WorldWideScience

Sample records for wc operative orthopedics

  1. A touch probe method of operating an implantable RFID tag for orthopedic implant identification.

    Science.gov (United States)

    Liu, Xiaoyu; Berger, J Lee; Ogirala, Ajay; Mickle, Marlin H

    2013-06-01

    The major problem in operating an implantable radio-frequency identification (RFID) tag embedded on an orthopedic implant is low efficiency because of metallic interference. To improve the efficiency, this paper proposes a method of operating an implantable passive RFID tag using a touch probe at 13.56 MHz. This technology relies on the electric field interaction between two pairs of electrodes, one being a part of the touch probe placed on the surface of tissue and the other being a part of the tag installed under the tissue. Compared with using a conventional RFID antenna such as a loop antenna, this method has a better performance in the near field operation range to reduce interference with the orthopedic implant. Properly matching the touch probe and the tag to the tissue and the implant reduces signal attenuation and increases the overall system efficiency. The experiments have shown that this method has a great performance in the near field transcutaneous operation and can be used for orthopedic implant identification.

  2. Influence of different anesthesia methods on stress reaction and hemodynamics for elderly orthopedics patients during operations

    Directory of Open Access Journals (Sweden)

    Lin Li

    2017-07-01

    Full Text Available Objective: To study the influence of general anesthesia, epidural anesthesia and combined spinal and epidural anesthesia method on stress reaction and hemodynamics for elderly orthopedics patients during operations. Methods: A total of 90 cases of elder patients who received orthopedic operations were randomly divided to group A, B and C, with 30 cases per group. Three groups of patients were separately given by general anesthesia, epidural anesthesia and combined spinal and epidural anesthesia for operations; The variations of adrenocorticotrophic hormone (ACTH, Cortisol (Cor, β-endorphin (β-EP, Angiotensin- Ⅱ(Ang-Ⅱ, heart rate (HR and blood pressure (SBP, DBP on patients in three groups before anesthesia (T0, during skin incision (T1, after skin incision (T2 and extubation after operation (T3 were compared and analyzed. Results: During T1, T2, ACTH, Cor, β-EP and Ang-Ⅱlevels in 3 groups of patients were significantly higher than those during T0; SBP and DBP were significantly lower than that during T0; HR during T2 was significantly lower than that during T0; During T3, every index in 3 groups were recovered to levels close to that during T0; During T1, T2, ACTH, Cor, β-EP, Ang-Ⅱ levels in group B and C were significantly lower than that in group A. And levels in C was lower than that in B; SBP and DBP in group B and C were significantly higher than A. No HR statistical significance appeared between each group. Conclusions: During clinical anesthesia, we should choose suitable anesthesia method combined with actual situations of patients. Combined spinal and epidural anesthesia had a slight influence on hemodynamics of elder orthopedics patients during operation, and it could effectively alleviate stress reaction during operation.

  3. Hypobaric spinal anesthesia in the operative management of orthopedic emergencies in geriatric patients.

    Science.gov (United States)

    Sidi, A; Pollak, D; Floman, Y; Davidson, J T

    1984-07-01

    Hypobaric spinal anesthesia was administered to 40 patients undergoing lower limb surgery. Twenty-nine of the patients were debilitated geriatric patients who presented with orthopedic emergencies, in most cases a fractured hip. Hypobaric spinal anesthesia was found to be a simple and safe procedure that provided adequate analgesia. Due to its inherent nature, hypobaric spinal anesthesia does not necessitate positioning of the patient on the injured, painful side (unlike hyperbaric spinal or epidural anesthesia) and, therefore, facilitates a smooth and painless transfer of the patient to the operating table. Complications encountered were similar to those following hyperbaric anesthesia.

  4. Safety in the operating room during orthopedic trauma surgery-incidence of adverse events related to technical equipment and logistics

    NARCIS (Netherlands)

    van Delft, E. A. K.; Schepers, T.; Bonjer, H. J.; Kerkhoffs, G. M. M. J.; Goslings, J. C.; Schep, N. W. L.

    2017-01-01

    Safety in the operating room is widely debated. Adverse events during surgery are potentially dangerous for the patient and staff. The incidence of adverse events during orthopedic trauma surgery is unknown. Therefore, we performed a study to quantify the incidence of these adverse events. Primary

  5. Cold and compression in the management of musculoskeletal injuries and orthopedic operative procedures: a narrative review

    Directory of Open Access Journals (Sweden)

    Jon E Block

    2010-07-01

    Full Text Available Jon E BlockJon E Block, PhD., Incorporated, San Francisco, CA, USAAbstract: Cold and compression are routinely applied immediately after acute injury or ­following surgery to alleviate pain, reduce swelling and speed functional recovery. The objective of this literature review is to describe the published clinical findings regarding combined cold and compression therapy in the management of musculoskeletal injuries and after orthopedic operative procedures. Of 33 potential articles triaged, the findings of 21 randomized controlled trials were assessed and summarized. The findings reported by these 21 studies were largely subjective pain outcomes and, to a lesser degree, swelling and range of motion, and were inconsistent and divergent, making it difficult to recommend the most appropriate, effective clinical application of cold and compression. Further, 18 of the 21 reported studies evaluated cold and static compression, where the extent and duration of the compression was not uniform within or across studies. Operative procedures may offer a more controlled environment for rigorous investigations. However, such studies must be powered sufficiently to account for variations in surgical procedure that could affect outcomes. More uniform operative procedures, such as total knee arthroplasty, represent a well circumscribed intervention for studying the clinical utility of cold compression therapy because the operative technique is standardized, surgical tissue damage is extensive, intraoperative blood loss is high, and post-operative edema and pain are severe. Findings from randomized controlled trials of knee arthroplasty generally showed cold compression therapy provides better outcomes such as pain relief than alternative interventions. While the effects of cold and static compression are clearly better than no treatment, they do not appear to be directly additive.Keywords: cryotherapy, injury

  6. COMPARATIVE ANALYSIS OF THE TREATMENT OF THE EOSINOPHILIC GRANULOMA WITH VERTEBRAL INVOLVEMENT USING ORTHOPEDIC CORSET AND SURGICAL OPERATION

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    A. I. Snetkov

    2010-01-01

    Full Text Available The results of treatment of 72 patients with pathological fracture of vertebra bodies against eosinophilic granuloma a spine are analysed. Orthopedic corset technologies are used in treatment of 42 patients, surgical treatment was applied. Orthopedic corset may be used in patients with eosinophilic granuloma of backbone. This method of treatment was used in a case of the absence of spine secondary deformations and neurologic semiology. Orthopedic corset treatment is associated with long immobilization on the average within 1,5-2 years and never leads to a complete recovery of the damaged spine. Surgical treatment consists in use only at loss of height of a body to 30-40%, when destruction of spine more severe it is necessary to use operative treatment in two stages. Absolute indications to surgical treatment are the neurologic deficit and secondary deformations of a spine. Surgical treatment allows to reduce terms of treatment till 3-4 months and quickly to return the patient to an active life.

  7. Tourniquets and exsanguinators: a potential source of infection in the orthopedic operating theater?

    LENUS (Irish Health Repository)

    Brennan, Stephen A

    2009-04-01

    BACKGROUND AND PURPOSE: Fomites are increasingly being recognised as a source of hospital-acquired infection. We have therefore assessed tourniquets and exsanguinators for the presence of bacterial pathogens in 1 elective and 2 trauma orthopedic hospitals. MATERIAL AND METHODS: Swabs were taken prior to and after decontaminating these devices with 1 of 3 different cleaning modalities. These were then assessed for colony counts and organisms identified. RESULTS: Bacteria commonly implicated in surgical site infections such as coagulase-negative staphylococci, Staphylococcus aureus and Proteus spp. were prevalent. We also found a resistant strain of Acinetobacter and Candida. Exsanguinators were the most heavily contaminated devices, and colony counts in the trauma hospitals were up to 400% higher than in the elective hospital. Alcohol- and non-alcohol-based sterile wipes were both highly effective in decontaminating the devices. INTERPRETATION: Infectious organisms reside on the tourniquets and exsanguinators presently used in the orthopedic theater. These fomites may possibly be a source of surgical site infection. We have demonstrated a simple and effective means of decontaminating these devices between cases.

  8. Orthopedic radiology in the postoperative patient (practical orthopedic radiology)

    International Nuclear Information System (INIS)

    Weissman, B.N.; Gelman, M.I.

    1987-01-01

    This course examines various aspects of the radiologic examination of postoperative orthopedic patients. The operative indications, pertinent aspects of surgical technique, expected postoperative radiographic appearances, and radiographic findings indicating postoperative complications are discussed. The evaluation of total joint replacement surgery, spinal surgery, lower extremity procedures, and failed orthopedic devices and appliances are covered

  9. Medical Issues: Orthopedics

    Science.gov (United States)

    ... Information Packets Equipment Pool Living With SMA Medical Issues Palliative Breathing Orthopedics Nutrition Equipment Daily Life At ... curesma.org > support & care > living with sma > medical issues > orthopedics Orthopedics In SMA, muscle weakness can cause ...

  10. Comparison between mixed and laminar airflow systems in operating rooms and the influence of human factors: experiences from a Swedish orthopedic center.

    Science.gov (United States)

    Erichsen Andersson, Annette; Petzold, Max; Bergh, Ingrid; Karlsson, Jón; Eriksson, Bengt I; Nilsson, Kerstin

    2014-06-01

    The importance of laminar airflow systems in operating rooms as protection from surgical site infections has been questioned. The aim of our study was to explore the differences in air contamination rates between displacement ventilation and laminar airflow systems during planned and acute orthopedic implant surgery. A second aim was to compare the influence of the number of people present, the reasons for traffic flow, and the door-opening rates between the 2 systems. Active air sampling and observations were made during 63 orthopedic implant operations. The laminar airflow system resulted in a reduction of 89% in colony forming units in comparison with the displacement system (P operating rooms offer high-quality air during surgery, with very low levels of colony forming units close to the surgical wound. The continuous maintenance of laminar air flow and other technical systems are crucial, because minor failures in complex systems like those in operating rooms can result in a detrimental effect on air quality and jeopardize the safety of patients. The technical ventilation solutions are important, but they do not guarantee clean air, because many other factors, such as the organization of the work and staff behavior, influence air cleanliness. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  11. Sampling and analysis of inactive radioactive waste tanks W-17, W-18, WC-5, WC-6, WC-8, and WC-11 through WC-14 at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Sears, M.B.; Giaquinto, J.M.; Griest, W.H.; Pack, R.T.; Ross, T.; Schenley, R.L.

    1995-12-01

    The sampling and analysis of nine inactive liquid low-level waste (LLLW) tanks at the Oak Ridge National Laboratory (ORNL) are described-tanks W-17, W-18, WC-5, WC-6, WC-8, and WC-11 through WC-14. Samples of the waste tank liquids and sludges were analyzed to determine (1) the major chemical constituents, (2) the principal radionuclides, (3) metals listed on the US Environmental Protection Agency (EPA) Contract Laboratory Program Inorganic Target Analyte List, (4) organic compounds, and (5) some physical properties. The organic chemical characterization consisted of determinations of the EPA Contract Laboratory Program Target Compound List volatile and semivolatile compounds, pesticides, and polychlorinated biphenyis (PCBs). This report provides data (1) to meet requirements under the Federal Facility Agreement (FFA) for the Oak Ridge Reservation to characterize the contents of LLLW tanks which have been removed from service and (2) to support planning for the treatment and disposal of the wastes.

  12. Sampling and analysis of inactive radioactive waste tanks W-17, W-18, WC-5, WC-6, WC-8, and WC-11 through WC-14 at ORNL

    International Nuclear Information System (INIS)

    Sears, M.B.; Giaquinto, J.M.; Griest, W.H.; Pack, R.T.; Ross, T.; Schenley, R.L.

    1995-12-01

    The sampling and analysis of nine inactive liquid low-level waste (LLLW) tanks at the Oak Ridge National Laboratory (ORNL) are described-tanks W-17, W-18, WC-5, WC-6, WC-8, and WC-11 through WC-14. Samples of the waste tank liquids and sludges were analyzed to determine (1) the major chemical constituents, (2) the principal radionuclides, (3) metals listed on the US Environmental Protection Agency (EPA) Contract Laboratory Program Inorganic Target Analyte List, (4) organic compounds, and (5) some physical properties. The organic chemical characterization consisted of determinations of the EPA Contract Laboratory Program Target Compound List volatile and semivolatile compounds, pesticides, and polychlorinated biphenyis (PCBs). This report provides data (1) to meet requirements under the Federal Facility Agreement (FFA) for the Oak Ridge Reservation to characterize the contents of LLLW tanks which have been removed from service and (2) to support planning for the treatment and disposal of the wastes

  13. Greening of orthopedic surgery.

    Science.gov (United States)

    Lee, Rushyuan J; Mears, Simon C

    2012-06-01

    Every year, 4 billion pounds of waste are produced by health care facilities, and the amount continues to increase annually. In response, a movement toward greening health care has been building, with a particular focus on the operating room. Between 20% and 70% of health care waste originates from a hospital's operating room, and up to 90% of operating room waste is improperly sorted and sent for costly and unneeded hazardous waste processing. Recent successful changes include segregation of hospital waste, substitution of the ubiquitous polypropylene plastic wrap used for the sterilization and handling of surgical equipment with metal cases, and the reintroduction of reusable surgical gowns. Orthopedic-related changes include the successful reprocessing and reuse of external fixators, shavers, blades, burs, and tourniquets. These changes have been shown to be environmentally and economically beneficial. Early review indicates that these changes are feasible, but a need exists for further evaluation of the effect on the operating room and flow of the surgical procedure and of the risks to the surgeons and operating room staff. Other key considerations are the effects of reprocessed and reused equipment on patient care and outcome and the role of surgeons in helping patients make informed decisions regarding surgical care. The goals of this study were to summarize the amount and types of waste produced in hospitals and operating rooms, highlight the methods of disposal used, review disposal methods that have been developed to reduce waste and improve recycling, and explore future developments in greening health care. Copyright 2012, SLACK Incorporated.

  14. Fabrication and evaluation of atmospheric plasma spraying WC-Co-Cu-MoS2 composite coatings

    International Nuclear Information System (INIS)

    Yuan Jianhui; Zhu Yingchun; Zheng Xuebing; Ji Heng; Yang Tao

    2011-01-01

    Research highlights: → Protective WC-Co-based coatings containing solid lubricant Cu and MoS 2 used in wear applications were investigated in this study. → It was found that the MoS 2 composition in the feed powder was kept in WC-Co-Cu-MoS 2 coatings, and the decomposition and decarburization of WC in APS process were improved. → Combining the wear resistance of WC with the lubricating properties of Cu and MoS 2 has an extremely beneficial effect on improving the tribological performance of the resulting coating. - Abstract: Protective WC-Co-based coatings containing solid lubricant Cu and MoS 2 used in wear applications were investigated in this study. These coatings were deposited on mild steel substrates by atmospheric plasma spraying (APS). The feedstock powders were prepared by mechanically mixing the solid lubricant powders and WC-Co powder, followed by sintering and crushing the mixtures to avoid different particle flighting trajectories at plasma. The tribological properties of the coatings against stainless steel balls were examined by ball-on-disk (BOD) tribometer under normal atmospheric condition. The microstructure of the coatings was studied by optical microscope, scanning electron microscope and X-ray diffraction. It was found that the MoS 2 composition in the feed powder was kept in WC-Co-Cu-MoS 2 coatings, and the decomposition and decarburization of WC in APS process were improved, which were attributed to the protection of Cu around them. The friction and wear behaviors of all the WC-Co-Cu-MoS 2 coatings were superior to that of WC-Co coating. Such behavior was associated to different wear mechanisms operating for WC-Co coating and the WC-Co-Cu-MoS 2 coatings.

  15. Infiltration Behavior Of Mechanical Alloyed 75 wt% Cu-25 wt% WC Powders Into Porous WC Compacts

    Directory of Open Access Journals (Sweden)

    Şelte A.

    2015-06-01

    Full Text Available In this work infiltration behavior of mechanical alloyed 75 wt% Cu – 25 wt% WC powders into porous WC compacts were studied. Owing to their ductile nature, initial Cu powders were directly added to mechanical alloying batch. On the other hand initial WC powders were high energy milled prior to mechanical alloying. Contact infiltration method was selected for densification and compacts prepared from processed powders were infiltrated into porous WC bodies. After infiltration, samples were characterized via X-Ray diffraction studies and microstructural evaluation of the samples was carried out via scanning electron microscopy observations. Based on the lack of solubility between WC and Cu it was possible to keep fine WC particles in Cu melt since solution reprecipitation controlled densification is hindered. Also microstructural characterizations via scanning electron microscopy confirmed that the transport of fine WC fraction from infiltrant to porous WC skeleton can be carried out via Cu melt flow during infiltration.

  16. Comparison of the Effect of Noise Levels on Stress Response in Two Different Operation Groups in an Orthopedic Surgery Room

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    Hasibe Baytan Yildiz

    2016-09-01

    Full Text Available Aim: The aim of this randomized, single-blinded study was to evaluate the effects of noise on hemodynamic and neuroendocrine stress response by measuring the level of noise in the surgery rooms of patients undergoing knee operations under neuroaxial anesthesia. Gerec ve Yontem: We compared patient responses from two groups of patients: those undergoing knee operations in a surgery room where the noise level (measured in decibels is high, and those undergoing meniscus operations in a surgery room with lower noise levels. The STAI, the State-Trait Anxiety Inventory (STAI-1, and the anxiety test (STAI-2wereperformed at preoperative and postoperative periods. 20 ml of blood sample was taken for basal, intraoperative 30th minute, and postoperative 1st hour measurements. Systolic, diastolic, and mean arterial blood pressures were found to be higher in the high noise level group. ACTH levels were increased during the early postoperative period and became normal during the late postoperative period in the high noise level group whereas ACTH levels were significantly decreased in the low-noise level group. Basal cortisol levels were significantly higher in the high noise level group. HCRP, an inflammatory response mediator was found to be decreased in both groups. Early and late blood glucose levels were significantly higher in the high noise group. There was a greater increase in early and late blood glucose levels in the high noise group. In the postoperative period, although the state-trait anxiety inventory (STAI-2 levels being higher in patients subject to noisier environment determines how people feel independent of the conditions and state they are in, this result made us consider that the noise the patients were subjected to in the intraoperative period may cause a stress response. Discussion: As a result we believe that standard noise levels should be achieved by reducing the factors causing high noise levels in the operating room. This will

  17. Cold compaction behavior and pressureless sinterability of ball milled WC and WC/Cu powders

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    Hashemi Seyed R.

    2016-01-01

    Full Text Available In this research, cold compaction behavior and pressureless sinterability of WC, WC-10%wtCu and WC-30%wtCu powders were investigated. WC and WC/Cu powders were milled in a planetary ball mill for 20h. The milled powders were cold compacted at 100, 200, 300 and 400 MPa pressures. The compressibility behavior of the powders was evaluated using the Heckel, Panelli-Ambrosio and Ge models. The results showed that the Panelli-Ambrosio was the preferred equation for description the cold compaction behavior of the milled WC and WC-30%wtCu powders. Also, the most accurate model for describing the compressibility of WC-10%wtCu powders was the Heckel equation. The cold compacts were sintered at 1400°C. It was found that by increasing the cold compaction pressure of powder compacts before sintering, the sinterability of WC-30%wtCu powder compacts was enhanced. However, the cold compaction magnitude was not affected significantly on the sinterability of WC and WC-10%wtCu powders. The microstructural investigations of the sintered samples by Scanning Electron Microscopy (SEM confirmed the presence of porosities at the interface of copper-tungsten carbide phases.

  18. Morpho-Structural Characterization of WC20Co Deposited Layers

    Science.gov (United States)

    Tugui, C. A.; Vizureanu, P.

    2017-06-01

    Hydroelectric power plants use the power of water to produce electricity. In this paper we propose a solution that will increase the efficiency of turbine operation by implementing new innovative technologies to increase the working characteristics by depositing hard thin films of tungsten carbide. For this purpose hard tough deposits with WC20Co and Jet Plasma Jet on X3CrNiMo13-4 stainless steel were used for the realization of the Francis turbine with vertical shaft.

  19. Tourniquets in orthopedic surgery

    Directory of Open Access Journals (Sweden)

    Jai Prakash Sharma

    2012-01-01

    Full Text Available Tourniquets are commonly used in limb surgeries, be it orthopedic or plastic surgeries. But the inflation pressures, the duration, and release guidelines are still not clear. According to a survey, majority of orthopedic surgeons inflate the tourniquet to fixed pressures for the upper and the lower limbs without considering the baseline blood pressure of the patient on whom the tourniquets are being applied. This review was designed to recall and review the safe use of tourniquets and the various techniques that can be employed to minimize the complications of tourniquet use. Google, science direct, and pubmed were searched for appropriate literature and relevant articles were identified.

  20. Pd enhanced WC catalyst to promote heterogeneous methane combustion

    International Nuclear Information System (INIS)

    Terracciano, Anthony Carmine; De Oliveira, Samuel; Siddhanti, Deepti; Blair, Richard; Vasu, Subith S.; Orlovskaya, Nina

    2017-01-01

    Highlights: • Pd enhanced WC catalyst particles were synthesized via mechanochemical alloying. • Catalyst was characterized by XRD, XRF, SEM, and EDS. • Catalyst was deposited on porous ZrO_2 and evaluated in heterogeneous combustion. • During combustion temperature profiles and spectral emissions were collected. - Abstract: The efficiency of combustion for low cost heat production could be greatly enhanced if an active and low cost catalyst would be used to facilitate the chemical reactions occurring during combustor operation. Within this work an experimental study of palladium (Pd) enhanced tungsten carbide (WC) catalyst, synthesized via high energy ball milling and deposited by dip coating onto a magnesia partially stabilized zirconia (MgO-ZrO_2) porous matrix of 10 ppin was evaluated in heterogeneous methane combustion. The synthesized powder was characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) analysis, as well as by X-ray Fluorescence (XRF); and the morphology of the deposited WC-Pd coating was also characterized using SEM and EDS. Performance evaluation of the heterogeneous combustor with WC-Pd coated MgO-ZrO_2 porous media was conducted at constant air flow rate and various equivalence ratios of methane/air gaseous mixtures, while monitoring axial temperature profiles within the combustion chamber using thermocouples, as well as thermal radiative and acoustic emissions from the combustor exhaust using an externally placed CCD camera and a microphone. It was found that there is a strong dependence of flame position and maximum temperature on equivalence ratio (φ) over the range of 0.47 ± 0.02 ⩽ φ ⩽ 0.75 ± 0.02. Additionally it was found that over the same equivalence ratio range, there is a characteristic 4 peak acoustic signature between 200 and 500 Hz. It was found that at higher equivalence ratios 0.51 ± 0.02 ⩽ φ ⩽ 0.75 ± 0.02 the performance of combustor

  1. Microstructure, Wear Behavior and Corrosion Resistance of WC-FeCrAl and WC-WB-Co Coatings

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    Janette Brezinová

    2018-05-01

    Full Text Available The paper is focused on investigating the quality of two grades of thermally sprayed coatings deposited by high-velocity oxygen fuel (HVOF technology. One grade contains WC hard particles in an environmentally progressive Ni- and Co-free FeCrAl matrix, while the second coating contains WC and WB hard particles in a cobalt matrix. The aim of the experimental work was to determine the effect of thermal cyclic loading on the coatings’ resistance to adhesive, abrasive and erosive wear. Abrasive wear was evaluated using abrasive cloth of two grit sizes, and erosive wear was evaluated by a dry-pot wear test in a pin mill at two sample angles. Adhesion wear resistance of the coatings was determined by a sliding wear test under dry friction conditions and in a 1 mol water solution of NaCl. Corrosion resistance of the coatings was evaluated using potentiodynamic polarization tests. Metallographic cross-sections were used for measurement of the microhardness and thickness and for line energy-dispersive X-ray (EDX analysis. The tests proved the excellent resistance of both coatings against adhesive, abrasive, and erosive wear, as well as the ability of the WC-WB-Co coating to withstand alternating temperatures of up to 600 °C. The “green carbide” coating (WC-FeCrAl can be recommended as an environmentally friendly replacement for Ni- and Co-containing coatings, but its operating temperature is strictly limited to 500 °C in air.

  2. Effects of WC Particle Size and Co Content on the Graded Structure in Functionally Gradient WC-Co Composites

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    Yuan Yigao

    2016-01-01

    Full Text Available Functionally gradient WC-Co composites having a Co depleted surface zone and not comprising the h phase can be manufactured via carburizing process. During carburizing, besides carburizing process parameters, the microstructural parameters of WC-Co materials, such as WC grain size and Co content, also have significant influences on the formation of Co gradient structure. In this study, the effects of WC particle size and Co content on the gradient structure within gradient hardmetals have been studied, based on a series of carburizing experiments of WC-Co materials with different WC particle sizes and cobalt contents. The results show that both the thickness and the amplitude of the gradients within gradient WC-Co materials increase with increasing initial WC particle size and Co content of WC-Co alloys. The reason for this finding is discussed.

  3. Observation of WC grain shapes determined by carbon content during liquid phase sintering of WC-Co alloys

    International Nuclear Information System (INIS)

    Sona Kim; Hyoun-Ee Kim; Seok-Hee Han; Jong-Ku Park

    2001-01-01

    In the composite materials of WC-Co alloys, the faceted WC grains as a hard phase are dispersed in the ductile matrix of cobalt. Properties of WC-Co alloys are affected by microstructural factors such as volume fraction of WC phase, size of WC grains, and carbon content (kinds of constituent phases). Although the properties of WC-Co alloys are inevitably affected by the shape of WC grains, the shape of WC grains has not been thrown light on the properties of WC-Co alloys yet, because it has been regarded to have a uniform shape regardless of alloy compositions. It is proved that the WC grains have various shapes varying reversibly with carbon content in the sintered WC-Co compacts. This dependency of grain shape on the carbon content is attributed to asymmetric atomic structure of WC crystal. The {10 1 - 0} prismatic planes are distinguished into two groups with different surface energy according to their atomic structures. The prismatic planes of high surface energy tend to disappear in the compacts with high carbon content. In addition, these high energy prismatic planes tend to split into low energy surfaces in the large WC grains. (author)

  4. Characteristics of Orthopedic Publications in High-Impact General Medical Journals.

    Science.gov (United States)

    Nwachukwu, Benedict U; Kahlenberg, Cynthia A; Lehman, Jason D; Lyman, Stephen; Marx, Robert G

    2017-05-01

    Orthopedic studies are occasionally published in high-impact general medical journals; these studies are often given high visibility and have significant potential to impact health care policy and inform clinical decision-making. The purpose of this review was to investigate the characteristics of operative orthopedic studies published in high-impact medical journals. The number of orthopedic studies published in high-impact medical journals is relatively low; however, these studies demonstrate methodological characteristics that may bias toward nonoperative treatment. Careful analysis and interpretation of orthopedic studies published in these journals is warranted. [Orthopedics. 2017; 40(3):e405-e412.]. Copyright 2017, SLACK Incorporated.

  5. Metal modified tungsten carbide (WC) for catalytic and electrocatalytic applications

    Science.gov (United States)

    Mellinger, Zachary J.

    One of the major challenges in the commercialization of proton exchange membrane fuel cells (PEMFC) is the cost, and low CO tolerance of the anode electrocatalyst material. The anode typically requires a high loading of precious metal electrocatalyst (Pt or Pt--Ru) to obtain a useful amount of electrical energy from the electrooxidation of methanol (CH3OH) or ethanol (C2H5OH). The complete electro--oxidation of methanol or ethanol on these catalysts produces strongly adsorbed CO on the surface, which reduces the activity of the Pt or Pt--Ru catalysts. Another major disadvantage of these electrocatalyst components is the scarcity and consequently high price of both Pt and Ru. Tungsten monocarbide (WC) has shown similar catalytic properties to Pt, leading to the utilization of WC and metal modified WC as replacements to Pt and Pt--Ru. In this thesis we investigated WC and Pt--modified WC as a potentially more CO--tolerant electrocatalysts as compared to pure Pt. These catalysts would reduce or remove the high loading of Pt used industrially. The binding energy of CO, estimated using temperature programmed desorption, is weaker on WC and Pt/WC than on Pt, suggesting that it should be easier to oxidize CO on WC and Pt/WC. This hypothesis was verified using cyclic voltammetry to compare the electro--oxidation of CO on WC, Pt/WC, and Pt supported on carbon substrates, which showed a lower voltage for the onset of oxidation of CO on WC and Pt/WC than on Pt. After observing these improved properties on the Pt/WC catalysts, we decided to expand our studies to investigate Pd--modified WC as Pd is less expensive than Pt and has shown more ideal properties for alcohol electrocatalysis in alkaline media. Pd/WC showed a lower binding energy of CO than both its parent metal Pd as well as Pt. Then, density functional theory (DFT) calculations were performed to determine how the presence of Pd affected the bonding of methanol and ethanol on the WC surface. The DFT studies showed

  6. Orthopedic X-ray diagnostics

    International Nuclear Information System (INIS)

    Bernau, A.

    1982-01-01

    Positioning techniques have been developed as a means of standardizing skeleton pictures so as to facilitate functional interpretations in orthopedics. Standard positions are described as well as specific orthopedic and traumatological problems. The list of positions must, of course, be incomplete as there are too many. Access to the subject is facilitated by a systematic approach. (orig.) [de

  7. On the preparation of fine V8C7-WC and V4C3-WC powders

    CSIR Research Space (South Africa)

    Osborne, C

    1997-01-01

    Full Text Available The aim of this work was to produce V8C7-WC and V4C3-WC powders with grain size between 1 and 2mu-m, as a first stage of the preparation of fine grained WC-VC-Co hardmetal. V8C7-WC powder was produced via two routes: starting from preformed V8C7...

  8. WC-3015 alloy (high-temperature alloy)

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    WC-3015 Nb alloy containing 28 to 30 Hf, 1 to 2 Zr, 13 to 16 W, 0 to 4 Ta, 0 to 5 Ti, 0.07 to 0.33 C, less than or equal to 0.02 N, less than or equal to 0.03 O, less than or equal to 0.001 H was developed for use at high temperature in oxidizing environments. Its composition can be tailored to meet specific requirements. When WC-3015 is exposed to O at elevated temperature, Hf and Nb oxidized preferentially and HfO 2 dissolves in Nb 2 O 5 to form 6HfO-Nb 2 O 5 . This complex oxide has a tight cubic lattice which resists the diffusion of O into the substrate. During 24-h exposure to air at 2400 0 F, the alloy oxidizes to a depth of approximately 0.035 in. with a surface recession of 0 to 0.004 in. Oxidation resistance of WC-3015 welds and base material can be further enhanced greatly by applying silicide coatings. WC-3015 alloy can be machined by conventional and electrical-discharge methods. It can be hot worked readily by extrusion, forging or rolling. Cold working can be used at room or elevated temperature. It can be welded by the electron-beam or Tig processes. Physical constants, typical mechanical properties at 75 to 2400 0 F, and effects of composition and heat treatment on tensile and stress-rupture properties of the alloy are tabulated

  9. The effect and clinical significance of Shuxuetong injection on the changes of plasma TXB2 and 6-Keto-PGF1α levels in patients after hip orthopedic operation

    International Nuclear Information System (INIS)

    Mao Zhaoguang; Xu Shenggen; Wu Qingxin; Zhu Huihua; Liu Bingsheng; Yu Binwei; Xu Shang'ao; Zheng Yihua

    2011-01-01

    Objective: To investigate shuxuetong injection on the changes of thromboxane B 2 (TXB 2 ) and 6-keto-prostacyclin(6-Keto-PGF 1α ) levels on the patients after hip orthopedic operation and its clinical significance. Methods: 50 hip orthopedic surgery patients were randomly divided into the shuxuetong group and the low-molecular-weight heparin (LMWH) group. Both groups were treated with conventional therapy. Shuxuetong group were 23 cases, including 7 cases of total hip replacement (THR), 16 patients of internal fixation after hip fracture. Each patient were given Shuxuetong intravenous injection 6 ml once a day, LMWH group contain 27 patients, including 9 cases of total hip replacement(THR), 18 patients of applying internal fixation to hip fracture. Each patient was given LMWH 5000 IU subcutaneously once daily. Both groups were treated for 14 days. In the day of surgery and the morning after therapy,fasting venous blood were collected respectively. The levels of plasma TXB 2 and 6-Keto-PGF 1α were measured by radioimmunoassay. Seven days after the surgery, patients in both groups were given low extremity venography examination. The changes of TXB 2 , 6-Keto-PGF 1α level and the incidence of lower extremity deep vein thrombosis (DVT) between two groups were compared before and after treatment. Results: The levels of TXB 2 and 6-Keto-PGF 1α is not mach significant difference between the two groups before treatment (P>0.05). After treatment,the increased of 6-Keto-PGF 1α and the decreased of TXB 2 were statistically significant difference (P 1α level of LMWH group was significantly higher after the treatment (P 2 had no obvious difference (P>0.05). The levels of TXB 2 and 6-Keto-PGF 1α was significant difference between the two groups after treatment(P 0.05). Two groups were not found more intraoperative and postoperative bleeding and the consequent adverse reactions. Conclusion: Shuxuetong injection adjust the plasma TXB 2 /6-Keto-PGF 1α balance after hip

  10. Interactions between tungsten carbide (WC) particulates and metal matrix in WC-reinforced composites

    International Nuclear Information System (INIS)

    Lou, D.; Hellman, J.; Luhulima, D.; Liimatainen, J.; Lindroos, V.K.

    2003-01-01

    A variety of experimental techniques have been used to investigate the interactions between tungsten carbide (WC-Co 88/12) particulates and the matrix in some new wear resistant cobalt-based superalloy and steel matrix composites produced by hot isostatic pressing. The results show that the chemical composition of the matrix has a strong influence on the interface reaction between WC and matrix and the structural stability of the WC particulates in the composite. Some characteristics of the interaction between matrix and reinforcement are explained by the calculation of diffusion kinetics. The three-body abrasion wear resistance of the composites has been examined based on the ASTM G65-91 standard procedure. The wear behavior of the best composites of this study shows great potential for wear protection applications

  11. Sampling and analysis of the inactive waste tanks TH-2, WC-1, and WC-15

    International Nuclear Information System (INIS)

    Autrey, J.W.; Keller, J.M.; Griest, W.H.; Botts, J.L.; Schenley, R.L.; Sipe, M.A.

    1992-02-01

    Thirty-eight inactive liquid low-level radioactive waste tanks are currently managed by the Environmental Restoration Program of Oak Ridge National Laboratory. The contents of these tanks are to be characterized in preparation for future corrective actions and remediation activities as part of compliance with the pending Federal Facility Agreement for the Oak Ridge Reservation. Twenty-nine of these tanks were sampled and analyzed in 1989. Three of the tanks (TH-2, WC-1, and WC-15) were not accessible from the surface and thus were not sampled until 1990. This report presents the sampling and analytical results of that campaign. All three tanks in this report had negligible regulatory organic compounds in the samples that were collected. There were no US Environmental Protection Agency (EPA) Target Compound List (TCL) constituents for volatile organics detected in any of the aqueous samples. The only semivolatile organics detected were 2-chlorophenol (52 μg/L) in tank TH-2 and dichloroethane (14--15 μg/L) and diethyl either (15--17 μg/L) in tank WC-15. A thin oil layer was discovered floating on top of the aqueous contents in tank WC-15. The analysis of the oil layer detected no volatile organics and showed only one EPA TCL constituent, di-n-butylphthalate, at 1900 μg/L. Low levels of Resource Conservation and Recovery Act (RCRA) metals were observed in the samples from tank TH-2, but only the mercury level exceeded the RCRA limit. Samples from tank WC-1 had elevated levels of the RCRA metals barium, chromium, and lead. There were also finely suspended particles in one of the samples from tank WC-1, which was filtered and analyzed separately. This solid fines have levels of transuranium elements 238 Pu and 241 Am high enough to classified as transuranic waste

  12. COBRA-WC: a version of COBRA for single-phase multiassembly thermal hydraulic transient analysis

    International Nuclear Information System (INIS)

    George, T.L.; Basehore, K.L.; Wheeler, C.L.; Prather, W.A.; Masterson, R.E.

    1980-07-01

    The objective of this report is to provide the user of the COBRA-WC (Whole Core) code a basic understanding of the code operation and capabilities. Included in this manual are the equations solved and the assumptions made in their derivations, a general description of the code capabilities, an explanation of the numerical algorithms used to solve the equations, and input instructions for using the code. Also, the auxiliary programs GEOM and SPECSET are described and input instructions for each are given. Input for COBRA-WC sample problems and the corresponding output are given in the appendices. The COBRA-WC code has been developed from the COBRA-IV-I code to analyze liquid Metal Fast Breeder Reactor (LMFBR) assembly transients. It was specifically developed to analyze a core flow coastdown to natural circulation cooling

  13. WC as a non-platinum hydrogen evolution electrocatalyst for high temperature PEM water electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    2012-01-01

    Tungsten carbide (WC) nanopowder was tested as a non-platinum cathode electrocatalyst for polymer electrolyte membrane (PEM) water electrolysers, operating at elevated temperatures. It was prepared in thermal plasma reactor with confined plasma jet from WO3 precursor in combination with CH4...

  14. Metallography and quality of dies made from WC-Co cemented carbides; Metallographie und Qualitaetskontrolle von WC-Co-Hartmetallmatrizen

    Energy Technology Data Exchange (ETDEWEB)

    Forejt, M. [Inst. of Technology, Faculty of Mechanical Engineering, Technical Univ., Brno (Czech Republic); Krejcova, J. [Inst. of Technology, Faculty of Mechanical Engineering, Technical Univ., Brno (Czech Republic); Smutna, J. [Inst. of Physics of Materials, ASCR, Brno (Czech Republic); Krejci, J. [Inst. of Physics of Materials, ASCR, Brno (Czech Republic)

    1995-05-01

    As opposite to cutting tools made from cemented carbides, forming tools (dies) seem to be on the periphery of the interest, although specific loading conditions (increased temperature, relatively high strain rate, high pressure and cyclic loading) impose different requirements on the material. The present paper contains results of light and SEM metallography of WC + Co cemented carbide dies used for screw nuts production. Two problems were pursued viz. final preparation of the surface of operative cavity after drilling and defects that appear when recycled cemented carbides are used for die production. (orig.) [Deutsch] Im Gegensatz zu Hartmetall-Schneidwerkzeugen scheinen Formwerkzeuge (Matrizen) nur am Rande des Interesses zu liegen, obwohl hier die spezifischen Beanspruchungsbedingungen (hoehere Temperaturen, relativ hohe Dehnrate, hoher Druck und zyklische Belastung) zu besonderen Anforderungen an den Werkstoff fuehren. Es werden die Ergebnisse der lichtmikroskopischen und REM-Untersuchungen an WC-Co-Hartmetallmatrizen fuer die Mutternherstellung beschrieben. Zwei Themen werden behandelt, und zwar die Endbearbeitung der Formhohlraum-Oberflaeche nach dem Bohren und die Fehler, die durch die Verwendung von Hartmetallschrott fuer die Matrizenherstellung auftreten koennen. (orig.)

  15. Orthopedic injuries associated with backyard trampoline use in children.

    Science.gov (United States)

    Black, G Brian; Amadeo, Ryan

    2003-06-01

    Trampolining on an outdoor oval or circular trampoline is a popular activity for children but is associated with a number of orthopedic injuries, especially in children between the ages of 5 and 15 years. In this paper we review the orthopedic injuries in children associated with backyard trampoline use, through our experience with a series of children admitted to the Winnipeg Children's Hospital, the only tertiary care pediatric centre in Manitoba. We reviewed the charts, x-ray films and operative reports for 80 children under 16 years old (mean 9 yr, with 14 [18%] children between 2 and 4 yr) with an orthopedic injury sustained when using a trampoline in the backyard. We noted the mechanism of injury and type and severity of orthopedic injury sustained. Fifty-two (65%) children were injured on the trampoline mat, and 24 (30%) were injured when they were ejected from the trampoline. Sixty (75%) children sustained a fracture or fracture-dislocation. Forty-eight (80%) orthopedic injuries occurred in the upper extremity. No child died as a result of a trampoline injury. The use of the "backyard" trampoline by young children can cause significant orthopedic injury.

  16. The Quality of Cost-Utility Analyses in Orthopedic Trauma.

    Science.gov (United States)

    Nwachukwu, Benedict U; Schairer, William W; O'Dea, Evan; McCormick, Frank; Lane, Joseph M

    2015-08-01

    As health care in the United States transitions toward a value-based model, there is increasing interest in applying cost-effectiveness analysis within orthopedic surgery. Orthopedic trauma care has traditionally underemphasized economic analysis. The goals of this review were to identify US-based cost-utility analysis in orthopedic trauma, to assess the quality of the available evidence, and to identify cost-effective strategies within orthopedic trauma. Based on a review of 971 abstracts, 8 US-based cost-utility analyses evaluating operative strategies in orthopedic trauma were identified. Study findings were recorded, and the Quality of Health Economic Studies (QHES) instrument was used to grade the overall quality. Of the 8 studies included in this review, 4 studies evaluated hip and femur fractures, 3 studies analyzed upper extremity fractures, and 1 study assessed open tibial fracture management. Cost-effective interventions identified in this review include total hip arthroplasty (over hemiarthroplasty) for femoral neck fractures in the active elderly, open reduction and internal fixation (over nonoperative management) for distal radius and scaphoid fractures, limb salvage (over amputation) for complex open tibial fractures, and systems-based interventions to prevent delay in hip fracture surgery. The mean QHES score of the studies was 79.25 (range, 67-89). Overall, there is a paucity of cost-utility analyses in orthopedic trauma; however, the available evidence suggests that certain operative interventions can be cost-effective. The quality of these studies, however, is fair, based on QHES grading. More attention should be paid to evaluating the cost-effectiveness of operative intervention in orthopedic trauma. Copyright 2015, SLACK Incorporated.

  17. Medical students' and interns' interest in orthopedic surgery: the gender factor.

    Science.gov (United States)

    Schroeder, Joshua E; Zisk-Rony, Rachel Y; Liebergall, Meir; Tandeter, Howard; Kaplan, Leon; Weiss, Yoram G; Weissman, Charles

    2014-01-01

    There is an extremely small proportion of female medical students choosing to specialize in orthopedic surgery. The aim of the study was to assess medical students' and interns' interests and perceptions of orthopedic surgery and explore why women are not interested in orthopedic surgery. Questionnaires were distributed to final-year medical students and interns assessing their interests and perception of orthopedic surgery. Final-year medical students and interns. Responses were obtained from 317 students and 199 interns. Among the medical students, 15% were interested in orthopedic surgery, but only 2% were women. Both male and female students perceived orthopedics as an "action"-packed, procedure-based profession, providing instant gratification, time in the operating room, high income, and the option for private practice. Female medical students considered it boring. Among interns, 11% were interested in orthopedic surgery; however, only 2% were women. When compared with the interns who were not interested in orthopedic surgery, a greater number of the interns interested in orthopedic surgery rated time with family and a procedure-intensive profession as important. Female students and interns were also interested in other surgical fields. The increasing majority of women among medical students will reshape the future of physician workforce by dictating changes in workforce participation, working conditions, and intercollegial relationships. Orthopedic surgery will need to adapt to these realities. Published by Elsevier Inc.

  18. Contribution to the quantum study of neutral tungsten carbide WC and ionized (WC"q"+, q=1 and 2)

    International Nuclear Information System (INIS)

    Sabor, Said

    2015-01-01

    Metal carbides and oxides are more interesting in catalytic and industrial domains. Tungsten carbide WC has been detected as serious substituent of platinum Pt catalytic. The ultimate goal of this thesis is theoretical studies of electronic structure, stability and the bound nature on WC, WO and its cations. Our preliminary research were motivated by the available spectroscopic data on W, W"+, W"2"+, WC and WC"2"+. We used the methodology (CASSCF/MRCI/MRCI+Q/aug-cc-pV5Z(-PP)) implemented on MOLPRO package to perform quantum calculations with high accuracy taking into account the correlation and relativistic effects with a specific treatment of spin orbit coupling for some low lying excited electronic states of WC"n"+, (n=0, 1 et 2). Our results are shown in good agreement with those available in the literature. Furthermore, in this work for the first time we demonstrated that a carbide dication (WC"2"+) is thermodynamically stable. (author) [fr

  19. Medical photography: principles for orthopedics.

    Science.gov (United States)

    Uzun, Metin; Bülbül, Murat; Toker, Serdar; Beksaç, Burak; Kara, Adnan

    2014-04-05

    Medical photography is used clinically for patient evaluation, treatment decisions, and scientific documentation. Although standards for medical photography exist in many branches of medicine, we have not encountered such criteria in publications in the area of orthopedics. This study aims to (1) assess the quality of medical images used in an orthopedic publication and (2) to propose standards for medical photography in this area. Clinical photographs were reviewed from all issues of a journal published between the years 2008 and 2012. A quality of clinical images was developed based on the criteria published for the specialties of dermatology and cosmetic surgery. All images were reviewed on the appropriateness of background, patient preparation, and technique. In this study, only 44.9% of clinical images in an orthopedic publication adhered to the proposed conventions. Standards have not been established for medical photography in orthopedics as in other specialty areas. Our results suggest that photographic clinical information in orthopedic publications may be limited by inadequate presentation. We propose that formal conventions for clinical images should be established.

  20. Analysis on Risk Factors of Nosocomial Infection in Orthopedic Patients and Research on Nursing Strategies

    Directory of Open Access Journals (Sweden)

    Guo Zhitao

    2016-03-01

    Full Text Available Orthopedic patients mostly comprise traumatic patients and elderly or sick individuals. More patients with emergency surgery suffer from open wounds and serious pollution, and operation time is relatively long. Thus, orthopedic patients with surgical incision infection account for a large proportion of incidence of hospital infection. Orthopedic patients are also bedridden for long periods, and they receive poor bone tissue blood supply. In surgical incision infections, mild cases suffer from delayed wound healing, whereas severe cases can form osteomyelitis. This study reviews progress of research on risk factors of nosocomial infection among orthopedic patients in recent years.

  1. The iron curtain of WC9 stars

    International Nuclear Information System (INIS)

    Hucht, K.A. van der; Willis, A.J.

    1982-01-01

    High resolution (Δlambda approximately equal to 0.1 A) IUE spectra have been obtained of the two WC9 stars HD 164270 and HD 136488, covering the wavelength range lambdalambda1150-2050. The former star shows P Cygni profiles indicating a stellar wind terminal velocity of Vsub(infinity) approximately equal to 1400 km s -1 , and the latter Vsub(infinity) approximately equal to -1800 km s -1 . A common feature in the spectra of both stars is narrow displaced absorptions due to Fe III (UV34) transitions arising from a metastable lower level. These features are displaced at sub-terminal velocities (-830 km s -1 for HD 164270 and -1030 km s -1 for Hd 136488) and are believed to be formed in the deceleration region of their stellar winds. The properties of these inferred Fe III circumstellar shells derived from these data are discussed. (Auth.)

  2. Prevention of Infection in Orthopedic Prosthetic Surgery.

    Science.gov (United States)

    Chirca, Ioana; Marculescu, Camelia

    2017-06-01

    Total joint arthroplasty is a generally safe orthopedic procedure; however, infection is a potentially devastating complication. Multiple risk factors have been identified for development of prosthetic joint infections. Identification of patients at risk and preoperative correction of known risk factors, such as smoking, diabetes mellitus, anemia, malnutrition, and decolonization of Staphylococcus carriers, represent well-established actions to decrease the infection risk. Careful operative technique, proper draping and skin preparation, and appropriate selection and dosing of antimicrobials for perioperative prophylaxis are also very important in prevention of infection. Published by Elsevier Inc.

  3. Grinding of WC-Co hard-metals

    NARCIS (Netherlands)

    Hegeman, J.B.J.W.; Hosson, de J.Th.M.; With, de G.

    2001-01-01

    Morphol. of ground surface of WC-Co cermets with 10 and 20% Co was studied. A deformed and detached surface layer was found on top of the specimens after surface grinding with a diamond wheel. Etching the surface layer revealed WC grains in the subsurface of the machined specimens. Most of these

  4. Imaging of orthopedic sports injuries

    International Nuclear Information System (INIS)

    Vanhoenacker, F.M.; Gielen, J.L.; Maas, M.

    2007-01-01

    This volume provides an updated review of imaging abnormalities in orthopedic sports injuries. The first part of the book contains background information on relevant basic science and general imaging principles in sports traumatology. The second part comprises a topographic discussion of sports injuries. Each chapter highlights the merit of different imaging techniques, focused on a specific clinical problem. In the third part, natural history, monitoring and follow-up by imaging are discussed. This well-illustrated book will be of value for musculoskeletal radiologists, orthopedic surgeons, sports physicians and everyone else involved in sports medicine. (orig.)

  5. Metallic artifact in MRI after removal of orthopedic implants

    International Nuclear Information System (INIS)

    Bagheri, Mohammad Hadi; Hosseini, Mehrdad Mohammad; Emami, Mohammad Jafar; Foroughi, Amin Aiboulhassani

    2012-01-01

    Objective: The aim of the present study was to evaluate the metallic artifacts in MRI of the orthopedic patients after removal of metallic implants. Subjects and methods: From March to August 2009, 40 orthopedic patients operated for removal of orthopedic metallic implants were studied by post-operative MRI from the site of removal of implants. A grading scale of 0–3 was assigned for artifact in MR images whereby 0 was considered no artifact; and I–III were considered mild, moderate, and severe metallic artifacts, respectively. These grading records were correlated with other variables including the type, size, number, and composition of metallic devices; and the site and duration of orthopedic devices stay in the body. Results: Metallic susceptibly artifacts were detected in MRI of 18 of 40 cases (45%). Screws and pins in removed hardware were the most important factors for causing artifacts in MRI. The artifacts were found more frequently in the patients who had more screws and pins in the removed implants. Gender, age, site of implantation of the device, length of the hardware, composition of the metallic implants (stainless steel versus titanium), and duration of implantation of the hardware exerted no effect in producing metallic artifacts after removal of implants. Short TE sequences of MRI (such as T1 weighted) showed fewer artifacts. Conclusion: Susceptibility of metallic artifacts is a frequent phenomenon in MRI of patients upon removal of metallic orthopedic implants.

  6. Metallic artifact in MRI after removal of orthopedic implants.

    Science.gov (United States)

    Bagheri, Mohammad Hadi; Hosseini, Mehrdad Mohammad; Emami, Mohammad Jafar; Foroughi, Amin Aiboulhassani

    2012-03-01

    The aim of the present study was to evaluate the metallic artifacts in MRI of the orthopedic patients after removal of metallic implants. From March to August 2009, 40 orthopedic patients operated for removal of orthopedic metallic implants were studied by post-operative MRI from the site of removal of implants. A grading scale of 0-3 was assigned for artifact in MR images whereby 0 was considered no artifact; and I-III were considered mild, moderate, and severe metallic artifacts, respectively. These grading records were correlated with other variables including the type, size, number, and composition of metallic devices; and the site and duration of orthopedic devices stay in the body. Metallic susceptibly artifacts were detected in MRI of 18 of 40 cases (45%). Screws and pins in removed hardware were the most important factors for causing artifacts in MRI. The artifacts were found more frequently in the patients who had more screws and pins in the removed implants. Gender, age, site of implantation of the device, length of the hardware, composition of the metallic implants (stainless steel versus titanium), and duration of implantation of the hardware exerted no effect in producing metallic artifacts after removal of implants. Short TE sequences of MRI (such as T1 weighted) showed fewer artifacts. Susceptibility of metallic artifacts is a frequent phenomenon in MRI of patients upon removal of metallic orthopedic implants. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  7. Direct laser sintered WC-10Co/Cu nanocomposites

    Science.gov (United States)

    Gu, Dongdong; Shen, Yifu

    2008-04-01

    In the present work, the direct metal laser sintering (DMLS) process was used to prepare the WC-Co/Cu nanocomposites in bulk form. The WC reinforcing nanoparticles were added in the form of WC-10 wt.% Co composite powder. The microstructural features and mechanical properties of the laser-sintered sample were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDX), and nanoindentation tester. It showed that the original nanometric nature of the WC reinforcing particulates was well retained without appreciable grain growth after laser processing. A homogeneous distribution of the WC reinforcing nanoparticles with a coherent particulate/matrix interfacial bonding was obtained in the laser-sintered structure. The 94.3% dense nanocomposites have a dynamic nanohardness of 3.47 GPa and a reduced elastic modulus of 613.42 GPa.

  8. Direct laser sintered WC-10Co/Cu nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Gu Dongdong [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China)], E-mail: dongdonggu@nuaa.edu.cn; Shen Yifu [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China)

    2008-04-30

    In the present work, the direct metal laser sintering (DMLS) process was used to prepare the WC-Co/Cu nanocomposites in bulk form. The WC reinforcing nanoparticles were added in the form of WC-10 wt.% Co composite powder. The microstructural features and mechanical properties of the laser-sintered sample were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDX), and nanoindentation tester. It showed that the original nanometric nature of the WC reinforcing particulates was well retained without appreciable grain growth after laser processing. A homogeneous distribution of the WC reinforcing nanoparticles with a coherent particulate/matrix interfacial bonding was obtained in the laser-sintered structure. The 94.3% dense nanocomposites have a dynamic nanohardness of 3.47 GPa and a reduced elastic modulus of 613.42 GPa.

  9. Direct laser sintered WC-10Co/Cu nanocomposites

    International Nuclear Information System (INIS)

    Gu Dongdong; Shen Yifu

    2008-01-01

    In the present work, the direct metal laser sintering (DMLS) process was used to prepare the WC-Co/Cu nanocomposites in bulk form. The WC reinforcing nanoparticles were added in the form of WC-10 wt.% Co composite powder. The microstructural features and mechanical properties of the laser-sintered sample were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDX), and nanoindentation tester. It showed that the original nanometric nature of the WC reinforcing particulates was well retained without appreciable grain growth after laser processing. A homogeneous distribution of the WC reinforcing nanoparticles with a coherent particulate/matrix interfacial bonding was obtained in the laser-sintered structure. The 94.3% dense nanocomposites have a dynamic nanohardness of 3.47 GPa and a reduced elastic modulus of 613.42 GPa

  10. Porous metal for orthopedics implants

    OpenAIRE

    Matassi, Fabrizio; Botti, Alessandra; Sirleo, Luigi; Carulli, Christian; Innocenti, Massimo

    2013-01-01

    Porous metal has been introduced to obtain biological fixation and improve longevity of orthopedic implants. The new generation of porous metal has intriguing characteristics that allows bone healing and high osteointegration of the metallic implants. This article gives an overview about biomaterials properties of the contemporary class of highly porous metals and about the clinical use in orthopaedic surgery.

  11. Orthopedic trauma surgery in the morbidly obese patient.

    Science.gov (United States)

    Bozzio, Anthony E; Gala, Raj J; Villasenor, Mario A; Hao, Jiandon; Mauffrey, Cyril

    2014-05-01

    The treatment of morbidly obese patients in orthopedic trauma differs in many ways compared to injured patients with normal body mass indices. This paper highlights key differences and ways to overcome obstacles. We present specific tips, as well as considerations for initial planning, positioning for surgery, intra-operative strategies, and a discussion on both anesthesia and imaging. Several treatment strategies have been shown to have better results in morbidly obese patients. Pre-operative planning is necessary for minimizing risk to the patient. The prevalence of morbid obesity has increased in the USA in the past quarter century. Treatment for orthopedic injuries in morbidly obese patients requires a multidisciplinary approach that addresses not only their orthopedic injuries, but also medical co-morbidities. A team of medicine doctors, anesthesiologists, X-ray technicians, physical and occupational therapists, respiratory therapists, and social workers is needed in addition to the orthopedic surgeon. Modifications in both pre-operative planning and intra-operative strategies may be necessary in order to accommodate the patient. This paper presents numerous technical tips that can aid in providing stable fixation for fractures, as well as addressing peri-operative issues specific to the morbidly obese.

  12. Does thromboprophylaxis prevent venous thromboembolism after major orthopedic surgery?

    Directory of Open Access Journals (Sweden)

    Evrim Eylem Akpinar

    2013-06-01

    Full Text Available OBJECTIVE: Pulmonary embolism (PE is an important complication of major orthopedic surgery. The aim of this study was to evaluate the incidence of venous thromboembolism (VTE and factors influencing the development of VTE in patients undergoing major orthopedic surgery in a university hospital. METHODS: Patients who underwent major orthopedic surgery (hip arthroplasty, knee arthroplasty, or femur fracture repair between February of 2006 and June of 2012 were retrospectively included in the study. The incidences of PE and deep vein thrombosis (DVT were evaluated, as were the factors influencing their development, such as type of operation, age, and comorbidities. RESULTS: We reviewed the medical records of 1,306 patients. The proportions of knee arthroplasty, hip arthroplasty, and femur fracture repair were 63.4%, 29.9%, and 6.7%, respectively. The cumulative incidence of PE and DVT in patients undergoing major orthopedic surgery was 1.99% and 2.22%, respectively. Most of the patients presented with PE and DVT (61.5% and 72.4%, respectively within the first 72 h after surgery. Patients undergoing femur fracture repair, those aged ≥ 65 years, and bedridden patients were at a higher risk for developing VTE. CONCLUSIONS: Our results show that VTE was a significant complication of major orthopedic surgery, despite the use of thromboprophylaxis. Clinicians should be aware of VTE, especially during the perioperative period and in bedridden, elderly patients (≥ 65 years of age.

  13. Electrochemical properties of mixed WC and Pt-black powders

    Directory of Open Access Journals (Sweden)

    MAJA D. OBRADOVIC

    2008-12-01

    Full Text Available The electrochemical characteristics of a mixture of Pt-black and WC powders and its catalytic activity for methanol and formic acid oxidation were investigated in acid solution. XRD and AFM measurements revealed that the WC powder employed for the investigation was a single-phase material consisting of crystallites/spherical particles of average size of about 50 nm, which were agglomerated into much larger particles. Cyclic voltammetry showed that the WC underwent electrochemical oxidation, producing tungstate species. In the case of the mixed Pt + WC powders, the tungstate species were deposited on the Pt as a thin film of hydrous tungsten oxide. Enhanced hydrogen intercalation in the hydrous tungsten oxide was observed and it was proposed to be promoted in mixed powders by the presence of hydrogen adatoms on bare Pt sites. The determination of Pt surface area in the Pt + WC layer by stripping of underpotentially deposited Cu revealed that the entire Pt surface was accessible for underpotential deposition of Cu. Investigation of the electrochemical oxidation of methanol and formic acid on Pt + WC and pure Pt layers did not indicate electrocatalytic promotion due to the presence of WC.

  14. Analysis of PTA hardfacing with CoCrWC and CoCrMoSi alloys

    Directory of Open Access Journals (Sweden)

    Adriano Scheid

    2013-12-01

    Full Text Available CoCrWC alloys are widely used to protect components that operate under wear and high temperature environments. Enhanced performance has been achieved with the CoCrMoSi alloys but processing this alloy system is still a challenge due to the presence of the brittle Laves phase, particularly when welding is involved. This work evaluated Plasma Transferred Arc coatings processed with the Co-based alloy CoMoCrSi - Tribaloy T400, reinforced with Laves phase, comparing its weldability to the CoCrWC - Stellite 6, reinforced with carbides. Coatings were also analyzed regarding the response to temperature exposure at 600°C for 7 days and subsequent effect on microstructure and sliding abrasive wear. Coatings characterization was carried out by light and scanning electron microscopy, X-ray diffraction and Vickers hardness. CoCrWC coatings exhibited a Cobalt solid solution dendritic microstructure and a thin interdendritic region with eutectic carbides, while CoCrMoSi deposits exhibit a large lamellar eutectic region of Laves phase and Cobalt solid solution and a small fraction of primary Laves phase. Although phase stability was observed by X-ray diffraction, coarsening of the microstructure occurred for both alloys. CoCrMoSi showed thicker lamellar Laves phase and CoCrWC coarser eutectic carbides. Coatings stability assessed by wear tests revealed that although the wear rate of the as-deposited CoCrMoSi alloy was lower than that of CoCrWC alloy its increase after temperature exposure was more significant, 22% against 15%. Results were discussed regarding the protection of industrial components in particular, bearings in 55AlZn hot dip galvanizing components.

  15. The Nature of Bonding in WC and WN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The nature of bonding in the title compounds has been studied by using CASSCF and FOCl techniques. The ground states of WC and WN are found to be 3Δ and 4∑- state arising primarily from:...1σ2σ21π41δ13σ1 and ...1σ2σ21π41δ23σ1 configuration respectively. WC shows a strong character of covalent bond while WN have obvious character of ionic bond and the dissociation energy of WN is larger than that of WC (6.15 and 5.41 eV respective).

  16. Improving surgeon utilization in an orthopedic department using simulation modeling

    Directory of Open Access Journals (Sweden)

    Simwita YW

    2016-10-01

    Full Text Available Yusta W Simwita, Berit I Helgheim Department of Logistics, Molde University College, Molde, Norway Purpose: Worldwide more than two billion people lack appropriate access to surgical services due to mismatch between existing human resource and patient demands. Improving utilization of existing workforce capacity can reduce the existing gap between surgical demand and available workforce capacity. In this paper, the authors use discrete event simulation to explore the care process at an orthopedic department. Our main focus is improving utilization of surgeons while minimizing patient wait time.Methods: The authors collaborated with orthopedic department personnel to map the current operations of orthopedic care process in order to identify factors that influence poor surgeons utilization and high patient waiting time. The authors used an observational approach to collect data. The developed model was validated by comparing the simulation output with the actual patient data that were collected from the studied orthopedic care process. The authors developed a proposal scenario to show how to improve surgeon utilization.Results: The simulation results showed that if ancillary services could be performed before the start of clinic examination services, the orthopedic care process could be highly improved. That is, improved surgeon utilization and reduced patient waiting time. Simulation results demonstrate that with improved surgeon utilizations, up to 55% increase of future demand can be accommodated without patients reaching current waiting time at this clinic, thus, improving patient access to health care services.Conclusion: This study shows how simulation modeling can be used to improve health care processes. This study was limited to a single care process; however the findings can be applied to improve other orthopedic care process with similar operational characteristics. Keywords: waiting time, patient, health care process

  17. Effects of WC phase contents on the microstructure, mechanical properties and tribological behaviors of WC/a-C superlattice coatings

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Jibin [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); He, Dongqing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Wang, Liping, E-mail: lpwang@licp.cas.cn [Key Laboratory of Marine Materials and Related Technologies, Key Laboratory of Marine Materials and Protective Technologies of Zhejiang Province, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-12-01

    Graphical abstract: - Highlights: • WC/a-C superlattice coatings were synthesized with various WC phase content. • Superlattice structure diminished residual stress and densified microstructure. • Nanocomposite coating with W 5.43 at.% achieved the optimal tribological properties. • Friction triggered WO{sub 3} lead to a low friction coefficient at 200 °C. - Abstract: Nanocomposite WC/a-C coatings with variable contents of tungsten carbide (WC{sub 1−x}) and amorphous carbon (a-C) were successfully fabricated using a magnetron sputtering process. The microstructure, mechanical properties and tribological behaviors of the as-fabricated coatings were investigated and compared. The results showed that the “superlattice coating” feature of an alternating multilayer structure with a-C and WC{sub 1−x} nanocrystallites layers on the nanoscale was formed. These multilayer superlattice structures led to diminished residual stress and improved the strength of the adhesion to the substrate. The WC/a-C coating with W 5.43 at.% exhibited low friction coefficients of 0.05 at 25 °C and 0.28 at 200 °C. This significant improvement in the tribological performances of the WC/a-C coating was mainly attributed to the superior “superlattice” microstructure and the formation of a continuously compacted tribofilms, which was rich in graphitized carbon at 25 °C and dominated by the friction triggered WO{sub 3} at 200 °C. Moreover, the WC/a-C coating with W 5.43 at.% achieved optimal anti-wear properties at 25 °C due to the synergistic combination of the enhancement effects of the WC{sub 1−x} nanoparticles and the partition effect from the transfer film that restricted direct contact of the steel ball with the coating and thus prevented further intense wear. The accelerated wear of the WC/a-C coating with the increase of the WC phase content at 200 °C might be due to the combination of oxidation wear and abrasive wear that originated from the WC{sub 1−x} phase.

  18. Fracture toughness measurements of WC-based hard metals

    International Nuclear Information System (INIS)

    Prakash, L.; Albert, B.

    1983-01-01

    The fracture toughness of WC-based cemented carbides was determined by different methods. The values obtained are dependent on the procedure of measurement. Each method thoughness of hard metals mutually. (orig.) [de

  19. Micromechanics of fracture in WC-Co hardmetals

    International Nuclear Information System (INIS)

    Dusza, J.; Parilak, L.

    1986-01-01

    A study has been made in WC-Co cemented carbides with grain sizes of 2.1 - 3.6 μm and 13 - 32 vol% Co, of the relationship between the fracture toughness and microstructural parameters and micromechanisms of fracture. Regression analyses have been used to derive empirical relationships between fracture toughness, and the binder spacing, the contiguity and the relative proportions of fracture in the binder phase and between contiguous WC grains

  20. Completion report for the isolation and remediation of inactive liquid low-level radioactive waste tanks WC-5, WC-6, WC-8, WC-19, 3002-A, 7560, and 7562 at Oak Ridge National Laboratory Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-12-01

    The Federal Facility Agreement (FFA) between the U.S. Environmental Protection Agency (EPA), Tennessee Department of Environment and Conservation (TDEC), and U.S. Department of Energy (DOE) requires that all liquid low-level waste tanks at Oak Ridge National Laboratory removed from service, designated in the FFA as Category D, be remediated in accordance with Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements. A human health risk screening assessment was conducted for inactive Tanks WC-5, WC-6, WC-8, WC-19, 3002-A, 7560, and 7562 as part of an evaluation to determine the method of remediation necessary to safely and permanently isolate and remediate the tanks. Risk screening assessment results indicated that the health risks associated with these tanks were within or below the EPA range of concern of 1 x 10 -4 to 1 x 10 -6 . On the basis of these results and with regulators concurrence, it was determined that either no action or in-place stabilization of the tanks would satisfy risk-based remediation goals. Therefore, decisions were made and approved by DOE to remediate these tanks in-place as maintenance actions rather than actions under the CERCLA process. Letters documenting these decisions were approved by DOE and subsequently submitted to TDEC and EPA, who concurred with the maintenance actions. Tanks WC-5, WC-6, WC-8, WC-19, 3002-A, 7560, and 7562 were isolated from associated piping, electrical systems, and instrumentation and were grouted in-place. Tank 7562 was originally isolated from associated piping and instrumentation and left in-place empty for future remedial consideration. Upon further consideration, the decision was made by DOE, with concurrence by the regulators, to complete the maintenance action of Tank 7562 by grouting it in-place in March 1997

  1. Fracture toughness of a nanoscale WC-Co tool steel

    International Nuclear Information System (INIS)

    Densley, J.M.; Hirth, J.P.

    1997-01-01

    Tungsten carbide tool steels, comprising WC particles with 6.7--25wt% Co distributed in the interparticle regions as a quasi-continuous binder phase, can be considered as WC-Co composites. The fracture toughness of such WC-Co composites is dependent on the volume fraction, contiguity and thickness of the cobalt binder, and the size of the tungsten carbide grains. Research has shown that the ductile binder undergoes nearly all the plastic deformation during fracture, which provides the primary energy consuming process that enhances fracture resistance. Recent manufacturing developments have given rise to the production of a WC-6.7wt% Co cermet having an average WC grain size of 70 nm, with a corresponding binder mean thickness, h, of 9 nm calculated from d = h(1-V f )/V f where d = 70 nm and V f = 0.114. This composite has shown a higher wear resistance than that of conventional cermets in proportion to their hardness. Such improvement has been attributed to the difficulty in forming dislocations in the very small grains. There are also indications that the Co binder in the nanoscale cermet contains higher contents of dissolved W and C than for conventional scale cermets. Because plastic deformation is initially confined to the binder phase, it was of interest to perform mode 1 and mixed mode toughness tests on the nanoscale cermet to determine whether flow localization influenced mixed mode toughness as in bulk materials. Two generations of this cermet were provided by Rogers Tool Works. The first generation, A, had lower binder contiguity, with occasional agglomerations of WC grains. The second generation, B, was cleaner, with the cobalt binder more uniformly separating the WC grains

  2. Wholistic orthopedics: Is this the right way to treat geriatric orthopedic patients?

    OpenAIRE

    John Ebnezar; Yogita Bali; Rakesh John

    2017-01-01

    Geriatric orthopedic problems poses different challenges in their management. Conventional treatment methods like drugs, physiotherapy and surgeries are inadequate. A Geriatric orthopedic patient suffers as a whole and not in isolation. This article highlights the importance of managing geriatric orthopedic patients as a whole and outlines the various steps of wholistic management.

  3. Wholistic orthopedics: Is this the right way to treat geriatric orthopedic patients?

    Directory of Open Access Journals (Sweden)

    John Ebnezar

    2017-01-01

    Full Text Available Geriatric orthopedic problems poses different challenges in their management. Conventional treatment methods like drugs, physiotherapy and surgeries are inadequate. A Geriatric orthopedic patient suffers as a whole and not in isolation. This article highlights the importance of managing geriatric orthopedic patients as a whole and outlines the various steps of wholistic management.

  4. Wear resistance and fracture mechanics of WC-Co composites

    International Nuclear Information System (INIS)

    Kaytbay, Saleh; El-Hadek, Medhat

    2014-01-01

    Manufacturing of WC-Co composites using the electroless precipitation method at different sintering temperatures of 1 100, 1 250, 1 350 and 1 500 C was successfully achieved. The chemical composition of the investigated materials was 90 wt.% WC with 10 wt.% Co, and 80 wt.% WC with 20 wt.% Co. The specific density, densification, and Vickers microhardness measurements were found to increase with increased sintering temperature for both the WC-Co compositions. The composites of tungsten carbide with 10 wt.% Co had a higher specific density and Vickers microhardness measurements than those for the composites of tungsten carbide with 20 wt.% Co. Composites with WC-10 wt.% Co had better wear resistance. The stress-strain and transverse rupture strength increased monotonically with the increase in sintering temperatures, agreeing with the material hardness and wear resistance behavior. Fractographical scanning electron microscopy analysis of the fracture surface demonstrated a rough characteristic conical shape failure in the direction of the maximum shear stress. A proposed mechanism for the formation of the conical fracture surface under compression testing is presented. (orig.)

  5. Reactive Sintering of Bimodal WC-Co Hardmetals

    Directory of Open Access Journals (Sweden)

    Marek Tarraste

    2015-09-01

    Full Text Available Bimodal WC-Co hardmetals were produced using novel technology - reactive sintering. Milled and activated tungsten and graphite powders were mixed with commercial coarse grained WC-Co powder and then sintered. The microstructure of produced materials was free of defects and consisted of evenly distributed coarse and fine tungsten carbide grains in cobalt binder. The microstructure, hardness and fracture toughness of reactive sintered bimodal WC-Co hardmetals is exhibited. Developed bimodal hardmetal has perspective for demanding wear applications for its increased combined hardness and toughness. Compared to coarse material there is only slight decrease in fracture toughness (K1c is 14.7 for coarse grained and 14.4 for bimodal, hardness is increased from 1290 to 1350 HV units.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7511

  6. Hot isostatic pressing of nanosized WC-Co hardmetals

    International Nuclear Information System (INIS)

    Azcona, I.; Ordonez, A.; Sanchez, J.M.; Castro, F.; Dominguez, L.

    2001-01-01

    A new technique based on hot isostatic pressing (HIP) has been developed to produce dense nanosized WC-Co hardmetals without the addition of grain growth inhibitors. The glass encapsulation process is the key for the effective application of isostatic pressure at temperatures well below those usually required for reaching the closed porosity state in the WC-Co system. Fully dense WC-Co samples with cobalt contents ranging from 10 to 12 wt. % have been obtained by this technique at temperatures between 1000 o C and 1200 o C with 150 MPa of applied isostatic pressure for 30 minutes. The role of isostatic pressure on the activation of densification mechanisms is discussed. (author)

  7. Physicians founders of orthopedic surgery in Serbia

    Directory of Open Access Journals (Sweden)

    Bumbaširević Marko

    2004-01-01

    Full Text Available The beginnings of the development of orthopedic surgery in Serbia have been related to the name of Dr Nikola Krstic and his first radiography of the hand in 1908. The foundation of the Orthopedic Ward, led by Dr Nikola Krstic, within the General State Hospital in Belgrade, in 1919, marks the definition of orthopedics as a separate branch of surgery. In addition to Dr Nikola Krstic, Dr Borivoje Lalovic and Temp. Docent Dr Borivoje Gradojevic, who published the first orthopedics textbook in Serbian in 1934, also worked at the orthopedic ward between the two world wars. The work at the orthopedic ward, which grew into a clinic in 1947, was continued by Prof. Dr Milos Simovic, Prof. Dr Svetislav Stojanovic and Prof, dr Ljubisa Boric. Their successors would have high achievements: Prof. Dr Zivojin Bumbasirevic became the only orthopedist who was a regular member of the Serbian Academy of Sciences and Arts, and Chief of Staff Dr Predrag Klisic and Prof. Dr Branko Radulovic provide impetus for further development of orthopedics by founding Specialist Orthopedics Hospital "Banjica".

  8. Imaging of orthopedic trauma and surgery

    International Nuclear Information System (INIS)

    Berquist, T.H.

    1986-01-01

    This book bridges the communication gap, between the radiologist and the orthopedic surgeon in regard to trauma. It also combines ease of use with authoritative information, and includes in each discussion a review of the pertinent anatomy, mechanism of injury, and radiology and orthopedic classification

  9. Strategies for achieving orthopedic service line success.

    Science.gov (United States)

    Lang, Stacey; Powers, Kristi

    2013-12-01

    Healthcare finance leaders can work with orthopedic surgeons to support better outcomes, clinically and financially, by: Establishing innovative partnerships among hospital leaders, orthopedic surgeons, and implant vendors. Developing and enforcing expectations around contracting and vendor behavior. Establishing a forum for open communication. Building a bundled payment structure. Finding ways to differentiate from the competition.

  10. Lightning Tests on the WC-130 Research Aircraft.

    Science.gov (United States)

    1982-12-01

    in the WC-136 tests at various times.) E- Feild Fiber Optic Test Article Sensor Transmitter (Typ)WiePr Indtuced Voltag Sensor"" *Fiber I"=Current optic...well-characterized. 5.1 Skin Current Measurements Skin current vectors were measured at five fuselage locations on the left side of the WC-130 at a...MGL-S7) which were mounted so that they sampled two orthogonal components of the skin current vector . The measured responses were then inte- grated

  11. Phase size distribution in WC/Co hardmetal

    International Nuclear Information System (INIS)

    Roebuck, B.; Bennett, E.G.

    1986-01-01

    A high-resolution field emission scanning electron microscope was used to perform accurate quantitative metallography on a variety of WC/Co hardmetals. Particular attention was paid to obtaining the mean size and size distribution of the cobalt phase by linear analysis. Cobalt regions are frequently submicron and difficult to resolve adequately by conventional methods. The WC linear intercept distributions, and contiguity were also measured at the same time. The results were used to examine the validity of theoretic derivations of cobalt intercept size

  12. Infrared processed Cu composites reinforced with WC particles

    International Nuclear Information System (INIS)

    Deshpande, P.K.; Li, J.H.; Lin, R.Y.

    2006-01-01

    Copper matrix composites with WC particle reinforcements have been prepared with an innovative infrared infiltration technique. The volume content of the reinforcement particles in the composite is about 53%. The relative composite density of as high as 99.9% has been obtained with this process. The electric conductivity of composites prepared in this study as determined by a four-point probe method, is similar to commercially available Cu/W composites containing 52 vol% tungsten. Microhardness, microstructure and wear resistance of the composites were also determined. The microstructure of Cu/WC composite reveals excellent wetting between the two constituent phases, WC and copper. The microhardness values of all completely infiltrated Cu/WC composites were in the range of 360-370 HV which is significantly higher than the microhardness of pure copper, 65 HV. Wear resistance of the composites was determined with a pin on disk wear test technique. The wear test results show that composites prepared in this study performed much better than those commercially available Cu/W composites by more than two-fold against silicon carbide abrasive disks

  13. WC Nanocrystals Grown on Vertically Aligned Carbon Nanotubes: An Efficient and Stable Electrocatalyst for Hydrogen Evolution Reaction.

    Science.gov (United States)

    Fan, Xiujun; Zhou, Haiqing; Guo, Xia

    2015-05-26

    Single nanocrystalline tungsten carbide (WC) was first synthesized on the tips of vertically aligned carbon nanotubes (VA-CNTs) with a hot filament chemical vapor deposition (HF-CVD) method through the directly reaction of tungsten metal with carbon source. The VA-CNTs with preservation of vertical structure integrity and alignment play an important role to support the nanocrystalline WC growth. With the high crystallinity, small size, and uniform distribution of WC particles on the carbon support, the formed WC-CNTs material exhibited an excellent catalytic activity for hydrogen evolution reaction (HER), giving a η10 (the overpotential for driving a current of 10 mA cm(-2)) of 145 mV, onset potential of 15 mV, exchange current density@ 300 mV of 117.6 mV and Tafel slope values of 72 mV dec(-1) in acid solution, and η10 of 137 mV, onset potential of 16 mV, exchange current density@ 300 mV of 33.1 mV and Tafel slope values of 106 mV dec(-1) in alkaline media, respectively. Electrochemical stability test further confirms the long-term operation of the catalyst in both acidic and alkaline media.

  14. Our experience with orthopedic surgery in hemophiliacs

    Directory of Open Access Journals (Sweden)

    Poenaru Dan V.

    2006-01-01

    Full Text Available Introduction: Patients having severe hemophilia (levels of deficient factor below 1% frequently suffer from disabling chronic arthropathy. An adequate substitution treatment using the coagulation factor VIII or IX concentrates renders an elective surgery feasible. Objective: The objective of the study was to check the results of different surgical procedures in the treatment of hemophilic arthropathies, and to propose the best protocol of their treatment. Methods: This is a retrospective study on 26 hemophilic patients operated in the Orthopedics and Trauma Clinic II, Timisoara, from 2002 to 2005. Elective surgical procedures were mainly performed in the knee (21 arthroscopic procedures, 1 open arthrodesis, elbow (2 open synovectomies, 2 radial head excisions, ankle (1 arthroscopic synovectomy and debridement and thigh (1 giant pseudo tumor excision, other minor procedures. The results after operations on moderate and severe chronic knee, elbow and ankle arthropathy were evaluated, with approximately 24-month follow-up period. Results: Arthroscopic procedures (22 yielded good and satisfactory results with significant improvement according to the evaluation criteria recommended by the World Hemophilia Federation (Gilbert clinical score, Pettersson radiological score, NUSS MRI score. Conclusion: Mini-invasive elective surgery in moderate to severe chronic arthropathy produces good results when performed in a specialized center and with multi-disciplinary approach.

  15. Safety analysis report for packaging: the ORNL DOT Specification 20WC-5 - special form packaging

    International Nuclear Information System (INIS)

    Schaich, R.W.

    1982-10-01

    The ORNL DOT Specification 20WC-5 - Special Form Package was fabricated for the transport of large quantities of solid nonfissile radioactive materials in special form. The package was evaluated on the basis of tests performed at Sandia National Laboratories, Albuquerque, New Mexico on an identical fire and impact shield and special form tests performed on a variety of stainless steel capsules at ORNL by Operations Division personnel. The results of these evaluations demonstrate that the package is in compliance with the applicable regulations for the transport of large quantities of nonfissile radioactive materials in special form

  16. What expects orthopedic surgeon from bone scan?

    International Nuclear Information System (INIS)

    Sutter, B.; Cazenave, A.

    2003-01-01

    The isotope bone scan continues to be one of the 'lost widely performed nuclear medicine investigations. Beyond the common clinical indication like detection of skeletal metastases, bone scan use is increasing in benign orthopedic conditions, and after orthopedic surgery, despite development of new investigations modalities (US, MRI). Three (or two) phase bone scintigraphy, Single Photon Emission Computer Tomography have increased its value and provided new clinical roles. This review emphasizes through some practical clinical examples how to increase diagnostic value of the method and to offer an adapted response to the orthopedic surgeon's attempts. (author)

  17. [Orthopedic and trauma surgery in the German DRG System 2007].

    Science.gov (United States)

    Franz, D; Kaufmann, M; Siebert, C H; Windolf, J; Roeder, N

    2007-03-01

    The German Diagnosis-Related Groups (DRG) System was further developed into its 2007 version. For orthopedic and trauma surgery, significant changes were made in terms of the coding of diagnoses and medical procedures, as well as in the DRG structure itself. The German Societies for Trauma Surgery and for Orthopedics and Orthopedic Surgery (Deutsch Gesellschaft für Unfallchirurgie, DGU; and Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie, DGOOC) once again cooperated constructively with the German DRG Institute InEK. Among other innovations, new International Classification of Diseases (ICD) codes for second-degree burns were implemented. Procedure codes for joint operations, endoprosthetic-surgery and spine surgery were restructured. Furthermore, a specific code for septic surgery was introduced in 2007. In addition, the DRG structure was improved. Case allocation of patients with more than one significant operation was established. Further DRG subdivisions were established according to the patients age and the Patient Clinical Complexity Level (PCCL). DRG developments for 2007 have improved appropriate case allocation, but once again increased the system's complexity. Clinicians need an ever growing amount of specific coding know-how. Still, further adjustments to the German DRG system are required to allow for a correct allocation of cases and funds.

  18. Orthopedic surgeons’ knowledge regarding risk of radiation exposition: a survey analysis

    Directory of Open Access Journals (Sweden)

    Tunçer Nejat

    2017-01-01

    Full Text Available Introduction: The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. Methods: A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants’ knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. Results: The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30% had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88% protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%. A dosimeter was used 5% of the time. Conclusion: According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons.

  19. Orthopedic surgeons' knowledge regarding risk of radiation exposition: a survey analysis.

    Science.gov (United States)

    Tunçer, Nejat; Kuyucu, Ersin; Sayar, Şafak; Polat, Gökhan; Erdil, İrem; Tuncay, İbrahim

    2017-01-01

    The purpose of this study is to evaluate the knowledge levels of orthopedic surgeons working in Turkey about the uses and possible risks of fluoroscopy and assess methods for preventing radiation damage. A questionnaire with a total of 12 questions was sent to 1121 orthopedic surgeons working in Turkey. The questionnaire evaluated participants' knowledge about the uses and risks of fluoroscopy and methods for preventing damage. One thousand and twenty-four orthopedic surgeons were found to be suitable for inclusion in the study. The effects of fluoroscopy on patients were not assessed in our study. The data obtained were statistically evaluated. Of the surveyed surgeons, 313 (30%) had used fluoroscopy in over 50% of their operations. The average number of fluoroscopy shots per case was 54.5. A lead apron was the most commonly used (88%) protection from the harmful effects of radiation. Fluoroscopy shots were performed with the help of operating room personnel (86%). A dosimeter was used 5% of the time. According to the survey results, the need for fluoroscopy was very high in orthopedic surgery. However, orthopedic surgeons have inadequate knowledge about the uses and risks of fluoroscopy and methods for preventing damage. Therefore, we believe that training on this topic should be provided to all orthopedic surgeons. © The Authors, published by EDP Sciences, 2017.

  20. Binder extrusion of sliding wear of WC-Co alloys

    International Nuclear Information System (INIS)

    Larsen-Basse, J.

    1985-01-01

    It has previously been proposed that preferential removal of the cobalt binder is an important mechanism in the abrasive wear of cemented carbides in the WC-Co family. It is here demonstrated that binder extrusion occurs also in metal-to-metal sliding wear contacts. The wear scar generated by sliding a hardened steel ball repeatedly over a polished WC-Co surface was studied by SEM. The extruded cobalt fragments accumulate by surface defects, such as cracks caused by the sliding loaded ball, and gradual microfragmentation of the carbide grains follows. The energy required to extrude the cobalt and cause the gradual change in surface layer microstructure is provided by the frictional forces

  1. [Daily routine in orthopedics and traumatology - results of a nationwide survey of residents].

    Science.gov (United States)

    Merschin, D; Münzberg, M; Stange, R; Schüttrumpf, J P; Perl, M; Mutschler, M

    2014-10-01

    The subject orthopedics and traumatology suffers by a loss of attractiveness which results in a lack of young blood. The aim of this study of the Youth Forum of the German Society of Orthopedics and Traumatology (DGOU) is to register the working conditions of residents in orthopedics. In the months September and October 2013 we performed a survey on members of the following German societies: German Society of Orthopedics and Traumatology (DGOU), German Society of Traumatology (DGU) and the German Society of Orthopedics and Orthopedic Surgery (DGOOC), (age working time per week is 55 hours. 73 % of all participants do more than 5 emergency services per month. 52 % are more than 3 times on duty for 24 hours. Only 13 % of all residents have well ordered working hours. Normally working time is divided into three parts: one third for bureaucracy, one for operation theatre and the last for other activities (e.g. ward round). 35,6 % do only one surgery per week, 12 % do not perform any surgeries. An annual report is performed only in 45 %. A structured concept of training only exists in 16 % of all hospitals. In addition to clinical work 45 % are involved in scientific projects, mostly in their spare-time. Finally 58 % of all surgeons would still recommend orthopedics and traumatology. In order to maintain orthopedics and traumatology as an attractive it is necessary to implement flexible working time models and to reorganize and improve training-concepts. Georg Thieme Verlag KG Stuttgart · New York.

  2. Compression deformation of WC: atomistic description of hard ceramic material

    Science.gov (United States)

    Feng, Qing; Song, Xiaoyan; Liu, Xuemei; Liang, Shuhua; Wang, Haibin; Nie, Zuoren

    2017-11-01

    The deformation characteristics of WC, as a typical hard ceramic material, were studied on the nanoscale using atomistic simulations for both the single-crystal and polycrystalline forms under uniaxial compression. In particular, the effects of crystallographic orientation, grain boundary coordination and grain size on the origin of deformation were investigated. The deformation behavior of the single-crystal and polycrystalline WC both depend strongly on the orientation towards the loading direction. The grain boundaries play a significant role in the deformation coordination and the potential high fracture toughness of the nanocrystalline WC. In contrast to conventional knowledge of ceramics, maximum strength was obtained at a critical grain size corresponding to the turning point from a Hall-Petch to an inverse Hall-Petch relationship. For this the mechanism of the combined effect of dislocation motion within grains and the coordination of stress concentration at the grain boundaries were proposed. The present work has moved forward our understanding of plastic deformability and the possibility of achieving a high strength of nanocrystalline ceramic materials.

  3. [Orthopedic management of spina bifida].

    Science.gov (United States)

    Biedermann, R

    2014-07-01

    Spina bifida is associated with congenital deformities, such as kyphosis, spinal malformations, teratological hip dislocations, clubfeet, vertical talus and also with acquired deformities due to muscle imbalance and impaired biomechanics. The degree of the acquired deformities and the mobility of the patient depend on the level of the spinal lesion. Neurological symptoms are mostly asymmetric and there is an inconsistent correlation between the anatomical level of the lesion and muscle function. Deficits of sensation are usually one to two levels lower than the motor level. An exact neurological diagnosis should not be made before the second or third year of life and an early prognosis about walking ability should be avoided. The level L3 and therefore function of the quadriceps is a functional milestone after which modified independent ambulation with the use of ankle foot orthoses (AFO) and crutches is possible. The basic principle is to support verticalization and gait even when loss of ambulation is later expected. It is also important to support and maintain sitting ability for high lesions, if necessary with correction of the spinal deformity. Findings in gait analysis have shifted the focus of treatment from radiological criteria to functional improvement, thus maintenance of the flexibility of the hip is the main goal of hip surgery. Reduction of the hip often leads to stiffness and has a high redislocation rate. Clubfoot deformities should be treated early and foot arthrodesis and stiffness have to be avoided. Another focus is the prevention of joint contracture by early prophylactic treatment. The purpose of management is to maximize the functional potential of the child. Subjective well-being, absence of pain, mobility and socialization are the main goals. This does not necessarily imply ambulation; nevertheless, verticalization and associated orthotic management is one major objective of the orthopedic management of spina bifida.

  4. New biomaterials for orthopedic implants

    Directory of Open Access Journals (Sweden)

    Ong KL

    2015-09-01

    Full Text Available Kevin L Ong, Brian Min Yun, Joshua B WhiteExponent, Inc., Philadelphia, PA, USAAbstract: With the increasing use of orthopedic implants worldwide, there continues to be great interest in the development of novel technologies to further improve the effective clinical performance of contemporary treatment modalities and devices. Continuing research interest also exists in developing novel bulk biomaterials (eg, polycarbonate urethanes, silicon or novel formulations of existing but less widely used biomaterials (eg, polyaryletherketones, polyetheretherketone. There is also growing focus on customizing the material properties of bioabsorbables and composite materials with fillers such as bioactive ceramics. In terms of tissue engineering, more recent developments have focused on basic engineering and biological fundamentals to use cells, signaling factors, and the scaffold material itself to better restore tissue and organ structure and function. There has also been recent controversy with the use of injectables as a nonsurgical approach to treat joint disorders, but more attention is being directed toward the development of newer formulations with different molecular weights. The industry has also continuously sought to improve coatings to supplement the function of existing implants, with the goal of improving their osseointegrative qualities and incorporating antimicrobial properties. These include the use of bone morphogenetic protein, bisphosphonates, calcium phosphate, silicon nitride, and iodine. Due to the widespread use of bone graft materials, recent developments in synthetic graft materials have explored further development of bioactive glass, ceramic materials, and porous titanium particles. This review article provides an overview of ongoing efforts in the above research areas.Keywords: coatings, scaffolds, bioabsorbables, bone graft, injectables

  5. Atomic layer deposition synthesis and evaluation of core–shell Pt-WC electrocatalysts

    International Nuclear Information System (INIS)

    Hsu, Irene J.; Chen, Jingguang G.; Jiang, Xiaoqiang; Willis, Brian G.

    2015-01-01

    Pt-WC core shell particles were produced using atomic layer deposition (ALD) to deposit Pt layers onto WC particle substrates. A range of Pt depositions were used to determine the growth mechanism for the Pt-WC powder system. TEM imaging and Cu stripping voltammetry found that Pt ALD growth on WC powder substrates was similar to that on WC thin films. However, excess free carbon was found to affect Pt ALD by blocking adsorption sites on WC. The Pt-WC samples were evaluated for the oxygen reduction reaction using a rotating disk electrode to obtain quantitative activity information. The mass and specific activities for the 30 and 50 ALD cycle samples were found to be comparable to a 10 wt. % Pt/C catalyst. However, higher overpotentials and lower limiting currents were observed with ALD Pt-WC compared to Pt/C catalysts, indicating that the oxygen reduction mechanism is not as efficient on Pt-WC as on bulk Pt. Additionally, these Pt-WC catalysts were used to demonstrate hydrogen evolution reaction activity and were found to perform as well as bulk Pt catalyst but with a fraction of the Pt loading, in agreement with the previous work on Pt-WC thin film catalysts

  6. Artificial intelligence for analyzing orthopedic trauma radiographs.

    Science.gov (United States)

    Olczak, Jakub; Fahlberg, Niklas; Maki, Atsuto; Razavian, Ali Sharif; Jilert, Anthony; Stark, André; Sköldenberg, Olof; Gordon, Max

    2017-12-01

    Background and purpose - Recent advances in artificial intelligence (deep learning) have shown remarkable performance in classifying non-medical images, and the technology is believed to be the next technological revolution. So far it has never been applied in an orthopedic setting, and in this study we sought to determine the feasibility of using deep learning for skeletal radiographs. Methods - We extracted 256,000 wrist, hand, and ankle radiographs from Danderyd's Hospital and identified 4 classes: fracture, laterality, body part, and exam view. We then selected 5 openly available deep learning networks that were adapted for these images. The most accurate network was benchmarked against a gold standard for fractures. We furthermore compared the network's performance with 2 senior orthopedic surgeons who reviewed images at the same resolution as the network. Results - All networks exhibited an accuracy of at least 90% when identifying laterality, body part, and exam view. The final accuracy for fractures was estimated at 83% for the best performing network. The network performed similarly to senior orthopedic surgeons when presented with images at the same resolution as the network. The 2 reviewer Cohen's kappa under these conditions was 0.76. Interpretation - This study supports the use for orthopedic radiographs of artificial intelligence, which can perform at a human level. While current implementation lacks important features that surgeons require, e.g. risk of dislocation, classifications, measurements, and combining multiple exam views, these problems have technical solutions that are waiting to be implemented for orthopedics.

  7. [Research and analysis to Shui nationality medicine treatment orthopedics & traumatology].

    Science.gov (United States)

    Hu, Jian-Shan; Li, Pu; Yang, Yong; Chen, Xin-Chun; Lin, Li

    2013-05-01

    To investigated Shui nationality folk medicine's awareness to orthopedics & traumatology, the history of orthopedics & traumatology treatment, Shui nationality folk doctors' practicing medicine, heritage, diagnosis and treatment methods and tools, etc, through investigated drug resources category and distribution characteristics of Shui nationality medicine to orthopedics & traumatology treatment, explored and finished Shui nationality medicine orthopedics & traumatology treatment theoretical system. After more than 5 years' exploration and finishing, preliminarily formed the theoretical system framework and medicine application characteristics of Shui nationality medicine treating orthopedics & traumatology. Shui nationality medicine treatment orthopedics & traumatology has distinctive national style, and worthy to further exploration and research.

  8. Validation study of the COBRA-WC computer program for LMFBR core thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Khan, E.U.; Bates, J.M.

    1982-01-01

    The COBRA-WC (Whole Core) computer program has been developed as a benchmark code to predict flow and temperature fields in LMFBR rod bundles. Consequently, an extensive validation study has been conducted to reinforce its credibility. A set of generalized parameters predicts data well for a wide range of geometries and operating conditions which include conventional (current generation LMFBRs) fuel and blanket assembly geometry in the forced, mixed, and natural convection regimes. The data base used for validating COBRA-WC was obtained from out-of-pile and in-pile tests. Most of the data was obtained in fully heated bundles with bundle power skew across flats up to 3:1 (max:min), Reynolds number between 500 and 80,000, and coolant mixed-mean temperature rise (δ anti T) in the range, 78 0 F less than or equal to δ anti T less than or equal to 340 0 F. Within the bundle, 95% of the predicted coolant temperature data points fall within +-25 0 F for 150 0 F less than or equal to δ anti T less than or equal to 340 0 F and within +-17 0 F for 78 0 F less than or equal to δ anti T less than or equal to 150 0 F

  9. Machinability of Al-SiC metal matrix composites using WC, PCD and MCD inserts

    Energy Technology Data Exchange (ETDEWEB)

    Beristain, J.; Gonzalo, O.; Sanda, A.

    2014-04-01

    The aim of this work is the study of the machinability of aluminium-silicon carbide Metal Matrix Composites (MMC) in turning operations. The cutting tools used were hard metal (WC) with and without coating, different grades and geometries of Poly-Crystalline Diamond (PCD) and Mono-Crystalline Diamond (MCD). The work piece material was AMC225xe, composed of aluminium-copper alloy AA 2124 and 25% wt of SiC, being the size of the SiC particles around 3 {mu}m. Experiments were conducted at various cutting speeds and cutting parameters in facing finishing operations, measuring the surface roughness, cutting forces and tool wear. The worn surface of the cutting tool was examined by Scanning Electron Microscope (SEM). It was observed that the Built Up Edge (BUE) and stuck material is higher in the MCD tools than in the PCD tools. The BUE acts as a protective layer against abrasive wear of the tool. (Author)

  10. [Acute inpatient conservative multimodal treatment of complex and multifactorial orthopedic diseases in the ANOA concept].

    Science.gov (United States)

    Psczolla, M

    2013-10-01

    In Germany there is a clear deficit in the non-operative treatment of chronic and complex diseases and pain disorders in acute care hospitals. Only about 20 % of the treatments are carried out in orthopedic hospitals. Hospitals specialized in manual medicine have therefore formed a working group on non-operative orthopedic manual medicine acute care clinics (ANOA). The ANOA has developed a multimodal assessment procedure called the OPS 8-977 which describes the structure and process quality of multimodal and interdisciplinary diagnosis and treatment of the musculoskeletal system. Patients are treated according to clinical pathways oriented on the clinical findings. The increased duration of treatment in the German diagnosis-related groups (DRG) system is compensated for with a supplemental remuneration. Thus, complex and multifactorial orthopedic diseases and pain disorders are conservatively and appropriately treated as inpatient departments of acute care hospitals.

  11. Orthopedic Management of Patients with Pompe Disease: A Retrospective Case Series of 8 Patients

    Directory of Open Access Journals (Sweden)

    Gerrit Haaker

    2014-01-01

    Full Text Available Introduction. Pompe disease (PD, a lysosomal storage disease as well as a neuromuscular disorder, is a rare disease marked by progressive muscle weakness. Enzyme replacement therapy (ERT in recent years allowed longer survival but brought new problems to the treatment of PD with increasing affection of the musculoskeletal system, particularly with a significantly higher prevalence of scoliosis. The present paper deals with the orthopedic problems in patients with PD and is the first to describe surgical treatment of scoliosis in PD patients. Patients and Methods. The orthopedic problems and treatment of eight patients with PD from orthopedic consultation for neuromuscular disorders are retrospectively presented. We analyzed the problems of scoliosis, hip dysplasia, feet deformities, and contractures and presented the orthopedic treatment options. Results. Six of our eight PD patients had scoliosis and two young patients were treated by operative spine stabilization with benefits for posture and sitting ability. Hip joint surgery, operative contracture release, and feet deformity correction were performed with benefits for independent activity. Conclusion. Orthopedic management gains importance due to extended survival and musculoskeletal involvement under ERT. Surgical treatment is indicated in distinct cases. Further investigation is required to evidence the effect of surgical spine stabilization in PD.

  12. Performances and reliability of WC based thermal spray coatings

    International Nuclear Information System (INIS)

    Scrivani, A.; Rosso, M.; Salvarani, L.

    2001-01-01

    Thermal spray processes are used for a lot of traditional and innovative applications and their importance is becoming higher and higher. WC/CoCr based thermal spray coatings represent one of the most important class of coatings that find application in a wide range of industrial sectors. This paper will address a review of current applications and characteristics of this kind of coating. The most important spraying processes, namely HVOF (high velocity oxygen fuel) are examined, the characterization of the coatings from the point of view of corrosion and wear resistance is considered. (author)

  13. TEM INVESTIGATIONS OF WC-Co ALLOYS AFTER CREEP EXPERIMENTS

    OpenAIRE

    Lay , S.; Osterstock , F.; Vicens , J.

    1986-01-01

    Carbide tungsten cobalt alloys were deformed in compression or in three point bending in a temperature range 1000-1350°C and in a stress domain 30-1000MPa. In these conditions, the stress exponent n of WC-Co alloys is a function of only the cobalt volumic ratio and tends towards n = 1 for pure carbide. The apparent activation energy is 550 kj mole-1. T.E.M. investigations on pure carbide deformed at 1450°C show an extensive intragranular deformation. Analysis of these defects have been perfor...

  14. Awareness campaign. Orthopedic Hospital of Oklahoma launches awareness campaign.

    Science.gov (United States)

    2007-01-01

    The Orthopedic Hospital of Oklahoma is a 25-bed inpatient and outpatient center with one focus: Orthopedics. To acquaint people with its services and build brand awareness to drive market share, the hospital launched a print campaign featuring actual patients.

  15. Prosthesis infections after orthopedic joint replacement

    DEFF Research Database (Denmark)

    Song, Zhijun; Borgwardt, Lotte; Høiby, Niels

    2013-01-01

    Prosthesis-related infection is a serious complication for patients after orthopedic joint replacement, which is currently difficult to treat with antibiotic therapy. Consequently, in most cases, removal of the infected prosthesis is the only solution to cure the infection. It is, therefore...

  16. Molecular imaging promotes progress in orthopedic research.

    Science.gov (United States)

    Mayer-Kuckuk, Philipp; Boskey, Adele L

    2006-11-01

    Modern orthopedic research is directed towards the understanding of molecular mechanisms that determine development, maintenance and health of musculoskeletal tissues. In recent years, many genetic and proteomic discoveries have been made which necessitate investigation under physiological conditions in intact, living tissues. Molecular imaging can meet this demand and is, in fact, the only strategy currently available for noninvasive, quantitative, real-time biology studies in living subjects. In this review, techniques of molecular imaging are summarized, and applications to bone and joint biology are presented. The imaging modality most frequently used in the past was optical imaging, particularly bioluminescence and near-infrared fluorescence imaging. Alternate technologies including nuclear and magnetic resonance imaging were also employed. Orthopedic researchers have applied molecular imaging to murine models including transgenic mice to monitor gene expression, protein degradation, cell migration and cell death. Within the bone compartment, osteoblasts and their stem cells have been investigated, and the organic and mineral bone phases have been assessed. These studies addressed malignancy and injury as well as repair, including fracture healing and cell/gene therapy for skeletal defects. In the joints, molecular imaging has focused on the inflammatory and tissue destructive processes that cause arthritis. As described in this review, the feasibility of applying molecular imaging to numerous areas of orthopedic research has been demonstrated and will likely result in an increase in research dedicated to this powerful strategy. Molecular imaging holds great promise in the future for preclinical orthopedic research as well as next-generation clinical musculoskeletal diagnostics.

  17. Emotional intelligence in orthopedic surgery residents.

    Science.gov (United States)

    Chan, Kevin; Petrisor, Brad; Bhandari, Mohit

    2014-04-01

    Emotional intelligence (EI) is the ability to understand and manage emotions in oneself and others. It was originally popularized in the business literature as a key attribute for success that was distinct from cognitive intelligence. Increasing focus is being placed on EI in medicine to improve clinical and academic performance. Despite the proposed benefits, to our knowledge, there have been no previous studies on the role of EI in orthopedic surgery. We evaluated baseline data on EI in a cohort of orthopedic surgery residents. We asked all orthopedic surgery residents at a single institution to complete an electronic version of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). We used completed questionnaires to calculate total EI scores and 4 branch scores. Data were analyzed according to a priori cutoff values to determine the proportion of residents who were considered competent on the test. Data were also analyzed for possible associations with age, sex, race and level of training. Thirty-nine residents (100%) completed the MSCEIT. The mean total EI score was 86 (maximum score 145). Only 4 (10%) respondents demonstrated competence in EI. Junior residents (p = 0.026), Caucasian residents (p = 0.009) and those younger than 30 years (p = 0.008) had significantly higher EI scores. Our findings suggest that orthopedic residents score low on EI based on the MSCEIT. Optimizing resident competency in noncognitive skills may be enhanced by dedicated EI education, training and testing.

  18. Neonatal maxillary orthopedics: past to present

    NARCIS (Netherlands)

    Kuijpers-Jagtman, A.M.; Prahl, C.; Berkowitz, S.

    2013-01-01

    Neonatal maxillary orthopedics was introduced in the treatment protocol for cleft lip and palate in the 1950s of the last century. A wide range of appliances has been designed with pin-retained active appliances at one end of the spectrum and passive appliances at the other. Although neonatal

  19. Prediction of crack paths in WC-Co alloys

    International Nuclear Information System (INIS)

    Spiegler, R.; Fischmeister, H.F.

    1992-01-01

    This paper reports on a crack propagating through the WC-o microstructure which has to choose between paths along the binder/carbide interface and paths across binder regions. The latter paths are selected when the crack enters a binder region at a large angle from the nearest carbide interface, while the interface paths are preferred by cracks entering at a small angle. A critical angle can be defined for the switch from one type of crack path to the other. Empirical data for the area fractions of the two crack paths in widely different WC-Co alloys can be accounted for by a single critical angle, var-phi c = 25 degrees. Finite element analysis of the stress field in a region of binder enclosed between carbide grains shows that the preferred site for the growth of stress-induced microvoids will move from the carbide grain flanks to the interior of the binder region when the entry angle of the crack exceeds 24 degrees. Thus the observation of a critical angle deciding the crack path is verified by the stress field analysis and given a physical explanation in terms of the most likely site for microvoid formation

  20. Stellar C III Emissions as a New Classification Parameter for (WC) Central Stars

    Science.gov (United States)

    Feibelman, W. A.

    1999-01-01

    We report detection of stellar C III lambda 1909 emission in International Ultraviolet Explorer (IUE) echelle spectra of early-type [WC] planetary nebula central stars (CSPNs). Additionally, stellar C III emission at lambda 2297 is observed in early- and late-type [WC) CSPNS. Inclusion of these C III features for abundance determinations may resolve a conflict of underabundance of C/O for early type [WC2] - [WC4] CSPNS. A linear dependence on stellar C III lambda 2297 equivalent widths can be used to indicate a new classification of type [WCUV] central stars.

  1. The Particle Shape of WC Governing the Fracture Mechanism of Particle Reinforced Iron Matrix Composites.

    Science.gov (United States)

    Li, Zulai; Wang, Pengfei; Shan, Quan; Jiang, Yehua; Wei, He; Tan, Jun

    2018-06-11

    In this work, tungsten carbide particles (WC p , spherical and irregular particles)-reinforced iron matrix composites were manufactured utilizing a liquid sintering technique. The mechanical properties and the fracture mechanism of WC p /iron matrix composites were investigated theoretically and experimentally. The crack schematic diagram and fracture simulation diagram of WC p /iron matrix composites were summarized, indicating that the micro-crack was initiated both from the interface for spherical and irregular WC p /iron matrix composites. However, irregular WC p had a tendency to form spherical WC p . The micro-cracks then expanded to a wide macro-crack at the interface, leading to a final failure of the composites. In comparison with the spherical WC p , the irregular WC p were prone to break due to the stress concentration resulting in being prone to generating brittle cracking. The study on the fracture mechanisms of WC p /iron matrix composites might provide a theoretical guidance for the design and engineering application of particle reinforced composites.

  2. Surgical simulation training in orthopedics: current insights.

    Science.gov (United States)

    Kalun, Portia; Wagner, Natalie; Yan, James; Nousiainen, Markku T; Sonnadara, Ranil R

    2018-01-01

    While the knowledge required of residents training in orthopedic surgery continues to increase, various factors, including reductions in work hours, have resulted in decreased clinical learning opportunities. Recent work suggests residents graduate from their training programs without sufficient exposure to key procedures. In response, simulation is increasingly being incorporated into training programs to supplement clinical learning. This paper reviews the literature to explore whether skills learned in simulation-based settings results in improved clinical performance in orthopedic surgery trainees. A scoping review of the literature was conducted to identify papers discussing simulation training in orthopedic surgery. We focused on exploring whether skills learned in simulation transferred effectively to a clinical setting. Experimental studies, systematic reviews, and narrative reviews were included. A total of 15 studies were included, with 11 review papers and four experimental studies. The review articles reported little evidence regarding the transfer of skills from simulation to the clinical setting, strong evidence that simulator models discriminate among different levels of experience, varied outcome measures among studies, and a need to define competent performance in both simulated and clinical settings. Furthermore, while three out of the four experimental studies demonstrated transfer between the simulated and clinical environments, methodological study design issues were identified. Our review identifies weak evidence as to whether skills learned in simulation transfer effectively to clinical practice for orthopedic surgery trainees. Given the increased reliance on simulation, there is an immediate need for comprehensive studies that focus on skill transfer, which will allow simulation to be incorporated effectively into orthopedic surgery training programs.

  3. Theoretical studies on the electronic and optoelectronic properties of [A.2AP(w)/A*.2AP(WC)/C.2AP(w)/C*.2AP(WC)/C.A(w)/C*.A(WC)]-Au8 mismatch nucleobase complexes

    Science.gov (United States)

    Srivastava, Ruby

    2018-01-01

    The electronic and optoelectronic properties of [A.2AP(w)/A*.2AP(WC)/C.2AP(w)/C*.2AP(WC)/C.A(w)/ C*.A(WC)]-Au8 metal-mismatch nucleobase complexes are investigated by means of density functional theory and time-dependent methods. We selected these mispairs as 2-aminopurine (2AP) produces incorporation errors when binding with cytosine (C) into the wobble (w) C.2AP(w) mispair, and is tautomerised into Watson-Crick (WC)-like base mispair C*.2AP(WC) and less effectively produces A.2AP(w)/A*.2AP(WC) mispairs. The vertical ionisation potential, vertical electron affinity, hardness and electrophilicity index of these complexes have also been discussed. The modifications of energy levels and charge density distributions of the frontier orbitals are also analysed. The absorption spectra of these complexes lie in the visible region, which suggests their application in fluorescent-bio imaging. The mechanism of cooperativity effect is studied by molecular orbital potential (MEP), atoms-in-molecules (AIM) and natural bond orbital analyses. Most metalated pairs have smaller HOMO-LUMO band gaps than the isolated mismatch nucleobases which suggest interesting consequences for electron transfer through DNA duplexes.

  4. Study on single step solid state synthesis of WC@C nanocomposite and electrochemical stability of synthesized WC@C & Pt/WC@C for alcohol oxidation (methanol/ethanol)

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Gourav, E-mail: gsinghla@gmail.com; Singh, K., E-mail: kusingh@thapar.edu; Pandey, O.P., E-mail: oppandey@thapar.edu

    2016-04-25

    WC@C nano composite was prepared by a single step solid–state reaction through in situ reduction and carburization of WO{sub 3} in the presence of Mg and activated charcoal. The XRD results and thermodynamics analysis showed that the optimization of reaction temperature facilitates the reduction as well as carburization of tungsten oxide(s) at different reaction temperature. Thermogravimetric analysis of the product was done to assess the thermal stability in air. The Raman spectroscopy was used to find out the nature (amorphous/graphitic) of carbon in the obtained phase. The N{sub 2} adsorption–desorption measurement showed a narrow pore size distribution from 3 to 4 nm with BET surface area of up to 522.5 m{sup 2}/g. TEM/HRTEM images confirmed formation of the WC nano particles with spherical morphology. Electrochemical stability of pure and platinized carbide sample (Pt/WC) has been investigated using cyclic voltammetry in acidic media for alcohol (methanol and ethanol) oxidation. - Highlights: • Tungsten carbide nano powder was synthesized using charcoal as carbon source. • Formation of WC occurs through the formation of lower tungsten oxide. • CO{sub 2}/CO ratio effect the formation of WC. • Mesoporous tungsten carbide with surface areas 522.5 m{sup 2}/g obtained by using charcoal. • Pt modified WC powder showed higher electrochemical stability.

  5. Do Astronauts have a Higher Rate of Orthopedic Shoulder Conditions than a Cohort of Working Professionals?

    Science.gov (United States)

    Laughlin, Mitzi S.; Murray, Jocelyn D.; Young, Millenia; Wear, Mary L.; Tarver, W. J.; Van Baalen, Mary

    2016-01-01

    Occupational surveillance of astronaut shoulder injuries began with operational concerns at the Neutral Buoyancy Laboratory (NBL) during Extra Vehicular Activity (EVA) training. NASA has implemented several occupational health initiatives during the past 20 years to decrease the number and severity of injuries, but the individual success rate is unknown. Orthopedic shoulder injury and surgery rates were calculated, but classifying the rates as normal, high or low was highly dependent on the comparison group. The purpose of this study was to identify a population of working professionals and compare orthopedic shoulder consultation and surgery rates.

  6. Regional mapping of photovoltaic plants ranging from 100 to 999 kWc in 2013

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    In a context of the expectation of a strong political lead, small and intermediate photovoltaic installations keep on developing. The map gives for each France's region the number of operating installations whose power output ranges between 100 and 999 kWc, and the number and the capacity of the installations that are completed but not yet connected to the grid. The sunshine level curves are also drawn. Polycrystal and monocrystal technologies are the most used 48% and 32% respectively, while the thin layer technology is used in only 5% of the installations. Concerning the type of the setting a great majority of the installations (85%) are integrated to the building while less than 1% are set on the ground. (A.C.)

  7. Adhesion at WC/diamond interfaces - A theoretical study

    International Nuclear Information System (INIS)

    Padmanabhan, Haricharan; Rao, M. S. Ramachandra; Nanda, B. R. K.

    2015-01-01

    We investigate the adhesion at the interface of face-centered tungsten-carbide (001) and diamond (001) from density-functional calculations. Four high-symmetry model interfaces, representing different lattice orientations for either side of the interface, are constructed to incorporate different degrees of strain arising due to lattice mismatch. The adhesion, estimated from the ideal work of separation, is found to be in the range of 4 - 7 J m −2 and is comparable to that of metal-carbide interfaces. Maximum adhesion occurs when WC and diamond slabs have the same orientation, even though such a growth induces large epitaxial strain at the interface. From electronic structure calculations, we attribute the adhesion to covalent interaction between carbon p-orbitals as well as partial ionic interaction between the tungsten d- and carbon p-orbitals across the interface

  8. Adhesion at WC/diamond interfaces - A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Padmanabhan, Haricharan [Department of Engineering Design, Indian Institute of Technology Madras, Chennai – 600036 (India); Rao, M. S. Ramachandra [Department of Physics and Nano-Functional Materials Technology Centre, Indian Institute of Technology Madras, Chennai – 600036 (India); Nanda, B. R. K., E-mail: nandab@iitm.ac.in [Department of Physics, Indian Institute of Technology Madras, Chennai – 600036 (India)

    2015-06-24

    We investigate the adhesion at the interface of face-centered tungsten-carbide (001) and diamond (001) from density-functional calculations. Four high-symmetry model interfaces, representing different lattice orientations for either side of the interface, are constructed to incorporate different degrees of strain arising due to lattice mismatch. The adhesion, estimated from the ideal work of separation, is found to be in the range of 4 - 7 J m{sup −2} and is comparable to that of metal-carbide interfaces. Maximum adhesion occurs when WC and diamond slabs have the same orientation, even though such a growth induces large epitaxial strain at the interface. From electronic structure calculations, we attribute the adhesion to covalent interaction between carbon p-orbitals as well as partial ionic interaction between the tungsten d- and carbon p-orbitals across the interface.

  9. Macroparticle generation in DC arc discharge from a WC cathode

    Science.gov (United States)

    Zhirkov, Igor; Polcik, Peter; Kolozsvári, Szilard; Rosen, Johanna

    2017-03-01

    We have studied macroparticle generation from a tungsten carbide cathode used in a dc vacuum arc discharge. Despite a relatively high decomposition/melting point (˜3100 K), there is an intensive generation of visible particles with sizes in the range 20-35 μm. Visual observations during the discharge and scanning electron microscopy of the cathode surface and of collected macroparticles indicate a new mechanism for particle formation and acceleration. Based on the W-C phase diagram, there is an intensive sublimation of carbon from the melt resulting from the cathode spot. The sublimation supports the formation of a sphere, which is accelerated upon an explosion initiated by Joule heating at the critical contact area between the sphere and the cathode body. The explosive nature of the particle acceleration is confirmed by surface features resembling the remains of a splash on the droplet surface.

  10. iPad apps for orthopedic surgeons.

    Science.gov (United States)

    Franko, Orrin I; Bhola, Siddharth

    2011-12-01

    The development and distribution of mobile applications, or apps, designed for medical professionals and patients is quickly expanding, and within this group are apps designed specifically for orthopedic use. Currently, the most popular mobile apps are sponsored by private companies and focus on delivering device-specific information. If this trend toward the use of privately funded educational materials continues, regulations may need to be established to ensure that the information provided is accurate, honest, and supported by peer-reviewed literature. It will likely be the responsibility of the orthopedic community to ensure that the development and use of these apps has appropriate oversight and validation as they are incorporated into clinical practice and training. Copyright © 2011, SLACK Incorporated.

  11. Robotics in Orthopedics: A Brave New World.

    Science.gov (United States)

    Parsley, Brian S

    2018-02-16

    Future health-care projection projects a significant growth in population by 2020. Health care has seen an exponential growth in technology to address the growing population with the decreasing number of physicians and health-care workers. Robotics in health care has been introduced to address this growing need. Early adoption of robotics was limited because of the limited application of the technology, the cumbersome nature of the equipment, and technical complications. A continued improvement in efficacy, adaptability, and cost reduction has stimulated increased interest in robotic-assisted surgery. The evolution in orthopedic surgery has allowed for advanced surgical planning, precision robotic machining of bone, improved implant-bone contact, optimization of implant placement, and optimization of the mechanical alignment. The potential benefits of robotic surgery include improved surgical work flow, improvements in efficacy and reduction in surgical time. Robotic-assisted surgery will continue to evolve in the orthopedic field. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Influence of WC addition on the microstructure and mechanical properties of NbC-Co cermets

    International Nuclear Information System (INIS)

    Huang, S.G.; Li, L.; Van der Biest, O.; Vleugels, J.

    2007-01-01

    NbC-24.5 wt.% Co cermets with up to 30 wt.% WC were obtained by solid state hot pressing at 1300 o C under a pressure of 45 MPa for 10 min and pressureless liquid phase sintering at 1360 o C for 60 min. The effect of WC addition on the microstructure and mechanical properties of NbC-Co based cermets was investigated. The hot pressed cermets exhibited interconnected and irregular niobium carbide (NbC) or (Nb,W)C grains, whereas the shape of the NbC grains changed from faceted with rounded corners to spherical, as the WC content increased in the pressureless sintered cermets. The undissolved WC increased with increasing WC addition. A clear core/rim structure was observed in the hot pressed cermets with 10-30 wt.% WC additions, whereas this structure was gradually eliminated when pressureless sintering. The hardness remains nearly constant whereas the fracture toughness slightly increases with increasing WC addition. The dissolution of WC in the Co binder and NbC grains, as well as the formation of a solid solution (Nb,W)C phase were supported by thermodynamic calculations

  13. An alternative approach to estimate the W/C ratio of hardened concrete using image analysis

    NARCIS (Netherlands)

    Valcke, S.; Nijland, T.G.; Larbi, J.A.

    2009-01-01

    The water cement (w/c) ratio is a typical quality parameter for concrete. The NT Build 361 Nordtest method is a standard for estimating the w/c ratio in hardened concrete and is based on the relationship between the ilc ratio and the capillary porosity in the cement paste. The latter can be

  14. Evaluation of WC-9Co-4Cr laser surface alloyed coatings on stainless steel

    CSIR Research Space (South Africa)

    Obadele, A

    2011-07-01

    Full Text Available spectrometer (EDS), while the phase changed were observed using x-ray diffraction (XRD). The surface hardness was determined using the Vickers microhardness tester. The decomposition of WC-9Co-4Cr into W2C, C and W is as a result of low heat of formation of WC...

  15. Dodecahedral W@WC Composite as Efficient Catalyst for Hydrogen Evolution and Nitrobenzene Reduction Reactions.

    Science.gov (United States)

    Chen, Zhao-Yang; Duan, Long-Fa; Sheng, Tian; Lin, Xiao; Chen, Ya-Feng; Chu, You-Qun; Sun, Shi-Gang; Lin, Wen-Feng

    2017-06-21

    Core-shell composites with strong phase-phase contact could provide an incentive for catalytic activity. A simple, yet efficient, H 2 O-mediated method has been developed to synthesize a mesoscopic core-shell W@WC architecture with a dodecahedral microstructure, via a one-pot reaction. The H 2 O plays an important role in the resistance of carbon diffusion, resulting in the formation of the W core and W-terminated WC shell. Density functional theory (DFT) calculations reveal that adding W as core reduced the oxygen adsorption energy and provided the W-terminated WC surface. The W@WC exhibits significant electrocatalytic activities toward hydrogen evolution and nitrobenzene electroreduction reactions, which are comparable to those found for commercial Pt/C, and substantially higher than those found for meso- and nano-WC materials. The experimental results were explained by DFT calculations based on the energy profiles in the hydrogen evolution reactions over WC, W@WC, and Pt model surfaces. The W@WC also shows a high thermal stability and thus may serve as a promising more economical alternative to Pt catalysts in these important energy conversion and environmental protection applications. The current approach can also be extended or adapted to various metals and carbides, allowing for the design and fabrication of a wide range of catalytic and other multifunctional composites.

  16. Methods of orthopedic treatment of dentition defects

    Directory of Open Access Journals (Sweden)

    Konnov V.V.

    2016-09-01

    Full Text Available The article is devoted to the methods of orthopedic treatment of dentition defects. To restore the functionality and individual aesthetic standards of dental system, with different types of partial loss of teeth, depending on the anatomical and topographical conditions, various kinds of dental prosthesis designs are used in the oral cavity: non-removable (bridges, cantilever, adhesive dentures and removable (laminar and clasp dental prostheses, as well as their combinations.

  17. Level of evidence gap in orthopedic research.

    Science.gov (United States)

    Baldwin, Keith D; Bernstein, Joseph; Ahn, Jaimo; McKay, Scott D; Sankar, Wudbhav N

    2012-09-01

    Level of evidence is the most widely used metric for the quality of a publication, but instances exist in which a Level I study is neither feasible nor desirable. The goal of this study was to evaluate the level of evidence gap in current orthopedic research, which the authors defined as the disparity between the level of evidence that would be required to optimally answer the primary research question and the level of evidence that was actually used. Five orthopedic surgeons (K.D.B., J.B., J.A., S.D.M., W.N.S.) evaluated blinded articles from the first 6 months of 2010 in the Journal of Bone and Joint Surgery (American Volume) (JBJS-Am), classifying the study type and design and extracting a primary research question from each article. Each evaluator then defined the study type and method, along with the level of evidence that would ideally be used to address the primary research question. The level of evidence gap was then calculated by subtracting the actual level of evidence of the manuscript from the level of evidence of the idealized study. Of the 64 JBJS-Am manuscripts eligible for analysis, the average level of evidence was between Level II and III (mean, 2.73). The average level of evidence gap was 1.06 compared with the JBJS-Am-designated level of evidence and 1.28 compared with the evaluators' assessment. Because not all questions require Level I studies, level of evidence alone may not be the best metric for the quality of orthopedic surgery literature. Instead, the authors' concept of a level of evidence gap may be a better tool for assessing the state of orthopedic research publications. Copyright 2012, SLACK Incorporated.

  18. An advanced simulator for orthopedic surgical training.

    Science.gov (United States)

    Cecil, J; Gupta, Avinash; Pirela-Cruz, Miguel

    2018-02-01

    The purpose of creating the virtual reality (VR) simulator is to facilitate and supplement the training opportunities provided to orthopedic residents. The use of VR simulators has increased rapidly in the field of medical surgery for training purposes. This paper discusses the creation of the virtual surgical environment (VSE) for training residents in an orthopedic surgical process called less invasive stabilization system (LISS) surgery which is used to address fractures of the femur. The overall methodology included first obtaining an understanding of the LISS plating process through interactions with expert orthopedic surgeons and developing the information centric models. The information centric models provided a structured basis to design and build the simulator. Subsequently, the haptic-based simulator was built. Finally, the learning assessments were conducted in a medical school. The results from the learning assessments confirm the effectiveness of the VSE for teaching medical residents and students. The scope of the assessment was to ensure (1) the correctness and (2) the usefulness of the VSE. Out of 37 residents/students who participated in the test, 32 showed improvements in their understanding of the LISS plating surgical process. A majority of participants were satisfied with the use of teaching Avatars and haptic technology. A paired t test was conducted to test the statistical significance of the assessment data which showed that the data were statistically significant. This paper demonstrates the usefulness of adopting information centric modeling approach in the design and development of the simulator. The assessment results underscore the potential of using VR-based simulators in medical education especially in orthopedic surgery.

  19. Proximal spinal muscular atrophy: current orthopedic perspective

    Directory of Open Access Journals (Sweden)

    Haaker G

    2013-11-01

    Full Text Available Gerrit Haaker, Albert Fujak Department of Orthopaedic Surgery, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany Abstract: Spinal muscular atrophy (SMA is a hereditary neuromuscular disease of lower motor neurons that is caused by a defective "survival motor neuron" (SMN protein that is mainly associated with proximal progressive muscle weakness and atrophy. Although SMA involves a wide range of disease severity and a high mortality and morbidity rate, recent advances in multidisciplinary supportive care have enhanced quality of life and life expectancy. Active research for possible treatment options has become possible since the disease-causing gene defect was identified in 1995. Nevertheless, a causal therapy is not available at present, and therapeutic management of SMA remains challenging; the prolonged survival is increasing, especially orthopedic, respiratory and nutritive problems. This review focuses on orthopedic management of the disease, with discussion of key aspects that include scoliosis, muscular contractures, hip joint disorders, fractures, technical devices, and a comparative approach of conservative and surgical treatment. Also emphasized are associated complications including respiratory involvement, perioperative care and anesthesia, nutrition problems, and rehabilitation. The SMA disease course can be greatly improved with adequate therapy with established orthopedic procedures in a multidisciplinary therapeutic approach. Keywords: spinal muscular atrophy, scoliosis, contractures, fractures, lung function, treatment, rehabilitation, surgery, ventilation, nutrition, perioperative management

  20. [Orthopedics and patients under national socialism dictatorship].

    Science.gov (United States)

    Thomann, K D; Rauschmann, M

    2001-10-01

    The 12-year dictatorship of National Socialism represents a decisive event in the history of orthopedics in Germany. Treatment and care was limited to those patients whose prognosis promised their reintegration into the work force. Those orthopedic patients with mental and psychological handicaps no longer came under the care of orthopedists and were potential candidates for annihilation. Despite concerted efforts to the contrary, as can be gleaned from the lists of topics at the annual meetings, the prevailing political circumstances encumbered scientific activities. The almost total isolation from international contacts had a negative effect. Orthopedists were hindered in their work by the law on sterilization, which provided for sterilization in cases of severe physical deformity. Some orthopedists even considered the presence of hip dysplasia to be an indication. The roles played by Georg Hohmann, Hellmut Eckhardt, Lothar Kreuz, and other leading orthopedists are described in detail. It can be regarded as certain that Hohmann and Eckhardt were able to prevent dire consequences for their orthopedic patients and the profession by cautious tactics. The ethnical problems of involvement with National Socialism are thoroughly discussed.

  1. High Temperature Dry Sliding Friction and Wear Performance of Laser Cladding WC/Ni Composite Coating

    Directory of Open Access Journals (Sweden)

    YANG Jiao-xi

    2016-06-01

    Full Text Available Two different types of agglomerate and angular WC/Ni matrix composite coatings were deposited by laser cladding. The high temperature wear resistance of these composite coatings was tested with a ring-on-disc MMG-10 apparatus. The morphologies of the worn surfaces were observed using a scanning electron microscopy (SEM equipped with an energy dispersive spectroscopy (EDS for elemental composition. The results show that the high temperature wear resistance of the laser clad WC/Ni-based composite coatings is improved significantly with WC mass fraction increasing. The 60% agglomerate WC/Ni composite coating has optimal high temperature wear resistance. High temperature wear mechanism of 60% WC/Ni composite coating is from abrasive wear of low temperature into composite function of the oxidation wear and abrasive wear.

  2. Resource recovery of WC-Co cermet using hydrothermal oxidation technique

    International Nuclear Information System (INIS)

    Gao Ningfeng; Inagaki, F.; Sasai, R.; Itoh, H.; Watari, K.

    2005-01-01

    WC-Co cermet is widely used in industrial applications such as cutting tools, dies, wear parts and so on. It is of great importance to establish the recycling process for the precious metal resources contained in WC-Co cermet, because all these metals used in Japan are imported. In this paper we reported a hydrothermal oxidation technique using nitric acid for the reclamation of WC and Co. The WC-Co cermet specimens with various WC particle sizes and Co contents were hydrothermally treated in HNO 3 aqueous solutions at temperatures of 110-200 C for durations of 6-240 h. The Co was preferentially leached out into the acidic solution, while the WC was oxidized to insoluble WO 3 hydrate which was subsequently separated by filtration. The hydrothermal treatment parameters such as solvent concentrations, treatment temperatures, holding time were optimized in respect to different kinds of WC-Co cermets. A hydrothermal oxidation treatment in 3M HNO 3 aqueous solution at 150 C for 24 h was capable of fully disintegrating the cermet chip composed of coarse WC grains of 1-5 μm in size with 20 wt% of Co as binder. While the more oxidation resistant specimen composed of fine WC grains of 0.5-1.0 μm in size with 13 wt% of Co, was completely disintegrated by a treatment in 7 M HNO 3 aqueous solution at 170 C for 24 h. The filtered solid residues were composed of fine WO 3 .0.33H 2 O powder and a small amount of WO 3 . The recovered WO 3 .0.33H 2 O powder can be easily returned to the industrial process for the synthesis of WC powder so that the overall recycling cost can be possibly lowered. (orig.)

  3. Fretting and wear behaviors of Ni/nano-WC composite coatings in dry and wet conditions

    International Nuclear Information System (INIS)

    Benea, Lidia; Başa, Sorin-Bogdan; Dănăilă, Eliza; Caron, Nadège; Raquet, Olivier; Ponthiaux, Pierre; Celis, Jean-Pierre

    2015-01-01

    Highlights: • The friction and wear properties of Ni/nano-WC composite were studied. • Nano-WC reinforcement decreased friction coefficient in dry and wet conditions. • Nano-WC reinforcement fraction was seen to be 12 wt.%. • Nanohardness increased by 27% compared to nickel without WC reinforcements. • Ennoblement of OCP corresponding to the Ni/nano-WC composite coating. - Abstract: The fretting and wear behaviors of Ni/nano-WC composite coatings were studied by considering the effect of fretting frequency of 1 Hz during 10,000 cycles, at different applied loads in dry or wet conditions. The studies were performed on a ball-on-disk tribometer and the results were compared with pure Ni coating. The nanohardness of pure Ni and Ni/nano-WC composite coatings was tested by nanoindentation technique. To evaluate the wet wear (tribocorrosion) behavior the open circuit potential (OCP) was measured before, during and after the fretting tests at room temperature in the solution that simulates the primary water circuit of Pressurized Water Reactors (PWRs). The results show that Ni/nano-WC composite coatings exhibited a low friction coefficient, high nanohardness and wear resistance compared with pure Ni coatings under similar experimental conditions. Ni/nano-WC composite coatings were obtained on stainless steel support by electrochemical codeposition of nano-sized WC particles (diameter size of ∼60 nm) with nickel, from a standard nickel Watts plating bath. The surface morphology and the composition of the coatings were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) respectively

  4. Structure and hardness of a hard metal alloy prepared with a WC powder synthesized at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Costa, F.A. da [Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil)], E-mail: francineac@yahoo.com; Medeiros, F.F.P. de [Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil); Silva, A.G.P. da [Laboratorio de Materiais Avancados, UENF, 28015-620 Campos de Goytacazes, RJ (Brazil); Gomes, U.U. [Departamento de Fisica Teorica e Experimental, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil); Filgueira, M. [Laboratorio de Materiais Avancados, UENF, 28015-620 Campos de Goytacazes, RJ (Brazil); Souza, C.P. de [Laboratorio de Termodinamica e Reatores, UFRN, Campus Universitario, 59072-970 Natal, RN (Brazil)

    2008-06-25

    The structure and hardness of a WC-10 wt% Co alloy prepared with an experimental WC powder are compared with those of another alloy of the same composition produced under the same conditions and prepared with a commercial WC powder. The experimental WC powder was synthesized by a gas-solid reaction between APT and methane at low temperature and the commercial WC powder was conventionally produced by a solid-solid reaction between tungsten and carbon black. WC-10 wt% Co alloys with the two powders were prepared under the same conditions of milling and sintering. The structure of the sample prepared with the experimental WC powder is homogeneous and coarse grained. The structure of the sample prepared with the commercial powder is heterogeneous. Furthermore the size and shape of the WC grains are significantly different.

  5. Influence of orthopedic reinforced gloves versus double standard gloves on contamination events during small animal orthopedic surgery.

    Science.gov (United States)

    Hayes, Galina; Singh, Ameet; Gibson, Tom; Moens, Noel; Oblak, Michelle; Ogilvie, Adam; Reynolds, Debbie

    2017-10-01

    To determine the influence of orthopedic reinforced gloves on contamination events during small animal orthopedic surgery. Prospective randomized controlled trial SAMPLE POPULATION: Two hundred and thirty-seven pairs of orthopedic gloves (474 gloves) and 203 pairs of double standard gloves (812 gloves) worn during 193 orthopedic procedures. Primary and assistant surgeons were randomized to wear either orthopedic reinforced gloves or double gloves. Gloves were leak tested to identify perforations at the end of procedures. Perforations detected intraoperatively or postoperatively were recorded. A contamination event was defined as at least one perforation on either hand for orthopedic reinforced gloves, or a perforation of both the inner and outer glove on the same hand for double gloves. Baseline characteristics between the 2 intervention groups were similar. There was no difference in contamination events between the double-gloved and orthopedic gloved groups (OR = 0.95, 95% CI = 0.49-1.87, P = .89). The same percentage of contamination events (8% glove pairs used) occurred in the double gloved group (17 contamination events) and in the orthopedic gloved group (19 contamination events). The odds of a contamination event increased by 1.02 (95% CI 1.01-1.03, P contamination events in small animal orthopedic procedures. Surgeons reluctant to double glove due to perceptions of decreased dexterity and discomfort may safely opt for wearing orthopedic gloves, which may improve their compliance. © 2017 The American College of Veterinary Surgeons.

  6. In-vivo orthopedic implant diagnostic device for sensing load, wear, and infection

    Science.gov (United States)

    Evans, III, Boyd McCutchen; Thundat, Thomas G.; Komistek, Richard D.; Dennis, Douglas A.; Mahfouz, Mohamed

    2006-08-29

    A device for providing in vivo diagnostics of loads, wear, and infection in orthopedic implants having at least one load sensor associated with the implant, at least one temperature sensor associated with the implant, at least one vibration sensor associated with the implant, and at least one signal processing device operatively coupled with the sensors. The signal processing device is operable to receive the output signal from the sensors and transmit a signal corresponding with the output signal.

  7. Nanotechnology-enhanced orthopedic materials fabrications, applications and future trends

    CERN Document Server

    Yang, Lei

    2015-01-01

    Nanotechnology-Enhanced Orthopedic Materials provides the latest information on the emergence and rapid development of nanotechnology and the ways it has impacted almost every aspect of biomedical engineering. This book provides readers with a comprehensive overview of the field, focusing on the fabrication and applications of these materials, presenting updated, practical, and systematic knowledge on the synthesis, processing, and modification of nanomaterials, along with the rationale and methodology of applying such materials for orthopedic purposes. Topics covered include a wide range of orthopedic material formulations, such as ceramics, metals, polymers, biomolecules, and self-assemblies. Final sections explore applications and future trends in nanotechnology-enhanced orthopedic materials. Details practical information on the fabrication and modification of new and traditional orthopedic materials Analyzes a wide range of materials, designs, and applications of nanotechnology for orthopedics Investigate...

  8. Orthopedic complications of linear morphea: Implications for early interdisciplinary care.

    Science.gov (United States)

    Schoch, Jennifer J; Schoch, Bradley S; Werthel, Jean David; McIntosh, Amy L; Davis, Dawn M R

    2018-01-01

    Linear morphea of the limb primarily affects children, and extracutaneous manifestations are common. Orthopedic surgeons are often essential in the care of patients with linear morphea, yet there are few reports outlining specific orthopedic complications in this population. We sought to improve the understanding of orthopedic complications in linear morphea of the limb. Between 1999 and 2014, 51 children were evaluated for linear morphea of an extremity. Twenty-six (51%) had documented orthopedic manifestations. Outcome measures included limb length discrepancy, angular malalignment, limb atrophy, and orthopedic surgical intervention. Joint contractures were most common, affecting 88% of patients, followed by limb atrophy, angular deformity, and limb length discrepancy; 14% required surgical intervention. Despite the use of systemic immunosuppressive therapy in many patients, approximately half of patients with linear morphea of an extremity have orthopedic disease. Early orthopedist involvement is crucial to improve limb alignment and preserve function. © 2017 Wiley Periodicals, Inc.

  9. Soft phonon modes driven huge difference on lattice thermal conductivity between topological semimetal WC and WN

    Science.gov (United States)

    Guo, San-Dong; Chen, Peng

    2018-04-01

    Topological semimetals are currently attracting increasing interest due to their potential applications in topological qubits and low-power electronics, which are closely related to their thermal transport properties. Recently, the triply degenerate nodal points near the Fermi level of WC are observed by using angle-resolved photoemission spectroscopy. In this work, by solving the Boltzmann transport equation based on first-principles calculations, we systematically investigate the phonon transport properties of topological semimetals WC and WN. The predicted room-temperature lattice thermal conductivities of WC (WN) along the a and c directions are 1140.64 (7.47) W m-1 K-1 and 1214.69 (5.39) W m-1 K-1. Considering the similar crystal structure of WC and WN, it is quite interesting to find that the thermal conductivity of WC is more than two orders of magnitude higher than that of WN. It is found that, different from WN, the large acoustic-optical (a-o) gap prohibits the acoustic+acoustic → optical (aao) scattering, which gives rise to very long phonon lifetimes, leading to ultrahigh lattice thermal conductivity in WC. For WN, the lack of an a-o gap is due to soft phonon modes in optical branches, which can provide more scattering channels for aao scattering, producing very short phonon lifetimes. Further deep insight can be attained from their different electronic structures. Distinctly different from that in WC, the density of states of WN at the Fermi level becomes very sharp, which leads to destabilization of WN, producing soft phonon modes. It is found that the small shear modulus G and C44 limit the stability of WN, compared with WC. Our studies provide valuable information for phonon transports in WC and WN, and motivate further experimental studies to study their lattice thermal conductivities.

  10. Nursing documentation and length of stay in orthopedic surgery

    NARCIS (Netherlands)

    Paans, Wolter; Krijnen, Wim

    2016-01-01

    Nursing outcome calculation, and future possibilities. An example in orthopedic specialty nursing. Comparing nursing diagnoses in hip prosthesis patients and knee prosthesis patients in a Dutch hospital.

  11. Trends in Medicare Reimbursement for Orthopedic Procedures: 2000 to 2016.

    Science.gov (United States)

    Eltorai, Adam E M; Durand, Wesley M; Haglin, Jack M; Rubin, Lee E; Weiss, Arnold-Peter C; Daniels, Alan H

    2018-03-01

    Understanding trends in reimbursement is critical to the financial sustainability of orthopedic practices. Little research has examined physician fee trends over time for orthopedic procedures. This study evaluated trends in Medicare reimbursements for orthopedic surgical procedures. The Medicare Physician Fee Schedule was examined for Current Procedural Terminology code values for the most common orthopedic and nonorthopedic procedures between 2000 and 2016. Prices were adjusted for inflation to 2016-dollar values. To assess mean growth rate for each procedure and subspecialty, compound annual growth rates were calculated. Year-to-year dollar amount changes were calculated for each procedure and subspecialty. Reimbursement trends for individual procedures and across subspecialties were compared. Between 2000 and 2016, annual reimbursements decreased for all orthopedic procedures examined except removal of orthopedic implant. The orthopedic procedures with the greatest mean annual decreases in reimbursement were shoulder arthroscopy/decompression, total knee replacement, and total hip replacement. The orthopedic procedures with the least annual reimbursement decreases were carpal tunnel release and repair of ankle fracture. Rate of Medicare procedure reimbursement change varied between subspecialties. Trauma had the smallest decrease in annual change compared with spine, sports, and hand. Annual reimbursement decreased at a significantly greater rate for adult reconstruction procedures than for any of the other subspecialties. These findings indicate that reimbursement for procedures has steadily decreased, with the most rapid decrease seen in adult reconstruction. [Orthopedics. 2018; 41(2):95-102.]. Copyright 2018, SLACK Incorporated.

  12. Medical Crowdfunding for Patients Undergoing Orthopedic Surgery.

    Science.gov (United States)

    Durand, Wesley M; Johnson, Joseph R; Eltorai, Adam E M; Daniels, Alan H

    2018-01-01

    Crowdfunding for medical expenses is growing in popularity. Through several websites, patients create public campaign profiles to which donors can contribute. Research on medical crowdfunding is limited, and there have been no studies of crowdfunding in orthopedics. Active medical crowdfunding campaigns for orthopedic trauma, total joint arthroplasty, and spine surgery were queried from a crowdfunding website. The characteristics and outcomes of crowdfunding campaigns were abstracted and analyzed. For this study, 444 campaigns were analyzed, raising a total of $1,443,528. Among the campaigns that received a donation, mean amount raised was $4414 (SE, $611). Multivariate analysis showed that campaigns with unspecified location (odds ratio, 0.26; P=.0008 vs West) and those for total joint arthroplasty (odds ratio, 0.35; P=.0003 vs trauma) had significantly lower odds of receipt of any donation. Description length was associated with higher odds of donation receipt (odds ratio, 1.13 per +100 characters; Pcrowdfunding may be disproportionately available to patients with specific diagnoses, those from specific regions, those who are able to craft a lengthy descriptive narrative, and those with access to robust digital social networks. Clinicians are likely to see a greater proportion of patients turning to crowdfunding as it grows in popularity. Patients may ask physicians for information about crowdfunding or request testimonials to support campaigns. Surgeons should consider their response to such requests individually. These findings shed light on the dynamics of medical crowdfunding and support robust personal and professional deliberation. [Orthopedics. 2018; 41(1):e58-e63.]. Copyright 2017, SLACK Incorporated.

  13. Development and kinetic analysis of cobalt gradient formation in WC-Co composites

    Science.gov (United States)

    Guo, Jun

    2011-12-01

    Functionally graded cemented tungsten carbide (FG WC-Co) is one of the main research directions in the field of WC-Co over decades. Although it has long been recognized that FG WC-Co could outperform conventional homogeneous WC-Co owing to its potentially superior combinations of mechanical properties, until recently there has been a lack of effective and economical methods to make such materials. The lack of the technology has prevented the manufacturing and industrial applications of FG WC-Co from becoming a reality. This dissertation is a comprehensive study of an innovative atmosphere heat treatment process for producing FG WC-Co with a surface cobalt compositional gradient. The process exploited a triple phase field in W-C-Co phase diagram among three phases (solid WC, solid Co, and liquid Co) and the dependence of the migration of liquid Co on temperature and carbon content. WC-Co with a graded surface cobalt composition can be achieved by controlling the diffusion of carbon transported from atmosphere during sintering or during postsintering heat treatment. The feasibility of the process was validated by the successful preparations of FG WC-Co via both carburization and decarburization process following conventional liquid phase sintering. A study of the carburization process was undertaken to further understand and quantitatively modeled this process. The effects of key processing parameters (including heat treating temperature, atmosphere, and time) and key materials variables (involving Co content, WC grain size, and addition of grain growth inhibitors) on the formation of Co gradients were examined. Moreover, a carbon-diffusion controlled kinetic model was developed for simulating the formation of the gradient during the process. The parameters involved in this model were determined by thermodynamic calculations and regression-fit of simulation results with experimental data. In summary, this research first demonstrated the principle of the approach

  14. Damage control in orthopedics and traumatology

    International Nuclear Information System (INIS)

    Martinez R, Alfredo

    2006-01-01

    The damage control allows the clinician to institute a rapid process that avoids early death from over aggressive treatment of an injury and lack of attention to the underlying physiological state of victim. This concept allows rapid control and support of the patients underlying physiological condition in an attempt to avoid the triad of death: bleeding, hypothermia and metabolic acidosis. We revised the several indications to damage control in orthopedics in the patients with polytrauma, isolated extremity injury as femur fracture, and the geriatric patients and crane cephalic trauma

  15. Imaging of orthopedic trauma and surgery

    International Nuclear Information System (INIS)

    Berquist, T.H.

    1985-01-01

    This book presents papers on imaging techniques for diagnosis of trauma of bones. A comparative evaluation is presented for planning of proper diagnosis and treatment. Various techniques discussed are routine radiography; computerized tomography, NMR imaging, angiography, ultrasonography; and use of radioisotopes. The mechanism of injury of bone joints of upper and lower limbs and spine is discussed after discussing the anatomy of each in the beginning of each paper. Topics titled are healing of fractures; fractures of pelvis; knee; shoulder; foot and ankle; fractures of humerus; stress fractures; and orthopedic radiology. Prosthesis use and plastic surgery of joints is also discussed

  16. Orthopedic Resident Anatomy Review Course: A Collaboration between Anatomists and Orthopedic Surgeons

    Science.gov (United States)

    DeFriez, Curtis B.; Morton, David A.; Horwitz, Daniel S.; Eckel, Christine M.; Foreman, K. Bo; Albertine, Kurt H.

    2011-01-01

    A challenge for new residents and senior residents preparing for board examinations is refreshing their knowledge of basic science disciplines, such as human gross anatomy. The Department of Orthopaedics at the University of Utah School of Medicine has for many years held an annual Orthopedic Resident Anatomy Review Course during the summer months…

  17. Pericytes for the treatment of orthopedic conditions.

    Science.gov (United States)

    James, Aaron W; Hindle, Paul; Murray, Iain R; West, Christopher C; Tawonsawatruk, Tulyapruek; Shen, Jia; Asatrian, Greg; Zhang, Xinli; Nguyen, Vi; Simpson, A Hamish; Ting, Kang; Péault, Bruno; Soo, Chia

    2017-03-01

    Pericytes and other perivascular stem cells are of growing interest in orthopedics and tissue engineering. Long regarded as simple regulators of angiogenesis and blood pressure, pericytes are now recognized to have MSC (mesenchymal stem cell) characteristics, including multipotentiality, self-renewal, immunoregulatory functions, and diverse roles in tissue repair. Pericytes are typified by characteristic cell surface marker expression (including αSMA, CD146, PDGFRβ, NG2, RGS5, among others). Although alone no marker is absolutely specific for pericytes, collectively these markers appear to selectively identify an MSC-like pericyte. The purification of pericytes is most well described as a CD146 + CD34 - CD45 - cell population. Pericytes and other perivascular stem cell populations have been applied in diverse orthopedic applications, including both ectopic and orthotopic models. Application of purified cells has sped calvarial repair, induced spine fusion, and prevented fibrous non-union in rodent models. Pericytes induce these effects via both direct and indirect mechanisms. In terms of their paracrine effects, pericytes are known to produce and secrete high levels of a number of growth and differentiation factors both in vitro and after transplantation. The following review will cover existing studies to date regarding pericyte application for bone and cartilage engineering. In addition, further questions in the field will be pondered, including the phenotypic and functional overlap between pericytes and culture-derived MSC, and the concept of pericytes as efficient producers of differentiation factors to speed tissue repair. Copyright © 2016. Published by Elsevier Inc.

  18. Disparities in internet use among orthopedic outpatients.

    Science.gov (United States)

    Walsh, Kenneth P; Rehman, Saqib; Goldhirsh, Jessie

    2014-02-01

    Internet access has lagged behind for patients with lower incomes and from certain ethnic groups. This study investigated the possible improvement of access to health-related information on the Internet for all patients in an urban outpatient setting, regardless of socioeconomic background. A 28-question survey was completed by 100 orthopedic outpatients evaluating associations between their age, ethnicity, income, or education level and their access to the Internet. The survey also examined how patients used the Internet to obtain information about their medical condition, their privacy concerns when conducting online research, and their use of mobile phones as a primary means of Internet access. The Internet was used by 57% of orthopedic outpatients in this urban setting. Internet access decreased with advancing age but increased with increasing income and education, findings consistent with similar studies. Despite the inability to identify an association between ethnicity and Internet access in this patient population, fewer Latinos (33%) than whites (67%) or African Americans (77%) sought information about their medical condition. Among patients who used a mobile phone as the primary method for online access, 74% were African American or Latino and 26% were white. This difference in mobile phone use for online access suggests that mobile phones have provided ethnic minorities with greater Internet access and thus may have narrowed the digital divide among the races. Copyright 2014, SLACK Incorporated.

  19. Erosion resistance of FeAl-TiB2 and FeAl-WC at room and elevated temperatures

    International Nuclear Information System (INIS)

    Alman, D.E.; Tylczak, J.H.; Hawk, J.A.

    2000-01-01

    The resistance of FeAl-40%TiB 2 and FeAl-80%WC cermets to solid particle erosion at 25, 180, 500 and 700 C was evaluated and compared to the behavior of WC-6%Co (Co-90%WC) cemented carbides. Even though the WC-Co contained a higher volume fraction of the hard phase, the erosion rates of the FeAl-cermets were similar in magnitude to the erosion rates of the WC-Co. However, the erosion rates of the FeAl-cermets either were constant (FeAl-TiB 2 ) or decreased (FeAl-WC) with increasing test temperature; whereas, the erosion rates of the WC-Co cemented carbides increased with increasing test temperature. This indicated that once the microstructures of the FeAl-cermets are optimized for wear resistance, these materials might make promising candidates for high-temperature wear applications

  20. A study on erosive wear behavior of HVOF sprayed nanostructured WC-CoCr coatings

    International Nuclear Information System (INIS)

    Thakur, Lalit; Arora, Navneet

    2013-01-01

    WC-CoCr cermet coatings were deposited on stainless steel substrate using high-velocity oxy-fuel (HVOF) thermal spray process. The coatings were developed with two different thermal spray powders: one has WC grains of conventional micron size and the other is composed of nanosized (near-nanostructured) grains. HVOF spraying was assisted with in-flight particle temperature and velocity measurement system to control the process parameters that have resulted in quality coatings. Cavitation erosion testing was performed using a vibratory test apparatus based on ASTM standard G32-98. Surface morphology of powders and coatings was examined using the FESEM images, and phase identification was performed by XRD analysis. The erosion behavior of coatings and mechanism of material removal was discussed by examining the microstructure images of worn-out surfaces. WC-CoCr cermet coating deposited with nanosized WC grains exhibited higher cavitation erosion resistance as compared to conventional coating.

  1. A study on erosive wear behavior of HVOF sprayed nanostructured WC-CoCr coatings

    Energy Technology Data Exchange (ETDEWEB)

    Thakur, Lalit; Arora, Navneet [Indian Institute of Technology Roorkee, Roorkee (India)

    2013-05-15

    WC-CoCr cermet coatings were deposited on stainless steel substrate using high-velocity oxy-fuel (HVOF) thermal spray process. The coatings were developed with two different thermal spray powders: one has WC grains of conventional micron size and the other is composed of nanosized (near-nanostructured) grains. HVOF spraying was assisted with in-flight particle temperature and velocity measurement system to control the process parameters that have resulted in quality coatings. Cavitation erosion testing was performed using a vibratory test apparatus based on ASTM standard G32-98. Surface morphology of powders and coatings was examined using the FESEM images, and phase identification was performed by XRD analysis. The erosion behavior of coatings and mechanism of material removal was discussed by examining the microstructure images of worn-out surfaces. WC-CoCr cermet coating deposited with nanosized WC grains exhibited higher cavitation erosion resistance as compared to conventional coating.

  2. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Habiballah, B.; Abdelaziz, I.; Alzimami, K.; Osman, H.; Omer, H.; Sassi, S. A.

    2014-08-01

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  3. Evaluation of occupational and patient radiation doses in orthopedic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Sulieman, A. [Salman bin Abdulaziz University, College of Applied Medical Sciences, Radiology and Medical Imaging Department, P.O. Box 422, Alkharj (Saudi Arabia); Habiballah, B.; Abdelaziz, I. [Sudan Univesity of Science and Technology, College of Medical Radiologic Sciences, P.O. Box 1908, Khartoum (Sudan); Alzimami, K. [King Saud University, College of Applied Medical Sciences, Radiological Sciences Department, P.O. Box 10219, 11433 Riyadh (Saudi Arabia); Osman, H. [Taif University, College of Applied Medical Science, Radiology Department, Taif (Saudi Arabia); Omer, H. [University of Dammam, Faculty of Medicine, Dammam (Saudi Arabia); Sassi, S. A., E-mail: Abdelmoneim_a@yahoo.com [Prince Sultan Medical City, Department of Medical Physics, Riyadh (Saudi Arabia)

    2014-08-15

    Orthopedists are exposed to considerable radiation dose during orthopedic surgeries procedures. The staff is not well trained in radiation protection aspects and its related risks. In Sudan, regular monitoring services are not provided for all staff in radiology or interventional personnel. It is mandatory to measure staff and patient exposure in order to radiology departments. The main objectives of this study are: to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (Dhs) and (i i) Dynamic Cannula Screw (Dcs); to estimate the risk of the aforementioned procedures and to evaluate entrance surface dose (ESD) and organ dose to specific radiosensitive patients organs. The measurements were performed in Medical Corps Hospital, Sudan. The dose was measured for unprotected organs of staff and patient as well as scattering radiation. Calibrated Thermoluminescence dosimeters (TLD-Gr-200) of lithium fluoride (LiF:Mg, Cu,P) were used for ESD measurements. TLD signal are obtained using automatic TLD Reader model (Plc-3). The mean patients doses were 0.46 mGy and 0.07 for Dhs and Dcs procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean radiation dose for staff was higher in Dhs compared to Dcs. This can be attributed to the long fluoroscopic exposures due to the complication of the procedures. Efforts should be made to reduce radiation exposure to orthopedic patients, and operating surgeons especially those with high work load. Staff training and regular monitoring will reduce the radiation dose for both patients and staff. (Author)

  4. Nanotoxicity: emerging concerns regarding nanomaterial safety and occupational hard metal (WC-Co) nanoparticle exposure.

    Science.gov (United States)

    Armstead, Andrea L; Li, Bingyun

    As the number of commercial and consumer products containing engineered nanomaterials (ENMs) continually rises, the increased use and production of these ENMs presents an important toxicological concern. Although ENMs offer a number of advantages over traditional materials, their extremely small size and associated characteristics may also greatly enhance their toxic potentials. ENM exposure can occur in various consumer and industrial settings through inhalation, ingestion, or dermal routes. Although the importance of accurate ENM characterization, effective dosage metrics, and selection of appropriate cell or animal-based models are universally agreed upon as important factors in ENM research, at present, there is no "standardized" approach used to assess ENM toxicity in the research community. Of particular interest is occupational exposure to tungsten carbide cobalt (WC-Co) "dusts," composed of nano- and micro-sized particles, in hard metal manufacturing facilities and mining and drilling industries. Inhalation of WC-Co dust is known to cause "hard metal lung disease" and an increased risk of lung cancer; however, the mechanisms underlying WC-Co toxicity, the inflammatory disease state and progression to cancer are poorly understood. Herein, a discussion of ENM toxicity is followed by a review of the known literature regarding the effects of WC-Co particle exposure. The risk of WC-Co exposure in occupational settings and the updates of in vitro and in vivo studies of both micro- and nano-WC-Co particles are discussed.

  5. Phase composition and microstructure of WC-Co alloys obtained by selective laser melting

    Science.gov (United States)

    Khmyrov, Roman S.; Shevchukov, Alexandr P.; Gusarov, Andrey V.; Tarasova, Tatyana V.

    2018-03-01

    Phase composition and microstructure of initial WC, BK8 (powder alloy 92 wt.% WC-8 wt.% Co), Co powders, ball-milled powders with four different compositions (1) 25 wt.% WC-75 wt.% Co, (2) 30 wt.% BK8-70 wt.% Co, (3) 50 wt.% WC-50 wt.% Co, (4) 94 wt.% WC-6 wt.% Co, and bulk alloys obtained by selective laser melting (SLM) from as-milled powders in as-melted state and after heat treatment were investigated by scanning electron microscopy and X-ray diffraction analysis. Initial and ball-milled powders consist of WC, hexagonal α-Co and face-centered cubic β-Co. The SLM leads to the formation of major new phases W3Co3C, W4Co2C and face-centered cubic β-Co-based solid solution. During the heat treatment, there occurs partial decomposition of the face-centered cubic β-Co-based solid solution with the formation of W2C and hexagonal α-Co solid solution. The microstructure of obtained bulk samples, in general, corresponds to the observed phase composition.

  6. Nuclear magnetic resonance imaging in orthopedics

    International Nuclear Information System (INIS)

    Peters, P.E.; Matthiass, H.H.; Reiser, M.

    1990-01-01

    NMR imaging (MR tomography) allows the non-invasive diagnostic evaluation of cartilage, ligaments, tendons and muscles of the limbs, joints and the vertebral spine. The images are characterized by a good spatial resolution, and in contrast to the X-ray CT, sectional images can be done in all planes, as well as three-dimensional image reconstructions. The book reviews the current state of the art and foreseeable developments of NMR imaging of the supporting and connective tissue, also discussing the application of paramagnetic contrast media, and the novel NMR spectroscopy as a method pointing into the future. All contributions discussing the clinical aspects have been written jointly by experts in orthopedics and radiology. (orig.) With 153 figs., 8 tabs [de

  7. Bioactive glass coatings for orthopedic metallic implants

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Esteban, Sonia; Saiz, Eduardo; Fujino, Sigheru; Oku, Takeo; Suganuma, Katsuaki; Tomsia, Antoni P.

    2003-06-30

    The objective of this work is to develop bioactive glass coatings for metallic orthopedic implants. A new family of glasses in the SiO2-Na2O-K2O-CaO-MgO-P2O5 system has been synthesized and characterized. The glass properties (thermal expansion, softening and transformation temperatures, density and hardness) are in line with the predictions of established empirical models. The optimized firing conditions to fabricate coatings on Ti-based and Co-Cr alloys have been determined and related to the glass properties and the interfacial reactions. Excellent adhesion to alloys has been achieved through the formation of 100-200 nm thick interfacial layers (Ti5Si3 on Ti-based alloys and CrOx on Co-Cr). Finally, glass coatings, approximately 100 mu m thick, have been fabricated onto commercial Ti alloy-based dental implants.

  8. Gene number determination and genetic polymorphism of the gamma delta T cell co-receptor WC1 genes

    Directory of Open Access Journals (Sweden)

    Chen Chuang

    2012-10-01

    Full Text Available Abstract Background WC1 co-receptors belong to the scavenger receptor cysteine-rich (SRCR superfamily and are encoded by a multi-gene family. Expression of particular WC1 genes defines functional subpopulations of WC1+ γδ T cells. We have previously identified partial or complete genomic sequences for thirteen different WC1 genes through annotation of the bovine genome Btau_3.1 build. We also identified two WC1 cDNA sequences from other cattle that did not correspond to sequences in the Btau_3.1 build. Their absence in the Btau_3.1 build may have reflected gaps in the genome assembly or polymorphisms among animals. Since the response of γδ T cells to bacterial challenge is determined by WC1 gene expression, it was critical to understand whether individual cattle or breeds differ in the number of WC1 genes or display polymorphisms. Results Real-time quantitative PCR using DNA from the animal whose genome was sequenced (“Dominette” and sixteen other animals representing ten breeds of cattle, showed that the number of genes coding for WC1 co-receptors is thirteen. The complete coding sequences of those thirteen WC1 genes is presented, including the correction of an error in the WC1-2 gene due to mis-assembly in the Btau_3.1 build. All other cDNA sequences were found to agree with the previous annotation of complete or partial WC1 genes. PCR amplification and sequencing of the most variable N-terminal SRCR domain (domain 1 which has the SRCR “a” pattern of each of the thirteen WC1 genes showed that the sequences are highly conserved among individuals and breeds. Of 160 sequences of domain 1 from three breeds of cattle, no additional sequences beyond the thirteen described WC1 genes were found. Analysis of the complete WC1 cDNA sequences indicated that the thirteen WC1 genes code for three distinct WC1 molecular forms. Conclusion The bovine WC1 multi-gene family is composed of thirteen genes coding for three structural forms whose

  9. Results of single-event multilevel orthopedic surgery in children with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Akhmed Tomov

    2015-11-01

    Full Text Available Background: Single-event multilevel orthopedic surgery is a modern approach in the operative treatment of children with cerebral palsy. Methods: Single-event multilevel orthopedic surgery was carried out in 108 patients with cerebral palsy. Patients’ average age was 11.3±1.7 years. Surgical results were analyzed at follow-up after 18 to 24 months, by way of detailed physical examination, functional assessment, imaging, the Edinburgh Visual Gait Score and Gillette Functional Assessment Questionnaire. Results: In our series, 647 procedures were performed during 141 surgeries. Patients had an average of 4.59 procedures per surgery. Observational gait analysis showed an improvement in stance and swing gait phases in ambulatory children. According to the Gillette Functional Assessment Questionnaire, an increase of functional level was noted in 50 patients but did not change in 32 patients. Conclusions: For children with cerebral palsy, single-event multilevel surgery is defined as two or more surgical procedures of the soft tissue or bone at two or more anatomical levels during one operative procedure. In cases where a large volume of surgery is required, two separate operations with a short break in between, but requiring only one hospital admission and one rehabilitation period, are also included. This approach requires adapted methods of surgical intervention, and appropriate methods of anesthesia and pain control in the postoperative period to the start of rehabilitation. Compliance with the above principles allowed the necessary correction of orthopedic complications to be achieved in all cases.

  10. Noticeable Variations in the Educational Exposure During Residency in Danish Orthopedic Departments

    DEFF Research Database (Denmark)

    Brand, Eske; Fridberg, Marie; Knudsen, Ulrik Kragegaard

    2016-01-01

    . CONCLUSIONS: A large variation in the educational exposure was found among the Danish orthopedic departments. Numbers indicate that Danish residents, compared with their US counterparts, operate considerably less during residency. Most residents work overtime and many of them work for free to participate......OBJECTIVE: The objective of the study was to examine the educational exposure during residency in Danish orthopedic departments. DESIGN: Questionnaire-based cross-sectional study. SETTING: Data were gathered from January 1, 2014 to April 30, 2014 through a nationwide web-based questionnaire...... procedures as primary surgeon was 16 (range: 8-35) per month. In all, 18 of 22 (81%) departments offered the possibility to participate in research facilitated by the department and 38 of 96 (40%) worked for free (an average of 10h a month [range: 3-60]) to increase the amount of surgical procedures...

  11. Effect of Load on Friction-Wear Behavior of HVOF-Sprayed WC-12Co Coatings

    Science.gov (United States)

    Yifu, Jin; Weicheng, Kong; Tianyuan, Sheng; Ruihong, Zhang; Dejun, Kong

    2017-07-01

    A WC-12Co coating was sprayed on AISI H13 hot work mold steel using a high-velocity oxygen fuel. The morphologies, phase compositions, and distributions of chemical elements of the obtained coatings were analyzed using a field emission scanning electron microscope, x-ray diffraction, and energy-dispersive spectroscope (EDS), respectively. The friction-wear behaviors under different loads were investigated using a reciprocating wear tester; the morphologies and distributions of the chemical elements of worn tracks were analyzed using a SEM and its configured EDS, respectively. The results show the reunited grains of WC are held together by the Co binder; the primary phases of the coating are WC, Co, and a small amount of W2C and W, owing to the oxidation and decarburization of WC. Inter-diffusion of Fe and W between the coating and the substrate is shown, which indicates a good coating adhesion. The values of the average coefficient of friction under the loads of 40, 80, and 120 N are 0.29, 0.31, and 0.49, respectively. The WC grains are pulled out of the coating during the sliding wear test, but the coating maintains its integrity, suggesting that the coating is intact and continuously protects the substrate from wearing.

  12. Microstructure and property of WC particles ceramic-metal composite coatings by laser surface cladding

    International Nuclear Information System (INIS)

    Zeng Xiaoyan; Zhu Beidi; Tao Zengyi; Yang Shuguo; Cui Kun

    1993-01-01

    Ceramic-metal is widely used as a kind of good hardfacing material. The coarse WC particles ceramic-metal composite coatings with WC density of 67% it weight and the thickness of 1.6-2.0 mm have been cladded on 20Ni 4 Mo steel surface by a 2kw CO 2 laser. The sintered WC particles with the size of 600-1,000 μm are chosen as the main strengthening phase, Ni-base self-flux alloy as the binder in the composite coatings. The microstructure and micro-hardness of both WC particles and binder are analyzed. The rigid ball indention with acoustic emission technique is used to evaluate the brittleness of the coating. Finally, the abrasive wear resistance of the coatings are tested, Besides, the coatings with the same ratio and size of WC particles within low carbon steel tube were cladded on 20Ni 4 Mo steel by atomic hydrogen welding technique and analyzed by the same ways their result are compared

  13. Microstructural examination by TEM of WC/Co composites prepared by conventional and Microwave processes

    International Nuclear Information System (INIS)

    Agrawal, D.; Cheng, J.; Papworth, A.J.; Jain, H.; Williams, D.B.

    2001-01-01

    Recently, significant developments and advances have taken place in the field of microwave processing of ceramics, composites and metals. Microwave sintering technology of WC/Co based hard metal parts has been now developed for commercial products. Microwave processed WC/Co parts reportedly have exhibited superior performance over standard parts. Additionally, the microwave process requires only one tenth of the total cycle time employed in a conventional process. Laboratory corrosion and impact resistance tests have proved that microwave processed WC/Co parts are several times more resistant than the conventional parts of the same composition. The scanning transmission electron microscopic (STEM) examination conducted an conventionally and microwave sintered WC/Co samples exhibited remarkable difference in the chemistry of cobalt binder phase. It is understood that the superior mechanical properties of microwave sintered part are due to the pure cobalt phase present at the grain boundary of WC grains, while the conventionally sintered part showed there was substantial inter-alloying of Co with tungsten. (author)

  14. Physical properties and microstructure of Ti(CN)-based cermets with different WC particle size

    International Nuclear Information System (INIS)

    Deng, Ying; Deng, Ling; Xiong, Xiang; Ye, J.W.; Li, P.P.

    2014-01-01

    Ti(CN)-based cermets with different WC particle sizes from 0.2 to 4 μm were prepared at 1450 °C with 2 MPa Air pressure. The microstructure of cermets was investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), Transmission electron microscope (TEM). The results showed that all the cermets with different WC particle sizes have a typical “core–rim” structure. With the increase of WC powder sizes, the frequency and portion of Ti(C 0.7 N 0.3 ) cores and rim are somewhat decreased while the portion of white core is increased, due to the relative dissolution rate decreasing. In addition, the fracture mode of Ti(C,N) based cermets is a mixture of trans-granular (primary) and inter-granular (subordinate) fracture. The TRS (about 1850 MPa) of the cermets fluctuate slightly with the WC particle sizes from 0.2 to 1.0 μm, but decrease evidently with WC particle sizes up to 2 μm

  15. The Synthesis of Nanostructured WC-Based Hardmetals Using Mechanical Alloying and Their Direct Consolidation

    Directory of Open Access Journals (Sweden)

    N. Al-Aqeeli

    2014-01-01

    Full Text Available Tungsten carbide- (WC- based hardmetals or cemented carbides represent an important class of materials used in a wide range of industrial applications which primarily include cutting/drilling tools and wear resistant components. The introduction and processing of nanostructured WC-based cemented carbides and their subsequent consolidation to produce dense components have been the subject of several investigations. One of the attractive means of producing this class of materials is by mechanical alloying technique. However, one of the challenging issues in obtaining the right end-product is the possible loss of the nanocrystallite sizes due to the undesirable grain growth during powder sintering step. Many research groups have engaged in multiple projects aiming at exploring the right path of consolidating the nanostructured WC-based powders without substantially loosing the attained nanostructure. The present paper highlights some key issues related to powder synthesis and sintering of WC-based nanostructured materials using mechanical alloying. The path of directly consolidating the powders using nonconventional consolidation techniques will be addressed and some light will be shed on the advantageous use of such techniques. Cobalt-bonded hardmetals will be principally covered in this work along with an additional exposure of the use of other binders in the WC-based hardmetals.

  16. New WC-Cu thermal barriers for fusion applications: High temperature mechanical behaviour

    Science.gov (United States)

    Tejado, E.; Dias, M.; Correia, J. B.; Palacios, T.; Carvalho, P. A.; Alves, E.; Pastor, J. Y.

    2018-01-01

    The combination of tungsten carbide and copper as a thermal barrier could effectively reduce the thermal mismatch between tungsten and copper alloy, which are proposed as base armour and heat sink, respectively, in the divertor of future fusion reactors. Furthermore, since the optimum operating temperature windows for these divertor materials do not overlap, a compatible thermal barrier interlayer between them is required to guarantee a smooth thermal transition, which in addition may mitigate radiation damage. The aim of this work is to study the thermo-mechanical properties of WC-Cu cermets fabricated by hot pressing. Focus is placed on the temperature effect and composition dependence, as the volume fraction of copper varies from 25 to 50 and 75 vol%. To explore this behaviour, fracture experiments are performed within a temperature range from room temperature to 800 °C under vacuum. In addition, elastic modulus and thermal expansion coefficient are estimated from these tests. Results reveal a strong dependence of the performance on temperature and on the volume fraction of copper and, surprisingly, a slight percent of Cu (25 vol%) can effectively reduce the large difference in thermal expansion between tungsten and copper alloy, which is a critical point for in service applications. The thermal performance of these materials, together with their mechanical properties could indeed reduce the heat transfer from the PFM to the underlying element while supporting the high thermal stresses of the joint. Thus, the presence of these cermets could allow the reactor to operate above the ductile to brittle transition temperature of tungsten, without compromising the underlying materials.

  17. Orthopedic Health: Osteoarthritis— What You Should Know (quiz)

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues Orthopedic Health Osteoarthritis— What You Should Know Past Issues / Spring 2009 ... Javascript on. How much do you know about osteoarthritis, its causes, and its therapies? Take this quiz ...

  18. Comparing consensus guidelines on thromboprophylaxis in orthopedic surgery

    NARCIS (Netherlands)

    Struijk-Mulder, M. C.; Ettema, H. B.; Verheyen, C. C.; Büller, H. R.

    2010-01-01

    BACKGROUND: Different guidelines exist regarding the prevention of venous thromboembolism (VTE) in orthopedic surgery. OBJECTIVES: We aimed to compare (inter)national guidelines and analyse differences. Methods: MEDLINE, the Cochrane Library and the internet were searched for guidelines on the

  19. Comparative studies on mechanical properties of WC-Co composites sintered by SPS and conventional techniques

    Directory of Open Access Journals (Sweden)

    Pristinskiy Yuri

    2017-01-01

    Full Text Available Spark plasma sintering (SPS is an extremely fast solidification technique for compounds that are difficult to sinter within the material group metals, ceramics, or composites thereof, SPS uses a uniaxial pressure and a very rapid heating cycle to consolidate these materials. With SPS the main benefit is the ability to control the WC grain size due to the short sintering times at high temperature. Additionally, its allows to avoid negative reactions between WC and cobalt and to minimize the formation of undesirable phases in sintered composites. The WC-6wt.% Co cermet prepared by SPS processing achieves the enhanced mechanical properties with the hardness of 18.3 GPa and the fracture toughness of 15.5 MPa·m1/2 in comparison to standard reference tungsten carbide/cobalt material.

  20. Surface analysis of WC--Co composite materials (2) Quantitative Auger electron spectrometry

    International Nuclear Information System (INIS)

    Tongson, L.L.; Biggers, J.V.; Dayton, G.O.; Bind, J.M.; Knox, B.E.

    1978-01-01

    The unique sensitivity of Auger electron spectrometry (AES) to combined carbon has been exploited in measuring the surface compositions of hot-pressed, conventionally sintered and mixed powders of WC--Co composite materials. AES sensitivity factors for tungsten and carbon (in WC) relative to cobalt were determined. The concentrations of the major elements in hot-pressed samples measured with AES using the relative sensitivity method were compared to those obtained independently by electron microprobe (EMP) and x-ray fluorescence (XRF) techniques. Corollary studies using ion scattering spectrometry (ISS) showed the absence of (1) matrix effects in the AES measurements, (2) preferential sputtering during ion bombardment, and (3) deposition of the easier-to-sputter component (cobalt) onto WC

  1. Measuring c-quark polarization in W+c samples at ATLAS and CMS

    CERN Document Server

    Kats, Yevgeny

    2016-01-01

    The process $pp \\to W^-c$ produces polarized charm quarks. The polarization is expected to be partly retained in $\\Lambda_c$ baryons when those form in the $c$-quark hadronization. We argue that it will likely be possible for ATLAS and CMS to measure the $\\Lambda_c$ polarization in the $W$+$c$ samples in Run 2 of the LHC. This can become the first measurement ever of a longitudinal polarization of charm quarks. Its results will provide a unique input to the understanding of polarization transfer in fragmentation. They will also allow applying the same measurement technique to other (e.g., new physics) samples of charm quarks in which the polarization is a priori unknown. The proposed analysis is similar to the ATLAS and CMS measurements of the $W$+$c$ cross section in the 7 TeV run that used reconstructed $D$-meson decays for charm tagging.

  2. Synthesis and Multi Scale Tribological Behavior of WC-Co/Nanodiamond Nanocomposites.

    Science.gov (United States)

    Nieto, Andy; Jiang, Lin; Kim, Jaekang; Kim, Dae-Eun; Schoenung, Julie M

    2017-08-01

    Nanodiamonds (ND) present a unique combination of desirable mechanical, functional, and chemical characteristics that are ideally suited for reinforcing and enhancing the wear resistance of carbide based materials. Tungsten carbide cobalt (WC-Co) matrix nanocomposites reinforced with varying amounts of ND (2 - 10 vol.%) were synthesized here by spark plasma sintering. The rapid thermal consolidation route enabled attainment of dense samples with a significant retention of the metastable diamond phase. NDs affected the microstructural evolution, chemistry, and mechanical properties of WC-Co. Macroscale reciprocating pin-on-disk tests were conducted to assess wear behavior under conditions relevant to service environments, e.g., high cycles and high contact pressure. Microscale tribological properties were assessed using microscratch tests in order to investigate the intrinsic effects of ND on the localized mechanical and tribological response of WC-Co-ND composites. The incorporation of 10 vol.% ND enhanced wear resistance at both the micro- and macroscale, by 28% and 35%, respectively.

  3. Pediatric orthopedic surgery in humanitarian aid.

    Science.gov (United States)

    Sales de Gauzy, J; Trinchero, J-F; Jouve, J-L

    2017-02-01

    Pediatric orthopedic surgery in humanitarian aid is conducted mainly in cooperation with emerging countries. Each mission is different, and depends on numerous parameters such as the country, the frequency of such missions, the pathologies encountered, the local structure and team, and the non-governmental organization (NGO) involved. Pathologies vary in etiology (tuberculosis, poliomyelitis) and severity. Each mission requires the presence of an experienced surgeon. Working conditions are often rudimentary. Surgical indications should be restricted to procedures that are going to be effective, with minimal postoperative complications, without any surgical "acrobatics". Teaching should be in association with the local university, and adapted to local needs. Mission objectives need to be realistic. Surgical indications should be adapted to local conditions, and the surgeon needs to be able to say "no" to procedures involving undue risk. The surgeon on mission should cooperate with local teams and be able to adapt to unusual situations. Assessment of results is essential to improving efficacy and evaluating the success of the mission. Copyright © 2016. Published by Elsevier Masson SAS.

  4. Orthopedic rehabilitation using the "Rutgers ankle" interface.

    Science.gov (United States)

    Girone, M; Burdea, G; Bouzit, M; Popescu, V; Deutsch, J E

    2000-01-01

    A novel ankle rehabilitation device is being developed for home use, allowing remote monitoring by therapists. The system will allow patients to perform a variety of exercises while interacting with a virtual environment (VE). These game-like VEs created with WorldToolKit run on a host PC that controls the movement and output forces of the device via an RS232 connection. Patients will develop strength, flexibility, coordination, and balance as they interact with the VEs. The device will also perform diagnostic functions, measuring the ankle's range of motion, force exertion capabilities and coordination. The host PC transparently records patient progress for remote evaluation by therapists via our existing telerehabilitation system. The "Rutgers Ankle" Orthopedic Rehabilitation Interface uses double-acting pneumatic cylinders, linear potentiometers, and a 6 degree-of-freedom (DOF) force sensor. The controller contains a Pentium single-board computer and pneumatic control valves. Based on the Stewart platform, the device can move and supply forces and torques in 6 DOFs. A proof-of-concept trial conducted at the University of Medicine and Dentistry of New Jersey (UMDNJ) provided therapist and patient feedback. The system measured the range of motion and maximum force output of a group of four patients (male and female). Future medical trials are required to establish clinical efficacy in rehabilitation.

  5. Physician-Hospital Alignment in Orthopedic Surgery.

    Science.gov (United States)

    Bushnell, Brandon D

    2015-09-01

    The concept of "alignment" between physicians and hospitals is a popular buzzword in the age of health care reform. Despite their often tumultuous histories, physicians and hospitals find themselves under increasing pressures to work together toward common goals. However, effective alignment is more than just simple cooperation between parties. The process of achieving alignment does not have simple, universal steps. Alignment will differ based on individual situational factors and the type of specialty involved. Ultimately, however, there are principles that underlie the concept of alignment and should be a part of any physician-hospital alignment efforts. In orthopedic surgery, alignment involves the clinical, administrative, financial, and even personal aspects of a surgeon's practice. It must be based on the principles of financial interest, clinical authority, administrative participation, transparency, focus on the patient, and mutual necessity. Alignment can take on various forms as well, with popular models consisting of shared governance and comanagement, gainsharing, bundled payments, accountable care organizations, and other methods. As regulatory and financial pressures continue to motivate physicians and hospitals to develop alignment relationships, new and innovative methods of alignment will also appear. Existing models will mature and evolve, with individual variability based on local factors. However, certain trends seem to be appearing as time progresses and alignment relationships deepen, including regional and national collaboration, population management, and changes in the legal system. This article explores the history, principles, and specific methods of physician-hospital alignment and its critical importance for the future of health care delivery. Copyright 2015, SLACK Incorporated.

  6. Regional anesthesia techniques for ambulatory orthopedic surgery.

    LENUS (Irish Health Repository)

    O'Donnell, Brian D

    2012-02-03

    PURPOSE OF REVIEW: The purpose of this review is to present advances in the use of regional anesthetic techniques in ambulatory orthopedic surgery. New findings regarding the use of both neuraxial anesthesia and peripheral nerve block are discussed. RECENT FINDINGS: Neuraxial anesthesia: The use of short-acting local anesthetic agents such as mepivacaine, 2-chloroprocaine, and articaine permits rapid onset intrathecal anesthesia with early recovery profiles. Advantages and limitations of these agents are discussed.Peripheral nerve block: Peripheral nerve blocks in limb surgery have the potential to transform this patient cohort into a truly ambulatory, self-caring group. Recent trends and evidence regarding the benefits of regional anesthesia techniques are presented.Continuous perineural catheters permit extension of improved perioperative analgesia into the ambulatory home setting. The role and reported safety of continuous catheters are discussed. SUMMARY: In summary, shorter acting, neuraxial, local anesthetic agents, specific to the expected duration of surgery, may provide superior recovery profiles in the ambulatory setting. A trend towards more peripheral and selective nerve blocks exists. The infrapatellar block is a promising technique to provide analgesia following knee arthroscopy. Improved analgesia seen in the perioperative period can be safely and effectively extended to the postoperative period with the use of perineural catheters.

  7. 布比卡因等比重液腰-硬联合阻滞在高龄高危老年骨科手术患者中的应用%The Application of Combined Spinal-Epidural Anesthesia With Isobaric Bupivacaine Used in the Elderly and High-Risk Elderly Patients in Department of Orthopedics Operation

    Institute of Scientific and Technical Information of China (English)

    曹志峰

    2016-01-01

    目的:分析布比卡因等比重液腰-硬联合阻滞在高龄高危老年骨科手术患者中的应用价值。方法选取我院收治的84例高龄高危老年骨科手术患者,随机分为两组,各42例。对照组行硬膜外阻滞麻醉,观察组行布比卡因等比重液腰-硬联合阻滞。对比观察两组患者麻醉优良率。结果观察组麻醉优良率为97.62%,对照组为80.95%,差异有统计学意义(P<0.05)。结论高龄高危老年患者骨科手术中采用布比卡因等比重液腰-硬联合阻滞,可取得较好麻醉效果。%Objective To analyze the value of combined spinal-epidural anesthesia with isobaric bupivacaine used in the elderly and high-risk elderly patients in the elderly high-risk elderly patients in department of orthopedics operation.Methods Selected 84 cases of elderly high-risk elderly patients in our hospital, randomly divided into two groups, each group had 42 cases. The control group was treated with epidural anesthesia, combined spinal-epidural anesthesia with isobaric bupivacaine in the observation group. The good rate of anesthesia in the two groups were compared and observed.Results The excellent rate of anesthesia in the observation group was 97.62%, and the control group was 80.95%, the difference was statistically signiifcant (P<0.05).Conclusion Elderly high-risk elderly patients used combined spinal-epidural anesthesia with isobaric bupivacaine, can achieve good anesthesia effect.

  8. 3D-printed patient-specific applications in orthopedics

    OpenAIRE

    Wong KC

    2016-01-01

    Kwok Chuen Wong Department of Orthopedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong Abstract: With advances in both medical imaging and computer programming, two-dimensional axial images can be processed into other reformatted views (sagittal and coronal) and three-dimensional (3D) virtual models that represent a patients’ own anatomy. This processed digital information can be analyzed in detail by orthopedic surgeons to perform p...

  9. How Useful are Orthopedic Surgery Residency Web Pages?

    Science.gov (United States)

    Oladeji, Lasun O; Yu, Jonathan C; Oladeji, Afolayan K; Ponce, Brent A

    2015-01-01

    Medical students interested in orthopedic surgery residency positions frequently use the Internet as a modality to gather information about individual residency programs. Students often invest a painstaking amount of time and effort in determining programs that they are interested in, and the Internet is central to this process. Numerous studies have concluded that program websites are a valuable resource for residency and fellowship applicants. The purpose of the present study was to provide an update on the web pages of academic orthopedic surgery departments in the United States and to rate their utility in providing information on quality of education, faculty and resident information, environment, and applicant information. We reviewed existing websites for the 156 departments or divisions of orthopedic surgery that are currently accredited for resident education by the Accreditation Council for Graduate Medical Education. Each website was assessed for quality of information regarding quality of education, faculty and resident information, environment, and applicant information. We noted that 152 of the 156 departments (97%) had functioning websites that could be accessed. There was high variability regarding the comprehensiveness of orthopedic residency websites. Most of the orthopedic websites provided information on conference, didactics, and resident rotations. Less than 50% of programs provided information on resident call schedules, resident or faculty research and publications, resident hometowns, or resident salary. There is a lack of consistency regarding the content presented on orthopedic residency websites. As the competition for orthopedic websites continues to increase, applicants flock to the Internet to learn more about orthopedic websites in greater number. A well-constructed website has the potential to increase the caliber of students applying to a said program. Copyright © 2015 Association of Program Directors in Surgery. Published by

  10. Nanotoxicity: emerging concerns regarding nanomaterial safety and occupational hard metal (WC-Co nanoparticle exposure

    Directory of Open Access Journals (Sweden)

    Armstead AL

    2016-12-01

    Full Text Available Andrea L Armstead,1,2 Bingyun Li1–3 1Department of Orthopaedics, School of Medicine, 2School of Pharmacy, West Virginia University, 3Mary Babb Randolph Cancer Center, Morgantown, WV, USA Abstract: As the number of commercial and consumer products containing engineered nanomaterials (ENMs continually rises, the increased use and production of these ENMs presents an important toxicological concern. Although ENMs offer a number of advantages over traditional materials, their extremely small size and associated characteristics may also greatly enhance their toxic potentials. ENM exposure can occur in various consumer and industrial settings through inhalation, ingestion, or dermal routes. Although the importance of accurate ENM characterization, effective dosage metrics, and selection of appropriate cell or animal-based models are universally agreed upon as important factors in ENM research, at present, there is no “standardized” approach used to assess ENM toxicity in the research community. Of particular interest is occupational exposure to tungsten carbide cobalt (WC-Co “dusts,” composed of nano- and micro-sized particles, in hard metal manufacturing facilities and mining and drilling industries. Inhalation of WC-Co dust is known to cause “hard metal lung disease” and an increased risk of lung cancer; however, the mechanisms underlying WC-Co toxicity, the inflammatory disease state and progression to cancer are poorly understood. Herein, a discussion of ENM toxicity is followed by a review of the known literature regarding the effects of WC-Co particle exposure. The risk of WC-Co exposure in occupational settings and the updates of in vitro and in vivo studies of both micro- and nano-WC-Co particles are discussed. Keywords: engineered nanomaterial, occupational exposure, lung disease, cancer, toxicity, particle

  11. Benzotriazole (BTA), A Promising Corrosion Inhibitor for WC-Co Hardmetal

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Stoessel-Sittig, C.; Koetz, R.; Hochstrasser-Kurz, S. [ETH Zuerich (Switzerland); Virtanen, S. [ETH Zuerich (Switzerland); Jaeggi, Ch. [University of Bern (Switzerland); Eichenberger, N. [University of Bern (Switzerland); Szoecs, E. [University of Bern (Switzerland); Siegenthaler, H. [University of Bern (Switzerland); Ziegler, P. [AGIE SA (Switzerland); Beltrami, I. [AGIE SA (Switzerland)

    2004-03-01

    Wire Electro-Discharge Machining (W-EDM) of tungsten carbide with Co-binder may lead to corrosion and discolouration at the surface. The corrosion behaviour of WC-Co based hardmetal was investigated in different aqueous solutions (acidic, neutral, and alkaline solutions). At open-circuit potential WC-Co based hardmetals show rather high dissolution rates in all types of electrolyte. An efficient corrosion inhibitor (benzotriazole, C{sub 6}H{sub 5}N{sub 3}) could be found for a borate buffer solution, pH = 8.4. (author)

  12. Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

    Directory of Open Access Journals (Sweden)

    Fang Luo

    2015-03-01

    Full Text Available Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

  13. PREPARATION OF WC-Co POWDER BY DIRECT REDUCTION AND CARBONIZATION

    Institute of Scientific and Technical Information of China (English)

    Zhonglai Yi; Gangqin Shao; Xinglong Duan; Peng Sun; Xiaoliang Shi; Zhen Xiong; Jingkun Guo

    2005-01-01

    A new approach to produce superfine WC-Co powder by direct reduction and carbonization is proposed.Water-soluble salts containing W and Co were used as raw materials. Tungsten and cobalt oxide powder (CoWO4/WO3)was first formed by a spray-pyrolysis technique, which was then mixed with carbon black and converted to WC-Co composite powder at 950℃ for 4 h in N2 atmosphere. The resulting powder has a particle size of 100-300 nm.

  14. Hydrogen effects in anodic grinding of WC-Co sintered alloy

    International Nuclear Information System (INIS)

    Lunarska, E.; Zaborski, St.

    2001-01-01

    The effects of anodic polarization applied in grinding of sintered WC C o alloy on properties of surface layer, quality of ground surface and efficiency of the treatment were studied. The nonmonotonical change of the surface roughness, the energy consumption and the wear of tool was stated at increasing anodic polarization. The optimum values of above parameters were achieved at application of anodic polarization at which the Co selective dissolution and hydrogen ingress into the ground metal. affecting the internal friction spectra were stated. The assistance of hydrogen induced deterioration and Co selective dissolution in the surface layer in the anodic grinding of WC-Co alloy has been discussed. (author)

  15. Regularities of structure formation on different stages of WC-Co hard alloys fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Chernyavskij, K S

    1987-03-01

    Some regularities of structural transformations in powder products of the hard alloys fabrication have been formulated on the basis of results of the author works and other native and foreign reseachers. New data confirming the influene of technological prehistory of carbide powder on the mechanism of its particle grinding as well as the influence of the structural-energy state of WC powder on the course of the WC-Co alloy structure formation processes are given. Some possibilities for the application in practice of the regularities studied are considered.

  16. Development of an orthopedic surgery trauma patient handover checklist.

    Science.gov (United States)

    LeBlanc, Justin; Donnon, Tyrone; Hutchison, Carol; Duffy, Paul

    2014-02-01

    In surgery, preoperative handover of surgical trauma patients is a process that must be made as safe as possible. We sought to determine vital clinical information to be transferred between patient care teams and to develop a standardized handover checklist. We conducted standardized small-group interviews about trauma patient handover. Based on this information, we created a questionnaire to gather perspectives from all Canadian Orthopaedic Association (COA) members about which topics they felt would be most important on a handover checklist. We analyzed the responses to develop a standardized handover checklist. Of the 1106 COA members, 247 responded to the questionnaire. The top 7 topics felt to be most important for achieving patient safety in the handover were comorbidities, diagnosis, readiness for the operating room, stability, associated injuries, history/mechanism of injury and outstanding issues. The expert recommendations were to have handover completed the same way every day, all appropriate radiographs available, adequate time, all appropriate laboratory work and more time to spend with patients with more severe illness. Our main recommendations for safe handover are to use standardized checklists specific to the patient and site needs. We provide an example of a standardized checklist that should be used for preoperative handovers. To our knowledge, this is the first checklist for handover developed by a group of experts in orthopedic surgery, which is both manageable in length and simple to use.

  17. PCA and Postoperative Pain Management After Orthopedic Surgeries

    Directory of Open Access Journals (Sweden)

    S.M. Hashemi

    2016-08-01

    Full Text Available Background: Patients often suffer from inadequate treatment of postoperative pain. The aim of this study was to investigate effect of PCA on postoperative pain management and patients’ satisfaction from use of PCA. Materials and Methods: In this prospective study, between 2010 to 2011, patients presented by orthopedic specialists to acute and chronic pain service of Akhtar Hospital. A satisfaction questionnaire was given on discharge to this patients, were asked to fill out it . Then collected by ward nurse. Results: patients’ satisfaction from pain relief with use of PCA was high ( 94.9% . In this patient pain relief at third day after surgery and require analgesic was low, significantly (p=0.0001. Significant patients’ satisfaction from effect of PCA in pain control and products support was high (p=0.0001.     Conclusion: Patient controlled analgesia is a safe, effective and noninvasive method for post operative pain management and in this study patients’ satisfaction for pain management was high for use of PCA and pain service. 

  18. [Orthopedic and trauma surgery in the German DRG system. Recent developments].

    Science.gov (United States)

    Franz, D; Schemmann, F; Selter, D D; Wirtz, D C; Roeder, N; Siebert, H; Mahlke, L

    2012-07-01

    Orthopedics and trauma surgery are subject to continuous medical advancement. The correct and performance-based case allocation by German diagnosis-related groups (G-DRG) is a major challenge. This article analyzes and assesses current developments in orthopedics and trauma surgery in the areas of coding of diagnoses and medical procedures and the development of the 2012 G-DRG system. The relevant diagnoses, medical procedures and G-DRGs in the versions 2011 and 2012 were analyzed based on the publications of the German DRG Institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes were made for the International Classification of Diseases (ICD) coding of complex cases with medical complications, the procedure coding for spinal surgery and for hand and foot surgery. The G-DRG structures were modified for endoprosthetic surgery on ankle, shoulder and elbow joints. The definition of modular structured endoprostheses was clarified. The G-DRG system for orthopedic and trauma surgery appears to be largely consolidated. The current phase of the evolution of the G-DRG system is primarily aimed at developing most exact descriptions and definitions of the content and mutual delimitation of operation and procedures coding (OPS). This is an essential prerequisite for a correct and performance-based case allocation in the G-DRG system.

  19. Comparing the use of Memantine with Dextromethorphan and Placebo to Reduce Pain before Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    Mehrdad Taheri

    2017-12-01

    Full Text Available Introduction: To compare the use of Memantine with Dextromethorphan and placebo to reduce pain after orthopedic surgery.Materials and Methods: The present study was a double-blind clinical trial including180 patients undergoing elective orthopedic surgery of the lower limbs. Patients were divided randomly into three groups of 60 patients each. The first group (Group M received 30 mg Memantine orally, the second group (Group D received 45 mg of Dextromethorphan and the third group (Group P received only placebo, two and a half hours before the operation. The intensity of pain (VAS score, sedation score, and nausea and vomiting were recorded postoperatively.Results: In this study, 60 patients were enrolled in each group. The total VAS (Visual Analogue Scale score was significantly lower among patients receiving Memantine and the satisfaction was significantly higher compared to the Dextromethorphan and placebo groups (P-value <0.001.Conclusion: The present study results indicate that Memantine has a relatively better outcome compared to Dextromethorphan or placebo in reducing the post surgical pain among patients undergoing orthopedic surgeries. It also reduced the need for post surgical opioid use and improved the patients’ satisfaction.  

  20. Exploring the potential role of tungsten carbide cobalt (WC-Co) nanoparticle internalization in observed toxicity toward lung epithelial cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Armstead, Andrea L. [Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506 (United States); Pharmaceutical and Pharmacological Sciences Graduate Program, School of Pharmacy, West Virginia University, Morgantown, WV 26506 (United States); Arena, Christopher B. [Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506 (United States); E.J. Van Liere Research Program, School of Medicine, West Virginia University, Morgantown, WV 26506 (United States); Li, Bingyun, E-mail: bili@hsc.wvu.edu [Biomaterials, Bioengineering and Nanotechnology Laboratory, Department of Orthopaedics, School of Medicine, West Virginia University, Morgantown, WV 26506 (United States); Pharmaceutical and Pharmacological Sciences Graduate Program, School of Pharmacy, West Virginia University, Morgantown, WV 26506 (United States); E.J. Van Liere Research Program, School of Medicine, West Virginia University, Morgantown, WV 26506 (United States); Mary Babb Randolph Cancer Center, Morgantown, WV 26506 (United States)

    2014-07-01

    Tungsten carbide cobalt (WC-Co) has been recognized as a workplace inhalation hazard in the manufacturing, mining and drilling industries by the National Institute of Occupational Safety and Health. Exposure to WC-Co is known to cause “hard metal lung disease” but the relationship between exposure, toxicity and development of disease remain poorly understood. To better understand this relationship, the present study examined the role of WC-Co particle size and internalization on toxicity using lung epithelial cells. We demonstrated that nano- and micro-WC-Co particles exerted toxicity in a dose- and time-dependent manner and that nano-WC-Co particles caused significantly greater toxicity at lower concentrations and shorter exposure times compared to micro-WC-Co particles. WC-Co particles in the nano-size range (not micron-sized) were internalized by lung epithelial cells, which suggested that internalization may play a key role in the enhanced toxicity of nano-WC-Co particles over micro-WC-Co particles. Further exploration of the internalization process indicated that there may be multiple mechanisms involved in WC-Co internalization such as actin and microtubule based cytoskeletal rearrangements. These findings support our hypothesis that WC-Co particle internalization contributes to cellular toxicity and suggest that therapeutic treatments inhibiting particle internalization may serve as prophylactic approaches for those at risk of WC-Co particle exposure. - Highlights: • Hard metal (WC-Co) particle toxicity was established in lung epithelial cells. • Nano-WC-Co particles caused greater toxicity than micro-WC-Co particles. • Nano- and micro-WC-Co particles were capable of inducing cellular apoptosis. • Nano-WC-Co particles were internalized by lung epithelial cells. • WC-Co particle internalization was mediated by actin dynamics.

  1. Exploring the potential role of tungsten carbide cobalt (WC-Co) nanoparticle internalization in observed toxicity toward lung epithelial cells in vitro

    International Nuclear Information System (INIS)

    Armstead, Andrea L.; Arena, Christopher B.; Li, Bingyun

    2014-01-01

    Tungsten carbide cobalt (WC-Co) has been recognized as a workplace inhalation hazard in the manufacturing, mining and drilling industries by the National Institute of Occupational Safety and Health. Exposure to WC-Co is known to cause “hard metal lung disease” but the relationship between exposure, toxicity and development of disease remain poorly understood. To better understand this relationship, the present study examined the role of WC-Co particle size and internalization on toxicity using lung epithelial cells. We demonstrated that nano- and micro-WC-Co particles exerted toxicity in a dose- and time-dependent manner and that nano-WC-Co particles caused significantly greater toxicity at lower concentrations and shorter exposure times compared to micro-WC-Co particles. WC-Co particles in the nano-size range (not micron-sized) were internalized by lung epithelial cells, which suggested that internalization may play a key role in the enhanced toxicity of nano-WC-Co particles over micro-WC-Co particles. Further exploration of the internalization process indicated that there may be multiple mechanisms involved in WC-Co internalization such as actin and microtubule based cytoskeletal rearrangements. These findings support our hypothesis that WC-Co particle internalization contributes to cellular toxicity and suggest that therapeutic treatments inhibiting particle internalization may serve as prophylactic approaches for those at risk of WC-Co particle exposure. - Highlights: • Hard metal (WC-Co) particle toxicity was established in lung epithelial cells. • Nano-WC-Co particles caused greater toxicity than micro-WC-Co particles. • Nano- and micro-WC-Co particles were capable of inducing cellular apoptosis. • Nano-WC-Co particles were internalized by lung epithelial cells. • WC-Co particle internalization was mediated by actin dynamics

  2. WC1 is a hybrid γδ TCR coreceptor and pattern recognition receptor for pathogenic bacteria.

    Science.gov (United States)

    Hsu, Haoting; Chen, Chuang; Nenninger, Ariel; Holz, Lauren; Baldwin, Cynthia L; Telfer, Janice C

    2015-03-01

    WC1 proteins are uniquely expressed on γδ T cells and belong to the scavenger receptor cysteine-rich (SRCR) superfamily. While present in variable, and sometimes high, numbers in the genomes of mammals and birds, in cattle there are 13 distinct genes (WC1-1 to WC1-13). All bovine WC1 proteins can serve as coreceptors for the TCR in a tyrosine phosphorylation dependent manner, and some are required for the γδ T cell response to Leptospira. We hypothesized that individual WC1 receptors encode Ag specificity via coligation of bacteria with the γδ TCR. SRCR domain binding was directly correlated with γδ T cell response, as WC1-3 SRCR domains from Leptospira-responsive cells, but not WC1-4 SRCR domains from Leptospira-nonresponsive cells, bound to multiple serovars of two Leptospira species, L. borgpetersenii, and L. interrogans. Three to five of eleven WC1-3 SRCR domains, but none of the eleven WC1-4 SRCR domains, interacted with Leptospira spp. and Borrelia burgdorferi, but not with Escherichia coli or Staphylococcus aureus. Mutational analysis indicated that the active site for bacterial binding in one of the SRCR domains is composed of amino acids in three discontinuous regions. Recombinant WC1 SRCR domains with the ability to bind leptospires inhibited Leptospira growth. Our data suggest that WC1 gene arrays play a multifaceted role in the γδ T cell response to bacteria, including acting as hybrid pattern recognition receptors and TCR coreceptors, and they may function as antimicrobials. Copyright © 2015 by The American Association of Immunologists, Inc.

  3. Orthopedic resident work-shift analysis: are we making the best use of resident work hours?

    Science.gov (United States)

    Hamid, Kamran S; Nwachukwu, Benedict U; Hsu, Eugene; Edgerton, Colston A; Hobson, David R; Lang, Jason E

    2014-01-01

    Surgery programs have been tasked to meet rising demands in patient surgical care while simultaneously providing adequate resident training in the midst of increasing resident work-hour restrictions. The purpose of this study was to quantify orthopedic surgery resident workflow and identify areas needing improved resident efficiency. We hypothesize that residents spend a disproportionate amount of time involved in activities that do not relate directly to patient care or maximize resident education. We observed 4 orthopedic surgery residents on the orthopedic consult service at a major tertiary care center for 72 consecutive hours (6 consecutive shifts). We collected minute-by-minute data using predefined work-task criteria: direct new patient contact, direct existing patient contact, communications with other providers, documentation/administrative time, transit time, and basic human needs. A seventh category comprised remaining less-productive work was termed as standby. In a 720-minute shift, residents spent on an average: 191 minutes (26.5%) performing documentation/administrative duties, 167.0 minutes (23.2%) in direct contact with new patient consults, 129.6 minutes (17.1%) in communication with other providers regarding patients, 116.2 (16.1%) minutes in standby, 63.7 minutes (8.8%) in transit, 32.6 minutes (4.5%) with existing patients, and 20 minutes (2.7%) attending to basic human needs. Residents performed an additional 130 minutes of administrative work off duty. Secondary analysis revealed residents were more likely to perform administrative work rather than directly interact with existing patients (p = 0.006) or attend to basic human needs (p = 0.003). Orthopedic surgery residents spend a large proportion of their time performing documentation/administrative-type work and their workday can be operationally optimized to minimize nonvalue-adding tasks. Formal workflow analysis may aid program directors in systematic process improvements to better align

  4. Production and Characterization of WC-Reinforced Co-Based Superalloy Matrix Composites

    Science.gov (United States)

    Özgün, Özgür; Dinler, İlyas

    2018-05-01

    Cobalt-based superalloy matrix composite materials were produced through the powder metallurgy technique using element powders at high purity and nano-sized wolfram carbide (WC) reinforcement in this study. An alloy that had the same chemical composition as the Stellite 6 alloy but not containing carbon was selected as the matrix alloy. The powder mixtures obtained as a result of mixing WC reinforcing member and element powders at the determined ratio were shaped by applying 300 MPa of pressure. The green components were sintered under argon atmosphere at 1240 °C for 120 minutes. The densities of the sintered components were determined by the Archimedes' principle. Microstructural characterization was performed via X-ray diffraction analysis, scanning electron microscope examinations, and energy-dispersive spectrometry. Hardness measurements and tensile tests were performed for determining mechanical characteristics. The relative density values of the sintered components increased by increasing the WC reinforcement ratio and they could almost reach the theoretical density. It was determined from the microstructural examinations that the composite materials consisted of fine and equiaxed grains and coarse carbides demonstrating a homogeneous dispersion along the microstructure at the grain boundaries. As it was the case in the density values, the hardness and strength values of the composites increased by increasing the WC ratio.

  5. Microstructure and hardness of WC-Co particle reinforced iron matrix surface composite

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2013-11-01

    Full Text Available In this study, a high Cr cast iron surface composite material reinforced with WC-Co particles 2-6 mm in size was prepared using a pressureless sand mold infiltration casting technique. The composition, microstructure and hardness were determined by means of energy dispersive spectrometry (EDS, electron probe microanalysis (EPMA, scanning electron microscope (SEM and Rockwell hardness measurements. It is determined that the obtained composite layer is about 15 mm thick with a WC-Co particle volumetric fraction of ~38%. During solidification, interface reaction takes place between WC-Co particles and high chromium cast iron. Melting and dissolving of prefabricated particles are also found, suggesting that local Co melting and diffusion play an important role in promoting interface metallurgical bonding. The composite layer is composed of ferrite and a series of carbides, such as (Cr, W, Fe23C6, WC, W2C, M6C and M12C. The inhomogeneous hardness in the obtained composite material shows a gradient decrease from the particle reinforced metal matrix composite layer to the matrix layer. The maximum hardness of 86.3 HRA (69.5 HRC is obtained on the particle reinforced surface, strongly indicating that the composite can be used as wear resistant material.

  6. Data of evolutionary structure change: 1A9WC-2ZLWD [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1A9WC-2ZLWD 1A9W 2ZLW C D -VLSPADKTNVKAAWGKVGAHAGEYGAEALERMFLSFPT...R VQLSGEEKAAVLALWDKVN--EEEVGGEALGRLLVVYPWTQRFFDSFGDLSNPGAVMGNPKVKAHGKKVLHSFGEGVHHLDNLKGTFAALSEL...onfEVID> 1 2ZLW D 2ZLWD... CA 264 LYS CA 243 2ZLW D 2ZLWD DLSNPGAVMGNPKVK HHHH

  7. Elastic properties and 2D icosahedral bonding in borides of hexagonal WC type

    International Nuclear Information System (INIS)

    Music, Denis; Schneider, Jochen M.

    2005-01-01

    Using ab initio calculations we have identified materials with bulk moduli comparable to cubic BN. These are WB, IrB, ReB and OsB crystallizing in the hexagonal WC structure. In the (0 0 0 2) planes of these compounds, we find 2D icosahedral bonding between adjacent B atoms, which has previously not been reported

  8. Pt-Ni/WC Alloy Nanorods Arrays as ORR Catalyst for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Mahbuba; Yurukcu, Mesut; Yurtsever, Fatma; Ergul, Busra; Kariuki, Nancy; Myers, Deborah J.; Karabacak, Tansel

    2017-08-24

    Polymer electrolyte membrane fuel cells (PEMFCs) among the other types of fuel cell technology are attractive power sources, especially for electric vehicle applications. While significant progress and plausible prospects of PEMFCs have been achieved, there are still some challenges related to the performance, durability, and cost that need to be overcome to make them economically viable for widespread commercialization. Our strategy is to develop thin films of high-active and stable catalyst coated on vertically aligned nanorod arrays of conductive and stable support. In this work, we fabricated tungsten carbide (WC) nanorods as support and coated them with a platinum-nickel (Pt-Ni) alloy shell denoted as Pt-Ni/WC catalysts. The Pt- Ni/WC nanorods were deposited on glassy carbon disks as well as on silicon substrates for evaluation of their electrocatalytic oxygen reduction reaction (ORR) activity and physical properties. Cyclic voltammetry experiments using rotating disk electrode were performed in perchloric acid (0.1 M HClO4) electrolyte at room temperature to characterize the ORR activity and stability of Pt-Ni/WC nanorods catalysts. Scanning electron microscopy and X-ray diffraction techniques were utilized to study the morphology and crystallographic properties, respectively.

  9. Mechanical properties of hot-pressed Al-4.5 wt. % Cu/WC composite

    Directory of Open Access Journals (Sweden)

    Samaneh Bernoosi

    2014-12-01

    Full Text Available In this study, the elemental powders of aluminum and copper were initially subjected to mechanical alloying using an attrition ball mill under argon atmosphere to produce an Al-4.5 wt% Cu powder alloy. The WC nanoparticles were then added to the powder alloy and milled in a planetary ball mill to explore the role of the WC nanoparticles on the mechanical properties of the fabricated composite powder. The experimental results revealed that a solid solution of Al-Cu could be formed after MA and a good dispersion of the WC nanoparticles in the aluminum matrix was obtained as characterized using X-ray diffraction and scanning electron microscopy, respectively. The results of hardness and compression tests of the hot pressed composites indicated that the MA followed by the hot-press processes was successful to fabricate an alloy and a metal matrix composite with considerable mechanical properties. However, a decreasing trend in the hardness and strength of the composites with the WC contents of more than 5wt% was observed. The maximum values of 260 HV and 575 MPa were obtained for a composite containing 5 wt% of nano ceramic particles.

  10. Fundamentals of grinding : surface conditions of ground WC-Co systems

    NARCIS (Netherlands)

    Hegeman, JBJW; De Hosson, JTM; Shulepov, SY; Lousberg, N; de With, G; Brebbia, CA; Kenny, JM

    1999-01-01

    This paper concentrates on the fundamentals of grinding of inorganic materials. A statistical grinding model was developed based on the topography of the grinding wheel. The results of the model are compared with the results of grinding experiments on WC-Co hardmetals. The calculated profiles and

  11. Ultra-short-period WC/SiC multilayer coatings for x-ray applications

    DEFF Research Database (Denmark)

    Fernandez-Perea, M.; Pivovaroff, M. J.; Soufli, R.

    2013-01-01

    developed multilayers with ultra-shortperiods between 1 and 2 nm based on the material system WC/SiC. This material system was selected because it possesses very sharp and stable interfaces. In this article, we show highlights from a series of experiments performed in order to characterize the stress...

  12. Atomic composition of WC/ and Zr/O-terminated diamond Schottky interfaces close to ideality

    Energy Technology Data Exchange (ETDEWEB)

    Piñero, J.C., E-mail: josecarlos.pinero@uca.es [Dpto. Ciencias de los Materiales, Universidad de Cádiz, Puerto Real, Cádiz,11510 (Spain); Araújo, D. [Dpto. Ciencias de los Materiales, Universidad de Cádiz, Puerto Real, Cádiz,11510 (Spain); Fiori, A. [National Institute for Materials Science, Tsukuba, Ibaraki (Japan); Traoré, A. [Institut Néel, CNRS-UJF, av. des Martyrs, Grenoble,38042 France (France); Villar, M.P. [Dpto. Ciencias de los Materiales, Universidad de Cádiz, Puerto Real, Cádiz,11510 (Spain); Eon, D.; Muret, P.; Pernot, J. [Institut Néel, CNRS-UJF, av. des Martyrs, Grenoble,38042 France (France); Teraji, T. [National Institute for Materials Science, Tsukuba, Ibaraki (Japan)

    2017-02-15

    Highlights: • Metal/O-terminated diamond interfaces are analyzed by a variety of TEM techniques. • Thermal treatment is shown to modify structural and chemical interface properties. • Electrical behavior vs annealing is shown to be related with interface modification. • Interfaces are characterized with atomic resolution to probe inhomogeneities. • Oxide formation and modification is demonstrated in both Schottky diodes. - Abstract: Electrical and nano-structural properties of Zr and WC-based Schottky power diodes are compared and used for investigating oxide-related effects at the diamond/metal interface. Differences in Schottky barrier heights and ideality factors of both structures are shown to be related with the modification of the oxygen-terminated diamond/metal interface configuration. Oxide formation, oxide thickness variations and interfacial oxygen redistribution, associated with thermal treatment are demonstrated. Ideality factors close to ideality (n{sub WC} = 1.02 and n{sub Zr} = 1.16) are obtained after thermal treatment and are shown to be related with the relative oxygen content at the surface (OCR{sub WC} = 3.03 and OCR{sub Zr} = 1.5). Indeed, thermal treatment at higher temperatures is shown to promote an escape of oxygen for the case of the WC diode, while it generates a sharper accumulation of oxygen at the metal/diamond interface for the case of Zr diode. Therefore, the metal-oxygen affinity is shown to be a key parameter to improve diamond-based Schottky diodes.

  13. New results on the relationship between hardness and fracture toughness of WC-Co hardmetal

    CSIR Research Space (South Africa)

    O'Quigley, DGF

    1996-05-01

    Full Text Available Two sets of WC-Co grades were produced, with cobalt content ranging from 3 to 50 wt.%. The mean grain size of the two sets was 2.2 and 6 mu m respectively. The two sets of grades were used to investigate the relationship between hardness...

  14. CVD of alternated microcrystalline (MCD) and nanocrystalline (NCD) diamond films on WC-TIC-CO substrates

    International Nuclear Information System (INIS)

    Campos, Raonei Alves; Contin, Andre; Trava-Airoldi, Vladimir J.; Corat, Evaldo Jose; Barquete, Danilo Maciel

    2010-01-01

    CVD Diamond coating of WC-TiC-Co cutting tools has been an alternative to increase tool lifetime. Experiments have shown that residual stresses produced during films growth on WC-TiC-Co substrates significantly increases with increasing film thickness up to 20 μm and usually leads to film delamination. In this work alternated micro- and nanocrystalline CVD diamond films have been used to relax interface stresses and to increase diamond coatings performance. WC-TiC-Co substrates have been submitted to a boronizing thermal diffusion treatment prior to CVD diamond films growth. After reactive heat treatment samples were submitted to chemical etching in acid and alkaline solution. The diamond films deposition was performed using HFCVD reactor with different gas concentrations for microcrystalline (MCD) and nano-crystalline (NCD) films growth. As a result, we present the improvement of diamond films adherence on WC-TiC-Co, evaluated by indentation and machining tests. Samples were characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) for qualitative analysis of diamond films. X-ray Diffraction (XRD) was used for phases identification after boronizing process. Diamond film compressive residual stresses were analyzed by Raman Scattering Spectroscopy (RSS). (author)

  15. Elastic properties and 2D icosahedral bonding in borides of hexagonal WC type

    Energy Technology Data Exchange (ETDEWEB)

    Music, Denis [Materials Chemistry, RWTH-Aachen, Kopernikusstr. 16, D-52074 Aachen (Germany)]. E-mail: music@mch.rwth-aachen.de; Schneider, Jochen M. [Materials Chemistry, RWTH-Aachen, Kopernikusstr. 16, D-52074 Aachen (Germany)

    2005-01-15

    Using ab initio calculations we have identified materials with bulk moduli comparable to cubic BN. These are WB, IrB, ReB and OsB crystallizing in the hexagonal WC structure. In the (0 0 0 2) planes of these compounds, we find 2D icosahedral bonding between adjacent B atoms, which has previously not been reported.

  16. Corrosion of WC-VC-Co hardmetal in neutral chloride containing media

    CSIR Research Space (South Africa)

    Machio, Christopher N

    2013-01-01

    Full Text Available , “Electrochemical oxidation of WC in acidic sulphate solution,” Corrosion Science, vol. 46, no. 2, pp. 453–469, 2004. [18] T. Kubo and Y. Nishikitani, “Deposition temperature depen- dence of optical gap and coloration efficiency spectrum in elec- trochromic tungsten...

  17. The influence of aggregates type on W/C ratio on the strength and other properties of concrete

    Science.gov (United States)

    Malaiskiene, J.; Skripkiunas, G.; Vaiciene, M.; Karpova, E.

    2017-10-01

    The influence of different types of aggregates and W/C ratio on concrete properties is analysed. In order to achieve this aim, lightweight (with expanded clay aggregate) and normal concrete (with gravel aggregate) mixtures are prepared with different W/C ratios. Different W/C ratios are selected by reducing the amount of cement when the amount of water is constant. The following properties of concrete have been determined: density, compressive strength and water absorption. Additionally, the statistical data analysis is performed and influence of aggregate type and W/C ratio on concrete properties is determined. The empirical equations indicating dependence between concrete strength and W/C and strength of aggregate are obtained for normal concrete and light-weight concrete.

  18. 3D-printed patient-specific applications in orthopedics

    Directory of Open Access Journals (Sweden)

    Wong KC

    2016-10-01

    Full Text Available Kwok Chuen Wong Department of Orthopedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong Abstract: With advances in both medical imaging and computer programming, two-dimensional axial images can be processed into other reformatted views (sagittal and coronal and three-dimensional (3D virtual models that represent a patients’ own anatomy. This processed digital information can be analyzed in detail by orthopedic surgeons to perform patient-specific orthopedic procedures. The use of 3D printing is rising and has become more prevalent in medical applications over the last decade as surgeons and researchers are increasingly utilizing the technology’s flexibility in manufacturing objects. 3D printing is a type of manufacturing process in which materials such as plastic or metal are deposited in layers to create a 3D object from a digital model. This additive manufacturing method has the advantage of fabricating objects with complex freeform geometry, which is impossible using traditional subtractive manufacturing methods. Specifically in surgical applications, the 3D printing techniques can not only generate models that give a better understanding of the complex anatomy and pathology of the patients and aid in education and surgical training, but can also produce patient-specific surgical guides or even custom implants that are tailor-made to the surgical requirements. As the clinical workflow of the 3D printing technology continues to evolve, orthopedic surgeons should embrace the latest knowledge of the technology and incorporate it into their clinical practice for patient-specific orthopedic applications. This paper is written to help orthopedic surgeons stay up-to-date on the emerging 3D technology, starting from the acquisition of clinical imaging to 3D printing for patient-specific applications in orthopedics. It 1 presents the necessary steps to prepare the medical images that are

  19. Managing orthopedics and neurosciences costs through standard treatment protocols.

    Science.gov (United States)

    McGinnity, E S; Pluth, T E

    1994-06-01

    High-cost, high-volume specialty programs such as orthopedics and neurosciences find themselves in a position of evaluating the costs and in some cases the appropriateness of medical practices in response to payer scrutiny and provider selection processes. Orthopedics and neurosciences programs are at a stage of development analogous to that of cardiovascular care several years ago. Many of the same trends have come into play, such as payer "carve-outs" for orthopedic services, payer selection of centers of excellence based on cost and quality, reduction of Medicare reimbursement, greater use of high-cost technology, the decline of profitability due to "older, sicker, and tougher" patients, and the recent emergence of national orthopedic specialty networks oriented to national contracts for care. In an era in which payers demand value on both sides of the cost-plus-quality equation, programs are challenged to maximize the return on a patient population rife with "no-win" situations. In the orthopedic service line these include a high proportion of Medicare patients and chronic conditions such as workers' compensation medical back cases or repetitive motion injuries, which can be elusive to diagnose and expensive to treat. Many hospitals continue to lose money on joint replacement surgeries, the largest-volume orthopedic inpatient service, primarily because of the high Medicare population and the cost of implants. Neuroservices, while still relatively well reimbursed, face a rising proportion of Medicare payments as patients live longer and develop chronic, degenerative conditions. Inpatient days are decreasing due to payer pressures to limit hospital stays and to shift inpatient care to outpatient services. Some hospitals "have lost interest in (the orthopedic) service line during the last five years because of recent trends in orthopedic-related inpatient volume and payment." But by managing costs strategically, both the neurosciences and orthopedics service lines

  20. Microstructure and mechanical properties of TiB2–TiC–WC composite ceramic tool materials

    International Nuclear Information System (INIS)

    Song, Jinpeng; Huang, Chuanzhen; Zou, Bin; Liu, Hanlian; Wang, Jun

    2012-01-01

    Highlights: ►Effect of sintering parameters on TiB 2 –TiC–WC composites has been investigated. ► Ni element was dispersed in the interface between WC and matrix grains. ► The fracture mode changed from intergranular fracture to transgranular fracture. ► The microstructure and mechanical properties of the composite were improved. -- Abstract: TiB 2 –TiC–WC composites with Ni as a sintering aid were fabricated by a hot-press technique at 1700 °C and 1650 °C for 1 h, respectively. The microstructure and mechanical properties were investigated. The composites were analyzed by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS). The matrix phases consisted of TiB 2 and TiC. No severe chemical reactions happened between the additive and matrix. The microstructure consisted of the fine WC grains and uniform matrix grains. When the proper WC content added to TiB 2 –TiC composites, the growth of matrix grains was inhibited and the mechanical properties of the composites were improved. The interface energy was strengthened by Ni that dispersed in the interfaces among WC grains and matrix grains, which made the fracture mode change from intergranular fracture to transgranular fracture. The transgranular fracture and the pulling out of WC grains played a predominant role in the propagating of cracks when WC content was 20 wt.% in TiB 2 –TiC–WC composites. The optimal mechanical properties of TiB 2 –TiC–20 wt.%WC composite were 955.71 MPa of flexural strength, 7.5 MPa m 1/2 of fracture toughness and 23.5 GPa of Vickers hardness.

  1. Liquid Phase Sintering of (Ti,Zr)C with WC-Co.

    Science.gov (United States)

    Ma, Taoran; Borrajo-Pelaez, Rafael; Hedström, Peter; Blomqvist, Andreas; Borgh, Ida; Norgren, Susanne; Odqvist, Joakim

    2017-01-11

    (Ti,Zr)C powder was sintered with WC-Co following an industrial process, including an isotherm at 1410 °C. A series of interrupted sintering trials was performed with the aim of studying the sintering behavior and the microstructural evolution during both solid-state and liquid-state sintering. Reference samples, using the same elemental compositions but with the starting components TiC and ZrC instead of (Ti,Zr)C, were also sintered. The microstructure was investigated using scanning electron microscopy and energy dispersive X-ray spectroscopy. It is found that the (Ti,Zr)C phase decomposes into Ti-rich and Zr-rich nano-scale lamellae before the liquid-state of the sintering initiates. The final microstructure consists of the binder and WC as well as two different γ phases, rich in either Ti (γ₁) or Zr (γ₂). The γ₂ phase grains have a core-shell structure with a (Ti,Zr)C core following the full sintering cycle. The major differences observed in (Ti,Zr)C with respect to the reference samples after the full sintering cycle were the referred core-shell structure and the carbide grain sizes; additionally, the microstructural evolution during sintering differs. The grain size of carbides (WC, γ₁, and γ₂) is about 10% smaller in WC-(Ti,Zr)C-Co than WC-TiC-ZrC-Co. The shrinkage behavior and hardness of both composites are reported and discussed.

  2. Anisotropic atomic packing model for abnormal grain growth mechanism of WC-25 wt.% Co alloy

    International Nuclear Information System (INIS)

    Ryoo, H.S.; Hwang, S.K.

    1998-01-01

    During liquid phase sintering, cemented carbide particles grow into either faceted or non-faceted grain shapes depending on ally system. In case of WC-Co alloy, prism-shape faceted grains with (0001) planes and {1 bar 100} planes on each face are observed, and furthermore an abnormal grain growth has been reported to occur. When abnormal grain growth occurs in WC crystals, dimension ratio, R, of the length of the side of the triangular prism face to the height of the prism is higher than 4 whereas that for normal grains is approximately 2. Abnormal grain growth in this alloy is accelerated by the fineness of starting powders and by high sintering temperature. To account for the mechanism of the abnormal grain growth, there are two proposed models which drew much research attention: nucleation and subsequent carburization and transformation of η (W 3 Co 3 C) phase into WC, and coalescence of coarse WC grains through dissolution and re-precipitation. Park et al. proposed a two-dimensional nucleation theory to explain the abnormal grain growth of faceted grains. There are questions, however, on the role of η phase on abnormal grain growth. The mechanism of coalescence of spherical grains as proposed by Kingery is also unsuitable for faceted grains. So far theories on abnormal grain growth do not provide a satisfactory explanation on the change of R value during the growth process. In the present work a new mechanism of nucleation and growth of faceted WC grains is proposed on the ground of anisotropic packing sequence of each atom

  3. Liquid Phase Sintering of (Ti,ZrC with WC-Co

    Directory of Open Access Journals (Sweden)

    Taoran Ma

    2017-01-01

    Full Text Available (Ti,ZrC powder was sintered with WC-Co following an industrial process, including an isotherm at 1410 °C. A series of interrupted sintering trials was performed with the aim of studying the sintering behavior and the microstructural evolution during both solid-state and liquid-state sintering. Reference samples, using the same elemental compositions but with the starting components TiC and ZrC instead of (Ti,ZrC, were also sintered. The microstructure was investigated using scanning electron microscopy and energy dispersive X-ray spectroscopy. It is found that the (Ti,ZrC phase decomposes into Ti-rich and Zr-rich nano-scale lamellae before the liquid-state of the sintering initiates. The final microstructure consists of the binder and WC as well as two different γ phases, rich in either Ti (γ1 or Zr (γ2. The γ2 phase grains have a core-shell structure with a (Ti,ZrC core following the full sintering cycle. The major differences observed in (Ti,ZrC with respect to the reference samples after the full sintering cycle were the referred core-shell structure and the carbide grain sizes; additionally, the microstructural evolution during sintering differs. The grain size of carbides (WC, γ1, and γ2 is about 10% smaller in WC-(Ti,ZrC-Co than WC-TiC-ZrC-Co. The shrinkage behavior and hardness of both composites are reported and discussed.

  4. Serious Leisure and People with Orthopedic Impairment: Benefits and Constraints

    Directory of Open Access Journals (Sweden)

    Manolya AKSATAN

    2017-12-01

    Full Text Available There are many people around the world who have different types of disabilities. Understanding their needs is the first step of developing policies to increase their quality of life and satisfaction. Leisure is an essential need of disabled people and it plays an important role in disabled people’s lives. The purpose of this study is to gain a deep understanding on the serious leisure activities of people with orthopedic impairment, and also both benefits and constraints involved with serious leisure. Therefore, semi-structured in-depth interviews were conducted with 17 people who have orthopedic impairment. The data collected through interviews was analyzed by using a coding process. Findings of the study indicate that people with orthopedic impairment pursue many leisure activities. The research revealed that the participants were aware of significant individual and community benefits of serious leisure activities. Although the benefits of leisure for private and community life are obvious for people with orthopedic impairment, it is not always easy for them to pursue serious leisure activities. Disabled people recognize that there are many constraints involved with serious leisure. Based on the findings, these constraints are explained as psychological factors, family support, level of orthopedic impairment, community awareness and environmental factors, work and income.

  5. Patient Attitudes Toward Orthopedic Surgeon Ownership of Related Ancillary Businesses.

    Science.gov (United States)

    Yi, Paul H; Cross, Michael B; Johnson, Staci R; Rasinski, Kenneth A; Nunley, Ryan M; Della Valle, Craig J

    2016-08-01

    Physician ownership of businesses related to orthopedic surgery, such as surgery centers, has been criticized as potentially leading to misuse of health care resources. The purpose of this study was to determine patients' attitudes toward surgeon ownership of orthopedic-related businesses. We surveyed 280 consecutive patients at 2 centers regarding their attitudes toward surgeon ownership of orthopedic-related businesses using an anonymous questionnaire. Three surgeon ownership scenarios were presented: (1) owning a surgery center, (2) physical therapy (PT), and (3) imaging facilities (eg, Magnetic Resonance Imaging scanner). Two hundred fourteen patients (76%) completed the questionnaire. The majority agreed that it is ethical for a surgeon to own a surgery center (73%), PT practice (77%), or imaging facility (77%). Most (>67%) indicated that their surgeon owning such a business would have no effect on the trust they have in their surgeon. Although >70% agreed that a surgeon in all 3 scenarios would make the same treatment decisions, many agreed that such surgeons might perform more surgery (47%), refer more patients to PT (61%), or order more imaging (58%). Patients favored surgeon autonomy, however, believing that surgeons should be allowed to own such businesses (78%). Eighty-five percent agreed that patients should be informed if their surgeon owns an orthopedic-related business. Although patients express concern over and desire disclosure of surgeon ownership of orthopedic-related businesses, the majority believes that it is an ethical practice and feel comfortable receiving care at such a facility. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Patient refusal for regional anesthesia in elderly orthopedic population: A cross-sectional survey at a tertiary care hospital.

    Science.gov (United States)

    Salam, Asma Abdus; Afshan, Gauhar

    2016-01-01

    Improvements in pain management techniques in the last decade have had a major impact on the practice of orthopedic surgeries, for example, total hip arthroplasty and total knee arthroplasty. Although there are a number of treatment options for postoperative pain, a gold standard has not been established. In our institution, both general anesthesia and regional anesthesia (RA), are being offered to the elderly orthopedic population but RA is not frequently accepted by elderly population. The objective of this study was to determine the frequency of various reasons for refusal of RA in elderly patients undergoing orthopedic surgeries. A prospective study conducted over a period of 1 year, had 549 patients with ages above 60 years who underwent different types of elective orthopedic procedures 182 patients who refused RA were interviewed according to a structured questionnaire designed to assess the reasons of refusal. Most common reason for the refusal of RA was surgeon's choice (38.5%), whereas 20.3% of the patients were unaware about the RA. There was a significant association between female gender and refusing RA due to backache (17.2%) and fear of being awake during the operation (24.1%) respectively. This survey showed that the main reasons among elderly female population were the fear of remaining awake and backache. However, overall it was the surgeon's choice which made patients refuse RA, and the anesthesiologists were the main source of information.

  7. Reducing bacterial contamination in an Orthopedic Theatre ventilated by natural ventilation, in a Developing Country.

    Science.gov (United States)

    Thomas, Stephanie; Palmer, Rish; Phillipo, Edward; Chipungu, Geoffrey

    2016-05-31

    All surgical procedures have the potential for infection and some of the main sources are contamination from airborne particles, theatre personnel and the theatre environment.  There is strong evidence that the use of ultra-clean air flow systems in orthopedic operating theatres reduces the incidence of deep sepsis after surgery. In the developing world however, this is often an unrealistic solution. The aim of this study was to establish baseline levels of contamination in a working orthopedic theatre, at the Queen Elizabeth Central Hospital, Blantyre, Malawi. To feedback results to the theatre team, promote infection prevention discussion and work with the team to implement workable and realistic goals to improve the intra-operative environment. Samples were collected from theatre equipment available at the time of surgery, from theatre water and theatre air using passive air sampling techniques. Samples were immediately transferred to the Central Microbiology Laboratory for culture on basic culture media. Bacterial contamination of theatre equipment, intra-operative theatre air and water was detected. Results were discussed with the theatre and infection prevention team who were receptive to feedback with regards to infection prevention strategies and keen to develop simple measures which could be put in place to change practice. In this setting, we suggest that implementing workable and realistic goals such as, establishing baseline rates of bacterial contamination and introduction of strict protocols for asepsis and theatre etiquette, may reduce bacterial contamination rates and subsequent intra-operative infection in the absence of expensive engineering solutions.

  8. Influence of electrical discharge machining on the tribological characteristics of WC-Co alloys; Influencia de la electroerosion sobre las caracteristicas tribologicas de materiales compuestos WC-Co

    Energy Technology Data Exchange (ETDEWEB)

    Casas, B.; Martinez, E.; Esteve, J.; Anglada, M.; Llanes, L.

    2001-07-01

    The influence of electrical discharge machining (EDM) on the abrasive wear resistance of two WC-10 %{sub w}tCo cemented carbides with different carbide grain size has been studied. Different surface finish conditions were evaluated corresponding to sequential EDM as well as grinding and polishing with diamond. The abrasive wear resistance was determined through microscratch measurements using a nano indentation system. Contrary to the results obtained from hardness measurements, this techniques allows to discern tribological differences among the distinct surface finish conditions studied. Finally, the abrasive wear resistance degradation associated with sequential EDM is discussed as a function of microstructure in terms of a damage parameters. (Author) 9 refs.

  9. CT and MRI techniques for imaging around orthopedic hardware

    Energy Technology Data Exchange (ETDEWEB)

    Do, Thuy Duong; Skornitzke, Stephan; Weber, Marc-Andre [Heidelberg Univ. (Germany). Dept. of Clinical Radiology; Sutter, Reto [Uniklinik Balgrist, Zurich (Switzerland). Radiology

    2018-01-15

    Orthopedic hardware impairs image quality in cross-sectional imaging. With an increasing number of orthopedic implants in an aging population, the need to mitigate metal artifacts in computed tomography and magnetic resonance imaging is becoming increasingly relevant. This review provides an overview of the major artifacts in CT and MRI and state-of-the-art solutions to improve image quality. All steps of image acquisition from device selection, scan preparations and parameters to image post-processing influence the magnitude of metal artifacts. Technological advances like dual-energy CT with the possibility of virtual monochromatic imaging (VMI) and new materials offer opportunities to further reduce artifacts in CT and MRI. Dedicated metal artifact reduction sequences contain algorithms to reduce artifacts and improve imaging of surrounding tissue and are essential tools in orthopedic imaging to detect postoperative complications in early stages.

  10. Evolving trauma and orthopedics training in the UK.

    Science.gov (United States)

    Inaparthy, Praveen K; Sayana, Murali K; Maffulli, Nicola

    2013-01-01

    The ever-growing population of the UK has resulted in increasing demands on its healthcare service. Changes have been introduced in the UK medical training system to avoid loss of training time and make it more focused and productive. Modernizing medical careers (MMC) was introduced in 2005. This promised to reduce the training period for a safe trauma specialist, in trauma and orthopedics, to 10 years. At around the same time, the European Working Time Directive (EWTD) was introduced to reduce the working hours for junior doctors in training, to improve patient safety and also work-life balance of junior doctors. Introduction of the assessment tools from Orthopedic Competency assessment project (OCAP) will help tailor the training according to the needs of the trainee. The aim of this article is to review the changes in the UK orthopedic surgical training over the past two decades. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  11. The WC-130 Meteorological System and Its Utilization in Operational Weather Reconnaissance.

    Science.gov (United States)

    1980-08-01

    made using a J-scan display on the face of a cathode ray tube (CRT) in the indicator unit. The display is in the form of a base circle with two lobes...76-12W 31000 Ft NCA 35-42N 77-26W 31000 Ft ILM 34-21N 77-52W 31000 Ft CRY 33-49N 78-43W 31000 Ft CHS 32-54N 80-02W 31000 Ft 350 GOIF A 1A IF P\\ I V...Weather Service Ak6PE MS Primitive L -uation Nedel C PFC Central Pacific Hurricane Center CMI cathode ray tube2 LkJC Departmnent of Commierce WkL

  12. Exploring the potential role of tungsten carbide cobalt (WC-Co) nanoparticle internalization in observed toxicity toward lung epithelial cells in vitro.

    Science.gov (United States)

    Armstead, Andrea L; Arena, Christopher B; Li, Bingyun

    2014-07-01

    Tungsten carbide cobalt (WC-Co) has been recognized as a workplace inhalation hazard in the manufacturing, mining and drilling industries by the National Institute of Occupational Safety and Health. Exposure to WC-Co is known to cause "hard metal lung disease" but the relationship between exposure, toxicity and development of disease remain poorly understood. To better understand this relationship, the present study examined the role of WC-Co particle size and internalization on toxicity using lung epithelial cells. We demonstrated that nano- and micro-WC-Co particles exerted toxicity in a dose- and time-dependent manner and that nano-WC-Co particles caused significantly greater toxicity at lower concentrations and shorter exposure times compared to micro-WC-Co particles. WC-Co particles in the nano-size range (not micron-sized) were internalized by lung epithelial cells, which suggested that internalization may play a key role in the enhanced toxicity of nano-WC-Co particles over micro-WC-Co particles. Further exploration of the internalization process indicated that there may be multiple mechanisms involved in WC-Co internalization such as actin and microtubule based cytoskeletal rearrangements. These findings support our hypothesis that WC-Co particle internalization contributes to cellular toxicity and suggest that therapeutic treatments inhibiting particle internalization may serve as prophylactic approaches for those at risk of WC-Co particle exposure. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. A simple strategy to reduce stereotype threat for orthopedic residents.

    Science.gov (United States)

    Gomez, Everlyne; Wright, James G

    2014-04-01

    Stereotype threat, defined as the predicament felt by people in either positive or negative learning experiences where they could conform to negative stereotypes associated with their own group membership, can interfere with learning. The purpose of this study was to determine if a simple orientation session could reduce stereotype threat for orthopedic residents. The intervention group received an orientation on 2 occasions focusing on their possible responses to perceived poor performance in teaching rounds and the operating room (OR). Participants completed a survey with 7 questions typical for stereotype threat evaluating responses to their experiences. The questions had 7 response options with a maximum total score of 49, where higher scores indicated greater degree of experiences typical of stereotype threat. Of the 84 eligible residents, 49 participated: 22 in the nonintervention and 27 in the intervention group. The overall scores were 29 and 29.4, and 26.2 and 25.8 in the nonintervention and intervention groups for their survey responses to perceived poor performance in teaching rounds (p = 0.85) and the OR (p = 0.84), respectively. Overall, responses typical of stereotype threat were greater for perceived poor performance at teaching rounds than in the OR (p = 0.001). Residents experience low self-esteem following perceived poor performance, particularly at rounds. A simple orientation designed to reduce stereotype threat was unsuccessful in reducing this threat overall. Future research will need to consider longer-term intervention as possible strategies to reduce perceived poor performance at teaching rounds and in the OR.

  14. Applications of Metal Additive Manufacturing in Veterinary Orthopedic Surgery

    Science.gov (United States)

    Harrysson, Ola L. A.; Marcellin-Little, Denis J.; Horn, Timothy J.

    2015-03-01

    Veterinary medicine has undergone a rapid increase in specialization over the last three decades. Veterinarians now routinely perform joint replacement, neurosurgery, limb-sparing surgery, interventional radiology, radiation therapy, and other complex medical procedures. Many procedures involve advanced imaging and surgical planning. Evidence-based medicine has also become part of the modus operandi of veterinary clinicians. Modeling and additive manufacturing can provide individualized or customized therapeutic solutions to support the management of companion animals with complex medical problems. The use of metal additive manufacturing is increasing in veterinary orthopedic surgery. This review describes and discusses current and potential applications of metal additive manufacturing in veterinary orthopedic surgery.

  15. Improvement in tribological properties of atmospheric plasma-sprayed WC-Co coating followed by Cu electrochemical impregnation

    International Nuclear Information System (INIS)

    Yuan Jianhui; Zhu Yingchun; Zheng Xuebing; Ruan Qichao; Ji Heng

    2009-01-01

    The WC-Co coating obtained by atmospheric plasma spraying (APS) was modified by Cu electrochemical impregnation. The copper has infiltrated into and filled up the pores in WC-Co coating. The tribological properties of the coating against the stainless steel ball as sliding pairs were investigated with a ball-on-disc (BOD) configuration in air at room temperature. The as-prepared samples were characterized by means of optical microscope, scanning electron microscope and X-ray diffraction. It was found that the frictional behavior of the WC-Co coating followed by Cu electrochemical impregnation was superior to that of WC-Co coating. The wear mechanism of the WC-Co coating followed by Cu electrochemical impregnation was microcutting, whilst that of a WC-Co coating was the fatigue wear. The improvement in tribological properties of the WC-Co coating followed by Cu electrochemical impregnation was attributed to the formation of self-lubricating Cu film on the wear surface which induces the transformation of wear mechanism.

  16. Performance and characterisation of CVD diamond coated, sintered diamond and WC-Co cutting tools for dental and micromachining applications

    International Nuclear Information System (INIS)

    Sein, Htet; Ahmed, Waqar; Jackson, Mark; Woodwards, Robert; Polini, Riccardo

    2004-01-01

    Diamond coatings are attractive for cutting processes due to their high hardness, low friction coefficient, excellent wear resistance and chemical inertness. The application of diamond coatings on cemented tungsten carbide (WC-Co) tools was the subject of much attention in recent years in order to improve cutting performance and tool life. WC-Co tools containing 6% Co and 94% WC substrate with an average grain size 1-3 μm were used in this study. In order to improve the adhesion between diamond and WC substrates, it is necessary to etch away the surface Co and prepare the surface for subsequent diamond growth. Hot filament chemical vapour deposition with a modified vertical filament arrangement has been employed for the deposition of diamond films. Diamond film quality and purity have been characterised using scanning electron microscopy and micro-Raman spectroscopy. The performance of diamond coated WC-Co bur, uncoated WC-Co bur, and diamond embedded (sintered) bur have been compared by drilling a series of holes into various materials such as human teeth, borosilicate glass and porcelain teeth. Flank wear has been used to assess the wear rates of the tools. The materials subjected to cutting processes have been examined to assess the quality of the finish. Diamond coated WC-Co microdrills and uncoated microdrills were also tested on aluminium alloys. Results show that there was a 300% improvement when the drills were coated with diamond compared to the uncoated tools

  17. A theoretical understanding on the CO-tolerance mechanism of the WC(0001) supported Pt monolayer: Some improvement strategies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xilin [College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007 (China); Lu, Zhansheng [College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Henan Province (China); Yang, Zongxian, E-mail: yzx@henannu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, 453007 (China); Collaborative Innovation Center of Nano Functional Materials and Applications, Henan Province (China)

    2016-12-15

    Highlights: • The mechanism of CO tolerance and oxidation on Pt{sub ML}/WC(0001) is clarified. • The high tolerance of Pt{sub ML}/WC(0001) to CO originate from the weak adsorption. • The minimum energy path and the rate-determining step are identified. • The activity of Pt{sub ML}/WC(0001) to CO oxidation is comparable to that of Pt(111). • Some probable strategies are proposed to improve the activity of Pt{sub ML}/WC(0001). - Abstract: The deposition of platinum on the tungsten carbide (Pt/WC) have been achieved and proved with high stability, activity and CO-tolerance toward some reactions in experiments. Although a lot of experimental efforts have been focused on understanding the activity, stability and CO-tolerance of Pt/WC, the relevant theoretical works related to the CO-tolerance mechanism are still scarce. In current study, the adsorption and oxidation of CO on the Pt monolayer supported on WC(0001) surface (Pt{sub ML}/WC(0001)) are investigated using density functional theory calculations. It is found that the oxidation of CO on Pt{sub ML}/WC(0001) proceeds preferably along the Langmuir-Hinshelwood mechanism. The energy barrier of 1.06 eV for the rate-determining step of OOCO formation is almost equal to that (1.05 eV) for CO oxidation by atomic O on Pt(111), while the adsorption energy of 1.59 eV for CO on Pt{sub ML}/WC(0001) is smaller than that on Pt(111) (1.85 eV), indicating that the high resistance to CO poisoning of Pt{sub ML}/WC(0001) may originate from the weak interaction between them. To further improve the CO tolerance, some probable strategies are proposed based on the relevant kinetics results. The current results are helpful to understanding the origin of the highly resistant to CO poisoning of Pt{sub ML}/WC(0001) and rationally designing catalysts to improve the CO oxidation activity.

  18. Small-sized and contacting Pt-WC nanostructures on graphene as highly efficient anode catalysts for direct methanol fuel cells.

    Science.gov (United States)

    Wang, Ruihong; Xie, Ying; Shi, Keying; Wang, Jianqiang; Tian, Chungui; Shen, Peikang; Fu, Honggang

    2012-06-11

    The synergistic effect between Pt and WC is beneficial for methanol electro-oxidation, and makes Pt-WC catalyst a promising anode candidate for the direct methanol fuel cell. This paper reports on the design and synthesis of small-sized and contacting Pt-WC nanostructures on graphene that bring the synergistic effect into full play. Firstly, DFT calculations show the existence of a strong covalent interaction between WC and graphene, which suggests great potential for anchoring WC on graphene with formation of small-sized, well-dispersed WC particles. The calculations also reveal that, when Pt attaches to the pre-existing WC/graphene hybrid, Pt particles preferentially grow on WC rather than graphene. Our experiments confirmed that highly disperse WC nanoparticles (ca. 5 nm) can indeed be anchored on graphene. Also, Pt particles 2-3 nm in size are well dispersed on WC/graphene hybrid and preferentially grow on WC grains, forming contacting Pt-WC nanostructures. These results are consistent with the theoretical findings. X-ray absorption fine structure spectroscopy further confirms the intimate contact between Pt and WC, and demonstrates that the presence of WC can facilitate the crystallinity of Pt particles. This new Pt-WC/graphene catalyst exhibits a high catalytic efficiency toward methanol oxidation, with a mass activity 1.98 and 4.52 times those of commercial PtRu/C and Pt/C catalysts, respectively. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Experimental investigation of surface quality in ultrasonic machining of WC-Co composites through Taguchi method

    Directory of Open Access Journals (Sweden)

    B. S. Pabla

    2016-08-01

    Full Text Available In manufacturing industries, the demand of WC-Co composite is flourishing because of the distinctive characteristics it offers such as: toughness (with hardness, good dimensional stability, higher mechanical strength etc. However, the difficulties in its machining restrict the application and competitiveness of this material. The current article has been targeted at evaluation of the effect of process conditions (varying power rating, cobalt content, tool material, part thickness, tool geometry, and size of abrasive particle on surface roughness in ultrasonic drilling of WC-Co composite. Results showed that abrasive grit size is most influential factor. From the microstructure analysis, the mode of material deformation has been observed and the parameters, i.e. work material properties, grit size, and power rating was revealed as the most crucial for the deformation mode.

  20. THE STRUCTURE AND PROPERTIES OF COMPOSITE LASER CLAD COATINGS WITH Ni BASED MATRIX WITH WC PARTICLES

    Directory of Open Access Journals (Sweden)

    Zita Iždinská

    2010-09-01

    Full Text Available In this work, the influence of the processing conditions on the microstructure and abrasive wear behavior of composite laser clad coatings with Ni based matrix reinforced with 50% WC particles is analyzed. Composite powder was applied in the form of coatings onto a mild steel substrate (Fe–0.17% C by different laser powers and cladding speeds. The microstructure of the coatings was analyzed by scanning electron microscopy (SEM. Tribological properties of coatings were evaluated by pin-on-disc wear test. It appeared that the hardness of the matrix of composite coatings decreases with increasing cladding speed. However, wear resistance of composite coatings with decreasing hardness of Ni based matrix increases. Significantly enhanced wear resistance of WC composite coatings in comparison with Ni based coatings is attributed to the hard phase structures in composite coatings.

  1. Interfacial reaction in cast WC particulate reinforced titanium metal matrix composites coating produced by laser processing

    Science.gov (United States)

    Liu, Dejian; Hu, Peipei; Min, Guoqing

    2015-06-01

    Laser injection of ceramic particle was conducted to produce particulate reinforced metal matrix composites (MMCs) coating on Ti-6Al-4V alloy. Cast WC particle (WCp) was used as injection reinforcement to avoid excessive release of carbon atoms into the melt pool. The interfaces and boundaries between WC and Ti matrix were investigated by electron microscopy study. Compared with single crystal WCp, cast WCp was an appropriate solution to control the reaction products (TiC) in the matrix and the total amount of reaction products was significantly reduced. Irregular-shape reaction layers were formed around cast WCp. The reaction layers consist of a W2C layer and a mixed layer of W and TiC. Such reaction layers are effective in load transfer under an external load.

  2. PCB extraction from ORNL tank WC-14 using a unique solvent

    International Nuclear Information System (INIS)

    Bloom, G.A.; Lucero, A.J.; Koran, L.J.; Turner, E.N.

    1995-09-01

    This report summarizes the development work of the Engineering Development Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) for an organic extraction method for removing polychlorinated biphenyls (PCBs) from tank WC-14. Tank WC-14 is part of the ORNL liquid low-level radioactive tank waste system and does not meet new secondary containment and leak detection regulations. These regulations require the tank to be taken out of service, and remediated before tank removal. To remediate the tank, the PCBs must be removed; the tank contents can then be transferred to the Melton Valley Storage Tanks before final disposal. The solvent being used for the PCB extraction experiments is triethylamine, an aliphatic amine that is soluble in water below 60 degrees F but insoluble in water above 90 degrees F. This property will allow the extraction to be carried out under fully miscible conditions within the tank; then, after tank conditions have been changed, the solvent will not be miscible with water and phase separation will occur. Phase separation between sludge, water, and solvent will allow solvent (loaded with PCBs) to be removed from the tank for disposal. After removing the PCBs from the sludge and removing the sludge from the tank, administrative control of the tank can be transferred to ORNL's Environmental Restoration Program, where priorities will be set for tank removal. Experiments with WC-14 sludge show that greater than 90% extraction efficiencies can be achieved with one extraction stage and that PCB concentration in the sludge can be reduced to below 2 ppm in three extractions. It is anticipated that three extractions will be necessary to reduce the PCB concentration to below 2 ppm during field applications. The experiments conducted with tank WC-14 sludge transferred less than 0.03% of the original alpha contamination and less than 0.002% of the original beta contamination

  3. Machinability and scratch wear resistance of carbon-coated WC inserts

    Energy Technology Data Exchange (ETDEWEB)

    Pazhanivel, B., E-mail: palcecri@yahoo.co.in; Kumar, T. Prem; Sozhan, G.

    2015-03-15

    Highlights: • Cemented WC inserts were coated with carbon by CVD. • The deposits were either loosely held MWCNTs or adherent carbides. • Co-efficient of friction (ramp load; 1–13 N); 0.2 and 0.1 μ, respectively, for the uncoated and carbide-coated inserts. • The carbide-coated insert exhibited better machinability and surface finish than a commercial TiCN-coated insert. - Abstract: In this work, cemented tungsten carbide (WC) inserts were coated with nanocarbons/carbides by chemical vapor deposition (CVD) and their machinability and scratch wear resistance were investigated. The hardness and surface conditions of the WC substrate were studied before and after coating. The CVD-generated nanocarbons on the insert surfaces were examined by SEM, FE-SEM and TEM. The electron microscopic images revealed that the carbons generated were multi-walled carbon nanotubes (MWCNTs) or carbides depending on the experimental conditions. In both the cases, the cutting edges of the inserts had dense deposits. Scratch wear test with the coated inserts showed that the co-efficient of friction was 0.1 μ as against 0.2 μ for the uncoated inserts under a ramp load of 1–13 N. The machinability characteristics of commercially available TiCN-coated inserts and the carbon-coated WC inserts were compared by using a CNC machine and a Rapid I vision inspection system. It was found that the carbide-coated inserts exhibited machinability with better surface finish comparable to that of the TiCN-coated inserts while the MWCNT-coated inserts showed inferior adhesion properties.

  4. Laser surface alloying of aluminium with WC+Co+NiCr for improved wear resistance

    CSIR Research Space (South Africa)

    Nath, S

    2012-03-01

    Full Text Available Department of Metallurgical & Materials Engineering, IIT Kharagpur, West Bengal, India 2National Laser Centre, CSIR, Pretoria, South Africa Abstract In the present study, laser surface alloying of aluminium with WC+Co+NiCr (in the ratio of 70... be used for dispersion of ceramic materials into metallic matrix and hence, form a ceramic dispersed metal matrix composite on metallic substrate [3]. The advantages of laser surface alloying include refinement of the microstructure, uniform dispersion...

  5. Looking at the Social Activity for Adolescents with Orthopedic Impairments

    Science.gov (United States)

    Biastro, Leslie; Frank, Heather; Larwin, Karen H.

    2015-01-01

    Adolescents with identified orthopedic impairments are often less likely to participate in social activities outside of the school setting. However, the adolescents who are able to participate in activities have higher social skills, more academic successes, and show more satisfaction in their roles as family member or friend. The aim of this…

  6. Socioeconomic value of orthopedic devices: evidence and methodological challenges

    Directory of Open Access Journals (Sweden)

    Sorenson C

    2012-10-01

    Full Text Available Corinna Sorenson,1,2 Michael Drummond2,31LSE Health, London School of Economics, London, UK; 2European Health Technology Institute for Socioeconomic Research, Brussels, Belgium; 3Centre for Health Economics, University of York, York, UKAbstract: With continued technological advances in orthopedic devices and increasingly limited health care resources, greater attention will be placed on substantiating the socioeconomic value of these devices. Therefore, this study focused on a systematic review of available economic evaluations of selected orthopedic devices (n = 33 studies to assess their impact on different clinical and economic outcomes. The existing evidence suggests that they have important benefits to patients, including reduced risk of fractures, increased mobility and functioning, and enhanced quality of life, and do so cost effectively or with cost savings. However, we have identified several methodological obstacles to sufficient ascertainment of value, such as a lack of robust information on health economic outcomes and long-term evidence. We also identify areas where additional research is needed to assess more fully the value of orthopedic devices.Keywords: medical devices, orthopedics, health economic evaluation

  7. Clinical potential of implantable wireless sensors for orthopedic treatments.

    Science.gov (United States)

    Karipott, Salil Sidharthan; Nelson, Bradley D; Guldberg, Robert E; Ong, Keat Ghee

    2018-04-01

    Implantable wireless sensors have been used for real-time monitoring of chemicals and physical conditions of bones, tendons and muscles to diagnose and study orthopedic diseases and injuries. Due to the importance of these sensors in orthopedic care, a critical review, which not only analyzes the underlying technologies but also their clinical implementations and challenges, will provide a landscape view on their current state and their future clinical role. Areas covered: By conducting an extensive literature search and following the leaders of orthopedic implantable wireless sensors, this review covers the battery-powered and battery-free wireless implantable sensor technologies, and describes their implementation for hips, knees, spine, and shoulder stress/strain monitoring. Their advantages, limitations, and clinical challenges are also described. Expert commentary: Currently, implantable wireless sensors are mostly limited for scientific investigations and demonstrative experiments. Although rapid advancement in sensors and wireless technologies will push the reliability and practicality of these sensors for clinical realization, regulatory constraints and financial viability in medical device industry may curtail their continuous adoption for clinical orthopedic applications. In the next five years, these sensors are expected to gain increased interest from researchers, but wide clinical adoption is still unlikely.

  8. Survey of 2582 Cases of Acute Orthopedic Trauma

    Science.gov (United States)

    Soleymanha, Mehran; Mobayen, Mohammadreza; Asadi, Kamran; Adeli, Alborz; Haghparast-Ghadim-Limudahi, Zahra

    2014-01-01

    Background: Orthopedic injuries are among the most common causes of mortality, morbidity, hospitalization, and economic burden in societies. Objectives: In this research, we study the prevalence of different types of trauma requiring orthopedic surgery. Patients and Methods: We conducted a cross-sectional study on 2582 patients with acute orthopedic injuries admitted to the orthopedic emergency ward at the Poursina Hospital (a referral center in Guilan province (northern Iran), during December 2010 through September 2011. Patients were examined and the data collection form was filled for each patient. Data were analyzed by SPSS software version 19 and were listed in tables. Results: Of 2582 included cases, 1940 were male and 642 were female, with a mean age of 34.5 years. Most injuries were seen in the 25 to 44 year age group from rural areas. The highest frequency of trauma related to falls. On the other hand, bicycling and shooting had the lowest frequencies. There were 18 cases with limb amputation. Overall, 66.5% of patients had fractures, 5% had soft tissue lacerations, and 10% had dislocations. Conclusions: Identification of risk factors and methods of prevention is one of the most important duties of healthcare systems. Devising plans to minimize these risk factors and familiarizing people with them is prudent. PMID:25717444

  9. Rivaroxaban for Thromboprophylaxis After Nonelective Orthopedic Trauma Surgery in Switzerland

    DEFF Research Database (Denmark)

    Hoffmeyer, Pierre; Simmen, Hanspeter; Jakob, Marcel

    2017-01-01

    This study investigated the effectiveness and the outcomes of rivaroxaban vs the standard of care for venous thromboembolic prophylaxis in patients undergoing fracture-related surgery. A total of 413 patients undergoing fracture-related surgery from 9 Swiss orthopedic and trauma centers were enro...

  10. Frequency of orthopedic diseases in horses: A retrospective study

    Directory of Open Access Journals (Sweden)

    Kovač Milomir

    2002-01-01

    Full Text Available This retrospective study determined the frequency of orthopedic diseases in horses. It was possible to establish 141 specific orthopedic diagnoses in 1955 horses with lameness. In 14.58 % horses, multiple pathologic orthopedic changes were determined. In 61.84 % cases, the pathologic changes were present on the thoracic limb, 28,86 % on the pelvic limb and other parts of the oganism (neck, spine, muscles in 9.29 % cases. Pathologic changes on the tendons, ligaments, tendon sheats, bursae and muscles were determined in 31.51 % cases. Diseases of the hoof were present in 25.82 % cases. According to our investigation the most frequent orthopedic diseases are: podarthritis (acute, chronic, septic (5.04 %, navicular disease (4.69 %, tendinitis m. flexor digitalis superfacialis (4.51 %, kissing spine syndrom (4.30 % periarthritis et osteoarthrosis tarsi (3.30 %, distal metacarpal/metatarzophalengeal tendovaginitis (3.30 % and high suspensory ligament desmitis (3.12 %. Most frequent fractures were diagnosed on the metacarpal/metatarsal bone II and IV (2.56 %. Osteochondrossis dissecans was most frequently determined in the tarsocrural (1.26 % and the metacarpophalengeal joint (1.56 %.

  11. Web-based patient education in orthopedics : Systematic review

    NARCIS (Netherlands)

    Dekkers, T.; Melles, M.; Groeneveld, B.S.; de Ridder, H.

    2018-01-01

    Background: Patients with orthopedic conditions frequently use the internet to find health information. Patient education that is distributed online may form an easily accessible, time- and cost-effective alternative to education delivered through traditional channels such as one-on-one

  12. Radiation injuries to the skeleton and their orthopedic treatment

    International Nuclear Information System (INIS)

    Franz, R.; Rahnfeld, R.

    1978-01-01

    70 patients subjected to orthopedic treatment and radiotherapy for skeletal tumors have been examined. It was found that serious radiation injuries frequently occurred. Above all there were contractures, disordered healing of wounds, ulcerations, and scolioses and kyphoses of the growing skeleton. Therefore, in the case of diseases of the skeleton, it is recommended to restrain radiotherapy. It has to be rejected in child's age

  13. Readability of Orthopedic Trauma Patient Education Materials on the Internet.

    Science.gov (United States)

    Mohan, Rohith; Yi, Paul H; Morshed, Saam

    In this study, we used the Flesch-Kincaid Readability Scale to determine the readability levels of orthopedic trauma patient education materials on the American Academy of Orthopaedic Surgeons (AAOS) website and to examine how subspecialty coauthorship affects readability level. Included articles from the AAOS online patient education library and the AAOS OrthoPortal website were categorized as trauma or broken bones and injuries on the AAOS online library or were screened by study authors for relevance to orthopedic trauma. Subsequently, the Flesch-Kincaid scale was used to determine each article's readability level, which was reported as a grade level. Subspecialty coauthorship was noted for each article. A total of 115 articles from the AAOS website were included in the study and reviewed. Mean reading level was grade 9.1 for all articles reviewed. Nineteen articles (16.5%) were found to be at or below the eighth-grade level, and only 1 article was at or below the sixth-grade level. In addition, there was no statistically significant difference between articles coauthored by the various orthopedic subspecialties and those authored exclusively by AAOS. Orthopedic trauma readability materials on the AAOS website appear to be written at a reading comprehension level too high for the average patient to understand.

  14. TRIBOLOGICAL PROPERTIES OF TiBx AND WC/C COATINGS

    Directory of Open Access Journals (Sweden)

    PETER KÚŠ

    2011-12-01

    Full Text Available Tribological properties of TiBx and WC/C coatings have been studied using the ball-on-disc method at room and elevated temperatures in air to investigate their behavior under conditions approaching high performance dry cutting. The average room temperature coefficients of friction (COF of both nanocomposite DC magnetron sputtered TiBx coatings and PECVD WC/C coatings were in the range 0.2-0.6. The lowest value of TiBx coatings of 0.16 was achieved in case of prefferentially oriented stuctures deposited at the highest negative bias. The lowest COF of WC/C was around 0.11. The increase of testing temperature to 450°C caused the increase of COF up to approximately 0.7-0.8. The experiments at elevated temperatures suggest the existence of the oxide transfer film with higher COF than that of the sliding contact without the film. Although both coating systems have relatively high COF values at elevated temperatures, they exhibit elements of some adaptive behavior.

  15. DURABILITY AND TRIBOLOGICAL PROPERTIES OF THERMALLY SPRAYED WC CERMET COATING IN LUBRICATED ROLLING WITH SLIDING CONTACT

    Directory of Open Access Journals (Sweden)

    Mohammad Ali

    2010-09-01

    Full Text Available Durability and tribological properties of thermally sprayed WC-Cr-Ni cermet coating were investigated experimentally in lubricated rolling with sliding contact conditions. By means of the high energy type flame spraying (Hi-HVOF method, the coating was formed onto the axially ground and circumferentially ground roller specimens made of a thermally refined carbon steel. In the experiments, the WC cermet coated steel roller was mated with the carburized hardened steel roller without coating in line contact condition. The coated roller was mated with the smooth non-coated roller under a contact pressure of 1.0 or 1.2 GPa, and it was mated with the rough non-coated roller under a contact pressure of 0.6 or 0.8 GPa. As a result, it was found that in general, the coating on the circumferentially ground substrate shows a lower durability compared with that on the axially ground substrate and this difference appears more distinctly for the higher contact pressure for both smooth mating surface and rough mating surface. It was also found that there are significant differences in the tribological properties of WC cermet coating depending on the contact pressure. In addition, depending on the smooth or rough mating surface, remarkable differences in the tribological properties were found.

  16. Laser pulse heating of steel mixing with WC particles in a irradiated region

    Science.gov (United States)

    Shuja, S. Z.; Yilbas, B. S.; Ali, H.; Karatas, C.

    2016-12-01

    Laser pulse heating of steel mixing with tungsten carbide (WC) particles is carried out. Temperature field in the irradiated region is simulated in line with the experimental conditions. In the analysis, a laser pulse parameter is introduced, which defines the laser pulse intensity distribution at the irradiated surface. The influence of the laser parameter on the melt pool size and the maximum temperature increase in the irradiated region is examined. Surface temperature predictions are compared with the experimental data. In addition, the distribution of WC particles and their re-locations in the treated layer, due to combination of the natural convection and Marangoni currents, are predicted. The findings are compared to the experimental data. It is found that surface temperature predictions agree well with the experimental data. The dislocated WC particles form a streamlining in the near region of the melt pool wall, which agree with the experimental findings. The Gaussian distribution of the laser pulse intensity results in the maximum peak temperature and the maximum flow velocity inside the melt pool. In this case, the melt pool depth becomes the largest as compared to those corresponding to other laser pulse intensity distributions at the irradiated surface.

  17. Investigation of aperiodic W/C multi-layer mirror for X-ray optics

    International Nuclear Information System (INIS)

    Wang Zhanshan; Cheng Xinbin; Zhu Jingtao; Huang Qiushi; Zhang Zhong; Chen Lingyan

    2011-01-01

    Design, fabrication and characterization of aperiodic tungsten/carbon (W/C) multi-layer mirror were studied. W/C multi-layer was designed as a broad-angle reflective supermirror for Cu-Kα line (λ = 0.154 nm) in the grazing incident angular range (0.9-1.1 deg.) using simulated annealing algorithm. To deposit the W/C depth-graded multi-layer mirror accurately, we introduce an effective layer growth rate as a function of layer thickness. This method greatly improves the reflectivity curve compared to the conventional multi-layer mirror prepared with constant growth rate. The deposited multi-layer mirror exhibits an average reflectivity of 19% over the grazing incident angle range of 0.88-1.08 deg. which mainly coincides with the designed value. Furthermore, the physical mechanisms were discussed and the re-sputtering process of light-atom layers is accounted for the modification of layer thicknesses which leads to the effective growth rates. Using this calibration method, the aperiodic multi-layer mirrors can be better fabricated for X-ray optics.

  18. Publication Productivity of Early-Career Orthopedic Trauma Surgeons.

    Science.gov (United States)

    Hake, Mark E; Lee, John J; Goulet, James A

    2016-01-01

    The goals of this study were to: (1) define the publication productivity of early-career orthopedic trauma surgeons over time; (2) compare the early-career publication productivity of recent orthopedic trauma fellowship graduates vs their more senior colleagues; and (3) determine the proportion of fellowship graduates who meet the Orthopaedic Trauma Association (OTA) publication criteria for active membership early in their careers. Orthopedic trauma fellowship graduates from 1982 to 2007 were analyzed. A literature search was performed for each fellow's publications for the 6-year period beginning the year of fellowship graduation. Publication productivity was compared between early and recent groups of graduates, 1987 to 1991 and 2003 to 2007, respectively. Fulfillment of OTA publication criteria was determined. Seventy-nine percent of graduates contributed to 1 or more publications. The recent group produced more total publications per graduate (4.06 vs 3.29, P=.01) and more coauthor publications (2.60 vs 2.04, P=.019) than the early group. The number of first-author publications did not differ between groups (1.46 vs 1.25, P=.26). A greater percentage of the recent group met current OTA publication criteria compared with the early group (51% vs 35%, P=.04). The findings showed that recent orthopedic trauma graduates had increased publication productivity compared with their more senior colleagues, although a proportion had not qualified for active OTA membership 6 years into their career. Overall, these data are encouraging and suggest that young orthopedic trauma surgeons remain committed to sustaining a high level of academic excellence. Copyright 2016, SLACK Incorporated.

  19. Administration of antibiotic agents before intraoperative sampling in orthopedic infections alters culture results.

    Science.gov (United States)

    Al-Mayahi, Mohamed; Cian, Anais; Lipsky, Benjamin A; Suvà, Domizio; Müller, Camillo; Landelle, Caroline; Miozzari, Hermès H; Uçkay, Ilker

    2015-11-01

    Many physicians and surgeons think that prescribing antibiotics before intraoperative sampling does not alter the microbiological results. Case-control study of adult patients hospitalized with orthopedic infections. Among 2740 episodes of orthopedic infections, 1167 (43%) had received antibiotic therapy before surgical sampling. Among these, 220 (19%) grew no pathogens while the proportion of culture-negative results in the 2573 who had no preoperative antibiotic therapy was only 6%. By multivariate analyses, pre-operative antibiotic exposure was associated with significantly more culture-negative results (odds ratio 2.8, 95% confidence interval 2.1-3.7), more non-fermenting rods and skin commensals (odds ratio 2.8 and 3.0, respectively). Even a single pre-operative dose of antibiotic was significantly associated with subsequent culture-negative results (19/93 vs. 297/2350; χ²-test, p = 0.01) and skin commensals (17/74 vs. 274/2350; p = 0.01) compared to episodes without preceding prophylaxis. Prior antibiotic use, including single-dose prophylactic administrations, is three-fold associated with culture-negative results, non-fermenting rods and resistant skin commensals. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  20. Validation of HVOF WC/Co Thermal Spray Coatings as a Replacement for Hard Chrome Plating on Aircraft Landing Gear

    National Research Council Canada - National Science Library

    Sartwell, Bruce

    2004-01-01

    .... This document constitutes the final report on a project to quality high-velocity oxygen-fuel (HVOF) thermal spray WC/Co coatings as a replacement for hard chrome plating on landing gear components...

  1. Wear Evaluation of AISI 4140 Alloy Steel with WC/C Lamellar Coatings Sliding Against EN 8 Using Taguchi Method

    Science.gov (United States)

    Kadam, Nikhil Rajendra; Karthikeyan, Ganesarethinam

    2016-10-01

    The purpose of the experiments in this paper is to use the Taguchi methods to investigate the wear of WC/C coated nitrided AISI 4140 alloy steel. A study of lamellar WC/C coating which were deposited by a physical vapor deposition on nitrided AISI 4140 alloy steel. The investigation includes wear evaluation using Pin-on-disk configuration. When WC/C coated AISI 4140 alloy steel slides against EN 8 steel, it was found that carbon-rich coatings show much lower wear of the countersurface than nitrogen-rich coatings. The results were correlated with the properties determined from tribological and mechanical characterization, therefore by probably selecting the proper processing parameters the deposition of WC/C coating results in decreasing the wear rate of the substrate which shows a potential for tribological application.

  2. THE PORTION OF AUTOLOGOUS BLOOD IN ORTHOPEDIC DEPARTMENT OF GENERAL HOSPITAL NOVA GORICA IN FIVE YEARS PERIOD (1996–2000

    Directory of Open Access Journals (Sweden)

    Janka Černe-Zavadlav

    2002-04-01

    Full Text Available Background. The presentation of autologous blood donation with analysis of used blood and the percentage of autologous blood on Orthopedic Department in the years 1996–2000.Methods. From card-index of autologous blood donors we analysed 363 preoperative autologous blood donations.We followed the number of doses in one patient and type of operating procedure.We analysed the usage of blood from transfusion issue protocols and the usage of postoperative autotransfusion from patient protocols.Results. 91% of all preoperative blood donations in our hospital in five years period were from Orthopedic Department. There were 280 operating procedures (hip and knee arthroplasty that needed blood transfusion. 196 of these (70% were included in preoperative blood donation programme. We collected 330 doses: 1 dose in 61 cases, 2 doses in 100, 3 doses in 34 and 4 doses in 1 case or 1.68 doses per patient. The relationship between used autologous and allogenic blood were 46 : 54 (doses or 38 : 62 (mL. Autologous blood represented 38% of all used blood on Orthopedic Department, only 11% of autologous blood were discarded.Conclusions. The program of preoperative blood donation is well organized on The Orthopedic Department of our Hospital. To our experience we make the most of profit of autotransfusion (to avoid risks of allogenic blood, optimal patient colaboration, low percentage of discarded blood with two predonated doses in combination with postoperative autotransfusion. Regard to The Law of Blood supply (may 2000 we are going to introduce this protocol of preoperative blood donation for all programed operating procedures in our Hospital, which need blood transfusion.

  3. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia

    International Nuclear Information System (INIS)

    Sierra C, B. Y.; Jimenez, Y.; Plazas, M. C.; Eslava S, J.; Groot R, H.

    2014-08-01

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  4. Mechanical Properties and Wear Behavior of AA5182/WC Nanocomposite Fabricated by Friction Stir Welding at Different Tool Traverse Speeds

    Science.gov (United States)

    Paidar, Moslem; Asgari, Ali; Ojo, Olatunji Oladimeji; Saberi, Abbas

    2018-03-01

    Grain growth inhibition at the heat-affected zone, improved weld strength and superior tribological properties of welds are desirable attributes of modern manufacturing. With the focused on these attributes, tungsten carbide (WC) nanoparticles were employed as reinforcements for the friction stir welding of 5-mm-thick AA5182 aluminum alloy by varying tool traverse speeds. The microstructure, microhardness, ultimate tensile strength, fracture and wear behavior of the resultant WC-reinforced welds were investigated, while unreinforced AA5182 welds were employed as controls for the study. The result shows that the addition of WC nanoparticles causes substantial grain refinement within the weld nugget. A decrease in traverse speed caused additional particle fragmentation, improved hardness value and enhanced weld strength in the reinforced welds. Improved wear rate and friction coefficient of welds were attained at a reduced traverse speed of 100 mm/min in the WC-reinforced welds. This improvement is attributed to the effects of reduced grain size/grain fragmentation and homogeneous dispersion of WC nanoparticles within the WC-reinforced weld nugget.

  5. Recent advances in standing equine orthopedic surgery.

    Science.gov (United States)

    O'Brien, Thomas; Hunt, Robert J

    2014-04-01

    In all surgeries with the patient standing under chemical and physical restraint, patient compliance is of the utmost importance. All fractures of the third metacarpal or metatarsal condyles and sagittal fracture of the first phalanx are not amenable to internal fixation with the horse standing, and young unhandled horses may not have a suitable disposition for standing surgical treatment of septic pedal osteitis, or implantation and removal of transphyseal screws. Previous operator experience in performing the procedure or technique under general anesthesia is beneficial. Appreciation of appropriate topographic anatomic landmarks is important, and intraoperative radiographic control is useful. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. On-the-fly augmented reality for orthopedic surgery using a multimodal fiducial.

    Science.gov (United States)

    Andress, Sebastian; Johnson, Alex; Unberath, Mathias; Winkler, Alexander Felix; Yu, Kevin; Fotouhi, Javad; Weidert, Simon; Osgood, Greg; Navab, Nassir

    2018-04-01

    Fluoroscopic x-ray guidance is a cornerstone for percutaneous orthopedic surgical procedures. However, two-dimensional (2-D) observations of the three-dimensional (3-D) anatomy suffer from the effects of projective simplification. Consequently, many x-ray images from various orientations need to be acquired for the surgeon to accurately assess the spatial relations between the patient's anatomy and the surgical tools. We present an on-the-fly surgical support system that provides guidance using augmented reality and can be used in quasiunprepared operating rooms. The proposed system builds upon a multimodality marker and simultaneous localization and mapping technique to cocalibrate an optical see-through head mounted display to a C-arm fluoroscopy system. Then, annotations on the 2-D x-ray images can be rendered as virtual objects in 3-D providing surgical guidance. We quantitatively evaluate the components of the proposed system and, finally, design a feasibility study on a semianthropomorphic phantom. The accuracy of our system was comparable to the traditional image-guided technique while substantially reducing the number of acquired x-ray images as well as procedure time. Our promising results encourage further research on the interaction between virtual and real objects that we believe will directly benefit the proposed method. Further, we would like to explore the capabilities of our on-the-fly augmented reality support system in a larger study directed toward common orthopedic interventions.

  7. Relationship of microstructure to fracture topography in orthopedic alloys

    International Nuclear Information System (INIS)

    Gilbertson, L.N.

    1976-01-01

    Two major alloys used for orthopedic implants are 316L stainless steel and a cast cobalt--chromium--molybdenum alloy similar to Haynes Stellite 21. Another alloy that is just being introduced is Ti--6Al--4V. All three of these alloys are used in different conditions with different microstructures. Standard specimens with typical microstructures encountered in orthopedic applications were loaded to fracture in both overload and fatigue modes. Different rates of loading were also used in some cases. The fracture surfaces of these standard samples were analyzed in the Scanning Electron Microscope. An attempt was made to relate the fracture behavior, as evidenced by the fracture typography, to the microstructure of the alloy as revealed by metallography

  8. Evaluation of Patient Radiation Dose during Orthopedic Surgery

    International Nuclear Information System (INIS)

    Osman, H; Elzaki, A.; Sam, A.K.; Sulieman, A.

    2013-01-01

    The number of orthopedic procedures requiring the use of the fluoroscopic guidance has increased over the recent years. Consequently the patient exposed to un avoidable radiation doses. The aim of the current study was to evaluate patient radiation dose during these procedures.37 patients under went dynamic hip screw (DHS) and dynamic cannulated screw (DCS) were evaluated using calibrated Thermolumincent Dosimeters (TLDs), under carm fluoroscopic machines ,in three centers in Khartoum-Sudan. The mean Entrance Skin Dose (ESD) was 7.9 m Gy per procedure. The bone marrow and gonad organ exposed to significant doses. No correlation was found between ESD and Body Mass Index (BMI), or patient weight. Well correlation was found between kilo voltage applied and ESD. Orthopedic surgeries delivered lower radiation dose to patients than cardiac catheterization or hysterosalpingraphy (HSG) procedures. More study should be implemented to follow radiation dose before surgery and after surgery

  9. Web-Based Patient Education in Orthopedics: Systematic Review.

    Science.gov (United States)

    Dekkers, Tessa; Melles, Marijke; Groeneveld, Bob Sander; de Ridder, Huib

    2018-04-23

    Patients with orthopedic conditions frequently use the internet to find health information. Patient education that is distributed online may form an easily accessible, time- and cost-effective alternative to education delivered through traditional channels such as one-on-one consultations or booklets. However, no systematic evidence for the comparative effectiveness of Web-based educational interventions exists. The objective of this systematic review was to examine the effects of Web-based patient education interventions for adult orthopedic patients and to compare its effectiveness with generic health information websites and traditional forms of patient education. CINAHL, the Cochrane Library, EMBASE, MEDLINE, PsycINFO, PUBMED, ScienceDirect, Scopus, and Web of Science were searched covering the period from 1995 to 2016. Peer-reviewed English and Dutch studies were included if they delivered patient education via the internet to the adult orthopedic population and assessed its effects in a controlled or observational trial. A total of 10 trials reported in 14 studies involving 4172 patients were identified. Nine trials provided evidence for increased patients' knowledge after Web-based patient education. Seven trials reported increased satisfaction and good evaluations of Web-based patient education. No compelling evidence exists for an effect of Web-based patient education on anxiety, health attitudes and behavior, or clinical outcomes. Web-based patient education may be offered as a time- and cost-effective alternative to current educational interventions when the objective is to improve patients' knowledge and satisfaction. However, these findings may not be representative for the whole orthopedic patient population as most trials included considerably younger, higher-educated, and internet-savvy participants only. ©Tessa Dekkers, Marijke Melles, Bob Sander Groeneveld, Huib de Ridder. Originally published in the Journal of Medical Internet Research (http

  10. Web-Based Patient Education in Orthopedics: Systematic Review

    Science.gov (United States)

    Melles, Marijke; Groeneveld, Bob Sander; de Ridder, Huib

    2018-01-01

    Background Patients with orthopedic conditions frequently use the internet to find health information. Patient education that is distributed online may form an easily accessible, time- and cost-effective alternative to education delivered through traditional channels such as one-on-one consultations or booklets. However, no systematic evidence for the comparative effectiveness of Web-based educational interventions exists. Objective The objective of this systematic review was to examine the effects of Web-based patient education interventions for adult orthopedic patients and to compare its effectiveness with generic health information websites and traditional forms of patient education. Methods CINAHL, the Cochrane Library, EMBASE, MEDLINE, PsycINFO, PUBMED, ScienceDirect, Scopus, and Web of Science were searched covering the period from 1995 to 2016. Peer-reviewed English and Dutch studies were included if they delivered patient education via the internet to the adult orthopedic population and assessed its effects in a controlled or observational trial. Results A total of 10 trials reported in 14 studies involving 4172 patients were identified. Nine trials provided evidence for increased patients’ knowledge after Web-based patient education. Seven trials reported increased satisfaction and good evaluations of Web-based patient education. No compelling evidence exists for an effect of Web-based patient education on anxiety, health attitudes and behavior, or clinical outcomes. Conclusions Web-based patient education may be offered as a time- and cost-effective alternative to current educational interventions when the objective is to improve patients’ knowledge and satisfaction. However, these findings may not be representative for the whole orthopedic patient population as most trials included considerably younger, higher-educated, and internet-savvy participants only. PMID:29685869

  11. Medication Review and Patient Outcomes in an Orthopedic Department

    DEFF Research Database (Denmark)

    Lisby, Marianne; Bonnerup, Dorthe Krogsgaard; Brock, Birgitte

    2015-01-01

    OBJECTIVE: We investigated the health-related effect of systematic medication review performed by a clinical pharmacist and a clinical pharmacologist on nonelective elderly orthopedic patients. METHODS: This is a nonblinded randomized controlled study of 108 patients 65 years or older treated...... with at least 4 drugs. For the intervention, the clinical pharmacist reviewed the participants' medication after completion of the usual medication routine. Information was collected from medical charts, interviews with participants, and database registrations of drug purchase. Results were conferred...

  12. Serious Leisure and People with Orthopedic Impairment: Benefits and Constraints

    OpenAIRE

    Manolya AKSATAN; Zehra Gökçe SEL

    2017-01-01

    There are many people around the world who have different types of disabilities. Understanding their needs is the first step of developing policies to increase their quality of life and satisfaction. Leisure is an essential need of disabled people and it plays an important role in disabled people’s lives. The purpose of this study is to gain a deep understanding on the serious leisure activities of people with orthopedic impairment, and also both benefits and constraints ...

  13. Lamellipodia and Membrane Blebs Drive Efficient Electrotactic Migration of Rat Walker Carcinosarcoma Cells WC 256

    Science.gov (United States)

    Sroka, Jolanta; Krecioch, Izabela; Zimolag, Eliza; Lasota, Slawomir; Rak, Monika; Kedracka-Krok, Sylwia; Borowicz, Pawel; Gajek, Marta; Madeja, Zbigniew

    2016-01-01

    The endogenous electric field (EF) may provide an important signal for directional cell migration during wound healing, embryonic development and cancer metastasis but the mechanism of cell electrotaxis is poorly understood. Additionally, there is no research addressing the question on the difference in electrotactic motility of cells representing various strategies of cell movement—specifically blebbing vs. lamellipodial migration. In the current study we constructed a unique experimental model which allowed for the investigation of electrotactic movement of cells of the same origin but representing different modes of cell migration: weakly adherent, spontaneously blebbing (BC) and lamellipodia forming (LC) WC256 cells. We report that both BC and LC sublines show robust cathodal migration in a physiological EF (1–3 V/cm). The directionality of cell movement was completely reversible upon reversing the field polarity. However, the full reversal of cell direction after the change of EF polarity was much faster in the case of BC (10 minutes) than LC cells (30 minutes). We also investigated the distinct requirements for Rac, Cdc42 and Rho pathways and intracellular Ca2+ in electrotaxis of WC256 sublines forming different types of cell protrusions. It was found that Rac1 is required for directional movement of LC to a much greater extent than for BC, but Cdc42 and RhoA are more crucial for BC than for LC cells. The inhibition of ROCK did not affect electrotaxis of LC in contrast to BC cells. The results also showed that intracellular Ca2+ is essential only for the electrotactic reaction of BC cells. Moreover, inhibition of MLCK and myosin II did not affect the electrotaxis of LC in contrast to BC cells. In conclusion, our results revealed that both lamellipodia and membrane blebs can efficiently drive electrotactic migration of WC 256 carcinosarcoma cells, however directional migration is mediated by different signalling pathways. PMID:26863616

  14. WC-Co coatings deposited by the electro-thermal chemical spray method

    Energy Technology Data Exchange (ETDEWEB)

    Zhitomirsky, V.N. [Tel Aviv Univ. (Israel). Faculty of Engineering; Wald, S.; Rabani, L.; Zoler, D. [Propulsion Physics Division, SOREQ NRC, 81800, Yavne (Israel); Factor, M.; Roman, I. [School of Applied Sciences, The Hebrew University, 91904, Jerusalem (Israel); Cuperman, S.; Bruma, C. [School of Physics and Astronomy, Tel-Aviv University, 69978, Tel-Aviv (Israel)

    2000-10-02

    A novel thermal spray technology - an electro-thermal chemical spray (ETCS) for producing hard coatings is presented. The experimental coating apparatus consists of a machine gun barrel, a cartridge containing the coating material in powder form, a solid propellant, and a plasma ignition system. The plasma ignition system produces plasma in pulsed mode to ignite the solid propellant. On ignition, the drag force exerted by the combustion gases accelerates the powder particles towards the substrate. Using the ETCS technique, the process of single-shot WC-Co coating deposition on stainless steel substrate was studied. The influence of process parameters (plasma energy, mass of the solid propellant and the coated powder, distance between the gun muzzle and the substrate) on the coating structure and some of its properties were investigated. It was shown that ECTS technique effectively deposited the WC-Co coating with deposition thicknesses of 100-200 {mu}m per shot, while deposition yield of {proportional_to}70% was attained. The WC-Co coatings consisted of carbide particles distributed in amorphous matrix. The powder particle velocity was found to depend on the solid propellant mass and was weakly dependent on the plasma energy, while the particle processing temperature was strongly dependent on the plasma energy and almost independent of the solid propellant mass. Whilst increasing the solid propellant mass from 5 to 7 g, the deposition rate and yield correspondingly increased. When increasing the plasma energy, the temperature of the powder particles increased, the average carbide particle size decreased and their shape became more rounded. The deposition yield and microhardness at first increased and then achieved saturation by increasing the plasma energy. (orig.)

  15. Abnormal growth of faceted (WC) grains in a (Co) liquid matrix

    International Nuclear Information System (INIS)

    Park, Y.J.; Yoon, D.Y.

    1996-01-01

    If the grains dispersed in a liquid matrix are spherical, their surface atomic structure is expected to be rough (diffuse), and their coarsening has been observed to be controlled by diffusion in the matrix. They do not, furthermore, undergo abnormal growth. On the other hand, in some compound material systems, the grains in liquid matrices are faceted and often show abnormal coarsening behavior. Their faceted surface planes are expected to be singular (atomically flat) and therefore grow by a defect-assisted process and two-dimensional (2-D) nucleation. Contrary to the usual coarsening theories, their growth velocity is not linearly dependent on the driving force arising from the grain size difference. If the growth of the faceted grains occurs by 2-D nucleation, the rate is expected to increase abruptly at a critical supersaturation, as has been observed in crystal growth in melts and solutions. It is proposed that this growth mechanism leads to the abnormal grain coarsening. The 2-D nucleation theory predicts that there is a threshold initial grain size for the abnormal grain growth (AGG), and the propensity for AGG will increase with the heat-treatment temperature. The AGG behavior will also vary with the defects in the grains. These predictions are qualitatively confirmed in the sintered WC-Co alloy prepared from fine (0.85-microm) and coarse (5.48-microm) WC powders and their mixtures. The observed dependence of the AGG behavior on the sintering temperature and the milling of the WC powder is also qualitatively consistent with the predicted behavior

  16. Lamellipodia and Membrane Blebs Drive Efficient Electrotactic Migration of Rat Walker Carcinosarcoma Cells WC 256.

    Directory of Open Access Journals (Sweden)

    Jolanta Sroka

    Full Text Available The endogenous electric field (EF may provide an important signal for directional cell migration during wound healing, embryonic development and cancer metastasis but the mechanism of cell electrotaxis is poorly understood. Additionally, there is no research addressing the question on the difference in electrotactic motility of cells representing various strategies of cell movement-specifically blebbing vs. lamellipodial migration. In the current study we constructed a unique experimental model which allowed for the investigation of electrotactic movement of cells of the same origin but representing different modes of cell migration: weakly adherent, spontaneously blebbing (BC and lamellipodia forming (LC WC256 cells. We report that both BC and LC sublines show robust cathodal migration in a physiological EF (1-3 V/cm. The directionality of cell movement was completely reversible upon reversing the field polarity. However, the full reversal of cell direction after the change of EF polarity was much faster in the case of BC (10 minutes than LC cells (30 minutes. We also investigated the distinct requirements for Rac, Cdc42 and Rho pathways and intracellular Ca2+ in electrotaxis of WC256 sublines forming different types of cell protrusions. It was found that Rac1 is required for directional movement of LC to a much greater extent than for BC, but Cdc42 and RhoA are more crucial for BC than for LC cells. The inhibition of ROCK did not affect electrotaxis of LC in contrast to BC cells. The results also showed that intracellular Ca2+ is essential only for the electrotactic reaction of BC cells. Moreover, inhibition of MLCK and myosin II did not affect the electrotaxis of LC in contrast to BC cells. In conclusion, our results revealed that both lamellipodia and membrane blebs can efficiently drive electrotactic migration of WC 256 carcinosarcoma cells, however directional migration is mediated by different signalling pathways.

  17. Lamellipodia and Membrane Blebs Drive Efficient Electrotactic Migration of Rat Walker Carcinosarcoma Cells WC 256.

    Science.gov (United States)

    Sroka, Jolanta; Krecioch, Izabela; Zimolag, Eliza; Lasota, Slawomir; Rak, Monika; Kedracka-Krok, Sylwia; Borowicz, Pawel; Gajek, Marta; Madeja, Zbigniew

    2016-01-01

    The endogenous electric field (EF) may provide an important signal for directional cell migration during wound healing, embryonic development and cancer metastasis but the mechanism of cell electrotaxis is poorly understood. Additionally, there is no research addressing the question on the difference in electrotactic motility of cells representing various strategies of cell movement-specifically blebbing vs. lamellipodial migration. In the current study we constructed a unique experimental model which allowed for the investigation of electrotactic movement of cells of the same origin but representing different modes of cell migration: weakly adherent, spontaneously blebbing (BC) and lamellipodia forming (LC) WC256 cells. We report that both BC and LC sublines show robust cathodal migration in a physiological EF (1-3 V/cm). The directionality of cell movement was completely reversible upon reversing the field polarity. However, the full reversal of cell direction after the change of EF polarity was much faster in the case of BC (10 minutes) than LC cells (30 minutes). We also investigated the distinct requirements for Rac, Cdc42 and Rho pathways and intracellular Ca2+ in electrotaxis of WC256 sublines forming different types of cell protrusions. It was found that Rac1 is required for directional movement of LC to a much greater extent than for BC, but Cdc42 and RhoA are more crucial for BC than for LC cells. The inhibition of ROCK did not affect electrotaxis of LC in contrast to BC cells. The results also showed that intracellular Ca2+ is essential only for the electrotactic reaction of BC cells. Moreover, inhibition of MLCK and myosin II did not affect the electrotaxis of LC in contrast to BC cells. In conclusion, our results revealed that both lamellipodia and membrane blebs can efficiently drive electrotactic migration of WC 256 carcinosarcoma cells, however directional migration is mediated by different signalling pathways.

  18. Postoperative constipation risk assessment in Turkish orthopedic patients.

    Science.gov (United States)

    Şendir, Merdiye; Büyükıylmaz, Funda; Aştı, Türkinaz; Gürpınar, Şengül; Yazgan, İlknur

    2012-01-01

    This descriptive, correlational study was conducted to describe constipation risk assessment and the affecting factors of constipation risk of patients who have undergone major orthopedic surgery. Data were collected using a patient information form and the Constipation Risk Assessment Scale (CRAS) on the second postoperative day. Data were analyzed using the SPSS version 11.5 for Windows. The mean age of the 83 patients studied was 53.75 ± 21.29 years. Subjects were hospitalized in the orthopedic wards for 14.39 ± 15.17 days, and their current bowel habit was 2.18 ± 1.80 stools per week. Of the sample, 63.9% were female, 69.9% of the patients had a history of previous surgery, 45.8% had hip/knee arthroplasty surgery, and 55.4% had bowel problems during the hospitalization period. Patients had a medium risk for constipation according to the CRAS subscale (gender, mobility, and pharmacological agents). Total CRAS score was 12.73 ± 4.75 (medium risk) on the second postoperative day. In addition, age, marital status, educational level, having a history of surgery, and bowel elimination problems did have a significant effect on constipation risk. On the basis of the findings from this study, nurses must learn the postoperative constipation risk of orthopedic patients to implement safe and effective interventions.

  19. Questionable Word Choice in Scientific Writing in Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    Casey M. O`Connor

    2017-07-01

    Full Text Available Background: Given the strong influence of thoughts, emotions, and behaviors on musculoskeletal symptoms andlimitations it’s important that both scientific and lay writing use the most positive, hopeful, and adaptive words andconcepts consistent with medical evidence. The use of words that might reinforce misconceptions about preferencesensitiveconditions (particularly those associated with age could increase symptoms and limitations and might alsodistract patients from the treatment preferences they would select when informed and at ease.Methods: We reviewed 100 consecutive papers published in 2014 and 2015 in 6 orthopedic surgery scientific journals.We counted the number and proportion of journal articles with questionable use of one or more of the following words:tear, aggressive, required, and fail. For each word, we counted the rate of misuse per journal and the number of specificterms misused per article per journalResults: Eighty percent of all orthopedic scientific articles reviewed had questionable use of at least one term. Tearwas most questionably used with respect to rotator cuff pathology. The words fail and require were the most commonquestionably used terms overall.Conclusion: The use of questionable words and concepts is common in scientific writing in orthopedic surgery. It’sworth considering whether traditional ways or referring to musculoskeletal illness merit rephrasing.

  20. Comparing consensus guidelines on thromboprophylaxis in orthopedic surgery.

    Science.gov (United States)

    Struijk-Mulder, M C; Ettema, H B; Verheyen, C C; Büller, H R

    2010-04-01

    Different guidelines exist regarding the prevention of venous thromboembolism (VTE) in orthopedic surgery. We aimed to compare (inter)national guidelines and analyse differences. MEDLINE, the Cochrane Library and the internet were searched for guidelines on the prevention of VTE in orthopedic surgery. From these, we constructed a table comparing the different antithrombotic regimens during different orthopedic surgical and plaster cast treatments. Eleven guidelines from nine different countries and one international guideline were included. Few guidelines advise on thrombosis prophylaxis after plaster cast immobilization, (prolonged) arthroscopic surgery and isolated lower extremity trauma. Different opinions exist on the sole use of aspirin and mechanical prophylaxis and on the use of vitamin K antagonists after major hip and knee surgery. Based on the same available literature, different guidelines recommend different thromboprophylactic regimens. Ideally, the grade of recommendation should be based on the same level of evidence world-wide. Whilst there is no agreement on the relevance of different endpoints (e.g. asymptomatic DVT), it is very difficult to reach a consensus. Thromboprophylaxis guidelines should be reviewed and updated on a regular basis, because the evidence is evolving rapidly.

  1. Use of Google Scholar public profiles in orthopedics.

    Science.gov (United States)

    Tetsworth, Kevin; Fraser, Dave; Glatt, Vaida; Hohmann, Erik

    2017-01-01

    The purpose of this study was to survey the growth of Google Scholar public profiles in orthopedics over a 12-month period and to investigate global patterns. Data was prospectively acquired from June 2013 to June 2014. Google Scholar queries specific to orthopedic surgery were performed at 90-day intervals. Demographic aspects of each user were also compiled, including gender, current location, and primary interests. To determine differences between the growth of Google Scholar public profile registrations and citation counts, as well as differences in growth in different regions, repeated measures of analysis of variance (RMANOVA) were used. RMANOVA revealed statistically significant differences ( p = 0.0001) for regional growth. The largest growth was observed in the United Kingdom ( p = 0.009, 289%), followed by the Asia-Pacific region ( p = 0.004, 177%) and "Other" ( p = 0.006, 172%). The mean growth per 90-day interval is 19.9% ( p = 0.003) and the mean 12-month growth is 107% ( p = 0.05). Statistically significant differences between gender (male vs. female) and basic and clinical sciences ( χ 2 = 22.4, p = 0.0001) were observed. This study suggests an exponential growth in the number of authors in the field of orthopedic surgery creating a Google Scholar public profile, and at the current rate participation doubles every 10.6 months.

  2. Wear evaluation of WC inserts coated with TiN/TiAlN multinanolayers

    OpenAIRE

    Moreno, L. H.; Ciacedo, J. C.; Martinez, F.; Bejarano, G.; Battaille, T. S.; Prieto, P.

    2010-01-01

    TiN/TiAlN multilayers were deposited by radio frequency, r.f., reactive magnetron sputtering by using titanium and aluminum targets with 10 cm diameter and 99.99% purity in an argon/nitrogen atmosphere, applying a substrate temperature of 300 ºC. WC inserts were used as substrates to improve the mechanical and tribological properties of TiN/TiAlN multilayered coatings compared to other types of coatings like TiAlN monolayers and to manage greater efficiency of these coatings in different indu...

  3. The functionally graded sintered steel WC-Co-NbC matrix

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.A.A.; Silva Junior, J.F. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil)

    2009-07-01

    Full text: The high speed steels are used for machining, including cutting tools at high speeds because their wear resistance, high temperature properties and excellent hardness. They are ferrous based alloys of the Fe-C-X component system where X represents a group of elements comprising Cr, W or Mo, V and Co. The aim of this work was to study the feasibility of powder metallurgy technique to develop functionally graded alloy material added by WC, Co and NbC. The morphology of the composite powders and sintered MMC were characterized by scanning electron microscopy and XRD measurements. (author)

  4. Production and mechanical properties of sintered carbides (hard steels WC-Co)

    International Nuclear Information System (INIS)

    Batalha, G.F.

    1987-09-01

    Densification and mechanical characteristics or WC-Co Cemented Carbides, were investigated by dilatometry, Hardness and bending tests, as a function of the two principal micro-structural parameters: the cobalt content and the particle size of carbide crystals. Vickers hardness of the studied compositions showed a linear variation with the increase of the cobalt content. By three point bending, the transverse rupture strenght increases with cobalt content, however, for larger grain size reaches a maximum, eventually reduced by brittle phases and incomplete dispersion. The results of brittle facture tests were statistically analised and fitted better to the 'Weakest Link Model' (Weibull distribution) than the 'Chain Model' (Gaussian distribution). (author) [pt

  5. Microestructura y propiedades mecánicas de carburos cementados de wc-nbc-co

    OpenAIRE

    Centeno, Oscarly; Sáez, Adolfredo; Piñero, María A; Castro, Gustavo; Barrios, Estebán; Arenas, Freddy J

    2008-01-01

    Se evaluó la densificación, fases constituyentes y cambios microestructurales, dureza y tenacidad de una serie de sólidos de WC-NbC-10%Co, con porcentajes nominales en peso de NbC variable entre 0 y 20%. Los sólidos estudiados fueron manufacturados mediante técnicas convencionales de pulvimetalurgia. La caracterización microestructural de los compactos sinterizados fue realizada utilizando Difracción de Rayos X (DRX), Microscopia Electrónica de Barrido (MEB) y Análisis Químico de Rayos X por ...

  6. Influence of electrical discharge machining on the tribological characteristics of WC-Co alloys

    International Nuclear Information System (INIS)

    Casas, B.; Martinez, E.; Esteve, J.; Anglada, M.; Llanes, L.

    2001-01-01

    The influence of electrical discharge machining (EDM) on the abrasive wear resistance of two WC-10 % w tCo cemented carbides with different carbide grain size has been studied. Different surface finish conditions were evaluated corresponding to sequential EDM as well as grinding and polishing with diamond. The abrasive wear resistance was determined through microscratch measurements using a nano indentation system. Contrary to the results obtained from hardness measurements, this techniques allows to discern tribological differences among the distinct surface finish conditions studied. Finally, the abrasive wear resistance degradation associated with sequential EDM is discussed as a function of microstructure in terms of a damage parameters. (Author) 9 refs

  7. Cross-linked PEEK-WC proton exchange membrane for fuel cell

    CSIR Research Space (South Africa)

    Lou, H

    2009-10-01

    Full Text Available was added to the 15 wt% of SsPEEK-WC solution in NMP with magnetic stir. The solution was cast on a glass Petri dish. The solvent was then removed in a vacuum oven at 130 °C. The membrane was peeled off from the Petri dish. Thereafter, the membrane... and polyetherketone for fuel cell applications. Journal of Membrane Science, 2001. 185(1): p. 41-58. [6] Kerres, J.A., Development of ionomer membranes for fuel cells. Journal of Membrane Science, 2001. 185(1): p. 3-27. [7] Basile, A.; Paturzo, L.; Iulianelli, A...

  8. Value and clinical application of orthopedic metal artifact reduction algorithm in CT scans after orthopedic metal implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yi; Pan, Shinong; Zhao, Xudong; Guo, Wenli; He, Ming; Guo, Qiyong [Shengjing Hospital of China Medical University, Shenyang (China)

    2017-06-15

    To evaluate orthopedic metal artifact reduction algorithm (O-MAR) in CT orthopedic metal artifact reduction at different tube voltages, identify an appropriate low tube voltage for clinical practice, and investigate its clinical application. The institutional ethical committee approved all the animal procedures. A stainless-steel plate and four screws were implanted into the femurs of three Japanese white rabbits. Preoperative CT was performed at 120 kVp without O-MAR reconstruction, and postoperative CT was performed at 80–140 kVp with O-MAR. Muscular CT attenuation, artifact index (AI) and signal-to-noise ratio (SNR) were compared between preoperative and postoperative images (unpaired t test), between paired O-MAR and non-O-MAR images (paired Student t test) and among different kVp settings (repeated measures ANOVA). Artifacts' severity, muscular homogeneity, visibility of inter-muscular space and definition of bony structures were subjectively evaluated and compared (Wilcoxon rank-sum test). In the clinical study, 20 patients undertook CT scan at low kVp with O-MAR with informed consent. The diagnostic satisfaction of clinical images was subjectively assessed. Animal experiments showed that the use of O-MAR resulted in accurate CT attenuation, lower AI, better SNR, and higher subjective scores (p < 0.010) at all tube voltages. O-MAR images at 100 kVp had almost the same AI and SNR as non-O-MAR images at 140 kVp. All O-MAR images were scored ≥ 3. In addition, 95% of clinical CT images performed at 100 kVp were considered satisfactory. O-MAR can effectively reduce orthopedic metal artifacts at different tube voltages, and facilitates low-tube-voltage CT for patients with orthopedic metal implants.

  9. Value and clinical application of orthopedic metal artifact reduction algorithm in CT scans after orthopedic metal implantation

    International Nuclear Information System (INIS)

    Hu, Yi; Pan, Shinong; Zhao, Xudong; Guo, Wenli; He, Ming; Guo, Qiyong

    2017-01-01

    To evaluate orthopedic metal artifact reduction algorithm (O-MAR) in CT orthopedic metal artifact reduction at different tube voltages, identify an appropriate low tube voltage for clinical practice, and investigate its clinical application. The institutional ethical committee approved all the animal procedures. A stainless-steel plate and four screws were implanted into the femurs of three Japanese white rabbits. Preoperative CT was performed at 120 kVp without O-MAR reconstruction, and postoperative CT was performed at 80–140 kVp with O-MAR. Muscular CT attenuation, artifact index (AI) and signal-to-noise ratio (SNR) were compared between preoperative and postoperative images (unpaired t test), between paired O-MAR and non-O-MAR images (paired Student t test) and among different kVp settings (repeated measures ANOVA). Artifacts' severity, muscular homogeneity, visibility of inter-muscular space and definition of bony structures were subjectively evaluated and compared (Wilcoxon rank-sum test). In the clinical study, 20 patients undertook CT scan at low kVp with O-MAR with informed consent. The diagnostic satisfaction of clinical images was subjectively assessed. Animal experiments showed that the use of O-MAR resulted in accurate CT attenuation, lower AI, better SNR, and higher subjective scores (p < 0.010) at all tube voltages. O-MAR images at 100 kVp had almost the same AI and SNR as non-O-MAR images at 140 kVp. All O-MAR images were scored ≥ 3. In addition, 95% of clinical CT images performed at 100 kVp were considered satisfactory. O-MAR can effectively reduce orthopedic metal artifacts at different tube voltages, and facilitates low-tube-voltage CT for patients with orthopedic metal implants

  10. Testing the feasibility and safety of the Nintendo Wii gaming console in orthopedic rehabilitation: a pilot randomized controlled study.

    Science.gov (United States)

    Ficklscherer, Andreas; Stapf, Jonas; Meissner, Kay Michael; Niethammer, Thomas; Lahner, Matthias; Wagenhäuser, Markus; Müller, Peter E; Pietschmann, Matthias F

    2016-12-01

    The Nintendo Wii game console is already used as an additional training device for e.g. neurological wards. Still there are limited data available regarding orthopedic rehabilitation. The authors' objective was to examine whether the Nintendo Wii is an appropriate and safe tool in rehabilitation after orthopedic knee surgery. A prospective, randomized, controlled study comparing standard physiotherapy vs. standard physiotherapy plus game console training (Wii group) in patients having anterior cruciate ligament (ACL) repair or knee arthroplasty was conducted. The subjects of the Wii group ( n = 17; mean age: 54 ±19 years) performed simple knee exercises daily under the supervision of a physiotherapist in addition to the normal rehabilitation program. The patients of the control group ( n = 13; 52 ±18 years) were treated with physiotherapy only. The participants of both groups completed a questionnaire including the International Knee Documentation Committee (IKDC) score, the Modified Cincinnati Rating System and the Tegner Lysholm Knee Score prior to the operation, before discharge from hospital and four weeks after treatment. There was no significant difference in the score results between the Wii and the control group ( p > 0.05). We demonstrated that physiotherapy using the Nintendo Wii gaming console after ACL reconstruction and knee arthroplasty does not negatively influence outcome. Because training with the Wii device was highly accepted by patients, we see an opportunity whereby additional training with a gaming console for a longer period of time could lead to even better results, regarding the training motivation and the outcome after orthopedic surgery.

  11. Tribological behavior of Al-WC nano-composites fabricated by ultrasonic cavitation assisted stir-cast method

    Science.gov (United States)

    Pal, Arpan; Poria, Suswagata; Sutradhar, Goutam; Sahoo, Prasanta

    2018-03-01

    In the present study, the effects of WC nano-particles content on the microstructure, hardness, wear, and friction behavior of aluminum matrix composites are investigated. Al-WC nano composites with varying wt% of WC (0, 1, 1.5, and 2) are fabricated using ultrasonic cavitation assisted stir-cast method. The microstructure of the nano-composite samples is analyzed using optical microscopy and scanning electron microscopy. Elemental composition is determined by energy dispersive x-ray analysis. Vicker’s microhardness test is performed in different locations on the composite sample surface with a load of 50 gf and 10s dwell time. Wear and friction of the composites under dry sliding is studied using a pin-on-disk tribotester for varying normal load (10–40 N) and sliding speed (0.1–0.4 m/s). Uniform distribution of nano-WC is observed over composite surface without noticeable clustering. Reinforcement of nano-WC particles improves wear resistance and frictional behavior of the composite. Hardness is seen to increase with increase in wt% of nano-particles. Wear behavior of composites depends on formation of layers over the surface mixed with oxidized debris and counter-face particles. Wear mechanism changes from adhesion to abrasion with increase in wt% of hard nano particles.

  12. Genotoxicity of tungsten carbide-cobalt (WC-Co) nanoparticles in vitro: mechanisms-of-action studies.

    Science.gov (United States)

    Moche, Hélène; Chevalier, Dany; Vezin, Hervé; Claude, Nancy; Lorge, Elisabeth; Nesslany, Fabrice

    2015-02-01

    We showed previously that tungsten carbide-cobalt (WC-Co) nanoparticles (NP) can be used as a nanoparticulate positive control in some in vitro mammalian genotoxicity assays. Here, we investigate the mechanisms of action involved in WC-Co NP genotoxicity in L5178Y mouse lymphoma cells and primary human lymphocytes, in vitro. Data from the micronucleus assay coupled with centromere staining and from the chromosome-aberration assay show the involvement of both clastogenic and aneugenic events. Experiments with the formamidopyrimidine DNA glycosylase (FPG)-modified comet assay showed a slight (non-significant) increase in FPG-sensitive sites in the L5178Y mouse lymphoma cells but not in the human lymphocytes. Electron paramagnetic resonance spin-trapping results showed the presence of hydroxyl radicals (•OH) in WC-Co NP suspensions, with or without cells, but with time-dependent production in the presence of cells. However, a significant difference in •OH production was observed between human lymphocytes from two different donors. Using H2O2, we showed that WC-Co NP can participate in Fenton-like reactions. Thus, •OH might be produced either via intrinsic generation by WC-Co NP or through a Fenton-like reaction in the presence of cells. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Cyclic oxidation behavior of plasma sprayed NiCrAlY/WC-Co/cenosphere coating

    Science.gov (United States)

    Mathapati, Mahantayya; Ramesh M., R.; Doddamani, Mrityunjay

    2018-04-01

    Components working at elevated temperature like boiler tubes of coal and gas fired power generation plants, blades of gas and steam turbines etc. experience degradation owing to oxidation. Oxidation resistance of such components can be increased by developing protective coatings. In the present investigation NiCrAlY-WC-Co/Cenosphere coating is deposited on MDN 321 steel substrate using plasma spray coating. Thermo cyclic oxidation behavior of coating and substrate is studied in static air at 600 °C for 20 cycles. The thermo gravimetric technique is used to approximate the kinetics of oxidation. X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray mapping techniques are used to characterize the oxidized samples. NiCrAlY-WC-Co/Cenosphere coating exhibited lower oxidation rate in comparison to MDN 321 steel substrate. The lower oxidation rate of coating is attributed to formation of Al2O3, Cr2O3, NiO and CoWO4 oxides on the outermost surface.

  14. Arecibo and Goldstone radar images of near-Earth Asteroid (469896) 2005 WC1

    Science.gov (United States)

    Lawrence, Kenneth J.; Benner, Lance A. M.; Brozovic, Marina; Ostro, Steven J.; Jao, Joseph S.; Giorgini, Jon D.; Slade, Martin A.; Jurgens, Raymond F.; Nolan, Michael C.; Howell, Ellen S.; Taylor, Patrick A.

    2018-01-01

    We report radar observations of near-Earth asteroid (469896) 2005 WC1 that were obtained at Arecibo (2380 MHz, 13 cm) and Goldstone (8560 MHz, 3.5 cm) on 2005 December 14-15 during the asteroid's approach within 0.020 au The asteroid was a strong radar target. Delay-Doppler images with resolutions as fine as 15 m/pixel were obtained with 2 samples per baud giving a correlated pixel resolution of 7.5 m. The radar images reveal an angular object with 100 m-scale surface facets, radar-dark regions, and an estimated diameter of 400 ± 50 m. The rotation of the facets in the images gives a rotation period of ∼2.6 h that is consistent with the estimated period of 2.582 h ± 0.002 h from optical lightcurves reported by Miles (private communication). 2005 WC1 has a circular polarization ratio of 1.12 ± 0.05 that is one of the highest values known, suggesting a structurally-complex near-surface at centimeter to decimeter spatial scales. It is the first asteroid known with an extremely high circular polarization ratio, relatively low optical albedo, and high radar albedo.

  15. Stripping methods studies for HVOF WC-10Co-4Cr coating removal

    Science.gov (United States)

    Menini, Richard; Salah, Nihad Ben; Nciri, Rachid

    2004-04-01

    The use of high-velocity oxyfuel (HVOF) cermet coatings is considered to be a valuable and innovative alternative technology to replace Cr(VI) electroplating. Among others, a WC-10Co-4Cr coating is one of the best choices for landing gear components due to its excellent tribology and corrosion properties. The stripping process of such a cermet coating was studied due to its importance for the repair and overhaul of landing gear components. Stripping solutions fulfill the following criteria: keep substrate integrity; exhibit a high strip rate (SR); lead to uniform dissolution; show no galvanic corrosion; and be environmentally friendly. Three different high-strength steel substrates (4340, 300M, and Aermet100) were studied. Five different stripping solutions were selected for the electrochemical study. Only three met the targeted criteria: the meta-nitrobenzane sulfonate-sodium cyanide solution; the Rochelle salt; and a commercial nickel stripper. It was found that the process must be electrolytic, and that ultrasonic agitation is needed to enhance the overall mass transport and removal of WC particles and metallic matrix residues. When choosing the most efficient solution and conditions, the SR was found to be as high as 162 µm h-1, which is a very acceptable SR for productivity sake.

  16. Optimization of Ni-Based WC/Co/Cr Composite Coatings Produced by Multilayer Laser Cladding

    Directory of Open Access Journals (Sweden)

    Andrea Angelastro

    2013-01-01

    Full Text Available As a surface coating technique, laser cladding (LC has been developed for improving wear, corrosion, and fatigue properties of mechanical components. The main advantage of this process is the capability of introducing hard particles such as SiC, TiC, and WC as reinforcements in the metallic matrix such as Ni-based alloy, Co-based alloy, and Fe-based alloy to form ceramic-metal composite coatings, which have very high hardness and good wear resistance. In this paper, Ni-based alloy (Colmonoy 227-F and Tungsten Carbides/Cobalt/Chromium (WC/Co/Cr composite coatings were fabricated by the multilayer laser cladding technique (MLC. An optimization procedure was implemented to obtain the combination of process parameters that minimizes the porosity and produces good adhesion to a stainless steel substrate. The optimization procedure was worked out with a mathematical model that was supported by an experimental analysis, which studied the shape of the clad track generated by melting coaxially fed powders with a laser. Microstructural and microhardness analysis completed the set of test performed on the coatings.

  17. The evaluation of microstructure and mechanical properties of sintered sub-micron WC-Co powders

    International Nuclear Information System (INIS)

    Nor Izan Izura; Mohd Asri Selamat; Noraizham Mohamad Diah; Talib Ria Jaafar

    2007-01-01

    A cemented tungsten carbide (WC-Co) is widely used for a variety of machining, cutting, drilling and other applications. The properties of this tungsten heavy alloy are sensitive to processing and degraded by residual porosity. The sequence of high end powder metallurgy process include mixing, compacting and followed by multi-atmosphere sintering of green compact were analyzed. The sub micron (<1.0 μm) and less than 10.0 μm of WC powders are sintered with a metal binder 6% Co to provide pore-free part. The powder compacts were sintered at temperatures cycle in the range of 1200 degree Celsius-1550 degree Celsius in nitrogen-based sintering atmosphere. To date, however there have been few reported studies in the literature that the best sintering was carried out via liquid phase sintering in vacuum at approximately 1500 degree Celsius. from this study we found that in order to attain high mechanical properties, a fine grain size of powder is necessary. Therefore, the attention of this work is to develop and produce wear resistant component with better properties or comparable to the commercial ones. (author)

  18. Elastic-Plastic Constitutive Equation of WC-Co Cemented Carbides with Anisotropic Damage

    International Nuclear Information System (INIS)

    Hayakawa, Kunio; Nakamura, Tamotsu; Tanaka, Shigekazu

    2007-01-01

    Elastic-plastic constitutive equation of WC-Co cemented carbides with anisotropic damage is proposed to predict a precise service life of cold forging tools. A 2nd rank symmetric tensor damage tensor is introduced in order to express the stress unilaterality; a salient difference in uniaxial behavior between tension and compression. The conventional framework of irreversible thermodynamics is used to derive the constitutive equation. The Gibbs potential is formulated as a function of stress, damage tensor, isotropic hardening variable and kinematic hardening variable. The elastic-damage constitutive equation, conjugate forces of damage, isotropic hardening and kinematic hardening variable is derived from the potential. For the kinematic hardening variable, the superposition of three kinematic hardening laws is employed in order to improve the cyclic behavior of the material. For the evolution equation of the damage tensor, the damage is assumed to progress by fracture of the Co matrix - WC particle interface and by the mechanism of fatigue, i.e. the accumulation of microscopic plastic strain in matrix and particles. By using the constitutive equations, calculation of uniaxial tensile and compressive test is performed and the results are compared with the experimental ones in the literature. Furthermore, finite element analysis on cold forward extrusion was carried out, in which the proposed constitutive equation was employed as die insert material

  19. Eclipses and dust formation by WC9 type Wolf-Rayet stars

    Science.gov (United States)

    Williams, P. M.

    2014-12-01

    Visual photometry of 16 WC8-9 dust-making Wolf-Rayet (WR) stars during 2001-2009 was extracted from the All-Sky Automated Survey All Star Catalogue (ASAS-3) to search for eclipses attributable to extinction by dust formed in clumps in our line of sight. Data for a comparable number of dust-free WC6-9 stars were also examined to help characterize the data set. Frequent eclipses were observed from WR 104, and several from WR 106, extending the 1994-2001 studies by Kato et al., but not supporting their phasing the variations in WR 104 with its `pinwheel' rotation period. Only four other stars showed eclipses, WR 50 (one of the dust-free stars), WR 69, WR 95 and WR 117, and there may have been an eclipse by WR 121, which had shown two eclipses in the past. No dust eclipses were shown by the `historic' eclipsers WR 103 and WR 113. The atmospheric eclipses of the latter were observed but the suggestion by David-Uraz et al. that dust may be partly responsible for these is not supported. Despite its frequent eclipses, there is no evidence in the infrared images of WR 104 for dust made in its eclipses, demonstrating that any dust formed in this process is not a significant contributor to its circumstellar dust cloud and suggesting that the same applies to the other stars showing fewer eclipses.

  20. Effect of surface texturing on friction properties of WC/Co cemented carbide

    International Nuclear Information System (INIS)

    Wu, Ze; Deng, Jianxin; Xing, Youqiang; Cheng, Hongwei; Zhao, Jun

    2012-01-01

    Highlights: ► Tribological properties of surface textured WC/Co cemented carbide were studied. ► Textured surfaces have better performance of antifriction and antiwear. ► Area density of textures has significant effect on tribological performance. -- Abstract: An experimental study was carried out to investigate the tribological properties of different surface textured WC/Co cemented carbide. The influence of applied load, sliding speed and area density of textures on frictional performance of surface textured patterns was investigated by Taguchi method. Results show that the textured surfaces filled with molybdenum disulfide solid lubricants can reduce the average friction coefficient, wear rates of Ti–6Al–4V alloy balls and adhesion of Ti–6Al–4V alloy materials on the worn track of cemented carbide compared with un-textured ones. Variance analysis of the experimental data indicates that the area density of textures plays major contribution of both average friction coefficient and wear rate of Ti–6Al–4V alloy balls. Higher area density of textures is beneficial to improve tribological performance of the cemented carbide samples. Sliding speed seems to have no effect on the tribological performance of textured surfaces within the reliability interval of 90%. Applied load has effect on both average friction coefficient and wear rate of Ti–6Al–4V alloy balls at the reliability interval of 95%.

  1. Study of carbide-forming element interlayers for diamond nucleation and growth on silicon and WC-Co substrates

    International Nuclear Information System (INIS)

    Tang, Y.; Li, Y.S.; Yang, Q.; Hirose, A.

    2010-01-01

    Diamond nucleation and growth on several typical carbide-forming elements (CFE) (Ti, Cr and W) coated Si and WC-Co substrates were studied. The ion beam sputtered CFE interlayers show an amorphous/nanocrystalline microstructure. The diamond formed on the CFE coated substrates shows higher nucleation density and rate and finer grain structure than on uncoated substrates. Consequently, nanocrystalline diamond thin films can be formed on the CFE coated substrates under conventional microcrystalline diamond growth conditions. Among the three tested CFE interlayers, diamond has the highest nucleation density and rate on W layer and the lowest on Ti layer. The diamond nucleation density and rate on CFE coated WC-Co are much higher than those on widely used metal nitride coated WC-Co.

  2. Free energies of formation of WC and WzC and the thermodynamic properties of carbon in solid tungsten

    Science.gov (United States)

    Gupta, D. K.; Seigle, L. L.

    1974-01-01

    The activity of carbon in the two-phase regions - W + WC and W + W2C was obtained from the carbon content of iron rods equilibrated with mixtures of metal plus carbide powders. From this activity data the standard free energies of formation of WC and W2C were calculated. The temperature of the invariant reaction W2C = W + WC was fixed at 1570 + or - 5K. Using available solubility data for C in solid W, the partial molar free energy of C in the dilute solid solution was also calculated. The heat of solution of C in W, and the excess entropy for the interstitial solid solution, were computed, assuming that the carbon atoms reside in the octahedral interstices of bcc W.

  3. Fabrication of hard cermets by in-situ synthesis and infiltration of metal melts into WC powder compacts

    Directory of Open Access Journals (Sweden)

    Guanghua Liu

    2017-12-01

    Full Text Available Hard carbide cermets are prepared by in-situ synthesis and infiltration of metal melts into WC powder compacts. Ni–W and Ni–W–Cr metal melts are in-situ synthesized from thermite reactions and infiltrated into WC powder compacts under high-gravity. During the infiltration, W in the metal melts reacts with WC to form W2C, and more W2C and W are observed at the upper parts of the cermets than the lower parts. The cermets show a maximum hardness of 15.4 GPa, which is higher than most commercial cemented carbides, although they are not fully dense and have a porosity of 15–20%.

  4. Modification of WC-Co Hard Metal by Ion Implantation with Ti+, AI+, N+, C+ and B+

    International Nuclear Information System (INIS)

    Rassoul, El.M.A.; Saleh, Z.A.; Waheed, A.F.; Abdel- Samad, S.M.; EI- Awadi, G.A.

    2010-01-01

    WC/Co hard metal was implanted by Ti + , AI + , N + , C + , and B + ions at a dose of 5x 10 17 ions/cm 2 at different energies ranging from 50 keV to 200 keV. The implanted layers were investigated by means of nano indentation, calotte measurements, SEM, X-ray diffraction XRD, tribometer and EDX. The maximum implanted zone was about 0.13 μm. The hardness of WC-Co was increased by a factor of 140% after its implantation by Ti, AI, and N and increased by a factor of 170 % after implantation by Ti + , AI + , C + , N + and B + ions as compared to the original value. Also friction coefficient of WC/Co was improved after ion implantation.

  5. Properties of hard alloys on the basis of WC-Co with the additives of nanodisperse TiN

    International Nuclear Information System (INIS)

    Ordanyan, S.S.; Andronova, T.E.; Vladimirova, M.A.; Pantelejev, I.B.; Zalite, I.

    2001-01-01

    The addition of nanodisperse titanium nitride (specific surface area of 20 - 30 m 2 /g, medium diameter of grains of 50 - 100 nm) to the starting hard alloy WC-Co in the stage of wet grinding allows to get some advantages: the growth of WC grains is retarded by the nanoparticles of TiN, being as a barrier for the process of secondary crystallization, and the toughness of hard alloy is being increased due to the formation of finely dispersed structure; the exploitation characteristics of cutting instruments are increased due to the volume alloying by means of titanium nitride having a decreased adhesion to the treated metal and decreased coefficient of friction; the formation of diffusion porosity is being eliminated due to the small size of TiN during the unavoidable dissolution of WC in TiN. (author)

  6. Direct laser metal deposition of WC/Co/Cr powder by means of the functionally graded materials strategy

    Science.gov (United States)

    Angelastro, A.; Campanelli, S. L.

    2017-12-01

    One of the many applications of direct laser metal deposition (DLMD) is the realization of multilayer thick coatings having particular mechanical characteristics, such as high hardness. The objective of this work was to obtain a thick, very hard and wear resistant coating, containing a high percentage of tungsten carbide (WC), on an AISI 304 stainless steel substrate. In order to achieve this result, a tungsten carbide-cobalt-chrome (WC/Co/Cr) powder was processed by the DLMD method. WC/Co/Cr is a composite widely used as a wear-resistant material for cutting tools, molds, coatings and other severe applications. Because of its high hardness, poor ductility and low thermal expansion coefficient, depositing this material directly on the stainless steel substrate is very difficult. In order to overcome this problem, the strategy of functionally graded materials (FGM) was used. Colmonoy 227-F nickel alloy was chosen for this purpose in order to generate a mixture with the WC/Co/Cr powder. Four different materials were deposited, layer by layer, by mixing Colmonoy 227-F with an increasing amount of WC/Co/Cr powders, until obtaining a thick surface coating with a maximum amount of WC of 77.4 wt%. For each powder mixture, a mathematical model was applied to calculate optimal values of translation speed and overlap percentages. A metallographic examination was performed in order to detect macro- and micro-structures of the different materials. Finally, Vickers micro-hardness was measured at various locations along the transverse section to appreciate the gradual increase of the FGM hardness, starting from the substrate and culminating at the top surface of the last deposited material.

  7. Catalytic activity of tungsten carbide-carbon (WC@C) core-shell structured for ethanol electro-oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Gourav, E-mail: gsinghla@gmail.com; Singh, K., E-mail: kusingh@thapar.edu; Pandey, O.P., E-mail: oppandey@thapar.edu

    2017-01-15

    In this study, carbon coated WC (WC@C) was synthesized through solvothermal reactions in the presence of reducing agent magnesium (Mg) by employing tungsten oxide (WO{sub 3}) as a precursor, acetone (C{sub 3}H{sub 6}O) as a carbon source. The formation of WC@C nano particles is confirmed by X-ray diffraction and Transmission electron microscopy. The thermal stability of the synthesized powder examined in air shows its stability up to 550 °C. In this method, in-situ produced outer carbon layer increase the surface area of materials which is 52.6 m{sup 2} g{sup −1} with pore volume 0.213 cm{sup 3} g{sup −1}. The Electrocatalytic activity of ethanol oxidation on a synthesized sample with and without Pt nano particles have been investigated using cyclic voltammetry (CV). The CV results show the enhancement in oxidation stability of WC@C in acidic media as well as better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles as compared to without Pt nano particles. - Highlights: • Tungsten carbide nano powder was synthesized using acetone as carbon source. • In-situ produced outer carbon layer increase the surface area of materials. • Mesoporous WC with surface areas 52.6 m{sup 2}/g obtained. • Pt modified WC powder showed higher electrochemical stability. • Better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles.

  8. Critical Damage Analysis of WC-Co Tip of Conical Pick due to Coal Excavation in Mines

    Directory of Open Access Journals (Sweden)

    Saurabh Dewangan

    2015-01-01

    Full Text Available WC-Co based tools are widely used in the field of coal and rock excavation because of their unique combination of strength, hardness, and resistance to abrasive wear. Conical pick is one of the coal cutting tools. The tip of the pick is made of WC-Co material. As coal and rock are heterogeneous elements, they pose various constraints during excavation. As a result the tools wear out during the process. Other parameters like cutting techniques, tool orientation, and environmental conditions also affect the tool significantly. The wearing phenomenon greatly reduces the service life of the tools and thereby cuts down the production rate. To prevent such wearing process, it is important to investigate the different wear mechanisms in WC-Co. Simultaneously, there has to be an ongoing endeavour for the development of better quality WC-Co. This paper focuses on different wear mechanisms in a conical pick which has been used in a continuous miner machine for coal cutting. The worn out surface has been observed by using FE-SEM (field emission scanning electron microscopy and EDS (energy dispersive X-ray spectroscopy. The mechanisms, namely, coal/rock intermixing, cracking and crushing of WC grains, and adhesion of rock particles, have been predominantly investigated in this study. A little indication of corrosive decay in the WC grain has also been reported. The EDS has detected material concentration in a selected area or point of the worn-out surface. The spectrograph confirms the presence of coal/rock materials. Elements such as W, C, Ca, K, O, and Co have been mainly found in different concentrations at different positions.

  9. Trends in the orthopedic job market and the importance of fellowship subspecialty training.

    Science.gov (United States)

    Morrell, Nathan T; Mercer, Deana M; Moneim, Moheb S

    2012-04-01

    Previous studies have examined possible incentives for pursuing orthopedic fellowship training, but we are unaware of previously published studies reporting the trends in the orthopedic job market since the acceptance of certain criteria for fellowship programs by the Accreditation Council for Graduate Medical Education (ACGME) in 1985. We hypothesized that, since the initiation of accredited postresidency fellowship programs, job opportunities for fellowship-trained orthopedic surgeons have increased and job opportunities for nonfellowship-trained orthopedic surgeons have decreased. We reviewed the job advertisements printed in the Journal of Bone and Joint Surgery, American Volume, for the years 1984, 1994, 2004, and 2009. We categorized the job opportunities as available for either a general (nonfellowship-trained) orthopedic surgeon or a fellowship-trained orthopedic surgeon. Based on the advertisements posted in the Journal of Bone and Joint Surgery, American Volume, a trend exists in the orthopedic job market toward seeking fellowship-trained orthopedic surgeons. In the years 1984, 1994, 2004, and 2009, the percentage of job opportunities seeking fellowship-trained orthopedic surgeons was 16.7% (95% confidence interval [CI], 13.1%-20.3%), 40.6% (95% CI, 38.1%-43.1%), 52.2% (95% CI, 48.5%-55.9%), and 68.2% (95% CI, 65.0%-71.4%), respectively. These differences were statistically significant (analysis of variance, Ptraining is thus a worthwhile endeavor. Copyright 2012, SLACK Incorporated.

  10. The organizational and financial viability of an orthopedic trauma service.

    Science.gov (United States)

    Harris, Mitchel B; Cayen, Barry

    2009-12-01

    This study was designed to explore the effect of establishing an Orthopedic Trauma Service (OTS) on departmental revenue within an academic orthopedic department. The effect of the OTS on physician and resident perceptions of job satisfaction, education, and quality of patient care were also evaluated. A proforma financial analysis was undertaken using an optimization model to predict the potential financial performance of an OTS before its implementation. Financial data were then collected prospectively for the first year of the OTS and compared with the preceding year's financial data. All residents and faculty in the department completed visual analog scale surveys after the formation of the service. While maintaining a fixed amount of work production (work relative value units [WRVUs]) per year, our model predicted an $111,000 increase in departmental charges as a result of a shift in the elective case mix. After implementation of the OTS, elective charges/WRVU increased by 7.4% while trauma charges/WRVU increased by 2.6%. This, combined with a minor increase in departmental work volume (115,661 WRVUs pre-OTS vs. 117,577 WRVUs post-OTS) and an improvement in collections/charge (47-48%), yielded a departmental collection increase of 11% ($1.1 million). Resident and faculty job satisfaction improved, as did the perception of the quality of trauma care that was being provided. The organization and implementation of an OTS within an academic orthopedic department can lead to an improved professional experience for residents and faculty, the perception of improved patient care for the trauma patient, and an increase in departmental revenue.

  11. [Femoral artery pseudoaneurysms encountered in orthopedics and traumatology].

    Science.gov (United States)

    Raherinantenaina, F; Rajaonanahary, T M A; Rakoto Ratsimba, H N

    2015-12-01

    Most published articles regarding orthopedic- and trauma-related femoral artery pseudoaneurysms (FAPs) are case reports in English. Reported cases are often associated with a literature review but actually provide little robust data. We wanted to summarize the current knowledge on diagnostic and therapeutic features of these FAPs. A new case of superficial FAP is described followed by a review of the literature. A bibliographic search was performed online (PubMed, ScinceDirect) from 1964 to 2015 using the descriptors "traumatic femoral pseudoaneurysm, orthopedic surgery, osteochondroma". A total of 64 cases of FAPs was analyzed. There were 50 men with an average age of 40.72±26.45 years old. The most common clinical presentation was painful swelling (34%). Arteriography was the commonest radiological investigation used (63%). The main etiologies were orthopedic injuries (47%), surgery of the upper thigh (30%) and femoral osteochondromas (23%). Arterial injuries included superficial femoral (47%) and profunda femoris artery (50%). The treatment was open surgery (56%) or endovascular repair (36%). Deep femoral artery and its branches were embolized (47%) or ligated (38%). Endovascular stenting was performed in 30% of posttraumatic FAPs. All FAPs relating to osteochondromas were repaired surgically. Postoperative courses were uneventful in 95% of patients. Endovascular embolization is preferred in management of postsurgical FAPs which have usually involved the deep femoral artery. Endovascular stenting graft may be proposed for posttraumatic FAPs, for which the superficial femoral trunk is the most often involved vessel. Surgical repair should be performed when endovascular stenting graft is not feasible. Surgical repair is mandatory for all FAPs secondary to traumatic exostoses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. E-learning in orthopedic surgery training: A systematic review.

    Science.gov (United States)

    Tarpada, Sandip P; Morris, Matthew T; Burton, Denver A

    2016-12-01

    E-learning is the use of internet-based resources in education. In the field of surgical education, this definition includes the use of virtual patient cases, digital modeling, online tutorials, as well as video recordings of surgical procedures and lectures. In recent years, e-learning has increasingly been considered a viable alternative to traditional teaching within a number of surgical fields. Here we present (1) a systematic review of literature assessing the efficacy of e-learning modules for orthopedic education and (2) a discussion of their relevance. A systematic search of PubMed, Embase, Web of Science, and the Cochrane Library was conducted according to the guidelines defined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA). The search yielded a total of 255 non-duplicate citations that were screened using predetermined inclusion/exclusion criteria. A total of 9 full text articles met inclusion criteria, which included the use of an objective outcome measure to evaluate an orthopedic e-learning module. Six studies assessed knowledge using a multiple-choice test and 4 assessed skills using a clinical exam. All studies showed positive score improvement pre- to post-intervention, and a majority showed greater score improvement than standard teaching methods in both knowledge (4/6 studies) and clinical skills (3/4 studies). E-learning represents an effective supplement or even alternative to standard teaching techniques within orthopedic education for both medical students and residents. Future work should focus on validating specific e-learning programs using standardized outcome measures and assessing long-term knowledge retention using e-learning platforms.

  13. Validity of subjective smoking status in orthopedic patients

    Directory of Open Access Journals (Sweden)

    Bender D

    2015-08-01

    Full Text Available Daniel Bender,* Patrick Haubruck,* Sonja Boxriker, Sebastian Korff, Gerhard Schmidmaier, Arash Moghaddam Trauma and Reconstructive Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany *These authors contributed equally to this work Purpose: In this level 1 diagnostic study, we analyzed the validity of subjective smoking status and, as secondary research question, the smoking cessation adherence in orthopedic patients during a routine hospital stay of nonunion patients by measuring serum cotinine.  Methods: We included patients undergoing revision surgery due to nonunion of long bones. Patients were interviewed about their smoking status. Blood samples were taken from all the patients prior to surgery and for an additional 6 weeks following surgery. Serum levels of cotinine were measured, and coherence between subjective smoking status and objective cotinine analysis was evaluated.  Results: Between March 2012 and August 2014, we enrolled 136 patients. Six of the 26 “previous smokers” (23% and four of the 65 “nonsmokers” (6% had serum cotinine above cutoff levels. In self-labeled smokers, serum cotinine levels averaged at 2,367.4±14,885.9 ng/mL (with a median of 100 ng/mL, whereas in previous smokers the levels averaged at 4,270±19,619.4 ng/mL (with a median of 0 ng/mL and in the nonsmokers group the levels averaged at 12±53.9 ng/mL (with a median of 0.03 ng/mL. Overall, the subjective smoking status matched serum cotinine testing in 88% of the cases. Sensitivity was 79.6% and specificity was 93.1%. Ninety-one percent of the patients with preoperative positive serum values were still positive at follow-up.  Conclusion: In this study, we could show that subjective smoking status in orthopedic patients is predominantly reliable as validated by objective cotinine measurements; however, patients who declare themselves as “previous smokers” are at elevated risk

  14. Semuloparin for prevention of venous thromboembolism after major orthopedic surgery

    DEFF Research Database (Denmark)

    Lassen, M R; Fisher, W; Mouret, P

    2012-01-01

    BACKGROUND: Semuloparin is a novel ultra-low-molecular-weight heparin under development for venous thromboembolism (VTE) prevention in patients at increased risk, such as surgical and cancer patients. OBJECTIVES: Three Phase III studies compared semuloparin and enoxaparin after major orthopedic...... was to be performed between days 7 and 11. The primary efficacy endpoint was a composite of any deep vein thrombosis, non-fatal pulmonary embolism or all-cause death. Safety outcomes included major bleeding, clinically relevant non-major (CRNM) bleeding, and any clinically relevant bleeding (major bleeding plus CRNM...

  15. N +-implantation induced enhanced adhesion in WC1-x/Ti-6Al-4V

    Science.gov (United States)

    Laidani, Nadhira; Dorigoni, Carla; Miotello, Antonio

    1996-12-01

    In this work, the potentiality of the N +-implantation to promote adhesion in WC1-x/Ti-6Al-4V bilayers has been investigated. The WC 1- x films were deposited by rf sputtering in Ar discharge. N +-implantations were performed at 160 keV with ion dose ranging from 5 × 10 15 to 2 × 10 17N +/cm 2. The implantations have been carried out at two sample temperatures: 363 K and 423 K. Adhesion strength was measured by means of the scratch test in conjunction with scanning electron microscopy and energy dispersive spectrometry (EDS). Auger electron spectroscopy (AES), Rutherford backscattering spectrometry (RBS) and X-ray diffraction (XRD) analyses were used to study the chemical, compositional and structural changes of the WC1-x/Ti-6Al-4V interface. As a general result, N +-implantation modifies the adhesion failure mechanism which from adhesive, before implantation, becomes cohesive. The implantation temperature had a strong effect on the critical loads Lc. N +-implantation at 423 K resulted in a slight increase of Lc, from 2N (unimplanted systems) to 5N for all ion doses. This weak improvement of the adhesion strength was associated with the particular interface processes which allowed C, but not W, mixing into the substrate. In this case, TiC bondings formed which contributed to the substrate embrittlement. When the implantations were carried out at 363 K, both C and W underwent mixing with Ti-6Al-4V: this favoured not only an interface composition grading but also a graded chemistry across the interface, with a strong increase of Lc for low ion dose ( Lc = 14N for 1 × 10 16 N +/cm 2). Implantation with higher doses (5 × 10 16N -/cm 2 and 2 × 10 17N +/cm 2) exhibited lower efficiency ( Lc = 7N for 2 × 10 17 N +/cm 2). This ion dose dependence of the adhesion strength was attributed to the formation of different phases across the interface, probably structurally incompatible.

  16. Pt catalysts on PANI coated WC/C nanocomposites for methanol electro-oxidation and oxygen electro-reduction in DMFC

    International Nuclear Information System (INIS)

    Yaldagard, Maryam; Jahanshahi, Mohsen; Seghatoleslami, Naser

    2014-01-01

    Highlights: • In this work nanosized WC/C were successfully coated by PANI. • Pt particles (10.56 nm) were uniformly dispersed on the surface of PANI/WC/C support. • The Pt/PANI/WC/C exhibited higher MOR activity and CO tolerance than Pt/C. • The Pt/PANI/WC/C exhibited higher activity for ORR than Pt/C in RDE experiments. • Pt/PANI/WC/C showed good stability than that of Pt/C in the presence of methanol. - Abstract: In the present study a Pt/PANI/WC/C electrocatalyst was developed to increase the methanol electro-oxidation and oxygen electro-reduction activity and stability of commercial Pt/C electrocatalyst. WC/C was coated with protonated polyaniline (PANI) in situ during the polymerization of aniline. Fourier transform infrared (FTIR) results illustrate the presence of PANI in the composite. The conductivity of PANI coated – WC/C has been compared with the conductivity of the corresponding mixtures of WC/C and Vulcan XC-72. X-ray diffraction results showed that Pt particles were dispersed on the support with mean particle size of about 10.56 nm. Transition electron microscopy images showed that the nanosized WC/C were successfully coated by PANI. Based on the electrochemical properties characterized by cyclic voltammetry, CO stripping and rotating disk electrode measurements it was found that the as prepared Pt/PANI/WC/C electrocatalyst exhibited a comparable activity for methanol oxidation reaction and oxygen reduction reaction with respect to the commercial one. A significant reduction in the potential of CO electro-oxidation peak from 0.75 V for Pt/C to 0.52 V for Pt/PANI/WC/C electrocatalyst indicates that an increase in the activity for CO electro-oxidation is achieved by replacing the carbon support by PANI coated WC/C. Chronoamerometry results also showed, in the presence of methanol the Pt/PANI/WC/C electrocatalyst still maintains a higher current density than Pt/WC/C and Pt/C

  17. Pt catalysts on PANI coated WC/C nanocomposites for methanol electro-oxidation and oxygen electro-reduction in DMFC

    Energy Technology Data Exchange (ETDEWEB)

    Yaldagard, Maryam, E-mail: m_yaldagard@yahoo.com [Department of Chemical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111 (Iran, Islamic Republic of); Nanotechnology Research Institute, School of Chemical Engineering, Babol University of Technology (Iran, Islamic Republic of); Jahanshahi, Mohsen, E-mail: mjahan@nit.um.ac.ir [Nanotechnology Research Institute, School of Chemical Engineering, Babol University of Technology (Iran, Islamic Republic of); Seghatoleslami, Naser, E-mail: Slami@um.ac.ir [Department of Chemical Engineering, Ferdowsi University of Mashhad, P.O. Box 91775-1111 (Iran, Islamic Republic of)

    2014-10-30

    Highlights: • In this work nanosized WC/C were successfully coated by PANI. • Pt particles (10.56 nm) were uniformly dispersed on the surface of PANI/WC/C support. • The Pt/PANI/WC/C exhibited higher MOR activity and CO tolerance than Pt/C. • The Pt/PANI/WC/C exhibited higher activity for ORR than Pt/C in RDE experiments. • Pt/PANI/WC/C showed good stability than that of Pt/C in the presence of methanol. - Abstract: In the present study a Pt/PANI/WC/C electrocatalyst was developed to increase the methanol electro-oxidation and oxygen electro-reduction activity and stability of commercial Pt/C electrocatalyst. WC/C was coated with protonated polyaniline (PANI) in situ during the polymerization of aniline. Fourier transform infrared (FTIR) results illustrate the presence of PANI in the composite. The conductivity of PANI coated – WC/C has been compared with the conductivity of the corresponding mixtures of WC/C and Vulcan XC-72. X-ray diffraction results showed that Pt particles were dispersed on the support with mean particle size of about 10.56 nm. Transition electron microscopy images showed that the nanosized WC/C were successfully coated by PANI. Based on the electrochemical properties characterized by cyclic voltammetry, CO stripping and rotating disk electrode measurements it was found that the as prepared Pt/PANI/WC/C electrocatalyst exhibited a comparable activity for methanol oxidation reaction and oxygen reduction reaction with respect to the commercial one. A significant reduction in the potential of CO electro-oxidation peak from 0.75 V for Pt/C to 0.52 V for Pt/PANI/WC/C electrocatalyst indicates that an increase in the activity for CO electro-oxidation is achieved by replacing the carbon support by PANI coated WC/C. Chronoamerometry results also showed, in the presence of methanol the Pt/PANI/WC/C electrocatalyst still maintains a higher current density than Pt/WC/C and Pt/C.

  18. In-situ investigation of laser surface modifications of WC-Co hard metals inside a scanning electron microscope

    Science.gov (United States)

    Mueller, H.; Wetzig, K.; Schultrich, B.; Pompe, Wolfgang; Chapliev, N. I.; Konov, Vitaly I.; Pimenov, S. M.; Prokhorov, Alexander M.

    1989-05-01

    The investigation of laser interaction with solid surfaces and of the resulting mechanism of surface modification are of technical interest to optimize technological processes, and they are also of fundamental scientific importance. Most instructive indormation is available with the ail of the in-situ techniques. For instance, measuring of the photon emission of the irradiated surface ane the plasma torch (if it is produced) simultaneously to laser action, makes it possible to gain a global characterization of the laser-solid interaction. In order to obtain additional information about surface and structure modifications in microscopic detail , a laser and scanning electron microscope were combined in to a tandem equipment (LASEM). Inside this eqiipment the microscopic observation is carried out directly at the laser irradiated area without any displacement of the sample. In this way, the stepwise development of surface modification during multipulse irradiation is visible in microscopic details and much more reliable information about the surface modification process is obtainable in comparison to an external laser irradiation. Such kind of equipments were realized simultaneously and independently in the Institut of General Physics (Moscow) and the Central Institute of Solid State Physics and Material Research (Dresden) using a CO2 and a LTd-glass-laser, respectively. In the following the advantages and possibilities of a LASEM shall be demonstrated by some selected investigations of WC-CO hardmeta. The results were obtained in collaboration by both groups with the aid of the pulsed CO2-laser. The TEA CO2 laser was transmitted through a ZnSe-window into the sample chamber of the SEM and focused ofAo tfte sample surface. It was operated in TEM - oo mode with a repetition rate of about 1 pulse per second. A peak power density of about 160 MW/cm2 was achieved in front of the sample surface.

  19. Validation of orthopedic postoperative pain assessment methods for dogs: a prospective, blinded, randomized, placebo-controlled study.

    Directory of Open Access Journals (Sweden)

    Pascale Rialland

    Full Text Available In the context of translational research, there is growing interest in studying surgical orthopedic pain management approaches that are common to humans and dogs. The validity of postoperative pain assessment methods is uncertain with regards to responsiveness and the potential interference of analgesia. The hypothesis was that video analysis (as a reference, electrodermal activity, and two subjective pain scales (VAS and 4A-VET would detect different levels of pain intensity in dogs after a standardized trochleoplasty procedure. In this prospective, blinded, randomized study, postoperative pain was assessed in 25 healthy dogs during a 48-hour time frame (T. Pain was managed with placebo (Group 1, n = 10, preemptive and multimodal analgesia (Group 2, n = 5, or preemptive analgesia consisting in oral tramadol (Group 3, n = 10. Changes over time among groups were analyzed using generalized estimating equations. Multivariate regression tested the significance of relationships between pain scales and video analysis. Video analysis identified that one orthopedic behavior, namely 'Walking with full weight bearing' of the operated leg, decreased more in Group 1 at T24 (indicative of pain, whereas three behaviors indicative of sedation decreased in Group 2 at T24 (all p<0.004. Electrodermal activity was higher in Group 1 than in Groups 2 and 3 until T1 (p<0.0003. The VAS was not responsive. 4A-VET showed divergent results as its orthopedic component (4A-VETleg detected lower pain in Group 2 until T12 (p<0.0009, but its interactive component (4A-VETbeh was increased in Group 2 from T12 to T48 (p<0.001. Concurrent validity established that 4A-VETleg scores the painful orthopedic condition accurately and that pain assessment through 4A-VETbeh and VAS was severely biased by the sedative side-effect of the analgesics. Finally, the video analysis offered a concise template for assessment in dogs with acute orthopedic pain. However, subjective pain

  20. Comparing Written and Planned Training On Anxiety among Patients Undergoing Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    maryam tolyat

    2017-03-01

    Full Text Available Introduction and objectives: The prevalence of preoperative state anxiety is an unavoidable complication. Aside from its type and scope, the surgical operation is considered as a severe stressful situation for patients. Considering the importance of reducing the state anxiety in patients undergoing surgery, there are different methods, one of which is patient education; therefore the aim of the current study was compare the effect of written and planned training on the state anxiety among patients undergoing orthopedic surgery. Method: In this study, 81 patients candidate for orthopedic surgery were selected using convenience sampling and were randomly divided into 3 groups, including planned training, pamphlet and control groups. All patients answered 20 questions-State-Traits Anxiety Inventory (STAI Questionnaire the day before surgery and the intervention was later carried out in the planned training and pamphlet groups. Then the effect of preoperative state anxiety was re-evaluated about half an hour after training in three groups. For data analysis, in addition to mean and standard deviation, independent t-test and ANOVA were used in Spss16. Results: The results of comparing pre- and post-training mean score of the state anxiety in three groups showed that the mean score of state anxiety reached from 50.41 to 41.03, 52.41 to 44.37 and 45.04 to 50.56 in planned, pamphlet and control groups, respectively. ANOVA test showed that there is a significant difference in this comparison. The results of Tukey's test also revealed that the mean score of state anxiety in the planned and pamphlet groups was lower significantly than the control group (p<0.05. Conclusion: Based on research findings, the planned training method was more effective in decreasing state anxiety among patients compared to the pamphlet group before orthopedic surgery. Therefore, considering the fact that nurses play an important role in examining and relieving the state anxiety

  1. How to manage RI venography in pre-orthopedic surgery patients

    International Nuclear Information System (INIS)

    Terazawa, Kaori; Otsuka, Hideki; Otomi, Yoichi; Morita, Naomi; Takao, Shoichiro; Iwamoto, Seiji; Osaki, Kyosuke; Harada, Masafumi; Nishitani, Hiromu

    2010-01-01

    The preoperative evaluation of venous thromboembolism (VTE) is important to avoid complications, because VTE is often induced by orthopedic surgery. We focused on radioisotope venography (RIV) using 99m Tc-macroaggregated human serum albumin, examining orthopedic patients. We conducted 34 examinations in 33 patients who were referred for RIV and lung perfusion scintigraphy for the pre-orthopedic operative evaluation of VTE. Two board-certified (one nuclear medicine board-certified) radiologists interpreted the images based on the following: flow defect of the lower extremities; interruption of flow; irregular or asymmetric filling of the deep vein (low flow); presence of collateral vessels; and abnormal RI retention on delayed-phase images. Scoring was based on a 5-point scale, and more than 2 points was considered VTE positive. Abnormal findings were noted in 27 of the 34 examinations performed in the 33 patients and normal findings in the other 7 examinations. According to the RI score, 21 patients were classified into the VTE-positive group and 12 into the VTE-negative group. Surgery was canceled because of advanced age and respiratory dysfunction in 2 of the 21 patients in the VTE-positive group. Of the 19 patients who underwent surgery, an IVH filter was placed before surgery in 2 and anticoagulant treatment with heparin and warfarin was initiated on the day of surgery in 12 to prevent postoperative VTE, and only one of the patients receiving anticoagulant treatment developed PTE after surgery. Surgery was canceled due to advanced age and at patient's request in 2 of 12 patients in the VTE-negative group. Anticoagulant treatment with heparin/warfarin was performed to prevent postoperative VTE in only 3 patients: one with a past medical history of pulmonary infarction, one with atrial fibrillation, and one suspected of having antiphospholipid antibody syndrome. No patient in the VTE-negative group developed VTE after surgery. The preoperative identification of

  2. Thermal interaction between WC-Co coating and steel substrate in process of HVOF spraying

    International Nuclear Information System (INIS)

    Guilemany, J.M.; Sobolev, V.V.; Nutting, J.; Dong, Z.; Calero, J.A.

    1994-01-01

    The WC-Co powders can be used to produce good adhesive and wear resistant HVOF thermal spray coatings on steel and light alloys substrates. In order to understand the properties of this kind of coating, the phases which are present in the coatings and structure changes during post heat treatments have been investigated. Although the coating properties depend very much on the structure developed in the substrate-coating interfacial region it has not been yet investigated in detail. The present study is devoted to the experimental and theoretical analysis of this interfacial region. The structure characterization has been performed mainly through the use of transmission electron microscopy. To provide a theoretical investigation a realistic prediction model of the process has been developed and on its base the mathematical simulation of the substrate-coating thermal interaction has been undertaken

  3. Physical chemistry of WC-12 %Co coatings deposited by thermal spraying at different standoff distances

    Energy Technology Data Exchange (ETDEWEB)

    Afzal, Muhammad; Ahmed, Furqan; Anwar, Muhammad Yousaf; Ali, Liaqat; Ajmal, Muhammad [Univ. of Engineering and Technology, Metallurgical and Materials Engineering, Lahore (Pakistan); Khan, Aamer Nusair [Institute of Industrial and Control System, Rawalpindi (Pakistan)

    2015-09-15

    In the present research, WC-12 %Co cermet coatings were deposited on AISI-321 stainless steel substrate using air plasma spraying. During the deposition process, the standoff distance was varied from 80 to 130 mm with 10 mm increments. Other parameters such as current, voltage, time, carrier gas flow rate and powder feed rate etc. were kept constant. The objective was to study the effects of spraying distance on the microstructure of as-sprayed coatings. The microscopic analyses revealed that the band of spraying distance ranging from 90 to 100 mm was the threshold distance for optimum results, provided that all the other spraying parameters were kept constant. In this range of threshold distance, minimum percentages of porosity and defects were observed. Further, the formation of different phases, at six spraying distances, was studied using X-ray diffraction, and the phase analysis was correlated with hardness results.

  4. Ultra-short-period WC/SiC multilayer coatings for x-ray applications

    International Nuclear Information System (INIS)

    Fernández-Perea, Mónica; Pivovaroff, Mike J.; Soufli, Regina; Alameda, Jennifer; Mirkarimi, Paul; Descalle, Marie-Anne; Baker, Sherry L.; McCarville, Tom; Ziock, Klaus; Hornback, Donald; Romaine, Suzanne; Bruni, Ric; Zhong, Zhong; Honkimäki, Veijo; Ziegler, Eric; Christensen, Finn E.; Jakobsen, Anders C.

    2013-01-01

    Multilayer coatings enhance x-ray mirror performance at incidence angles steeper than the critical angle, allowing for improved flux, design flexibility and facilitating alignment. In an attempt to extend the use of multilayer coatings to photon energies higher than previously achieved, we have developed multilayers with ultra-short periods between 1 and 2 nm based on the material system WC/SiC. This material system was selected because it possesses very sharp and stable interfaces. In this article, we show highlights from a series of experiments performed in order to characterize the stress, microstructure and morphology of the multilayer films, as well as their reflective performance at photon energies from 8 to 384 keV

  5. Mechanical characterization of cemented carbide WC-6Co (%wt) manufactured by SPS (Spark Plasma Sintering

    International Nuclear Information System (INIS)

    Boidi, G.; Tertuliano, A.J.; Machado, I.F.

    2016-01-01

    This work aimed to manufacture cemented carbide (WC-6%wtCo) obtained by SPS (Spark Plasma Sintering) process and to carry out the mechanical characterization by hardness and fracture toughness. The material was consolidated at 1100 deg C for different holding times (1 min, 5 min, 10 min), in order to evaluate the densification. A reference sample was also used to be compared to SPS. Optical and scanning electron microscopy were carried out to characterize the microstructural features of the samples and mechanical properties were obtained by hardness measurements (micro and macro) and instrumented indentation. The fracture toughness was calculated with the method of Palmqvist. Best results were found in the material sintered by SPS for 10 minutes of holding time, in which 97% of relative density and about 1600 HV_1_0 was reached. (author)

  6. Thermomagnetic method to determine cobalt content in solid WC-Co alloys

    International Nuclear Information System (INIS)

    Tumanov, V.I.; Loshakov, A.L.; Korchakova, E.A.

    1980-01-01

    A thermomagnetic method of cobalt amount determination in tungsten solid alloys is suggested. The method consists in the following: a sample of solid alloy is placed in a magnetic field sufficient to achieve technical saturation (not less than 10 kOe), and specific magnetization of saturation of the alloy σ is determined, then the sample is heated and according to the curves of magnetic permeability dependence on the temperature the Curie point of the alloy THETA is determined and cobalt amount is calculated by the formula qsub(Co)=σ100/(kTHETA+b). The analysis duration is approximately 30 min. Comparative data of cobalt amount determination in solid alloys WC-Co using thermonagnetic and potentiometric methods are presented. Results obtained by thermomagnetic and chemical method are in good agreement. Efficiency of the thermomagnetic method is much higher

  7. Regional mapping of 100 - 999 kWc photovoltaic plants in 2014

    International Nuclear Information System (INIS)

    Tuille, F.

    2014-01-01

    This article presents the distribution over the French soil of intermediate photovoltaic plants in mid 2014. The map gives the number of photovoltaic plants, the total connected capacity per region, and the curves of sunlight. The total number of photovoltaic plants with a capacity ranging from 100 to 999 kWc is 2895 totaling 626,5 MWc. Most of these plants (82%) are integrated into the roofs of buildings while 10% are installed on the roofs. 53% of the solar panels are made of polycrystalline photovoltaic cells while 32% are composed on monocrystalline cells and 7% are based on thin film technology. There are very few plants waiting to be connected to the grid which means that this sector is losing its impetus. (A.C.)

  8. Measurement and modeling of room temperature co-deformation in WC-10 wt.%

    Energy Technology Data Exchange (ETDEWEB)

    Livescu, V. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)]. E-mail: vlivescu@lanl.gov; Clausen, B. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Paggett, J.W. [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211 (United States); Krawitz, A.D. [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211 (United States); Drake, E.F. [REEDHycalogTM/Grant Prideco, Houston, TX 77252 (United States); Bourke, M.A.M. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2005-06-15

    In situ neutron diffraction measurements were performed on a tungsten carbide (WC)-10 wt.% cobalt (Co) cemented carbide composite subjected to compressive loading. The sample was subjected to consecutive load/unload cycles to -500, -1000, -2000 and -2100 MPa. Thermal residual stresses measured before loading reflected large hydrostatic tensile stresses in the binder phase and compressive stresses in the carbide phase. The carbide phase behaved elastically at all but the highest load levels, whereas plasticity was present in the binder phase from values of applied stress as low as -500 MPa. A finite element simulation utilizing an interpenetrating microstructure model showed remarkable agreement with the complex mean phase strain response during the loading cycles despite its under-prediction of thermal residual strains.

  9. Crystal orientation mapping applied to the Y-TZP/WC composite

    CERN Document Server

    Faryna, M; Sztwiertnia, K

    2002-01-01

    Crystal orientation measurements made by electron backscattered diffraction (EBSD) in the scanning electron microscope (SEM) and microscopic observations provided the basis for a quantitative investigation of microstructure in an yttria stabilized, tetragonal zirconia-based (Y-TZP) composite. Automatic crystal orientation mapping (ACOM) in a SEM can be preferable to transmission electron microscopy (TEM) for microstructural characterization, since no sample thinning is required, extensive crystal data is already available, and the analysis area is greatly increased. A composite with a 20 vol.% tungsten carbide (WC) content was chosen since it revealed crystal relationships between the matrix and carbide phase already established by TEM analysis. However, this composite was difficult to investigate in the EBSD/ SEM since it is non-conductive, the Y-TZP grain size is of the order of the system resolution, and the sample surface, though carefully prepared, reveals a distinctive microtopography. In this paper, so...

  10. Self-propagating high-temperature synthesis of TiC-WC composite materials

    International Nuclear Information System (INIS)

    Mas-Guindal, M.J.; Contreras, L.; Turrillas, X.; Vaughan, G.B.M.; Kvick, A.; Rodriguez, M.A.

    2006-01-01

    TiC-WC composites have been obtained in situ by self-propagating high-temperature synthesis (SHS) from a mixture of compacted powders of elemental titanium, tungsten and graphite. The Rietveld method has proved to be a useful tool to quantify the different phases in the reaction and calculate the cell parameters of the solid solution found in the products. The reaction has also been followed in real time by X-ray diffraction at the European Synchrotron Radiation Facility (ESRF ID-11 Materials Science Beamline). The mechanism of the reaction is discussed in terms of the diffusion of liquid titanium to yield titanium carbide with a solid solution of tungsten. The microstructures of the materials obtained by this method are presented

  11. OSTEOPLASTY BY G.A. ILIZAROV IN ORTHOPEDIC REHABILITATION OF PATIENTS WITH PRIMARY TUMORS OF LEG BONES

    Directory of Open Access Journals (Sweden)

    P. I. Balaev

    2013-01-01

    Full Text Available The analysis of orthopedic rehabilitation of 49 patients with primary tumors of leg bones using ostheosynthesis technique was presented. Patients with bone sarcoma underwent non-free osteoplasty by G.A. Ilizarov after combined treatment including radical tumor resection and neoadjuvant chemotherapy. In the group of patients with benign tumors the rehabilitation measures for anatomic-and-functional recovery of the limb operated were made in a single-stage fashion. The use of the transosseous osteosynthesis technologies according to Ilizarov allowed replacement of post-resection bone defects and optimal limb reconstruction not only in adults, but also in children with incomplete skeletal formation.

  12. An IRAS-Based Search for New Dusty Late-Type WC Wolf-Rayet Stars

    Science.gov (United States)

    Cohen, Martin

    1995-01-01

    I have examined all Infrared Astronomical Satellite (IRAS) data relevant to the 173 Galactic Wolf-Rayet (W-R) stars in an updated catalog, including the 13 stars newly discovered by Shara and coworkers. Using the W-R coordinates in these lists, I have examined the IRAS Point Source Catalog (PSC), the Faint Source Catalog, and the Faint Source Reject Catalog, and have generated one-dimensional spatial profiles, 'ADDSCANs', and two-dimensional full-resolution images, 'FRESCOS'. The goal was to assemble the best set of observed IRAS color indices for different W-R types, in particular for known dusty late-type WC Wolf-Rayet (WCL) objects. I have also unsuccessfully sought differences in IRAS colors and absolute magnitudes between single and binary W-R stars. The color indices for the entire ensemble of W-R stars define zones in the IRAS color-color ([12] - [25], [25] - [60])-plane. By searching the PSC for otherwise unassociated sources that satisfy these colors, I have identified potential new W-R candidates, perhaps too faint to have been recognized in previous optical searches. I have extracted these candidates' IRAS low-resolution spectrometer (LRS) data and compared the spectra with the highly characteristic LRS shape for known dusty WCL stars. The 13 surviving candidates must now be ex amined by optical spectroscopy. This work represents a much more rigorous and exhaustive version of the LRS study that identified IRAS 17380 - 3031 (WR98a) as the first new W-R (WC9) star discovered by IPAS. This search should have detected dusty WCL stars to a distance of 7.0 kpc from the Sun, for l is greater than 30 degrees, and to 2.9 kpc even in the innermost galaxy. For free-free-dominated W-R stars the corresponding distances are 2.5 and 1.0 kpc, respectively.

  13. As(III) oxidation by MnO{sub 2} coated PEEK-WC nanostructured capsules

    Energy Technology Data Exchange (ETDEWEB)

    Criscuoli, Alessandra, E-mail: a.criscuoli@itm.cnr.it [Institute on Membrane Technology, ITM-CNR, Via P. Bucci Cubo 17/C, 87030 Rende (CS) (Italy); Majumdar, Swachchha [Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Rd., 700032 Kolkata (India); Figoli, Alberto, E-mail: a.figoli@itm.cnr.it [Institute on Membrane Technology, ITM-CNR, Via P. Bucci Cubo 17/C, 87030 Rende (CS) (Italy); Sahoo, Ganesh C. [Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Rd., 700032 Kolkata (India); Bafaro, Patrizia [Institute on Membrane Technology, ITM-CNR, Via P. Bucci Cubo 17/C, 87030 Rende (CS) (Italy); Department of Chemical Engineering and Materials, University of Calabria, Via P. Bucci Cubo 42/A, 87030 Rende (CS) (Italy); Bandyopadhyay, Sibdas [Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Rd., 700032 Kolkata (India); Drioli, Enrico [Institute on Membrane Technology, ITM-CNR, Via P. Bucci Cubo 17/C, 87030 Rende (CS) (Italy); Department of Chemical Engineering and Materials, University of Calabria, Via P. Bucci Cubo 42/A, 87030 Rende (CS) (Italy)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Successful preparation of PEEK-WC nanostructured capsules coated by MnO{sub 2}. Black-Right-Pointing-Pointer Preliminary tests of As(III) oxidation carried out in batch. Black-Right-Pointing-Pointer Complete oxidation obtained for feed concentrations of 0.1 and 0.3 ppm. - Abstract: PEEK-WC nanostructured capsules were prepared by the phase inversion technique and used as support for the coating of a manganese dioxide layer. The coating was done by a chemical treatment of the capsules followed by a thermal one. The presence of the MnO{sub 2} layer was confirmed by scanning electron microscopy (SEM), back scattering electron (BSE), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The produced capsules were, then, tested for As(III) oxidation in batch. The experiments consisted in treating 165 ml of As(III) solution with 1 g of coated capsules at fixed temperature (15 Degree-Sign C) and pH (5.7-5.8). In particular, the efficiency of the system was investigated for different As(III) concentrations (0.1, 0.3, 0.7 and 1 ppm). For feeds at lower As(III) content (0.1-0.3 ppm), tests lasted for 8 h, while prolonged runs (up to 48 h) were carried out on more concentrated solutions (0.7 and 1 ppm). The produced capsules were able to oxidize As(III) into As(V) leading to complete conversion after 3 and 4 h for feed concentrations of 0.1 and 0.3 ppm, respectively.

  14. Nd:YOV4 laser polishing on WC-Co HVOF coating

    Science.gov (United States)

    Giorleo, L.; Ceretti, E.; Montesano, L.; La Vecchia, G. M.

    2017-10-01

    WC/Co coatings are widely applied to different types of components due to their extraordinary performance properties including high hardness and wear properties. In industrial applications High Velocity Oxy-Fuel (HVOF) technique is extensively used to deposit hard metal coatings. The main advantage of HVOF compared to other thermal spray techniques is the ability to accelerate the melted powder particles of the feedstock material at a relatively high velocity, leading to obtain good adhesion and low porosity level. However, despite the mentioned benefits, the surface finish quality of WC-Co HVOF coatings results to be poor (Ra higher than 5 µm) thus a mechanical polishing process is often needed. The main problem is that the high hardness of coating leads the polishing process expensive in terms of time and tool wear; moreover polishing becomes difficult and not always possible in case of limited accessibility of a part, micro dimensions or undercuts. Nowadays a different technique available to improve surface roughness is the laser polishing process. The polishing principle is based on focused radiation of a laser beam that melts a microscopic layer of surface material. Compared to conventional polishing process (as grinding) it ensures the possibility of avoiding tool wear, less pollution (no abrasive or liquids), no debris, less machining time and coupled with a galvo system it results to be more suitable in case of 3D complex workpieces. In this paper laser polishing process executed with a Nd:YOV4 Laser was investigated: the effect of different process parameters as initial coating morphology, laser scan speed and loop cycles were tested. Results were compared by a statistical approach in terms of average roughness along with a morphological analysis carried out by Scanning Electron Microscope (SEM) investigation coupled with EDS spectra.

  15. The study of stiffness modulus values for AC-WC pavement

    Science.gov (United States)

    Lubis, AS; Muis, Z. A.; Iskandar, T. D.

    2018-02-01

    One of the parameters of the asphalt mixture in order for the strength and durability to be achieved as required is the stress-and-strain showing the stiffness of a material. Stiffness modulus is a very necessary factor that will affect the performance of asphalt pavements. If the stiffness modulus value decreases there will be a cause of aging asphalt pavement crack easily when receiving a heavy load. The high stiffness modulus asphalt concrete causes more stiff and resistant to bending. The stiffness modulus value of an asphalt mixture material can be obtained from the theoretical (indirect methods) and laboratory test results (direct methods). For the indirect methods used Brown & Brunton method, and Shell Bitumen method; while for the direct methods used the UMATTA tool. This study aims to determine stiffness modulus values for AC-WC pavement. The tests were conducted in laboratory that used 3 methods, i.e. Brown & Brunton Method, Shell Bitumen Method and Marshall Test as a substitute tool for the UMATTA tool. Hotmix asphalt made from type AC-WC with pen 60/70 using a mixture of optimum bitumen content was 5.84% with a standard temperature variation was 60°C and several variations of temperature that were 30, 40, 50, 70 and 80°C. The stiffness modulus value results obtained from Brown & Brunton Method, Shell Bitumen Method and Marshall Test which were 1374,93 Mpa, 235,45 Mpa dan 254,96 Mpa. The stiffness modulus value decreases with increasing temperature of the concrete asphalt. The stiffness modulus value from the Bitumen Shell method and the Marshall Test has a relatively similar value.The stiffness modulus value from the Brown & Brunton method is greater than the Bitumen Shell method and the Marshall Test, but can not measure the stiffness modulus value at temperature above 80°C.

  16. Developments in ambulatory surgery in orthopedics in France in 2016.

    Science.gov (United States)

    Hulet, C; Rochcongar, G; Court, C

    2017-02-01

    Under the new categorization introduced by the Health Authorities, ambulatory surgery (AS) in France now accounts for 50% of procedures, taking all surgical specialties together. The replacement of full hospital admission by AS is now well established and recognized. Health-care centers have learned, in coordination with the medico-surgical and paramedical teams, how to set up AS units and the corresponding clinical pathways. There is no single model handed down from above. The authorities have encouraged these developments, partly by regulations but also by means of financial incentives. Patient eligibility and psychosocial criteria are crucial determining factors for the success of the AS strategy. The surgeons involved are strongly committed. Feedback from many orthopedic subspecialties (shoulder, foot, knee, spine, hand, large joints, emergency and pediatric surgery) testify to the rise of AS, which now accounts for 41% of all orthopedic procedures. Questions remain, however, concerning the role of the GP in the continuity of care, the role of innovation and teaching, the creation of new jobs, and the attractiveness of AS for surgeons. More than ever, it is the patient who is "ambulatory", within an organized structure in which surgical technique and pain management are well controlled. Not all patients can be eligible, but the AS concept is becoming standard, and overnight stay will become a matter for medical and surgical prescription. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Indications for CT, MRI, and scintiscanning in orthopedics and traumatology

    International Nuclear Information System (INIS)

    Hahn, K.; Heine, J.; Thelen, T.

    1994-01-01

    Successful treatment of disease of the locomotor system requires as exact as possible diagnostic evaluation of the individual conditions, and this in turn can be achieved only by collaborative efforts of experts from a variety of subject fields. The book in hand is the result of such a collaborative approach, presenting the knowledge and experience of orthopedic surgeons, radiologists, and nuclear medicine experts who establish an order of priority and diagnostic value of computed tomography, magnetic resonance imaging, and various scintiscanning methods with respect to the diagnosis of orthopedic lesions. On the basis of this order of priority, specific recommendations are presented and explained for the best possible diagnostic procedure for evaluation of the various cases. The material is arranged into the following chapters: Examination modalities, techniques and cost - Inflammatory lesions of the locomotive system - Specific traumatology - Tumors of the locomotive system - Lesions of the hip joint - Lesions of the knee joint - Lesions of the spine -Lesions of the shoulder. (orig./MG) [de

  18. Intraoperative Secondary Insults During Orthopedic Surgery in Traumatic Brain Injury.

    Science.gov (United States)

    Algarra, Nelson N; Lele, Abhijit V; Prathep, Sumidtra; Souter, Michael J; Vavilala, Monica S; Qiu, Qian; Sharma, Deepak

    2017-07-01

    Secondary insults worsen outcomes after traumatic brain injury (TBI). However, data on intraoperative secondary insults are sparse. The primary aim of this study was to examine the prevalence of intraoperative secondary insults during orthopedic surgery after moderate-severe TBI. We also examined the impact of intraoperative secondary insults on postoperative head computed tomographic scan, intracranial pressure (ICP), and escalation of care within 24 hours of surgery. We reviewed medical records of TBI patients 18 years and above with Glasgow Coma Scale score Secondary insults examined were: systemic hypotension (systolic blood pressurehypertension (ICP>20 mm Hg), cerebral hypotension (cerebral perfusion pressure40 mm Hg), hypocarbia (end-tidal CO2hypertension), hyperglycemia (glucose>200 mg/dL), hypoglycemia (glucose38°C). A total of 78 patients (41 [18 to 81] y, 68% male) met the inclusion criteria. The most common intraoperative secondary insults were systemic hypotension (60%), intracranial hypertension and cerebral hypotension (50% and 45%, respectively, in patients with ICP monitoring), hypercarbia (32%), and hypocarbia (29%). Intraoperative secondary insults were associated with worsening of head computed tomography, postoperative decrease of Glasgow Coma Scale score by ≥2, and escalation of care. After Bonferroni correction, association between cerebral hypotension and postoperative escalation of care remained significant (Psecondary insults were common during orthopedic surgery in patients with TBI and were associated with postoperative escalation of care. Strategies to minimize intraoperative secondary insults are needed.

  19. Presurgical cleft lip and palate orthopedics: an overview

    Directory of Open Access Journals (Sweden)

    Alzain I

    2017-05-01

    Full Text Available Ibtesam Alzain,1 Waeil Batwa,2 Alex Cash,3 Zuhair A Murshid2 1Pediatric Dentistry, 2Orthodontic Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 3Cleft Lip and Palate Orthodontics, Queen Victoria NHS Foundation Trust, South Thames Cleft Service, London, UK Abstract: Patients with cleft lip and/or palate go through a lifelong journey of multidisciplinary care, starting from before birth and extending until adulthood. Presurgical orthopedic (PSO treatment is one of the earliest stages of this care plan. In this paper we provide a review of the PSO treatment. This review should help general and specialist dentists to better understand the cleft patient care path and to be able to answer patient queries more efficiently. The objectives of this paper were to review the basic principles of PSO treatment, the various types of techniques used in this therapy, and the protocol followed, and to critically evaluate the advantages and disadvantages of some of these techniques. In conclusion, we believe that PSO treatment, specifically nasoalveolar molding, does help to approximate the segments of the cleft maxilla and does reduce the intersegment space in readiness for the surgical closure of cleft sites. However, what we remain unable to prove equivocally at this point is whether the reduction in the dimensions of the cleft presurgically and the manipulation of the nasal complex benefit our patients in the long term. Keywords: presurgical orthopedic, nasoalveolar molding, cleft lip and palate

  20. [Orthopedic and trauma surgery in the German DRG system 2008].

    Science.gov (United States)

    Franz, D; Kaufmann, M; Siebert, C H; Windolf, J; Roeder, N

    2008-04-01

    The German DRG (diagnosis-related groups) system has been modified and updated into version 2008. For orthopedic and trauma surgery significant changes concerning coding of diagnoses, medical procedures and the DRG structure were made. The modified version has been analyzed in order to ascertain whether the DRG system is suitably qualified to fulfill the demands of the reimbursement system or whether further improvements are necessary. Analysis of the severity of relevant side-effect diagnoses, medical procedures and G-DRGs in the versions 2007 and 2008 was carried out based on the publications of the German DRG institute (InEK) and the German Institute of Medical Documentation and Information (DIMDI). Changes for 2008 focused on the development of DRG structure, DRG validation and codes for medical procedures. The outcome of these changes for German hospitals may vary depending on the range of activities. G-DRG system has become even more complex and the new regulations have also resulted in new problems associated with complications.. High demands are made on correct and complete coding of complex orthopedic and trauma surgery cases. Quality of case allocation within the G-DRG system has been improved. Nevertheless, further improvements of the G-DRG system are necessary, especially for cases with severe injuries.

  1. Effects of obesity on rehabilitation outcomes after orthopedic trauma.

    Science.gov (United States)

    Vincent, Heather K; Seay, Amanda N; Vincent, Kevin R; Atchison, James W; Sadasivan, Kalia

    2012-12-01

    This study examined whether differences existed in inpatient rehabilitation outcomes and therapy participation in nonobese and obese patients with orthopedic trauma. This was a retrospective study of 294 consecutive patients admitted to an inpatient rehabilitation hospital. Main outcomes included participation in therapy sessions, Functional Independence Measure (FIM) ratings, walking distance and stair climb, length of stay, FIM efficiency (FIM score gain/length of stay), and discharge to home. Data were stratified by patient body mass index values (nonobese, obese, ≥30 kg/m). There were no differences in therapy participation or length of stay between groups. Both total and motor FIM ratings at discharge were lower in obese patients compared with nonobese patients (P obese than in the nonobese group (2.6 ± 1.5 vs. 3.1 ± 1.5 points gained per day; P = 0.05). Walking distance and stair climb ability were similar between groups by discharge. Even morbidly obese patients attained some improvement with independence in walking. Obese patients make significant functional improvement during rehabilitation, but at a lesser magnitude and rate as their nonobese counterparts. Even with morbid obesity, small but important functional gains can occur during rehabilitation for orthopedic trauma.

  2. [Diagnostic control. Psychiatric comorbidity in patients of technical orthopedic units].

    Science.gov (United States)

    Lange, C; Heuft, G; Wetz, H H

    2001-04-01

    Because of the new hospital finance law a DRG (Diagnosis Related Groups) controlled discount liquidation under consideration of the medical impairment becomes necessary. In this paper the importance of a correct and complete description of the psychic comorbidity for the development of German-Refined-DRGs (GR-DRGs) in the orthopedic field is described. Therefore we analysed data of orthopedic in-patients, who are diagnosed by consultation of the clinic for psychosomatics and psychotherapy. A psychic comorbidity (ICD-10 Chapter F (V)) was diagnosed by 95% of the consulted patient. 30% of the patients showed difficulties in coping with their disease. 40% suffered from chronical psychoneurotic patterns and conflicts, which can be explained (a) as consequence of a difficult psychosocial adaptation by chronic disease or after an amputation (b) as basic mental disorders (c) as cause of the orthopaedic complications. Therefore the number of indications for a psychotherapeutic or psychiatric treatment is very high. The knowledge about a psychic comorbidity can--beside financial aspects--help the team on the orthopaedic station in the treatment of difficult patient.

  3. Nanotechnology: the scope and potential applications in orthopedic surgery.

    Science.gov (United States)

    Gavaskar, Ashok; Rojas, D; Videla, F

    2018-03-30

    Nanotechnology involves manipulation of matter measuring 1-100 nm in at least one of its dimensions at the molecular level. Engineering and manipulation of matter at the molecular level has several advantages in the field of medicine (nanomedicine) since most of the biological molecules exist and function at a nanoscale. Though promising, questions still remain on how much of this will ultimately translate into achieving better patient care. Concerns of cost-effectiveness and nanotechnology safety still remain unclear. Orthopedics is an attractive area for the application of nanotechnology since the bone, and its constituents such as hydroxyapatite, Haversian systems, and the collagen fibrils are nanocompounds. The major orthopedic applications of nanotechnology involve around (i) effective drug delivery systems for antibiotics and chemotherapeutic agents, (ii) surface preparation of implants and prosthesis to improve osteointegration and reduce biofilm formation, (iii) controlled drug eluting systems to combat implant-related infections, (iv) tissue engineering for scaffolds preparation to deal with bone and cartilage defects, and (v) diagnostic applications in the field of oncology and musculoskeletal infections.

  4. Prevalence of internet and social media usage in orthopedic surgery.

    Science.gov (United States)

    Curry, Emily; Li, Xinning; Nguyen, Joseph; Matzkin, Elizabeth

    2014-08-08

    Prior studies in other specialties have shown that social networking and Internet usage has become an increasingly important means of patient communication and referral. The purpose of this study is to evaluate the prevalence of Internet or social media usage in new patients referred to a major academic orthopedics center and to identify new avenues to optimize patient recruitment and communication. New patients were surveyed (n=752) between December 2012 to January 2013 in a major academic orthopaedic center to complete a 15-item questionnaire including social media and Internet usage information. Data was collected for all orthopaedic sub-specialties and statistical analysis was performed. Fifty percent of patients use social networking sites, such as Facebook. Sports medicine patients tend to be higher social networking users (35.9%) relative to other services (9.8-17.9%) and was statistically higher when compared to the joints/tumor service (Psocial media. Patients that travelled between 120 to 180 miles from the hospital for their visits were significantly more likely to be social media users, as were patients that did research on their condition prior to their new patient appointment. We conclude that orthopedic patients who use social media/Internet are more likely to be younger, researched their condition prior to their appointment and undergo a longer average day's travel (120-180 miles) to see a physician. In an increasingly competitive market, surgeons with younger patient populations will need to utilize social networking and the Internet to capture new patient referrals.

  5. The Effects of Particle Size on the Surface Properties of an HVOF Coating of WC-Co

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Tong Yul; Yoon, Jae Hong; Yoon, Sang Hwan; Joo, Yun Kon [Changwon National University, Changwon (Korea, Republic of); Choi, Won Ho; Son, Young Bok [Xinix Metallizing Co., Ltd, Gyungnam (Korea, Republic of)

    2017-04-15

    The effects of particle size on the surface properties of HVOF spray coating were studied to improve of the durability of metal components. Micro and nano sized WC-12Co powders were coated on the surface of Inconel718, and the effects of particle size on surface properties were studied. Surface hardness was reduced when the particle sizes of the powder were decreased, because the larger specific surface area of the smaller particles caused greater heat absorption and decomposition of the hard WC to less hard W{sub 2}C and graphite. Porosity was increased by decreasing the particle size, because the larger specific surface area of the smaller particles caused a greater decomposition of WC to W{sub 2}C and free carbon. The free carbon formed carbon oxide gases which created the porous surface. The friction coefficient was reduced by decreasing the particle size because the larger specific surface area of the smaller particles produced more free carbon free Co and Co oxide which acted as solid lubricants. The friction coefficient increased when the surface temperature was increased from 25 to 500 ℃, due to local cold welding. To improve the durability of metal mechanical components, WC-Co coating with the proper particle size is recommended.

  6. A study of Ni-based WC composite coatings by laser induction hybrid rapid cladding with elliptical spot

    International Nuclear Information System (INIS)

    Zhou Shengfeng; Huang Yongjun; Zeng Xiaoyan

    2008-01-01

    Ni-based WC composite coatings by laser induction hybrid rapid cladding (LIHRC) with elliptical spot were investigated. Results indicate that the efficiency using the elliptical spot of 6 mm x 4 mm (the major and minor axis of laser beam are 6 mm and 4 mm, respectively, the major axis is parallel to the direction of laser scanning) is higher than that using the elliptical spot of 4 mm x 6 mm (the major axis is perpendicular to the direction of laser scanning). The precipitated carbides with the blocky and bar-like shape indicate that WC particles suffer from the heat damage of 'the disintegration pattern + the growth pattern', whichever elliptical spot is used at low laser scanning speed. However, at high laser scanning speed, the blocky carbides are only formed if the elliptical spot of 6 mm x 4 mm is adopted, showing that WC particles present the heat damage of 'the disintegration pattern', whereas the fine carbides are precipitated when the elliptical spot of 4 mm x 6 mm is used, showing that WC particles take on the heat damage of 'the radiation pattern'. Especially, the efficiency of LIHRC is increased much four times higher than that of the general laser cladding and crack-free ceramic-metal coatings can be obtained

  7. Semi-empirical relationship between the hardness, grain size and mean free path of WC-Co

    CSIR Research Space (South Africa)

    Makhele-Lekala, L

    2001-01-01

    Full Text Available , grain size of WC and mean free path in Co was obtained. It was found that the empirical formula fitted our measured hardness well. However, when used against results of other researchers, it did not reproduce them satisfactorily at values higher than...

  8. Perioperative dexketoprofen or lornoxicam administration for pain management after major orthopedic surgery: a randomized, controlled study.

    Science.gov (United States)

    Sivrikoz, Nükhet; Koltka, Kemalettin; Güresti, Ece; Büget, Mehmet; Sentürk, Mert; Özyalçın, Süleyman

    2014-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for multimodal postoperative pain management. The purpose of this study was to evaluate the postoperative pain relief and opioid-sparing effects of dexketoprofen and lornoxicam after major orthopedic surgery. After obtaining ethical committee approval and informed consent, 120 patients undergoing elective hip or knee replacement under general anesthesia were randomized to receive two intravenous injections of 50 mg dexketoprofen (GD), 8 mg lornoxicam (GL) or saline as placebo (GP) intravenously. Postoperatively, patient-controlled analgesia (PCA) morphine was started as a 0.01 mg.kg-1 bolus dose, with lockout time of 10 minutes without continuous infusion. Pain assessment was made using the Visual Analogue Scale (VAS) at rest or during movement at postoperative 1, 2, 4, 6, 8, 12, and 24 hours. The three groups were similar in terms of age, gender, American Society of Anesthesiologists (ASA) class, number of patients who underwent hip or knee surgery, weight, height, and operation duration. Patients in GD and GL demonstrated significantly reduced pain scores at rest and active motion compared to GP, with lower scores in the dexketoprofen group. Patients in GD and GL used significantly less morphine in the postoperative period compared to GP. The total morphine consumption of patients in GD was lower than in GL. Intravenous application of 50 mg dexketoprofen twice a day and 8 mg lornoxicam twice a day improved analgesia and decreased morphine consumption following major orthopedic surgery. When the two active drugs were compared, it was found that dexketoprofen was superior to lornoxicam in terms of analgesic efficacy and opioid consumption.

  9. Near-miss event assessment in orthopedic surgery: Antimicrobial prophylaxis noncompliance.

    Science.gov (United States)

    Bonfait, H; Delaunay, C; de Thomasson, E; Charrois, O

    2010-09-01

    Antimicrobial prophylaxis is one of the main safety measures to be enforced when implanting any medical device; surveys of practice, however, have found poor compliance. This study is based on analysis of 153 dedicated in-depth analysis forms sent to orthopedic surgeons who had reported an antimicrobial prophylaxis-related near-miss event (NME) during the year 2008 as part of their certification report to the official organization, Orthorisq (orthopaedic Patient safety risk management agency). Antimicrobial prophylaxis guidelines exist in 95% of French centers, but in 14% are not available in the right place. 88% of orthopedic surgeons consider them well-adapted to their practice. Most declarations follow fortuitous discovery by the surgeon of an immediate peri-operative malfunction. Human causes were found in 92% of declarations, general organizational causes in 50% and material causes in 28%. Regarding corrective action, 65% of respondents reported implementing a second-order procedure, and only 20% were able to resume truly regular antimicrobial prophylaxis. The main reason for poor or non-performance of antimicrobial prophylaxis was "omission by negligence or oversight", reported in 56% of declarations. Proposals for improvement were: revised antimicrobial prophylaxis guidelines specifying "who does what"; guideline awareness checks on new, temporary and locum-tenens staff; patient involvement in personal data collection; and implementation of a check-list in line with WHO and French Health Authority recommendations. These improvement proposals were taken on board in the antimicrobial prophylaxis consensus update currently being drawn up by the French Society for Anesthesia and Intensive Care. Level IV, Decision Analyses Study. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  10. Reliability and Validity of 3 Methods of Assessing Orthopedic Resident Skill in Shoulder Surgery.

    Science.gov (United States)

    Bernard, Johnathan A; Dattilo, Jonathan R; Srikumaran, Uma; Zikria, Bashir A; Jain, Amit; LaPorte, Dawn M

    Traditional measures for evaluating resident surgical technical skills (e.g., case logs) assess operative volume but not level of surgical proficiency. Our goal was to compare the reliability and validity of 3 tools for measuring surgical skill among orthopedic residents when performing 3 open surgical approaches to the shoulder. A total of 23 residents at different stages of their surgical training were tested for technical skill pertaining to 3 shoulder surgical approaches using the following measures: Objective Structured Assessment of Technical Skills (OSATS) checklists, the Global Rating Scale (GRS), and a final pass/fail assessment determined by 3 upper extremity surgeons. Adverse events were recorded. The Cronbach α coefficient was used to assess reliability of the OSATS checklists and GRS scores. Interrater reliability was calculated with intraclass correlation coefficients. Correlations among OSATS checklist scores, GRS scores, and pass/fail assessment were calculated with Spearman ρ. Validity of OSATS checklists was determined using analysis of variance with postgraduate year (PGY) as a between-subjects factor. Significance was set at p shoulder approaches. Checklist scores showed superior interrater reliability compared with GRS and subjective pass/fail measurements. GRS scores were positively correlated across training years. The incidence of adverse events was significantly higher among PGY-1 and PGY-2 residents compared with more experienced residents. OSATS checklists are a valid and reliable assessment of technical skills across 3 surgical shoulder approaches. However, checklist scores do not measure quality of technique. Documenting adverse events is necessary to assess quality of technique and ultimate pass/fail status. Multiple methods of assessing surgical skill should be considered when evaluating orthopedic resident surgical performance. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights

  11. The Orthopedically Disabled Child: Psychological Implications with an Individual Basis. July 1984 Revision.

    Science.gov (United States)

    Sigmon, Scott B.

    This study describes the implications of the Individual Psychology of Alfred Adler and field theory associated with Kurt Lewin in understanding orthopedically disabled children and points out that orthopedically disabled youngsters have a remarkable range of individual differences both in type of disability as well as level of adjustment.…

  12. Evaluation the effects of adding ketamine to morphine in intravenous patient-controlled analgesia after orthopedic surgery

    Directory of Open Access Journals (Sweden)

    Godrat Akhavanakbari

    2014-01-01

    Full Text Available Background: Intravenous patient-controlled analgesia (PCA with morphine is commonly used for post-operative pain after major surgery. Ketamine has analgesic property at lower doses, and in combination with opioids it could have synergistic effect. The aim of this study is to determine effects of the addition of ketamine to morphine for PCA after orthopedic surgery. Materials and Methods: In this double-blind randomized clinical trial, 60 patients were randomly allocated to receive PCA consisting: Group 1 (morphine 0.2 mg/ml, Group 2 (morphine 0.2 mg/ml + ketamine 1 mg/ml, and Group 3 (morphine 0.1 mg/ml + ketamine 2 mg/ml. In this, anesthesiologists managed study, patients had orthopedic surgery. Assessments were made at 24 h and 48 h post-operatively. Visual analog scale (VAS was used for recording pain score. PCA morphine use was recorded at 24 h and 48 h. VAS scores over 48 h were analyzed with analysis of variance for repeated measures. Significance level was taken as 0.05. Results: There is no significant difference between demographic information of the three groups ( P > 0.05. Control of pain in Group 2 and Group 3 was better than in Group 1 (only morphine ( P = 0.001 but there was no significant difference between Group 2 and Group 3 ( P > 0.05. Rate of narcotic consumption in groups 2 and 3 was significantly lower than Group 1 ( P < 0.05. Conclusion: After orthopedic surgery, the addition of ketamine to morphine for intravenous PCA was superior to Intravenous PCA opioid alone. The combination induces a significant reduction in pain score and cumulative morphine consumption.

  13. The application of telemedicine in orthopedic surgery in singapore: a pilot study on a secure, mobile telehealth application and messaging platform.

    Science.gov (United States)

    Daruwalla, Zubin Jimmy; Wong, Keng Lin; Thambiah, Joseph

    2014-06-05

    in the operating room or watching procedures being performed remotely, providing both patient and parent reassurance in pediatric orthopedic patients, and finally in the setting of outpatient clinics. With our pilot study having excellent results in terms of acceptance and satisfaction, the integration of a secure, mobile telehealth application, and messaging platform, not only in the orthopedic department but also the hospital in general, has an exciting and limitless potential. More so in this era where downsizing hospital costs is beneficial, doing so may also be mandatory in order to comply with the soon to be introduced personal data protection act.

  14. Coating Properties of WC-Ni Cold Spray Coating for the Application in Secondary Piping System of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, JeongWon; Kim, Seunghyun; Kim, Ji Hyun [UNIST, Ulsan (Korea, Republic of)

    2015-10-15

    As a result of FAC(flow accelerated corrosion), severe accidents, failure of carbon steel like a Mihama Unit-3 occurred. Chemical composition change of carbon steel or coating to inner surface is one of methods to improve corrosion properties. Among them, thermal spray coating is convenient solution to apply at industry. Powder is melted at blast furnace and ejected to substrate. After adhesion, substrate and coating layer is cooled down and coated layer protects steel from corrosion finally. However high thermal energy is transferred to substrate and coating layer so it leads high thermal residual stress in coating procedure. Besides, high temperature for melting powder makes unexpected chemical reaction of powder like an oxidation or carburization. Whereas, cold spray uses low temperature comparing with other thermal spray. Thermal energy is used for not melting powder but high kinetic energy of powder and plastic deformation during collision. Therefore, fuel such as oxygen-acetylene gas is not needed. It needs carrier gas, compressed air, nitrogen or helium, to increase kinetic energy of powder and move powder to substrate. Comparing cold spray with high velocity oxy fuel (HVOF), one of thermal spray, cold spray coating layer contains only WC and Co. One of other problem about WC is brittleness during coating. To improve deformability of WC, binder metal is added. For example, Co, Cr, Ni, Cu, Al, Fe or etc. Additionally, binder metal lowering melting temperature of composite powder increases coating properties. Among them, Co which is widely used as binder metal maintains mechanical properties like a hardness and improves corrosion properties. Therefore Co is not suitable for binder metal of WC coating. In contrast, Ni has better corrosion resistance to alkaline environment and makes lower melting temperature. Moreover, in a view of cold spray, FCC structure has better deformability than BCC or HCP, and BCC has lowest deformability. WC is BCC structure so it

  15. Comparative study of the friction and wear behavior of plasma sprayed conventional and nanostructured WC-12%Co coatings on stainless steel

    International Nuclear Information System (INIS)

    Zhao Xiaoqin; Zhou Huidi; Chen Jianmin

    2006-01-01

    Conventional and nanostructured WC-12%Co coatings were deposited on 1Cr18Ni9Ti stainless steel substrate using air plasma spraying. The hardness of the coatings was measured, while their friction and wear behavior sliding against Si 3 N 4 at room temperature and elevated temperatures up to 400 deg. C was comparatively studied. The microstructures and worn surface morphologies of the coatings were comparatively analyzed as well by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDXA). It was found that the as-sprayed WC-12%Co coatings were composed of WC as the major phase and W 2 C, WC 1-x , and W 3 Co 3 C as the minor phases. The plasma sprayed nanostructured WC-12%Co coating had much higher hardness and refined microstructures than the conventional WC-12%Co coating. This largely accounted for the better wear resistance of the nanostructured WC-12%Co coating than the conventional coating. Besides, the two types of WC-12%Co coatings showed minor differences in friction coefficients, though the nanostructured WC-12%Co coating roughly had slightly smaller friction coefficient than the conventional coating under the same sliding condition. Moreover, both the conventional and nanostructured WC-12%Co coatings recorded gradually increased wear rate with increasing temperature, and the nanostructured coating was less sensitive to the temperature rise in terms of the wear resistance. The worn surfaces of the conventional WC-12%Co coating at different sliding conditions showed more severe adhesion, microfracture, and peeling as compared to the nanostructured WC-12%Co coating, which well conformed to the corresponding wear resistance of the two types of coatings. The nanostructured WC-12%Co coating with a wear rate as small as 1.01 x 10 -7 mm 3 /Nm at 400 deg. C could be promising candidate coating for the surface-modification of some sliding components subject to harsh working conditions involving elevated

  16. Gallium-containing hydroxyapatite for potential use in orthopedics

    International Nuclear Information System (INIS)

    Melnikov, P.; Teixeira, A.R.; Malzac, A.; Coelho, M. de B.

    2009-01-01

    A novel material that may be recommended for grafts and implants stimulating bone growth has been obtained by introducing gallium ions (up to 11.0 mass%) into crystalline lattice of hydroxyapatite. The doping was carried out using gallium nitrate and sodium gallate solutions. In both cases, lattice parameters of gallium-doped hydroxyapatite are identical to those of pure synthetic hydroxyapatite. Gallium does not replace calcium as a result of heterovalent substitution and consequently produces no distortions in the framework of hydroxyapatite matrix. It remains strongly fixed in the form of solid solution of intercalation. According to scanning electron microscopy images gallium insertion does not cause any morphological alterations in hydroxyapatite structure and the product developed meets physico-chemical criteria for biomaterial to be employed in orthopedic practice and local handling of traumatic injuries. Its future usage opens the opportunity to enhance osteosynthesis and calcium retention in loco.

  17. Effects of external stress on biodegradable orthopedic materials: A review

    Directory of Open Access Journals (Sweden)

    Xuan Li

    2016-09-01

    Full Text Available Biodegradable orthopedic materials (BOMs are used in rehabilitation and reconstruction of fractured tissues. The response of BOMs to the combined action of physiological stress and corrosion is an important issue in vivo since stress-assisted degradation and cracking are common. Although the degradation behavior and kinetics of BOMs have been investigated under static conditions, stress effects can be very serious and even fatal in the dynamic physiological environment. Since stress is unavoidable in biomedical applications of BOMs, recent work has focused on the evaluation and prediction of the properties of BOMs under stress in corrosive media. This article reviews recent progress in this important area focusing on biodegradable metals, polymers, and ceramics.

  18. Barriers to the clinical translation of orthopedic tissue engineering.

    Science.gov (United States)

    Evans, Christopher H

    2011-12-01

    Tissue engineering and regenerative medicine have been the subject of increasingly intensive research for over 20 years, and there is concern in some quarters over the lack of clinically useful products despite the large sums of money invested. This review provides one perspective on orthopedic applications from a biologist working in academia. It is suggested that the delay in clinical application is not atypical of new, biologically based technologies. Some barriers to progress are acknowledged and discussed, but it is also noted that preclinical studies have identified several promising types of cells, scaffolds, and morphogenetic signals, which, although not optimal, are worth advancing toward human trials to establish a bridgehead in the clinic. Although this transitional technology will be replaced by more sophisticated, subsequent systems, it will perform valuable pioneering functions and facilitate the clinical development of the field. Some strategies for achieving this are suggested. © Mary Ann Liebert, Inc.

  19. Evaluation of occupational and patient radiation doses in orthopedic surgery

    International Nuclear Information System (INIS)

    Sulieman, A.; Alzimami, K.; Habeeballa, B.; Osman, H.; Abdelaziz, I.; Sassi, S.A.; Sam, A.K.

    2015-01-01

    This study intends to measure the radiation dose to patients and staff during (i) Dynamic Hip Screw (DHS) and (ii) Dynamic Cannula Screw (DCS) and to evaluate entrance surface Air kerma (ESAK) dose and organ doses and effective doses. Calibrated Thermoluminescence dosimeters (TLD-GR200A) were used. The mean patients’ doses were 0.46 mGy and 0.07 mGy for DHS and DCS procedures, respectively. The mean staff doses at the thyroid and chest were 4.69 mGy and 1.21 mGy per procedure. The mean organ and effective dose for patients and staff were higher in DHS compared to DCS. Orthopedic surgeons were exposed to unnecessary radiation doses due to the lack of protection measures. The radiation dose per hip procedure is within the safety limit and less than the previous studies

  20. Power harvesting using PZT ceramics embedded in orthopedic implants.

    Science.gov (United States)

    Chen, Hong; Liu, Ming; Jia, Chen; Wang, Zihua

    2009-09-01

    Battery lifetime has been the stumbling block for many power-critical or maintenance-free real-time embedded applications, such as wireless sensors and orthopedic implants. Thus a piezoelectric material that could convert human motion into electrical energy provides a very attractive solution for clinical implants. In this work, we analyze the power generation characteristics of stiff lead zirconate titanate (PZT) ceramics and the equivalent circuit through extensive experiments. Our experimental framework allows us to explore many important design considerations of such a PZT-based power generator. Overall we can achieve a PZT element volume of 0.5 x 0.5 x 1.8 cm, which is considerably smaller than the results reported so far. Finally, we outline the application of our PZT elements in a total knee replacement (TKR) implant.

  1. Orthopedic specialty hospitals: centers of excellence or greed machines?

    Science.gov (United States)

    Badlani, Neil; Boden, Scott; Phillips, Frank

    2012-03-07

    Orthopedic specialty hospitals have recently been the subject of debate. They are patient-centered, physician-friendly health care alternatives that take advantage of the economic efficiencies of specialization. Medically, they provide a higher quality of care and increase patient and physician satisfaction. Economically, they are more efficient and profitable than general hospitals. They also positively affect society through the taxes they pay and the beneficial aspects of the competition they provide to general hospitals. Their ability to provide a disruptive innovation to the existing hospital industry will lead to lower costs and greater access to health care. However, critics say that physician ownership presents potential conflicts of interest and leads to overuse of medical care. Some general hospitals are suffering as a result of unfair specialty hospital practices, and a few drastic medical complications have occurred at specialty hospitals. Specialty hospitals have been scrutinized for increasing the inequality of health care and continue to be a target of government regulations. In this article, the pros and cons are examined, and the Emory Orthopaedics and Spine Hospital is analyzed as an example. Orthopedic specialty hospitals provide excellent care and are great assets to society. Competition between specialty and general hospitals has provided added value to patients and taxpayers. However, physicians must take more responsibility in their appropriate and ethical leadership. It is critical to recognize financial conflicts of interest, disclose ownership, and act ethically. Patient care cannot be compromised. With thoughtful and efficient leadership, specialty hospitals can be an integral part of improving health care in the long term. Copyright 2012, SLACK Incorporated.

  2. Marijuana use and mortality following orthopedic surgical procedures.

    Science.gov (United States)

    Moon, Andrew S; Smith, Walter; Mullen, Sawyer; Ponce, Brent A; McGwin, Gerald; Shah, Ashish; Naranje, Sameer M

    2018-03-20

    The association between marijuana use and surgical procedures is a matter of increasing societal relevance that has not been well studied in the literature. The primary aim of this study is to evaluate the relationship between marijuana use and in-hospital mortality, as well as to assess associated comorbidities in patients undergoing commonly billed orthopedic surgeries. The National Inpatient Sample (NIS) database from 2010 to 2014 was used to determine the odds ratios for the associations between marijuana use and in-hospital mortality, heart failure (HF), stroke, and cardiac disease (CD) in patients undergoing five common orthopedic procedures: hip (THA), knee (TKA), and shoulder arthroplasty (TSA), spinal fusion, and traumatic femur fracture fixation. Of 9,561,963 patients who underwent one of the five selected procedures in the four-year period, 26,416 (0.28%) were identified with a diagnosis of marijuana use disorder. In hip and knee arthroplasty patients, marijuana use was associated with decreased odds of mortality compared to no marijuana use (pmarijuana use (0.70%), which was associated with decreased odds of mortality (p = 0.0483), HF (p = 0.0076), and CD (p = 0.0003). For spinal fusions, marijuana use was associated with increased odds of stroke (pMarijuana use in patients undergoing shoulder arthroplasty was associated with decreased odds of mortality (pmarijuana use was associated with decreased mortality in patients undergoing THA, TKA, TSA and traumatic femur fixation, although the significance of these findings remains unclear. More research is needed to provide insight into these associations in a growing surgical population.

  3. Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein.

    Directory of Open Access Journals (Sweden)

    Andreas Baranowski

    Full Text Available Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES, and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants

  4. Orthopedic surgery in cerebral palsy: Instructional course lecture

    Directory of Open Access Journals (Sweden)

    Deepak Sharan

    2017-01-01

    Full Text Available Orthopedic surgery (OS plays an important role in the management of cerebral palsy (CP. The objectives of OS are to optimize functions and prevent deformity. Newer developments in OS for CP include emphasis on hip surveillance, minimally invasive procedures, use of external fixators instead of plates and screws, better understanding of lever arm dysfunctions (that can only be corrected by bony OS, orthopedic selective spasticity-control surgery, and single-event multilevel lever arm restoration and anti spasticity surgery, which have led to significant improvements in gross motor function and ambulation, especially in spastic quadriplegia, athetosis, and dystonia. The results of OS can be dramatic and life altering for the person with CP and their caregivers if it is performed meticulously by a specialized surgical team, at the appropriate age, for the correct indications, employing sound biomechanical principles and is followed by physician-led, protocol based, intensive, multidisciplinary, institutional rehabilitation, and long term followup. However, OS can be a double-edged sword, and if performed less than optimally, and without the supporting multidisciplinary medical and rehabilitation team, expertise and infrastructure, it often leads to significant functional worsening of the person with CP, including irretrievable loss of previous ambulatory capacity. OS must be integrated into the long term management of the person with CP and should be anticipated and planned at the optimal time and not viewed as a “last resort” intervention or failure of rehabilitation. This instructional course lecture reviews the relevant contemporary principles and techniques of OS in CP.

  5. SPECT/CT imaging in general orthopedic practice.

    Science.gov (United States)

    Scharf, Stephen

    2009-09-01

    The availability of hybrid devices that combine the latest single-photon emission computed tomography (SPECT) imaging technology with multislice computed tomography (CT) scanning has allowed us to detect subtle, nonspecific abnormalities on bone scans and interpret them as specific focal areas of pathology. Abnormalities in the spine can be separated into those caused by pars fractures, facet joint arthritis, or osteophyte formation on vertebral bodies. Compression fractures can be distinguished from severe degenerative disease, both of which can cause intense activity across the spine on either planar or SPECT imaging. Localizing activity in patients who have had spinal fusion can provide tremendous insight into the causes of therapeutic failures. Infections of the spine now can be diagnosed with gallium SPECT/CT, despite the fact that gallium has long been abandoned because of its failure to detect spine infection on either planar or SPECT imaging. Small focal abnormalities in the feet and ankles can be localized well enough to make specific orthopedic diagnoses on the basis of their location. Moreover, when radiographic imaging provides equivocal or inadequate information, SPECT/CT can provide a road map for further diagnostic studies and has been invaluable in planning surgery. Our ability to localize activity within a bone or at an articular surface has allowed us to distinguish between fractures and joint disease. Increased activity associated with congenital anomalies, such as tarsal coalition and Bertolotti's syndrome have allowed us to understand the pathophysiology of these conditions, to confirm them as the cause of the patient's symptoms, and to provide information that is useful in determining appropriate clinical management. As our experience broadens, SPECT/CT will undoubtedly become an important tool in the evaluation and management of a wider variety of orthopedic patients.

  6. The Electro-Spark Deposited WC-Cu Coatings Modified by Laser Treatment / Powłoki WC-Cu Naniesione Elektroiskrowo I Modyfikowane Obróbką Laserową

    Directory of Open Access Journals (Sweden)

    Radek N.

    2015-12-01

    Full Text Available The main objective of the present work was to determine the influence of laser treatment on microstructure, X-ray diffraction, microhardness, surface geometric structure and roughness, corrosion resistance and tribological properties of coatings deposited on C45 carbon steel by the electro-spark deposition (ESD process. The studies were conducted using WC-Cu electrodes produced by the powder metallurgy route. The tests show that the laser-treated electro-spark deposited WC-Cu coatings are characterized by higher corrosion resistance, surface roughness and seizure resistance which come at the expense of lower microhardness. The laser treatment process causes the homogenization of the chemical composition, structure refinement and healing of microcracks and pores of the electro-spark deposited coatings. Laser treated ESD coatings can be applied in sliding friction pairs and as protective coatings.

  7. Influence of podiatry on orthopedic surgery at a level I trauma center.

    Science.gov (United States)

    Jakoi, Andre M; Old, Andrew B; O'Neill, Craig A; Stein, Benjamin E; Stander, Eric P; Rosenblatt, Joseph; Herman, Martin J

    2014-06-01

    Level I trauma centers frequently see trauma at or below the ankle, which requires consultation with the orthopedic surgery department. However, as podiatry programs begin to firmly establish themselves in more Level I trauma centers, their consultations increase, ultimately taking those once seen by orthopedic surgery. A review of the literature demonstrates that this paradigm shift has yet to be discussed. The purpose of this study was to determine how many, if any, lower extremity fracture consultations a newly developed podiatry program would take from the orthopedic surgery department. A retrospective review was performed of emergency department records from January 2007 to December 2011. Seventeen different emergency department diagnoses were used to search the database. Ultimately, each patient's emergency department course was researched. Several trends were noted. First, if trauma surgery was involved, only the orthopedic surgery department was consulted for any injuries at or below the ankle. Second, the emergency department tended to consult the podiatry program only between the hours of 8 am and 6 pm. Third, as the podiatry program became more established, their number of consultations increased yearly, and, coincidentally, the orthopedic surgery department's consultations decreased. Finally, high-energy traumas involved only the orthopedic surgery department. Whether the orthopedic surgery department or podiatry program is consulted regarding trauma surgery is likely hospital dependent. Copyright 2014, SLACK Incorporated.

  8. The efficiency of a dedicated staff on operating room turnover time in hand surgery.

    Science.gov (United States)

    Avery, Daniel M; Matullo, Kristofer S

    2014-01-01

    To evaluate the effect of orthopedic and nonorthopedic operating room (OR) staff on the efficiency of turnover time in a hand surgery practice. A total of 621 sequential hand surgery cases were retrospectively reviewed. Turnover times for sequential cases were calculated and analyzed with regard to the characteristics of the OR staff being primarily orthopedic or nonorthopedic. A total of 227 turnover times were analyzed. The average turnover time with all nonorthopedic staff was 31 minutes, for having only an orthopedic surgical technician was 32 minutes, for having only an orthopedic circulator was 25 minutes, and for having both an orthopedic surgical technician and a circulator was 20 minutes. Statistical significance was seen when comparing only an orthopedic surgical technician versus both an orthopedic circulator and a surgical technician and when comparing both nonorthopedic staff versus both an orthopedic circulator and a surgical technician. OR efficiency is being increasingly evaluated for its effect on hospital revenue and OR staff costs. Reducing turnover time is one aspect of a multifaceted solution in increasing efficiency. Our study showed that, for hand surgery, orthopedic-specific staff can reduce turnover time. Economic/Decision Analysis III. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. WC1+ γδ T cells from cattle naturally infected with Mycobacterium avium subsp. paratuberculosis respond differentially to stimulation with PPD-J.

    Science.gov (United States)

    Albarrak, S M; Waters, W R; Stabel, J R; Hostetter, J M

    2017-08-01

    A role for γδ T cells in protection against mycobacterial infections including Johne's disease (JD) has been suggested. In neonatal calves where the risk to infection with Mycobacterium avium subsp. paratuberculosis (MAP) is high, the majority of circulating CD3 + lymphocytes are γδ TCR + . Bovine γδ T cells are divided into two major subsets based on the surface expression of workshop cluster 1 (WC1). The WC1 + subset, the predominant subset in periphery, is further divided into WC1.1 + and WC1.2 + subpopulations. The ability of γδ T cells to produce IFN-γ prior to CD4 + αβ T cell activation could be crucial to the outcome of MAP infection. In the current study, cattle were naturally infected with MAP and were classified as either in the subclinical or clinical stage of infection. Compared to the control non-infected group, γδ T cell frequency in circulating lymphocytes was significantly lower in the clinical group. The observed decline in frequency was restricted to the WC1.2 + subset, and was not associated with preferential migration to infection sites (distal-ileum). γδ T cells proliferated significantly in recall responses to stimulation with purified protein derivative from MAP (PPD-J) only in subclinically infected cattle. These responses were a heterogeneous mixture of WC1.1 and WC1.2 subsets. Proliferation and IFN-γ production by the WC1.1 + γδ T cell subset was significantly higher in the subclinical group compared to the control and clinical groups. Our data indicates differences in MAP-specific ex-vivo responses of peripheral WC1 + γδ T cells of cattle with the subclinical or clinical form of JD. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. High hardness-high toughness WC-20Co nanocomposites: Effect of VC variation and sintering temperature

    International Nuclear Information System (INIS)

    Kumar, Devender; Singh, K.

    2016-01-01

    WC-Co nanocomposites with variable VC content are synthesized by liquid phase sintering at two different temperatures. The as synthesized samples are characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) and optical microscope. The mechanical properties are obtained by Vickers indentation method. The high content of VC, lead to high porosity when sintering temperature is increased from 1350 to 1400 °C. The relative density of all the samples is more than 95%. Microstructure reveals that agglomeration of W-Co-C and V-W-C increases at 1400 °C, which generates layered interfaces in radial direction and hence the material inhomogeneity. XRD pattern shows that the formation of η phase increases at 1400 °C, which is responsible to decrease the fracture toughness of the present samples. The average particle size of 102 nm, highest hardness of 1870.6 kgf/mm"2 with fracture toughness of 14.4 MN/mm"3"/"2 is observed in sample having 7.5 wt% VC, sintered at 1350 °C for one minute. This combination shows the highest hardness and reasonably high toughness as compared to conventionally sintered materials reported so far.

  11. Investigation of cosputtered W--C thin films as diffusion barriers

    International Nuclear Information System (INIS)

    Yang, H.Y.; Zhao, X.

    1988-01-01

    Polycrystalline thin films of W--C were deposited on single-crystal Si or SiO 2 substrates by rf planar magnetron cosputtering of graphite (C) and W targets. The performance of cosputtered W 75 C 25 thin films as diffusion barriers between a Si substrate and metallic overlayers of Ag, Au, or Al was investigated. Backscattering spectrometry and x-ray diffraction are used to detect metallurgical interactions. Four-point probe measurement of resistance is employed to monitor the electrical stability of the metallization schemes upon thermal annealing in a vacuum for 30 min in temperature ranges from 500 to 700 0 C. The electrical resistivity of W 75 C 25 films is 140 μΩ cm. A W 75 C 25 layer 1100 A thick prevents metallurgical interdiffusion and reaction between Au or Ag overlayers and the Si substrates up to 700 0 C, and between an Al overlayer and the Si substrate up to 450 0 C.tential

  12. Tribology study on TiB2+WSi2 composite against WC

    Science.gov (United States)

    Murthy, T. S. R. Ch.; Basha, M. M.; Sonber, J. K.; Singh, K.; Raju, K.; Sairam, K.; Nagaraj, A.; Majumdar, S.; Rao, G. V. S. Nageswara; Kain, Vivekanand

    2018-04-01

    Titanium diboride (TiB2) is one of the potential material for green energy applications such as neutron absorber in high temperature/advanced nuclear reactors, receiver materials for second generation concentrated solar power. We developed the process flow sheet for synthesis and consolidation of various series of TiB2 based materials in our laboratory. Amongst these, TiB2+WSi2 exhibited better sinterability and oxidation resistance properties. In the present work, tribology properties of TiB2+2.5%WSi2 composite was studied against WC-Co ball using different normal loads (5, 10 and 20 N) and frequencies (10, 15 Hz) under dry condition. Coefficient of friction (COF) and wear rate was measured at all test conditions. Wear mechanism was analyzed by microstructural characterization. It was found that COF is decreased from 0.46 to 0.36 with increasing load (5 to 20 N) at 15 Hz frequency; whereas at 10 Hz frequency COF is measured a constant average value of 0.49. The specific wear rate measured was minimum at 5 N load and 15 Hz frequency combination and was found to be 2.84×10-6 mm3/N m. The wear mechanisms identified during reciprocative sliding wear of composite were abrasion and surface tribo-oxidative reactions with delamination from tribo-zone.

  13. Sintering, microstructure and properties of WC-AISI304 powder composites

    International Nuclear Information System (INIS)

    Marques, B.J.; Fernandes, C.M.; Senos, A.M.R.

    2013-01-01

    Highlights: ► Total replacement of Co binder by stainless steel AISI 304 in WC based composites. ► Processing conditions for WC–stainless steel composites. ► Mechanical behavior and oxidation resistance of WC–stainless steel composites. -- Abstract: Tungsten carbide–stainless steel (AISI 304) based composites were successfully prepared by powder metallurgy routes using vacuum sintering at a maximum temperature of 1500 °C. The effects of the binder amount (between 6 and 15 wt.%) on the phase composition, microstructure and mechanical properties, namely hardness and fracture toughness, were investigated. Appreciable amount of (M,W) 6 C up to 12 wt.% was detected, especially for the higher SS contents. However, a good compromise between toughness and hardness was observed. Besides that, improved oxidation resistance was noticed in WC–SS based composites compared with WC–Co composites. The results are discussed having in mind the correlation between chemical composition, phase composition, microstructure and mechanical behavior

  14. Corrosion behaviour of WC-Co based hardmetal in neutral chloride and acid sulphate media

    Energy Technology Data Exchange (ETDEWEB)

    Bozzini, B.; Serra, M.; Fanigliulo, A.; Bogani, F. [Lecce Univ. (Italy). Dipt. di Ingegneria dell' Innovazione; Gaudenzi, G.P. de [Harditalia s.r.l. (OMCD Group), Genova (Italy)

    2002-05-01

    A comparative study of the corrosion behaviour of WC-Co based hardmetals with Ni and Cr{sub 3}C{sub 2} additions is carried out. The aggressive environments are neutral and acidic aerated aqueous solutions of NaCl and H{sub 2}SO{sub 4}. This study is based on electrochemical (linear sweep voltammery), compositional (surface EDX analyses, AAS analyses of attack solutions), structural (XRD) and morphological (SEM) investigations. Electrochemical figures of merit were computed from linear sweep voltammograms in order to rank the corrosion behaviour close to free-immersion conditions in the studied environments and with presence of oxidising agents. EDX and XRD analyses allow to accurately characterise the penetration depth of the attack as well as the preferential dissolution of the constituents. Binders containing Ni show a significantly improved corrosion resistance in the studied systems. The amount of Ni in the binder is the single most important factor affecting corrosion performance. Cr{sub 3}C{sub 2} additions to hardmetals with lower-Ni binders cannot balance the effect of Ni, but give an improved resistance in neutral chloride-containing solutions. (orig.)

  15. On modeling the CNC end milling characteristics of Al-7075/WC powder metallurgy composites

    Science.gov (United States)

    Hanuman, N. S. V. N.; Rao, P. Gangadhara; Kumar, B. Sudheer; Karthik, N.

    2017-07-01

    Surface finish and material removal rate are two important factors in the manufacturing which affect acceptability of the product which in turn reflects on the profitability of the organization. The worth of the production setup to produce the components with high material removal rate (MRR) without sacrificing the surface requirements can play vital role in sustainability and profitability of the organization. In this paper, the effect of process parameters on metal removal rate and surface roughness has been investigated in milling of Al7075-MMC with WC as reinforcement element. Cutting speed, feed and depth of cut have been taken as input factors in three level response surface methodologies used for experimentation. Mathematical models have been developed using response surface methodology to predict surface finish, and metal removal rate in term of machining parameters. Depth of cut and feed rate are found to be a dominant parameter for surface roughness; whereas feed rate mainly affects the metal removal rate. The results of mathematical models have been compared with the experimental and found to be in good agreement. The results of predicted model can be used in selection of process parameters to insure desired quality and improved productivity.

  16. Material mixing on W/C twin limiter in TEXTOR-94

    International Nuclear Information System (INIS)

    Tanabe, T.; Ohgo, T.; Wada, M.; Rubel, M.; Philipps, V.; Seggern, J. von; Ohya, K.; Huber, A.; Pospieszczyk, A.; Schweer, B.

    2000-01-01

    In order to investigate the effect of mutual contamination between tungsten (W) and carbon (C) and its influence on the plasma, a W-C twin test limiter, half made of W and the other half of C, was inserted into the edge plasma of TEXTOR-94 under ohmic and NBI heating conditions. The contamination process was observed by spectroscopy, and the intensity distribution of WI showed migration of W onto the C side by the successive cycles of sputtering and prompt redeposition. On the other hand, the deposition of C on the W surface was not obvious. Most of the hydrogen (deuterium) on the limiter was found to be retained in the deposited layers and that in the deposited C layer much higher than that in the deposited W layer. This indicates that tritium retention is smaller in metallic deposits above 500 K. The AES analysis conducted after the exposure of the test limiter showed that W deposited on C reacted with the substrate to form carbides at higher temperatures. The thickness of carbide layer, and/or the content of W in C were influenced by the temperature and flux distributions, and no carbide layer was formed at the limiter edge where the temperature was relatively low

  17. Perspectives of Orthopedic Surgeons on Racial/Ethnic Disparities in Care.

    Science.gov (United States)

    Adelani, Muyibat A; O'Connor, Mary I

    2017-08-01

    Racial/ethnic disparities in healthcare, including orthopedics, have been extensively documented. However, the level of knowledge among orthopedic surgeons regarding racial/ethnic disparities is unknown. The purpose of this study is to determine the views of orthopedic surgeons on (1) the extent of racial/ethnic disparities in orthopedic care, (2) patient and system factors that may contribute, and (3) the potential role of orthopedic surgeons in the reduction of disparities. Three hundred five members of the American Orthopaedic Association completed a survey to assess their knowledge of racial/ethnic disparities and their perceptions about the underlying causes. Twelve percent of respondents believe that patients often receive different care based on race/ethnicity in healthcare in general, while 9 % believe that differences exist in orthopedic care in general, 3 % believe that differences exist within their hospitals/clinics, and 1 % reported differences in their own practices. Despite this, 68 % acknowledge that there is evidence of disparities in orthopedic care. Fifty-one percent believe that a lack of insurance significantly contributes to disparities. Thirty-five percent believe that diversification of the orthopedic workforce would be a "very effective" strategy in addressing disparities, while 25 % percent believe that research would be "very effective" and 24 % believe that surgeon education would be "very effective." Awareness regarding racial/ethnic disparities in musculoskeletal care is low among orthopedic surgeons. Additionally, respondents were more likely to acknowledge disparities within the practices of others than their own. Increased diversity, research, and education may help improve knowledge of this problem.

  18. Value Added: the Case for Point-of-View Camera use in Orthopedic Surgical Education.

    Science.gov (United States)

    Karam, Matthew D; Thomas, Geb W; Taylor, Leah; Liu, Xiaoxing; Anthony, Chris A; Anderson, Donald D

    2016-01-01

    Orthopedic surgical education is evolving as educators search for new ways to enhance surgical skills training. Orthopedic educators should seek new methods and technologies to augment and add value to real-time orthopedic surgical experience. This paper describes a protocol whereby we have started to capture and evaluate specific orthopedic milestone procedures with a GoPro® point-of-view video camera and a dedicated video reviewing website as a way of supplementing the current paradigm in surgical skills training. We report our experience regarding the details and feasibility of this protocol. Upon identification of a patient undergoing surgical fixation of a hip or ankle fracture, an orthopedic resident places a GoPro® point-of-view camera on his or her forehead. All fluoroscopic images acquired during the case are saved and later incorporated into a video on the reviewing website. Surgical videos are uploaded to a secure server and are accessible for later review and assessment via a custom-built website. An electronic survey of resident participants was performed utilizing Qualtrics software. Results are reported using descriptive statistics. A total of 51 surgical videos involving 23 different residents have been captured to date. This includes 20 intertrochanteric hip fracture cases and 31 ankle fracture cases. The average duration of each surgical video was 1 hour and 16 minutes (range 40 minutes to 2 hours and 19 minutes). Of 24 orthopedic resident surgeons surveyed, 88% thought capturing a video portfolio of orthopedic milestones would benefit their education. There is a growing demand in orthopedic surgical education to extract more value from each surgical experience. While further work in development and refinement of such assessments is necessary, we feel that intraoperative video, particularly when captured and presented in a non-threatening, user friendly manner, can add significant value to the present and future paradigm of orthopedic surgical

  19. Action memorandum for the Waste Area Grouping 1 Tank WC-14 removal action at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1994-11-01

    This action memorandum documents approval for a Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended (CERCLA), time-critical action. The action will remove radiologically contaminated water from Tank WC-14. The water contains a polychlorinated biphenyl (PCB) at a level below regulatory concern. Tank WC-14 is located in the Waste Area Grouping (WAG) 1 WC-10 Tank Farm at the Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee. Contaminated sludge remaining in the tank after removal of the liquid will be the subject of a future action

  20. Pre: Surgical orthopedic pre-maxillary alignment in bilateral cleft lip and palate patient

    Directory of Open Access Journals (Sweden)

    Vijaya Prasad Kamavaram Ellore

    2012-01-01

    Full Text Available Pre-surgical orthopedic appliances are mainly used to retract and align the protruded and deviated pre-maxilla and to facilitate initial lip repair. This article presents a case report of a five year old male child patient with bilateral cleft lip and palate in whom a special custom made pre-surgical orthopedic appliance was delivered. Use of a special custom made presurgical orthopedic appliance for repositioning pre-maxilla in bilateral cleft lip and palate patient is discussed in this article.

  1. From the risk analysis to the development of interventions and training for the prevention and control of healthcare associated infections. The experience of G. Pini Orthopedic Institute.

    Science.gov (United States)

    Navone, P; Conti, C; Domeniconi, G; Nobile, M

    2015-01-01

    Health-care associated infections (HAIs) represents a phenomenon of central importance all over Europe. Every year 4,5 millions cases are detected in European Union, with 37.000 related deaths. Surgical-site infections (SSIs) are one of the most common HAIs, that are associated with an increased length of stay, re-operation rate, intensive care admissions rate, and higher mortality rate. G. Pini Orthopedics Institute implemented in the last two years a multimodal strategy for controlling and preventing HAIs, in particular for SSIs. This paper describes the prevention's strategies adopted for prevention of HAIs, at G. Pini Orthopedic Institute. Our findings show that application of a multi modal promotion strategy was associated with an improvement in HAI prevention.

  2. Effect of W/C Ratio on Durability and Porosity in Cement Mortar with Constant Cement Amount

    Directory of Open Access Journals (Sweden)

    Yun-Yong Kim

    2014-01-01

    Full Text Available Water is often added to concrete placing for easy workability and finishability in construction site. The additional mixing water can help easy mixing and workability but causes increased porosity, which yields degradation of durability and structural performances. In this paper, cement mortar samples with 0.45 of W/C (water to cement ratio are prepared for control case and durability performances are evaluated with additional water from 0.45 to 0.60 of W/C. Several durability tests including strength, chloride diffusion, air permeability, saturation, and moisture diffusion are performed, and they are analyzed with changed porosity. The changing ratios and patterns of durability performance are evaluated considering pore size distribution, total porosity, and additional water content.

  3. Direct fabrication of a W-C SNS Josephson junction using focused-ion-beam chemical vapour deposition

    International Nuclear Information System (INIS)

    Dai, Jun; Kometani, Reo; Ishihara, Sunao; Warisawa, Shin’ichi; Onomitsu, Koji; Krockenberger, Yoshiharu; Yamaguchi, Hiroshi

    2014-01-01

    A tungsten-carbide (W-C) superconductor/normal metal/superconductor (SNS) Josephson junction has been fabricated using focused-ion-beam chemical vapour deposition (FIB-CVD). Under certain process conditions, the component ratio has been tuned from W: C: Ga = 26%: 66%: 8% in the superconducting wires to W: C: Ga = 14%: 79%: 7% in the metallic junction. The critical current density at 2.5 K in the SNS Josephson junction is 1/3 of that in W-C superconducting nanowire. Also, a Fraunhofer-like oscillation of critical current in the junction with four periods is observed. FIB-CVD opens avenues for novel functional superconducting nanodevices. (paper)

  4. SiC interlayer by laser-cladding on WC-Co substrates for CVD diamond deposition

    Energy Technology Data Exchange (ETDEWEB)

    Contin, Andre; Fraga, Mariana Amorim; Vieira, Jose; Trava-Airoldi, Vladimir Jesus; Corat, Evaldo Jose, E-mail: andrecontin@yahoo.com.br [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Campos, Raonei Alves [Universidade Federal do Sul e Sudeste do Para (UNIFESSPA), Belem, PA (Brazil); Vasconcelos, Getulio [Instituto de Estudos Avancados (IEA), Sao Jose dos Campos, SP (Brazil)

    2016-07-01

    Full text: Despite their huge industrial potential and commercial interest, the direct diamond coating on cemented carbide (WC-Co) is limited, mainly because of the catalytic effect of Cobalt (Co) and the high difference in thermal expansion coefficient [1]. This results in poor adherence between diamond and WC-Co. In addition, the low diamond film adhesion to the cemented carbide useless for machining applications. Removal of Co binder from the substrate surface by superficial etching is one of the techniques used to improve the adhesion between diamond and WC-Co. For the present study, diamond films were deposited on WC-Co substrates with an intermediate barrier to block the Co diffusion to the surface substrate. The laser cladding process produced the SiC barrier, in which a powder layer is melted by a laser irradiation to create the coating on the substrate. The use of laser cladding is the novel method for an intermediate barrier for cemented carbides. The advantages of laser cladding include a faster processing speed, precision, versatility. We reported the application of pretreatment method called ESND (Electrostatic self-assembly seeding of nanocrystalline diamond). The nucleation density was around 10{sup 11}part/cm{sup 2}. Diamond films were grown by Hot Filament Chemical Vapor Deposition. Characterization of samples included Field Emission Gun-Scanning Electron Microscopy (FEG-SEM), Energy Dispersive X-ray (EDX), X-ray diffraction (XRD) and Raman Scattering Spectroscopy. Results showed that laser irradiation formed stable Co compounds in the interfacial barrier. It is because nucleation and good quality of diamond film since the cobalt are no longer free to migrate to the surface during the CVD diamond deposition. Reference: [1] Y. X. Cui, B. Shen, F. H. Sun. Diamond deposition on WC–Co substrate with amorphous SiC interlayer, Surface Engineering, 30, (2014) 237-243. (author)

  5. 1-Methoxy-agroclavine from Penicillium sp. WC75209, a novel inhibitor of the Lck tyrosine kinase.

    Science.gov (United States)

    Padmanabha, R; Shu, Y Z; Cook, L S; Veitch, J A; Donovan, M; Lowe, S; Huang, S; Pirnik, D; Manly, S P

    1998-03-17

    A high-throughput screen was developed and implemented to identify inhibitors of the Lck tyrosine kinase. This report describes the identification of a specific inhibitor of this enzyme from the solid fermentation culture of the Penicillium sp., WC75209. The active compound was isolated and structurally characterized as 1-methoxy-5R, 10S-agroclavine, a new member of the ergot alkaloid family.

  6. Laboratorium Study of Asphalt Starbit E-55 Polymer Modified Application on Asphalt Concrete Wearing Course (Ac-Wc

    Directory of Open Access Journals (Sweden)

    Damianus Kans Pangaraya

    2015-09-01

    Full Text Available The conventional asphalt road has almost been considered fail to serve the transportation needs. It is indicated by the occurrence of premature damage which is caused by vehicle load and climate. Starbit E-55, the polymer modified bitumen, is formulated to meet the requirement of transport development. Considering those needs, it is important to investigate the feasibility level of that modified bitumen as alternate asphalt instead of the conventional one. This research began with the measurement of the properties of hard layered AC-WC Starbit E-55, then comparing the result to 60/70 penetration of Pertamina asphalt. The next step is then, to determine the converted value so as to be close to that of Pertamina (60/70 penetration. This step is conducted by applying durability and ITS tests on the mixture. Result of the tests showed that hard layered AC-WC Starbit E-55 has better characteristic at 5.7% optimum level asphalt and 6.4% of Pertamina asphalt (60/70 penetration. Starbit E-55 converted level within hard-layered ACWC is 5.6%. The performance test result on immersion with variance of 1, 3, 5, 7 and 14 days shows that durability value of Starbit E-55 AC-WC has better performance. During the process, Starbit E-55 required 15.38% higher energy consumption.

  7. FIB-SEM Sectioning Study of Decarburization Products in the Microstructure of HVOF-Sprayed WC-Co Coatings

    Science.gov (United States)

    Katranidis, Vasileios; Gu, Sai; Cox, David C.; Whiting, Mark J.; Kamnis, Spyros

    2018-05-01

    The thermal dissolution and decarburization of WC-based powders that occur in various spray processes are a widely studied phenomenon, and mechanisms that describe its development have been proposed. However, the exact formation mechanism of decarburization products such as metallic W is not yet established. A WC-17Co coating is sprayed intentionally at an exceedingly long spray distance to exaggerate the decarburization effects. Progressive xenon plasma ion milling of the examined surface has revealed microstructural features that would have been smeared away by conventional polishing. Serial sectioning provided insights on the three-dimensional structure of the decarburization products. Metallic W has been found to form a shell around small splats that did not deform significantly upon impact, suggesting that its crystallization occurs during the in-flight stage of the particles. W2C crystals are more prominent on WC faces that are in close proximity with splat boundaries indicating an accelerated decarburization in such sites. Porosity can be clearly categorized in imperfect intersplat contact and oxidation-generated gases via its shape.

  8. Nanoindentation study of WC-12Co hardmetals obtained from nanocrystalline powders: Evaluation of hardness and modulus on individual phases

    International Nuclear Information System (INIS)

    Bonache, V.; Rayon, E.; Salvador, M.D.; Busquets, D.

    2010-01-01

    With the development of finer hardmetals, the study of mechanical properties of the different constituents down the micrometric level is a question of concern for materials optimization. Nanoindentation has been developed in last years in order to cope with mechanical characterisation at the nanolevel, but difficulties on phase detection are an issue. In the present work, individual hardness and Young's modulus of the constituents of WC-12Co composite were obtained by the use of very shallow nanoindentations (30 nm depth), with the aid of in situ 3D imaging to identify these. By this method three different phases at the sub-micrometric level have been identified and characterised: namely cobalt matrix, tungsten carbide and η phase. The presence of the latter phase and its characterisation is of paramount importance in understanding the behaviour of hardmetals. Values of hardness from 8 (cobalt matrix) to 25 GPa (η phase) have been obtained. Also, for these phases Young's modulus varied from 250 to 400 GPa respectively. Furthermore, it is firstly reported these values for the WC prismatic planes {1 0 1 0} being in the range of 40-55 and 700-900 GPa respectively. These values decrease to a hardness in the range of 25-30 GPa and modulus in the range from 450 to 550 GPa for the WC basal plane {0 0 0 1}.

  9. Reduction of travellers' diarrhoea by WC/rBS oral cholera vaccine in young, high-risk travellers.

    Science.gov (United States)

    Torrell, Josep Ma Ramon; Aumatell, Cristina Masuet; Ramos, Sergi Morchon; Mestre, Laura Gavaldà; Salas, Carme Micheo

    2009-06-19

    A bidirectional cohort study investigates whether pre-travel vaccination with whole cell/recombinant B subunit inactivated, killed oral cholera vaccine reduces the incidence of diarrhoea in young adult travellers to high-risk areas. Risk of travellers' diarrhoea was assessed according to destination and reason for travel in high-risk travellers of a travel clinic in Barcelona, Spain. Those at high-risk between January and December 2005 were advised on water/food safety and hygiene. High-risk travellers between January and December 2006 were additionally vaccinated with WC/rBS oral cholera vaccine. Data regarding diarrhoea were gathered by structured telephone interview or e-mailed questionnaire following the travellers' return. The incidence of diarrhoea in the group vaccinated with WC/rBS oral cholera vaccine (n=321) was 17.4%, compared with 39.7% in the non-vaccinated group (n=337) (adjusted risk ratio 0.40). The first episode was significantly shorter in the vaccinated group (mean 2.3 days) than in the non-vaccinated group (mean 3.8 days) (pyoung, high-risk travellers. Vaccination with the WC/rBS oral cholera vaccine as well as food safety and hygiene advice could offer effective means of reducing the risk of diarrhoea while abroad.

  10. Computer-assisted surgery in orthopedic oncology : Technique, indications, and a descriptive study of 130 cases

    NARCIS (Netherlands)

    Gerbers, Jasper G.; Stevens, Martin; Ploegmakers, Joris J. W.; Bulstra, Sjoerd K.; Jutte, Paul C.

    2014-01-01

    Background and purpose - In orthopedic oncology, computerassisted surgery (CAS) can be considered an alternative to fluoroscopy and direct measurement for orientation, planning, and margin control. However, only small case series reporting specific applications have been published. We therefore

  11. PEEK Biomaterials in Trauma, Orthopedic, and Spinal Implants

    Science.gov (United States)

    Kurtz, S. M.; Devine, J. N.

    2007-01-01

    Since the 1980s, polyaryletherketones (PAEKs) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. We have synthesized the extensive polymer science literature as it relates to structure, mechanical properties, and chemical resistance of PAEK biomaterials. With this foundation, one can more readily appreciate why this family of polymers will be inherently strong, inert, and biocompatible. Due to its relative inertness, PEEK biomaterials are an attractive platform upon which to develop novel bioactive materials, and some steps have already been taken in that direction, with the blending of HA and TCP into sintered PEEK. However, to date, blended HA-PEEK composites have involved a trade-off in mechanical properties in exchange for their increased bioactivity. PEEK has had the greatest clinical impact in the field of spine implant design, and PEEK is now broadly accepted as a radiolucent alternative to metallic biomaterials in the spine community. For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature. PMID:17686513

  12. Presurgical cleft lip and palate orthopedics: an overview

    Science.gov (United States)

    Alzain, Ibtesam; Batwa, Waeil; Cash, Alex; Murshid, Zuhair A

    2017-01-01

    Patients with cleft lip and/or palate go through a lifelong journey of multidisciplinary care, starting from before birth and extending until adulthood. Presurgical orthopedic (PSO) treatment is one of the earliest stages of this care plan. In this paper we provide a review of the PSO treatment. This review should help general and specialist dentists to better understand the cleft patient care path and to be able to answer patient queries more efficiently. The objectives of this paper were to review the basic principles of PSO treatment, the various types of techniques used in this therapy, and the protocol followed, and to critically evaluate the advantages and disadvantages of some of these techniques. In conclusion, we believe that PSO treatment, specifically nasoalveolar molding, does help to approximate the segments of the cleft maxilla and does reduce the intersegment space in readiness for the surgical closure of cleft sites. However, what we remain unable to prove equivocally at this point is whether the reduction in the dimensions of the cleft presurgically and the manipulation of the nasal complex benefit our patients in the long term. PMID:28615974

  13. [Technical aspects in the provision of orthopedic shoes for athletes].

    Science.gov (United States)

    Walther, M; Volkering, C; Röser, A

    2013-03-01

    From the technical point of view different groups must be distinguished in the provision of orthopedic shoes for athletes. The one group encompasses athletes who are provided with insoles in the hope of improved comfort or better performance. The other group includes athletes with diseases or injuries of the lower limbs for whom the provision of appropriate shoes and insoles makes it possible for them to participate again actively in their chosen sport. In such cases one has to differentiate between the purely physical disorder of the foot and biomechanical disorders. For the first group the correct fitting of the shoe is the most important factor whereas in the second group attempts are made to correct and/or compensate for the deficit by means of insoles and wedges as well as supporting or bedding elements. The particular challenge for all such measures is to achieve an as small as possible impairment on the sport activity or, in the ideal cases, even to support it. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Snow Catastrophe Conditions: What is its Impact on Orthopedic Injuries?

    Directory of Open Access Journals (Sweden)

    Mohsen Mardani-Kivi

    2014-06-01

    Full Text Available Background:   Iran places sixth amongst high risk natural disaster countries and Guilan province of Iran shoulders a large amount of socio-economic burden due to snow catastrophes. The more knowledge of circumstances we have, the more efficient our future encounters will be. Methods: In this retrospective study, of all of the patients admitted to Poursina Hospital due to snow and ice related trauma in the first two weeks of February 2014, 306 cases were found eligible for entry into the present study. Results: Of the 306 eligible patients (383 injuries, there were 175 men (57.2% and 131 women (42.8%. Most patients suffered from orthopedic injuries (81% and the most common fractures were distal radius fractures in the upper extremities and hip fractures in the lower extremities. Slipping was the most common and motor vehicle accidents had the rarest injury mechanisms. It was shown that the frequency of injuries were higher on icy days (67.6% than snowy days (32.4%. Conclusions: Snow crises may lead to increased risk of slipping and falling situations, especially on icy days. The peak of injury rates is a few days after snowfall with the most common injury being distal radius fracture. Providing essential instructions and supporting resource allocation to better handle such catastrophes may improve outcomes.

  15. The Top 100 Cited Articles in Clinical Orthopedic Sports Medicine.

    Science.gov (United States)

    Nayar, Suresh K; Dein, Eric J; Spiker, Andrea M; Bernard, Johnathan A; Zikria, Bashir A

    2015-08-01

    Orthopedic sports medicine continues to evolve, owing much of its clinical management and practice to rigorous academic research. In this review, we identify and describe the top 100 cited articles in clinical sports medicine and recognize the authors and institutions driving the research. We collected articles (excluding basic science, animal, and cadaveric studies) from the 25 highest-impact sports medicine journals and analyzed them by number of citations, journal, publication date, institution, country, topic, and author. Mean number of citations was 408 (range, 229-1629). The articles were published in 7 journals, most in the 1980s to 2000s, and represented 15 countries. Thirty topics were addressed, with a heavy emphasis on anterior cruciate ligament injury and reconstruction, knee rating systems, rotator cuff reconstruction, and chondrocyte transplantation. The 3 most cited articles, by Insall and colleagues, Constant and Murley, and Tegner and Lysholm, addressed a knee, a shoulder, and another knee rating system, respectively. Several authors contributed multiple articles. The Hospital for Special Surgery and the University of Bern contributed the most articles (5 each). This study provides a comprehensive list of the past century's major academic contributions to sports medicine. Residents and fellows may use this list to guide their scholarly investigations.

  16. Current concept review: quality and process improvement in orthopedics

    Directory of Open Access Journals (Sweden)

    Pinney SJ

    2015-12-01

    Full Text Available Stephen J Pinney,1 Alexandra E Page,2 David S Jevsevar,3 Kevin J Bozic4 1Department of Orthopaedic Surgery, St Mary's Medical Center, San Francisco, CA, USA; 2Orthopaedic Surgery, AAOS Health Care Systems Committee, San Diego, CA, USA; 3Department of Orthopaedics, Geisel School of Medicine, Dartmouth University, Hanover, NH, USA; 4Department of Surgery and Perioperative Care, Dell Medical School at the University of Texas, Austin, TX, USAAbstract: Multiple health care stakeholders are increasingly scrutinizing musculoskeletal care to optimize quality and cost efficiency. This has led to greater emphasis on quality and process improvement. There is a robust set of business strategies that are increasingly being applied to health care delivery. These quality and process improvement tools (QPITs have specific applications to segments of, or the entire episode of, patient care. In the rapidly changing health care world, it will behoove all orthopedic surgeons to have an understanding of the manner in which care delivery processes can be evaluated and improved. Many of the commonly used QPITs, including checklist initiatives, standardized clinical care pathways, lean methodology, six sigma strategies, and total quality management, embrace basic principles of quality improvement. These principles include focusing on outcomes, optimizing communication among health care team members, increasing process standardization, and decreasing process variation. This review summarizes the common QPITs, including how and when they might be employed to improve care delivery. Keywords: clinical care pathway, musculoskeletal care, outcomes, quality management, six sigma, lean thinking

  17. Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

    Science.gov (United States)

    Parcharoen, Yardnapar; Kajitvichyanukul, Puangrat; Sirivisoot, Sirinrath; Termsuksawad, Preecha

    2014-08-01

    Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO2) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO2 nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH4F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO2 nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO2 nanotubes were found when high viscous electrolyte, NH4F in glycerol, was used. Negative voltage (-4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO2 nanotubes was significantly increased by times. The TiO2 nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO2 nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that growing on titanium plate surface.

  18. Deep venous thrombosis after orthopedic surgery in adult cancer patients.

    Science.gov (United States)

    Lin, P P; Graham, D; Hann, L E; Boland, P J; Healey, J H

    1998-05-01

    Patients with cancer and patients undergoing major orthopedic procedures are two groups at risk of deep venous thrombosis (DVT). The objective was to determine the rate of venous thromboembolic disease in patients with a malignant neoplasm and major orthopaedic surgery of the lower limb. The study included 169 patients. All patients were given knee-high intermittent pneumatic compression devices for prophylaxis. Postoperative surveillance for thrombosis was performed on all patients with venous duplex doppler ultrasonography. Proximal DVT occurred in 24 of 169 patients (14.2%). One patient (0.6%) developed a symptomatic, nonfatal pulmonary embolus (PE). The development of DVT was not associated with age, sex, type of surgery, type of neoplasm, location, or pathologic fracture. The addition of anticoagulant medication such as warfarin did not significantly reduce the rate of DVT in a subset of 54 patients. In three patients, the DVT occurred only in the contralateral limb, and in four patients, there were bilateral DVTs. When intermittent compression boots were used for prophylaxis in conjunction with ultrasound screening, the risk of proximal DVT was substantial (14.2%), but the rate of symptomatic PE was low (0.6%).

  19. Residual stress and crack initiation in laser clad composite layer with Co-based alloy and WC + NiCr

    International Nuclear Information System (INIS)

    Lee, Changmin; Park, Hyungkwon; Yoo, Jaehong; Lee, Changhee; Woo, WanChuck; Park, Sunhong

    2015-01-01

    Highlights: • Major problem, clad cracking in laser cladding process, was researched. • Residual stress measurements were performed quantitatively by neutron diffraction method along the surface of specimens. • Relationship between the residual stress and crack initiation was showed clearly. • Ceramic particle effect in the metal matrix was showed from the results of residual stress measurements. • Initiation sites of generating clad cracks were specifically studied in MMC coatings. - Abstract: Although laser cladding process has been widely used to improve the wear and corrosion resistance, there are unwanted cracking issues during and/or after laser cladding. This study investigates the tendency of Co-based WC + NiCr composite layers to cracking during the laser cladding process. Residual stress distributions of the specimen are measured using neutron diffraction and elucidate the correlation between the residual stress and the cracking in three types of cylindrical specimens; (i) no cladding substrate only, (ii) cladding with 100% stellite#6, and (iii) cladding with 55% stellite#6 and 45% technolase40s. The microstructure of the clad layer was composed of Co-based dendrite and brittle eutectic phases at the dendritic boundaries. And WC particles were distributed on the matrix forming intermediate composition region by partial melting of the surface of particles. The overlaid specimen exhibited tensile residual stress, which was accumulated through the beads due to contraction of the coating layer generated by rapid solidification, while the non-clad specimen showed compressive. Also, the specimen overlaid with 55 wt% stellite#6 and 45 wt% technolase40s showed a tensile stress higher than the specimen overlaid with 100% stellite#6 possibly, due to the difference between thermal expansion coefficients of the matrix and WC particles. Such tensile stresses can be potential driving force to provide an easy crack path ways for large brittle fractures

  20. Residual stress and crack initiation in laser clad composite layer with Co-based alloy and WC + NiCr

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Changmin; Park, Hyungkwon; Yoo, Jaehong [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Changhee, E-mail: chlee@hanyang.ac.kr [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Woo, WanChuck [Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Park, Sunhong [Research Institute of Industrial Science & Technology, Hyo-ja-dong, Po-Hang, Kyoung-buk, San 32 (Korea, Republic of)

    2015-08-01

    Highlights: • Major problem, clad cracking in laser cladding process, was researched. • Residual stress measurements were performed quantitatively by neutron diffraction method along the surface of specimens. • Relationship between the residual stress and crack initiation was showed clearly. • Ceramic particle effect in the metal matrix was showed from the results of residual stress measurements. • Initiation sites of generating clad cracks were specifically studied in MMC coatings. - Abstract: Although laser cladding process has been widely used to improve the wear and corrosion resistance, there are unwanted cracking issues during and/or after laser cladding. This study investigates the tendency of Co-based WC + NiCr composite layers to cracking during the laser cladding process. Residual stress distributions of the specimen are measured using neutron diffraction and elucidate the correlation between the residual stress and the cracking in three types of cylindrical specimens; (i) no cladding substrate only, (ii) cladding with 100% stellite#6, and (iii) cladding with 55% stellite#6 and 45% technolase40s. The microstructure of the clad layer was composed of Co-based dendrite and brittle eutectic phases at the dendritic boundaries. And WC particles were distributed on the matrix forming intermediate composition region by partial melting of the surface of particles. The overlaid specimen exhibited tensile residual stress, which was accumulated through the beads due to contraction of the coating layer generated by rapid solidification, while the non-clad specimen showed compressive. Also, the specimen overlaid with 55 wt% stellite#6 and 45 wt% technolase40s showed a tensile stress higher than the specimen overlaid with 100% stellite#6 possibly, due to the difference between thermal expansion coefficients of the matrix and WC particles. Such tensile stresses can be potential driving force to provide an easy crack path ways for large brittle fractures

  1. A Survey on Transfusion Status in Orthopedic Surgery at a Trauma Center

    OpenAIRE

    Soleimanha, Mehran; Haghighi, Mohammad; Mirbolook, Ahmadreza; Sedighinejad, Abbas; Mardani-Kivi, Mohsen; Naderi-Nabi, Bahram; Chavoshi, Tahereh; Mehrnoosh, Mehrnoosh Ghandili

    2016-01-01

    Background: Increased costs and mortality associated with inappropriate blood transfusions have led to investigations about blood request and blood transfusion techniques. We investigated the transfusion status in patients who underwent orthopedic surgery in Poursina Hospital (Rasht, Iran) to optimizing blood usage and determine if a scheduled transfusion program for every orthopedic surgery could improve blood transfusion management. Method: In this descriptive-prospective study, all orthop...

  2. Relationship of orthopedic examination, goniometric measurements, and radiographic signs of degenerative joint disease in cats

    OpenAIRE

    Lascelles, B Duncan X; Dong, Yaa-Hui; Marcellin-Little, Denis J; Thomson, Andrea; Wheeler, Simon; Correa, Maria

    2012-01-01

    Abstract Background Available information suggests a mismatch between radiographic and orthopedic examination findings in cats with DJD. However, the extent of the discrepancy between clinical and radiographic signs of OA in companion animals has not been described in detail. This study aimed to evaluate the relationship between orthopedic examination findings, joint goniometry, and radiographic signs of DJD in 100 cats, in a prospective observational design. Cat temperament, pain response to...

  3. Relation between type and local of orthopedic injuries with physical activity in horses

    OpenAIRE

    Sousa,Nicole Ruas de; Luna,Stelio Pacca Loureiro; Pizzigatti,Dietrich; Martins,Mayra Teixeira Alas; Possebon,Fabio Sossai; Aguiar,Adriana Cristina Saldanha

    2017-01-01

    ABSTRACT: Equine sport modalities influence the prevalence and predisposition of musculoskeletal injuries in horses. This study aimed to evaluate the prevalence of location and type of orthopedic injuries of horses undergoing various physical activities. Data from 116 horses of different breeds and ages was analyzed. Physical activities included dressage, racing, polo pony, jumping, work and western performance. All horses had history of orthopedic lameness diagnosed by radiographs and/or ult...

  4. An Experimental Study on Slurry Erosion Resistance of Single and Multilayered Deposits of Ni-WC Produced by Laser-Based Powder Deposition Process

    Science.gov (United States)

    Balu, Prabu; Hamid, Syed; Kovacevic, Radovan

    2013-11-01

    Single and multilayered deposits containing different mass fractions of tungsten carbide (WC) in nickel (Ni)-matrix (NT-20, NT-60, NT-80) are deposited on a AISI 4140 steel substrate using a laser-based powder deposition process. The transverse cross section of the coupons reveals that the higher the mass fraction of WC in Ni-matrix leads to a more uniform distribution through Ni-matrix. The slurry erosion resistance of the fabricated coupons is tested at three different impingement angles using an abrasive water jet cutting machine, which is quantified based on the erosion rate. The top layer of a multilayered deposit (i.e., NT-60 in a two-layer NT-60 over NT-20 deposit) exhibits better erosion resistance at all three tested impingement angles when compared to a single-layer (NT-60) deposit. A definite increase in the erosion resistance is noted with an addition of nano-size WC particles. The relationship between the different mass fractions of reinforcement (WC) in the deposited composite material (Ni-WC) and their corresponding matrix (Ni) hardness on the erosion rate is studied. The eroded surface is analyzed in the light of a three-dimensional (3-D) profilometer and a scanning electron microscope (SEM). The results show that a volume fraction of approximately 62% of WC with a Ni-matrix hardness of 540 HV resulting in the gouging out of WC from the Ni-matrix by the action of slurry. It is concluded that the slurry erosion resistance of the AISI 4140 steel can be significantly enhanced by introducing single and multilayered deposits of Ni-WC composite material fabricated by the laser-based powder deposition process.

  5. Role of WC additive on reaction, solid-solution and densification in HfB2–SiC ceramics

    DEFF Research Database (Denmark)

    Hu, Dong-Li; Zheng, Qiang; Gu, Hui

    2014-01-01

    A comparative study of phase components and compositions was performed for the pressureless sintered HfB2–SiC–WC composites by various analytical methods. The relative decrease of HfB2 phase leads to a new reaction of HfO2 removal by WC to create B2O3. By using SiC instead of Si3N4 as milling med...

  6. Academic characteristics of orthopedic team physicians affiliated with high school, collegiate, and professional teams.

    Science.gov (United States)

    Makhni, Eric C; Buza, John A; Byram, Ian; Ahmad, Christopher S

    2015-11-01

    We conducted a study to determine the academic involvement and research productivity of orthopedic team physicians at high school, college, and professional levels of sport. Through Internet and telephone queries, we identified 1054 team physicians from 362 institutions, including 120 randomly selected high schools and colleges and 122 professional teams (baseball, basketball, football, hockey). For all physicians included in the study, we performed a comprehensive search of the Internet and of a citation database to determine academic affiliations, number of publications, and h-index values. Of the 1054 physicians, 678 (64%) were orthopedic surgeons. Percentage of orthopedic team physicians affiliated with an academic medical center was highest in professional sports (64%; 173/270) followed by collegiate sports (36%; 98/275) and high school sports (20%; 27/133). Median number of publications per orthopedic team physician was significantly higher in professional sports (30.6) than in collegiate sports (10.7) or high school sports (6). Median number of publications by orthopedic physicians also varied by sport, with the highest number in Major League Baseball (37.9; range, 0-225) followed by the National Basketball Association (32.0; range, 0-227) and the National Football League (30.4; range, 0-460), with the lowest number within the National Hockey League (20.7; range, 0-144). Academic affiliation and research productivity of orthopedic team physicians vary by competition level and professional sporting league.

  7. Tribological Behavior of Multilayered WC-Ti1-xAlxN Coatings Deposited by Cathodic Arc Deposition Process on High Speed Steel

    International Nuclear Information System (INIS)

    Kim, Jung Gu; Hwang, Woon Suk

    2006-01-01

    Recently, much of the current development in surface modification engineering are focused on multilayered coatings. Multilayered coatings have the potential to improve the tribological properties. Four different multilayered coatings were deposited on AISI D2 steel. The prepared samples are designed as WC-Ti 0.6 Al 0.4 N, WC-Ti 0.53 Al 0.47 N, WC-Ti 0.5 Al 0.5 N and WC-Ti 0.43 Al 0.57 N. The multilayered coatings were investigated with respect to coating surface and cross-sectional morphology, roughness, adhesion, hardness, porosity and tribological behavior. Especially, wear tests of four multilayered coatings were preformed by using a ball-on-disc configuration with a linear sliding speed of 0.017 m/sec, 5.38 N load. The tests were carried out at room temperature in air by employing AISI 52100 steel ball (H R = 66) having a diameter of 10 mm. The surface morphology, and topography of the wear scars of samples and balls have been determined by using scanning electron spectroscopy (SEM). Results have showed an improved wear resistance of the WC-Ti 1-x 6Al x N coatings with increasing of Al concentration. WC-Ti 0.43 Al 0.57 N coating with the lower surface roughness and porosity with good adhesion enhanced wear resistance

  8. Delayed diagnosis and worsening of pain following orthopedic surgery in patients with complex regional pain syndrome (CRPS).

    Science.gov (United States)

    Lunden, Lars K; Kleggetveit, Inge P; Jørum, Ellen

    2016-04-01

    Complex regional pain syndrome (CRPS) is a serious and disabling chronic pain condition, usually occurring in a limb. There are two main types, CRPS 1 with no definite nerve lesion and CRPS 2 with an identified nerve lesion. CRPS 1 and 2 may occur following an injury (frequently following fractures), surgery or without known cause. An early diagnosis and start of adequate treatment is considered desirable for patients with CRPS. From the clinical experience of the principal investigator, it became apparent that CRPS often remained undiagnosed and that the clinical conditions of many patients seemed to be worsened following orthopedic surgery subsequent to the initial eliciting event. The aim of the present retrospective study of 55 patients, all diagnosed with either CRPS 1 or 2, was to evaluate the time from injury until diagnosis of CRPS and the effect on pain of orthopedic surgical intervention subsequent to the original injury/surgery. Clinical symptoms with an emphasis on pain were assessed by going through the patients' records and by information given during the investigation at Oslo University Hospital, where the patients also were examined clinically and with EMG/neurography. Alteration in pain was evaluated in 27 patients who underwent orthopedic surgery subsequent to the eliciting injury. Of a total of 55 patients, 28 women and 27 men (mean age 38.7 (SD 12.3), 38 patients were diagnosed with CRPS type 1, and 17 with CRPS type 2. Mean time before diagnosis was confirmed was 3.9 years (SD1.42, range 6 months-10 years). The eliciting injuries for both CRPS type 1 and type 2 were fractures, squeeze injuries, blunt injuries, stretch accidents and surgery. A total of 27 patients (14 men and 13 women) were operated from one to 12 times at a later stage (from 6 months to several years) following the initial injury or any primary operation because of fracture. A total of 22 patients reported a worsening of pain following secondary surgical events, while four

  9. A low power cyclic ADC design for a wireless monitoring system for orthopedic implants

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yi; Li Fule; Chen Hong; Zhang Chun; Wang Zhihua, E-mail: chenyi02@mails.tsinghua.edu.c [Tsinghua National Laboratory for Information Science and Technology, Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2009-08-15

    This paper presents a low power cyclic analog-to-digital convertor (ADC) design for a wireless monitoring system for orthopedic implants. A two-stage cyclic structure including a single to differential converter, two multiplying DAC functional blocks (MDACs) and some comparators is adopted, which brings moderate speed and moderate resolution with low power consumption. The MDAC is implemented with the common switched capacitor method. The 1.5-bit stage greatly simplifies the design of the comparator. The operational amplifier is carefully optimized both in schematic and layout for low power and offset. The prototype chip has been fabricated in a United Microelectronics Corporation (UMC) 0.18-{mu}m 1P6M CMOS process. The core of the ADC occupies only 0.12 mm{sup 2}. With a 304.7-Hz input and 4-kHz sampling rate, the measured peak SNDR and SFDR are 47.1 dB and 57.8 dBc respectively and its DNL and INL are 0.27 LSB and 0.3 LSB, respectively. The power consumption of the ADC is only 12.5 {mu}W in normal working mode and less than 150 nW in sleep mode. (semiconductor integrated circuits)

  10. ANALYSIS OF OTORHINOLARYNGOLOGY, ORTHOPEDICS AND THORACIC SURGERY JOURNALS.

    Science.gov (United States)

    Lima, Wilma Terezinha Anselmo

    2015-01-01

    To perform an extensive analysis of journals in Medicine III - CAPES, and specifically those in the areas of Otorhinolaryngology, Orthopedics and Traumatology and Chest Surgery. An active search for the impact factors in the Journal Citation Reports, Scimago, their indexation in Scielo, Lilacs, Scopus and Google Scholar, and their stratification in WebQualis was done. Forty-four journals with measured impact factors ranging from 3.006 to 0.128 were detected in the area of Otorhinolaryngology; however, only 26 of them (60%) had a Qualis measured by CAPES; in the stratification, no journal was detected in A1, three were A2 and nine B1. Three journals were located for Chest Surgery, with only one of them having a measured Qualis (A2) with a mean of 3.61. Sixty-seven journals were detected for Orthopedics and Traumatology, with an impact factor ranging from 4.699 to 0.156; Qualis was measured in only 38 of them (60%); there were three journal stratified as A1, seven as A2 and 25 as B1. The search for journals of higher impact induces authors to not publish in journals related to their area and facing more difficulties than investigators from other areas. Realizar análise ampla dos periódicos da Medicina III - CAPES e, especificamente, os pertencentes à Otorrinolaringologia, Ortopedia e Traumatologia, e Cirurgia Torácica. Busca ativa do fator de impacto dos periódicos das áreas citadas no Journal Citation Report e Scimago, sua indexação no Scielo, Lilacs, Scopus, Google Scholar e sua estratificação no WebQualis. Para a Otorrinolaringologia foram encontrados 44 periódicos, cujo fator de impacto variou de 3.006 a 0.128; entretanto, apenas 26 deles (60%) tinham Qualis medido pela CAPES; nas estratificações encontrou-se nenhuma revista em A1, três em A2 e nove em B1. Para a Cirurgia Torácica foram localizados três periódicos, sendo que apenas um tinha Qualis medido (A2) com média de 3.61. Os resultados da busca para a Ortopedia e Traumatologia permitiu

  11. Chitosan for gene delivery and orthopedic tissue engineering applications.

    Science.gov (United States)

    Raftery, Rosanne; O'Brien, Fergal J; Cryan, Sally-Ann

    2013-05-15

    Gene therapy involves the introduction of foreign genetic material into cells in order exert a therapeutic effect. The application of gene therapy to the field of orthopaedic tissue engineering is extremely promising as the controlled release of therapeutic proteins such as bone morphogenetic proteins have been shown to stimulate bone repair. However, there are a number of drawbacks associated with viral and synthetic non-viral gene delivery approaches. One natural polymer which has generated interest as a gene delivery vector is chitosan. Chitosan is biodegradable, biocompatible and non-toxic. Much of the appeal of chitosan is due to the presence of primary amine groups in its repeating units which become protonated in acidic conditions. This property makes it a promising candidate for non-viral gene delivery. Chitosan-based vectors have been shown to transfect a number of cell types including human embryonic kidney cells (HEK293) and human cervical cancer cells (HeLa). Aside from its use in gene delivery, chitosan possesses a range of properties that show promise in tissue engineering applications; it is biodegradable, biocompatible, has anti-bacterial activity, and, its cationic nature allows for electrostatic interaction with glycosaminoglycans and other proteoglycans. It can be used to make nano- and microparticles, sponges, gels, membranes and porous scaffolds. Chitosan has also been shown to enhance mineral deposition during osteogenic differentiation of MSCs in vitro. The purpose of this review is to critically discuss the use of chitosan as a gene delivery vector with emphasis on its application in orthopedic tissue engineering.

  12. Machining of a bioactive nanocomposite orthopedic fixation device.

    Science.gov (United States)

    Sparnell, Amie; Aniket; El-Ghannam, Ahmed

    2012-08-01

    Bioactive ceramics bond to bone and enhance bone formation. However, they have poor mechanical properties which restrict their machinability as well as their application as load bearing implants. The goal of this study was to machine bioactive fixation screws using a silica-calcium phosphate nanocomposite (SCPC50). The effect of compact pressure, holding time, and thermal treatment on the microstructure, machinability, and mechanical properties of SCPC50 cylinders were investigated. Samples prepared by powder metallurgy technique at compact pressure range of 100-300 MPa and treated at 900°C/1 h scored a poor machinability rating of (1/5) due to the significant formation of amorphous silicate phase at the grain boundaries. On the other hand, lowering of compact pressure and sintering temperature to 30 MPa/3 h and 700°C/2 h, respectively, minimized the formation of the amorphous phase and raised the machinability rating to (5/5). The modulus of elasticity and ultimate strength of machinable SCPC50 were 10.8 ± 2.0 GPa and 72.8 ± 22.8 MPa, respectively, which are comparable to the corresponding values for adult human cortical bone. qRT-PCR analyses showed that bone cells attached to SCPC50 significantly upregulated osteocalcin mRNA expression as compared to the cells on Ti-6Al-4V. Moreover, cells attached to SCPC50 produced mineralized bone-like tissue within 8 days. On the other hand, cells attached to Ti-6Al-4V failed to produce bone mineral under the same experimental conditions. Results of the study suggest that machinable SCPC50 has the potential to serve as an attractive new material for orthopedic fixation devices. Copyright © 2012 Wiley Periodicals, Inc.

  13. Hydroxyapatite electrodeposition on anodized titanium nanotubes for orthopedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Parcharoen, Yardnapar [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Kajitvichyanukul, Puangrat [Center of Excellence on Environmental Research and Innovation, Faculty of Engineering, Naresuan University, Phitsanulok (Thailand); Sirivisoot, Sirinrath [Department of Biological Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand); Termsuksawad, Preecha, E-mail: preecha.ter@kmutt.ac.th [Division of Materials Technology, School of Energy, Environment and Materials, King Mongkut' s University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, ThungKhru, Bangkok 10140 (Thailand)

    2014-08-30

    Highlights: • We found that different anodization time of titanium significantly effects on nanotube length which further impacts adhesion strength of hydroxyapatite coating layers. • Adhesion strength of Hydroxyapatite (HA) coated on titanium dioxide nanotubes is better than that of HA coated on titanium plate. • Hydroxyapatite coated on titanium dioxide nanotubes showed higher cell density and better spreading of MC3T3-E1 cells (bone-forming cells) than that coated on titanium plate surface. - Abstract: Nanotubes modification for orthopedic implants has shown interesting biological performances (such as improving cell adhesion, cell differentiation, and enhancing osseointegration). The purpose of this study is to investigate effect of titanium dioxide (TiO{sub 2}) nanotube feature on performance of hydroxyapatite-coated titanium (Ti) bone implants. TiO{sub 2} nanotubes were prepared by anodization using ammonium fluoride electrolyte (NH{sub 4}F) with and without modifiers (PEG400 and Glycerol) at various potential forms, and times. After anodization, the nanotubes were subsequently annealed. TiO{sub 2} nanotubes were characterized by scanning electron microscope and X-ray diffractometer. The amorphous to anatase transformation due to annealing was observed. Smooth and highly organized TiO{sub 2} nanotubes were found when high viscous electrolyte, NH{sub 4}F in glycerol, was used. Negative voltage (−4 V) during anodization was confirmed to increase nanotube thickness. Length of the TiO{sub 2} nanotubes was significantly increased by times. The TiO{sub 2} nanotube was electrodeposited with hydroxyapatite (HA) and its adhesion was estimated by adhesive tape test. The result showed that nanotubes with the tube length of 560 nm showed excellent adhesion. The coated HA were tested for biological test by live/dead cell straining. HA coated on TiO{sub 2} nanotubes showed higher cells density, higher live cells, and more spreading of MC3T3-E1 cells than that

  14. Friction and wear properties of Ti6Al4V/WC-Co in cold atmospheric plasma jet

    International Nuclear Information System (INIS)

    Xu Wenji; Liu Xin; Song Jinlong; Wu Libo; Sun Jing

    2012-01-01

    Highlights: ► Cold plasma jet can effectively reduce the friction coefficients of Ti6Al4V/WC-Co friction pairs. ► Cold plasma jet can easily form nitrides on the surface of Ti6Al4V and on new surfaces generated by tool wear. ► The nitrides can reduce the friction coefficients and protect the friction surface. - Abstract: The friction and wear properties of Ti6Al4V/WC-Co friction pair were studied using an autonomous atmospheric pressure bare electrode cold plasma jet generating device and block-on-ring friction/wear tester, respectively. The study was conducted under air, air jet, nitrogen jet, air cold plasma jet, and nitrogen cold plasma jet atmospheres. Both nitrogen cold and air cold plasma jets effectively reduced the friction coefficients of the friction pairs and decreased friction temperature. The friction coefficient in the nitrogen cold plasma jet decreased to almost 60% compared with that in the air. The scanning electron microscope, energy-dispersive X-ray spectroscope, and X-ray diffraction analyses illustrated that adhesive wear was relieved and the friction surfaces of Ti6Al4V were smoother, both in the nitrogen cold and air cold plasma jets. The roughness value R a of the Ti6Al4V friction surfaces can reach 1.107 μm. A large number of nitrogen particles in the ionic and excited states contained by cold plasma jets reacts easily on the friction surface to produce a large amount of nitrides, which can excellently reduce the wear of Ti6Al4V/WC-Co friction pairs in real-time.

  15. Friction and wear properties of high-velocity oxygen fuel sprayed WC-17Co coating under rotational fretting conditions

    Science.gov (United States)

    Luo, Jun; Cai, Zhenbing; Mo, Jiliang; Peng, Jinfang; Zhu, Minhao

    2016-05-01

    Rotational fretting which exist in many engineering applications has incurred enormous economic loss. Thus, accessible methods are urgently needed to alleviate or eliminate damage by rotational fretting. Surface engineering is an effective approach that is successfully adopted to enhance the ability of components to resist the fretting damage. In this paper, using a high-velocity oxygen fuel sprayed (HVOF) technique WC-17Co coating is deposited on an LZ50 steel surface to study its properties through Vickers hardness testing, scanning electric microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffractrometry (XRD). Rotational fretting wear tests are conducted under normal load varied from 10 N to 50 N, and angular displacement amplitudes vary from 0.125° to 1°. Wear scars are examined using SEM, EDX, optical microscopy (OM), and surface topography. The experimental results reveal that the WC-17Co coating adjusted the boundary between the partial slip regime (PSR) and the slip regime (SR) to the direction of smaller amplitude displacement. As a result, the coefficients of friction are consistently lower than the substrate's coefficients of friction both in the PSR and SR. The damage to the coating in the PSR is very slight. In the SR, the coating exhibits higher debris removal efficiency and load-carrying capacity. The bulge is not found for the coating due to the coating's higher hardness to restrain plastic flow. This research could provide experimental bases for promoting industrial application of WC-17Co coating in prevention of rotational fretting wear.

  16. UTILIZATION OF TORAY FLY ASH AS FILLER SUBSTITUTION IN THE HOT ROLLED SHEET-WEARING COURSE (HRS-WC MIXTURE

    Directory of Open Access Journals (Sweden)

    F. Candra

    2012-02-01

    Full Text Available In road construction materials, the utilization of fly ash as additive materials is limited and also small in quantity, while the disposal of fly ash is quite high. An abundance of fly ash can be found at PT Toray Company in Jakarta and Surabaya. Toray fly ash is disposed coal ash resulting from coal-fired electricity generating power plants. Toray fly ash in this research is used as substitute mineral filler in asphalt paving mixtures. Research on utilization of Toray fly ash as filler is conducted in the Hot Rolled Sheet – Wearing Course Mixture.  Filler content in the HRS –WC mixture is 9%. Variations of Toray fly ash in the mixture tested are 0%, 25%, 50%, 75%, 100% and the variations of asphalt content are 6%, 6.5%, 7%, 7.5%, 8%. Marshall test is  performed to determine the Optimum Asphalt Content  and Marshall Stability, Indirect Tensile Strength (ITS test and Tensile Strength Ratio (TSR to select the optimum Toray fly ash utilization in the mixture based on the moisture susceptibility of specimens. The research results show that in variations of 0%, 25%, 50%, 75% and 100% Toray fly ash in the HRS-WC Mixture, the Optimum Asphalt Contents are at 6.8%, 7.0%, 7.0%, 7.1% and 7.6%  and Marshall Stability values of the variations are 1649 kg, 1541 kg, 1568 kg, 1678 kg, 1718 kg respectively. TSR values in variations of Toray fly ash are 98.32%, 90.28%, 89.38%, 87.62%, 64.71% respectively, with Minimum TSR value required is 80%. Based on the overall parameters, the optimum Toray fly ash utilization in the HRS-WC Mixture recommended is 75% of Toray fly ash at 7.1% Optimum Asphalt Content.

  17. Influence of the microstructure of WC-Co cemented carbides on the fracture toughness and abrasive wear

    International Nuclear Information System (INIS)

    Zum Gahr, K.H.; Fischer, A.

    1981-01-01

    Fracture toughness and abrasive wear resistance of WC-Co cemented carbides were investigated by using the indentation cracking test (Palmqvist test) and the pin-on-disk method respectively. Size distribution of tungsten carbides and means free path between them were found to be important microstructural parameters related to the mechanical behavior. Results showed that selection of cemented carbides for heavy wear loading is complicated by contradictory influence of microstructural parameters on fracture toughness and abrasion resistance. Knowledge of the relation between microstructure and resistance to fracture or wear is necessary for optimum use of cemented carbides. (orig.) [de

  18. Investigation on cored-eutectic structure in Ni60/WC composite coatings fabricated by wide-band laser cladding

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qunshuang, E-mail: maqunshuang@126.com; Li, Yajiang, E-mail: yajli@sdu.edu.cn; Wang, Juan, E-mail: jwang@sdu.edu.cn; Liu, Kun, E-mail: liu_kun@163.com

    2015-10-05

    Highlights: • Perfect composite coatings were fabricated using wide-band laser cladding. • Special cored-eutectic structure was synthesized in Ni60/WC composite coatings. • Cored-eutectic consists of hard carbide compounds and fine lamellar eutectic of M{sub 23}C{sub 6} carbides and γ-Ni(Fe). • Wear resistance of coating layer was significantly improved due to precipitation of M{sub 23}C{sub 6} carbides. - Abstract: Ni60 composite coatings reinforced with WC particles were fabricated on the surface of Q550 steel using LDF4000-100 fiber laser device. The wide-band laser and circular beam laser used in laser cladding were obtained by optical lens. Microstructure, elemental distribution, phase constitution and wear properties of different composite coatings were investigated. The results showed that WC particles were partly dissolved under the effect of wide-band fiber laser irradiation. A special cored-eutectic structure was synthesized due to dissolution of WC particles. According to EDS and XRD results, the inside cores were confirmed as carbides of M{sub 23}C{sub 6} enriched in Cr, W and Fe. These complex carbides were primarily separated out in the molten metal when solidification started. Eutectic structure composed of M{sub 23}C{sub 6} carbides and γ-Ni(Fe) grew around carbides when cooling. Element content of Cr and W is lower at the bottom of cladding layer. In consequence, the eutectic structure formed in this region did not have inside carbides. The coatings made by circular laser beam were composed of dendritic matrix and interdendritic eutectic carbides, lacking of block carbides. Compared to coatings made by circular laser spot, the cored-eutectic structure formed in wide-band coatings had advantages of well-distribution and tight binding with matrix. The uniform power density and energy distribution and the weak liquid convection in molten pool lead to the unique microstructure evolution in composite coatings made by wide-band laser

  19. Current Status of Simulation-based Training Tools in Orthopedic Surgery: A Systematic Review.

    Science.gov (United States)

    Morgan, Michael; Aydin, Abdullatif; Salih, Alan; Robati, Shibby; Ahmed, Kamran

    To conduct a systematic review of orthopedic training and assessment simulators with reference to their level of evidence (LoE) and level of recommendation. Medline and EMBASE library databases were searched for English language articles published between 1980 and 2016, describing orthopedic simulators or validation studies of these models. All studies were assessed for LoE, and each model was subsequently awarded a level of recommendation using a modified Oxford Centre for Evidence-Based Medicine classification, adapted for education. A total of 76 articles describing orthopedic simulators met the inclusion criteria, 47 of which described at least 1 validation study. The most commonly identified models (n = 34) and validation studies (n = 26) were for knee arthroscopy. Construct validation was the most frequent validation study attempted by authors. In all, 62% (47 of 76) of the simulator studies described arthroscopy simulators, which also contained validation studies with the highest LoE. Orthopedic simulators are increasingly being subjected to validation studies, although the LoE of such studies generally remain low. There remains a lack of focus on nontechnical skills and on cost analyses of orthopedic simulators. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  20. Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

    Science.gov (United States)

    Riester, Scott M.; Bonin, Carolina A.; Kremers, Hilal Maradit; Dudakovic, Amel; Kakar, Sanjeev; Cohen, Robert C.; Westendorf, Jennifer J.

    2015-01-01

    The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant–bone interface and thereby improve long-term clinical outcomes. PMID:25348836

  1. Mobile Device Trends in Orthopedic Surgery: Rapid Change and Future Implications.

    Science.gov (United States)

    Andrawis, John P; Muzykewicz, David A; Franko, Orrin I

    2016-01-01

    Mobile devices are increasingly becoming integral communication and clinical tools. Monitoring the prevalence and utilization characteristics of surgeons and trainees is critical to understanding how these new technologies can be best used in practice. The authors conducted a prospective Internet-based survey over 7 time points from August 2010 to August 2014 at all nationwide American Council for Graduate Medical Education-accredited orthopedic programs. The survey questionnaire was designed to evaluate the use of devices and mobile applications (apps) among trainees and physicians in the clinical setting. Results were analyzed and summarized for orthopedic surgeons and trainees. During the 48-month period, there were 7 time points with 467, 622, 329, 223, 237, 111, and 134 responses. Mobile device use in the clinical setting increased across all fields and levels of training during the study period. Orthopedic trainees increased their use of Smartphone apps in the clinical setting from 60% to 84%, whereas attending use increased from 41% to 61%. During this time frame, use of Apple/Android platforms increased from 45%/13% to 85%/15%, respectively. At all time points, 70% of orthopedic surgeons believed their institution/hospital should support mobile device use. As measured over a 48-month period, mobile devices have become an ubiquitous tool in the clinical setting among orthopedic surgeons and trainees. The authors expect these trends to continue and encourage providers and trainees to be aware of the limitations and risks inherent with new technology. Copyright 2016, SLACK Incorporated.

  2. Collaborative multicenter trials in Latin America: challenges and opportunities in orthopedic and trauma surgery.

    Science.gov (United States)

    Moraes, Vinicius Ynoe de; Belloti, Joao Carlos; Faloppa, Flavio; Bhandari, Mohit

    2013-01-01

    CONTEXT AND OBJECTIVE Orthopedic research agendas should be considered from a worldwide perspective. Efforts should be planned as the means for obtaining evidence that is valid for health promotion with global outreach. DESIGN AND SETTING Exploratory study conducted at Universidade Federal de São Paulo (Unifesp), São Paulo, Brazil, and McMaster University, Hamilton, Canada. METHODS We identified and analyzed collaborative and multicenter research in Latin America, taking into account American and Canadian efforts as the reference points. We explored aspects of the data available from official sources and used data from traffic accidents as a model for discussing collaborative research in these countries. RESULTS The evaluation showed that the proportion of collaborative and multicenter studies in our setting is small. A brief analysis showed that the death rate due to traffic accidents is very high. Thus, it seems clear to us that initiatives involving collaborative studies are important for defining and better understanding the patterns of injuries resulting from orthopedic trauma and the forms of treatment. Orthopedic research may be an important tool for bringing together orthopedic surgeons, researchers and medical societies for joint action. CONCLUSIONS We have indicated some practical guidelines for initiatives in collaborative research and have proposed some solutions with a summarized plan of action for conducting evidence-based research involving orthopedic trauma.

  3. Effect of helium plasma gas flow rate on the properties of WC-12 wt.%Co coatings sprayed by atmospheric plasma

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2014-06-01

    Full Text Available The cermet coatings of WC-12wt.%Co are extensively used to improve the wear resistance of a wide range of technical components. This paper analyses the influence of the plasma gas flow of helium on the microstructure and mechanical properties of WC-12wt.%Co coatings deposited by plasma spraying at atmospheric pressure (APS. In order to obtain homogeneous and denser coatings, three different flows of He ( 8 l/min., 16 l/min. and 32 l/min were used in the research. With the application of He, coatings achieved higher values of hardness due to less degradation of the primary WC carbides. The main goal was to deposit dense and homogeneous layers of WC-12wt.%Co coatings with improved wear resistance for different applications. The test results of the microstructure of the layers were evaluated under a light microscope. The analysis of the microstructure and the mechanical properties of the deposited layers was made in accordance with the standard of Pratt-Whitney. The morphology of the powder particles and the microstructure of the best coating was examined on the SEM (scanning electron microscope. The evaluation of the mechanical properties of the layers was done by applying the HV0.3 method for microhardness testing and by applying tensile testing to test the bond strength. The research has shown that the flow of He plasma gas significantly affects the microstructure, the mechanical properties and the structure of WC-12 wt.%Co coatings.

  4. On the sintering behaviour of steel bonded TiC-Cr3C2 and TiC-Cr3C2-WC mixed carbides

    International Nuclear Information System (INIS)

    Stojanov, L.G.; Exner, H.E.

    1978-01-01

    Powder mixtures of TiC+Cr 3 C 2 and TiC+Cr 3 C 2 + WC were hot pressed to nearly full density. The lattice parameter of the resulting cubic mixed crystal decreases linearly with increasing additions of Cr 3 C 2 and (Cr 3 C 2 +WC 1:1). Microhardness increases with Cr 3 C 2 content up to 20 wt.%. By addition of WC, microhardness is increased further and reaches a maximum value of approx. 38 000 MN/m 2 for 20 wt.% Cr 3 C 2 and 20 wt.% WC. From these solid solutions powder compositions of Ferro-TiC type were produced by milling with 55 wt.% Fe and 0.4 wt.% C. The sintering behaviour of these powders was studied in a vacuum dilatometer. The pronounced increase of shrinkage by Cr 3 C 2 and higher amounts of Cr 3 C 2 +WC dissolved in TiC previous to binder phase melting is attributed to the increased solubility of the carbide in solid iron. Presintering at 700 0 C in hydrogen has a negative influence on sintering activity and requires much higher temperatures for complete densification during subsequent vacuum sintering. (orig.) [de

  5. Improvement of Surface Properties of Inconel718 by HVOF Coating with WC-Metal Powder and by Laser Heat Treatment of the Coating

    Directory of Open Access Journals (Sweden)

    Hui Gon Chun

    2015-01-01

    Full Text Available High-velocity oxygen-fuel (HVOF thermal spray coating with WC-metal powder was carried out by using optimal coating process on an Inconel718 surface for improvement of the surface properties, friction, wear, and corrosion resistance. Binder metals such as Cr and Ni were completely melted and WC was decomposed partially to W2C and graphite during the high temperature (up to 3500°C thermal spraying. The melted metals were bonded with WC and other carbides and were formed as WC-metal coating. The graphite and excessively sprayed oxygen formed carbon oxide gases, and these gases formed porous coating by evolution of the gases. The surface properties were improved by HVOF coating and were improved further by CO2 laser heat treatment (LH. Wear resistance of In718 surface was improved by coating and LH at 25°C and an elevated temperature of 450°C, resulting in reduction of wear trace traces, and was further improved by LH of the coating in reducing wear depth. Corrosion resistance due to coating in sea water was improved by LH. HVOF coating of WC-metal powder on a metal surface and a LH of the coating were highly recommended for the improvement of In718 surface properties, the friction behavior, and wear resistance.

  6. Microstructure and wear resistance of laser cladded composite coatings prepared from pre-alloyed WC-NiCrMo powder with different laser spots

    Science.gov (United States)

    Yao, Jianhua; Zhang, Jie; Wu, Guolong; Wang, Liang; Zhang, Qunli; Liu, Rong

    2018-05-01

    The distribution of WC particles in laser cladded composite coatings can significantly affect the wear resistance of the coatings under aggressive environments. In this study, pre-alloyed WC-NiCrMo powder is deposited on SS316L via laser cladding with circular spot and wide-band spot, respectively. The microstructure and WC distribution of the coatings are investigated with optical microscope (OM), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). The wear behavior of the coatings is investigated under dry sliding-wear test. The experimental results show that the partially dissolved WC particles are uniformly distributed in both coatings produced with circular spot and wide-band spot, respectively, and the microstructures consist of WC and M23C6 carbides and γ-(Ni, Fe) solid solution matrix. However, due to Fe dilution, the two coatings have different microstructural characteristics, resulting in different hardness and wear resistance. The wide-band spot laser prepared coating shows better performance than the circular spot laser prepared coating.

  7. Studi Karakteristik Campuran Aspal Beton Lapis Aus (AC-WC Menggunakan Aspal Penetrasi 60/70 dengan Penambahan Lateks

    Directory of Open Access Journals (Sweden)

    I Nyoman Arya Thanaya

    2016-12-01

    Full Text Available Asphalt on pavement in long term may undergo hardening, so it needs addition of additive that can make it remain flexible. This experiment tried to produce asphalt concrete wearing course (AC-WC using asphalt penetration 60/70 with the addition of latex, with aim to know the characteristic of AC-WC mix at the optimum of asphalt content with addition of  latex in variation of 0%, 2%, 4%, 6%, 8%, and 10% of the total binder. Latex was initially mixed with the asphalt, then the aggregates were proportioned based on ideal grading. The samples were produced in hotmix process. The density of latex was found 0.977 with dry rubber content of 61.95%. The optimum of asphalt content that was 5.7%, where all Marshall characteristics were met. It was chosen the mix with 4% latex by total binder where all properties of asphalt binder were still met. It was obtained that the Stability value  was 1439.26 kg (≥ 800 kg, Flow 3.84 mm (2-4 mm, Marshall Quotient 379.66 kg / mm (≥ 250 kg / mm, VIM  4.437% (3-5%, VMA 15.280% (≥ 15%, VFB 70.961 (≥ 65%. The mixture that contains latex had better resistance to deformation under dynamic creep loading at 40 °C.

  8. Erosion-oxidation behavior of thermal sprayed Ni20Cr alloy and WC and Cr3C2 cermet coatings

    Directory of Open Access Journals (Sweden)

    Clarice Terui Kunioshi

    2005-06-01

    Full Text Available An apparatus to conduct high temperature erosion-oxidation studies up to 850 °C and with particle impact velocities up to 15 m.s-1 was designed and constructed in the Corrosion Laboratories of IPEN. The erosion-oxidation behavior of high velocity oxy fuel (HVOF sprayed alloy and cermet coatings of Ni20Cr, WC 20Cr7Ni and Cr3C2 Ni20Cr on a steel substrate has been studied. Details of this apparatus and the erosion-oxidation behavior of these coatings are presented and discussed. The erosion-oxidation behavior of HVOF coated Cr3C2 25(Ni20Cr was better than that of WC 20Cr7Ni, and the erosion-oxidation regimes have been identified for these coatings at particle impact velocity of 3.5 m.s-1, impact angle of 90° and temperatures in the range 500 to 850 °C.

  9. Sliding friction of nanocomposite WC1-x/C coatings: transfer film and its influence on tribology.

    Science.gov (United States)

    Liu, Y; Gubisch, M; Spiess, L; Schaefer, J A

    2009-06-01

    The transfer film on steel spheres formed in reciprocating sliding against nanocomposite coatings based on nanocrystalline WC1-x in amorphous carbon matrix is characterized and correlated with the tribological properties measured by a precision microtribometer. With the presence of transfer film, a coefficient of friction approximately 0.13 and a depth wear rate approximately 0.35 x 10(-10) m/N.Pass were obtained. The central zone of the transfer film covering approximately 25% of the Hertz contact area is intact while cracks and wear debris are found in the vast peripheral area. It is also heavily oxidized due to the absence of carbon, which is located at the peripherals and acts as lubricants. We propose that the oxidation of WC and adhesion of the oxides to the surface of sphere is the main mechanism for the buildup of the transfer films. With the thickening of the film, the internal stress increases. Under the shear stress, spalling and cracking of the transfer film take place. The overall tribological performance of the coatings is therefore a competing process of buildup and spalling of transfer films.

  10. The effect of w/c ratio on microstructure of self-compacting concrete (SCC) with sugarcane bagasse ash (SCBA)

    Science.gov (United States)

    Hanafiah, Saloma, Victor, Amalina, Khoirunnisa Nur

    2017-11-01

    Self-Compacting Concrete (SCC) is a concrete that can flow and compact by itself without vibrator. The ability of SCC to flow by itself makes this concrete very suitable for construction that has very small reinforcement gaps. In this study, SCC was designed to get a compressive strength above 60 MPa at the age of 28 days. Sugarcane bagasse ash was used as substitution material for cement replacement. Percentages of sugarcane bagasse ash used were 10%, 15%, and 20%. There were three w/c values that vary from 0.275, 0.300, and 0.325. Testing standards referred to ASTM, EFNARC and ACI. The fresh concrete test was slump flow, L-box and V-funnel. The maximum compressive strength was in the mixture with the sugarcane bagasse ash composition of 15% and w/c=0.275 which was 67.24 MPa. The result of SEM test analysis found that the mixture composition with 15% sugarcane bagasse ash has solid CSH structure, small amount of pores, and smaller pore diameter than other mixtures.

  11. Influence of powder and spray parameters on erosion and corrosion properties of HVOF sprayed WC-Co-Cr coatings

    Energy Technology Data Exchange (ETDEWEB)

    Berget, John

    1998-07-01

    Thermal spraying is a generic term including various processes used to deposit coatings on surfaces. The coating material is in the form of powder or a wire and is melted or softened by means of a heat source. A gas stream accelerates the material towards a prepared surface and deposits it there to form the coating. Examples of components being maintained by application of thermal spray coatings are gate valves and ball valves for the offshore industry and turbine blades in power generations installations. Recent investigation has shown that the commonly used coating material WC-Co is not corrosion resistant. But it can be improved by the addition of Cr. The main objective of this thesis is to study the influence of spray process control variables and powder characteristics on the erosion and erosion-corrosion properties of the coatings. Spray process variables investigated include energy input, powder feed rate and spray distance. Powder characteristics studied are average size of the WC particles, relative proportions of Co and Cr in the metal phase and powder grain size distribution.

  12. Sulfonation of PEEK-WC polymer via chloro-sulfonic acid for potential PEM fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Iulianelli, A.; Clarizia, G.; Gugliuzza, A.; Ebrasu, D.; Basile, A. [Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, Via P. Bucci, Cubo 17/C, 87030 Rende (CS) (Italy); Bevilacqua, A. [Research Centre Italsistemi S.r.l., Via Avogadro, 88900 Crotone (KR) (Italy); Trotta, F. [Department of Organic Chemistry, University of Torino, C.So M. D' Azeglio 48, 10125 Torino (TO) (Italy)

    2010-11-15

    The preparation and characterization of thin dense sulfonated poly-ether-ether-ketone with cardo group (PEEK-WC) membranes for proton exchange membrane fuel cell (PEMFC) applications are described. The sulfonation of PEEK-WC polymer was realized via chloro-sulfonic acid and different kinds of membrane samples were prepared with a sulfonation degree ranging from 67 to 99%. The degree of sulfonation, homogeneity and thickness significantly affect both the membrane transport properties and the electrochemical performances. The dense character of the membranes was confirmed by SEM analysis. Proton conductivity measurements were carried out in a temperature range from 30 to 80 C and at 100% of relative humidity, reaching 5.40 x 10{sup -3} S/cm{sup -1} as best value at 80 C and with a sulfonation degree (DS) of 99%. At the same conditions, a water uptake of 17% was achieved. DSC and TGA characterizations were used in order to determine the thermal stability of the membranes, confirming a T{sub g} ranging between 206 and 216 C depending on the DS, whereas FT-IR yielded indication about intermolecular interactions and water uptake at various sulfonation degrees. (author)

  13. On the performances and wear of WC-diamond like carbon coated tools in drilling of CFRP/Titanium stacks

    Science.gov (United States)

    Boccarusso, L.; Durante, M.; Impero, F.; Minutolo, F. Memola Capece; Scherillo, F.; Squillace, A.

    2016-10-01

    The use of hybrid structures made of CFRP and titanium alloys is growing more and more in the last years in the aerospace industry due to the high strength to weight ratio. Because of their very different characteristics, the mechanical fastening represent the most effective joining technique for these materials. As a consequence, drilling process plays a key role in the assembly. The one shot drilling, i.e. the contemporary drilling of the stack of the two materials, seems to be the best option both in terms of time saving and assembly accuracy. Nevertheless, due to the considerable different machinability of fiber reinforced plastics and metallic materials, the one shot drilling is a critical process both for the holes quality and for the tools wear. This research was carried out to study the effectiveness of new generation tools in the drilling of CFRP/Titanium stacks. The tools are made of sintered grains of tungsten carbide (WC) in a binder of cobalt and coated with Diamond like carbon (DLC), and are characterized by a patented geometry; they mainly differ in parent WC grain size and binder percentage. Both the cutting forces and the wear phenomena were accurately investigated and the results were analyzed as a function of number of holes and their quality. The results show a clear increase of the cutting forces with the number of holes for all the used drilling tools. Moreover, abrasive wear phenomena that affect initially the tools coating layer were observed.

  14. The role of La2O3 in direct laser sintering of submicrometre WC-Cop/Cu MMCs

    International Nuclear Information System (INIS)

    Gu Dongdong; Shen Yifu

    2008-01-01

    This paper presents a detailed investigation of the influence of rare earth (RE) oxide (La 2 O 3 ) addition on densification and microstructure of direct laser sintered submicrometre WC-Co p /Cu metal matrix composites (MMCs) possessing 50.0 wt% reinforcement (WC-Co). It was found that with increasing La 2 O 3 addition to a suitable amount (1.0 wt%), the particulate dispersion was homogenized and the particulate/matrix interfacial bonding was improved. However, with an excessive addition of La 2 O 3 (1.5 wt%), a heterogeneous microstructure consisting of highly accumulated particulates was present. The exact metallurgical roles of RE element in direct laser sintering of particulate reinforced MMCs were addressed. It showed that a proper addition of RE element (i) decreased surface tension of the melt and enhanced solid-liquid wettability; (ii) dragged and/or pinned grain/phase boundaries and resisted grain coarsening and particulate aggregating. However, the balling phenomenon occurred and the activity of RE atoms decreased at an even higher La 2 O 3 content, thereby producing detrimental effects on laser forming ability

  15. Development and Evaluation of Polyvinyl Alcohol-Hydrogels as an Artificial Atrticular Cartilage for Orthopedic Implants

    Directory of Open Access Journals (Sweden)

    Masanori Kobayashi

    2010-04-01

    Full Text Available Due to its excellent biocompatibility and mechanical properties, various different applications of polyvinyl alcohol-hydrogels (PVA-H has been attempted in many fields. In the field of orthopedic surgery, we have been engaged for long time in research on the clinical applications of PVA-H as a artificial cartilage, and have performed many basic experiments on the mechanical properties, synthesis of PVA-H, and developed orthopedic implants using PVA-H. From these studies, many applications of artificial articular cartilage, intervertbral disc and artificial meniscus etc. have been developed. This review will present the overview of the applications and recent advances of PVA-H cartilages, and discuss clinical potential of PVA-H for orthopedics implant.

  16. Development and Evaluation of Polyvinyl Alcohol-Hydrogels as an Artificial Atrticular Cartilage for Orthopedic Implants

    Science.gov (United States)

    Kobayashi, Masanori; Hyu, Hyon Suong

    2010-01-01

    Due to its excellent biocompatibility and mechanical properties, various different applications of polyvinyl alcohol-hydrogels (PVA-H) has been attempted in many fields. In the field of orthopedic surgery, we have been engaged for long time in research on the clinical applications of PVA-H as a artificial cartilage, and have performed many basic experiments on the mechanical properties, synthesis of PVA-H, and developed orthopedic implants using PVA-H. From these studies, many applications of artificial articular cartilage, intervertbral disc and artificial meniscus etc. have been developed. This review will present the overview of the applications and recent advances of PVA-H cartilages, and discuss clinical potential of PVA-H for orthopedics implant.

  17. [How many generalists and how many specialists does orthopedics and traumatology need?].

    Science.gov (United States)

    Achatz, G; Perl, M; Stange, R; Mutschler, M; Jarvers, J S; Münzberg, M

    2013-01-01

    The training in orthopedic and trauma surgery has changed significantly with the introduction of the new residency program. The contents taught have already been reduced in breadth and the current developments in the outpatient and particularly in the clinical landscape also contribute to increasing specialization. This trend favors structures in which comprehensive medical care for the population in Germany in orthopedic and trauma surgery appears to be endangered and in which the future efforts for e.g. polytraumatised patients need to be questioned. The Young Forum of the German Society for Orthopedics and Traumatology actively accompanies a discussion about the necessity and value of generalists to ensure the level of care in Germany in addition to the specialists.

  18. Alternative procedures for reducing allogeneic blood transfusion in elective orthopedic surgery.

    Science.gov (United States)

    Kleinert, Kathrin; Theusinger, Oliver M; Nuernberg, Johannes; Werner, Clément M L

    2010-09-01

    Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

  19. PREPARATION AND CHARACTERIZATION OF Ti-Al-Nb ALLOYS FOR ORTHOPEDIC IMPLANTS

    Directory of Open Access Journals (Sweden)

    Oliveira V.

    1998-01-01

    Full Text Available Pure titanium shows very interesting characteristics such as high strength-to-weight ratio, very good corrosion resistance and excellent biocompatibility, which make this material appropriate for use in orthopedic and dental implants. Due to the mechanical properties of pure titanium, its use in implants is restricted to applications which involve moderate mechanical stress, such as dental implants. In applications where high mechanical strength is necessary, like orthopedic implants, it is appropriate to employ titanium-based alloys, which have better properties than pure titanium. The present work is related to the microstructure and corrosion resistance characterization of the Ti-6Al-7Nb alloy, designed to be used in orthopedic prostheses.

  20. Thirty-Day Readmission Rates in Orthopedics: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Bernatz, James T.; Tueting, Jonathan L.; Anderson, Paul A.

    2015-01-01

    Background Hospital readmission rates are being used to evaluate performance. A survey of the present rates is needed before policies can be developed to decrease incidence of readmission. We address three questions: What is the present rate of 30-day readmission in orthopedics? How do factors such as orthopedic specialty, data source, patient insurance, and time of data collection affect the 30-day readmission rate? What are the causes and risk factors for 30-day readmissions? Methods/Findings A review was first registered with Prospero (CRD42014010293, 6/17/2014) and a meta-analysis was performed to assess the current 30-day readmission rate in orthopedics. Studies published after 2006 were retrieved, and 24 studies met the inclusion criteria. The 30-day readmission rate was extrapolated from each study along with the orthopedic subspecialty, data source, patient insurance, time of collection, patient demographics, and cause of readmission. A sensitivity analysis was completed on the stratified groups. The overall 30-day readmission rate across all orthopedics was 5.4 percent (95% confidence interval: 4.8,6.0). There was no significant difference between subspecialties. Studies that retrieved data from a multicenter registry had a lower 30-day readmission rate than those reporting data from a single hospital or a large national database. Patient populations that only included Medicare patients had a higher 30-day readmission rate than populations of all insurance. The 30-day readmission rate has decreased in the past ten years. Age, length of stay, discharge to skilled nursing facility, increased BMI, ASA score greater than 3, and Medicare/Medicaid insurance showed statistically positive correlation with increased 30-day readmissions in greater than 75 percent of studies. Surgical site complications accounted for 46 percent of 30-day readmissions. Conclusions This meta-analysis shows the present rate of 30-day readmissions in orthopedics. Demonstrable

  1. The TROJAN Project: Creating a Customized International Orthopedic Training Program for Junior Doctors.

    Science.gov (United States)

    Kalraiya, Ashish; Buddhdev, Pranai

    2015-03-03

    Musculoskeletal problems account for a vast proportion of presentations encountered by doctors globally, with figures ranging from 15-36%. However, the time medical schools allocate to learning orthopedics is by no means proportional to this. This study aims to bridge this gap by developing an international orthopedic teaching program tailored to the specific knowledge and skills required by junior doctors in different countries. This prospective study asked fifty junior doctors, who had recently completed an orthopedics job, what three orthopedic teaching topics taught retrospectively would have benefitted their clinical practice. The most requested topics were used to design educational workshops for junior doctors and these consequently comprised the TROJAN (Teaching Requested by Orthopaedic Juniors And Novices) training program. Data was collected from twenty-five junior doctors in KwaZulu-Natale State, South Africa, and twenty-five in London, UK. It is therefore in these two countries that the TROJAN program was subsequently made available. Participants who selected topics were within two years of graduating medical school and had worked an orthopedic or Accident and Emergency job within the last year. 49% of topics chosen by SA doctors were practical skills such as wrist and ankle fracture reduction techniques, and management of open fractures. The most requested topic by UK doctors (11 out of 25) was management of neck of femur fractures. This is rationalized by the fact South African doctors require more hands-on responsibility in their daily practice whereas in the UK greater emphasis is placed on optimizing patients for theatre and making sound management plans. TROJAN currently develops orthopedic skills and knowledge in junior doctors in South Africa and United Kingdom with teaching customized based upon location. Feedback has been exceptionally positive with every candidate thus far rating the usefulness of TROJAN as the highest option, very useful.

  2. Multi-detector CT imaging in the postoperative orthopedic patient with metal hardware

    International Nuclear Information System (INIS)

    Vande Berg, Bruno; Malghem, Jacques; Maldague, Baudouin; Lecouvet, Frederic

    2006-01-01

    Multi-detector CT imaging (MDCT) becomes routine imaging modality in the assessment of the postoperative orthopedic patients with metallic instrumentation that degrades image quality at MR imaging. This article reviews the physical basis and CT appearance of such metal-related artifacts. It also addresses the clinical value of MDCT in postoperative orthopedic patients with emphasis on fracture healing, spinal fusion or arthrodesis, and joint replacement. MDCT imaging shows limitations in the assessment of the bone marrow cavity and of the soft tissues for which MR imaging remains the imaging modality of choice despite metal-related anatomic distortions and signal alteration

  3. Examination to assess the clinical examination and documentation of spine pathology among orthopedic residents.

    Science.gov (United States)

    Haglin, Jack M; Zeller, John L; Egol, Kenneth A; Phillips, Donna P

    2017-12-01

    The Accreditation Council for Graduate Medical Education (ACGME) guidelines requires residency programs to teach and evaluate residents in six overarching "core competencies" and document progress through educational milestones. To assess the progress of orthopedic interns' skills in performing a history, physical examination, and documentation of the encounter for a standardized patient with spinal stenosis, an objective structured clinical examination (OSCE) was conducted for 13 orthopedic intern residents, following a 1-month boot camp that included communications skills and curriculum in history and physical examination. Interns were objectively scored based on their performance of the physical examination, communication skills, completeness and accuracy of their electronic medical record (EMR), and their diagnostic conclusions gleaned from the patient encounter. The purpose of this study was to meaningfully assess the clinical skills of orthopedic post-graduate year (PGY)-1 interns. The findings can be used to develop a standardized curriculum for documenting patient encounters and highlight common areas of weakness among orthopedic interns with regard to the spine history and physical examination and conducting complete and accurate clinical documentation. A major orthopedic specialty hospital and academic medical center. Thirteen PGY-1 orthopedic residents participated in the OSCE with the same standardized patient presenting with symptoms and radiographs consistent with spinal stenosis. Videos of the encounters were independently viewed and objectively evaluated by one investigator in the study. This evaluation focused on the completeness of the history and the performance and completion of the physical examination. The standardized patient evaluated the communication skills of each intern with a separate objective evaluation. Interns completed these same scoring guides to evaluate their own performance in history, physical examination, and communications

  4. [Improving the effectiveness of functional jaw orthopedics in Class II malocclusion by appropriate treatment timing].

    Science.gov (United States)

    Baccetti, Tiziano

    2010-12-01

    Time can be considered the fourth dimension in dento-facial orthopedics. Treatment timing can play a significant role in the outcomes of treatment aimed to produce an orthopedic effect in the craniofacial structures. The results of methodologically-sound cephalometric studies of both the past and the recent history of orthodontics clearly indicate that optimal treatment timing for Class II skeletal disharmony with a functional appliance (e.g. twin block) is during or slightly after the peak in mandibular growth as revealed by a reliable biologic indicator of individual skeletal maturity such as the cervical vertebral maturation method. © EDP Sciences, SFODF, 2010.

  5. Slurry Erosion Behavior of F6NM Stainless Steel and High-Velocity Oxygen Fuel-Sprayed WC-10Co-4Cr Coating

    Science.gov (United States)

    Cui, S. Y.; Miao, Q.; Liang, W. P.; Huang, B. Z.; Ding, Z.; Chen, B. W.

    2017-02-01

    WC-10Co-4Cr coating was applied to the surface of F6NM stainless steel by high-velocity oxygen-fuel spraying. The slurry erosion behavior of the matrix and coating was examined at different rotational speeds using a self-made machine. This experiment effectively simulates real slurry erosion in an environment with high silt load. At low velocity (<6 m/s), the main failure mechanism was cavitation. Small bubbles acted as an air cushion, obstructing direct contact between sand and the matrix surface. However, at velocity above 9 m/s, abrasive wear was the dominant failure mechanism. The results indicate that WC-10Co-4Cr coating significantly improved the slurry resistance at higher velocity, because it created a thin and dense WC coating on the surface.

  6. Structural analysis of sputtered (W-C)1-xMx (M≡Fe,Co) films with 0≤x≤0.20

    International Nuclear Information System (INIS)

    Cavaleiro, A.; Trindade, B.; Vieira, M.T.

    1993-01-01

    Structural characterization of (W-C) 1-x M x (M≡Fe,Co) films with 0≤x≤0.20 was carried out using electron probe microanalysis (EPMA), X-ray diffraction (XRD) and transmission electron microscopy-electron diffraction (TEM-ED). The results showed that the structure of these films depends on the percentage of iron and cobalt and becomes amorphous with increasing content of these elements. The microstructure of the crystalline coatings was found to be composed of small grains of β-WC 1-x with a high number of defects. A strong β-WC 1-x [311] texture was observed for iron and cobalt contents around 5.5 at.%. The films richer in iron and cobalt showed typical amorphous XRD and ED patterns, exhibiting two broad peaks and two wide diffuse rings respectively. Moreover, bright-field analysis revealed fairly contrasted images, the structure of these films being difficult to resolve. (orig.)

  7. Comparison of the effects and complications of unilateral spinal anesthesia versus standard spinal anesthesia in lower-limb orthopedic surgery

    Directory of Open Access Journals (Sweden)

    Seyyed Mostafa Moosavi Tekye

    2014-06-01

    Full Text Available Introduction: A restricted sympathetic block during spinal anesthesia may minimize hemodynamic changes. This prospective randomized study compared unilateral and bilateral spinal anesthesia with respect to the intra- and postoperative advantages and complications of each technique. Material and methods: Spinal anesthesia was induced with 0.5% hyperbaric bupivacaine and a 25-G Quincke needle (Dr. J in two groups of patients with physical status ASA I-II who had been admitted for orthopedic surgeries. In group A, dural puncture was performed with the patient in a seated position using 2.5 cm3 of hyperbaric bupivacaine. Each patient was then placed in the supine position. In group B, dural puncture was performed with the patient in the lateral decubitus position with 1.5 cm3 of hyperbaric bupivacaine. The lower limb was the target limb. The speed of injection was 1 mL/30 s, and the duration of time spent in the lateral decubitus position was 20 min. Results: The demographic data were similar in both groups. The time to the onset of the sensory and motor block was significantly shorter in group A (p = 0.00. The duration of motor and sensory block was shorter in group B (p < 0.05. The success rate for unilateral spinal anesthesia in group B was 94.45%. In two patients, the spinal block spread to the non-dependent side. The incidence of complications (nausea, headache, and hypotension was lower in group B (p = 0.02. Conclusion: When unilateral spinal anesthesia was performed using a low-dose, low-volume and low-flow injection technique, it provides adequate sensory-motor block and helps to achieve stable hemodynamic parameters during orthopedic surgery on a lower limb. Patients were more satisfied with this technique as opposed to the conventional approach. Furthermore, this technique avoids unnecessary paralysis on the non-operated side.

  8. Selective laser sintering of calcium phosphate materials for orthopedic implants

    Science.gov (United States)

    Lee, Goonhee

    control of micro and macro pore structure, to maximize bone healing and provide sufficient mechanical strength. It also permits the complete removal of the polymeric binders that are resided in the SLS process. In collaboration with the University of Texas Health Science Center at San Antonio and BioMedical Enterprises, Inc., porous implants based on anatomical geometry have been successfully implanted in rabbits and dogs. These histologic animal studies reveal excellent biocompatibility and show its great potential for commercial custom-fit implant manufacture. The second research effort involves fabrication of fully dense bone for application in dental restoration and load-bearing orthopedic functions. Calcium phosphate glass melts, proven to be biocompatible in the first effort, were cast into carbon molds. Processes were developed for preparing the molds. These carbon molds of anatomic shape can be prepared from either Computer Numerical Control (CNC) milling of slab stock or SLS processing of thermoset-coated graphite powder. The CNC milling method provides accurate dimension of the molds in a short period of time, however, the capable geometries are limited; generally two pieces of molds are required for complex shapes. The SLS method provides very complex shape green molds. However, they need to go through pyrolysis of thermoset binder to provide the high temperature capability reached at calcium phosphate melt temperatures (1100°C) and noticeable shrinkage was observed during pyrolysis. The cast glass was annealed to develop polycrystalline calcium phosphate. This process also exhibits great potential.

  9. Effect of Mo2C/(Mo2C + WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

    International Nuclear Information System (INIS)

    Xu, Qingzhong; Zhao, Jun; Ai, Xing; Qin, Wenzhen; Wang, Dawei; Huang, Weimin

    2015-01-01

    To optimize the Mo 2 C content in Ti(C,N)-based cermet tool materials used for cutting the high-strength steel of 42CrMo (AISI 4140/4142 steel), the cermets with different Mo 2 C/(Mo 2 C + WC) weight ratios were prepared. And the microstructure and mechanical properties of cermets were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and measurements of transverse rupture strength (TRS), Vickers hardness (HV) and fracture toughness (K IC ). The results indicate that the Mo 2 C/(Mo 2 C + WC) ratios have great influences on the microstructure features and mechanical properties of Ti(C,N)-based cermets. When the Mo 2 C/(Mo 2 C + WC) ratio increases, the Ti(C,N) grains become finer with smaller black cores surrounded by thinner rims, and the structure of cermets tends to be more compact with smaller binder mean free path. Owing to the medium grains and moderate rims, the cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 exhibit better mechanical properties, and can be chosen as the tool material for machining 42CrMo steel due to the lower Mo content. - Highlights: • Mo 2 C/(Mo 2 C + WC) ratios affect microstructure and mechanical properties of cermets. • Grains become fine and structure of cermets tends to be compact with raised Mo 2 C. • The cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 can be used to machine 42CrMo steel

  10. Rising incidence of Enterococcus species in microbiological specimens from orthopedic patients correlates to increased use of cefuroxime

    DEFF Research Database (Denmark)

    Siesing, Peter Christian; Alva-Jørgensen, Jens Peter; Brodersen, Jakob

    2013-01-01

    Enterococci are emerging causes of severe infections, including wound and bone infections in orthopedic patients. The main purpose of this study was to determine whether there was a correlation between the incidence of enterococci in tissue samples (biopsies) from orthopedic patients and consumpt...

  11. Variability in Resident Operative Hand Experience by Specialty.

    Science.gov (United States)

    Silvestre, Jason; Lin, Ines C; Levin, L Scott; Chang, Benjamin

    2018-01-01

    Recent attention has sought to standardize hand surgery training in the United States. This study analyzes the variability in operative hand experience for orthopedic and general surgery residents. Case logs for orthopedic and general surgery residency graduates were obtained from the American Council of Graduate Medical Education (2006-2007 to 2014-2015). Plastic surgery case logs were not available for comparison. Hand surgery case volumes were compared between specialties with parametric tests. Intraspecialty variation in orthopedic surgery was assessed between the bottom and top 10th percentiles in procedure categories. Case logs for 9605 general surgery residents and 5911 orthopedic surgery residents were analyzed. Orthopedic surgery residents performed a greater number of hand surgery cases than general surgery residents ( P < .001). Mean total hand experience ranged from 2.5 ± 4 to 2.8 ± 5 procedures for general surgery residents with no reported cases of soft tissue repairs, vascular repairs, and replants. Significant intraspecialty variation existed in orthopedic surgery for all hand procedure categories (range, 3.3-15.0). As the model for hand surgery training evolves, general surgeons may represent an underutilized talent pool to meet the critical demand for hand surgeon specialists. Future research is needed to determine acceptable levels of training variability in hand surgery.

  12. Mechanical characterization of cemented carbide WC-6Co (%wt) manufactured by SPS (Spark Plasma Sintering; Caracterizacao mecanica de metal duro WC-6Co (%massa) sinterizado via SPS (Spark Plasma Sintering)

    Energy Technology Data Exchange (ETDEWEB)

    Boidi, G.; Tertuliano, A.J.; Machado, I.F., E-mail: guido.boidi@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Engenharia Mecatronica e Sistemas Mecanicos; Rodrigues, D. [BRATS- Filtros Sinterizados e Pos Metalicos, Cajamar, SP (Brazil)

    2016-07-01

    This work aimed to manufacture cemented carbide (WC-6%wtCo) obtained by SPS (Spark Plasma Sintering) process and to carry out the mechanical characterization by hardness and fracture toughness. The material was consolidated at 1100 deg C for different holding times (1 min, 5 min, 10 min), in order to evaluate the densification. A reference sample was also used to be compared to SPS. Optical and scanning electron microscopy were carried out to characterize the microstructural features of the samples and mechanical properties were obtained by hardness measurements (micro and macro) and instrumented indentation. The fracture toughness was calculated with the method of Palmqvist. Best results were found in the material sintered by SPS for 10 minutes of holding time, in which 97% of relative density and about 1600 HV{sub 10} was reached. (author)

  13. Study of the sintering behavior of fine, ultrafine and nanocrystalline WC-CO mixtures obtained by high energy milling; Estudio del comportamiento durante la sinterizacion de mezclas WC-Co finas, ultrafinas y nanocristalinas obtenidas por molienda de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, M. D.; Bonache, V.; Amigo, V.; Busquets, D.

    2008-07-01

    In this work the sintering behaviour of fine, ultrafine and nanocrystalline WC-12Co mixtures obtained by high energy milling, as well commercial nano powders, have been studied, in order to evaluate the effect of the particle size and the powder processing, in the densification, microstructural development and mechanical properties of the final product. The consolidation of the mixtures has been made by uniaxial pressing and sintering in vacuum, and by hot isostatic pressing. The sintered materials have been evaluated by measures of density, hardness and indentation fracture toughness, and micro structurally characterized by optical microscopy and scanning and transmission electronic microscopy (SEM and TEM). The results show the improvements in resistant behaviour of the materials obtained from nanocrystalline powders, in spite of the grain growth experienced during the sintering. The best results were obtained for the milling nanocrystalline material, which presents values of hardness higher than 180 HV. (Author) 46 refs.

  14. A Survey on Transfusion Status in Orthopedic Surgery at a Trauma Center

    Directory of Open Access Journals (Sweden)

    Mehran Soleimanha

    2016-01-01

    Full Text Available Background: Increased costs and mortality associated with inappropriate blood transfusions have led to investigations about blood request and blood transfusion techniques. We investigated the transfusion status in patients who underwent orthopedic surgery in Poursina Hospital (Rasht, Iran to optimizing blood usage and determine if a scheduled transfusion program for every orthopedic surgery could improve blood transfusion management. Method: In this descriptive-prospective study, all orthopedic surgeries in Poursina Hospital, Rasht, between April to June 2013 were reviewed. All patient information was recorded, including: demographics, type of surgery, hemoglobin level, cross-match test, duration of surgery, and blood loss, and transfusion. Based on the one-way ANOVA and independent samples test analysis, cross-match to transfusion ratio and transfusion possibility, the transfusion index, and maximal surgical blood order schedule were calculated to determine blood transfusion status. Results: Among 872 selected orthopedic surgery candidates, 318 of them were cross-matched and among those, 114 patients received a blood transfusion. In this study, the cross-match to transfusion ratio was 6.4, transfusion possibility 36.47%, transfusion index 0.6, and maximal surgical blood order schedule 0.9. Conclusion: We found that blood ordering was moderately higher than the standard; so it is highly recommended to focus on the knowledge of evidence based on transfusion and standard guidelines for blood transfusion to avoid over-ordering.

  15. Application of computer graphics in the design of custom orthopedic implants.

    Science.gov (United States)

    Bechtold, J E

    1986-10-01

    Implementation of newly developed computer modelling techniques and computer graphics displays and software have greatly aided the orthopedic design engineer and physician in creating a custom implant with good anatomic conformity in a short turnaround time. Further advances in computerized design and manufacturing will continue to simplify the development of custom prostheses and enlarge their niche in the joint replacement market.

  16. The Effect of Orthopedic Advertising and Self-Promotion on a Naïve Population.

    Science.gov (United States)

    Mohney, Stephen; Lee, Daniel J; Elfar, John C

    2016-01-01

    There has been a marked increase in the number of physicians marketing themselves directly to patients and consumers. However, it is unclear how different promotional styles affect patients' perceptions of their physicians. We hypothesized that self-promoting orthopedic surgeons enjoy a more positive impact on nonphysician patients as compared to non-self-promoting surgeons, as well as a corresponding negative impact on their peer-surgeons. Surgeon websites were selected from the 5 largest population centers in the United States. Subjects with varying degrees of familiarity with orthopedic surgery evaluated Internet profiles of surgeons on a forced choice Likert scale to measure the amount of self-promotion. The naïve subjects judged self-promoting surgeons more favorably than the orthopedic surgeons. In contrast, board-certified orthopedic surgeons viewed self-promoting surgeons more negatively than did their nonphysician counterparts. In summary, the present study revealed that the potential for self-promotion to unduly influence potential patients is real and should be a considerable concern to surgeons, patients, and the profession.

  17. The orthopedic gender gap: trends in authorship and editorial board representation over the past 4 decades.

    Science.gov (United States)

    Okike, Kanu; Liu, Bella; Lin, Yijie Brittany; Torpey, Jennifer L; Kocher, Mininder S; Mehlman, Charles T; Bhandari, Mohit; Biermann, J Sybil

    2012-07-01

    The purpose of this study was to quantify the representation of women among the authors and editorial board members of prominent general orthopedics journals and to determine how these proportions have changed over time. Gender was determined for the authors of all original research studies, case reports, and review articles published in 2 prominent general orthopedics journals in 1970, 1980, 1990, 2000, and 2007. Gender was also determined for each individual serving on the editorial boards of these journals during these years. Between 1970 and 2007, the representation of women increased from 0.8% to 6.5% among first authors (P<.001), from 0.0% to 4.3% among last authors (P = .015), and from 1.6% to 5.4% among editorial board members (P = .16). However, the rates of increase observed in orthopedics were lower than those observed in other fields (P<.05). Between 1970 and 2007, female representation increased significantly among physicians publishing in 2 prominent general orthopedics journals, but these rates of increase were lower than those observed in other fields of medicine.

  18. Social Networking as a Tool for Lifelong Learning with Orthopedically Impaired Learners

    Science.gov (United States)

    Ersoy, Metin; Güneyli, Ahmet

    2016-01-01

    This paper discusses how Turkish Cypriot orthopedically impaired learners who are living in North Cyprus use social networking as a tool for leisure and education, and to what extent they satisfy their personal development needs by means of these digital platforms. The case study described, conducted in North Cyprus in 2015 followed a qualitative…

  19. Contributing risk factors for orthopedic device related infections in sina hospital, tehran, iran.

    Science.gov (United States)

    Hadadi, A; Zehtab, M J; Babagolzadeh, H; Ashraf, H

    2011-02-01

    In spite of decreasing incidence of orthopedic device-related infections to 1%, nowadays, device-related infection still remains a diagnostic, therapeutic and cost-related problem. The objective of this study is to evaluate the contributing risk factors for orthopedic device-related infections in Sina Hospital, Tehran, Iran. Three hundred and thirty patients who underwent orthopedic device implantation from 2002-2006 were enrolled; among them, 110 patients were complicated with infection. Descriptive and logistic regression analyses were performed to determine the risk factors for device related infections. Patients with infection were older compared to those without infection. The Staphylococcus aureus was the commonest organism. A correlation was observed between wound infection and external fixation, an underlying health condition, and addiction which were independent risk factors for a device related infection. Orthopedic device-related infection puts a great financial burden on patients and hospital resources and could lead to morbidity and mortality in patients. So, appropriate pre and postoperative wound care for dirty wounds, especially when external fixators are used, and in patients with poor conditions or addiction should be done with more caution.

  20. Magnitude and meaningfulness of change in SF-36 scores in four types of orthopedic surgery

    DEFF Research Database (Denmark)

    Busija, Lucy; Osborne, Richard H; Nilsdotter, Anna

    2008-01-01

    BACKGROUND: The Medical Outcomes General Health Survey (SF-36) is a widely used health status measure; however, limited evidence is available for its performance in orthopedic settings. The aim of this study was to examine the magnitude and meaningfulness of change and sensitivity of SF-36...

  1. High energy devices versus low energy devices in orthopedics treatment modalities

    Science.gov (United States)

    Schultheiss, Reiner

    2003-10-01

    The orthopedic consensus group defined in 1997 the 42 most likely relevant parameters of orthopedic shock wave devices. The idea of this approach was to correlate the different clinical outcomes with the physical properties of the different devices with respect to their acoustical waves. Several changes in the hypothesis of the dose effect relationship have been noticed since the first orthopedic treatments. The relation started with the maximum pressure p+, followed by the total energy, the energy density; and finally the single treatment approach using high, and then the multiple treatment method using low energy. Motivated by the reimbursement situation in Germany some manufacturers began to redefine high and low energy devices independent of the treatment modality. The OssaTron as a high energy, single treatment electro hydraulic device gained FDA approval as the first orthopedic ESWT device for plantar fasciitis and, more recently, for lateral epicondylitis. Two low energy devices have now also gained FDA approval based upon a single treatment. Comparing the acoustic data, differences between the OssaTron and the other devices are obvious and will be elaborated upon. Cluster analysis of the outcomes and the acoustical data are presented and new concepts will be suggested.

  2. Late orthopedic effects in children with Wilms' tumor treated with abdominal irradiation

    International Nuclear Information System (INIS)

    Rate, W.R.; Butler, M.S.; Robertson, W.W. Jr.; D'Angio, G.J.

    1991-01-01

    Between 1970 and 1984, 31 children with biopsy-proven Wilms' tumor received nephrectomy, chemotherapy, and abdominal irradiation and were followed beyond skeletal maturity. Three patients (10%) developed late orthopedic abnormalities requiring intervention. Ten children received orthovoltage irradiation, and all cases requiring orthopedic intervention or developing a scoliotic curve of greater than 20 degrees were confined to this group, for a complication frequency of 50%. Those children who developed a significant late orthopedic abnormality (SLOA) as defined were treated to a higher median dose (2,890 cGy) and a larger field size (150 cm2) than those who did not (2,580 cGy and 120 cm2). Age at irradiation, sex, and initial stage of disease did not appear to influence the risk of developing an SLOA. No child who received megavoltage irradiation developed an SLOA despite treatment up to 4,000 cGy or to field sizes of 400 cm2. We conclude that modern radiotherapy techniques rarely lead to significant late orthopedic abnormalities previously associated with abdominal irradiation in children with Wilms' tumor

  3. Readability of Patient Education Materials From the Web Sites of Orthopedic Implant Manufacturers.

    Science.gov (United States)

    Yi, Meghan M; Yi, Paul H; Hussein, Khalil I; Cross, Michael B; Della Valle, Craig J

    2017-12-01

    Prior studies indicate that orthopedic patient education materials are written at a level that is too high for the average patient. The purpose of this study was to assess the readability of online patient education materials provided by orthopedic implant manufacturers. All patient education articles available in 2013 from the web sites of the 5 largest orthopedic implant manufacturers were identified. Each article was evaluated with the Flesch-Kincaid (FK) readability test. The number of articles with readability ≤ the eighth-grade level (average reading ability of US adults) and the sixth-grade level (recommended level for patient education materials) was determined. Mean readability levels of each company's articles were compared using analysis of variance (significance set at P articles were reviewed from the 5 largest implant manufacturers. The mean overall FK grade level was 10.9 (range, 3.8-16.1). Only 58 articles (10%) were written ≤ the eighth-grade level, and only 13 (2.2%) were ≤ the sixth-grade level. The mean FK grade level was significantly different among groups (Smith & Nephew = 12.0, Stryker = 11.6, Biomet = 11.3, DePuy = 10.6, Zimmer = 10.1; P education materials from implant manufacturers are written at a level too high to be comprehended by the average patient. Future efforts should be made to improve the readability of orthopedic patient education materials. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Automatic bone detection and soft tissue aware ultrasound-CT registration for computer-aided orthopedic surgery.

    Science.gov (United States)

    Wein, Wolfgang; Karamalis, Athanasios; Baumgartner, Adrian; Navab, Nassir

    2015-06-01

    The transfer of preoperative CT data into the tracking system coordinates within an operating room is of high interest for computer-aided orthopedic surgery. In this work, we introduce a solution for intra-operative ultrasound-CT registration of bones. We have developed methods for fully automatic real-time bone detection in ultrasound images and global automatic registration to CT. The bone detection algorithm uses a novel bone-specific feature descriptor and was thoroughly evaluated on both in-vivo and ex-vivo data. A global optimization strategy aligns the bone surface, followed by a soft tissue aware intensity-based registration to provide higher local registration accuracy. We evaluated the system on femur, tibia and fibula anatomy in a cadaver study with human legs, where magnetically tracked bone markers were implanted to yield ground truth information. An overall median system error of 3.7 mm was achieved on 11 datasets. Global and fully automatic registration of bones aquired with ultrasound to CT is feasible, with bone detection and tracking operating in real time for immediate feedback to the surgeon.

  5. Risk assessment of accidental exposure of surgeons to blood during orthopedic surgery. Are we safe in surgical gloves?

    Directory of Open Access Journals (Sweden)

    Dariusz Timler

    2014-03-01

    Full Text Available Aim. To analyze tears in sterile surgical gloves used by surgeons in the operating theatre of the Trauma and Orthopedic Surgery Department, Copernicus Memorial Hospital, Łódź, Poland Materials and Method. This study analyzes tears in sterile surgical gloves used by surgeons by ICD-9 and ICD-10 codes. 1,404 gloves were collected from 581 surgical procedures. All gloves were tested immediately following surgery using the test method described in Standard EN455–1 (each glove was inflated with 1,000 ± 50 ml of water and observed for leaks for 2–3 min.. Results. Analysis of tears took into consideration the role of medical personnel (operator, first assistant, second assistant during surgical procedure, the type of procedure according to ICD-9 and ICD-10 codes, and the elective or emergency nature of the procedure. The results of the study show that these factors have a significant influence on the risk of glove tears. Significant differences were observed in tear frequency and tear location depending on the function performed by the surgeon during the procedure. Conclusion. The study proved that the role performed by the surgeon during the procedure (operator, first assistant, second assistant has a significant influence on the risk of glove tearing. The role in the procedure determines exposure to glove tears. Implementing a double gloving procedure in surgical procedures or using single gloves characterized by higher tear resistance should be considered.

  6. Study of the sintering behavior of fine, ultrafine and nanocrystalline WC-CO mixtures obtained by high energy milling

    International Nuclear Information System (INIS)

    Salvador, M. D.; Bonache, V.; Amigo, V.; Busquets, D.

    2008-01-01

    In this work the sintering behaviour of fine, ultrafine and nanocrystalline WC-12Co mixtures obtained by high energy milling, as well commercial nano powders, have been studied, in order to evaluate the effect of the particle size and the powder processing, in the densification, microstructural development and mechanical properties of the final product. The consolidation of the mixtures has been made by uniaxial pressing and sintering in vacuum, and by hot isostatic pressing. The sintered materials have been evaluated by measures of density, hardness and indentation fracture toughness, and micro structurally characterized by optical microscopy and scanning and transmission electronic microscopy (SEM and TEM). The results show the improvements in resistant behaviour of the materials obtained from nanocrystalline powders, in spite of the grain growth experienced during the sintering. The best results were obtained for the milling nanocrystalline material, which presents values of hardness higher than 180 HV. (Author) 46 refs

  7. The Effect of ZrO₂ Nanoparticles on the Microstructure and Properties of Sintered WC-Bronze-Based Diamond Composites.

    Science.gov (United States)

    Sun, Youhong; Wu, Haidong; Li, Meng; Meng, Qingnan; Gao, Ke; Lü, Xiaoshu; Liu, Baochang

    2016-05-06

    Metal matrix-impregnated diamond composites are widely used in diamond tool manufacturing. In order to satisfy the increasing engineering requirements, researchers have paid more and more attention to enhancing conventional metal matrices by applying novel methods. In this work, ZrO₂ nanoparticles were introduced into the WC-bronze matrix with and without diamond grits via hot pressing to improve the performance of conventional diamond composites. The effects of ZrO₂ nanoparticles on the microstructure, density, hardness, bending strength, and wear resistance of diamond composites were investigated. The results indicated that the hardness and relative density increased, while the bending strength decreased when the content of ZrO₂ nanoparticles increased. The grinding ratio of diamond composites increased significantly by 60% as a result of nano-ZrO₂ addition. The enhancement mechanism was discussed. Diamond composites showed the best overall properties with the addition of 1 wt % ZrO₂ nanoparticles, thus paving the way for further applications.

  8. Wear resistance of nano- and micro-crystalline diamond coatings onto WC-Co with Cr/CrN interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Polini, Riccardo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy); Barletta, Massimiliano, E-mail: barletta@ing.uniroma2.i [Dipartimento di Ingegneria Meccanica, Universita di Roma Tor Vergata, Via del Politecnico, 1, Rome, 00133 (Italy); Cristofanilli, Giacomo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy)

    2010-12-30

    Cr/CrN bi-layers have been used recently to promote the growth of high quality Hot Filament Chemical Vapour Deposition (HFCVD) diamond coatings onto Co-cemented tungsten carbide (WC-6 wt.%Co) substrates. In the present investigation, the influence of the crystalline size of the diamond coatings on their wear endurance is looked into. Nano- (NDC) and micro-crystalline Diamond Coatings (MDC) were deposited by HFCVD onto untreated and Fluidized Bed (FB) treated Cr/CrN interlayers. NDCs, characterized by a cauliflower-like morphology, showed improved wear resistance. However, the superimposition of NDCs onto Cr/CrN interlayers micro-corrugated by FB treatment was found to be the most promising choice, leading to the formation of highly adherent and wear resistant coatings.

  9. Quantitative analysis of the orthodontic and orthopedic effects of maxillary traction.

    Science.gov (United States)

    Baumrind, S; Korn, E L; Isaacson, R J; West, E E; Molthen, R

    1983-11-01

    This article analyzes differences in displacement of ANS and of the upper first molar when different vectors of force are delivered to the maxilla in non-full-banded Phase I mixed-dentition treatment of Class II malocclusion. The sample is identical to that for which we have previously reported differences in change in several key measures of mandibular and facial shape. It includes a cervical-traction group, a high-pull-to-upper-molar group, a modified-activator group, and an untreated Class II control group. Using newly developed computer-conducted procedures, which are described, we have been able to partition the orthodontic and orthopedic components of upper molar displacement and also to isolate treatment effects from those attributable to spontaneous growth and development. In the region of ANS, small but statistically significant and clinically meaningful differences were noted between treatments. When the intercurrent effects of growth and development had been factored out (Table III), orthopedic distal displacement of ANS was significantly greater in the high-pull and cervical groups than in the activator group. Orthopedic downward displacement of ANS was seen to be significantly greater in the cervical group than in the high-pull and activator groups. In the region of the first molar cusp, mean distal displacement of the tooth as an orthopedic effect was found to be almost identical in the cervical and high-pull groups (although variability was greater in the cervical group), but the mean orthodontic effect was significantly greater in the high-pull group than in the cervical group. In the cervical group, where relatively light forces were used for relatively long treatment periods on average, more of the total distal displacement of the upper molar was of an orthopedic character than of an orthodontic character. Conversely, in the high-pull group, in which relatively heavier forces tended to be used for briefer treatment periods, most of the distal

  10. Physico-chemical profiles of the wobble ↔ Watson-Crick G*·2AP(w) ↔ G·2AP(WC) and A·2AP(w) ↔ A*·2AP(WC) tautomerisations: a QM/QTAIM comprehensive survey.

    Science.gov (United States)

    Brovarets', Ol'ha O; Voiteshenko, Ivan S; Hovorun, Dmytro M

    2017-12-20

    This study is intended to clarify in detail the tautomeric transformations of the wobble (w) G*·2AP(w) and A·2AP(w) nucleobase mispairs involving 2-aminopurine (2AP) into the Watson-Crick (WC) G·2AP(WC) and A*·2AP(WC) base mispairs (asterisks denote mutagenic tautomers of the DNA bases), respectively, by quantum-mechanical methods and Bader's Quantum Theory of Atoms in Molecules. Our previously reported methodology has been used, which allows the evolution of the physico-chemical parameters to be tracked along the entire internal reaction coordinate (IRC), not exclusively in the stationary states of these reactions. These biologically important G*·2AP(w) ↔ G·2AP(WC) and A·2AP(w) ↔ A*·2AP(WC) w ↔ WC tautomerisations, which are involved in mutagenic tautomerically-conformational pathways, determine the origin of the transitions and transversions induced by 2AP. In addition, it is established that they proceed through planar, highly stable, zwitterionic transition states and they exhibit similar physico-chemical profiles and stages of sequential intrapair proton transfer, followed by spatial rearrangement of the nucleobases relative to each other within the base pairs. These w ↔ WC tautomerisations occur non-dissociatively and are accompanied by a significant alteration in geometry (from wobble to Watson-Crick and vice versa) and redistribution of the specific intermolecular interactions, which can be divided into 10 patterns including AHB H-bonds and loosened A-H-B covalent bridges along the IRC of tautomerisation. Based on the redistribution of the geometrical and electron-topological parameters of the intrapair hydrogen bonds, exactly 9 key points have been allocated to characterize the evolution of these reactions.

  11. The impact of a hospitalist on role boundaries in an orthopedic environment

    Directory of Open Access Journals (Sweden)

    Webster F

    2012-10-01

    Full Text Available Fiona Webster,1 Samantha Bremner,2 Megan Jackson,3 Vikas Bansal,2 Joanna Sale41Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada; 2Holland Orthopedic and Arthritic Centre, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 3Faculty of Social Science, University of Western Ontario, London, ON, Canada; 4Mobility Program Clinical Research Unit, St Michael's Hospital, Toronto, ON, CanadaPurpose: Hospitalists specialize in the management of hospitalized patients. They work with several health care professionals to provide patient care. There has been little research examining the perceived impact of the hospitalist's role on staff working in an orthopedic environment. This study examined the experiences of staff across several professional backgrounds in working with a hospitalist in an orthopedic environment.Participants and methods: A qualitative descriptive approach was taken to investigate the experience of staff working with a hospitalist at a specialized orthopedic hospital. Purposive sampling was used to recruit interview participants including nurses, internists, pharmacists, physiotherapists, anesthetists, senior administration, and orthopedic surgeons to the point of theoretical saturation, which occurred after 12 interviews. Interviews were coded, and these codes were combined into categories and predominant themes were identified.Findings: Overall, staff believed that the hospitalist role was a positive addition to the facility. The role benefitted patients and supported the clinical well-being and education of staff. Many staff felt the hospitalist had no impact on their workload, but others reported that their work had decreased or increased. Several described the potential for role overlap between the hospitalist and other physicians.Conclusion: The importance of interprofessional collaboration in the implementation of the hospitalist role was a recurring theme in our analysis. This study

  12. Enhanced osteoblast adhesion on nanostructured selenium compacts for anti-cancer orthopedic applications

    Directory of Open Access Journals (Sweden)

    Phong Tran

    2008-10-01

    Full Text Available Phong Tran1, Thomas J Webster21Physics Department; 2Division of Engineering and Department of Orthopedics, Brown University, Providence, USAAbstract: Metallic bone implants possess numerous problems limiting their long-term efficacy, such as poor prolonged osseointegration, stress shielding, and corrosion under in vivo environments. Such problems are compounded for bone cancer patients since numerous patients receive orthopedic implants after cancerous bone resection. Unfortunately, current orthopedic materials were not originally developed to simultaneously increase healthy bone growth (as in traditional orthopedic implant applications while inhibiting cancerous bone growth. The long-term objective of the present research is to investigate the use of nano-rough selenium to prevent bone cancer from re-occurring while promoting healthy bone growth for this select group of cancer patients. Selenium is a well known anti-cancer chemical. However, what is not known is how healthy bone cells interact with selenium. To determine this, selenium, spherical or semispherical shots, were pressed into cylindrical compacts and these compacts were then etched using 1N NaOH to obtain various surface structures ranging from the micron, submicron to nano scales. Changes in surface chemistry were also analyzed. Through these etching techniques, results of this study showed that biologically inspired surface roughness values were created on selenium compacts to match that of natural bone roughness. Moreover, results showed that healthy bone cell adhesion increased with greater nanometer selenium roughness (more closely matching that of titanium. In this manner, this study suggests that nano-rough selenium should be further tested for orthopedic applications involving bone cancer treatment.Keywords: selenium, nano-rough, osteoblast, cancer, chemopreventive

  13. Developing a minimum data set of the information management system for orthopedic injuries in iran.

    Science.gov (United States)

    Ahmadi, Maryam; Mohammadi, Ali; Chraghbaigi, Ramin; Fathi, Taimur; Shojaee Baghini, Mahdieh

    2014-07-01

    Orthopedic injuries are the most common types of injuries. To identify the main causes of injuries, collecting data in a standard manner at the national level are needed, which justifies necessity of making a minimum data set (MDS). The aim of this study was to develop an MDS of the information management system for orthopedic injuries in Iran. This descriptive cross-sectional study was performed in 2013. Data were collected from hospitals affiliated with Tehran University of Medical Sciences that had orthopedic department, medical documents centers, legal medicine centers, emergency centers, internet access, and library. Investigated documents were orthopedic injury records in 2012, documents that retrieved from the internet, and printed materials. Records with Random sampling by S22-S99 categories from ICD-10 were selected and the related internet-sourced data were evaluated entirely. Data were collected using a checklist. In order to make a consensus about the data elements, the decision Delphi technique was applied by a questionnaire. The content validity and reliability of the questionnaire were assessed by expert's opinions and test-retest method, respectively. AN MDS OF ORTHOPEDIC INJURIES WERE ASSIGNED TO TWO CATEGORIES: administrative category with six classes including 142 data elements, and clinical category with 17 classes including 250 data elements. This study showed that some of the essential data elements included in other country's MDS or required for organizations and healthcare providers were not included. Therefore, a complete list of an MDS elements was created. Existence of comprehensive data concerning the causes and mechanisms of injuries informs public health policy-makers about injuries occurrence and enables them to take rationale measures to deal with these problems.

  14. Communication with Orthopedic Trauma Patients via an Automated Mobile Phone Messaging Robot.

    Science.gov (United States)

    Anthony, Chris A; Volkmar, Alexander; Shah, Apurva S; Willey, Mike; Karam, Matt; Marsh, J Lawrence

    2017-12-20

    Communication with orthopedic trauma patients is traditionally problematic with low response rates (RRs). The purpose of this investigation was to (1) evaluate the feasibility of communicating with orthopedic trauma patients postoperatively, utilizing an automated mobile phone messaging platform; and (2) assess the first 2 weeks of postoperative patient-reported pain and opioid use after lower extremity orthopedic trauma procedures. This was a prospective investigation at a Level 1 trauma center in the United States. Adult patients who were capable of mobile phone messaging and were undergoing common, lower extremity orthopedic trauma procedures were enrolled in the study. Patients received a daily mobile phone message protocol inquiring about their current pain level and amount of opioid medication they had taken in the past 24 h starting on postoperative day (POD) 3 and continuing through POD 17. Our analysis considered (1) Patient completion rate of mobile phone questions, (2) Patient-reported pain level (0-10 scale), and (3) Number and percentage of daily prescribed opioid medication patients reported taking. Twenty-five patients were enrolled in this investigation. Patients responded to 87.5% of the pain and opioid medication inquiries they received over the 2-week study period. There were no differences in RRs by patient age, sex, or educational attainment. Patient-reported pain decreased over the initial 2-week study period from an average of 4.9 ± 1.7 on POD 3 to 3 ± 2.2 on POD 16-17. Patients took an average of 68% of their maximum daily narcotic prescription on POD 3 compared with 35% of their prescribed pain medication on POD 16-17. We found that in orthopedic trauma patients, an automated mobile phone messaging platform elicited a high patient RR that improved upon prior methods in the literature. This method may be used to reliably obtain pain and medication utilization data after trauma procedures.

  15. Evaluation of radiation protection in interventional orthopedic procedures in Khartoum state

    International Nuclear Information System (INIS)

    Ibrahim, M. Y. A.

    2013-06-01

    In this study an evaluation of radiation safety and protection in interventional orthopedic procedures for the staff in three theatres in Khartoum state was conducted. To evaluate radiation protection program and staff knowledge with regard to radiation protection a questionnaire was designed and distributed among the staff there. Integrity check was conducted on the available radiation tools ( lead aprons) to ensure that they provide optimal protection when positioned appropriately. Also dose rate was measured around the theatre to evaluate the level of leakage radiation. Finally the absorbed dose to orthopedic specialists was measured during several procedures. The study showed the absence of most of the radiation protection and safety procedures that ensure the protection of of workers and lack of radiation protection program. The integrity check conducted on lead aprons showed uncapable crack in about 24% of the checked aprons. And in spite of this, there was no action taken to withdraw those faulty aprons or to replace them due to the acute shortage of the aprons available in the three centers and this will cause unjustified radiation exposure to the staff. The level of radiation around the theatres was found to fall within the acceptable limit according to the international commission of radiation protection (ICRP) recommendations that -if implemented -could improve the status of radiation protection in interventional orthopedic procedures. The improve. The important recommendations are to establish a single regulatory authority in Sudan independent from any user or promotion of radiation as well as to conduct periodically training courses for orthopedic staff on radiation protection in orthopedic interventional procedures.(Author)

  16. Personal dosimetry TLD 100 in orthopedic surgeons exposed to ionizing radiation in Bogota - Colombia; Dosimetria personal TLD 110 en medicos ortopedistas expuestos a radiacion ionizante en Bogota - Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Sierra C, B. Y.; Jimenez, Y. [Universidad Nacional de Colombia, Departamento de Fisica, Grupo de Fisica Medica, Carrera 45 No. 26-85, Bogota (Colombia); Plazas, M. C. [Hospital Universitario Fundacion Santa Fe de Bogota, Instituto de Oncologia Carlos Ardila Lulle, Calle 119, No. 7-90, 220246 Bogota (Colombia); Eslava S, J. [Universidad Nacional de Colombia, Instituto de Investigaciones Clinicas, Grupo Equidad en Salud, Carrera 45 No. 26-85, Bogota (Colombia); Groot R, H., E-mail: brigith.sierra@gmail.com [Universidad de los Andes, Laboratorio de Genetica Humana, Carrera 1 No. 18A -12, Bogota (Colombia)

    2014-08-15

    Orthopedic surgeons should be considered as professionals occupationally exposed to ionizing radiation, for using C arc (fluoroscope) an equipment of X type radiation emission, during surgical procedures for imaging generation. Some health institutes, use of C arc under uncontrolled circumstances, such a lack of dosimetry control, incomplete or absence of personnel protective elements and protective measures, which in turn, lead to a high exposition to the personnel. Materials and methods. Study of double match cohort by age and gender, was conducted, in four health institutions of second and third level of attention in Bogota city. Personal dosimetry measurements with TLD-100 dosimetry crystals in both cohorts and environmental dosimetry in each of operation rooms used for orthopedic procedures, were carry out during six months of follow up. Dosimetry crystals were read in a Harshaw 4500 - Bicron equipment, in the Medical Physics Laboratory of National University of Colombia. Results. Dosimetry measurements are compatibles with those of occupationally exposed personnel 3.44 mSv/6 m CI 95% (1.66-3.99), even does not overpass ICRP recommendations, are higher as were expect at the beginning of the study. The median of effective accumulative dose in thorax is 3,4 mSv CI 95% (1,66-3,99), higher in comparison with neck value 2,7 mSv CI 95% (1,73-3,80) and hand dosimetry 1,42 mSv CI 95% (0,96-2,34). Conclusions: Orthopedic surgeons should be considered occupational exposed to ionizing radiation, who has to accomplish to the radiological protection measures, dosimetric follow up and maintenance of the used X ray equipment. It was confirm throughout this study that dosimetry shows higher levels as expected at the beginning of the study, compatible with occupationally exposed personnel. (Author)

  17. Southern Vermont College (SVC) and Wheelock College (WC): 2010 Urban and Rural Healthcare Academy Program (HAP) for College Progress and Workforce Development

    Science.gov (United States)

    DeCiccio, Albert C.

    2010-01-01

    (Purpose) This is a report about the Urban and Rural Healthcare Academy Pilot Program (HAP) that launched at Southern Vermont College (SVC) and Wheelock College (WC) in summer 2010. HAP enabled 18 vulnerable high school students to learn about how to progress to college, how to transition when they arrive on a college campus, and how to prepare…

  18. An imitative calculation of W/C, Mo/Si articifial multilayered films' structures and properties as X-ray monochromators

    International Nuclear Information System (INIS)

    Liu Wen; Liu Wenhan; Wu Ziqin

    1989-01-01

    An imitative calculation on W/C and Mo/Si artificial multilayered films have been made. The influences of total period numbers and deviation of period thickness on X-ray diffraction peak were given. Two difference diviations, random fluctuation and system linear deviation have been imitated, their influences on X-ray energy distinguish power have been compared

  19. Empirical ranking of a wide range of WC-Co grades in terms of their abrasion resistance measured by the ASTM standard B 611-85 test

    CSIR Research Space (South Africa)

    O'Quigley, DGF

    1997-01-01

    Full Text Available This paper reports the results of a comprehensive investigation into the abrasion resistance of WC-Co alloys, as measured by the ASTM Standard B 611-85 test. The alloys ranged from 3 to 50 wt% and from 0.6 to 5 mu-m average grain size. Careful...

  20. Composite coating containing WC/12Co cermet and Fe-based metallic glass deposited by high-velocity oxygen fuel spraying

    International Nuclear Information System (INIS)

    Terajima, Takeshi; Takeuchi, Fumiya; Nakata, Kazuhiro; Adachi, Shinichiro; Nakashima, Koji; Igarashi, Takanori

    2010-01-01

    A composite coating containing WC/12Co cermet and Fe 43 Cr 16 Mo 16 C 15 B 10 metallic glass was successfully deposited onto type 304 stainless steel by high-velocity oxygen fuel (HVOF) spraying, and the microstructure and tribological properties were investigated. The microstructure of the coating was characterized by scanning electron microscopy/electron probe micro-analysis (SEM/EPMA) and X-ray diffractometry (XRD). The hardness, adhesion strength and tribological properties of the coating were tested with a Vickers hardness tester, tensile tester and reciprocating wear tester, respectively. The composite coating, in which flattened WC/12Co was embedded in amorphous Fe 43 Cr 16 Mo 16 C 15 B 10 layers, exhibited high hardness, good wear resistance and a low friction coefficient compared to the monolithic coating. The addition of 8% WC/12Co to the Fe 43 Cr 16 Mo 16 C 15 B 10 matrix increased the cross-sectional hardness from 660 to 870 HV and reduced the friction coefficient from 0.65 to 0.5. WC/12Co reinforcement plays an important role in improving the tribological properties of the Fe 43 Cr 16 Mo 16 C 15 B 10 coating.

  1. Effect of SiC Nanowhisker on the Microstructure and Mechanical Properties of WC-Ni Cemented Carbide Prepared by Spark Plasma Sintering

    Directory of Open Access Journals (Sweden)

    Xiaoyong Ren

    2014-01-01

    Full Text Available Ultrafine tungsten carbide-nickel (WC-Ni cemented carbides with varied fractions of silicon carbide (SiC nanowhisker (0–3.75 wt.% were fabricated by spark plasma sintering at 1350°C under a uniaxial pressure of 50 MPa with the assistance of vanadium carbide (VC and tantalum carbide (TaC as WC grain growth inhibitors. The effects of SiC nanowhisker on the microstructure and mechanical properties of the as-prepared WC-Ni cemented carbides were investigated. X-ray diffraction analysis revealed that during spark plasma sintering (SPS Ni may react with the applied SiC nanowhisker, forming Ni2Si and graphite. Scanning electron microscopy examination indicated that, with the addition of SiC nanowhisker, the average WC grain size decreased from 400 to 350 nm. However, with the additional fractions of SiC nanowhisker, more and more Si-rich aggregates appeared. With the increase in the added fraction of SiC nanowhisker, the Vickers hardness of the samples initially increased and then decreased, reaching its maximum of about 24.9 GPa when 0.75 wt.% SiC nanowhisker was added. However, the flexural strength of the sample gradually decreased with increasing addition fraction of SiC nanowhisker.

  2. Effectiveness and economic analysis of the whole cell/recombinant B subunit (WC/rbs inactivated oral cholera vaccine in the prevention of traveller's diarrhoea

    Directory of Open Access Journals (Sweden)

    Diez-Diaz Rosa

    2009-05-01

    Full Text Available Abstract Background Nowadays there is a debate about the indication of the oral whole-cell/recombinant B-subunit cholera vaccine (WC/rBS in traveller's diarrhoea. However, a cost-benefit analysis based on real data has not been published. Methods A cost-effectiveness and cost-benefit study of the oral cholera vaccine (WC/rBS, Dukoral® for the prevention of traveller's diarrhoea (TD was performed in subjects travelling to cholera risk areas. The effectiveness of WC/rBS vaccine in the prevention of TD was analyzed in 362 travellers attending two International Vaccination Centres in Spain between May and September 2005. Results The overall vaccine efficacy against TD was 42,6%. Direct healthcare-related costs as well as indirect costs (lost vacation days subsequent to the disease were considered. Preventive vaccination against TD resulted in a mean saving of 79.26 € per traveller. Conclusion According to the cost-benefit analysis performed, the recommendation for WC/rBS vaccination in subjects travelling to zones at risk of TD is beneficial for the traveller, regardless of trip duration and visited continent.

  3. Characterisation of Pristine and Recoated electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings on AISI M2 steel and WC-Co substrates

    International Nuclear Information System (INIS)

    Avelar-Batista, J.C.; Spain, E.; Housden, J.; Fuentes, G.G.; Rebole, R.; Rodriguez, R.; Montala, F.; Carreras, L.J.; Tate, T.J.

    2005-01-01

    This paper is focussed on the characterisation of electron beam evaporation plasma-assisted physical vapour deposition Cr-N coatings deposited on AISI M2 steel and hardmetal (K10) substrates in two different conditions: Pristine (i.e., coated) and Recoated (i.e., stripped and recoated). Analytical methods, including X-ray diffraction (XRD), scanning electron microscopy, scratch adhesion and pin-on-disc tests were used to evaluate several coating properties. XRD analyses indicated that both Pristine and Recoated coatings consisted of a mixture of hexagonal Cr 2 N and cubic CrN, regardless of substrate type. For the M2 steel substrate, only small differences were found in terms of coating phases, microstructure, adhesion, friction and wear coefficients between Pristine and Recoated. Recoated on WC-Co (K10) exhibited a less dense microstructure and significant inferior adhesion compared to Pristine on WC-Co (K10). The wear coefficient of Recoated on WC-Co was 100 times higher than those exhibited by all other specimens. The results obtained confirm that the stripping process did not adversely affect the Cr-N properties when this coating was deposited onto M2 steel substrates, but it is clear from the unsatisfactory tribological performance of Recoated on WC-Co that the stripping process is unsuitable for hardmetal substrates

  4. Referrals of Ethiopian Orthopedic Patients for Treatment Abroad.

    African Journals Online (AJOL)

    dell

    developing country could be able to receive patients from abroad and generate a foreign currency. ... from Europe/US are getting operated in Asia or Africa. There are also ... Worries about the standards of surgical practice, .... their specialty and expected to work to the same high standards, following policies and acceptable.

  5. Radiation exposure to anesthesiologist and nurse in the orthopedic room

    Energy Technology Data Exchange (ETDEWEB)

    Arita, Tetsuhiko; Matsuzaki, Akio [Fukuoka Univ., Chikushino (Japan). Chikusi Hospital

    1996-09-01

    We report the radiation exposure dose received by the anesthesiologist and nurse in the orthopaedic operating room, when a fluoroscopic image intensifier is in use. This study was done in 12 femoral neck fracture operations performed from January to May 1995. Radiation was monitored with the MYDOSE MINIX PDM 107 made by Aloka Co. which were attached in front and behind the nurse`s lead apron, in front of the lead apron of the anesthesiologist. The average imaging time was 9.78 min. The average radiation dose in front of the anesthesiologist is lead apron was 2.08{mu}SV, and in front and behind the nurse`s lead apron were 5.67{mu}SV, 0.08{mu}SV respectively. This study and review of the literature indicate that the operating room anesthesiologist and nurse receive a lower exposure than the orthopaedist. We can disregard the problem of radiation exposure to the anesthesiologist and nurse during an orthopaedic operation when they wear lead aprons and stand far from the patient. (author)

  6. Radiation exposure to anesthesiologist and nurse in the orthopedic room

    International Nuclear Information System (INIS)

    Arita, Tetsuhiko; Matsuzaki, Akio

    1996-01-01

    We report the radiation exposure dose received by the anesthesiologist and nurse in the orthopaedic operating room, when a fluoroscopic image intensifier is in use. This study was done in 12 femoral neck fracture operations performed from January to May 1995. Radiation was monitored with the MYDOSE MINIX PDM 107 made by Aloka Co. which were attached in front and behind the nurse's lead apron, in front of the lead apron of the anesthesiologist. The average imaging time was 9.78 min. The average radiation dose in front of the anesthesiologist is lead apron was 2.08μSV, and in front and behind the nurse's lead apron were 5.67μSV, 0.08μSV respectively. This study and review of the literature indicate that the operating room anesthesiologist and nurse receive a lower exposure than the orthopaedist. We can disregard the problem of radiation exposure to the anesthesiologist and nurse during an orthopaedic operation when they wear lead aprons and stand far from the patient. (author)

  7. Declining trends in invasive orthopedic interventions for people with hemophilia enrolled in the Universal Data Collection program (2000–2010)

    Science.gov (United States)

    TOBASE, P.; LANE, H.; SIDDIQI, A.-E-A.; INGRAM-RICH, R.; WARD, R. S.

    2016-01-01

    Introduction Recurrent joint hemarthroses due to hemophilia (Factor VIII and Factor IX deficiency) often lead to invasive orthopedic interventions to decrease frequency of bleeding and/or to alleviate pain associated with end-stage hemophilic arthropathy. Aim Identify trends in invasive orthopedic interventions among people with hemophilia who were enrolled in the Universal Data Collection (UDC) program during the period 2000–2010. Methods Data were collected from 130 hemophilia treatment centers in the United States annually during the period 2000–2010, in collaboration with the Centers for Disease Control and Prevention (CDC). The number of visits in which an invasive orthopedic intervention was reported was expressed as a proportion of the total visits in each year of the program. Invasive orthopedic interventions consisted of arthroplasty, arthrodesis, and synovectomy. Joints included in this study were the shoulder, elbow, hip, knee, and ankle. Results A 5.6% decrease in all invasive orthopedic interventions in all joints of people with hemophilia enrolled in the UDC program over the 11-year study period was observed. Conclusions These data reflect a declining trend in invasive orthopedic interventions in people with hemophilia. Further research is needed to understand the characteristics that may influence invasive orthopedic interventions. PMID:27030396

  8. Effects of NbC additions on the microstructure and properties of non-uniform structure WC-Co cemented carbides

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yang; Yan, Ming-Yuan, E-mail: 704878879@qq.com; Luo, Bing-Hui, E-mail: luobinghui@csu.edu.cn; Ouyang, Sheng; Chen, Wei; Bai, Zhen-hai; Jing, Hui-bo; Zhang, Wen-Wen

    2017-02-27

    In this work, the effects of NbC additions on microstructure and properties of non-uniform structure WC-7Co cemented carbides were investigated X-ray diffractometer, scanning electron microscopy (SEM), electron probe microanalysis (EPMA), mechanical properties tester and electrochemical workstation, respectively. The results show that WC phase can be partially dissolved into the NbC to form a (Nb,W)C solid solution. According to EPMA analysis, the amount of W atoms, dissolving into the NbC grains, increases with the NbC addition. Moreover, when the content of NbC is beyond 1%, the WC-Co cemented carbides with non-uniform structure are formed with significant reduction of average grain size of WC. With NbC addition increasing from 0 wt% to 2 wt%, the hardness is increased from 1475 MPa to 1570 MPa while the fracture toughness decreased from 12.1 MPa m{sup 1/2} to 10.3 MPa m{sup 1/2}. However, with the further addition of NbC, the hardness slightly decreased. With NbC addition between 0 and 1 wt%, the TRS is gradually decreased from 2982 MPa to 2745 MPa, while, as the NbC content exceeds 1 wt%, the TRS leveled off. Because of the decrease of grain size and the (Nb,W)C phase formation, caused by NbC addition, the crack defection was weakened, which led to the decrease of fracture toughness. Meanwhile, the corrosion resistance of non-uniform structure WC-Co cemented carbides can be significantly improved by adding NbC to the material due to increased α-Co in binder phase.

  9. Investigations of mussel-inspired polydopamine deposition on WC and Al{sub 2}O{sub 3} particles: The influence of particle size and material

    Energy Technology Data Exchange (ETDEWEB)

    Mondin, Giovanni, E-mail: giovanni.mondin@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Haft, Marcel, E-mail: m.haft@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Solid State Research, Helmholtzstr. 20, 01069 Dresden (Germany); Wisser, Florian M., E-mail: florian.wisser@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Leifert, Annika, E-mail: annika.leifert@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Mohamed-Noriega, Nasser, E-mail: nasser.mohamed-noriega@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Dörfler, Susanne, E-mail: susanne.doerfler@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Hampel, Silke, E-mail: s.hampel@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Institute for Solid State Research, Helmholtzstr. 20, 01069 Dresden (Germany); Grothe, Julia, E-mail: stefan.kaskel@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany); Kaskel, Stefan, E-mail: julia.grothe@chemie.tu-dresden.de [Department of Inorganic Chemistry, Dresden University of Technology, Bergstrasse 66, 01069 Dresden (Germany)

    2014-12-15

    Polydopamine, formed by oxidation of dopamine, is a bioinspired polymer developed for multifunctional coatings by Lee et al. in 2007 by drawing inspiration from the adhesive proteins found in mussels. Due to their high versatility and substrate-independence, polydopamine coatings are gaining considerable attention in a plethora of research fields, particularly in the coating of particles, but systematic investigations of the polydopamine coating process are lacking in the literature. In this study, we explore by TEM and thermogravimetric analysis the polydopamine coating process on alumina microparticles, tungsten carbide microparticles and tungsten carbide nanoparticles. By choosing two substrates with similar size but different material (Al{sub 2}O{sub 3} and WC), as well as two substrates of the same material but different size (WC micro- and nanoparticles) we investigate the effects of both substrate material and substrate size, in order to gain some insights into the polydopamine particle coating process. As opposed to what is generally assumed in the literature, we found that the polydopamine coating thicknesses on particles, as well as the thickness growing trend, depend on the particles size and material. In particular, after 24 h of polymerization time the polydopamine coatings reached a thickness of 65 ± 10 nm in the case of Al{sub 2}O{sub 3} microparticles, 18 ± 4 nm in the case of WC microparticles and 33 ± 6 nm in the case of WC nanoparticles. - Highlights: • The coating of different particles with polydopamine was systematically investigated. • Al{sub 2}O{sub 3} microparticles and WC microparticles and nanoparticles were investigated. • The thickness of the polydopamine coating depends on the particle size. • The thickness of the polydopamine coating depends on the particle material.

  10. Update on thromboprophylaxis in orthopedic surgery and critical appraisal of the role of enoxaparin

    Directory of Open Access Journals (Sweden)

    Wong JM

    2012-05-01

    Full Text Available Jan Man Wong, Yoon Kong LokeNorwich Medical School, University of East Anglia, Norwich, United KingdomAbstract: Orthopedic surgery is considered one of the most prominent risk factors for venous thromboembolism (VTE, but the optimal strategy for thromboprophylaxis remains a debatable topic. Consistent and reliable definitions of clinically relevant VTE and major bleeds in orthopedic research are particularly contentious areas, resulting in uncertainty about the actual benefit–harm balance of available interventions. For the newer oral anticoagulants, short-term clinical trials in highly selected patients with asymptomatic VTE (from mandatory radiological screening must be supplemented by long-term efficacy and safety data in real-world settings (such as the Global Orthopedic Registry. The evidence gap leads to visible differences among recent recommendations from bodies such as the American College of Chest Physicians (2012, the American Academy of Orthopedic Surgeons (2011, and the National Institute of Clinical Excellence, England (NICE, 2012. While thromboprophylaxis after hip and knee arthroplasty is clearly recommended by all three bodies, there is no consistent agreement on the optimal agent or the duration of prophylaxis. Differences in opinion stem from subjective judgments on the relative weighting given to asymptomatic as opposed to symptomatic VTE, and the impact of major bleeding. While the newer oral anticoagulants (such as rivaroxaban and apixaban seem to offer significant benefits compared to enoxaparin in the reduction of asymptomatic VTE, the data are limited by the paucity of symptomatic VTE and inconsistencies in capturing major bleeds. The lack of long-term experience in real world patients means that it is too early to judge whether the obvious convenience of newer oral anticoagulants will result in better patient adherence, safety, and quality of life as compared to enoxaparin. Further research should focus on clinically

  11. Effect of hydromorphone hydrochloride combined with ropivacaine for PCEA after orthopedic surgery on the synthesis of pain mediators, inflammatory mediator and oxygen free radicals

    Directory of Open Access Journals (Sweden)

    Liang-Ying Luo

    2017-08-01

    Full Text Available Objective: To explore the effect of hydromorphone hydrochloride combined with ropivacaine for PCEA after orthopedic surgery on the synthesis of pain mediators, inflammatory mediator and oxygen free radicals. Methods: A total of 120 patients with fracture who underwent operation in the hospital between July 2014 and December 2016 were collected and divided into control group and observation group according to the random number table method, 60 cases in each group. Control group received morphine hydrochloride combined with ropivacaine for analgesia, observation group received hydromorphone hydrochloride combined with ropivacaine for analgesia, and the postoperative analgesia lasted for 48 h. The differences in serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were compared between the two groups. Results: Immediately after operation, the differences in serum levels of pain mediators, inflammatory mediators and oxidative stress indexes were not statistically significant between the two groups. 48 h after operation, serum PGE2, SP, β-EP, IL-6, MCP-1, HMGB-1 and MDA levels of both groups of patients were significantly lower than those immediately after operation while Cu-Zn SOD and GSH-Px levels were significantly higher than those immediately after operation, and serum PGE2, SP, β-EP, IL-6, MCP-1, HMGB-1 and MDA levels of observation group were significantly lower than those of control group while Cu-Zn SOD and GSH-Px levels were significantly higher than those of control group. Conclusion: Hydromorphone hydrochloride combined with ropivacaine for PCEA after orthopedic surgery is effective in alleviating pain and inhibiting systemic inflammatory response.

  12. C-reactive protein, erythrocyte sedimentation rate and orthopedic implant infection.

    Directory of Open Access Journals (Sweden)

    Kerryl E Piper

    Full Text Available BACKGROUND: C-reactive protein (CRP and erythrocyte sedimentation rate (ESR have been shown to be useful for diagnosis of prosthetic hip and knee infection. Little information is available on CRP and ESR in patients undergoing revision or resection of shoulder arthroplasties or spine implants. METHODS/RESULTS: We analyzed preoperative CRP and ESR in 636 subjects who underwent knee (n=297, hip (n=221 or shoulder (n=64 arthroplasty, or spine implant (n=54 removal. A standardized definition of orthopedic implant-associated infection was applied. Receiver operating curve analysis was used to determine ideal cutoff values for differentiating infected from non-infected cases. ESR was significantly different in subjects with aseptic failure infection of knee (median 11 and 53.5 mm/h, respectively, p=<0.0001 and hip (median 11 and 30 mm/h, respectively, p=<0.0001 arthroplasties and spine implants (median 10 and 48.5 mm/h, respectively, p=0.0033, but not shoulder arthroplasties (median 10 and 9 mm/h, respectively, p=0.9883. Optimized ESR cutoffs for knee, hip and shoulder arthroplasties and spine implants were 19, 13, 26, and 45 mm/h, respectively. Using these cutoffs, sensitivity and specificity to detect infection were 89 and 74% for knee, 82 and 60% for hip, and 32 and 93% for shoulder arthroplasties, and 57 and 90% for spine implants. CRP was significantly different in subjects with aseptic failure and infection of knee (median 4 and 51 mg/l, respectively, p<0.0001, hip (median 3 and 18 mg/l, respectively, p<0.0001, and shoulder (median 3 and 10 mg/l, respectively, p=0.01 arthroplasties, and spine implants (median 3 and 20 mg/l, respectively, p=0.0011. Optimized CRP cutoffs for knee, hip, and shoulder arthroplasties, and spine implants were 14.5, 10.3, 7, and 4.6 mg/l, respectively. Using these cutoffs, sensitivity and specificity to detect infection were 79 and 88% for knee, 74 and 79% for hip, and 63 and 73% for shoulder arthroplasties, and 79 and

  13. Comportamiento a desgaste de recubrimientos de WC proyectados por plasma a partir de polvos micro y nanoestructurados

    Directory of Open Access Journals (Sweden)

    Salvador, M. D.

    2008-06-01

    Full Text Available The aim of the present work is the study of wear behaviour of different WC coatings deposited on stainless steel substrate by means of atmospheric plasma spraying (APS. Two types of WC commercial powders, with different metal binder (12% Cobalt and 10% Nickel have been deposited in order to analyse the influence of the metal matrix and thickness of the coating in tribological properties.The microstructure of the depositions was characterized using scanning electron microscopy (SEM and X-ray diffraction analysis (XRD. On the other hand, tribology characterization of the coatings was made by pin-on-disk wear tests against alumina (2400HV and silicon nitride (1600HV ceramic balls, without lubrication. Wear rates and friction coefficient evolution have been calculated. Finally, wear tracks and wear debris have been analysed with the help of SEM.The results of each pair of tested materials show different mechanisms of wear related to the nature of the ball that has been used, obtaining higher wear rates with silicone nitride ball..In a second phase of the study, in order to examine the influence of the initial particle size on the wear properties of the coatings, cobalt based coatings have been analysed with different initial particle size (micrometric and nanometric particles.Results show that nanostructured coatings have higher wear resistance than microstrutured ones for high loads. However for low loads, behaviour is similar in spite of the microstructural differences appreciated.

    El objetivo de este trabajo es estudiar el comportamiento a desgaste de distintos recubrimientos de WC sobre acero inoxidable mediante proyección por plasma atmosférico. Se proyectan dos tipos de polvos comerciales con base cobalto (12 % y níquel (10 %, con el objeto de analizar la influencia de la matriz e incluso del espesor del recubrimiento. Los recubrimientos obtenidos se caracterizan microestructuralmente por microscopía electrónica de barrido y

  14. The Medical Education and Best Practice in Orthopedic Patient Care in Poland.

    Science.gov (United States)

    Rosiek, Anna; Leksowski, Krzysztof

    2012-07-01

    The leadership organization focuses on education, teamwork, customer relationship and developing strategy which help in building added value, in managing activities, time and quality. Everyday orthopedic experience shows that medical education is a mixture of: specific knowledge, skills and attitudes of people working together, and that creates effective teamwork in a hospital environment. Apart from the main reason of medical education, teaching about disease treatment and health problem solving, medical education should also concentrate on human factors and behavioral aspects of patient treatment in hospital.Assessment of an organization and medical education process by cultural and teamwork criteria, offers a powerful new way to think about performance at the frontlines of healthcare and in the future it could be gold standard for assessing the success of an organization, and standards in medical education, not only in orthopedics.

  15. Clinical applicability of nursing outcomes in the evolution of orthopedic patients with Impaired Physical Mobility.

    Science.gov (United States)

    da Silva, Marcos Barragan; Almeida, Miriam de Abreu; Panato, Bruna Paulsen; Siqueira, Ana Paula de Oliveira; da Silva, Mariana Palma; Reisderfer, Letícia

    2015-01-01

    to evaluate the clinical applicability of outcomes, according to the Nursing Outcomes Classification (NOC) in the evolution of orthopedic patients with Impaired Physical Mobility longitudinal study conducted in 2012 in a university hospital, with 21 patients undergoing Total Hip Arthroplasty, evaluated daily by pairs of trained data collectors. Data were collected using an instrument containing five Nursing Outcomes, 16 clinical indicators and a five point Likert scale, and statistically analyzed. The outcomes Body Positioning: self-initiated, Mobility, Knowledge: prescribed activity, and Fall Prevention Behavior presented significant increases in mean scores when comparing the first and final evaluations (p<0.001) and (p=0.035). the use of the NOC outcomes makes it possible to demonstrate the clinical progression of orthopedic patients with Impaired Physical Mobility, as well as its applicability in this context.

  16. Use of extracorporeal shock waves in the treatment of tendinopathy and other orthopedic diseases

    Directory of Open Access Journals (Sweden)

    Dushyant Nadar

    2000-01-01

    Full Text Available Objective: Use of extracorporeal shock waves in the treatment of tendinopathy and other orthopedic diseases. Patients and methods: 35 patients received shock wave therapy using Econolith 2000 lithotripter 19 patients had isolated lateral epicondylitis, 12 medical epicondylitis and 4 plantar fascitis. A total of 120 shock waves were given in the first sitting. Each patient received a total of three sittings with a gap of one week between each of them. Results: Based on the patients′ self-assessment, about 75% pain relief was observed in 60% of the patients. Fur-ther, in patients having isolated tendinopathies, the pain relief was better. Conclusion: The study indicated that the application of shock waves is not restricted to the fragmentation of urinary calculi. The shock waves can be effectively used for the pain relief in the common orthopedic diseases. Thus, the urologists can widen the application of lithotripters, in a cost-effective manner, to the other medical speciali-ties.

  17. [On practicability of implementing the speciality "podiatry" in traumatology and orthopedics].

    Science.gov (United States)

    2011-01-01

    The absence of single opinion concerning the classification of foot and ankle joint pathology does not permit to formulate universal and practical approach to the identification of pathological syndromes in case of patient foot lesion. The situation is aggravated by the unsolved issues related to the terminological definition of podiatry as a direction in orthopedics to solve the issues of foot and ankle joint pathology. In actual conditions the implementation of new technologies into the structure of traumatological orthopedics care is needed. This approach permits to combine the qualities of models of effective and optimized care to patients with foot and ankle joint pathology. The study of issue related to the systematization of podiatric pathology revealed that actually no single universal classification easy-to-use in practice exists. Hence the development of original applied working scheme of foot and ankle joint pathology is proposed.

  18. A Systematic Review of Early Prognostic Factors for Persistent Pain Following Acute Orthopedic Trauma

    Directory of Open Access Journals (Sweden)

    Fiona J Clay

    2012-01-01

    Full Text Available Persistent or chronic pain is prevalent in many developed countries, with estimates ranging from 10% to higher than 50%, and is a major economic burden to individuals and societies. However, the variation in pain outcomes after acute orthopedic trauma and treatment confronts treating physicians with uncertainty in providing prognostic advice regarding long-term recovery. Although several previous reviews have addressed the determinants of chronic pain outcomes secondary to acute trauma, they have primarily focused on specific injury samples and, furthermore, lack consistency with respect to the important prognostic factors, which limits the generalizability of findings. This review, however, aimed specifically to identify the early prognostic factors associated with variation in persistent pain outcomes following acute orthopedic trauma presenting with a spectrum of pathologies.

  19. Practical X-ray diagnostics orthopedics and trauma surgery. Indication, adjustment technique and radiation protection

    International Nuclear Information System (INIS)

    Flechtenmacher, Johannes; Sabo, Desiderius

    2014-01-01

    The book on X-ray diagnostics in orthopedics and trauma surgery includes the following chapters: 1. Introduction: radiation protection, equipment technology radiological diagnostics of skeleton carcinomas, specific aspects of trauma surgery, special aspects of skeleton radiology for children. 2. X-ray diagnostics of different anatomical regions: ankle joint, knee, hips and pelvis, hand and wrist joint, elbow, shoulder, spinal cord. 3. Appendix: radiation protection according to the X-ray regulations.

  20. Readability of Spine-Related Patient Education Materials From Leading Orthopedic Academic Centers.

    Science.gov (United States)

    Ryu, Justine H; Yi, Paul H

    2016-05-01

    Cross-sectional analysis of online spine-related patient education materials from leading academic centers. To assess the readability levels of spine surgery-related patient education materials available on the websites of academic orthopedic surgery departments. The Internet is becoming an increasingly popular resource for patient education. Yet many previous studies have found that Internet-based orthopedic-related patient education materials from subspecialty societies are written at a level too difficult for the average American; however, no prior study has assessed the readability of spine surgery-related patient educational materials from leading academic centers. All spine surgery-related articles from the online patient education libraries of the top five US News & World Report-ranked orthopedic institutions were assessed for readability using the Flesch-Kincaid (FK) readability test. Mean readability levels of articles amongst the five academic institutions and articles were compared. We also determined the number of articles with readability levels at or below the recommended sixth- or eight-grade levels. Intraobserver and interobserver reliability of readability assessment were assessed. A total of 122 articles were reviewed. The mean overall FK grade level was 11.4; the difference in mean FK grade level between each department varied significantly (range, 9.3-13.4; P Online patient education materials related to spine from academic orthopedic centers are written at a level too high for the average patient, consistent with spine surgery-related patient education materials provided by the American Academy of Orthopaedic Surgeons and spine subspecialty societies. This study highlights the potential difficulties patients might have in reading and comprehending the information in publicly available education materials related to spine. N/A.

  1. Patient Satisfaction Is Associated With Time With Provider But Not Clinic Wait Time Among Orthopedic Patients.

    Science.gov (United States)

    Patterson, Brendan M; Eskildsen, Scott M; Clement, R Carter; Lin, Feng-Chang; Olcott, Christopher W; Del Gaizo, Daniel J; Tennant, Joshua N

    2017-01-01

    Clinic wait time is considered an important predictor of patient satisfaction. The goal of this study was to determine whether patient satisfaction among orthopedic patients is associated with clinic wait time and time with the provider. The authors prospectively enrolled 182 patients at their outpatient orthopedic clinic. Clinic wait time was defined as the time between patient check-in and being seen by the surgeon. Time spent with the provider was defined as the total time the patient spent in the examination room with the surgeon. The Consumer Assessment of Healthcare Providers and Systems survey was used to measure patient satisfaction. Factors associated with increased patient satisfaction included patient age and increased time with the surgeon (P=.024 and P=.037, respectively), but not clinic wait time (P=.625). Perceived wait time was subject to a high level of error, and most patients did not accurately report whether they had been waiting longer than 15 minutes to see a provider until they had waited at least 60 minutes (P=.007). If the results of the current study are generalizable, time with the surgeon is associated with patient satisfaction in orthopedic clinics, but wait time is not. Further, the study findings showed that patients in this setting did not have an accurate perception of actual wait time, with many patients underestimating the time they waited to see a provider. Thus, a potential strategy for improving patient satisfaction is to spend more time with each patient, even at the expense of increased wait time. [Orthopedics. 2017; 40(1):43-48.]. Copyright 2016, SLACK Incorporated.

  2. [Normal and pathologic mandible development: practical deductions in maxillo-dento-facial orthopedics].

    Science.gov (United States)

    Salagnac, Jean-Michel

    2016-09-01

    The mandible consists of different segments, each of which possess its own specific characteristics regarding emergence, ossification during growth and pathologies. Orthodontists need to be very familiar with these developmental anomalies if they are to avoid failure in their orthopedic or orthodontic treatments and in order to understand the reasons for the lack of success of "conventional" treatments. Each segment must develop correctly if the mandible is to achieve optimal development and occupy a normal position within the cranio-facial complex. The position of the mandible in the cranio-facial block is also conditioned by its attachment to the base of the skull. Combining a detailed semiologic study and a three-dimensional architectural and structural radiologic analysis of clinical cases, this article investigates the various anomalies affecting the mandibular segments and their impact on the craniofacial structure as a whole. An understanding of these anomalies and this analytical method can enable clinicians to perform early diagnosis, avoid undertaking orthopedic and orthodontic treatments which are likely to fail, understand the reasons for unsuccessful "conventional" treatments, provide an orthopedic-surgical guide and make it possible to inform patients correctly. Anomalies affecting the growth of the mandible and its position on the cranial base and their impact on cranio-facial skeletal balance are clearly revealed by structural and architectural analysis, which pinpoints the different clinical elements in skeletal Class II et III cases. In maxilla-dento-facial orthopedics when confronted with a pathology of mandibular origin, it is essential to carefully study the radiographs of each segment of the mandible, to seek out the minor forms of the anomalies and to calculate the position of the mandible on the cranial base relative to the neighboring structures; the skull, the cervical vertebrae and the maxilla. © EDP Sciences, SFODF, 2016.

  3. Rivaroxaban for venous thromboembolism prevention after major orthopedic surgery: translating trial data into routine clinical practice

    Directory of Open Access Journals (Sweden)

    Beyer-Westendorf J

    2017-01-01

    Full Text Available Jan Beyer-Westendorf,1 Patrick Mouret,2 Alexander GG Turpie3 1Thrombosis Research and Angiology, Dresden University Clinic, Dresden, Germany; 2Orthopedic Clinic, Klinikum Frankfurt Höchst GmbH, Frankfurt, Germany; 3Department of Medicine, General Division, Hamilton Health Sciences, Hamilton, ON, Canada Abstract: An established standard of care for the prevention of venous thromboembolism after major orthopedic surgery has been subcutaneous low-molecular-weight heparin. The non-vitamin K antagonist oral anticoagulant rivaroxaban has demonstrated superior efficacy and similar safety to all tested regimens of enoxaparin in large Phase III clinical studies of venous thromboembolism prevention after elective hip and knee arthroplasty. Despite regulatory approval of rivaroxaban for this indication, concerns remain among physicians regarding its optimal and effective use in routine clinical practice. Real-life studies, such as XAMOS and ORTHO-TEP, are providing physicians with more information on the routine use of rivaroxaban for venous thromboembolism prevention after orthopedic surgery, helping to establish its safety and effectiveness in everyday clinical care. Among the most important issues are the risk of bleeding complications, wound healing, timing of first dose, impact of type of anesthesia on thromboprophylaxis effectiveness, patient comorbidities and comedication use, periprocedural management, associated costs, and clinical outcomes in trauma-related fractures. Many of these issues are difficult to study in randomized, double-blind, Phase III trials, and can be assessed more readily using real-life data. In particular, real-life or noninterventional studies lack many of the strict inclusion and exclusion criteria associated with Phase III trials and involve unselected patients who often present with significant comorbidities or comedication use. Keywords: anticoagulants, arthroplasty, orthopedics, rivaroxaban, thrombosis

  4. Knowledge deficiency of work-related radiation hazards associated with psychological distress among orthopedic surgeons

    Science.gov (United States)

    Fan, Guoxin; Wang, Yueye; Guo, Changfeng; Lei, Xuefeng; He, Shisheng

    2017-01-01

    Abstract Knowledge and concern degree about work-related radiation hazards remained unknown among orthopedic surgeons. The aim of the cross-sectional study is to investigate whether the knowledge degree of work-related radiation is associated with psychological distress among orthopedic surgeons. This cross-sectional study sent electronic questionnaire via WeChat to orthopedic surgeons nationwide. Concern and knowing degree over radiation exposure was evaluated by a single self-reported question. Professional evaluation of concern degree was reflected by general psychological distress, which was assessed with the Kessler 10 scale (K10) and depressive symptoms with the Center for Epidemiologic Studies Depression Scale (CES-D). Only 43.23% (115/266) respondents knew well about radiation and a total of 78.20% (208/266) respondents considered radiation exposure as a great concern. Among those who reported concerns about radiation exposure, a total of 57.69% (120/208) respondents reported knowing little about radiation. Respondents who reported concerns over radiation exposure were significantly associated with higher scores on CES-D and K10 (P < .05). Among respondents who reported concerns over radiation exposure, those who have fewer knowledge about radiation, had higher CES-D and K10 scores than those who knew well about radiation (P < .05). Among respondents who reported no concerns over radiation exposure, those who knew little about radiation still had higher CES-D and K10 scores (P < .05). Fewer radiation knowledge tends to induce more radiation concerns associated with higher psychological distress in orthopedic surgeons. Radiation knowledge should be enhanced for surgeons who daily work with radiation-related fluoroscopy. PMID:28538368

  5. Safety, Efficacy, and Cost-effectiveness of Tranexamic Acid in Orthopedic Surgery.

    Science.gov (United States)

    Lin, Zilan X; Woolf, Shane K

    2016-01-01

    Perioperative bleeding and postsurgical hemorrhage are common in invasive surgical procedures, including orthopedic surgery. Tranexamic acid (TXA) is a pharmacologic agent that acts through an antifibrinolytic mechanism to stabilize formed clots and reduce active bleeding. It has been used successfully in orthopedics to reduce perioperative blood loss, particularly in total hip and knee arthroplasty and spine surgery. Numerous research studies have reported favorable safety and efficacy in orthopedic cases, although there is no universal standard on its administration and its use has not yet become the standard of practice. Reported administration methods often depend on the surgeon's preference, with both topical and intravenous routes showing efficacy. The type and anatomic site of the surgery seem to influence the decision making but also result in conflicting opinions. Reported complication rates with TXA use are low. The incidence of both arterial and venous thromboembolic events, particularly deep venous thrombosis and pulmonary embolism, has not been found to be significantly different with TXA use for healthy patients. The route of administration and dosage do not appear to affect complication rates either. However, data on patients with higher-risk conditions are deficient. In addition, TXA has shown potential to reduce blood loss, transfusion rates and volumes, perioperative hemoglobin change, and hospital-related costs at various degrees among the published studies. Conservation of blood products, reduced laboratory costs, and shorter hospital stays are likely the major factors driving the cost savings associated with TXA use. This article reviews current data supporting the safety, efficacy, and cost-effectiveness of TXA in orthopedic surgery. Copyright 2016, SLACK Incorporated.

  6. Orthopedic Injuries and Their Treatment in Children During Earthquakes: A Systematic Review.

    Science.gov (United States)

    Morelli, Ilaria; Sabbadini, Maria Grazia; Bortolin, Michelangelo

    2015-10-01

    Orthopedic injuries commonly affect children during earthquakes, but reports about them are rare. This setting may lead to different standards of care, but guidelines are still missing in this field. A systematic review was performed to: (1) assess type and body distribution of pediatric earthquake-related injuries, treatment performed, length of stay, and complications; and (2) identify starting points to define standards of care. PubMed database was researched for papers (1999-2014 period) in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. Inclusion criteria were: English, French, Spanish, or Italian language and data reported about orthopedic lesions in children (≤18 years old). Reviews, letters, commentaries, editorials, and single case reports were excluded. Two independent reviewers selected articles after abstract and full-text reading. Traumatic injuries caused child hospital admissions ranging from 46.9% to 100.0%; 16% to 53% suffered fractures. Lower limbs mostly were involved. Soft-tissue injuries affected 55% of patients. Debridement and external fixation (EF) were the most frequent surgical treatments. Amputation rates varied from 5% to 11%. This study revealed that field hospitals should be prepared to: (1) treat mainly lower extremities fractures in children; and (2) use especially EF techniques. The presence of orthopedic surgeons familiar with pediatric traumatology should be considered.

  7. [Implementation of the eLearning project NESTOR. A network for students in traumatology and orthopedics].

    Science.gov (United States)

    Back, D A; Haberstroh, N; Hoff, E; Plener, J; Haas, N P; Perka, C; Schmidmaier, G

    2012-01-01

    Modern internet-based information technologies offer great possibilities to create and improve teaching methods for students. The eLearning tool NESTOR (Network for Students in Traumatology and Orthopedics) presented here was designed to complement the existing clinical teaching in orthopedics and traumatology at the Charité, University Medicine Berlin. Using a learning management system, videos, podcasts, X-ray diagnosis, virtual patients, tests and further tools for learning and study information were combined. After implementation the eLearning project was evaluated by students. The NESTOR project offers various possibilities for knowledge acquisition. Students using the program voluntarily showed a high acceptance whereby 82.4% were very satisfied with the contents offered and 95.3% supported the idea of a future use of NESTOR in teaching. The blended learning approach was positively evaluated by 93.5% of the students. The project received the eLearning seal of quality of the Charité University Medicine Berlin. Using complex eLearning tools, such as the NESTOR project represents a contemporary teaching approach in the teaching of traumatology and orthopedics and should be offered in a blended learning context as they are well accepted by students.

  8. Biodegradable Orthopedic Magnesium-Calcium (MgCa Alloys, Processing, and Corrosion Performance

    Directory of Open Access Journals (Sweden)

    Yuebin Guo

    2012-01-01

    Full Text Available Magnesium-Calcium (Mg-Ca alloy has received considerable attention as an emerging biodegradable implant material in orthopedic fixation applications. The biodegradable Mg-Ca alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable Mg-Ca implant is the fast corrosion in the human body environment. The ability to adjust degradation rate of Mg-Ca alloys is critical for the successful development of biodegradable orthopedic implants. This paper focuses on the functions and requirements of bone implants and critical issues of current implant biomaterials. Microstructures and mechanical properties of Mg-Ca alloys, and the unique properties of novel magnesium-calcium implant materials have been reviewed. Various manufacturing techniques to process Mg-Ca based alloys have been analyzed regarding their impacts on implant performance. Corrosion performance of Mg-Ca alloys processed by different manufacturing techniques was compared. In addition, the societal and economical impacts of developing biodegradable orthopedic implants have been emphasized.

  9. Albumin and fibrinogen levels′ relation with orthopedics traumatic patients′ outcome after massive transfusion

    Directory of Open Access Journals (Sweden)

    Mohammadreza Bazavar

    2014-01-01

    Full Text Available Background: Severe bleeding is common during limb trauma. It can lead to hemorrhagic shock required to massive blood transfusion. Coagulopathy is the major complication of massive transfusion-induced increased mortality rate. Aim of this study was evaluation of fibrinogen and albumin levels association with orthopedics traumatic patients′ outcome who received massive transfusion. Methods: In a cross sectional study, 23 patients with severe limb injury admitted to orthopedic emergency department were studied. All the patients received massive transfusion, that is, >10 unit blood. Albumin and fibrinogen levels are measured at admission and 24 h later, and compared according to final outcome. Results: Twenty-three traumatic patients with severe limb injuries were studied, out of which ten (43.2% died and 13 (56.8% were alive. There was significant difference between patients outcome in fibrinogen level after 24 h, but no difference was observed in albumin levels. Based on regression model, fibrinogen after 24 h had a significant role in determining the final outcome in traumatic patients who received massive transfusion (odds ratio 0.48, 95% confidence interval 0.15-0.92, P = 0.02. Conclusions: According to our results, fibrinogen level is the most important factor in determination of orthopedics traumatic patients when received massive transfusion. However, serum albumin does not play any role in patients′ outcome.

  10. Sol-Gel Derived Hydroxyapatite Coating on Mg-3Zn Alloy for Orthopedic Application

    Science.gov (United States)

    Singh, Sanjay; Manoj Kumar, R.; Kuntal, Kishor Kumar; Gupta, Pallavi; Das, Snehashish; Jayaganthan, R.; Roy, Partha; Lahiri, Debrupa

    2015-04-01

    In recent years, magnesium and its alloys have gained a lot of interest as orthopedic implant constituents because their biodegradability and mechanical properties are closer to that of human bone. However, one major concern with Mg in orthopedics is its high corrosion rate that results in the reduction of mechanical integrity before healing the bone tissue. The current study evaluates the sol-gel-derived hydroxyapatite (HA) coating on a selected Mg alloy (Mg-3Zn) for decreasing the corrosion rate and increasing the bioactivity of the Mg surface. The mechanical integrity of the coating is established as a function of the surface roughness of the substrate and the sintering temperature of the coating. Coating on a substrate roughness of 15-20 nm and sintering at 400°C shows the mechanical properties in similar range of bone, thus making it suitable to avoid the stress-shielding effect. The hydroxyapatite coating on the Mg alloy surface also increases corrosion resistance very significantly by 40 times. Bone cells are also found proliferating better in the HA-coated surface. All these benefits together establish the candidature of sol-gel HA-coated Mg-3Zn alloy in orthopedic application.

  11. The omni-relevance of surgery: how medical specialization shapes orthopedic surgeons' treatment recommendations.

    Science.gov (United States)

    Hudak, Pamela L; Clark, Shannon J; Raymond, Geoffrey

    2013-01-01

    This article examines treatment recommendations in orthopedic surgery consultations and shows how surgery is treated as "omni-relevant" within this activity, providing a context within which the broad range of treatment recommendations proposed by surgeons is offered. Using conversation analysis to analyse audiotaped encounters between orthopedic surgeons and patients, we highlight how surgeons treat surgery as having a special, privileged status relative to other treatment options by (1) invoking surgery (whether or not it is actually being recommended) and (2) presenting surgery as the "last best resort" (in relation to which other treatment options are calibrated, described and considered). This privileged status surfaces in the design and delivery of recommendations as a clear asymmetry: Recommendations for surgery are proposed early, in relatively simple and unmitigated form. In contrast, recommendations not for surgery tend to be delayed and involve significantly more interactional work in their delivery. Possible implications of these findings, including how surgeons' structuring of recommendations may shape patient expectations (whether for surgery or some alternative), and potentially influence the distribution of orthopedic surgery procedures arising from these consultations, are considered.

  12. Malnutrition - An underestimated factor in the inpatient treatment of traumatology and orthopedic patients: A prospective evaluation of 1055 patients.

    Science.gov (United States)

    Ihle, Christoph; Freude, Thomas; Bahrs, Christian; Zehendner, Eva; Braunsberger, Janick; Biesalski, Hans Konrad; Lambert, Christine; Stöckle, Ulrich; Wintermeyer, Elke; Grünwald, Julia; Grünwald, Leonard; Ochs, Gunnar; Flesch, Ingo; Nüssler, Andreas

    2017-03-01

    Suboptimal nutritional status is often observed among hospitalized patients across all medical specialties. The objective of the present study was to (1) analyze the prevalence of malnutrition in hospitalized orthopedic and trauma patients and (2) to evaluate the relationship between malnutrition and selected clinical outcomes. The prospective field study was conducted between 06/2014 and 06/2015 in a German level I trauma center (Department of Traumatology, Septic Trauma Surgery and Arthroplasty) with a total number of 1055 patients. At hospital admission, patients were checked for malnutrition using the validated Nutritional Risk Screening (NRS). Patients at risk for malnutrition were defined as NRS≥3. Quality of life (SF-36) was assessed to evaluate the physical and mental health status prior to hospitalization. Clinical outcomes under consideration included 1) rate of adverse events, 2) length of hospitalization, and 3) mobilization after operative and conservative treatment. Patients were included independently of surgical intervention or age. 22.3% (235) of our patients were at risk for malnutrition (NRS≥3) while a regular nutritional status (NRSmalnutrition was found in Septic Surgery with 31.0% (106), followed by Traumatology with 19.2% (100) and Arthroplasty with 15.1% (29). Higher prevalence of malnutrition was observed among patients with typical fractures of the elderly, such as lumbar spine and pelvis (47.4%), proximal femur (36.4%) and proximal humeral (26.7%) fractures. Furthermore, patients at risk for malnutrition showed prolonged hospitalization (13.7±11.1 vs. 18.2±11.7days), delayed postoperative mobilization (2.2±2.9 vs. 4.0±4.9days) and delayed mobilization after conservative treatment (1.1±2.7 vs. 1.8±1.9days). A statistically significant correlation of NRS with each parameter (Spearman's rank correlation, pmalnutrition was statistically significantly higher compared to that of patients with a regular nutritional status (37.2% vs. 21

  13. XMM-Newton X-ray observations of γ2 Velorum (WC8 + O7.5III)

    International Nuclear Information System (INIS)

    Raassen, A.J.J.; Mewe, R.; Hucht, K.A. van der; Schmutz, W.; Schild, H.; Dumm, T.; Guedel, M.; Audard, M.; Leutenegger, M.A.; Skinner, S.L.

    2004-01-01

    The spectrum of the binary system γ 2 Velorum (WC8 + O7.5III) has been observed with RGS and EPIC-MOS aboard XMM-Newton. The system shows a 'high state' when the O-star is between the Wolf-Rayet star and the observer (near periastron) and a 'low state' when most of the spectrum is absorbed by the dense stellar wind of the Wolf-Rayet star (near apastron). The spectrum has been model-led by a 4-T plasma, using SPEX. The absorption affects the hot temperature component (kT = 1.5 keV) that is formed by the collision of the Wolf-Rayet wind and the O-star wind, and the second hot component (kT 0.65 keV) for which the origin is still unclear. Part of the spectrum is not sensitive to the absorption by the stellar wind. This concerns a low-temperature component (kT = 0.23 keV) and features that are produced by plasma that has been photoionized by X-ray radiation from the hot component. In the RGS spectrum features of Radiative Recombination Continua (RRC) of C VI and C V of this photoionized plasma are detected

  14. Statistical Optimization of Reactive Plasma Cladding to Synthesize a WC-Reinforced Fe-Based Alloy Coating

    Science.gov (United States)

    Wang, Miqi; Zhou, Zehua; Wu, Lintao; Ding, Ying; Xu, Feilong; Wang, Zehua

    2018-04-01

    A new compound Fe-W-C powder for reactive plasma cladding was fabricated by precursor carbonization process using sucrose as a precursor. The application of quadratic general rotary unitized design was highlighted to develop a mathematical model to predict and accomplish the desired surface hardness of plasma-cladded coating. The microstructure and microhardness of the coating with optimal parameters were also investigated. According to the developed empirical model, the optimal process parameters were determined as follows: 1.4 for C/W atomic ratio, 20 wt.% for W content, 130 A for scanning current and 100 mm/min (1.67 mm/s) for scanning rate. The confidence level of the model was 99% according to the results of the F-test and lack-of-fit test. Microstructural study showed that the dendritic structure was comprised of a mechanical mixture of α-Fe and carbides, while the interdendritic structure was a eutectic of α-Fe and carbides in the composite coating with optimal parameters. WC phase generation can be confirmed from the XRD pattern. Due to good preparation parameters, the average microhardness of cladded coating can reach 1120 HV0.1, which was four times the substrate microhardness.

  15. Effect of cobalt content on wear and corrosion behaviors of electrodeposited Ni-Co/WC nano-composite coatings.

    Science.gov (United States)

    Amadeh, A; Ebadpour, R

    2013-02-01

    Metal-ceramic composite coatings are widely used in automotive and aerospace industries as well as micro-electronic systems. Electrodeposition is an economic method for application of these coatings. In this research, nickel-cobalt coatings reinforced by nano WC particles were applied on carbon steel substrate by pulse electrodeposition from modified Watts bath containing different amounts of cobalt sulphate as an additive. Saccharin and sodium dodecyl sulphate (SDS) were also added to electroplating bath as grain refiner and surfactant, respectively. The effect of cobalt content on wear and corrosion behavior of the coatings was investigated. Wear and corrosion properties were assessed by pin-on-disk and potentiodynamic polarization methods, respectively. Phase analysis was performed by X-ray diffraction (XRD) using CuK(alpha) radiation and the worn surfaces were studied by means of Scanning Electron Microscopy (SEM). The results showed that the addition of cobalt improved the wear resistance of the coatings. In the presence of 18 g/L cobalt in electrodeposition bath, the wear rate of the coating decreased to 0.002 mg/m and the coefficient of friction reduced to 0.695 while they were 0.004 mg/m and 0.77 in the absence of cobalt, respectively. This improvement in wear properties can be attributed to the formation of hcp phase in metallic matrix. Meanwhile, the corrosion resistance of the coatings slightly reduced because cobalt is more active metal with respect to nickel.

  16. Microstructural characterization of WC-TiC-Co cutting tools during high-speed machining of P20 mold steel

    International Nuclear Information System (INIS)

    Farhat, Z.N.

    2003-01-01

    The wear behavior of tungsten carbide (WC)-TiC-Co cutting tools during cutting P20 tool steel was investigated. Orthogonal cutting tests were performed on a CNC lathe using five speeds, namely, 60, 120, 240, 380 and 600 m/min. Wear, as the width of the wear land, was monitored at five time intervals. Wear characterization of the rake and the flank surfaces as well as the collected chips was performed using scanning electron microscopy (SEM), backscattered electron imaging and energy-dispersive X-ray analysis (EDX). Microhardness of collected chips was also performed to monitor strain hardening effects during cutting. Two dominant wear mechanisms were identified: at high speed (380-600 m/min), wear was found to occur by a melt wear mechanism; at low speed (60-120 m/min), adhesion (built-up edge) followed by delamination was found to be the cause of wear damage. It was also found that deformation in the chips occurred by localized shear deformation

  17. Design and simulation of thermal residual stresses of coatings on WC-Co cemented carbide cutting tool substrate

    International Nuclear Information System (INIS)

    Li, Anhai; Zhao, Jun; Zang, Jian; Zheng, Wei

    2016-01-01

    Large thermal residual stresses in coatings during the coating deposition process may easily lead to coating delamination of coated carbide tools in machining. In order to reduce the possibility of coating delamination during the tool failure process, a theoretical method was proposed and a numerical method was constructed for the coating design of WC-Co cemented carbide cutting tools. The thermal residual stresses of multi-layered coatings were analytically modeled based on equivalent parameters of coating properties, and the stress distribution of coatings are simulated by Finite element method (FEM). The theoretically calculated results and the FEM simulated results were verified and in good agreement with the experimental test results. The effects of coating thickness, tool substrate, coating type and interlayer were investigated by the proposed geometric and FEM model. Based on the evaluations of matchability of tool substrate and tool coatings, the basic principles of tool coating design were proposed. This provides theoretical basis for the selection and design of coatings of cutting tools in high-speed machining

  18. Comparison of Intravenous Morphine with Sublingual Buprenorphine in Management of Postoperative Pain after Closed Reduction Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    Ghasem Soltani

    2015-09-01

    Full Text Available Background: Postoperative pain is a common side effect following surgery that can significantly reduce surgical quality and patient’s satisfaction. Treatment options are morphine and buprenorphine. We aimed to compare the efficacy of a single dose of intravenous morphine with sublingual buprenorphine in postoperative pain control following closed reduction surgery. Methods: This triple blind clinical trial was conducted on 90 patients referred for closed reduction orthopedic surgery. They were older than 18 years and in classes I and II of the American Society of Anesthesiologists (ASA with an operation time of 30-90 minutes. Patients were divided into two groups of buprenorphine (4.5μg/kg sublingually and morphine (0.2mg/kg intravenously. Baseline characteristics, vital signs, pain score, level of sedation and pharmacological side effects were recorded in the recovery room (at 0 and 30 minutes, and in the ward (at 3, 6 and 12 hours. SPSS version 19 software was used for data analysis and the significance level was set at P Results: Ninety patients were studied, 60 males and 30 females with a mean age of 37.7±16.2 years. There was no significant difference between the two groups in terms of baseline characteristics.Pain score in the morphine group was significantly higher than the buprenorphine group with an average score of 2.5 (P

  19. Comparison of Intravenous Morphine with Sublingual Buprenorphine in Management of Postoperative Pain after Closed Reduction Orthopedic Surgery

    Directory of Open Access Journals (Sweden)

    Ghasem Soltani

    2015-10-01

    Full Text Available Background: Postoperative pain is a common side effect following surgery that can significantly reduce surgical quality and patient’s satisfaction. Treatment options are morphine and buprenorphine. We aimed to compare the efficacy of a single dose of intravenous morphine with sublingual buprenorphine in postoperative pain control following closed reduction surgery. Methods: This triple blind clinical trial was conducted on 90 patients referred for closed reduction orthopedic surgery. They were older than 18 years and in classes I and II of the American Society of Anesthesiologists (ASA with an operation time of 30-90 minutes. Patients were divided into two groups of buprenorphine (4.5μg/kg sublingually and morphine (0.2mg/kg intravenously. Baseline characteristics, vital signs, pain score, level of sedation and pharmacological side effects were recorded in the recovery room (at 0 and 30 minutes, and in the ward (at 3, 6 and 12 hours. SPSS version 19 software was used for data analysis and the significance level was set at P Results: Ninety patients were studied, 60 males and 30 females with a mean age of 37.7±16.2 years. There was no significant difference between the two groups in terms of baseline characteristics.Pain score in the morphine group was significantly higher than the buprenorphine group with an average score of 2.5 (P

  20. Multilevel orthopedic surgery for crouch gait in cerebral palsy: An evaluation using functional mobility and energy cost

    Directory of Open Access Journals (Sweden)

    Dhiren Ganjwala

    2011-01-01

    Full Text Available Background: The evidence for the effectiveness of orthopaedic surgery to correct crouch gait in cerebral dip