skinned polyamide/poly(vinylidene fluoride)/cellulose acetate membranes with embedded woven

    KAUST Repository

    Duong, Phuoc H.H.

    2016-08-31

    We propose multilayer membranes including (i) a thin selective polyamide (PA) layer prepared via interfacial polymerization, (ii) a poly (vinylidene fluoride) (PVDF) asymmetric porous support with high adhesion to the PA layer and high mechanical strength, (iii) a strong woven fabric, and (iv) fouling resistant porous cellulose acetate (CA) layer. The PA layer rejects solutes of the draw solution. The PVDF/woven fabric/CA (PVDF/CA) integrated layer performs as a mechanical support with unique properties for forward osmosis (FO) applications. It consists of a modified PVDF top layer suitable for the deposition of a PA layer and a highly hydrophilic bottom layer (CA) with a tunable pore size to minimize foulant deposition and intrusion onto and into the support. The experimental results using bovine serum albumin (BSA) as a model foulant show that the presence of the CA layer at the bottom of the FO membrane (PA/PVDF/CA) reduces 75% fouling propensity compared to the simple FO membrane made of PVDF, woven fabric and PA (PA/PVDF). Fouling tests with 2000 ppm oily feed faced the bottom of the FO membranes further indicate the superiority of the PA/PVDF/CA membrane compared to the PA/PVDF membrane. Moreover, the bottom CA layer can be adjusted with a flexible range of pore size, varied from sub-micron to sub-nanometer depending on the feed composition. The newly developed multilayer FO membrane has comparable performance to the state-of-the-art membrane with added tailored fouling resistance for specific wastewater feeds.

  16. Influence of Laundering on the Quality of Sewn Cotton and Bamboo Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Jurgita KOŽENIAUSKIENĖ

    2013-03-01

    Full Text Available In the presented study the effect of laundering on the quality of sewn cotton and bamboo plain woven fabrics was investigated considering both the textile parameters and the type of chemical treatment. Quality parameters of sewn cotton and bamboo woven fabrics such as: fabric strength, seam strength and seam slippage at the moment of 4 mm seam opening were evaluated before and after washing with “Tide” washing powder without softeners or with softeners: “Surcare” and “Pflege Weicspuler”. There was also determined surface density, warp and weft densities as well as thicknesses under the pressures 0.625 kPa and 3.125 kPa, and calculated the comparative thickness that was considered as softness or porosity of fabrics. Notwithstanding that both the investigated fabrics were cellulosic their behavior after laundering was different. Under the tested conditions, unwashed and laundered with or without chemical softeners cotton fabric didn’t demonstrate seam slippage. The seam slippage resistance of laundered without or with softener specimens of bamboo fabric was increased in respect to control fabric. The larger changes in seam efficiency and seam strength because of laundering were determined for bamboo woven fabric then for cotton fabric. They could be influenced by the higher changes in bamboo fabric’s structure. The highest difference between the structure parameters of both fabrics was determined for comparative thickness. It was significantly increased for cotton fabric and decreased for bamboo fabric after chemical softening comparing to untreated fabrics.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3831

  17. Experimental methods to characterize the woven composite prepreg behavior during the preforming process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weizhao; Ren, Huaqing; Lu, Jie; Zhang, Zixuan; Su, Lingxuan; Wang, Q Jane; Zeng, Danielle; Su, Xuming; Cao, Jian

    2016-09-19

    This paper reports several characterization methods of the properties of the uncured woven prepreg during the preforming process. The uniaxial tension, bias-extension, and bending tests are conducted to measure the in-plane properties of the material. The friction tests utilized to reveal the prepreg-prepreg and prepreg-forming tool interactions. All these tests are performed within the temperature range of the real manufacturing process. The results serve as the inputs to the numerical simulation for the product prediction and preforming process parameter optimization.

  18. Quick analytical separation of glucose and fructose with impregnated woven glass fiber

    International Nuclear Information System (INIS)

    Jones, S.C.

    1978-01-01

    (1) A wide separation of glucose and fructose was obtained in 30 min with simple, inexpensive equipment using polysilicic impregnated woven glass fiber and the solvent acetone-n-butanol-1 M H 3 BO 3 (50:40:10). (2) A calibration of a radiochromatogram scanner was performed for 11 C. (3) Three Rsub(F) values could be compared to provide positive chemical identification of [ 11 C]glucose and [ 11 C]fructose. (4) Radiochemical composition and approximate specific activity were determined from a small aliquot (1-4 μl). (Auth.)

  19. Advanced soft coverpad made of non-woven fabric; Soft fushokufu coverpad no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, t; Kamezaki, K; Tokita, T [Takashimaya Nippatsu Kogyo, Aichi (Japan); Yamada, Y; Ono, H; Araki, O [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    At the present expected to enhance the product-value of automobile, it can be considered that advancement of touching and fitting feeling of seat would be important factors. For the purpose of materializing of these factors, We have noted softening of seat cover and carried out development of cover pad made of non-woven fablic. As a result of pursuing compatibility of soft feeling and durability of the cover pad, we could achieve to ensure the quality required for the material as the seat cover pad. 3 refs., 15 figs., 4 tabs.

  20. STRESS - STRAIN CURVE ANALYSIS OF WOVEN FABRICS MAD E FROM COMBED YARNS TYPE WOOL

    OpenAIRE

    VÎLCU Adrian; HRISTIAN Liliana; BORDEIANU Demetra L.; VÎLCU Catalin

    2014-01-01

    The paper analyses the tensile behavior of woven fabrics made from 45%Wool + 55% PES used for garments. Analysis of fabric behavior during wearing has shown that these are submitted to simple and repeated uni-axial or bi-axial tensile strains. The level of these strains is often within the elastic limit, rarely going over yielding. Therefore the designer must be able to evaluate the mechanical behavior of such fabrics in order to control the fabric behavior in the garment. This evaluation is ...

  1. Osseointegration Of Implants In Rabbit Bone With A Low Calcium Diet And Irradiation

    International Nuclear Information System (INIS)

    Kim, So Jung; Hwang, Eui Hwan; Lee, Sang Rae

    2000-01-01

    To investigate osseointergration of titanium implants into the tibia of rabbits, which were fed a low calcium diet and irradiated. To prepare the experimental model, control group was fed a normal diet and experimental group was fed a low calcium diet for 4 weeks. And then, titanium implants were inserted into the tibia of each rabbit. Experimental group was subdivided into two groups; low calcium diet/non-irradiation group and low calcium diet/irradiation group. The low calcium diet/irradiation group was irradiated with a single absorbed dose of 15 Gy at the 5th postoperative days. On the 12th, 19th, 33rd, 47th, and 61st days after implantation(1, 2, 4, 6, and 8 weeks after irradiation), the bone formation in the bone-implant interface area was examined by light microscopy and fluorescent microscopy. 1. In the control group, there began to form woven bone in the bone-implant interface area on the 12th days after implantation. As the experimental time was going on, the amount of bone which was in contact with the implant was increased. 2. In the low calcium diet/non-irradiation group, there began to form woven bone in the bone-implant interface area on the 19th days after implantation. Although the amount of bone which was in contact with the implant was increased as the experimental time was going on, the extent of increased bone was slightly weak as compared with control group. 3. In the low calcium diet/irradiation group, there began to form woven bone incompletely in the bone-implant interface area on the 19th days after implantation, but there were vascular connective tissues in the bone- implant interface area over the entire experimental period. 4. In the control group and low calcium diet/non-irradiation group, bone labeling bands were observed on the 33rd days after implantation, which suggests that the bone formation and remodeling was in process, but interstitial bone remodeling was not observed in the low calcium diet/irradiation group.

  2. High energy ballistic and fracture comparison between multilayered armor systems using non-woven curaua fabric composites and aramid laminates

    Directory of Open Access Journals (Sweden)

    Fábio de Oliveira Braga

    2017-10-01

    Full Text Available For personal protection against high kinetic energy projectiles, multilayered armor systems (MAS are usually the best option. They combine synergistically the properties of different materials such as ceramics, composites and metals. In the present work, ballistic tests were performed to evaluate multilayered armor systems (MAS using curaua non-woven fabric epoxy composites as second layer. A comparison to a MAS using aramid (Kevlar™ fabric laminates was made. The results showed that the curaua non-woven fabric composites are suitable to the high ballistic applications, and are promising substitutes for aramid fabric laminates. Keywords: Composite, Natural fiber, Curaua fiber, Non-woven fabric, Aramid laminate, Ballistic test

  3. Analysis and modeling of delamination factor in drilling of woven kenaf fiber reinforced epoxy using Box Behnken experimental design

    Science.gov (United States)

    Suhaily, M.; Che Hassan, C. H.; Jaharah, A. G.; Afifah, M. A.; Nor Khairusshima, M. K.

    2018-01-01

    In this research study, it presents a comprehensive mathematical model for correlating the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates using the Box Behnken experimental design. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated HSS drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs.

  4. Nutritional factors affecting poultry bone health.

    Science.gov (United States)

    Fleming, Robert H

    2008-05-01

    Outlined are two main current research concerns relating to skeletal disorders in poultry: (a) osteoporosis in egg-laying hens; (b) leg problems caused by rapid bone growth in broiler chickens. Surveys indicate that 30% of caged laying hens suffer at least one lifetime fracture (a severe welfare issue). Modern hybrids produce one egg per d for 50 weeks. For this period 'normal' bone turnover ceases; only medullary bone (MB) is formed, a woven bone type of limited structural value. MB is resorbed for eggshell formation alongside structural bone, leading to increased fracture risk. Avian osteoporosis is reduced by activity and genetic selection but nutrition is also important. Fluoride and vitamin K are beneficial but the timing of nutritional intervention is important. Ca, inorganic P and vitamin D must be adequate and the form of Ca is critical. Limestone fed as particulates benefits skeletal and eggshell quality. In hens fed particulate limestone compared with flour-fed hens the tibiotarsus breaking strength and radiographic density are increased at 56 weeks of age (Pbroiler (meat) chickens selection for rapid growth from approximately 50 g to 3 kg in 42 d has inadvertently produced skeletal disorders such as tibial dyschondroplasia, rickets and associated valgus-varus deformities leading to lameness. The beneficial skeletal effects during growth of increased dietary n-3 PUFA:n-6 PUFA (utilising salmon oil) have been demonstrated. Experiments simulating daylight UVB levels have produced beneficial skeletal effects in Ca- and vitamin D-deficient chicks.

  5. Dynamic mechanical analysis and high strain-rate energy absorption characteristics of vertically aligned carbon nanotube reinforced woven fiber-glass composites

    Science.gov (United States)

    The dynamic mechanical behavior and energy absorption characteristics of nano-enhanced functionally graded composites, consisting of 3 layers of vertically aligned carbon nanotube (VACNT) forests grown on woven fiber-glass (FG) layer and embedded within 10 layers of woven FG, with polyester (PE) and...

  6. Mechanical properties and fabrication of small boat using woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite

    International Nuclear Information System (INIS)

    Misri, S; Leman, Z; Sapuan, S M; Ishak, M R

    2010-01-01

    In recent years, sugar palm fibre has been found to have great potential to be used as fibre reinforcement in polymer matrix composites. This research investigates the mechanical properties of woven glass/sugar palm fibres reinforced unsaturated polyester hybrid composite. The composite specimens made of different layer of fibres such as strand mat, natural and hand woven of sugar palm fibres. The composites were fabricated using a compression moulding technique. The tensile and impact test was carried out in accordance to ASTM 5083 and ASTM D256 standard. The fibre glass boat is a familiar material used in boat industry. A lot of research on fabrication process such as lay-up, vacuum infusion mould and resin transfer mould has been conducted. Hybrid material of sugar palm fibre and fibre glass was used in fabricating the boat. This research investigates the method selection for fabrication of small boat application of natural fibre composites. The composite specimens made of different layer of fibres; woven glass fibre, strand mat, natural and hand woven of woven sugar palm fibres were prepared. The small boat were fabricated using a compression moulding and lay up technique. The results of the experiment showed that the tensile strength, tensile modulus, elongation at break value and impact strength were higher than the natural woven sugar palm fibre. The best method for fabricating the small boat was compression moulding technique. As a general conclusion, the usage of glass fibre had improved the tensile properties sugar palm fibre composites and compression moulding technique is suitable to be used in making a small boat application of natural fibre composites.

  7. 3D printed hyperelastic "bone" scaffolds and regional gene therapy: A novel approach to bone healing.

    Science.gov (United States)

    Alluri, Ram; Jakus, Adam; Bougioukli, Sofia; Pannell, William; Sugiyama, Osamu; Tang, Amy; Shah, Ramille; Lieberman, Jay R

    2018-04-01

    The purpose of this study was to evaluate the viability of human adipose-derived stem cells (ADSCs) transduced with a lentiviral (LV) vector to overexpress bone morphogenetic protein-2 (BMP-2) loaded onto a novel 3D printed scaffold. Human ADSCs were transduced with a LV vector carrying the cDNA for BMP-2. The transduced cells were loaded onto a 3D printed Hyperelastic "Bone" (HB) scaffold. In vitro BMP-2 production was assessed using enzyme-linked immunosorbent assay analysis. The ability of ADSCs loaded on the HB scaffold to induce in vivo bone formation in a hind limb muscle pouch model was assessed in the following groups: ADSCs transduced with LV-BMP-2, LV-green fluorescent protein, ADSCs alone, and empty HB scaffolds. Bone formation was assessed using radiographs, histology and histomorphometry. Transduced ADSCs BMP-2 production on the HB scaffold at 24 hours was similar on 3D printed HB scaffolds versus control wells with transduced cells alone, and continued to increase after 1 and 2 weeks of culture. Bone formation was noted in LV-BMP-2 animals on plain radiographs at 2 and 4 weeks after implantation; no bone formation was noted in the other groups. Histology demonstrated that the LV-BMP-2 group was the only group that formed woven bone and the mean bone area/tissue area was significantly greater when compared with the other groups. 3D printed HB scaffolds are effective carriers for transduced ADSCs to promote bone repair. The combination of gene therapy and tissue engineered scaffolds is a promising multidisciplinary approach to bone repair with significant clinical potential. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1104-1110, 2018. © 2018 Wiley Periodicals, Inc.

  8. Permeability measurements and modeling of topology-optimized metallic 3-D woven lattices

    International Nuclear Information System (INIS)

    Zhao, Longyu; Ha, Seunghyun; Sharp, Keith W.; Geltmacher, Andrew B.; Fonda, Richard W.; Kinsey, Alex H.; Zhang, Yong; Ryan, Stephen M.; Erdeniz, Dinc; Dunand, David C.; Hemker, Kevin J.; Guest, James K.; Weihs, Timothy P.

    2014-01-01

    Topology optimization was combined with a 3-D weaving technique to design and fabricate structures with optimized combinations of fluid permeability and mechanical stiffness. Two different microarchitected structures are considered: one is a “standard” weave in which all wires were included, while the other is termed an “optimized” weave as specific wires were removed to maximize the permeability of the resulting porous materials with only a limited reduction in stiffness. Permeability was measured and predicted for both structures that were 3-D woven with either Cu or Ni–20Cr wires. The as-woven wires in the Cu lattices were bonded at contact points using solder or braze while the Ni–20Cr wires were bonded at contact points using pack aluminization. Permeability was measured under laminar flow conditions in all three normal directions for unbonded and bonded samples and in the optimized structure it was found to increase between 200% and 600%, depending on direction, over the standard structures. Permeability was also predicted using finite-element modeling with as-fabricated wires positions that were identified with optical microscopy or X-ray tomography; the measurements and predictions show good agreement. Lastly, the normalized permeability values significantly exceed those found for stochastic, metallic foams and other periodic structures with a material volume fraction of over 30%

  9. Modeling and characterization of through-the-thickness properties of 3D woven composites

    Science.gov (United States)

    Hartranft, Dru; Pravizi-Majidi, Azar; Chou, Tsu-Wei

    1995-01-01

    The through-the-thickness properties of three-dimensionally (3D) woven carbon/epoxy composites have been studied. The investigation aimed at the evaluation and development of test methodologies for the property characterization in the thickness direction, and the establishment of fiber architectures were studied: layer-to-layer Angle Interlock, through-the-thickness Orthogonal woven preform with surface pile was also designed and manufactured for the fabrication of tensile test coupons with integrated grips. All the preforms were infiltrated by the resin transfer molding technique. The microstructures of the composites were characterized along the warp and fill (weft) directions to determine the degree of yarn undulations, yarn cross-sectional shapes, and microstructural dimensions. These parameters were correlated to the fiber architecture. Specimens were designed and tested for the direct measurement of the through-the-thickness tensile, compressive and shear properties of the composites. Design optimization was conducted through the analysis of the stress fields within the specimen coupled with experimental verification. The experimentally-derived elastic properties in the thickness direction compared well with analytical predictions obtained from a volume averaging model.

  10. The Pathology of Weaving and Production of the Hand-woven Carpets: Heriz Region Case Study

    Directory of Open Access Journals (Sweden)

    Sepideh Taravati Mahjoubi

    2017-04-01

    Full Text Available The carpet, as one of the most precious achievement of people, is a culture. The world’s recognition of Iranian carpet and its glorification originates from endeavor of people who have integrated artistic verve with mysterious attractions of national culture and arts. This study is descriptive-analytic. The data were collected through field research method and direct communication with people and workshops of drawing, weaving, and dyeing. In fact, the assessment tools were taken to the field, and data collection was completed by questioning, interview, observation, and shooting. Then, they were used for derivation, classification, and analysis. SPSS software also used to analyze collected data. . According to the result of this study, regarding the latest forecasts for Iranian hand-woven carpet industry, carpet exports will increase in the future. Therefore, it is better to consider the weaving and marketing of the carpet as a luxury product in order to achieve the profits maintaining the incentive of production in all units involved in the hand-woven carpet’s production and also to reduce poor quality carpets available in the market.

  11. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    Science.gov (United States)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  12. Wear Behavior of Woven Roving Aramid / Epoxy Composite under Different Conditions

    Directory of Open Access Journals (Sweden)

    Asad A. Khalid

    2012-09-01

    Full Text Available Wear behavior studies of aramid woven roving /epoxy composite has been conducted. Sliding the material against smooth steel counter face under dry and  lubricated with oil conditions has been investigated. Powder of Silicon carbide has been mixed with the epoxy resin and tested also. The powder was mixed in a volumetric fraction of 10% with the epoxy resin. Four Laminates of six layers were fabricated by hand lay up  method. A pin on disc apparatus has been fabricated to conduct the sliding wear tests on specimens of (4 mm   4 mm   12 mm in size have been cut from the four laminates. The effect of sliding condition including dry, lubricated, dry with additives and lubricated with additives have been studied. Wear rate tests have been conducted at different sliding speeds and loads. Results show that the wear characteristics are influenced by the operating conditions and the construction of the composite material used. It was also found that the wear of aramid /epoxy composite onto the steel counter face were significantly reduced by using lubricant and additives but still took place.Keywords: Wear, Composite materials, Woven roving aramid, Epoxy, Additives, Lubricant.

  13. Comparative Analysis of Soft Computing Models in Prediction of Bending Rigidity of Cotton Woven Fabrics

    Science.gov (United States)

    Guruprasad, R.; Behera, B. K.

    2015-10-01

    Quantitative prediction of fabric mechanical properties is an essential requirement for design engineering of textile and apparel products. In this work, the possibility of prediction of bending rigidity of cotton woven fabrics has been explored with the application of Artificial Neural Network (ANN) and two hybrid methodologies, namely Neuro-genetic modeling and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling. For this purpose, a set of cotton woven grey fabrics was desized, scoured and relaxed. The fabrics were then conditioned and tested for bending properties. With the database thus created, a neural network model was first developed using back propagation as the learning algorithm. The second model was developed by applying a hybrid learning strategy, in which genetic algorithm was first used as a learning algorithm to optimize the number of neurons and connection weights of the neural network. The Genetic algorithm optimized network structure was further allowed to learn using back propagation algorithm. In the third model, an ANFIS modeling approach was attempted to map the input-output data. The prediction performances of the models were compared and a sensitivity analysis was reported. The results show that the prediction by neuro-genetic and ANFIS models were better in comparison with that of back propagation neural network model.

  14. Rate Dependent Multicontinuum Progressive Failure Analysis of Woven Fabric Composite Structures under Dynamic Impact

    Directory of Open Access Journals (Sweden)

    James Lua

    2004-01-01

    Full Text Available Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions. In this work, a strain-rate dependent continuum damage model is incorporated with multicontinuum technology (MCT to predict damage and failure progression for composite material structures. MCT treats the constituents of a woven fabric composite as separate but linked continua, thereby allowing a designer to extract constituent stress/strain information in a structural analysis. The MCT algorithm and material damage model are numerically implemented with the explicit finite element code LS-DYNA3D via a user-defined material model (umat. The effects of the strain-rate hardening model are demonstrated through both simple single element analyses for woven fabric composites and also structural level impact simulations of a composite panel subjected to various impact conditions. Progressive damage at the constituent level is monitored throughout the loading. The results qualitatively illustrate the value of rate dependent material models for marine composite materials under extreme dynamic loading conditions.

  15. Numerical Simulation with Experimental Validation of the Draping Behavior of Woven Fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, William [General Motors LLC; Pasupuleti, Praveen [ESI Group NA; Zhao, Selina [General Motors LLC; Wathen, Terry [General Motors LLC; Doroudian, Mark [ESI Group NA; Aitharaju, Venkat [General Motors LLC

    2017-10-23

    Woven fabric composites are extensively used in molding complex geometrical shapes due to their high conformability compared to other fabrics. Preforming is an important step in the overall process. In this step, the two-dimensional fabric is draped to become the three-dimensional shape of the part prior to resin injection. During preforming, the orientation of the tows may change significantly compared to the initial orientations. Accurate prediction of the tow orientations after molding is important for evaluating the structural performance of the final part. This paper investigates the fiber angle changes for carbon fiber woven fabrics during draping over a truncated pyramid tool designed and fabricated at the General Motors Research Labs. This aspect of study is a subset of the broad study conducted under the purview of a Department of Energy project funded to GM in developing state of the art computational tools for integrated manufacturing and structural performance prediction of carbon fiber composites. Fabric bending, picture frame testing, and bias-extension evaluations were carried out to determine the material parameters for these fabrics. The PAM-FORM computer program was used to model the draping behavior of these fabrics. Following deformation, fiber angle changes at different locations on the truncated pyramid were measured experimentally. The predicted angles matched the experimental results well as measured along the centerline and at several different locations on the deformed fabric. Details of the test methods used as well as the numerical results with various simulation parameters will be provided.

  16. Bone marrow aspiration

    Science.gov (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  17. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  18. Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study.

    Directory of Open Access Journals (Sweden)

    Hongbin Lu

    Full Text Available This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point. The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate

  19. 78 FR 64472 - Laminated Woven Sacks From the People's Republic of China: Final Results of Expedited First...

    Science.gov (United States)

    2013-10-29

    ... the People's Republic of China: Final Results of Expedited First Sunset Review of the Antidumping Duty...'') initiated the first five-year (``sunset'') review of the antidumping duty order on laminated woven sacks from the People's Republic of China (``PRC'') pursuant to section 751(c) of the Tariff Act of 1930, as...

  20. Experimental and Numerical Simulation Analysis of Typical Carbon Woven Fabric/Epoxy Laminates Subjected to Lightning Strike

    Science.gov (United States)

    Yin, J. J.; Chang, F.; Li, S. L.; Yao, X. L.; Sun, J. R.; Xiao, Y.

    2017-12-01

    To clarify the evolution of damage for typical carbon woven fabric/epoxy laminates exposed to lightning strike, artificial lightning testing on carbon woven fabric/epoxy laminates were conducted, damage was assessed using visual inspection and damage peeling approaches. Relationships between damage size and action integral were also elucidated. Results showed that damage appearance of carbon woven fabric/epoxy laminate presents circular distribution, and center of the circle located at the lightning attachment point approximately, there exist no damage projected area dislocations for different layers, visual damage territory represents maximum damage scope; visible damage can be categorized into five modes: resin ablation, fiber fracture and sublimation, delamination, ablation scallops and block-shaped ply-lift; delamination damage due to resin pyrolysis and internal pressure exist obvious distinguish; project area of total damage is linear with action integral for the same type specimens, that of resin ablation damage is linear with action integral, but no correlation with specimen type, for all specimens, damage depth is linear with logarithm of action integral. The coupled thermal-electrical model constructed is capable to simulate the ablation damage for carbon woven fabric/epoxy laminates exposed to simulated lightning current through experimental verification.

  1. 76 FR 21333 - Laminated Woven Sacks From the People's Republic of China: Final Results of Second Antidumping...

    Science.gov (United States)

    2011-04-15

    ..., 75 FR 60076 (September 29, 2010). The review was initiated with respect to Zibo Aifudi Plastic... one or both sides of the fabric; laminated by any method either to an exterior ply of plastic film... weight. Laminated woven sacks are typically used for retail packaging of consumer goods such as pet foods...

  2. 75 FR 81218 - Laminated Woven Sacks From the People's Republic of China: Preliminary Results of the Second...

    Science.gov (United States)

    2010-12-27

    ... the People's Republic of China: Preliminary Results of the Second Administrative Review AGENCY: Import... laminated woven sacks (``LWS'') from the People's Republic of China (``PRC'') covering the period August 1, 2009, through July 31, 2010. This review covers imports of subject merchandise from one manufacturer...

  3. Current options for the treatment of Paget’s disease of the bone

    Directory of Open Access Journals (Sweden)

    Daniela Merlotti

    2009-07-01

    Full Text Available Daniela Merlotti, Luigi Gennari, Giuseppe Martini, Ranuccio NutiDepartment of Internal Medicine, Endocrine-Metabolic Sciences and Biochemistry, University of Siena, Siena, ItalyAbstract: Paget’s disease of bone (PDB is a chronic bone remodeling disorder characterized by increased osteoclast-mediated bone resorption, with subsequent compensatory increases in new bone formation, resulting in a disorganized mosaic of woven and lamellar bone at affected skeletal sites. This disease is most often asymptomatic but can be associated with bone pain or deformity, fractures, secondary arthritis, neurological complications, deafness, contributing to substantial morbidity and reduced quality of life. Neoplastic degeneration of pagetic bone is a relatively rare event, occurring with an incidence of less than 1%, but has a grave prognosis. Specific therapy for PDB is aimed at decreasing the abnormal bone turnover and bisphosphonates are currently considered the treatment of choice. These treatments are associated with a reduction in plasma alkaline phosphatase (ALP activity and an improvement in radiological and scintigraphic appearance and with a reduction in bone pain and bone deformity, Recently, the availability of newer, more potent nitrogen-containing bisphosphonates has improved treatment outcomes, allowing a more effective and convenient management of this debilitating disorder.Keywords: Paget’s disease of bone, bisphosphonates, aminobisphosphonates, bone remodeling

  4. Welded-woven fabrics for use as synthetic, minimally invasive orthopaedic implants

    Science.gov (United States)

    Rodts, Timothy W.

    The treatment of osteoarthritis in healthcare today focuses on minimizing pain and retaining mobility. Osteoarthritis of the knee is a common disease and known to be associated with traumatic injuries, among other factors. An identified trend is that patients are younger and have expectations of life with the preservation of an active lifestyle. As a result, great strain is placed on the available offerings of healthcare professionals and device manufacturers alike. This results in numerous design challenges for managing pain and disease over an extended period of time. The available treatments are being extended into younger populations, which increasingly suffer traumatic knee injuries. However, these patients are not good candidates for total joint replacement. A common problem for young patients is localized cartilage damage. This can heal, but often results in a painful condition that requires intervention. A welded-woven three-dimensional polymer fabric was developed to mimic the properties of articular cartilage. A process for the laser welding reinforcement of the surface layers of three-dimensional fabrics was investigated. Confined compression creep and pin-on-disc wear studies were conducted to characterize the contribution of the surface welding reinforcement. All materials used in the studies have previously been used in orthopaedic devices or meet the requirements for United States Pharmacopeial Convention (USP) Class VI biocompatibility approval. The compressive behavior of three-dimensional fabrics was tailored by the inclusion of surface welds. The compressive properties of the welded-woven fabrics were shown to better approximate articular cartilage compressive properties than conventional woven materials. The wear performance was benchmarked against identical fabrics without welding reinforcement. The wear rates were significantly reduced and the lifespan of the fabrics was markedly improved due to surface welding. Welding reinforcement offers a

  5. Bone tumors

    International Nuclear Information System (INIS)

    Moylan, D.J.; Yelovich, R.M.

    1991-01-01

    Primary bone malignancies are relatively rare with less than 4,000 new cases per year. Multiple myeloma (more correctly a hematologic malignancy) accounts for 40%; osteosarcomas, 28%; chondrosarcomas, 13%; fibrosarcomas arising in bone, 4%; and Ewing's sarcoma, 7%. The authors discuss various treatments for bone tumors, including radiotherapy, chemotherapy and surgery

  6. Histomorphometric evaluation of bone regeneration using autogenous bone and beta-tricalcium phosphate in diabetic rabbits

    Directory of Open Access Journals (Sweden)

    Živadinović Milka

    2016-01-01

    Full Text Available Background/Aim. The mechanism of impaired bone healing in diabetes mellitus includes different tissue and cellular level activities due to micro- and macrovascular changes. As a chronic metabolic disease with vascular complications, diabetes affects a process of bone regeneration as well. The therapeutic approach in bone regeneration is based on the use of osteoinductive autogenous grafts as well as osteoconductive synthetic material, like a β-tricalcium phosphate. The aim of the study was to determine the quality and quantity of new bone formation after the use of autogenous bone and β-tricalcium phosphate in the model of calvarial critical-sized defect in rabbits with induced diabetes mellitus type I. Methods. The study included eight 4-month-old Chincilla rabbits with alloxan-induced diabetes mellitus type I. In all animals, there were surgically created two calvarial bilateral defects (diameter 12 mm, which were grafted with autogenous bone and β-tricalcium phosphate (n = 4 or served as unfilled controls (n = 4. After 4 weeks of healing, animals were sacrificed and calvarial bone blocks were taken for histologic and histomorphometric analysis. Beside descriptive histologic evaluation, the percentage of new bone formation, connective tissue and residual graft were calculated. All parameters were statistically evaluated by Friedman Test and post hock Wilcoxon Singed Ranks Test with a significance of p < 0.05. Results. Histology revealed active new bone formation peripherally with centrally located connective tissue, newly formed woven bone and well incorporated residual grafts in all treated defects. Control samples showed no bone bridging of defects. There was a significantly more new bone in autogeonous graft (53% compared with β-tricalcium phosphate (30%, (p < 0.030 and control (7%, (p < 0.000 groups. A significant difference was also recorded between β-tricalcium phosphate and control groups (p < 0.008. Conclusion. In the present

  7. A biomimetic multilayer nanofiber fabric fabricated by electrospinning and textile technology from polylactic acid and Tussah silk fibroin as a scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Weili [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); He, Jianxin, E-mail: hejianxin771117@163.com [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Han, Qiming [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Sang, Feng [Department of Acquired Immune Deficiency Syndrome Treatment and Research Center, The First Affiliated Hospital of Henan University of Traditional Chinese Medicine, Zhengzhou 450000 (China); Wang, Qian [Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); Chen, Li [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Cui, Shizhong [Key Laboratory of Advanced Textile Composites, Ministry of Education, Institute of Textile Composites, Tianjin Polytechnic University, Tianjin 300387 (China); Henan provincial key laboratory of functional textile materials, Zhongyuan University of Technology, Zhengzhou 450007 (China); Collaborative Innovation Center of Textile and Garment Industry, Henan Province, Zhengzhou 450007 (China); and others

    2016-10-01

    To engineer bone tissue, a scaffold with good biological properties should be provided to approximate the hierarchical structure of collagen fibrils in natural bone. In this study, we fabricated a novel scaffold consisting of multilayer nanofiber fabrics (MLNFFs) by weaving nanofiber yarns of polylactic acid (PLA) and Tussah silk fibroin (TSF). The yarns were fabricated by electrospinning, and we found that spinnability, as well as the mechanical properties of the resulting scaffold, was determined by the ratio between polylactic acid and Tussah silk fibroin. In particular, a 9:1 mixture can be spun continuously into nanofiber yarns with narrow diameter distribution and good mechanical properties. Accordingly, woven scaffolds based on this mixture had excellent mechanical properties, with Young's modulus 417.65 MPa and tensile strength 180.36 MPa. For nonwoven scaffolds fabricated from the same materials, the Young's modulus and tensile strength were 2- and 4-fold lower, respectively. Woven scaffolds also supported adhesion and proliferation of mouse mesenchymal stem cells, and promoted biomineralization via alkaline phosphatase and mineral deposition. Finally, the scaffolds significantly enhanced the formation of new bone in damaged femoral condyle in rabbits. Thus, the scaffolds are potentially suitable for bone tissue engineering because of biomimetic architecture, excellent mechanical properties, and good biocompatibility. - Highlights: • A novel strategy to mimic the hierarchical collagen fibril in bone is proposed by electrospinning and conventional textile technology. • The tensile strength of the woven scaffold was nearly 4-fold larger than that of nonwoven mats. • The nanofiber woven scaffolds show excellent cytocompatibility and accelerate osteoblast differentiation. • The composite scaffold significantly enhanced formation of new bone in damaged condyles in rabbit femur.

  8. A biomimetic multilayer nanofiber fabric fabricated by electrospinning and textile technology from polylactic acid and Tussah silk fibroin as a scaffold for bone tissue engineering

    International Nuclear Information System (INIS)

    Shao, Weili; He, Jianxin; Han, Qiming; Sang, Feng; Wang, Qian; Chen, Li; Cui, Shizhong

    2016-01-01

    To engineer bone tissue, a scaffold with good biological properties should be provided to approximate the hierarchical structure of collagen fibrils in natural bone. In this study, we fabricated a novel scaffold consisting of multilayer nanofiber fabrics (MLNFFs) by weaving nanofiber yarns of polylactic acid (PLA) and Tussah silk fibroin (TSF). The yarns were fabricated by electrospinning, and we found that spinnability, as well as the mechanical properties of the resulting scaffold, was determined by the ratio between polylactic acid and Tussah silk fibroin. In particular, a 9:1 mixture can be spun continuously into nanofiber yarns with narrow diameter distribution and good mechanical properties. Accordingly, woven scaffolds based on this mixture had excellent mechanical properties, with Young's modulus 417.65 MPa and tensile strength 180.36 MPa. For nonwoven scaffolds fabricated from the same materials, the Young's modulus and tensile strength were 2- and 4-fold lower, respectively. Woven scaffolds also supported adhesion and proliferation of mouse mesenchymal stem cells, and promoted biomineralization via alkaline phosphatase and mineral deposition. Finally, the scaffolds significantly enhanced the formation of new bone in damaged femoral condyle in rabbits. Thus, the scaffolds are potentially suitable for bone tissue engineering because of biomimetic architecture, excellent mechanical properties, and good biocompatibility. - Highlights: • A novel strategy to mimic the hierarchical collagen fibril in bone is proposed by electrospinning and conventional textile technology. • The tensile strength of the woven scaffold was nearly 4-fold larger than that of nonwoven mats. • The nanofiber woven scaffolds show excellent cytocompatibility and accelerate osteoblast differentiation. • The composite scaffold significantly enhanced formation of new bone in damaged condyles in rabbit femur.

  9. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  10. Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

  11. Measurement of Electromagnetic Shielding Effectiveness of Woven Fabrics Containing Metallic Yarns by Mobile Devices

    Directory of Open Access Journals (Sweden)

    Erhan Kenan ÇEVEN

    2016-10-01

    Full Text Available In this study, we introduce an alternative method to evaluate the electromagnetic shielding effectiveness (EMSE of woven fabrics containing metal wires. For experimental measurements, hybrid silk viscose yarns containing metal wires were first produced. Conductive test fabrics were then produced using the hybrid weft yarns and polyester warp yarns. The produced fabrics were separated in two parts and laminated together after rotating one fabric by 90 degrees to create a grid structure. The laminated fabrics were then folded by several times to create multiple layers such as 2,4,8,12,16. The EMSE of the multiple layered fabrics was measured over GSM signals received by a mobile device. For EMSE evaluation, the mobile device was placed between the laminated fabrics. The EMSE values of the fabrics were then calculated in accordance with the power variations of GSM signals.

  12. Damage development in woven fabric composites during tension-tension fatigue

    DEFF Research Database (Denmark)

    Hansen, U.

    1999-01-01

    of the operating fatigue damage mechanism(s). Fatigue leads to a degradation of material properties. Consequently, in connection with impact induced local stress raisers, fatigue produces continuously changing non-uniform stress fields because of stress redistribution effects. Other models addressing evolution...... of fatigue damage in composite materials have not been able to simulate evolving nonuniform stress fields. Therefore. in the second part of this paper, an analytical/numerical approach capable of addressing these issues is also proposed.......Impacted woven fabric composites were tested in tension-tension fatigue. In contrast to results from static testing, the effects of low energy impact damage in a fatigue environment were found to be the critical element leading to failure of the specimen. This difference emphasizes the need...

  13. CEMCAN Software Enhanced for Predicting the Properties of Woven Ceramic Matrix Composites

    Science.gov (United States)

    Murthy, Pappu L. N.; Mital, Subodh K.; DiCarlo, James A.

    2000-01-01

    Major advancements are needed in current high-temperature materials to meet the requirements of future space and aeropropulsion structural components. Ceramic matrix composites (CMC's) are one class of materials that are being evaluated as candidate materials for many high-temperature applications. Past efforts to improve the performance of CMC's focused primarily on improving the properties of the fiber, interfacial coatings, and matrix constituents as individual phases. Design and analysis tools must take into consideration the complex geometries, microstructures, and fabrication processes involved in these composites and must allow the composite properties to be tailored for optimum performance. Major accomplishments during the past year include the development and inclusion of woven CMC micromechanics methodology into the CEMCAN (Ceramic Matrix Composites Analyzer) computer code. The code enables one to calibrate a consistent set of constituent properties as a function of temperature with the aid of experimentally measured data.

  14. An Integrated Computational Materials Engineering Method for Woven Carbon Fiber Composites Preforming Process

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weizhao; Ren, Huaqing; Wang, Zequn; Liu, Wing K.; Chen, Wei; Zeng, Danielle; Su, Xuming; Cao, Jian

    2016-10-19

    An integrated computational materials engineering method is proposed in this paper for analyzing the design and preforming process of woven carbon fiber composites. The goal is to reduce the cost and time needed for the mass production of structural composites. It integrates the simulation methods from the micro-scale to the macro-scale to capture the behavior of the composite material in the preforming process. In this way, the time consuming and high cost physical experiments and prototypes in the development of the manufacturing process can be circumvented. This method contains three parts: the micro-scale representative volume element (RVE) simulation to characterize the material; the metamodeling algorithm to generate the constitutive equations; and the macro-scale preforming simulation to predict the behavior of the composite material during forming. The results show the potential of this approach as a guidance to the design of composite materials and its manufacturing process.

  15. Vacuum Characterization of a Woven Carbon Fiber Cryosorber in Presence of $H_2$

    CERN Document Server

    Baglin, V; Garcin, T

    2004-01-01

    Some of the cold bores of the Large Hadron Collider (LHC) will operate at 4.5K. In these elements, the desorbed H2 pressure will rapidly reach the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be potentially used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications for the LHC are discussed.

  16. Static and Dynamic Mechanical Properties of Graphene Oxide-Incorporated Woven Carbon Fiber/Epoxy Composite

    Science.gov (United States)

    Adak, Nitai Chandra; Chhetri, Suman; Kim, Nam Hoon; Murmu, Naresh Chandra; Samanta, Pranab; Kuila, Tapas

    2018-03-01

    This study investigates the synergistic effects of graphene oxide (GO) on the woven carbon fiber (CF)-reinforced epoxy composites. The GO nanofiller was incorporated into the epoxy resin with variations in the content, and the CF/epoxy composites were manufactured using a vacuum-assisted resin transfer molding process and then cured at 70 and 120 °C. An analysis of the mechanical properties of the GO (0.2 wt.%)/CF/epoxy composites showed an improvement in the tensile strength, Young's modulus, toughness, flexural strength and flexural modulus by 34, 20, 83, 55 and 31%, respectively, when compared to the CF/epoxy composite. The dynamic mechanical analysis of the composites exhibited an enhancement of 56, 114 and 22% in the storage modulus, loss modulus and damping capacity (tan δ), respectively, at its glass transition temperature. The fiber-matrix interaction was studied using a Cole-Cole plot analysis.

  17. Textile electrodes woven by carbon nanotube-graphene hybrid fibers for flexible electrochemical capacitors.

    Science.gov (United States)

    Cheng, Huhu; Dong, Zelin; Hu, Chuangang; Zhao, Yang; Hu, Yue; Qu, Liangti; Chen, Nan; Dai, Liming

    2013-04-21

    Functional graphene-based fibers are promising as new types of flexible building blocks for the construction of wearable architectures and devices. Unique one-dimensional (1D) carbon nanotubes (CNTs) and 2D graphene (CNT/G) hybrid fibers with a large surface area and high electrical conductivity have been achieved by pre-intercalating graphene fibers with Fe3O4 nanoparticles for subsequent CVD growth of CNTs. The CNT/G hybrid fibers can be further woven into textile electrodes for the construction of flexible supercapacitors with a high tolerance to the repeated bending cycles. Various other applications, such as catalysis, separation, and adsorption, can be envisioned for the CNT/G hybrid fibers.

  18. Dielectric Behaviour of Some Woven Fabrics on the Basis of Natural Cellulosic Fibers

    Directory of Open Access Journals (Sweden)

    Florin St. C. Mustata

    2014-01-01

    Full Text Available The electrical permittivity of the weaves obtained from natural cellulosic yarns or mixed with synthetic fibers was established with capacitor method. The highest value of relative electrical permittivity in case of the woven fabric from natural cellulosic fibers has been observed at the weave made of pure hemp (13.55 and the lowest at the weave obtained from the pure jute—weave packing (1.87. Electrical permittivity value of the pure jute weave packing is comparable to that of the permittivity for the glass thread, when the work conditions are as follows: temperature 25°C and air humidity 35%. The relative electrical permittivity of the weave is depending on the degree of crimping yarns especially in the weft direction, technological density in direction of the warp and weft, and surface mass of the weave.

  19. Tension-Compression Fatigue Behavior of Plain Woven Kenaf/Kevlar Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2016-02-01

    Full Text Available The applications of hybrid natural/synthetic reinforced polymer composites have been rapidly gaining market share in structural applications due to their remarkable characteristics and the fact that most of the components made of these materials are subjected to cyclic loading. Their fatigue properties have received a lot of attention because predicting their behavior is a challenge due to the effects of the synergies between the fibers. The purpose of this work is to characterize the tension, compression, and tensile-compression fatigue behavior of six layers of Kevlar hybridized with one layer of woven kenaf reinforced epoxy, at a 35% weight fraction. Fatigue tests were carried out and loaded cyclically at 60%, 70%, 80%, and 90% of their ultimate compressive stress. The results give a complete description for tensile and compression properties and could be used to predict fatigue-induced failure mechanisms.

  20. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  1. Drop Weight Impact Studies of Woven Fibers Reinforced Modified Polyester Composites

    Directory of Open Access Journals (Sweden)

    Muhammed Tijani ISA

    2014-02-01

    Full Text Available Low velocity impact tests were conducted on modified unsaturated polyester reinforced with four different woven fabrics using hand-layup method to investigate the effect of fiber type and fiber combinations. The time-load curves were analysed and scanning electron microscopy was used to observe the surface of the impacted composite laminates. The results indicated that all the composites had ductility index (DI of above two for the test conducted at impact energy of 27J with the monolithic composite of Kevlar having the highest DI. The damage modes observed were mainly matrix cracks and fiber breakages. Hybridization of the fibers in the matrix was observed to minimize these damages.

  2. Strain Sharing Assessment in Woven Fiber Reinforced Concrete Beams Using Fiber Bragg Grating Sensors.

    Science.gov (United States)

    Montanini, Roberto; Recupero, Antonino; De Domenico, Fabrizio; Freni, Fabrizio

    2016-09-22

    Embedded fiber Bragg grating sensors have been extensively used worldwide for health monitoring of smart structures. In civil engineering, they provide a powerful method for monitoring the performance of composite reinforcements used for concrete structure rehabilitation and retrofitting. This paper discusses the problem of investigating the strain transfer mechanism in composite strengthened concrete beams subjected to three-point bending tests. Fiber Bragg grating sensors were embedded both in the concrete tensioned surface and in the woven fiber reinforcement. It has been shown that, if interface decoupling occurs, strain in the concrete can be up to 3.8 times higher than that developed in the reinforcement. A zero friction slipping model was developed which fitted very well the experimental data.

  3. Mesoscopic Strains Maps in Woven Composite Laminas During Off-axis Tension

    Directory of Open Access Journals (Sweden)

    Nicoletto G.

    2010-06-01

    Full Text Available The mechanics of woven carbon-fiber reinforced plastic (CFRP composites is influenced by the complex architecture of the reinforcement phase. Computational (i.e. finite element based approaches have been used increasingly to model not only the global laminate stiffness, but also damage evolution and laminate strength. The modeling combines the identification of the architectural unit cell (UC, the selection of suitable constitutive models of the different phases, the creation of a fine discretization of the UC in finite elements, the application of an incremental solution procedure that solves iteratively for the stresses and strains in the UC, [1]. The experimental validation of computational models is carried out mainly at the macroscopical level, i.e. simulation of the macroscopic stress-strain curve. Damage, however, is a localized, straindependent phenomenon and therefore only accurate strain distribution within the UC (at the mesolevel can identify critical conditions in terms of damage location, extension and evolution. The validation of computational damage procedures is a key task and full-field optical strain analysis methods appear the ideal instrument. However, only limited examples of direct finte element method (FEM vs experimental strain correlation are found because of the limited sensitivity and spatial resolution of some techniques and the complexity and applicative difficulty of others. The aim of the present paper is to present the application of the digital image correlation (DIC technique, [2], to the full-field strain analysis at the mesoscopic level (i.e. within the UC of a woven CFRP lamina when the direction of loading forms an angle to the material direction. The material under consideration is a woven carbon fiber reinforced epoxy composite. Orthogonal yarns, each made of of several thousand fibers, are woven according the twill-weave architecture is shown in Fig. 1a. Single-ply laminas were manufactured and tested to

  4. Studies of LENRA-Toughened PVC non-woven membranes prepared by electro spinning technique

    International Nuclear Information System (INIS)

    Dahlan Mohd; Mahathir Mohamed; Khirul Hafiz mohd Yusof

    2010-01-01

    Lately research in use of so-called green chemicals draws strong interest from research community due to the climate change issues. Malaysia is in strong position to take this advantage because we are among the world biggest producers of natural rubber and palm oil - the two sources of important green renewable chemical feedstock in the near future. For the last couple of years we have shown how modified natural rubbers especially liquid natural rubber and its derivatives such as liquid epoxidized natural rubber acrylate (LENRA) could be used in various applications via among others sol-gel technique and radiation curing technology. This time around we will show another application on how non-woven membranes made from PVC can be prepared by electro spinning technique using radiation curable LENRA as toughener. The electro spinning technique has great potential in producing nano fiber materials to be used in various applications to ensure sustainable energy and environments for the future. (author)

  5. The homing of bone marrow MSCs to non-osseous sites for ectopic bone formation induced by osteoinductive calcium phosphate

    Science.gov (United States)

    Song, Guodong; Habibovic, Pamela; Bao, Chongyun; Hu, Jing; van Blitterswijk, Clemens A.; Yuan, Huipin; Chen, Wenchuan; Xu, Hockin H.K.

    2013-01-01

    Osteoinductive biomaterials are promising for bone repair. There is no direct proof that bone marrow mesenchymal stem cells (BMSCs) home to non-osseous sites and participate in ectopic bone formation induced by osteoinductive bioceramics. The objective of this study was to use a sex-mismatched beagle dog model to investigate BMSC homing via blood circulation to participate in ectopic bone formation via osteoinductive biomaterial. BMSCs of male dogs were injected into female femoral marrow cavity. The survival and stable chimerism of donor BMSCs in recipients were confirmed with polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH). Biphasic calcium phosphate (BCP) granules were implanted in dorsal muscles of female dogs. Y chromosomes were detected in samples harvested from female dogs which had received male BMSCs. At 4 weeks, cells with Y-chromosomes were distributed in the new bone matrix throughout the BCP granule implant. At 6 weeks, cells with Y chromosomes were present in newly mineralized woven bone. TRAP positive osteoclast-like cells were observed in 4-week implants, and the number of such cells decreased from 4 to 6 weeks. These results show that osteoprogenitors were recruited from bone marrow and homed to ectopic site to serve as a cell source for calcium phosphate-induced bone formation. In conclusion, BMSCs were demonstrated to migrate from bone marrow through blood circulation to non-osseous bioceramic implant site to contribute to ectopic bone formation in a canine model. BCP induced new bone in muscles without growth factor delivery, showing excellent osteoinductivity that could be useful for bone tissue engineering. PMID:23298780

  6. Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

    Science.gov (United States)

    Jones, Justin S.; Polis, Daniel L.; Segal, Kenneth N.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to traditionally manufactured barrel segments. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the z-fiber weave to a fully interlocked weave with comparable fiber bias, the z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

  7. Bone banking.

    Science.gov (United States)

    Howard, W

    1999-04-01

    The use of human organs and tissues for transplantation in Australia has increased significantly over the past 30 years. In 1997, the Australian Coordinating Committee on Organ Registries and Donation (ACCORD) reported a total number of 190 organ donors, 636 corneal donors and 1509 bone donors Australia wide. Of the 1509 bone donations, 143 came from cadaveric sources and 1366 were made by living donors. Bone transplantation is not as widely recognised as solid organ or corneal transplantation. Due to improved technology and surgical skills, the demand for bone transplantation has increased markedly. This Clinical Update will provide an overview of the physiological aspects of bone transplantation and explore bone banking, a key step in the complex and critical process of bone transplantation.

  8. Long bone histology and growth patterns in ankylosaurs: implications for life history and evolution.

    Directory of Open Access Journals (Sweden)

    Martina Stein

    Full Text Available The ankylosaurs are one of the major dinosaur groups and are characterized by unique body armor. Previous studies on other dinosaur taxa have revealed growth patterns, life history and evolutionary mechanisms based on their long bone histology. However, to date nothing is known about long bone histology in the Ankylosauria. This study is the first description of ankylosaurian long bone histology based on several limb elements, which were sampled from different individuals from the Ankylosauridae and Nodosauridae. The histology is compared to that of other dinosaur groups, including other Thyreophora and Sauropodomorpha. Ankylosaur long bone histology is characterized by a fibrolamellar bone architecture. The bone matrix type in ankylosaurs is closest to that of Stegosaurus. A distinctive mixture of woven and parallel-fibered bone together with overall poor vascularization indicates slow growth rates compared to other dinosaurian taxa. Another peculiar characteristic of ankylosaur bone histology is the extensive remodeling in derived North American taxa. In contrast to other taxa, ankylosaurs substitute large amounts of their primary tissue early in ontogeny. This anomaly may be linked to the late ossification of the ankylosaurian body armor. Metabolically driven remodeling processes must have liberated calcium to ossify the protective osteodermal structures in juveniles to subadult stages, which led to further remodeling due to increased mechanical loading. Abundant structural fibers observed in the primary bone and even in remodeled bone may have improved the mechanical properties of the Haversian bone.

  9. Bone development

    DEFF Research Database (Denmark)

    Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.

    2007-01-01

    The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram.......01). Furthermore, AKG administration induced significantly higher bone mineral density of the cortical bone by 7.1% (P

  10. Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Maqsood Muhammad

    2016-09-01

    Full Text Available The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

  11. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    Science.gov (United States)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  12. A Mesoscopic Analytical Model to Predict the Onset of Wrinkling in Plain Woven Preforms under Bias Extension Shear Deformation

    Directory of Open Access Journals (Sweden)

    Abbas Hosseini

    2017-10-01

    Full Text Available A mesoscopic analytical model of wrinkling of Plain-Woven Composite Preforms (PWCPs under the bias extension test is presented, based on a new instability analysis. The analysis is aimed to facilitate a better understanding of the nature of wrinkle formation in woven fabrics caused by large in-plane shear, while it accounts for the effect of fabric and process parameters on the onset of wrinkling. To this end, the mechanism of wrinkle formation in PWCPs in mesoscale is simplified and an equivalent structure composed of bars and different types of springs is proposed, mimicking the behavior of a representative PWCP element at the post-locking state. The parameters of this equivalent structure are derived based on geometric and mechanical characteristics of the PWCP. The principle of minimum total potential energy is employed to formluate the model, and experimental validation is carried out to reveal the effectiveness of the derived wrinkling prediction equation.

  13. An Evaluation of 3D Woven Orthogonal Composites' Potential in the Automotive Supply Chain

    Science.gov (United States)

    Taylor, Dalia

    The automotive supply chain and its management can be a very complex process and comprises a long dynamic and complex network that consists of four primary segments: original equipment manufacturers (OEMs), first tier suppliers, sub tiers suppliers, and infrastructure suppliers. During the analysis of the current automotive industry it was identified that textile industry importance is considerable increasing as a part of the global automotive supply chain, because textile products are used for interior, exterior and even suspension parts and components. Automotive industry has an increasing demand for higher quality exterior panels with better functional properties and reduced weight. One of the main potentials for this demand is based on the three-dimensional woven composites technology innovations which can replace an existing technology. The new role of the textile industry could make important changes in the automotive supply chain industry, such as: changes in the size of the supply chain, the time to the market and the position of textile industry in the automotive supply chain structure. 3D composite materials from high performance fibers, such as glass and carbon, have been used for automotive applications in a limited way due to the low production rate and the lack of research and development. This research will contribute to the understanding of textile composites in transportation and the textile parameters that affect the performance characteristics of these materials. The research examines the performance characteristics of lighter and stronger 3D woven fabric composites made from fiberglass with the aim to improve fuel efficiency by reducing the total vehicle weight while maintaining safety standards. The performance characteristics of the 3D woven fabric composite can be designed by changing different construction parameters, such as picks density, pick roving linear density, arrangements of warp and z-yarns, and the number of warp and picks layers

  14. The thermal non-equilibrium porous media modelling for CFD study of woven wire matrix of a Stirling regenerator

    International Nuclear Information System (INIS)

    Costa, S.C.; Barreno, I.; Tutar, M.; Esnaola, J.A.; Barrutia, H.

    2015-01-01

    Highlights: • A numerical procedure to derive porous media’s coefficients is proposed. • The local thermal non-equilibrium porous media model is more suitable for regenerators. • The regenerator temperature profiles can be better fitted to a logarithmic curve. • The wound woven wire matrix provides lower performance compared to stacked. • The numerical characterization methodology is useful for the multi-D Stirling engine models. - Abstract: Different numerical methods can be applied to the analysis of the flow through the Stirling engine regenerator. One growing approach is to model the regenerator as porous medium to simulate and design the full Stirling engine in three-dimensional (3-D) manner. In general, the friction resistance coefficients and heat transfer coefficient are experimentally obtained to describe the flow and thermal non-equilibrium through a porous medium. A finite volume method (FVM) based non-thermal equilibrium porous media modelling approach characterizing the fluid flow and heat transfer in a representative small detailed flow domain of the woven wire matrix is proposed here to obtain the porous media coefficients without further requirement of experimental studies. The results are considered to be equivalent to those obtained from the detailed woven wire matrix for the pressure drop and heat transfer. Once the equivalence between the models is verified, this approach is extended to model oscillating regeneration cycles through a full size regenerator porous media for two different woven wire matrix configurations of stacked and wound types. The results suggest that the numerical modelling approach proposed here can be applied with confidence to model the regenerator as a porous media in the multi-dimensional (multi-D) simulations of Stirling engines

  15. The Use of Decorative Styles of Woven Songket as a Source of Learning in the Course Textile Design and Decoration

    Directory of Open Access Journals (Sweden)

    Made Budhyani I Dewa Ayu

    2018-01-01

    Full Text Available The use of learning sources in the learning process greatly contributes to the achievement of its goal. The use of learning sources greatly affects the teaching and learning process. It is necessary to use different learning sources when creating a textile design in order to produce a quality product. The decorative style of woven songket can be used as one of the learning sources. The different decorative types of the woven songket contain aesthetic values. The decorative type of woven songket is a product of the crafter’s feeling, creativity, and intention inspired by the environment. The natural objects such as plants, animals, human beings, and geometric elements are stylized into the decorative forms. The decorative style used on the woven songket can be used as the learning source in order to create the decorative style in the course Textile Design and Decoration. There are several aesthetic elements which inspire where the decorative style is placed; they are composition, rhythm, balance, the harmonious layout of the decorative style, and the variation of the decorative style on the textile design. In general, the composition of the placement of the main object of the decorative style is more dominant on the piece of fabric. Rhythm and how the decorative style is composed are shown through the composition of the decorative motive forms such as how big and small they are, how high and low they are and how long and short they are. The ways in which the decorative motives and colors are entirely shown contribute to the harmony and placement of decorative style. The symmetric balance is used to create balance and avoid the impression of being biased. The placement of what the motives contain and how they are composed are used to determine the variation of the decorative style used. The placement of objects and the marginal decoration of the fabric also determine the variation used.

  16. Broken bone

    Science.gov (United States)

    ... Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Broken bone URL of this page: //medlineplus.gov/ency/ ... following steps to reduce your risk of a broken bone: Wear protective ... pads. Create a safe home for young children. Place a gate at stairways ...

  17. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    The bisphosphonates have been introduced as alternatives to hormone replacement therapy (HRT) for the treatment and prevention of postmenopausal osteoporosis. The expected increasing application in at clinical practice demands cost-effective and easily handled methods to monitor the effect on bone....... The weak response at the distal forearm during antiresorptive treatment has restricted the use of bone densitometry at this region. We describe a new model for bone densitometry at the distal forearm, by which the response obtained is comparable to the response in other regions where bone densitometry...... is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  18. Woven electrochemical fabric-based test sensors (WEFTS): a new class of multiplexed electrochemical sensors.

    Science.gov (United States)

    Choudhary, Tripurari; Rajamanickam, G P; Dendukuri, Dhananjaya

    2015-05-07

    We present textile weaving as a new technique for the manufacture of miniature electrochemical sensors with significant advantages over current fabrication techniques. Biocompatible silk yarn is used as the material for fabrication instead of plastics and ceramics used in commercial sensors. Silk yarns are coated with conducting inks and reagents before being handloom-woven as electrodes into patches of fabric to create arrays of sensors, which are then laminated, cut and packaged into individual sensors. Unlike the conventionally used screen-printing, which results in wastage of reagents, yarn coating uses only as much reagent and ink as required. Hydrophilic and hydrophobic yarns are used for patterning so that sample flow is restricted to a small area of the sensor. This simple fluidic control is achieved with readily available materials. We have fabricated and validated individual sensors for glucose and hemoglobin and a multiplexed sensor, which can detect both analytes. Chronoamperometry and differential pulse voltammetry (DPV) were used to detect glucose and hemoglobin, respectively. Industrial quantities of these sensors can be fabricated at distributed locations in the developing world using existing skills and manufacturing facilities. We believe such sensors could find applications in the emerging area of wearable sensors for chemical testing.

  19. Vacuum infusion method for woven carbon/Kevlar reinforced hybrid composite

    Science.gov (United States)

    Hashim, N.; Majid, D. L.; Uda, N.; Zahari, R.; Yidris, N.

    2017-12-01

    The vacuum assisted resin transfer moulding (VaRTM) or Vacuum Infusion (VI) is one of the fabrication methods used for composite materials. Compared to other methods, this process costs lower than using prepregs because it does not need to use the autoclave to cure. Moreover, composites fabricated using this VI method exhibit superior mechanical properties than those made through hand layup process. In this study, the VI method is used in fabricating woven carbon/Kevlar fibre cloth with epoxy matrix. This paper reports the detailed methods on fabricating the hybrid composite using VI process and several precautions that need to be taken to avoid any damage to the properties of the composite material. The result highlights that the successfully fabricated composite has approximately 60% of fibres weight fraction. Since the composites produced by the VI process have a higher fibre percentage, this process should be considered for composites used in applications that are susceptible to the conditions where the fibres need to be the dominant element such as in tension loading.

  20. Extended FMEA for Sustainable Manufacturing: An Empirical Study in the Non-Woven Fabrics Industry

    Directory of Open Access Journals (Sweden)

    Thanh-Lam Nguyen

    2016-09-01

    Full Text Available Failure modes and effects analysis ( F M E A substantially facilitates the efforts of industrial manufacturers in prioritizing failures that require corrective actions to continuously improve product quality. However, the conventional approach fails to provide satisfactory explanation of the aggregate effects of a failure from different perspectives such as technical severity, economic severity, and production capacity in some practical applications. To fulfill the existing gap in the F M E A literature, this paper proposes an extension by considering associated quality cost and the capability of failure detection system as additional determinants to signify the priority level for each failure mode. The quality cost and capacity are considered as key factors for sustainable survival and development of an industrial manufacturer in the fierce competition market these days. The performance of the extended scheme was tested in an empirical case at a non-woven fabrics manufacturer. Analytical results indicate that the proposed approach outperforms the traditional one and remarkably reduces the percentage of defective fabrics from about 2.41% before the trial period to 1.13%,thus significantly reducing wastes and increasing operation efficiency, thereby providing valuable advantages to improve organizational competition power for their sustainable growth.

  1. Protozoa and metazoa relations to technological conditions of non-woven textile filters for wastewater treatment.

    Science.gov (United States)

    Spychała, Marcin; Sowińska, Aleksandra; Starzyk, Justyna; Masłowski, Adam

    2015-01-01

    The objective of this study was a preliminary identification of basic groups of micro-organisms in the cross-sectional profile of geotextile filters for septic tank effluent (STE) treatment and their relations to technological conditions. Reactors with textile filters treating wastewater were investigated on a semi-technical scale. Filters were vertically situated and STE was filtered through them under hydrostatic pressure at a wastewater surface height of 7-20 cm. Filters were made of four layers of non-woven TS 20 geotextile of 0.9 mm thickness. Various groups of organisms were observed; the most abundant group comprised free-swimming and crawling ciliates, less abundant were stalked ciliates and the least numerous were nematodes. The individual counts of all groups of micro-organisms investigated during the study were variable according to time and space. The high abundance of Opercularia, a commonly observed genus of stalked ciliates, was related to the high efficiency of wastewater treatment and dissolved oxygen concentration of about 1.0 g/m3. Numbers of free-swimming and crawling ciliates had a tendency to decrease in relation to the depth of filter cross-sectional profile. The variability in counts of particular groups of organisms could be related to the local stress conditions. No correlation between identified organism count and total mass concentration in the cross-sectional filter profile was found.

  2. Plasma penetration depth and mechanical properties of atmospheric plasma-treated 3D aramid woven composites

    International Nuclear Information System (INIS)

    Chen, X.; Yao, L.; Xue, J.; Zhao, D.; Lan, Y.; Qian, X.; Wang, C.X.; Qiu, Y.

    2008-01-01

    Three-dimensional aramid woven fabrics were treated with atmospheric pressure plasmas, on one side or both sides to determine the plasma penetration depth in the 3D fabrics and the influences on final composite mechanical properties. The properties of the fibers from different layers of the single side treated fabrics, including surface morphology, chemical composition, wettability and adhesion properties were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle measurement and microbond tests. Meanwhile, flexural properties of the composites reinforced with the fabrics untreated and treated on both sides were compared using three-point bending tests. The results showed that the fibers from the outer most surface layer of the fabric had a significant improvement in their surface roughness, chemical bonding, wettability and adhesion properties after plasma treatment; the treatment effect gradually diminished for the fibers in the inner layers. In the third layer, the fiber properties remained approximately the same to those of the control. In addition, three-point bending tests indicated that the 3D aramid composite had an increase of 11% in flexural strength and 12% in flexural modulus after the plasma treatment. These results indicate that composite mechanical properties can be improved by the direct fabric treatment instead of fiber treatment with plasmas if the fabric is less than four layers thick

  3. The Electrical and Thermal Conductivity of Woven Pristine and Intercalated Graphite Fiber-Polymer Composites

    Science.gov (United States)

    Gaier, James R.; Vandenburg, Yvonne Yoder; Berkebile, Steven; Stueben, Heather; Balagadde, Frederick

    2002-01-01

    A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity.

  4. Periodic flow hydrodynamic resistance parameters for woven screen matrices at cryogenic temperatures

    Science.gov (United States)

    Perrella, M. D.; Ghiaasiaan, S. M.

    2017-12-01

    The regenerator is a critical component in all Stirling and Pulse Tube cryocoolers. It generally consists of a microporous metallic or rare-earth filler material contained within a cylindrical shell. Accurate modelling of the hydrodynamic and thermal behaviour of different regenerator materials is crucial to the successful design of cryogenic systems. Previous investigations have used experimental measurements at steady and periodic flow conditions in conjunction with pore-level CFD analysis to determine the pertinent hydrodynamic parameters, namely the Darcy permeability and Forchheimer coefficients. Due to the difficulty associated with experimental measurement at cryogenic temperatures, past investigations were mostly performed at ambient conditions and their results are assumed to be appropriate for cryogenic temperatures. In this study, a regenerator filled with woven screen matrices such as 400 mesh T316 stainless steel were assembled and experimentally tested under periodic helium flow at cryogenic temperatures. The mass flow and pressure drop data were analysed using CFD to determine the dimensionless friction factor, Darcy Permeability and Forchheimer coefficients. These results are compared to previous investigations at ambient temperature conditions, and the relevance of room-temperature models and correlations to cryogenic temperatures is critically assessed.

  5. Influence of Chemical Surface Modification of Woven Fabrics on Ballistic and Stab Protection of Multilayer Packets

    Directory of Open Access Journals (Sweden)

    Diana GRINEVIČIŪTĖ

    2014-06-01

    Full Text Available In order to achieve enhanced protective and wear (flexibility, less bulkiness properties of ballistic and stab protecting panels the investigation of chemical surface modification of woven p-aramid fabrics was performed applying different chemical composition shear thickening fluid (STF which improves friction inside fabric structure. For the chemical treatment silicic acid and acrylic dispersion water solutions were used and influence of their different concentrations on panels’ protective properties were investigated. Results of ballistic tests of multilayer protective panel have revealed that shear thickening effect was negligible when shooting at high energy range (E > 440 J. Determination of stab resistance of p-aramid panels has shown that different chemical composition of STFs had different influence on protective properties of the panels. Application of low concentrations of silicic acid determined higher stab resistance values comparing to higher concentrations of acrylic dispersion water solutions. At this stage of research stab tests results as ballistic ones determined that STF application for multilayer p-aramid fabrics protective panels is more efficient at low strike energy levels. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.3138

  6. Experimental Tensile Strength Analysis of Woven-Glass/Epoxy Composite Plates with Central Circular Hole

    Science.gov (United States)

    Hadi, Bambang K.; Rofa, Bima K.

    2018-04-01

    The use of composite materials in aerospace engineering, as well as in maritime structure has increased significantly during the recent years. The extensive use of composite materials in industrial applications should make composite structural engineers and scientists more aware of the advantage and disadvantage of this material and provide them with necessary data and certification process. One of the problems in composite structures is the existence of hole. Hole can not be avoided in actual structures, since it may be the necessity of providing access for maintenance or due to impact damage. The presence of hole will weaken the structures. Therefore, in this paper, the effect of hole on the strength of glass-woven/epoxy composite will be discussed. Extensive tests have been carried out to study the effect of hole-diameter on the tensile strengths of these specimens. The results showed that the bigger the hole-diameter compared to the width of the specimens has weakened the structures further, as expected. Further study should be carried in the future to model it with the finite element and theoretical analysis precisely.

  7. Basic Comparison of the Properties of the Loop and Frotte Yarns, Woven and Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Ewa Grabowska Katarzyna

    2014-09-01

    Full Text Available Both loop fancy yarns and frotte fancy yarns belong to the group of yarns with continuous effects. The difference between frotte and loop yarn relies on the fact that the loop yarn is constructed with two core yarns and the frotte yarn is constructed with only one core yarn. The differences are evident in the shape of these two types of fancy yarns. These shape differences are the functions of the tensions of component yarns during the twisting process. The shape and construction of the fancy yarn influence its properties. The properties of loop and frotte fancy yarns, woven and knitted fabrics are compared in this article in order to find out the optimal yarn’s and fabric’s production condition to satisfy the final user and maintain low production costs. In terms of economy aspects only, the frotte fancy yarns are believed to be cheaper in production due to lower quantity of components utilize for their production to compare with loop fancy yarns, under conditions of the same settings of ring twisting frame.

  8. Micro-mechanics based damage mechanics for 3D Orthogonal Woven Composites: Experiment and Numerical Modelling

    KAUST Repository

    Saleh, Mohamed Nasr

    2016-01-08

    Damage initiation and evolution of three-dimensional (3D) orthogonal woven carbon fibre composite (3DOWC) is investigated experimentally and numerically. Meso-scale homogenisation of the representative volume element (RVE) is utilised to predict the elastic properties, simulate damage initiation and evolution when loaded in tension. The effect of intra-yarns transverse cracking and shear diffused damage on the in-plane transverse modulus and shear modulus is investigated while one failure criterion is introduced to simulate the matrix damage. The proposed model is based on two major assumptions. First, the effect of the binder yarns, on the in-plane properties, is neglected, so the 3DOWC unit cell can be approximated as a (0o/90o) cross-ply laminate. Second, a micro-mechanics based damage approach is used at the meso-scale, so damage indicators can be correlated, explicitly, to the density of cracks within the material. Results from the simulated RVE are validated against experimental results along the warp (0o direction) and weft (90o direction). This approach paves the road for more predictive models as damage evolution laws are obtained from micro mechanical considerations and rely on few well-defined material parameters. This largely differs from classical damage mechanics approaches in which the evolution law is obtained by retrofitting experimental observations.

  9. Micro-mechanics based damage mechanics for 3D Orthogonal Woven Composites: Experiment and Numerical Modelling

    KAUST Repository

    Saleh, Mohamed Nasr; Lubineau, Gilles; Potluri, Prasad; Withers, Philip; Soutis, Constantinos

    2016-01-01

    Damage initiation and evolution of three-dimensional (3D) orthogonal woven carbon fibre composite (3DOWC) is investigated experimentally and numerically. Meso-scale homogenisation of the representative volume element (RVE) is utilised to predict the elastic properties, simulate damage initiation and evolution when loaded in tension. The effect of intra-yarns transverse cracking and shear diffused damage on the in-plane transverse modulus and shear modulus is investigated while one failure criterion is introduced to simulate the matrix damage. The proposed model is based on two major assumptions. First, the effect of the binder yarns, on the in-plane properties, is neglected, so the 3DOWC unit cell can be approximated as a (0o/90o) cross-ply laminate. Second, a micro-mechanics based damage approach is used at the meso-scale, so damage indicators can be correlated, explicitly, to the density of cracks within the material. Results from the simulated RVE are validated against experimental results along the warp (0o direction) and weft (90o direction). This approach paves the road for more predictive models as damage evolution laws are obtained from micro mechanical considerations and rely on few well-defined material parameters. This largely differs from classical damage mechanics approaches in which the evolution law is obtained by retrofitting experimental observations.

  10. Study of the Contact Resistance of Interlaced Stainless Steel Yarns Embedded in Hybrid Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Vasile Simona

    2017-06-01

    Full Text Available The contact resistance of two interlacing electro-conductive yarns embedded in a hybrid woven fabric will constitute a problem for electro-conductive textiles under certain circumstances. A high contact resistance can induce hotspots, while a variable contact resistance may cause malfunctioning of the components that are interconnected by the electro-conductive yarns. Moreover, the contact robustness should be preserved over time and various treatments such as washing or abrading should not alter the functioning of the electro-conductive textiles. The electrical resistance developed in the contact point of two interlacing electro-conductive yarns is the result of various factors. The influence of diameter of the electro-conductive stainless steel yarns, the weave pattern, the weft density, and the abrasion on the contact resistance was investigated. Hybrid polyester fabrics were produced according to the design of experiments (DoE and statistical models were found that describe the variation of the contact resistance with the selected input parameters. It was concluded that the diameter of the stainless steel warp and weft yarns has a statistically significant influence on the contact resistance regardless of the weave. Weft density had a significant influence on the contact resistance but only in case of the twill fabrics. Abrasion led to an increase in contact resistance regardless of the weave pattern and the type of stainless steel yarn that was used. Finally, a combination of parameters that leads to plain and twill fabrics with low contact resistance and robust contacts is recommended.

  11. A woven 2D touchpad sensor and a 1D slide sensor using soft capacitor fibers

    International Nuclear Information System (INIS)

    Gorgutsa, Stephan; Gu, Jian Feng; Skorobogatiy, Maksim

    2012-01-01

    Recently reported soft conductive-polymer-based capacitor fibers are used to build a fully woven 2D touchpad sensor and a 1D slide sensor. An individual capacitor fiber features a swiss-roll like structure having two dielectric and two conductive polymer films rolled together in a classic multilayer capacitor configuration. The soft fibers of sub-1 mm outer diameter are fabricated using a fiber drawing procedure from a macroscopic polymeric preform. An individual capacitor fiber is then demonstrated to act as a distributed sensor that allows the touch position to be determined by measuring the fiber’s AC response. In other words, a single fiber acts as a 1D slide sensor. Furthermore, we develop an electrical ladder network model to predict the distributed sensor properties of an individual fiber and show that this model describes the experimental measurements very well. Finally, a two-dimensional touchpad sensor is presented. The sensor is built by weaving a one-dimensional array of capacitor fibers in parallel to each other. The performance of the touchpad sensor is then characterized. (paper)

  12. A self-healing 3D woven fabric reinforced shape memory polymer composite for impact mitigation

    International Nuclear Information System (INIS)

    Nji, Jones; Li, Guoqiang

    2010-01-01

    In this paper, a three-dimensional (3D) woven fabric reinforced shape memory polymer composite for impact mitigation was proposed, fabricated, programmed using a three-step strain-controlled thermomechanical cycle at a pre-strain level of 5% and machined to two groups of specimens (G1 and G2) with dimensions 152.4 mm × 101.6 mm × 12.7 mm. The specimens were impact tested, transversely, centrally and repeatedly with 32 and 42 J of energy. G1 specimens were healed after each impact until perforation occurred. G2 specimens were not healed after each impact and served as controls. At 32 J impact energy, G2 specimens were perforated at the 9th impact while G1 specimens lasted until the 15th impact; at 42 J impact energy, G2 specimens were perforated at the 5th impact while G1 specimens were perforated at the 7th impact. Visual inspection, C-scan, and scanning electron microscopy techniques were used to evaluate damage, failure modes, and healing efficiency

  13. Temperature Effects on Mechanical Properties of Woven Thermoplastic Composites for Secondary Aircraft Structure Applications

    Directory of Open Access Journals (Sweden)

    Wang Yue

    2017-01-01

    Full Text Available The effect of temperature on the mechanical behavior of 8-H satin woven glass fabric/polyethylene sulfide (GF/PPS was investigated in this paper. Static-tensile tests were both conducted on notched and unnotched specimens at typical temperatures (ambient, 95°C and 125°C based on the glass transition temperatures (Tg of the neat resin and composite, their strength and moduli were obtained and compared. The damage patterns of failed specimens of notched and unnotched were examined with the aid of high-definition camera and stereomicroscope. The results of stress-strain relationships showed that the slight nonlinearity of the curves were observed for these two specimens, which was associated with the plastic deformation of localized resin. The damage patterns of notched and unnotched specimens at different temperatures proved that damage and plastic deformation were two simultaneous mechanisms and it was prominent in the notched. It was the overstress accommodation mechanism that led to a relative high strength rentention for the notched and a reduction of the hole sensitivity. The results obtained in this paper indicated that GF/PPS can be used as secondary aircraft structures at elevated temperatures higher than its Tg.

  14. Tensile and Compressive Properties of Woven Kenaf/Glass Sandwich Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Mohaiman J. Sharba

    2016-01-01

    Full Text Available Monotonic (tensile and compression properties of woven kenaf/glass reinforced unsaturated polyester sandwich hybrid composites have been experimentally investigated. Five types of composites laminates were fabricated using a combination of hand lay-up and cold press techniques, postcured for two hours at 80°C and left for 48 hours at room temperature. The hybrid composites contained fixed six layers of glass as a shell, three on each side, whereas the number of core kenaf layers was changed in three stages to get S1, S2, and S3 hybrid composites. Composites specimens with pure glass and kenaf were also fabricated for comparison. It was found that one kenaf layer replaced about 20% of total fiber weight fraction of the composite; this leads to reducing the density of final hybrid composite by 13%. Besides, in mechanical properties perspective, there are less than 1% reduction in compression strength and 40% in tensile strength when compared to pure glass composite. Generally, the results revealed that the best performance was observed in S1, which showed a good balance of all mechanical properties determined in this work.

  15. Investigation of Effects of Material Architecture on the Elastic Response of a Woven Ceramic Matrix Composite

    Science.gov (United States)

    Goldberg, Robert K.; Bonacuse, Peter J.; Mital, Subodh K.

    2012-01-01

    To develop methods for quantifying the effects of the microstructural variations of woven ceramic matrix composites on the effective properties and response of the material, a research program has been undertaken which is described in this paper. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, CVI SiC/SiC, composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents and collect relevant statistics such as within ply tow spacing. This information was then used to build two dimensional finite element models that approximated the observed section geometry. With the aid of geometrical models generated by the microstructural characterization process, finite element models were generated and analyses were performed to quantify the effects of the microstructure and its variation on the effective stiffness and areas of stress concentration of the material. The results indicated that the geometry and distribution of the porosity appear to have significant effects on the through-thickness modulus. Similarly, stress concentrations on the outer surface of the composite appear to correlate to regions where the transverse tows are separated by a critical amount.

  16. Mechanical Properties of Non-Woven Polyester Fibers and Polymer-Modified Bitumen Composites

    Directory of Open Access Journals (Sweden)

    V. Hadadi

    2007-12-01

    Full Text Available Blown bitumen (110/10 was mixed with heavy vacuum slops (H.V.S, 60/70 penetration grade bitumen and recycled isotactic polypropylene (iPP at different levels. The resulting resins were used to impregnate non-woven poly(ethylene terephthalate fibers to form composites. The modulus and penetration grade of the resulting bituminous resins were determined. It was found that these bituminous resins drastically affect the modulus of the composites formed by low-Young’s modulus fibers such as polyesters. Consequently, interactions between resin and fibers and the correlation length of asphalthenes (in absence of iPP and interdiffused coalescence and segregated network of asphalthenes (in presence of iPP result in a non-linear behavior of composite’s modulus. The behavior of the composites with or without iPP is controlled by resin toughness and resin interactions with the fiber through the viscosity. Comparison of the experimental composite modulus data with the theoretical modulus data revealed that the Takayanangi’s model best predicts the behavior of these composites. The adjustment factors of this model were reported and proposed as an indication of fiber-resin interaction. It was also found that the modulus of fibers is affected by toughness, viscosity and the iPP content of the bituminous resin.

  17. Preparation of Non-Woven Fiber Mats by Mixture of PVC and Epoxidized Natural Rubber

    International Nuclear Information System (INIS)

    Muhammad Hariz Othman; Mahathir Mohamed; Dahlan Mohd

    2014-01-01

    Eletrospun non-woven fibre mats prepared from ENR modified PVC were successfully fabricated at ambient temperature by electro spinning method. Liquid epoxidized natural rubber (LENR) was used because it is easier to handle compared to dried ENR. PVC was mixed with LENR based on 3 different ratios (9:1, 8:2 and 7:3). The effect of ENR on electrospinnibality of PVC was investigated.The morphologies and thermal properties of the electro span fibre mats were characterized and assessed using scanning calorimetry (DSC). The polymer solution concentration 16 aut % formed a diameter of the fibres were mainly affected by the addition of natural rubber and weight ratio of the solution. The diameter of the fibres also decreased with increasing amount of LENR in the solution. Thermal degradation involved two-step degradation with the first degradation representing the dehydro chlorination of PVC to form polyene and followed by the decomposition of LENR and the polyene.Addition of LENR into the sample caused the T g of electro spun fibre mats of PVC/LENR to shift toward lower temperature. (author)

  18. Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones.

    Science.gov (United States)

    Sugiyama, Toshihiro; Price, Joanna S; Lanyon, Lance E

    2010-02-01

    In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19 weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2 weeks (approximately 7 min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC+STATIC group were subjected to a peak dynamic load of 11.5 N (40 cycles with 10-s intervals between cycles) superimposed upon a static "pre-load" of 2.0 N. This total load of 13.5 N engendered peak longitudinal strains of approximately 1400 microstrain on the medial surface of the tibia at a middle/proximal site. The right tibiae/fibulae in the STATIC group received the static "pre-load" alone while the NOLOAD group received no artificial loading. After 2 weeks, the animals were sacrificed and both tibiae, fibulae, femora, ulnae and radii analyzed by three-dimensional high-resolution (5 mum) micro-computed tomography (microCT). In the DYNAMIC+STATIC group, the proximal trabecular percent bone volume and cortical bone volume at the proximal and middle levels of the right tibiae as well as the cortical bone volume at the middle level of the right fibulae were markedly greater than the left. In contrast, the left bones in the DYNAMIC+STATIC group showed no differences compared to the left or right bones in the NOLOAD or STATIC group. These microCT data were confirmed by two-dimensional examination of fluorochrome labels in bone sections which showed the predominantly woven nature of the new bone formed in the loaded bones. We conclude that the adaptive response in both cortical and trabecular regions of bones subjected to short periods of dynamic loading, even when this response is sufficiently vigorous to stimulate woven bone formation, is confined to the loaded bones and does not involve changes in other bones that are adjacent, contra-lateral or remote to them. (c) 2009 Elsevier Inc

  19. Bone healing and bone substitutes.

    Science.gov (United States)

    Costantino, Peter D; Hiltzik, David; Govindaraj, Satish; Moche, Jason

    2002-02-01

    With the advent of new biomaterials and surgical techniques, the reconstructive surgeon has a wider range of treatment modalities for the rehabilitation and reconstruction of craniofacial skeletal deformities than ever before. These innovative substances act as true bone graft substitutes, thereby allowing the surgeon to avoid the use of autogenous bone grafts and their associated donor site morbidity. Surgeons have long been interested in producing a composite graft that can heal faster by induction, incorporate with surrounding tissues, and be remodeled to resemble native bone. Currently, there are a host of bone graft substitutes available that vary in both their composition and properties. Craniomaxillofacial surgeons must therefore become comfortable with numerous biomaterials to best tailor the treatment for each patient individually. Ongoing investigations into the next phase of tissue engineering will continue to bring us closer to the ability to regenerate or replace bone.

  20. Continuous and intermittent exposure of neonatal rat calvarial cells to PTHrP (1-36 inhibits bone nodule mineralization in vitro by downregulating bone sialoprotein expression via the cAMP signaling pathway [v2; ref status: indexed, http://f1000r.es/18x

    Directory of Open Access Journals (Sweden)

    Suzan A Kamel

    2013-06-01

    Full Text Available The development and growth of the skeleton in the absence of parathyroid-hormone-related protein (PTHrP is abnormal.  The shortening of appendicular bones in PTHrP gene null mice is explained by an effect of PTHrP on endochondral bone growth.  Whether or not PTHrP influences intramembranous ossification is less clear.  The purpose of this study was to determine the effect of exogenous PTHrP on intramembranous ossification in vitro.  Neonatal rat calvarial cells maintained in primary cell culture conditions that permit spontaneous formation of woven bone nodules by intramembranous ossification were studied. The expression of PTHrP, parathyroid hormone 1 receptor (PTH1R, and alkaline phosphatase (AP by osteogenic cells in developing nodules and the effects of PTHrP (1-36 on nodule development was determined over 3-18 days. PTHrP and PTH1R were detected colonies of osteogenic cells on culture day three, and AP was detected on day six. PTHrP and its receptor were localized in pre-osteoblasts, osteoblasts, and osteocytes, and AP activity was detected in pre-osteoblasts and osteoblasts but not osteocytes. Continuous and intermittent exposure to PTHrP (1-36 decreased the number of mineralized bone nodules and bone sialoprotein (BSP mRNA and protein, but had no effect on the number of AP-positive osteogenic cell colonies, cell proliferation, apoptosis, or osteopontin (OPN mRNA. These results demonstrate that osteogenic cells that participate in the formation of woven bone nodules in vitro exhibit PTHrP and PTH1R before they demonstrate AP activity. Exogenous PTHrP (1-36 inhibits the mineralization of woven bone deposited during bone nodule formation in vitro, possibly by reducing the expression of BSP.

  1. The influence of FLiNaK salt impregnation on the mechanical properties of a 2D woven C/C composite

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Dongsheng, E-mail: zhangdongsheng@sinap.ac.cn; Xia, Huihao; Yang, Xinmei, E-mail: yangxinmei@sinap.ac.cn; Feng, Shanglei; Song, Jinliang; Zhou, Xingtai

    2017-03-15

    Impregnating of molten LiF-NaF-KF salt (LiF-NaF-KF: 46.5–11.5-42 mol%, FLiNaK) into a 2D woven C/C composite was performed at 650 °C under different pressure. The weight gain and mechanical properties change of the 2D woven C/C composite after FLiNaK salt impregnation were measured. The FLiNaK salt distribution into the 2D woven C/C composite was observed by X-ray computed tomography (X-ray CT) and scanning electron microscopy. The results showed that the weight gain of the 2D woven C/C composite increased with increasing impregnating pressure. In X-ray CT images, FLiNaK salt was distributed into the open pores and fissures among fiber bundles and neighboring plies. The interlaminar shear strength, compressive strength, and flexural strength of the 2D woven C/C composite increased with the increase of weight gain. The influence of FLiNaK salt impregnation on the mechanical properties was attributed to the coupling effect of re-densification of FLiNaK salt impregnation and residual stress formed in 2D woven C/C composite. - Highlights: • FLiNaK salt was distributed into the open pores and fissures among fiber bundles. • The mechanical properties of the 2D woven C/C composite increased with the increase of weight gain. • The influence of FLiNaK was attributed to the re-densification of FLiNaK salt and residual stress.

  2. Bone Biopsy

    Science.gov (United States)

    ... several inches long with a hollow core to capture the bone specimen. The CT scanner is typically ... IV), ultrasound machine and devices that monitor your heart beat and blood pressure. top of page How ...

  3. Bone pain

    DEFF Research Database (Denmark)

    Frost, Charlotte Ørsted; Hansen, Rikke Rie; Heegaard, Anne-Marie

    2016-01-01

    Skeletal conditions are common causes of chronic pain and there is an unmet medical need for improved treatment options. Bone pain is currently managed with disease modifying agents and/or analgesics depending on the condition. Disease modifying agents affect the underlying pathophysiology...... of the disease and reduce as a secondary effect bone pain. Antiresorptive and anabolic agents, such as bisphosphonates and intermittent parathyroid hormone (1-34), respectively, have proven effective as pain relieving agents. Cathepsin K inhibitors and anti-sclerostin antibodies hold, due to their disease...... modifying effects, promise of a pain relieving effect. NSAIDs and opioids are widely employed in the treatment of bone pain. However, recent preclinical findings demonstrating a unique neuronal innervation of bone tissue and sprouting of sensory nerve fibers open for new treatment possibilities....

  4. Bone sarcomas

    International Nuclear Information System (INIS)

    Mudry, P.

    2008-01-01

    Bone sarcomas are malignancies with peak incidence in adolescents and young adults. The most frequent are osteosarcoma and Ewing sarcoma/PNET, in an older adults are seen chondrosarcomas, other ones are rare. In general, biology of sarcomas is closely related to pediatric malignancies with fast growth, local aggressiveness, tendency to early hematogenic dissemination and chemo sensitivity. Diagnostics and treatment of bone sarcomas should be done in well experienced centres due to low incidence and broad issue of this topic. An interdisciplinary approach and staff education is essential in due care of patients with bone sarcoma. If these criteria are achieved, the cure rate is contemporary at 65 - 70 %, while some subpopulation of patients has chance for cure up to 90 %. Osteosarcoma and Ewing sarcoma/PNET are discussed below as types of most frequent bone sarcoma. (author)

  5. Addition of Adipose-Derived Stem Cells to Mesenchymal Stem Cell Sheets Improves Bone Formation at an Ectopic Site

    Directory of Open Access Journals (Sweden)

    Zhifa Wang

    2016-02-01

    Full Text Available To determine the effect of adipose-derived stem cells (ADSCs added to bone marrow-derived mesenchymal stem cell (MSC sheets on bone formation at an ectopic site. We isolated MSCs and ADSCs from the same rabbits. We then prepared MSC sheets for implantation with or without ADSCs subcutaneously in the backs of severe combined immunodeficiency (SCID mice. We assessed bone formation at eight weeks after implantation by micro-computed tomography and histological analysis. In osteogenic medium, MSCs grew to form multilayer sheets containing many calcium nodules. MSC sheets without ADSCs formed bone-like tissue; although neo-bone and cartilage-like tissues were sparse and unevenly distributed by eight weeks after implantation. In comparison, MSC sheets with ADSCs promoted better bone regeneration as evidenced by the greater density of bone, increased mineral deposition, obvious formation of blood vessels, large number of interconnected ossified trabeculae and woven bone structures, and greater bone volume/total volume within the composite constructs. Our results indicate that although sheets of only MSCs have the potential to form tissue engineered bone at an ectopic site, the addition of ADSCs can significantly increase the osteogenic potential of MSC sheets. Thus, the combination of MSC sheets with ADSCs may be regarded as a promising therapeutic strategy to stimulate bone regeneration.

  6. Bacteria in non-woven textile filters for domestic wastewater treatment.

    Science.gov (United States)

    Spychała, Marcin; Starzyk, Justyna

    2015-01-01

    The objective of this study was preliminary identification of heterotrophic and ammonia oxidizing bacteria (AOB) cell concentration in the cross-sectional profile of geotextile filters for wastewater treatment. Filters of thicknesses 3.6 and 7.2 mm, made of non-woven textile TS20, were supplied with septic tank effluent and intermittently dosed and filtered under hydrostatic pressure. The cumulative loads of chemical oxygen demand (COD) and total solids were about 1.36 and 1.06 kg/cm2, respectively. The filters under analysis reached a relatively high removal efficiency for organic pollution 70-90% for biochemical oxygen demand (BOD5) and 60-85% for COD. The ammonia nitrogen removal efficiency level proved to be unstable (15-55%). Biomass samples for dry mass identification were taken from two regions: continuously flooded with wastewater and intermittently flooded with wastewater. The culturable heterotrophic bacteria were determined as colony-forming units (CFUs) on microbiological-selective media by means of the plate method. AOB and nitrite oxidizing bacteria (NOB) were examined using the FISH technique. A relatively wide range of heterotrophic bacteria was observed from 7.4×10(5)/cm2 to 3.8×10(6)/cm2 in geotextile layers. The highest concentration of heterotrophic bacteria (3.8×10(6)/cm2) was observed in the first layer of the textile filter. AOB were identified occasionally--about 8-15% of all bacteria colonizing the last filter layer, but occasionally much higher concentrations and ammonia nitrogen efficiency were achieved. Bacteria oxidizing nitrite to nitrate were not observed. The relation of total and organic fraction of biomass to culturable heterotrophic bacteria was also found.

  7. ENCULTURATION AND GENDER IN WOVEN FABRICT INDUSTRY AT SUBDISTRICT OF SANGKARAGUNG, DISTRICT OF NEGARA, JEMBRANA

    Directory of Open Access Journals (Sweden)

    Putu Sukardja

    2012-11-01

    Full Text Available This research reveals the process of enculturation and gender in the woven fabricindustry at Sangkaragung, district of Negara, Jembrana. The weaving tradition andenculturation process give the women at Sangkaragung a hope to change their ideology ingender and socio cultural construction. This study aims at discussing the factors makingthe women at Sangkaragung do weaving activities, the process of weaving enculturationand the development of gender taking place there, and the impacts and meaning of theweaving enculturation on their socio-cultural life.In analyzing the problems above, the theory of post-structuralism, the theory ofpractice, and the theory of social change were used. To find out the relevant data, aqualitative method was applied in which the data were collected by deep interviews,observation, and documentation.The result shows that the factors making the women do such activities are: mythson women and weaving activities; globalization and socio-cultural changes, and fulfillmentof daily needs. The process of weaving enculturation done through cultural transmissionand socialization in weaving results in acculturation and enculturation which then give adeeper understanding to the society of the pattern and system related to the weavingactivities. The weaving enculturation also causes some forms of changes at Sangkaragungsuch as work division between men and women. The weaving enculturation and thedevelopment of gender have affected the ways in which decisions are made in someaspects of life such as in the context of traditional and religious rituals, the expenditures forprimary family needs, health care, and children’s education. Although the women areacknowledged and appreciated that they have economically contributed to their families,full emancipation has not been given to them due to patriarchal, social and cultural systemswhich are still attached to the society.

  8. The Woven EndoBridge (WEB) as primary treatment for unruptured intracranial aneurysms.

    Science.gov (United States)

    van Rooij, Sanne Bt; van Rooij, Willem Jan; Peluso, Jo P; Sluzewski, Menno

    2018-01-01

    Purpose The intrasaccular flow disruptor Woven EndoBridge (WEB) device is developed for the treatment of wide-necked aneurysms without supportive devices. We used the WEB as primary treatment for unruptured aneurysms suitable for the device, regardless of neck size. Methods Between February 2015 and June 2017, 59 aneurysms in 51 patients were selectively treated with the WEB. There were 15 men and 36 women with a mean age of 59 years. Mean aneurysm size was 7.0 mm (range 3-22 mm). Of 59 aneurysms, 45 (76%) had a wide neck defined as ≥4 mm or dome-neck ratio ≤1.5. No stents or supporting balloons were used. Results Initial WEB position was judged good in all 59 unruptured aneurysms. One patient with a basilar tip aneurysm had a late thrombotic posterior cerebral artery occlusion by protrusion of the WEB over the artery. There were no procedural ruptures. Overall complication rate was 2.0% (1 of 51, 95% CI 0.01-11.3%). Imaging follow-up was available in 55 of 59 aneurysms (93%). At 3 months, 41 of 57 aneurysms (72%) were completely occluded, 12 (21%) had a neck remnant and 4 (7%) were incompletely occluded. Conclusion WEB treatment is safe and effective in selected unruptured aneurysms suitable for the device, regardless of neck size or location. There was no need for supportive devices. Three-quarters of all unruptured small aneurysms could be treated with the WEB. In our opinion, the WEB is a valuable alternative to coils, especially in wide-necked aneurysms.

  9. Bone--bone marrow interactions

    International Nuclear Information System (INIS)

    Patt, H.M.

    1976-01-01

    Within medullary cavities, blood formation tends to be concentrated near bone surfaces and this raises interesting questions about hematopoietic consequences of radionuclide fixation in osseous tissue. Thus, it may be important, on the one hand, to consider the medullary radiation dose distribution as well as total marrow dose from bone-bound radioelements and, on the other, to inquire about possible hematopoietic implications of radiation damage to endosteal surfaces per se. The reasons for this are discussed

  10. The Bone Black Pigment Identification by Noninvasive, In Situ Infrared Reflection Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alessia Daveri

    2018-01-01

    Full Text Available Two real case studies, an oil painting on woven paper and a cycle of mural paintings, have been presented to validate the use of infrared reflection spectroscopy as suitable technique for the identification of bone black pigment. By the use of the sharp weak band at 2013 cm−1, it has been possible to distinguish animal carbon-based blacks by a noninvasive method. Finally, an attempt for an eventual assignment for the widely used sharp band at 2013 cm−1 is discussed.

  11. Influence of locational states of submicron fibers added into matrix on mechanical properties of plain-woven Carbon Fiber Composite

    Directory of Open Access Journals (Sweden)

    Kumamoto Soichiro

    2016-01-01

    Full Text Available The aim of this study was to show the influence of locational states of submicron fibers added into epoxy matrix on mechanical properties of modified plane-woven carbon fiber reinforced plastic (CFRP. To change the locational states of submicron fibers, two kinds of fabrication processes were applied in preparing specimen by hand lay-up method. Submicron fibers were simply added into epoxy resin with ethanol after they were stirred by a dispersion process using homogenizer to be located far from the interface between reinforcement and matrix. In contrast, submicron fibers were attached onto the carbon fibers by injecting from a spray nozzle accompanying with ethanol to be located near the interface, after they were tentatively contained in ethanol. The plain-woven CFRP plates were fabricated by hand lay-up method and cured at 80 degree-C for 1 hour and then at 150 degree-C for 3 hours. After curing, the plain-woven CFRP plates were cut into the dimension of specimen. Tensile shear strength and Mode-II fracture toughness of CFRP were determined by tensile lap-shear test and End-notched flexure(ENF test, respectively. When submicron fibers were located far from the interface between carbon fibers and epoxy resin, tensile shear strength and Mode-II fracture toughness of CFRP were improved 30% and 18% compared with those of unmodified case. The improvement ratio in modified case was rather low (about few percentages in the case where submicron fibers were located near the interface. The result suggested that crack propagation should be prevented when submicron fibers were existed far from the interface due to the effective stress state around the crack tip.

  12. The construction phase’s influence to the moving ability of cross-sections of woven structure

    Science.gov (United States)

    Inogamdjanov, D.; Daminov, A.; Kasimov, O.

    2017-10-01

    The purpose of this study is to work out bases to predict properties for single layer flat woven fabrics depending on changes of construction phases. A structural model of cross-section of single layered fabric is described based on the Pierce’s model. Form transformation of the yarn like straight, semi-arch and arch yarn is considered according to the alteration of yarn tension under the theory of Novikov. The value contributions to movement index of warp and weft yarn and their total moving ability in cross-sections at all structure phases of fabric are summarized.

  13. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

  14. From bone biology to bone analysis.

    NARCIS (Netherlands)

    Schoenau, E.; Saggese, G.; Peter, F.; Baroncelli, G.I.; Shaw, N.J.; Crabtree, N.J.; Zadik, Z.; Neu, C.M.; Noordam, C.; Radetti, G.; Hochberg, Z.

    2004-01-01

    Bone development is one of the key processes characterizing childhood and adolescence. Understanding this process is not only important for physicians treating pediatric bone disorders, but also for clinicians and researchers dealing with postmenopausal and senile osteoporosis. Bone densitometry has

  15. Bone lesion biopsy

    Science.gov (United States)

    Bone biopsy; Biopsy - bone ... the cut, then pushed and twisted into the bone. Once the sample is obtained, the needle is ... sample is sent to a lab for examination. Bone biopsy may also be done under general anesthesia ...

  16. Facts about Broken Bones

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Broken Bones KidsHealth / For Kids / Broken Bones What's in this ... sticking through the skin . What Happens When a Bone Breaks? It hurts to break a bone! It's ...

  17. Broken Bones (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Broken Bones KidsHealth / For Parents / Broken Bones What's in this ... bone fragments in place. When Will a Broken Bone Heal? Fractures heal at different rates, depending upon ...

  18. CFD Simulation and Experimental Analyses of a Copper Wire Woven Heat Exchanger Design to Improve Heat Transfer and Reduce the Size of Adsorption Beds

    Directory of Open Access Journals (Sweden)

    John White

    2016-02-01

    Full Text Available The chief objective of this study is the proposal design and CFD simulation of a new compacted copper wire woven fin heat exchanger and silica gel adsorbent bed used as part of an adsorption refrigeration system. This type of heat exchanger design has a large surface area because of the wire woven fin design. It is estimated that this will help improve the coefficient of performance (COP of the adsorption phase and increase the heat transfer in this system arrangement. To study the heat transfer between the fins and porous adsorbent reactor bed, two experiments were carried out and matched to computational fluid dynamics (CFD results.

  19. Bone scans

    International Nuclear Information System (INIS)

    Hetherington, V.J.

    1989-01-01

    Oftentimes, in managing podiatric complaints, clinical and conventional radiographic techniques are insufficient in determining a patient's problem. This is especially true in the early stages of bone infection. Bone scanning or imaging can provide additional information in the diagnosis of the disorder. However, bone scans are not specific and must be correlated with clinical, radiographic, and laboratory evaluation. In other words, bone scanning does not provide the diagnosis but is an important bit of information aiding in the process of diagnosis. The more useful radionuclides in skeletal imaging are technetium phosphate complexes and gallium citrate. These compounds are administered intravenously and are detected at specific time intervals postinjection by a rectilinear scanner with minification is used and the entire skeleton can be imaged from head to toe. Minification allows visualization of the entire skeleton in a single image. A gamma camera can concentrate on an isolated area. However, it requires multiple views to complete the whole skeletal image. Recent advances have allowed computer augmentation of the data received from radionucleotide imaging. The purpose of this chapter is to present the current radionuclides clinically useful in podiatric patients

  20. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling...... of aged bones....

  1. Bone graft revascularization strategies

    NARCIS (Netherlands)

    Willems, W.F.

    2014-01-01

    Reconstruction of avascular necrotic bone by pedicled bone grafting is a well-known treatment with little basic research supporting its application. A new canine model was used to simulate carpal bone avascular necrosis. Pedicled bone grafting proved to increase bone remodeling and bone blood flow,

  2. Effect of Reinforced Hybrid Palm Shells on Mechanical Properties of Polyurethane-Jute Woven/ Vinyl Ester Sandwich Board

    International Nuclear Information System (INIS)

    Cheng, T.S.; Nurul Ain Nanyan; Lan, D.N.U.; Leng, T.P.

    2014-01-01

    A natural fiber sandwich was constructed from palm shells/polyurethane core and jute woven/vinyl ester face sheets by the in-situ sandwich process (core and panel prepared simultaneously). The polyurethane sandwich core was reinforced by hybrid shell systems of dried palm shell (DPS) and palm kernel shell (PKS) (50P-50D, 25P-75D), and single shell system of PKS (100P) as well as 20 phr empty fruit bunch (EFB) based on hundred part of polyurethane. The sandwich face sheets are prepared by using two jute woven layers and impregnated by vinyl ester. Interlocking between DPS and polyurethane matrix was formed, which hence enhanced the mechanical properties. The interfacial adhesion between DPS, PKS, and EFB with the polyurethane binder played the important role to achieve high mechanical properties. It was found that hybrid shells exhibited high reinforcement for sandwich's performance resulting better compression (50P-50D) and flexural (25P-75D) properties. The single shell 100P showed only improvement on flexural modulus.The fracture surface morphology of sandwich under mechanical test was performed by using optical microscopy. (author)

  3. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    International Nuclear Information System (INIS)

    Al Meslmani, Bassam M.; Mahmoud, Gihan F.; Leichtweiß, Thomas; Strehlow, Boris; Sommer, Frank O.; Lohoff, Michael D.; Bakowsky, Udo

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm"2, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  4. Covalent immobilization of lysozyme onto woven and knitted crimped polyethylene terephthalate grafts to minimize the adhesion of broad spectrum pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Al Meslmani, Bassam M., E-mail: almeslmanib@yahoo.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Mahmoud, Gihan F., E-mail: mahmoudg@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Department of Pharmaceutics and Industrial Pharmacy, Helwan University, Ain Helwan, 11795 Cairo (Egypt); Leichtweiß, Thomas, E-mail: Thomas.Leichtweiss@phys.Chemie.uni-giessen.de [Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, 35392 Giessen (Germany); Strehlow, Boris, E-mail: strehlo4@staff.uni-marburg.de [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany); Sommer, Frank O., E-mail: sommerf@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Lohoff, Michael D., E-mail: lohoff@med.uni-marburg.de [Institute for Medical Microbiology and Hospital Hygiene, Marburg University, Hans Meerwein Str 2, 35032 Marburg (Germany); Bakowsky, Udo, E-mail: ubakowsky@aol.com [Department of Pharmaceutical Technology and Biopharmaceutics, Marburg University, Ketzerbach 63, 35037 Marburg (Germany)

    2016-01-01

    Graft-associated infections entirely determine the short-term patency of polyethylene terephthalate PET cardiovascular graft. We attempted to enzymatically inhibit the initial bacterial adhesion to PET grafts using lysozyme. Lysozyme was covalently immobilized onto woven and knitted forms of crimped PET grafts by the end-point method. Our figures of merit revealed lysozyme immobilization yield of 15.7 μg/cm{sup 2}, as determined by the Bradford assay. The activity of immobilized lysozyme on woven and knitted PET manifested 58.4% and 55.87% using Micrococcus lysodeikticus cells, respectively. Noteworthy, the adhesion of vein catheter-isolated Staphylococcus epidermidis decreased by 6- to 8-folds and of Staphylococcus aureus by 11- to 12-folds, while the Gram-negative Escherichia coli showed only a decrease by 3- to 4-folds. The anti-adhesion efficiency was specific for bacterial cells and no significant effect was observed on adhesion and growth of L929 cells. In conclusion, immobilization of lysozyme onto PET grafts can inhibit the graft-associated infection. - Highlights: • Lysozyme was covalently immobilized on crimped polyethylene terephthalate (PET). • The activity of immobilized lysozyme was meaningfully reduced. • The maintained activity significantly declined the adhesion of Gram-positive stains. • The enzymatic anti-adhesion efficiency reported lesser extent against Gram-negative. • The anti-bacterial activity displayed no significant effect on cells compatibility.

  5. Mechanical properties of banana/kenaf fiber-reinforced hybrid polyester composites: Effect of woven fabric and random orientation

    International Nuclear Information System (INIS)

    Alavudeen, A.; Rajini, N.; Karthikeyan, S.; Thiruchitrambalam, M.; Venkateshwaren, N.

    2015-01-01

    Highlights: • This paper is presents the fabrications of kenaf/banana fiber hybrid composites. • Effect of weaving pattern and random orientation on mechanical properties was studied. • Role of interfacial adhesion due to chemical modifications were analyzed with the aid of SEM. • Hybridization of kenaf and banana fibers in plain woven composites exhibits maximum mechanical strength. - Abstract: The present work deals with the effect of weaving patterns and random orientatation on the mechanical properties of banana, kenaf and banana/kenaf fiber-reinforced hybrid polyester composites. Composites were prepared using the hand lay-up method with two different weaving patterns, namely, plain and twill type. Of the two weaving patterns, the plain type showed improved tensile properties compared to the twill type in all the fabricated composites. Furthermore, the maximum increase in mechanical strength was observed in the plain woven hybrid composites rather than in randomly oriented composites. This indicates minimum stress development at the interface of composites due to the distribution of load transfer along the fiber direction. Moreover, alkali (NaOH) and sodium lauryl sulfate (SLS) treatments appear to provide an additional improvement in mechanical strength through enhanced interfacial bonding. Morphological studies of fractured mechanical testing samples were performed by scanning electron microscopy (SEM) to understand the de-bonding of fiber/matrix adhesion

  6. Effect of Mesoscale and Multiscale Modeling on the Performance of Kevlar Woven Fabric Subjected to Ballistic Impact: A Numerical Study

    Science.gov (United States)

    Jia, Xin; Huang, Zhengxiang; Zu, Xudong; Gu, Xiaohui; Xiao, Qiangqiang

    2013-12-01

    In this study, an optimal finite element model of Kevlar woven fabric that is more computational efficient compared with existing models was developed to simulate ballistic impact onto fabric. Kevlar woven fabric was modeled to yarn level architecture by using the hybrid elements analysis (HEA), which uses solid elements in modeling the yarns at the impact region and uses shell elements in modeling the yarns away from the impact region. Three HEA configurations were constructed, in which the solid element region was set as about one, two, and three times that of the projectile's diameter with impact velocities of 30 m/s (non-perforation case) and 200 m/s (perforation case) to determine the optimal ratio between the solid element region and the shell element region. To further reduce computational time and to maintain the necessary accuracy, three multiscale models were presented also. These multiscale models combine the local region with the yarn level architecture by using the HEA approach and the global region with homogenous level architecture. The effect of the varying ratios of the local and global area on the ballistic performance of fabric was discussed. The deformation and damage mechanisms of fabric were analyzed and compared among numerical models. Simulation results indicate that the multiscale model based on HEA accurately reproduces the baseline results and obviously decreases computational time.

  7. Physical, Mechanical, and Morphological Properties of Woven Kenaf/Polymer Composites Produced Using a Vacuum Infusion Technique

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2015-01-01

    Full Text Available Nowadays, due to renewable issues, environmental concerns, and the financial problems of synthetic fibres, the development of high-performance engineering products made from natural resources is increasing all over the world. Lately, kenaf fibre has been used among many different types of natural resources in various shapes. Unidirectional long fibres or randomly oriented short fibre shapes are the most common type of kenaf fibres that have been investigated in previous works. This work characterises and evaluates the physical, mechanical, and morphological properties of plain woven kenaf fabric and its composites with three types of thermoset resin at 0°/90° and 45°/−45° orientation, in order to assess their suitability as lignocellulosic reinforced polymer composites. A vacuum infusion manufacturing technique was used to prepare the specimens with fibre weight content of 35% ± 2%. Eight specimens were prepared for each test, and five replications were adopted. A total of 78 samples were tested in this study. The results show that the composites with 0°/90° had the highest tensile, flexural strengths, and modulus. The morphological properties of composite samples were analysed through scanning electron microscopy (SEM images and these clearly demonstrated the better interfacial adhesion between the woven kenaf and the epoxy matrix.

  8. Bone marker gene expression in calvarial bones: different bone microenvironments.

    Science.gov (United States)

    Al-Amer, Osama

    2017-12-01

    In calvarial mice, mesenchymal stem cells (MSCs) differentiate into osteoprogenitor cells and then differentiate into osteoblasts that differentiate into osteocytes, which become embedded within the bone matrix. In this case, the cells participating in bone formation include MSCs, osteoprogenitor cells, osteoblasts and osteocytes. The calvariae of C57BL/KaLwRijHsD mice consist of the following five bones: two frontal bones, two parietal bones and one interparietal bone. This study aimed to analyse some bone marker genes and bone related genes to determine whether these calvarial bones have different bone microenvironments. C57BL/KaLwRijHsD calvariae were carefully excised from five male mice that were 4-6 weeks of age. Frontal, parietal, and interparietal bones were dissected to determine the bone microenvironment in calvariae. Haematoxylin and eosin staining was used to determine the morphology of different calvarial bones under microscopy. TaqMan was used to analyse the relative expression of Runx2, OC, OSX, RANK, RANKL, OPG, N-cadherin, E-cadherin, FGF2 and FGFR1 genes in different parts of the calvariae. Histological analysis demonstrated different bone marrow (BM) areas between the different parts of the calvariae. The data show that parietal bones have the smallest BM area compared to frontal and interparietal bones. TaqMan data show a significant increase in the expression level of Runx2, OC, OSX, RANKL, OPG, FGF2 and FGFR1 genes in the parietal bones compared with the frontal and interparietal bones of calvariae. This study provides evidence that different calvarial bones, frontal, parietal and interparietal, contain different bone microenvironments.

  9. Assessing a relationship between bone microstructure and growth rate: a fluorescent labelling study in the king penguin chick (Aptenodytes patagonicus).

    Science.gov (United States)

    de Margerie, E; Robin, J-P; Verrier, D; Cubo, J; Groscolas, R; Castanet, J

    2004-02-01

    Microstructure-function relationships remain poorly understood in primary bone tissues. The relationship between bone growth rate and bone tissue type, although documented in some species by previous works, remains somewhat unclear and controversial. We assessed this relationship in a species with extreme adaptations, the king penguin (Aptenodytes patagonicus). These birds have a peculiar growth, interrupted 3 months after hatching by the austral winter. Before this interruption, chicks undergo extremely rapid statural and ponderal growth. We recorded experimentally (by means of fluorescent labelling) the growth rate of bone tissue in four long bones (humerus, radius, femur and tibiotarsus) of four king penguin chicks during their fastest phase of growth (3-5 weeks after hatching) and identified the associated bone tissue types ('laminar', 'longitudinal', 'reticular' or 'radial' fibro-lamellar bone tissue). We found the highest bone tissue growth rate known to date, up to 171 microm day(-1) (mean 55 microm day(-1)). There was a highly significant relationship between bone tissue type and growth rate (P<10(-6)). Highest rates were obtained with the radial microarchitecture of fibro-lamellar bone, where cavities in the woven network are aligned radially. This result supports the heuristic value of a relationship between growth rate and bone primary microstructure. However, we also found that growth rates of bone tissue types vary according to the long bone considered (P<10(-5)) (e.g. growth rates were 38% lower in the radius than in the other long bones), a result that puts some restriction on the applicability of absolute growth rate values (e.g. to fossil species). The biomechanical disadvantages of accelerated bone growth are discussed in relation to the locomotor behaviour of the chicks during their first month of life.

  10. Tissue-engineered bone formation using human bone marrow stromal cells and novel β-tricalcium phosphate

    International Nuclear Information System (INIS)

    Liu Guangpeng; Zhao Li; Cui Lei; Liu Wei; Cao Yilin

    2007-01-01

    In this study we investigated not only the cellular proliferation and osteogenic differentiation of human bone marrow stromal cells (hBMSCs) on the novel β-tricalcium phosphate (β-TCP) scaffolds in vitro but also bone formation by ectopic implantation in athymic mice in vivo. The interconnected porous β-TCP scaffolds with pores of 300-500 μm in size were prepared by the polymeric sponge method. β-TCP scaffolds with the dimension of 3 mm x 3 mm x 3 mm were combined with hBMSCs, and incubated with (+) or without (-) osteogenic medium in vitro. Cell proliferation and osteogenic differentiation on the scaffolds were evaluated by scanning electron microscopy (SEM) observation, MTT assay, alkaline phosphatase (ALP) activity and osteocalcin (OCN) content measurement. SEM observation showed that hBMSCs attached well on the scaffolds and proliferated rapidly. No significant difference in the MTT assay could be detected between the two groups, but the ALP activity and OCN content of scaffolds (+) were much higher than those of the scaffolds (-) (p < 0.05). These results indicated that the novel porous β-TCP scaffolds can support the proliferation and subsequent osteogenic differentiation of hBMSCs in vitro. After being cultured in vitro for 14 days, the scaffolds (+) and (-) were implanted into subcutaneous sites of athymic mice. In β-TCP scaffolds (+), woven bone formed after 4 weeks of implantation and osteogenesis progressed with time. Furthermore, tissue-engineered bone could be found at 8 weeks, and remodeled lamellar bone was also observed at 12 weeks. However, no bone formation could be found in β-TCP scaffolds (-) at each time point checked. The above findings illustrate that the novel porous β-TCP scaffolds developed in this work have prominent osteoconductive activity and the potential for applications in bone tissue engineering

  11. Tissue-engineered bone formation using human bone marrow stromal cells and novel {beta}-tricalcium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangpeng [National Tissue Engineering Research and Development Center, Shanghai 200235 (China); Zhao Li [National Tissue Engineering Research and Development Center, Shanghai 200235 (China); Cui Lei [National Tissue Engineering Research and Development Center, Shanghai 200235 (China); Liu Wei [National Tissue Engineering Research and Development Center, Shanghai 200235 (China); Cao Yilin [National Tissue Engineering Research and Development Center, Shanghai 200235 (China)

    2007-06-01

    In this study we investigated not only the cellular proliferation and osteogenic differentiation of human bone marrow stromal cells (hBMSCs) on the novel {beta}-tricalcium phosphate ({beta}-TCP) scaffolds in vitro but also bone formation by ectopic implantation in athymic mice in vivo. The interconnected porous {beta}-TCP scaffolds with pores of 300-500 {mu}m in size were prepared by the polymeric sponge method. {beta}-TCP scaffolds with the dimension of 3 mm x 3 mm x 3 mm were combined with hBMSCs, and incubated with (+) or without (-) osteogenic medium in vitro. Cell proliferation and osteogenic differentiation on the scaffolds were evaluated by scanning electron microscopy (SEM) observation, MTT assay, alkaline phosphatase (ALP) activity and osteocalcin (OCN) content measurement. SEM observation showed that hBMSCs attached well on the scaffolds and proliferated rapidly. No significant difference in the MTT assay could be detected between the two groups, but the ALP activity and OCN content of scaffolds (+) were much higher than those of the scaffolds (-) (p < 0.05). These results indicated that the novel porous {beta}-TCP scaffolds can support the proliferation and subsequent osteogenic differentiation of hBMSCs in vitro. After being cultured in vitro for 14 days, the scaffolds (+) and (-) were implanted into subcutaneous sites of athymic mice. In {beta}-TCP scaffolds (+), woven bone formed after 4 weeks of implantation and osteogenesis progressed with time. Furthermore, tissue-engineered bone could be found at 8 weeks, and remodeled lamellar bone was also observed at 12 weeks. However, no bone formation could be found in {beta}-TCP scaffolds (-) at each time point checked. The above findings illustrate that the novel porous {beta}-TCP scaffolds developed in this work have prominent osteoconductive activity and the potential for applications in bone tissue engineering.

  12. Effects of calcium phosphate/chitosan composite on bone healing in rats: calcium phosphate induces osteon formation.

    Science.gov (United States)

    Fernández, Tulio; Olave, Gilberto; Valencia, Carlos H; Arce, Sandra; Quinn, Julian M W; Thouas, George A; Chen, Qi-Zhi

    2014-07-01

    Vascularization of an artificial graft represents one of the most significant challenges facing the field of bone tissue engineering. Over the past decade, strategies to vascularize artificial scaffolds have been intensively evaluated using osteoinductive calcium phosphate (CaP) biomaterials in animal models. In this work, we observed that CaP-based biomaterials implanted into rat calvarial defects showed remarkably accelerated formation and mineralization of new woven bone in defects in the initial stages, at a rate of ∼60 μm/day (0.8 mg/day), which was considerably higher than normal bone growth rates (several μm/day, 0.1 mg/day) in implant-free controls of the same age. Surprisingly, we also observed histological evidence of primary osteon formation, indicated by blood vessels in early-region fibrous tissue, which was encapsulated by lamellar osteocyte structures. These were later fully replaced by compact bone, indicating complete regeneration of calvarial bone. Thus, the CaP biomaterial used here is not only osteoinductive, but vasculogenic, and it may have contributed to the bone regeneration, despite an absence of osteons in normal rat calvaria. Further investigation will involve how this strategy can regulate formation of vascularized cortical bone such as by control of degradation rate, and use of models of long, dense bones, to more closely approximate repair of human cortical bone.

  13. [Frontier in bone biology].

    Science.gov (United States)

    Takeda, Shu

    2015-10-01

    Bone is an active organ in which bone mass is maintained by the balance between osteoblastic bone formation and osteoclastic bone resorption, i.e., coupling of bone formation and bone resorption. Recent advances in molecular bone biology uncovered the molecular mechanism of the coupling. A fundamental role of osteocyte in the maintenance of bone mass and whole body metabolism has also been revealed recently. Moreover, neurons and neuropeptides have been shown to be intimately involved in bone homeostasis though inter-organ network, in addition to "traditional" regulators of bone metabolism such as soluble factors and cytokines

  14. Dating of cremated bones

    NARCIS (Netherlands)

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process.

  15. Experimental Analysis of the Influence of Drill Point Angle and Wear on the Drilling of Woven CFRPs

    Directory of Open Access Journals (Sweden)

    Norberto Feito

    2014-05-01

    Full Text Available This paper focuses on the effect of the drill geometry on the drilling of woven Carbon Fiber Reinforced Polymer composite (CFRPs. Although different geometrical effects can be considered in drilling CFRPs, the present work focuses on the influence of point angle and wear because they are the important factors influencing hole quality and machining forces. Surface quality was evaluated in terms of delamination and superficial defects. Three different point angles were tested representative of the geometries commonly used in the industry. Two wear modes were considered, being representative of the wear patterns commonly observed when drilling CFRPs: flank wear and honed cutting edge. It was found that the crossed influence of the point angle and wear were significant to the thrust force. Delamination at the hole entry and exit showed opposite trends with the change of geometry. Also, cutting parameters were checked showing the feed’s dominant influence on surface damage.

  16. Preparation and characterization of thermal-responsive non-woven poly (propylene) materials grafted with N-isopropylacrylamide/β-cyclodextrin

    DEFF Research Database (Denmark)

    Amiri, Setareh; Zadhoush, Ali; Mallakpour, Shadpour

    2013-01-01

    A temperature-sensitive hydrogel was successfully grafted on the surface of non-woven poly(propylene) materials. This was carried out by the application of unmodified β-cyclodextrin and N-isopropylacrylamide monomer in order to develop new functional hydrogels for textile science and technology......(N-isopropylacrylamide) and β-cyclodextrin components on the surface of the textile. Unmodified β-cyclodextrin content was estimated by the use of elemental analysis to be 97 µg/cm2. The water uptake measurements and differential scanning calorimetry analyses showed that the hydrogel maintained its temperature...... of smart textiles which possess the temperature-sensitive property of poly(N-isopropylacrylamide) and the ability of inclusion complex formation with guest molecules due to the presence of unmodified β-cyclodextrin in the hydrogel network....

  17. A study on damage and fatigue characteristics of plain woven carbon fiber reinforced composite material(I)

    International Nuclear Information System (INIS)

    Kim, Kwang Soo; Kim, Sang Tae

    1993-01-01

    The characteristics of damage and fatigue subjected to tensile fatigue loading in plain woven carbon fiber reinforced composite material were studied. Constant amplitude load of 90% stress of notch strength was applied to each specimen, which had different initial notch length, and crack dectectvie compliance curve was determined form load-displacement data. The effective crack length(a eff ) was obtained form this compliance curve and the effective crack growth could be divided to three-steps and explained separately. After cycling the shape of fatigue crack was observed by S.E.M.. Change of elastic modulus(E N ) during fatigue cycle was explained by repeated sudden-death medel. The material constant determined by Jen-Hsu model was more useful to evaluate damage than Wang-Chim model. (Author)

  18. Multi scale analysis by acoustic emission of damage mechanisms in natural fibre woven fabrics/epoxy composites.

    Directory of Open Access Journals (Sweden)

    Touchard F.

    2010-06-01

    Full Text Available This paper proposes to develop an experimental program to characterize the type and the development of damage in composite with complex microstructure. A multi-scale analysis by acoustic emission has been developed and applied to hemp fibre woven fabrics/epoxy composite. The experimental program consists of tensile tests performed on single yarn, neat epoxy resin and composite materials to identify their AE amplitude signatures. A statistical analysis of AE amplitude signals has been realised and correlated with microscopic observations. Results have enabled to identify three types of damage in composites and their associated AE amplitudes: matrix cracking, interfacial debonding and reinforcement damage and fracture. Tracking of these damage mechanisms in hemp/epoxy composites has been performed to show the process of damage development in natural fibre reinforced composites.

  19. “You’re such a good friend”: A woven autoethnographic narrative discussion of disability and friendship in Higher Education

    Directory of Open Access Journals (Sweden)

    Mark Anthony Castrodale

    2015-02-01

    Full Text Available In this article, the authors discuss friendship as a method of qualitative inquiry. After defining friendship and positing it as a kind of fieldwork, the methodological foundations of friendship as method are established (Tillmann-Healy, 2003. The purpose of this narrative woven autoethnographic study is to examine the role of friendship in describing disabling physical and attitudinal access barriers in a university setting. Friendship represents a critical analytic lens through which disabled/nondisabled individuals alike may examine their positions, understandings, regimes of practices, and particular knowledges. Friends —Mark and Dan — discuss their experiences of disablement and reflections on dis/ability. The authors draw from their experiences of friendship and disability in higher education and their allied identities to discuss and examine questions of access, disclosure, and inclusion.

  20. Experimental Strength of Single-Lap Hybrid Joints on Woven Fabric Kenaf Fiber Composites Under Quasi Static Condition

    Directory of Open Access Journals (Sweden)

    Yee Lee Sim

    2016-01-01

    Full Text Available For the past decades, usage of natural fiber reinforced composites in low bearing load applications are increasing tremendously due to drawbacks concerning the use of synthetic fibers. Kenaf fibers have a good potential to be used as composite reinforcements as they possesses excellent fiber strength compared to own self-weight. Current work concentrates on mechanical properties of woven fabric kenaf composites with single-lap hybrid joints configurations. Four width to diameter ratio, (W/d of cross-ply lay-up joints as designed in testing series were tested by using quasi static mechanical testing. Experimental results showed that the failure load increased with the increasing of W/d ratios. Thinner lay-up had better bearing strength compared to thicker lay-up as found in current study.

  1. Inhibition of the HDAC/Suv39/G9a pathway restores the expression of DNA damage-dependent major histocompatibility complex class I-related chain A and B in cancer cells.

    Science.gov (United States)

    Nakajima, Nakako Izumi; Niimi, Atsuko; Isono, Mayu; Oike, Takahiro; Sato, Hiro; Nakano, Takashi; Shibata, Atsushi

    2017-08-01

    Immunotherapy is expected to be promising as a next generation cancer therapy. Immunoreceptors are often activated constitutively in cancer cells, however, such levels of ligand expression are not effectively recognized by the native immune system due to tumor microenvironmental adaptation. Studies have demonstrated that natural-killer group 2, member D (NKG2D), a major activating immunoreceptor, responds to DNA damage. The upregulation of major histocompatibility complex class I-related chain A and B (MICA/B) (members of NKG2D ligands) expression after DNA damage is associated with NK cell-mediated killing of cancer cells. However, the regulation of DNA damage-induced MICA/B expression has not been fully elucidated in the context of the types of cancer cell lines. In the present study, we found that MICA/B expression varied between cancer cell lines after DNA damage. Screening in terms of chromatin remodeling identified that inhibitors related to chromatin relaxation via post-translational modification on histone H3K9, i.e. HDAC, Suv39 or G9a inhibition, restored DNA damage-dependent MICA/B expression in insensitive cells. In addition, we revealed that the restored MICA/B expression was dependent on ATR as well as E2F1, a transcription factor. We further revealed that low‑dose treatment of an HDAC inhibitor was sufficient to restore MICA/B expression in insensitive cells. Finally, we demonstrated that HDAC inhibition restored DNA damage‑dependent cytotoxic NK activity against insensitive cells. Thus, the present study revealed that DNA damage‑dependent MICA/B expression in insensitive cancer cells can be restored by chromatin relaxation via the HDAC/Suv39/G9a pathway. Collectively, manipulation of chromatin status by therapeutic cancer drugs may potentiate the antitumor effect by enhancing immune activation following radiotherapy and DNA damage-associated chemotherapy.

  2. Changes in tissue morphology and collagen composition during the repair of cortical bone in the adult chicken.

    Science.gov (United States)

    Glimcher, M J; Shapiro, F; Ellis, R D; Eyre, D R

    1980-09-01

    An animal model was developed to study the histology and collagen chemistry of healing cortical bone. A hole was cut through the cortex of the mid-shaft of the humerus of the adult chicken, which allowed for repair at a mechanically stable site. After one to two weeks the collagen of the repair tissue, which consisted principally of woven bone, contained almost three times as much hydroxylysine as the collagen of normal adult bone and thus resembled the collagen of embryonic long bones. By eight weeks, when lamellar one predominated, the hydroxylysine content had fallen to normal levels. Type I was the major genetic type of collagen present throughout. No type-II collagen, characteristic of cartilage, was detected; this was consistent with the histological findings. The results established that hydroxylysine-rich type-I collagen can be made by osteoblasts of adult animals as well as by those of embryos and early postnates. In order to understand the biological characteristics of fracture healing, it is vital to study not only the macroscopic organization of the repair tissue but also the chemical properties of its molecular components. The strength of healing fractured bone, and indeed of normal bone, depends largely on the properties of the structural protein collagen. To date, it is not known whether the collagen in healing fractures is the same as that in normal bone, or whether it has distinct chemical features that may suit it for bone repair.

  3. Immunohistochemical characterization of nanocrystalline hydroxyapatite silica gel (NanoBone(r)) osteogenesis: a study on biopsies from human jaws.

    Science.gov (United States)

    Götz, Werner; Gerber, Thomas; Michel, Barbara; Lossdörfer, Stefan; Henkel, Kai-Olaf; Heinemann, Friedhelm

    2008-10-01

    Bone substitute biomaterials may be osteogenic, osteoconductive or osteoinductive. To test for these probable characteristics in a new nanoporous grafting material consisting of nanocrystalline hydroxyapatite embedded in a porous silica gel matrix (NanoBone(s)), applied in humans, we studied biopsies from 12 patients before dental implantation following various orofacial augmentation techniques with healing times of between 3.5 and 12 months. Sections from decalcified specimens were investigated using histology, histochemistry [periodic acid Schiff, alcian blue staining and tartrate-resistant acid phosphatase (TRAP)] and immunohistochemistry, with markers for osteogenesis, bone remodelling, resorption and vessel walls (alkaline phosphatase, bone morphogenetic protein-2, collagen type I, ED1, osteocalcin, osteopontin, runx2 and Von-Willebrand factor). Histologically, four specific stages of graft transformation into lamellar bone could be characterized. During early stages of healing, bone matrix proteins were absorbed by NanoBone(s) granules, forming a proteinaceous matrix, which was invaded by small vessels and cells. We assume that the deposition of these molecules promotes early osteogenesis in and around NanoBone(s) and supports the concomitant degradation probably by osteoclast-like cells. TRAP-positive osteoclast-like cells were localized directly on the granular surfaces. Runx2-immunoreactive pre-osteoblasts, which are probably involved in direct osteogenesis forming woven bone that is later transformed into lamellar bone, were attracted. Graft resorption and bone apposition around the graft granules appear concomitantly. We postulate that NanoBone(s) has osteoconductive and biomimetic properties and is integrated into the host's physiological bone turnover at a very early stage.

  4. Bone histology in extant and fossil penguins (Aves: Sphenisciformes).

    Science.gov (United States)

    Ksepka, Daniel T; Werning, Sarah; Sclafani, Michelle; Boles, Zachary M

    2015-11-01

    Substantial changes in bone histology accompany the secondary adaptation to life in the water. This transition is well documented in several lineages of mammals and non-avian reptiles, but has received relatively little attention in birds. This study presents new observations on the long bone microstructure of penguins, based on histological sections from two extant taxa (Spheniscus and Aptenodytes) and eight fossil specimens belonging to stem lineages (†Palaeospheniscus and several indeterminate Eocene taxa). High bone density in penguins results from compaction of the internal cortical tissues, and thus penguin bones are best considered osteosclerotic rather than pachyostotic. Although the oldest specimens sampled in this study represent stages of penguin evolution that occurred at least 25 million years after the loss of flight, major differences in humeral structure were observed between these Eocene stem taxa and extant taxa. This indicates that the modification of flipper bone microstructure continued long after the initial loss of flight in penguins. It is proposed that two key transitions occurred during the shift from the typical hollow avian humerus to the dense osteosclerotic humerus in penguins. First, a reduction of the medullary cavity occurred due to a decrease in the amount of perimedullary osteoclastic activity. Second, a more solid cortex was achieved by compaction. In extant penguins and †Palaeospheniscus, most of the inner cortex is formed by rapid osteogenesis, resulting an initial latticework of woven-fibered bone. Subsequently, open spaces are filled by slower, centripetal deposition of parallel-fibered bone. Eocene stem penguins formed the initial latticework, but the subsequent round of compaction was less complete, and thus open spaces remained in the adult bone. In contrast to the humerus, hindlimb bones from Eocene stem penguins had smaller medullary cavities and thus higher compactness values compared with extant taxa. Although

  5. Malignant bone tumors

    International Nuclear Information System (INIS)

    Zedgenidze, G.A.; Kishkovskij, A.N.; Elashov, Yu.G.

    1984-01-01

    Clinicoroentgenologic semiotics of malignant bone tumors as well as metastatic bone tumors are presented. Diagnosis of malignant and metastatic bone tumors should be always complex, representing a result of cooperation of a physician, roentgenologist, pathoanatomist

  6. Bone Graft Alternatives

    Science.gov (United States)

    ... Spine Treatment Spondylolisthesis BLOG FIND A SPECIALIST Treatments Bone Graft Alternatives Patient Education Committee Patient Education Committee ... procedure such as spinal fusion. What Types of Bone Grafts are There? Bone grafts that are transplanted ...

  7. Menopause and Bone Loss

    Science.gov (United States)

    Fact Sheet & Menopause Bone Loss How are bone loss and menopause related? Throughout life your body keeps a balance between the ... lose bone faster than it can be replaced. Menopause—the time when menstrual periods end, which usually ...

  8. Bone and fat connection in aging bone.

    Science.gov (United States)

    Duque, Gustavo

    2008-07-01

    The fat and bone connection plays an important role in the pathophysiology of age-related bone loss. This review will focus on the age-induced mechanisms regulating the predominant differentiation of mesenchymal stem cells into adipocytes. Additionally, bone marrow fat will be considered as a diagnostic and therapeutic approach to osteoporosis. There are two types of bone and fat connection. The 'systemic connection', usually seen in obese patients, is hormonally regulated and associated with high bone mass and strength. The 'local connection' happens inside the bone marrow. Increasing amounts of bone marrow fat affect bone turnover through the inhibition of osteoblast function and survival and the promotion of osteoclast differentiation and activation. This interaction is regulated by paracrine secretion of fatty acids and adipokines. Additionally, bone marrow fat could be quantified using noninvasive methods and could be used as a therapeutic approach due to its capacity to transdifferentiate into bone without affecting other types of fat in the body. The bone and fat connection within the bone marrow constitutes a typical example of lipotoxicity. Additionally, bone marrow fat could be used as a new diagnostic and therapeutic approach for osteoporosis in older persons.

  9. New bone formation and trabecular bone microarchitecture of highly porous tantalum compared to titanium implant threads: A pilot canine study.

    Science.gov (United States)

    Lee, Jin Whan; Wen, Hai Bo; Gubbi, Prabhu; Romanos, Georgios E

    2018-02-01

    This study evaluated new bone formation activities and trabecular bone microarchitecture within the highly porous region of Trabecular Metal™ Dental Implants (TM) and between the threads of Tapered Screw-Vent® Dental Implants (TSV) in fresh canine extraction sockets. Eight partially edentulated dogs received four implants (4.1 mmD × 13 mmL) bilaterally in mandibular fresh extraction sockets (32 TM, 32 TSV implants), and allowed to heal for 2, 4, 8, and 12 weeks. Calcein was administered to label mineralizing bone at 11 and 4 days before euthanasia for dogs undergoing all four healing periods. Biopsies taken at each time interval were examined histologically. Histomorphometric assay was conducted for 64 unstained and 64 stained slides at the region of interest (ROI) (6 mm long × 0.35 mm deep) in the midsections of the implants. Topographical and chemical analyses were also performed. Histomorphometry revealed significantly more new bone in the TM than in the TSV implants at each healing time (p = .0014, .0084, .0218, and .0251). Calcein-labeled data showed more newly mineralized bone in the TM group than in the TSV group at 2, 8, and 12 weeks (p = .045, .028, .002, respectively) but not at 4 weeks (p = .081). Histologically TM implants exhibited more bone growth and dominant new immature woven bone at an earlier time point than TSV implants. The parameters representing trabecular bone microarchitecture corroborated faster new bone formation in the TM implants when compared to the TSV implants. TM exhibited an irregular faceted topography compared to a relatively uniform microtextured surface for TSV. Chemical analysis showed peaks associated with each implant's composition material, and TSV also showed peaks reflecting the elements of the calcium phosphate blasting media. Results suggest that the healing pathway associated with the highly porous midsection of TM dental implant could enable faster and stronger secondary implant stability than

  10. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  11. Production of chitosan-based non-woven membranes using the electrospinning process

    Science.gov (United States)

    Pakravan Lonbani, Mehdi

    Chitosan is a modified natural polymer mainly produced from chitin, one of the most abundant organic materials in the world. Highly porous chitosan mats present the specific physicochemical properties of the base material and also benefit from the physical characteristics of nanoporous membranes. Electrospinning is a novel technique developed long time ago and revisited recently that can generate polymeric fibers with nanometric size. The ultimate purpose of this work is to fabricate microporous non-woven chitosan membranes for wound healing dressings and heavy metal ion removal from drinking water. In this dissertation, two approaches have been utilized to prepare chitosan-based nanofibers; blending and co-axial electrospinning of chitosan solution with a readily electrospinnable solution, i.e. an aqueous solution of polyethylene oxide (PEO). Consequently, understanding the phase behavior and miscibility of aqueous acidic solutions of chitosan and PEO and their blends is of crucial importance, as any phase separation occurring during the electrospinning process greatly changes the morphology and physico-mechanical properties of the final products. First we employed the rheological approach on a well-known aqueous PEO solution to develop the experimental protocol. By comparing these critical points with that obtained from other experimental techniques, we showed that rheological measurements can sensitively detect early stages of phase separation. Subsequently the method was applied to 50 wt% aqueous acetic acid solutions of PEO, chitosan and their blends at different ratios. These solutions showed a lower critical solution temperature (LCST) phase diagram that is attributed to the existence of hydrogen bonds between active groups on chitosan and PEO backbone and the solvent. Critical decomposition temperatures for binodal and spinodal points were estimated from isochronal temperature sweep experiments. The obtained binodal temperatures confirmed that chitosan

  12. Tensile testing and damage analysis of woven glass-cloth/epoxy laminates at low temperature

    International Nuclear Information System (INIS)

    Kumagai, S.; Shindo, Y.; Horiguchi, K.

    2002-01-01

    In order to evaluate the tensile properties of SL-ES30 glass-cloth/epoxy laminates for superconducting magnets in fusion energy systems, tensile tests were examined both experimentally and analytically. The tensile tests were conducted in accordance with JIS K 7054 at room temperature and liquid nitrogen temperature (77 K). The general specimen geometry was a rectangular dog-bone shape with constant gage length, but with each specimen size having a different specimen width. The experimental finding provides the data for analytical modeling. The model utilizes two damage variables which are determined from experimental data. A finite element method coupled with damage was adopted for the extensional analysis. The effects of temperature, specimen geometry and gripping method on the tensile properties are examined

  13. The effects of low-intensity pulsed ultrasound on tendon-bone healing in a transosseous-equivalent sheep rotator cuff model.

    Science.gov (United States)

    Lovric, Vedran; Ledger, Michael; Goldberg, Jerome; Harper, Wade; Bertollo, Nicky; Pelletier, Matthew H; Oliver, Rema A; Yu, Yan; Walsh, William R

    2013-02-01

    The purpose of this study was to examine the effects Low-intensity Pulsed Ultrasound has on initial tendon-bone healing in a clinically relevant extra-articular transosseous-equivalent ovine rotator cuff model. Eight skeletally mature wethers, randomly allocated to either control group (n = 4) or treatment group (n = 4), underwent rotator cuff surgery following injury to the infraspinatus tendon. All animals were killed 28 days post surgery to allow examination of early effects of Low-intensity Pulsed Ultrasound treatment. General improvement in histological appearance of tendon-bone integration was noted in the treatment group. Newly formed woven bone with increased osteoblast activity along the bone surface was evident. A continuum was observed between the tendon and bone in an interdigitated fashion with Sharpey's fibres noted in the treatment group. Low-intensity Pulsed Ultrasound treatment also increased bone mineral density at the tendon-bone interface (p < 0.01), while immunohistochemistry results revealed an increase in the protein expression patterns of VEGF (p = 0.038), RUNX2 (p = 0.02) and Smad4 (p = 0.05). The results of this study indicate that Low-intensity Pulsed Ultrasound may aid in the initial phase of tendon-bone healing process in patients who have undergone rotator cuff repair. This treatment may also be beneficial following other types of reconstructive surgeries involving the tendon-bone interface.

  14. Modeling the Monotonic and Cyclic Tensile Stress-Strain Behavior of 2D and 2.5D Woven C/SiC Ceramic-Matrix Composites

    Science.gov (United States)

    Li, L. B.

    2018-05-01

    The deformation of 2D and 2.5 C/SiC woven ceramic-matrix composites (CMCs) in monotonic and cyclic loadings has been investigated. Statistical matrix multicracking and fiber failure models and the fracture mechanics interface debonding approach are used to determine the spacing of matrix cracks, the debonded length of interface, and the fraction of broken fibers. The effects of fiber volume fraction and fiber Weibull modulus on the damage evolution in the composites and on their tensile stress-strain curves are analyzed. When matrix multicracking and fiber/matrix interface debonding occur, the fiber slippage relative to the matrix in the debonded interface region of the 0° warp yarns is the main reason for the emergance of stress-strain hysteresis loops for 2D and 2.5D woven CMCs. A model of these loops is developed, and histeresis loops for the composites in cyclic loadings/unloadings are predicted.

  15. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  16. Bone scan in rheumatology

    International Nuclear Information System (INIS)

    Morales G, R.; Cano P, R.; Mendoza P, R.

    1993-01-01

    In this chapter a revision is made concerning different uses of bone scan in rheumatic diseases. These include reflex sympathetic dystrophy, osteomyelitis, spondyloarthropaties, metabolic bone diseases, avascular bone necrosis and bone injuries due to sports. There is as well some comments concerning pediatric pathology and orthopedics. (authors). 19 refs., 9 figs

  17. Bone Marrow Diseases

    Science.gov (United States)

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can ... the platelets that help with blood clotting. With bone marrow disease, there are problems with the stem ...

  18. Bone grafts in dentistry

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar

    2013-01-01

    Full Text Available Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

  19. Environmental Effects on Long Term Displacement Data of Woven Fabric Webbings Under Constant Load for Inflatable Structures

    Science.gov (United States)

    Kenner, WInfred S.; Jones, Thomas C.; Doggett, William R.; Duncan, Quinton; Plant, James

    2015-01-01

    An experimental study of the effects of environmental temperature and humidity conditions on long-term creep displacement data of high strength Kevlar and VectranTM woven fabric webbings under constant load for inflatable structures is presented. The restraint layer of an inflatable structure for long-duration space exploration missions is designed to bear load and consists of an assembly of high strength webbings. Long-term creep displacement data of webbings can be utilized by designers to validate service life parameters of restraint layers of inflatable structures. Five groups of high-strength webbings were researched over a two year period. Each group had a unique webbing length, load rating, applied load, and test period. The five groups consisted of 1.) 6K Vectran webbings loaded to 49% ultimate tensile strength (UTS), 2.) 6K Vectran webbings loaded to 55% UTS, 3.) 12.5K Vectran webbings loaded to 22% UTS, 4.) 6K Kevlar webbings loaded to 40% and 43% UTS, and 5.) 6K Kevlar webbings loaded to 48% UTS. Results show that all webbing groups exhibit the initial two stages of three of a typical creep curve of an elastic material. Results also show that webbings exhibit unique local wave patterns over the duration of the test period. Data indicate that the local pattern is primarily generated by daily variations in relative humidity values within the test facility. Data indicate that after a three to six month period, where webbings reach a steady-state creep condition, an annual sinusoidal displacement pattern is exhibited, primarily due to variations in annual mean temperature values. Data indicates that variations in daily temperature values and annual mean humidity values have limited secondary effects on creep displacement behavior. Results show that webbings in groups 2 and 5 do not exhibit well defined annual displacement patterns because the magnitude of the applied loads cause large deformations, and data indicate that material yielding within a webbing

  20. Mesenchymal stem cells-seeded bio-ceramic construct for bone regeneration in large critical-size bone defect in rabbit

    Directory of Open Access Journals (Sweden)

    Maiti SK

    2016-11-01

    Full Text Available Bone marrow derived mesenchymal stem cells (BMSC represent an attractive cell population for tissue engineering purpose. The objective of this study was to determine whether the addition of recombinant human bone morphogenetic protein (rhBMP-2 and insulin-like growth factor (IGF-1 to a silica-coated calcium hydroxyapatite (HASi - rabbit bone marrow derived mesenchymal stem cell (rBMSC construct promoted bone healing in a large segmental bone defect beyond standard critical -size radial defects (15mm in rabbits. An extensively large 30mm long radial ostectomy was performed unilaterally in thirty rabbits divided equally in five groups. Defects were filled with a HASi scaffold only (group B; HASi scaffold seeded with rBMSC (group C; HASi scaffold seeded with rBMSC along with rhBMP-2 and IGF-1 in groups D and E respectively. The same number of rBMSC (five million cells and concentration of growth factors rhBMP-2 (50µg and IGF-1 (50µg was again injected at the site of bone defect after 15 days of surgery in their respective groups. An empty defect served as the control group (group A. Radiographically, bone healing was evaluated at 7, 15, 30, 45, 60 and 90 days post implantation. Histological qualitative analysis with microCT (µ-CT, haematoxylin and eosin (H & E and Masson’s trichrome staining were performed 90 days after implantation. All rhBMP-2-added constructs induced the formation of well-differentiated mineralized woven bone surrounding the HASi scaffolds and bridging bone/implant interfaces as early as eight weeks after surgery. Bone regeneration appeared to develop earlier with the rhBMP-2 constructs than with the IGF-1 added construct. Constructs without any rhBMP-2 or IGF-1 showed osteoconductive properties limited to the bone junctions without bone ingrowths within the implantation site. In conclusion, the addition of rhBMP-2 to a HASi scaffold could promote bone generation in a large critical-size-defect.

  1. Application of bone scintigraphy

    International Nuclear Information System (INIS)

    Rondain, J.E.S.

    1996-01-01

    Bone scanning has varied applications, particularly in the file of oncology. It is used in the diagnosis and follow-up of patients with cancers that metastatize to the bones (breast, prostate CA), also in primary bone cancers, infections of the bones and joints. In early stages of primary breast CA (stage I and II), the incidence of unsuspected bone metastasis is only 1-5%. On the other hand, bone scans serve as a baseline study if bone mets occur at some later stage. In patients with stage II and III breast CA, the conversion from normal to abnormal bone scans is 15% and 17%, respectively, clearly in favor of a baseline bone scan. For prostate CA, bone scanning should be used in conjunction with PSA level determination. In advanced disease, a bone scan will define the extent of the metastases, show problematic lesions in weight-bearing bones, and even allow us to evaluate response to therapy in follow-up bone scans. In patients with lung CA, a positive bone scan will make surgery of the primary lesion inappropriate. For other cancers, a bone scan maybe used if there are other signs, whether clinical or chemical, indicating bone involvement. In patients with GIT, liver, skin, brain or bladder CA, routine bone scanning may be considered superfluous. For patients with suspected infection, a 3-phase bone scan is more desirable. In patients with septic arthritis, the bones of each side of the joint take up the radiopharmaceutical while in patients with cellulitis without bony involvement, only the first two phases (dynamic and bloodpool images) will be abnormal. Bone scanning is also used in avascular lesions such as Legg-calve-Perthes disease where one will see reduced uptake of Tc99m MDP. The advent of SPECT imaging has greatly increased the sensitivity in diagnosing AVN. (author)

  2. Vladimir Byurchiev, Ankle Bones

    OpenAIRE

    Churyumov, Anton

    2017-01-01

    Vladimir says that today not many children play with ankle bones. He recalls when he was young, children played with bones more often. According to Vladimir, various games using ankle bones develop flexibility, agility, and muscle in children’s hands. Ankles bones are taken from the back legs of a cow or a sheep. It is possible to determine the age and health of animals by examining this particular bone. Arcadia

  3. Healing of extraction sockets filled with BoneCeramic® prior to implant placement: preliminary histological findings.

    Science.gov (United States)

    De Coster, Peter; Browaeys, Hilde; De Bruyn, Hugo

    2011-03-01

    Various grafting materials have been designed to minimize edentulous ridge volume loss following tooth extraction by encouraging new bone formation in healing sockets. BoneCeramic® is a composite of hydroxyapatite and bèta-tricalcium phosphate with pores of 100-500 microns. The aim of this study was to evaluate bone regeneration in healing sockets substituted with BoneCeramic® prior to implant procedures. Fifteen extraction sockets were substituted with BoneCeramic® and 14 sockets were left to heal naturally in 10 patients (mean age 59.6 years). Biopsies were collected only from the implant recipient sites during surgery after healing periods ranging from 6-74 weeks (mean 22). In total, 24 biopsies were available; 10 from substituted and 14 from naturally healed sites. In one site, the implant was not placed intentionally and, in four substituted sites, implant placement had to be postponed due to inappropriate healing, hence from five sites biopsies were not available. Histological sections were examined by transmitted light microscope. At the time of implant surgery, bone at substituted sites was softer than in controls, compromising initial implant stability. New bone formation at substituted sites was consistently poorer than in controls, presenting predominantly loose connective tissue and less woven bone. The use of BoneCeramic® as a grafting material in fresh extraction sockets appears to interfere with normal healing processes of the alveolar bone. On the basis of the present preliminary findings, its indication as a material for bone augmentation, when implant placement is considered within 6-38 weeks after extraction, should be revised. © 2009, Copyright the Authors. Journal Compilation © 2011, Wiley Periodicals, Inc.

  4. NELL-1 Injection Maintains Long-Bone Quantity and Quality in an Ovariectomy-Induced Osteoporotic Senile Rat Model

    Science.gov (United States)

    Kwak, Jinny; Zara, Janette N.; Chiang, Michael; Ngo, Richard; Shen, Jia; James, Aaron W.; Le, Khoi M.; Moon, Crystal; Zhang, Xinli; Gou, Zhongru; Ting, Kang

    2013-01-01

    Over 10 million Americans have osteoporosis, and is the predominant cause of fractures in the elderly. Treatment of fractures in the setting of osteoporosis is complicated by a suboptimal bone regenerative response due to a decline in the number of osteoblasts, their function, and survival. Consequently, an osteogenic therapeutic to prevent and treat fractures in patients with osteoporosis is needed. Nel-like molecule-1 (NELL-1), a novel osteoinductive growth factor, has been shown to promote bone regeneration. In this study, we aim to demonstrate the capacity of recombinant NELL-1 to prevent ovariectomy (OVX)-induced osteoporosis in a senile rat model. Ten-month-old female Sprague-Dawley rats underwent either sham surgery or OVX. Subsequently, 50 μL of 600 μg/mL NELL-1 lyophilized onto a 0–50-μm tricalcium phosphate (TCP) carrier was injected into the femoral bone marrow cavity while phosphate-buffered saline (PBS) control was injected into the contralateral femur. Our microcomputed tomography results showed that OVX+PBS/TCP control femurs showed a continuous decrease in the bone volume (BV) and bone mineral density (BMD) from 2 to 8 weeks post-OVX. In contrast, OVX+NELL-1/TCP femurs showed resistance to OVX-induced bone resorption showing BV and BMD levels similar to that of SHAM femurs at 8 weeks post-OVX. Histology showed increased endosteal-woven bone, as well as decreased adipocytes in the bone marrow of NELL-1-treated femurs compared to control. NELL-1-treated femurs also showed increased immunostaining for bone differentiation markers osteopontin and osteocalcin. These findings were validated in vitro, in which addition of NELL-1 in OVX bone marrow stem cells resulted in increased osteogenic differentiation. Thus, NELL-1 effectively enhances in situ osteogenesis in the bone marrow, making it potentially useful in the prevention and treatment of osteoporotic fractures. PMID:23083222

  5. Anorexia Nervosa and Bone

    Science.gov (United States)

    Misra, Madhusmita; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiologic estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

  6. Optimal determination of the elastic constants of woven 2D SiC/SiC composite materials

    International Nuclear Information System (INIS)

    Mouchtachi, A; Guerjouma, R El; Baboux, J C; Rouby, D; Bouami, D

    2004-01-01

    For homogeneous materials, the ultrasonic immersion method, associated with a numerical optimization process mostly based on Newton's algorithm, allows the determination of elastic constants for various synthetic and natural composite materials. Nevertheless, a principal limitation of the existing optimization procedure occurs when the considered material is at the limit of the homogeneous hypothesis. Such is the case of the woven bidirectional SiC matrix and SiC fibre composite material. In this study, we have developed two numerical methods for the determination of the elastic constants of the 2D SiC/SiC composite material (2D SiC/SiC). The first one is based on Newton's algorithm: the elastic constants are obtained by minimizing the square deviation between experimental and calculated velocities. The second method is based on the Levenberg-Marquardt algorithm. We show that these algorithms give the same results in the case of homogeneous anisotropic composite materials. For the 2D SiC/SiC composite material, the two methods, using the same measured velocities, give different sets of elastic constants. We then note that the Levenberg-Marquardt algorithm enables a better convergence towards a global set of elastic constants in good agreement with the elastic properties, which can be measured using classical quasi-static methods

  7. Residual Tensile Property of Plain Woven Jute Fiber/Poly(Lactic Acid Green Composites during Thermal Cycling

    Directory of Open Access Journals (Sweden)

    Hideaki Katogi

    2016-07-01

    Full Text Available This study investigated the residual tensile properties of plain woven jute fiber reinforced poly(lactic acid (PLA during thermal cycling. Temperature ranges of thermal cycling tests were 35–45 °C and 35–55 °C. The maximum number of cycles was 103 cycles. The quasi-static tensile tests of jute fiber, PLA, and composite were conducted after thermal cycling tests. Thermal mechanical analyses of jute fiber and PLA were conducted after thermal cycling tests. Results led to the following conclusions. For temperatures of 35–45 °C, tensile strength of composite at 103 cycles decreased 10% compared to that of composite at 0 cycles. For temperatures of 35–55 °C, tensile strength and Young’s modulus of composite at 103 cycles decreased 15% and 10%, respectively, compared to that of composite at 0 cycles. Tensile properties and the coefficient of linear expansion of PLA and jute fiber remained almost unchanged after thermal cycling tests. From observation of a fracture surface, the length of fiber pull out in the fracture surface of composite at 103 cycles was longer than that of composite at 0 cycles. Therefore, tensile properties of the composite during thermal cycling were decreased, probably because of the decrease of interfacial adhesion between the fiber and resin.

  8. Identification of a set of macroscopic elastic parameters in a 3D woven composite: Uncertainty analysis and regularization

    KAUST Repository

    Gras, Renaud

    2015-03-01

    Performing a single but complex mechanical test on small structures rather than on coupons to probe multiple strain states/histories for identification purposes is nowadays possible thanks to full-field measurements. The aim is to identify many parameters thanks to the heterogeneity of mechanical fields. Such an approach is followed herein, focusing on a blade root made of 3D woven composite. The performed test, which is analyzed using global Digital Image Correlation (DIC), provides heterogeneous kinematic fields due to the particular shape of the sample. This displacement field is further processed to identify the four in-plane material parameters of the macroscopic equivalent orthotropic behavior. The key point, which may limit the ability to draw reliable conclusions, is the presence of acquisition noise in the original images that has to be tracked along the DIC/identification processing to provide uncertainties on the identified parameters. A further regularization based on a priori knowledge is finally introduced to compensate for possible lack of experimental information needed for completing the identification.

  9. Residual Tensile Property of Plain Woven Jute Fiber/Poly(Lactic Acid) Green Composites during Thermal Cycling.

    Science.gov (United States)

    Katogi, Hideaki; Takemura, Kenichi; Akiyama, Motoki

    2016-07-14

    This study investigated the residual tensile properties of plain woven jute fiber reinforced poly(lactic acid) (PLA) during thermal cycling. Temperature ranges of thermal cycling tests were 35-45 °C and 35-55 °C. The maximum number of cycles was 10³ cycles. The quasi-static tensile tests of jute fiber, PLA, and composite were conducted after thermal cycling tests. Thermal mechanical analyses of jute fiber and PLA were conducted after thermal cycling tests. Results led to the following conclusions. For temperatures of 35-45 °C, tensile strength of composite at 10³ cycles decreased 10% compared to that of composite at 0 cycles. For temperatures of 35-55 °C, tensile strength and Young's modulus of composite at 10³ cycles decreased 15% and 10%, respectively, compared to that of composite at 0 cycles. Tensile properties and the coefficient of linear expansion of PLA and jute fiber remained almost unchanged after thermal cycling tests. From observation of a fracture surface, the length of fiber pull out in the fracture surface of composite at 10³ cycles was longer than that of composite at 0 cycles. Therefore, tensile properties of the composite during thermal cycling were decreased, probably because of the decrease of interfacial adhesion between the fiber and resin.

  10. 3D Orthogonal Woven Triboelectric Nanogenerator for Effective Biomechanical Energy Harvesting and as Self-Powered Active Motion Sensors.

    Science.gov (United States)

    Dong, Kai; Deng, Jianan; Zi, Yunlong; Wang, Yi-Cheng; Xu, Cheng; Zou, Haiyang; Ding, Wenbo; Dai, Yejing; Gu, Bohong; Sun, Baozhong; Wang, Zhong Lin

    2017-10-01

    The development of wearable and large-area energy-harvesting textiles has received intensive attention due to their promising applications in next-generation wearable functional electronics. However, the limited power outputs of conventional textiles have largely hindered their development. Here, in combination with the stainless steel/polyester fiber blended yarn, the polydimethylsiloxane-coated energy-harvesting yarn, and nonconductive binding yarn, a high-power-output textile triboelectric nanogenerator (TENG) with 3D orthogonal woven structure is developed for effective biomechanical energy harvesting and active motion signal tracking. Based on the advanced 3D structural design, the maximum peak power density of 3D textile can reach 263.36 mW m -2 under the tapping frequency of 3 Hz, which is several times more than that of conventional 2D textile TENGs. Besides, its collected power is capable of lighting up a warning indicator, sustainably charging a commercial capacitor, and powering a smart watch. The 3D textile TENG can also be used as a self-powered active motion sensor to constantly monitor the movement signals of human body. Furthermore, a smart dancing blanket is designed to simultaneously convert biomechanical energy and perceive body movement. This work provides a new direction for multifunctional self-powered textiles with potential applications in wearable electronics, home security, and personalized healthcare. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Ultrahigh-Energy Density Lithium-Ion Cable Battery Based on the Carbon-Nanotube Woven Macrofilms.

    Science.gov (United States)

    Wu, Ziping; Liu, Kaixi; Lv, Chao; Zhong, Shengwen; Wang, Qinghui; Liu, Ting; Liu, Xianbin; Yin, Yanhong; Hu, Yingyan; Wei, Di; Liu, Zhongfan

    2018-05-01

    Moore's law predicts the performance of integrated circuit doubles every two years, lasting for more than five decades. However, the improvements of the performance of energy density in batteries lag far behind that. In addition, the poor flexibility, insufficient-energy density, and complexity of incorporation into wearable electronics remain considerable challenges for current battery technology. Herein, a lithium-ion cable battery is invented, which is insensitive to deformation due to its use of carbon nanotube (CNT) woven macrofilms as the charge collectors. An ultrahigh-tap density of 10 mg cm -2 of the electrodes can be obtained, which leads to an extremely high-energy density of 215 mWh cm -3 . The value is approximately seven times than that of the highest performance reported previously. In addition, the battery displays very stable rate performance and lower internal resistance than conventional lithium-ion batteries using metal charge collectors. Moreover, it demonstrates excellent convenience for connecting electronics as a new strategy is applied, in which both electrodes can be integrated into one end by a CNT macrorope. Such an ultrahigh-energy density lithium-ion cable battery provides a feasible way to power wearable electronics with commercial viability. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Non-woven Textile Materials from Waste Fibers for Cleanup of Waters Polluted with Petroleum and Oil Products

    Science.gov (United States)

    Neznakomova, Margarita; Boteva, Silvena; Tzankov, Luben; Elhag, Mohamed

    2018-04-01

    The aim of this work was to investigate the possibility of using non-woven materials (NWM) from waste fibers for oil spill cleanup and their subsequent recovery. Manufacture of textile and readymade products generates a significant amount of solid waste. A major part of it is deposited in landfills or disposed of uncontrollably. This slowly degradable waste causes environmental problems. In the present study are used two types of NWM obtained by methods where waste fibers are utilized. Thus, real textile products are produced (blankets) with which spills are covered and removed by adsorption. These products are produced by two methods: the strengthening of the covering from recovered fibers is made by entanglement when needles of special design pass through layers (needle-punching) or by stitching with thread (technology Maliwatt). Regardless of the random nature of the fiber mixture, the investigated products are good adsorbents of petroleum products. The nature of their structure (a significant void volume and developed surface) leads to a rapid recovery of the spilled petroleum products without sinking of the fiber layer for the sampled times. The used NWM can be burned under special conditions.

  13. Moisture transfer and pressure drop of humidifying elements made of non-woven fabric (Rayon/PET)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nae-Hyun [Incheon National University, Incheon (Korea, Republic of)

    2017-06-15

    In modern buildings, humidity control is an essential constituent of the building management, where spray-type humidifying element is widely used. For the spray-type element, there is a concern about the durability and the resistance to formation of mold. In this study, we made new humidifying elements were made using non-woven fabric rayon/PET and investigated the moisture transfer and pressure drop characteristics. Samples consisted of two different rayon compositions (30 % and 50 %). From the results the sample with 50 % rayon and 50 % PET showed superior moisture transfer performance than the sample with 50 % Kraft fiber and 50 % PET, probably due to better water absorption characteristics of rayon over Kraft fiber. However, pressure drop of the rayon/PET sample was larger than Kraft fiber/PET sample due to increased surface roughness. The moisture transfer performance of the rayon/PET sample deteriorated as the rayon content decreased. The efficiency (j{sub m}/{sup f}1/3) was the largest for rayon/PET (5:5) sample, followed by Kraft fiber/PET and rayon/PET (3:7) sample. The efficiency of commercially available Glasdek was much lower than other samples.

  14. The woven fiber organic electrochemical transistors based on polypyrrole nanowires/reduced graphene oxide composites for glucose sensing.

    Science.gov (United States)

    Wang, Yuedan; Qing, Xing; Zhou, Quan; Zhang, Yang; Liu, Qiongzhen; Liu, Ke; Wang, Wenwen; Li, Mufang; Lu, Zhentan; Chen, Yuanli; Wang, Dong

    2017-09-15

    Novel woven fiber organic electrochemical transistors based on polypyrrole (PPy) nanowires and reduced graphene oxide (rGO) have been prepared. SEM revealed that the introduction of rGO nanosheets could induce the growth and increase the amount of PPy nanowires. Moreover, it could enhance the electrical performance of fiber transistors. The hybrid transistors showed high on/off ratio of 10 2 , fast switch speed, and long cycling stability. The glucose sensors based on the fiber organic electrochemical transistors have also been investigated, which exhibited outstanding sensitivity, as high as 0.773 NCR/decade, with a response time as fast as 0.5s, a linear range of 1nM to 5μM, a low detection concentration as well as good repeatability. In addition, the glucose could be selectively detected in the presence of ascorbic acid and uric acid interferences. The reliability of the proposed glucose sensor was evaluated in real samples of rabbit blood. All the results indicate that the novel fiber transistors pave the way for portable and wearable electronics devices, which have a promising future for healthcare and biological applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. A spectral profile multiplexed FBG sensor network with application to strain measurement in a Kevlar woven fabric

    Science.gov (United States)

    Guo, Guodong; Hackney, Drew; Pankow, Mark; Peters, Kara

    2017-04-01

    A spectral profile division multiplexed fiber Bragg grating (FBG) sensor network is described in this paper. The unique spectral profile of each sensor in the network is identified as a distinct feature to be interrogated. Spectrum overlap is allowed under working conditions. Thus, a specific wavelength window does not need to be allocated to each sensor as in a wavelength division multiplexed (WDM) network. When the sensors are serially connected in the network, the spectrum output is expressed through a truncated series. To track the wavelength shift of each sensor, the identification problem is transformed to a nonlinear optimization problem, which is then solved by a modified dynamic multi-swarm particle swarm optimizer (DMS-PSO). To demonstrate the application of the developed network, a network consisting of four FBGs was integrated into a Kevlar woven fabric, which was under a quasi-static load imposed by an impactor head. Due to the substantial radial strain in the fabric, the spectrums of different FBGs were found to overlap during the loading process. With the developed interrogating method, the overlapped spectrum would be distinguished thus the wavelength shift of each sensor can be monitored.

  16. Experimental investigation of effects of stitching orientation on forming behaviors of 2D P-aramid multilayer woven preform

    Science.gov (United States)

    Abtew, Mulat Alubel; Boussu, François; Bruniaux, Pascal; Loghin, Carmen; Cristian, Irina; Chen, Yan; Wang, Lichuan

    2018-05-01

    In many textile applications stitching process is one of the widely used methods to join the multi-layer fabric plies not only due to its easy applicability and flexible production but also provide structural integrity throughout-the-thickness of materials. In this research, the influences of stitching pattern on various molding characteristics of multi-layer 2D para-aramid plain woven fabrics while deformation was investigated. The fabrics were made of high performance fiber with 930dtex yarn linear density and fabric areal density of 200gm/m2. First, different stitch pattern (orientation) was applied for joining the mentioned multi-layered fabrics keeping other stitching parameters such as stitch gap, stitch thread tension, stitch length, stitch type, stitch thread type etc. constant throughout the study. Then, a pneumatic based molding device with a low speed forming process specially designed for preforming of textile with a predefined hemispherical shape of punch. The result shows that stitching pattern is one of the parameter that influences the different molding behavior and should be consider while molding stitched multi-layer fabrics.

  17. Partial Replacement of Glass Fiber by Woven Kenaf in Hybrid Composites and its Effect on Monotonic and Fatigue Properties

    Directory of Open Access Journals (Sweden)

    Mohaiman Jaffar Sharba

    2016-02-01

    Full Text Available Natural–synthetic fiber hybrid composites offer a combination of high mechanical properties from the synthetic fibers and the advantages of renewable fibers to produce a material with highly specific and determined properties. In this study, plain-woven kenaf/glass reinforced unsaturated polyester (UP hybrid composites were fabricated using the hand lay-up method with a cold hydraulic press in a sandwich-configuration laminate. The glass was used as a shell with kenaf as a core, with an approximate total fiber content of 40%. Three glass/kenaf weight ratios percentages of (70/30% (H1, (55/45% (H2, and (30/70% (H3 were used to fabricate hybrid composites. Also pure glass/UP and kenaf/UP were fabricated for comparison purposes. Monotonic tests, namely tensile, compression, and flexural strengths of the composites, were performed. The morphological properties of tensile and compression failure of kenaf and hybrid composites were studied. In addition, uniaxial tensile fatigue life of hybrid composites were conducted and evaluated. The results revealed that the hybrid composite (H1 offered a good balance and the best static properties, but in tensile fatigue loading (H3 displayed low fatigue sensitivity when compared with the other hybrid composites.

  18. Low velocity impact properties of intra-ply hybrid composites based on basalt and nylon woven fabrics

    International Nuclear Information System (INIS)

    Dehkordi, Majid Tehrani; Nosraty, Hooshang; Shokrieh, Mahmood Mehrdad; Minak, Giangiacomo; Ghelli, Daniele

    2010-01-01

    In this paper, the low velocity impact behavior of homogenous and hybrid composite laminates reinforced by basalt-nylon intra-ply fabrics was experimentally investigated. Epoxy resin was used as matrix material. The purpose of using this hybrid composite is to combine the good mechanical properties of basalt fiber with the excellent impact resistant of nylon fiber. Five different types of woven fabrics were used as reinforcement with different volume percentages of nylon (0%, 25%, 33.3%, 50% and 100%). The effect of nylon/basalt fiber content on maximum force, maximum deflection, residual deflection, total absorbed energy, elastic energy, size and type of damage were studied at several low velocity impact nominal energy levels (16, 30 and 40 J). The results indicate that impact performance of these composites is significantly affected by the nylon/basalt fiber content. The visual inspection and ultrasonic C-scan of the impact damaged specimens reveals that content of nylon/basalt fiber controls the type and size of damage.

  19. Identification of trabecular excrescences, novel microanatomical structures, present in bone in osteoarthropathies

    Directory of Open Access Journals (Sweden)

    AM Taylor

    2012-04-01

    Full Text Available It is widely held that bone architecture is finely regulated in accordance with homeostatic requirements. Aberrant remodelling (hyperdensification and/or cyst formation in the immediately subchondral region has previously been described in bone underlying cartilage in arthropathies. The present study examined the trabecular architecture of samples of bone, initially in the severe osteoarthropathy of alkaptonuria, but subsequently in osteoarthritis using a combination of light microscopy, 3D scanning electron microscopy and quantitative backscattered electron scanning electron microscopy. We report an extraordinary and previously unrecognised bone phenotype in both disorders, including novel microanatomical structures. The underlying subchondral trabecular bone contained idiosyncratic architecture. Trabecular surfaces had numerous outgrowths that we have termed "trabecular excrescences", of which three distinct types were recognised. The first type arose from incomplete resorption of branching secondary trabeculae arising from the deposition of immature (woven bone in prior marrow space. These were characterised by very deeply scalloped surfaces and rugged edges. The second type had arisen in a similar way but been smoothed over by new bone deposition. The third type, which resembled coarse stucco, probably arises from resting surfaces that had been focally reactivated. These were poorly integrated with the prior trabecular wall. We propose that these distinctive microanatomical structures are indicative of abnormal osteoclast/osteoblast modelling in osteoarthropathies, possibly secondary to altered mechanical loading or other aberrant signalling. Identification of the mechanisms underlying the formation of trabecular excrescences will contribute to a better understanding of the role of aberrant bone remodelling in arthropathies and development of new therapeutic strategies.

  20. The phylogenetic distribution, anatomy and histology of the post-cloacal bones and adnexa of geckos.

    Science.gov (United States)

    Russell, Anthony P; Vickaryous, Matthew K; Bauer, Aaron M

    2016-02-01

    Post-cloacal bones of gekkotans may be present as a single (medial) pair, two pairs (medial and lateral), or may be lacking. We, herein, demonstrate that the presence of a single medial pair is the ancestral condition for the Gekkota, that the lateral pair is of sporadic occurrence within and between families, except for the Eublepharidae where it is universal, and that absence is also of sporadic occurrence except for the Sphaerodactylidae where it is the ancestral condition. Adult male Tokay geckos (Gekko gecko) possess only the medial pair of bones, and these exhibit a regionally-specific expression of woven, fibrolamellar, and lamellar bone, and an enclosed medullary cavity. Females and small juvenile males lack bony elements but exhibit a conspicuous band of dense connective tissue located about the anterior and lateral margins of the cloacal sacs. As males grow and attain sexual maturity, the medial post-cloacal bones condense in this band of dense connective tissue, and are thus shown to be dermal ossifications, similar to osteoderms but with muscular associations (although this is also known for crocodylians). Based upon ontogenetic data we set forth a scenario to explain the loss of the medial post-cloacal bones in various lineages. Differential staining of the cloacal sacs failed to reveal any specialized glandular structures. Investigation of the post-cloacal spurs shows them to be associated with cellular connective tissue of a type similar to that found in the vicinity of the medial post-cloacal bones. This suggests that the lateral post-cloacal bones may also be dermal bones, but histological evidence is needed to corroborate this. © 2015 Wiley Periodicals, Inc.

  1. Bony defect repair in rabbit using hybrid rapid prototyping polylactic co glycolic acid/β tricalciumphosphate collagen I/apatite scaffold and bone marrow mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Long Pang

    2013-01-01

    Full Text Available Background: In bone tissue engineering, extracellular matrix exerts critical influence on cellular interaction with porous biomaterial and the apatite playing an important role in the bonding process of biomaterial to bone tissue. The aim of this study was to observe the therapeutic effects of hybrid rapid prototyping (RP scaffolds comprising polylactic-co-glycolic acid (PLGA, β-tricalciumphosphate (β-TCP, collagen I and apatite (PLGA/β-TCP-collagen I/apatite on segmental bone defects in conjunction with combination with bone marrow mesenchymal stem cells (BMSCs. Materials and Methods: BMSCs were seeded into the hybrid RP scaffolds to repair 15 mm defect in the radius of rabbits. Radiograph, microcomputed tomography and histology were used to evaluate new bone formation. Results: Radiographic analysis done from 12 to 36 weeks postoperative period demonstrated that new bone formed at the radial defect site and continues to increase until the medullary cavity is recanalized and remodelling is complete. The bone defect remained unconnected in the original RP scaffolds (PLGA/β-TCP during the whole study. Histological observations conformed to the radiographic images. In hybrid RP scaffold group, woven bone united the radial defect at 12 weeks and consecutively remodeled into lamellar bone 24 weeks postoperation and finally matured into cortical bone with normal marrow cavity after another 12 weeks. No bone formation but connective tissue has been detected in RP scaffold at the same time. Conclusion: Collagen I/apatite sponge composite coating could improve new bone formation in vivo. The hybrid RP scaffold of PLGA/β-TCP skeleton with collagen I/apatite sponge composite coating is a promising candidate for bone tissue engineering.

  2. Roentgenological semiotics of bone and bone joints pathology

    International Nuclear Information System (INIS)

    Zedgenidze, G.A.; Kishkovskij, A.N.; Elashov, Yu.G.

    1984-01-01

    Physiologic and pathologic processes in bones followed by alternations of bone structure and reflected on roentgenograms are considered and described. Most frequent reasons for roentgenodiagnosis errors in diseases of bone and bone joint apparatus are presented

  3. A novel bio-inorganic bone implant containing deglued bone

    Indian Academy of Sciences (India)

    With the aim of developing an ideal bone graft, a new bone grafting material was developed using deglued bone, chitosan and gelatin. Deglued bone (DGB) which is a by-product of bone glue industries and has the close crystallographic similarities of hydroxyapatite was used as main component in the preparation of bone ...

  4. Smoking and Bone Health

    Science.gov (United States)

    ... consequences because building healthy bones in youth helps prevent osteoporosis and fractures later in life. However, it is never too late to adopt new habits for healthy bones. Smoking and Osteoporosis Cigarette smoking was first identified as ...

  5. Medicines and Bone Loss

    Science.gov (United States)

    ... The doses of thyroid hormone used to treat hypothyroidism (underactive thyroid) don’t harm bone and shouldn’t be cause for concern. Only high doses, used for thyroid cancer treatment, can cause bone loss. High doses or long- ...

  6. Bone substitute biomaterials

    CERN Document Server

    Mallick, K

    2014-01-01

    Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

  7. Radioactivity of bone cement

    International Nuclear Information System (INIS)

    Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

  8. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis - BMD ... need to undress. This scan is the best test to predict your risk of fractures, especially of ...

  9. What causes bone loss?

    Science.gov (United States)

    ... Paula FJA, Black DM, Rosen CJ. Osteoporosis and bone biology. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: ... HM. Bone development and remodeling. In: Jameson JL, De Groot ...

  10. Gracile bone dysplasias

    International Nuclear Information System (INIS)

    Kozlowski, Kazimierz; Masel, John; Sillence, David O.; Arbuckle, Susan; Juttnerova, Vera

    2002-01-01

    Gracile bone dysplasias constitute a group of disorders characterised by extremely slender bones with or without fractures. We report four newborns, two of whom showed multiple fractures. Two babies had osteocraniostenosis and one had features of oligohydramnios sequence. The diagnosis in the fourth newborn, which showed thin long bones and clavicles and extremely thin, poorly ossified ribs, is uncertain. Exact diagnosis of a gracile bone dysplasia is important for genetic counselling and medico-legal reasons. (orig.)

  11. Gracile bone dysplasias

    Energy Technology Data Exchange (ETDEWEB)

    Kozlowski, Kazimierz [Department of Medical Imaging, The Children' s Hospital at Westmead, Locked Bag 4001, Westmead 2145, NSW (Australia); Masel, John [Department of Radiology, Royal Children' s Hospital, Brisbane (Australia); Sillence, David O. [Department of Paediatrics and Child Health, The University of Sydney (Australia); Arbuckle, Susan [Department of Anatomical Pathology, The Children' s Hospital at Westmead, NSW (Australia); Juttnerova, Vera [Oddeleni Lekarske Genetiky, Hradec Kralove (Czech Republic)

    2002-09-01

    Gracile bone dysplasias constitute a group of disorders characterised by extremely slender bones with or without fractures. We report four newborns, two of whom showed multiple fractures. Two babies had osteocraniostenosis and one had features of oligohydramnios sequence. The diagnosis in the fourth newborn, which showed thin long bones and clavicles and extremely thin, poorly ossified ribs, is uncertain. Exact diagnosis of a gracile bone dysplasia is important for genetic counselling and medico-legal reasons. (orig.)

  12. [Biomaterials for bone filling: comparisons between autograft, hydroxyapatite and one highly purified bovine xenograft].

    Science.gov (United States)

    Chappard, D; Zhioua, A; Grizon, F; Basle, M F; Rebel, A

    1993-12-01

    Bone grafts are becoming increasingly common in orthopaedics, neurosurgery and periodontology. Twenty one New Zealand rabbits were used in the present study comparing several materials usable as bone substitutes. A 4.5 mm hole was drilled in the inner femoral condyles. Holes were filled with either an autograft (from the opposite condyle), an hydroxylapatite (Bioapatite), or a highly purified bovine xenograft (T650 Lubboc). Animals were sacrificed at 1, 3 and 6 months post implantation and a quantitative analysis of newly-formed bone volume (BNF/IV) and remaining biomaterials (BMAT/IV) was done. In addition, some holes were left unfilled and served as controls. At 6 months, there was no tendency for spontaneous repair in the control animals. The autografted animals have repaired their trabecular mass and architecture within the first month. Hydroxylapatite appeared unresorbed at six months and only thin and scanty new trabeculae were observed. The xenograft induced woven bone trabeculae formation on the first month. This was associated with resorption of the material by two multinucleated cell populations. At six months, the epiphyseal architecture was restored and the biomaterial has disappeared in most cases. Xenografts appear a promising alternative to autografts and allografts, whose infectious risks and ethical problems should always be borne in mind.

  13. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  14. Investigation on Shielding and Mechanical Behavior of Carbon/Stainless Steel Hybrid Yarn Woven Fabrics and Their Composites

    Science.gov (United States)

    Jagatheesan, Krishnasamy; Ramasamy, Alagirusamy; Das, Apurba; Basu, Ananjan

    2017-08-01

    This study investigates the shielding characteristics of carbon/stainless steel/polypropylene (C/SS/PP) hybrid woven fabrics and their composites in low frequency (50 MHz-1.5 GHz) and C band (4-6 GHz) regions. The hybrid yarns prepared from carbon and SS filaments using a direct twisting machine have been made into woven fabric samples using a sample loom. The composite has been made by sandwiching a hybrid yarn fabric between the polypropylene films in a compression molding machine at 180°C for 5 min. The shielding behavior of the fabric and the composites has been tested using a coaxial transmission holder for the low frequency range and a wave guide method for the C band frequency range. It has been observed that a 1 end float composite showed a higher SE of 81.4 dB than the 4 end float (76.2 dB) and the 8 end float composites (64 dB) at the low frequency region. However, at the C band frequency, the effect of fabric structures on shielding effectiveness (SE) of fabric composite depends on thread density. For example, at low thread density, (i.e.) 3.93 ppcm, the 8 end float fabric composite showed the highest SE of 22.7 dB than did the 4 end (20.4 dB) and the 1 end float (16.5 dB) fabric composite. However, at high thread density (6.3 ppcm), the case was the reverse. The 1 end float fabric composite showed the highest SE of 29.7 dB rather than 4 end and 8 end float fabric composites (25.9 dB). In addition, all the composites showed less SE than their fabric forms. The increase in thread density also increased the shielding behavior of composites in both frequency ranges. A nonlinear regression model was developed using the Box-Behnken design for predicting the shielding behavior of fabric composites in C band region. In addition to shielding behavior, mechanical strength of C/SS/PP hybrid yarn, the fabric and composite has been tested using a Zwick Roell tensile tester. It has been observed that the work of rupture of C/SS/PP hybrid yarn is higher (6830.3 g

  15. (unicameral) bone cysts

    African Journals Online (AJOL)

    SA JOURNAL OF RADIOLOGY • September 2007. When encountering a radiologically benign lucent bone lesion in a child, a simple bone cyst is a reasonable diagnostic consideration. Simple or unicameral bone cysts are expansile, serous-fluid-containing defects, that are not true neoplasms. Peak age ranges between 3 ...

  16. Polyester non-woven fabric finger cover as a TRUCT Braille reading assistance tool for Braille learners.

    Science.gov (United States)

    Doi, Kouki; Fujimoto, Hiroshi

    2007-11-01

    Transparent resinous ultraviolet-curing type (TRUCT) Braille signs are becoming more and more popular in Japan, especially when they are printed together with visual characters. These signs are made by screen printing, a technique that can be applied to various base materials, such as paper, metal, and plastic. TRUCT Braille signs have begun to be used in public facilities, such as on tactile maps and on handrails. Naturally, it is expected that Braille beginners will utilize these signs. However, it has been pointed out that the friction between the forefinger and the base material may affect reading accuracy and speed. In this study, we developed a finger cover made of soft, thin polyester non-woven fabric to reduce friction during Braille reading. We also carried out a study to investigate the effect of its use. The subjects were 12 Braille learners with acquired visual impairment, who were asked to read randomly selected characters with and without the finger cover. The results showed that most participants could read TRUCT Braille significantly faster and more accurately with a finger cover than without it, regardless of the base material and dot height. This result suggests that wearing the finger cover enables Braille learners to read TRUCT Braille more efficiently. The finger cover can be used as a Braille reading assistance tool for Braille learners. An additional, health-related advantage of the finger cover is that the forefinger remains clean. We expect that the finger cover will be in practical use in Japan within 1 or 2 years.

  17. Numerical simulating and experimental study on the woven carbon fiber-reinforced composite laminates under low-velocity impact

    Science.gov (United States)

    Liu, Hanyang; Tang, Zhanwen; Pan, Lingying; Zhao, Weidong; Sun, Baogang; Jiang, Wenge

    2016-05-01

    Impact damage has been identified as a critical form of the defects that constantly threatened the reliability of composite structures, such as those used in the aerospace structures and systems. Low energy impacts can introduce barely visible damage and cause the degradation of structural stiffness, furthermore, the flaws caused by low-velocity impact are so dangerous that they can give rise to the further extended delaminations. In order to improve the reliability and load carrying capacity of composite laminates under low-velocity impact, in this paper, the numerical simulatings and experimental studies on the woven fiber-reinforced composite laminates under low-velocity impact with impact energy 16.7J were discussed. The low velocity impact experiment was carried out through drop-weight system as the reason of inertia effect. A numerical progressive damage model was provided, in which the damages of fiber, matrix and interlamina were considered by VUMT subroutine in ABAQUS, to determine the damage modes. The Hashin failure criteria were improved to cover the failure modes of fiber failure in the directions of warp/weft and delaminations. The results of Finite Element Analysis (FEA) were compared with the experimental results of nondestructive examination including the results of ultrasonic C-scan, cross-section stereomicroscope and contact force - time history curves. It is found that the response of laminates under low-velocity impact could be divided into stages with different damage. Before the max-deformation of the laminates occurring, the matrix cracking, fiber breakage and delaminations were simulated during the impactor dropping. During the releasing and rebounding period, matrix cracking and delaminations areas kept increasing in the laminates because of the stress releasing of laminates. Finally, the simulating results showed the good agreements with the results of experiment.

  18. The Effect of Temperature and Nanoclay on the Low Velocity and Ballistic Behavior of Woven Glass-Fiber Reinforced Composites

    Science.gov (United States)

    Patrin, Lauren

    The objective of this research was to study the effect of nanoclay and temperature on the behavior of woven glass-fabric reinforced epoxy composite under low velocity and ballistic impacts. The materials used in manufacturing the composite were S2 (6181) glass-fibers, epoxy resin (EPON 828), hardener (Epikure 3230), nanoclay and Heloxy 61 modifier. The nanoclay addition was 0%, 1%, 3% and 5% by weight, with respect to the resin. All specimens were manufactured at the City College facilities using vacuum infusion. Tensile tests were conducted to characterize the material and obtain the Young's modulus, ultimate stress, failure strain, Poisson's ratio, shear modulus and shear strength and their variation with nanoclay percentage and temperature. The tests were conducted at room temperature (21°C/70°F), -54°C (-65°F), -20°C (-4°F), 49°C (120°F) and 71°C (160°F). Next composite specimens with 0%, 1%, 3% and 5% nanoclay by weight, with respect to the resin, were subjected to low velocity impact at the previously specified temperatures to determine dynamic force, displacement and energy correlations. The extent of damage was studied using the ultrasound technique. Then ballistic tests were conducted on the nanoclay infused specimens at room temperature to obtain the ballistic limit (V50) and the damage behavior of the composite. The dynamic finite element analysis (FEA) software LS-DYNA was used to model and simulate the results of low velocity impact tests. Good agreement was obtained between experimental and numerical (FEA) results. Analytical analyses were undertaken to compare the results from the tensile experiments. The finite element analysis (FEA) allowed for further analytical comparison of the results. The FEA platform used was LS-DYNA due to its proficient dynamic and damage capabilities in composite materials. The FEA was used to model and simulate the low velocity impacts and compare the results to experiments.

  19. Multiparametric MRI of intracranial aneurysms treated with the Woven EndoBridge (WEB): a case of Faraday's cage?

    Science.gov (United States)

    Nawka, Marie Teresa; Sedlacik, Jan; Frölich, Andreas; Bester, Maxim; Fiehler, Jens; Buhk, Jan-Hendrik

    2018-02-10

    To evaluate multiparametric MRI including non-contrast and contrast-enhanced morphological and angiographic techniques for intracranial aneurysms treated with the single-layer Woven EndoBridge (WEB) embolization system applying simultaneous digital subtraction angiography (DSA) as the reference of standard. We retrospectively identified all patients with incidental and acute ruptured intracranial aneurysms treated with a WEB device (WEB SL and WEB SLS) between March 2014 and June 2016 in our neurovascular center with early (within 7 days) postinterventional multiparametric MRI as well as mid-term (5-8 months) follow-up MRI and DSA available. Occlusion rates were recorded both in DSA and MR angiography (MRA). In MRI, signal intensities within the WEB as well as in the occluded dome distal to the WEB, if present, were measured by region-of-interest (ROI) analysis. Twenty-five patients fulfilled the inclusion criteria. Rates of complete/adequate occlusion at mid-term follow-up were 84% with both MRA and DSA. A strong signal loss within the WEB was observed in all MR sequences at initial and follow-up examinations. ROI analysis did not reveal significant differences in non-contrast (P=0.946) and contrast-enhanced imaging (P=0.377). A T1-hyperintense thrombus in the non-WEB-carrying dome was a frequent observation. Signal intensity measurements in multiparametric MRI suggest that neither contrast-enhanced MRA nor morphological sequences are capable of revealing reliable information on the WEB lumen, presumably due to radio frequency shielding. MRI is therefore not suitable for confirming complete thrombus formation within the WEB. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Comparative evaluation of hydroxyapatite and nano-bioglass in two forms of conventional micro- and nano-particles in repairing bone defects (an animal study).

    Science.gov (United States)

    Nosouhian, Saied; Razavi, Mohammad; Jafari-Pozve, Nasim; Rismanchian, Mansour

    2015-01-01

    Many synthetic bone materials have been introduced for repairing bone defects. The aim of this study is to comparatively evaluate the efficacy of nano-hydroxyapatite (HA) and nano-bioglass bone materials with their traditional micro counterparts in repairing bone defects. In this prospective animal study, four healthy dogs were included. First to fourth premolars were extracted in each quadrant and five cavities in each quadrant were created using trephine. Sixteen cavities in each dog were filled by HA, nano-HA, bioglass, and nano-bioglass and four defects were left as the control group. All defects were covered by a nonrestorable membrane. Dogs were sacrificed after 15, 30, 45, and 60 days sequentially. All 20 samples were extracted by trephine #8 with a sufficient amount of surrounding bone. All specimens were investigated under an optical microscope and the percentage of total regenerated bone, lamellar, and woven bone were evaluated. Data analysis was carried out by SPSS Software ver. 15 and Mann-Whitney U-test (α =0.05). After 15 days, the bone formation percentage showed a significant difference between HA and nano-HA and between HA and bioglass (P bone formation after 15 days. Nano-bioglass and bioglass and nano-HA and nano-bioglass groups represented a significant difference and nano-bioglass showed the highest rate of bone formation after 30 days (P = 0.01). After 45 days, the bone formation percentage showed a significant difference between nano-bioglass and bioglass and between nano-HA and nano-bioglass groups (P = 0.01). Nano-HA and nano-bioglass biomaterials showed promising results when compared to conventional micro-particles in the repair of bone defects.

  1. Cortical bone metastases

    International Nuclear Information System (INIS)

    Davis, T.M. Jr.; Rogers, L.F.; Hendrix, R.W.

    1986-01-01

    Twenty-five cases of bone metastases involving the cortex alone are reviewed. Seven patients had primary lung carcinoma, while 18 had primary tumors not previously reported to produce cortical bone metastases (tumors of the breast, kidney, pancreas, adenocarcinoma of unknown origin, multiple myeloma). Radiographically, these cortical lesions were well circumscribed, osteolytic, and produced soft-tissue swelling and occasional periosteal reaction. A recurrent pattern of metadiaphyseal involvement of the long bones of the lower extremity (particularly the femur) was noted, and is discussed. Findings reported in the literature, review, pathophysiology, and the role of skeletal radiographs, bone scans, and CT scans in evaluating cortical bone metastases are addressed

  2. Cytology of Bone.

    Science.gov (United States)

    Barger, Anne M

    2017-01-01

    Cytology of bone is a useful diagnostic tool. Aspiration of lytic or proliferative lesions can assist with the diagnosis of inflammatory or neoplastic processes. Bacterial, fungal, and protozoal organisms can result in significant osteomyelitis, and these organisms can be identified on cytology. Neoplasms of bone including primary bone tumors such as osteosarcoma, chondrosarcoma, fibrosarcoma, synovial cell sarcoma, and histiocytic sarcoma and tumors of bone marrow including plasma cell neoplasia and lymphoma and metastatic neoplasia can result in significant bone lysis or proliferation and can be diagnosed effectively with cytology. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Enzymatic maceration of bone

    DEFF Research Database (Denmark)

    Uhre, Marie-Louise; Eriksen, Anne Marie; Simonsen, Kim Pilkjær

    2015-01-01

    and afterwards macerated by one of the two methods. DNA extraction was performed to see the effect of the macerations on DNA preservation. Furthermore, the bone pieces were examined in a stereomicroscope to assess for any bone damage. The results demonstrated that both methods removed all flesh/soft tissue from...... the bones. The DNA analysis showed that DNA was preserved on all the pieces of bones which were examined. Finally, the investigation suggests that enzyme maceration could be gentler on the bones, as the edges appeared less frayed. The enzyme maceration was also a quicker method; it took three hours compared...

  4. [Prefabrication of bone transplants].

    Science.gov (United States)

    Jagodzinski, M; Kokemüller, H; Jehn, P; Vogt, P; Gellrich, N-C; Krettek, C

    2015-03-01

    Prefabrication of bone transplants is a promising option for large defects of the long bones, especially if there is compromised vascularization of the defect. This is especially true for postinfection bone defects and other types of atrophic nonunion. The generation of a foreign body membrane (Masquelet's technique) has been investigated in order to ameliorate the response of the host tissue surrounding the defect. In an experimental animal study, a blood vessel within a bone construct could be used to generate customized, vascularized osteogenic constructs that can be used to treat large bone defects in the future.

  5. Otosclerosis: Temporal Bone Pathology.

    Science.gov (United States)

    Quesnel, Alicia M; Ishai, Reuven; McKenna, Michael J

    2018-04-01

    Otosclerosis is pathologically characterized by abnormal bony remodeling, which includes bone resorption, new bone deposition, and vascular proliferation in the temporal bone. Sensorineural hearing loss in otosclerosis is associated with extension of otosclerosis to the cochlear endosteum and deposition of collagen throughout the spiral ligament. Persistent or recurrent conductive hearing loss after stapedectomy has been associated with incomplete footplate fenestration, poor incus-prosthesis connection, and incus resorption in temporal bone specimens. Human temporal bone pathology has helped to define the role of computed tomography imaging for otosclerosis, confirming that computed tomography is highly sensitive for diagnosis, yet limited in assessing cochlear endosteal involvement. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Thermo-responsive wound dressings by grafting chitosan and poly(N-isopropylacrylamide) to plasma-induced graft polymerization modified non-woven fabrics

    International Nuclear Information System (INIS)

    Chen, Jyh-Ping; Kuo, Chang-Yi; Lee, Wen-Li

    2012-01-01

    Highlights: ► Poly(N-isopropylacrylamide) and chitosan were grafted to polypropylene non-wovens. ► An easily stripped off thermo-responsive wound dressing was developed. ► The wound dressing is biocompatible, has antibacterial and wound healing abilities. ► The bigraft non-woven will be a potential wound dressing for biomedical use. - Abstract: To obtain a chitosan wound dressings with temperature-responsive characteristics, polypropylene (PP) non-woven fabric (NWF) was modified by direct current pulsed oxygen plasma-induced grafting polymerization of acrylic acid (AAc) to improve hydrophilicity and to introduce carboxylic acid groups. Conjugation of chitosan and poly(N-isopropylacrylamide) (PNIPAAm) followed by using water-soluble carbodiimide as a coupling agent to form a novel bigraft PP-g-chitosan-g-PNIPAAm wound dressing. The amount of chitosan and PNIPAAm grafted to PP-g-chitosan-g-PNIPAAm were 83.0 ± 4.6 μg/cm 2 and 189.5 ± 8.2 μg/cm 2 , respectively. The surface chemical composition and microstructure of the NWF were studied by electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy (SEM). The linkages between AAc, chitosan, and PNIPAAm were confirmed with the formation of amide bonds. Physical properties of the NWF were characterized and potentials of these NWFs as wound dressings were evaluated using SD rat as the animal model. NWFs contained PNIPAAm were better than those contained only chitosan in wound healing rates and the wound areas covered by PP-g-chitosan-g-PNIPAAm wound dressings healed completely in 17 days.

  7. Aneurysmal bone cyst of the temporal bone

    International Nuclear Information System (INIS)

    Buxi, Tarvinder; Sud Seema; Vohra, Rakesh; Sud, Aditi; Singh, Satnam

    2004-01-01

    Aneurysmal bone cyst (ABC) of the temporal bone is rare. The nature of the underlying disorder that converted into the ABC might, however, be difficult to ascertain on imaging as well as on histopathology. The unusual CT and MRI findings in a case of ABC of the temporal bone are presented. This had transdural intracerebral spread with a large component of solid enhancing matrix but no peripheral calcific rim. The patient was an adult of 45 years with a history of headache for more than 1 year Copyright (2004) Blackwell Publishing Asia Pty Ltd

  8. BONES WITH BIOCERAMICS

    Directory of Open Access Journals (Sweden)

    Wijianto Wijianto

    2017-01-01

    Full Text Available This paper discuss about ceramics in application as bone implant. Bioceramics for instance Hydroxyapatite, usually is abbreviated with HA or HAp, is a mineral that is very good physical properties as bone replacement in human body. To produce Hydroxyapatite, coating process is used which have good potential as they can exploit the biocompatible and bone bonding properties of the ceramic. There are many advantages and disadvantages of bioceramics as bone implant. Advantages of hydroxyapatite as bone implant are rapidly integrated into the human body, and is most interesting property that will bond to bone forming indistinguishable unions. On contrary, disadvantages of hydroxyapatite as bone implant are poor mechanical properties (in particular fatigue properties mean that hydroxyapatite cannot be used in bulk form for load bearing applications such as orthopaedics and poor adhesion between the calcium phosphate coating and the material implant will occur.

  9. Bone allografting in children

    Science.gov (United States)

    Sadovoy, M. A.; Kirilova, I. A.; Podorognaya, V. T.; Matsuk, S. A.; Novoselov, V. P.; Moskalev, A. V.; Bondarenko, A. V.; Afanasev, L. M.; Gubina, E. V.

    2017-09-01

    A total of 522 patients with benign and intermediate bone tumors of various locations, aged 1 to 15 years, were operated in the period from 1996 to 2016. To diagnose skeleton tumors, we used clinical observation, X-ray, and, if indicated, tomography and tumor site biopsy. In the extensive bone resection, we performed bone reconstruction with the replacement of a defect with an allograft (bone strips, deproteinized and spongy grafts), sometimes in the combination with bone autografting. After segmental resection, the defects were filled with bone strips in the form of matchstick grafts; the allografts were received from the Laboratory for Tissue Preparation and Preservation of the Novosibirsk Research Institute of Traumatology and Orthopedics. According to the X-ray data, a complete reorganization of bone grafts occurred within 1.5 to 3 years. The long-term result was assessed as good.

  10. Bone disease in diabetes

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram V.; Hansen, Stinus; Frost, Morten

    2017-01-01

    Type 1 and type 2 diabetes are generally accepted to be associated with increased bone fracture risk. However, the pathophysiological mechanisms of diabetic bone disease are poorly understood, and whether the associated increased skeletal fragility is a comorbidity or a complication of diabetes...... remains under debate. Although there is some indication of a direct deleterious effect of microangiopathy on bone, the evidence is open to question, and whether diabetic osteopathy can be classified as a chronic, microvascular complication of diabetes remains uncertain. Here, we review the current...... knowledge of potential contributory factors to diabetic bone disease, particularly the association between diabetic microangiopathy and bone mineral density, bone structure, and bone turnover. Additionally, we discuss and propose a pathophysiological model of the effects of diabetic microvascular disease...

  11. Bone scintiscanning updated.

    Science.gov (United States)

    Lentle, B C; Russell, A S; Percy, J S; Scott, J R; Jackson, F I

    1976-03-01

    Use of modern materials and methods has given bone scintiscanning a larger role in clinical medicine, The safety and ready availability of newer agents have led to its greater use in investigating both benign and malignant disease of bone and joint. Present evidence suggests that abnormal accumulation of 99mTc-polyphosphate and its analogues results from ionic deposition at crystal surfaces in immature bone, this process being facilitated by an increase in bone vascularity. There is, also, a component of matrix localization. These factors are in keeping with the concept that abnormal scintiscan sites represent areas of increased osteoblastic activity, although this may be an oversimplification. Increasing evidence shows that the bone scintiscan is more sensitive than conventional radiography in detecting focal disease of bone, and its ability to reflect the immediate status of bone further complements radiographic findings. The main limitation of this method relates to nonspecificity of the results obtained.

  12. Pressure Drop Across Woven Screens Under Uniform and Nonuniform Flow Conditions. [flow characteristics of water through Dutch twill and square weave fabrics

    Science.gov (United States)

    Ludewig, M.; Omori, S.; Rao, G. L.

    1974-01-01

    Tests were conducted to determine the experimental pressure drop and velocity data for water flowing through woven screens. The types of materials used are dutch twill and square weave fabrics. Pressure drop measures were made at four locations in a rectangular channel. The data are presented as change in pressure compared with the average entry velocity and the numerical relationship is determined by dividing the volumetric flow rate by the screen area open to flow. The equations of continuity and momentum are presented. A computer program listing an extension of a theoretical model and data from that computer program are included.

  13. [Bone homeostasis and Mechano biology.

    Science.gov (United States)

    Nakashima, Tomoki

    The weight-bearing exercises help to build bones and to maintain them strength. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication between bone component cells such as osteoclasts, osteoblasts and osteocytes. An imbalance of this process is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the regulation of bone remodeling in response to mechanical and endocrine stimuli.

  14. Synchrotron Phase Tomography: An Emerging Imaging Method for Microvessel Detection in Engineered Bone of Craniofacial Districts

    Directory of Open Access Journals (Sweden)

    Alessandra Giuliani

    2017-09-01

    Full Text Available The engineering of large 3D constructs, such as certain craniofacial bone districts, is nowadays a critical challenge. Indeed, the amount of oxygen needed for cell survival is able to reach a maximum diffusion distance of ~150–200 μm from the original vascularization vector, often hampering the long-term survival of the regenerated tissues. Thus, the rapid growth of new blood vessels, delivering oxygen and nutrients also to the inner cells of the bone grafts, is mandatory for their long-term function in clinical practice. Unfortunately, significant progress in this direction is currently hindered by a lack of methods with which to visualize these processes in 3D and reliably quantify them. In this regard, a challenging method for simultaneous 3D imaging and analysis of microvascularization and bone microstructure has emerged in recent years: it is based on the use of synchrotron phase tomography. This technique is able to simultaneously identify multiple tissue features in a craniofacial bone site (e.g., the microvascular and the calcified tissue structure. Moreover, it overcomes the intrinsic limitations of both histology, achieving only a 2D characterization, and conventional tomographic approaches, poorly resolving the vascularization net in the case of an incomplete filling of the newly formed microvessels by contrast agents. Indeed, phase tomography, being based on phase differences among the scattered X-ray waves, is capable of discriminating tissues with similar absorption coefficients (like vessels and woven bone in defined experimental conditions. The approach reviewed here is based on the most recent experiences applied to bone regeneration in the craniofacial region.

  15. Polypropylene non-woven fabric membrane via surface modification with biomimetic phosphorylcholine in Ce(IV)/HNO{sub 3} redox system

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jie; Shi Qiang; Luan Shifang; Song Lingjie; Yang Huawei [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2012-10-01

    Surface modification of polypropylene non-woven fabric membrane (NWF) for improving its hemocompatibility was developed by grafting a biomimic monomer, 2-methacryloyloxyethyl phosphorycholine (MPC). The NWF membrane surface was first activated by potassium peroxydisulfate to form hydroxyl groups, and then grafted with MPC using ceric (IV) ammonium nitrate as the redox initiator. The surface chemical changes before and after modification were confirmed by Fourier transform infrared spectroscopy with an ATR unit (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS); the water contact angle results showed the gradual changes in wettability from hydrophobic to hydrophilic surface. Meanwhile, the hemocompatibility of these samples was also evaluated by protein adsorption and platelet adhesion. These experimental results exhibited that the introduction of poly(MPC) onto the NWF membrane surfaces substantially improved their hemocompatibility. The feasibility and simplicity of this procedure may lead to potential applications of NWF membranes in biomedical separation and blood purification. - Graphical abstract: 2-methacryloyloxyethyl phosphorycholine (MPC), was grafted onto non-woven fabric (NWF) membrane surface by Ce(IV)/HNO{sub 3} redox system. The protein adsorption and platelet adhesion were substantially suppressed by the introduction of poly(MPC). Highlights: Black-Right-Pointing-Pointer MPC was successfully grafted onto NWF PP membrane surface. Black-Right-Pointing-Pointer Obviously enhanced hemocompatibility was acquired by the modified samples. Black-Right-Pointing-Pointer A facile redox grafting was adopted in the whole process.

  16. Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

    Science.gov (United States)

    Liu, Kuang C.; Arnold, Steven M.

    2011-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

  17. Biomaterials and bone mechanotransduction

    Science.gov (United States)

    Sikavitsas, V. I.; Temenoff, J. S.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

  18. Biophotonics and Bone Biology

    Science.gov (United States)

    Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

    2004-01-01

    One of the more-serious side effects of extended space flight is an accelerated bone loss [Bioastronautics Critical Path Roadmap, http://research.hq.nasa.gov/code_u/bcpr/index.cfm]. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It shows that an extrapolation of the microgravity induced bone loss rates to longer time scales, such as a 2.5 year round-trip to Mars (6 months out at 0 g, 1.5 year stay on Mars at 0.38 g, 6 months back at 0 g), could severely compromise the skeletal system of such a person.

  19. Bone cells in birds show exceptional surface area, a characteristic tracing back to saurischian dinosaurs of the late Triassic.

    Directory of Open Access Journals (Sweden)

    John M Rensberger

    Full Text Available Dinosaurs are unique among terrestrial tetrapods in their body sizes, which range from less than 3 gm in hummingbirds to 70,000 kg or more in sauropods. Studies of the microstructure of bone tissue have indicated that large dinosaurs, once believed to be slow growing, attained maturity at rates comparable to or greater than those of large mammals. A number of structural criteria in bone tissue have been used to assess differences in rates of osteogenesis in extinct taxa, including counts of lines of arrested growth and the density of vascular canals.Here, we examine the density of the cytoplasmic surface of bone-producing cells, a feature which may set an upper limit to the rate of osteogenesis. Osteocyte lacunae and canaliculi, the cavities in bone containing osteocytes and their extensions, were measured in thin-sections of primary (woven and parallel fibered bone in a diversity of tetrapods. The results indicate that bone cell surfaces are more densely organized in the Saurischia (extant birds, extinct Mesozoic Theropoda and Sauropodomorpha than in other tetrapods, a result of denser branching of the cell extensions. The highest postnatal growth rates among extant tetrapods occur in modern birds, the only surviving saurischians, and the finding of exceptional cytoplasmic surface area of the cells that produce bone in this group suggests a relationship with bone growth rate. In support of this relationship is finding the lowest cell surface density among the saurischians examined in Dinornis, a member of a group of ratites that evolved in New Zealand in isolation from mammalian predators and show other evidence of lowered maturation rates.

  20. Bone cells in birds show exceptional surface area, a characteristic tracing back to saurischian dinosaurs of the late Triassic.

    Science.gov (United States)

    Rensberger, John M; Martínez, Ricardo N

    2015-01-01

    Dinosaurs are unique among terrestrial tetrapods in their body sizes, which range from less than 3 gm in hummingbirds to 70,000 kg or more in sauropods. Studies of the microstructure of bone tissue have indicated that large dinosaurs, once believed to be slow growing, attained maturity at rates comparable to or greater than those of large mammals. A number of structural criteria in bone tissue have been used to assess differences in rates of osteogenesis in extinct taxa, including counts of lines of arrested growth and the density of vascular canals. Here, we examine the density of the cytoplasmic surface of bone-producing cells, a feature which may set an upper limit to the rate of osteogenesis. Osteocyte lacunae and canaliculi, the cavities in bone containing osteocytes and their extensions, were measured in thin-sections of primary (woven and parallel fibered) bone in a diversity of tetrapods. The results indicate that bone cell surfaces are more densely organized in the Saurischia (extant birds, extinct Mesozoic Theropoda and Sauropodomorpha) than in other tetrapods, a result of denser branching of the cell extensions. The highest postnatal growth rates among extant tetrapods occur in modern birds, the only surviving saurischians, and the finding of exceptional cytoplasmic surface area of the cells that produce bone in this group suggests a relationship with bone growth rate. In support of this relationship is finding the lowest cell surface density among the saurischians examined in Dinornis, a member of a group of ratites that evolved in New Zealand in isolation from mammalian predators and show other evidence of lowered maturation rates.

  1. Effects of magnetic resonance-guided high-intensity focused ultrasound ablation on bone mechanical properties and modeling.

    Science.gov (United States)

    Yeo, Sin Yuin; Arias Moreno, Andrés J; van Rietbergen, Bert; Ter Hoeve, Natalie D; van Diest, Paul J; Grüll, Holger

    2015-01-01

    Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a promising technique for palliative treatment of bone pain. In this study, the effects of MR-HIFU ablation on bone mechanics and modeling were investigated. A total of 12 healthy rat femurs were ablated using 10 W for 46 ± 4 s per sonication with 4 sonications for each femur. At 7 days after treatments, all animals underwent MR and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Then, six animals were euthanized. At 1 month following ablations, the remaining six animals were scanned again with MR and SPECT/CT prior to euthanization. Thereafter, both the HIFU-treated and contralateral control bones of three animals from each time interval were processed for histology, whereas the remaining bones were subjected to micro-CT (μCT), three-point bending tests, and micro-finite element (micro-FE) analyses. At 7 days after HIFU ablations, edema formation around the treated bones coupled with bone marrow and cortical bone necrosis was observed on MRI and histological images. SPECT/CT and μCT images revealed presence of bone modeling through an increased uptake of (99m)Tc-MDP and formation of woven bone, respectively. At 31 days after ablations, as illustrated by imaging and histology, healing of the treated bone and the surrounding soft tissue was noted, marked by decreased in amount of tissue damage, formation of scar tissue, and sub-periosteal reaction. The results of three-point bending tests showed no significant differences in elastic stiffness, ultimate load, and yield load between the HIFU-treated and contralateral control bones at 7 days and 1 month after treatments. Similarly, the elastic stiffness and Young's moduli determined by micro-FE analyses at both time intervals were not statistically different. Multimodality imaging and histological data illustrated the presence of HIFU-induced bone damage at the cellular level, which activated the

  2. Multiscale Modeling of Bone

    Science.gov (United States)

    2014-12-01

    is an ordered array of bone fibers in a matrix material [1]. It is the dominant form of bone and closely resembles a layered fiber - reinforced ...mineral [3], [14]. These fibers are not independent structures, but exist only within the complex lamellar bone [13], similar to a fiber reinforced ...accuracy of this method. What this model does not provide is the transverse properties or a Poisson ’ s ratio for TC. Thus, we must assume that

  3. Extraskeletal and intraskeletal new bone formation induced by demineralized bone matrix combined with bone marrow cells

    International Nuclear Information System (INIS)

    Lindholm, T.S.; Nilsson, O.S.; Lindholm, T.C.

    1982-01-01

    Dilutions of fresh autogenous bone marrow cells in combination with allogeneic demineralized cortical bone matrix were tested extraskeletally in rats using roentgenographic, histologic, and 45 Ca techniques. Suspensions of bone marrow cells (especially diluted 1:2 with culture media) combined with demineralized cortical bone seemed to induce significantly more new bone than did demineralized bone, bone marrow, or composite grafts with whole bone marrow, respectively. In a short-term spinal fusion experiment, demineralized cortical bone combined with fresh bone marrow produced new bone and bridged the interspace between the spinous processes faster than other transplantation procedures. The induction of undifferentiated host cells by demineralized bone matrix is further complemented by addition of autogenous, especially slightly diluted, bone marrow cells

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  5. Exercise for Your Bone Health

    Science.gov (United States)

    ... FAQs Breadcrumb Home Exercise for Your Bone Health Exercise for Your Bone Health Vital at every age ... A Complete Osteoporosis Program For Your Information Why Exercise? Like muscle, bone is living tissue that responds ...

  6. Bone Cancer—Patient Version

    Science.gov (United States)

    Bone cancer is rare and includes several types. Some bone cancers, including osteosarcoma and Ewing sarcoma, are seen most often in children and young adults. Start here to find information on bone cancer treatment, research, and statistics.

  7. Bone-building exercise (image)

    Science.gov (United States)

    Exercise plays an important role in the retention of bone density in the aging person. Studies show that exercises requiring muscles to pull on bones cause the bones to retain and possibly gain density.

  8. Blood and Bone Marrow Transplant?

    Science.gov (United States)

    ... Topics / Blood and Bone Marrow Transplant Blood and Bone Marrow Transplant Also known as Hematopoietic Stem Cell Transplant , Hematopoietic ... person, called a donor, it is an allogeneic transplant. Blood or bone marrow transplants most commonly are used to treat ...

  9. Healthy Bones Matter

    Science.gov (United States)

    ... Also, women generally have less bone tissue than men. So, it’s especially important for girls to build up their bone “bank account” during their teenage years by exercising regularly and getting enough calcium and vitamin D. What to do for strong bones—today and tomorrow Osteoporosis is usually a ...

  10. Benign bone tumors

    International Nuclear Information System (INIS)

    Gilday, D.L.; Ash, J.M.

    1976-01-01

    There is little information in the literature concerning the role of bone scanning in benign bone neoplasms except for sporadic reports. Since the advent of /sup 99m/Tc-polyphosphate, bone imaging has proven feasible and useful in locating the cause of bone pain, such as in osteoid osteomas, which are not always radiologically apparent, and in evaluating whether or not a radiologic lesion is indeed benign and solitary. Blood-pool images are particularly important in neoplastic disease, since the absence of hyperemia in the immediate postinjection period favors the diagnosis of a benign neoplasm, as does low-grade uptake on the delayed study. The scan, including pinhole magnification images, is especially valuable in diagnosing lesions in the spine and pelvis, which are poorly seen radiologically. We have studied various types of benign bone tumors, including simple and aneurysmal bone cysts, fibrous cortical defects, and nonossifying fibromas, all of which had minimal or no increased uptake of the radiopharmaceutical, unless traumatized. Although osteochondromas and enchondromas showed varied accumulation of activity, the scan was useful in differentiating these from sarcomatous lesions. All osteoid osteomas demonstrated marked activity, and could be accurately located preoperatively, as could the extent of fibrous dysplasia. The bone scan in the reticuloses also showed abnormal accumulation of activity, and aided in arriving at the prognosis and treatment of histiocytic bone lesions

  11. Radiopharmaceuticals for bone scintillators

    International Nuclear Information System (INIS)

    Rey, A.M.

    1994-01-01

    One of the diagnostic techniques used in nuclear medicine is the bone scintiscanning with labelled compounds for obtain skeletal images. The main sections in this work are: (1) bone composition and anatomy;(2)skeletal radiopharmaceutical development;(3)physical properties of radionuclides;(4)biological behaviour and chemical structures;(5)radiopharmaceuticals production for skeletal scintillation;(6)kits;(7)dosimetry and toxicity.tabs

  12. Treated unicameral bone cysts

    International Nuclear Information System (INIS)

    Weinman, J.; Servaes, S.; Anupindi, S.A.

    2013-01-01

    Unicameral bone cysts (UBCs) are a common benign entity involving the metaphysis of growing bone, occurring within the first two decades of life. Assessment of these lesions, both before and after surgery, is performed routinely utilizing radiographs. We present a review of UBCs at various stages of treatment, including both successful and incomplete healing, and describe the imaging findings throughout their postoperative course

  13. Pseudoanaplastic tumors of bone

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Won-Jong [Uijongbu St. Mary Hospital, The Catholic University of Korea, Department of Orthopaedic Surgery, Gyunggido, 480-821 (Korea); Mirra, Joseph M. [Orthopaedic Hospital, Orthopedic Oncology, Los Angeles, California (United States)

    2004-11-01

    To discuss the concept of pseudoanaplastic tumors of bone, which pathologically show hyperchromatism and marked pleomorphism with quite enlarged, pleomorphic nuclei, but with no to extremely rare, typical mitoses, and to propose guidelines for their diagnosis. From a database of 4,262 bone tumors covering from 1971 to 2001, 15 cases of pseudoanaplastic bone tumors (0.35% of total) were retrieved for clinical, radiographic and pathologic review. Postoperative follow-up after surgical treatment was at least 3 years and a maximum of 7 years. There were eight male and seven female patients. Their ages ranged from 10 to 64 years with average of 29.7 years. Pathologic diagnoses of pseudoanaplastic variants of benign bone tumors included: osteoblastoma (4 cases), giant cell tumor (4 cases), chondromyxoid fibroma (3 cases), fibrous dysplasia (2 cases), fibrous cortical defect (1 case) and aneurysmal bone cyst (1 case). Radiography of all cases showed features of a benign bone lesion. Six cases, one case each of osteoblastoma, fibrous dysplasia, aneurysmal bone cyst, chondromyxoid fibroma, giant cell tumor and osteoblastoma, were initially misdiagnosed as osteosarcoma. The remaining cases were referred for a second opinion to rule out sarcoma. Despite the presence of significant cytologic aberrations, none of our cases showed malignant behavior following simple curettage or removal of bony lesions. Our observation justifies the concept of pseudoanaplasia in some benign bone tumors as in benign soft tissue tumors, especially in their late evolutionary stage when bizarre cytologic alterations strongly mimic a sarcoma. (orig.)

  14. Caisson disease of bone.

    Science.gov (United States)

    Gregg, P J; Walder, D N

    1986-09-01

    Caisson disease of bone, which may affect compressed air workers and divers, is characterized by regions of bone and marrow necrosis that may lead to secondary osteoarthrosis of the hip and shoulder joints. A review of the pathologic, radiologic, and clinical aspects demonstrated uncertainties in the exact etiology. Early diagnosis is often not possible because of the delayed appearance of radiologic abnormalities. Research into these two aspects of this condition was carried out by the Medical Research Council Decompression Sickness Research Team in Newcastle upon Tyne over a ten-year period (1972 to 1982). Because no suitable animal model exists for the study of this condition, bone and marrow necrosis was produced by embolism of bone blood vessels with glass microspheres. With this model, it was shown that the presence of bone and marrow necrosis could be detected by bone scintigraphy using 99mTc-MDP and by measuring changes in serum ferritin concentration at a much earlier stage than was possible by radiography. However, only the former method has proved useful in clinical practice. Investigations into the etiology of caisson disease of bone have shown evidence for an increase in marrow fat cell size resulting from hyperoxia. This phenomenon may play a role in the production and localization of gas bubble emboli, which are thought to be the cause of the bone and marrow necrosis.

  15. Children's bone health

    NARCIS (Netherlands)

    I.M. van der Sluis (Inge)

    2002-01-01

    textabstractThe thesis can be divided in two main parts. In the first part (Chapter 2 to 5) bone mineral density, bone metabolism and body composition in healthy children and young adults have been evaluated, while in the second part (Chapter 6 to 10) these issues were studied in children

  16. Unicameral (simple) bone cysts.

    Science.gov (United States)

    Baig, Rafath; Eady, John L

    2006-09-01

    Since their original description by Virchow, simple bone cysts have been studied repeatedly. Although these defects are not true neoplasms, simple bone cysts may create major structural defects of the humerus, femur, and os calcis. They are commonly discovered incidentally when x-rays are taken for other reasons or on presentation due to a pathologic fracture. Various treatment strategies have been employed, but the only reliable predictor of success of any treatment strategy is the age of the patient; those being older than 10 years of age heal their cysts at a higher rate than those under age 10. The goal of management is the formation of a bone that can withstand the stresses of use by the patient without evidence of continued bone destruction as determined by serial radiographic follow-up. The goal is not a normal-appearing x-ray, but a functionally stable bone.

  17. Enzymatic maceration of bone

    DEFF Research Database (Denmark)

    Uhre, Marie-Louise; Eriksen, Anne Marie; Simonsen, Kim Pilkjær

    2015-01-01

    This proof of concept study investigates the removal of soft tissue from human ribs with the use of two common methods: boiling with a laundry detergent and using enzymes. Six individuals were autopsied, and one rib from each individual was removed for testing. Each rib was cut into pieces...... and afterwards macerated by one of the two methods. DNA extraction was performed to see the effect of the macerations on DNA preservation. Furthermore, the bone pieces were examined in a stereomicroscope to assess for any bone damage. The results demonstrated that both methods removed all flesh/soft tissue from...... the bones. The DNA analysis showed that DNA was preserved on all the pieces of bones which were examined. Finally, the investigation suggests that enzyme maceration could be gentler on the bones, as the edges appeared less frayed. The enzyme maceration was also a quicker method; it took three hours compared...

  18. [Biomaterials in bone repair].

    Science.gov (United States)

    Puska, Mervi; Aho, Allan J; Vallittu, Pekka K

    2013-01-01

    In orthopedics, traumatology, and craniofacial surgery, biomaterials should meet the clinical demands of bone that include shape, size and anatomical location of the defect, as well as the physiological load-bearing stresses. Biomaterials are metals, ceramics, plastics or materials of biological origin. In the treatment of large defects, metallic endoprostheses or bone grafts are employed, whereas ceramics in the case of small defects. Plastics are employed on the artificial joint surfaces, in the treatment of vertebral compression fractures, and as biodegradable screws and plates. Porosity, bioactivity, and identical biomechanics to bone are fundamental for achieving a durable, well-bonded, interface between biomaterial and bone. In the case of severe bone treatments, biomaterials should also imply an option to add biologically active substances.

  19. Cartilage and bone neoformation in rabbit carotid bifurcation aneurysms after endovascular coil embolization

    Directory of Open Access Journals (Sweden)

    H Plenk

    2008-11-01

    Full Text Available Occurrence and histomorphology of cartilage and bone neoformations was retrospectively evaluated in rabbit experimental aneurysms after endovascular coil embolization. During product development, 115 carotid bifurcation aneurysms were treated with hydrogel-containing devices (HydroCoil®, n=77; HydroSoft®, n=28; prototype Hydrogel-only, n=10; MicroVentionTerumo, Aliso Viejo, CA. Additional 29 aneurysms were treated with standard (n=22 or with degradable polymer-covered (n=7 platinum coils. After 4 to 52 weeks, the retrieved aneurysms were methylmethacrylate embedded, and ground sections were surface-stained with Rapid Bone Stain and Giemsa solution. Cartilage and/or bone tissue was assessed by light microscopy; respective tissue areas in the aneurysms were determined by computerized histomorphometry. Cartilage neoformation was observed from 26 to 52 weeks. Single chondrocytes to hyaline or fibrous cartilage areas, occupying up to 29% of the aneurysm cavity, were found in 6 aneurysms, treated with HydroCoil (n=4, Hydrogel-only (n=1, and resorbable polymer (n=1 devices. Chondral ossification associated cartilage neoformation in 2 of these 4 HydroCoil-treated aneurysms. Membranous woven and lamellar bone ossicles were observed from 13 to 52 weeks in 7 aneurysms, treated with HydroCoil (n=3 and platinum coil (n=4 devices. Altogether, cartilage and/or bone neoformation was observed in 13 (9% of 144 rabbit bifurcation aneurysms treated with various embolic devices. Incidence was low until 26 weeks, but increased at 52 weeks in both, HydroCoil and standard platinum coil treated aneurysms. As the neoformations were predominantly located in proximity to the aneurysm neck, they could be related to the long-term mechanobiology of cell differentiation during fibrovascular healing of blood flow-exposed embolized aneurysms.

  20. Perfluorodecalin and bone regeneration

    Directory of Open Access Journals (Sweden)

    F Tamimi

    2013-01-01

    Full Text Available Perfluorodecalin (PFD is a chemically and biologically inert biomaterial and, as many perfluorocarbons, is also hydrophobic, radiopaque and has a high solute capacity for gases such as oxygen. In this article we have demonstrated, both in vitro and in vivo, that PFD may significantly enhance bone regeneration. Firstly, the potential benefit of PFD was demonstrated by prolonging the survival of bone marrow cells cultured in anaerobic conditions. These findings translated in vivo, where PFD incorporated into bone-marrow-loaded 3D-printed scaffolds substantially improved their capacity to regenerate bone. Secondly, in addition to biological applications, we have also shown that PFD improves the radiopacity of bone regeneration biomaterials, a key feature required for the visualisation of biomaterials during and after surgical implantation. Finally, we have shown how the extreme hydrophobicity of PFD enables the fabrication of highly cohesive self-setting injectable biomaterials for bone regeneration. In conclusion, perfluorocarbons would appear to be highly beneficial additives to a number of regenerative biomaterials, especially those for bone regeneration.

  1. Gut microbiome and bone.

    Science.gov (United States)

    Ibáñez, Lidia; Rouleau, Matthieu; Wakkach, Abdelilah; Blin-Wakkach, Claudine

    2018-04-11

    The gut microbiome is now viewed as a tissue that interacts bidirectionally with the gastrointestinal, immune, endocrine and nervous systems, affecting the cellular responses in numerous organs. Evidence is accumulating of gut microbiome involvement in a growing number of pathophysiological processes, many of which are linked to inflammatory responses. More specifically, data acquired over the last decade point to effects of the gut microbiome on bone mass regulation and on the development of bone diseases (such as osteoporosis) and of inflammatory joint diseases characterized by bone loss. Mice lacking a gut microbiome have bone mass alteration that can be reversed by gut recolonization. Changes in the gut microbiome composition have been reported in mice with estrogen-deficiency osteoporosis and have also been found in a few studies in humans. Probiotic therapy decreases bone loss in estrogen-deficient animals. The effect of the gut microbiome on bone tissue involves complex mechanisms including modulation of CD4 + T cell activation, control of osteoclastogenic cytokine production and modifications in hormone levels. This complexity may contribute to explain the discrepancies observed betwwen some studies whose results vary depending on the age, gender, genetic background and treatment duration. Further elucidation of the mechanisms involved is needed. However, the available data hold promise that gut microbiome manipulation may prove of interest in the management of bone diseases. Copyright © 2018 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  2. Bone scan in pediatrics

    International Nuclear Information System (INIS)

    Gordon, I.; Peters, A.M.

    1987-01-01

    In 1984, a survey carried out in 21 countries in Europe showed that bone scintigraphy comprised 16% of all paediatric radioisotope scans. Although the value of bone scans in paediatrics is potentially great, their quality varies greatly, and poor-quality images are giving this valuable technique a bad reputation. The handling of children requires a sensitive staff and the provision of a few simple inexpensive items of distraction. Attempting simply to scan a child between two adult patients in a busy general department is a recipe for an unhappy, uncooperative child with the probable result of poor images. The intravenous injection of isotope should be given adjacent to the gamma camera room, unless dynamic scans are required, so that the child does not associate the camera with the injection. This injection is best carried out by someone competent in paediatric venipunture; the entire procedure should be explained to the child and parent, who should remain with child throughout. It is naive to think that silence makes for a cooperative child. The sensitivity of bone-seeking radioisotope tracers and the marked improvement in gamma camera resolution has allowed the bone scanning to become an integrated technique in the assessment of children suspected of suffering from pathological bone conditions. The tracer most commonly used for routine bone scanning is 99m Tc diphosphonate (MDP); other isotopes used include 99m Tc colloid for bone marrow scans and 67 Ga citrate and 111 In white blood cells ( 111 In WBC) for investigation of inflammatory/infective lesions

  3. Mechanotransduction by bone cells in vitro: mechanobiology of bone tissue

    NARCIS (Netherlands)

    Mullender, M.; El Haj, A.J.; Yang, Y.; van Duin, M.A.; Burger, E.H.; Klein-Nulend, J.

    2004-01-01

    Mechanical force plays an important role in the regulation of bone remodelling in intact bone and bone repair. In vitro, bone cells demonstrate a high responsiveness to mechanical stimuli. Much debate exists regarding the critical components in the load profile and whether different components, such

  4. Probabilistic Modeling of High-Temperature Material Properties of a 5-Harness 0/90 Sylramic Fiber/ CVI-SiC/ MI-SiC Woven Composite

    Science.gov (United States)

    Nagpal, Vinod K.; Tong, Michael; Murthy, P. L. N.; Mital, Subodh

    1998-01-01

    An integrated probabilistic approach has been developed to assess composites for high temperature applications. This approach was used to determine thermal and mechanical properties and their probabilistic distributions of a 5-harness 0/90 Sylramic fiber/CVI-SiC/Mi-SiC woven Ceramic Matrix Composite (CMC) at high temperatures. The purpose of developing this approach was to generate quantitative probabilistic information on this CMC to help complete the evaluation for its potential application for HSCT combustor liner. This approach quantified the influences of uncertainties inherent in constituent properties called primitive variables on selected key response variables of the CMC at 2200 F. The quantitative information is presented in the form of Cumulative Density Functions (CDFs). Probability Density Functions (PDFS) and primitive variable sensitivities on response. Results indicate that the scatters in response variables were reduced by 30-50% when the uncertainties in the primitive variables, which showed the most influence, were reduced by 50%.

  5. Bearing Stress at Failure of Double-Lap Hybrid Joints in Woven Fabric Kenaf Fiber Composite Plates under Quasi-static Loading

    Directory of Open Access Journals (Sweden)

    Lee Sim Yee

    2017-01-01

    Full Text Available The present paper is focused on the bearing stress at failure of double-lap woven fabric kenaf fiber reinforced polymer (KFRP hybrid bonded-bolted joints in experimental frameworks. The effects of different normalized plate width (plate width/hole diameter, W/d, lay-up types and bolt loads were incorporated in current study as specified in testing series. Generally, hybrid joint coupons separated within adhesive layer prior to net-tension failure or bearing/net-tension failure. The bearing stress at failure increased as W/d ratio increment, critical W/d is given as four and three in clamped and finger tight condition respectively. Lay-up types present insignificant effect to bearing stress at failure due to low volume fiber fraction in kenaf fiber composites. Combination of thicker and clamped conditions plate demonstrated greater bearing stress than equivalent finger-tight (FT conditions due to higher load transferred from friction, as expected.

  6. Making silent bones speak

    DEFF Research Database (Denmark)

    Ivanovaite, Livija; Jensen, Mathias Paul Bjørnevad; Philippsen, Bente

    2017-01-01

    , Obšrūtai and Kamšai were subjected to the AMS dating, tandem mass spectrometry for animal species identification as well as technological and use-wear analysis. The results revealed that all four bone points could be dated to the Boreal period and imply early-to-middle Mesolithic dates. Harpoons from...... of the present research, the paper shortly describes other scientific methods which could be applied to orphaned bone and antler tools including biomolecular and stable isotope analysis. Digital recording methods can be useful for bone artefact recording. This is relevant today, as the demand for good quality...

  7. Bone scintigraphy for horses

    International Nuclear Information System (INIS)

    Jahn, Werner

    2010-01-01

    Scintigraphy (bone scan) is being used approximately since 1980 in the horse under general anaesthesia. With the construction of custom-made overhead gantries for gamma-cameras scintigraphy found widespread entry in big equine referral hospitals for bone-scanning of the standing horse. Indications for the use of a bone scan in the horse are inflammatory alterations in the locomotor apparatus. It is primarily used for diagnosis of lameness of unknown origin, suspect of stress fracture or hairline fracture and for horses with bad riding comfort with suspected painful lesions in the spine. (orig.)

  8. Bone changes in endometrosis

    International Nuclear Information System (INIS)

    Jensen, P.S.; Orphanoudakis, S.C.; Hutchinson-Williams, K.; Lewis, A.B.; Lovett, L.; Polan, M.L.; DeCherney, A.H.; Comite, F.

    1989-01-01

    In this study, quantitative CT is used to measure bone in the distal radius in normal women, women with endometriosis who had not been treated, and women with endometriosis who had been treated with danazol--an anabolic (androgen) steroid. Measurements of cortex and trabeculae indicate that untreated women have decreased bone mass (1125 HU and 160 HU, respectively), compared with bone mass in normal women (1269 HU and 257 HU; P < .05) and treated women (1238 HU and 255 HU). This finding is important because the most effective way to reduce the complications of osteoporosis is identification of risk factors, prevention, and early treatment

  9. Periodontal bone lesions

    International Nuclear Information System (INIS)

    Linden, L.W.J. van der.

    1985-01-01

    In the course of life the periodontum is subject to changes which may be physiological or pathological. Intraoral radiographs give insight into the hard structures of the dentomaxillar region and provides information on lesions in the bone of the periodontum in that they show radiopacities and radiolucencies caused by such lesions. In this thesis the relation is investigated between the true shape and dimensions of periodontal bone lesions and their radiographic images. A method is developed and tested of making standardized and reproducible radiographs suitable for longitudinal studies of periodontal lesions. Also the possibility is demonstrated of an objective and reproducible interpretation of radiographic characteristics of periodontal bone lesions. (Auth.)

  10. Posttranslational heterogeneity of bone alkaline phosphatase in metabolic bone disease.

    Science.gov (United States)

    Langlois, M R; Delanghe, J R; Kaufman, J M; De Buyzere, M L; Van Hoecke, M J; Leroux-Roels, G G

    1994-09-01

    Bone alkaline phosphatase is a marker of osteoblast activity. In order to study the posttranscriptional modification (glycosylation) of bone alkaline phosphatase in bone disease, we investigated the relationship between mass and catalytic activity of bone alkaline phosphatase in patients with osteoporosis and hyperthyroidism. Serum bone alkaline phosphatase activity was measured after lectin precipitation using the Iso-ALP test kit. Mass concentration of bone alkaline phosphatase was determined with an immunoradiometric assay (Tandem-R Ostase). In general, serum bone alkaline phosphatase mass and activity concentration correlated well. The activity : mass ratio of bone alkaline phosphatase was low in hyperthyroidism. Activation energy of the reaction catalysed by bone alkaline phosphatase was high in osteoporosis and in hyperthyroidism. Experiments with neuraminidase digestion further demonstrated that the thermodynamic heterogeneity of bone alkaline phosphatase can be explained by a different glycosylation of the enzyme.

  11. Radionuclide bone image in growing and stable bone island

    International Nuclear Information System (INIS)

    Go, R.T.; El-Khoury, G.Y.; Iowa Univ., Iowa City; Wehbe, M.A.

    1980-01-01

    A normal radionuclide bone image can facilitate distinction between a bone island and significant pathologic processes, especially an osteoblastic metastasis. This distinction becomes more crucial when growth is detected in an isolated sclerotic bone lesion or if a relatively large sclerotic lesion is detected de novo in patients with a known neoplasm. This report presents three patients with isolated bone islands: two with interval growth, the other with a relatively large stable lesion; all showing a normal radionuclide bone image. (orig.) [de

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  14. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  16. Bone scan indications in oncology

    International Nuclear Information System (INIS)

    Rocha, A.F.G. da; Marquiotti, M.

    1986-01-01

    The scintigraphic method is described and a critical analysis of its value in the research of bone metastases is presented. The method validity, the positivity of bone scan for metastases at the first examination and the preferencial distribution metastases in skeleton are related.Bone pain and the results of bone scintigram are correlated. (M.A.C.) [pt

  17. Craniotomy Frontal Bone Defect

    African Journals Online (AJOL)

    2018-03-01

    Mar 1, 2018 ... Defect reconstruction and fixation of the graft: The defect of ... where all loose fragments of fractured frontal bone was removed via the ... Mandible. • Ilium. • Allograft ... pediatric patients owing to skull growth. Thus, autologous ...

  18. Preoperative bone scans

    International Nuclear Information System (INIS)

    Charkes, N.D.; Malmud, L.S.; Caswell, T.; Goldman, L.; Hall, J.; Lauby, V.; Lightfoot, W.; Maier, W.; Rosemond, G.

    1975-01-01

    Strontium nitrate Sr-87m bone scans were made preoperatively in a group of women with suspected breast cancer, 35 of whom subsequently underwent radical mastectomy. In 3 of the 35 (9 percent), the scans were abnormal despite the absence of clinical or roentgenographic evidence of metastatic disease. All three patients had extensive axillary lymph node involvement by tumor, and went on to have additional bone metastases, from which one died. Roentgenograms failed to detect the metastases in all three. Occult bone metastases account in part for the failure of radical mastectomy to cure some patients with breast cancer. It is recommended that all candidates for radical mastectomy have a preoperative bone scan. (U.S.)

  19. Sodium and bone health

    DEFF Research Database (Denmark)

    Teucher, B.; Dainty, J. R.; Spinks, C. A.

    2008-01-01

    High salt intake is a well-recognized risk factor for osteoporosis because it induces calciuria, but the effects of salt on calcium metabolism and the potential impact on bone health in postmenopausal women have not been fully characterized. This study investigated adaptive mechanisms in response.......9 Versus 11.2 g) diets, reflecting lower and upper intakes in post men opausal women consuming a Western-style diet, were provided. Stable isotope labeling techniques were used to measure calcium absorption and excretion, compartmental modeling was undertaken to estimate bone calcium balance......, and biomarkers of bone formation and resorption were measured in blood and urine. Moderately high salt intake (11.2 g/d) elicited a significant increase in urinary calcium excretion (p = 0.0008) and significantly affected bone calcium balance with the high calcium diet 0.024). Efficiency of calcium absorption...

  20. The petrous bone

    DEFF Research Database (Denmark)

    Jørkov, Marie Louise Schjellerup; Heinemeier, Jan; Lynnerup, Niels

    2009-01-01

    Intraskeletal variation in the composition of carbon (delta(13)C) and nitrogen (delta(15)N) stable isotopes measured in collagen is tested from various human bones and dentine. Samples were taken from the femur, rib, and petrous part of the temporal bone from well-preserved skeletons of both adults...... (n = 34) and subadults (n = 24). Additional samples of dentine from the root of 1st molars were taken from 16 individuals. The skeletal material is from a medieval cemetery (AD 1200-1573) in Holbaek, Denmark. Our results indicate that the petrous bone has an isotopic signal that differs significantly...... from that of femur and rib within the single skeleton (P bone and the 1st molar. The intraskeletal variation may reflect differences...

  1. Bone and glucocorticoids.

    Science.gov (United States)

    Briot, Karine

    2018-06-01

    Corticosteroid-induced osteoporosis is the most common form of secondary osteoporosis and the most frequent cause of osteoporosis in young people. Bone loss and fracture risk increase rapidly after the initiation of corticosteroid therapy and are proportional to dose and treatment duration. The increase in fracture risk is not fully assessed by bone mineral density measurement, as it is also related to impaired bone quality and increased risk of falls. Prevention should be considered in all patients beginning corticosteroid therapy, especially as the underlying inflammation in itself impairs bone quality. Bisphosphonates and teriparatide have shown efficacy in the treatment of corticosteroid-induced osteoporosis. Several national and international guidelines are available to improve management of corticosteroid-induced osteoporosis, which remains inadequate. Duration of anti-osteoporotic treatment should be discussed at the individual level, depending on the subject's characteristics and on the progression of the underlying inflammation. Copyright © 2018. Published by Elsevier Masson SAS.

  2. Bone marrow transplant

    Science.gov (United States)

    ... Arrange medical leave from work Take care of bank or financial statements Arrange care of pets Arrange ... Bleeding during cancer treatment Bone marrow transplant - discharge Central venous catheter - dressing change Central venous catheter - flushing ...

  3. Bone tumor imaging

    International Nuclear Information System (INIS)

    McLeod, R.A.; Berquist, T.H.

    1988-01-01

    The emphasis of this chapter is on the contribution of computed tomography (CT) and magnetic resonance imaging (MRI) to the care of patients with bone neoplasms. These modalities are emphasized because of their relative newness and not because they are considered more significant than the other more established examinations. Routine radiographs remain the most informative and essential imaging procedures for the diagnosis of bone tumors

  4. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  5. Bone changes in leprosy

    Energy Technology Data Exchange (ETDEWEB)

    Mende, B.; Stein, G.; Kreysel, H.W.

    1985-02-01

    Bone lesions is a frequent organic manifestation in leprosy. Osseal destructions caused by granulomatous process induced by M. leprae are so-called specific lesions in contrast to non specific lesions based on nerval or arterial diseases. The specific osseal alterations are characterized by cystic brightenings in roentgenograms while non specific osseal changes show absorption to bone structure as akroosterolysis and osteoporosis. Typical radiologic findings in different stages of mutilation are demonstrated.

  6. Treated unicameral bone cysts.

    Science.gov (United States)

    Weinman, J; Servaes, S; Anupindi, S A

    2013-06-01

    Unicameral bone cysts (UBCs) are a common benign entity involving the metaphysis of growing bone, occurring within the first two decades of life. Assessment of these lesions, both before and after surgery, is performed routinely utilizing radiographs. We present a review of UBCs at various stages of treatment, including both successful and incomplete healing, and describe the imaging findings throughout their postoperative course. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  7. Uranium in fossil bones

    International Nuclear Information System (INIS)

    Koul, S.L.

    1978-01-01

    An attempt has been made to determine the uranium content and thus the age of certain fossil bones Haritalyangarh (Himachal Pradesh), India. The results indicate that bones rich in apatite are also rich in uranium, and that the radioactivity is due to radionuclides in the uranium series. The larger animals apparently have a higher concentration of uranium than the small. The dating of a fossil jaw (elephant) places it in the Pleistocene. (Auth.)

  8. Diffuse lymphangiomatosis of bone

    International Nuclear Information System (INIS)

    Maki, D.D.; Nesbit, M.E.; Griffiths, H.J.

    1999-01-01

    Two cases of lymphangiomatosis of bone, a very rare systemic condition characterised by both skeletal and parenchymal lesions, are presented. The skeletal changes have an appearance similar to haemangiomas in the spine, and soap-bubbly lesions in the flat bones. One case carried the diagnosis of eosinophilic granuloma for 18 years. The findings on MRI, which have not been previously well-established, are discussed. Copyright (1999) Blackwell Science Pty Ltd

  9. Bone changes in leprosy

    International Nuclear Information System (INIS)

    Mende, B.; Stein, G.; Kreysel, H.W.

    1985-01-01

    Bone lesions is a frequent organic manifestation in leprosy. Osseal destructions caused by granulomatous process induced by M. leprae are so-called specific lesions in contrast to non specific lesions based on nerval or arterial diseases. The specific osseal alterations are characterized by cystic brightenings in roentgenograms while non specific osseal changes show absorption to bone structure as akroosterolysis and osteoporosis. Typical radiologic findings in different stages of mutilation are demonstrated. (orig.) [de

  10. Bone scintigraphy in children

    International Nuclear Information System (INIS)

    Mann, M.D.

    2004-01-01

    Full text: Bone scintigraphy is an integral part of the evaluation of bone disease in children. Common indications are suspected infection or inflammation, bone tumours and metastases, trauma and avascular necrosis. In all these disorders the sensitivity of scintigraphy is high. Gallium scintigraphy is often useful in children with clinical signs of infection not responding to treatment but the radiation dose is high. High quality images are essential. They depend on the full participation and co-operation of the child, parents and radiographers, the administration of appropriate analgesics, gentle but firm handling of the child, the injection of the appropriate amount of radiopharmaceutical, good positioning and immobilization, optimised equipment, and the acquisition of a suitable number of counts in an appropriate matrix size. Unless there are specific reasons for not doing so, we routinely perform two phase bone scintigraphy. This usually involves whole body blood pool and delayed images followed by static images of selected areas and, less often, pinhole images or SPECT. The interpretation of bone scan images in children requires knowledge of the age dependent differences in bone metabolism in the developing skeleton and the effect on the appearance of the maturing skeleton. (author)

  11. Bone changes in phenylketonuria

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Hyun Sook; Lee, Hae Kyung; Kwon, Kui Hyang; Choi, Deuk Lin; Lee, Dong Hwan [Soonchunhyang Univ., Seoul (Korea, Republic of). Hospital

    1998-02-01

    While treating 14 phenylketonurial (PKU) patients, we evaluated bone density, changes in bone age, and bony changes such as spiculation or metaphyseal widening. A total of 14 PKU patients aged between 1 month and 14 years (mean, 6.4 years) were under dietary treatment. Eight and eleven patients underwent radiography of the left hand and wrist and bone densitometry (BMD) of the lumbar spine, respectively. The results were reviewed with regard to abnormal bony changes, delayed bone age, and osteopenia. Patients were assigned to either the early or late treatment group, depending on whether or not dietary therapy was started before 3 months of age. Those in whom a blood phenylalanine level of under 10 mg/dl was maintained were assigned to the good control group; others were classified as variable control. The findings of radiographs of the left hand and lumbar BMD were evaluated in relation to the time of dietary therapy, and adequacy of treatment. None of the 14 PKU patients who underwent dietary therapy had bony abnormalities such as spiculation or metaphyseal widening. In four of the 11, bone age was at least one year less than chronological age, and on lumbar BMD, osteoporosis was seen. For the evaluation of bone change in PKU patients, plain radiography and BMD are thus complementary. (author). 18 refs., 1 tab., 2 figs.

  12. Bone changes in phenylketonuria

    International Nuclear Information System (INIS)

    Hong, Hyun Sook; Lee, Hae Kyung; Kwon, Kui Hyang; Choi, Deuk Lin; Lee, Dong Hwan

    1998-01-01

    While treating 14 phenylketonurial (PKU) patients, we evaluated bone density, changes in bone age, and bony changes such as spiculation or metaphyseal widening. A total of 14 PKU patients aged between 1 month and 14 years (mean, 6.4 years) were under dietary treatment. Eight and eleven patients underwent radiography of the left hand and wrist and bone densitometry (BMD) of the lumbar spine, respectively. The results were reviewed with regard to abnormal bony changes, delayed bone age, and osteopenia. Patients were assigned to either the early or late treatment group, depending on whether or not dietary therapy was started before 3 months of age. Those in whom a blood phenylalanine level of under 10 mg/dl was maintained were assigned to the good control group; others were classified as variable control. The findings of radiographs of the left hand and lumbar BMD were evaluated in relation to the time of dietary therapy, and adequacy of treatment. None of the 14 PKU patients who underwent dietary therapy had bony abnormalities such as spiculation or metaphyseal widening. In four of the 11, bone age was at least one year less than chronological age, and on lumbar BMD, osteoporosis was seen. For the evaluation of bone change in PKU patients, plain radiography and BMD are thus complementary. (author). 18 refs., 1 tab., 2 figs

  13. Guided bone regeneration : the influence of barrier membranes on bone grafts and bone defects

    NARCIS (Netherlands)

    Gielkens, Pepijn Frans Marie

    2008-01-01

    Guided bone regeneration (GBR) can be described as the use of a barrier membrane to provide a space available for new bone formation in a bony defect. The barrier membrane protects the defect from in-growth of soft tissue cells and allows bone progenitor cells to develop bone within a blood clot

  14. Recombinant human bone morphogenetic protein induces bone formation

    International Nuclear Information System (INIS)

    Wang, E.A.; Rosen, V.; D'Alessandro, J.S.; Bauduy, M.; Cordes, P.; Harada, T.; Israel, D.I.; Hewick, R.M.; Kerns, K.M.; LaPan, P.; Luxenberg, D.P.; McQuaid, D.; Moutsatsos, I.K.; Nove, J.; Wozney, J.M.

    1990-01-01

    The authors have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 μg of partially purified recombinant human BMP-2A resulted in cartilage by day 7 and bone formation by day 14. The time at which bone formation occurred was dependent on the amount of BMP-2A implanted; at high doses bone formation could be observed at 5 days. The cartilage- and bone-inductive activity of the recombinant BMP-2A is histologically indistinguishable from that of bone extracts. Thus, recombinant BMP-2A has therapeutic potential to promote de novo bone formation in humans

  15. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    Full Text Available Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.Our findings suggested a new bioactive

  16. Evolutionary Patterns of Bone Histology and Bone Compactness in Xenarthran Mammal Long Bones

    OpenAIRE

    Straehl, Fiona; Scheyer, Torsten; Forasiepi, Analia Marta; Macphee, Ross; Sanchez-Villagra, Marcelo

    2015-01-01

    Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xen...

  17. Bone marrow transplantation immunology

    International Nuclear Information System (INIS)

    Trentin, J.J.; Kiessling, R.; Wigzell, H.; Gallagher, M.T.; Datta, S.K.; Kulkarni, S.S.

    1977-01-01

    Tests were made to determine whether genetic resistance (GR) to bone marrow transplantation represents a natural lymphoma-leukemia defense mechanism, as follows: (C57 x AKR) F 1 hybrid mice show GR to C57 parental bone marrow cells, but not to AKR parental bone marrow cells (C3H x AKR) F 1 hybrids show no GR to bone marrow transplantation from either parental strain. However, transplantation of AKR lymphoma cells into lethally irradiated ''resistant'' (C57 x AKR) F 1 and ''nonresistant'' (C3H x AKR) F 1 hybrids produced lymphomatous spleen colonies in ''nonresistant'' hybrids but not in ''resistant'' hybrids. Thus ''resistant'' (C57 x AKR) F 1 hybrids can recognize and reject AKR lymphoma cells, but not normal AKR bone marrow cells. A normal biologic role of leukemia-lymphoma surveillance was postulated for genetic resistance to marrow transplantation, directed at antigens which, like TL, are expressed on normal hemopoietic cells of some strains, but only on leukemic cells of other strains

  18. Fibrosarcoma of bone

    International Nuclear Information System (INIS)

    Taconis, W.K.

    1982-01-01

    A general clinical-radiological description of fibrosarcoma of bone, including tumours with features of malignant fibrous histiocytoma is presented. 104 patients with fibrosarcoma of the long bones are analysed in terms of age and sex distribution, symptoms, duration of symptoms and tumour localization. The radiological findings obtained in patients with fibrosarcoma of the long bones are discussed. The treatment and course of fibrosarcoma of the long bones are discussed. Data on the type of therapy given were available on 103 patients: 67 were treated by ablative surgery either immediately or within three months of preceding local surgery and/or radiotherapy. In the remaining 36 cases treatment consisted of local surgery, radiotherapy or a combination of these, or non-curative (palliative) treatment. In a few cases ablative surgery was performed at a later stage. 13 patients with fibrosarcoma of the axial skeleton and 14 with fibrosarcoma of the jaws are considered. A causistic discussion of patients with a secondary fibrosarcoma is presented. Secondary fibrosarcoma was found in a total of 19 patients (14%); 4 after irradiation. The features of significance for the course of the disease are discussed: general features such as age and sex, tumour localization in the long bones, presence or absence of a pathological fracture, and the radiological and histological characteristics of the tumour. The type of therapy and the occurrence of lung metastases in relation to the course of the disease is also discussed. (Auth.)

  19. [Bone Cell Biology Assessed by Microscopic Approach. Bone histomorphometry of remodeling, modeling and minimodeling].

    Science.gov (United States)

    Yamamoto, Noriaki; Shimakura, Taketoshi; Takahashi, Hideaki

    2015-10-01

    Bone histomorphometry is defined as a quantitative evaluation of bone remodeling. In bone remodeling, bone resorption and bone formation are coupled with scalloped cement lines. Another mechanism of bone formation is minimodeling which bone formation and resorption are independent. The finding of minimodeling appeared in special condition with metabolic bone disease or anabolic agents. We need further study for minimodeling feature and mechanism.

  20. Relative 238Pu content of bone and bone marrow

    International Nuclear Information System (INIS)

    McClanahan, B.J.

    1979-01-01

    Selected bones from a dog that inhaled 238 PuO 2 were subjected to ultrasonic cell disruption to separate the marrow elements from bone, in order to determine the plutonium content of the two components of the skeleton

  1. Analysis of bone mineral density of human bones for strength ...

    Indian Academy of Sciences (India)

    Different types of bone strength are required for various ... To statically analyse various methods to find BMD and related material ... bone study for research purpose. ..... and Dagoberto Vela Arvizo 2007 A qualitative stress analysis of a cross ...

  2. Fibrous dysplasia of bone

    International Nuclear Information System (INIS)

    Kim, Kyung Soo; Lee, Sang Wook; Cho, Young Jun; Kim, Young Sook

    1983-01-01

    Fibrous dysplasia of bone is a skeletal development anomaly of unknown etiology characterized by single or multiple areas of fibrous tissue replacement of medullary cavity of one or more bones. The disease may be localized to single bone (monostotic form) or may affect multiple bones (polyostotic form). Eighteen cases of fibrous dysplasia diagnosed by roentgenlogic or histologic assessment at Chosun University Hospital, Chosun University Hospital and Kwangju Christian Hospital during recent ten tears were analyzed clinically and radiologically. The results were as follows: 1. 16 case of them had monostotic involvement, and 2 cases showed polyostotic disease, but none of our series presented Albright's syndrome. 2. The male to female ratio in this series was 10 : 8, but then 2 polyostotic forms of them were females. In age distribution, peak incidence at the time of diagnosis was in the age group of second decade (10 cases). 3. Maxilla (6 cases) and femur (4 case) were frequently involved sites in patients with monostotic lesion, whereas polyostotic lesions diffusely affected skull, pelvis, ribs and limb bones. 4. The clinical symptoms according to the extent and site of disease were very variable, which were localized painless or painful swelling, nasal obstruction, deformity of face or extremity and incidentally during routine roentgen study. 5. The chemical abnormality of blood serum was moderate degree of elevated serum alkaline phosphatase in only one patients with monostotic lesion. 6. The main radiologic findings of fibrous dysplasia were relatively well circumscribed single or multiloculated cystilike appearance, bone expansion, cortical thinning and/or erosion, bony deformity and pathologic fracture, but especially in maxilla, dense homogenous area with expanding lesion was observed in our series

  3. Prebiotics and Bone.

    Science.gov (United States)

    Whisner, Corrie M; Weaver, Connie M

    2017-01-01

    Recent advancements in food science have resulted in the extraction and synthesis of novel dietary fibers or prebiotics. Subsequently, great interest has emerged in developing strategies to improve metabolic conditions like osteoporosis by modulating the intestinal microbiome with fiber. Prebiotics have been shown to increase calcium absorption in the lower gut of both animals and humans as well as improve measures of bone mineral density and strength in rodent models. Fewer data are available in humans, but data from growing children and postmenopausal women suggest that prebiotics have both short- and long-term effects that beneficially affect bone turnover and mineral accretion in the skeleton. Currently, the exact mechanism by which these products elicit their effects on bone is poorly understood, but emerging data suggest that the gut microbiota may be involved in one or more direct and indirect pathways. The most well-accepted mechanism is through microbial fermentation of prebiotics which results in the production of short-chain fatty acids and a concomitant decrease in pH which increases the bioavailability of calcium in the colon. While other mechanisms may be eliciting a prebiotic effect on bone, the current data suggest that novel dietary fibers may be an affordable and effective method of maximizing mineral accretion in growing children and preventing bone loss in later years when osteoporosis is a greater risk. This chapter will discuss the dynamic role of prebiotics in bone health by discussing the current state of the art, addressing gaps in knowledge and their role in public health.

  4. Bone pathology inpsoriatic arthritis

    Directory of Open Access Journals (Sweden)

    V. V. Badokin

    2007-01-01

    Full Text Available Objective. To study different variants of osteolysis in pts with psoriatic arthritis (PA and to reveal their relationship with other clinico-radiological features of joint damage. Material and methods. 370 pts with definite PA having different variants of joint damage were included. Radiological examination of bones and joints (in some cases large picture frame was performed. Morphological evaluation of synovial biopsies was done in 34 pts with PA and 10 pts with rheumatoid arthritis (RA. Results. Different types of osteolysis were revealed in 80 (21,6% pts. Osteolytic variant of joint damage was present in 29 pts. 33 pts had acral, 48 — intra-articular osteolysis and 16 - true bone atrophy. Frequency and intensity of bone resorption were associated with severity of PA. Acral osteolysis correlated with arthritis of distal interphalangeal joints and onychodystrophy. Intra-articular osteolysis was most often present in distal interphalangeal joints of hands and metacarpophalangeal joints (39,6% and 41,7% respectively. Characteristic feature of PA was combination of prominent resorption with formation of bone ankylosis and periosteal reaction. Ankylosis was present in 33,3% of pts with intra-articular osteolysis and in 60% of pts with combination of different osteolysis variants. Systemic reaction of microcirculation in synovial biopsies was most prominent in osteolytic variant: marked thickening of capillary and venule basal membrane with high level of acid phosphatase, increased capillary and precapillary blood flow with stasis features, vascular lymphocyte and macrophage infiltration, productive vasculitis with annular wall thickening, thrombovasculitis and villi deep layer sclerosis. Conclusion. Different variants of osteolysis show bone involvement in PA. Acral and intra- articular osteolysis association with bone ankylosis and periostitis proves their common pathogenetic entity.

  5. Biochemical markers of bone turnover

    International Nuclear Information System (INIS)

    Kim, Deog Yoon

    1999-01-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays

  6. Is cortical bone hip? What determines cortical bone properties?

    Science.gov (United States)

    Epstein, Sol

    2007-07-01

    Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

  7. Bone - marrow postirradiation syndrome

    International Nuclear Information System (INIS)

    Sesztakova, E.; Bilek, J.; Benova, K.; Novakova, J.; Culenova, K.

    2006-01-01

    Quantitative and qualitative changes in haemopoietic cells in chicken bone Marrow were investigated after acute single irradiation with doses 4.5 Gy and 5 Gy. Samples of bone marrow were obtained from proximal femoral epiphysis of decapitated chickens. Marrow smears were prepared and stained according to Pappenheim. Qualitative examination of myelogram showed proliferation of adipose tissue, hypocellularity, caryolyosis, caryorexis, disintegration of cells and proliferation of cells which could not be differentiated. Quantitative examination revealed high radiosensitivity of blast cells and lymphocytes shortly after irradiation. (authors)

  8. HEEL BONE RECONSTRUCTIVE OSTEOSYNTHESIS

    Directory of Open Access Journals (Sweden)

    A. N. Svetashov

    2010-01-01

    Full Text Available To detect the most appropriate to heel bone injury severity variants of reconstructive osteosynthesis it was analyzed treatment results of 56 patients. In 15 (26.8% patients classic methods of surgical service were applied, in 41 (73.2% cases to restore the defect porous implants were used. Osteosynthesis without heel bone plastic restoration accomplishment was ineffective in 60% patients from control group. Reconstructive osteosynthesis method ensures long-term good functional effect of rehabilitation in 96.4% patients from the basic group.

  9. Solitary (unicameral) bone cyst

    International Nuclear Information System (INIS)

    Struhl, S.; Edelson, C.; Pritzker, H.; Seimon, L.P.; Dorfman, H.D.; Montefiore Medical Center, Bronx, NY

    1989-01-01

    The fallen fragment sign is a prominent radiologic feature in a minority of cases of unicameral bone cyst (20% in this series). This sign is always associated with pathologic fracture. Intramedullary fracture fragments may be single or multiple and may or may not be entirely dislodged from overlying periosteum. The finding appears limited to unicameral bone cysts in patients with open physes. When present, the fallen fragment is a pathognomonic finding as it defines the interior of the cyst as nonsolid. (orig./GDG)

  10. Scanning of bone metastases

    International Nuclear Information System (INIS)

    Robillard, J.

    1977-01-01

    The Centers against cancer of Caen, Angers, Montpellier, Strasbourg and 'the Curie Foundation' have confronted their experience in detection of bone metastases by total body scanning. From the investigation by this procedure, of 1,467 patients with cancer, it results: the confrontation between radio and scanning shows a rate of false positive and false negative identical to the literature ones; the countage scanning allows to reduce the number of false positive; scanning allows to direct bone biopsy and to improve efficiency of histological examination [fr

  11. Significance of bone scintollography

    International Nuclear Information System (INIS)

    Wioland, M.; Milhaud, G.

    1985-01-01

    Artificial radioactivity enables visualisation of the principal organs in the forms of scintiscans, introduces a new order of sensitivity in quantitative hormonal analysis, thanks to radio-immunology and remains unrivalled in compartmental analyses of the various metabolism. The diagnosis of local skeletal conditions is reviewed and the indications for this quantitative examination are described for the diagnosis of numerous bone metabolic diseases. Finally, mono- and bi- photonic absorptiometry, the latest developments in isotopic techniques, are introduced. They are likely to provide numerical data on the state of mineralisation of bone tissue. The use of these nuclear techniques for the diagnosis and surveillance of osteoporosis is detailed [fr

  12. Hydrated disease of bone

    International Nuclear Information System (INIS)

    Mishwani, A.H.; Ahmed, M.; Anwar, S.D.

    2003-01-01

    A case of primary hydatid disease of the right femur is reported that presented with pathological fracture and was diagnosed at the time of exploration for biopsy. The patient was treated by removal of all cysts, irrigation with colloidal solution, bone grafting and immobilization of the fracture followed by four cycles of oral Albendazole. Eosinophilia and serological tests reverted to normal but the patient died due to acute myocardial infarction six months later. This uncommon condition should be considered in the differential diagnosis of pathological fractures, bone pain or osteolytic lesions, especially in patients of rural and farmer background.(author)

  13. Fractures (Broken Bones): First Aid

    Science.gov (United States)

    First aid Fractures (broken bones) Fractures (broken bones): First aid By Mayo Clinic Staff A fracture is a ... 10, 2018 Original article: http://www.mayoclinic.org/first-aid/first-aid-fractures/basics/ART-20056641 . Mayo Clinic ...

  14. Blood and Bone Marrow Donation

    Science.gov (United States)

    ... for a stem cell transplant. Risks Bone marrow donation The most serious risk associated with donating bone ... you feel fully recovered. Peripheral blood stem cell donation The risks of this type of stem cell ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Radiography) - Bone Bone x-ray uses a very small dose of ionizing radiation to produce pictures of ... exposing a part of the body to a small dose of ionizing radiation to produce pictures of ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray ( ... leg (shin), ankle or foot. top of page What are some common uses of the procedure? A ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... produce pictures of any bone in the body. It is commonly used to diagnose fractured bones or ... pass through most objects, including the body. Once it is carefully aimed at the part of the ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... to produce pictures of any bone in the body. It is commonly used to diagnose fractured bones ... x-rays involves exposing a part of the body to a small dose of ionizing radiation to ...

  19. Children's Bone Health and Calcium

    Science.gov (United States)

    ... Twitter Pinterest Email Print Children's Bone Health and Calcium: Condition Information What is bone health and how ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  20. Breast Cancer and Bone Loss

    Science.gov (United States)

    ... Menopause Map Featured Resource Find an Endocrinologist Search Breast Cancer and Bone Loss July 2010 Download PDFs English ... G. Komen Foundation What is the link between breast cancer and bone loss? Certain treatments for breast cancer ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in metabolic conditions. assist ... of the unaffected limb, or of a child's growth plate (where new bone is forming), for comparison ...

  2. Vitamin D, Calcium, and Bone Health

    Science.gov (United States)

    ... Bone Health Featured Resource Find an Endocrinologist Search Vitamin D, Calcium, and Bone Health Download PDFs English ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  3. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  4. Growth hormone and bone health.

    Science.gov (United States)

    Bex, Marie; Bouillon, Roger

    2003-01-01

    Growth hormone (GH) and insulin-like growth factor-I have major effects on growth plate chondrocytes and all bone cells. Untreated childhood-onset GH deficiency (GHD) markedly impairs linear growth as well as three-dimensional bone size. Adult peak bone mass is therefore about 50% that of adults with normal height. This is mainly an effect on bone volume, whereas true bone mineral density (BMD; g/cm(3)) is virtually normal, as demonstrated in a large cohort of untreated Russian adults with childhood-onset GHD. The prevalence of fractures in these untreated childhood-onset GHD adults was, however, markedly and significantly increased in comparison with normal Russian adults. This clearly indicates that bone mass and bone size matter more than true bone density. Adequate treatment with GH can largely correct bone size and in several studies also bone mass, but it usually requires more than 5 years of continuous treatment. Adult-onset GHD decreases bone turnover and results in a mild deficit, generally between -0.5 and -1.0 z-score, in bone mineral content and BMD of the lumbar spine, radius and femoral neck. Cross-sectional surveys and the KIMS data suggest an increased incidence of fractures. GH replacement therapy increases bone turnover. The three controlled studies with follow-up periods of 18 and 24 months demonstrated a modest increase in BMD of the lumbar spine and femoral neck in male adults with adult-onset GHD, whereas no significant changes in BMD were observed in women. GHD, whether childhood- or adult-onset, impairs bone mass and strength. Appropriate substitution therapy can largely correct these deficiencies if given over a prolonged period. GH therapy for other bone disorders not associated with primary GHD needs further study but may well be beneficial because of its positive effects on the bone remodelling cycle. Copyright 2003 S. Karger AG, Basel

  5. [Bone structure in rheumatoid arthritis].

    Science.gov (United States)

    Ono, Kumiko; Ohashi, Satoru; Tanaka, Sakae; Matsumoto, Takuya

    2013-07-01

    In rheumatoid arthritis (RA) , the osteoclast pathway is activated by abnormal immune conditions accompanied by chronic inflammation, resulting in periarticular osteoporosis and local bone destruction around joints. In addition, multiple factors, including reduced physical activity and pharmacotherapies such as steroids, lead to systemic osteoporosis. These conditions cause decreasing bone mineral density and deterioration of bone quality, and expose patients to increased risk of fracture. Understanding the bone structures of RA and evaluating fracture risk are central to the treatment of RA.

  6. Chemical Makeup of Microdamaged Bone Differs from Undamaged Bone

    International Nuclear Information System (INIS)

    Ruppel, M.; Burr, D.; Miller, L.

    2006-01-01

    Microdamage naturally occurs in bone tissue as a result of cyclic loading placed on the body from normal daily activities. While it is usually repaired through the bone turnover process, accumulation of microdamage may result in reduced bone quality and increased fracture risk. It is unclear whether certain areas of bone are more susceptible to microdamage than others due to compositional differences. This study examines whether areas of microdamaged bone are chemically different than undamaged areas of bone. Bone samples (L3 vertebrae) were harvested from 15 dogs. Samples were stained with basic fuchsin, embedded in poly-methylmethacrylate, and cut into 5-(micro)m-thick sections. Fuchsin staining was used to identify regions of microdamage, and synchrotron infrared microspectroscopic imaging was used to determine the local bone composition. Results showed that microdamaged areas of bone were chemically different than the surrounding undamaged areas. Specifically, the mineral stoichiometry was altered in microdamaged bone, where the carbonate/protein ratio and carbonate/phosphate ratio were significantly lower in areas of microdamage, and the acid phosphate content was higher. No differences were observed in tissue mineralization (phosphate/protein ratio) or crystallinity between the microdamaged and undamaged bone, indicating that the microdamaged regions of bone were not over-mineralized. The collagen cross-linking structure was also significantly different in microdamaged areas of bone, consistent with ruptured cross-links and reduced fracture resistance. All differences in composition had well-defined boundaries in the microcrack region, strongly suggesting that they occurred after microcrack formation. Even so, because microdamage results in an altered bone composition, an accumulation of microdamage might result in a long-term reduction in bone quality

  7. Cellular and Molecular Mechanisms of Bone Remodeling*

    OpenAIRE

    Raggatt, Liza J.; Partridge, Nicola C.

    2010-01-01

    Physiological bone remodeling is a highly coordinated process responsible for bone resorption and formation and is necessary to repair damaged bone and to maintain mineral homeostasis. In addition to the traditional bone cells (osteoclasts, osteoblasts, and osteocytes) that are necessary for bone remodeling, several immune cells have also been implicated in bone disease. This minireview discusses physiological bone remodeling, outlining the traditional bone biology dogma in light of emerging ...

  8. Electron Microscopy of Bone

    NARCIS (Netherlands)

    Everts, V.; Hoeben, K. A.

    2012-01-01

    Mineralized tissues like bone, dentin and mineralized cartilage are difficult to prepare for ultrastructural analysis. In general, the higher the level of mineralization is, the more difficult it is to obtain ultrathin sections of these tissue. Tissues with a low level of mineral, e.g. from young

  9. Bone scintiscanning in metastases

    International Nuclear Information System (INIS)

    Cayla, J.; Basset, J.Y.

    1986-01-01

    The three fold interest of bone scintiscanning is discussed in relation to 182 cases of bone metastases of various origins. Firstly, this technic facilitates early diagnosis of invasion of the bone by the detection of metastatic lesions which, in 7.7% of cases are still infraradiologic, or even of reflex algodystrophy of the legs, which can be detected only from a scintiscan, long before X-ray plates can show the lumbar metastasis which is responsible. Secondly, the method is able to pick up more metastasic sites in 54.4% of cases than can be detected by X-ray; this is confirmed by investigation of the S/R ratio (ratio of the number of strongly binding sites to the number of sites showing radiologic damage) which is greater than unity for a considerable period. Thirdly, repeated scintiscanography provides a prognosis, because the survival time appears to be fairly closely correlated with the regression, stability or extension of strongly binding sites, although a ''flare phenomenon'' may give the erroneous impression that the metastatic process has deteriorated. Repeated scintiscanography also provides a good way of evaluating the efficacy of medical treatment, particularly in the case of bone metastases of mammary or prostatic origin. Sometimes, the decision for or against prophylactic or palliative orthopedic surgery may be based to a considerable extent on data provided by scintiscan [fr

  10. Bone Marrow Matters

    Science.gov (United States)

    Dunne, Mark; Maklad, Rania; Heaney, Emma

    2014-01-01

    As a final-year student teacher specialising in primary science, Emma Heaney faced the challenge of having to plan, organise, and conduct a small-scale, classroom-based research project. She had to teach about bones in the final block practice session and thought it would be a good idea to bring in some biological specimens obtained from the local…

  11. Bone scintigraphy in psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, K.; Thiers, G.; Eissner, D.; Holzmann, H.

    1980-08-01

    Since 1973 bone scintigraphy using sup(99m)Tc-phosphate-complexes was carried out in 382 patients with psoriasis. For comparison with the results of nuclear medicine, roentgenologic and clinical findings a group af 121 patients with psoriasis aged between 11 and 74 years was compared to a group of 42 patients aged between 20 and 49 years without roentgenologic and clinical signs of psoriasis arthritis. We found by means of isotope investigation that an essentially greater part of the bones adjacent to the joints was involved than was expected according to X-ray and clinical findings. In addition, in 205 patients with psoriasis whole-body scintigraphy, using sup(99m)Tc-MDP, was carried out since 1977/78. In 17 patients we found an increased accumulation of activity in the region of extraarticular structures of the skull as well as of the skeletal thorax. According to these results we conclude that in addition to the clinically and roentgenologically defined psoriatic arthritis in patients with psoriasis an osteopathy may exist, which can only be demonstrated by skeletal scintigraphy and which is localized in bones adjacent to the joints but can also be demonstrated in the region of extraarticular bones.

  12. Wounded to the bone

    DEFF Research Database (Denmark)

    Boucherie, Alexandra; Jørkov, M L S; Smith, Martin

    2017-01-01

    avenue for achieving both greater detail and accuracy through digital microscopy. Patterns of injury were investigated among 45 individuals from a Medieval Danish mass grave (Sandbjerget, AD 1300–1350). Injuries were recorded on every anatomical element, except hand and foot bones. Each was photographed...

  13. Bones of the Earth

    Science.gov (United States)

    Correa, Jose Miguel

    2014-01-01

    The film "Bones of the Earth" (Riglin, Cunninham & Correa, 2014) is an experience in collective inquiry and visual creation based on arts-based research. Starting from the meeting of different subjectivities and through dialogue, planning, shooting and editing, an audiovisual text that reconstructs a reflexive process of collective…

  14. Are Bones Alive?

    Science.gov (United States)

    Caravita, Silvia; Falchetti, Elisabetta

    2005-01-01

    Many studies have investigated the classification of living things. Our study deals with a different problem: the attribution of life to one component of a living organism, specifically the bones. The task involves not only specifying what we mean by "alive", but also requires "informed thinking" leading to an understanding of…

  15. Chondroblastoma of temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Tanohta, K.; Noda, M.; Katoh, H.; Okazaki, A.; Sugiyama, S.; Maehara, T.; Onishi, S.; Tanida, T.

    1986-07-01

    The case of a 55-year-old female with chondroblastoma arising from the left temporal bone is presented. Although 10 cases of temporal chondroblastoma have been reported, this is the first in which plain radiography, pluridirectional tomography, computed tomography (CT) and angiography were performed. We discuss the clinical and radiological aspects of this rare tumor.

  16. Bone scintigraphy in chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Humphry, A.; Gilday, D.L.; Brown, R.G.

    1980-11-01

    Scintigraphy in 3 patients with chondroblastoma showed that the tumors were hyperemic and avidly accumulated the radionuclide. These changes were also present in adjacent normal bone, but to a lesser degree. This suggests that radionuclide uptake in chondroblastoma is a function of the blood supply to the tumor rather than primary matrix extraction.

  17. Chondroblastoma of temporal bone

    International Nuclear Information System (INIS)

    Tanohta, K.; Noda, M.; Katoh, H.; Okazaki, A.; Sugiyama, S.; Maehara, T.; Onishi, S.; Tanida, T.

    1986-01-01

    The case of a 55-year-old female with chondroblastoma arising from the left temporal bone is presented. Although 10 cases of temporal chondroblastoma have been reported, this is the first in which plain radiography, pluridirectional tomography, computed tomography (CT) and angiography were performed. We discuss the clinical and radiological aspects of this rare tumor. (orig.)

  18. Bone scintigraphy in psoriasis

    International Nuclear Information System (INIS)

    Hahn, K.; Thiers, G.; Eissner, D.; Holzmann, H.; Frankfurt Univ.

    1980-01-01

    Since 1973 bone scintigraphy using sup(99m)Tc-phosphate-complexes was carried out in 382 patients with psoriasis. For comparison with the results of nuclear medicine, roentgenologic and clinical findings a group af 121 patients with psoriasis aged between 11 and 74 years was compared to a group of 42 patients aged between 20 and 49 years without roentgenologic and clinical signs of psoriasis arthritis. We found by means of isotope investigation that an essentially greater part of the bones adjacent to the joints was involved than was expected according to X-ray and clinical findings. In addition, in 205 patients with psoriasis whole-body scintigraphy, using sup(99m)Tc-MDP, was carried out since 1977/78. In 17 patients we found an increased accumulation of activity in the region of extraarticular structures of the skull as well as of the skeletal thorax. According to these results we conclude that in addition to the clinically and roentgenologically defined psoriatic arthritis in patients with psoriasis an osteopathy may exist, which can only be demonstrated by skeletal scintigraphy and which is localized in bones adjacent to the joints but can also be demonstrated in the region of extraarticular bones. (orig.) [de

  19. Nanotechnology and bone healing.

    Science.gov (United States)

    Harvey, Edward J; Henderson, Janet E; Vengallatore, Srikar T

    2010-03-01

    Nanotechnology and its attendant techniques have yet to make a significant impact on the science of bone healing. However, the potential benefits are immediately obvious with the result that hundreds of researchers and firms are performing the basic research needed to mature this nascent, yet soon to be fruitful niche. Together with genomics and proteomics, and combined with tissue engineering, this is the new face of orthopaedic technology. The concepts that orthopaedic surgeons recognize are fabrication processes that have resulted in porous implant substrates as bone defect augmentation and medication-carrier devices. However, there are dozens of applications in orthopaedic traumatology and bone healing for nanometer-sized entities, structures, surfaces, and devices with characteristic lengths ranging from 10s of nanometers to a few micrometers. Examples include scaffolds, delivery mechanisms, controlled modification of surface topography and composition, and biomicroelectromechanical systems. We review the basic science, clinical implications, and early applications of the nanotechnology revolution and emphasize the rich possibilities that exist at the crossover region between micro- and nanotechnology for developing new treatments for bone healing.

  20. Bone island and leprosy

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero, P.; Garcia-Frasquet, A. [Department of Orthopaedic Surgery, Cordoba University, Medical School, Reina Sofia University Hospital, Cordoba (Spain); Tarradas, E. [Department of Imaging, Cordoba University, Medical School, Cordoba (Spain); Logrono, C. [Department of Dermatology, Reina Sofia University Hospital, Cordoba (Spain); Carrascal, A. [Department of Radiology, Infanta Elena Hospital, Huelva (Spain); Carreto, A. [Department of Radiology, Reina Sofia University Hospital, Cordoba (Spain)

    1998-06-01

    Objective. To determine the incidence of bone islands in leprosy patients. Design. X-rays of feet and hands of patients with Hansen`s disease (leprosy) were reviewed retrospectively. A second group of related age- and sex-matched patients who did not have Hansen`s disease was used for control purposes. Controls had undergone hand or foot X-rays during diagnosis of other pathologies. The patients with Hansen`s disease were compared with the control group, and were also analyzed as subgroups with different types of leprosy. The results were subjected to statistical analysis. Patients. Ninety patients with Hansen`s disease were randomly selected for this study. Patients who had had ulcers on hands or feet were excluded from the study. Results and conclusions. Bone islands were demonstrated in 20 patients with Hansen`s disease; no bone islands were observed in the controls. This was statistically significant (P<0.01). Bone islands were only seen in patients with lepromatous leprosy and borderline types but were not demonstrated in patients with tuberculoid leprosy. There was also a statistically significant relationship for a disease duration of 15 years or more. The cause of this raised incidence of enostosis in leprosy patients is not clear, but there may be a genetic predisposition in patients with leprosy, or it may be a side effect of leprosy, especially the lepromatous form. (orig.) With 4 figs., 2 tabs., 9 refs.

  1. Bone island and leprosy

    International Nuclear Information System (INIS)

    Carpintero, P.; Garcia-Frasquet, A.; Tarradas, E.; Logrono, C.; Carrascal, A.; Carreto, A.

    1998-01-01

    Objective. To determine the incidence of bone islands in leprosy patients. Design. X-rays of feet and hands of patients with Hansen's disease (leprosy) were reviewed retrospectively. A second group of related age- and sex-matched patients who did not have Hansen's disease was used for control purposes. Controls had undergone hand or foot X-rays during diagnosis of other pathologies. The patients with Hansen's disease were compared with the control group, and were also analyzed as subgroups with different types of leprosy. The results were subjected to statistical analysis. Patients. Ninety patients with Hansen's disease were randomly selected for this study. Patients who had had ulcers on hands or feet were excluded from the study. Results and conclusions. Bone islands were demonstrated in 20 patients with Hansen's disease; no bone islands were observed in the controls. This was statistically significant (P<0.01). Bone islands were only seen in patients with lepromatous leprosy and borderline types but were not demonstrated in patients with tuberculoid leprosy. There was also a statistically significant relationship for a disease duration of 15 years or more. The cause of this raised incidence of enostosis in leprosy patients is not clear, but there may be a genetic predisposition in patients with leprosy, or it may be a side effect of leprosy, especially the lepromatous form. (orig.)

  2. [Metabolic bone disease osteomalacia].

    Science.gov (United States)

    Reuss-Borst, M A

    2014-05-01

    Osteomalacia is a rare disorder of bone metabolism leading to reduced bone mineralization. Underlying vitamin D deficiency and a disturbed phosphate metabolism (so-called hypophosphatemic osteomalacia) can cause the disease. Leading symptoms are dull localized or generalized bone pain, muscle weakness and cramps as well as increased incidence of falls. Rheumatic diseases, such as polymyalgia rheumatica, rheumatoid arthritis, myositis and fibromyalgia must be considered in the differential diagnosis. Alkaline phosphatase (AP) is typically elevated in osteomalacia while serum phosphate and/or 25-OH vitamin D3 levels are reduced. The diagnosis of osteomalacia can be confirmed by an iliac crest bone biopsy. Histological correlate is reduced or deficient mineralization of the newly synthesized extracellular matrix. Treatment strategies comprise supplementation of vitamin D and calcium and for patients with intestinal malabsorption syndromes vitamin D and calcium are also given parenterally. In renal phosphate wasting syndromes substitution of phosphate is the treatment of choice, except for tumor-induced osteomalacia when removal of the tumor leads to a cure in most cases.

  3. Oral Health and Bone Disease

    Science.gov (United States)

    ... that the loss of alveolar bone mineral density leaves bone more susceptible to periodontal bacteria, increasing the ... bone density will have a favorable impact on dental health. Bisphosphonates, a group of medications available for the treatment of osteoporosis, have been linked to the development ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  5. Playing with bone and fat

    DEFF Research Database (Denmark)

    Gimble, Jeffrey M.; Zvonic, Sanjin; Floyd, Z. Elisabeth

    2006-01-01

    The relationship between bone and fat formation within the bone marrow microenvironment is complex and remains an area of active investigation. Classical in vitro and in vivo studies strongly support an inverse relationship between the commitment of bone marrow-derived mesenchymal stem cells...

  6. Understanding the Structure of Bones

    Science.gov (United States)

    OI Issues: Understanding Bone Structure Introduction: Structural Organization of Bone The structure of bone is very similar to reinforced concrete that is used to make a building or a bridge. When the building or bridge is first assembled, an initial frame ...

  7. Gout: Value of bone scanning

    International Nuclear Information System (INIS)

    Oliva, J.P.; Cardenas, R.; Bell, L.; Gonzalez Griego, J.

    1986-01-01

    11 male patients with gout were studied by means of bone scintigraphy with 99m TcMDP. This diagnostic method rendered possible the diagnosis of clinically or roentgenologically occult bone involvement. Bone scintigraphy may be useful procedure to monitor therapy of gout. (orig.) [de

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of bone cancer . locate foreign objects in soft tissues around or in bones. top of page How should I prepare? Most ... absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more ...

  9. Comparison of three different methods for effective introduction of platelet-rich plasma on PLGA woven mesh.

    Science.gov (United States)

    Lee, Ji-Hye; Nam, Jinwoo; Kim, Hee Joong; Yoo, Jeong Joon

    2015-03-11

    For successful tissue regeneration, effective cell delivery to defect site is very important. Various types of polymer biomaterials have been developed and applied for effective cell delivery. PLGA (poly lactic-co-glycolic acid), a synthetic polymer, is a commercially available and FDA approved material. Platelet-rich plasma (PRP) is an autologous growth factor cocktail containing various growth factors including PDGF, TGFβ-1 and BMPs, and has shown positive effects on cell behaviors. We hypothesized that PRP pretreatment on PLGA mesh using different methods would cause different patterns of platelet adhesion and stages which would modulate cell adhesion and proliferation on the PLGA mesh. In this study, we pretreated PRP on PLGA using three different methods including simple dripping (SD), dynamic oscillation (DO) and centrifugation (CE), then observed the amount of adhered platelets and their activation stage distribution. The highest amount of platelets was observed on CE mesh and calcium treated CE mesh. Moreover, calcium addition after PRP coating triggered dramatic activation of platelets which showed large and flat morphologies of platelets with rich fibrin networks. Human chondrocytes (hCs) and human bone marrow stromal cells (hBMSCs) were next cultured on PRP-pretreated PLGA meshes using different preparation methods. CE mesh showed a significant increase in the initial cell adhesion of hCs and proliferation of hBMSCs compared with SD and DO meshes. The results demonstrated that the centrifugation method can be considered as a promising coating method to introduce PRP on PLGA polymeric material which could improve cell-material interaction using a simple method.

  10. Comparison of three different methods for effective introduction of platelet-rich plasma on PLGA woven mesh

    International Nuclear Information System (INIS)

    Lee, Ji-Hye; Nam, Jinwoo; Kim, Hee Joong; Yoo, Jeong Joon

    2015-01-01

    For successful tissue regeneration, effective cell delivery to defect site is very important. Various types of polymer biomaterials have been developed and applied for effective cell delivery. PLGA (poly lactic-co-glycolic acid), a synthetic polymer, is a commercially available and FDA approved material. Platelet-rich plasma (PRP) is an autologous growth factor cocktail containing various growth factors including PDGF, TGFβ-1 and BMPs, and has shown positive effects on cell behaviors. We hypothesized that PRP pretreatment on PLGA mesh using different methods would cause different patterns of platelet adhesion and stages which would modulate cell adhesion and proliferation on the PLGA mesh. In this study, we pretreated PRP on PLGA using three different methods including simple dripping (SD), dynamic oscillation (DO) and centrifugation (CE), then observed the amount of adhered platelets and their activation stage distribution. The highest amount of platelets was observed on CE mesh and calcium treated CE mesh. Moreover, calcium addition after PRP coating triggered dramatic activation of platelets which showed large and flat morphologies of platelets with rich fibrin networks. Human chondrocytes (hCs) and human bone marrow stromal cells (hBMSCs) were next cultured on PRP-pretreated PLGA meshes using different preparation methods. CE mesh showed a significant increase in the initial cell adhesion of hCs and proliferation of hBMSCs compared with SD and DO meshes. The results demonstrated that the centrifugation method can be considered as a promising coating method to introduce PRP on PLGA polymeric material which could improve cell-material interaction using a simple method. (paper)

  11. Super bone scans on bone scintigraphy in patients with metastatic bone tumor

    International Nuclear Information System (INIS)

    Morita, Koichi; Fukunaga, Masao; Otsuka, Nobuaki

    1988-01-01

    Eight patients with malignant tumor (3 with gastric cancer, 4 with prostatic cancer, 1 with transitional cell carcinoma), which showed diffusely increased uptake of 99m Tc labelled phosphorous compound in axial skeleton (''Super Bone Scan'') on bone scintigraphy were clinically studied. No relationship with its histological type of the tumor was recognized. All cases revealed extremely high serum ALP concentration, which might reflect increased osteoblastic activity. Furthermore, on bone roentgenograms all cases showed predominantly osteosclerotic change in the metastatic bones, while some did locally osteolytic change. In three cases with gastric cancer, although they had diffuse skeletal metastases, two had no evidence of liver metastases. Thus, it seemed that clinical study of patients with ''Super Bone Scan'' was interesting to evaluate the mechanism of accumulation of 99m Tc labelled phosphorous compound to bone and bone metabolism, and the pathophysiology in the pathway of bone metastases. (author)

  12. Alterations to the subchondral bone architecture during osteoarthritis : bone adaptation versus endochondral bone formation

    NARCIS (Netherlands)

    Cox, L.G.E.; Donkelaar, van C.C.; Rietbergen, van B.; Emans, P.J.; Ito, K.

    2013-01-01

    Objective Osteoarthritis (OA) is characterized by loss of cartilage and alterations in subchondral bone architecture. Changes in cartilage and bone tissue occur simultaneously and are spatially correlated, indicating that they are probably related. We investigated two hypotheses regarding this

  13. Bone metastases from gastric cancer. Clinical evaluation on bone scintigram

    Energy Technology Data Exchange (ETDEWEB)

    Seto, Mikito; Tonami, Norihisa; Koizumi, Kiyoshi; Sui, Osamu; Hisada, Kinichi [Kanazawa Univ. (Japan). School of Medicine

    1983-07-01

    We have studied bone scintigrams in 60 patients with gastric cancer. Of these 60 patients, bone metastases were found in 15 patients (25 %). There were no evidence of bone metastases in polypoid lesions, cancers of the antrum, carcinomas in situ, advanced cancers without invasion to serosa, cancer with N/sub 0/ or N/sub 1/ regional lymph node metastases, highly differentiated adenocarcinomas and papillary adenocarcinomas. On the contrary, high rates of bone metastases were seen in cancers of the corpus, advanced cancers with invasion to neighbouring structures and tubular adenocarcinomas. Of these 15 patients with bone metastasis, 3 patients showed very similar clinical features and the findings of ''diffuse bone metastases on bone scintigrams.'' Cancer of the antrum showed high rates of liver metastases, while cancers of the corpus showed high rates of bone metastases. Sixty percent of the patients with bone metastases did not have liver metastases and there seemed to be no significant relationship between liver metastases and bone metastases. From these results we suppose that non-portal tract through the vertebral venous plexus instead of portal tract may be the other route of bone metastases from gastric cancer.

  14. Multifunctional bioactive and improving the performance durability nanocoatings for finishing PET/CO woven fabrics by the sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, Dorota, E-mail: dkowalczyk@iw.lodz.pl; Brzeziński, Stefan; Kamińska, Irena

    2015-11-15

    The paper presents the results of studies on multifunctional thin-coatings of textiles, simultaneously imparting to them bioactive properties in relations to bacteria and fungi as well as an increased abrasion resistance and anti-pilling effect with the use of modified hybrid materials produced by the sol–gel method from two precursors: (3-glycidoxypropyl)trimethoxysilane (GPTMS) and aluminum isopropoxide (ALIPO). The sol obtained was modified with bioactive particles in the form of nanopowder of metallic silver and copper alloy (Ag/Cu). Al{sub 2}O{sub 3}/SiO{sub 2} sol containing nanoparticles of Ag/Cu alloy was deposited on a polyester/cotton blend woven fabric (PET/CO 67/33) by the padding method. After drying and curing process, a thin and elastic bioactive silica coating was obtained on the fabric fibers surfaces. The fabrics with deposited nanocoatings were characterized by very good bioactive properties and increased resistance to abrasion and formation of pilling. - Highlights: • Multifunctional thin coating layer was prepared on the fabric using sol–gel method. • Modification of the hybrid Al{sub 2}O{sub 3}/SiO{sub 2} sol by Ag/Cu alloy nanoparticles. • Bioactive fabric created by deposition of Al{sub 2}O{sub 3}/SiO{sub 2} sol with Ag/Cu. • 30% increase the abrasion resistance of the thin coating fabric.

  15. Development of an embedded thin-film strain-gauge-based SHM network into 3D-woven composite structure for wind turbine blades

    Science.gov (United States)

    Zhao, Dongning; Rasool, Shafqat; Forde, Micheal; Weafer, Bryan; Archer, Edward; McIlhagger, Alistair; McLaughlin, James

    2017-04-01

    Recently, there has been increasing demand in developing low-cost, effective structure health monitoring system to be embedded into 3D-woven composite wind turbine blades to determine structural integrity and presence of defects. With measuring the strain and temperature inside composites at both in-situ blade resin curing and in-service stages, we are developing a novel scheme to embed a resistive-strain-based thin-metal-film sensory into the blade spar-cap that is made of composite laminates to determine structural integrity and presence of defects. Thus, with fiberglass, epoxy, and a thinmetal- film sensing element, a three-part, low-cost, smart composite laminate is developed. Embedded strain sensory inside composite laminate prototype survived after laminate curing process. The internal strain reading from embedded strain sensor under three-point-bending test standard is comparable. It proves that our proposed method will provide another SHM alternative to reduce sensing costs during the renewable green energy generation.

  16. A comparison of woven versus nonwoven polypropylene (PP) and expanded versus condensed polytetrafluoroethylene (PTFE) on their intraperitoneal incorporation and adhesion formation.

    Science.gov (United States)

    Raptis, Dimitri Aristotle; Vichova, Barbora; Breza, Jan; Skipworth, James; Barker, Stephen

    2011-07-01

    To compare known and novel synthetic materials useful for incisional hernia repair and to test independently, whether they justify common perceptions related to their use. Four types of synthetic materials were implanted in to 12 pigs to compare incorporation histology and adhesion formation 90 d after placement. Woven polypropylene (WPP), nonwoven polypropylene (NWPP), expanded polytetrafluoroethylene (ePTFE). and condensed polytetrafluoroethylene (cPTFE) were placed intraperitoneally (IP). Intraperitoneally, WPP became fully peritonealized, but generated thick and plentiful adhesions. NWPP became fully peritonealized and generated filmy and far less numerous adhesions. ePTFE formed some filmy adhesions and did not peritonealize. cPTFE and WPP became fully peritonealized. However, bowel became adherent on raised edges of cPTFE and WPP. We conclude that NWPP incorporates extremely well intraperitoneally, promotes few adhesions, and its use is likely to be suitable for hernia repair. cPTFE performs well and promotes few adhesions, but to minimize potentially serious complications, its edges must be secured around its entire circumference. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Non-woven PET fabric reinforced and enhanced the performance of ultrafiltration membranes composed of PVDF blended with PVDF-g-PEGMA for industrial applications

    Science.gov (United States)

    Wang, Shuai; Li, Tong; Chen, Chen; Chen, Sheng; Liu, Baicang; Crittenden, John

    2018-03-01

    Ultrafiltration (UF) membranes composed of poly(vinylidene fluoride) (PVDF) blended with poly(vinylidene fluoride)-graft-poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) can present high flux and excellent foulant removal efficiencies under suitable preparation conditions. However, these PVDF/PVDF-g-PEGMA blended membranes cannot be applied industrially because of the insufficient mechanical strength (strength-to-break value of 8.4 ± 0.6 MPa). We incorporated two types of non-woven polyethylene terephthalate (PET) fabrics (thin hydrophobic and thick hydrophilic fabrics) as support layers to improve the mechanical properties of the blended membranes. The thin and thick PET fabrics were able to significantly improve the tensile strength to 23.3 ± 3.7 MPa and 30.1 ± 1.4 MPa, respectively. The PET fabrics had a limited impact on the separation-related membrane performance such as hydrophilicity, foulant rejection, whereas the mechanical strength and pure water flux was improved several folds. The enhanced flux was attributed to the higher surface porosity and wider finger-like voids in the cross-section. The thin PET fabric with larger porosity was able to maintain a consistent toughness simultaneously; thus it is recommended as a support material for this blended membrane.

  18. Self-healing woven glass fabric/epoxy composites with the healant consisting of micro-encapsulated epoxy and latent curing agent

    International Nuclear Information System (INIS)

    Yin Tao; Zhou Lin; Rong Minzhi; Zhang Mingqiu

    2008-01-01

    This paper reports a study of self-healing woven glass fabric reinforced epoxy composites. The healing agent was a two-component one synthesized in the authors' laboratory, which consisted of epoxy-loaded urea-formaldehyde microcapsules as the polymerizable binder and CuBr 2 (2-methylimidazole) 4 (CuBr 2 (2-MeIm) 4 ) as the latent hardener. Both the microcapsules and the matching catalyst were pre-embedded and pre-dissolved in the composites' matrix, respectively. When the microcapsules are split by propagating cracks, the uncured epoxy can be released into the damaged areas and then consolidated under the catalysis of CuBr 2 (2-MeIm) 4 that was homogeneously distributed in the composites' matrix on a molecular scale. As a result, the cracked faces can be bonded together. The influence of the content of the self-healing agent on the composites' tensile properties, interlaminar fracture toughness and healing efficiency was evaluated. It was found that a healing efficiency over 70% relative to the fracture toughness of virgin composites was obtained in the case of 30 wt% epoxy-loaded microcapsules and 2 wt% latent hardener

  19. In-situ growth of high-performance all-solid-state electrode for flexible supercapacitors based on carbon woven fabric/ polyaniline/ graphene composite

    Science.gov (United States)

    Lin, Yingxi; Zhang, Haiyan; Deng, Wentao; Zhang, Danfeng; Li, Na; Wu, Qibai; He, Chunhua

    2018-04-01

    For the development of wearable electronic devices, it is crucial to develop energy storage components combining high-capacity and flexibility. Herein, an all-solid-state supercapacitor is prepared through an in-situ "growth and wrapping" method. The electrode contains polyaniline deposited on a carbon woven fabric and wrapped with a graphene-based envelop. The hybrid electrode exhibits excellent mechanical and electrochemical performance. The optimized few layer graphene wrapping layer provides for a conductive network, which effectively enhances the cycling stability as 88.9% of the starting capacitance is maintained after 5000 charge/discharge cycles. Furthermore, the assembled device delivers a high areal capacity (of 790 F cm-2) at the current density of 1 A cm-2, a high areal energy (28.21 uWh cm-2) at the power densities of 0.12 mW cm-2 and shows no significant decrease in the performance with a bending angle of 180°. This unique flexible supercapacitor thus exhibits great potential for wearable electronics.

  20. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90–100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene. PMID:28074877

  1. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene.

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-11

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  2. Biocompatibility of polypropylene non-woven fabric membrane via UV-induced graft polymerization of 2-acrylamido-2-methylpropane sulfonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Song Lingjie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhao Jie; Yang Huawei; Jin Jing; Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-10-15

    This work described the graft polymerization of a sulfonic acid terminated monomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), onto the surface of polypropylene non-woven (NWF PP) membrane by O{sub 2} plasma pretreatment and UV-induced photografting method. The chemical structure and composition of the modified surfaces were analyzed by FTIR-ATR and XPS, respectively. The wettability was investigated by water contact angle and equilibrium water adsorption. And the biocompatibility of the modified NWF PP membranes was evaluated by protein adsorption and platelet adhesion. It was found that the graft density increased with prolonging UV irradiation time and increasing AMPS concentration; the water contact angles of the membranes decreased from 124{sup o} to 26{sup o} with the increasing grafting density of poly(AMPS) from 0 to 884.2 {mu}g cm{sup -2}, while the equilibrium water adsorption raised from 5 wt% to 75 wt%; the protein absorption was effectively suppressed with the introduction of poly(AMPS) even at the low grafting density (132.4 {mu}g cm{sup -2}); the number of platelets adhering to the modified membrane was dramatically reduced when compared with that on its virgin surface. These results indicated that surface modification of NWF PP membrane with AMPS was a facile approach to construct biocompatible surface.

  3. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, Doyoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  4. Influence of Fiber Content on Mechanical and Morphological Properties of Woven Kenaf Reinforced PVB Film Produced Using a Hot Press Technique

    Directory of Open Access Journals (Sweden)

    Suhad D. Salman

    2016-01-01

    Full Text Available This work addresses the results of experimental investigation carried out on mechanical and morphological properties of plain woven kenaf fiber reinforced PVB film which was prepared by hot press technique. The composites were prepared with various fiber contents: 0%, 10%, 20%, 30%, 40%, 50%, and 60% (by weight, with the processing parameters 165°C, 20 min, and at a pressure of 8 MPa applied on the material. Tensile, flexural, and Charpy impact properties were studied as well as morphological properties of impact fracture surface. With the increase in kenaf fibers content up to 40%, the PVB composites have shown lower tensile and flexural strength accompanied with reduction in the ultimate strain of the composite. The results showed that impact properties were affected in markedly different ways by using various kenaf contents and decrease with the increase in kenaf fiber content up to 40%; however, high impact strength was observed even with 40% kenaf fiber content. Furthermore, scanning electron microscopy for impact samples was utilised to demonstrate the different failures in the fracture surfaces for various kenaf fibers contents.

  5. Bone marrow oedema associated with benign and malignant bone tumours

    Energy Technology Data Exchange (ETDEWEB)

    James, S.L.J. [Department of Radiology, Royal Orthopaedic Hospital, Birmingham, B31 2AP (United Kingdom)], E-mail: steven.james@roh.nhs.uk; Panicek, D.M. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Davies, A.M. [Department of Radiology, Royal Orthopaedic Hospital, Birmingham, B31 2AP (United Kingdom)

    2008-07-15

    Bone marrow oedema is associated with a wide variety of pathological processes including both benign and malignant bone tumours. This imaging finding in relation to intraosseous tumours can aid in providing a more focused differential diagnosis. In this review, we will discuss the MR imaging of bone marrow oedema surrounding intraosseous neoplasms. The different pulse sequences used in differentiating underlying tumour from surrounding oedema are discussed along with the role of dynamic contrast enhanced MRI. Benign lesions commonly associated with bone marrow oedema include osteoid osteoma, osteoblastoma, chondroblastoma and Langerhan's cell histiocytosis. Metastases and malignant primary bone tumours such as osteosarcoma, Ewing's sarcoma and chondrosarcoma may also be surrounded by bone marrow oedema. The imaging findings of these conditions are reviewed and illustrated. Finally, the importance of bone marrow oedema in assessment of post chemotherapeutic response is addressed.

  6. Multicellular tumor spheroid interactions with bone cells and bone

    International Nuclear Information System (INIS)

    Wezeman, F.H.; Guzzino, K.M.; Waxler, B.

    1985-01-01

    In vitro coculture techniques were used to study HSDM1C1 murine fibrosarcoma multicellular tumor spheroid (HSDM1C1-MTS) interactions with mouse calvarial bone cells having osteoblastic characteristics and mouse bone explants. HSDM1C1-MTS attached to confluent bone cell monolayers and their attachment rate was quantified. HSDM1C1-MTS interaction with bone cells was further demonstrated by the release of 3 H-deoxyuridine from prelabeled bone cells during coculture with multicellular tumor spheroids. HSDM1C1-MTS-induced cytotoxicity was mimicked by the addition of 10(-5) M prostaglandin E2 (PGE2) to 3 H-deoxyuridine-labeled bone cells. The effects of low (10(-9) M) and high (10(-5) M) concentrations of PGE2 on bone cell proliferation were also studied. Higher concentrations of PGE2 inhibited bone cell proliferation. HSDM1C1-MTS resorbed living explants in the presence of indomethacin, suggesting that other tumor cell products may also participate in bone resorption. HSDM1C1-MTS caused direct bone resorption as measured by the significantly elevated release of 45 Ca from prelabeled, devitalized calvaria. However, the growth of a confluent bone cell layer on devitalized, 45 Ca-prelabeled calvaria resulted in a significant reduction in the amount of 45 Ca released subsequent to the seeding of HSDM1C1-MTS onto the explants. Bone cells at the bone surface may act as a barrier against invasion and tumor cell-mediated bone resorption. Violation of this cellular barrier is achieved, in part, by tumor cell products

  7. Metastases to bone in medulloblastoma

    International Nuclear Information System (INIS)

    Vieco, P.T.; Azouz, E.M.; Hoeffel, J.C.

    1989-01-01

    Medulloblastoma is a relatively common intracranial neoplasm in childhood. Its extraneural spread was, until recently, thought to be a rare occurrence. Metastases are most commonly to bone. Five patients with medulloblastoma metastatic to bone are presented, and findings are compared to those of previous reports. Two of the five cases showed patchy extensive osteosclerosis of the pelvis and/or proximal femora. One case had concurrent lymph node involvement. In patients with past or present medulloblastoma and bone pain, metastases to bone should be excluded. Medulloblastoma metastatic to bone is a rare cause of extensive osteosclerosis. (orig.)

  8. Bone metastases from gastric cancer

    International Nuclear Information System (INIS)

    Seto, Mikito; Tonami, Norihisa; Koizumi, Kiyoshi; Sui, Osamu; Hisada, Kinichi

    1983-01-01

    We have studied bone scintigrams in 60 patients with gastric cancer. Of these 60 patients, bone metastases were found in 15 patients (25 %). There were no evidence of bone metastases in polypoid lesions, cancers of the antrum, carcinomas in situ, advanced cancers without invasion to serosa, cancer with N 0 or N 1 regional lymph node metastases, highly deferenciated adenocarcinomas and papillary adenocarcinomas. On the contrary, high rates of bone metastases were seen in cancers of the corpus, advanced cancers with invasion to neighbouring structures and tubular adenocarcinomas. Of these 15 patients with bone metastasis, 3 patients showed very similar clinical features and the findings of ''diffuse bone metastases on bone scintigrams.'' Cancer of the antrum showed high rates of liver metastases, while cancers of the corpus showed high rates of bone stastases. Sixty percent of the patients with bone metastases did not have liver metastases and there seemed to be no significant relationship between liver metastases and bone metastases. From these results we suppose that non-portal tract through the vertebral venous plexus instead of portal tract may be the other route of bone metastases from gastric cancer. (author)

  9. Scanning electron microscopy of bone.

    Science.gov (United States)

    Boyde, Alan

    2012-01-01

    This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

  10. Bone Metabolism in Anorexia Nervosa

    Science.gov (United States)

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

    Anorexia nervosa (AN), a psychiatric disorder predominantly affecting young women, is characterized by self-imposed chronic nutritional deprivation and distorted body image. AN is associated with a number of medical co-morbidities including low bone mass. The low bone mass in AN is due to an uncoupling of bone formation and bone resorption, which is the result of hormonal adaptations aimed at decreasing energy expenditure during periods of low energy intake. Importantly, the low bone mass in AN is associated with a significant risk of fractures and therefore treatments to prevent bone loss are critical. In this review, we discuss the hormonal determinants of low bone mass in AN and treatments that have been investigated in this population. PMID:24419863

  11. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S

    2015-01-01

    The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled...... with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA......-SiO (34.47%), followed by BCP 60/40 (23.64%)) was significantly higher than the more rapidly substituted autogenous bone (17.1%). Autogenous bone yielded significantly more new bone (21.81%) over all test groups (4.91%-7.74%) and significantly more osteoid (5.53%) than BCP 60/40 (3%) and DBBM (2...

  12. MRI in bone marrow lesions

    International Nuclear Information System (INIS)

    Linden, A.; Theissen, P.; Schauerte, G.; Schicha, H.; Diehl, V.

    1989-01-01

    MRI has the potential to demonstrate bone marrow pathology due to its good soft tissue contrast. Inflammation and necrosis can be detected very early before there is evidence of radiological changes. In bone tumors intramedullary infiltration can be visualized in addition to soft tissue changes. Metastases of bone and bone marrow, especially in spinal and pelvic regions, are well depicted, often before bone scintigraphy yields pathological findings. In haematological disorders MRI permits follow-up studies due to its good reproducibility. Infiltration by malignant lymphoma and multiple myeloma and its extension in bone marrow can be visualized by MRI, too. However, the most common pathological MRI findings in bone marrow are not very specific, and final diagnosis requires further clinical or histological information. (orig.) [de

  13. Aging and bone. X-ray bone densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Rikushi (Shiga Univ. of Medical Sciences, Otsu (Japan))

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.).

  14. Bone graft viability evaluated by three phase bone scan

    International Nuclear Information System (INIS)

    Ljiljana Jaukovic Rajko Spaic; Marijan Novakovic; Srbislav Stosic

    2004-01-01

    Bone defects resulting war injury can be replaced by microvascular bone grafts from fibula. Aim: The aim of this study was to assess the value of three phase (3P) bone scintigraphy in the early detection of the bone graft complications. Method: 3P bone scans were performed in four patients (two after mandible reconstruction with micro vascular fibular bone grafts, one after fibular transplantation for ulnar and one with humeral reconstruction). First dynamic phase scan was performed immediately after iv injection of 740 MBq Tc- 99m DPD, acquiring 15 two seconds duration frames. Second, early static scan was performed during next 300 seconds, and third, delayed scan three hours later. All scans were obtained under the bone graft region. The scans were evaluated using ROI under graft region and the corresponding contra lateral area. Blood flow in graft region was determined using first phase scan, and tracer uptake in the same region was determined using second and third phase scans. Results: in all patients blood flow in graft region was particularly normal. Tracer uptake in one of two patients with mandible reconstruction was diffusely increased in graft, strongly suggesting infection; In the other patient delayed scan showed no tracer uptake in graft center .Both patients with ulnar and humeral reconstruction showed only slightly decreased tracer uptake in bone grafts. 3 phase bone scintigraphy may play a role in the evaluation of bone graft viability by predicting the infection and necrosis. (authors)

  15. Bone- and bone marrow scintigraphy in Gaucher disease type 1

    International Nuclear Information System (INIS)

    Mikosch, P.; Zitter, F.; Gallowitsch, H.J.; Lind, P.; Wuertz, F.; Mehta, A.B.; Hughes, D.A.

    2008-01-01

    Scintigraphy is a method for imaging metabolism and should be viewed as complimentary to morphological imaging. Bone and bone marrow scintigraphy can particularly contribute to the detection of focal disease in Gaucher disease. In bone crises it can discriminate within three days after pain onset between local infection and aseptic necrosis. A further advantage of bone- and bone marrow scintigraphy is the visualization of the whole skeleton within one setting. Whole body imaging for focal lesions might thus be an objective in GD, in particular in patients complaining of several painful sites. Direct imaging of bone marrow deposits in GD by MIBI scintigraphy might be of special interest in children in whom bone marrow undergoes a developmental conversion from red to yellow marrow in the ap-pendicular skeleton. MRI interpretation in young GD patients is thus difficult in order to estimate the exact amount and extent of bone marrow infiltration by Gaucher cells. 99mTc-MIBI scintigraphy with its direct visualization of lipid storage could thus add interesting additional information not shown with other methods including MRI. Although MRI is the most accepted imaging modality in assessing the skeletal status in GD, a selective use of scintigraphy for imaging bone and bone marrow may add information in the evaluation of patients with Gaucher disease

  16. Aging and bone. X-ray bone densitometry

    International Nuclear Information System (INIS)

    Morita, Rikushi

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.)

  17. Occipital bone lacunae

    International Nuclear Information System (INIS)

    Pavlica, P.; Sciascia, R.

    1988-01-01

    Sixteen patients with lacunar alterations of the squamous occipital bone were studied in various radiographic projections; in many cases studies were also performed. In 7 cases lacunae in the cerebral fossa were observed, with an average diameter of 3 cm. These defects were due to a thinning of the inner table of the theca. In 9 cases smaller lacunae were demonstrated bilaterally, which were more radiolucent, isolated or confluent, located in the area corresponding to the internal occipital protuberance at the ridges of cruciform eminence. The latter were representative of diploic venous lakes, as the best demonstrated in lateral projection. This kind of lacunae are considered as anatomic variants, because no bone destruction is demonstrable, as confirmed by technetium scintigraphy

  18. Risk estimates for bone

    International Nuclear Information System (INIS)

    Schlenker, R.A.

    1982-01-01

    Bone sarcoma data for 226 228 Ra and 224 Ra are analyzed within the dosage ranges where the observed risk is zero. The uncertainty in the risk may be effectively illustrated by using pairs of functions based on a statistically-based measure of confidence. For radiation protection, the appropriate measure of risk is cumulative incidence in the presence of competing risks, as this takes into account the reduction of radiation effects brought about by natural mortality

  19. Perfluoroalkyl substances in human bone: concentrations in bones and effects on bone cell differentiation.

    Science.gov (United States)

    Koskela, A; Koponen, J; Lehenkari, P; Viluksela, M; Korkalainen, M; Tuukkanen, J

    2017-07-28

    Perfluoroalkyl substances (PFAS), including two most commonly studied compounds perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are widely distributed environmental pollutants, used extensively earlier. Due to their toxicological effects the use of PFAS is now regulated. Based on earlier studies on PFOA's distribution in bone and bone marrow in mice, we investigated PFAS levels and their possible link to bone microarchitecture of human femoral bone samples (n = 18). Soft tissue and bone biopsies were also taken from a 49-year old female cadaver for PFAS analyses. We also studied how PFOA exposure affects differentiation of human osteoblasts and osteoclasts. PFAS were detectable from all dry bone and bone marrow samples, PFOS and PFOA being the most prominent. In cadaver biopsies, lungs and liver contained the highest concentrations of PFAS, whereas PFAS were absent in bone marrow. Perfluorononanoic acid (PFNA) was present in the bones, PFOA and PFOS were absent. In vitro results showed no disturbance in osteogenic differentiation after PFOA exposure, but in osteoclasts, lower concentrations led to increased resorption, which eventually dropped to zero after increase in PFOA concentration. In conclusion, PFAS are present in bone and have the potential to affect human bone cells partly at environmentally relevant concentrations.

  20. HIV and bone disease.

    Science.gov (United States)

    Stone, Benjamin; Dockrell, David; Bowman, Christine; McCloskey, Eugene

    2010-11-01

    Advances in management have resulted in a dramatic decline in mortality for individuals infected with human immunodeficiency virus (HIV). This decrease in mortality, initially the result of improved prophylaxis and treatment of opportunistic infections but later mediated by the use of highly-active antiretroviral therapy (HAART) has led to the need to consider long-term complications of the disease itself, or its treatment. Bone disease is increasingly recognised as a concern. The prevalence of reduced BMD and possibly also fracture incidence are increased in HIV-positive individuals compared with HIV-negative controls. There are many potential explanations for this - an increased prevalence of established osteoporosis risk factors in the HIV-positive population, a likely direct effect of HIV infection itself and a possible contributory role of ARV therapy. At present, the assessment of bone disease and fracture risk remains patchy, with little or no guidance on identifying those at increased risk of reduced BMD or fragility fracture. Preventative and therapeutic strategies with bone specific treatments need to be developed. Limited data suggest bisphosphonates may be beneficial in conjunction with vitamin D and calcium supplementation in the treatment of reduced BMD in HIV-infected patients but larger studies of longer duration are needed. The safety and cost-effectiveness of these and other treatments needs to be evaluated. Copyright © 2010. Published by Elsevier Inc.

  1. Evaluation of autogenous PRGF+β-TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical in vivo study.

    Science.gov (United States)

    Batas, Leonidas; Stavropoulos, Andreas; Papadimitriou, Serafim; Nyengaard, Jens R; Konstantinidis, Antonios

    2016-08-01

    The aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a β-TCP particulate carrier. Large box-type defects (10 × 6 mm; W × D) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6 mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on β-TCP particles and either covered with a collagen membrane (PRGF/β-TCP+CM) (6 defects) or left without a membrane (PRGF/β-TCP) (5 defects). Histology 4 months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual β-TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.2 ± 9.86 vs. 39.9 ± 13.7 in the PRGF/β-TCP+CM and PRGF/β-TCP group (P = 0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 ± 16.45 vs. 35.91 ± 24.45, respectively (P = 0.5). First, bone-to-implant contact from the implant top was 4.1 ± 1.5 and 3.2 ± 2.3 (P = 0.9), in the PRGF/β-TCP+CM and PRGF/β-TCP group, respectively. Implantation of chair-side prepared autologous PRGF adsorbed on a β-TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Long bone reconstruction using multilevel lengthening of bone defect fragments.

    Science.gov (United States)

    Borzunov, Dmitry Y

    2012-08-01

    This paper presents experimental findings to substantiate the use of multilevel bone fragment lengthening for managing extensive long bone defects caused by diverse aetiologies and shows its clinical introduction which could provide a solution for the problem of reducing the total treatment time. Both experimental and clinical multilevel lengthening to bridge bone defect gaps was performed with the use of the Ilizarov method only. The experimental findings and clinical outcomes showed that multilevel defect fragment lengthening could provide sufficient bone formation and reduction of the total osteosynthesis time in one stage as compared to traditional Ilizarov bone transport. The method of multilevel regeneration enabled management of critical-size defects that measured on average 13.5 ± 0.7 cm in 78 patients. The experimental and clinical results proved the efficiency of the Ilizarov non-free multilevel bone plasty that can be recommended for practical use.

  3. Denosumab for bone diseases: translating bone biology into targeted therapy.

    Science.gov (United States)

    Tsourdi, Elena; Rachner, Tilman D; Rauner, Martina; Hamann, Christine; Hofbauer, Lorenz C

    2011-12-01

    Signalling of receptor activator of nuclear factor-κB (RANK) ligand (RANKL) through RANK is a critical pathway to regulate the differentiation and activity of osteoclasts and, hence, a master regulator of bone resorption. Increased RANKL activity has been demonstrated in diseases characterised by excessive bone loss such as osteoporosis, rheumatoid arthritis and osteolytic bone metastases. The development and approval of denosumab, a fully MAB against RANKL, has heralded a new era in the treatment of bone diseases by providing a potent, targeted and reversible inhibitor of bone resorption. This article summarises the molecular and cellular biology of the RANKL/RANK system and critically reviews preclinical and clinical studies that have established denosumab as a promising novel therapy for metabolic and malignant bone diseases. We will discuss the potential indications for denosumab along with a critical review of safety and analyse its potential within the concert of established therapies.

  4. Multiple myeloma: radiology or bone scanning

    International Nuclear Information System (INIS)

    Leonard, R.C.F.; Owen, J.P.; Proctor, S.J.; Hamilton, P.J.

    1981-01-01

    A comparative study of radionuclide bone scanning and skeletal radiology in patients with multiple myeloma revealed four principal findings: (i) There were no cases of negative bone scans with positive skeletal radiographs. (ii) Lytic bone lesions were seriously underestimated by bone scans. (iii) Bone scans tended to pick up lesions in ribs missed on the skeletal surveys. (iv) Patients with bone pain were more likely to have positive bone scans and skeletal radiographs than asymptomatic patients. (author)

  5. [Guided bone regeneration: general survey].

    Science.gov (United States)

    Cosyn, Jan; De Bruyn, Hugo

    2009-01-01

    The principle of 'guided bone regeneration' was first described in 1988 on the basis of animal-experimental data. Six weeks after transmandibular defects had been created and protected by non-resorbable teflonmembranes, complete bone regeneration was found. The technique was based on the selective repopulation of the wound: every infiltration of cells outside the neighbouring bone tissue was prevented by the application of the membrane. Additional animal experiments showed that guided bone regeneration was a viable treatment option for local bone defects surrounding dental implants. Clinical practice, however, showed that premature membrane exposure was a common complication, which was responsible for a tremendous reduction in regenerated bone volume. In addition, a second surgical intervention was always necessary to remove the membrane. As a result, resorbable alternatives were developed. Since these are less rigid, bone fillers are usually used simultaneously. These comprise autogenous bone chips and bone substitutes from allogenic or xenogenic origine. Also alloplastic materials could be used for this purpose. Based on their characteristics this article provides an overview of the biomaterials that could be considered for guided bone regeneration. Specific attention goes to their application in clinical practice.

  6. Bone disease in primary hyperparathyroidism

    Science.gov (United States)

    Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.

    2015-01-01

    Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

  7. Paget's disease of bone resembling bone metastasis from gastric cancer.

    Science.gov (United States)

    Shimoyama, Yasuyuki; Kusano, Motoyasu; Shimoda, Yoko; Ishihara, Shingo; Toyomasu, Yoshitaka; Ohno, Tetsuro; Mochiki, Erito; Sano, Takaaki; Hirato, Junko; Mori, Masatomo

    2011-08-01

    A 74-year-old man had an endoscopic type 0'-IIc tumor in the upper gastric body on the greater curvature and biopsy showed the tumor to be a well-differentiated adenocarcinoma (Group 5). He was referred to us for endoscopic submucosal dissection (ESD). Endoscopy revealed fold convergency, fold swelling, and fusion of the fold, indicating tumor invasion into the submucosa, which was outside the indications for ESD. In addition, there was an increase of serum bone-type alkaline phosphatase (ALP-III and ALP-IV) and urinary cross-linked N-terminal telopeptide of type I collagen (a bone metabolism marker), while (18)F-fluorodeoxyglucose positron emission tomography showed increased uptake in the left pelvis and Th10, suggesting bone metastases. We first diagnosed gastric cancer with bone metastases; however, the symptoms suggested pathological bone fracture and no bone pain. Therefore, a computed tomography-guided aspiration bone biopsy was performed to exclude the possibility of Paget's disease of bone. Biopsy specimens revealed no tumor and a mosaic pattern. No increased uptake of (18)F-FAMT (L-[3-(18)F] α-methyltyrosine) supported a diagnosis of no bone metastases from gastric cancer. We finally diagnosed gastric cancer accompanied by Paget's disease of bone and performed a laparoscopy-assisted proximal gastrectomy. The pathological diagnosis was U less 0-IIb, and U post 0-IIc ypT1a (M) N0H0P0M0 yp stage IA. In gastric cancer patients with suspected bone metastasis, we also need to consider Paget's disease of bone.

  8. Engineering bone grafts with enhanced bone marrow and native scaffolds.

    Science.gov (United States)

    Hung, Ben P; Salter, Erin K; Temple, Josh; Mundinger, Gerhard S; Brown, Emile N; Brazio, Philip; Rodriguez, Eduardo D; Grayson, Warren L

    2013-01-01

    The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds. © 2013 S. Karger AG, Basel

  9. Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis

    Science.gov (United States)

    Pennline, James A.; Werner, Christopher R.; Lewandowski, Beth; Thompson, Bill; Sibonga, Jean; Mulugeta, Lealem

    2015-01-01

    Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

  10. Differentiation of bone marrow cells with irradiated bone in vitro

    International Nuclear Information System (INIS)

    Toshiyuki Tominaga; Moritoshi Itoman; Izumi, T.; Wakita, R.; Uchino, M.

    1999-01-01

    Disease transmission or infection is an important issue in bone allograft, and irradiation is used for sterilization of graft bones. One of the advantages of bone allograft over biomaterials is that graft bones have osteoinductive factors such as growth factors. Irradiation is reported to decrease the osteoinductive activity in vivo. We investigated the osteoinductive activity of irradiated bone by alkaline phosphatase (ALP) activity in rat bone marrow cell culture. Bones (tibias and femurs of 12-week-old Wistar rats) were cleaned of adhering soft tissue, and the marrow was removed by washing. The bones were defatted, lyophilized, and cut into uniform 70 mg fragments. Then the Bone fragments were irradiated at either 10, 20, 25, 30, 40, or 50 kGy at JAERI. Bone marrow cells were isolated from tibias and femurs of 4-week-old Wistar rats. Cells were plated in tissue culture flask. When primary cultures reached confluence, cells were passaged (4 x 103 cell / cm2) to 6 wells plates. The culture medium consisted of minimum essential medium, 10% fetal bovine serum, ascorbic acid, and antibiotics. At confluence, a cell culture insert was set in the well, and an irradiated bone fragment was placed in it. Then, medium was supplemented with 10 mM ?-glycerophosphate and 1 x 10-8 M dexamethasone. Culture wells were stained by naphthol AS-MX phosphate, N,N-dimethyl formamide, Red violet LB salt on day 0, 7, 14. The density of ALP staining was analyzed by a personal computer. Without bones, ALP staining increased by 50% on day 7 and by 100% on day 14, compared with that on day 0. The other side, with bones irradiated at 30 kGy or lower, ALP staining increased by 150% on day 7, and by 180% on day 14, compared with that on day 0. In the groups of irradiated bones of 40 kGy or higher, the increase in ALP staining was less prominent compared with the groups of irradiated bones of 30 kGy or lower. In the groups of 0-30 kGy irradiation, ALP staining increased in the early period

  11. Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takao; Iizuka, Tadashi; Kanamori, Takeshi; Yokoyama, Atsuro [Department of Oral Functional Prosthodontics, Division of Oral Functional Science, Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo, Hokkaido 060-8586 (Japan); Matsumura, Sachiko; Shiba, Kiyotaka [Division of Protein Engineering, Cancer Institute, Japanese Foundation for Cancer Research, 3-8-31, Ariake, koutou-ku, Tokyo 135-8550 (Japan); Yudasaka, Masako; Iijima, Sumio, E-mail: tkasai@den.hokudai.ac.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology, Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

    2011-02-11

    A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.

  12. Clinical research of bone scan characteristics for metabolic bone diseases

    International Nuclear Information System (INIS)

    Zhu Ruisen; Luo Qiong; Lu Haikui; Chen Libo; Luo Quanyong

    2009-01-01

    Characteristic images of 99m Tc-MDP bone scintigraphy in patients with metabolic bone diseases (MBD) were analyzed and compared, in an attempt to improve the capability of differential diagnosis in this aspect. A total of 142 cases, clinically confirmed as (MBD), were categorized into six groups: hyperparathyroidism (117), renal osteodystrophy (4), Paget's disease (16), hypophosphatemic osteomalacia (2), Albers-Schonberg disease (2), and Brittle bone disease (1). They were diagnosed clinically or pathologically, and scanned with 99m Tc-MDP bone scintegraphy, from which the 142 MBD cases were classified into 4 types. The cases of Type I had increased amount of 99m Tc-MDP uptake in whole body bones, including hyperparathyroidism, Albers-Schonberg disease, brittle bone disease and renal osteodystrophy. The cases of Type II had high uptake of 99m Tc-MDP in local region of bones, including paget's disease, hypophosphatemic osteomalacia and hyperparathyroidism. A Type I case with pathological fracture or secondary osteopathy was classified as Type III. Type IV cases were in early stage of hyperparathyroidism, with normal bone scan image. Analysis of the characteristics of 99m Tc-MDP bone scintigraphic findings (locations, morphology and intensities) in patients with MBD may be helpful in the differential diagnosis of MBD, in association with the patient's history and X-ray data altogether. (authors)

  13. Study of bone metastasis of cervical carcinoma by bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Okamura, Shinsuke; Okamoto, Yoshiaki; Maeda, Takayoshi; Sano, Takashi; Ueki, Minoru; Sugimoto, Osamu; Sakata, Tsunehiko; Yamasaki, Kouichi; Akagi, Hiroaki

    1985-04-01

    In carrying out bone scintigraphy in 224 cases over the 5 years from June, 1978 to May, 1983 as a part of the post-treatment management of cervical carcinoma. Bone metastases were seen in 12.5% (28 cases) of the subjects, about 6% of the total post-treatment cases of cervical carcinoma in the corresponding period (466 cases). Bone metastases were seen in 9.3% (16/172) of post-operative cases, compared with 23.1% (12/52) of non-operative cases. Bone metastases were not seen in clinical stages Ia through IIa (49 cases) but were seen in IIb or higher stages. Bone metastasis rates by histological type, according to WHO classification, were 12.8% (26/203) in squamous cell carcinoma, 5.9% (1/17) in adenocarcinoma, and 25% (1/4) in adenosquamous carcinoma. Among the squamous cell carcinoma cases, small cell non-keratinizing type had the highest bone metastasis rate. Of 172 post-operative cases, 20.8% (11/53) of those with lymph node metastasis exhibited bone metastasis, higher than the 4.2% (5/119) in cases without lymph node metastasis. As to CPL classification, bone metastasis was seen more often in L type (18.8%) than C(0.0%) or P types (6.6%). Our risk classification of 168 cases demonstrated that bone metastasis was not seen in risk I group (74 cases), but was seen in 6.7% (1/17) of risk II group and in 19.0% (15/79) of risk III group. Twenty-eight cases with bone metastasis included 11 cases with local recurrence, 8 with pulmonary metastases, 4 with hepatic metastases and 4 with Virchow's lymphnode metastases. The 28 bone metastasis cases included 10 cases with multiple bone metastases and 5 with only a single bone metastasis. Most bone metastases were seen in the lumbar vertebrae and the pelvic bone. Post-operative cases had more distant metastases than non-operative cases. On diagnosis of bone metastases and 17 of the 28 patients had pain, 6 of the remaining 11 patients developing pain thereafter. (J.P.N.).

  14. Mandibular reconstruction using bone allografts

    International Nuclear Information System (INIS)

    Chang Joon Yim

    1999-01-01

    Further understanding of bone healing mechanisms, bone physiology and bone biology, transplantation immunology, and development of Tissue Banking procedures has enabled oral and maxillofacial surgeons to reconstruct even the most difficult bony defects successfully with the preserved allogeneic bone implant. Although it had been known that bone allografts were clinically effective, its application has not been widespread until the reports of Inclan (I 942), Hyatt and Butler (I 950), and Wilson (I 95 1). Tissue Banking provides the surgeon with a readily available, relatively inexpensive, and relatively safe selection of allogeneic bone for clinical use. Now autogenous bone and allogeneic bone implants present a wide variety of surgical options to surgeons, whether used separately or in combination. The surgeons are able to make judicious and fruitful choices, only with a thorough knowledge of the above-mentioned biological principles and skillful techniques. Many kinds of bone grafting techniques have been tried for reconstructing defective osseous tissues of the oral and maxillofacial region, though they have varying degrees of success. The osseous defects which require grafting include those of various size, shape, position, or amount. Unlike autogenous grafts, whose function is to provide osteogenic cells, allografts are purely passive, offering only a matrix for the inductive phase of bone healing. The condition of the recipient bed is of primary importance, because the host must produce all of the essential elements for the bone allograft to become incorporated. Depending on the processing methods of the allogeneic bone, the bone graft materials have different qualities, different healing potentials and different indications. Proper selection of grafts and surgical techniques requires an understanding of graft immunology and the mechanisms of graft healing. The surgeons should know about the biological principles to raise the clinical success rate

  15. Shear behavior of thermoformed woven-textile thermoplastic prepregs: An analysis combining bias-extension test and X-ray microtomography

    Science.gov (United States)

    Gassoumi, M.; Rolland du Roscoat, S.; Casari, P.; Dumont, P. J. J.; Orgéas, L.; Jacquemin, F.

    2017-10-01

    Thermoforming allows the manufacture of structural parts for the automotive and aeronautical domains using long fiber thermoplastic prepregs with short cycle times. During this operation, several sheets of molten prepregs are stacked and subjected to large macroscale strains, mainly via in-plane shear, out-of-plane consolidation or dilatation, and bending of the fibrous reinforcement. These deformation modes and the related meso and microstructure evolutions are still poorly understood. However, they can drastically alter the end-use macroscale properties of fabricated parts. To better understand these phenomena, bias extension tests were performed using specimens made of several stacked layers of glass woven fabrics and polyamide matrix. The macroscale shear behavior of these prepregs was investigated at various temperatures. A multiscale analysis of deformed samples was performed using X-ray microtomography images of the deformed specimens acquired at two different spatial resolutions. The low-resolution images were used to analyze the deformation mechanisms and the structural characteristics of prepregs at the macroscale and bundle scales. It was possible to analyze the 3D shapes of deformed samples and, in particular, the spatial variations of their thickness so as to quantify the out-of-plane dilatancy or consolidation phenomena induced by the in-plane shear of prepregs. At a lower scale, the analysis of the high-resolution images showed that these mechanisms were accompanied by the growth of pores and the deformation of fiber bundles. The orientation of the fiber bundles and its through-thickness evolution were measured along the weft and warp directions in the deformed samples, allowing the relevance of geometrical models currently used to analyze bias extension tests to be discussed. Results can be used to enhance the current rheological models for the prediction of thermoforming of thermoplastic prepregs.

  16. Fabrication and Synthesis of Highly Ordered Nickel Cobalt Sulfide Nanowire-Grown Woven Kevlar Fiber/Reduced Graphene Oxide/Polyester Composites.

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K; Kim, DoYoung; Roh, Hyung Doh; Park, Young-Bin; Park, Hyung Wook

    2017-10-18

    Well-aligned NiCo 2 S 4 nanowires, synthesized hydrothermally on the surface of woven Kevlar fiber (WKF), were used to fabricate composites with reduced graphene oxide (rGO) dispersed in polyester resin (PES) by means of vacuum-assisted resin transfer molding. The NiCo 2 S 4 nanowires were synthesized with three precursor concentrations. Nanowire growth was characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Hierarchical and high growth density of the nanowires led to exceptional mechanical properties of the composites. Compared with bare WKF/PES, the tensile strength and absorbed impact energy were enhanced by 96.2% and 92.3%, respectively, for WKF/NiCo 2 S 4 /rGO (1.5%)/PES. The synergistic effect of NiCo 2 S 4 nanowires and rGO in the fabricated composites improved the electrical conductivity of insulating WKF/PES composites, reducing the resistance to ∼10 3 Ω. Joule heating performance depended strongly on the precursor concentration of the nanowires and the presence of rGO in the composite. A maximum surface temperature of 163 °C was obtained under low-voltage (5 V) application. The Joule heating performance of the composites was demonstrated in a surface deicing experiment; we observed that 17 g of ice melted from the surface of the composite in 14 min under an applied voltage of 5 V at -28 °C. The excellent performance of WKF/NiCo 2 S 4 /rGO/PES composites shows great potential for aerospace structural applications requiring outstanding mechanical properties and Joule heating capability for deicing of surfaces.

  17. In vitro hemocompatibility of sulfonated polypropylene non-woven fabric prepared via a facile γ-ray pre-irradiation grafting method

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Wu, Guozhong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031 (China); Ye, Yin, E-mail: yeyin@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-11-30

    Graphical abstract: - Highlights: • Sulfonated PP{sub NWF} was successfully fabricated via γ-ray pre-irradiation-induced graft polymerization of SSS method with the aid of AAm. • Compared with the pristine PP{sub NWF}, the sulfonated PP{sub NWF} material presented outstanding hydrophilicity. • The sulfonated PP{sub NWF} exhibited good hemocompatibility. - Abstract: Sulfonated polypropylene non-woven fabric (PP{sub NWF}) was successfully prepared via γ-ray pre-irradiation-induced graft polymerization of sodium styrenesulfonate (SSS) and acrylamide (AAm). The effect of pre-irradiation dose, reaction temperature, reaction time and concentration of binary monomer on the degree of grafting (DG) was studied. The chemical structure of the original and modified PP{sub NWF} materials were investigated by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to confirm the successful introduction of sulfonated (−SO{sub 3}{sup −}) group. The wettability was examined via measurement of de-ionized water adsorption percentage, which demonstrated that the hydrophilicity of PP{sub NWF} was greatly enhanced after graft modification. A little amount of bovine serum albumin (BSA) adsorption and nearly no platelet adhesion on the surface of modified PP{sub NWF} and low hemolytic ratio of the modified PP{sub NWF} revealed that the sulfonated PP{sub NWF} exhibited good hemocompatibility. Besides, blood clotting time measurement indicated that the anticoagulant property of PP{sub NWF} was effectively enhanced via SSS modification. Consequently, the hydrophilicity, in vitro hemocompatibility and anticoagulant effect of PP{sub NWF} were significantly improved by γ-ray pre-irradiation-induced graft polymerization of SSS.

  18. Bone health in cancer patients

    DEFF Research Database (Denmark)

    Coleman, R; Body, J J; Aapro, M

    2014-01-01

    There are three distinct areas of cancer management that make bone health in cancer patients of increasing clinical importance. First, bone metastases are common in many solid tumours, notably those arising from the breast, prostate and lung, as well as multiple myeloma, and may cause major...... morbidity including fractures, severe pain, nerve compression and hypercalcaemia. Through optimum multidisciplinary management of patients with bone metastases, including the use of bone-targeted treatments such as potent bisphosphonates or denosumab, it has been possible to transform the course of advanced...... cancer for many patients resulting in a major reduction in skeletal complications, reduced bone pain and improved quality of life. Secondly, many of the treatments we use to treat cancer patients have effects on reproductive hormones, which are critical for the maintenance of normal bone remodelling...

  19. Tarsal bone disintegration in leprosy

    International Nuclear Information System (INIS)

    Haverson, G.; Warren, A.G.

    1979-01-01

    Tarsal bone disintegration is characterised by fragmentation and progressive collapse of one or more tarsal bones. It occurs in 10% of leprosy patients, and is responsible for many severe foot deformities associated with this disease. The main cause is micro-traumata, but sensory impairment, sepsis and osteoporosis are predisposing factors. In this series of 400 consecutive patients the talus and navicular were involved most frequently (72% of 119 tarsal lesions). Treatment, including prolonged immobilisation of the foot, results in dense sclerosis of the affected bone, and leaves a functional limb. Initial radiological features include bone fragmentation, calcified fragments in adjacent soft tissues, linear fractures, progressive compression and deformity of the affected bone, loss of density of the affected bone and flattening of the longitudinal plantar arch. Illustrative case histories are presented, and the differential diagnosis discussed. (author)

  20. Stress fractures and bone pain

    International Nuclear Information System (INIS)

    Groshar, D.; Even-Sapir, E.; Lam, M.; Israel, O.; Front, D.

    1984-01-01

    Stress fractures result from an unusual repetitive physical activity causing absorption of bone in excess of repair and bone formation. This leads to the weakening of the bone and subsequently to a fracture. It is a benign condition that if recognized in time does not need any treatment besides rest. However, if diagnosis is not made and physical activity continues it may result in severe injury to the bone and a frank fracture may result. Pain is the typical clinical feature and bone scintigraphy, being more sensitive than radiography, is done to establish early diagnosis. The presence of asymptomatic sites of abnormal bone uptake typical of stress fracture in which pain appeared only about 2 weeks after scintigraphy, drew the authors' attention to the question of how close is the relationship between stress fractures and bone pain. Sixty-four military recruits diagnosed as suffering from stress fracture were investigated in order to correlate sites with abnormal uptake of Tc-99m MDP on bone scintigraphy with sites of local pain. In 37 (58%) subjects multiple sites of abnormal uptake were recognised. Of 123 sites of abnormal uptake, 31 (25%) were asymptomatic. In three patients bone pain appeared at the site of the abnormal uptake two weeks after scintigraphy. Bone scintigraphy appears to be more sensitive than bone pain in the diagnosis of stress fractures. The osteoblastic activity which manifests itself by abnormal uptake appears in some cases earlier than the pain caused by the fracture. Present findings may suggest that under certain circumstances, in a population prone to stress fracture, bone scan should be considered as a screening method