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Sample records for ppf replace circumferential

  1. Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review

    PubMed Central

    Fan, Lihong; Ge, Zhaogang; Zhang, Chen; Li, Jia; Yu, Zefeng; Dang, Xiaoqian; Wang, Kunzheng

    2015-01-01

    The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement. PMID:25801456

  2. Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review.

    PubMed

    Fan, Lihong; Ge, Zhaogang; Zhang, Chen; Li, Jia; Yu, Zefeng; Dang, Xiaoqian; Wang, Kunzheng

    2015-03-24

    The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement.

  3. Circumferential electrocautery of the patella in primary total knee replacement without patellar replacement: a meta-analysis and systematic review

    NASA Astrophysics Data System (ADS)

    Fan, Lihong; Ge, Zhaogang; Zhang, Chen; Li, Jia; Yu, Zefeng; Dang, Xiaoqian; Wang, Kunzheng

    2015-03-01

    The purpose of this meta-analysis and systematic review was to identify and assess whether circumferential electrocautery is useful for improving outcomes after primary total knee replacement(TKR). We searched MEDLINE, EMBASE, PubMed, SpringerLink, Web of Knowledge, OVID CINAHL, OVID EBM and Google Scholar and included articles published through January 2014. A total of 6 articles met the inclusion criteria. Of the 776 cases included in the analysis, 388 cases involved patellar denervation, and 388 cases were designated as the control group. The meta-analysis revealed no significant difference in the incidence of anterior knee pain (AKP, p = 0.18) or in the visual analogue scale score (VAS, p = 0.23) between the two groups. In addition, AKSS Function Score indicated no significant difference between the two groups (p = 0.28). However, the OKS (p = 0.02), patellar score (p = 0.01), AKSS-Knee Score (p = 0.004), range of motion (ROM, p < 0.0001) and WOMAC Score (p = 0.0003) indicated that circumpatellarelectrocautery improved clinical outcomes compared with non-electrocautery. The results indicate that circumferential electrocautery of the patella does not significantly improve AKP compared with non-electrocautery techniques but that circumferential electrocautery significantly improves patients' knee function after surgery. Therefore, we believe that circumferential electrocautery is beneficial to the outcome of primary TKR surgery without patellar replacement.

  4. Multimodal imaging of sustained drug release from 3-D poly(propylene fumarate) (PPF) scaffolds.

    PubMed

    Choi, Jonghoon; Kim, Kyobum; Kim, Taeho; Liu, Guanshu; Bar-Shir, Amnon; Hyeon, Taeghwan; McMahon, Michael T; Bulte, Jeff W M; Fisher, John P; Gilad, Assaf A

    2011-12-10

    The potential of poly(propylene fumarate) (PPF) scaffolds as drug carriers was investigated and the kinetics of the drug release quantified using magnetic resonance imaging (MRI) and optical imaging. Three different MR contrast agents were used for coating PPF scaffolds. Initially, iron oxide (IONP) or manganese oxide nanoparticles (MONP) carrying the anti-cancer drug doxorubicin were absorbed or mixed with the scaffold and their release into solution at physiological conditions was measured with MRI and optical imaging. A slow (hours to days) and functional release of the drug molecules into the surrounding solution was observed. In order to examine the release properties of proteins and polypeptides, protamine sulfate, a chemical exchange saturation transfer (CEST) MR contrast agent, was attached to the scaffold. Protamine sulfate showed a steady release rate for the first 24h. Due to its biocompatibility, versatile drug-loading capability and constant release rate, the porous PPF scaffold has potential in various biomedical applications, including MR-guided implantation of drug-dispensing materials, development of drug carrying vehicles, and drug delivery for tumor treatment.

  5. Circumferential pressure probe

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K. (Inventor); Moore, Thomas C. (Inventor); Fantl, Andrew J. (Inventor)

    1989-01-01

    A probe for measuring circumferential pressure inside a body cavity is disclosed. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors which typically comprise support tube sections with flexible side wall areas. These are arranged along the length of the probe in two areas, one just proximal to the tip for the sensing of fluid pressure inside the bladder, and five in the sensing section which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections interspersed with flexible support tube sections in the form of bellows to provide flexibility.

  6. Isolation and characterization of Pseudomonas putida PpF1 mutants defective in the toluene dioxygenase enzyme system.

    PubMed Central

    Finette, B A; Subramanian, V; Gibson, D T

    1984-01-01

    Pseudomonas putida PpF1 degraded toluene via a dihydrodiol pathway to tricarboxylic acid cycle intermediates. The initial reaction was catalyzed by a multicomponent enzyme, toluene dioxygenase, which oxidized toluene to (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene (cis-toluene dihydrodiol). The enzyme consisted of three protein components: NADH-ferredoxintol oxidoreductase (reductasetol), ferredoxintol, and a terminal oxygenase which is an iron-sulfur protein (ISPtol). Mutants blocked in each of these components were isolated after mutagenesis with nitrosoguanidine. Mutants occurred as colony morphology variants when grown in the presence of toluene on indicator plates containing agar, mineral salts, a growth-supporting nutrient (arginine), 2,3,5-triphenyltetrazolium chloride (TTC), and Nitro Blue Tetrazolium (NBT). Under these conditions, wild-type colonies appeared large and red as a result of TTC reduction. Colonies of reductasetol mutants were white or white with a light blue center, ferredoxintol strains were light blue with a dark blue center, and strains that lacked ISPtol gave dark blue colonies. Blue color differences in the mutant colonies were due to variations in the extent of NBT reduction. Strains lacking all three components appeared white. Toluene dioxygenase mutants were characterized by assaying toluene dioxygenase activity in crude cell extracts which were complemented with purified preparations of each protein component. Between 40 and 60% of the putative mutants selected from the NBT-TTC indicator plates were unable to grow with toluene as the sole source of carbon and energy. This method should prove extremely useful in isolating mutants in other multicomponent oxygenase enzyme systems. Images PMID:6501223

  7. Circumferential cracking of steam generator tubes

    SciTech Connect

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  8. Guided Circumferential Waves in Layered Poroelastic Cylinders

    NASA Astrophysics Data System (ADS)

    Shah, S. A.; Apsar, G.

    2016-12-01

    The present paper investigates the propagation of time harmonic circumferential waves in a two-dimensional hollow poroelastic cylinder with an inner shaft (shaft-bearing assembly). The hollow poroelastic cylinder and inner shaft are assumed to be infinite in axial direction. The outer surface of the cylinder is stress free and at the interface, between the inner shaft and the outer cylinder, it is assumed to be free sliding and the interfacial shear stresses are zero, also the normal stress and radial displacements are continuous. The frequency equation of guided circumferential waves for a permeable and an impermeable surface is obtained. When the angular wave number vanish the frequency equation of guided circumferential waves for a permeable and an impermeable surface degenerates and the dilatational and shear waves are uncoupled. Shear waves are independent of the nature of surface. The frequency equation of a permeable and an impermeable surface for bore-piston assembly is obtained as a particular case of the model under consideration when the outer radius of the hollow poroelastic cylinder tends to infinity. Results of previous studies are obtained as a particular case of the present study. Nondimensional frequency as a function of wave number is presented graphically for two types of models and discussed. Numerical results show that, in general, the first modes are linear for permeable and impermeable surfaces and the frequency of a permeable surface is more than that of an impermeable surface.

  9. View of exterior circumferential path at northeast side of building ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of exterior circumferential path at northeast side of building beneath trellis, looking southeast - National Zoological Park, Bird House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

  10. Axial-Loading Circumferential Dovetail Turbine-Blade Mount

    NASA Technical Reports Server (NTRS)

    Pierce, Martin J.; Ward, Steven D.; Eskridge, Ronald R.

    1992-01-01

    In new configuration, retaining ring holds base of blades in circumferential dovetail slot. Blades inserted axially via loading slots into circumferential dovetail slot. Ring placed over loading slots and fastened with split ring held by arm of disk. Blades less likely to be shaken loose during operation.

  11. View of exterior circumferential path at northwest side of building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of exterior circumferential path at northwest side of building, looking east toward building entrance - National Zoological Park, Bird House, 3001 Connecticut Avenue NW, Washington, District of Columbia, DC

  12. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.345-7 Circumferential... strength of the shell material in combination with the frame and reinforcement produces...

  13. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.345-7 Circumferential... strength of the shell material in combination with the frame and reinforcement produces...

  14. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.345-7 Circumferential... strength of the shell material in combination with the frame and reinforcement produces...

  15. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Except for doubler plates and knuckle pads, no reinforcement may cover any circumferential joint. (c... from the applicable formula: I/C = 0.00027WL, for MS, HSLA and SS; or I/C = 0.000467WL, for...

  16. Structural and leakage integrity of tubes affected by circumferential cracking

    SciTech Connect

    Hernalsteen, P.

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  17. Development of circumferential seal for helicopter transmissions: Results of bench and flight tests

    NASA Technical Reports Server (NTRS)

    Strom, T. N.; Ludwig, L. P.

    1975-01-01

    A modified circumferential segmented ring seal was designed for direct replacement of a helicopter transmission elastomeric lip seal operating on a shaft diameter of 13.91 centimeters (5.481 in.) at sliding velocities to 52.48 m/sec (10 330 ft/min). The modifications involved the garter spring tension, shaft roundness, seal housing flatness, and pumping grooves to inhibit leakage. Operation of the seals in bench tests under simulated helicopter transmission conditions revealed that the seal leakage rate was within acceptable limits and that the wear rate was negligible. The low leakage and wear rates were confirmed in flight tests of 600 and 175 hours (sliding speed, 48.11 m/sec (9470 ft/min)). An additional 200 hours of air worthiness qualification testing (aircraft tie down) demonstrated that the seal can operate at the advanced sliding conditions of 52.48 m/sec (10 330 ft/min).

  18. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Circumferential joints in pipes, tubes and headers... Circumferential joints in pipes, tubes and headers (modifies PW-41). (a) Circumferential welded joints of pipes, tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel...

  19. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Circumferential joints in pipes, tubes and headers... Circumferential joints in pipes, tubes and headers (modifies PW-41). (a) Circumferential welded joints of pipes, tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel...

  20. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Circumferential joints in pipes, tubes and headers... Circumferential joints in pipes, tubes and headers (modifies PW-41). (a) Circumferential welded joints of pipes, tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel...

  1. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Circumferential joints in pipes, tubes and headers... Circumferential joints in pipes, tubes and headers (modifies PW-41). (a) Circumferential welded joints of pipes, tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel...

  2. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Circumferential joints in pipes, tubes and headers... Circumferential joints in pipes, tubes and headers (modifies PW-41). (a) Circumferential welded joints of pipes, tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel...

  3. Relation of midwall circumferential systolic stress to equatorial midwall fibre shortening in chronic aortic regurgitation. Value as a predictor of postoperative outcome.

    PubMed Central

    Almeida, P; Córdoba, M; Goicolea, J; Hernández Antolín, R; Rico, L A; Rey, M; Rábago, P; Rábago, G

    1984-01-01

    Nineteen patients with chronic aortic regurgitation and a large increase in heart size were studied before aortic valve replacement. By relating midwall circumferential systolic stress to midwall circumferential fibre shortening (Cs/Cd) before operation the patients could be divided into two well defined groups. Twelve patients (group 1) had a pronounced decrease in heart size as measured by the cardiothoracic ratio and an excellent clinical outcome six months after operation. Seven patients (group 2) had no significant decrease in heart size and a less good clinical outcome. The ratio of midwall circumferential systolic stress to end systolic volume index was significantly higher in group 1 than in group 2. Group 2 had more severe left ventricular hypertrophy determined by the ratio of the wall thickness to the minor internal radius of the left ventricle (h:r ratio), total left ventricular mass, and left ventricular mass to end diastolic volume ratio. There were no significant differences in any other haemodynamic or angiographic indices between the two groups. Thus the relation of midwall circumferential systolic stress to fibre shortening is useful in determining the prognosis in individual patients with chronic aortic regurgitation undergoing aortic valve replacement. PMID:6235830

  4. Circumferential pressure distributions in a model labyrinth seal

    NASA Technical Reports Server (NTRS)

    Leong, Y. M. M. S.; Brown, R. D.

    1982-01-01

    A research program to isolate and study leakage flow through labyrinth glands was initiated. Circumferential pressure distributions were measured in the labyrinth glands with geometry appropriate to the high pressure labyrinths in large steam turbines. Knowledge of this pressure distribution is essential as it is this unequal pressure field that results in the destabilizing force. Parameters that are likely to affect the pressure distributions are incorporated into the test rig. Some preliminary pressure profiles are presented.

  5. Circumferential nonlocal effect on the buckling and vibration of nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, Cheng Yuan; Li, Xiao Hu; Luo, Ying

    2016-04-01

    The nonlocal beam theories are widely used to study the mechanics of cylindrical nanotubes (NTs). The one-dimensional models however are unable to account for the nonlocal effect in the circumferential direction, which may substantially affect the applicability of the nonlocal beam models. To address the issue this letter examines the circumferential nonlocal effect (CNE) on the buckling and vibration of the NTs. Here the CNE is characterized by the difference between the nonlocal beam model considering the axial nonlocal effect only and the nonlocal shell model with both axial and circumferential nonlocal effects. The aspect ratio and radius-dependence of the CNE are calculated for the singlewall carbon NTs selected as a typical example. The results show that the CNE is substantial for the buckling and vibration of the NTs with small radius (e.g., <1 nm) and aspect ratio (e.g., <15). It however decreases with the rising radius and the aspect ratio, and turns out to be small for relatively wide and long NTs. The nonlocal beam theories thus may overestimate the buckling load and vibration frequency for the thin and short NTs.

  6. Circumferential gap propagation in an anisotropic elastic bacterial sacculus

    NASA Astrophysics Data System (ADS)

    Taneja, Swadhin; Levitan, Benjamin A.; Rutenberg, Andrew D.

    2014-01-01

    We have modeled stress concentration around small gaps in anisotropic elastic sheets, corresponding to the peptidoglycan sacculus of bacterial cells, under loading corresponding to the effects of turgor pressure in rod-shaped bacteria. We find that under normal conditions the stress concentration is insufficient to mechanically rupture bacteria, even for gaps up to a micron in length. We then explored the effects of stress-dependent smart autolysins, as hypothesized by A. L. Koch [Adv. Microb. Physiol. 24, 301 (1983), 10.1016/S0065-2911(08)60388-4; Res. Microbiol. 141, 529 (1990), 10.1016/0923-2508(90)90017-K]. We show that the measured anisotropic elasticity of the peptidoglycan (PG) sacculus can lead to stable circumferential propagation of small gaps in the sacculus. This is consistent with the recent observation of circumferential propagation of PG-associated MreB patches in rod-shaped bacteria. We also find a bistable regime of both circumferential and axial gap propagation, which agrees with behavior reported in cytoskeletal mutants of B. subtilis. We conclude that the elastic anisotropies of a bacterial sacculus, as characterized experimentally, may be relevant for maintaining rod-shaped bacterial growth.

  7. Improved circumferential shaft seal for aircraft gear transmissions

    NASA Technical Reports Server (NTRS)

    Ludwig, L. P.; Strom, T. N.

    1973-01-01

    Operation under simulated aircraft transmission conditions of speeds to 2850 m/min (9350 ft/min), lubricant temperatures to 394 K (250 F), shaft radial runouts to 0.254 mm (0.010 in.) F.I.R. (full indicator reading), and pressure differentials to 1.03 N/cm2 (1.5 psi) revealed that conventional circumferential seals leaked excessively. Modifying the conventional seal by adding helical grooves to the seal bore reduced leakage rates to within the acceptable level of 10 cm3/hr. The leakage rate of this modified seal was not significantly affected by lubricant flooding or by shaft radial runout.

  8. Esophageal Rings and Stricture Related to a Circumferential Inlet Patch

    PubMed Central

    Scott, Larry

    2016-01-01

    Inlet patches are sometimes seen during upper endoscopy, usually in the proximal esophagus. Complications of inlet patches can cause a wide array of symptoms and complications. A man presented with dysphagia and was found to have 2 rings in the upper esophagus, just above and below a circumferential inlet patch. The more distal ring caused a stenosis, which produced the symptoms. Savary dilation and treatment with a proton pump inhibitor led to symptom resolution. Pathology was missed on the patient's first endoscopy, highlighting the importance of looking for pathology throughout the entire esophagus, not just in the distal esophagus. PMID:27807576

  9. J-integral of circumferential crack in large diameter pipes

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Chao, Yuh J.; Sutton, M. A.; Lam, P. S.; Mertz, G. E.

    Large diameter thin-walled pipes are encountered in a low pressure nuclear power piping system. Fracture parameters such as K and J, associated with postulated cracks, are needed to assess the safety of the structure, for example, prediction of the onset of tile crack growth and the stability of the crack. The Electric Power Research Institute (EPRI) has completed a comprehensive study of cracks in pipes and handbook-type data is available. However, for some large diameter, thin-walled pipes the needed information is not included in the handbook. This paper reports our study of circumferential cracks in large diameter, thin-walled pipes (R/t=30 to 40) under remote bending or tension loads. Elastic-Plastic analyses using the finite element method were performed to determine the elastic and fully plastic J values for various pipe/crack geometries. A non-linear Ramberg-Osgood material model is used with strain hardening exponents (n) that range from 3 to 10. A number of circumferential, through thickness cracks were studied with half crack angles ranging from 0.063(pi) to 0.5(pi). Results are tabulated for use with the EPRI estimation scheme.

  10. Ankle replacement

    MedlinePlus

    ... is surgery to replace the damaged bone and cartilage in the ankle joint. Artificial joint parts (prosthetics) ... Your surgeon will remove the damaged bone and cartilage. Your surgeon will replace the damaged part of: ...

  11. Hip Replacement

    MedlinePlus

    ... replacement is an operation in which a damaged hip joint is removed and replaced with an artificial joint. ... are many medical conditions that can damage the hip joint. (Watch the video to learn about what goes ...

  12. Transverse shear effect in a circumferentially cracked cylindrical shell

    NASA Technical Reports Server (NTRS)

    Delale, F.; Erdogan, F.

    1979-01-01

    The objectives of the paper are to solve the problem of a circumferentially-cracked cylindrical shell by taking into account the effect of transverse shear, and to obtain the stress intensity factors for the bending moment as well as the membrane force as the external load. The formulation of the problem is given for a specially orthotropic material within the framework of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions as to moment and stress resultants on the crack surface. The effect of Poisson's ratio on the stress intensity factors and the nature of the out-of-plane displacement along the edges of the crack, i.e., bulging, are also studied.

  13. Vascular Repair by Circumferential Cell Therapy Using Magnetic Nanoparticles and Tailored Magnets.

    PubMed

    Vosen, Sarah; Rieck, Sarah; Heidsieck, Alexandra; Mykhaylyk, Olga; Zimmermann, Katrin; Bloch, Wilhelm; Eberbeck, Dietmar; Plank, Christian; Gleich, Bernhard; Pfeifer, Alexander; Fleischmann, Bernd K; Wenzel, Daniela

    2016-01-26

    Cardiovascular disease is often caused by endothelial cell (EC) dysfunction and atherosclerotic plaque formation at predilection sites. Also surgical procedures of plaque removal cause irreversible damage to the EC layer, inducing impairment of vascular function and restenosis. In the current study we have examined a potentially curative approach by radially symmetric re-endothelialization of vessels after their mechanical denudation. For this purpose a combination of nanotechnology with gene and cell therapy was applied to site-specifically re-endothelialize and restore vascular function. We have used complexes of lentiviral vectors and magnetic nanoparticles (MNPs) to overexpress the vasoprotective gene endothelial nitric oxide synthase (eNOS) in ECs. The MNP-loaded and eNOS-overexpressing cells were magnetic, and by magnetic fields they could be positioned at the vascular wall in a radially symmetric fashion even under flow conditions. We demonstrate that the treated vessels displayed enhanced eNOS expression and activity. Moreover, isometric force measurements revealed that EC replacement with eNOS-overexpressing cells restored endothelial function after vascular injury in eNOS(-/-) mice ex and in vivo. Thus, the combination of MNP-based gene and cell therapy with custom-made magnetic fields enables circumferential re-endothelialization of vessels and improvement of vascular function.

  14. Shoulder replacement

    MedlinePlus

    ... the opening at the end of the shoulder blade, called the socket. This type of joint allows ... head. The socket part (glenoid) of your shoulder blade will be replaced with a smooth plastic shell ( ...

  15. Fracture behavior of short circumferentially surface-cracked pipe

    SciTech Connect

    Krishnaswamy, P.; Scott, P.; Mohan, R.

    1995-11-01

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission`s (NRC) research program entitled ``Short Cracks in Piping and Piping Welds`` that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC`s PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria.

  16. Nonlinear giant magnetoimpedance and the asymmetric circumferential magnetization process in soft magnetic wires

    NASA Astrophysics Data System (ADS)

    Gómez-Polo, C.; Duque, J. G. S.; Knobel, M.

    2004-07-01

    The magnetoimpedance effect and its nonlinear terms are analysed for a (Co0.94Fe0.06)72.5Si12.5B15 amorphous wire. In order to enhance the nonlinear contribution the sample was previously subjected to current annealing (Joule heating) to induce a circumferential anisotropy. The effect of the application of a torsional strain on the nonlinear magnetoimpedance is analysed in terms of the torsional dependence of the magnetic permeability, evaluated through experimental circumferential hysteresis loops. The results obtained clearly confirm the direct correlation between the asymmetric circumferential magnetization process and the occurrence of nonlinear second-harmonic terms in the magnetoimpedance voltage.

  17. Design of optical cloaks and illusion devices along a circumferential direction in curvilinear coordinates

    NASA Astrophysics Data System (ADS)

    Chen, Tungyang; Yu, Shang-Ru

    2010-11-01

    We propose a cloaking and illusion device of circumferential topology based on the concept of transformation optics. The device is capable to cloak an object and/or simultaneously generate illusion images along a circumferential direction in curvilinear orthogonal coordinates. This feature allows us to construct multiple illusions in different ways, irrespective of the profile and direction of incident wave. Particularly when the device is served as a building brick of a larger device, one can generate a circumferential array of illusions in a periodic or any preferred pattern. We demonstrate the effectiveness of the proposed illusion devices by carrying out full wave simulations based on finite element calculations.

  18. Circumferential cracking in steam generator tubes repaired by mechanical sleeving

    SciTech Connect

    Stubbe, J.; Pierson, E.; Laire, C.; Nedden, L. zur; Somville, P.; Royen, P. Van

    1995-12-31

    After one service cycle, leaks were detected in Doel 4 steam generator (SG) tubes repaired by mechanical sleeving (hydraulically + roll expanded). Two tubes were pulled and examined, one of them showing a big leak and the second being, pulled randomly. They both revealed through wall circumferential primary water stress corrosion cracking (PWSCC) at the upper hydraulic transition so that it was concluded that the problem was generic. A thorough assessment of the root causes of failure was undertaken, including stress and strain direct measurement by X-ray diffraction and photoelasticity, local stresses and temperature evaluation by calculation and stress corrosion cracking tests. Stress corrosion tests were carried out in 10 % NAOH environment, on mock-ups manufactured from reserve tubing of the plant simulating not only the upper joint but also the complete assembly (two joints). An estimate of the expected life was performed by comparison with reference mock-ups representative of the roll transitions (including the kiss roll). The findings are that the hydraulic expansion may generate high residual stresses, in spite of the very low residual deformations. Concerning, the temperature however, there are some indications that it could be substantially lower at the level of the cracking than at the tube to tubesheet roll transitions, which makes the quantified evaluation somewhat inaccurate. It is concluded that repair by mechanical sleeving is influenced by many parameters, including details of the installation procedure. Lifetime may be very limited when applied to PWSCC sensitive tubes and must be evaluated by appropriate testing. In particular, corrosion mock-ups should represent the entire sleeve, with both joints.

  19. Understanding the link between circumferential dikes and eruptive fissures around calderas based on numerical and analog models

    NASA Astrophysics Data System (ADS)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-06-01

    Active calderas are seldom associated with circumferential eruptive fissures, but eroded magmatic complexes reveal widespread circumferential dikes. This suggests that, while the conditions to emplace circumferential dikes are easily met, mechanisms must prevent them from reaching the surface. We explain this discrepancy with experiments of air injection into gelatin shaped as a volcano with caldera. Analog dikes show variable deflection, depending on the competition between overpressure, Pe, and topographic unloading, Pl; when Pl/Pe = 4.8-5.3, the dikes propagate orthogonal to the least compressive stress. Due to the unloading, they become circumferential and stall below the caldera rim; buoyancy is fundamental for the further rise and circumferential fissure development. Numerical models quantitatively constrain the stress orientation within the gelatin, explaining the observed circumferential dikes. Our results explain how dikes propagate below the rim of felsic and mafic calderas, but only in the latter they are prone to feed circumferential fissures.

  20. Circumferential decompression of the foramen magnum for the treatment of syringomyelia associated with basilar invagination.

    PubMed

    Collignon, Frederic P; Cohen-Gadol, Aaron A; Krauss, William E

    2004-07-01

    Posterior fossa decompression utilizing suboccipital craniectomy and duraplasty remains the standard surgical treatment for Chiari-associated syringomyelia. In the presence of basilar invagination, anterior decompression, typically transoral odontoidectomy, or posterior decompression may be performed. We report two cases in which anterior and posterior (circumferential) decompression of the foramen magnum was used to treat cervical syringomyelia successfully. These cases demonstrate that circumferential decompression of the foramen magnum may be necessary in some cases of cervical syringomyelia associated with basilar invagination and Chiari malformation.

  1. Steady and Unsteady Flow Effects of Circumferential Grooves Casing Treatment in a Transonic Compressor Rotor

    NASA Technical Reports Server (NTRS)

    Hah, Chunill

    2011-01-01

    The current paper reports on an investigation of steady and unsteady flow effects of circumferential grooves casing treatment in a transonic compressor rotor. Circumferential grooves casing treatment is used mainly to increase stall margin in axial compressors with a relatively small decrease in aerodynamic efficiency. It is widely believed that flow mechanisms of circumferential grooves casing treatment near stall conditions are not yet well understood even though this treatment has been used widely in real engines. Numerical analysis based on steady Reynolds-averaged Navier-Stokes (RANS) has been the primary tool used to understand flow mechanism for circumferential grooves casing treatment. Although steady RANS explains some flow effects of circumferential grooves casing treatment, it does not calculate all the measured changes in the compressor characteristics. Therefore, design optimization of circumferential grooves with steady RANS has not been very successful. As a compressor operates toward the stall condition, the flow field becomes transient. Major sources of self-generated flow unsteadiness are shock oscillation and interaction between the passage shock and the tip leakage vortex. In the present paper, an unsteady Reynolds-averaged Navier-Stokes (URANS) approach is applied to study the effects of circumferential grooves in a transonic compressor. The results from URANS are compared with the results from RANS and measured data. The current investigation shows that there are significant unsteady flow effects on the performance of the circumferential grooves casing treatment. For the currently investigated rotor, the unsteady effects are of the same magnitude as the steady effects in terms of extending the compressor stall margin.

  2. Segmental Analysis of Cardiac Short-Axis Views Using Lagrangian Radial and Circumferential Strain.

    PubMed

    Ma, Chi; Wang, Xiao; Varghese, Tomy

    2016-11-01

    Accurate description of myocardial deformation in the left ventricle is a three-dimensional problem, requiring three normal strain components along its natural axis, that is, longitudinal, radial, and circumferential strains. Although longitudinal strains are best estimated from long-axis views, radial and circumferential strains are best depicted in short-axis views. An algorithm that utilizes a polar grid for short-axis views previously developed in our laboratory for a Lagrangian description of tissue deformation is utilized for radial and circumferential displacement and strain estimation. Deformation of the myocardial wall, utilizing numerical simulations with ANSYS, and a finite-element analysis-based canine heart model were adapted as the input to a frequency-domain ultrasound simulation program to generate radiofrequency echo signals. Clinical in vivo data were also acquired from a healthy volunteer. Local displacements estimated along and perpendicular to the ultrasound beam propagation direction are then transformed into radial and circumferential displacements and strains using the polar grid based on a pre-determined centroid location. Lagrangian strain variations demonstrate good agreement with the ideal strain when compared with Eulerian results. Lagrangian radial and circumferential strain estimation results are also demonstrated for experimental data on a healthy volunteer. Lagrangian radial and circumferential strain tracking provide accurate results with the assistance of the polar grid, as demonstrated using both numerical simulations and in vivo study.

  3. The link between circumferential dikes and eruptive fissures around calderas: insights from numerical and analog models

    NASA Astrophysics Data System (ADS)

    Corbi, Fabio; Rivalta, Eleonora; Pinel, Virginie; Maccaferri, Francesco; Acocella, Valerio

    2016-04-01

    Active calderas are seldom associated with circumferential eruptive fissures along their rim, but eroded portions of extinct magmatic complexes reveal widespread evidence of circumferential dikes. This discrepancy suggests that, while the conditions to emplace circumferential dikes below volcanoes are easily met, mechanisms must exist to arrest the dikes before they reach the surface. Here we explain this discrepancy with laboratory experiments of air injection into a gelatin medium shaped to mimic a volcanic edifice with caldera. Our models show that the ascending dikes experience a variable degree of deflection, depending on the competition between dike overpressure, Pe, and the forcing induced by the topographic load, Pl. When Pl/Pe = 4.3 - 4.5 the analog dikes proceed almost insensitive to the stress rotation and erupt within the caldera. When Pl/Pe = 4.8 - 5.3 the analog dikes closely propagate orthogonal to the least compressive stress σ3 and stall below the caldera rim in a circumferential arrangement. Progressive buoyancy increase through repeated supply of fluid is fundamental for the occurrence of circumferential fissures. Complementary numerical models explain the observed circumferential arrangement and validate the experiments. These results contribute defining the shallow magma transfer and related hazard assessment within calderas.

  4. Circumferentially aligned fibers guided functional neoartery regeneration in vivo.

    PubMed

    Zhu, Meifeng; Wang, Zhihong; Zhang, Jiamin; Wang, Lina; Yang, Xiaohu; Chen, Jingrui; Fan, Guanwei; Ji, Shenglu; Xing, Cheng; Wang, Kai; Zhao, Qiang; Zhu, Yan; Kong, Deling; Wang, Lianyong

    2015-08-01

    An ideal vascular graft should have the ability to guide the regeneration of neovessels with structure and function similar to those of the native blood vessels. Regeneration of vascular smooth muscle cells (VSMCs) with circumferential orientation within the grafts is crucial for functional vascular reconstruction in vivo. To date, designing and fabricating a vascular graft with well-defined geometric cues to facilitate simultaneously VSMCs infiltration and their circumferential alignment remains a great challenge and scarcely reported in vivo. Thus, we have designed a bi-layered vascular graft, of which the internal layer is composed of circumferentially aligned microfibers prepared by wet-spinning and an external layer composed of random nanofibers prepared by electrospinning. While the internal circumferentially aligned microfibers provide topographic guidance for in vivo regeneration of circumferentially aligned VSMCs, the external random nanofibers can offer enhanced mechanical property and prevent bleeding during and after graft implantation. VSMCs infiltration and alignment within the scaffold was then evaluated in vitro and in vivo. Our results demonstrated that the circumferentially oriented VSMCs and longitudinally aligned ECs were successfully regenerated in vivo after the bi-layered vascular grafts were implanted in rat abdominal aorta. No formation of thrombosis or intimal hyperplasia was observed up to 3 month post implantation. Further, the regenerated neoartery exhibited contraction and relaxation property in response to vasoactive agents. This new strategy may bring cell-free small diameter vascular grafts closer to clinical application.

  5. Toward Optimum Configuration of Circumferential Groove Casing Treatment in Transonic Compressor Rotors

    NASA Technical Reports Server (NTRS)

    Hah, Chunill

    2011-01-01

    The current paper first reviews experimental and numerical investigations to understand flow physics and to develop optimum configurations of circumferential grooves in compressor rotors. Circumferential grooves are used mainly to increase stall margin in axial compressors with small decrease in aerodynamic efficiency. Although circumferential groove casing treatment has been used widely, flow mechanisms of the circumferential grooves at near stall conditions are not well understood yet. Detailed time-dependent flow measurement inside tip gap in a high speed compressor is still a big challenge even though significant advance has been made in non-intrusive flow measurement technique. Therefore numerical approaches have been used to study relevant flow physics. However, optimum design of circumferential grooves to a given compressor with the computational tools is not practical yet. In the present paper, various investigations to study flow physics of circumferential groove casing treatment in axial compressor are reviewed first. Possible missing flow physics are identified and future research efforts for the optimum design are discussed.

  6. Hip Replacement

    MedlinePlus

    ... cemented and uncemented prostheses are comparable. However, more long-term data are available in the United States for hip replacements with cemented prostheses, because doctors have been using them ... period. Because it takes a long time for the natural bone to grow and ...

  7. High Rate of Positive Circumferential Resection Margins Following Rectal Cancer Surgery: A Call to Action

    PubMed Central

    Rickles, Aaron S.; Dietz, David W.; Chang, George J.; Wexner, Steven D.; Berho, Mariana E.; Remzi, Feza H.; Greene, Frederick L.; Fleshman, James W.; Abbas, Maher A.; Peters, Walter; Noyes, Katia; Monson, John R.T.; Fleming, Fergal J.

    2017-01-01

    Objective To identify predictors of positive circumferential resection margin following rectal cancer resection in the United States. Background Positive circumferential resection margin is associated with a high rate of local recurrence and poor morbidity and mortality for rectal cancer patients. Prior study has shown poor compliance with national rectal cancer guidelines, but whether this finding is reflected in patient outcomes has yet to be shown. Methods Patients who underwent resection for stage I-III rectal cancer were identified from the 2010-2011 National Cancer Database. The primary outcome was a positive circumferential resection margin. The relationship between patient, hospital, tumor, and treatment-related characteristics was analyzed using bivariate and multivariate analysis. Findings A positive circumferential resection margin was noted in 2,859 (17.2%) of the 16,619 patients included. Facility location, clinical T and N stage, histologic type, tumor size, tumor grade, lymphovascular invasion, perineural invasion, type of operation, and operative approach were significant predictors of positive circumferential resection margin on multivariable analysis. Total proctectomy had nearly a 30% increased risk of positive margin compared to partial proctectomy (OR 1.293, 95%CI 1.185-1.411) and a laparoscopic approach had nearly 22% less risk of a positive circumferential resection margin compared to an open approach (OR 0.882, 95%CI 0.790-0.985). Interpretation Despite advances in surgical technique and multimodality therapy, rates of positive circumferential resection margin remain high in the United States. Several tumor and treatment characteristics were identified as independent risk factors, and advances in rectal cancer care are necessary to approach the outcomes seen in other countries. PMID:26473651

  8. A review on the safety of one-stage circumferential ring constriction release.

    PubMed

    Prasetyono, Theddeus O H; Sitorus, Ade S N

    2015-02-01

    The study was undertaken to investigate the use of one-stage circumferential ring-constriction release with Z-plasties regarding the safety, aesthetic appearance, and limb function. A thorough review was conducted on all English publications in PubMed during the period of 2001 through 2011. Titles and abstracts were identified using online search engine from National Library of Medicine's PubMed database under the keywords "limb constriction ring," "limb constriction band," "amniotic band," "annular constriction," and "circumferential constriction." We used Boolean operator and field of title. Evaluation was done to search indications, timing of the first surgical intervention, time interval between surgeries, patients' gender, anatomic location of the ring, wound healing problems, and scar quality. Fourteen publications met the criteria. There were 17 patients with 25 ring constrictions in total. Sixteen ring constrictions (64%) were circumferential; nine (36%) were semi-circumferential. Mean age of 14 patients treated with one-stage release was 4.8 years. Six articles mentioned about normal development of postoperative limb function. Mean age of three patients treated with staged release was 10.5 months. Two articles mentioned regained distal muscle function postoperatively. It is confirmed that surgeons may continue the practice to release circumferential CRS in one stage.

  9. Ranakinestatin-PPF from the Skin Secretion of the Fukien Gold-Striped Pond Frog, Pelophylax plancyi fukienensis: A Prototype of a Novel Class of Bradykinin B2 Receptor Antagonist Peptide from Ranid Frogs

    PubMed Central

    Ma, Jie; Ge, Lilin; Zhang, Yingqi; Duan, Jinao; Shaw, Chris

    2014-01-01

    The defensive skin secretions of many amphibians are a rich source of bradykinins and bradykinin-related peptides (BRPs). Members of this peptide group are also common components of reptile and arthropod venoms due to their multiple biological functions that include induction of pain, effects on many smooth muscle types, and lowering systemic blood pressure. While most BRPs are bradykinin receptor agonists, some have curiously been found to be exquisite antagonists, such as the maximakinin gene-related peptide, kinestatin—a specific bradykinin B2-receptor antagonist from the skin of the giant fire-bellied toad, Bombina maxima. Here, we describe the identification, structural and functional characterization of a heptadecapeptide (DYTIRTRLHQGLSRKIV), named ranakinestatin-PPF, from the skin of the Chinese ranid frog, Pelophylax plancyi fukienensis, representing a prototype of a novel class of bradykinin B2-receptor specific antagonist. Using a preconstricted preparation of rat tail arterial smooth muscle, a single dose of 10−6 M of the peptide effectively inhibited the dose-dependent relaxation effect of bradykinin between 10−11 M and 10−5 M and subsequently, this effect was pharmacologically-characterized using specific bradykinin B1- (desArg-HOE140) and B2-receptor (HOE140) antagonists; the data from which demonstrated that the antagonism of the novel peptide was mediated through B2-receptors. Ranakinestatin—PPF—thus represents a prototype of an amphibian skin peptide family that functions as a bradykinin B2-receptor antagonist herein demonstrated using mammalian vascular smooth muscle. PMID:25161395

  10. Circumferential arrays used for UT endoscopy on heat exchanger tubes

    SciTech Connect

    Liebig, V.; Koehler, B.; Gebhardt, W.; Kroening, M.; Mummert, K.

    1994-12-31

    Corrosion damage on steam generator (SG) heat exchanger tubes of nuclear power plants has repeatedly been the cause of limitations in availability and steam generator replacements. The objective here is to develop an ultrasonic testing (UT) method which enables damage phenomena on SG heat exchanger tubes to be determined and assessed. The method is based on the use of miniaturized ultrasonic array probes of piezoelectric composite materials whose characteristic impedance can be well matched to the load medium (water) and therefore guarantees a high signal efficiency with a good time resolution.

  11. Circumferential periosteal sleeve resection for limb length inequality complicated by growth plate tether.

    PubMed

    Al Hussainy, H A J; Jones, S; Ali, F; Davies, A G

    2004-09-01

    Correction of limb length inequality can be achieved by stimulation of growth of the short limb. Circumferential periosteal sleeve resection has been reported as a safe and reliable method of stimulating longitudinal bone growth. We report the complication of growth tethers to the distal tibial physes in two patients following circumferential periosteal sleeve resection to the distal femur, tibia and fibula. This was done under direct vision. This complication may have arisen due to damage to the perichondrial ring as a result of raising the periosteum too close to the distal tibial physes. A limited response may be seen in young patients following this procedure as a result of this complication. Circumferential periosteal sleeve resection for limb length inequality is a treatment option that is not without complication.

  12. Evidence for hydrated spermidine-calf thymus DNA toruses organized by circumferential DNA wrapping.

    PubMed Central

    Marx, K A; Ruben, G C

    1983-01-01

    In spermidine-condensed calf thymus DNA preparations, torus-shaped condensates were shown by transmission electron microscopy to exist under the hydrated conditions of the freeze fracture experiment. Using extremely low Pt metal deposition levels (9 A Pt/C) high-contrast replicas of the spermidine-DNA toruses were obtained that showed circumferential wrapping of single DNA double helix-size surface fibres. Stereoscopic analysis of high magnification stereomicrographs established some details of the three-dimensional organization of two DNA double helix sections winding circumferentially on the inner surface of one such torus. These measurements demonstrate the usefulness of stereoscopic analysis of these high macromolecular organization magnification. Measurements on a number of torus-shaped complexes (n = 16) yielded these average dimensions: inner circumference (1840 +/- 204 A) outer circumference (2800 +/- 222 A), torus ring thickness (143 +/- 18 A). These data support a continuous circumferential DNA-winding model of torus organization proposed by Marx & Reynolds. Images PMID:6835840

  13. Application of induced circumferential current for cracks inspection on pipe string

    NASA Astrophysics Data System (ADS)

    Yuan, Xin'an; Li, Wei; Yin, Xiaokang; Chen, Guoming; Ge, Jiuhao

    2016-02-01

    Pipe strings (such as drill pipe, tube, pipeline, riser) are critical facilities in oil & gas industry, which are highly susceptible to cracks caused by stress corrosion and fatigue damage. The most common defects are longitudinal and transverse surface cracks on pipe strings in oil & gas industry. Conventional nondestructive testing (NDT) methods are inadequate for these surface cracks on pipe strings. In this paper, a full 360° circumferential current induced by a coaxial excitation coil is present for inspection of longitudinal and transverse surface cracks on pipe strings. The finite element method (FEM) is employed to obtain characteristics signals by analyzing the distorted electromagnetic field above the cracks. The induced circumferential current test system is set up and crack inspection experiments are carried out. The results show that both longitudinal and transverse surface cracks can be detected effectively at one pass scanning on pipe string using the induced circumferential current.

  14. Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications

    NASA Technical Reports Server (NTRS)

    Bjorkman, Gerry; Cantrell, Mark; Carter, Robert

    2003-01-01

    Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading

  15. Complete 360° circumferential gonioscopic optical coherence tomography imaging of the iridocorneal angle

    PubMed Central

    McNabb, Ryan P.; Challa, Pratap; Kuo, Anthony N.; Izatt, Joseph A.

    2015-01-01

    Clinically, gonioscopy is used to provide en face views of the ocular angle. The angle has been imaged with optical coherence tomography (OCT) through the corneoscleral limbus but is currently unable to image the angle from within the ocular anterior chamber. We developed a novel gonioscopic OCT system that images the angle circumferentially from inside the eye through a custom, radially symmetric, gonioscopic contact lens. We present, to our knowledge, the first 360° circumferential volumes (two normal subjects, two subjects with pathology) of peripheral iris and iridocorneal angle structures obtained via an internal approach not typically available in the clinic. PMID:25909021

  16. Feasibility study of negative lift circumferential type seal for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Goldring, E. N.

    1977-01-01

    A new seal concept, the negative lift circumferential type seal, was evaluated under simulated helicopter transmission conditions. The bore of the circumferential seal contains step type geometry which produces a negative lift that urges the sealing segments towards the shaft surface. The seal size was a 2.5 inch bore and the test speeds were 7000 and 14,250 rpm. During the 300 hour test at typical transmission seal pressure (to 2 psig) the leakage was within acceptable limits and generally less than 0.1 cc/hour during the last 150 hours of testing. The wear to the carbon segments during the 300 hours was negligible.

  17. Compact MEMS-driven pyramidal polygon reflector for circumferential scanned endoscopic imaging probe.

    PubMed

    Mu, Xiaojing; Zhou, Guangya; Yu, Hongbin; Du, Yu; Feng, Hanhua; Tsai, Julius Ming Lin; Chau, Fook Siong

    2012-03-12

    A novel prototype of an electrothermal chevron-beam actuator based microelectromechanical systems (MEMS) platform has been successfully developed for circumferential scan. Microassembly technology is utilized to construct this platform, which consists of a MEMS chevron-beam type microactuator and a micro-reflector. The proposed electrothermal microactuators with a two-stage electrothermal cascaded chevron-beam driving mechanism provide displacement amplification, thus enabling a highly reflective micro-pyramidal polygon reflector to rotate a large angle for light beam scanning. This MEMS platform is ultra-compact, supports circumferential imaging capability and is suitable for endoscopic optical coherence tomography (EOCT) applications, for example, for intravascular cancer detection.

  18. A second patient with MCA/MR syndrome with multiple circumferential skin creases.

    PubMed

    Leonard, N J

    2002-09-15

    Symmetrical congenital circumferential skin creases are a rare feature described in only a few conditions. We report a case of a 29-month-old boy with symmetrical circumferential skin creases on arms, legs, and digits, and other features reminiscent of the single case reported by Cohen et al. [1993: Clin Dysmorphol 2:39-46] and reviewed by Elliott et al. [1996: Am J Med Genet 62:23-25]. The key features also include epicanthic folds, microphthalmia, microcornea, microcephaly, small, low-set posteriorly angulated ears with thick overfolded helices, cleft palate, and moderate-severe psychomotor developmental delay.

  19. Characterization of circumferential guided waves in a cylindrical cortical bone-mimicking phantom.

    PubMed

    Nauleau, Pierre; Cochard, Etienne; Minonzio, Jean-Gabriel; Grimal, Quentin; Laugier, Pascal; Prada, Claire

    2012-04-01

    The femoral neck cortical shell was recently demonstrated to act like a waveguide for circumferential waves. Femoral neck assessment with ultrasound could be enhanced by guided waves measurement. In this study, the decomposition of the time reversal operator (DORT) method is used to measure the phase velocities of circumferential guided modes in a circular tube with dimensions characteristic of femoral neck. The tube is made of a bone-mimicking material. Five guided modes are obtained and compared to theoretical predictions. The work substantiates the feasibility of measuring guided waves in a relatively thick tube of attenuating material with the DORT method.

  20. Circumferential distortion modeling of the TF30-P-3 compression system

    NASA Technical Reports Server (NTRS)

    Mazzawy, R. S.; Banks, G. A.

    1977-01-01

    Circumferential inlet pressure and temperature distortion testing of the TF30 P-3 turbofan engine was conducted. The compressor system at the test conditions run was modelled according to a multiple segment parallel compressor model. Aspects of engine operation and distortion configuration modelled include the effects of compressor bleeds, relative pressure-temperature distortion alignment and circumferential distortion extent. Model predictions for limiting distortion amplitudes and flow distributions within the compression system were compared with test results in order to evaluate predicted trends. Relatively good agreement was obtained. The model also identified the low pressure compressor as the stall-initiating component, which was in agreement with the data.

  1. Aerodynamic Inner Workings of Circumferential Grooves in a Transonic Axial Compressor

    NASA Technical Reports Server (NTRS)

    Hah, Chunill; Mueller, Martin; Schiffer, Heinz-Peter

    2007-01-01

    The current paper reports on investigations of the fundamental flow mechanisms of circumferential grooves applied to a transonic axial compressor. Experimental results show that the compressor stall margin is significantly improved with the current set of circumferential grooves. The primary focus of the current investigation is to advance understanding of basic flow mechanics behind the observed improvement of stall margin. Experimental data and numerical simulations of a circumferential groove were analyzed in detail to unlock the inner workings of the circumferential grooves in the current transonic compressor rotor. A short length scale stall inception occurs when a large flow blockage is built on the pressure side of the blade near the leading edge and incoming flow spills over to the adjacent blade passage due to this blockage. The current study reveals that a large portion of this blockage is created by the tip clearance flow originating from 20% to 50% chord of the blade from the leading edge. Tip clearance flows originating from the leading edge up to 20% chord form a tip clearance core vortex and this tip clearance core vortex travels radially inward. The tip clearance flows originating from 20% to 50% chord travels over this tip clearance core vortex and reaches to the pressure side. This part of tip clearance flow is of low momentum as it is coming from the casing boundary layer and the blade suction surface boundary layer. The circumferential grooves disturb this part of the tip clearance flow close to the casing. Consequently the buildup of the induced vortex and the blockage near the pressure side of the passage is reduced. This is the main mechanism of the circumferential grooves that delays the formation of blockage near the pressure side of the passage and delays the onset of short length scale stall inception. The primary effect of the circumferential grooves is preventing local blockage near the pressure side of the blade leading edge that

  2. Optimization of the axial compressor flow passage to reduce the circumferential distortion

    NASA Astrophysics Data System (ADS)

    Popov, G.; Kolmakova, D.; Shklovets, A.; Ermakov, A.

    2015-08-01

    This work is motivated by the necessity to reduce the effects of the flow circumferential distortion in the flow passage of the aircraft gas turbine engine (GTE). In previous research, the authors have proposed the approaches to decrease of the flow circumferential distortion arising from the mid-support racks of GTE compressor and having a negative impact on the blade rows, located upstream. In particular, the idea of introducing the circumferentially non-uniform blade pitch and profile stagger angle of guide vanes located in front of the support was contributed in order to redistribute the flow and decrease the dynamic stresses in the rotor wheel of the same stage. During the research presented in this paper, another principal of reduction of the flow circumferential distortion was chosen. Firstly, the variants of upgrading the existing support racks were found. Secondly, the new design of support was offered. Both the first and the second version of the support design variation took into account the availability of technological and structural limitations associated with the location of oil pipes, springs and others elements in the support racks. Investigations of modified design showed that the support with altered racks provides a reduction of dynamic stresses by 20% at resonance with the most dangerous harmonic, and the new design of support can give the decrease of 30%.

  3. Expanded plug method for developing circumferential mechanical properties of tubular materials

    DOEpatents

    Hendrich, William Ray; McAfee, Wallace Jefferson; Luttrell, Claire Roberta

    2006-11-28

    A method for determining the circumferential properties of a tubular product, especially nuclear fuel cladding, utilizes compression of a polymeric plug within the tubular product to determine strain stress, yield stress and other properties. The process is especially useful in the determination of aging properties such as fuel rod embrittlement after long burn-down.

  4. Circumferential optical coherence tomography angiography imaging of the swine esophagus using a micromotor balloon catheter

    PubMed Central

    Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Liang, Kaicheng; Wang, Zhao; Cleveland, Cody; Booth, Lucas; Potsaid, Benjamin; Jayaraman, Vijaysekhar; Cable, Alex E.; Mashimo, Hiroshi; Langer, Robert; Traverso, Giovanni; Fujimoto, James G.

    2016-01-01

    We demonstrate a micromotor balloon imaging catheter for ultrahigh speed endoscopic optical coherence tomography (OCT) which provides wide area, circumferential structural and angiographic imaging of the esophagus without contrast agents. Using a 1310 nm MEMS tunable wavelength swept VCSEL light source, the system has a 1.2 MHz A-scan rate and ~8.5 µm axial resolution in tissue. The micromotor balloon catheter enables circumferential imaging of the esophagus at 240 frames per second (fps) with a ~30 µm (FWHM) spot size. Volumetric imaging is achieved by proximal pullback of the micromotor assembly within the balloon at 1.5 mm/sec. Volumetric data consisting of 4200 circumferential images of 5,000 A-scans each over a 2.6 cm length, covering a ~13 cm2 area is acquired in <18 seconds. A non-rigid image registration algorithm is used to suppress motion artifacts from non-uniform rotational distortion (NURD), cardiac motion or respiration. En face OCT images at various depths can be generated. OCT angiography (OCTA) is computed using intensity decorrelation between sequential pairs of circumferential scans and enables three-dimensional visualization of vasculature. Wide area volumetric OCT and OCTA imaging of the swine esophagus in vivo is demonstrated. PMID:27570688

  5. MEMS-based non-rotatory circumferential scanning optical probe for endoscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Yingshun; Singh, Janak; Siang, Teo Hui; Ramakrishna, Kotlanka; Premchandran, C. S.; Sheng, Chen Wei; Kuan, Chuah Tong; Chen, Nanguang; Olivo, Malini C.; Sheppard, Colin J. R.

    2007-07-01

    In this paper, we present a non-rotatory circumferential scanning optical probe integrated with a MEMS scanner for in vivo endoscopic optical coherence tomography (OCT). OCT is an emerging optical imaging technique that allows high resolution cross-sectional imaging of tissue microstructure. To extend its usage to endoscopic applications, a miniaturized optical probe based on Microelectromechanical Systems (MEMS) fabrication techniques is currently desired. A 3D electrothermally actuated micromirror realized using micromachining single crystal silicon (SCS) process highlights its very large angular deflection, about 45 degree, with low driving voltage for safety consideration. The micromirror is integrated with a GRIN lens into a waterproof package which is compatible with requirements for minimally invasive endoscopic procedures. To implement circumferential scanning substantially for diagnosis on certain pathological conditions, such as Barret's esophagus, the micromirror is mounted on 90 degree to optical axis of GRIN lens. 4 Bimorph actuators that are connected to the mirror on one end via supporting beams and springs are selected in this micromirror design. When actuators of the micromirror are driven by 4 channels of sinusoidal waveforms with 90 degree phase differences, beam focused by a GRIN is redirected out of the endoscope by 45 degree tilting mirror plate and achieve circumferential scanning pattern. This novel driving method making full use of very large angular deflection capability of our micromirror is totally different from previously developed or developing micromotor-like rotatory MEMS device for circumferential scanning.

  6. Variations of mechanical property of out circumferential lamellae in cortical bone along the radial by nanoindentation

    NASA Astrophysics Data System (ADS)

    Sun, Xingdong; Zhao, Hongwei; Yu, Yang; Zhang, Shizhong; Ma, Zhichao; Li, Ning; Yu, Miao; Hou, Pengliang

    2016-11-01

    Because the out circumferential lamellae have a special protective effect on the cortical bone, it is very important to understand the variations of the mechanical property of the out circumferential lamellae in cortical bone. For the purpose, the elasticity modulus and hardness of out circumferential lamellae in cortical bone were investigated in two orthogonal planes by nanoindentation, and the comparisons were made for both elasticity modulus and hardness between the two orthogonal planes. From the experiments, the decreasing trend was discovered for elasticity modulus from inside to outside in the transverse plane and ruleless variations tendency was presented in the longitudinal plane. The hardness presented the same variations in two orthogonal planes with elasticity modulus in respective plane. In the same layer, the elasticity modulus in the transverse plane was higher than that in the longitudinal plane, and the difference values between them turned to be smaller. In contrast, the hardness in the longitudinal plane was higher than that in the transverse plane in all the layers. From the heterogeneity and the microstructure of the material, the influence factors were discussed. A soft to hard structure model was put forward, and the coordinating protection mechanism of buffer and support was described. Investigation of variations of mechanical properties of out circumferential lamellae in cortical bone can provide some new understanding in researches of fracture of bone, interface load effect and design of bone graft.

  7. Molecular Modeling of the Axial and Circumferential Elastic Moduli of Tubulin

    PubMed Central

    Zeiger, A. S.; Layton, B. E.

    2008-01-01

    Microtubules play a number of important mechanical roles in almost all cell types in nearly all major phylogenetic trees. We have used a molecular mechanics approach to perform tensile tests on individual tubulin monomers and determined values for the axial and circumferential moduli for all currently known complete sequences. The axial elastic moduli, in vacuo, were found to be 1.25 GPa and 1.34 GPa for α- and β-bovine tubulin monomers. In the circumferential direction, these moduli were 378 MPa for α- and 460 MPa for β-structures. Using bovine tubulin as a template, 269 homologous tubulin structures were also subjected to simulated tensile loads yielding an average axial elastic modulus of 1.10 ± 0.14 GPa for α-tubulin structures and 1.39 ± 0.68 GPa for β-tubulin. Circumferentially the α- and β-moduli were 936 ± 216 MPa and 658 ± 134 MPa, respectively. Our primary finding is that that the axial elastic modulus of tubulin diminishes as the length of the monomer increases. However, in the circumferential direction, no correlation exists. These predicted anisotropies and scale dependencies may assist in interpreting the macroscale behavior of microtubules during mitosis or cell growth. Additionally, an intergenomic approach to investigating the mechanical properties of proteins may provide a way to elucidate the evolutionary mechanical constraints imposed by nature upon individual subcellular components. PMID:18621829

  8. Saturn S-11 Production Operations Techniques, Production Welding. Volume 3: Circumferential Welding

    NASA Technical Reports Server (NTRS)

    Abel, D. G.

    1970-01-01

    Special processes and techniques are described for the circumferential welding of Saturn 2 cylinder and bulkhead assemblies to complete the LO2 and LH2 tankage and to maximize efficiency and personnel performance during S-2 follow-on or restart activities. The processes are only applicable to aluminum alloys within the 2000 series.

  9. A method for measuring mean circumferential fiber shortening rate from gated blood pool scans.

    PubMed

    Bhargava, V; Costello, D; Slutsky, R; Verba, J

    1982-01-01

    Ejection fraction and ejection rate are easily obtained from gated cardiac images, but no method is available for calculating mean circumferential fiber shortening rate. We assumed that the cube root of left ventricular end-diastolic volume or counts is proportional to the minor axis of the left ventricle at end-diastole or end-systole. Mean circumferential fiber shortening rate is then equal to the [cube root of the end-diastolic volume (count) minus cube root of end-systolic volume (count)] divided by [cube root of end-diastolic volume (count) multiplied by the ejection time]. In 250 contrast ventriculograms, the standard mean circumferential fiber shortening rate (MCFSR) and that derived by the cube root method correlated well (r = 0.94). The mean value of MCFSR (0.85 +/- 0.35) was greater than the cube root value (0.75 +/- 0.35) (P less than 0.001). The regression equation was y = 0.86x + 0.02. Similar correlations were obtained from gated radionuclide images using a semiautomated program (r = 0.93) in 24 subjects or completely automated program (r = 0.85) in 28 patients. The regression equation between MCFSR and that derived from the cube root of counts for the semiautomated program was y = 0.82x + 0.04 and for the automated program was y = 0.84x + 0.004. Similar correlations, slopes, and intercepts were seen using circumferential fractional shortening for angiographic data when correlated with both the semiautomated and automated gated blood pool scan programs. These data indicate that MCFSR and circumferential fractional shortening may be obtained from gated blood pool images using cube root estimates of end-diastolic and end-systolic radii with a high degree of correlation with the standard contrast ventriculographic technique.

  10. Mucosal breaks show same circumferential distribution in majority of patients with recurrent reflux esophagitis

    PubMed Central

    Fukuda, Naoki; Ishimura, Norihisa; Okada, Mayumi; Izumi, Daisuke; Mikami, Hironobu; Okimoto, Eiko; Aimi, Masahito; Mishiro, Tsuyoshi; Oshima, Naoki; Ishihara, Shunji; Kinoshita, Yoshikazu

    2017-01-01

    Background and study aims Esophageal mucosal breaks in patients with reflux esophagitis (RE) have a unique circumferential distribution. However, the specific location of mucosal breaks during recurrence of RE remains unclear. We investigated the circumferential distribution of mucosal breaks in patients with recurrent RE and compared their location to that noted at the initial diagnosis. Patients and methods We retrospectively enrolled patients with recurrent RE with Los Angeles (LA) grade A-C who were treated at our University Hospital between July 1996 and June 2014. The circumferential distribution of esophageal mucosal breaks was evaluated at the time of the initial diagnosis and again at the time of recurrence. Information regarding clinical parameters, including proton pump inhibitor administration, presence of hiatal hernia, and mucosal atrophy, was also reviewed. Results A total of 114 patients with recurrent RE were examined during the study period, with a mean duration to recurrence after initial diagnosis of 39.4 months. The majority (72.8 %) had the same LA grade at recurrence. In addition, recurrent mucosal breaks in 96 (84.2 %) patients were observed to have occurred in the same circumferential location as at the initial diagnosis, while those in 18 (15.8 %) were observed in a different location. When recurrent lesions had a different location, the LA grade also tended to be different (P = 0.02). Conclusions We found that most patients with recurrent RE developed lesions in the same circumferential location as noted for the initial lesions. Those in different locations at recurrence were associated with a change in LA grade. PMID:28317018

  11. Skin resurfacing in a circumferential full thickness burn to the penis: lessons learnt.

    PubMed

    Jabir, Shehab; Frew, Quentin; Thompson, Richard; Dziewulski, Peter

    2013-08-13

    A circumferential full-thickness burn to the penis is a rarely encountered injury. However, when it does occur, it proves a management challenge to the plastic and burns surgeon in terms of reconstruction. This is due to the need of not only regaining adequate function of the organ, but also because of the need for a pleasing aesthetic outcome. Split-skin grafts have been utilised successfully to resurface full thickness burns of the penis and have given good results. Yet the success of split-skin grafts, especially those applied to an anatomically challenging region of the body such as the penis, depends on a number of carefully thought-out steps. We discuss the case of a circumferential full-thickness burn to the penis which was treated with split-skin grafting and highlight important pitfalls that the plastic and burns surgeon need to be aware of to ensure a successful outcome.

  12. A "watch window" technique for monitoring buried free jejunum flaps during circumferential pharyngolaryngectomy reconstruction.

    PubMed

    Li, Quan; Zhang, Xin-Rui; Liu, Xue-Kui; Zhang, Zhi-Gang; Liu, Wei-Wei; Li, Hao; Guo, Zhu-Ming

    2012-07-01

    The free jejunum flap approach is the optimal option for circumferential pharyngolaryngectomy reconstruction. In this study, we designed a "watch window" for monitoring buried free jejunum flaps, thereby allowing us to assess graft viability. From 2007 to 2011, 14 patients with hypopharyngeal cancer underwent circumferential pharyngolaryngectomy that was reconstructed using a free jejunum flap at the Sun Yat-sen University Cancer Centre. During the closing of the neck incision, a "watch window" was designed for postoperative monitoring. Two patients experienced thrombosis of the pedicle. One was detected early and successfully rescued by removal of the thrombosis, the other one managed with a second free jejunum flap. The success rate of the buried flaps was 92.9%. No pharyngocutaneous fistulas or strictures occurred. All patients eventually resumed oral feeding and swallowing. The "watch window" technique for monitoring buried free jejunum flaps is simple, reliable and useful for finding vascular problems. Level of evidence Case series.

  13. Measurement of dispersion curves of circumferential guided waves radiating from curved shells: Theory and numerical validation.

    PubMed

    Chekroun, Mathieu; Minonzio, Jean-Gabriel; Prada, Claire; Laugier, Pascal; Grimal, Quentin

    2016-02-01

    A method is proposed to evaluate in a non-contact way the phase velocity dispersion curves of circumferential waves around a shell of arbitrary shape immersed in a fluid. No assumptions are made about the thickness or the material of the shell. A geometrical model is derived to describe the shape of the radiated wavefronts in the surrounding fluid, and predict the positions of its centers of curvature. Then the time-reversal principle is applied to recover these positions and to calculate the phase velocity of the circumferential waves. Numerical finite-difference simulations are performed to evaluate the method on a circular and on an elliptic thin shell. Different dispersion curves can be recovered with an error of less than 10%.

  14. Evaluation of circumferential airflow uniformity entering combustors from compressors. Volume 1: Discussion of data and results

    NASA Technical Reports Server (NTRS)

    Shadowen, J. H.; Egan, W. J., Jr.

    1972-01-01

    The compressor discharge airflow uniformity of two compressors from advanced engines, the J58 and F100/F401, was studied. Compressor discharge pressures and temperatures at up to 33 circumferential rake locations allowed the airflow distribution to be ascertained and computer plotted. Several flight conditions and compressor variables, i.e., inlet distortion, modified seals, etc., were analyzed. An unexpectedly high nonuniform airflow was found for both compressors. Circumferential airflow deviation differences of up to 52% from maximum to minimum were found for the J58, and up to 40% for the F100/F401. The effects of aerodynamic and thermal distortion were found to be additive. The data were analyzed for influence of exit guide vane wakes and found free of any effect. Data system errors were small in relation to the measured pressure and temperature variations.

  15. Assessment of accumulated damage in circular tubes using nonlinear circumferential guided wave approach: A feasibility study.

    PubMed

    Deng, Mingxi; Gao, Guangjian; Xiang, Yanxun; Li, Mingliang

    2017-03-01

    The feasibility of using the nonlinear effect of primary Circumferential Guided Wave (CGW) propagation for assessing accumulated damage in circular tubes has been investigated. For a given circular tube, an appropriate mode pair of fundamental and double frequency CGWs is chosen to enable that the second harmonic of the primary wave mode can accumulate along the circumferential direction. After the given circular tube is subjected to compression-compression repeated loading for different numbers of loading cycles, the corresponding ultrasonic measurements are conducted. It is found that there is a direct correlation between the acoustic nonlinearity parameter measured with CGWs propagating through one full circumference and the level of accumulated damage in the circular tube. The experimental result obtained validates the feasibility for quantitative assessment of the accumulated damage in circular tubes using the effect of second-harmonic generation by CGW propagation.

  16. The effect of circumferential distortion on fan performance at two levels of blade loading

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Sanger, N. L.

    1975-01-01

    Single stage fans designed for two levels of pressure ratio or blade loading were subjected to screen-induced circumferential distortions of 90-degree extent. Both fan rotors were designed for a blade tip speed of 425 m/sec, blade solidity of 1.3 and a hub-to-tip radius ratio of 0.5. Circumferential measurements of total pressure, temperature, static pressure, and flow angle were obtained at the hub, mean and tip radii at five axial stations. Rotor loading level did not appear to have a significant influence on rotor response to distorted flow. Losses in overall pressure ratio due to distortion were most severe in the stator hub region of the more highly loaded stage. At the near stall operating condition tip and hub regions of (either) rotor demonstrated different response characteristics to the distorted flow. No effect of loading was apparent on interactions between rotor and upstream distorted flow fields.

  17. Skin resurfacing in a circumferential full thickness burn to the penis: lessons learnt

    PubMed Central

    Jabir, Shehab; Frew, Quentin; Thompson, Richard; Dziewulski, Peter

    2013-01-01

    A circumferential full-thickness burn to the penis is a rarely encountered injury. However, when it does occur, it proves a management challenge to the plastic and burns surgeon in terms of reconstruction. This is due to the need of not only regaining adequate function of the organ, but also because of the need for a pleasing aesthetic outcome. Split-skin grafts have been utilised successfully to resurface full thickness burns of the penis and have given good results. Yet the success of split-skin grafts, especially those applied to an anatomically challenging region of the body such as the penis, depends on a number of carefully thought-out steps. We discuss the case of a circumferential full-thickness burn to the penis which was treated with split-skin grafting and highlight important pitfalls that the plastic and burns surgeon need to be aware of to ensure a successful outcome. PMID:23946511

  18. Ligation-assisted endoscopic submucosal resection with circumferential mucosal incision for duodenal carcinoid tumor.

    PubMed

    Harada, Hideaki; Suehiro, Satoshi; Shimizu, Takanori; Katsuyama, Yasushi; Hayasaka, Kenji; Ito, Hideto

    2015-09-14

    Here we present the case of a 64-year-old female with a duodenal carcinoid tumor treated by ligation-assisted endoscopic submucosal resection (ESMR-L) with circumferential mucosal incision (CMI). Band ligation was effective in resecting the duodenal carcinoid tumor after CMI, with an uneventful post-procedural course. Histopathological examination showed clear tumor margins at deeper tissue levels. Thus, in the present case, ESMR-L with CMI was useful for the treatment of duodenal carcinoid tumor.

  19. Regulatory Activities Related to Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles

    SciTech Connect

    Hiser, Allen L. Jr.

    2002-07-01

    The recent discoveries of cracked and leaking Alloy 600 vessel head penetration (VHP) nozzles, including control rod drive mechanism (CRDM) and thermocouple nozzles, at four pressurized water reactors (PWRs) have raised concerns about the structural integrity of VHP nozzles throughout the PWR industry. Nozzle cracking at Oconee Nuclear Station Unit 1 in November 2000 and Arkansas Nuclear One Unit 1 in February 2001 was limited to axial cracking, an occurrence deemed to be of limited safety concern in the NRC staff's generic safety evaluation on the cracking of VHP nozzles dated November 19, 1993. However, the discovery of circumferential cracking at Oconee Nuclear Station Unit 3 in February 2001 and Oconee Nuclear Station Unit 2 in April 2001 particularly the large circumferential cracking identified in two CRDM nozzles at ONS3 has raised concerns about the potential safety implications and prevalence of cracking in VHP nozzles in PWRs. In response to the circumferential cracking identified at the Oconee units, the NRC issued Bulletin 2001-01, 'Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles', on August 3, 2001. This bulletin requests information from licensees related to the structural integrity of the reactor pressure VHP nozzles for their facilities, including the extent of VHP nozzle leakage and cracking that has been found to date, the inspections and repairs that have been undertaken to satisfy applicable regulatory requirements, future plans to inspect VHP nozzles, and a description of how future inspection plans will ensure compliance with applicable regulatory requirements. This paper summarizes the staff's review and assessment of licensee responses to NRC Bulletin 2001-01. (author)

  20. The elasticity problem for a thick-walled cylinder containing a circumferential crack

    NASA Technical Reports Server (NTRS)

    Nied, H. F.; Erdogan, F.

    1982-01-01

    The elasticity problem for a long hollow circular cylinder containing an axisymmetric circumferential crack subjected to general nonaxisymmetric external loads is considered. The problem is formulated in terms of a system of singular integral equations with the Fourier coefficients of the derivative of the crack surface displacement as density functions. The stress intensity factors and the crack opening displacement are calculated for a cylinder under uniform tension, bending by end couples, and self-equilibrating residual stresses.

  1. Role of circumferential flow in the stability of fluid-handling machine rotors

    NASA Technical Reports Server (NTRS)

    Bently, D. E.; Muszynska, A.

    1989-01-01

    The recent studies of the dynamic stiffness properties of fluid lubricated bearing and seals by the authors have yielded most of the generalized characteristics discussed and used in this paper. They include bearing and seal nonlinear fluid film properties associated with stiffness, damping, and fluid average circumferential velocity ratio. Analytical relationships yield the rotor system's dynamic stiffness characteristics. This paper shows the combination of these data to provide the fluid-induced rotor stability equations.

  2. Influence of the heart rate on mean circumferential shortening velocity: echocardiographic study of 183 normal subjects.

    PubMed

    Mangiarotti, R; Martinotti, R; Monzani, V; Sardella, F; Pierini, A; Pastori, M; Randazzo, A

    1986-01-01

    Echocardiography was used to explore the influence of independent variables (age, body surface area and heart rate) on the mean circumferential shortening velocity (MVCF) in 183 healthy subjects. Multiple stepwise regression analysis shows that heart rate is the only variable of the three just mentioned that influences MVCF. A regression equation is evolved and proposed as an index of MVCF correction for varying heart rates.

  3. Circumferential phased array of shear-horizontal wave magnetostrictive patch transducers for pipe inspection.

    PubMed

    Kim, Hoe Woong; Lee, Joo Kyung; Kim, Yoon Young

    2013-02-01

    Several investigations report effective uses of magnetostrictive patch transducers to generate and measure longitudinal and torsional guided waves in a pipe. They can be used to form a phased array for the circumferential inspection of pipes. Although there are circumferential phased arrays employing piezoelectric transducers or EMAT's, no magnetostrictive patch transducer based array system has been attempted. In this investigation, we aim to develop a circumferential phased magnetostrictive patch transducer (PMPT) array that can focus shear-horizontal waves at any target point on a cylindrical surface of a pipe. For the development, a specific configuration of a PMPT array employing six magnetostrictive patch transducers is proposed. A wave simulation model is also developed to determine time delays and amplitudes of signals generated by the transducers of the array. This model should be able to predict accurately the angular profiles of shear-horizontal waves generated by the transducers. For wave focusing, the time reversal idea will be utilized. The wave focusing ability of the developed PMPT array is tested with multiple-crack detection experiments. Imaging of localized surface inspection regions is also attempted by using wave signals measured by the developed PMPT array system.

  4. A novel in vitro model for microvasculature reveals regulation of circumferential ECM organization by curvature.

    PubMed

    Barreto-Ortiz, Sebastian F; Zhang, Shuming; Davenport, Matthew; Fradkin, Jamie; Ginn, Brian; Mao, Hai-Quan; Gerecht, Sharon

    2013-01-01

    In microvascular vessels, endothelial cells are aligned longitudinally whereas several components of the extracellular matrix (ECM) are organized circumferentially. While current three-dimensional (3D) in vitro models for microvasculature have allowed the study of ECM-regulated tubulogenesis, they have limited control over topographical cues presented by the ECM and impart a barrier for the high-resolution and dynamic study of multicellular and extracellular organization. Here we exploit a 3D fibrin microfiber scaffold to develop a novel in vitro model of the microvasculature that recapitulates endothelial alignment and ECM deposition in a setting that also allows the sequential co-culture of mural cells. We show that the microfibers' nanotopography induces longitudinal adhesion and alignment of endothelial colony-forming cells (ECFCs), and that these deposit circumferentially organized ECM. We found that ECM wrapping on the microfibers is independent of ECFCs' actin and microtubule organization, but it is dependent on the curvature of the microfiber. Microfibers with smaller diameters (100-400 µm) guided circumferential ECM deposition, whereas microfibers with larger diameters (450 µm) failed to support wrapping ECM. Finally, we demonstrate that vascular smooth muscle cells attached on ECFC-seeded microfibers, depositing collagen I and elastin. Collectively, we establish a novel in vitro model for the sequential control and study of microvasculature development and reveal the unprecedented role of the endothelium in organized ECM deposition regulated by the microfiber curvature.

  5. Nonlinear Bulging Factors for Longitudinal and Circumferential Cracks in Cylindrical Shells Subjected to Combined Loads

    NASA Technical Reports Server (NTRS)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased crack-tip stresses due to curvature for longitudinal and circumferential cracks in unstiffened cylindrical shells subjected to combined loads are presented. Nondimensional parameters varied in the study include the shell curvature parameter, l , which is a function of the shell radius, the shell wall thickness, and the crack length; a pressure loading parameter, h , which is a function of the shell geometry, material properties and the applied internal pressure; and a biaxial loading parameter, c , which is the ratio of the farfield axial stress to the farfield circumferential stress. The major results are presented in the form of contour plots of the bulging factor as a function of these three nondimensional parameters. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant, and show the effect of the biaxial loads on the value of the bulging factor. Simple empirical expressions for the bulging factor are then derived from the numerical results and are shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks.

  6. Nonlinear vibrations and energy exchange of single-walled carbon nanotubes. Circumferential flexural modes

    NASA Astrophysics Data System (ADS)

    Strozzi, Matteo; Smirnov, Valeri V.; Manevitch, Leonid I.; Milani, Massimo; Pellicano, Francesco

    2016-10-01

    In this paper, the nonlinear vibrations and energy exchange of single-walled carbon nanotubes (SWNTs) are studied. The Sanders-Koiter theory is applied to model the nonlinear dynamics of the system in the case of finite amplitude of vibration. The SWNT deformation is described in terms of longitudinal, circumferential and radial displacement fields. Simply supported, clamped and free boundary conditions are considered. The circumferential flexural modes (CFMs) are investigated. Two different approaches based on numerical and analytical models are compared. In the numerical model, an energy method based on the Lagrange equations is used to reduce the nonlinear partial differential equations of motion to a set of nonlinear ordinary differential equations, which is solved by using the implicit Runge-Kutta numerical method. In the analytical model, a reduced form of the Sanders-Koiter theory assuming small circumferential and tangential shear deformations is used to get the nonlinear ordinary differential equations of motion, which are solved by using the multiple scales analytical method. The transition from energy beating to energy localization in the nonlinear field is studied. The effect of the aspect ratio on the analytical and numerical values of the nonlinear energy localization threshold for different boundary conditions is investigated. Time evolution of the total energy distribution along the axis of a simply supported SWNT

  7. Laminar mixed convection in horizontal concentric annuli with non-uniform circumferential heating

    NASA Astrophysics Data System (ADS)

    Habib, M. A.; Negm, A. A. A.

    Steady, laminar, mixed convection in the fully developed region of horizontal concentric annuli has been investigated numerically for the case of non-uniform circumferential heating. Two heating conditions were studied, one in which a 180∘ arc encompassing the top half of inner surface of the inner cylinder is uniformly heated while the bottom half is kept insulated, and the other in which the heated and the insulated surfaces were reversed. The fluid flow and heat transfer characteristics were found to be affected by the heating conditions. For the investigated range of the governing buoyancy parameter, the modified Grashof number (Gr*), it was found that bottom heating arrangement gives rise to a vigorous secondary flow, with the result that the average Nusselt numbers are much higher than those for pure forced convection. On the other hand, the local Nusselt numbers are nearly circumferentially uniform. In the case of top heating arrangement, a less vigorous secondary flow is induced because of temperature stratification, with average Nusselt numbers that are substantially lower than those for bottom heating and with large circumferential variation of the local Nusselt number.

  8. Lumbar extracavitary corpectomy with a single stage circumferential arthrodesis: surgical technique and clinical series.

    PubMed

    Singh, Kern; Park, Daniel K

    2012-07-01

    Circumferential arthrodesis and reconstruction is necessary after a lumbar corpectomy in the setting of malignancy and infection. The advent of expandable cage technology now allows for safe anterior column reconstruction via a posterior approach with no transection and minimal retraction of the lumbar spinal nerve roots. Fifteen patients underwent a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach. Posterior segmental pedicle screw fixation and iliac crest bone graft was used in all cases. Fifteen lumbar extracavitary corpectomy nerve root-sparing procedures have been performed to date, with at least 1-year follow-up (12 tumors/3 infections). No patient suffered any neurological complications. One patient suffered from a postoperative myocardial infarction 10 days after the procedure. Two patients had medical complications that were treated without sequelae. We present a technical description and case series of patients undergoing a single-stage, circumferential corpectomy and anterior spinal reconstruction with an expandable cage via a midline, posterior, lateral lumbar extracavitary approach with at least 1-year follow-up. The technique is safe, technically feasible, and obviates an anterior approach in this oftentimes critically ill patient population.

  9. Circumferential alignment of vascular smooth muscle cells in a circular microfluidic channel.

    PubMed

    Choi, Jong Seob; Piao, Yunxian; Seo, Tae Seok

    2014-01-01

    The circumferential alignment of human aortic smooth muscle cells (HASMCs) in an orthogonally micropatterned circular microfluidic channel is reported to form an in vivo-like smooth muscle cell layer. To construct a biomimetic smooth muscle cell layer which is aligned perpendicular to the axis of blood vessel, a half-circular polydimethylsiloxane (PDMS) microchannel is first fabricated by soft lithography using a convex PDMS mold. Then, the orthogonally microwrinkle patterns are generated inside the half-circular microchannel by a strain responsive wrinkling method. During the UV treatment on a PDMS substrate with uniaxial 40% stretch and a subsequent strain releasing step, the microwrinkle patterns perpendicular to the axial direction of the circular microchannel are generated, which can guide the circumferential alignment of HASMCs during cultivation. The analysis of orientation angle, shape index, and contractile protein marker expression indicates that the cultured HASMCs reveal the in vivo-like cell phenotype. Finally, a fully circular microchannel is produced by bonding two half-circular microchannels, and the HASMCs are cultured circumferentially inside the channels with high alignment and viability for 5 days. These results demonstrated the creation of an in vivo-like 3D smooth muscle cell layer in the circular microfluidic channel which can provide a bioassay platforms for in-depth study of HASMC biology and vascular function.

  10. Shoulder replacement - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000178.htm Shoulder replacement - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder replacement surgery to replace the bones of your shoulder ...

  11. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  12. Hip replacement - discharge

    MedlinePlus

    ... surgery to replace all or part of your hip joint with an artificial joint called a prosthesis. This ... You're in the Hospital You had a hip joint replacement surgery to replace all or part of ...

  13. Influence of the circumferential speed of a resin bond grinding wheel on the properties of a ground aspheric surface

    NASA Astrophysics Data System (ADS)

    Matousek, Ondrej; Tomka, David; Prochaska, Frantisek; Polak, Jaroslav

    2015-01-01

    In recent times, resin bond grinding wheels have often been used for the precise grinding of aspheric surfaces. In this paper, the influence of changes in the circumferential speed of the resin bond grinding wheel on the microroughness of the produced surface and also on the volume of the structures and the scratches is presented. The article also discusses how the cutting wear of the tool affects the surface quality and shows the correlation between the circumferential speed and the rate of degradation of the resin bond grinding wheel. A circumferential speed interval from 12 m/s to 24 m/s was investigated and the effect of tool degradation was observed at 1.9-hour intervals. The results of the experiment show that the optimal circumferential speed of the tool lies around 20 m/s. At this speed, the tool produces a perfectly polishable surface and tool degradation is minimized.

  14. On guided circumferential waves in soft electroactive tubes under radially inhomogeneous biasing fields

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Su, Yipin; Chen, Weiqiu; Zhang, Chuanzeng

    2017-02-01

    Soft electroactive (EA) tube actuators and many other cylindrical devices have been proposed recently in literature, which show great advantages over those made from conventional hard solid materials. However, their practical applications may be limited because these soft EA devices are prone to various failure modes. In this paper, we present an analysis of the guided circumferential elastic waves in soft EA tube actuators, which has potential applications in the in-situ nondestructive evaluation (NDE) or online structural health monitoring (SHM) to detect structural defects or fatigue cracks in soft EA tube actuators and in the self-sensing of soft EA tube actuators based on the concept of guided circumferential elastic waves. Both circumferential SH and Lamb-type waves in an incompressible soft EA cylindrical tube under inhomogeneous biasing fields are considered. The biasing fields, induced by the application of an electric voltage difference to the electrodes on the inner and outer cylindrical surfaces of the EA tube in addition to an axial pre-stretch, are inhomogeneous in the radial direction. Dorfmann and Ogden's theory of nonlinear electroelasticity and the associated linear theory for small incremental motion constitute the basis of our analysis. By means of the state-space formalism for the incremental wave motion along with the approximate laminate technique, dispersion relations are derived in a particularly efficient way. For a neo-Hookean ideal dielectric model, the proposed approach is first validated numerically. Numerical examples are then given to show that the guided circumferential wave propagation characteristics are significantly affected by the inhomogeneous biasing fields and the geometrical parameters. Some particular phenomena such as the frequency veering and the nonlinear dependence of the phase velocity on the radial electric voltage are discussed. Our numerical findings demonstrate that it is feasible to use guided circumferential

  15. Scalp ulceration from a circumferential head dressing after craniotomy: Case report of an uncommon complication due to human error.

    PubMed

    Singhal, Ashutosh; Bray, Peter W; Bernstein, Mark

    2004-01-01

    The present paper describes a previously unpublished complication of the application of a circumferential head dressing after cranial neuro-surgery. A 34-year-old woman developed a large area of skin necrosis on her forehead from a circumferential head dressing applied after the surgical removal of a colloid cyst. Neurological recovery was excellent but plastic surgical repair of her iatrogenic cosmetic injury was required.

  16. Soft Tissue Reconstruction of Complete Circumferential Defects of the Upper Extremity

    PubMed Central

    Ng, Zhi Yang; Tan, Shaun Shi Yan; Lellouch, Alexandre Gaston; Chim, Harvey Wei Ming

    2017-01-01

    Background Upper extremity soft tissue defects with complete circumferential involvement are not common. Coupled with the unique anatomy of the upper extremity, the underlying etiology of such circumferential soft tissue defects represent additional reconstructive challenges that require treatment to be tailored to both the patient and the wound. The aim of this study is to review the various options for soft tissue reconstruction of complete circumferential defects in the upper extremity. Methods A literature review of PubMed and MEDLINE up to December 2016 was performed. The current study focuses on forearm and arm defects from the level at or proximal to the wrist and were assessed based on Tajima's classification (J Trauma 1974). Data reviewed for analysis included patient demographics, causality, defect size, reconstructive technique(s) employed, and postoperative follow-up and functional outcomes (when available). Results In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 14 unique articles were identified for a total of 50 patients (mean=28.1 years). Underlying etiologies varied from extensive thermal or electrical burns to high impact trauma leading to degloving or avulsion, crush injuries, or even occur iatrogenically after tumor extirpation or extensive debridement. Treatment options ranged from the application of negative pressure wound dressings to the opposite end of the spectrum in hand transplantation. Conclusions With the evolution of reconstructive techniques over time, the extent of functional and aesthetic rehabilitation of these complex upper extremity injuries has also improved. The proposed management algorithm comprehensively addresses the inherent challenges associated with these complex cases. PMID:28352600

  17. Single stage circumferential lingual mucosal graft urethroplasty in near obliterative bulbar urethra stricture: A novel technique

    PubMed Central

    Sharma, Umesh; Yadav, Sher Singh; Tomar, Vinay; Garg, Amit

    2016-01-01

    Aims: This is a prospective study of the use and efficacy of a novel technique of circumferential tubularised lingual mucosal graft (LMG) in obliterative and near obliterative bulbar urethral stricture of >2 cm where excisional and augmented anastomotic urethroplasty are not feasible. Materials and Methods: The stenotic urethral segment was opened dorsally in midline and fibrosed urethra was excised taking care to preserve the healthy spongiosum tissue. LMG (av. Length 3 cm) was placed from one end of corporal body towards spongy tissue in a circumferential manner. Another LMG was placed in similar manner to deal with longer stricture. The urethra was tubularised over 14 Fr silicone catheter. Results: A total of 12 men, of mean age 47 years underwent this procedure. The mean follow up period was 11 months starting from July 2014 till manuscript submission. Follow up included voiding cystourethrogram at 3 weeks, cystoscopy at 3 months (one patient didn’t turned up) and subsequent follow up. Mean stricture length was 4.66 cm (range, 3–8.5 cm) and mean operative time was 195 min. (range, 160 to 200 min.). The technique was successful (normal voiding with no need for any post-operative procedure) in 11(91.6%) patients. One patient developed early recurrence at 4 month of surgery and had anastomotic stricture which was successfully managed by direct visual internal urethrotomy. Conclusion: Single stage circumferential tubularised graft urethroplasty is an excellent technique for strictures that include segments of obliterative and near obliterative diseased urethra. It provide a wider neourethra than patch graft urethroplasty. PMID:27141182

  18. Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis

    PubMed Central

    Skovrlj, Branko; Guzman, Javier Z.; Caridi, John; Cho, Samuel K.

    2015-01-01

    Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach. PMID:26835214

  19. Generalized thermoelastic wave propagation in circumferential direction of transversely isotropic cylindrical curved plates

    NASA Astrophysics Data System (ADS)

    Sharma, J. N.; Pathania, Vijayata

    2005-03-01

    The propagation of thermoelastic waves along circumferential direction in homogeneous, transversely isotropic, cylindrical curved plates has been investigated in the context of theories of thermoelasticity. This type of study is important for ultrasonic non-destructive inspection of large-diameter pipes, which helps in the health monitoring of ailing infrastructure. Longitudinal stress-corrosion cracks are usually temperature dependent and can be detected more efficiently by inducing circumferential waves; hence the study of generalized thermoelastic wave propagation in the circumferential direction in a pipe wall is essential. Mathematical modeling of the problem of obtaining dispersion curves for curved transversely isotropic thermally conducting elastic plates leads to coupled differential equations. The model has been simplified by using the Helmholtz decomposition technique and the resulting equations have been solved by using separation of variable method to obtain the secular equations in isolated mathematical conditions for the plates with stress-free or rigidly fixed, thermally insulated and isothermal boundary surfaces. The closed form solutions are also obtained under different situations and conditions. The longitudinal shear motion and axially symmetric shear vibration modes get decoupled from the rest of the motion and are not affected by thermal variations, whereas for the non-axially symmetric case of plane strain vibrations, these modes remain coupled and are affected by temperature changes. Moreover, these vibration modes are found to be dispersive and dissipative in character. In order to illustrate theoretical development, numerical solutions are obtained and presented graphically for a zinc plate. The obtained results are also compared with those available in the literature in case of waves in cylindrical shell/circular annulus in the absence of thermomechanical coupling and thermal relaxation times.

  20. Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis.

    PubMed

    Skovrlj, Branko; Guzman, Javier Z; Caridi, John; Cho, Samuel K

    2016-02-01

    Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach.

  1. Aspects of circumferential waves in determining buckling capacity of cylindrical shells

    SciTech Connect

    Xu, J.; Bandyopadhyay, K.K.

    1996-12-01

    In an effort to quantify the failure behavior of a cylindrical shell when geometric imperfections are present and is subjected to a combination of axial load and internal pressure, the authors have carried out a series of analyses to investigate the effects of various load combinations and material behavior on the shell`s buckling capacity. To complete the characterization of buckling behavior of cylindrical shells, an evaluation was performed to examine the deformation modes in terms of circumferential waves in relation to the shell`s buckling capacity. This paper presents the results of the investigation.

  2. Limit pressure of a circumferentially reinforced SiC/Ti ring

    NASA Technical Reports Server (NTRS)

    Robinson, D. N.; Pastor, M. S.

    1991-01-01

    Limit loads under plane stress and plane strain are found for a circumferentially reinforced elastoplastic ring subjected to interior pressure. These are used as bounds on an estimate of the failure pressure of a SiC/Ti test rig that is being fabricated and tested. The ring is to serve as a benchmark against which deformation and failure analysis methods can be assessed. An anisotropic perfect plasticity idealization of the SiC/Ti ring material is made and used in the limit load calculations. An estimate of the failure pressure of the NASA/PW benchmark test ring is given.

  3. Growth behavior of surface cracks in the circumferential plane of solid and hollow cylinders

    NASA Technical Reports Server (NTRS)

    Forman, R. G.; Shivakumar, V.

    1986-01-01

    Experiments were conducted to study the growth behavior of surface fatigue cracks in the circumferential plane of solid and hollow cylinders. In the solid cylinders, the fatigue cracks were found to have a circular arc crack front with specific upper and lower limits to the arc radius. In the hollow cylinders, the fatigue cracks were found to agree accurately with the shape of a transformed semiellipse. A modification to the usual nondimensionalization expression used for surface flaws in flat plates was found to give correct trends for the hollow cylinder problem.

  4. Investigations on an axial flow fan stage subjected to circumferential inlet flow distortion and swirl

    NASA Astrophysics Data System (ADS)

    Govardhan, M.; Viswanath, K.

    1997-12-01

    The combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage are reported in this paper. The study involves measurements at the inlet of the rotor and exit of the rotor and stator at design and off design flow conditions. The study indicated that at the design flow condition, swirl had caused deterioration of the performance in addition to that caused by distortion. Pressure rise imparted in the distortion zone is higher than in the free zone. The attenuation of distortion is high in the presence of swirl.

  5. Experimental study of flow distribution and pressure loss with circumferential inlet and outlet manifolds

    NASA Technical Reports Server (NTRS)

    Dittrich, R. T.

    1972-01-01

    Water flow tests with circumferential inlet and outlet manifolds were conducted to determine factors affecting fluid distribution and pressure losses. Various orifice sizes and manifold geometries were tested over a range of flow velocities. With inlet manifolds, flow distribution was related directly to orifice discharge coefficients. A correlation indicated that nonuniform distribution resulted when the velocity head ratio at the orifice was not in the range of constant discharge coefficient. With outlet manifolds, nonuniform flow was related to static pressure variations along the manifold. Outlet manifolds had appreciably greater pressure losses than comparable inlet manifolds.

  6. Determination of the axial and circumferential mechanical properties of the skin tissue using experimental testing and constitutive modeling.

    PubMed

    Karimi, Alireza; Navidbakhsh, Mahdi; Haghighatnama, Maedeh; Haghi, Afsaneh Motevalli

    2015-01-01

    The skin, being a multi-layered material, is responsible for protecting the human body from the mechanical, bacterial, and viral insults. The skin tissue may display different mechanical properties according to the anatomical locations of a body. However, these mechanical properties in different anatomical regions and at different loading directions (axial and circumferential) of the mice body to date have not been determined. In this study, the axial and circumferential loads were imposed on the mice skin samples. The elastic modulus and maximum stress of the skin tissues were measured before the failure occurred. The nonlinear mechanical behavior of the skin tissues was also computationally investigated through a suitable constitutive equation. Hyperelastic material model was calibrated using the experimental data. Regardless of the anatomic locations of the mice body, the results revealed significantly different mechanical properties in the axial and circumferential directions and, consequently, the mice skin tissue behaves like a pure anisotropic material. The highest elastic modulus was observed in the back skin under the circumferential direction (6.67 MPa), while the lowest one was seen in the abdomen skin under circumferential loading (0.80 MPa). The Ogden material model was narrowly captured the nonlinear mechanical response of the skin at different loading directions. The results help to understand the isotropic/anisotropic mechanical behavior of the skin tissue at different anatomical locations. They also have implications for a diversity of disciplines, i.e., dermatology, cosmetics industry, clinical decision making, and clinical intervention.

  7. Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

    NASA Technical Reports Server (NTRS)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

  8. Circumferential wall tension due to hypertension plays a pivotal role in aorta remodelling.

    PubMed

    Prado, Cibele M; Rossi, Marcos A

    2006-12-01

    The present study was carried out to investigate the role of hypertension in the genesis and localization of intimal lesions and medial remodelling found in the prestenotic segment in relation to a severe stenosis of the abdominal aorta just below the diaphragm. Male young rats were divided randomly into operated group, animals submitted to surgical abdominal aorta stenosis, and sham-operated group, a control group of animals submitted to sham operation to simulate abdominal aorta stenosis. Aortas in the hypertensive prestenotic segment with increased circumferential wall tension associated with normal tensile stress, laminar flow/normal wall shear stress were characterized by enlarged heterogeneous endothelial cells elongated in the direction of the blood flow, diffusely distributed conspicuous neointimal plaques and medial thickening. The immunohistochemical analysis revealed an increased expression of eNOS, iNOS, nitrotyrosine and transforming growth factor-beta (TGF-beta) in endothelial cells and/or smooth muscle cells in this segment. Our findings suggest that increased circumferential wall tension due to hypertension plays a pivotal role in the remodelling of the prestenotic segment through biomechanical effects on oxidative stress and increased TGF-beta expression. Further studies are needed to clarify the intrinsic pathogenetic mechanism of focal distribution of the neointimal plaques in the hypertensive segment.

  9. Efficacy of circumferential pulmonary vein ablation of atrial fibrillation in endurance athletes

    PubMed Central

    Calvo, Naiara; Mont, Lluís; Tamborero, David; Berruezo, Antonio; Viola, Graziana; Guasch, Eduard; Nadal, Mercè; Andreu, David; Vidal, Barbara; Sitges, Marta; Brugada, Josep

    2010-01-01

    Aims Long-term endurance sport practice has been increasingly recognized as a risk factor for lone atrial fibrillation (AF). However, data on the outcome of circumferential pulmonary vein ablation (CPVA) in endurance athletes are scarce. The aim of the study was to evaluate the efficacy of CPVA in AF secondary to endurance sport practice. Methods and results Patients submitted to CPVA answered a questionnaire about lifetime history of endurance sport practice. Endurance athletes were defined as those who engaged in >3 h per week of high-intensity exercise for at least the 10 years immediately preceding their AF diagnosis. A series of 182 consecutive patients was included (51 ± 11 years, 65% with paroxysmal AF, 81% men, 42 ± 6 mm mean left atrial diameter); 107 (59%) patients had lone AF, and 42 of them (23% of the study population) were classified as endurance athletes (lone AF sport group). Freedom from arrhythmia after a single CPVA was similar in the lone AF sport group compared with the remaining patients (P = 0.446). Left atrial size and long-standing AF were the only independent predictors for arrhythmia recurrence after ablation. Conclusion Circumferential pulmonary vein ablation was as effective in AF secondary to endurance sport practice as in other aetiologies of AF. PMID:19923171

  10. Parameter measurement of the cylindrically curved thin layer using low-frequency circumferential Lamb waves.

    PubMed

    Chen, Xiao; Wan, Mingxi

    2005-03-01

    The characteristic parameters of a cylindrically curved thin layer include its elastic constants, thickness and curved radius. A layer is considered thin if the echoes from the front and back surfaces of the layer cannot be separated in the time domain, and/or that the wave arrivals corresponding to longitudinal and shear wave part cannot be identified in the time or space domain. This paper describes a low-frequency circumferential Lamb wave method to characterize those parameters of a cylindrically curved thin layer. The technique is based on the measurement of circumferential Lamb wave phase velocity and the unknown parameter is estimated through minimizing the mean square error obtained by comparing theoretical and experimental phase velocities. The sensitivity and accuracy of the proposed technique to different parameters are analyzed. Using the present technique, a cylindrically curved thin layer with thickness down to ten percent of the longitudinal wavelength can be successfully measured with an average relative error less than two-percent in our experiment.

  11. Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

    PubMed

    Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

  12. Smooth Muscle-Like Tissue Constructs with Circumferentially Oriented Cells Formed by the Cell Fiber Technology

    PubMed Central

    Hsiao, Amy Y.; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments. PMID:25734774

  13. Recent evaluations of crack-opening-area in circumferentially cracked pipes

    SciTech Connect

    Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

    1997-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

  14. Status of the steam generator tube circumferential ODSCC degradation experienced at the Doel 4 plant

    SciTech Connect

    Roussel, G.

    1997-02-01

    Since the 1991 outage, the Doel Unit 4 nuclear power plant is known to be affected by circumferential outside diameter intergranular stress corrosion cracking at the hot leg tube expansion transition. Extensive non destructive examination inspections have shown the number of tubes affected by this problem as well as the size of the cracks to have been increasing for the three cycles up to 1993. As a result of the high percentage of tubes found non acceptable for continued service after the 1993 in-service inspection, about 1,700 mechanical sleeves were installed in the steam generators. During the 1994 outage, all the tubes sleeved during the 1993 outage were considered as potentially cracked to some extent at the upper hydraulic transition and were therefore not acceptable for continued service. They were subsequently repaired by laser welding. Furthermore all the tubes not sleeved during the 1993 outage were considered as not acceptable for continued service and were repaired by installing laser welded sleeves. During the 1995 outage, some unexpected degradation phenomena were evidenced in the sleeved tubes. This paper summarizes the status of the circumferential ODSCC experienced in the SG tubes of the Doel 4 plant as well as the other connected degradation phenomena.

  15. Circumferential flow of particles in the suprachoroidal space is impeded by the posterior ciliary arteries

    PubMed Central

    Chiang, Bryce; Kim, Yoo Chun; Edelhauser, Henry F.; Prausnitz, Mark R.

    2016-01-01

    Microneedle injection into the suprachoroidal space (SCS) enables targeted drug delivery for treatment of posterior segment diseases (e.g., posterior uveitis). This study sought to identify and characterize anatomical barriers to circumferential spread of particles in the SCS of rabbit and human cadaver eyes. These barriers could make targeting specific regions within the SCS challenging. A hollow microneedle (33-gauge, 750 μm long) was used to inject fluorescent particles into albino New Zealand White rabbit eyes ex vivo at six different positions around the limbus and a limited number of conditions in vivo. SCS injections were also performed in human cadaver eyes 8 mm and 2 mm from the optic nerve (ON). Eyes were dissected and particle distribution was quantified. In rabbit eyes, injections made in the superior or inferior hemispheres (even when injected temporally immediately adjacent to the long posterior ciliary artery (LPCA)) did not significantly cross into the other hemisphere, apparently due to a barrier formed by the LPCA. The vortex veins had a minor effect on particle deposition, limited to only around the vortex vein root. In human eyes, the short posterior ciliary arteries (SPCAs) prevented circumferential spread towards the macula and ON. In conclusion, the rabbit LPCA and the human SPCA were anatomical barriers to particle spread within the SCS. Therefore, design of drug delivery protocols targeting the SCS need to account for barriers formed by anatomical structures in order for injected drug to reach target tissues. PMID:26976663

  16. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    SciTech Connect

    Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M.

    1996-12-01

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

  17. Mutations in Either TUBB or MAPRE2 Cause Circumferential Skin Creases Kunze Type

    PubMed Central

    Isrie, Mala; Breuss, Martin; Tian, Guoling; Hansen, Andi Harley; Cristofoli, Francesca; Morandell, Jasmin; Kupchinsky, Zachari A.; Sifrim, Alejandro; Rodriguez-Rodriguez, Celia Maria; Dapena, Elena Porta; Doonanco, Kurston; Leonard, Norma; Tinsa, Faten; Moortgat, Stéphanie; Ulucan, Hakan; Koparir, Erkan; Karaca, Ender; Katsanis, Nicholas; Marton, Valeria; Vermeesch, Joris Robert; Davis, Erica E.; Cowan, Nicholas J.; Keays, David Anthony; Van Esch, Hilde

    2015-01-01

    Circumferential skin creases Kunze type (CSC-KT) is a specific congenital entity with an unknown genetic cause. The disease phenotype comprises characteristic circumferential skin creases accompanied by intellectual disability, a cleft palate, short stature, and dysmorphic features. Here, we report that mutations in either MAPRE2 or TUBB underlie the genetic origin of this syndrome. MAPRE2 encodes a member of the microtubule end-binding family of proteins that bind to the guanosine triphosphate cap at growing microtubule plus ends, and TUBB encodes a β-tubulin isotype that is expressed abundantly in the developing brain. Functional analyses of the TUBB mutants show multiple defects in the chaperone-dependent tubulin heterodimer folding and assembly pathway that leads to a compromised yield of native heterodimers. The TUBB mutations also have an impact on microtubule dynamics. For MAPRE2, we show that the mutations result in enhanced MAPRE2 binding to microtubules, implying an increased dwell time at microtubule plus ends. Further, in vivo analysis of MAPRE2 mutations in a zebrafish model of craniofacial development shows that the variants most likely perturb the patterning of branchial arches, either through excessive activity (under a recessive paradigm) or through haploinsufficiency (dominant de novo paradigm). Taken together, our data add CSC-KT to the growing list of tubulinopathies and highlight how multiple inheritance paradigms can affect dosage-sensitive biological systems so as to result in the same clinical defect. PMID:26637975

  18. Partial knee replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  19. The pattern of circumferential and radial eruptive fissures on the volcanoes of Fernandina and Isabela islands, Galapagos

    USGS Publications Warehouse

    Chadwick, W.W.; Howard, K.A.

    1991-01-01

    Maps of the eruptive vents on the active shield volcanoes of Fernandina and Isabela islands, Galapagos, made from aerial photographs, display a distinctive pattern that consists of circumferential eruptive fissures around the summit calderas and radial fissures lower on the flanks. On some volcano flanks either circumferential or radial eruptions have been dominant in recent time. The location of circumferential vents outside the calderas is independent of caldera-related normal faults. The eruptive fissures are the surface expression of dike emplacement, and the dike orientations are interpreted to be controlled by the state of stress in the volcano. Very few subaerial volcanoes display a pattern of fissures similar to that of the Galapagos volcanoes. Some seamounts and shield volcanoes on Mars morphologically resemble the Galapagos volcanoes, but more specific evidence is needed to determine if they also share common structure and eruptive style. ?? 1991 Springer-Verlag.

  20. New circumferential seal design concept using self-acting lift geometries

    NASA Technical Reports Server (NTRS)

    Hady, W. F.; Ludwig, L. P.

    1972-01-01

    Seal operating temperatures, leakage (pressurizing gas flow), torque, and wear of a conventional circumferential shaft seal were measured and compared to those of a conventional seal modified to have self-acting lift geometries. Both seal types had a 2.625-in diameter bore and were operated at a sliding velocity of 150 ft/sec with differential pressures ranging from 0 to 100 psi. Results of this investigation show that the self-acting seal operated at lower bulk carbon temperatures with half the torque and approximately one-tenth the wear of the conventional seal. Seal leakage of the self-acting seal was of order of 0.04 scfm for pressures above 60 psi which is well within the accepted range for gas turbine engine applications.

  1. Crack shape developments and leak rates for circumferential complex-cracked pipes

    SciTech Connect

    Brickstad, B.; Bergman, M.

    1997-04-01

    A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

  2. Soil sampling device with latch assembly having a variable circumferential shape

    DOEpatents

    Meyer, Robert D.

    1996-01-01

    The invention relates to an improved sampler which can be operated in any orientation. The design features a positive gripping of the operating rod in a manner to reduce point loads so as to reduce any possibility of jamming of the rod on a retraction stroke until such time as it is positively retained in the fully withdrawn position. In the preferred embodiment, a pair of mating cylindrical latch pieces, held together by a circumferential spring, are used for positive actuation. The inner rod has an angular cut-out which provides the base for the latch when aligned with the latch. A release fixture can be used to free the latch from the cone rod after actuation. The latches are formed in such a manner as they may support themselves within the housing of the sampler until they engage the operating rod.

  3. Soil sampling device with latch assembly having a variable circumferential shape

    DOEpatents

    Meyer, R.D.

    1996-12-24

    The invention relates to an improved sampler which can be operated in any orientation. The design features a positive gripping of the operating rod in a manner to reduce point loads so as to reduce any possibility of jamming of the rod on a retraction stroke until such time as it is positively retained in the fully withdrawn position. In the preferred embodiment, a pair of mating cylindrical latch pieces, held together by a circumferential spring, are used for positive actuation. The inner rod has an angular cut-out which provides the base for the latch when aligned with the latch. A release fixture can be used to free the latch from the cone rod after actuation. The latches are formed in such a manner as they may support themselves within the housing of the sampler until they engage the operating rod. 11 figs.

  4. Stress intensity magnification factors for fully circumferential cracks in valve bodies (thick cylinders)

    SciTech Connect

    Toor, P.M.

    1998-11-01

    The stress intensity solutions presented herein were obtained using an energy method in conjunction with a two-dimensional finite element program in order to explicitly account for curvature effect for fully circumferential cracks. The magnification factors for a specific crack depth were calculated by successively loading the crack surface by a uniform, linear, quadratic, and a cubic loading distribution. The magnification factors can be used to calculate the stress intensity factors by superposition method. The functions for each load condition in terms of radius to thickness ratio (R/t) and a fractional distance in terms of crack depth to thickness ratio (a/t) were developed. The validity of these functions is R/t = 1.5 to 10.0 and for 0.0125 {le} a/t {le} 0.8125. The functions agree to within 1% of the finite elements solutions for most magnification factors.

  5. Development of a used fuel cladding damage model incorporating circumferential and radial hydride responses

    NASA Astrophysics Data System (ADS)

    Chen, Qiushi; Ostien, Jakob T.; Hansen, Glen

    2014-04-01

    At the completion of the fuel drying process, used fuel Zry4 cladding typically exhibits a significant population of δ-hydride inclusions. These inclusions are in the form of small platelets that are generally oriented both circumferentially and radially within the cladding material. There is concern that radially-oriented hydride inclusions may weaken the cladding material and lead to issues during used fuel storage and transportation processes. A high fidelity model of the mechanical behavior of hydrides has utility in both designing fuel cladding to be more resistant to this hydride-induced weakening and also in suggesting modifications to drying, storage, and transport operations to reduce the impact of hydride formation and/or the avoidance of loading scenarios that could overly stress the radial inclusions. We develop a mechanical model for the Zry4-hydride system that, given a particular morphology of hydride inclusions, allows the calculation of the response of the hydrided cladding under various loading scenarios. The model treats the Zry4 matrix material as J2 elastoplastic, and treats the hydrides as platelets oriented in predefined directions (e.g., circumferentially and radially). The model is hosted by the Albany analysis framework, where a finite element approximation of the weak form of the cladding boundary value problem is solved using a preconditioned Newton-Krylov approach. Instead of forming the required system Jacobian operator directly or approximating its action with a differencing operation, Albany leverages the Trilinos Sacado package to form the Jacobian via automatic differentiation. We present results that describe the performance of the model in comparison with as-fabricated Zry4 as well as HB Robinson fuel cladding. Further, we also present performance results that demonstrate the efficacy of the overall solution method employed to host the model.

  6. Successful treatment of cervical myelopathy with minimal morbidity by circumferential decompression and fusion

    PubMed Central

    Sanchez-Mejia, Rene O.; Ben-Haim, Sharona; Ames, Christopher P.

    2007-01-01

    Circumferential cervical decompression and fusion (CCDF) is an important technique for treating patients with severe cervical myelopathy. While circumferential cervical decompression and fusion may provide improved spinal cord decompression and stability compared to unilateral techniques, it is commonly associated with increased morbidity and mortality. We performed a retrospective analysis of patients undergoing CCDF at the University of California, San Francisco (UCSF) between January 2003 and December 2004. We identified 53 patients and reviewed their medical records to determine the effectiveness of CCDF for improving myelopathy, pain, and neurological function. Degree of fusion, functional anatomic alignment, and stability were also assessed. Operative morbidity and mortality were measured. The most common causes of cervical myelopathy, instability, or deformity were degenerative disease (57%) and traumatic injury (34%). Approximately one-fifth of patients had a prior fusion performed elsewhere and presented with fusion failure or adjacent-level degeneration. Postoperatively, all patients had stable (22.6%) or improved (77.4%) Nurick grades. The average preoperative and postoperative Nurick grades were 2.1 ± 1.9 and 0.4 ± 0.9, respectively. Pain improved in 85% of patients. All patients had radiographic evidence of fusion at last follow-up. The most common complication was transient dysphagia. Our average clinical follow-up was 27.5 ± 9.5 months. We present an extensive series of patients and demonstrate that cervical myelopathy can successfully be treated with CCDF with minimal operative morbidity. CCDF may provide more extensive decompression of the spinal cord and may be more structurally stable. Concerns regarding operation-associated morbidity should not strongly influence whether CCDF is performed. PMID:17216528

  7. The Extended Posterior Circumferential Decompression Technique in the Management of Tubercular Spondylitis with and without Paraplegia

    PubMed Central

    Rathinavelu, Barani; Krishnan, Venkatesh; Amritanand, Rohit; Sundararaj, Gabriel David

    2014-01-01

    Study Design Retrospective clinical series. Purpose To study the clinical, functional and radiological results of patients with tuberculous spondylitis with and without paraplegia, treated surgically using the "Extended Posterior Circumferential Decompression (EPCD)" technique. Overview of Literature With the increasing possibility of addressing all three columns by a single approach, posterior and posterolateral approaches are gaining acceptance. A single exposure for cases with neurological deficit and kyphotic deformity requiring circumferential decompression, anterior column reconstruction and posterior instrumentation is helpful. Methods Forty-one patients with dorsal/dorsolumbar/lumbar tubercular spondylitis who were operated using the EPCD approach between 2006 to 2009 were included. Postoperatively, patients were started on nine-month anti-tuberculous treatment. They were serially followed up to thirty-six months and both clinical measures (including pain, neurological status and ambulatory status) and radiological measures (including kyphotic angle correction, loss of correction and healing status) were used for assessment. Results Disease-healing with bony fusion (interbody fusion) was seen in 97.5% of cases. Average deformity (kyphosis) correction was 54.6% in dorsal spine and 207.3% in lumbar spine. Corresponding loss of correction was 3.6 degrees in dorsal spine and 1.9 degrees in the lumbar spine. Neurological recovery in Frankel B and C paraplegia was 85.7% and 62.5%, respectively. Conclusions The EPCD approach permits all the advantages of a single or dual session anterior and posterior surgery, with significant benefits in terms of decreased operative time, reduced hospital stay and better kyphotic angle correction. PMID:25558312

  8. Amniotic Membrane Grafts for the Prevention of Esophageal Stricture after Circumferential Endoscopic Submucosal Dissection

    PubMed Central

    Barret, Maximilien; Pratico, Carlos Alberto; Camus, Marine; Beuvon, Frédéric; Jarraya, Mohamed; Nicco, Carole; Mangialavori, Luigi; Chaussade, Stanislas; Batteux, Frédéric; Prat, Frédéric

    2014-01-01

    Background and Aims The prevention of esophageal strictures following circumferential mucosal resection remains a major clinical challenge. Human amniotic membrane (AM) is an easily available material, which is widely used in ophthalmology due to its wound healing, anti-inflammatory and anti-fibrotic properties. We studied the effect of AM grafts in the prevention of esophageal stricture after endoscopic submucosal dissection (ESD) in a swine model. Animals and Methods In this prospective, randomized controlled trial, 20 swine underwent a 5 cm-long circumferential ESD of the lower esophagus. In the AM Group (n = 10), amniotic membrane grafts were placed on esophageal stents; a subgroup of 5 swine (AM 1 group) was sacrificed on day 14, whereas the other 5 animals (AM 2 group) were kept alive. The esophageal stent (ES) group (n = 5) had ES placement alone after ESD. Another 5 animals served as a control group with only ESD. Results The prevalence of symptomatic strictures at day 14 was significantly reduced in the AM group and ES groups vs. the control group (33%, 40% and 100%, respectively, p = 0.03); mean esophageal diameter was 5.8±3.6 mm, 6.8±3.3 mm, and 2.6±1.7 mm for AM, ES, and control groups, respectively. Median (range) esophageal fibrosis thickness was 0.87 mm (0.78–1.72), 1.19 mm (0.28–1.95), and 1.65 mm (0.7–1.79) for AM 1, ES, and control groups, respectively. All animals had developed esophageal strictures by day 35. Conclusions The anti-fibrotic effect of AM on esophageal wound healing after ESD delayed the development of esophageal stricture in our model. However, this benefit was of limited duration in the conditions of our study. PMID:24992335

  9. Self-acting lift-pad geometry for circumferential seals: A noncontacting concept. [performance tests on hydrodynamic seals

    NASA Technical Reports Server (NTRS)

    Allen, G. P.

    1980-01-01

    A segmented circumferential seal with lift pads for hydrodynamic action was analyzed over ranges of speed and sealed pressure. Performance predictions, which predicted noncontact operation for speeds as high as 600 revolutions per second at sealed pressures to 86 N/sq cm, are discussed. Performance tests were performed on the seals and compared with the performance predictions.

  10. High speed OH-PLIF measurement of self-excited circumferential instabilities in an annular combustion chamber

    NASA Astrophysics Data System (ADS)

    Worth, Nicholas; Dawson, James

    2012-11-01

    Self-excited thermo-acoustic instabilities are a significant issue in the development of lean burn gas turbine combustors. Such instabilities arise through coupling of the unsteady heat release and acoustic waves, which can propagate both longitudinally and circumferentially in annular combustor geometries. Although a large number of studies have investigated longitudinal fluctuations in single axisymmetric flames, it is currently uncertain whether these results can be used to emulate circumferential oscillations in annular geometry. Therefore, the aim of the current project is to investigate the flame dynamics in an annular model gas turbine combustor during self-excited circumferential oscillations. Pressure measurements are used to characterise the circumferential oscillations, with high-speed OH chemiluminescence and OH-PLIF used to capture the flame dynamics. The flame structure and dynamics are significantly affected by both the proximity of neighbouring flames and the excitation mode; with different responses observed for small and large separation distances, and standing and spinning modes. These observations indicate that results from single flame investigations may only be representative of self-excited flames in annular geometry under in a limited set of conditions.

  11. Circumferentially segmented duct lines optimized for axisymmetric and standing wave sources. [reducing noise from turbofan engines galerkin method acoustic attenuation

    NASA Technical Reports Server (NTRS)

    Watson, W. R.

    1982-01-01

    Optimum and off-optimum properties of circumferentially segmented duct liners are compared with those of uniform liners to identify any potential benefits of circumferentially segmented liners. High- and low-order spinning-mode sources are considered in the study. The solution for the segmented liner is obtained by a multimodal expansion of the segmented-liner eigenmodes in terms of a series of hardwall duct models. The coefficients in the hard-wall series are obtained by using Galerkin's method. Results show that for some frequencies and duct lengths, circumferentially segmented liners scatter energy equally between a higher and lower order circumferential wave number. Studies for higher order spinning-mode sources show that an optimized segmented liner with a hard-wall/soft-wal admittance variation representing an optimum configuration gives better performance than an optimized uniform liner. Overall, the greatest benefit of the segmented liner over the uniform liner occurs under off-optimum conditions. The optimized segmented liner gives more effective broadband performance than the optimized uniform liner.

  12. Puppy line, metaphyseal sclerosis, and caudolateral curvilinear and circumferential femoral head osteophytes in early detection of canine hip dysplasia.

    PubMed

    Risler, Amanda; Klauer, Julia M; Keuler, Nicholas S; Adams, William M

    2009-01-01

    Ventrodorsal extended hip radiographs were analyzed from Foxhounds, Irish setters, Greyhounds, and Labrador retrievers radiographed four to seven times between 8 and 110 weeks of age. Occurrence in these 91 dogs of a puppy line, an ill-defined zone of proximal femoral metaphyseal sclerosis, a femoral neck linear sclerosis, or circumferential linear femoral head osteophytosis at 15-17 weeks of age were compared with hip joint laxity, as measured by distraction index, and to later findings of caudal curvilinear femoral neck osteophytes, circumferential femoral head osteophytes, hip incongruity consistent with hip dysplasia and degenerative joint disease by 52 weeks of age. A puppy line and/or femoral metaphyseal sclerosis was common at 15-17 weeks of age for dogs at mimimal risk (Greyhounds) and high risk (Foxhounds) of developing early degenerative joint disease associated with canine hip dysplasia. Though 44% of Greyhound hips had puppy lines and 28% had femoral metaphyseal sclerosis at 15-17 weeks of age, no Greyhound had a caudolateral curvilinear osteophyte or circumferential femoral head osteophyte at 24-27 or 52 weeks of age. No significant relationship was found between occurrence of a puppy line, a circumferential femoral head osteophyte or femoral metaphyseal sclerosis at 15-17 weeks and canine hip dysplasia or degenerative joint disease incidence at 42-52 weeks. Presence of a caudolateral curvilinear osteophyte in at least one hip at 24-27 weeks was significantly related to the diagnosis of canine hip dysplasia by 42-52 weeks. When both a caudolateral curvilinear osteophyte and a circumferential femoral head osteophyte were present in a hip at 24-27 weeks, degenerative joint disease was evident in all such hips by 42-52 weeks of age.

  13. Radiation Source Replacement Workshop

    SciTech Connect

    Griffin, Jeffrey W.; Moran, Traci L.; Bond, Leonard J.

    2010-12-01

    This report summarizes a Radiation Source Replacement Workshop in Houston Texas on October 27-28, 2010, which provided a forum for industry and researchers to exchange information and to discuss the issues relating to replacement of AmBe, and potentially other isotope sources used in well logging.

  14. Modeling and numerical investigation of the inlet circumferential fluctuations of swept and bowed blades

    NASA Astrophysics Data System (ADS)

    Tang, Mingzhi; Jin, Donghai; Gui, Xingmin

    2017-02-01

    The circumferential fluctuation (CF) source terms induced by the inviscid blade force can affect the inlet distribution of flow parameters and radial equilibrium of swept and bowed blades. However, these phenomena cannot be adequately described by throughflow methods based on the axisymmetric assumption. A transport model for the CF stresses is proposed and correlated to the distribution of circulation to reflect the effect of the inviscid blade force. To investigate the effect of the inlet CFs on swept and bowed blades, the model is integrated into a throughflow model and applied to a series of cascades with different sweep and bow angles. For swept cascades, the CF source terms change the distributions of incidence angles, as well as the radial equilibrium at the inlet of the blade passage. And the influence is enhanced as the absolute value of the sweep angle increases. For bowed cascades, the distributions of incidence angles are also altered. For both cases, the model can offer a good prediction of the inlet CF source terms, and prove to exert a better prediction of blade design key parameters such as flow angles.

  15. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats

    PubMed Central

    TAKANO, Hiroshi; ISOGAI, Tomomi; AOKI, Takuma; WAKAO, Yoshito; FUJII, Yoko

    2014-01-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart. PMID:25373881

  16. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats.

    PubMed

    Takano, Hiroshi; Isogai, Tomomi; Aoki, Takuma; Wakao, Yoshito; Fujii, Yoko

    2015-02-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart.

  17. Leak before break behaviour of austenitic and ferritic pipes containing circumferential defects

    SciTech Connect

    Stadtmueller, W.; Sturm, D.

    1997-04-01

    Several research projects carried out at MPA Stuttgart to investigate the Leak-before-Break (LBB) behavior of safety relevant pressure bearing components are summarized. Results presented relate to pipes containing circumferential defects subjected to internal pressure and external bending loading. An overview of the experimentally determined results for ferritic components is presented. For components containing postulated or actual defects, the dependence of the critical loading limit on the defect size is shown in the form of LBB curves. These are determined experimentally and/or by calculation for through-wall slits, and represent the boundary curve between leakage and massive fracture. For surface defects and a given bending moment and internal pressure, no fracture will occur if the length at leakage remains smaller than the critical defect length given by the LBB curve for through-wall defects. The predictive capability of engineering calculational methods are presented by way of example. The investigation programs currently underway, testing techniques, and initial results are outlined.

  18. A circular inclusion with circumferentially inhomogeneous imperfect interface in harmonic materials

    NASA Astrophysics Data System (ADS)

    McArthur, D. R.; Sudak, L. J.

    2016-03-01

    In the following analysis, we present a rigorous solution for the problem of a circular elastic inclusion surrounded by an infinite elastic matrix in finite plane elastostatics. The inclusion and matrix are separated by a circumferentially inhomogeneous imperfect interface characterized by the linear spring-type imperfect interface model where the interface is such that the same degree of imperfection is realized in both the normal and tangential directions. Through the use of analytic continuation, a set of first-order coupled ordinary differential equations with variable coefficients are developed for two analytic potential functions. The unknown coefficients of the potential functions are determined from their analyticity requirements and some additional problem-specific constraints. An example is then presented for a specific class of interface where the inclusion mean stress is contrasted between the homogeneous interface and inhomogeneous interface models. It is shown that, for circumstances where a homogeneously imperfect interface may not be warranted, the inhomogeneous model has a pronounced effect on the mean stress within the inclusion.

  19. Total Hip Replacement

    MedlinePlus

    ... ankle pump exercises, and early mobilization. Leg-length Inequality Sometimes after a hip replacement, one leg may ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 12 ) AAOS does ...

  20. Ankle replacement - discharge

    MedlinePlus

    You had an ankle replacement. Your surgeon removed and reshaped damaged bones, and put in an artificial ankle joint. You received pain medicine and were shown how to treat swelling around your new ankle joint.

  1. Replacing a Missing Tooth

    MedlinePlus

    ... This may be accomplished by adding plastic or porcelain filling material or a porcelain crown to reshape its appearance. What options are ... there is no danger of nerve involvement. A porcelain replacement tooth is held in place by metal ...

  2. Carbohydrates as Fat Replacers.

    PubMed

    Peng, Xingyun; Yao, Yuan

    2017-02-28

    The overconsumption of dietary fat contributes to various chronic diseases, which encourages attempts to develop and consume low-fat foods. Simple fat reduction causes quality losses that impede the acceptance of foods. Fat replacers are utilized to minimize the quality deterioration after fat reduction or removal to achieve low-calorie, low-fat claims. In this review, the forms of fats and their functions in contributing to food textural and sensory qualities are discussed in various food systems. The connections between fat reduction and quality loss are described in order to clarify the rationales of fat replacement. Carbohydrate fat replacers usually have low calorie density and provide gelling, thickening, stabilizing, and other texture-modifying properties. In this review, carbohydrates, including starches, maltodextrins, polydextrose, gums, and fibers, are discussed with regard to their interactions with other components in foods as well as their performances as fat replacers in various systems.

  3. Androgen replacement for women.

    PubMed Central

    Basson, R.

    1999-01-01

    OBJECTIVES: To determine whether a postmenopausal syndrome comprising specific changes in sexual desire and response associated with low free testosterone exists. To determine whether this syndrome is ameliorated by testosterone replacement. QUALITY OF EVIDENCE: Literature documenting that replacement of physiological levels of testosterone is beneficial and safe is scant. Only one randomized prospective blinded study examines sexual outcome in detail. MAIN MESSAGE: Testosterone is an important metabolic and sex hormone produced by the ovary throughout life. The variable reduction in ovarian testosterone production coincident with menopause is sometimes associated with a syndrome of specific changes in sexual desire and sexual response. Estrogen deficiency also impairs sexual response, but its replacement will not improve and might exacerbate sexual symptoms from androgen loss. Diagnosis of androgen deficiency is clinical, based on accurate assessment of a woman's sexual status before and after menopause and only confirmed (rather than diagnosed) by a low level of free testosterone. Partial androgen replacement restores much of the sexual response and facilitates sexual desire that is triggered by external cues. Avoiding supraphysiological levels of testosterone lessens risk of masculinization. Avoiding alkylated testosterone lessens hepatic or lipid impairment. CONCLUSION: Further prospective randomized studies of replacement of physiological levels of testosterone in women with androgen deficiency syndrome are needed, using formulations of testosterone available in Canada. The consistency of sexual changes, the associated personal and relationship distress, together with our clinical experience of the gratifying response to physiological replacement, make further studies urgently needed. PMID:10509222

  4. Methods for disassembling, replacing and assembling parts of a steam cooling system for a gas turbine

    DOEpatents

    Wilson, Ian D.; Wesorick, Ronald R.

    2002-01-01

    The steam cooling circuit for a gas turbine includes a bore tube assembly supplying steam to circumferentially spaced radial tubes coupled to supply elbows for transitioning the radial steam flow in an axial direction along steam supply tubes adjacent the rim of the rotor. The supply tubes supply steam to circumferentially spaced manifold segments located on the aft side of the 1-2 spacer for supplying steam to the buckets of the first and second stages. Spent return steam from these buckets flows to a plurality of circumferentially spaced return manifold segments disposed on the forward face of the 1-2 spacer. Crossover tubes couple the steam supply from the steam supply manifold segments through the 1-2 spacer to the buckets of the first stage. Crossover tubes through the 1-2 spacer also return steam from the buckets of the second stage to the return manifold segments. Axially extending return tubes convey spent cooling steam from the return manifold segments to radial tubes via return elbows. The bore tube assembly, radial tubes, elbows, manifold segments and crossover tubes are removable from the turbine rotor and replaceable.

  5. Measurement of circumferential Lamb waves using a line-focus poly(vinylidene fluoride) transducer and cross correlation waveform analysis.

    PubMed

    Lin, Chun-I; Lu, Yan; He, Cunfu; Song, Guorong; Lee, Yung-Chun

    2015-11-01

    This paper presents a method for measuring circumferential Lamb waves propagating on a cylindrically curved thin plate. The measurement is carried out using a wideband and line-focused poly(vinylidene fluoride) transducer along with a defocusing waveform measurement method. After synthesizing the acquired waveforms, interference patterns can be obtained and a cross correlation method is developed to accurately extract the wave velocity as a function of wave frequency. Using three stainless steel thin plates of different thicknesses (100, 150, and 300 μm) and a radius of curvature of 10 mm, dispersion curves for several fundamental and higher order modes of circumferential Lamb waves are simultaneously determined. Theoretical dispersion curves are also calculated and compared with their experimental counterparts. Very good agreements are observed, which concludes the measurement accuracy of this measurement method.

  6. Circumferential negative-pressure dressing (VAC) to bolster skin grafts in the reconstruction of the penile shaft and scrotum.

    PubMed

    Weinfeld, Adam Bryce; Kelley, Patrick; Yuksel, Eser; Tiwari, Pankaj; Hsu, Patrick; Choo, Joshua; Hollier, Larry H

    2005-02-01

    This paper presents 4 consecutive cases using negative-pressure dressings (VAC) to bolster skin grafts in male genital reconstruction. In this series reconstruction followed 1 case of tumor ablation and 3 cases of debridement of abscesses or Fornier's gangrene. The VAC was applied circumferentially to the penis to secure skin grafts either directly to the penile shaft or to facilitate skin grafting to the scrotum. Graft areas ranged from 75 to 250 cm. All cases resulted in successful genital wound coverage; minor complications are described. Three practical points are brought forth. First, the VAC facilitates skin grafting to the complex contour of male genitalia. Second, the VAC can be applied circumferentially to the penis without the need for perfusion monitoring or fears of avascular necrosis. Third, with the use of the VAC, bolster use can likely be discontinued as early as 72 hours with good graft adherence and survival.

  7. Traumatic elbow luxation in a free-ranging hedgehog (Erinaceus europaeus): surgical management using circumferential suture prostheses.

    PubMed

    Vallefuoco, Rosario; Pignon, Charly; Furst, Anna; Personne, Lauriane; Courreau, Jean-Francois; Moissonnier, Pierre

    2013-06-01

    A free-ranging adult female hedgehog (Erinaceus europaeus) was presented injured, presumably from vehicular trauma. Clinical and radiographic examination under general anesthesia revealed a lateral elbow luxation. Closed reduction was unsuccessful, so a surgical approach with circumferential suture prostheses was used to stabilize the elbow. Neither perioperative nor postoperative complications were recorded. The hedgehog regained good range of motion of the elbow and was fully able to run and to roll into a ball.

  8. Comparison of treatment for 153 cases of circumferential facial paralysis by low-power laser and galvan acupuncture

    NASA Astrophysics Data System (ADS)

    Li, Hai-Ling; Zhuo, Qing-shan

    1993-03-01

    Seventy-six patients were treated by low power He-Ne laser irradiation on Yangbai, Sibai, and other related acupoints. The other 77 cases were treated by Galvan-acupuncture with infrared radiation on the same acupoints. There was little difference between the therapeutic effects of these two groups (P > 0.05). However, the laser group had a much shorter treatment time than the other group. According to the theory of traditional Chinese medicine, circumferential facial paralysis is caused by exposure to cold which blocks the channel of vital energy resulting in the damage of bodily function. Acupuncture and moxibustion on certain acupoints can warm up the channels and remove the stasis allowing vital energy to pass through their passages to regulate bodily functions. Laser can do the same effectively with much less time. The laser therapy also features painlessness, safeness, and is free of bacteria. Circumferential facial paralysis is a common disease, which is clinically treated by acupuncture with reliable results. However, acupuncture is not fit for children who are not cooperative and those patients who are afraid of the pain accompanied with acupuncture. So we applied low power laser irradiation in the treatment of circumferential facial paralysis starting in 1985. The results were favorable. And the treatment time was shortened. The treatment procedures are reported.

  9. What Is a Hip Replacement?

    MedlinePlus

    ... Replacement PDF Version Size: 123 KB Audio Version Time: 10:01 Size: 9.4 MB November 2014 What Is a Hip Replacement? Fast Facts: An Easy-to-Read Series of Publications for the Public Hip replacement surgery ...

  10. Measurement of the circumferential mechanical properties of the umbilical vein: experimental and numerical analyses.

    PubMed

    Karimi, Alireza; Navidbakhsh, Mahdi; Rezaee, Taraneh; Hassani, Kamran

    2015-01-01

    Coronary artery disease is responsible for almost 30% of all deaths worldwide. The saphenous vein and umbilical vein (UV) are the most common veins using for treatment as a coronary artery bypass graft (CABG). The mechanical properties of UV belonging to its long-term patency for CABG are very important. However, there is a lack of knowledge on the linear elastic and nonlinear hyperelastic mechanical properties of the UV. In this study, three stress definitions (second Piola-Kichhoff stress, engineering stress and true stress) and four strain definitions (Almansi-Hamel strain, Green-St Venant strain, engineering strain and true strain) are used to determine the elastic modulus, maximum stress and strain of eight human UVs under circumferential loading. The nonlinear mechanical behaviour of the UV is computationally investigated using Mooney-Rivlin hyperelastic model. A numerical finite element analysis is also carried out to simulate the constitutive modelling versus its numerical results. The results show that the Almansi-Hamel strain definition overestimates the elastic modulus while Green-St Venant strain definition underestimates the elastic modulus at different stress definitions. The true stress-true strain definition, which gives more accurate measurements of the tissue's response using the instantaneous values, reveals the Young's modulus and maximum stress of 2.18 and 6.01 MPa, respectively. The Mooney-Rivlin material model is well represented by the nonlinear mechanical behaviour of the UV. The findings of this study could have implications not only for understanding the extension and rupture mechanism of UV but also for interventions and surgeries, including balloon angioplasty, bypass and stenting.

  11. The Interaction between Fluid Wall Shear Stress and Solid Circumferential Strain Affects Endothelial Gene Expression.

    PubMed

    Amaya, Ronny; Pierides, Alexis; Tarbell, John M

    2015-01-01

    Endothelial cells lining the walls of blood vessels are exposed simultaneously to wall shear stress (WSS) and circumferential stress (CS) that can be characterized by the temporal phase angle between WSS and CS (stress phase angle - SPA). Regions of the circulation with highly asynchronous hemodynamics (SPA close to -180°) such as coronary arteries are associated with the development of pathological conditions such as atherosclerosis and intimal hyperplasia whereas more synchronous regions (SPA closer to 0°) are spared of disease. The present study evaluates endothelial cell gene expression of 42 atherosclerosis-related genes under asynchronous hemodynamics (SPA=-180 °) and synchronous hemodynamics (SPA=0 °). This study used a novel bioreactor to investigate the cellular response of bovine aortic endothelial cells (BAECS) exposed to a combination of pulsatile WSS and CS at SPA=0 or SPA=-180. Using a PCR array of 42 genes, we determined that BAECS exposed to non-reversing sinusoidal WSS (10±10 dyne/cm2) and CS (4 ± 4%) over a 7 hour testing period displayed 17 genes that were up regulated by SPA = -180 °, most of them pro-atherogenic, including NFκB and other NFκB target genes. The up regulation of NFκB p50/p105 and p65 by SPA =-180° was confirmed by Western blots and immunofluorescence staining demonstrating the nuclear translocation of NFκB p50/p105 and p65. These data suggest that asynchronous hemodynamics (SPA=-180 °) can elicit proatherogenic responses in endothelial cells compared to synchronous hemodynamics without shear stress reversal, indicating that SPA may be an important parameter characterizing arterial susceptibility to disease.

  12. Comparative analysis of glucagonergic cells, glia, and the circumferential marginal zone in the reptilian retina.

    PubMed

    Todd, Levi; Suarez, Lilianna; Squires, Natalie; Zelinka, Christopher Paul; Gribbins, Kevin; Fischer, Andy J

    2016-01-01

    Retinal progenitors in the circumferential marginal zone (CMZ) and Müller glia-derived progenitors have been well described for the eyes of fish, amphibians, and birds. However, there is no information regarding a CMZ and the nature of retinal glia in species phylogenetically bridging amphibians and birds. The purpose of this study was to examine the retinal glia and investigate whether a CMZ is present in the eyes of reptilian species. We used immunohistochemical analyses to study retinal glia, neurons that could influence CMZ progenitors, the retinal margin, and the nonpigmented epithelium of ciliary body of garter snakes, queen snakes, anole lizards, snapping turtles, and painted turtles. We compare our observations on reptile eyes to the CMZ and glia of fish, amphibians, and birds. In all species, Sox9, Pax6, and the glucocorticoid receptor are expressed by Müller glia and cells at the retinal margin. However, proliferating cells were found only in the CMZ of turtles and not in the eyes of anoles and snakes. Similar to eyes of chickens, the retinal margin in turtles contains accumulations of GLP1/glucagonergic neurites. We find that filamentous proteins, vimentin and GFAP, are expressed by Müller glia, but have different patterns of subcellular localization in the different species of reptiles. We provide evidence that the reptile retina may contain nonastrocytic inner retinal glial cells, similar to those described in the avian retina. We conclude that the retinal glia, glucagonergic neurons, and CMZ of turtles appear to be most similar to those of fish, amphibians, and birds.

  13. Toxicology of chlorofluorocarbon replacements.

    PubMed

    Dekant, W

    1996-03-01

    Chlorofluorocarbons (CFCs) are stable in the atmosphere and may reach the stratosphere. They are cleaved by UV-radiation in the stratosphere to yield chlorine radicals, which are thought to interfere with the catalytic cycle of ozone formation and destruction and deplete stratospheric ozone concentrations. Due to potential adverse health effects of ozone depletion, chlorofluorocarbon replacements with much lower or absent ozone depleting potential are developed. The toxicology of these compounds that represent chlorofluorohydrocarbons (HCFCs) or fluorohydrocarbons (HFCs) has been intensively studied. All compounds investigated (1, 1-dichloro-1-fluoroethane [HCFC-141b], 1,1,1,2-tetrafluoroethane [HFC-134a], pentafluoroethane [HFC-125], 1-chloro- 1,2,2,2-tetrafluoroethane [HCFC-124], and 1,1-dichloro-2,2,2-trifluoroethane [HCFC-123]) show only a low potential for skin and eye irritation. Chronic adverse effects on the liver (HCFC-123) and the testes (HCFC-141b and HCFC-134a), including tumor formation, were observed in long-term inhalation studies in rodents using very high concentrations of these CFC replacements. All CFC replacements are, to varying extents, biotransformed in the organism, mainly by cytochrome P450-catalyzed oxidation of C-H bonds. The formed acyl halides are hydrolyzed to give excretable carboxylic acids; halogenated aldehydes that are formed may be further oxidized to halogenated carboxylic acids or reduced to halogenated alcohols, which are excretory metabolites in urine from rodents exposed experimentally to CFC replacements. The chronic toxicity of the CFC replacements studied is unlikely to be of relevance for humans exposed during production and application of CFC replacements.

  14. Partially Premixed Flame (PPF) Research for Fire Safety

    NASA Technical Reports Server (NTRS)

    Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Hegde, Uday

    2004-01-01

    Incipient fires typically occur after the partial premixing of fuel and oxidizer. The mixing of product species into the fuel/oxidizer mixture influences flame stabilization and fire spread. Therefore, it is important to characterize the impact of different levels of fuel/oxidizer/product mixing on flame stabilization, liftoff and extinguishment under different gravity conditions. With regard to fire protection, the agent concentration required to achieve flame suppression is an important consideration. The initial stage of an unwanted fire in a microgravity environment will depend on the level of partial premixing and the local conditions such as air currents generated by the fire itself and any forced ventilation (that influence agent and product mixing into the fire). The motivation of our investigation is to characterize these impacts in a systematic and fundamental manner.

  15. Validation of the Predicted Circumferential and Radial Mode Sound Power Levels in the Inlet and Exhaust Ducts of a Fan Ingesting Distorted Inflow

    NASA Technical Reports Server (NTRS)

    Koch, L. Danielle

    2012-01-01

    Fan inflow distortion tone noise has been studied computationally and experimentally. Data from two experiments in the NASA Glenn Advanced Noise Control Fan rig have been used to validate acoustic predictions. The inflow to the fan was distorted by cylindrical rods inserted radially into the inlet duct one rotor chord length upstream of the fan. The rods were arranged in both symmetric and asymmetric circumferential patterns. In-duct and farfield sound pressure level measurements were recorded. It was discovered that for positive circumferential modes, measured circumferential mode sound power levels in the exhaust duct were greater than those in the inlet duct and for negative circumferential modes, measured total circumferential mode sound power levels in the exhaust were less than those in the inlet. Predicted trends in overall sound power level were proven to be useful in identifying circumferentially asymmetric distortion patterns that reduce overall inlet distortion tone noise, as compared to symmetric arrangements of rods. Detailed comparisons between the measured and predicted radial mode sound power in the inlet and exhaust duct indicate limitations of the theory.

  16. Hexachloroethane Obscurant Replacement

    DTIC Science & Technology

    2012-01-01

    suggest that neither the alkali metal hydroxides nor chlorides are extremely toxic (11). Oral rat LD50 values are indeed lower for hydroxide salts...analyze for toxicity of combustion gases and particulates. Compositions containing boron potassium nitrate igniter blended with halide salts...variants were identified which should have improved performance. 15. SUBJECT TERMS Non- toxic obscurant, hexachloroethane smoke replacement 16

  17. Python import replacement

    SciTech Connect

    2011-10-01

    SmartImport.py is a Python source-code file that implements a replacement for the standard Python module importer. The code is derived from knee.py, a file in the standard Python diestribution , and adds functionality to improve the performance of Python module imports in massively parallel contexts.

  18. Prioritizing equipment for replacement.

    PubMed

    Capuano, Mike

    2010-01-01

    It is suggested that clinical engineers take the lead in formulating evaluation processes to recommend equipment replacement. Their skill, knowledge, and experience, combined with access to equipment databases, make them a logical choice. Based on ideas from Fennigkoh's scheme, elements such as age, vendor support, accumulated maintenance cost, and function/risk were used.6 Other more subjective criteria such as cost benefits and efficacy of newer technology were not used. The element of downtime was also omitted due to the data element not being available. The resulting Periop Master Equipment List and its rationale was presented to the Perioperative Services Program Council. They deemed the criteria to be robust and provided overwhelming acceptance of the list. It was quickly put to use to estimate required capital funding, justify items already thought to need replacement, and identify high-priority ranked items for replacement. Incorporating prioritization criteria into an existing equipment database would be ideal. Some commercially available systems do have the basic elements of this. Maintaining replacement data can be labor-intensive regardless of the method used. There is usually little time to perform the tasks necessary for prioritizing equipment. However, where appropriate, a clinical engineering department might be able to conduct such an exercise as shown in the following case study.

  19. Window Replacement Tips.

    ERIC Educational Resources Information Center

    Wiens, Janet

    2001-01-01

    Explores ways to replace facility windows more easily and efficiently by evaluating long-term needs and window options. Recommends obtaining references from window manufacturer and installer, scheduling the work during times the facility is unoccupied, and ensuring that historic and life-safety issues be considered. (GR)

  20. Control of circumferential wall stress and luminal shear stress within intact vascular segments perfused ex vivo.

    PubMed

    El-Kurdi, Mohammed S; Vipperman, Jeffrey S; Vorp, David A

    2008-10-01

    Proportional, integral, and derivative (PID) controllers have proven to be robust in controlling many applications, and remain the most widely used control system architecture. The purpose of this work was to use this architecture for designing and tuning two PID controllers. The first was used to control the physiologic arterial circumferential wall stress (CWS) and the second to control the physiologic arterial shear stress (SS) imposed on intact vascular segments that were implanted into an ex vivo vascular perfusion system (EVPS). In order to most accurately control the stresses imposed onto vascular segments perfused ex vivo, analytical models were derived to calculate the CWS and SS. The mid-vein-wall CWS was calculated using the classical Lame solution for thick-walled cylinders in combination with the intraluminal pressure and outer diameter measurements. Similarly, the SS was calculated using the Hagen-Poiseuille equation in combination with the flow rate and outer diameter measurements. Performance of each controller was assessed by calculating the root mean square of the error (RMSE) between the desired and measured process variables. The performance experiments were repeated ten times (N=10) and an average RMSE was reported for each controller. RMSE standard deviations were calculated to demonstrate the reproducibility of the results. Sterile methods were utilized for making blood gas and temperature measurements in order to maintain physiologic levels within the EVPS. Physiologic blood gases (pH, pO(2), and pCO(2)) and temperature within the EVPS were very stable and controlled manually. Blood gas and temperature levels were recorded hourly for several (N=9) 24 h perfusion experiments. RMSE values for CWS control (0.427+/-0.027 KPa) indicated that the system was able to generate a physiologic CWS wave form within 0.5% error of the peak desired CWS over each cardiac cycle. RMSE values for SS control (0.005+/-0.0007 dynescm(2)) indicated that the system

  1. ARRANGEMENT FOR REPLACING FILTERS

    DOEpatents

    Blomgren, R.A.; Bohlin, N.J.C.

    1957-08-27

    An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

  2. NARC Rayon Replacement Program

    NASA Technical Reports Server (NTRS)

    Wilson, Kenneth P.; McCool, Alex (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on the search for a replacement product for the aerospace grade rayon formerly used in the reusable solid rocket motor (RSRM). The rayon used in RSRMs is no longer produced by the North American Rayon Corporation (NARC), though NASA has stockpiled rayon to be used until a suitable replacement is found to be used in the RSRM nozzle carbon cloth phenolic (CCP). The primary considerations are performance, process ability, variability, long term availability, and cost. The preference will be given to commercial off-the-shelf products as opposed to those which are custom made. The candidate materials have been tested in previous phases of this selection process, and Enka Textile Rayon has emerged as a possible fabric, though its availability is still in question.

  3. Celotex (Registered) Replacement Study

    SciTech Connect

    Couture, S; Hafner, R

    2002-10-01

    The AL-R8 is the pit storage container in most widespread use at Pantex. The AL-R8 container family consists of standard 20-in.-diameter steel drums, 30 to 60 in. in height, with insulation inserts made of Celotex{reg_sign}--a fiberboard product made from processed sugar cane. Celotex is an acceptable material for inserts in many radioactive material shipping and storage containers. It is a good shock mitigator/insulator, does a fair job in fire protection (when oxygen is excluded), shielding, and criticality, and is inexpensive and easily available. However, the fiberboard absorbs water in humid environments which, when combined with chemical residues in the fiberboard, forms corrosive compounds that can shorten the life of the container and affect container contents. To protect the contents from this potentially damaging environment, the AL-R8 SI was developed to isolate the contents within a sealed stainless steel vessel inside the AL-R8. Although the SI protected the contents, corrosion studies indicated the SI lid bolts might corrode over time and surveillance showed that areas of the outer drum were still subject to corrosion. To address this potential problem, DOE/Albuquerque sponsored bolt and Celotex replacement studies. The bolt replacement study was assigned to Mason and Hanger's Pantex Facility and this Celotex Replacement Study to Lawrence Livermore National Laboratory. The Celotex Replacement Study evaluated options for replacing Celotex with a material that is chemically compatible with the AL-R8 SI container. The evaluation was limited to materials either used previously in nuclear materials shipping and storage containers or materials with known properties in a low-radiation environment. This limitation was set to ensure that the long-term aging effect on the new material is known a priori. Initial material evaluations narrowed the material choices to foam and cork. Although cork performed better than foam in some tests, cork was considered a less

  4. Hospital Ship Replacement

    DTIC Science & Technology

    2011-08-01

    designed to operate primarily when anchored to reduce the effects of roll. Quantum markets two separate zero speed active roll fin models for small ...ships. Feasibility of scaling fins to the size of the hospital ship requires validation. 3.12 Lifeboats and Liferafts The safety appliances designated ...for Innovation in Ship Design Technical Report Hospital Ship Replacement By Hannah Allison, Christopher Mehrvarzi, Rebecca Piks, Beau Lovdahl

  5. Renal Replacement Therapy

    PubMed Central

    Ricci, Zaccaria; Romagnoli, Stefano; Ronco, Claudio

    2016-01-01

    During the last few years, due to medical and surgical evolution, patients with increasingly severe diseases causing multiorgan dysfunction are frequently admitted to intensive care units. Therapeutic options, when organ failure occurs, are frequently nonspecific and mostly directed towards supporting vital function. In these scenarios, the kidneys are almost always involved and, therefore, renal replacement therapies have become a common routine practice in critically ill patients with acute kidney injury. Recent technological improvement has led to the production of safe, versatile and efficient dialysis machines. In addition, emerging evidence may allow better individualization of treatment with tailored prescription depending on the patients’ clinical picture (e.g. sepsis, fluid overload, pediatric). The aim of the present review is to give a general overview of current practice in renal replacement therapies for critically ill patients. The main clinical aspects, including dose prescription, modality of dialysis delivery, anticoagulation strategies and timing will be addressed. In addition, some technical issues on physical principles governing blood purification, filters characteristics, and vascular access, will be covered. Finally, a section on current standard nomenclature of renal replacement therapy is devoted to clarify the “Tower of Babel” of critical care nephrology. PMID:26918174

  6. Ulnar head replacement.

    PubMed

    Herbert, Timothy J; van Schoonhoven, Joerg

    2007-03-01

    Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioulnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the ulnar head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone ulnar head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert ulnar head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after ulnar head excision and that the materials (ceramic head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an ulnar head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for ulnar head replacement and details the surgical procedure, rehabilitation, and likely outcomes.

  7. Immediate total tooth replacement.

    PubMed

    Garber, D A; Salama, M A; Salama, H

    2001-03-01

    Successful implant placement at the time of extraction has been documented. Implant placement at the time of extraction was initially performed as a two-stage procedure often with barrier membranes and sophisticated second-stage surgical uncoverings. The authors describe the next generation of this technique, including atraumatic tooth removal with simultaneous root form, implant placement, and temporization at one appointment. This technique of "Immediate Total Tooth Replacement" allows for the maintenance of the bony housing and soft-tissue form that existed before extraction, while at the same time establishing a root form anchor in the bone for an esthetic restoration.

  8. Total ankle joint replacement.

    PubMed

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  9. Application of the line-spring model to a cylindrical shell containing a circumferential or axial part-through crack

    NASA Technical Reports Server (NTRS)

    Delale, F.; Erdogan, F.

    1981-01-01

    An approximate solution was obtained for a cylindrical shell containing a part-through surface crack. It was assumed that the shell contains a circumferential or axial semi-elliptic internal or external surface crack and was subjected to a uniform membrane loading or a uniform bending moment away from the crack region. A Reissner type theory was used to account for the effects of the transverse shear deformations. The stress intensity factor at the deepest penetration point of the crack was tabulated for bending and membrane loading by varying three dimensionless length parameters of the problem formed from the shell radius, the shell thickness, the crack length, and the crack depth. The upper bounds of the stress intensity factors are provided by the results of the elasticity solution obtained from the axisymmetric crack problem for the circumferential crack, and that found from the plane strain problem for a circular ring having a radial crack for the axial crack. The line-spring model gives the expected results in comparison with the elasticity solutions. Results also compare well with the existing finite element solution of the pressurized cylinder containing an internal semi-elliptic surface crack.

  10. Refinement and evaluation of crack-opening-area analyses for circumferential through-wall cracks in pipes

    SciTech Connect

    Rahman, S.; Brust, F.; Ghadiali, N.; Krishnaswamy, P.; Wilkowski, G.; Choi, Y.H. |; Moberg, F.; Brickstad, B. |

    1995-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for crack-opening-area analyses of pipes with circumferential through-wall cracks. Twenty-five pipe experiments were analyzed to determine the accuracy of the predictive models. Several practical aspects of crack-opening such as; crack-face pressure, off-center cracks, restraint of pressure-induced bending, cracks in thickness transition regions, weld residual stresses, crack-morphology models, and thermal-hydraulic analysis, were also investigated. 140 refs., 105 figs., 41 tabs.

  11. Effects of extensive circumferential periosteal stripping on the microstructure and mechanical properties of the murine femoral cortex.

    PubMed

    Mercurio, Andrew D; Motta, Tatiana; Green, Eric; Noble, Garrett; Hart, Richard T; Allen, Matthew J

    2012-04-01

    Extensive periosteal stripping (PS) is a risk factor for post-radiation pathologic fracture following surgery for extremity soft tissue tumors. The purpose of this study was to determine the effects of PS on bone structure and mechanical properties. Thirty-one skeletally mature mice underwent PS, with circumferential removal of periosteum from an 8-mm segment of the mid-diaphysis of the left femur. Thirty-one control mice underwent sham surgery in which the femur was isolated without manipulation of the periosteum. At 2, 6, 12, or 26 weeks following surgery, the left femora were examined by micro-CT to quantify cortical thickness (CtTh), cross-sectional area (CSA), bone volume (BV), and polar moment of inertia (PMI). Three-point mechanical bend testing was performed and peak load, stiffness, and energy to failure were determined. PS resulted in significantly decreased CtTh, CSA, BV, and PMI at all time points. Peak load, stiffness, and energy to failure were significantly reduced at 2, 6, and 12 weeks. There were no significant differences in mechanical properties at 26 weeks. In this mouse model, extensive circumferential PS resulted in sustained changes in bone structure that were still evident after 6 months, accompanied by reductions in bone strength that persisted for at least 3 months.

  12. The Aerodynamic Performance of an Over-the-Rotor Liner With Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

    NASA Technical Reports Server (NTRS)

    Bozak, Richard F.; Hughes, Christopher E.; Buckley, James

    2013-01-01

    While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1 percent which is within the repeatability of this experiment.

  13. The Aerodynamic Performance of an Over-The-Rotor Liner with Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

    NASA Technical Reports Server (NTRS)

    Bozak, Rick; Hughes, Christopher; Buckley, James

    2013-01-01

    While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1% which is within the repeatability of this experiment.

  14. Measurement of the longitudinal and circumferential muscular activity associated with peristalsis using a single fibre grating array

    NASA Astrophysics Data System (ADS)

    Arkwright, J. W.; Blenman, N. G.; Underhill, I. D.; Maunder, S. A.; Spencer, N. J.; Costa, M.; Brooks, S. J.; Szczesniak, M. M.; Dinning, P. G.

    2010-09-01

    Diagnostic catheters based on fibre Bragg gratings (FBG's) are proving to be highly effective for measurement of the muscular activity associated with peristalsis in the human gut. The primary muscular contractions that generate peristalsis are circumferential in nature; however, it has long been known that there is also a component of longitudinal contractility present, acting in harmony with the circumferential component to improve the overall efficiency of material movement. To date, there have been relatively few reports on the measurement or inference of longitudinal contractions in humans and all have been limited to detection at a single location only. This is due to the lack of a viable recording technique suitable for real-time in-vivo measurement of this type of activity over extended lengths of the gut. We report the detection of longitudinal motion in lengths of excised mammalian colon using an FBG technique that should be viable for similar detection in humans. The longitudinal sensors have been combined with our previously reported FBG pressure sensing elements to form a composite catheter that allows the relative phase between the two components to be detected. The catheter output has been validated using digital video mapping in an ex-vivo animal preparation using lengths of rabbit ileum.

  15. Power Plant Replacement Study

    SciTech Connect

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self‐funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty‐three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  16. Power Plant Replacement Study

    SciTech Connect

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University’s aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  17. Cadmium plating replacements

    SciTech Connect

    Nelson, M.J.; Groshart, E.C.

    1995-03-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  18. Total disc replacement.

    PubMed

    Vital, J-M; Boissière, L

    2014-02-01

    Total disc replacement (TDR) (partial disc replacement will not be described) has been used in the lumbar spine since the 1980s, and more recently in the cervical spine. Although the biomechanical concepts are the same and both are inserted through an anterior approach, lumbar TDR is conventionally indicated for chronic low back pain, whereas cervical TDR is used for soft discal hernia resulting in cervicobrachial neuralgia. The insertion technique must be rigorous, with precise centering in the disc space, taking account of vascular anatomy, which is more complex in the lumbar region, particularly proximally to L5-S1. All of the numerous studies, including prospective randomized comparative trials, have demonstrated non-inferiority to fusion, or even short-term superiority regarding speed of improvement. The main implant-related complication is bridging heterotopic ossification with resulting loss of range of motion and increased rates of adjacent segment degeneration, although with an incidence lower than after arthrodesis. A sufficiently long follow-up, which has not yet been reached, will be necessary to establish definitively an advantage for TDR, particularly in the cervical spine.

  19. Power Plant Replacement Study

    SciTech Connect

    Reed, Gary

    2010-09-30

    This report represents the final report for the Eastern Illinois University power plant replacement study. It contains all related documentation from consideration of possible solutions to the final recommended option. Included are the economic justifications associated with the chosen solution along with application for environmental permitting for the selected project for construction. This final report will summarize the results of execution of an EPC (energy performance contract) investment grade audit (IGA) which lead to an energy services agreement (ESA). The project includes scope of work to design and install energy conservation measures which are guaranteed by the contractor to be self-funding over its twenty year contract duration. The cost recovery is derived from systems performance improvements leading to energy savings. The prime focus of this EPC effort is to provide a replacement solution for Eastern Illinois University's aging and failing circa 1925 central steam production plant. Twenty-three ECMs were considered viable whose net impact will provide sufficient savings to successfully support the overall project objectives.

  20. Cadmium plating replacements

    NASA Technical Reports Server (NTRS)

    Nelson, Mary J.; Groshart, Earl C.

    1995-01-01

    The Boeing Company has been searching for replacements to cadmium plate. Two alloy plating systems seem close to meeting the needs of a cadmium replacement. The two alloys, zinc-nickel and tin-zinc are from alloy plating baths; both baths are neutral pH. The alloys meet the requirements for salt fog corrosion resistance, and both alloys excel as a paint base. Currently, tests are being performed on standard fasteners to compare zinc-nickel and tin-zinc on threaded hardware where cadmium is heavily used. The Hydrogen embrittlement propensity of the zinc-nickel bath has been tested, and just beginning for the tin-zinc bath. Another area of interest is the electrical properties on aluminum for tin-zinc and will be discussed. The zinc-nickel alloy plating bath is in production in Boeing Commercial Airplane Group for non-critical low strength steels. The outlook is promising that these two coatings will help The Boeing Company significantly reduce its dependence on cadmium plating.

  1. Sutureless aortic valve replacement

    PubMed Central

    Phan, Kevin

    2015-01-01

    The increasing incidence of aortic stenosis and greater co-morbidities and risk profiles of the contemporary patient population has driven the development of minimally invasive aortic valve surgery and percutaneous transcatheter aortic valve implantation (TAVI) techniques to reduce surgical trauma. Recent technological developments have led to an alternative minimally invasive option which avoids the placement and tying of sutures, known as “sutureless” or rapid deployment aortic valves. Potential advantages for sutureless aortic prostheses include reducing cross-clamp and cardiopulmonary bypass (CPB) duration, facilitating minimally invasive surgery and complex cardiac interventions, whilst maintaining satisfactory hemodynamic outcomes and low paravalvular leak rates. However, given its recent developments, the majority of evidence regarding sutureless aortic valve replacement (SU-AVR) is limited to observational studies and there is a paucity of adequately-powered randomized studies. Recently, the International Valvular Surgery Study Group (IVSSG) has formulated to conduct the Sutureless Projects, set to be the largest international collaborative group to investigate this technology. This keynote lecture will overview the use, the potential advantages, the caveats, and current evidence of sutureless and rapid deployment aortic valve replacement (AVR). PMID:25870807

  2. Antenna grout replacement system

    NASA Technical Reports Server (NTRS)

    Mcclung, C. E. (Inventor)

    1983-01-01

    An epoxy grout suitable for use in mounting and positioning bearing runner plates used in hydrostatic bearing assemblies for rotatably mounting large radio telescope structures to stationary support pedestals is described. The epoxy grout may be used in original mountings or may be used as part of a replacement system for repairing cavities in existing grout resulting from grout deterioration. The epoxy grout has a relatively short work life and cure time even in the presence of hydraulic oil. The epoxy grout cures without shrinking or sagging to form a grout which is sufficiently strong and durable to provide a grout especially well suited for use under the high pressure loading and close tolerance requirements of large hydrostatic bearing assemblies.

  3. Functional replacements for gluten.

    PubMed

    Zannini, Emanuele; Jones, Julie Miller; Renzetti, Stefano; Arendt, Elke K

    2012-01-01

    Celiac disease (CD) is an immune-mediated disease triggered in genetically susceptible individuals by ingested gluten from wheat, rye, barley, and other closely related cereal grains. Currently, the only therapy able to normalize the clinical and histological manifestation of the disease is a strict and life-long gluten-free (GF) diet. The replacement of gluten presents a significant technological challenge, as it is an essential structure-building protein, which is necessary for formulating high-quality baked goods. The objective of this paper is to review some basics about CD, its current prevalence, and the recent advances in the preparation of high-quality GF breads using GF flours, starches, hydrocolloids, gums, and novel functional ingredients and technologies.

  4. Hormone replacement therapy and longevity.

    PubMed

    Comhaire, F

    2016-02-01

    To assess whether hormone replacement therapy influences longevity, an analysis was made of published life tables allowing for the calculation of the relative benefit of hormone replacement therapy on longevity in men with late onset hypogonadism and in post-menopausal women. It was found that testosterone replacement therapy of men suffering from late onset hypogonadism increased survival rate by 9-10% in 5 years, similar to that of eugonadal, non-LOH men with normal endogenous testosterone secretion. Oestrogen replacement therapy resulted in increased survival by 2.6% in 5 years. It is concluded that hormone replacement therapy increases longevity.

  5. Effects of radial and circumferential inlet velocity profile distortions on performance of a short-length double-annular ram induction combustor

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Perkins, P. J.

    1972-01-01

    Inlet air velocity profile tests were conducted on a full-scale short-length 102-centimeter-diameter annual combustor designed for advanced gas turbine engine applications. The inlet profiles studied include radial distortions that were center peaked, and tip peaked, as well as a circumferential distortion which was center peaked for one-third of the circumference and flat for the other two-thirds. An increase in combustor pressure loss was the most significant effect of the radial air velocity distortions. With the circumferential distortion, exit temperature pattern factor doubled when compared to a flat velocity profile.

  6. Aortic valve leaflet replacement with bovine pericardium to preserve native dynamic capabilities of the aortic annulus.

    PubMed

    Kim, Kyung Hwa; Choi, Jong Bum; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn

    2014-02-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations.

  7. Aortic Valve Leaflet Replacement with Bovine Pericardium to Preserve Native Dynamic Capabilities of the Aortic Annulus

    PubMed Central

    Kim, Kyung Hwa; Kim, Min Ho; Kim, Won Ho; Lee, Mi Kyung; Lee, Sam Youn

    2014-01-01

    Valve replacement is typically the most appropriate option for treating aortic valve stenotic insufficiency. However, neither mechanical nor bioprosthetic replacement components preserve the circumferential expansion and contraction of a native aortic annulus during the cardiac cycle, because the prosthetic ring is affixed to the annulus. A 64-year-old man presented with a bicuspid and stenotic aortic valve, and the native annulus was too small to accommodate a porcine replacement valve. We fashioned new aortic leaflets from bovine pericardium with use of a template, and we affixed the sinotubular junction with use of inner and outer stabilization rings. Postoperative echocardiograms revealed coaptation of the 3 new leaflets with no regurgitation. At the patient's 5.5-year follow-up examination, echocardiograms showed flexible leaflet movement with a coaptation height of 7 mm, and expansion and contraction of the aortic annulus similar to that of a normal native annulus. The transvalvular pressure gradient was insignificant. If long-term durability of the new leaflets is confirmed, this method of leaflet replacement and fixation of the sinotubular junction might serve as an acceptable alternative to valve replacement in the treatment of aortic valve stenosis. We describe the patient's case and present our methods and observations. PMID:24512414

  8. Transverse shear effects on the stress-intensity factor for a circumferentially cracked, specially orthotropic cylindrical shell

    NASA Technical Reports Server (NTRS)

    Delale, F.; Erdogan, F.

    1977-01-01

    The problem of a cylindrical shell containing a circumferential through crack is considered by taking into account the effect of transverse shear deformations. The formulation is given for a specially orthotropic material within the confines of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions regarding moment and stress resultants on the crack surface. Consequently, aside from multiplicative constants representing the stress intensity factors, the membrane and bending components of the asymptotic stress fields near the crack tip are found to be identical. The stress intensity factors are calculated separately for a cylinder under a uniform membrane load, and that under a uniform bending moment. Sample results showing the nature of the out-of-plane crack surface displacement and the effect of the Poisson's ratio are presented.

  9. High-Density Electron-Beam Recording of Circumferentially Aligned Dots by Using Substrates with Low Atomic Numbers

    NASA Astrophysics Data System (ADS)

    Okada, Takeru; Aida, Makoto; Fujimori, Jiro; Katsumura, Masahiro; Iida, Tetsuya

    2012-01-01

    Reducing proximity effects is a key factor for achieving a higher resolution in electron-beam lithography and realizing the mastering of patterned media. The effect of substrate materials on backscattering electrons was investigated by simulation and experiment, and resolution enhancement was demonstrated. In Monte Carlo simulations with 100 keV incident electrons, the intensity of backscattering electrons decreased with decreasing atomic number of substrates. On the other hand, both the density of substrates and the existence of 10 nm thin films had negligible effects on the intensity of backscattering electrons. The measured exposure distributions from line-scanned electron beams supported the results of simulations. The intensity of backscattering electrons was reduced by using a carbon substrate, and circumferentially aligned high-density patterns of 878 Gbit/in.2 were resolved.

  10. Circumferential targeted renal sympathetic nerve denervation with preservation of the renal arterial wall using intra-luminal ultrasound

    NASA Astrophysics Data System (ADS)

    Roth, Austin; Coleman, Leslie; Sakakura, Kenichi; Ladich, Elena; Virmani, Renu

    2015-03-01

    An intra-luminal ultrasound catheter system (ReCor Medical's Paradise System) has been developed to provide circumferential denervation of the renal sympathetic nerves, while preserving the renal arterial intimal and medial layers, in order to treat hypertension. The Paradise System features a cylindrical non-focused ultrasound transducer centered within a balloon that circulates cooling fluid and that outputs a uniform circumferential energy pattern designed to ablate tissues located 1-6 mm from the arterial wall and protect tissues within 1 mm. RF power and cooling flow rate are controlled by the Paradise Generator which can energize transducers in the 8.5-9.5 MHz frequency range. Computer simulations and tissue-mimicking phantom models were used to develop the proper power, cooling flow rate and sonication duration settings to provide consistent tissue ablation for renal arteries ranging from 5-8 mm in diameter. The modulation of these three parameters allows for control over the near-field (border of lesion closest to arterial wall) and far-field (border of lesion farthest from arterial wall, consisting of the adventitial and peri-adventitial spaces) depths of the tissue lesion formed by the absorption of ultrasonic energy and conduction of heat. Porcine studies have confirmed the safety (protected intimal and medial layers) and effectiveness (ablation of 1-6 mm region) of the system and provided near-field and far-field depth data to correlate with bench and computer simulation models. The safety and effectiveness of the Paradise System, developed through computer model, bench and in vivo studies, has been demonstrated in human clinical studies.

  11. Task IV: Development of Circumferential Inlet Distortion through a Representative Eleven Stage High-speed Axial Compressor

    NASA Technical Reports Server (NTRS)

    Tan, Choon-Sooi; Suder, Kenneth (Technical Monitor)

    2003-01-01

    The concepts and the procedure developed in Task I and Task III were used to determine the response of an eleven-stage high-speed compressor to an inlet distortion of 180 deg. circumferential extent for contrasting against its performance under uniform inlet flow. Using the computed results at the inlet to and outlet of the compressor, the computed total pressure ratio and efficiency for the clean condition are determined to be 14.22 and 76.9 percent respectively. As for the distorted case, these are determined to be 10.35 and 71.8 percent respectively, showing deterioration 76.9 percent vs 71.8 percent). The physical consistency of the computed flow field was assessed as a means of demonstrating the applicability and utility of the body force representation for inlet distortion computations. Specifically the computed evolution of the distorted pattern in static pressure and total pressure from compressor inlet to exit is examined. For the eleven-stage compressor examined here, the deterioration in performance has been found to be particularly severe in the last 2 stages. This suggests that the last two stages could be redesigned to alleviate the observed deterioration thus making the compressor performance insensitive to circumferential inlet distortion. This can potentially be accomplished by first determining what should the body force distribution of the last two stages should be to achieve minimal or no deterioration in performance in the last two stages. One can then in principle proceed to determine the blade design to yield such a body force distribution.

  12. CFD Study of the Hydrocarbon Boost Low-Pressure Inducer and Kicker in the Presence of a Circumferential Groove

    NASA Technical Reports Server (NTRS)

    Coker, Robert

    2011-01-01

    Results are presented of a computational fluid dynamics (CFD) study done in support of Marshall Space Flight Center's (MSFC) sub-scale water flow experiments of the Hydrocarbon Boost (HCB) Oxidizer Turbopump (OTP) being developed by the Air Force Research Laboratory (AFRL) and Aerojet. A circumferential groove may be added to the pump to reduce synchronous cavitation and subsequent bearing loads at a minimal performance cost. However, the energy may reappear as high order cavitation (HOC) that spans a relatively large frequency range. Thus, HOC may have implications for the full-scale OTP inducer in terms of reduced structural margin at higher mode frequencies. Simulations using the LOCI/Stream CFD program were conducted in order to explore the fluid dynamical impact of the groove on the low-pressure inducer and kicker. It was found that the circumferential groove has minimal head performance impact, but causes back-flowing high-swirl fluid to interact with the nearly-axial incoming fluid just above the inducer blades. The high-shear interface between the fluids is Kelvin-Helmholtz unstable, resulting in trains of low pressure regions or 'pearls' forming near the upstream edge of the groove. When the static pressure in these regions becomes low enough and they get cut by the blade leading edge, HOC is thought to occur. Although further work is required, the numerical models indicate that HOC will occur in the runbox of the AFRL/Aerojet HCB OTP. Comparisons to the ongoing water flow experiments will be discussed, as well as possible designs that may mitigate HOC while continuing to reduce synchronous cavitation. December 2011 MSS/LPS/SPS Joint Subcommittee Meeting ABSTRACT SUBMITTAL FORM

  13. Single implant tooth replacement.

    PubMed

    Briley, T F

    1998-01-01

    It has been shown that direct bone anchorage of dental implants will provide long-term predictability for single tooth implants and multi-unit implants. The function of implant-supported restoration is now routinely achieved. The real challenge facing the restorative dentist and laboratory technician is to achieve optimal aesthetics. The learning objective of this article is to review the prosthodontic procedures essential to maximizing natural aesthetics in implant supported restorations. It will provide a review of master impression techniques, prepable titanium abutments and designing the cement on restoration. Particular emphasis is directed to the soft tissue model from which a series of sequenced techniques can be followed to achieve optimal aesthetics. Analysis of the implant alignment with regard to the neighboring teeth will result in having to make a choice of which prepable abutment will maximize the aesthetic result. The following case outlines how to replace a single missing tooth using an externally hexed implant system and a prefabricated titanium abutment on a 26-year-old male patient.

  14. Reuse, replace, recycle

    PubMed Central

    McMurray, Michael A.; Thorner, Jeremy W.

    2015-01-01

    Septins are guanine nucleotide-binding proteins that form hetero-oligomeric complexes, which assemble into filaments and higher-order structures at sites of cell division and morphogenesis in eukaryotes. Dynamic changes in the organization of septin-containing structures occur concomitantly with progression through the mitotic cell cycle and during cell differentiation. Septins also undergo stage-specific post-translational modifications, which have been implicated in regulating their dynamics, in some cases via purported effects on septin turnover. In our recent study, the fate of two of the five septins expressed in mitotic cells of budding yeast (Saccharomyces cerevisiae) was tracked using two complementary fluorescence-based methods for pulse-chase analysis. During mitotic growth, previously-made molecules of both septins (Cdc10 and Cdc12) persisted through multiple successive divisions and were incorporated equivalently with newly synthesized molecules into hetero-oligomers and higher-order structures. Similarly, in cells undergoing meiosis and the developmental program of sporulation, pre-existing copies of Cdc10 were incorporated into new structures. In marked contrast, Cdc12 was irreversibly excluded from septin complexes and replaced by another septin, Spr3. Here, we discuss the broader implications of these results and related findings with regard to how septin dynamics is coordinated with the mitotic cell cycle and in the yeast life cycle, and how these observations may relate to control of the dynamics of other complex multi-subunit assemblies. PMID:19164941

  15. Antenna Controller Replacement Software

    NASA Technical Reports Server (NTRS)

    Chao, Roger Y.; Morgan, Scott C.; Strain, Martha M.; Rockwell, Stephen T.; Shimizu, Kenneth J.; Tehrani, Barzia J.; Kwok, Jaclyn H.; Tuazon-Wong, Michelle; Valtier, Henry; Nalbandi, Reza; Wert, Michael; Leung, Patrick

    2010-01-01

    The Antenna Controller Replacement (ACR) software accurately points and monitors the Deep Space Network (DSN) 70-m and 34-m high-efficiency (HEF) ground-based antennas that are used to track primarily spacecraft and, periodically, celestial targets. To track a spacecraft, or other targets, the antenna must be accurately pointed at the spacecraft, which can be very far away with very weak signals. ACR s conical scanning capability collects the signal in a circular pattern around the target, calculates the location of the strongest signal, and adjusts the antenna pointing to point directly at the spacecraft. A real-time, closed-loop servo control algorithm performed every 0.02 second allows accurate positioning of the antenna in order to track these distant spacecraft. Additionally, this advanced servo control algorithm provides better antenna pointing performance in windy conditions. The ACR software provides high-level commands that provide a very easy user interface for the DSN operator. The operator only needs to enter two commands to start the antenna and subreflector, and Master Equatorial tracking. The most accurate antenna pointing is accomplished by aligning the antenna to the Master Equatorial, which because of its small size and sheltered location, has the most stable pointing. The antenna has hundreds of digital and analog monitor points. The ACR software provides compact displays to summarize the status of the antenna, subreflector, and the Master Equatorial. The ACR software has two major functions. First, it performs all of the steps required to accurately point the antenna (and subreflector and Master Equatorial) at the spacecraft (or celestial target). This involves controlling the antenna/ subreflector/Master-Equatorial hardware, initiating and monitoring the correct sequence of operations, calculating the position of the spacecraft relative to the antenna, executing the real-time servo control algorithm to maintain the correct position, and

  16. The effect of non-uniform bending deformation on the stability of circumferential growth of through-wall cracks in brass tubes

    NASA Astrophysics Data System (ADS)

    Smith, E.; Wilding, M. J.

    EXPERIMENTAL results on the stability of circumferential growth of through-wall cracks in brass tubes, show that non-uniform bending can adversely affect the crack stability criterion. The results are relevant to the important technological problem of crack stability in 304 stainless steel pipes used in Boiling Water Reactors.

  17. An Experimental Study on the Ultimate Strength of the Adventitia and Media of Human Atherosclerotic Carotid Arteries in Circumferential and Axial Directions

    PubMed Central

    Teng, Zhongzhao; Tang, Dalin; Zheng, Jie; Woodard, Pamela K.; Hoffman, Allen H.

    2009-01-01

    Atherosclerotic plaque may rupture without warning causing heart attack or stroke. Knowledge of the ultimate strength of human atherosclerotic tissues is essential for understanding the rupture mechanism and predicting cardiovascular events. Despite its great importance, experimental data on ultimate strength of human atherosclerotic carotid artery remains very sparse. This study determined the uniaxial tensile strength of human carotid artery sections containing type II and III lesions (AHA classifications). Axial and circumferential oriented adventitia, media and intact specimens (total=73) were prepared from 6 arteries. The ultimate strength in uniaxial tension was taken as the peak stress recorded when the specimen showed the first evidence of failure and the extensibility was taken as the stretch ratio at failure. The mean adventitia strength values calculated using the 1st Piola-Kirchoff stress were 1996±867kPa and 1802±703kPa in the axial and circumferential directions respectively, while the corresponding values for the media sections were 519±270kPa and 1230±533kPa. The intact specimens showed ultimate strengths similar to media in circumferential direction but were twice as strong as the media in the axial direction. Results also indicated that adventitia, media and intact specimens exhibited similar extensibility at failure, in both the axial and circumferential directions (stretch ratio 1.50 +/−0.22). These measurements of the material strength limits for human atherosclerotic carotid arteries could be useful in improving computational models that assess plaque vulnerability. PMID:19665126

  18. Using your shoulder after replacement surgery

    MedlinePlus

    Joint replacement surgery - using your shoulder; Shoulder replacement surgery - after ... You have had shoulder replacement surgery to replace the bones of your shoulder joint with artificial parts. The parts include a stem made of metal and a ...

  19. The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

    USGS Publications Warehouse

    Chadwick, W.W.; Jonsson, Sigurjon; Geist, Dennis J.; Poland, M.; Johnson, Daniel J.; Batt, S.; Harpp, Karen S.; Ruiz, A.

    2011-01-01

    The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45–60°) toward the caldera at the surface and more gently dipping (~12–14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another.

  20. Educating My Replacement

    NASA Astrophysics Data System (ADS)

    Tarter, Jill

    , in partnership with the dedicated teachers out there, I think I can help promote the critical thinking skills and scientific literacy of the next generation of voters. Hopefully, I can also help train my replacement to be a better scientist, capable of seizing all the opportunities generated by advances in technology and our improved understanding of the universe to craft search strategies with greater probability of success than those I have initiated.

  1. [Ascending aorta replacement late after aortic valve replacement].

    PubMed

    Hayashi, Yasunari; Ito, Toshiaki; Maekawa, Atsuo; Sawaki, Sadanari; Fujii, Genyo; Hoshino, Satoshi; Tokoro, Masayoshi; Yanagisawa, Junji

    2013-07-01

    Replacement of the asceding aorta is indicated in patients undergoing aortic valve replacement( AVR), if the diameter of the ascending aorta is greater than 5.0 cm. If the diameter of the asceding aorta is from 4.0 to 5.0 cm, it was arguable whether replacement of the ascending aorta should be performed. Nine patients who underwent reoperative ascending aorta replacement after AVR were reviewed retrospectively. Reoperation on the asending aorta replacement was performed 11.8±7.2 years (range 1y5m~23y3m) after AVR. Mean patient age was 69.9±6.3 (range 60~81). In 2 cases, reoperations were performed early year after AVR. Although ascending aorta was dilated at the 1st operation, replacement wasn't performed for the age and minimally invasive cardiac surgery (MICS). In 3 cases, reoperations were performed more than 10 years later. On these cases, ascending aorta aneurysm and dissection occurred with no pain and were pointed out by computed tomography(CT) or ultrasonic cardiogram(UCG). We think that patients with dilatation of the ascending aorta should undergo AVR and aorta replacement at the 1st operation regardness of age. It is important that patients who underwent AVR should undergo a regular checkup on the ascending aorta.

  2. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  3. Elbow Reconstruction With Compression Plate Arthrodesis and Circumferential Muscle-Sparing Latissimus Dorsi Flap After Tumor Resection

    PubMed Central

    Ng, Zhi Yang; Ramachandran, Savitha; Tan, Bien-Keem; Foo, Leon; Ng, Siew-Weng

    2016-01-01

    Background: The goals of limb-sparing surgery in the setting of extremity malignancies are 2-fold: oncological clearance and the rehabilitation of function and aesthetics. Treatment success should be defined by the extent of restoration of the patient’s premorbid function for reintegration into society. Methods: We would like to report an unusual case of a patient with a chronically ankylosed elbow with joint invasion by basal cell carcinoma which resulted from malignant transformation of an overlying, long-standing wound due to inadequately treated septic arthritis from his childhood years. Results: Following R0 resection, upper limb shortening and compression plate elbow arthrodesis were performed with the aim of restoring the degree of upper limb function that the patient had been accustomed to preoperatively. The resultant circumferential defect was then closed with a contralateral, free muscle-sparing latissimus dorsi flap. Conclusions: Functional preservation may therefore be more important than the mere restoration of anatomical defects in these especially challenging situations. PMID:27418897

  4. Contribution to the leak before break behavior of piping made of high tough material and containing circumferential flaws

    SciTech Connect

    Stadtmueller, W.; Sturm, D.

    1996-12-31

    Since 1993 MPA Stuttgart is engaged in two new research projects in the field of Leak-Before-Break (LBB) behavior of austenitic piping. The pipes are fabricated in the dimensions O.D. {times} t = 219 x 14 mm resp. 331 x 32 mm and prepared with fatigue precracked, circumferential flaws of various depth and up to a crack length equivalent to 2{alpha} = 270 deg. The flaw location is in the base material or in site-made girth welds. The pipes are loaded with internal pressure and external bending moment at room temperature. In this paper the results of the tested pipes with 219 mm diameter containing through-wall flaws are represented as a comparison with the results of applied analytical methods. On these pipes the crack initiation clearly occurred before maximum bending moment, which was attained under full yielding conditions even in case of the 180 deg through-wall flaw. With the applied analytical methods crack initiation as well as maximum load could be assessed in a realistic manner.

  5. Fracture After Total Hip Replacement

    MedlinePlus

    ... er Total Hip Replacement cont. • Dislocation • Limb length inequality • Poor fracture healing • Repeat fracture • Lack of in- ... Surgeons (AAOS). To learn more about your orthopaedic health, please visit orthoinfo.org. Page ( 5 ) AAOS does ...

  6. Options for Heart Valve Replacement

    MedlinePlus

    ... which may include human or animal donor tissue) Ross Procedure — “Borrowing” your healthy valve and moving it ... Considerations for Surgery Medications Valve Repair Valve Replacement - Ross Procedure - Newer Surgery Options - What is TAVR? - Types ...

  7. Single Project Replaces District's Windows.

    ERIC Educational Resources Information Center

    American School and University, 1981

    1981-01-01

    The towns of Maplewood and South Orange (New Jersey) earmarked over $1 million, raised from a bond issue, to replace with thermal aluminum-framed units the 2400 worn out windows in eight 50-year-old schools. (Author)

  8. Prioritization Methodology for Chemical Replacement

    NASA Technical Reports Server (NTRS)

    Cruit, W.; Schutzenhofer, S.; Goldberg, B.; Everhart, K.

    1993-01-01

    This project serves to define an appropriate methodology for effective prioritization of efforts required to develop replacement technologies mandated by imposed and forecast legislation. The methodology used is a semiquantitative approach derived from quality function deployment techniques (QFD Matrix). This methodology aims to weigh the full environmental, cost, safety, reliability, and programmatic implications of replacement technology development to allow appropriate identification of viable candidates and programmatic alternatives. The results are being implemented as a guideline for consideration for current NASA propulsion systems.

  9. Influence of circumferential notch and fatigue crack on the mechanical integrity of biodegradable magnesium-based alloy in simulated body fluid.

    PubMed

    Bobby Kannan, M; Singh Raman, R K; Witte, F; Blawert, C; Dietzel, W

    2011-02-01

    Applications of magnesium alloys as biodegradable orthopaedic implants are critically dependent on the mechanical integrity of the implant during service. In this study, the mechanical integrity of an AZ91 magnesium alloy was studied using a constant extension rate tensile (CERT) method. The samples in two different geometries that is, circumferentially notched (CN), and circumferentially notched and fatigue cracked (CNFC), were tested in air and in simulated body fluid (SBF). The test results show that the mechanical integrity of the AZ91 magnesium alloy decreased substantially (∼50%) in both the CN and CNFC samples exposed to SBF. Fracture surface analysis revealed secondary cracks suggesting stress corrosion cracking susceptibility of the alloy in SBF.

  10. Method and Apparatus for Determining Changes in Intracranial Pressure Utilizing Measurement of the Circumferential Expansion or Contraction of a Patient's Skull

    NASA Technical Reports Server (NTRS)

    Yos, William T. (Inventor); Cantrell, John H., Jr. (Inventor)

    2004-01-01

    A method and apparatus for measuring changes in intracranial pressure (ICP) utilizing the variation of the surface wave propagation parameters of the patient's skull to determine the change in ICP. In one embodiment, the method comprises the steps of transmitting an ultrasonic bulk compressional wave onto the surface of the skull at a predetermined angle with respect to the skull so as to produce a surface wave, receiving the surface wave at an angle with respect tn the skull which is substantially the same as the predetermined angle and at a location that is a predetermined distance from where the ultrasonic bulk compressional wave was transmitted upon the skull, determining the retardation or advancement in phase of the received surface wave with respect to a reference phase, and processing the determined retardation or advancement in phase to determine circumferential expansion or contraction of the skull and utilizing the determined circumferential change to determine the change in intracranial pressure.

  11. Propagation and radiation of sound from flanged circular ducts with circumferentially varying wall admittances. I Semi-infinite ducts. II - Finite ducts with sources

    NASA Technical Reports Server (NTRS)

    Fuller, C. R.

    1984-01-01

    Sound propagation in infinite, semiinfinite, and finite circular ducts with circumferentially varying wall admittances is investigated analytically. The infinite case is considered, and an example demonstrates the effects of wall-admittance distribution on dispersion characteristics and mode shapes. An exact solution is obtained for the semiinfinite case, a circular duct with a flanged opening: sidelobe suppression and circumferential-mode energy scattering leading to radiated-field asymmetry are found. A finite duct system with specified hard-walled pressure sources is examined in detail, evaluating reflection coefficients, transmission losses, and radiated-field directivity. Graphs and diagrams are provided, and the implications of the results obtained for the design of aircraft-turbofan inlet liners are discussed.

  12. Blade row dynamic digital compression program. Volume 2: J85 circumferential distortion redistribution model, effect of Stator characteristics, and stage characteristics sensitivity study

    NASA Technical Reports Server (NTRS)

    Tesch, W. A.; Steenken, W. G.

    1978-01-01

    The results of dynamic digital blade row compressor model studies of a J85-13 engine are reported. The initial portion of the study was concerned with the calculation of the circumferential redistribution effects in the blade-free volumes forward and aft of the compression component. Although blade-free redistribution effects were estimated, no significant improvement over the parallel-compressor type solution in the prediction of total-pressure inlet distortion stability limit was obtained for the J85-13 engine. Further analysis was directed to identifying the rotor dynamic response to spatial circumferential distortions. Inclusion of the rotor dynamic response led to a considerable gain in the ability of the model to match the test data. The impact of variable stator loss on the prediction of the stability limit was evaluated. An assessment of measurement error on the derivation of the stage characteristics and predicted stability limit of the compressor was also performed.

  13. Ultrasound speckle tracking for radial, longitudinal and circumferential strain estimation of the carotid artery--an in vitro validation via sonomicrometry using clinical and high-frequency ultrasound.

    PubMed

    Larsson, Matilda; Heyde, Brecht; Kremer, Florence; Brodin, Lars-Åke; D'hooge, Jan

    2015-02-01

    Ultrasound speckle tracking for carotid strain assessment has in the past decade gained interest in studies of arterial stiffness and cardiovascular diseases. The aim of this study was to validate and directly contrast carotid strain assessment by speckle tracking applied on clinical and high-frequency ultrasound images in vitro. Four polyvinyl alcohol phantoms mimicking the carotid artery were constructed with different mechanical properties and connected to a pump generating carotid flow profiles. Gray-scale ultrasound long- and short-axis images of the phantoms were obtained using a standard clinical ultrasound system, Vivid 7 (GE Healthcare, Horten, Norway) and a high-frequency ultrasound system, Vevo 2100 (FUJIFILM, VisualSonics, Toronto, Canada) with linear-array transducers (12L/MS250). Radial, longitudinal and circumferential strains were estimated using an in-house speckle tracking algorithm and compared with reference strain acquired by sonomicrometry. Overall, the estimated strain corresponded well with the reference strain. The correlation between estimated peak strain in clinical ultrasound images and reference strain was 0.91 (p<0.001) for radial strain, 0.73 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain and for high-frequency ultrasound images 0.95 (p<0.001) for radial strain, 0.93 (p<0.001) for longitudinal strain and 0.90 (p<0.001) for circumferential strain. A significant larger bias and root mean square error was found for circumferential strain estimation on clinical ultrasound images compared to high frequency ultrasound images, but no significant difference in bias and root mean square error was found for radial and longitudinal strain when comparing estimation on clinical and high-frequency ultrasound images. The agreement between sonomicrometry and speckle tracking demonstrates that carotid strain assessment by ultrasound speckle tracking is feasible.

  14. Prioritization methodology for chemical replacement

    NASA Technical Reports Server (NTRS)

    Cruit, Wendy; Goldberg, Ben; Schutzenhofer, Scott

    1995-01-01

    Since United States of America federal legislation has required ozone depleting chemicals (class 1 & 2) to be banned from production, The National Aeronautics and Space Administration (NASA) and industry have been required to find other chemicals and methods to replace these target chemicals. This project was initiated as a development of a prioritization methodology suitable for assessing and ranking existing processes for replacement 'urgency.' The methodology was produced in the form of a workbook (NASA Technical Paper 3421). The final workbook contains two tools, one for evaluation and one for prioritization. The two tools are interconnected in that they were developed from one central theme - chemical replacement due to imposed laws and regulations. This workbook provides matrices, detailed explanations of how to use them, and a detailed methodology for prioritization of replacement technology. The main objective is to provide a GUIDELINE to help direct the research for replacement technology. The approach for prioritization called for a system which would result in a numerical rating for the chemicals and processes being assessed. A Quality Function Deployment (QFD) technique was used in order to determine numerical values which would correspond to the concerns raised and their respective importance to the process. This workbook defines the approach and the application of the QFD matrix. This technique: (1) provides a standard database for technology that can be easily reviewed, and (2) provides a standard format for information when requesting resources for further research for chemical replacement technology. Originally, this workbook was to be used for Class 1 and Class 2 chemicals, but it was specifically designed to be flexible enough to be used for any chemical used in a process (if the chemical and/or process needs to be replaced). The methodology consists of comparison matrices (and the smaller comparison components) which allow replacement technology

  15. Optimization of station battery replacement

    NASA Astrophysics Data System (ADS)

    Jancauskas, J. R.; Shook, D. A.

    1994-08-01

    During a loss of ac power at a nuclear generating station (including diesel generators), batteries provide the source of power which is required to operate safety-related components. Because traditional lead-acid batteries have a qualified life of 20 years, the batteries must be replaced a minimum of once during a station's lifetime, twice if license extension is pursued, and more often depending on actual in-service dates and the results of surveillance tests. Replacement of batteries often occurs prior to 20 years as a result of systems changes caused by factors such as Station Blackout Regulations, control system upgrades, incremental load growth, and changes in the operating times of existing equipment. Many of these replacement decisions are based on the predictive capabilities of manual design basis calculations. The inherent conservatism of manual calculations may result in battery replacements occurring before actually required. Computerized analysis of batteries can aid in optimizing the timing of replacements as well as in interpreting service test data. Computerized analysis also provides large benefits in maintaining the as-configured load profile and corresponding design margins, while also providing the capability to quickly analyze proposed modifications and respond to internal and external audits.

  16. [Hip replacement in military personnel].

    PubMed

    Maksimov, I B; Paniushin, K A; Brizhan', L K; Buriachenko, B P; Varfolomeev, D I; Mimanchev, O V

    2014-01-01

    Hip joint diseases and injuries are common for orthopedic pathology among military personnel. Hip replacement is one of the most frequent operations. Authors evaluated hip replacement in 136 servicemen treated at the center of traumatology and orthopedics of Burdenko General Military Clinical Hospital of the Ministry of Defense of Russia in 2010-2013. On the basis of the conducted analysis the main disease groups were revealed, peculiarities of pathology among this category of patients. Authors proposed surgical doctrine for the treatment of this contingent. Effective surgical treatment, in particular, hip replacement surgery, conducted with the use of the proposed principles, as a rule, fully functionally cured patients and contributes to return them in the system that contributes to the strengthening of defensibility of the country.

  17. HST Replacement Battery Initial Performance

    NASA Technical Reports Server (NTRS)

    Krol, Stan; Waldo, Greg; Hollandsworth, Roger

    2009-01-01

    The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

  18. Prioritization methodology for chemical replacement

    NASA Technical Reports Server (NTRS)

    Goldberg, Ben; Cruit, Wendy; Schutzenhofer, Scott

    1995-01-01

    This methodology serves to define a system for effective prioritization of efforts required to develop replacement technologies mandated by imposed and forecast legislation. The methodology used is a semi quantitative approach derived from quality function deployment techniques (QFD Matrix). QFD is a conceptual map that provides a method of transforming customer wants and needs into quantitative engineering terms. This methodology aims to weight the full environmental, cost, safety, reliability, and programmatic implications of replacement technology development to allow appropriate identification of viable candidates and programmatic alternatives.

  19. Will peanut hulls replace oil

    SciTech Connect

    Not Available

    1980-12-01

    A low-cost, fast-curing wood adhesive has been recently developed by the University of Georgia, in which up to 80% of the petroleum ingredients can be replaced with a substance extracted from peanut hulls. An outline of the process is given.

  20. Replaceable Sleeve Protects Welder Coil

    NASA Technical Reports Server (NTRS)

    Baker, W. L.; Simpson, C., E.

    1983-01-01

    New replaceable carbon insert for deflection coil in electron-beam welder promises to decrease maintenance costs. Inserts made from materials other than carbon (not yet tried) are less expensive, thus reducing costs even further. With carbon insert, deflection coils last longer and are easier to maintain.

  1. Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement.

    PubMed

    Ghazanfari, Samaneh; Driessen-Mol, Anita; Hoerstrup, Simon P; Baaijens, Frank P T; Bouten, Carlijn V C

    2016-01-01

    The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that

  2. Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement

    PubMed Central

    Ghazanfari, Samaneh; Driessen-Mol, Anita; Hoerstrup, Simon P.; Baaijens, Frank P.T.; Bouten, Carlijn V.C.

    2016-01-01

    The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that

  3. Gene replacement in Lactobacillus helveticus.

    PubMed Central

    Bhowmik, T; Fernández, L; Steele, J L

    1993-01-01

    An efficient method for gene replacement in Lactobacillus helveticus CNRZ32 was developed by utilizing pSA3 as an integration vector. This plasmid is stably maintained in CNRZ32 at 37 degrees C but is unstable at 45 degrees C. This method consisted of a two-step gene-targeting technique: (i) chromosomal integration of a plasmid carrying an internal deletion in the gene of interest via homologous recombination and (ii) excision of the vector and the wild-type gene via homologous recombination, resulting in gene replacement. By using this procedure, the chromosomal X-prolyl dipeptidyl aminopeptidase gene (pepXP) of CNRZ32 was successfully inactivated. Images PMID:8104928

  4. [MINIMALLY INVASIVE AORTIC VALVE REPLACEMENT].

    PubMed

    Tabata, Minoru

    2016-03-01

    Minimally invasive aortic valve replacement (MIAVR) is defined as aortic valve replacement avoiding full sternotomy. Common approaches include a partial sternotomy right thoracotomy, and a parasternal approach. MIAVR has been shown to have advantages over conventional AVR such as shorter length of stay and smaller amount of blood transfusion and better cosmesis. However, it is also known to have disadvantages such as longer cardiopulmonary bypass and aortic cross-clamp times and potential complications related to peripheral cannulation. Appropriate patient selection is very important. Since the procedure is more complex than conventional AVR, more intensive teamwork in the operating room is essential. Additionally, a team approach during postoperative management is critical to maximize the benefits of MIAVR.

  5. Hinge total knee replacement revisited

    PubMed Central

    Cameron, Hugh U.; Hu, Cungen; Vyamont, Didier

    1997-01-01

    Objective To determine if aseptic loosening is a major problem in hinge total knee replacement. Design A cohort study. Setting A university-affiliated institute, specializing in elective orthopedic surgery. Patients Fifty-eight patients, mainly those requiring revision, in whom the conditions were such that it was felt only a totally constrained implant was appropriate. In 7 patients the implant was press-fitted; in the remainder it was cemented. Five patients required fusion or revision, and 8 died less than 2 years after implantation, leaving 45 for review. Follow-up was 2 to 13 years. Intervention Total knee replacement with a Guepar II prosthesis. Main outcome measures Radiolucency determined by the Cameron system and clinical scoring using the Hospital for Special Surgery system. Results Of the cemented components, 91% of femoral stems were type IA (no lucency), 9% were type IB (partial lucency), with no type II or III lucency. Tibial lucency was 87% type IA and 13% type IB, with no type II or III lucency. Of the noncemented components, 58% of femoral components were type IA and 42% type IB. Tibial lucency was 71% type IA and 29% type IB. Lucency was mainly present in zones 1 and 2 adjacent to the knee. Clinical rating was 18% excellent, 20% good, 20% fair and 42% poor. Postoperative complications included infection (13%), aseptic loosening (7%), quadriceps lag (16%) and extensor mechanism problems (16%). Conclusions Aseptic loosening is an uncommon problem in hinge total knee replacement. The complication rate in cases of sufficient severity as to require a hinge replacement remains high. Current indications for a hinge prosthesis are anteroposterior instability with a very large flexion gap, complete absence of the collateral ligaments and complete absence of a functioning extensor mechanism. PMID:9267296

  6. Nicotine Replacement Therapy: An Overview

    PubMed Central

    Wadgave, Umesh; Nagesh, L

    2016-01-01

    Today tobacco use is the single greatest preventable cause of death in the world. Tobacco use is often incorrectly perceived to be solely a personal choice. This is contradicted by the fact that when fully aware of the health impact, most tobacco users want to quit but find it difficult to stop due to the addictiveness of nicotine. Henceforth, Nicotine replacement therapy (NRT) came into existence which temporarily replaces much of the nicotine from tobacco to reduce motivation to consume tobacco and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence. Various alternative nicotine sources (gum, transdermal patch, nasal spray, inhaler and sublingual tablets/lozenges) have been incorporated into tobacco cessation programs. Recent research is more focusing on rapid delivery of nicotine (Nicotine preloading, true pulmonary inhaler) and immunological approaches (nicotine vaccine) to tackle nicotine dependence. These NRTs are in general well tolerated and have minimal adverse effects. The review aims to summarize literature on various modes of nicotine replacement therapy methods currently used to treat nicotine dependence, and to give an overview about future possible approaches to treat tobacco use disorder. PMID:27610066

  7. 2D versus 3D cross-correlation-based radial and circumferential strain estimation using multiplane 2D ultrafast ultrasound in a 3D atherosclerotic carotid artery model.

    PubMed

    Fekkes, Stein; Swillens, Abigail E S; Hansen, Hendrik H G; Saris, Anne E C M; Nillesen, Maartje M; Iannaccone, Francesco; Segers, Patrick; de Korte, Chris L

    2016-08-25

    Three-dimensional strain estimation might improve the detection and localization of high strain regions in the carotid artery for identification of vulnerable plaques. This study compares 2D vs. 3D displacement estimation in terms of radial and circumferential strain using simulated ultrasound images of a patient specific 3D atherosclerotic carotid artery model at the bifurcation embedded in surrounding tissue generated with ABAQUS software. Global longitudinal motion was superimposed to the model based on literature data. A Philips L11-3 linear array transducer was simulated which transmitted plane waves at 3 alternating angles at a pulse repetition rate of 10 kHz. Inter-frame radiofrequency ultrasound data were simulated in Field II for 191 equally spaced longitudinal positions of the internal carotid artery. Accumulated radial and circumferential displacements were estimated using tracking of the inter-frame displacements estimated by a two-step normalized cross-correlation method and displacement compounding. Least squares strain estimation was performed to determine accumulated radial and circumferential strain. The performance of the 2D and 3D method was compared by calculating the root-mean-squared error of the estimated strains with respect to the reference strains obtained from the model. More accurate strain images were obtained using the 3D displacement estimation for the entire cardiac cycle. The 3D technique clearly outperformed the 2D technique in phases with high inter-frame longitudinal motion. In fact the large inter-frame longitudinal motion rendered it impossible to accurately track the tissue and cumulate strains over the entire cardiac cycle with the 2D technique.

  8. 2-D Versus 3-D Cross-Correlation-Based Radial and Circumferential Strain Estimation Using Multiplane 2-D Ultrafast Ultrasound in a 3-D Atherosclerotic Carotid Artery Model.

    PubMed

    Fekkes, Stein; Swillens, Abigail E S; Hansen, Hendrik H G; Saris, Anne E C M; Nillesen, Maartje M; Iannaccone, Francesco; Segers, Patrick; de Korte, Chris L

    2016-10-01

    Three-dimensional (3-D) strain estimation might improve the detection and localization of high strain regions in the carotid artery (CA) for identification of vulnerable plaques. This paper compares 2-D versus 3-D displacement estimation in terms of radial and circumferential strain using simulated ultrasound (US) images of a patient-specific 3-D atherosclerotic CA model at the bifurcation embedded in surrounding tissue generated with ABAQUS software. Global longitudinal motion was superimposed to the model based on the literature data. A Philips L11-3 linear array transducer was simulated, which transmitted plane waves at three alternating angles at a pulse repetition rate of 10 kHz. Interframe (IF) radio-frequency US data were simulated in Field II for 191 equally spaced longitudinal positions of the internal CA. Accumulated radial and circumferential displacements were estimated using tracking of the IF displacements estimated by a two-step normalized cross-correlation method and displacement compounding. Least-squares strain estimation was performed to determine accumulated radial and circumferential strain. The performance of the 2-D and 3-D methods was compared by calculating the root-mean-squared error of the estimated strains with respect to the reference strains obtained from the model. More accurate strain images were obtained using the 3-D displacement estimation for the entire cardiac cycle. The 3-D technique clearly outperformed the 2-D technique in phases with high IF longitudinal motion. In fact, the large IF longitudinal motion rendered it impossible to accurately track the tissue and cumulate strains over the entire cardiac cycle with the 2-D technique.

  9. Semi-Circumferential Decompression: Microsurgical Total en-bloc Ligamentum Flavectomy to Treat Lumbar Spinal Stenosis with Grade I Degenerative Spondylolisthesis

    PubMed Central

    Choi, Jun Cheol; Oh, Sang Hun; Park, Sub Ri; Park, Sang Jun; Cho, Nam Ik

    2015-01-01

    Background To describe and assess clinical outcomes of the semi-circumferential decompression technique for microsurgical en-bloc total ligamentum flavectomy with preservation of the facet joint to treat the patients who have a lumbar spinal stenosis with degenerative spondylolisthesis. Methods We retrospectively analyzed the clinical and radiologic outcomes of 19 patients who have a spinal stenosis with Meyerding grade I degenerative spondylolisthesis. They were treated using the "semi-circumferential decompression" method. We evaluated improvements in back and radiating pain using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). We also evaluated occurrence of spinal instability on radiological exam using percentage slip and slip angle. Results The mean VAS score for back pain decreased significantly from 6.3 to 4.3, although some patients had residual back pain. The mean VAS for radiating pain decreased significantly from 8.3 to 2.5. The ODI score improved significantly from 25.3 preoperatively to 10.8 postoperatively. No significant change in percentage slip was observed (10% preoperatively vs. 12.2% at the last follow-up). The dynamic percentage slip (gap in percentage slip between flexion and extension X-ray exams) did not change significantly (5.2% vs. 5.8%). Slip angle and dynamic slip angle did not change (3.2° and 8.2° vs. 3.6° and 9.2°, respectively). Conclusions The results suggested that semi-circumferential decompression is a clinically recommendable procedure that can improve pain. This procedure does not cause spinal instability when treating patients who have a spinal stenosis with degenerative spondylolisthesis. PMID:26640630

  10. A new multichannel time reversal focusing method for circumferential Lamb waves and its applications for defect detection in thick-walled pipe with large-diameter.

    PubMed

    Liu, Zenghua; Xu, Qinglong; Gong, Yu; He, Cunfu; Wu, Bin

    2014-09-01

    This paper proposes a new multichannel time reversal focusing (MTRF) method for circumferential Lamb waves which is based on modified time reversal algorithm and applies this method for detecting different kinds of defects in thick-walled pipe with large-diameter. The principle of time reversal of circumferential Lamb waves in pipe is presented along with the influence from multiple guided wave modes and propagation paths. Experimental study is carried out in a thick-walled and large-diameter pipe with three artificial defects, namely two axial notches on its inner and outer surface respectively, and a corrosion-like defect on its outer surface. By using the proposed MTRF method, the multichannel signals focus at the defects, leading to the amplitude improvement of the defect scattered signal. Besides, another energy focus arises in the direct signal due to the partial compensation of dispersion and multimode of circumferential Lamb waves, alongside the multichannel focusing, during MTRF process. By taking the direct focus as a time base, accurate defect localization is implemented. Secondly, a new phenomenon is exhibited in this paper that defect scattered wave packet appears just before the right boundary of truncation window after time reversal, and to which two feasible explanations are given. Moreover, this phenomenon can be used as the theoretical basis in the determination of defect scattered waves in time reversal response signal. At last, in order to detect defects without prior knowing their exact position, a large-range truncation window is used in the proposed method. As a result, the experimental operation of MTRF method is simplified and defect detection and localization are well accomplished.

  11. Results of Single-Staged Posterior Decompression and Circumferential Fusion Using a Transpedicular Approach to Correct a Kyphotic Deformity due to Thoracolumbar Spinal Tuberculosis

    PubMed Central

    Modi, Jayprakash; Soman, Shardul; Patel, Harshil; Dhanani, Shrikant

    2016-01-01

    Study Design This is a prospective study. Purpose The aim of this study was to investigate the results of single-staged posterior decompression and circumferential fusion using a transpedicular approach to correct a kyphotic deformity due to thoracolumbar spinal tuberculosis. Overview of Literature Surgical management is frequently an imperative choice to achieve spinal decompression and deformity correction due to tuberculosis to relieve pain, improve neurology, and reconstruct the spine stability. Since the time anterior radical debridement and noninstrumented fusion was described, it has become apparent that even anterior debridement and bone grafting was often unsatisfactory in correcting or preventing the progression of kyphosis deformity. With the advent of modern segmental spinal instrumentation systems, isolated posterior instrumentation; combined anterior and posterior fusion; and single-staged posterior decompression and circumferential fusion have been described by many authors for correcting angular deformity and stabilizing the spine; however, there is a lack of consensus regarding the most effective means of correcting the deformity due to thoracolumbar spinal tuberculosis. Methods This is a prospective study of 20 patients with thoracolumbar spinal tuberculosis who underwent surgery at our institute. Results Twenty patients who were started on antituberculosis treatment underwent surgery using a single-staged posterior approach involving fixation, decompression, and kyphosis correction. Preoperatively, all patients had varying degrees of neurological deficit and a 27.45° average kyphotic angle, which improved. At the 1-year follow-up, correction was maintained at 6.9°, and 55% of patients showed neurological improvement. None of the patients experienced neurological deterioration. Two patients with lumbar spine tuberculosis underwent revision surgery because of nonunion. Conclusions The procedure of posterior decompression, fixation, and

  12. Fusion following failed total ankle replacement.

    PubMed

    Wünschel, Markus; Leichtle, Ulf G; Leichtle, Carmen I; Walter, Christian; Mittag, Falk; Arlt, Eva; Suckel, Andreas

    2013-04-01

    Although mid- to long-term results after total ankle replacement have improved because of available second- and third-generation devices, failure of total ankle replacement is still more common compared with total hip replacement and total knee replacement. The portfolio of available total ankle replacement revision component options is small. Furthermore, the bone stock of the tibiotalar region is scarce making it difficult and in some situations impossible to perform revision total ankle replacement. In these cases tibiotalar and tibiotalocalcaneal fusions are valuable options. This article describes which surgical procedures should be performed depending on the initial situation and gives detailed advice on surgical technique, postoperative care, and clinical results.

  13. In Defense of Artificial Replacement.

    PubMed

    Shiller, Derek

    2017-02-03

    If it is within our power to provide a significantly better world for future generations at a comparatively small cost to ourselves, we have a strong moral reason to do so. One way of providing a significantly better world may involve replacing our species with something better. It is plausible that in the not-too-distant future, we will be able to create artificially intelligent creatures with whatever physical and psychological traits we choose. Granted this assumption, it is argued that we should engineer our extinction so that our planet's resources can be devoted to making artificial creatures with better lives.

  14. Liver Replacement for Pediatric Patients

    PubMed Central

    Starzl, Thomas E.; Koep, Lawrence J.; Schröter, Gerhard P. J.; Halgrimson, Charles G.; Porter, Kendrick A.; Weil, Richard

    2010-01-01

    Between March 1963 and January 1978, 74 patients 18 years of age or younger have had liver replacements at the University of Colorado Medical Center, Denver. The most common cause of native liver failure was biliary atresia (48/74, 65%); the second most common cause was chronic aggressive hepatitis (12/74, 16%). Twenty-nine patients (39%) lived for at least one year, and 16 are still alive one to nine years after transplantation. Technical surgical problems, rejection, and infection were the main causes of death. Improved immunosuppression is needed; nevertheless, the quality of life in the long-term survivors has encouraged continuation of this difficult work. PMID:377201

  15. Solvent replacement for green processing.

    PubMed Central

    Sherman, J; Chin, B; Huibers, P D; Garcia-Valls, R; Hatton, T A

    1998-01-01

    The implementation of the Montreal Protocol, the Clean Air Act, and the Pollution Prevention Act of 1990 has resulted in increased awareness of organic solvent use in chemical processing. The advances made in the search to find "green" replacements for traditional solvents are reviewed, with reference to solvent alternatives for cleaning, coatings, and chemical reaction and separation processes. The development of solvent databases and computational methods that aid in the selection and/or design of feasible or optimal environmentally benign solvent alternatives for specific applications is also discussed. Images Figure 2 Figure 3 PMID:9539018

  16. Muscle transposition and circumferential vacuum-assisted closure to salvage the knee joint in transtibial amputation of the leg: case report.

    PubMed

    Tuncer, Serdar; Karaca, Sinan

    2011-06-01

    Degloving injury is the avulsion of the skin off the underlying muscle and bone, which may also involve the latter structures in high-energy trauma. This study reports the case of a 33-year-old male patient who sustained a motorcycle accident and presented with hypovolemic shock, multiple fractures, and multiplanar degloving injury of the leg. The foot and distal leg was not salvageable, and a transtibial amputation with anterior transposition of the posterior compartment muscles was performed; however, a circumferential skin necrosis involving the stump and the knee joint occurred. The wound granulated rapidly using circumferential vacuum-assisted closure therapy and subsequently repaired with split thickness skin grafts. The authors found the topical negative pressure using the Vacuum Assisted Closure (VAC) technique Trademark KCI, Texas, USA, method to be helpful in the care of lower extremity degloving injury, enabling less frequent dressing changes and facilitating formation of granulation tissue with rapid preparation of the wound bed for salvage of the knee joint.

  17. Accurate method for measurement of pipe wall thickness using a circumferential guided wave generated and detected by a pair of noncontact transducers

    NASA Astrophysics Data System (ADS)

    Nishino, H.; Taniguchi, Y.; Yoshida, K.

    2012-05-01

    A noncontact method of an accurate estimation of a pipe wall thickness using a circumferential (C-) Lamb wave is presented. The C-Lamb waves circling along the circumference of pipes are transmitted and received by the critical angle method using a pair of noncontact air-coupled ultrasonic transducers. For the accurate estimation of a pipe wall thickness, the accurate measurement of the angular wave number that changes minutely owing to the thickness must be achieved. To achieve the accurate measurement, a large number of tone-burst cycles are used so as to superpose the C-Lamb wave on itself along its circumferential orbit. In this setting, the amplitude of the superposed region changes considerably with the angular wave number, from which the wall thickness can be estimated. This paper presents the principle of the method and experimental verifications. As results of the experimental verifications, it was confirmed that the maximum error between the estimates and the theoretical model was less than 10 micrometers.

  18. Knee Replacement: MedlinePlus Health Topic

    MedlinePlus

    ... Arthritis and Musculoskeletal and Skin Diseases) Also in Spanish Knee Replacement (Mayo Foundation for Medical Education and ... American Academy of Orthopaedic Surgeons) - PDF Also in Spanish Total Knee Replacement (Arthroplasty) (Beyond the Basics) (UpToDate) ...

  19. Smokers Prone to Problems After Joint Replacement

    MedlinePlus

    ... fullstory_164137.html Smokers Prone to Problems After Joint Replacement: Study Cessation programs help reduce the rate ... that smokers do worse than non-smokers after joint replacements, and now this research shows there's good ...

  20. Total hip replacement in dancers.

    PubMed

    Buyls, Inge R A E; Rietveld, A B M Boni; Ourila, Tiia; Emerton, Mark E; Bird, H A

    2013-04-01

    A case report of a professional contemporary dancer who successfully returned to the stage after bilateral total hip replacements (THR) for osteoarthritis is presented, together with her own commentary and a retrospective cohort study of total hip replacements in dancers. In the presented cohort, there were no post-operative dislocations or infections, the original pain had been relieved, rehabilitation was objectively normal and all resumed their dance (teaching) activities. Nevertheless, they were disappointed about the prolonged rehabilitation. Due to their high demands as professional dancers, post-operative expectations were too optimistic in view of the usual quick and favourable results of THR in the older and less physically active, general population. In all dancers with unilateral osteoarthritis, the left hip was involved, which may reflect the tendency to use the left leg as standing leg and be suggestive that strenuous physical activity may lead to osteoarthritis. Better rehabilitation guidelines are needed for dancer patients undergoing THR, especially drawing their attention to realistic post-operative expectations.

  1. The Mitochondrial Replacement 'Therapy' Myth.

    PubMed

    Rulli, Tina

    2016-12-30

    This article argues that two forms of mitochondrial replacement therapy, maternal spindle transfer (MST) and pro-nuclear transfer (PNT), are not therapies at all because they do not treat children who are coming into existence. Rather, these technologies merely create healthy children where none was inevitable. Even if creating healthy lives has some value, it is not to be confused with the medical value of a cure or therapy. The article addresses a recent Bioethics article, 'Mitochondrial Replacement: Ethics and Identity,' by Wrigley, Wilkinson, and Appleby, who argue that PNT is morally favorable to MST due to the Non-Identity Problem. Wrigley et al. claim that PNT, since it occurs post-conception, preserves the identity of the resulting child, whereas MST, since it occurs pre-conception, is an identity-altering technique. As such, a child born with mitochondrial disease could complain that her parents failed to use PNT, but not MST. The present article argues that the authors are mistaken: both MST and PNT are identity-affecting techniques. But this is of little matter, for we should be cautious in drawing any moral conclusions from the application of the Non-Identity Problem to cases. The article then argues that the authors are mistaken in inferring that PNT is a type of embryonic cure or therapy for children with mitochondrial disease. The article cautions against the mistaken life-saving rhetoric that is common in bioethics discussions of MRTs.

  2. Should the patella be replaced in total knee replacement?

    PubMed

    Badhe, N; Dewnany, G; Livesley, P J

    2001-01-01

    In 170 total knee arthroplasties for osteoarthritis 71 did not receive a patellar replacement (group A), while 99 knees had a cemented polyethylene patella (group B). The mean follow-up time was 36 months (30-50 months). In group A 10 patients underwent second-stage patellar resurfacing and in group B 2 knees underwent revision of the patellar component. Radiologically the average patellar congruency was similar. In both groups there were 21 non-congruent knees. In group A 8 were symptomatic and had low scores compared to 2 in group B (P<0.05). The mean HSS score and patellar score were higher in group B than in group A (P<0.05).

  3. B Plant process piping replacement feasibility study

    SciTech Connect

    Howden, G.F.

    1996-02-07

    Reports on the feasibility of replacing existing embedded process piping with new more corrosion resistant piping between cells and between cells and a hot pipe trench of a Hanford Site style canyon facility. Provides concepts for replacement piping installation, and use of robotics to replace the use of the canyon crane as the primary means of performing/supporting facility modifications (eg, cell lining, pipe replacement, equipment reinstallation) and operational maintenenace.

  4. Hip Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Hip Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Hip Replacement Potpuna zamjena kuka - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Hip Replacement 全髋关节置换 - 简体中文 ( ...

  5. Knee Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Knee Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Knee Replacement Potpuna zamjena koljena - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Knee Replacement 全膝关节置换 - 简体中文 ( ...

  6. Molecular replacement then and now

    SciTech Connect

    Scapin, Giovanna

    2013-11-01

    A brief overview, with examples, of the evolution of molecular-replacement methods and models over the past few years is presented. The ‘phase problem’ in crystallography results from the inability to directly measure the phases of individual diffracted X-ray waves. While intensities are directly measured during data collection, phases must be obtained by other means. Several phasing methods are available (MIR, SAR, MAD, SAD and MR) and they all rely on the premise that phase information can be obtained if the positions of marker atoms in the unknown crystal structure are known. This paper is dedicated to the most popular phasing method, molecular replacement (MR), and represents a personal overview of the development, use and requirements of the methodology. The first description of noncrystallographic symmetry as a tool for structure determination was explained by Rossmann and Blow [Rossmann & Blow (1962 ▶), Acta Cryst.15, 24–31]. The term ‘molecular replacement’ was introduced as the name of a book in which the early papers were collected and briefly reviewed [Rossmann (1972 ▶), The Molecular Replacement Method. New York: Gordon & Breach]. Several programs have evolved from the original concept to allow faster and more sophisticated searches, including six-dimensional searches and brute-force approaches. While careful selection of the resolution range for the search and the quality of the data will greatly influence the outcome, the correct choice of the search model is probably still the main criterion to guarantee success in solving a structure using MR. Two of the main parameters used to define the ‘best’ search model are sequence identity (25% or more) and structural similarity. Another parameter that may often be undervalued is the quality of the probe: there is clearly a relationship between the quality and the correctness of the chosen probe and its usefulness as a search model. Efforts should be made by all structural biologists to

  7. ORO. The physical developer replacement?

    PubMed

    Wood, Michael A; James, Tim

    2009-12-01

    In the process of fingerprint development Physical Developer has been largely the method of choice on porous surfaces after coming into contact with wet environments. It is only recently that a new technique has been identified which could replace this standard technique. This study aims to build on previous research and expand knowledge regarding the technique. The study built on previous research and compared Physical Developer to Oil Red O, testing both on four paper types, while being placed in three different water types and an accelerant for various amounts of time. Marks were placed with both heavily 'loaded' sebaceous fingers and 'normal' un-washed fingers. Results show that Oil Red O consistently produced clearer more detailed marks from the 'loaded' fingers, but neither technique proved to work better on the 'normal' marks. Neither technique developed any prints from the accelerant.

  8. Mitochondrial Replacement: Ethics and Identity.

    PubMed

    Wrigley, Anthony; Wilkinson, Stephen; Appleby, John B

    2015-11-01

    Mitochondrial replacement techniques (MRTs) have the potential to allow prospective parents who are at risk of passing on debilitating or even life-threatening mitochondrial disorders to have healthy children to whom they are genetically related. Ethical concerns have however been raised about these techniques. This article focuses on one aspect of the ethical debate, the question of whether there is any moral difference between the two types of MRT proposed: Pronuclear Transfer (PNT) and Maternal Spindle Transfer (MST). It examines how questions of identity impact on the ethical evaluation of each technique and argues that there is an important difference between the two. PNT, it is argued, is a form of therapy based on embryo modification while MST is, instead, an instance of selective reproduction. The article's main ethical conclusion is that, in some circumstances, there is a stronger obligation to use PNT than MST.

  9. Replacement Sequence of Events Generator

    NASA Technical Reports Server (NTRS)

    Fisher, Forest; Gladden, Daniel Wenkert Roy; Khanampompan, Teerpat

    2008-01-01

    The soeWINDOW program automates the generation of an ITAR (International Traffic in Arms Regulations)-compliant sub-RSOE (Replacement Sequence of Events) by extracting a specified temporal window from an RSOE while maintaining page header information. RSOEs contain a significant amount of information that is not ITAR-compliant, yet that foreign partners need to see for command details to their instrument, as well as the surrounding commands that provide context for validation. soeWINDOW can serve as an example of how command support products can be made ITAR-compliant for future missions. This software is a Perl script intended for use in the mission operations UNIX environment. It is designed for use to support the MRO (Mars Reconnaissance Orbiter) instrument team. The tool also provides automated DOM (Distributed Object Manager) storage into the special ITAR-okay DOM collection, and can be used for creating focused RSOEs for product review by any of the MRO teams.

  10. Mitochondrial Replacement: Ethics and Identity

    PubMed Central

    Wilkinson, Stephen; Appleby, John B.

    2015-01-01

    Abstract Mitochondrial replacement techniques (MRTs) have the potential to allow prospective parents who are at risk of passing on debilitating or even life‐threatening mitochondrial disorders to have healthy children to whom they are genetically related. Ethical concerns have however been raised about these techniques. This article focuses on one aspect of the ethical debate, the question of whether there is any moral difference between the two types of MRT proposed: Pronuclear Transfer (PNT) and Maternal Spindle Transfer (MST). It examines how questions of identity impact on the ethical evaluation of each technique and argues that there is an important difference between the two. PNT, it is argued, is a form of therapy based on embryo modification while MST is, instead, an instance of selective reproduction. The article's main ethical conclusion is that, in some circumstances, there is a stronger obligation to use PNT than MST. PMID:26481204

  11. Optimal randomized scheduling by replacement

    SciTech Connect

    Saias, I.

    1996-05-01

    In the replacement scheduling problem, a system is composed of n processors drawn from a pool of p. The processors can become faulty while in operation and faulty processors never recover. A report is issued whenever a fault occurs. This report states only the existence of a fault but does not indicate its location. Based on this report, the scheduler can reconfigure the system and choose another set of n processors. The system operates satisfactorily as long as, upon report of a fault, the scheduler chooses n non-faulty processors. We provide a randomized protocol maximizing the expected number of faults the system can sustain before the occurrence of a crash. The optimality of the protocol is established by considering a closely related dual optimization problem. The game-theoretic technical difficulties that we solve in this paper are very general and encountered whenever proving the optimality of a randomized algorithm in parallel and distributed computation.

  12. Perspectives in hormone replacement therapy.

    PubMed

    Kenemans, P; van Unnik, G A; Mijatovic, V; van der Mooren, M J

    2001-06-15

    Estrogens have been convincingly shown to be highly effective in preventing and reversing menopause-related conditions, such as hot flushes, urogenital complaints, and postmenopausal bone loss. Observational studies report that long-term, estrogen-containing, postmenopausal hormone replacement therapy (HRT) leads to a substantial reduction in hip fractures, myocardial infarction, and possibly colonic cancer, with important consequences for health and quality of life. Estrogen replacement may postpone the onset of Alzheimer's disease and extend life. While many of these effects are biologically plausible, with a variety of cellular mechanisms being involved, only ongoing and future large-scale randomized clinical trials can and should define the effects of HRT more precisely. Long-term compliance is a key issue for long-term benefits, and offering women a choice of administration routes and regimens can only be beneficial in this respect. Pills, patches, gels, and implants are all widely prescribed. Intravaginal or intranasal forms of administration, which are very easy to use and adaptable on an individual level, are among the new options which could improve long-term continuation of HRT use. Fear of breast cancer and recurrence of vaginal bleeding are real concerns for many women considering HRT. This has led to research into lower-dose, estrogen-containing regimens, into continuous combined regimens, and into the potential of estrogen receptor alpha or beta binding molecules that may help to prevent such problems from arising. The prospects for safe and effective postmenopausal HRT with either estrogens or estrogen-like drugs are very promising when these drugs are used in a patient-tailored, risk profile-based manner.

  13. Self-Expandable Stent for Repairing Coarctation of the Left-Circumferential Aortic Arch with Right-sided Descending Aorta and Aberrant Right Subclavian Artery with Kommerell's Aneurysm.

    PubMed

    Khajali, Zahra; Sanati, Hamid Reza; Pouraliakbar, Hamidreza; Mohebbi, Bahram; Aeinfar, Kamran; Zolfaghari, Reza

    2017-01-01

    Endovascular treatment offers a great advantage in the management of main arteries stenoses. However, simultaneous presence of a group of anomalies may complicate the situation. Here we present a case of 21-year-old man with aortic coarctation. Radiographic imaging and angiography demonstrated aortic coarctation of the left-circumferential aortic arch, right-sided descending aorta, and Kommerell's diverticulum at the origin of right subclavian artery. These anomalies have rarely been reported to concurrently exist in the same case and the treatment is challenging. Percutaneous treatment for repair of aortic coarctation was successfully performed with deployment of self-expanding nitinol stents. Follow-up demonstrated the correction of blood pressure and improvement of the symptoms. It appears that deployment of self-expandable nitinol stents present a viable option for the management of coarcted aorta in patients having all or some of these anomalies together.

  14. Method for determining the minimum principle horizontal stress within a formation through use of a wireline retrievable circumferential acoustic scanning tool during an open hole microfrac test

    SciTech Connect

    Venditto, J.J.; McMechan, D.E.; Enderlin, M.B.

    1993-08-17

    A method is described for determining the magnitude of the minimum principle horizontal stress within a formation having an open hole well bore formed therein, comprising the steps of: supplying pressurized fracturing fluid to said well bore in a desired area of observation, said well bore exposing an interior surface of said formation; inserting a circumferential acoustic scanning tool into said well bore and positioning said tool in said area of observation, said acoustic scanning tool providing a viewable image of said interior surface of said formation; increasing the pressure on said fracturing fluid until fractures are initiated in said formation proximate the well bore; increasing the pressure acting on said fracturing fluid so as to cause said initiated fractures to further open; observing the interior surface of said formation during said opening of said previously initiated fractures; and noting the magnitude of the pressure acting on said fracturing fluid as said previously initiated fractures are opened.

  15. Dental ontogeny and replacement in Pliosauridae.

    PubMed

    Sassoon, Judyth; Foffa, Davide; Marek, Ryan

    2015-11-01

    Dental morphology and patterns of tooth replacement in representatives of the clade Pliosauridae (Reptilia, Sauropterygia) are evaluated in detail. The jaws of one basal (Thalassiodracon hawkinsii) and two derived species (Pliosaurus carpenteri, Pliosaurus kevani) were visualized by μCT scans, and the ontogenetic patterns, or 'movement paths', of replacement teeth could be mapped. Other specimens (Peloneustes philarchus and Pliosaurus westbuyensis) with well-preserved jaws containing functional and replacement teeth in situ were also examined directly, and waves of tooth replacement could be inferred from the degree of in situ tooth development and the fusion between functional and replacement alveoli. The analysis revealed symmetrical tooth eruption over the medial axis throughout the length of the jaw in the basal pliosaurid Thalassiodracon. By contrast, symmetrical tooth eruption patterns occur only along the anterior sections of the jaws of derived pliosaurids. In Pliosaurus, replacement schedules differ in the anterior and posterior portions of the jaws and appear to correlate with differences in tooth morphology and symmetrical replacement. The anterior teeth exhibit longer replacement cycle periods and symmetrical replacement, while shorter cycle periods and asymmetry are seen posteriorly. A longer period suggests slower replacement and is characteristic of large, specialized caniniform teeth in the longer snouted Late Jurassic taxa. Smaller posterior teeth have a shorter period and therefore a faster replacement cycle. The transition from long to short replacement period over the length of the jaw is thought to account for the loss of symmetry. This differentiation could relate to differential tooth function and a type of heterodonty. We therefore propose a new model of pliosaurid tooth replacement patterns and present it in a phylogenetic context.

  16. Dental ontogeny and replacement in Pliosauridae

    PubMed Central

    Sassoon, Judyth; Foffa, Davide; Marek, Ryan

    2015-01-01

    Dental morphology and patterns of tooth replacement in representatives of the clade Pliosauridae (Reptilia, Sauropterygia) are evaluated in detail. The jaws of one basal (Thalassiodracon hawkinsii) and two derived species (Pliosaurus carpenteri, Pliosaurus kevani) were visualized by μCT scans, and the ontogenetic patterns, or ‘movement paths’, of replacement teeth could be mapped. Other specimens (Peloneustes philarchus and Pliosaurus westbuyensis) with well-preserved jaws containing functional and replacement teeth in situ were also examined directly, and waves of tooth replacement could be inferred from the degree of in situ tooth development and the fusion between functional and replacement alveoli. The analysis revealed symmetrical tooth eruption over the medial axis throughout the length of the jaw in the basal pliosaurid Thalassiodracon. By contrast, symmetrical tooth eruption patterns occur only along the anterior sections of the jaws of derived pliosaurids. In Pliosaurus, replacement schedules differ in the anterior and posterior portions of the jaws and appear to correlate with differences in tooth morphology and symmetrical replacement. The anterior teeth exhibit longer replacement cycle periods and symmetrical replacement, while shorter cycle periods and asymmetry are seen posteriorly. A longer period suggests slower replacement and is characteristic of large, specialized caniniform teeth in the longer snouted Late Jurassic taxa. Smaller posterior teeth have a shorter period and therefore a faster replacement cycle. The transition from long to short replacement period over the length of the jaw is thought to account for the loss of symmetry. This differentiation could relate to differential tooth function and a type of heterodonty. We therefore propose a new model of pliosaurid tooth replacement patterns and present it in a phylogenetic context. PMID:26715998

  17. A method for the measurement of dispersion curves of circumferential guided waves radiating from curved shells: experimental validation and application to a femoral neck mimicking phantom.

    PubMed

    Nauleau, Pierre; Minonzio, Jean-Gabriel; Chekroun, Mathieu; Cassereau, Didier; Laugier, Pascal; Prada, Claire; Grimal, Quentin

    2016-07-07

    Our long-term goal is to develop an ultrasonic method to characterize the thickness, stiffness and porosity of the cortical shell of the femoral neck, which could enhance hip fracture risk prediction. To this purpose, we proposed to adapt a technique based on the measurement of guided waves. We previously evidenced the feasibility of measuring circumferential guided waves in a bone-mimicking phantom of a circular cross-section of even thickness. The goal of this study is to investigate the impact of the complex geometry of the femoral neck on the measurement of guided waves. Two phantoms of an elliptical cross-section and one phantom of a realistic cross-section were investigated. A 128-element array was used to record the inter-element response matrix of these waveguides. This experiment was simulated using a custom-made hybrid code. The response matrices were analyzed using a technique based on the physics of wave propagation. This method yields portions of dispersion curves of the waveguides which were compared to reference dispersion curves. For the elliptical phantoms, three portions of dispersion curves were determined with a good agreement between experiment, simulation and theory. The method was thus validated. The characteristic dimensions of the shell were found to influence the identification of the circumferential wave signals. The method was then applied to the signals backscattered by the superior half of constant thickness of the realistic phantom. A cut-off frequency and some portions of modes were measured, with a good agreement with the theoretical curves of a plate waveguide. We also observed that the method cannot be applied directly to the signals backscattered by the lower half of varying thicknesses of the phantom. The proposed approach could then be considered to evaluate the properties of the superior part of the femoral neck, which is known to be a clinically relevant site.

  18. Total spondylectomy of C2 and circumferential reconstruction via combined anterior and posterior approach to cervical spine for axis tumor surgery.

    PubMed

    Wu, Wei; Li, Feng; Fang, Zhong; Xiong, Wei; Guan, Han-feng; Xiao, Jun; Guo, Feng-jin; Chen, An-min

    2013-02-01

    As a result of the complex anatomy in upper cervical spine, the operative treatment of axis neoplasms is always complicated. Although the procedure for the second cervical vertebra (C2) surgery had been described previously in diverse approaches and reconstruction forms, each has its own limitations and restrictions that usually result in less satisfactory conclusions. The purpose of this study was to evaluate the operation efficacy for axis tumors by using a combined anterior (retropharyngeal) cervical and posterior approach in achieving total resection of C2 and circumferential reconstruction. Eight consecutive C2 tumor patients with mean age of 47.6 years in our institute sequentially underwent vertebra resection and fixation through aforementioned approach from Jan. 2006 to Dec. 2010. No surgical mortality or severe morbidity occurred in our group. In terms of complications, 2 cases developed transient difficulty in swallowing liquids (one of them experienced dysphonia) and 1 developed cerebrospinal fluid leakage (CSFL) that was resolved later. During a mean follow-up period of 31.9 months, the visual analogue scale (VAS) and Japanese orthopedic association (JOA) score revealed that the pain level and neurological function in all patients were improved postoperatively, and there was no evidence of fixation failure and local recurrence. It is concluded that the anterior cervical retropharyngeal approach permits a visible exposure to facilitate the C2 vertebra resection and perform an effective anterior reconstruction at the same time. The custom-made mesh cage applied in our cases can be acted as a firm and convenient implant in circumferential fixation.

  19. A method for the measurement of dispersion curves of circumferential guided waves radiating from curved shells: experimental validation and application to a femoral neck mimicking phantom

    NASA Astrophysics Data System (ADS)

    Nauleau, Pierre; Minonzio, Jean-Gabriel; Chekroun, Mathieu; Cassereau, Didier; Laugier, Pascal; Prada, Claire; Grimal, Quentin

    2016-07-01

    Our long-term goal is to develop an ultrasonic method to characterize the thickness, stiffness and porosity of the cortical shell of the femoral neck, which could enhance hip fracture risk prediction. To this purpose, we proposed to adapt a technique based on the measurement of guided waves. We previously evidenced the feasibility of measuring circumferential guided waves in a bone-mimicking phantom of a circular cross-section of even thickness. The goal of this study is to investigate the impact of the complex geometry of the femoral neck on the measurement of guided waves. Two phantoms of an elliptical cross-section and one phantom of a realistic cross-section were investigated. A 128-element array was used to record the inter-element response matrix of these waveguides. This experiment was simulated using a custom-made hybrid code. The response matrices were analyzed using a technique based on the physics of wave propagation. This method yields portions of dispersion curves of the waveguides which were compared to reference dispersion curves. For the elliptical phantoms, three portions of dispersion curves were determined with a good agreement between experiment, simulation and theory. The method was thus validated. The characteristic dimensions of the shell were found to influence the identification of the circumferential wave signals. The method was then applied to the signals backscattered by the superior half of constant thickness of the realistic phantom. A cut-off frequency and some portions of modes were measured, with a good agreement with the theoretical curves of a plate waveguide. We also observed that the method cannot be applied directly to the signals backscattered by the lower half of varying thicknesses of the phantom. The proposed approach could then be considered to evaluate the properties of the superior part of the femoral neck, which is known to be a clinically relevant site.

  20. Circumferential Strain Can Be Used to Detect Lipopolysaccharide-Induced Myocardial Dysfunction and Predict the Mortality of Severe Sepsis in Mice

    PubMed Central

    Chu, Ming; Gao, Yao; Zhou, Bin; Wu, Bingruo; Wang, Junhong; Xu, Di

    2016-01-01

    Background Sepsis-induced myocardial dysfunction is a common and severe complication of septic shock. However, conventional echocardiography often fails to reveal myocardial depression in severe sepsis. Recently, strain measurements based on speckle tracking echocardiography (STE) have been used to evaluate cardiac function. Aims To investigate the role of STE in detecting lipopolysaccharide (LPS)-induced cardiac dysfunction, M-mode and 2-D echocardiography were used in LPS-treated mice. Methods The mice were treated with a 10mg/kg (n = 10), 20mg/kg (n = 10) or 25mg/kg LPS (n = 30) to induce cardiac dysfunction. Subsequently, the ejection fraction (EF) and fractional shortening (FS) were measured with standard M-mode tracings, whereas the circumferential (Scirc) and radial strain (Srad) were measured with STE. Serum biochemical and cardiac histopathological examinations were performed to assess sepsis-induced myocardial injury. Results 20mg/kg LPS resulted in more deterioration, myocardial damage and cardiac contractile dysfunction based on serum biochemical and histological examinations. The mice that were subjected to 20mg/kg LPS exhibited reduced Scirc but no reduction in Srad, whereas on conventional echocardiography, the ejection fraction (EF) and fractional shortening (FS) were similar in the 10mg/kg and 20mg/kg groups. Moreover, Scirc was positively correlated with body temperature in the mice at 20 h after LPS injection (r = 0.746, p = 0.001), but no significant correlation was observed between Srad and body temperature (r = 0.356, p = 0.123). Moreover, the mice with high Scirc (-5.9% to -10.4%) exhibited reduced mortality following the administration of 25mg/kg LPS (p = 0.03) compared with the low-strain group (-2% to -5.9%). Conclusions Taken together, our findings indicate that circumferential strain is a specific and reliable indicator for evaluating LPS-induced cardiac dysfunction in mice. PMID:27177150

  1. Visual Image Sensor Organ Replacement

    NASA Technical Reports Server (NTRS)

    Maluf, David A.

    2014-01-01

    This innovation is a system that augments human vision through a technique called "Sensing Super-position" using a Visual Instrument Sensory Organ Replacement (VISOR) device. The VISOR device translates visual and other sensors (i.e., thermal) into sounds to enable very difficult sensing tasks. Three-dimensional spatial brightness and multi-spectral maps of a sensed image are processed using real-time image processing techniques (e.g. histogram normalization) and transformed into a two-dimensional map of an audio signal as a function of frequency and time. Because the human hearing system is capable of learning to process and interpret extremely complicated and rapidly changing auditory patterns, the translation of images into sounds reduces the risk of accidentally filtering out important clues. The VISOR device was developed to augment the current state-of-the-art head-mounted (helmet) display systems. It provides the ability to sense beyond the human visible light range, to increase human sensing resolution, to use wider angle visual perception, and to improve the ability to sense distances. It also allows compensation for movement by the human or changes in the scene being viewed.

  2. Engineering Alloplastic Temporomandibular Joint Replacements

    PubMed Central

    Sinno, Hani; Tahiri, Youssef; Gilardino, Mirko; Bobyn, Dennis

    2011-01-01

    Temporomandibular disorders (TMD) are part of a heterogeneous group of pathologies that manifest with a constellation of signs and symptoms. They are the most frequent cause of chronic orofacial pain and are prevalent in 12% of the general population. Despite the debilitating nature of these disorders, there is no standardization for treatment of the diseased temporomandibular joint (TMJ). In this review, we present an overview of the functional anatomy of the TMJ and the engineering concepts that must be understood to better understand the indications for surgical management, the types of available treatments and the requirements for reconstruction. A comparison is made of the clinical outcomes with autogenous versus alloplastic reconstruction, including a history of alloplastic materials and the design features of currently available implants. Emphasis is made on material selection, modulus, stiffness, notch sensitivity and modularity. For the treatment of TMD, engineered TMJ alloplastic replacements have had considerable promise with additional room for improvement using new materials and recent design concepts. PMID:22363183

  3. Arthroscopic treatment of unstable total hip replacement.

    PubMed

    Cuéllar, Ricardo; Aguinaga, Iñaki; Corcuera, Irene; Ponte, Juan; Usabiaga, Jaime

    2010-06-01

    Hip arthroscopy may be useful in the diagnosis and treatment of apparently well-implanted but unstable total hip replacement prostheses. We present 2 cases of arthroscopically assisted capsular tightening in unstable total hip replacements. Both cases had significant capsular laxity. Case 2 had impingement of the lower part of the acetabulum with the lesser trochanter that caused hip dislocation. Early revision surgery can be avoided with the use of this technique in selected cases of unstable total hip replacements.

  4. Biology of tooth replacement in amniotes

    PubMed Central

    Whitlock, John A; Richman, Joy M

    2013-01-01

    Tooth replacement is a common trait to most vertebrates, including mammals. Mammals, however, have lost the capacity for continuous tooth renewal seen in most other vertebrates, and typically have only 1–2 generations of teeth. Here, we review the mechanisms of tooth replacement in reptiles and mammals, and discuss in detail the current and historical theories on control of timing and pattern of tooth replacement and development. PMID:23788284

  5. Peach bottom recirculation piping replacement ALARA program

    SciTech Connect

    Englesson, G.A.; Hilsmeier, A.E.; Mann, B.J.

    1986-01-01

    In late 1983, Philadelphia Electric Company (PECo) began detailed planning to replace the recirculation, residual heat removal, and part of the reactor water cleanup piping of the Peach Bottom Unit 2 reactor. Included in this work was an estimate of the collective exposure expected during piping replacement. That initial estimate, 1945 man-rem, is compared with the actual collective dose incurred during the piping replacement program. Also included are the exposures incurred during two additional tasks (safe end replacement and recirculation pump disassembly and decontamination) not considered in the initial estimate.

  6. Opportunistic replacement of fusion power system parts

    SciTech Connect

    Day, J.A.; George, L.L.

    1981-10-26

    This paper describes a maintenance problem in a fusion power plant. The problem is to specify which life limited parts should be replaced when there is an opportunity. The objective is to minimize the cost rate of replacement parts and of maintenance actions while satisfying a power plant availability constraint. The maintenance policy is to look ahead and replace all parts that will reach their life limits within a time called a screen. Longer screens yield greater system availabilities because more parts are replaced prior to their life limits.

  7. Reoperations Following Cervical Disc Replacement

    PubMed Central

    Skovrlj, Branko; Lee, Dong-Ho; Caridi, John Michael

    2015-01-01

    Cervical disc replacement (CDR) has emerged as an alternative surgical option to cervical arthrodesis. With increasing numbers of patients and longer follow-ups, complications related to the device and/or aging spine are growing, leaving us with a new challenge in the management and surgical revision of CDR. The purpose of this study is to review the current literature regarding reoperations following CDR and to discuss about the approaches and solutions for the current and future potential complications associated with CDR. The published rates of reoperation (mean, 1.0%; range, 0%-3.1%), revision (mean, 0.2%; range, 0%-0.5%), and removal (mean, 1.2%; range, 0%-1.9%) following CDR are low and comparable to the published rates of reoperation (mean, 1.7%; range; 0%-3.4%), revision (mean, 1.5%; range, 0%-4.7%), and removal (mean, 2.0%; range, 0%-3.4%) following cervical arthrodesis. The surgical interventions following CDR range from the repositioning to explantation followed by fusion or the reimplantation to posterior foraminotomy or fusion. Strict patient selection, careful preoperative radiographic review and surgical planning, as well as surgical technique may reduce adverse events and the need for future intervention. Minimal literature and no guidelines exist for the approaches and techniques in revision and for the removal of implants following CDR. Adherence to strict indications and precise surgical technique may reduce the number of reoperations, revisions, and removals following CDR. Long-term follow-up studies are needed, assessing the implant survivorship and its effect on the revision and removal rates. PMID:26097667

  8. Total joint replacement preadmission programs.

    PubMed

    Messer, B

    1998-01-01

    Patients begin to formulate their expectations of the postoperative hospitalization during the preadmission program. The challenge is to better understand the factors patients consider when formulating judgments about the quality of preadmission education. For example, it may be that perceptions of the preadmission program are influenced by what patients believe about their postoperative pain and functional abilities. Specific attention needs to be given both preoperatively and postoperatively to instructing patients on realistic expectations for recovery. One other method of measuring patient outcomes is with the Health Status Profile (SF-36) (Response Healthcare Information Management, 1995). The SF-36 approach emphasizes the outcome of medical care as the patient sees it, in addition to a clinical evaluation of successful health care. This form is currently initiated in the physician's office and returned for scanning at the preadmission class. The patient then completes another SF-36 at 6 months and every year thereafter to compare measurable outcomes. Patients intending to have elective total joint replacements experience anxiety and require much support and education. An effective preadmission program is a major investment in a patient's recovery, as well as a unique marketing tool to customers. Preadmission programs can be viewed as an opportunity to enhance customer satisfaction. Preadmission clinics are an excellent means for nurses to improve the quality of patient care through patient education. the overall goal of preadmission testing programs is to ensure patient preparedness while increasing quality health care and overall customer satisfaction. To enhance program effectiveness, health care providers must lead collaborative efforts to improve the efficiency of systems.

  9. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement...

  10. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement...

  11. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 13 2014-01-01 2013-01-01 true Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement...

  12. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement...

  13. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true Replacement housing. 1944.659 Section 1944.659 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...) PROGRAM REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants § 1944.659 Replacement...

  14. International variation in hip replacement rates

    PubMed Central

    Merx, H; Dreinhofer, K; Schrader, P; Sturmer, T; Puhl, W; Gunther, K; Brenner, H

    2003-01-01

    Objectives: To summarise epidemiological data on the frequency of hip replacements in the countries of the developed world, especially in countries of the Organisation for Economic Cooperation and Development (OECD), and to investigate whether missing consensus criteria for the indication for total hip replacement (THR) result in different replacement rates. Methods: Country-specific hip replacement rates were collected using the available literature, different data sources of national authorities, and estimates of leading hip replacement manufacturers. Results: According to administrative and literature data sources the reported crude primary THR rate varied between 50 and 130 procedures/100 000 inhabitants in OECD countries in the 1990s. The crude overall hip implantation rate, summarising THR, partial hip replacement, and hip revision procedures, was reported to range from 60 to 200 procedures/100 000 inhabitants in the late 1990s. Moreover, large national differences were seen in the relationship between total and partial hip replacement procedures. Conclusion: The reported differences in hip replacement rates in OECD countries are substantial. They may be due to various causes, including different coding systems, country-specific differences in the healthcare system, in total expenditure on health per capita, in the population age structure, and in different indication criteria for THR. PMID:12594106

  15. Mercury Thermometer Replacements in Chemistry Laboratories

    ERIC Educational Resources Information Center

    Foster, Barbara L.

    2005-01-01

    The consequences of broken mercury-in-glass thermometers in academic laboratories results in various health and environmental hazards, which needs to be replaced, by long-stem digital thermometers and non-mercury glass thermometers. The factors that should be considered during the mercury replacement process are types of applications in the…

  16. Replacement of the heavily calcified ascending aorta in aortic valve replacement.

    PubMed

    Matsumoto, Kazuhisa; Hisashi, Yosuke; Imoto, Yutaka

    2015-03-01

    A totally calcified ascending aorta prevents aortic crossclamping and aortotomy during aortic valve replacement, and replacement of the ascending aorta is a valid option in these cases. We describe a simple technique for calcified ascending aorta replacement using the Cavitron Ultrasonic Surgical Aspirator. This can be used in aortic endarterectomy for removal of the calcified plaque in the anastomotic part.

  17. Aortic valve replacement with the Nicks annulus enlargement procedure 12 years after mitral valve replacement.

    PubMed

    Kazama, S; Kurata, A; Yamashita, Y

    1999-10-01

    An aortic valve replacement was successfully performed employing the Nicks annulus enlargement procedure in a case of aortic valve stenosis with small annulus 12 years after mitral valve replacement. Previous mitral valve replacement does not preclude feasibility of the Nicks procedure.

  18. Circumferential or sectored beam arrangements for stereotactic body radiation therapy (SBRT) of primary lung tumors: Effect on target and normal-structure dose-volume metrics

    SciTech Connect

    Rosenberg, Mara W.; Kato, Catherine M.; Carson, Kelly M.P.; Matsunaga, Nathan M.; Arao, Robert F.; Doss, Emily J.; McCracken, Charles L.; Meng, Lu Z.; Chen, Yiyi; Laub, Wolfram U.; Fuss, Martin; Tanyi, James A.

    2013-01-01

    To compare 2 beam arrangements, sectored (beam entry over ipsilateral hemithorax) vs circumferential (beam entry over both ipsilateral and contralateral lungs), for static-gantry intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) delivery techniques with respect to target and organs-at-risk (OAR) dose-volume metrics, as well as treatment delivery efficiency. Data from 60 consecutive patients treated using stereotactic body radiation therapy (SBRT) for primary non–small-cell lung cancer (NSCLC) formed the basis of this study. Four treatment plans were generated per data set: IMRT/VMAT plans using sectored (-s) and circumferential (-c) configurations. The prescribed dose (PD) was 60 Gy in 5 fractions to 95% of the planning target volume (PTV) (maximum PTV dose ∼ 150% PD) for a 6-MV photon beam. Plan conformality, R{sub 50} (ratio of volume circumscribed by the 50% isodose line and the PTV), and D{sub 2} {sub cm} (D{sub max} at a distance ≥2 cm beyond the PTV) were evaluated. For lungs, mean doses (mean lung dose [MLD]) and percent V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} Gy were assessed. Spinal cord and esophagus D{sub max} and D{sub 5}/D{sub 50} were computed. Chest wall (CW) D{sub max} and absolute V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} {sub Gy} were reported. Sectored SBRT planning resulted in significant decrease in contralateral MLD and V{sub 10}/V{sub 5} {sub Gy}, as well as contralateral CW D{sub max} and V{sub 10}/V{sub 5} {sub Gy} (all p < 0.001). Nominal reductions of D{sub max} and D{sub 5}/D{sub 50} for the spinal cord with sectored planning did not reach statistical significance for static-gantry IMRT, although VMAT metrics did show a statistically significant decrease (all p < 0.001). The respective measures for esophageal doses were significantly lower with sectored planning (p < 0.001). Despite comparable dose conformality, irrespective of planning configuration, R{sub 50} significantly improved with IMRT

  19. Anterior cruciate ligament replacement: a review.

    PubMed

    Silver, F H; Tria, A J; Zawadsky, J P; Dunn, M G

    1991-01-01

    The anterior cruciate ligament (ACL) is the major intra-articular mechanical element that limits motion of the tibia with respect to the femur. It is a multi-fasciculated structure composed of crimped aligned collagen fibers. The purpose of this paper is to review the literature on ACL structure and mechanical properties in an effort to stimulate the development of a new generation of more effective replacement devices. Replacement of the ACL is achieved using biologic and synthetic grafts. Biologic grafts include illiotibial band, semitendinosus and gracilis tendons, patellar tendon, and meniscus. Bone-patellar-bone complexes used to replace the ACL are revascularized and ultimately replaced by neo-ligament. Synthetic implants including the Integraft, Leads-Keio ligament, Gore-Tex¿ ligament and Kennedy Ligament Augmentation Device (LAD) have either not been approved or approved by the FDA for limited use as a replacement for the ACL. The Kennedy LAD has been found to increase the strength of autogenous tissue during revascularization. Based on the success of autografts and the Kennedy LAD, we conclude that the next generation of ACL replacement devices will consist of a scaffold and a biodegradable augmentation device. The scaffold will have a structure that mimics the normal ACL as well as stimulates revascularization and healing. A biodegradable augmentation device will be employed to mechanically reinforce the scaffold without stress shielding the neo-ligament. By combining the advantages of autografts and a biodegradable augmentation device, a new generation of ACL replacements will be achieved.

  20. Replacement solvents for use in chemical synthesis

    DOEpatents

    Molnar, Linda K.; Hatton, T. Alan; Buchwald, Stephen L.

    2001-05-15

    Replacement solvents for use in chemical synthesis include polymer-immobilized solvents having a flexible polymer backbone and a plurality of pendant groups attached onto the polymer backbone, the pendant groups comprising a flexible linking unit bound to the polymer backbone and to a terminal solvating moiety. The polymer-immobilized solvent may be dissolved in a benign medium. Replacement solvents for chemical reactions for which tetrahydrofuran or diethyl may be a solvent include substituted tetrahydrofurfuryl ethers and substituted tetrahydro-3-furan ethers. The replacement solvents may be readily recovered from the reaction train using conventional methods.

  1. Learning curve in a Western training center of the circumferential en bloc esophageal endoscopic submucosal dissection in an in vivo animal model.

    PubMed

    Tanimoto, Miguel A; Torres-Villalobos, Gonzalo; Fujita, Rikiya; Santillan-Doherty, Patricio; Albores-Saavedra, Jorge; Chable-Montero, Fredy; Martin-Del-Campo, Luis A; Vasquez, Lucia; Bravo-Reyna, Carlos; Villanueva, Octavio; Villalobos, Jose J; Uribe, Misael; Valdovinos, Miguel A

    2011-01-01

    Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE-) ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to "the Principles of Humane Experimental Technique, Russel and Burch." The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192 ± 35 minutes (range 140-235 minutes). All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999-2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15-18 mm) and 51 ± 6.99 width (range 40-60 mm). Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows.

  2. Learning Curve in a Western Training Center of the Circumferential En Bloc Esophageal Endoscopic Submucosal Dissection in an In Vivo Animal Model

    PubMed Central

    Tanimoto, Miguel A.; Torres-Villalobos, Gonzalo; Fujita, Rikiya; Santillan-Doherty, Patricio; Albores-Saavedra, Jorge; Chable-Montero, Fredy; Martin-del-Campo, Luis A.; Vasquez, Lucia; Bravo-Reyna, Carlos; Villanueva, Octavio; Villalobos, Jose J.; Uribe, Misael; Valdovinos, Miguel A.

    2011-01-01

    Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE-) ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to “the Principles of Humane Experimental Technique, Russel and Burch.” The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192 ± 35 minutes (range 140–235 minutes). All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999–2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15–18 mm) and 51 ± 6.99 width (range 40–60 mm). Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows. PMID:21976950

  3. Modeling of guided circumferential SH and Lamb-type waves in open waveguides with semi-analytical finite element and Perfectly Matched Layer method

    NASA Astrophysics Data System (ADS)

    Matuszyk, Paweł J.

    2017-01-01

    The circumferential guided waves (CGW) are of increasing interest for non-destructive inspecting pipes or other cylindrical structures. If such structures are buried underground, these modes can also deliver some valuable information about the surrounding medium or the quality of the contact between the pipe and the embedding medium. Toward this goal, the detailed knowledge of the dispersive characteristics of CGW is required; henceforth, the robust numerical method has to be established, which allows for the extensive study of the propagation of these modes under different loading conditions. Mathematically, this is the problem of the propagation of guided waves in an open waveguide. This problem differs significantly from the corresponding problem of a closed waveguide both in physical and numerical aspect. The paper presents a combination of semi-analytical finite element method with Perfectly Matched Layer technique for a class of coupled acoustics/elasticity problems with application to modeling of CGW. We discuss different aspects of our algorithm and validate the proposed approach against other established methods available in the literature. The presented numerical examples positively verify the robustness of the proposed method.

  4. Geologic interpretations of seismic data Route 128 (Northern Circumferential Highway) cut, and Hopkins Street grade separation stations 1-18 in Wakefield, Mass.

    USGS Publications Warehouse

    May, James E.; Lineham, Rev. Daniel

    1950-01-01

    The completion of a segment of the Northern Circumferential Highway, Route 126, in Wakefield, Mass., requires an underpass bridge at Hopkins Street, Station 5+50. The plan of the project shows approximately 1800 feet if approach cuts between stations 1 and 18. In October 1945 a preliminary seismic study was made of a segment of this cut between stations 6+50 and 13+30. Four profiles were made at this time and a report was submitted by Newton E. Chute and Rev. Daniel Linhan (file report of January 15). This work showed a relatively shallow (in general, 6 to 12 feet in depth) somewhat irregular bedrock surface between stations 6+50 and 13+50. That data indicated that much of this segment of the cut will be in bedrock. In order to obtain more complete data for the preparation of detailed estimates on the amount of bedrock to be excavated for this segment of the cut, and also to obtain sufficient data for the unexplored segment of the cut, 21 additional seismic traverses were made in September 1949. The present report contains only the results obtained from this later work. The work was performed as a part of a cooperative program of the Massachusetts Department of Public Works and the United States Geological Survey.

  5. Total ankle replacement - surgical treatment and rehabilitation.

    PubMed

    Prusinowska, Agnieszka; Krogulec, Zbigniew; Turski, Piotr; Przepiórski, Emil; Małdyk, Paweł; Księżopolska-Orłowska, Krystyna

    2015-01-01

    Functions of the ankle joint are closely connected with the gait and ability to maintain an upright position. Degenerative lesions of the joint directly contribute to postural disorders and greatly restrict propulsion of the foot, thus leading to abnormal gait. Development of total ankle replacement is connected with the use of the method as an efficient treatment of joint injuries and continuation of achievements in hip and knee surgery. The total ankle replacement technique was introduced as an alternative to arthrodesis, i.e. surgical fixation, which made it possible to preserve joint mobility and to improve gait. Total ankle replacement is indicated in post-traumatic degenerative joint disease and joint destruction secondary to rheumatoid arthritis. In this paper, total ankle replacement and various types of currently used endoprostheses are discussed. The authors also describe principles of early postoperative rehabilitation as well as rehabilitation in the outpatient setting.

  6. Assistance with Obtaining a Replacement Card Form

    EPA Pesticide Factsheets

    Form to be submitted to Section 608 Technician Certification Program Manager if a technician wants to replace a certification card, and the record of the original certification is in the data submitted by companies that have gone out of business.

  7. Renal replacement therapy for acute renal failure.

    PubMed

    Macedo, E; Bouchard, J; Mehta, R L

    2009-09-01

    Renal replacement therapy became a common clinical tool to treat patients with severe acute kidney injury (AKI) since the 1960s. During this time dialytic options have expanded considerably; biocompatible membranes, bicarbonate dialysate and dialysis machines with volumetric ultrafiltration control have improved the treatment for acute kidney injury. Along with advances in methods of intermittent hemodialysis, continuous renal replacement therapies have gained widespread acceptance in the treatment of dialysis-requiring AKI. However, many of the fundamental aspects of the renal replacement treatment such as indication, timing of dialytic intervention, and choice of dialysis modality are still controversial and may influence AKI patient's outcomes. This review outlines current concepts in the use of dialysis techniques for AKI and suggests an approach for selecting the optimal method of renal replacement therapy.

  8. 47 CFR 13.17 - Replacement license.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS General § 13.17 Replacement... Operator License, Marine Radio Operator Permit, First Class Radiotelegraph Operator's Certificate, Second... Radio Operator's License, Restricted GMDSS Radio Operator License, GMDSS Radio Maintainer's License,...

  9. Total ankle replacement. Design evolution and results.

    PubMed

    van den Heuvel, Alexander; Van Bouwel, Saskia; Dereymaeker, Greta

    2010-04-01

    The ankle joint has unique anatomical, biomechanical and cartilaginous structural characteristics that allow the joint to withstand the very high mechanical stresses and strains over years. Any minor changes to any of these features predispose the joint to osteoarthritis. Total ankle replacement (TAR) is evolving as an alternative to ankle arthrodesis for the treatment of end-stage ankle osteoarthritis. Initial implant designs from the early 1970s had unacceptably high failure and complication rates. As a result many orthopaedic surgeons have restricted the use of TAR in favour of ankle arthrodesis. Long term follow-up studies following ankle arthrodesis show risks of developing adjacent joint osteoarthritis. Therefore research towards a successful ankle replacement continues. Newer designs and longer-term outcome studies have renewed the interest in ankle joint replacement. We present an overview of the evolution, results and current concepts of total ankle replacement.

  10. Replacement Saltwell Pumping System Document Bibliography

    SciTech Connect

    BELLOMY, J.R.

    2000-12-07

    This document bibliography is prepared to identify engineering documentation developed during the design of the Replacement Saltwell Pumping System. The bibliography includes all engineering supporting documents and correspondence prepared prior to the deployment of the system in the field. All documents referenced are available electronically through the Records Management Information System (RMIS). Major components of the Replacement Saltwell Pumping System include the Sundyne Canned Motor Pump, the Water Filter Skid, the Injection Water Skid and the Backflow Preventer Assembly. Drawing H-14-104498 provides an index of drawings (fabrication details, P&IDs, etc.) prepared to support development of the Replacement Saltwell Pumping System. Specific information pertaining to new equipment can be found in Certified Vendor Information (CVI) File 50124. This CVI file has been established specifically for new equipment associated with the Replacement Saltwell Pumping System.

  11. Testosterone replacement in older men and women.

    PubMed

    Morley, J E

    2001-01-01

    This article examines in detail the present state of the art concerning androgen deficiency in aging males. There is increasing evidence that testosterone replacement in hypogonadal older males can result in an improvement in quality of life. The major effects of testosterone are on libido, muscles, bone, and cognition. Less information is available concerning the role of testosterone in postmenopausal women, but testosterone replacement may have a role to play in treating disorders of libido and the sarcopenia that occurs at menopause.

  12. Femoral osteolysis following total hip replacement

    PubMed Central

    Dattani, R

    2007-01-01

    Total hip replacement represents the most significant advance in orthopaedic surgery in the 20th century. Periprosthetic osteolysis remains the most significant long‐term complication with total hip replacement. It has been reported with all materials and prosthetic devices in use or that have been used to date. This paper reviews the current thinking on the aetiology, pathogenesis, management and future treatment options for osteolysis. PMID:17488859

  13. Annual report for Ion Replacement Program

    SciTech Connect

    Tomczuk, Z.; Willit, J.L.; Fischer, A.K.

    1993-07-01

    Ion replacement electrorefining is an innovative electrochemical approach to purifying and separating metals. This approach overcomes the shortcomings of conventional electrorefining and has the potential for processing a wider range of metals and metal halide salts. Salt waste is also minimized with this approach. The key element of ion replacement electrorefining is the ion replacement electrode. This electrode allows a decoupling of the electrotransport process into two separate steps, anodic dissolution and cathodic deposition. Three key accomplishments described in this report that demonstrate the feasibility of ion replacement electrorefining are: (1) we have identified a suitable sodium/{beta}{double_prime}-alumina/molten salt electrolyte system that functions reproducibly at 723 K, (2) we have oxidized and deposited dysprosium, lanthanum, uranium, and titanium by using a sodium ion replacement electrode. In several experiments, an actual separation of dysprosium and lanthanum was observed, and (3) we have identified a metal alloy, Li{sub x}Sb, as an alternative ion replacement electrode. The next stage in the program is the design, construction, and testing of a laboratory-scale electrorefiner. Follow-on development with funding from industrial and federal sponsors is being pursued.

  14. A replaceable reflective film for solar concentrators

    SciTech Connect

    Not Available

    1991-09-01

    The 3M Company manufactures a silvered acrylic film called ECP-305 that is regarded as the preferred reflective film for use on stretched-membrane heliostats. However, ECP-305 will degrade in time, due to both corrosion of the silver layer and delamination at the film's silver-to-acrylic interface, and will eventually need to be replaced. 3M uses a very aggressive adhesive on this film, and once it is laminated, replacement is very difficult. The purpose of this investigation was the development of a replaceable reflector, a reflective film that can be easily removed and replaced. A replaceable reflector was successfully configured by laminating ECP-305 to the top surface of a smooth, dimensionally stable polymer film, with a removable adhesive applied to the underside of the polymer film. Several stages of screening and testing led to the selection of a 0.010-inch thick polycarbonate (GE 8030) as the best polymer film and a medium tack tape (3M Y-9425) was selected as the best removable adhesive. To demonstrate the feasibility of the replaceable reflector concept and to provide a real-time field test, the chosen construction was successfully applied to the 50-m{sup 2} SKI heliostat at the Central Receiver Test Facility at Sandia National Laboratories in Albuquerque. 4 refs., 13 figs., 7 tabs.

  15. A study of circumferentially-heated and block-heated heat pipes. I - Experimental analysis and generalized analytical prediction of capillary limits. II - Three-dimensional numerical modeling as a conjugate problem

    NASA Technical Reports Server (NTRS)

    Schmalhofer, Joseph; Faghri, Amir

    1993-01-01

    The wall and centerline vapor temperatures and heat output are determined experimentally for a low-temperature copper-water heat pipe under uniform circumferential heating and block heating. The time required to reach a vapor temperature of 60 C from an initial ambient temperature of 21 C is determined for both modes of heating. The experimental capillary limit of the heat pipe is compared to the generalized capillary limits for block-heated pipes over a range of vapor temperatures. A three-dimensional numerical model is then developed for determining the temperature, pressure, and velocity distributions in the entire domain of a circumferentially heated and a block-heated pipe. The problem is formulated as a conjugate problem, without the assumption of a uniform vapor temperature. The predictions of the model are found to be in good agreement with the experimental data.

  16. The Scandinavian Total Ankle Replacement and the ideal biomechanical requirements of ankle replacements

    PubMed Central

    Robati, Shibby; Salih, Alan; Ghosh, Koushik; Vinayakam, Parthiban

    2016-01-01

    The complex anatomy of the articular bone surfaces, ligaments, tendon attachments and muscles makes the ankle joint difficult to replicate in prosthetic replacements. Ever since the early 1970s, which saw the dawn of the first total ankle replacements, there have been numerous other attempts at replicating the joint, often with poor clinical outcomes. The anatomy of the ankle is discussed, followed by evidence of the normal ankle biomechanics and the ideal requirements of an ankle replacement. We focus on the Scandinavian Total Ankle Replacement and evaluate whether these requirements have been met. PMID:26955224

  17. The Scandinavian Total Ankle Replacement and the ideal biomechanical requirements of ankle replacements.

    PubMed

    Robati, Shibby; Salih, Alan; Ghosh, Koushik; Vinayakam, Parthiban

    2016-03-01

    The complex anatomy of the articular bone surfaces, ligaments, tendon attachments and muscles makes the ankle joint difficult to replicate in prosthetic replacements. Ever since the early 1970s, which saw the dawn of the first total ankle replacements, there have been numerous other attempts at replicating the joint, often with poor clinical outcomes. The anatomy of the ankle is discussed, followed by evidence of the normal ankle biomechanics and the ideal requirements of an ankle replacement. We focus on the Scandinavian Total Ankle Replacement and evaluate whether these requirements have been met.

  18. Tracheal replacement with an aortic autograft.

    PubMed

    Azorin, Jacques F; Bertin, Francois; Martinod, Emmanuel; Laskar, Marc

    2006-02-01

    Tracheal replacement after extensive resection remains a challenge for the thoracic surgeon. We propose an innovative solution: the use of an aortic autograft. After an experimental work on animals with aortic autografts and allografts [Martinod E, Seguin A, Pfeuty K, Fornes P, Kambouchner M, Azorin JF, Carpentier AF. Long-term evaluation of the replacement of the trachea with an autologous aortic graft. Ann Thorac Surg 2003;75(5):1572-8; Martinod E, Seguin A, Holder-Espinasse M, Kambouchner M, Duterque-Coquillaud M, Azorin JF, Carpentier AF. Tracheal regeneration following tracheal replacement with an allogenic aorta. Ann Thorac Surg 2005;79(3):942-8], we present the first human case of long tracheal replacement with an aortic autograft. In this case we replaced 7 cm of a tumoral trachea using an aortic infra-renal autograft supported by a silicone stent. The early postoperative course was uneventful. The stent was removed at three months. The patient died at six months from an acute pulmonary infection without any sign of anastomosis leakage or graft rupture. A new field of clinical study has to be investigated.

  19. Kittiwakes strategically reduce investment in replacement clutches

    USGS Publications Warehouse

    Gasparini, J.; Roulin, A.; Gill, V.A.; Hatch, Shyla A.; Boulinier, T.

    2006-01-01

    Many life-history traits are expressed interactively in life, but to a varying extent on different occasions. Changes in trait expression can be accounted for by differences in the quality of the environment ('environmental constraint' hypothesis) or by strategic adjustments, if the relative contribution of the trait to fitness varies with time ('strategic allocation' hypothesis). In birds, egg production is lower in replacement clutches than in first clutches, but it is unknown whether this reduction results from an environmental constraint (e.g. food being less available at the time when the replacement clutch is produced) or from a strategic allocation of resources between the two breeding attempts. To distinguish between these two hypotheses, we performed an experiment with black-legged kittiwakes (Rissa tridactyla). Pairs were either food-supplemented or not before the first clutch was laid onwards and we induced them to produce a replacement clutch by removing eggs once when the first clutch was complete. As predicted by the 'strategic allocation' hypothesis, egg production of food-supplemented and non-food-supplemented birds decreased between first and replacement clutches. This suggests that kittiwakes strategically reduce investment in egg production for their replacement clutches compared to first clutches. ?? 2006 The Royal Society.

  20. 42 CFR 433.117 - Initial approval of replacement systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement system...

  1. Hip or knee replacement - before - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Review Date 3/5/2015 Updated by: C. ...

  2. Hip or knee replacement - after - what to ask your doctor

    MedlinePlus

    ... PA: Elsevier Mosby; 2012:chap 7. Read More Hip joint replacement Hip pain Knee joint replacement Knee pain ... joint replacement - discharge Taking care of your new hip joint Review Date 3/5/2015 Updated by: C. ...

  3. N-acetylcysteine for the prevention of stricture after circumferential endoscopic submucosal dissection of the esophagus: a randomized trial in a porcine model

    PubMed Central

    2012-01-01

    Background Circumferential endoscopic submucosal dissection (CESD) of the esophagus would allow for both the eradication of Barrett’s esophagus and its related complications, such as advanced neoplasia. However, such procedures generally induce inflammatory repair resulting in a fibrotic stricture. N-acetylcysteine (NAC) is an antioxidant that has shown some efficacy against pulmonary and hepatic fibrosis. The aim of our study was to evaluate the benefit of NAC in the prevention of esophageal cicatricial stricture after CESD in a swine model. Animals and methods Two groups of six pigs each were subjected to general anesthesia and CESD: after randomization, a first group received an oral NAC treatment regimen of 100 mg/kg/day, initiated one week before the procedure, whereas a second group was followed without any prophylactic treatment. Follow-up endoscopies took place seven, fourteen, twenty-one, and twenty-eight days after CESD. Necropsy, histological assessment of esophageal inflammation, and fibrosis were performed on day 28. Results The median esophageal lumen diameter on day 21 (main judgment criterion) was 4 mm (range 2 to 5) in group 1 and 3 mm (range 1 to 7) in group 2 (P = 0.95). No significant difference was observed between the two groups regarding clinical evaluation (time before onset of clinically significant esophageal obstruction), number of dilations, esophageal inflammation and fibrosis, or oxidative stress damage on immunohistochemistry. Conclusions Despite its antioxidant effect, systemic administration of NAC did not show significant benefit on esophageal fibrosis in our animal model of esophageal wound healing within the experimental conditions of this study. Since the administered doses were relatively high, it seems unlikely that NAC might be a valuable option for the prevention of post-endoscopic esophageal stricture. PMID:22640979

  4. Intraoperative Radiation Therapy Reduces Local Recurrence Rates in Patients With Microscopically Involved Circumferential Resection Margins After Resection of Locally Advanced Rectal Cancer

    SciTech Connect

    Alberda, Wijnand J.; Verhoef, Cornelis; Nuyttens, Joost J.; Meerten, Esther van; Rothbarth, Joost; Wilt, Johannes H.W. de; Burger, Jacobus W.A.

    2014-04-01

    Purpose: Intraoperative radiation therapy (IORT) is advocated by some for patients with locally advanced rectal cancer (LARC) who have involved or narrow circumferential resection margins (CRM) after rectal surgery. This study evaluates the potentially beneficial effect of IORT on local control. Methods and Materials: All surgically treated patients with LARC treated in a tertiary referral center between 1996 and 2012 were analyzed retrospectively. The outcome in patients treated with IORT with a clear but narrow CRM (≤2 mm) or a microscopically involved CRM was compared with the outcome in patients who were not treated with IORT. Results: A total of 409 patients underwent resection of LARC, and 95 patients (23%) had a CRM ≤ 2 mm. Four patients were excluded from further analysis because of a macroscopically involved resection margin. In 43 patients with clear but narrow CRMs, there was no difference in the cumulative 5-year local recurrence-free survival of patients treated with (n=21) or without (n=22) IORT (70% vs 79%, P=.63). In 48 patients with a microscopically involved CRM, there was a significant difference in the cumulative 5-year local recurrence-free survival in favor of the patients treated with IORT (n=31) compared with patients treated without IORT (n=17) (84 vs 41%, P=.01). Multivariable analysis confirmed that IORT was independently associated with a decreased local recurrence rate (hazard ratio 0.24, 95% confidence interval 0.07-0.86). There was no significant difference in complication rate of patients treated with or without IORT (65% vs 52%, P=.18) Conclusion: The current study suggests that IORT reduces local recurrence rates in patients with LARC with a microscopically involved CRM.

  5. Phaser.MRage: automated molecular replacement

    SciTech Connect

    Bunkóczi, Gábor; McCoy, Airlie J.; Oeffner, Robert D.; Read, Randy J.

    2013-11-01

    The functionality of the molecular-replacement pipeline phaser.MRage is introduced and illustrated with examples. Phaser.MRage is a molecular-replacement automation framework that implements a full model-generation workflow and provides several layers of model exploration to the user. It is designed to handle a large number of models and can distribute calculations efficiently onto parallel hardware. In addition, phaser.MRage can identify correct solutions and use this information to accelerate the search. Firstly, it can quickly score all alternative models of a component once a correct solution has been found. Secondly, it can perform extensive analysis of identified solutions to find protein assemblies and can employ assembled models for subsequent searches. Thirdly, it is able to use a priori assembly information (derived from, for example, homologues) to speculatively place and score molecules, thereby customizing the search procedure to a certain class of protein molecule (for example, antibodies) and incorporating additional biological information into molecular replacement.

  6. Testosterone replacement therapy and prostate health.

    PubMed

    Polackwich, A Scott; Ostrowski, Kevin A; Hedges, Jason C

    2012-12-01

    There is an emerging evolution in the understanding of the relationship between the prostate and testosterone. It has long been generally believed that with testosterone replacement therapy (TRT), increasing serum testosterone levels led to prostatic growth and worsening of voiding dysfunction and associated complications. A new theory, the Saturation Model of Testosterone and its effect on the Prostate has gained attention. This theory suggests that the prostate's response to increasing levels of serum testosterone reaches a limit beyond which there is minimal effect. This model predicts that testosterone replacement therapy occurs above this saturation point, and replacing testosterone to eugonadal levels should not worsen prostate related benign disease. We evaluated the recent published data, with an emphasis on clinical studies done within the last 3 years, for the effects of testosterone supplementation on benign prostatic disease.

  7. Dead pixel replacement in LWIR microgrid polarimeters.

    PubMed

    Ratliff, Bradley M; Tyo, J Scott; Boger, James K; Black, Wiley T; Bowers, David L; Fetrow, Matthew P

    2007-06-11

    LWIR imaging arrays are often affected by nonresponsive pixels, or "dead pixels." These dead pixels can severely degrade the quality of imagery and often have to be replaced before subsequent image processing and display of the imagery data. For LWIR arrays that are integrated with arrays of micropolarizers, the problem of dead pixels is amplified. Conventional dead pixel replacement (DPR) strategies cannot be employed since neighboring pixels are of different polarizations. In this paper we present two DPR schemes. The first is a modified nearest-neighbor replacement method. The second is a method based on redundancy in the polarization measurements.We find that the redundancy-based DPR scheme provides an order-of-magnitude better performance for typical LWIR polarimetric data.

  8. Nashville Gas treads carefully to replace pipe

    SciTech Connect

    1997-06-01

    The private gas utility, Nashville Gas, was responsible for replacing damaged or inadequate 2- and 4-inch steel gas lines beneath Music City, USA. The line replacements required either size for size or upsizing. The first choice was directional drilling, which was quickly determined to be unpractical because of rocky soil conditions. The second option was open trenching. Undoubtedly, trenching would mean having to contend with angry residents and tourists, since gas lines ran beneath yards, mature trees, sidewalks, roadways, and railways. In addition to the negative social factors, trenching would require additional funds for substantial landscaping and pavement replacement. It at all possible, a no-dig alternative was desired. Nashville Gas found Grundomat piercing tools which create a bore, then pushes pipe back through it. These same tools can simultaneously pull in pipe. These tools were customized for the Nashville project.

  9. Replacement of charcoal sorbent in the VOST

    SciTech Connect

    Johnson, L.D.; Fuerst, R.G.; Foster, A.L.; Bursey, J.T.

    1993-01-01

    EPA Method 0030, the Volatile Organic Sampling Train (VOST), for sampling volatile organics from stationary sources, specifies the use of petroleum-base charcoal in the second sorbent tube. Charcoal has proven to be a marginal performer as a sampling sorbent, partly due to inconsistency in analyte recovery. In addition, commercial availability of petroleum charcoal for VOST tubes has been variable. Lack of data on comparability and variability of charcoals for VOST application has created uncertainty when other charcoals are substituted. Five potential sorbent replacements for charcoal in Method 0030 were evaluated along with a reference charcoal. Two of the sorbents tested, Ambersorb XE-340 and Tenax GR, did not perform well enough to qualify as replacements. Three candidates, Anasorb 747, Carbosieve S-III and Kureha Beaded Activated Charcoal, performed adequately, and produced statistically equivalent results. Anasorb 747 appears to be an acceptable replacement for petroleum charcoal, based on a combination of performance, availability, and cost.

  10. HP replacement program increases efficiency, protection

    SciTech Connect

    1997-10-01

    For more than 50 years, compression equipment along the 2,000-mile Tennessee Gas Pipeline has been helping to supply natural gas needs for the Northeast. But increasing demand and a need for more environmentally safe equipment mean a major replacement program for the compressor stations that make the natural gas transmission possible. Today it is one of the longest gas pipelines in the world, carrying more than 1 Bcf/d of natural gas. New compression equipment is being installed to boost efficiency and meet more stringent environmental standards. In 1993, Tenneco Energy, purchased by El Paso Energy in December 1996, initiated a Horsepower Replacement Program intended to replace older, inefficient technology with more advanced equipment. A major objective was to improve operational effectiveness and to reduce harmful nitrogen oxide and carbon monoxide emissions by converting much of the machinery to electric-driven compression equipment.

  11. Rapid prototyping of ossicular replacement prostheses

    NASA Astrophysics Data System (ADS)

    Ovsianikov, A.; Chichkov, B.; Adunka, O.; Pillsbury, H.; Doraiswamy, A.; Narayan, R. J.

    2007-05-01

    Materials used in ossicular replacement prostheses must demonstrate appropriate biological compatibility, acoustic transmission, stability, and stiffness properties. Prostheses prepared using Teflon ®, titanium, Ceravital and other conventional materials have demonstrated several problems, including migration, perforation of the tympanic membrane, difficulty in shaping the prostheses, and reactivity with the surrounding tissues. We have used two-photon polymerization for rapid prototyping of Ormocer ® middle-ear bone replacement prostheses. Ormocer ® surfaces fabricated using two-photon polymerization exhibited acceptable cell viability and cell growth profiles. The Ormocer ® prosthesis was able to be inserted and removed from the site of use in the frozen human head without fracture. Our results demonstrate that two-photon polymerization is able to create ossicular replacement prostheses and other medical devices with a larger range of sizes, shapes and materials than other microfabrication techniques.

  12. [Update in continuous renal replacement techniques].

    PubMed

    Romero-García, M; de la Cueva-Ariza, L; Delgado-Hito, P

    2013-01-01

    Acute renal failure affects 25% of patients hospitalized in intensive care units. Despite technological advances, the mortality of these patients is still high due to its associated complications. Continuous renal replacement techniques are one of the treatments for acute renal failure because they make it possible to treat the complications and decrease mortality. The nurse's knowledge and skills regarding these techniques will be decisive for the success of the therapy. Consequently, the nurse's experience and training are key components. The objective of this article is to update the knowledge on continuous renal replacement techniques. Keeping this in mind, a review has been made of the physical and chemical principles such as diffusion and convection, among others. A description of the different continuous renal replacement techniques, a presentation of the main vascular access, and a description of the nursing cares and complications related to techniques used have also been provided.

  13. The echocardiography of replacement heart valves

    PubMed Central

    2016-01-01

    This is a practical description of how replacement valves are assessed using echocardiography. Normal transthoracic appearances including normal variants are described. The problem of differentiating normal function, patient–prosthesis mismatch and pathological obstruction in aortic replacement valves with high gradients is discussed. Obstruction and abnormal regurgitation is described for valves in the aortic, mitral and right-sided positions and when to use echocardiography in suspected infective endocarditis. The roles of transoesophageal and stress echocardiography are described and finally when other imaging techniques may be useful. PMID:27600454

  14. Using in vivo Cine and 3D multi-contrast MRI to determine human atherosclerotic carotid artery material properties and circumferential shrinkage rate and their impact on stress/strain predictions.

    PubMed

    Liu, Haofei; Canton, Gador; Yuan, Chun; Yang, Chun; Billiar, Kristen; Teng, Zhongzhao; Hoffman, Allen H; Tang, Dalin

    2012-01-01

    In vivo magnetic resonance image (MRI)-based computational models have been introduced to calculate atherosclerotic plaque stress and strain conditions for possible rupture predictions. However, patient-specific vessel material properties are lacking in those models, which affects the accuracy of their stress/strain predictions. A noninvasive approach of combining in vivo Cine MRI, multicontrast 3D MRI, and computational modeling was introduced to quantify patient-specific carotid artery material properties and the circumferential shrinkage rate between vessel in vivo and zero-pressure geometries. In vivo Cine and 3D multicontrast MRI carotid plaque data were acquired from 12 patients after informed consent. For each patient, one nearly-circular slice and an iterative procedure were used to quantify parameter values in the modified Mooney-Rivlin model for the vessel and the vessel circumferential shrinkage rate. A sample artery slice with and without a lipid core and three material parameter sets representing stiff, median, and soft materials from our patient data were used to demonstrate the effect of material stiffness and circumferential shrinkage process on stress/strain predictions. Parameter values of the Mooney-Rivlin models for the 12 patients were quantified. The effective Young's modulus (YM, unit: kPa) values varied from 137 (soft), 431 (median), to 1435 (stiff), and corresponding circumferential shrinkages were 32%, 12.6%, and 6%, respectively. Using the sample slice without the lipid core, the maximum plaque stress values (unit: kPa) from the soft and median materials were 153.3 and 96.2, which are 67.7% and 5% higher than that (91.4) from the stiff material, while the maximum plaque strain values from the soft and median materials were 0.71 and 0.293, which are about 700% and 230% higher than that (0.089) from the stiff material, respectively. Without circumferential shrinkages, the maximum plaque stress values (unit: kPa) from the soft, median, and

  15. Using In Vivo Cine and 3D Multi-Contrast MRI to Determine Human Atherosclerotic Carotid Artery Material Properties and Circumferential Shrinkage Rate and Their Impact on Stress/Strain Predictions

    PubMed Central

    Liu, Haofei; Canton, Gador; Yuan, Chun; Yang, Chun; Billiar, Kristen; Teng, Zhongzhao; Hoffman, Allen H.; Tang, Dalin

    2012-01-01

    Background In vivo magnetic resonance image (MRI)-based computational models have been introduced to calculate atherosclerotic plaque stress and strain conditions for possible rupture predictions. However, patient-specific vessel material properties are lacking in those models which affect the accuracy of their stress/strain predictions. A non-invasive approach of combining in vivo Cine MRI, multi-contrast 3D MRI and computational modeling was introduced to quantify patient-specific carotid artery material properties and circumferential shrinkage rate between vessel in vivo and zero-pressure geometries. Method In vivo Cine and 3D multicontrast MRI carotid plaque data were acquired from 12 patients after informed consent. For each patient, one nearly-circular slice and an iterative procedure were used to quantify parameter values in the modified Mooney-Rivlin model for the vessel and the vessel circumferential shrinkage rate. A sample artery slice with and without a lipid core and three material parameter sets representing stiff, median and soft materials from our patient data were used to demonstrate the effect of material stiffness and circumferential shrinkage process on stress/strain predictions. Results Parameter values of the Mooney-Rivlin models for the 12 patients were quantified. Effective Young's Modulus (YM, unit: kPa) values varied from 137 (soft), 431 (median) to 1435 (stiff), and corresponding circumferential shrinkages were 32%, 12.6% to 6%, respectively. Using the sample slice without the lipid core, the maximum plaque stress values (unit: kPa) from the soft and median materials were 153.3 and 96.2, 67.7% and 5% higher than that (91.4) from the stiff material, while the maximum plaque strain values from the soft and median materials were 0.71 and 0.293, about 700% and 230% higher than that (0.089) from the stiff material, respectively. Without circumferential shrinkages, the maximum plaque stress values (unit: kPa) from the soft, median and stiff

  16. 24 CFR 880.602 - Replacement reserve.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Replacement reserve. 880.602 Section 880.602 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT... AND URBAN DEVELOPMENT (SECTION 8 HOUSING ASSISTANCE PROGRAMS, SECTION 202 DIRECT LOAN PROGRAM,...

  17. Student Aggression: Prevention, Management, and Replacement Training.

    ERIC Educational Resources Information Center

    Goldstein, Arnold P.; And Others

    American society is violent, a fact which is well-reflected in schools. This book, designed specifically for school personnel, presents the primary techniques currently being employed by educators to prevent, manage, and replace student aggression. The volume opens with a description of the origins of aggressive behavior and offers some…

  18. REPLACING SOLVENT CLEANING WITH AQUEOUS CLEANING

    EPA Science Inventory

    The report documents actions taken by Robert Bosch Corp., Charleston, SC, in replacing the cleaning solvents 1, 1, 2- trichloro-1, 2, 2-trifluoroethane (CFC-113) and trichloroethylene (TCE) with aqueous solutions. Bosch has succeeded in eliminating all their CFC-113 use and so f...

  19. New developments in nucleus pulposus replacement technology.

    PubMed

    Carl, Allen; Ledet, Eric; Yuan, Hansen; Sharan, Alok

    2004-01-01

    Attempts to alleviate the pain attributed to degeneration of the nucleus pulposus using replacement or reinforcement techniques dating back to the 1950s are reviewed. The various materials and their insertion techniques are discussed as are results available from early clinical experiences. These techniques are in evolution and clinical outcomes will be necessary to establish the efficacy of these approaches.

  20. Nicotine Replacement: Effects on Postcessation Weight Gain.

    ERIC Educational Resources Information Center

    Gross, Janet; And Others

    1989-01-01

    Examined nicotine replacement effects on postcessation weight gain in smoking cessation volunteers. Randomly assigned abstinent subjects to active nicotine or placebo gum conditions for 10 weeks. Analyses revealed strong evidence for gum effect on weight gain, with active gum users gaining mean total of 3.8 pounds compared with 7.8 pounds for…

  1. Options for Replacing and Reformatting Deteriorated Materials.

    ERIC Educational Resources Information Center

    Banks, Jennifer

    This resource guide focuses on handling library materials that are too deteriorated to benefit from other preservation treatments. Hopeless case items, that would require an unreasonable amount of conservation work to fix, can be resolved through a process of reselecting items by replacing them or reformatting them. The reselection integrates…

  2. Aggression Replacement Training and Childhood Trauma

    ERIC Educational Resources Information Center

    Amendola, A. Mark; Oliver, Robert W.

    2013-01-01

    Aggression Replacement Training (ART) was developed by the late Arnold Goldstein of Syracuse University to teach positive alternatives to children and youth with emotional and behavioral problems (Glick & Gibbs, 2011; Goldstein, Glick, & Gibbs, 1998). ART provides cognitive, affective, and behavioral interventions to build competence in…

  3. Mitochondrial Replacement Techniques: Divergence in Global Policy.

    PubMed

    Schandera, Johanna; Mackey, Tim K

    2016-07-01

    In 2015, the UK became the first country permitting the clinical application of mitochondrial replacement techniques (MRT). Here, we explore how MRT have led to diverging international policy. In response, we recommend focused regulatory efforts coupled with United Nations (UN) leadership to build international consensus on the future of MRT.

  4. SYNERGISTIC WOOD PRESERVATIVES FOR REPLACEMENT OF CCA

    EPA Science Inventory

    The objective of this project was to evaluate the potential synergistic combinations of environmentally-safe biocides as wood preservatives. These wood preservatives could be potential replacements for the heavy-metal based CCA.

    Didecyldimethylammonium chloride [DDAC] was...

  5. Is physiological glucocorticoid replacement important in children?

    PubMed Central

    Porter, John; Blair, Joanne; Ross, Richard J

    2017-01-01

    Cortisol has a distinct circadian rhythm with low concentrations at night, rising in the early hours of the morning, peaking on waking and declining over the day to low concentrations in the evening. Loss of this circadian rhythm, as seen in jetlag and shift work, is associated with fatigue in the short term and diabetes and obesity in the medium to long term. Patients with adrenal insufficiency on current glucocorticoid replacement with hydrocortisone have unphysiological cortisol concentrations being low on waking and high after each dose of hydrocortisone. Patients with adrenal insufficiency complain of fatigue, a poor quality of life and there is evidence of poor health outcomes including obesity potentially related to glucocorticoid replacement. New technologies are being developed that deliver more physiological glucocorticoid replacement including hydrocortisone by subcutaneous pump, Plenadren, a once-daily modified-release hydrocortisone and Chronocort, a delayed and sustained absorption hydrocortisone formulation that replicates the overnight profile of cortisol. In this review, we summarise the evidence regarding physiological glucocorticoid replacement with a focus on relevance to paediatrics. PMID:27582458

  6. Analogue Assessment of the Replacement Behavior

    ERIC Educational Resources Information Center

    Cipani, Ennio

    2008-01-01

    The use of experimental analyses in determining behavioral function for problems behaviors is well established. Such analyses lead to functional treatment prescriptions for the target problem behavior. However, data indicative of the strength of the replacement behavior are often not collected during a functional behavioral assessment. I examine…

  7. HazMatID (trademark) Replacement Project

    DTIC Science & Technology

    2013-05-09

    uses FTIR spectroscopy. It has the capability to identify chemical warfare agents, explosives , toxic industrial chemicals, narcotics, and...off-the-shelf, Fourier transform infrared spectroscopy ( FTIR ) instruments 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18...replacement for the Smiths Detection HazMatIDTM on the 886H allowance standard, a search of Fourier transform infrared spectroscopy ( FTIR ) instruments was

  8. Recent Advances in Hydrocortisone Replacement Treatment.

    PubMed

    Mallappa, Ashwini; Debono, Miguel

    2016-01-01

    Since the first use of cortisone in patients around 65 years ago, the use of synthetic glucocorticoids has made a crucial impact on the treatment of several diseases in medicine. Although significant reductions in morbidity and mortality have occurred in patients suffering from cortisol deficiency, conventional hydrocortisone replacement treatment is still inadequate. A major limitation is that it fails to replace cortisol in a physiological manner. Cortisol has a distinct circadian rhythm and acts as a secondary messenger synchronizing the central to peripheral clocks, hence playing a key role in biological processes and the circadian timing system. Circadian misalignment has been associated with ill-health and so nonphysiological glucocorticoid treatment could explain the increased mortality rate, poor quality of life and metabolic complications in patients suffering from adrenal insufficiency. Attempts at replacing cortisol in a physiological manner have shown significant progress in the past decade with the development of modified-release formulations of hydrocortisone (Chronocort® and Plenadren®) and continuous subcutaneous hydrocortisone infusions. Initial studies investigating the use of these replacement regimens are promising, demonstrating both clinical and biochemical improvement. Larger studies are needed to determine whether this novel approach enhances long-term outcomes in both children and adults with cortisol deficiency. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply. Published by S. Karger AG, Basel.

  9. Measure Guideline: Window Repair, Rehabilitation, and Replacement

    SciTech Connect

    Baker, P.

    2012-12-01

    This measure guideline provides information and guidance on rehabilitating, retrofitting, and replacing existing window assemblies in residential construction. The intent is to provide information regarding means and methods to improve the energy and comfort performance of existing wood window assemblies in a way that takes into consideration component durability, in-service operation, and long term performance of the strategies.

  10. Mitochondrial replacement approaches: challenges for clinical implementation.

    PubMed

    Klopstock, Thomas; Klopstock, Barbara; Prokisch, Holger

    2016-11-25

    The advent of mitochondrial replacement techniques poses many scientific, regulatory, and ethical questions. Previous studies suggest good safety and efficacy profiles of these techniques, but challenges remain for clinical implementation and international consensus is needed on the regulation of these approaches.

  11. Knee disarticulation after total-knee replacement.

    PubMed

    Lambregts, S A M; Hitters, W M G C

    2002-12-01

    An 89-year-old woman who had a total-knee replacement in the past, underwent a knee disarticulation of the same leg because of an ischaemic foot. Eight (8) months postoperatively the stump is fully weight-bearing and the patient is able to walk safely, using a prosthesis and a walking frame.

  12. 25 CFR 700.53 - Dwelling, replacement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... § 700.55. (b) May include existing dwellings for resale, new construction, modular homes, mobile homes... person if, after he receives a replacement housing payment and any available housing assistance payments... supplemental income payments received from public agencies. If the person's monthly income pattern is...

  13. Winged scapula after aortic valve replacement.

    PubMed

    Schmitz, Christoph; Sodian, Ralf; Witt, Thomas N; Juchem, Gerd; Lang, Nora; Bruegger, Christian; Kowalski, Christian; Reichart, Bruno

    2009-04-01

    Iatrogenic nerve lesions affecting the long thoracic nerve are very rare after a median sternotomy. Here we report on a patient who developed clinical signs of a so-called "winged scapula" after an uneventful aortic valve replacement for infective endocarditis.

  14. Probability Issues in without Replacement Sampling

    ERIC Educational Resources Information Center

    Joarder, A. H.; Al-Sabah, W. S.

    2007-01-01

    Sampling without replacement is an important aspect in teaching conditional probabilities in elementary statistics courses. Different methods proposed in different texts for calculating probabilities of events in this context are reviewed and their relative merits and limitations in applications are pinpointed. An alternative representation of…

  15. A replaceable reflective film for solar concentrators

    NASA Astrophysics Data System (ADS)

    1991-09-01

    The 3M Company manufactures a silvered acrylic film called ECP-305 that is regarded as the preferred reflective film for use on stretched-membrane heliostats. However, ECP-305 will degrade in time, due to both corrosion of the silver layer and delamination at the film's silver-to-acrylic interface. The purpose of this investigation was the development of a replaceable reflector, a reflective film that can be easily removed and replaced. A replaceable reflector was successfully configured by laminating ECP-305 to the top surface of a smooth, dimensionally stable polymer film, with a removable adhesive applied to the underside of the polymer film. Several stages of screening and testing led to the selection of a 0.010-inch thick polycarbonate as the best polymer film and a medium tack tape was selected as the best removable adhesive. To demonstrate the feasibility of the replaceable reflector concept and to provide a real time field test, the chosen construction was successfully applied to the 50 sq m SKI heliostat at Sandia National Laboratories in Albuquerque.

  16. ANNUAL ESTIMATED REPLACEMENT FARMER OPPORTUNITIES IN NEBRASKA.

    ERIC Educational Resources Information Center

    GENEREUX, DOUGLAS G.

    AN ESTIMATE OF ANNUAL FARMER REPLACEMENT NEEDS IN THE 93 COUNTIES OF NEBRASKA WAS COMPUTED BY A FORMULA DEVELOPED BY CLARENCE BUNDY AT IOWA STATE UNIVERSITY AND APPLIED TO CENSUS DATA. THE FORMULA WAS USED TO DETERMINE THE NUMBER OF FARMER RETIREMENTS, OR FARMERS LEAVING FARMING, AND FARM CONSOLIDATION RATES. ACCORDING TO THE ESTIMATES, 951…

  17. Mineral replacement front propagation in deformed rocks

    NASA Astrophysics Data System (ADS)

    Beaudoin, Nicolas; Koehn, Daniel; Kelka, Ulrich

    2015-04-01

    Fluid migrations are a major agent of contaminant transport leading to mineral replacement in rocks, impacting their properties as porosity, permeability, and rheology. Understanding the physical and chemical mechanisms that govern mineralogical replacement during and after deformation is required to better understand complex interplays between fluid and rocks that are involved in faulting, seismic cycle, and resource distribution in the upper crust. Dolomitization process related to hydrothermal fluid flow is one of the most studied and debated replacement processes in earth sciences. Dolomitization of limestone is of economic importance as well, as it stands as unconventional oil reservoirs and is systematically observed in Mississippian-Valley Type ore deposit. Despite recent breakthrough about dolomitization processes at large-scale, the small-scale propagation of the reaction front remains unclear. It is poorly documented in the occurrence of stylolites and fractures in the medium while pressure-solution and fracture network development are the most efficient deformation accomodation mechanism in limestone from early compaction to layer-parallel shortening. Thus, the impact of such network on geometry of replaced bodies and on replacement front propagation deserves specific attention. This contribution illustrates the role of fracture and stylolites on the propagation of a reaction front. In a 2 dimensional numerical model we simulate the dolomitization front propagation in a heterogeneous porous medium. The propagation of the reaction front is governed by the competition between advection and diffusion processes, and takes into account reaction rates, disorder in the location of the potential replacement seeds, and permeability heterogeneities. We add stylolites and fractures that can act as barriers or drains to fluid flow according to their orientation and mineralogical content, which can or cannot react with the contaminant. The patterns produced from

  18. Blood conservation strategies in cardiac valve replacement

    PubMed Central

    Zheng, Junnan; Chen, Liangwei; Qian, Linfeng; Jiang, Jianjie; Chen, Yinglian; Xie, Jue; Shi, Liping; Ni, Yiming; Zhao, Haige

    2016-01-01

    Abstract We aimed to evaluate whether blood conservation strategies including intraoperative autologous donation (IAD) could reduce perioperative blood transfusion for patients undergoing cardiac valve replacement including mitral valve replacement, aortic valve replacement (AVR), and double valve replacement (DVR). A total of 726 patients were studied over a 3-year period (2011–2013) after the implementation of IAD and were compared with 919 patients during the previous 36-month period (January 2008–December 2010). The method of small-volume retrograde autologous priming, strict blood transfusion standard together with IAD constituted a progressive blood-saving strategy. Baseline characteristics and preoperative information showed no statistically significant difference between IAD group and non-IAD group. Most of the postoperative morbidities are statistically the same in the 2 groups. Chest tube output (415.2 vs 1029.8 mL, P < 0.001) and postoperative respiratory failure (5.9% vs 8.6%, P = 0.039) favored the IAD group, whereas hematocrit levels were more favorable in the non-IAD group (30.3% vs 33.0% at the end of the operation, P < 0.001; 30.4% vs 31.5% at the time of discharge). The use of blood product transfusion was higher in the non-IAD group (22.6% vs 43.3%, P < 0.001). Binary multivariate logistic regression analysis showed that high age, non-IAD, DVR surgery, and absent smoking history are associated with a higher risk of intra-/postoperative blood transfusion. Blood conservation is effective and safe in cardiac valve replacement surgeries. The use of intraoperative autologous donation can lead to improved outcomes including a significantly lower rate of intra-/postoperative blood transfusion and postoperative complications. PMID:27741149

  19. Coronary Ostial Stenosis after Aortic Valve Replacement

    PubMed Central

    Ziakas, Antonios G.; Economou, Fotios I.; Charokopos, Nicholas A.; Pitsis, Antonios A.; Parharidou, Despina G.; Papadopoulos, Thomas I.; Parharidis, Georgios E.

    2010-01-01

    Coronary ostial stenosis is a rare but potentially serious sequela after aortic valve replacement. It occurs in the left main or right coronary artery after 1% to 5% of aortic valve replacement procedures. The clinical symptoms are usually severe and may appear from 1 to 6 months postoperatively. Although the typical treatment is coronary artery bypass grafting, patients have been successfully treated by means of percutaneous coronary intervention. Herein, we present the cases of 2 patients in whom coronary ostial stenosis developed after aortic valve replacement. In the 1st case, a 72-year-old man underwent aortic valve replacement and bypass grafting of the saphenous vein to the left anterior descending coronary artery. Six months later, he experienced a non-ST-segment-elevation myocardial infarction. Coronary angiography revealed a critical stenosis of the right coronary artery ostium. In the 2nd case, a 78-year-old woman underwent aortic valve replacement and grafting of the saphenous vein to an occluded right coronary artery. Four months later, she experienced unstable angina. Coronary angiography showed a critical left main coronary artery ostial stenosis and occlusion of the right coronary artery venous graft. In each patient, we performed percutaneous coronary intervention and deployed a drug-eluting stent. Both patients were asymptomatic on 6-to 12-month follow-up. We attribute the coronary ostial stenosis to the selective ostial administration of cardioplegic solution during surgery. We conclude that retrograde administration of cardioplegic solution through the coronary sinus may reduce the incidence of postoperative coronary ostial stenosis, and that stenting may be an efficient treatment option. PMID:20844624

  20. Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

    PubMed

    Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

    2016-01-01

    This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints.

  1. 25 CFR 700.183 - Determination of replacement housing benefit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Determination of replacement housing benefit. 700.183... RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit. (a) Amount of benefit. The replacement housing benefit for a certified eligible head-of-household is...

  2. 25 CFR 700.189 - Expenditure of replacement home benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Expenditure of replacement home benefits. 700.189 Section 700.189 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement...

  3. [Aortic valve replacement and hemiarch replacement in a patient with a porcelain aorta].

    PubMed

    Okamoto, Y; Sakakibara, K; Inoue, H; Suzuki, S; Shindo, S; Matsumoto, M

    2009-07-01

    We report a case of aortic valve replacement and hemiarch replacement with reconstruction of the brachiocephalic artery in a patient with a porcelain aorta. A 65-year-old man was admitted to the hospital for aortic stenosis. Computed tomography demonstrated severe aortic calcification and extensive calcification covering a wide area of the aorta. The echocardiography showed a highly calcified aortic valve and a pressure gradient of 109 mmHg across the aortic valve. At surgery, calcification of the ascending aorta was severe and involved its entire circumference. Therefore, 2 cannulae were inserted to the right axillary and right femoral arteries for extracorporeal circulation. We performed replacement of the ascending aorta and hemiarch with reconstruction of the brachiocephalic artery under circulatory arrest and antegrade cerebral perfusion, as well as aortic valve replacement with a 21 mm St. Jude Medical mechanical valve. He had no major cardiac complications during the postoperative course, and was discharged on postoperative day 33.

  4. A complex method of equipment replacement planning. An advanced plan for the replacement of medical equipment.

    PubMed

    Dondelinger, Robert M

    2004-01-01

    This complex method of equipment replacement planning is a methodology; it is a means to an end, a process that focuses on equipment most in need of replacement, rather than the end itself. It uses data available from the maintenance management database, and attempts to quantify those subjective items important [figure: see text] in making equipment replacement decisions. Like the simple method of the last issue, it is a starting point--albeit an advanced starting point--which the user can modify to fit their particular organization, but the complex method leaves room for expansion. It is based on sound logic, documented facts, and is fully defensible during the decision-making process and will serve your organization well as provide a structure for your equipment replacement planning decisions.

  5. Autogenous Transplantation for Replacing a Hopeless Tooth

    PubMed Central

    Zakershahrak, Mehrsa; Moshari, Amirabbas; Vatanpour, Mehdi; Khalilak, Zohreh; Jalali Ara, Afsoon

    2017-01-01

    Autogenous tooth transplantation (ATT) is a simple and reasonable choice for replacing the missing teeth when a proper donor tooth is available. This report presents a case of successful ATT of a maxillary right third molar for replacement of mandibular right second molar with a concomitant endodontic-periodontal disease. The mandibular second molar was believed to be hopeless due to a severe damage to coronal tooth structure, inappropriate root canal treatment and apical radiolucency. After extraction of mandibular second molar and maxillary third molar (the donor), the tooth was re-implanted into the extracted socket of second molar site. Root canal therapy was then performed. After 3 years, clinical and radiographic examinations revealed satisfying results, with no signs and symptoms. The patient is asymptomatic and the transplanted tooth is still functional with no signs of marginal periodontal pathosis. Radiographies showed bone regeneration in the site of previous extensive periapical lesion, normal periodontal ligament with no signs of root resorption. PMID:28179939

  6. Minuteman Weapon System Test Set logic replacement

    NASA Astrophysics Data System (ADS)

    Royse, S. D.

    In the late 1960s, the Minuteman Weapon System Test Set was constructed as a part of the Minuteman development program. The missile Reentry Vehicle is that portion of the Minuteman missile system which reenters the atmosphere with the nuclear warhead. The test set has the objective to test the electrical/electro-mechanical systems and components of the reentry vehicle at both the repair depot and missile maintenance squadron levels. With the recent advances in semiconductor technologies, the Diode Transistor Logic (DTL) technology used to implement the test set logic became obsolete. The present paper is concerned with efforts to develop a prototype replacement for the test set logic. Attention is given to the functions of the test set, the documentation of existing logic, and the prototype design approach, which involves the subdivision of the logic into three basic functional groups. The logic replacement is based on the utilization of a multiple microprocessor system.

  7. Biosecurity and risk management for dairy replacements.

    PubMed

    Maunsell, Fiona; Donovan, G Arthur

    2008-03-01

    Biosecurity, biocontainment, and disease risk management on dairy replacement operations are time- and labor-intensive, planned programs. Oftentimes the value of these programs is realized only after disease is introduced to a facility or a disease outbreak occurs. There is no "one-plan-fits-all;" each plan must be tailored to meet the needs of management's goals and expectations and problems specific to a production enterprise or geographic region. A standard framework applicable to biosecurity programs includes: (1) hazard identification, (2) exposure assessment, (3) risk characterization, and (4) risk management. The discussion presented here helps lay the framework for development and implementation of biosecurity and risk-management programs within dairy replacement facilities.

  8. Material considerations for intervertebral disc replacement implants.

    PubMed

    Taksali, Sudeep; Grauer, Jonathan N; Vaccaro, Alexander R

    2004-01-01

    Cervical and lumbar disc replacements are being performed with increasing frequency. Much of the background for the development for these implants is drawn from the literature of other joint replacements that have been in evolution and use for decades. Important variables for the function and longevity of such disc arthroplasty implants are clearly defined by the material properties of the components used for their production. The most frequently considered materials are cobalt-chrome alloys, titanium alloys, stainless steels, polyethylene, polyurethane and ceramics. In addition to implant materials, the interfaces of such materials must be considered. The bearing surfaces of an implant, in particular, are at risk of wear and failure. Overall, successful, long-term total disc arthroplasty requires a thorough understanding of biomaterials and how they can be used to achieve their desired goals.

  9. Enzyme replacement therapy: conception, chaos and culmination.

    PubMed Central

    Brady, Roscoe O

    2003-01-01

    Soon after the enzymatic defects in Gaucher disease and in Niemann-Pick disease were discovered, enzyme replacement or enzyme supplementation was proposed as specific treatment for patients with these and related metabolic storage disorders. While relatively straightforward in concept, successful implementation of this approach required many years of intensive effort to bring it to fruition. Procedures were eventually developed to produce sufficient quantities of the requisite enzymes for clinical trials and to target therapeutic enzymes to lipid-storing cells. These achievements led to the development of effective enzyme replacement therapy for patients with Gaucher disease and for Fabry disease. These demonstrations provide strong incentive for the application of this strategy for the treatment of many human disorders of metabolism. PMID:12803925

  10. Heart Valve Replacements with Regenerative Capacity

    PubMed Central

    Dijkman, Petra E.; Fioretta, Emanuela S.; Frese, Laura; Pasqualini, Francesco S.; Hoerstrup, Simon P.

    2016-01-01

    The incidence of severe valvular dysfunctions (e.g., stenosis and insufficiency) is increasing, leading to over 300,000 valves implanted worldwide yearly. Clinically used heart valve replacements lack the capacity to grow, inherently requiring repetitive and high-risk surgical interventions during childhood. The aim of this review is to present how different tissue engineering strategies can overcome these limitations, providing innovative valve replacements that proved to be able to integrate and remodel in pre-clinical experiments and to have promising results in clinical studies. Upon description of the different types of heart valve tissue engineering (e.g., in vitro, in situ, in vivo, and the pre-seeding approach) we focus on the clinical translation of this technology. In particular, we will deepen the many technical, clinical, and regulatory aspects that need to be solved to endure the clinical adaptation and the commercialization of these promising regenerative valves. PMID:27721704

  11. Replacements For Ozone-Depleting Foaming Agents

    NASA Technical Reports Server (NTRS)

    Blevins, Elana; Sharpe, Jon B.

    1995-01-01

    Fluorinated ethers used in place of chlorofluorocarbons and hydrochlorofluorocarbons. Replacement necessary because CFC's and HCFC's found to contribute to depletion of ozone from upper atmosphere, and manufacture and use of them by law phased out in near future. Two fluorinated ethers do not have ozone-depletion potential and used in existing foam-producing equipment, designed to handle liquid blowing agents soluble in chemical ingredients that mixed to make foam. Any polyurethane-based foams and several cellular plastics blown with these fluorinated ethers used in processes as diverse as small batch pours, large sprays, or double-band lamination to make insulation for private homes, commercial buildings, shipping containers, and storage tanks. Fluorinated ethers proved useful as replacements for CFC refrigerants and solvents.

  12. Replacement Power Facility site selection report

    SciTech Connect

    Wike, L.D.; Toole, G.L.; Specht, W.L.

    1992-06-01

    The Department of Energy (DOE) has proposed the construction and operation of a Replacement Power Facility (RPF) for supplementing and replacing existing sources of steam and possibly electricity at the Savannah River Site (SRS). DOE is preparing an Environmental Impact Statement (EIS) for this project As part of the impact analysis of the proposed action, the EIS will include a detailed description of the environment where the RPF will be constructed. This description must be specific to the recommended site at SRS, which contains more than 300 square miles of land including streams, lakes, impoundments, wetlands, and upland areas. A formal site-selection process was designed and implemented to identify the preferred RPF site.

  13. Hormone Replacement Therapy, Iron, and Breast Cancer

    DTIC Science & Technology

    2005-10-01

    culture models with different status of estrogen and progesterone receptors as well as an iron loaded transgenic mouse model. Our results have shown that...Hormone replacement therapy, iron, estrogen, cell proliferation, progesterone , breast cancer 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...release an egg every month. Estrogen and progesterone together help regulate this event. As a woman matures, the ovaries have fewer eggs to stimulate

  14. Performance Evaluation of Vinyl Replacement Windows.

    DTIC Science & Technology

    1980-07-15

    VINYL REPLACEMENT WINDOWS P. B. SHEPHERD JOHNS - MANVILLE SALES CORPORATION LEU ! RESEARCH & DEVELOPMENT CENTER CLE 0 KEN-CARYL RANCH DENVER, COLORADO...PE F -I.. E RI.. Philip B.heperd/K^678D00 9. PERFORMING ORGANIZATION NAME AND ADDRESS SO. PROGRAM ELEMENT. PROJECT, TASK Johns - Manville Sales Corporatp...Development Center Ken-Caryl Ranch Denver. Colorado 80217 (303) 979-1000 October 23, 1979 Dear Sir: The Johns - Manville R&D Center has been contacted

  15. Indium Alloy as Cadmium Brush Plating Replacement

    DTIC Science & Technology

    2010-06-17

    Aged In- Sn Aged Cd In- Sn before Aging Cd before Aging Sn -Zn (12V) before Aging 18 Temperature Cycling Table 6. Temperature Cycling Conditions for Each...selection Key Requirements Candidate Cd Plating Replacement Processing Al Zn Ni Sn Zn-Ni Sn -Ni Sn -Zn Sn -In Meet Environmental Health and Safety (EHS...Corrosion Protection P P F P ? ? P P Whisker Growth (FOR INFO) ? F P F P P ? ? Al = Aluminum; In = Indium; Ni = Nickel; Sn =

  16. Alternatives to testosterone replacement: testosterone restoration.

    PubMed

    McCullough, Andrew

    2015-01-01

    The European Male Aging Study has demonstrated that the hypogonadism of male aging is predominantly secondary. Theoretically with appropriate stimulation from the pituitary, the aging testis should be able to produce eugonadal levels of testosterone. The strategies for the treatment of late onset hypogonadism (LOH) have focused on replacement with exogenous testosterone versus restoration of endogenous production. The purpose of this article is to review existing peer-reviewed literature supporting the concept of restoration of endogenous testosterone in the treatment of LOH.

  17. Comparing Alternatives For Replacing Harmful Chemicals

    NASA Technical Reports Server (NTRS)

    Cruit, W.; Schutzenhofer, S.; Goldberg, B.; Everhart, K.

    1995-01-01

    Methodology developed to provide guidance for replacement of industrial chemicals that must be phased out by law because they are toxic and/or affect environment adversely. Chemicals and processes ranked numerically. Applies mostly to chemicals contributing to depletion of ozone in upper atmosphere; some other harmful chemicals included. Quality function deployment matrix format provides convenient way to compare alternative processes and chemicals. Overall rating at bottom of each process-and-chemical column indicates relative advantage.

  18. [Hemoglobin solutions: volume replacement or oxygen therapy?].

    PubMed

    Standl, T

    1998-11-01

    The development of haemoglobin solutions has progressed significantly in the last 15 years because of a perceived short fall in allogeneic blood within the next decades and increased concern about transmitted infectious diseases. Animal studies have shown that modern highly purified and chemically modified haemoglobin preparations are free of toxic side effects, provide adequate volume replacement and have vasoconstrictive effects that enhance systemic vascular resistance and mean arterial pressures after haemorrhage and in models of nearly complete blood replacement. Microcirculatory effects of haemoglobin-based oxygen carriers are dependent on the respective organ and species in which they are applied and on their degree of purification and chemical modification. Because of different physico-chemical properties in comparison with red cells, haemoglobin solutions provide sufficient tissue oxygenation in areas with critically restricted perfusion even when applied in small doses. First studies in volunteers and patients showed efficacy and tolerability of different newly developed haemoglobin solutions during acute normovolaemic haemodilution and in perioperative blood replacement. However, only little information exists to date in terms of metabolism of haemoglobin preparations and their potential immunogenicity and immunosuppressive side effects. Technical problems with the clinical use of haemoglobin solutions arise because of interference of plasma haemoglobin with routine laboratory tests and oximetry. Future indications for haemoglobin solutions as an oxygen therapeutic allow for application of small doses of such preparations and may help to avoid major technical problems. More clinical studies have to be undertaken to confirm the effectivity and safety of the different haemoglobin solutions and to find out the optimal indications beyond acute preclinical and perioperative blood replacement.

  19. Challenges and future of renal replacement therapy.

    PubMed

    de Francisco, Angel L M; Piñera, Celestino

    2006-01-01

    Renal community increasingly recognizes the challenges of very high mortality, morbidity and low quality of life among dialysis patients. Current hemodialysis (HD) schedule provides less than 10% of the clearance power of the natural kidneys and therefore current standard HD treatment is still a long way from providing adequate renal replacement. In the future it would be expected to improve dialysis control with the development of new technology: membranes, dialysate buffer, electrolyte concentration, system interface, arteriovenous access monitoring. Online technology must be adapted to routine HD for new prescription monitoring such as creatinine online sensing technology, sodium-specific electrode or hydrogen ion concentration. Online convective therapies offer the opportunity for a more biological renal replacement therapy increasing convective transport in order to "reproduce" glomerular function and improving small and middle molecular clearance in an economically feasible and safe way. The paradigm of thrice-weekly dialysis is faced with diminishing returns, with the possible exception of long dialysis sessions. More frequent (daily) dialysis represents a very promising tool for improving dialysis outcomes and quality of life. Future technologies for renal replacement include bioartificial kidneys based in continuous hemofiltration and bioartificial tubules. Although Phase I/II clinical trial on 10 patients with acute renal failure has been reported the procedure requires further evaluation. Organogenesis, therapeutic cloning, or cloning and organogenesis combined might in the future produce a functional and histocompatible kidney. The continuous increase in incidence and prevalence of renal-replacement therapy is a world-wide phenomenon, although the rates in Europe are still much lower than in the U.S. The increase in rates applies especially to older patients, patients with diabetes mellitus and renal vascular disease and the consequences of this

  20. Total Hip Joint Replacement Biotelemetry System

    NASA Technical Reports Server (NTRS)

    Boreham, J. F.; Postal, R. B.; Luntz, R. A.

    1981-01-01

    The development of a biotelemetry system that is hermetically sealed within a total hip replacement implant is reported. The telemetry system transmits six channels of stress data to reconstruct the major forces acting on the neck of the prosthesis and uses an induction power coupling technique to eliminate the need for internal batteries. The activities associated with the telemetry microminiaturization, data recovery console, hardware fabrications, power induction systems, electrical and mechanical testing and hermetic sealing test results are discussed.

  1. Hardwire replaces PLC gear after interference problems

    SciTech Connect

    Cohn, L.

    1983-01-31

    Two Florida facilities are replacing powerline carrier (PLC) energy management systems with hard-wired equipment to correct problems with radio wave interference. Hardwiring uses electronic rather than radio signals, while PLC systems use existing building wiring. Interference from LORAN radio signals that guide ships at sea were the chief problem, which was intensified by the length of cables needed to connect multiple-building facilities. PLC systems are more appropriate for single-building installations. (DCK)

  2. Final Environmental Assessment, Horse Creek Bridge Replacement

    DTIC Science & Technology

    2010-10-01

    floodplain, deep swamp, meander scars, loops, and oxbow lakes . Sandy Run Creek, along the southern boundary of Robins AFB, has a floodplain up to 2,000...River floodplain (Figure 3). The erosion action of the Ocmulgee has created bluffs, high floodplain, deep swamp, meander scars, loops, and oxbow ... lakes . Robins Air Force Base Horse Creek Bridge Replacement J. Gross L. Neal 15268146 April 2010 CLIENT: TITLE: PROJECT: DATE: SCALE: FILE: DESIGNED

  3. Flow boiling test of GDP replacement coolants

    SciTech Connect

    Park, S.H.

    1995-08-01

    The tests were part of the CFC replacement program to identify and test alternate coolants to replace CFC-114 being used in the uranium enrichment plants at Paducah and Portsmouth. The coolants tested, C{sub 4}F{sub 10} and C{sub 4}F{sub 8}, were selected based on their compatibility with the uranium hexafluoride process gas and how well the boiling temperature and vapor pressure matched that of CFC-114. However, the heat of vaporization of both coolants is lower than that of CFC-114 requiring larger coolant mass flow than CFC-114 to remove the same amount of heat. The vapor pressure of these coolants is higher than CFC-114 within the cascade operational range, and each coolant can be used as a replacement coolant with some limitation at 3,300 hp operation. The results of the CFC-114/C{sub 4}F{sub 10} mixture tests show boiling heat transfer coefficient degraded to a minimum value with about 25% C{sub 4}F{sub 10} weight mixture in CFC-114 and the degree of degradation is about 20% from that of CFC-114 boiling heat transfer coefficient. This report consists of the final reports from Cudo Technologies, Ltd.

  4. [Total temporomandibular joint replacement with alloplastic prosthesis].

    PubMed

    García-Huerta, Marco Antonio; Romero-Flores, Jovita; Mena-Gómez, Eddy

    2012-01-01

    Three total temporomandibular joint (TMJ) replacement surgeries were performed on two patients with TMJ ankylosis using W. Lorenz system. The first surgery was performed on a female patient with osseous ankylosis who had no mandibular movement since she was 18 months old. The second surgery was on a patient with fibrous ankylosis who had an interincisive opening distance of 12 mm. Her condition was the result of a three year old subcondylar fracture which didn't receive any treatment. The first patient had total replacement of both TMJs, while the other just one TMJ. The follow up until today has been of eight months with an interincisive opening of 29 mm in the first patient and 34 mm in the other. There has not been any mandibular deviation during opening, nor postoperative pain in both cases. Facial nerve affection was not permanent in both patients. For all of this, we can conclude that total TMJ replacement is an effective treatment with stable results in patients with TMJ ankylosis.

  5. Analysis of circumferential and longitudinal left ventricular systolic function in patients with non-ischemic chronic heart failure and preserved ejection fraction (from the CARRY-IN-HFpEF study).

    PubMed

    Cioffi, Giovanni; Senni, Michele; Tarantini, Luigi; Faggiano, Pompilio; Rossi, Andrea; Stefenelli, Carlo; Russo, Tiziano Edoardo; Alessandro, Selmi; Furlanello, Francesco; de Simone, Giovanni

    2012-02-01

    Heart failure with preserved left ventricular ejection fraction (HFpEF) is implicitly attributed to diastolic dysfunction, often recognized in elderly patients with hypertension, diabetes, and renal dysfunction. In these patients, left ventricular circumferential and longitudinal shortening is often impaired despite normal ejection fraction. The aim of this prospective study was to analyze circumferential and longitudinal shortening and their relations in patients with nonischemic HFpEF. Stress-corrected midwall shortening (sc-MS) and mitral annular peak systolic velocity (S') were measured in 60 patients (mean age 73 ± 13 years) with chronic nonischemic HFpEF in stable New York Heart Association functional class II or III and compared to the values in 120 healthy controls and 120 patients with hypertension without HFpEF. Sc-MS was classified as low if <89% and S' as low if <8.5 cm/s (the 10th-percentile values of healthy controls). Isolated low sc-MS was detected in 46% of patients with HFpEF, 27% of patients with hypertension, and 2% of controls; isolated low S' was detected in 11% of patients with HFpEF, 7% of patients with hypertension, and 5% of controls; and combined low sc-MS and low S' was detected in 26% of patients with HFpEF, 9% of patients with hypertension, and 5% of controls (HFpEF vs others, all p values <0.001). Thus, any alteration of systolic function was found in 83% of patients with HFpEF. The relation between sc-MS and S' was nonlinear (cubic). Changes in S' within normal values corresponded to negligible variations in sc-MS, whereas the progressive decrease below 8.5 cm/s was associated with substantial decrease in sc-MS. In conclusion, circumferential and/or longitudinal systolic dysfunction is present in most patients with HFpEF. Circumferential shortening normalized by wall stress identifies more patients with concealed left ventricular systolic dysfunction than longitudinal shortening.

  6. [Exercise capacity after heart valve replacement].

    PubMed

    Horstkotte, D; Niehues, R; Schulte, H D; Strauer, B E

    1994-01-01

    Exercise capacity following heart-valve replacement is dependent on how close to normal the artificial device can restore valve function, to what degree a preoperative impaired myocardial function and/or an increased pulmonary vascular resistance is normalized. The postoperative functional result can be determined by the subjective improvement of the patient, his functional capacity, exercise capacity, the central hemodynamics at rest and during exercise, and the systolic and diastolic function of the left and right ventricular myocardium. The subjective improvement of individual symptoms is obviously dependent on the degree of postoperative normalization of hemodynamics, especially of pressures in the pulmonary circulation. Subjective improvement can be objectified by comparing the functional capacities before and after surgery. Post-operative normalization of central hemodynamics and myocardial function does not happen immediately but within 3 to more than 12 months. A 12-month period can generally be expected in patients with mitral stenosis and increased pulmonary vascular resistance (> 400 dyn.sec.cm-5) prior to surgery. In patients with mitral and aortic regurgitation as well as with aortic stenosis and preoperative decrease of their left ventricular ejection fraction during exercise, continuous improvement of left ventricular pump function also may need up to 12 months. Physiological hemodynamic conditions generally are not restored by valve replacement. All prostheses are stenotic to forward blood flow because of the obstruction created by the narrowing of the valve area by sewing cuff and valve poppet. This may result in a hemodynamically important stenosis, especially after atrio-ventricular valve implantation, and may limit subjective and functional improvement. Exercise capacity after aortic valve replacement depends mainly on whether or not myocardial damage persists postoperatively. A workload of 1.5 w/kg body weight (BW) has been performed by 100% of

  7. Experimental replacement of aragonite by hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Kasioptas, A.; Perdikouri, C.; Geisler, T.; Putnis, A.

    2009-04-01

    Hydrothermal treatment of aragonite with (NH4)2HPO4 solution has been shown to produce hydroxyapatite (HAP) with an overall identical and thus pre-determined morphology (Kasioptas et al, 2008). The preservation of the morphology is an outcome of the pseudomorphic nature of this particular reaction. We have investigated the mechanism of the replacement of aragonite by HAP using single, natural, inorganic aragonite crystals. Isothermal experiments were carried out with small crystals placed and sealed in autoclaves with (NH4)2HPO4 solution. After the experiments the aragonite crystals are partly replaced by a new phase. X-ray powder diffraction confirmed that the product phase is indeed HAP; however electron microprobe measurements revealed that the HAP is probably non-stoichiometric. Even when completely converted to HAP, scanning electron microscopy showed that the fine-structure of the aragonite has perfectly been retained. It was also observed that the HAP product phase exhibited a high porosity and was separated from the aragonite parent phase by a sharp interface (on the micrometer scale). The replacement of aragonite by HAP in an aqueous solution can be described in terms of a coupled dissolution-reprecipitation mechanism that takes place at an inward moving reaction front (Putnis& Putnis, 2007). The porosity in the HAP product phase allows the solution to reach the reaction interface. In addition, we have performed experiments with (NH4)2HPO4 solutions prepared with H2O enriched with 97 at.% 18O. The solutions were pre-heated separately to equilibrate the oxygen isotopes in the solution. Raman spectroscopy of the HAP product was used to identify the different vibration modes in the PO43-molecule due to the exchange of 16O with 18O atoms. Apart from the main ?1(PO4) band located near 962 cm-1, we observed four new bands near 945, 931, 919 and 908 cm-1. We have attributed the generation of these new bands to four different degrees of 18O atomic substitutions in

  8. Preliminary study of possible ORELA replacement options

    SciTech Connect

    Olsen, D.K.; Martin, J.A.; Horen, D.J.

    1984-06-01

    Based on two conceptual design studies performed by the LANL Accelerator Technology Division, the possibilities in terms of accelerator systems for replacing ORELA with a more intense Maxwellian-type continuous-energy neutron source are summarized and discussed. The neutron intensities from ORELA are compared with those from existing or potential accelerator systems used for cross-section and condensed-matter studies. The best replacement options seem to involve a spallation source from 200- to 400-MeV protons on an ORELA-like target. Pulsing and intensity desiderata with such a source are discussed which correspond to a spectrum-averaged 100-fold improved figure of merit over ORELA for TOF measurements with only a tenfold increased source strength. Existing accelerator designs seem to be inadequate for such a source. Consequently, two conceptual designs were developed for this study by the LANL Accelerator Technology Division. The first conceptual design is for a 200-MeV large linac capable of accelerating 1.3 A during a macropulse; this linac standing alone could serve as an ORELA replacement source. The second conceptual design is for a much smaller 250-MeV PIGMI linac with a 28-mA macropulse current which feeds a proton accumulator ring and bunch-compressor transport line. This linac-ring-compressor (LIRIC) option would give a more cost-effective neutron source for cross-section measurements, whereas the large linac, or a modified version of it, would give a much simpler system more suitable for expansion. In particular, both conceptual designs would incorporate the present ORELA building and would provide approximately 100-fold improved neutron sources over ORELA for cross-section measurements. The total estimated cost of the LIRIC system would be $43M (1984), whereas the cost of the large linac would be about a factor of two more. 55 references, 11 figures, 19 tables.

  9. Testosterone replacement therapy and voiding dysfunction

    PubMed Central

    Baas, Wesley

    2016-01-01

    Testosterone replacement therapy (TRT) represents an increasing popular treatment option for men with late-onset hypogonadism (LOH). Because of unsubstantiated beliefs of testosterone’s effect on the prostate, the FDA has recently placed a warning on testosterone products, stating that TRT may worsen benign prostatic hyperplasia (BPH). Within this review article we have demonstrated the current understanding of the physiology of testosterone and its relationship with prostatic and lower urinary tract physiology. The current evidence suggests that not only does TRT not worsen lower urinary tract symptoms (LUTS), but that hypogonadism itself is an important risk factor for LUTS/BPH. PMID:28078221

  10. Conformity in condylar replacement knee prosthesis.

    PubMed

    Walker, P S; Hsieh, H H

    1977-05-01

    Experiments were carried out to determine the optimum conformity between the femoral and tibial condyles in condylar replacement knee prostheses. Wear tests and observations from removed prostheses indicated that both high and low conformity produced characteristic abrasion and fatigue. Partly conforming condyles provided stability under load-bearing but allowed laxity to occur. Fixation to resist the various forces on the tibial components was enhanced by a short central intramedullary peg. Partial conformity is proposed as the optimum configuration between femoral and tibial components.

  11. Continuous renal replacement therapy in children.

    PubMed

    Sutherland, Scott M; Alexander, Steven R

    2012-11-01

    Over the past several decades, the epidemiology of acute kidney injury (AKI) in children has changed significantly. Pediatric patients with AKI frequently have co-morbid conditions, substantial fluid overload, and marked disease severity. At the same time, continuous renal replacement therapy (CRRT) has become the preferred modality for the management of these patients. This manuscript provides a state-of-the-art review of the technical aspects of pediatric CRRT and examines the most recent data regarding CRRT indications, timing of initiation, dosing, and outcomes in critically ill children.

  12. Immunoglobulin Replacement Therapy for Primary Immunodeficiency.

    PubMed

    Sriaroon, Panida; Ballow, Mark

    2015-11-01

    Immunoglobulin replacement therapy has been standard treatment in patients with primary immunodeficiency diseases for the past 3 decades. The goal of therapy is to reduce serious bacterial infections in individuals with antibody function defects. Approximately one-third of patients receiving intravenous immunoglobulin treatment experience adverse reactions. Recent advances in manufacturing processes have resulted in products that are safer and better tolerated. Self-infusion by the subcutaneous route has become popular and resulted in better quality of life. This review summarizes the use of immunoglobulin therapy in primary immunodeficiency diseases including its properties, dosing, adverse effects, and different routes of administration.

  13. Can electronic stability control replace studded tyres?

    PubMed

    Elvik, Rune

    2015-12-01

    Based on recent studies, this paper examines whether an increased use of electronic stability control can replace studded tyres. A re-analysis of a study that evaluated the effects on accidents of changes in the use of studded tyres in major cities in Norway is presented. It is found that if all cars have electronic stability control, the use of studded tyres can be reduced to about 15 percent before any increase in the number of accidents occurs. Even if studded tyres were eliminated entirely, any increase in the number of accidents is likely to be considerably smaller than it would have been if electronic stability control had never been invented.

  14. [How to stop hormone replacement therapy?].

    PubMed

    Polo, Päivi

    2015-01-01

    Hormone replacement therapy is indicated for the treatment of menopausal and urogenital symptoms. The therapy is recommended to be started at the lowest effective dose for a minimum period of time. Discontinuation of the therapy or at least reduction of the dose should be considered yearly. The treatment can be stopped immediately or gradually. The risk of recurrence of menopausal symptoms is equal for both techniques of cessation. Furthermore, the number of those having restarted the therapy does not differ between cessation techniques. A woman is thus able to choose her own cessation technique. Immediate cessation is often successful, whereby complicated instructions for drug reduction are avoided.

  15. MILA Antenna Control Unit Replacement Project

    NASA Technical Reports Server (NTRS)

    Bresette, Jeremy

    2007-01-01

    The Air to Ground Subsystem (AGS) Antenna Control Units at the MILA Ground Network Tracking Station are at end-of-life and are being replaced. AGS consists of two antennas at MILA (Quad-Helix and Teltrac). Software was taken from the existing Subsystem Controller and modified for the Antenna Control Unit (ACU). The software is capable of receiving and sending commands to and from the ACU. Moving the azimuth clockwise, counterclockwise, moving the elevation up or down, turning servo power on and off, and inputting azimuth and elevation angles are commands that the antenna can receive.

  16. [82 Rubidium PET to replace myocardial scintigraphy].

    PubMed

    Hasbak, Philip; Kjær, Andreas

    2011-02-21

    Since the 1970's nuclear cardiology has mainly been based on the use of gamma camera technology. While gamma cameras have undergone a rapid development, the number of perfusion tracers has been limited. In parallel, cardiac positron emission tomography (PET) has only been performed with short-lived isotopes at centres with access to a cyclotron, and only including a very limited number of patients. The number of PET scanners has increased markedly in Denmark and with the introduction of generator-produced 82-Rubidium, this modality may replace the traditional cardial single photon emission computed tomography (SPECT).

  17. Nimbus 3 alternating-pressure replacement mattress.

    PubMed

    Young, T

    Alternating-pressure surfaces have been shown to reduce the incidence of pressure sores compared with standard hospital mattresses and pressure-reducing (constant low-pressure) surfaces. Huntleigh Healthcare has recently introduced the Nimbus 3 to its range of alternating-pressure mattress replacement systems. This product has been developed according to new medical device regulations and is indicated for the treatment of patients with all grades of pressure sores and for prevention in patients who are at very high risk of developing pressure sores.

  18. Romit profile analysis for molecular replacements.

    PubMed

    Tsuchiya, D; Takenaka, A

    1998-01-01

    A new procedure for evaluation of molecular replacement has been examined by using an R factor calculated from the probe structure with some omitted parts (Romit). It has been demonstrated that changes in Romit from the conventional R factor for the whole structure are sensitive to the local fitness in the omitted region even for large molecules such as proteins. Their profile, plotted against residues, is effective for distinguishing the most probable one from several solutions. In addition, this profile analysis exhibits useful information for model building.

  19. Cervical total disk replacement: complications and avoidance.

    PubMed

    Salari, Behnam; McAfee, Paul C

    2012-01-01

    Anterior cervical diskectomy and fusion for neurologic deficits, radicular arm pain, and neck pain refractory to conservative management are successful. The approach and procedure were first described in 1955 and have become the anterior cervical standard of care for orthopedic surgeons and neurosurgeons. Advancements and innovations have addressed disease processes of the cervical spine with motion-preserving technology. The possibility of obtaining anterior cervical decompression while maintaining adjacent segment motion led to the advent of cervical total disk replacement. The Food and Drug Administration has approved 3 cervical devices with other investigational device exemption trials under way.

  20. Off label therapies for testosterone replacement

    PubMed Central

    DiGiorgio, Lorenzo

    2016-01-01

    The incidence of hypogonadism has been steadily increasing over the last few years. Exogenous testosterone has been the standard treatment for hypogonadal men, but is associated with suppression of spermatogenesis as well as other possible adverse effects. There are other medications, currently considered “off label” for androgen replenishment, that exert their effect through modulation of the hypothalamic-gonadal axis. These medications increase endogenous testosterone levels and offer a different therapeutic approach. This review will focus on these alternative (off-label) therapies for androgen replacement in men. PMID:28078215

  1. Can subretinal microphotodiodes successfully replace degenerated photoreceptors?

    PubMed

    Zrenner, E; Stett, A; Weiss, S; Aramant, R B; Guenther, E; Kohler, K; Miliczek, K D; Seiler, M J; Haemmerle, H

    1999-07-01

    The idea of implanting microphotodiode arrays as visual prostheses has aroused controversy on its feasibility from the moment it appeared in print. We now present results which basically support the concept of replacing damaged photoreceptors with subretinally implanted stimulation devices. Network activity in degenerated rat retinae could be modulated through local electrical stimulation in vitro. We also investigated the long term stability and biocompatibility of the subretinal implants and their impact on retinal physiology in rats. Ganzfeld electroretinograms and histology showed no significant side effect of subretinal implants on retinal function or the architecture of the inner retina.

  2. 30 CFR 75.1438 - End attachment replacement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1438 End attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  3. 30 CFR 75.1438 - End attachment replacement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1438 End attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  4. 30 CFR 75.1438 - End attachment replacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1438 End attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  5. 30 CFR 75.1438 - End attachment replacement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1438 End attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  6. 30 CFR 75.1438 - End attachment replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips Wire Ropes § 75.1438 End attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  7. 42 CFR 433.117 - Initial approval of replacement systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the...

  8. 42 CFR 433.117 - Initial approval of replacement systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the...

  9. 42 CFR 433.117 - Initial approval of replacement systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the...

  10. 42 CFR 433.117 - Initial approval of replacement systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... and Information Retrieval Systems § 433.117 Initial approval of replacement systems. (a) A replacement... information retrieval system. (b) The agency must submit a APD that includes— (1) The date the...

  11. 15 CFR 30.29 - Reporting of repairs and replacements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... have Schedule B or HTSUSA classification commodity number 9801.10.0000. The value reported in the EEI... replaced under warranty at no charge to the customer shall include the statement, “Product replaced...

  12. 15 CFR 30.29 - Reporting of repairs and replacements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... have Schedule B or HTSUSA classification commodity number 9801.10.0000. The value reported in the EEI... replaced under warranty at no charge to the customer shall include the statement, “Product replaced...

  13. Knee Replacement Doesn't Always Pay, Researchers Say

    MedlinePlus

    ... gov/news/fullstory_164320.html Knee Replacement Doesn't Always Pay, Researchers Say Less pain to begin ... 28, 2017 (HealthDay News) -- Knee replacement surgery isn't always a game changer, according to a new ...

  14. Concomitant aortic valve replacement and myocardial revascularization.

    PubMed Central

    Craver, J M; Jones, E L; Hatcher, C R; Farmer, J H

    1977-01-01

    Twenty-six consecutive patients underwent combined aortic valve replacement and myocardial revascularization at the Emory University Affiliated Hospitals between May, 1973 and March, 1976. Acute myocardial infarction resulted in two operative deaths (8%). There have been four late deaths, all Class IV preoperative. The age range was 37 to 79 years with an average age of 60. Preoperatively all patients were Class IV or late Class III. Twenty-three patients had symptoms of angina pectoris; congestive heart failure was evident in 56%. Postoperatively, 70% are now Class 1 or II. Single coronary bypass was performed in 16 patients, double in 6, and triple in three. Double bypass plus mitral valve replacement was required in two with aneurysmectomy in one. The rate of intraoperative infarction was 27% for the series but only 7% in the last year. The methods of intraoperative myocardial preservation and the technical approach for the operative procedures were variable. Results with each method are correlated, and currently preferred techniques are presented and discussed. Best results were obtained in patients who presented early in their symptomatic course with isolated proximal coronary lesions and good renoff vessels. Excellent results could be achieved despite advanced age of patients, requirement for multiple bypass grafts, and correction of other associated cardiac lesions. Poorest results were obtained when long-standing ventricular failure was combined with poor vessels distal to coronary stenoses. PMID:860881

  15. Toward replacement fertility in Egypt and Tunisia.

    PubMed

    Eltigani, Eltigani E

    2009-09-01

    Egypt and Tunisia began their fertility transition at almost identical fertility levels and at roughly the same time period, yet the difference in the pace of decline has been such that the total fertility rate (TFR) in Tunisia reached replacement level by the year 2001, whereas the TFR in Egypt remains above three live births per woman. This article draws on the secondary literature and on several nationally representative surveys from the two countries between 1978 and 2005 to provide empirical evidence of the difference in the pace of fertility decline and to analyze the determinants of the differential. Findings include (a) variation across the two countries in the consistency of fertility decline among the segments of the population leading the transition; (b) that the success of each country's family planning program was influenced by the role of political leaders and the extent of the program's integration within socioeconomic development objectives; (c) that the impact of contraception on TFR decline became an important factor in the mid-1980s; and (d) that the greatest determinant of the discrepancy in the pace of fertility decline is the disparity in age at marriage, which rose more significantly in Tunisia than in Egypt. The latter finding indicates that reaching replacement fertility in Egypt hinges primarily on further declines in marital fertility, resulting from reduction of wanted fertility and from an expansion of family planning program coverage and improved efficiency of service delivery and use.

  16. Pelvic position and movement during hip replacement.

    PubMed

    Grammatopoulos, G; Pandit, H G; da Assunção, R; Taylor, A; McLardy-Smith, P; De Smet, K A; Murray, D W; Gill, H S

    2014-07-01

    The orientation of the acetabular component is influenced not only by the orientation at which the surgeon implants the component, but also the orientation of the pelvis at the time of implantation. Hence, the orientation of the pelvis at set-up and its movement during the operation, are important. During 67 hip replacements, using a validated photogrammetric technique, we measured how three surgeons orientated the patient's pelvis, how much the pelvis moved during surgery, and what effect these had on the final orientation of the acetabular component. Pelvic orientation at set-up, varied widely (mean (± 2, standard deviation (sd))): tilt 8° (2sd ± 32), obliquity -4° (2sd ± 12), rotation -8° (2sd ± 14). Significant differences in pelvic positioning were detected between surgeons (p < 0.001). The mean angular movement of the pelvis between set-up and component implantation was 9° (sd 6). Factors influencing pelvic movement included surgeon, approach (posterior > lateral), procedure (hip resurfacing > total hip replacement) and type of support (p < 0.001). Although, on average, surgeons achieved their desired acetabular component orientation, there was considerable variability (2sd ± 16) in component orientation. We conclude that inconsistency in positioning the patient at set-up and movement of the pelvis during the operation account for much of the variation in acetabular component orientation. Improved methods of positioning and holding the pelvis are required.

  17. Neutron scattering at Australia's replacement research reactor

    NASA Astrophysics Data System (ADS)

    Robinson, R. A.; Kennedy, S. J.

    2002-01-01

    On August 25 1999, the Australian government gave final approval to build a research reactor to replace the existing HIFAR reactor at Lucas Heights. The replacement reactor, which will commence operation in 2005, will be multipurpose in function, with capabilities for both neutron-beam research and radioisotope production. Regarding beams, cold and thermal neutron sources are to be installed and the intent is to use supermirror guides, with coatings with critical angles up to 3 times that of natural Ni, to transport cold and thermal neutron beams into a large modern guide hall. The reactor and all the associated infrastructure, with the exception of the neutron beam instruments, is to be built by INVAP, SE and subcontractors in a turnkey contract. The goal is to have at least eight leading-edge neutron-beam instruments ready in 2005, and they will be developed by ANSTO and other contracted organisations, in consultation with the Australian user community and interested overseas parties. A review of the planned scientific capabilities, a description of the facility and a status report on the activities so far is given.

  18. Transdermal testosterone replacement therapy in men.

    PubMed

    Ullah, M Iftekhar; Riche, Daniel M; Koch, Christian A

    2014-01-01

    Androgen deficiency syndrome in men is a frequently diagnosed condition associated with clinical symptoms including fatigue, decreased libido, erectile dysfunction, and metabolic syndrome. Serum testosterone concentrations decline steadily with age. The prevalence of androgen deficiency syndrome in men varies depending on the age group, known and unknown comorbidities, and the respective study group. Reported prevalence rates may be underestimated, as not every man with symptoms of androgen deficiency seeks treatment. Additionally, men reporting symptoms of androgen deficiency may not be correctly diagnosed due to the vagueness of the symptom quality. The treatment of androgen deficiency syndrome or male hypogonadism may sometimes be difficult due to various reasons. There is no consensus as to when to start treating a respective man or with regards to the best treatment option for an individual patient. There is also lack of familiarity with treatment options among general practitioners. The formulations currently available on the market are generally expensive and dose adjustment protocols for each differ. All these factors add to the complexity of testosterone replacement therapy. In this article we will discuss the general indications of transdermal testosterone replacement therapy, available formulations, dosage, application sites, and recommended titration schedule.

  19. Testosterone replacement therapy in obese males.

    PubMed

    Drewa, Tomasz; Olszewska-Słonina, Dorota; Chlosta, Piotr

    2011-01-01

    Controversy surrounds testosterone replacement therapy in obese ageing due to no generally accepted lower limits of normal testosterone level and high prevalence of hypogonadal symptoms in the ageing male population and the non-specific nature of these symptoms. Late onset hypogonadism is a clinical and biochemical syndrome associated with advancing age, often coexisting with obesity and metabolic syndrome. High fat and carbohydrates (fructose) consumption is responsible for development of obesity and metabolic syndrome which is one of risk factors for hypogonadism in older men. High fructose intake has been shown to cause dyslipidemia and to impair hepatic insulin sensitivity. Obesity and lack of physical activity negatively influence testosterone level. Low testosterone level should be regarded as an effect of obesity, but reverse relationship has not been proved yet. The management of late-onset hypogonadism symptoms has to be treated by a change of a life style and prevented with healthy nutrition and physical activity. The question related to rational indications for testosterone replacement therapy in obese males seems to be still actual.

  20. Replacement of fossil fuels by hydrogen

    NASA Astrophysics Data System (ADS)

    Dahlberg, R.

    The replacement of fossil fuels by solar hydrogen plantations is considered. A model is proposed in which ten plantation families, situated in suitable deserted zones of the world after the year 2000, would generate enough electrical energy to produce solar cells and materials for the construction of ten new plantations within a decade. The technological growth process for identical solar plantation units could be completed about 50 years after construction of the first plantation. All ten plantation families would, by using their electrical energy for the electrolysis of water, generate an amount of hydrogen per year which is four to five times the energy of the world's present annual consumption of oil. This concept envisions the global replacement of fossil fuels by hydrogen within a period consistent with the remaining time span of fossil fuel availability. Storage and transportation of hydrogen would be economical, and the energy produced would not present any environmental problems. Advantages with respect to gains in international cooperation, world peace, and world economy are also discussed.

  1. Advances in Transcatheter Aortic Valve Replacement

    PubMed Central

    Kleiman, Neal S.; Reardon, Michael J.

    2016-01-01

    Transcatheter aortic valve replacement (TAVR) is becoming widely used for the treatment of symptomatic severe aortic stenosis in patients with high surgical risk. Data from The PARTNER Trial (Placement of AoRtic TraNscathetER Valves) and the Medtronic CoreValve® U.S. Pivotal Investigational Device Exemption trial indicate that survival for extreme-risk patients is superior to best medical therapy and equivalent or superior to surgical aortic valve replacement (SAVR), although long-term durability remains unknown. Paravalvular leak remains higher in TAVR than SAVR, as does permanent pacemaker implantation in self-expanding valves. New-generation valves are addressing these issues, especially for paravalvular leak. There is strong evidence that TAVR is appropriate for both extreme-risk and high-risk patients with symptomatic severe aortic stenosis, and the continued development of new valves are making implantation more reliable. This review discusses the studies supporting the use of TAVR and explores current advances in the field. PMID:27127560

  2. Testosterone replacement therapy for older men

    PubMed Central

    Borst, Stephen E; Mulligan, Thomas

    2007-01-01

    Despite intensive research on testosterone therapy for older men, important questions remain unanswered. The evidence clearly indicates that many older men display a partial androgen deficiency. In older men, low circulating testosterone is correlated with low muscle strength, with high adiposity, with insulin resistance and with poor cognitive performance. Testosterone replacement in older men has produced benefits, but not consistently so. The inconsistency may arise from differences in the dose and duration of testosterone treatment, as well as selection of the target population. Generally, studies reporting anabolic responses to testosterone have employed higher doses of testosterone for longer treatment periods and have targeted older men whose baseline circulating bioavailable testosterone levels were low. Most studies of testosterone replacement have reported anabolic that are modest compared to what can be achieved with resistance exercise training. However, several strategies currently under evaluation have the potential to produce greater anabolic effects and to do so in a safe manner. At this time, testosterone therapy can not be recommended for the general population of older men. Older men who are hypogonadal are at greater risk for the catabolic effects associated with a number of acute and chronic medical conditions. Future research is likely to reveal benefits of testosterone therapy for some of these special populations. Testosterone therapy produces a number of adverse effects, including worsening of sleep apnea, gynecomastia, polycythemia and elevation of PSA. Efficacy and adverse effects should be assessed frequently throughout the course of therapy. PMID:18225456

  3. Meniscus tear surgery and meniscus replacement

    PubMed Central

    Vaquero, Javier; Forriol, Francisco

    2016-01-01

    Summary Objective the menisci are easily injured and difficult to repair. The aim of this study was to analyze the current state of meniscal surgery aimed at preserving morphology and conserving the biomechanics of the knee to prevent joint degeneration. Methodology a search of the electronic medical literature database Medline was conducted, from http://www.ncbi.nlm.nih.gov/pubmed. The search was not limited by language. Candidate articles were identified by searching for those that included the keywords meniscus, surgery, suture, implant, allograft. The limits were included for clinical research and clinical trials. Basic research was not included. The studies selected were evaluated and classified in three different categories: basic science, reconstruction (suture and meniscectomy) and implants (scaffolds and allograft). Results the consequences of meniscectomy performed at a young age can lead to a joint cartilage degeneration twenty years later. There are few surgical options for the repair of meniscal injuries in order both to preserve the meniscus and to ensure the long term survival of the knee joint, meniscectomy, repair, suturing the tear, or reconstruction, when a meniscal allograft or synthetic substitute is used to replace the meniscus, but the biomechanical properties of the native meniscus are not reproduced entirely by the scaffolds that exist today. Conclusion therapies that successfully repair or replace the meniscus are therefore likely to prevent or delay osteoarthritis progression. PMID:27331034

  4. ARP/wARP and molecular replacement.

    PubMed

    Perrakis, A; Harkiolaki, M; Wilson, K S; Lamzin, V S

    2001-10-01

    The aim of ARP/wARP is improved automation of model building and refinement in macromolecular crystallography. Once a molecular-replacement solution has been obtained, it is often tedious to refine and rebuild the initial (search) model. ARP/wARP offers three options to automate that task to varying extents: (i) autobuilding of a completely new model based on phases calculated from the molecular-replacement solution, (ii) updating of the initial model by atom addition and deletion to obtain an improved map and (iii) docking of a structure onto a new (or mutated) sequence, followed by rebuilding and refining the side chains in real space. A few examples are presented where ARP/wARP made a considerable difference in the speed of structure solution and/or made possible refinement of otherwise difficult or uninterpretable maps. The resolution range allowing complete autobuilding of protein structures is currently 2.0 A, but for map improvement considerable advances over more conventional refinement techniques are evident even at 3.2 A spacing.

  5. [Unicondylar replacement of the knee joint.].

    PubMed

    Stedrý, V; Vanecek, L

    1999-01-01

    Twenty-nine unicondylar replacements of the knee joint (UKR) of St. Georg type were implanted in 27 patients at the Orthopaedic Clinic IPVZ in the period between 1985-1994. The average age in case of females was 73 years, in case of men 71 years. The most frequent indication was osteoarthritis of the knee joint of varus type. Two patients (7 %) had to be reoperated on for aseptic loosening of the tibial component, on average 5,5 years after the surgery. Revision surgery for breaking of femoral component was performed in five cases, on average 6 years after the primary implantation. The authores evaluated 16 patients with UKR still in situ. In 8 patients the prosthesis is entirely painless, in 10 joints operated on the radiograph showed a developed femoropatelar osteoarthritis, osteoarthritic changes of the opposite compartment in 2 of them and a radioluscent line up to 1 mm in 3 cases. Despite a high frequency of late complications the authors consider UKR for an alternative to high supratubercular osteotomy of tibia in older patients, for a suitable method of the treatment of osteochondritis dissecans and Ahlbäck disease of the knee joint. The success of this operation is conditioned by a perfect surgical technique and implant of suitable design. Key words: replacement of the knee joint, aseptic loosening, fatique failure of material.

  6. Repeat mitral valve replacement: 30-years' experience.

    PubMed

    Expósito, Víctor; García-Camarero, Tamara; Bernal, José M; Arnáiz, Elena; Sarralde, Aurelio; García, Iván; Berrazueta, José R; Revuelta, José M

    2009-08-01

    Prosthetic heart valve dysfunction is an acquired condition that carries a significant risk of emergency surgery. However, the long-term natural history of the condition is not well understood. Between 1974 and 2006, 1535 isolated mitral valve replacements were performed at our hospital (in-hospital mortality 5%). In total, 369 patients needed a second operation (in-hospital mortality 8.1%), while 80 (age 59.8+/-11.4 years) needed a third. The reasons for the third intervention were structural deterioration (67.5%), paravalvular leak (20%) and endocarditis (6.3%). Some 15 patients died in hospital (18.8%). After a mean follow-up period of 17.8 years, 21 patients needed another intervention (i.e., a fourth intervention). The actuarial reoperation-free rate at 20 years was 40.1+/-13.8%. The late mortality rate was 58.5% (18-year survival rate 15.4+/-5.4%). Indications for repeat mitral valve replacement must be judged on an individual basis given the high risk associated with surgery.

  7. Pharmacology of testosterone replacement therapy preparations

    PubMed Central

    Shoskes, Jennifer J.; Wilson, Meghan K.

    2016-01-01

    The goal of testosterone replacement therapy (TRT) is to return serum testosterone levels to within physiologic range and improve symptoms in hypogonadal men. Some of the symptoms aimed to improve upon include decreased libido, erectile dysfunction, infertility, hot flashes, depressed mood, and loss of muscle mass or hair. Clinical use of testosterone for replacement therapy began approximately 70 years ago. Over the decades, numerous preparations and formulations have been developed primarily focusing on different routes of delivery and thus pharmacokinetics (PKs). Currently the routes of delivery approved for use by the United States Food and Drug Administration encompasses buccal, nasal, subdermal, transdermal, and intramuscular (IM). Many factors must be considered when a clinician is choosing the most correct formulation for a patient. As this decision depends highly on the patient, active patient participation is important for effective selection. The aim of this review is to describe and compare all testosterone preparations currently available and approved by the United States Food and Drug Administration. Areas of focus will include pharmacology, PKs, adverse effects, and specifics related to individual delivery routes. PMID:28078214

  8. Metabolite identification of halon replacement compounds

    NASA Astrophysics Data System (ADS)

    Brashear, W. T.; Ketcha, M. M.; Pollard, D. L.; Godin, C. S.; Leahy, H. F.

    1992-06-01

    Halon 1211 is currently being used by the U.S. Air Force as a flight line fire extinguishant. Because of health and environmental concerns over ozone depletion, Halon 1211 must be phased out by the year 2000. Before an interim replacement can be chosen, the toxicity of prospective candidates needs to be evaluated. The metabolism was studied of the Halon replacement candidates perfluorohexane (PFH) and the hydrochlorofluorocarbons (HCFCs): HCFC-123, HCFC-124, and HCFC-142b. Fischer 344 and Sprague-Dawley rats were exposed via inhalation to a 1 pct. atmosphere for 2 h. Tissues were analyzed for volatile metabolites, and urine was analyzed for fluoride and carboxylic acid metabolites. Animals exposed to HCFC-123 or IICFC-124 excreted trifluoroacetic acid in their urine. The presence of trifluoroacetic acid indicates oxidative metabolism of HCFC-123 and IICFC-124. Increased fluoride was found in the urine of rats exposed to HCFC-124. HCFC-142b was metabolized to chlorodifluoroacetic acid, which was found in the urine of exposed rats. Fischer 344 and Sprague-Dawley rats exposed to HCFC-123 had small amounts of HCFC-133a and 2-chloro-1,1-difluoroethylene in liver tissue. The identification of HCFC-133a and 2-chloro-1,1-difluoroethylene following exposure indicates reductive metabolism of HCFC-123. No metabolites of PFH or Halon 1211 were identified in these investigations. Rats exposed to Halon 1211 had slightly elevated bromide levels in their urine compared to control values.

  9. 40 CFR 85.1714 - Replacement-engine exemption.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section....

  10. 21 CFR 870.3925 - Replacement heart valve.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of...

  11. 21 CFR 870.3925 - Replacement heart valve.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of...

  12. 21 CFR 870.3925 - Replacement heart valve.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Replacement heart valve. 870.3925 Section 870.3925...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3925 Replacement heart valve. (a) Identification. A replacement heart valve is a device intended to perform the function of...

  13. 30 CFR 57.19028 - End attachment replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 57.19028 Section 57.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Hoisting Wire Ropes § 57.19028 End attachment replacement. Wire rope attachments shall be replaced...

  14. 30 CFR 56.19028 - End attachment replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 56.19028 Section 56.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Wire Ropes § 56.19028 End attachment replacement. Wire rope attachments shall be replaced when...

  15. 40 CFR 85.1714 - Replacement-engine exemption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section....

  16. 40 CFR 85.1714 - Replacement-engine exemption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Replacement-engine exemption. 85.1714... Vehicle Engines § 85.1714 Replacement-engine exemption. (a) Engine manufacturers may use the provisions of 40 CFR 1068.240 to exempt new replacement heavy-duty highway engines as specified in this section....

  17. 39 CFR 777.24 - Replacement housing payments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Replacement housing payments. 777.24 Section 777... PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.24 Replacement housing payments. (a) Residential displaced persons are eligible for replacement housing payments as follows: (1)...

  18. 39 CFR 777.24 - Replacement housing payments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Replacement housing payments. 777.24 Section 777... PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.24 Replacement housing payments. (a) Residential displaced persons are eligible for replacement housing payments as follows: (1)...

  19. 25 CFR 700.95 - Replacement housing funds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Replacement housing funds. 700.95 Section 700.95 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.95 Replacement housing funds. Replacement...

  20. 25 CFR 700.95 - Replacement housing funds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Replacement housing funds. 700.95 Section 700.95 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.95 Replacement housing funds. Replacement...

  1. 39 CFR 777.24 - Replacement housing payments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Replacement housing payments. 777.24 Section 777... PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.24 Replacement housing payments. (a) Residential displaced persons are eligible for replacement housing payments as follows: (1)...

  2. 39 CFR 777.24 - Replacement housing payments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Replacement housing payments. 777.24 Section 777... PROPERTY ACQUISITION POLICIES Uniform Relocation Assistance § 777.24 Replacement housing payments. (a) Residential displaced persons are eligible for replacement housing payments as follows: (1)...

  3. 25 CFR 700.95 - Replacement housing funds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Replacement housing funds. 700.95 Section 700.95 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.95 Replacement housing funds. Replacement...

  4. 14 CFR 21.9 - Replacement and modification articles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to...

  5. 14 CFR 21.9 - Replacement and modification articles.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to...

  6. 14 CFR 21.9 - Replacement and modification articles.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to...

  7. 14 CFR 21.9 - Replacement and modification articles.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to...

  8. 14 CFR 21.9 - Replacement and modification articles.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to...

  9. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  10. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  11. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  12. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  13. 16 CFR 501.3 - Replacement bags for vacuum cleaners.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Replacement bags for vacuum cleaners. 501.3... REQUIREMENTS AND PROHIBITIONS UNDER PART 500 § 501.3 Replacement bags for vacuum cleaners. Replacement bags for vacuum cleaners, packaged and labeled for retail sale are exempt from the requirements of § 500.15a...

  14. 14 CFR 47.49 - Replacement of Certificate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... registered owner may submit to the Registry a written request that states the reason a replacement certificate is needed and the fee required by § 47.17. The Registry will send a replacement certificate to the... receipt of a replacement certificate. The Registry issues a temporary Certificate of Aircraft...

  15. 14 CFR 47.49 - Replacement of Certificate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... registered owner may submit to the Registry a written request that states the reason a replacement certificate is needed and the fee required by § 47.17. The Registry will send a replacement certificate to the... receipt of a replacement certificate. The Registry issues a temporary Certificate of Aircraft...

  16. 14 CFR 47.49 - Replacement of Certificate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... registered owner may submit to the Registry a written request that states the reason a replacement certificate is needed and the fee required by § 47.17. The Registry will send a replacement certificate to the... receipt of a replacement certificate. The Registry issues a temporary Certificate of Aircraft...

  17. 14 CFR 47.49 - Replacement of Certificate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... registered owner may submit to the Registry a written request that states the reason a replacement certificate is needed and the fee required by § 47.17. The Registry will send a replacement certificate to the... receipt of a replacement certificate. The Registry issues a temporary Certificate of Aircraft...

  18. 25 CFR 700.187 - Utilization of replacement home benefits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Utilization of replacement home benefits. 700.187 Section 700.187 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The...

  19. 25 CFR 700.187 - Utilization of replacement home benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Utilization of replacement home benefits. 700.187 Section 700.187 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The...

  20. 25 CFR 700.187 - Utilization of replacement home benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Utilization of replacement home benefits. 700.187 Section 700.187 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The...

  1. 25 CFR 700.187 - Utilization of replacement home benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Utilization of replacement home benefits. 700.187 Section 700.187 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The...

  2. 25 CFR 700.187 - Utilization of replacement home benefits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Utilization of replacement home benefits. 700.187 Section 700.187 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The...

  3. Environmental Assessment for the Replacement of Water Reservoirs

    DTIC Science & Technology

    2005-03-25

    Maximum 200 words ) This submittal provides the Final Environmental Assessment and Finding of No Significant Impact (FONSI) for the Replacement of Water ...Final Environmental Assessment for the Replacement of Water Reservoirs...IMPACT (FONSI) ENVIRONMENTAL ASSESSMENT FOR THE REPLACEMENT OF WATER RESERVOIRS TRAVIS AIR FORCE BASE, CALIFORNIA Introduction This Finding of No

  4. 43 CFR 4750.4-4 - Replacement animals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution...

  5. 43 CFR 4750.4-4 - Replacement animals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution...

  6. 43 CFR 4750.4-4 - Replacement animals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution...

  7. 43 CFR 4750.4-4 - Replacement animals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Replacement animals. 4750.4-4 Section 4750... FREE-ROAMING HORSES AND BURROS Private Maintenance § 4750.4-4 Replacement animals. The authorized officer shall replace an animal, upon request by the adopter, if (a) within 6 months of the execution...

  8. 49 CFR 24.404 - Replacement housing of last resort.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Replacement housing of last resort. 24.404 Section 24.404 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement Housing Payments § 24.404 Replacement housing of last resort....

  9. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  10. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  11. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker repair or replacement material. 870.3710... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3710 Pacemaker repair or replacement material. (a) Identification. A pacemaker repair or replacement material is...

  12. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Replacement of motor....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles...

  13. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Replacement of motor....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Heads of Contracting Activities may arrange to sell, as exchange sales, used motor vehicles...

  14. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... vehicles. 908.7101-4 Section 908.7101-4 Federal Acquisition Regulations System DEPARTMENT OF ENERGY....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with... Activities may arrange to sell, as exchange sales, used motor vehicles being replaced and to apply...

  15. Intravenous and subcutaneous immunoglobulin G replacement therapy.

    PubMed

    Bonilla, Francisco A

    2016-11-01

    Human polyclonal immunoglobulin G (IgG) for therapeutic use has been available for decades. This drug was developed for treatment of antibody deficiency (replacement therapy), although its use has expanded into many anti-inflammatory and immunomodulatory applications in recent years. This review focuses on IgG prescribing for replacement therapy. IgG for replacement is most often administered via the intravenous IgG (IVIG) or subcutaneous IgG (SCIG) routes. IVIG is usually administered every 34 weeks, and SCIG is usually administered weekly, although variations may be considered in all cases. Recently, a new product became available that uses hyaluronidase to facilitate absorption of large doses of SCIG less frequently (every 34 weeks, as with IVIG). There are important differences between the pharmacokinetics of these three routes of administration. IVIG therapy leads to high peaks and low troughs between infusions. IgG concentration fluctuates much less over time with SCIG. Hyaluronidase-facilitated SCIG is intermediate. SCIG may have lower bioavailability in comparison with IVIG and may require higher doses over time; this is not true for hyaluronidase SCIG. However, there are large variations in IgG half-life among individuals and with different products. Therefore, individualization of therapy is essential. Mild systemic flu-like adverse effects may affect up to 2025% of patients who receive IVIG, smaller fractions may experience more-severe symptoms, whereas anaphylaxis is exceedingly rare. General flu-like systemic adverse effects are minimal with SCIG (intermediate with hyaluronidase SCIG), but transient (24 hours), mild, local inflammatory symptoms at infusion sites are relatively common with both forms. Additional rare but important complications of IgG therapy include thrombotic events and hemolysis that can be seen at high doses with any route of administration. Renal adverse effects may occur with IVIG as well. The variety of IgG products and routes of

  16. Minimally Invasive Versus Conventional Aortic Valve Replacement

    PubMed Central

    Attia, Rizwan Q.; Hickey, Graeme L.; Grant, Stuart W.; Bridgewater, Ben; Roxburgh, James C.; Kumar, Pankaj; Ridley, Paul; Bhabra, Moninder; Millner, Russell W. J.; Athanasiou, Thanos; Casula, Roberto; Chukwuemka, Andrew; Pillay, Thasee; Young, Christopher P.

    2016-01-01

    Objective Minimally invasive aortic valve replacement (MIAVR) has been demonstrated as a safe and effective option but remains underused. We aimed to evaluate outcomes of isolated MIAVR compared with conventional aortic valve replacement (CAVR). Methods Data from The National Institute for Cardiovascular Outcomes Research (NICOR) were analyzed at seven volunteer centers (2006–2012). Primary outcomes were in-hospital mortality and midterm survival. Secondary outcomes were postoperative length of stay as well as cumulative bypass and cross-clamp times. Propensity modeling with matched cohort analysis was used. Results Of 307 consecutive MIAVR patients, 151 (49%) were performed during the last 2 years of study with a continued increase in numbers. The 307 MIAVR patients were matched on a 1:1 ratio. In the matched CAVR group, there was no statistically significant difference in in-hospital mortality [MIAVR, 4/307,(1.3%); 95% confidence interval (CI), 0.4%–3.4% vs CAVR, 6/307 (2.0%); 95% CI, 0.8%–4.3%; P = 0.752]. One-year survival rates in the MIAVR and CAVR groups were 94.4% and 94.6%, respectively. There was no statistically significant difference in midterm survival (P = 0.677; hazard ratio, 0.90; 95% CI, 0.56–1.46). Median postoperative length of stay was lower in the MIAVR patients by 1 day (P = 0.009). The mean cumulative bypass time (94.8 vs 91.3 minutes; P = 0.333) and cross-clamp time (74.6 vs 68.4 minutes; P = 0.006) were longer in the MIAVR group; however, this was significant only in the cross-clamp time comparison. Conclusions Minimally invasive aortic valve replacement is a safe alternative to CAVR with respect to operative and 1-year mortality and is associated with a shorter postoperative stay. Further studies are required in high-risk (logistic EuroSCORE > 10) patients to define the role of MIAVR. PMID:26926521

  17. Manual Replacement of Double J Stent Without Fluoroscopy (Double j stent replacement).

    PubMed

    Kose, Osman; Gorgel, Sacit Nuri; Ozbir, Sait; Yenigurbuz, Sekan; Kara, Cengiz

    2015-02-01

    It is not always possible to replace a ureteric stent with a new one due to the fact that tumoral effect increases in ureter with time. We present our experience of manual replacement of double J stent without fluoroscopy. The data from 23 female patients who underwent double J stent replacement with a total of 110 times was retrospectively analyzed. The steps of technique are as follows: take out distal end of the double J stent through urethra to external urethral meatus cystoscopically, insert a 0.035-inch guide wire through double J stent to the renal pelvis or intra pelvicaliceal system, take out old double J stent over guide wire, slide new stent over guide wire and at external meatus level take out guide wire while gently sliding distal end of double J stent over guide wire into urethra. The mean age was 58.39 ± 9.21 years. Cervical, endometrial, and ovarian cancer were diagnosed in 16, 4, and 3 patients respectively. The mean follow-up and indwelling period were 13.8 ± 5.2, 3.8 ± 0.6 months, respectively. Increased pelvicaliceal dilatation, serum creatinine level, or renal parenchymal loss was not observed. Replacement of double J stents with this technique is easy and can be used successfully in distal ureteral obstructions.

  18. Testosterone Replacement Therapy and the Cardiovascular System.

    PubMed

    Naderi, Sahar

    2016-04-01

    As testosterone replacement therapy (TRT) has emerged as a commonly prescribed therapy for symptomatic low testosterone, conflicting data have been reported in terms of both its efficacy and potential adverse outcomes. One of the most controversial associations has been that of TRT and cardiovascular morbidity and mortality. This review briefly provides background on the history of TRT, the indications for TRT, and the data behind TRT for symptomatic low testosterone. It then specifically delves into the rather limited data for cardiovascular outcomes of those with low endogenous testosterone and those who receive TRT. The available body of literature strongly suggests that more work, by way of clinical trials, needs to be done to better understand the impact of testosterone and TRT on the cardiovascular system.

  19. Modeling Regular Replacement for String Constraint Solving

    NASA Technical Reports Server (NTRS)

    Fu, Xiang; Li, Chung-Chih

    2010-01-01

    Bugs in user input sanitation of software systems often lead to vulnerabilities. Among them many are caused by improper use of regular replacement. This paper presents a precise modeling of various semantics of regular substitution, such as the declarative, finite, greedy, and reluctant, using finite state transducers (FST). By projecting an FST to its input/output tapes, we are able to solve atomic string constraints, which can be applied to both the forward and backward image computation in model checking and symbolic execution of text processing programs. We report several interesting discoveries, e.g., certain fragments of the general problem can be handled using less expressive deterministic FST. A compact representation of FST is implemented in SUSHI, a string constraint solver. It is applied to detecting vulnerabilities in web applications

  20. Material Science in Cervical Total Disc Replacement

    PubMed Central

    Pham, Martin H.; Mehta, Vivek A.; Tuchman, Alexander; Hsieh, Patrick C.

    2015-01-01

    Current cervical total disc replacement (TDR) designs incorporate a variety of different biomaterials including polyethylene, stainless steel, titanium (Ti), and cobalt-chrome (CoCr). These materials are most important in their utilization as bearing surfaces which allow for articular motion at the disc space. Long-term biological effects of implanted materials include wear debris, host inflammatory immune reactions, and osteolysis resulting in implant failure. We review here the most common materials used in cervical TDR prosthetic devices, examine their bearing surfaces, describe the construction of the seven current cervical TDR devices that are approved for use in the United States, and discuss known adverse biological effects associated with long-term implantation of these materials. It is important to appreciate and understand the variety of biomaterials available in the design and construction of these prosthetics and the considerations which guide their implementation. PMID:26523281

  1. Buprenorphine replacement therapy: a confirmed benefit.

    PubMed

    1999-08-01

    (1) Three years after high-dose buprenorphine preparations were first marketed in France, we examine their use as replacement therapy for heroin addiction. (2) Various surveys of community pharmacists have shown that the prescribing and dispensing conditions are feasible in the routine ambulatory setting. However, teamwork between physicians and pharmacists is rarely optimal, and fractionated dispensing is under-used. This could lead to abuse by a minority of patients. (3) During ambulatory management, at a mean dose of 8 mg/day sublingually, long-term buprenorphine therapy seems to yield a reduction in drug consumption by most patients, and can help with social reintegration. (4) The risks of buprenorphine treatment are mainly linked to abuse (massive doses, intravenous injection). Fatalities have occurred after high doses of buprenorphine combined with benzodiazepines, especially when taken intravenously. (5) The limited data on buprenorphine intake during pregnancy are reassuring.

  2. Replacing β-mercaptoethanol in RNA extractions.

    PubMed

    Mommaerts, Kathleen; Sanchez, Ignacio; Betsou, Fay; Mathieson, William

    2015-06-15

    RNA extractions are potentially compromised in terms of both yield and quality by ribonucleases (RNases). The pungent and toxic reducing agent β-mercaptoethanol (β-ME), therefore, is commonly added to the biospecimen's lysis buffer to aid in RNase deactivation. Using different tissue types (liver tissue, kidney tissue, and cell pellets), extraction kits (RNeasy Mini Kit, Illustra RNA Spin Mini Kit, and PureLink Mini Kit), RNA quality assays (RNA integrity numbers [RINs] and quantitative real-time polymerase chain reaction [qRT-PCR]), yield assessments, and in vitro functional RNase assays (RNaseAlert Kit), we demonstrate that β-ME should be replaced by the less toxic dithiothreitol (DTT) alternative.

  3. Growth hormone replacement therapy in Costello syndrome.

    PubMed

    Triantafyllou, Panagiota; Christoforidis, Athanasios; Vargiami, Euthymia; Zafeiriou, Dimitrios I

    2014-12-01

    Costello syndrome (CS) is considered an overgrowth disorder given the macrosomia that is present at birth .However, shortly after birth the weight drops dramatically and the patients are usually referred for failure to thrive. Subsequently, affected patients develop the distinctive coarse facial appearance and are at risk for cardiac anomalies and solid tumor malignancies. Various endocrine disorders, although not very often, have been reported in patients with CS, including growth hormone deficiency, hypoglycemia, ACTH deficiency, cryptorchidism and hypothyroidism. We report a case of Costello syndrome with hypothyroidism, cryptorchidism and growth hormone deficiency and we evaluate the long-term safety and efficacy of growth hormone replacement therapy. The index patient is a paradigm of successful and safe treatment with growth hormone for almost 7 years. Since patients with CS are at increased risk for cardiac myopathy and tumor development they deserve close monitoring during treatment.

  4. Replaceable Microfluidic Cartridges for a PCR Biosensor

    NASA Technical Reports Server (NTRS)

    Francis, Kevin; Sullivan, Ron

    2005-01-01

    The figure depicts a replaceable microfluidic cartridge that is a component of a miniature biosensor that detects target deoxyribonucleic acid (DNA) sequences. The biosensor utilizes (1) polymerase chain reactions (PCRs) to multiply the amount of DNA to be detected, (2) fluorogenic polynucleotide probe chemicals for labeling the target DNA sequences, and (3) a high-sensitivity epifluorescence-detection optoelectronic subsystem. Microfluidics is a relatively new field of device development in which one applies techniques for fabricating microelectromechanical systems (MEMS) to miniature systems for containing and/or moving fluids. Typically, microfluidic devices are microfabricated, variously, from silicon or polymers. The development of microfluidic devices for applications that involve PCR and fluorescence-based detection of PCR products poses special challenges

  5. Renal Replacement Therapy in Austere Environments

    PubMed Central

    Yuan, Christina M.; Perkins, Robert M.

    2011-01-01

    Myoglobinuric renal failure is the classically described acute renal event occurring in disaster environments—commonly after an earthquake—which most tests the ingenuity and flexibility of local and regional nephrology resources. In recent decades, several nephrology organizations have developed response teams and planning protocols to address disaster events, largely focusing on patients at risk for, or with, acute kidney injury (AKI). In this paper we briefly review the epidemiology and outcomes of patients with dialysis-requiring AKI after such events, while providing greater focus on the management of the end-stage renal disease population after a disaster which incapacitates a pre-existing nephrologic infrastructure (if it existed at all). “Austere” dialysis, as such, is defined as the provision of renal replacement therapy in any setting in which traditional, first-world therapies and resources are limited, incapacitated, or nonexistent. PMID:21603109

  6. NIF Laser Line Replaceable Units (LRUs)

    SciTech Connect

    Larson, D W

    2003-12-19

    The National Ignition Facility (NIF) is designed with its high value optical systems in cassettes called Line Replaceable Units (LRUs). Virtually all of the NIF's active components are assembled in one of the {approx}4000 electrical and optical LRUs that serve between two and eight of NIF's 192 laser beam lines. Many of these LRUs are optomechanical assemblies that are roughly the size of a telephone booth. The primary design challenges for this hardware include meeting stringent mechanical precision, stability and cleanliness requirements. Pre-production units of each LRU type have been fielded on the first bundle of NIF and used to demonstrate that NIF meets its performance objectives. This presentation provides an overview of the NIF LRUs, their design and production plans for building out the remaining NIF bundles.

  7. Iliopsoas bursitis following total hip replacement.

    PubMed

    Cheung, Y M; Gupte, C M; Beverly, M J

    2004-12-01

    We report the imaging features of a 52-year-old man presenting with a groin mass and gross lower limb oedema secondary to venous occlusion by massive cystic enlargement of the iliopsoas bursa 4 years after uncemented primary total hip replacement. Ultrasonography of the groin mass demonstrated a large cystic lesion extending into the pelvis. CT showed displacement of the external iliac vessels with venous compression. Bursography showed the bursa's margins and no communication with the hip joint. Diagnostic aspiration excluded infection, but fluid recollection occurred subsequently. Complete resolution of symptoms, including limb swelling, followed surgical excision with no recurrence at the 5-year follow-up. We believe iliopsoas bursitis occurred as a tissue response to polyethylene wear within the prosthetic hip and occurred even in the absence of loosening or a direct communication between bursa and joint.

  8. [Interventional mitral valve replacement. Current status].

    PubMed

    Lutter, G; Frank, D

    2016-02-01

    Approximately 30 % of patients suffering from severe valvular heart disease, such as mitral valve regurgitation are non-compliant to the gold standard of minimally invasive surgery, reconstruction or valve replacement. The number of these mostly old patients with severe comorbidities is increasing; therefore, transcatheter interventions have been developed to address an unmet clinical need and may be an alternative therapeutic option to the reference standard. Apart from the successful MitraClip therapy, alternative transcatheter reconstruction technologies are being developed. As with transcatheter aortic valve implantation (TAVI) procedures, the off-pump implantation of a valved stent into the mitral position mainly via a transapical approach will be of great benefit. Recently, the feasibility of transcatheter mitral valved stent implantation in high-risk patients has already been reported.

  9. Magnetic ranging tool accurately guides replacement well

    SciTech Connect

    Lane, J.B.; Wesson, J.P. )

    1992-12-21

    This paper reports on magnetic ranging surveys and directional drilling technology which accurately guided a replacement well bore to intersect a leaking gas storage well with casing damage. The second well bore was then used to pump cement into the original leaking casing shoe. The repair well bore kicked off from the surface hole, bypassed casing damage in the middle of the well, and intersected the damaged well near the casing shoe. The repair well was subsequently completed in the gas storage zone near the original well bore, salvaging the valuable bottom hole location in the reservoir. This method would prevent the loss of storage gas, and it would prevent a potential underground blowout that could permanently damage the integrity of the storage field.

  10. Revision of the aseptic and septic total ankle replacement.

    PubMed

    Espinosa, Norman; Wirth, Stephan Hermann

    2013-04-01

    Total ankle replacement has become a popular treatment of symptomatic end-stage ankle osteoarthritis. Contemporary total ankle replacement systems provide more anatomic and biomechanically sound function. However, longevity is still limited and long-term results of modern total ankle replacement designs are not available. In the case of failure, conversion into arthrodesis has remained the treatment of choice but at the cost of hindfoot function and potential degeneration of the adjacent joints. Thus, revision total ankle replacement by exchange of the prosthetic components represents an attractive solution. This article focuses on revision total ankle replacement and conversion to ankle arthrodesis.

  11. Income replacement ratios in the Health and Retirement Study.

    PubMed

    Purcell, Patrick J

    2012-01-01

    This article describes the income replacement ratio as a measure of retirement income adequacy and identifies several issues analysts must consider when calculating a replacement ratio. The article presents the income replacement ratios experienced by participants in the original sample cohort of the Health and Retirement Study (HRS), who were born between 1931 and 1941. Replacement ratios are shown by the respondent's birth cohort, age when first classified as retired in the HRS, and preretirement income quartile. Median replacement ratios fall as the retirement period grows longer.

  12. Locomotion in simulated microgravity: gravity replacement loads

    NASA Technical Reports Server (NTRS)

    McCrory, Jean L.; Baron, Heidi A.; Balkin, Sandy; Cavanagh, Peter R.

    2002-01-01

    BACKGROUND: When an astronaut walks or runs on a treadmill in microgravity, a subject load device (SLD) is used to return him or her back to the treadmill belt. The gravity replacement load (GRL) in the SLD is transferred, via a harness, to the pelvis and/or the shoulders. This research compared comfort and ground reaction forces during treadmill running in a microgravity locomotion simulator at GRLs of 60%, 80%, and 100% of body weight (BW). Two harness designs (shoulder springs only (SSO) and waist and shoulder springs (WSS)) were used. HYPOTHESES: 1) The 100% BW gravity replacement load conditions would be comfortably tolerated and would result in larger ground reaction forces and loading rates than the lower load conditions, and 2) the WSS harness would be more comfortable than the SSO harness. METHODS: Using the Penn State Zero Gravity Locomotion Simulator (ZLS), 8 subjects ran at 2.0 m x s(-1) (4.5 mph) for 3 min at each GRL setting in each harness. Subjective ratings of harness comfort, ground reaction forces, and GRL data were collected during the final minute of exercise. RESULTS: The 100% BW loading conditions were comfortably tolerated (2.3 on a scale of 0-10), although discomfort increased as the GRL increased. There were no overall differences in perceived comfort between the two harnesses. The loading rates (27.1, 33.8, 39.1 BW x s(-1)) and the magnitudes of the first (1.0, 1.4, 1.6 BW) and second (1.3, 1.7, 1.9 BW) peaks of the ground reaction force increased with increasing levels (60, 80, 100% BW respectively) of GRL. CONCLUSIONS: Subjects were able to tolerate a GRL of 100% BW well. The magnitude of the ground reaction force peaks and the loading rate is directly related to the magnitude of the GRL.

  13. Novel associated hydrogels for nucleus pulposus replacement.

    PubMed

    Thomas, Jonathan; Lowman, Anthony; Marcolongo, Michele

    2003-12-15

    Hydrogels of poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) blends may provide a material suitable for replacement of the nucleus pulposus of the intervertebral disc. This research examined the stability of these hydrogels under simulated physiological conditions. Polymer dissolution and stability were characterized over 120 days immersion, chemical surface analysis over 56 days immersion, and tensile mechanical behavior over 56 days immersion. Rubber elasticity theory was used by combining mechanical results with swelling data to calculate network characteristics such as the molecular weight between physical crosslinks and density of crosslinks. Properties were examined as a function of PVA/PVP composition as well as PVA molecular weight and PVP molecular weight. Results indicated that PVA/PVP blends prepared with moderate amounts of PVP (0.5-5%) resulted in a polymer network stabilized through interchain hydrogen bonding between hydroxyl groups on PVA chains and carbonyl groups on PVP chains. Most notably, a significant decrease in percentage of polymer mass loss was seen for blends prepared with 143K molecular weight PVA. Surface chemical analysis revealed that PVP unincorporated in the network structure suffered significant dissolution out of the polymer network and into solution. The molecular weight of PVA and PVP were shown to have a significant influence on the blends' network properties. Gels prepared with lower molecular weight PVA resulted in a more stable blend containing a higher density of crosslinks. However, blends prepared with a higher molecular weight PVA showed superior polymer network stability in dissolution studies. The blend that had the best combination of network stability under physiological conditions and a relatively tight, stable, and crosslinked network was prepared with 99% PVA (143K) and 1% PVP (40K). This material is proposed as an implant material for replacement of the degenerated nucleus pulposus.

  14. Contact replacement for NMR resonance assignment

    PubMed Central

    Xiong, Fei; Pandurangan, Gopal; Bailey-Kellogg, Chris

    2008-01-01

    Motivation: Complementing its traditional role in structural studies of proteins, nuclear magnetic resonance (NMR) spectroscopy is playing an increasingly important role in functional studies. NMR dynamics experiments characterize motions involved in target recognition, ligand binding, etc., while NMR chemical shift perturbation experiments identify and localize protein–protein and protein–ligand interactions. The key bottleneck in these studies is to determine the backbone resonance assignment, which allows spectral peaks to be mapped to specific atoms. This article develops a novel approach to address that bottleneck, exploiting an available X-ray structure or homology model to assign the entire backbone from a set of relatively fast and cheap NMR experiments. Results: We formulate contact replacement for resonance assignment as the problem of computing correspondences between a contact graph representing the structure and an NMR graph representing the data; the NMR graph is a significantly corrupted, ambiguous version of the contact graph. We first show that by combining connectivity and amino acid type information, and exploiting the random structure of the noise, one can provably determine unique correspondences in polynomial time with high probability, even in the presence of significant noise (a constant number of noisy edges per vertex). We then detail an efficient randomized algorithm and show that, over a variety of experimental and synthetic datasets, it is robust to typical levels of structural variation (1–2 AA), noise (250–600%) and missings (10–40%). Our algorithm achieves very good overall assignment accuracy, above 80% in α-helices, 70% in β-sheets and 60% in loop regions. Availability: Our contact replacement algorithm is implemented in platform-independent Python code. The software can be freely obtained for academic use by request from the authors. Contact: gopal@cs.purdue.edu; cbk@cs.dartmouth.edu PMID:18586716

  15. Enzyme replacement therapy and Fabry nephropathy.

    PubMed

    Warnock, David G; Daina, Erica; Remuzzi, Giuseppe; West, Michael

    2010-02-01

    Involvement of the kidneys in Fabry disease ("nephropathy") occurs in male and female individuals. The majority of patients with progressive nephropathy will have significant proteinuria and develop progressive loss of kidney function, leading to ESRD. All too often, treating physicians may ignore "normal" serum creatinine levels or "minimal" proteinuria and fail to assess properly the severity of kidney involvement and institute appropriate management. Fabry nephropathy is treatable, even in patients with fairly advanced disease. Although the cornerstone of therapy remains enzyme replacement therapy with agalsidase, this treatment alone does not reduce urine protein excretion. Treatment with angiotensin receptor blockers or angiotensin-converting enzyme inhibitors must be added to enzyme replacement therapy to reduce urine protein excretion with the hope that this will stabilize kidney function. Kidney function, with at least estimated GFR based on serum creatinine and measurements of urinary protein, should be measured at every clinic visit, and the rate of change of the estimated GFR should be followed over time. Antiproteinuric therapy can be dosed to a prespecified urine protein target rather than a specific BP goal, with the proviso that successful therapy will usually lower the BP below the goal of 130/80 mmHg that is used for other forms of kidney disease. The overall goal for treating Fabry nephropathy is to reduce the rate of loss of GFR to -1 ml/min per 1.73 m(2)/yr, which is that seen in the normal adult population. A systematic approach is presented for reaching this goal in the individual patient.

  16. Subsidence in Collarless Corail Hip Replacement

    PubMed Central

    Selvaratnam, Veenesh; Shetty, Vishwanath; Sahni, Vishal

    2015-01-01

    The purpose of this study was to assess whether subsidence occurs in collarless Corail hip replacement (CCHR) and to ascertain the extent and timing of subsidence if present. Retrospective case notes analysis was performed. Sixty eight patients who had CCHR were identified from our database. Male to female ratio was 32:36. Their mean age was 74.2 years (range 37-95 years). Indications for surgery were osteoarthritis in 64 (94%) patients, rheumatoid arthritis in two (3%) patients and avascular necrosis in two (3%) patients. Subsidence was measured at 6 weeks, 6 months and 1 year post-op compared to initial post-op x-rays. At 6 weeks x-ray 21 patients did not have any subsidence, 18 patients had 1 millimeter (mm) subsidence, 10 patients had 2mms subsidence, 4 patients had 3mms subsidence, 5 patients had 4mms subsidence, 1 patient had 5mms subsidence, 4 patients had 6 mms subsidence and 1 patient each had subsidence of 7mms, 9mms, 11mms, 13mms and 26 mms respectively. When compared with 6 months x-rays only 2 patients had a further subsidence of 2mms while another patient had 3mms subsidence. No further subsidence occurred at 1 year follow up x-rays. One patient had revision surgery due to symptomatic subsidence (29mms) at 6 months follow up. Subsidence does occur in the first 6 weeks in collarless Corail hip replacement, and to a lesser extent until 6 months postoperatively, but does not progress further. PMID:26069515

  17. Subsidence in Collarless Corail Hip Replacement.

    PubMed

    Selvaratnam, Veenesh; Shetty, Vishwanath; Sahni, Vishal

    2015-01-01

    The purpose of this study was to assess whether subsidence occurs in collarless Corail hip replacement (CCHR) and to ascertain the extent and timing of subsidence if present. Retrospective case notes analysis was performed. Sixty eight patients who had CCHR were identified from our database. Male to female ratio was 32:36. Their mean age was 74.2 years (range 37-95 years). Indications for surgery were osteoarthritis in 64 (94%) patients, rheumatoid arthritis in two (3%) patients and avascular necrosis in two (3%) patients. Subsidence was measured at 6 weeks, 6 months and 1 year post-op compared to initial post-op x-rays. At 6 weeks x-ray 21 patients did not have any subsidence, 18 patients had 1 millimeter (mm) subsidence, 10 patients had 2mms subsidence, 4 patients had 3mms subsidence, 5 patients had 4mms subsidence, 1 patient had 5mms subsidence, 4 patients had 6 mms subsidence and 1 patient each had subsidence of 7mms, 9mms, 11mms, 13mms and 26 mms respectively. When compared with 6 months x-rays only 2 patients had a further subsidence of 2mms while another patient had 3mms subsidence. No further subsidence occurred at 1 year follow up x-rays. One patient had revision surgery due to symptomatic subsidence (29mms) at 6 months follow up. Subsidence does occur in the first 6 weeks in collarless Corail hip replacement, and to a lesser extent until 6 months postoperatively, but does not progress further.

  18. [Role of fibula in replacement of mandible].

    PubMed

    Fülöp, Miklós; Branzaniuc, Klara; Kásler, Miklós

    2009-09-01

    The mandible and the fibula are two totally different bones of the human skeleton. The fibula is a long straight bone of the lower leg playing secondary role compared with the tibia. The mandible, or jaw bone, is the only facial bone that moves and has complex spatial structure. The blood supply of the mandible is mainly endosteal, the inferior mandibular artery, which is one of the more important branch of the maxillary artery is responsible for its arterial supply. The fibula shows the uniform pattern of periosteal blood supply receiving many small branches from the peroneal artery, and having only weak endosteal supply. The mandible articulates with the two temporal bone, and the fibula articulates with the tibia at the tibio-fibular syndesmosis and distally has a role in the formation of the lateral talocrural joint. The demand for mandibular replacement was approved simultaneously with the appearance of ablative surgery for head and neck cancer. As knowledge of physiology and pharmacology expanded in the twentieth century, major developments in the field of anesthesiology and surgery opened new windows of ablative cancer surgery that were previously unimaginable. Soldiers were badly wounded with extensive soft-tissue defects during World Wars and in certain countries, high gun ownership rates show substantial correlations with gun-related injuries. Health care development and the invention and wide-spread use of antibiotics revolutionized medical treatment and improved recovery rates and reduced mortality following trauma. Total or partial loss of the mandible without reconstruction incurs serious functional and psychological morbidity for patients. Prior to the development of advanced reconstruction options for mandibular defects, they were left with terrible cosmetic deformities. Throughout the second half of the twentieth century, various attempts were made to replace the mandible but the major breakthrough was the appearance of the microvascular technique

  19. Urban chaos and replacement dynamics in nature and society

    NASA Astrophysics Data System (ADS)

    Chen, Yanguang

    2014-11-01

    Replacements resulting from competition are ubiquitous phenomena in both nature and society. The evolution of a self-organized system is always a physical process substituting one type of components for another type of components. A logistic model of replacement dynamics has been proposed in terms of technical innovation and urbanization, but it fails to arouse widespread attention in the academia. This paper is devoted to laying the foundations of general replacement principle by using analogy and induction. The empirical base of this study is urban replacement, including urbanization and urban growth. The sigmoid functions can be employed to model various processes of replacement. Many mathematical methods such as allometric scaling and head/tail breaks can be applied to analyzing the processes and patterns of replacement. Among varied sigmoid functions, the logistic function is the basic and the simplest model of replacement dynamics. A new finding is that replacement can be associated with chaos in a nonlinear system, e.g., urban chaos is just a part of replacement dynamics. The aim of developing replacement theory is at understanding complex interaction and conversion. This theory provides a new way of looking at urbanization, technological innovation and diffusion, Volterra-Lotka’s predator-prey interaction, man-land relation, and dynastic changes resulting from peasant uprising, and all that. Especially, the periodic oscillations and chaos of replacement dynamics can be used to explain and predict the catastrophic occurrences in the physical and human systems.

  20. Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs

    PubMed Central

    Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

    2013-01-01

    Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently

  1. Kinematics of total facet replacement (TFAS-TL) with total disc replacement

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Sjovold, Simon G.; Funk, Michael; Carandang, Gerard; Zindrick, Daniel; Rosler, David M.; Patwardhan, Avinash G.

    2009-01-01

    Background Total disc replacement (TDR) and total facet replacement (TFR) have been the focus of recent kinematics evaluations. Yet their concurrent function as a total joint replacement of the lumbar spine's 3-joint complex has not been comprehensively reported. This study evaluated the effect of a TFR specifically designed to replace the natural facets and supplement the function with the natural disc and with TDR. The ability to replace degenerated facets to complement a pre-existing or simultaneously implanted TDR may allow surgeons to completely address degenerative pathologies of the 3-joint complex of the lumbar spine. We hypothesized that TFR would reproduce the biomechanical function of the natural facets when implanted in conjunction with TDR. Methods Lumbar spines (L1-5, 51.3 ± 14.2 years, N = 6) were tested sequentially as follows: (1) intact, (2) after TDR implantation, and (3) after TFR implantation in conjunction with TDR, all at L3-4. Specimens were tested in flexion-extension (+ 8 Nm to − 6 Nm), lateral bending (± 6 Nm), and axial rotation (± 5 Nm). A 400 N compressive follower preload was applied during flexion-extension tests. Three-dimensional segmental motion was recorded and analyzed using analysis of variance in Systat (Systat Software Inc., Chicago, Illinois) and multiple comparisons with Bonferroni correction. Results The TDR implantation (TDR + natural facets) allowed similar lateral bending (P = .66), but it generally increased flexion-extension (P = .06) and axial rotation (P < .05) range of motion (ROM) at the implanted level compared to intact. The TFR + TDR (following replacement of the natural facets with TFR) decreased ROM to levels similar to intact in lateral bending (P = .70) and axial rotation (P = .23). The TFR + TDR flexion-extension ROM was reduced in comparison to intact and TDR + natural facets (P < .05). Conclusions The TFR with TDR was able to restore stability to the lumbar segment after bilateral facetectomy, while

  2. Mineral replacement reactions and element mobilization

    NASA Astrophysics Data System (ADS)

    Putnis, Christine V.; Ruiz-Agudo, Encarnacion; King, Helen E.; Hövelmann, Jörn; Renard, François

    2016-04-01

    When a mineral is out of equilibrium with an aqueous fluid, reactions will take place in an attempt to reach a new equilibrium. Commonly in the Earth dissolution at a mineral-fluid interface initiates a coupled reaction involving dissolution and precipitation (Ruiz-Agudo et al., 2014). This is a ubiquitous reaction during such processes as metamorphism, metasomatism and weathering. When rock-forming minerals such as feldspars, olivine, pyroxenes are in contact with aqueous fluids (typically NaCl-rich) resultant new phases are formed and elements present in the parent mineral are released to the fluid and therefore mobilized for transport elsewhere. This has been shown in a number of systems such as the albitisation of feldspars (Hövelmann et al., 2010) when a Ca-bearing plagioclase is replaced by albite (NaAlSi3O8). However during this reaction not only is Ca released to the fluid but most other minor elements, such as Mg, Pb, rare earth elements amongst others, are almost totally mobilized and removed in solution. This interface-coupled dissolution-precipitation reaction has many implications for the redistributon of elements in the crust of the Earth. It is also of note that albitisation occurs often in areas of high mineralization, such as in the Curnamona Province in S. Australia (Au-Cu and Ag-Pb-Zn deposits) and the Bamble District of S. Norway. Secondly atomic force microscopy (AFM) has been used to image these reactions at a nanoscale, especially at the calcite-fluid interface, such as the formation of apatite from phosphate-bearing solutions, and the sequestration of toxic elements, eg., Se and As. References Ruiz-Agudo E., Putnis C.V., Putnis A. (2014) Coupled dissolution and precipitation at mineral-fluid interfaces. Chemical Geology, 383, 132-146. Putnis C.V. and Ruiz-Agudo E. (2013) The mineral-water interface: where minerals react with the environment. Elements, 9, 177-182. Hövelmann J., Putnis A., Geisler T., Schmidt B.C., Golla-Schindler U. (2009

  3. Androgen replacement therapy: present and future.

    PubMed

    Gooren, Louis J G; Bunck, Mathijs C M

    2004-01-01

    The major goal of androgen substitution is to replace testosterone at levels as close to physiological levels as is possible. For some androgen-dependent functions testosterone is a pro-hormone, peripherally converted to 5alpha-dihydrotestosterone (DHT) and 17beta-estradiol (E2), of which the levels preferably should be within normal physiological ranges. Furthermore, androgens should have a good safety profile without adverse effects on the prostate, serum lipids, liver or respiratory function, and they must be convenient to use and patient-friendly, with a relative independence from medical services. Natural testosterone is viewed as the best androgen for substitution in hypogonadal men. The reason behind the selection is that testosterone can be converted to DHT and E2, thus developing the full spectrum of testosterone activities in long-term substitution. The mainstays of testosterone substitution are parenteral testosterone esters (testosterone enantate and testosterone cipionate) administered every 2-3 weeks. A major disadvantage is the strongly fluctuating levels of plasma testosterone, which are not in the physiological range at least 50% of the time. Also, the generated plasma E2 is usually supraphysiological. A major improvement is parenteral testosterone undecanoate producing normal plasma levels of testosterone for 12 weeks, with normal plasma levels of DHT and E2 also. Subcutaneous testosterone implants provide the patient, depending on the dose of implants, with normal plasma testosterone for 3-6 months. However, their use is not widespread. Oral testosterone undecanoate dissolved in castor oil bypasses the liver via its lymphatic absorption. At a dosage of 80 mg twice daily, plasma testosterone levels are largely in the normal range, but plasma DHT tends to be elevated. For two decades transdermal testosterone preparations have been available and have an attractive pharmacokinetic profile. Scrotal testosterone patches generate supraphysiological

  4. Frequency and impact of informant replacement in Alzheimer disease research.

    PubMed

    Grill, Joshua D; Zhou, Yan; Karlawish, Jason; Elashoff, David

    2015-01-01

    Informants serve an essential role in Alzheimer disease research. Were an informant to be replaced during a longitudinal study, this could have negative implications. We used data from the National Alzheimer's Coordinating Center Uniform Data Set to examine the frequency of informant replacement among Alzheimer disease dementia participants, whether patient and informant characteristics were associated with replacement, and how replacement affected research outcome measures. Informant replacement was common (15.5%) and typically occurred after the first or the second research visit. Adult child (24%) and other (38%) informants were more frequently replaced than spouse informants (10%). Older spouse informant age and younger adult child informant age were associated with replacement. The between-visit change in Functional Assessment Questionnaire scores was greater in patients who replaced informants than in those with stable informants. Clinical Dementia Rating-Sum of Boxes, Functional Assessment Questionnaire, and Neuropsychiatric Inventory scores showed greater variability in between-visit change in patients who replaced informants compared with those with stable informants. These findings suggest that informant replacement is relatively common, may have implications to study analyses, and warrant further examination in the setting of clinical trials.

  5. Can Smartwatches Replace Smartphones for Posture Tracking?

    PubMed Central

    Mortazavi, Bobak; Nemati, Ebrahim; VanderWall, Kristina; Flores-Rodriguez, Hector G.; Cai, Jun Yu Jacinta; Lucier, Jessica; Naeim, Arash; Sarrafzadeh, Majid

    2015-01-01

    This paper introduces a human posture tracking platform to identify the human postures of sitting, standing or lying down, based on a smartwatch. This work develops such a system as a proof-of-concept study to investigate a smartwatch’s ability to be used in future remote health monitoring systems and applications. This work validates the smartwatches’ ability to track the posture of users accurately in a laboratory setting while reducing the sampling rate to potentially improve battery life, the first steps in verifying that such a system would work in future clinical settings. The algorithm developed classifies the transitions between three posture states of sitting, standing and lying down, by identifying these transition movements, as well as other movements that might be mistaken for these transitions. The system is trained and developed on a Samsung Galaxy Gear smartwatch, and the algorithm was validated through a leave-one-subject-out cross-validation of 20 subjects. The system can identify the appropriate transitions at only 10 Hz with an F-score of 0.930, indicating its ability to effectively replace smart phones, if needed. PMID:26506354

  6. Gray component replacement using color mixing models

    NASA Astrophysics Data System (ADS)

    Kang, Henry R.

    1994-05-01

    A new approach to the gray component replacement (GCR) has been developed. It employs the color mixing theory for modeling the spectral fit between the 3-color and 4-color prints. To achieve this goal, we first examine the accuracy of the models with respect to the experimental results by applying them to the prints made by a Canon Color Laser Copier-500 (CLC-500). An empirical halftone correction factor is used for improving the data fitting. Among the models tested, the halftone corrected Kubelka-Munk theory gives the closest fit, followed by the halftone corrected Beer-Bouguer law and the Yule-Neilsen approach. We then apply the halftone corrected BB law to GCR. The main feature of this GCR approach is based on the spectral measurements of the primary color step wedges and a software package implementing the color mixing model. The software determines the amount of the gray component to be removed, then adjusts each primary color until a good match of the peak wavelengths between the 3-color and 4-color spectra is obtained. Results indicate that the average (Delta) Eab between cmy and cmyk renditions of 64 color patches is 3.11 (Delta) Eab. Eighty-seven percent of the patches has (Delta) Eab less than 5 units. The advantage of this approach is its simplicity; there is no need for the black printer and under color addition. Because this approach is based on the spectral reproduction, it minimizes the metamerism.

  7. Delivering enhanced testosterone replacement therapy through nanochannels.

    PubMed

    Ferrati, Silvia; Nicolov, Eugenia; Bansal, Shyam; Zabre, Erika; Geninatti, Thomas; Ziemys, Arturas; Hudson, Lee; Ferrari, Mauro; Goodall, Randal; Khera, Mohit; Palapattu, Ganesh; Grattoni, Alessandro

    2015-02-18

    Primary or secondary hypogonadism results in a range of signs and symptoms that compromise quality of life and requires life-long testosterone replacement therapy. In this study, an implantable nanochannel system is investigated as an alternative delivery strategy for the long-term sustained and constant release of testosterone. In vitro release tests are performed using a dissolution set up, with testosterone and testosterone:2-hydroxypropyl-β-cyclodextrin (TES:HPCD) 1:1 and 1:2 molar ratio complexes release from the implantable nanochannel system and quantify by HPLC. 1:2 TES:HPCD complex stably achieve 10-15 times higher testosterone solubility with 25-30 times higher in vitro release. Bioactivity of delivered testosterone is verified by LNCaP/LUC cell luminescence. In vivo evaluation of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels by liquid chromatography mass spectrometry (LC/MS) and multiplex assay is performed in castrated Sprague-Dawley rats over 30 d. Animals are treated with the nanochannel implants or degradable testosterone pellets. The 1:2 TES:HPCD nanochannel implant exhibits sustained and clinically relevant in vivo release kinetics and attains physiologically stable plasma levels of testosterone, LH, and FSH. In conclusion, it is demonstrated that by providing long-term steady release 1:2 TES:HPCD nanochannel implants may represent a major breakthrough for the treatment of male hypogonadism.

  8. Extending life using tissue and organ replacement.

    PubMed

    Atala, Anthony

    2008-07-01

    There is a critical shortage of organs available for donation to patients suffering from degenerative diseases of various organ systems. This shortage becomes more severe yearly, as the aging population grows and such diseases become more common. The fields of regenerative medicine and tissue engineering now offer hope for these aging patients with new advances in material science, cell transplantation, and bioengineering. Novel methods and materials to construct biological substitutes for diseased and injured tissues are being developed, and the goal is to restore and maintain normal function to the patient. The field of stem cell research is rapidly advancing, offering unforeseen options for treatment. For example, therapeutic cloning, where an enucleated oocyte receives a donor cell nucleus, yielding pluripotent stem cells, offers a potentially limitless source of cells for tissue engineering applications. However, recent discoveries in this field indicate that the use of non-controversial cells and tissues also has enormous potential for tissue engineering purposes. This article gives an overview of recent advances in regenerative medicine and describes their applications in tissue and organ replacement technology, as well as how these technologies offer new therapies to a person facing end-stage organ failure. There is a growing optimism that the successes in this field will achieve the goal of significantly extending the life of the patient.

  9. Process optimized minimally invasive total hip replacement

    PubMed Central

    Gebel, Philipp; Oszwald, Markus; Ishaque, Bernd; Ahmed, Gaffar; Blessing, Recha; Thorey, Fritz; Ottersbach, Andreas

    2012-01-01

    The purpose of this study was to analyse a new concept of using the the minimally invasive direct anterior approach (DAA) in total hip replacement (THR) in combination with the leg positioner (Rotex- Table) and a modified retractor system (Condor). We evaluated retrospectively the first 100 primary THR operated with the new concept between 2009 and 2010, regarding operation data, radiological and clinical outcome (HOOS). All surgeries were perfomed in a standardized operation technique including navigation. The average age of the patients was 68 years (37 to 92 years), with a mean BMI of 26.5 (17 to 43). The mean time of surgery was 80 min. (55 to 130 min). The blood loss showed an average of 511.5 mL (200 to 1000 mL). No intra-operative complications occurred. The postoperative complication rate was 6%. The HOOS increased from 43 points pre-operatively to 90 (max 100 points) 3 months after surgery. The radiological analysis showed an average cup inclination of 43° and a leg length discrepancy in a range of +/− 5 mm in 99%. The presented technique led to excellent clinic results, showed low complication rates and allowed correct implant positions although manpower was saved. PMID:22577504

  10. Ulnar Head Replacement and Related Biomechanics

    PubMed Central

    Sauerbier, Michael; Arsalan-Werner, Annika; Enderle, Elena; Vetter, Miriam; Vonier, Daniel

    2013-01-01

    A stable distal radioulnar joint (DRUJ) is mandatory for the function and load transmission in the wrist and forearm. Resectional salvage procedures such as the Darrach procedure, Bowers arthroplasty, and Sauvé-Kapandji procedure include the potential risk of radioulnar instability and impingement, which can lead to pain and weakness. Soft tissue stabilizing techniques have only limited success rates in solving these problems. In an attempt to stabilize the distal forearm mechanically following ulnar head resection, various endoprostheses have been developed to replace the ulnar head. The prostheses can be used for secondary treatment of failed ulnar head resection, but they can also achieve good results in the primary treatment of osteoarthritis of the DRUJ. Our experience consists of twenty-five patients (follow-up 30 months) with DRUJ osteoarthritis who were treated with an ulnar head prosthesis, with improvement in pain, range of motion, and grip strength. An ulnar head prosthesis should be considered as a treatment option for a painful DRUJ. PMID:24436786

  11. Development of mitochondrial gene replacement therapy.

    PubMed

    Khan, Shaharyar M; Bennett, James P

    2004-08-01

    Many "classic" mitochondrial diseases have been described that arise from single homoplasmic mutations in mitochondrial DNA (mtDNA). These diseases typically affect nonmitotic tissues (brain, retina, muscle), present with variable phenotypes, can appear sporadically, and are untreatable. Evolving evidence implicates mtDNA abnormalities in diseases such as Alzheimer's, Parkinson's, and type II diabetes, but specific causal mutations for these conditions remain to be defined. Understanding the mtDNA genotype-phenotype relationships and developing specific treatment for mtDNA-based diseases is hampered by inability to manipulate the mitochondrial genome. We present a novel protein transduction technology ("protofection") that allows insertion and expression of the human mitochondrial genome into mitochondria of living cells. With protofection, the mitochondrial genotype can be altered, or exogenous genes can be introduced to be expressed and either retained in mitochondria or be directed to other organelles. Protofection also delivers mtDNA in vivo, opening the way to rational development of mitochondrial gene replacement therapy of mtDNA-based diseases.

  12. MMIC Replacement for Gunn Diode Oscillators

    NASA Technical Reports Server (NTRS)

    Crowe, Thomas W.; Porterfield, David

    2011-01-01

    An all-solid-state replacement for high-frequency Gunn diode oscillators (GDOs) has been proposed for use in NASA s millimeter- and submillimeter-wave sensing instruments. Highly developed microwave oscillators are used to achieve a low-noise and highly stable reference signal in the 10-40-GHz band. Compact amplifiers and high-power frequency multipliers extend the signal to the 100-500-GHz band with minimal added phase noise and output power sufficient for NASA missions. This technology can achieve improved output power and frequency agility, while maintaining phase noise and stability comparable to other GDOs. Additional developments of the technology include: a frequency quadrupler to 145 GHz with 18 percent efficiency and 15 percent fixed tuned bandwidth; frequency doublers featuring 124, 240, and 480 GHz; an integrated 874-GHz subharmonic mixer with a mixer noise temperature of 3,000 K DSB (double sideband) and mixer conversion loss of 11.8 dB DSB; a high-efficiency frequency tripler design with peak output power of 23 mW and 14 mW, and efficiency of 16 and 13 percent, respectively; millimeter-wave integrated circuit (MMIC) power amplifiers to the 30-40 GHz band with high DC power efficiency; and an 874-GHz radiometer suitable for airborne observation with state-of-the-art sensitivity at room temperature and less than 5 W of total power consumption.

  13. Testosterone Replacement Therapy: The Emperor's New Clothes.

    PubMed

    Sansone, Andrea; Sansone, Massimiliano; Lenzi, Andrea; Romanelli, Francesco

    2017-02-01

    The mean age of the world population has steadily increased in the last decades, as a result of increased life expectancy and reduced birth rate. Global aging has led to a greater worldwide cost for healthcare: hormonal alterations contribute to the pathogenesis of several conditions and might cause a significant reduction in the perceived sense of well-being. Menopause is archetypal of hormonal alterations occurring during aging: in males, sex hormones do not decrease abruptly, yet testosterone levels decrease steadily and continuously during aging, ultimately resulting in late-onset hypogonadism. Treatment of this condition might mitigate most symptoms; however, testosterone replacement therapy (TRT) should be prescribed only in selected patients and it should not be considered as an antiaging treatment. In recent years, different authors have questioned health risks associated with testosterone treatment; while position statements from many scientific societies seem to be reassuring, the Food and Drug Administration has issued a warning in regard to the possible side effects of this therapy. We aim to review recent controversies and discoveries in regard to TRT.

  14. Can smartwatches replace smartphones for posture tracking?

    PubMed

    Mortazavi, Bobak; Nemati, Ebrahim; VanderWall, Kristina; Flores-Rodriguez, Hector G; Cai, Jun Yu Jacinta; Lucier, Jessica; Naeim, Arash; Sarrafzadeh, Majid

    2015-10-22

    This paper introduces a human posture tracking platform to identify the human postures of sitting, standing or lying down, based on a smartwatch. This work develops such a system as a proof-of-concept study to investigate a smartwatch's ability to be used in future remote health monitoring systems and applications. This work validates the smartwatches' ability to track the posture of users accurately in a laboratory setting while reducing the sampling rate to potentially improve battery life, the first steps in verifying that such a system would work in future clinical settings. The algorithm developed classifies the transitions between three posture states of sitting, standing and lying down, by identifying these transition movements, as well as other movements that might be mistaken for these transitions. The system is trained and developed on a Samsung Galaxy Gear smartwatch, and the algorithm was validated through a leave-one-subject-out cross-validation of 20 subjects. The system can identify the appropriate transitions at only 10 Hz with an F-score of 0.930, indicating its ability to effectively replace smart phones, if needed.

  15. [SECOT consensus on painful knee replacement].

    PubMed

    Vaquero, J; Macule, F; Bello, S; Chana, F; Forriol, F

    2013-01-01

    The opinions of 21 experts in knee surgery were evaluated in this study, using a DELPHI questionnaire method in two successive rounds, on 64 controversial scenarios that covered both the diagnosis and possible treatment of painful knee replacements. The level of consensus was significantly unanimous in 42 items and of the design in 5, with no agreement in 17 of the questions presented. light of the published scientific evidence, the surgeons who took part showed to have a notable level of information on the most effective diagnostic tests, although, it should be pointed out that there was a lack of confidence in the possibility of ruling out an infection when the erythrocyte sedimentation rate and the C-reactive protein were within normal values, which have been demonstrated in the literature to have a high negative predictive value As regards the treatments to employ in the different situations, the responses of the expert panel were mainly in agreement with the data in the literature. The conclusions of this consensus may help other surgeons when they are faced with a painful knee prosthesis.

  16. The quest for physiologic insulin replacement.

    PubMed

    Owens, David R

    2004-11-01

    Historically, the objective of insulin replacement has been to simulate the 2 major components of insulin secretion in individuals without diabetes mellitus: the low-level basal secretion during the night and periods of fasting, and the prandial secretion in response to food intake. The variable pharmacokinetic and pharmacodynamic characteristics of conventional insulin preparations have made mimicking these physiologic profiles virtually impossible. Balancing the effects of diet, exercise, and the numerous factors contributing to intra- and inter-individual variations in insulin absorption and action, such as type, site of injection, and dosage of insulin, while avoiding the very serious side effect of hypoglycemia in seeking normoglycemia, presents a further challenge. Recently, these limitations have been addressed by recombinant DNA-mediated development of insulin analogues, such as rapid-acting insulin lispro, aspart and glulisine, and the long-acting insulin preparations, insulin glargine and detemir. The molecular structures of these analogues have produced time-action profiles that better approach prandial and basal insulin secretion, thus allowing for easier, safer, and more flexible treatment regimens.

  17. 3D Model of Surfactant Replacement Therapy

    NASA Astrophysics Data System (ADS)

    Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel

    2015-11-01

    Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.

  18. Andropause. Testosterone replacement therapy for aging men.

    PubMed Central

    Bain, J.

    2001-01-01

    OBJECTIVE: To review the rationale for treating symptomatic aging men whose testosterone levels are mildly reduced or low-normal with testosterone replacement therapy. QUALITY OF EVIDENCE: Large-scale multicentre prospective studies on the value of treating andropausal men with hormone therapy do not exist because the whole area of hormone therapy is barely 10 years old. Evidence presented is based on physiologic studies, particularly studies in which treatment has been assessed. These were largely uncontrolled open studies. Studies to date report positive responses to testosterone treatment with very few serious side effects. MAIN MESSAGE: Physicians should consider hypoandrogenism if male patients complain of loss of libido, erectile dysfunction, weakness, fatigue, lethargy, loss of motivation, or mood swings. Less obvious associations with reduced levels of testosterone are anemia and osteoporosis. The main cause of reduced testosterone production is primary gonadal insufficiency, but secondary causes, such as hypothalamic-pituitary disease, should be considered. Evidence shows that most men treated with testosterone will feel better about themselves and their lives. CONCLUSION: Andropause is a term of convenience describing a complex of symptoms in aging men who have low testosterone levels. Physicians should be aware of its existence, should consider ordering tests for men who have symptoms, and should treat carefully selected patients whose serum testosterone levels are low. PMID:11212438

  19. Constrained Implants in Total Knee Replacement.

    PubMed

    Touzopoulos, Panagiotis; Drosos, Georgios I; Ververidis, Athanasios; Kazakos, Konstantinos

    2015-05-01

    Total knee replacement (TKR) is a successful procedure for pain relief and functional restoration in patients with advanced osteoarthritis. The number of TKRs is increasing, and this has led to an increase in revision surgeries. The key to long-term success in both primary and revision TKR is stability, as well as adequate and stable fixation between components and underlying bone. In the vast majority of primary TKRs and in some revision cases, a posterior cruciate retaining or a posterior cruciate substituting device can be used. In some primary cases with severe deformity or ligamentous instability and in most of the revision cases, a more constrained implant is required. The purpose of this paper is to review the literature concerning the use of condylar constrained knee (CCK) and rotating hinge (RH) implants in primary and revision cases focusing on the indications and results. According to this review, although excellent and very good results have been reported, there are limitations of the existing literature concerning the indications for the use of constrained implants, the absence of long-term results, and the limited comparative studies.

  20. Nonclinical Development of BCG Replacement Vaccine Candidates.

    PubMed

    Velmurugan, Kamalakannan; Grode, Leander; Chang, Rosemary; Fitzpatrick, Megan; Laddy, Dominick; Hokey, David; Derrick, Steven; Morris, Sheldon; McCown, David; Kidd, Reginald; Gengenbacher, Martin; Eisele, Bernd; Kaufmann, Stefan H E; Fulkerson, John; Brennan, Michael J

    2013-04-16

    The failure of current Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccines, given to neonates to protect against adult tuberculosis and the risk of using these live vaccines in HIV-infected infants, has emphasized the need for generating new, more efficacious and safer replacement vaccines. With the availability of genetic techniques for constructing recombinant BCG (rBCG) strains containing well-defined gene deletions or insertions, new vaccine candidates are under evaluation at both the preclinical and clinical stages of development. Since most BCG vaccines in use today were evaluated in clinical trials decades ago and are produced by outdated processes, the development of new BCG vaccines offers a number of advantages that include a modern well-defined manufacturing process along with state-of-the-art evaluation of safety and efficacy in target populations. We provide a description of the preclinical development of two novel rBCGs, VPM1002 that was constructed by adding a modified hly gene coding for the protein listeriolysin O (LLO) from Listeria monocytogenes and AERAS-422, which carries a modified pfoA gene coding for the protein perfringolysin O (PFO) from Clostridium perfringens, and three genes from Mycobacterium tuberculosis. Novel approaches like these should be helpful in generating stable and effective rBCG vaccine candidates that can be better characterized than traditional BCG vaccines.