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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

    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.

  2. 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

  3. Circumferential shaft seal

    NASA Technical Reports Server (NTRS)

    Ludwig, L. P. (Inventor)

    1981-01-01

    A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band is disclosed. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

  4. Circumferential shaft seal

    NASA Technical Reports Server (NTRS)

    Ludwig, L. P. (Inventor)

    1980-01-01

    A circumferential shaft seal is described which comprises two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

  5. Computer simulation of PPF distribution under blue and red LED light source for plant growth.

    PubMed

    Takita, S; Okamoto, K; Yanagi, T

    1996-12-01

    The superimposed pattern of "luminescence spectrum of blue light emitting diode (LED)" and "that of red LED", corresponds well to light absorption spectrum of chlorophyll. If these two kinds of LED are used as a light source, various plant cultivation experiments are possible. The cultivation experiments which use such light sources are becoming increasingly active, and in such experiments, it is very important to know the distribution of the photosynthetic photon flux (PPF) which exerts an important influence on photosynthesis. Therefore, we have developed a computer simulation system which can visualize the PPF distribution under a light source equipped with blue and red LEDs. In this system, an LED is assumed to be a point light source, and only the photons which are emitted directly from LED are considered. This simulation system can display a perspective view of the PPF distribution, a transverse and a longitudinal section of the distribution, and a contour map of the distribution. Moreover, a contour map of the ratio of the value of the PPF emitted by blue LEDs to that by blue and red LEDs can be displayed. As the representation is achieved by colored lines according to the magnitudes of the PPF in our system, a user can understand and evaluate the state of the PPF well.

  6. Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification.

    PubMed

    Lan, Phung Xuan; Lee, Jin Woo; Seol, Young-Joon; Cho, Dong-Woo

    2009-01-01

    Poly(propylene fumarate) (PPF) is an ultraviolet-curable and biodegradable polymer with potential applications for bone regeneration. In this study, we designed and fabricated three-dimensional (3D) porous scaffolds based on a PPF polymer network using micro-stereolithography (MSTL). The 3D scaffold was well fabricated with a highly interconnected porous structure and porosity of 65%. These results provide a new scaffold fabrication method for tissue engineering. Surface modification is a commonly used and effective method for improving the surface characteristics of biomaterials without altering their bulk properties that avoids the expense and long time associated with the development of new biomaterials. Therefore, we examined surface modification of 3D scaffolds by applying accelerated biomimetic apatite and arginine-glycine-aspartic acid (RGD) peptide coating to promote cell behavior. The apatite coating uniformly covered the scaffold surface after immersion for 24 h in 5-fold simulated body fluid (5SBF) and then the RGD peptide was applied. Finally, the coated 3D scaffolds were seeded with MC3T3-E1 pre-osteoblasts and their biologic properties were evaluated using an MTS assay and histologic staining. We found that 3D PPF/diethyl fumarate (DEF) scaffolds fabricated with MSTL and biomimetic apatite coating can be potentially used in bone tissue engineering.

  7. Ultrasound catheters for circumferential cardiac ablation

    NASA Astrophysics Data System (ADS)

    Diederich, Chris J.; Nau, William H.; Taylor, Kevin; Maguire, Mark T.; Picazo, Guillermo; Gangu, Madhuri; Lesh, Michael D.

    1999-05-01

    The purpose of this study was to investigate performance characteristics of a catheter-based ultrasound applicator intended for circumferential ablation of cardiac tissue. The catheter design integrates a cylindrical ultrasound transducer within a distendable water filled balloon in order to produce circumferential lesions at sites in the atria (i.e., pulmonary vein ostia), intended for treatment of certain atrial arrhythmias. Biothermal simulations were used to investigate thermal lesion depths corresponding to variations in applied power, duration, balloon diameter, and acoustic efficiency. Prototype applicators of varying frequency (7 - 12 MHz) and balloon diameter were constructed and characterized using measurements of acoustic efficiency and rotational beam plots. In vitro studies were performed in freshly excised beef hearts to characterize the radial penetration, axial length, and angular uniformity of thermal lesions produced by these applicators. Selected applicators were tested in vivo within pulmonary veins, coronary sinus, and atrial appendage of canine and porcine hearts. These preliminary efforts have indicated that circumferential ablation of cardiac tissue using ultrasound balloon catheters is feasible, and devices between 7 - 12 MHz with balloon diameters of 1.5 - 2.0 cm are capable of producing uniform lesions between 1 - 5 mm depth or greater for treatment durations of 120 seconds or less.

  8. Circumferential truncal contouring: the belt lipectomy.

    PubMed

    Aly, Al; Mueller, Melissa

    2014-10-01

    The primary goal of belt lipectomy surgery is to improve the contour of the inferior truncal circumferential unit and to place the resultant scar in natural junctions. Excessive intra-abdominal content is a contraindication for belt lipectomy. The higher the presenting patient's body mass index (BMI), the higher the risk of postoperative complications and the less impressive the results. The converse is also true: the lower the BMI, the lower the risk of complications and the better the results. The most common complications are small wound separations and seromas.

  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. Device for identifying a circumferential position

    DOEpatents

    Mikesell, Charles R.

    1985-01-01

    A device is described which accurately and reproducibly identifies points on the circumference of a non-vertical pipe for use as reference marks for pipe inspections. The device comprises a light-permeable disk-shaped chamber having a plurality of pockets spaced about its circumference, a light source transmitting a beam of light through the chamber, and a light-activated switch positioned to detect the light beam. The chamber contains a freely moving ball sized to be retained by the pockets. The device is mounted to revolve about the axis of the pipe. As it revolves the ball moves from one pocket of the chamber to another, interrupting the beam of light and triggering the light-activated switch, thereby indicating that the device has passed to a pre-selected circumferential position on the non-vertical pipe.

  11. Device for identifying a circumferential position

    DOEpatents

    Mikesell, C.R.

    1982-06-29

    A device is described which accurately and reproducibly identifies points on the circumference of a non-vertical pipe for use as reference marks for pipe inspections. The device comprises a light-permeable disk-shaped chamber having a plurality of pockets spaced about its circumference, a light source transmitting a beam of light through the chamber, and a light-activated switch positioned to detect the light beam. The chamber contains a freely moving ball sized to be retained by the pockets. The device is mounted to revolve about the axis of the pipe. As it revolves the ball moves from one pocket of the chamber to another, interrupting the beam of light and triggering the light-activated switch, thereby indicating that the device has passed to a pre-selected circumferential position on the non-vertical pipe.

  12. CIRCUMFERENTIAL MFL IN-LINE INSPECTION FOR CRACKS IN PIPELINES

    SciTech Connect

    J.B. Nestleroth

    2003-06-01

    Circumferential MFL is a new implementation of a widely used technology that has potential to provide improved detection and quantification of axially oriented defects such as cracks, seam weld defects, mechanical damage, and groove corrosion. This implementation works by orienting the magnetic field around the pipe rather that along the axis. By orienting the magnetic field around the pipe (the circumferential direction), the axial defects that were magnetically transparent can disrupt more of the magnetic field and can be more easily detected. Initial implementations of circumferential MFL have found that flux leakage from cracks at the interior of the pipe is small, and the signals from cracks are difficult to detect. The objective of this project is to improve detection of cracks by changing the implementation along with using data from overlapping and complementary inspection techniques. Two technology enhancements were investigated: Combining high- and low-magnetization technology for stress detection; and Combining axial and circumferential MFL methods. Although a method combining high- and low-magnetization technology showed promise for characterizing gouges cause by third party excavation equipment, its commercial development was not successful for two reasons. First, the stress diminishes the crack signal, while the opening of the crack increases the signal. The stress-induced changes in flux leakage around cracks were small and any critical information on the severity of cracks and crack-like defects is difficult to distinguish from changes caused by the crack opening and other inspection variables. Second, it is difficult to magnetize pipe material in the circumferential direction. A relatively low, non-uniform magnetization level produced by the circumferential magnetizer makes detection of changes due to stress extremely difficult. This project also examined combining axial and circumferential MFL to improve crack detection and distinguish cracks for

  13. 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

  14. Characterization of the temperate phage vB_RleM_PPF1 and its site-specific integration into the Rhizobium leguminosarum F1 genome.

    PubMed

    Halmillawewa, Anupama P; Restrepo-Córdoba, Marcela; Perry, Benjamin J; Yost, Christopher K; Hynes, Michael F

    2016-02-01

    Bacteriophages may play an important role in regulating population size and diversity of the root nodule symbiont Rhizobium leguminosarum, as well as participating in horizontal gene transfer. Although phages that infect this species have been isolated in the past, our knowledge of their molecular biology, and especially of genome composition, is extremely limited, and this lack of information impacts on the ability to assess phage population dynamics and limits potential agricultural applications of rhizobiophages. To help address this deficit in available sequence and biological information, the complete genome sequence of the Myoviridae temperate phage PPF1 that infects R. leguminosarum biovar viciae strain F1 was determined. The genome is 54,506 bp in length with an average G+C content of 61.9 %. The genome contains 94 putative open reading frames (ORFs) and 74.5 % of these predicted ORFs share homology at the protein level with previously reported sequences in the database. However, putative functions could only be assigned to 25.5 % (24 ORFs) of the predicted genes. PPF1 was capable of efficiently lysogenizing its rhizobial host R. leguminosarum F1. The site-specific recombination system of the phage targets an integration site that lies within a putative tRNA-Pro (CGG) gene in R. leguminosarum F1. Upon integration, the phage is capable of restoring the disrupted tRNA gene, owing to the 50 bp homologous sequence (att core region) it shares with its rhizobial host genome. Phage PPF1 is the first temperate phage infecting members of the genus Rhizobium for which a complete genome sequence, as well as other biological data such as the integration site, is available. PMID:26377943

  15. Coronary artery circumferential stress: departure from Laplace expectations with aging.

    PubMed

    Tracy, Richard E; Eigenbrodt, Marsha L

    2009-09-15

    Normal, youthful arteries generally maintain constant radius/wall thickness ratios, with the relationship being described by the Laplace Law. Whether this relationship is maintained during aging is unclear. This study first examines the Laplace relationships in postmortem coronary arteries using a novel method to correct measurements for postmortem artifacts, uses data from the literature to provide preliminary validation, and then describes histology associated with low circumferential stress. Measurements of radius and wall thickness, taken at sites free from atheromas, were used with national population estimates of age-, gender-, and race-specific blood pressure data to calculate average circumferential stress within demographic groups. The estimated circumferential stress at ages 55-74 years was about half that at ages 18-24 years because of a disproportionate increase of wall thickness relative to artery radius at older ages, violating the expected relationships described by the Laplace Law. Arteries with low circumferential stress (estimated at sites distant from atherosclerosis) had more necrotic atheromas than arteries with high stress. At sites with low stress and intimal thickening, smooth muscle cells (SMCs) were spread apart, thereby diminishing their density within both the intima and media. Thus, older arteries displayed both low circumferential stress and abundant matrix of low cellularity microscopically. Such changes might alter SMC-matrix interactions.

  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. Tubular Hydrogels of Circumferentially Aligned Nanofibers to Encapsulate and Orient Vascular Cells

    PubMed Central

    McClendon, Mark T.; Stupp, Samuel I.

    2012-01-01

    There is a great clinical need for tissue engineered blood vessels that could be used to replace or bypass damaged arteries. The success of such grafts will depend strongly on their ability to mimic the cellular and matrix organization found in native arteries, but currently available cell scaffolds such as electrospun fibers or hydrogels lack the ability to simultaneously encapsulate and align cells. Our laboratory has recently developed liquid crystalline solutions of peptide amphiphile nanofibers that form aligned domains at exceedingly low concentrations (<1wt%), and can be trapped as gels with macroscopic alignment using low shear rates and ionic crosslinking. We describe here the use of these systems to fabricate tubes with macroscopic circumferential alignment and demonstrate their potential as arterial cell scaffolds. The nanofibers in these tubes were circumferentially aligned by applying small amounts of shear in a custom built flow chamber prior to gelation. Small angle X-ray scattering confirmed that the direction of nanofiber alignment was the same as the direction of shear flow. We also show the encapsulation of smooth muscle cells during the fabrication process without compromising cell viability. After two days in culture the encapsulated cells oriented their long axis in the direction of nanofiber alignment thus mimicking the circumferential alignment seen in native arteries. Cell density roughly doubled after 12 days demonstrating the scaffold’s ability to facilitate necessary graft maturation. Since these nanofiber gels are composed of >99% water by weight, the cells have abundant room for proliferation and remodeling. In contrast to previously reported arterial cell scaffolds, this new material can encapsulate cells and direct cellular organization without the requirement of external stimuli or gel compaction. PMID:22591610

  18. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 178.345-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... subchapter). (2) Where circumferential joints are made between conical shell sections, or between conical and... reinforcement must be located within one inch of the shell joint, unless otherwise reinforced with...

  19. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 178.345-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... subchapter). (2) Where circumferential joints are made between conical shell sections, or between conical and... reinforcement must be located within one inch of the shell joint, unless otherwise reinforced with...

  20. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 178.345-7 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... subchapter). (2) Where circumferential joints are made between conical shell sections, or between conical and... reinforcement must be located within one inch of the shell joint, unless otherwise reinforced with...

  1. Ultransonic circumferential waves in empty and water- filled tubes

    NASA Astrophysics Data System (ADS)

    Li, Xing

    Ultrasonic waves propagating in the circumference of elastic isotropic cylindrical shells are theoretically and experimentally studied. Dispersion relations of different circumferential modes, including the SH-type and Lamb-type families, are obtained by solving the wave equations numerically. Asymptotic solutions are also given for the SH-like modes. Various technologies are applied for generating and detecting the circumferential waves. In particular, a new approach is developed for experimental determination of the dispersion of the circumferential waves in cylindrical shells. With a chirp interdigital transducer (IDT) as a broadband transmitter and receiver made on a stainless steel tube coated with piezoelectric film, both the group and phase velocities of the circumferential waves are obtained over a wide frequency range, which covers the most sensitive region of the lowest flexural mode. Other transduction approaches are also used as complementary tools in the experiments. Experiments are carried out on both empty and fluid- loaded cylindrical shells at different frequencies. With the specially developed experimental configuration, propagation of a new flexural wave type in a water-filled tube is observed. Mode conversions are also observed between the A 0 mode in the shell and the compressional waves in the water. The results show good application potentials in liquid level sensing.

  2. 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 aluminum alloys; Where: I/C = Section modulus in inches 3 W = Tank width, or diameter, inches L = Spacing of...

  3. 49 CFR 178.345-7 - Circumferential reinforcements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) 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 aluminum alloys; Where: I/C = Section modulus in inches 3 W = Tank width, or diameter, inches L = Spacing of...

  4. Replace Double Replacement

    NASA Astrophysics Data System (ADS)

    Martin, R. Bruce

    1999-01-01

    Reactions described as double replacements in high school texts are poorly described by this designation. The driving force for such reactions is precipitation of a solid derived from ions in solution or the production of water in acid-base reactions.

  5. 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).

  6. 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.

  7. 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.

  8. Replacing London's cast iron mains

    SciTech Connect

    Thorne, A. ); Mathews, P. )

    1992-07-01

    This paper discusses the cast iron gas distribution systems that exist in many cities and contains considerable amounts of pipe that vary in age from 20 to 150 years. In many ways, cast iron is an excellent material. It is inherently corrosion resistant, easy to install and cheap. However, it is also brittle and smaller diameter cast iron pipe has a relatively low beam strength. This can lead, under some circumstances, to failure without external warning, with typically a full-circumferential failure. In congested areas this can lead to serious consequences. As a result, cast iron replacement programs are a common feature in such urban gas distribution systems.

  9. 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.

  10. 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.

  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. Hip Replacement

    MedlinePlus

    ... surgeon removes damaged cartilage and bone from your hip joint and replaces them with new, man-made parts. A hip replacement can Relieve pain Help your hip joint work better Improve walking and other movements The ...

  13. Ankle replacement

    MedlinePlus

    Ankle arthroplasty - total; Total ankle arthroplasty; Endoprosthetic ankle replacement; Ankle surgery ... You may not be able to have a total ankle replacement if you have had ankle joint infections ...

  14. Knee Replacement

    MedlinePlus

    Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

  15. Estimation of circumferential fiber shortening velocity by echocardiography.

    PubMed

    Ruschhaupt, D G; Sodt, P C; Hutcheon, N A; Arcilla, R A

    1983-07-01

    The M-mode and two-dimensional echocardiograms of 40 young patients were analyzed to compare the mean circumferential fiber shortening velocity (Vcf) of the left ventricle calculated separately by two methods. The mean circumferential fiber shortening velocity was derived from the M-mode echocardiogram as minor axis shortening/ejection time and derived from the two-dimensional echocardiogram as actual circumference change/ejection time. With computer assistance, circumference was determined from the short-axis two-dimensional echocardiographic images during end-diastole and end-systole. Good correlations were obtained between the left ventricular diameter derived by M-mode echocardiography and the vertical axis during end-diastole (r = 0.79) and end-systole (r = 0.88) derived by two-dimensional echocardiography. Likewise, high correlations were noted between diameter and circumference in end-diastole (r = 0.89) and end-systole (r = 0.88). However, comparison of Vcf obtained by M-mode echocardiography with that obtained by two-dimensional echocardiography showed only fair correlation (r = 0.68). Moreover, the diameter/circumference ratio determined in end-diastole and end-systole differed significantly (p less than 0.001), possibly owing to the change in geometry of the ventricular sector image during systole. Although Vcf derived by M-mode echocardiography is a useful index of left ventricular performance, it does not truly reflect the circumference change during systole.

  16. Complete 360° circumferential SSOCT gonioscopy of the iridocorneal angle

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    The ocular iridocorneal angle is generally an optically inaccessible area when viewed directly through the cornea due to the high angle of incidence required and the large index of refraction difference between air and cornea (nair = 1.000 and ncornea = 1.376) resulting in total internal reflection. Gonioscopy allows for viewing of the angle by removing the aircornea interface through the use of a special contact lens on the eye. Gonioscopy is used clinically to visualize the angle directly but only en face. Optical coherence tomography (OCT) has been used to image the angle and deeper structures via an external approach. Typically, this imaging technique is performed by utilizing a conventional anterior segment OCT scanning system. However, instead of imaging the apex of the cornea, either the scanner or the subject is tilted such that the corneoscleral limbus is orthogonal to the optical axis of the scanner requiring multiple volumes to obtain complete circumferential coverage of the ocular angle. We developed a novel gonioscopic OCT (GOCT) system that images the entire ocular angle within a single volume via an "internal" approach through the use of a custom radially symmetric gonioscopic contact lens. We present, to our knowledge, the first complete 360° circumferential volumes of the iridocorneal angle from a direct, internal approach.

  17. Stresses and deformations in composite tubes due to a circumferential temperature gradient

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Cooper, D. E.

    1986-01-01

    A linear elasticity solution for determining the response of composite tubes subjected to a circumferential temperature gradient is presented. Numerical examples are used to show that, in a single layer tube, fiber orientation strongly influences response. When the fibers are aligned axially, all stress components in the tube are small. When the fibers are aligned circumferentially, the hoop stress becomes large. This difference in behavior is due to the large difference between the radial and circumferential coefficients of thermal expansion when the fibers are oriented circumferentially. In multilayer tubes, stresses are quite high and just two constants characterize the overall bending and axial deformations of the tubes.

  18. Transient thermal stress problem for a circumferentially cracked hollow cylinder

    NASA Technical Reports Server (NTRS)

    Nied, H. F.; Erdogan, F.

    1982-01-01

    The transient thermal stress problem for a hollow elasticity cylinder containing an internal circumferential edge crack is considered. It is assumed that the problem is axisymmetric with regard to the crack geometry and the loading, and that the inertia effects are negligible. The problem is solved for a cylinder which is suddenly cooled from inside. First the transient temperature and stress distributions in an uncracked cylinder are calculated. By using the equal and opposite of this thermal stress as the crack surface traction in the isothermal cylinder the crack problem is then solved and the stress intensity factor is calculated. The numerical results are obtained as a function of the Fourier number tD/b(2) representing the time for various inner-to-outer radius ratios and relative crack depths, where D and b are respectively the coefficient of diffusivity and the outer radius of the cylinder.

  19. Transient thermal stress problem for a circumferentially cracked hollow cylinder

    NASA Technical Reports Server (NTRS)

    Nied, H. F.; Erdogan, F.

    1983-01-01

    The paper is concerned with the transient thermal stress problem for a long hollow circular cylinder containing an internal axisymmetric circumferential edge crack that is suddenly cooled from inside. It is assumed that the transient thermal stress problem is quasi-static, i.e., the inertial effects are negligible. Also, all thermoelastic coupling effects and the possible temperature dependence of the thermoelastic constants are neglected. The problem is considered in two parts. The first part is the evaluation of transient thermal stresses in an uncracked cylinder; the second part is the isothermal perturbation problem for the cracked cylinder in which the crack surface tractions, equal and opposite to the thermal stresses obtained from the first problem, are the only external loads. The superposition of the two solutions gives results for the cracked cylinder.

  20. Stator-Induced Circumferentially-Varying Preswirl Propulsor

    NASA Astrophysics Data System (ADS)

    Farnsworth, John; Amitay, Michael; Beal, David; Huyer, Stephen

    2008-11-01

    A propuslor capable of producing maneuvering forces in all directions effectively eliminates the need for additional control surfaces. Side forces can be generated by the propeller through the variation of the inflow swirl velocity to a conventional propeller. These control forces are generated based on the same geometric principles as a helicopter swash-plate. Instead of cyclically adjusting the propeller blade pitch angle, the relative pitch angle of a fixed pitch propeller is cyclically altered through a preswirled inflow generated by an upstream stator row. Experiments were conducted in a wind tunnel to quantify the effectiveness of an upstream stator row to generate a circumferentially varying swirled flow. Global flow measurements were acquired through static pressure and PIV measurements on a simplified propulsor model. From these and future measurements a full understanding of the fluidic interactions associated with the non-uniform upstream stator row and the propeller can be made.

  1. The relative impact of circumferential and longitudinal shortening on left ventricular ejection fraction and stroke volume

    PubMed Central

    MacIver, David H

    2012-01-01

    In vivo data have been unable to provide conclusive results with regard to the relative impact of circumferential and longitudinal shortening on stroke volume. The objective of the present study was to assess the relative contribution of circumferential and longitudinal myocardial shortening to left ventricular stroke volume and ejection fraction, and to evaluate the effect of left ventricular hypertrophy. A two-shell, three-dimensional mathematical model was used to assess the individual contributions of longitudinal and midwall circumferential shortening (or strain) to stroke volume and ejection fraction. Reducing either circumferential or longitudinal shortening resulted in a reduced ejection fraction and stroke volume. The stroke volume fell by 43% when circumferential strain was reduced from −20% to −5%, but only by 19% when longitudinal strain was similarly reduced. The sole contribution of circumferential and longitudinal shortening to stroke volume was 67% and 33%, respectively. These proportions were independent of wall thickness. The present study demonstrated that both longitudinal and midwall circumferential shortening contribute to different extents depending on the degree of abnormality of myocardial shortening. Contrary to most previous studies, the present study shows that circumferential shortening has a relatively greater contribution to stroke volume (ie, two-thirds) and ejection fraction than longitudinal shortening. These observations have important clinical and research implications in the assessment of left ventricular function. PMID:23204893

  2. The use of circumferentially varying stagger guide vanes in an axial flow pump or compressor

    NASA Astrophysics Data System (ADS)

    Horlock, J. H.

    1990-04-01

    An actuator disk analysis is given of the flow through a guide vane and rotor combination. It is shown that changes in total pressure across the rotor are, in general, related to circumferential variations in guide vane outlet angle. In particular, known variations in inlet total pressure may be eliminated by suitable circumferential changes in guide vane stagger.

  3. 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.

  4. 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.

  5. 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

    Ma, Jie; Luo, Yu; Ge, Lilin; Wang, Lei; Zhou, Mei; Zhang, Yingqi; Duan, Jinao; Chen, Tianbao; 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Free flap transplantation combined with skin grafting and vacuum sealing drainage for repair of circumferential or sub-circumferential soft-tissue wounds of the lower leg

    PubMed Central

    Li, Run-guang; Ren, Gao-hong; Tan, Xiong-jin; Yu, Bin; Hu, Ji-jie

    2013-01-01

    Background This study is aimed at evaluating the operation techniques and clinical significance of free flap transplantation combined with skin grafting and vacuum sealing drainage (VSD) in repairing severe traumatic extensive circumferential or semi-circumferential soft-tissue defects of the lower leg. Material/Methods Thirty patients with severe lower leg injuries were treated by free flap transplantation combined with skin grafting and VSD from January 2008 to June 2011. The size of the wounds ranged from 23×8 cm to 44×28 cm and all affected more 70% of the low leg circumferential area. Wounds were complicated by exposure, necrosis, or infection of deep tissues. The wounds were first debrided and covered by VSD. When the condition of the wound had improved (5 to 7 days later), free flaps were harvested to reconstruct damaged tissue and skin grafts and VSD was used to cover granulation tissues around the transplanted flap. Results Granulation tissues developed and the area requiring flap cover decreased in all 30 patients after debridement and VSD. In 28 of 30 cases, the transplanted flaps grew well without complication. Peripheral necrosis was observed in only 2 cases, which required a second debridement and skin graft. Ten wound areas covered by grafts were left with scattered peripheral wounds, which healed with the help of 1 more skin graft or dressing change. Morphological appearance and functional recovery were satisfactory in all 30 cases. Conclusions Initial debridement and the temporary VSD cover followed after several days by free flap transplantation combined with skin grafting and VSD protection is a reliable treatment regimen for traumatic large circumferential or sub-circumferential soft tissue wounds of the lower leg with deep tissue exposure. PMID:23807087

  11. Accelerated circumferential strain quantification of the left ventricle using CIRCOME: simulation and factor analysis

    NASA Astrophysics Data System (ADS)

    Moghaddam, Abbas N.; Finn, J. Paul

    2008-03-01

    Circumferential strain of the left ventricle reflects myocardial contractility and is considered a key index of cardiac function. It is also an important parameter in the quantitative evaluation of heart failure. Circumferential compression encoding, CIRCOME, is a novel method in cardiac MRI to evaluate this strain non-invasively and quickly. This strain encoding technique avoids the explicit measurement of the displacement field and does not require calculation of strain through spatial differentiation. CIRCOME bypasses these two time-consuming and noise sensitive steps by directly using the frequency domain (k-space) information from radially tagged myocardium, before and after deformation. It uses the ring-shaped crown region of the k-space, generated by the taglines, to reconstruct circumferentially compression-weighted images of the heart before and after deformation. CIRCOME then calculates the circumferential strain through relative changes in the compression level of corresponding regions before and after deformation. This technique can be implemented in 3D as well as 2D and may be employed to estimate the overall global or regional circumferential strain. The main parameters that affect the accuracy of this method are spatial resolution, signal to noise ratio, eccentricity of the center of radial taglines their fading and their density. Also, a variety of possible image reconstruction and filtering options may influence the accuracy of the method. This study describes the pulse sequence, algorithm, influencing factors and limiting criteria for CIRCOME and provides the simulated results.

  12. Correlation between longitudinal, circumferential, and radial moduli in cortical bone: effect of mineral content.

    PubMed

    Macione, J; Depaula, C A; Guzelsu, N; Kotha, S P

    2010-07-01

    Previous studies indicate that changes in the longitudinal elastic properties of bone due to changes in mineral content are related to the longitudinal strength of bone tissue. Changes in mineral content are expected to affect bone tissue mechanical properties along all directions, albeit to different extents. However, changes in tissue mechanical properties along the different directions are expected to be correlated to one another. In this study, we investigate if radial, circumferential, and longitudinal moduli are related in bone tissue with varying mineral content. Plexiform bovine femoral bone samples were treated in fluoride ion solutions for a period of 3 and 12 days to obtain bones with 20% and 32% lower effective mineral contents. Transmission ultrasound velocities were obtained in the radial, circumferential, and longitudinal axes of bone and combined with measured densities to obtain corresponding tensorial moduli. Results indicate that moduli decreased with fluoride ion treatments and were significantly correlated to one another (r(2) radial vs. longitudinal = 0.80, r(2) circumferential vs. longitudinal = 0.90, r(2) radial vs. circumferential = 0.85). Densities calculated from using ultrasound parameters, acoustic impedance and transmission velocities, were moderately correlated to those measured by the Archimedes principle (r(2)=0.54, p<0.01). These results suggest that radial and circumferential ultrasound measurements could be used to determine the longitudinal properties of bone and that ultrasound may not be able to predict in vitro densities of bones containing unbonded mineral. PMID:20416555

  13. 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

  14. 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.

  15. A simple model simulating a fan as a source of axial and circumferential body forces

    SciTech Connect

    Tzanos, C. P.; Chien, T. H.

    2002-07-01

    This software can be used in a computational fluids dynamics (CFD) code to represent a fan as a source of axial and circumferential body forces. The combined software can be used effectively in car design analyses that involve many underhood thermal management simulations. FANMOD uses as input the rotational speed of the fan, geometric fan data, and the lift and drag coefficients of the blades, and predicts the body forces generated by the fan in the axial and circumferential directions. These forces can be used as momentum forces in a CFD code to simulate the effect of the fan in an underhood thermal management simulation.

  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. A simple model simulating a fan as a source of axial and circumferential body forces

    2002-07-01

    This software can be used in a computational fluids dynamics (CFD) code to represent a fan as a source of axial and circumferential body forces. The combined software can be used effectively in car design analyses that involve many underhood thermal management simulations. FANMOD uses as input the rotational speed of the fan, geometric fan data, and the lift and drag coefficients of the blades, and predicts the body forces generated by the fan inmore » the axial and circumferential directions. These forces can be used as momentum forces in a CFD code to simulate the effect of the fan in an underhood thermal management simulation.« less

  18. 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

  19. Code System for Fracture Mechanics Analysis of Circumferential Surface Cracks in Pipes.

    1999-07-28

    Version 00 The NRCPIPES software is designed to perform elastic and elastic-plastic fracture mechanics analysis for a circumferential surface cracked pipe, i.e., to establish the fracture-failure condition in terms of sustainable load (or stress) or displacement. The NRCPIPES software also includes several evaluation procedures and acceptance criteria for circumferential surface flaws based on the ASME Boiler and Pressure Vessel Code, Section XI criteria, the British R6 Revision 3 Option 1 criteria, and the original Net-Section-Collapsemore » (limit-load) analysis.« less

  20. [Estrogen replacement].

    PubMed

    Søgaard, A J; Berntsen, G K; Magnus, J H; Tollan, A

    1998-02-10

    Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

  1. Nicotine replacement therapy

    MedlinePlus

    Smoking cessation - nicotine replacement; Tobacco - nicotine replacement therapy ... Bullen C, et al. Nicotine replacement therapy for smoking cessation. Cochrane Database Syst Rev. 2012 Nov 14;11: ...

  2. Pulmonary vein isolation during atrial fibrillation using a circumferential cryoablation catheter.

    PubMed

    Rostock, Thomas; Weiss, Christian; Ventura, Rodolfo; Willems, Stephan

    2004-07-01

    Pulmonary vein (PV) isolation for the treatment of atrial fibrillation is limited by procedure related complications, such as PV stenosis and occlusions. We report about a PV isolation using a circumferential cryoablation catheter which applies the ablation energy simultaneously at the entire circumference by cooling down to a minimal temperature of -80 degrees C.

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

    PubMed

    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

    2016-08-01

    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 cm(2) 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

  4. 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%.

  5. 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.

  6. 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

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

    PubMed

    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

    2016-08-01

    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 cm(2) 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.

  8. New Approaches to Nondestructive Evaluation of a Filament-Wound Composite Motor Case Using Circumferential Wave

    NASA Astrophysics Data System (ADS)

    Song, Sung-Jin; Choe, Ji-Ung; Bae, Dong-Ho

    For reliable quality assurance of filament-wound composite rocket motor (FCRM) cases by use of acoustic emission during hydroproof (AE/H) testing, it is necessary both to detect defects introduced in fabrication process and to monitor damage done due to hydraulic pressurization. The circumferential wave, which has strong directivity and weak anisotropy in wave propagation in the particular FCRM case under present investigation, has high potential to address such a need. To explore these outstanding capabilities of the circumferential wave, two kinds of experiments were conducted. The pitch-catch measurements of the circumferential wave that propagated through the artificial slits demonstrated its high potential for detection of flaws. The experiments for AE source location using a particular, triangular layout of AE sensors declared its capability for monitoring of damages. Inspired from the experiments, new approaches to nondestructive evaluation of the given FCRM case were proposed using the circumferential wave: 1) an ultrasonic pitch-catch scanning and 2) an AE/H testing with a suitable triangular layout of AE sensors.

  9. 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.

  10. A strategy for designing multi-taxa specific reference gene systems. example of application--ppi phosphofructokinase (ppi-PPF) used for the detection and quantification of three taxa: maize (Zea mays), cotton (Gossypium hirsutum) and rice (Oryza sativa).

    PubMed

    Chaouachi, Maher; Giancola, Sandra; Romaniuk, Marcel; Laval, Valérie; Bertheau, Yves; Brunel, Dominique

    2007-10-01

    In the first part of the paper, we report the description of a new strategy for the development of a plant reference gene system that can be used for genetically modified organism (GMO) analysis. On the basis of in silico research for candidate genes, the design of degenerate primers allowed the obtention of genomic sequences of the selected gene ppi-phosphofructokinase ( ppi-PPF) for nine taxa in which GMOs have been developed. The comparison and the analysis of inter- and intraspecies sequence variability were performed using a large number of species and cultivars. As an example of application following the detection of single nucleotide polymorphism, we designed specific conventional and real-time polymerase chain reaction tests for the detection and quantification of three taxa, namely, maize, cotton, and rice. This system was highly specific and sensitive. The gene copy number conservation among different cultivars was analyzed and confirmed with a sequencing step. This reference gene system is adequate for use in routine assays for the quantification of GMOs. We then explain briefly the constraints faced and propose recommendations when designing a reference gene system depending on the species to be targeted. PMID:17824661

  11. A strategy for designing multi-taxa specific reference gene systems. example of application--ppi phosphofructokinase (ppi-PPF) used for the detection and quantification of three taxa: maize (Zea mays), cotton (Gossypium hirsutum) and rice (Oryza sativa).

    PubMed

    Chaouachi, Maher; Giancola, Sandra; Romaniuk, Marcel; Laval, Valérie; Bertheau, Yves; Brunel, Dominique

    2007-10-01

    In the first part of the paper, we report the description of a new strategy for the development of a plant reference gene system that can be used for genetically modified organism (GMO) analysis. On the basis of in silico research for candidate genes, the design of degenerate primers allowed the obtention of genomic sequences of the selected gene ppi-phosphofructokinase ( ppi-PPF) for nine taxa in which GMOs have been developed. The comparison and the analysis of inter- and intraspecies sequence variability were performed using a large number of species and cultivars. As an example of application following the detection of single nucleotide polymorphism, we designed specific conventional and real-time polymerase chain reaction tests for the detection and quantification of three taxa, namely, maize, cotton, and rice. This system was highly specific and sensitive. The gene copy number conservation among different cultivars was analyzed and confirmed with a sequencing step. This reference gene system is adequate for use in routine assays for the quantification of GMOs. We then explain briefly the constraints faced and propose recommendations when designing a reference gene system depending on the species to be targeted.

  12. 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.

  13. Nonlinear Analysis of Two-phase Circumferential Motion in the Ablation Circumstance

    NASA Astrophysics Data System (ADS)

    Xiao-liang, Xu; Hai-ming, Huang; Zi-mao, Zhang

    2010-05-01

    In aerospace craft reentry and solid rocket propellant nozzle, thermal chemistry ablation is a complex process coupling with convection, heat transfer, mass transfer and chemical reaction. Based on discrete vortex method (DVM), thermal chemical ablation model and particle kinetic model, a computational module dealing with the two-phase circumferential motion in ablation circumstance is designed, the ablation velocity and circumferential field can be thus calculated. The calculated nonlinear time series are analyzed in chaotic identification method: relative chaotic characters such as correlation dimension and the maximum Lyapunov exponent are calculated, fractal dimension of vortex bulbs and particles distributions are also obtained, thus the nonlinear ablation process can be judged as a spatiotemporal chaotic process.

  14. In vivo vascular wall shear rate and circumferential strain of renal disease patients.

    PubMed

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-02-01

    This study measures the vascular wall shear rate at the vessel edge using decorrelation based ultrasound speckle tracking. Results for nine healthy and eight renal disease subjects are presented. Additionally, the vascular wall shear rate and circumferential strain during physiologic pressure, pressure equalization and hyperemia are compared for five healthy and three renal disease subjects. The mean and maximum wall shear rates were measured during the cardiac cycle at the top and bottom wall edges. The healthy subjects had significantly higher mean and maximum vascular wall shear rate than the renal disease subjects. The key findings of this research were that the mean vascular wall shear rates and circumferential strain changes between physiologic pressure and hyperemia that was significantly different between healthy and renal disease subjects.

  15. Guided waves based diagnostic imaging of circumferential cracks in small-diameter pipe.

    PubMed

    Liu, Kehai; Wu, Zhanjun; Jiang, Youqiang; Wang, Yishou; Zhou, Kai; Chen, Yingpu

    2016-02-01

    To improve the safety and reliability of pipeline structures, much work has been done using ultrasonic guided waves methods for pipe inspection. Though good for evaluating the defects in the pipes, most of the methods lack the capability to precisely identify the defects in the pipe features like welds or supports. Therefore, a novel guided wave based cross-sectional diagnostic imaging algorithm was developed to improve the ability of circumferential cracks identification in the pipe features. To ensure the accuracy of the imaging, an angular profile-based frequency selection method is presented. As validation, the approach was employed to identify the presence and location of a small circumferential crack with 1.13% cross sectional area (CSA) in the welding zone of a 48 mm diameter type 304 stainless steel pipe. Accurate identification results have demonstrated the effectiveness of the developed approach.

  16. Circumferential temperature distribution during nucleate pool boiling outside smooth and modified horizontal tubes

    SciTech Connect

    Dominiczak, Przemyslaw R.; Cieslinski, Janusz T.

    2008-10-15

    In the work an approach to avoid a circumferential temperature distribution existing during nucleate pool boiling on a horizontal cylinder within low heat flux densities is presented. The idea of the approach is local heat transfer enhancement by a porous layer application on a part of the heating surface. An experiment on nucleate pool boiling heat transfer from horizontal cylinders to saturated R141b and water under atmospheric pressure is reported. Experiments have been conducted using stainless steel tubes with the outside diameter between 8 mm and 23 mm with the active length of 250 mm. The outside surface of the tubes was smooth or partially coated with a porous metallic layer. In particular, measurements of inside circumferential temperature distribution have been performed. (author)

  17. 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.

  18. Guided waves based diagnostic imaging of circumferential cracks in small-diameter pipe.

    PubMed

    Liu, Kehai; Wu, Zhanjun; Jiang, Youqiang; Wang, Yishou; Zhou, Kai; Chen, Yingpu

    2016-02-01

    To improve the safety and reliability of pipeline structures, much work has been done using ultrasonic guided waves methods for pipe inspection. Though good for evaluating the defects in the pipes, most of the methods lack the capability to precisely identify the defects in the pipe features like welds or supports. Therefore, a novel guided wave based cross-sectional diagnostic imaging algorithm was developed to improve the ability of circumferential cracks identification in the pipe features. To ensure the accuracy of the imaging, an angular profile-based frequency selection method is presented. As validation, the approach was employed to identify the presence and location of a small circumferential crack with 1.13% cross sectional area (CSA) in the welding zone of a 48 mm diameter type 304 stainless steel pipe. Accurate identification results have demonstrated the effectiveness of the developed approach. PMID:26548527

  19. 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.

  20. Selective radiofrequency therapy as a non-invasive approach for contactless body contouring and circumferential reduction.

    PubMed

    Fajkošová, Kateřina; Machovcová, Alena; Onder, Meltem; Fritz, Klaus

    2014-03-01

    In this study, the efficacy of non-contact, selective radiofrequency (RF) were evaluated for body contouring as non-invasive fat and circumferential reduction of the abdomen. 40 healthy (36 female, 4 male) subjects showing significant volume of subcutaneous fat tissue on the abdomen and waistline were included. Once a week for 30 minutes, 4 sessions were performed. The applicator was placed on a supplied spacer covering the treatment area. Maximum power was 200W, which induced heat in the fat and connective tissue layer. The homogeneity of heat distribution and temperature of the skin surface were controlled. The circumferential reduction was measured at the baseline and after the last treatment. The photographs and adverse effects were recorded. Participants completed the self-evaluation questionnaires and rated their level of satisfaction. All subjects tolerated the treatments well. The only side effect was mild to moderate erythema. 35 subjects finished the protocol as planned and 5 subjects dropped off due to events not related to the study. 32 subjects had a 1-13 cm decrease in abdominal circumference and 3 subjects did not show significant response (0-1 cm). Most likely, a very thin fat layer was the reason for lack of response (the non-responding group was the thinnest patient group). No significant differences were found between men and women. The average decrease of 4.93 cm was calculated as a result of circumferential reduction statistical evidence. This study demonstrates that the selective RF system designed for contactless deep tissue heating is a painless, safe, and effective treatment for non-surgical body contouring and circumferential fat reduction.

  1. Hip joint replacement

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002975.htm Hip joint replacement To use the sharing features on this page, please enable JavaScript. Hip joint replacement is surgery to replace all or part ...

  2. 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.

  3. 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

  4. 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.

  5. 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. PMID:24120039

  6. 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.

  7. 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

  8. Magnetic resonance imaging characterization of circumferential and longitudinal strain under various coronary interventions in swine

    PubMed Central

    Suhail, Mohammed SA; Wilson, Mark W; Hetts, Steven W; Saeed, Maythem

    2013-01-01

    AIM: To compare the acute changes in circumferential and longitudinal strain after exposing a coronary artery to various interventions in swine. METHODS: Percutaneous balloon angioplasty catheter was guided to location aid device (LAD) under X-ray fluoroscopy to create different patterns of ischemic insults. Pigs (n = 32) were equally divided into 4 groups: controls, 90 min LAD occlusion/reperfusion, LAD microembolization, and combined LAD occlusion/microembolization/reperfusion. Three days after interventions, cine, tagged and viability magnetic resonance imaging (MRI) were acquired to measure and compare left and right circumferential strain, longitudinal strain and myocardial viability, respectively. Measurements were obtained using HARP and semi-automated threshold method and statistically analyzed using unpaired t-test. Myocardial and vascular damage was characterized microscopically. RESULTS: Coronary microemboli caused greater impairment in l left ventricular (LV) circumferential strain and dyssynchrony than LAD occlusion/reperfusion despite the significant difference in the extent of myocardial damage. Microemboli also caused significant decrease in peak systolic strain rate of remote myocardium and LV dyssynchrony. Cine MRI demonstrated the interaction between LV and right ventricular (RV) at 3 d after interventions. Compensatory increase in RV free wall longitudinal strain was seen in response to all interventions. Viability MRI, histochemical staining and microscopy revealed different patterns of myocardial damage and microvascular obstruction. CONCLUSION: Cine MRI revealed subtle changes in LV strain caused by various ischemic insults. It also demonstrated the interaction between the right and left ventricles after coronary interventions. Coronary microemboli with and without acute myocardial infarction (AMI) cause complex myocardial injury and ventricular dysfunction that is not replicated in solely AMI. PMID:24379934

  9. Longitudinal and circumferential spike patches in the canine small intestine in vivo.

    PubMed

    Lammers, Wim J E P; Donck, Luc Ver; Schuurkes, Jan A J; Stephen, Betty

    2003-11-01

    In an open-abdominal anesthetized and fasted canine model of the intact small intestine, the presence, location, shape, and frequency of spike patches were investigated. Recordings were performed with a 240-electrode array (24 x 10, 2-mm interelectrode distance) from several sites sequentially, spanning the whole length of the small intestine. All 240 electrograms were recorded simultaneously during periods of 5 min and were analyzed to reconstruct the origin and propagation of individual spikes. At every level in the small intestine, spikes propagated in all directions before stopping abruptly, thereby activating a circumscribed area termed a "patch." Two types of spikes were found: longitudinal spikes, which propagated predominantly in the longitudinal direction and occurred most often in the duodenum, and a second type, circumferential spikes, which propagated predominantly in the circular direction and occurred much more frequently in the jejunum and ileum. Circumferential spikes conducted faster than longitudinal spikes (17 +/- 6 and 7 +/- 2 cm/s, respectively; P < 0.001). Circumferential spikes originated in >90% of all cases from the antimesenteric border, whereas longitudinal spikes were initiated all around the circumference of the intestinal tube. Finally, the spatial sequence of spike patches after the slow wave was very irregular in the upper part of the intestine but much more regular in the lower part. In conclusion, spikes and spike patches occur throughout the small intestine, whereas their type, sites of origin, extent of propagation, and frequencies of occurrence differ along the length of the small intestine, suggesting differences in local patterns of motility. PMID:12842824

  10. 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

  11. 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. PMID:26835214

  12. Multiaxial stress concentration in an externally pressurized cylinder with an external circumferential groove

    SciTech Connect

    Tipton, S.M.; Sorem, J.R. Jr.; Hickey, K.A.; Rawson, M.S.

    1995-11-01

    Downhole oil tools are often comprised of cylindrical sections with external, circumferential stress concentrations. Frequently, it is necessary to design locally thin walls that are just capable of sustaining rare applications of severe external pressure with little or moderate amounts of yielding. Here, a thick-walled cylindrical specimen containing an external circumferential groove was subjected to external pressure. To investigate the maximum pressure sustainable by the reduced wall thickness, strain gage measurements were taken during external pressurization tests. For comparison to experimental results, an elastic-plastic notch stress-strain analysis was conducted based on Neuber`s rule. The analysis utilized multiaxial elastic finite element results along with elastic-plastic tensile test data for the cylinder material. It is demonstrated that the boundary conditions used to model the specimen had a substantial effect on the finite element results, even though the boundary was somewhat removed from the region of concentrated stress. Biaxial strain measurements are presented versus pressure over the elastic and into the plastic regime, and deformation plasticity theory was used to compute stress and radial strain components corresponding to measured strains. It is demonstrated that in order to apply a multiaxial Neuber`s rule to accurately estimate the elastic-plastic stress-strain response (using elastic stress concentration information and elastic-plastic material data), it is necessary to utilize an experimental observation that the ratio of the hoop to radial strain remains invariant from the elastic to the elastic-plastic regime. This differs from published assumptions about invariant hoop-to-axial strain ratios based on analysis of circumferentially grooved solid shafts. The predictions are accurate for moderate plastic strains, but correlation breaks down for bulk plastic deformation.

  13. 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.

  14. 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.

  15. 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.

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

    PubMed

    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

    2015-12-01

    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

  17. 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.

  18. 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

  19. 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.

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

    PubMed

    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

    2015-12-01

    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.

  1. 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. PMID:25734774

  2. 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.

  3. 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.

  4. 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

  5. Experimental investigation on circumferential and axial temperature gradient over fuel channel under LOCA

    NASA Astrophysics Data System (ADS)

    Yadav, Ashwini Kumar; kumar, Ravi; Gupta, Akhilesh; Chatterjee, Barun; Mukhopadhyay, Deb; Lele, H. G.

    2014-06-01

    In a nuclear reactor temperature rises drastically in fuel channels under loss of coolant accident due to failure of primary heat transportation system. Present investigation has been carried out to capture circumferential and axial temperature gradients during fully and partially voiding conditions in a fuel channel using 19 pin fuel element simulator. A series of experiments were carried out by supplying power to outer, middle and center rods of 19 pin fuel simulator in ratio of 1.4:1.1:1. The temperature at upper periphery of pressure tube (PT) was slightly higher than at bottom due to increase in local equivalent thermal conductivity from top to bottom of PT. To simulate fully voided conditions PT was pressurized at 2.0 MPa pressure with 17.5 kW power injection. Ballooning initiated from center and then propagates towards the ends and hence axial temperature difference has been observed along the length of PT. For asymmetric heating, upper eight rods of fuel simulator were activated and temperature difference up-to 250 °C has been observed from top to bottom periphery of PT. Such situation creates steep circumferential temperature gradient over PT and could lead to breaching of PT under high pressure.

  6. The circumferential actomyosin belt in epithelial cells is regulated by the Lulu2-p114RhoGEF system

    PubMed Central

    Nakajima, Hiroyuki; Tanoue, Takuji

    2012-01-01

    In epithelial cells, myosin-II-dependent forces regulate many aspects of animal morphogenesis, such as apical constriction, cell intercalation, cell sorting, and the formation and maintenance of the adherens junction. These forces are mainly generated by the circumferential actomyosin belt, which is composed of F-actin–myosin II bundles located along apical cell–cell junctions. Although several of the molecular pathways regulating the belt have been identified, the precise mechanisms underlying its function are largely unknown. Our recent studies identified Lulu proteins (Lulu1 and Lulu2), FERM-domain-containing molecules, as the regulators of the belt. Lulus activate the circumferential actomyosin belt and thereby induce apical constriction in epithelial cells; conversely, RNAi-mediated Lulu-knockdown results in the severe disorganization of the circumferential actomyosin belt. We also showed that p114RhoGEF is a downstream molecule of Lulu2 in its regulation of the belt; Lulu2 enhances the catalytic activity of p114RhoGEF through a direct interaction and thereby activates the circumferential actomyosin belt. We further identified aPKC and Patj as regulators of Lulu2-p114RhoGEF. In this commentary, we discuss current knowledge of the circumferential actomyosin belt's regulation, focusing on the Lulu2-p114RhoGEF system. PMID:22790195

  7. 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.

  8. 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.

  9. Tip clearance flow interaction with circumferential groove casing treatment in a transonic axial compressor

    NASA Astrophysics Data System (ADS)

    Ross, Mark Hamilton

    Experimental and computational studies were conducted to study the role of the tip leakage flow in axial compressor stall and the relationship between the tip clearance flow flow field and surge margin extension from circumferential groove casing treatment. The CFD results were used to identify the existence of an interface between the approach ow and the tip-leakage flow. The experiments used a surface streaking visualization method to identify the time-averaged location of this interface as a line of zero axial shear stress at the casing. The axial position of this line, denoted xzs, moved upstream with decreasing ow coefficient in both the experiments and computations. The line was consistently located at the rotor leading edge plane at the stalling flow coefficient, regardless of in flow boundary condition. These results were successfully modeled using a control volume approach that balanced the reverse axial momentum ux of the tip-leakage flow with the momentum flux of the approach fluid. Non-uniform tip clearance measurements demonstrated that movement of the interface upstream of the rotor leading edge plane leads to the generation of short length scale rotating disturbances. Therefore, stall was interpreted as a critical point in the momentum flux balance of the approach ow and the reverse axial momentum flux of the tip-leakage flow. Experimental measurements of surge margin extension from seven CGCT configurations with a fixed groove geometry demonstrated that the contribution of individual grooves in a multi-groove casing to surge margin extension is an (a) additive and (b) linear function of the smooth wall tip clearance axial momentum ux at the location of a each groove. Extending the axial momentum model to include the in uence of a CGCT showed that circumferential grooves reduce the tip leakage flow axial momentum through radial transport. The equivalent force due to a circumferential groove was demonstrated to be related to the smooth wall tip

  10. Acoustic attenuation, phase and group velocities in liquid-filled pipes III: nonaxisymmetric propagation and circumferential modes in lossless conditions.

    PubMed

    Baik, Kyungmin; Jiang, Jian; Leighton, Timothy G

    2013-03-01

    Equations for the nonaxisymmetric modes that are axially and circumferentially propagating in a liquid-filled tube with elastic walls surrounded by air/vacuum are presented using exact elasticity theory. Dispersion curves for the axially propagating modes are obtained and verified through comparison with measurements. The resulting theory is applied to the circumferential modes, and the pressures and the stresses in the liquid-filled pipe are calculated under external forced oscillation by an acoustic source. This provides the theoretical foundation for the narrow band acoustic bubble detector that was subsequently deployed at the Target Test Facility (TTF) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), TN.

  11. 3D modeling of circumferential SH guided waves in pipeline for axial cracking detection in ILI tools.

    PubMed

    Wang, Shen; Huang, Songling; Zhao, Wei; Wei, Zheng

    2015-02-01

    In this paper, SH (shear horizontal) guided waves propagating in the circumferential direction of pipeline are modeled in 3 dimensions, with the aim for axial cracking detection implementation in ILI (in-line inspection) tools in mind. A theoretical formulation is given first, followed by an explanation about the 3D numerical modeling work. Displacement wave structures from the simulation and dispersion equation are compared to verify the effectiveness of the FEM package. Transverse slots along the axial direction are modeled to simulate axial cracking. Reflection and transmission coefficients curves are obtained to provide insight in using circumferential SH guided waves for quantitative testing of axial pipeline cracking.

  12. Circumferential resonance modes of solid elastic cylinders excited by obliquely incident acoustic waves.

    PubMed

    Fan, Ying; Honarvar, Farhang; Sinclair, Anthony N; Jafari, Mohammad-Reza

    2003-01-01

    When an immersed solid elastic cylinder is insonified by an obliquely incident plane acoustic wave, some of the resonance modes of the cylinder are excited. These modes are directly related to the incidence angle of the insonifying wave. In this paper, the circumferential resonance modes of such immersed elastic cylinders are studied over a large range of incidence angles and frequencies and physical explanations are presented for singular features of the frequency-incidence angle plots. These features include the pairing of one axially guided mode with each transverse whispering gallery mode, the appearance of an anomalous pseudo-Rayleigh in the cylinder at incidence angles greater than the Rayleigh angle, and distortional effects of the longitudinal whispering gallery modes on the entire resonance spectrum of the cylinder. The physical explanations are derived from Resonance Scattering Theory (RST), which is employed to determine the interior displacement field of the cylinder and its dependence on insonification angle.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Reduced residual conduction gaps and favourable outcome in contact force-guided circumferential pulmonary vein isolation

    PubMed Central

    Itoh, Taihei; Kimura, Masaomi; Tomita, Hirofumi; Sasaki, Shingo; Owada, Shingen; Horiuchi, Daisuke; Sasaki, Kenichi; Ishida, Yuji; Kinjo, Takahiko; Okumura, Ken

    2016-01-01

    Aims Although contact force (CF)-guided circumferential pulmonary vein isolation (CPVI) for paroxysmal atrial fibrillation (PAF) is useful, AF recurrence at long-term follow-up still remains to be resolved. The purpose of this study was to assess safety and efficacy of CF-guided CPVI and to compare residual conduction gaps during CPVI and long-term outcome between the conventional (non-CF-guided) and the CF-guided CPVI. Methods and results We studied the 50 consecutive PAF patients undergoing CPVI by a ThermoCool EZ Steer catheter (conventional group, mean age 61 ± 10 years) and the other 50 consecutive PAF patients by a ThermoCool SmartTouch catheter (CF group, 65 ± 11 years). The procedure parameters and residual conduction gaps during CPVI, and long-term outcome for 12 months were compared between the two groups. Circumferential pulmonary vein isolation was successfully accomplished without any major complications in both groups. Total procedure and total fluoroscopy times were both significantly shorter in the CF group than in the conventional group (160 ± 30 vs. 245 ± 61 min, P < 0.001, and 17 ± 8 vs. 54 ± 27 min, P < 0.001, respectively). Total number of residual conduction gaps was significantly less in the CF group than in the conventional group (2.7 ± 1.7 vs. 6.3 ± 2.7, P < 0.05). The AF recurrence-free rates after CPVI during 12-month follow-up were 96% (48/50) in the CF group and 82% (41/50) in the conventional group (P = 0.02 by log rank test). Multivariate Cox regression analysis further supported this finding. Conclusion Contact force-guided CPVI is safe and more effective in reducing not only the procedure time but also the AF recurrence than the conventional CPVI, possibly due to reduced residual conduction gaps during CPVI procedure. PMID:26346921

  20. Ion replacement electrorefining

    SciTech Connect

    Willit, J.L.; Tomczuk, Z.; Miller, W.E.; Laidler, J.J.

    1994-04-01

    We are developing a two-step electrochemical process for purifying and separating metals called ion replacement electrorefining. In each step, metal cations formed by oxidation at an electrode replace other metal cations that are reduced at another elecmae. Using this approach, we have separated or purified uranium, dysprosium, and lanthanum on a laboratory scale. This paper explains the ion replacement concept and presents results of these demonstration experiments.

  1. Experimental tracheal replacement using tissue-engineered cartilage.

    PubMed

    Vacanti, C A; Paige, K T; Kim, W S; Sakata, J; Upton, J; Vacanti, J P

    1994-02-01

    The authors tested the feasibility of using tissue-engineered cartilage, grown in the shape of cylinders, for replacing large circumferential defects of the cervical trachea in rats. Chondrocytes obtained from the shoulder of newborn calves were seeded onto a synthetic nonwoven mesh, 100 microns thick, of polyglycolic acid fibers 15 microns in diameter, cut into pieces of 2.5 x 4 cm. Twenty cell-polymer constructs were wrapped around silastic tubes and implanted into 10 nude mice for 4 weeks. Specimens were then excised and evaluated grossly and histologically for the presence of new cartilage, and biomechanically for their ability to resist collapse upon application of negative pressure. Six cylinders of tissue-engineered cartilage were then sutured into large circumferential defects created in the cervical tracheas of nude rats to replace the excised trachea. Implantation of cell-polymer constructs resulted in the formation of cylinders of hyaline cartilage. When placed within the lumen of a segment of bowel denuded of its mucosal lining, the hollow cylinders resisted collapse in all instances upon administration of negative 200 mm Hg pressure. The cartilage was grossly and histologically identical to that from which the cells had been initially isolated. Four of the six animals receiving these cartilage cylinders as tracheal replacements survived the procedure and were able to breathe in an unassisted fashion. Three of these animals never recovered fully from the anesthetic and the operation, and expired at 24, 48, and 72 hours. The fourth animal fully recovered from the procedure, and breathed spontaneously for 1 week, with no apparent limitations. Increasing respiratory distress then developed, and the animal died.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Single-Stage Posterior Subtotal Corpectomy and Circumferential Reconstruction for the Treatment of Unstable Thoracolumbar Burst Fractures

    PubMed Central

    Jo, Dae-Jean; Kim, Ki-Tack; Kim, Sung-Min; Lee, Sang-Hun; Cho, Myung-Guk

    2016-01-01

    Objective To illustrate the technique of single-stage posterior subtotal corpectomy and circumferential reconstruction for the treatment of unstable thoracolumbar burst fractures and to evaluate the radiographical and clinical outcomes of patients treated using this technique. Methods 16 consecutive patients with unstable thoracolumbar burst fractures were treated with single-stage posterior subtotal corpectomy and circumferential reconstruction. The mean patient age was 54.8 years. The mean follower up period was 25 months. Five patients suffered from T12 fractures, 10 from L1, 1 from L2. The segmental kyphosis, neurologic status, visual analogue scale for back pain was evaluated before surgery and at follow up. Results The segmental kyphotic angle improved from 18.5 degrees before surgery to -9.2 degrees at the last follow up. The mean correction angle was 28.9 degrees. The mean surgical time was 255 minutes, and a mean intraoperative blood loss was 1073 mL. Intraoperative complications included two dural tears, and a superficial wound infection. There were no other severe complications. The mean visual analog scale of back pain decreased from a mean value of 6.6 to 2 at the last follow up. Conclusion The single-stage posterior subtotal corpectomy and circumferential reconstruction achieved satisfactory kyphosis correction with direct visualization of the circumferentially decompressed spinal cord, as well as good fusion with less blood loss and complications. It is a safe and reliable surgical treatment option for unstable thoracolumbar burst fractures. PMID:26962417

  3. 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.

  4. 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.

  5. Replacing a Missing Tooth

    MedlinePlus

    ... majority of patients with clefts will require full orthodontic treatment, especially if the cleft has passed through ... later replacement of the missing lateral incisor. During orthodontic treatment, an artificial tooth may be attached to ...

  6. Hormone Replacement Therapy

    MedlinePlus

    ... before and during menopause, the levels of female hormones can go up and down. This can cause ... hot flashes and vaginal dryness. Some women take hormone replacement therapy (HRT), also called menopausal hormone therapy, ...

  7. Kidney Replacement Therapy

    MedlinePlus

    ... their function with either dialysis or a transplant. Dialysis Dialysis, the more common form of kidney-replacement ... the result of diabetes, not of hemodialysis. Peritoneal dialysis Another form of dialysis is called peritoneal dialysis. ...

  8. Artificial Disc Replacement

    MedlinePlus

    ... treat this condition, alternatives to disc replacement include fusion, nonoperative care or no treatment. Typically, surgery is ... operative treatment for disc pain has been spinal fusion. This is a surgical procedure in which disc ...

  9. 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.

  10. Impact of local vessel curvature on the circumferential plaque distribution in coronary arteries

    NASA Astrophysics Data System (ADS)

    Wahle, Andreas; Medina, Ruben; Braddy, Kathleen C.; Fox, James M.; Brennan, Theresa M. H.; Lopez, John J.; Rossen, James D.; Sonka, Milan

    2003-05-01

    Plaque in native coronary arteries is hypothesized to accumulate more likely along the inner curvature of a vessel segment as compared to its outer curvature. This behavior is likely associated with differences in local shear stress, which tends to be lower on the inner bend of a curved vessel than on the outer bend. The reported in-vivo study evaluated how the circumferential plaque distribution depends on local vessel curvature in coronaries from a limited set of 12 patients. Geometrically correct models of the vessel segments were generated utilizing fusion between biplane angiography and intravascular ultrasound. The plaque thickness was derived from the 3-D borders of the lumen/plaque and media/adventitia interfaces. Within each frame, plaque thickness was classified into "below-average" and "above-average" regions. A local curvature index was defined for each point: A positive value indicates the "inner" curvature, a negative value the "outer" curvature, with the magnitude determined from differential geometry. In the majority of the examined vessels, regions of "below-average/outer-curvature" and "above-average/inner-curvature" combined outweighed the "below-average/inner-curvature" and "above-average/outer-curvature" regions. The ratio increased with the threshold to exclude lower-curvature regions, confirming the hypothesis that plaque is more likely to accumulate on the luminal surface along the inner curvature of the coronary segment.

  11. Characteristics and Prognostic Significance of Preoperative Magnetic Resonance Imaging-Assessed Circumferential Margin in Rectal Cancer.

    PubMed

    Ma, Xiaoji; Li, Xinxiang; Xu, Linghui; Shi, Debing; Tong, Tong; Huang, Dan; Ding, Ying; Cai, Sanjun; Peng, Junjie

    2015-01-01

    Purpose. To study the characteristics and prognostic significance of preoperative magnetic resonance imaging- (MRI-) assessed circumferential margin (CRM) in rectal cancer. Methods. Patients underwent preoperative high resolution pelvic MRI, followed by resection of primary tumor. The relationship between MRI-assessed CRM and pathological CRM (pCRM) was studied, and survival analysis was used to determine the prognostic significance of MRI-assessed CRM. Results. Of all the 203 patients, the total accuracy of MRI-assessed CRM for predicting involvement of pCRM was 84.2%, sensitivity was 50%, and specificity was 86.8%. Anterior tumors were more possible to assess involvement of CRM by MRI, while the false positive rate was significantly higher than lateral or posterior tumor (87.5% versus 50%, p = 0.0002). The 3-year local recurrence, disease-free survival, and overall survival rates were 35.6%, 58.1%, and 85.2% in patients with involved mrCRM, compared with 8.9%, 78.9%, and 92.3% in patients with clear mrCRM. In multivariate analysis, MRI-assessed CRM found an independent risk factor for local recurrence, with a hazard ratio of 3.49 (p = 0.003). Conclusions. High resolution MRI was accurate to assess CRM preoperatively, while anterior tumor should be assessed more cautiously. Involvement of mrCRM was significantly associated with local recurrence regardless of pCRM status.

  12. The Prognostic Value of Circumferential Resection Margin Involvement in Patients with Extraperitoneal Rectal Cancer.

    PubMed

    Shin, Dong Woo; Shin, Jin Yong; Oh, Sung Jin; Park, Jong Kwon; Yu, Hyeon; Ahn, Min Sung; Bae, Ki Beom; Hong, Kwan Hee; Ji, Yong Il

    2016-04-01

    The prognostic influence of circumferential resection margin (CRM) status in extraperitoneal rectal cancer probably differs from that of intraperitoneal rectal cancer because of its different anatomical and biological behaviors. However, previous reports have not provided the data focused on extraperitoneal rectal cancer. Therefore, the aim of this study was to examine the prognostic significance of the CRM status in patients with extraperitoneal rectal cancer. From January 2005 to December 2008, 248 patients were treated for extraperitoneal rectal cancer and enrolled in a prospectively collected database. Extraperitoneal rectal cancer was defined based on tumors located below the anterior peritoneal reflection, as determined intraoperatively by a surgeon. Cox model was used for multivariate analysis to examine risk factors of recurrence and mortality in the 248 patients, and multivariate logistic regression analysis was performed to identify predictors of recurrence and mortality in 135 patients with T3 rectal cancer. CRM involvement for extraperitoneal rectal cancer was present in 29 (11.7%) of the 248 patients, and was the identified predictor of local recurrence, overall recurrence, and death by multivariate Cox analysis. In the 135 patients with T3 cancer, CRM involvement was found to be associated with higher probability of local recurrence and mortality. In extraperitoneal rectal cancer, CRM involvement is an independent risk factor of recurrence and survival. Based on the results of the present study, it seems that CRM involvement in extraperitoneal rectal cancer is considered an indicator for (neo)adjuvant therapy rather than conventional TN status.

  13. A novel gastroscope intervention mechanism with circumferentially pneumatic-driven clamping function.

    PubMed

    Yanmin Li; Hao Liu; Hengzhi Wang; Zhenda Yang; Hongyi Li; Yunsheng Yang

    2015-01-01

    Robotic assisted gastroscope delivery could solve various problems like understaffing, radiation and infection risk. The friction rollers commonly used in the few existed systems for traditional flexible endoscope, however, has potential risk of destroying scopes for non-uniform clamping. This research develops a novel gastroscope intervention mechanism (GIM) with a specially designed airbag. It evenly clamps the gastroscope with circumferential uniform pneumatic pressure. The GIM realizes axial and radial motion by means of the relay delivery mode similar to clinician's operation. The critical slipping force at different air pressure was analyzed to provide guidelines for safe intervention. Experiments were performed to evaluate the delivery accuracy and velocity and measure the critical slipping force. The results showed the axial and radial accuracy for delivery are 0.025±0.2mm and -0.03±0.25deg, respectively. The average velocity of 6.00mm·s(-1) and 75 deg·s(-1) were achieved to push/pull and twist the gastroscope. The relationship between the critical slipping force and air pressure could be fitted with a quadratic polynomial. PMID:26738096

  14. SERI Surgical Scaffold as an Adjunct for Circumferential Abdominoplasty and Lower Body Lift

    PubMed Central

    2014-01-01

    Summary: Patients who have undergone massive weight loss typically have poor-quality skin and fascia and thus are prone to experiencing recurrent skin laxity, bulges, and poor scarring after body contouring efforts, even in the hands of experienced surgeons. Moreover, this challenging patient population often has nutritional deficiencies and concomitant medical problems, which may lead to delayed or suboptimal wound healing. A silk-derived biological scaffold (SBS) and its facilitation of autogenous tissue generation may be viewed as a qualitative reinforcement of the superficial fascial system. Therefore, it may help support and stabilize a superficial fascial system that has been weakened by obesity and other factors. When employed in body lifting for patients with massive weight loss who desire long-lasting aesthetic results, it may represent a paradigm shift that has the potential to solve at least some issues that plague this patient population. In the present case of circumferential abdominoplasty and lower body lift, this silk-based bioresorbable scaffold was implanted in one side of the patient’s body but not the other. Throughout the 7-month follow-up period, the patient and her husband (who were blinded as to which side received the SBS) and the author consistently observed more favorable results for the SBS side, which included greater postoperative comfort, better shape, higher buttock position, less recurrent laxity, and less descent of the scar. PMID:25506527

  15. 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.

  16. Lulu2 regulates the circumferential actomyosin tensile system in epithelial cells through p114RhoGEF

    PubMed Central

    Nakajima, Hiroyuki

    2011-01-01

    Myosin II–driven mechanical forces control epithelial cell shape and morphogenesis. In particular, the circumferential actomyosin belt, which is located along apical cell–cell junctions, regulates many cellular processes. Despite its importance, the molecular mechanisms regulating the belt are not fully understood. In this paper, we characterize Lulu2, a FERM (4.1 protein, ezrin, radixin, moesin) domain–containing molecule homologous to Drosophila melanogaster Yurt, as an important regulator. In epithelial cells, Lulu2 is localized along apical cell–cell boundaries, and Lulu2 depletion by ribonucleic acid interference results in disorganization of the circumferential actomyosin belt. In its regulation of the belt, Lulu2 interacts with and activates p114RhoGEF, a Rho-specific guanine nucleotide exchanging factor (GEF), at apical cell–cell junctions. This interaction is negatively regulated via phosphorylation events in the FERM-adjacent domain of Lulu2 catalyzed by atypical protein kinase C. We further found that Patj, an apical cell polarity regulator, recruits p114RhoGEF to apical cell–cell boundaries via PDZ (PSD-95/Dlg/ZO-1) domain–mediated interaction. These findings therefore reveal a novel molecular system regulating the circumferential actomyosin belt in epithelial cells. PMID:22006950

  17. 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.

  18. Toxicology of chlorofluorocarbon replacements.

    PubMed Central

    Dekant, W

    1996-01-01

    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. PMID:8722112

  19. 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.

  20. 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.

  1. Endoscopic mucosal resection with circumferential incision for treatment of rectal carcinoid tumours

    PubMed Central

    2014-01-01

    Background Endoscopic mucosal resection (EMR) is simple and quick and has low complication rates. However, the disadvantage of local recurrence or remnant rate limits the use of this technique. We aimed to analyse the outcomes of conventional EMR and EMR with circumferential incision (CIEMR), a simplified modification of EMR, in the endoscopic treatment of rectal carcinoid tumours. Methods A total of 59 consecutive patients with rectal carcinoid tumours without regional lymph node enlargement confirmed by endoscopic ultrasonography were included in the study. These patients underwent endoscopic treatment from January 2009 to September 2011 and were randomly designated into CIEMR (n = 31) or EMR group (n = 28). En bloc resection rate, pathological complete resection rate, procedure time, complications and follow-up outcomes were analysed. Results The en bloc resection rate was not significantly different between the CIEMR and EMR groups (100% versus 96.55%, P > 0.05). The pathological complete resection rate was higher in the CIEMR group than in the EMR group (96.7% versus 82.14%, P < 0.05). The overall complication rate, delayed bleeding and procedure time were not significantly different between the two groups. No recurrence was observed in either the EMR or CIEMR group. Conclusions CIEMR optimises the procedure of EMR and simplifies the technique of endoscopic submucosal dissection; thus, it has a better histologically complete resection rate and more acceptable complication rate than EMR. Thus, CIEMR may be preferable to conventional EMR for resection of rectal carcinoid tumours less than 15 mm. PMID:24472342

  2. Intraobserver and Interobserver Reproducibility for Radial, Circumferential and Longitudinal Strain Echocardiography

    PubMed Central

    Leischik, R.; Dworrak, B.; Hensel, K.

    2014-01-01

    Objectives: Strain echocardiography (StE) promises to be a new tool for quantitative assessment of cardiac function. Analysis of intra- and interobserver reliability is an important aspect in the process of developing these novel techniques from theory to the implementation into daily routine diagnostics.The purpose of the study was to estimate reliability of the segmental StE. Methods: Left ventricular strain analysis for radial strain (RS), circumferential strain (CS) and longitudinal strain (LS) was performed in 21 healthy volunteers. RS and CS values were obtained in the parasternal short axis at the level of the papillary muscles. LS values were determined in the apical 2-, 3- and 4-chamber views. Cine-loops were recorded and quantitative analyses were conducted on an off-line workstation. Results: Intraobserver reproducibility was highest using LS in the 4-chamber view (9 ± 13.6 % mean deviation, rho = 0.624, p = 0.003), followed by CS (13.3 ± 8.3 %, rho = 0.406, p = 0.068) and lowest in RS (26.3 ± 30.1 %, rho = 0.391, p = 0.080). Interobserver analyses of LS derived from 3-chamber view showed lowest deviation (11.9 ± 9.5 %, rho = 0.513, p = 0.017), followed by CS (15.2 ± 12.0 %, 0.263, p = 0.249) and the least consistent measurements in RS (35.9 ± 46.3 %, rho 0.382, p = 0.088). Conclusion: This study shows that the clinical utility of StE depends on the regional differences of LV wall motion and image quality. LS-values showed promising intra- and interobserver reproducibility values. For quantitative follow-up studies LS should be preferred. PMID:25356089

  3. Circumferential Strain Analysis Identifies Strata of Cardiomyopathy in Duchenne Muscular Dystrophy

    PubMed Central

    Hor, Kan N; Wansapura, Janaka; Markham, Larry W; Mazur, Wojciech; Cripe, Linda H; Fleck, Robert; Benson, D. Woodrow; Gottliebson, William M

    2009-01-01

    Objectives This study sought to evaluate the natural history of occult cardiac dysfunction in Duchenne Muscular Dystrophy (DMD). Background DMD is characterized by progressive cardiac dysfunction and myocardial fibrosis late in the disease process. We hypothesized that left ventricular myocardial peak circumferential strain (εcc) would decrease in DMD prior to global systolic functional abnormalities regardless of age or ventricular ejection fraction (EF). Methods We evaluated cardiac magnetic resonance image (CMR) data from 70 DMD patients and 16 aged-matched control subjects. Standard imaging data included steady-state free precession (SSFP) short-axis cine stack images, cine myocardial tagged images and myocardial delayed enhancement (MDE, an indicator of myocardial fibrosis) sequences. Analysis was performed using QMASS® and HARP® softwares. DMD patient data was subdivided by age (< 10 years or > 10 years), EF (> 55% or <55%) and the presence or absence of MDE. Results DMD patients with normal EF had reduced εcc at an early age (<10 years) compared to control subjects (p< 0.01). DMD patients >10 years with normal EF had further decline in εcc compared to younger DMD patients (p<0.01). There was further decline in εcc with age in patients with reduced EF (p<0.01) without MDE. The oldest patients, with both reduced EF and positive MDE, exhibited the lowest εcc. None of the patients had ventricular hypertrophy. Conclusions Myocardial strain abnormalities are prevalent in young DMD patients despite normal EF, and these strain values continue to decline with advancing age. Strain analysis in combination with standard CMR and MDE imaging provides a means to stratify DMD cardiomyopathy. PMID:19341862

  4. Numerical simulation of a fully baffled biological reactor: the differential circumferential averaging mixing plane approach.

    PubMed

    Dubey, Hitesh; Das, Sarit Kumar; Panda, Tapobrata

    2006-11-01

    A modified mixing plane approach for steady state simulation of flow field in fully baffled biological reactor is presented and discussed. Without requiring any experimental input, this approach of dividing the vessel into suitable number of connected and disconnected zones; solving steady state equation separately in each zone and then transferring information between them, provides a computationally less intensive alternative for simulating the flow in the whole vessel. Impeller used is the standard Rushton Turbine positioned at mid-height of the reactor and simulations are carried out using standard k-epsilon turbulence model implemented in CFD code FLUENT. Meshing is done using tetrahedral elements such that mesh size gradually increases from the center to the periphery. Most of the previous simulation works present only a few aspects of the flow field with scant importance to the energy balance in the tank and near tip turbulence. In this work, complete model prediction for velocity field and turbulence parameters (near tip and in the bulk region) are validated by comparison with experimental data. As compared to previous simulation works, the results predicted by this "Differential circumferential averaging mixing plane approach" show a better qualitative and quantitative agreement with the published experimental data. A distribution of energy dissipation in various zones of vessel is presented. Also a qualitative picture of flow field and stagnant zones inside the reactor is presented and discussed. Comparison of flow characteristics for different number of baffles shows that for the present dimension of the vessel, five baffles gives maximum enhanced mixing. PMID:16767780

  5. 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. PMID:26053997

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

    PubMed Central

    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. PMID:26147292

  7. Triple Starr Valve Replacement

    PubMed Central

    Braimbridge, M. V.; Clement, A. J.; Brown, A. Hedley; Sabar, E.; Mendel, D.

    1969-01-01

    Of nine patients who have had triple valve replacements for organic rheumatic triple valve disease two died in the postoperative period from inadequate myocardial reserve, and a third died four months later from cerebral embolism originating from clot on the left atrial wall. The remainder are well and, except for one, leading normal lives. Though cardiac transplantation has been recommended and used successfully for triple valve disease by Cooley, it is suggested that the long-term outlook today of triple valve replacement is likely to be better than that of transplantation. ImagesFig. 1Fig. 2Fig. 3 PMID:5809243

  8. Line Replaceable Unit Analysis

    NASA Technical Reports Server (NTRS)

    Oepomo, T.; Prouty, T. V.

    1982-01-01

    Shuttle LRU (Line Replaceable Unit) Analysis Program (SLAP) aids in evaluation of LRU interface voltages in Shuttle orbiter electrical system. Slap includes reduced model of Shuttle LRU circuit. Although primarily intended for analysis of Shuttle LRU's SLAP could be adapted for voltage analysis in other situations.

  9. Replacing America's Job Bank

    ERIC Educational Resources Information Center

    Vollman, Jim

    2009-01-01

    The Job Central National Labor Exchange (www.jobcentral.com) has become the effective replacement for America's Job Bank with state workforce agencies and, increasingly, with community colleges throughout the country. The American Association of Community Colleges (AACC) has formed a partnership with Job Central to promote its use throughout the…

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Total femoral replacement.

    PubMed

    Nerubay, J; Katznelson, A; Tichler, T; Rubinstein, Z; Morag, B; Bubis, J J

    1988-04-01

    Between 1973 and 1983, 19 patients with sarcoma of the femur were treated by adjuvant chemotherapy, excision of the entire femur, and replacement by a total femoral prosthesis. Five patients had excellent and nine had good functional results. Twelve patients died an average of 23 months after the procedure and seven are at present disease free. This limb-saving procedure permits rapid rehabilitation, prevents severe psychological problems, and improves the quality of life.

  17. 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

  18. Renal Replacement Therapy.

    PubMed

    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

  19. Circumferential wiring of mid-body and large basilar fractures of the proximal sesamoid bone in 15 horses.

    PubMed

    Martin, B B; Nunamaker, D M; Evans, L H; Orsini, J A; Palmer, S E

    1991-01-01

    Circumferential wiring was used to repair 12 mid-body fractures and four large basilar fractures of proximal sesamoid bones in 15 horses. Eighteen-gauge stainless steel wire was placed around both fragments in five horses, and through the proximal fragment and around the distal fragment in 10 horses. The horses were returned to work when they were clinically sound and fracture healing was evident radiographically. Eleven horses resumed athletic performance, three horses were used as breeding animals, and one horse was retired. Five horses performed at an athletic level equal to or better than their previous levels, and six horses performed at a lower level.

  20. Reflections on replacement.

    PubMed

    Ryder, N B

    1993-01-01

    In the United States, the total fertility rate is about 1.9 births per woman, down from a peak of 3.2 a generation ago and below the replacement level of 2.1 children. The proportion of women who will never have children has risen from 8% a generation ago to approximately 18% in 1993. The increase in the proportion of women in the labor force, a proximate explanation of the recent decline in intended fertility, is expected to continue. The demographic consequence is declining population with an older age structure. A pronatalist policy to alleviate this outcome, through monetary transfers from taxpayers to potential parents, is not only unlikely to succeed, it is politically unfeasible. An alternative solution, immediately effective but politically unpalatable, would be a generous immigration policy. Even with replacement level fertility, the population is destined to become much older. This inevitable aging of the population should be countered by appropriate institutional transformations: 1) with lower fertility, a larger proportion of women will be available to participate in the labor force to generate taxes needed to support a larger number of pensioners; 2) the institutional practice of ascribing a dependent status to anyone above a particular age can be changed; 3) concerns that an older labor force will have an obsolete education (and fewer years of it) can be countered by changing access to education. Yet, the most serious question is not merely the net reproduction rate, but producing adequate numbers of new adult citizens with responsibility and technical training in the modern world. The fundamental process of socializing children may be jeopardized by replacing the full-time parent with the hired care-giver, the peer group, and the television set. The attenuation of the bonds between parent and child may devalue the worth of childbearing itself. These portentous consequences deserve consideration. PMID:8313953

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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. PMID:24412045

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Aerocoat 7 Replacement Coatings

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Kennedy Space Center has used Aerocoat 7 (AR-7) to protect stainless-steel flex hoses at Launch Complex (LC-39) and hydraulic lines of the Mobile Launcher Platform (MLP) because it provides excellent corrosion protection in low-temperature applications. The Sovereign Company produced AR-7 exclusively for NASA but discontinued production because the coating released high levels of volatile organic compounds (VOCs) and had a significant environmental impact. The purpose of this project was to select and evaluate potential replacement coatings for AR-7 that would be more environmentally sound. The physical and mechanical properties of commercially available coatings were investigated through the Internet. The ideal coating would be fluid enough to penetrate the outer mesh of a stainless-steel flex hose and coat the inner hose, and flexible enough to withstand the movement of the hose, as well as the expansion and contraction of its metal caused by changes in temperature.

  14. 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.

  15. 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.

  16. 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.

  17. Ground Tests of a Radial Air-Cooled Engine to Correct a Poor Circumferential Pressure-Recovery Distribution

    NASA Technical Reports Server (NTRS)

    Gallagher, James J.

    1948-01-01

    This report presents the results of the tests of a power-plant installation to improve the circumferential pressure-recovery distribution at the face of the engine. An underslung "C" cowling was tested with two propellers with full cuffs and with a modification to one set of cuffs. Little improvement was obtained because the base sections of the cuffs were stalled. A set of guide vanes boosted the over-all pressures and helped the pressure recoveries for a few of the cylinders. Making the underslung cowling into a symmetrical "C" cowling evened the pressure distribution; however, no increases in front pressures were obtained. The pressures at the top cylinders remained low and the high pressures at the bottom cylinders were reduced. At higher powers and engine speeds, the symmetrical cowling appeared best from the standpoint of over-all cooling characteristics.

  18. 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.

  19. Influence of circumferential resection margin on prognosis in distal esophageal and gastroesophageal cancer approached through the transhiatal route.

    PubMed

    Scheepers, J J G; van der Peet, D L; Veenhof, A A F A; Cuesta, M A

    2009-01-01

    We studied the influence of circumferential resection margin (CRM) involvement on survival in patients with malignancies of the distal esophagus and gastroesophageal junction. One hundred ten consecutive patients undergoing a laparoscopic or open transhiatal esophagectomy for malignancy of the distal 5 cm of the esophagus, or a Siewert I gastroesophageal junction tumor were analyzed, retrospectively. Only patients with potentially resectable tumors were included. CRM status was defined as clear or involved (microscopic tumor within 1 mm of the resection margin). Statistical analysis was done by means of univariate and multivariate analysis using the Kaplan-Meier method and Cox proportional hazard model. One hundred ten patients were analyzed. Sixty patients underwent open transhiatal esophagectomy, and 50 patients underwent laparoscopic transhiatal esophagectomy. There were 6 (5%) T(1), 18 (16%) T(2), and 86 (89%) T(3) tumors. CRM was clear in 68 (62%) patients and involved in 42 (38%) patients. Median survival in these groups was 50 vs. 20 months (P = 0.000). Since CRM involvement was only seen in T(3) tumors, this group was analyzed in detail. Median survival in the T(3)CRM(-) and T(3)CRM(+) group was 33 vs. 19 months (P = 0.004). For T(3)N(0) tumors, median survival in CRM(-) and CRM(+) was 40 and 22 months, respectively (P = 0.036). Median survival for T(3)N(1) tumors in CRM(-) and CRM(+) was 22 and 13 months, respectively (P = 0.049). Involvement of the circumferential resection margin was found to be an independent prognostic factor on survival in our study. It predicts a poor prognosis in patients with potentially resectable malignancies of the distal 5 cm of the esophagus and Siewert I adenocarcinomas of the gastro esophageal junction.

  20. 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

  1. 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.

  2. 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

  3. 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 ...

  4. Replacement Cost of Domestic Crude

    1994-12-01

    The DEEPWATER model forecasts the replacement cost of domestic crude oil for 13 offshore regions in the lower 48 states. The replacement cost of domestic crude oil is the constant or levelized selling price that will recover the full expense of exploration, development, and productions with a reasonable return on capital.

  5. Dialogue Replacement for Student Productions.

    ERIC Educational Resources Information Center

    Hank, Stephen

    1997-01-01

    Argues that film students should be taught how dialog replacement fits into overall engineering of a sound track--replacing dialog offers advantages to the student filmmaker that can enhance a less than stellar performance. States that skills such as foley artistry, postsynchronization of sound effects, and sound track engineering are as important…

  6. 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.

  7. 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.

  8. Mitral Valve Replacement with Half-and-Half Technique for Recurrent Mitral Paravalvular Leakage.

    PubMed

    Morisaki, Akimasa; Kato, Yasuyuki; Takahashi, Yosuke; Shibata, Toshihiko

    2015-05-01

    Reoperation for paravalvular leakage can cause recurrent paravalvular leakage through severe damage to the mitral annulus. Previously, mitral valve replacement using a half-and-half technique for extensive mitral annular calcification was reported; here, application of the technique to treat recurrent paravalvular leakage is described. A 78-year-old male with three prior mitral valve replacements developed recurrent paravalvular leakage, for which he had undergone his third mitral valve replacement at the age of 69 years. On this occasion, a mechanical valve with circumferential equine pericardial patch reinforcement of the annulus had been used. Five years later, the patient developed hemolytic anemia and congestive heart failure due to recurrent paravalvular leakage. Intraoperatively, broad dehiscence was seen between the prosthetic valve and mitral annulus at two sites, the anterior and posterior commissures, without infection. A fourth mitral valve replacement was performed with a St. Jude Medical valve, using a half-and-half technique. This entailed the use of non-everting mattress sutures on the anterior half of the annulus, and everting mattress sutures on the left atrial wall around the posterior half of the annulus. Extensive annular defects required reinforcement of the posterior mitral annulus with a bovine pericardial patch. Postoperative echocardiography showed no paravalvular leakage. The half-and-half technique may be useful in treating recurrent paravalvular leakage of the mitral valve. PMID:26901904

  9. 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 ...

  10. When to Replace a Prosthesis

    MedlinePlus

    Donate Fundraise Connect Contact Us Materiales en español Amputee Coalition Navigation HOME WHO WE ARE About Us ... Advisory Committee Connect With Us! STORE CALENDAR SEARCH Amputee Coalition > Limb Loss Resource Center > When to Replace ...

  11. Meal replacements and energy balance.

    PubMed

    Heymsfield, Steven B

    2010-04-26

    Induction and maintenance of a period of negative energy balance are required for overweight and obese subjects to lose weight. Meal replacements, particularly in beverage form, have now evolved as part of the "toolbox" used by researchers and clinicians to achieve negative energy balance. This overview traces the historical development of beverage meal replacements, reviews key studies supporting their clinical efficacy, and examines concerns related to their safe use. This collective information supports the view that meal replacements, particularly in beverage form, are now an effective and safe component for use in the clinical setting. Further studies are needed to identify those subjects most likely to benefit from use of meal replacements as part of their comprehensive weight control program.

  12. 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.

  13. Effect of placement of occlusive membranes on root resorption and bone regeneration during healing of circumferential periodontal defects in dogs.

    PubMed

    Claffey, N; Hahn, R; Egelberg, J

    1989-07-01

    Previous studies indicate that root resorption is a frequent sequela to significant amounts of periodontal repair in animal models. A model was developed in labrador dogs to study periodontal wound healing in large circumferential defects in the absence of influence from the oral environment. A polytetrafluorethylene membrane of 1 micron pore size (GORE-TEX) was used to occlude cells from specific tissues from populating the healing dentin-connective tissue wound. 3 modalities were studied: (1) control, in which no membrane and therefore no cell occlusion was used, (2) flap occlusion, in which the internal surface of the flap was lined with the membrane preventing contribution of cells from the flap, (3) bone occlusion, in which the reduced alveolar bone was lined with the membrane preventing contribution from bone cells. Wound closure included total submergence of teeth and membranes. The membranes remained incorporated and no exposure of membranes or teeth occurred during the 3 months healing period. Histology revealed bone regrowth in all 3 treatment modalities. It is suggested that inductive elements in the connective tissue or dentin, or bone cells from periosteum were responsible for bone regrowth in the bone membrane treatment modality. No significant difference was seen for root resorption between the 3 treatment modalities. This study found that physical occlusion of cells from the inside of the surgical flap, or from the pre-existing bone, is not sufficient to prevent root resorption in periodontal wound healing.

  14. Fracture problem for an external circumferential crack in a functionally graded superconducting cylinder subjected to a parallel magnetic field

    NASA Astrophysics Data System (ADS)

    Yan, Z.; Gao, S. W.; Feng, W. J.

    2016-02-01

    In this study, the multiple isoparametric finite element method (MIFEM) is used to investigate external circumferential crack problem of a functionally graded superconducting cylinder subjected to electromagnetic forces. The superconducting cylinder is composed by Bi2223/Ag composite with material parameters varying. A crack reference region is defined to reflect the effects of crack on flux and current densities, and the magnetically impermeable crack surface condition and the generalized Irie-Yamafuji critical state model outside the crack region are adopted. The distributions of magnetic flux density in the superconducting cylinder are obtained analytically for both the zero-field cooling (ZFC) and the field cooling (FC) activation processes. Based on the MIFEM, the stress intensity factors (SIFs) at crack fronts in the process of field ascent and/or descent are then numerically calculated. It is interesting to note from numerical results that for the present crack model in the ZFC activation process, the crack is easily propagate and grow with the applied field increases, and that in the field descent process of either the ZFC case or FC case, the crack generally does not propagate. In addition, in the field ascent process of the ZFC case, the SIFs depend on not only the crack depths and model parameters but also the applied field. The present study should be helpful to the design and application of high-temperature superconductors with external edge cracks.

  15. 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.

  16. Changes in circumferential neck measurements during movements of the head in children and their relevance to extraoral traction.

    PubMed

    Samuels, R H; DiBiase, A T

    2001-02-01

    One of the causes of facebow injuries to patients wearing extraoral traction has been the catapult effect of the simple elasticized materials used in the past. A variety of safety or self-releasing modular systems to counteract this catapult effect are currently available. However, the strap extension provided by these modules varies considerably. To reduce the catapult effect to a minimum, it is desirable to fit a system with the minimal travel that will accommodate any changes in distance between the facebow and the back of the head or neck. To ascertain the minimal travel required for the straps, circumferential neck measurements were carried out on 105 children aged between 9 and 14 years. The change in circumference was recorded for 3 different head positions. The mean distance change between the back of the neck and the end of the facebow was 25 mm per side, with a range of 4 mm to 50 mm. This study suggests that on average, modules with a 25-mm extension will be required for cervical traction.

  17. In Vivo Validation of Longitudinal–Circumferential Area Change Ratio to Estimate Myofiber Shortening in the Heart

    PubMed Central

    Omens, Jeffrey H.

    2014-01-01

    The aim of this paper was to validate area change ratio (%AC) against myofiber shortening (%λf) in the heart in vivo. %AC is emerging as a mechanical index that may approximate %λf by incorporating both circumferential and longitudinal shortening. However, the physiological significance of %AC remains unclear. We studied the time course of %AC in the anterior midleft ventricular wall of normal canine heart in vivo (n = 14) during atrial pacing over the entire cardiac cycle using transmurally implanted markers and biplane cineradiography (8 ms/frame). %AC was calculated as the myocardial area change relative to the elemental material area on the circumferential–longitudinal plane at the reference configuration (=end diastole). %AC was compared with %λf that was determined from the transmural fiber orientation directly measured in the heart tissue. The time course of both %AC and %λf was determined in the subepicardial, midwall, and subendocardial layers. The time course of %AC and %λf was significantly different, and the difference was more pronounced towards the endocardium. %AC consistently overestimated %λf. The timing of the peak %AC was significantly delayed compared to that of the peak %λf. We conclude that %AC is significantly different from %λf both in magnitude and timing in vivo. %AC overestimates %λf, and the overestimation is worse toward the endocardial layers. This may be a potentially important limitation when applying %AC to optimization and responder identification for cardiac resynchronization therapy. PMID:22345526

  18. Replacing equipment due to obsolescence, fuel efficiency

    SciTech Connect

    Harbor, V.

    1982-08-23

    Southern Natural Gas' engine replacement program with regard to expansion problems, replacement justification, meeting requirements (e.g. FERC regulations), economics, and removal and replacement was examined. As a result of replacement, gas supplies are more plentiful; and due to increased load factors, the replacing of four 1,300-hp units is now under way.

  19. 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.

  20. Spermidine-condensed phi X174 DNA cleavage by micrococcal nuclease: torus cleavage model and evidence for unidirectional circumferential DNA wrapping.

    PubMed Central

    Marx, K A; Reynolds, T C

    1982-01-01

    Spermidine-condensed phi X174 replicative form (RF) II DNA was digested with micrococcal nuclease to yield seven identifiable DNA bands forming an arithmetic fragment-length series. The DNA monomer unit length was found to be 780 +/- 80 base pairs. This result is most consistent with a proposed model for micrococcal nuclease cleavage of a DNA torus organized by the unidirectional, circumferential wrapping of B-geometry DNA. By a topological consideration, the blunt-end-rod-fusion model for torus formation [Eickbush, T. H. & Moudrianakis, E. N. (1978) Cell 13, 295-306] is shown to be inconsistent with our empirical solution results. We propose a continuous, circumferential DNA wrapping model in which a significant fraction of the collapsed circular phi X174 RFII DNA molecules form regular toruses comprised of seven complete, unidirectional double-helical wraps. Images PMID:6216482

  1. Precise Measurement of Pipe Wall Thickness in Noncontact Manner Using a Circumferential Lamb Wave Generated and Detected by a Pair of Air-Coupled Transducers

    NASA Astrophysics Data System (ADS)

    Nishino, Hideo; Asano, Tadashi; Taniguchi, Yuta; Yoshida, Kenichi; Ogawa, Hitoshi; Takahashi, Masakazu; Ogura, Yukio

    2011-07-01

    In this paper, we present a novel method of accurately estimating pipe wall thickness by detecting the minute difference in the angular wave number of a circumferential (C-) Lamb wave. A C-Lamb wave circling along a circumference of a pipe is transmitted and received by a pair of noncontact air-coupled ultrasonic transducers. For the accurate detection of the angular wave number, 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 method is very useful to monitor the integrity of piping in high-temperature environments because of its noncontact nature. The principle of the method and experimental verification are shown.

  2. 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.

  3. 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

  4. 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.

  5. Homologous gene replacement in Physarum

    SciTech Connect

    Burland, T.G.; Pallotta, D.

    1995-01-01

    The protist Physarum polycephalum is useful for analysis of several aspects of cellular and developmental biology. To expand the opportunities for experimental analysis of this organism, we have developed a method for gene replacement. We transformed Physarum amoebae with plasmid DNA carrying a mutant allele, ardD{Delta}1, of the ardD actin gene; ardD{Delta}1 mutates the critical carboxy-terminal region of the gene product. Because ardD is not expressed in the amoeba, replacement of ardD{sup +} with ardD{Delta}1 should not be lethal for this cell type. Transformants were obtained only when linear plasmid DNA was used. Most transformants carried one copy of ardD{Delta}1 in addition to ardD{sup +}, but in two (5%), ardD{sup +} was replaced by a single copy of ardD{Delta}1. This is the first example of homologous gene replacement in Physarum. ardD{Delta}1 was stably maintained in the genome through growth, development and meiosis. We found no effect of ardD{Delta}l on viability, growth, or development of any of the various cell types of Physarum. Thus, the carboxy-terminal region of the ardD product appears not to perform a unique essential role in growth or development. Nevertheless, this method for homologous gene replacement can be applied to analyze the function of any cloned gene. 38 refs., 6 figs., 1 tab.

  6. Shear stress and circumferential stretch by pulsatile flow direct vascular endothelial lineage commitment of mesenchymal stem cells in engineered blood vessels.

    PubMed

    Kim, Dong Hwa; Heo, Su-Jin; Kang, Yun Gyeong; Shin, Ji Won; Park, So Hee; Shin, Jung-Woog

    2016-03-01

    Understanding the response of mesenchymal stem cells (MSCs) in the dynamic biomechanical vascular environment is important for vascular regeneration. Native vessel biomechanical stimulation in vitro is thought to be the most important contributor to successful endothelial differentiation of MSCs. However, the appropriate biomechanical stimulation conditions for differentiating MSCs into ECs have not been fully investigated. To accomplish an in vivo-like loading environment, a loading system was designed to apply flow induced stress and induce hMSC differentiation in vascular cells. Culturing MSCs on tubular scaffolds under flow-induced shear stress (2.5 dyne/cm(2)) for 4 days results in increased mRNA levels of EC markers (vWF, CD31, VE-cadherin and E-selectin) after one day. Furthermore, we investigated the effects of 2.5 dyne/cm(2) shear stress followed by 3% circumferential stretch for 3 days, and an additional 5% circumferential stretch for 4 days on hMSC differentiation into ECs. EC marker protein levels showed a significant increase after applying 5% stretch, while SMC markers were not present at levels sufficient for detection. Our results demonstrate that the expression of several hMSC EC markers cultured on double-layered tubular scaffolds were upregulated at the mRNA and protein levels with the application of fluid shear stress and cyclic circumferential stretch.

  7. Shear stress and circumferential stretch by pulsatile flow direct vascular endothelial lineage commitment of mesenchymal stem cells in engineered blood vessels.

    PubMed

    Kim, Dong Hwa; Heo, Su-Jin; Kang, Yun Gyeong; Shin, Ji Won; Park, So Hee; Shin, Jung-Woog

    2016-03-01

    Understanding the response of mesenchymal stem cells (MSCs) in the dynamic biomechanical vascular environment is important for vascular regeneration. Native vessel biomechanical stimulation in vitro is thought to be the most important contributor to successful endothelial differentiation of MSCs. However, the appropriate biomechanical stimulation conditions for differentiating MSCs into ECs have not been fully investigated. To accomplish an in vivo-like loading environment, a loading system was designed to apply flow induced stress and induce hMSC differentiation in vascular cells. Culturing MSCs on tubular scaffolds under flow-induced shear stress (2.5 dyne/cm(2)) for 4 days results in increased mRNA levels of EC markers (vWF, CD31, VE-cadherin and E-selectin) after one day. Furthermore, we investigated the effects of 2.5 dyne/cm(2) shear stress followed by 3% circumferential stretch for 3 days, and an additional 5% circumferential stretch for 4 days on hMSC differentiation into ECs. EC marker protein levels showed a significant increase after applying 5% stretch, while SMC markers were not present at levels sufficient for detection. Our results demonstrate that the expression of several hMSC EC markers cultured on double-layered tubular scaffolds were upregulated at the mRNA and protein levels with the application of fluid shear stress and cyclic circumferential stretch. PMID:26800691

  8. Familial LCAT deficiency: from renal replacement to enzyme replacement.

    PubMed

    Stoekenbroek, R M; van den Bergh Weerman, M A; Hovingh, G K; Potter van Loon, B J; Siegert, C E H; Holleboom, A G

    2013-01-01

    Familial LCAT deficiency (FLD) is a recessive lipid disorder ultimately leading to end-stage renal disease (ESRD). We present two brothers with considerable variation in the age at which they developed ESRD. Kidney biopsies revealed both tubular and glomerular pathology. To date, no causal therapy is available, yet enzyme replacement therapy is in development. PMID:23412821

  9. Longitudinally and circumferentially directed movements of the left ventricle studied by cardiovascular magnetic resonance phase contrast velocity mapping

    PubMed Central

    2010-01-01

    Objective Using high resolution cardiovascular magnetic resonance (CMR), we aimed to detect new details of left ventricular (LV) systolic and diastolic function, to explain the twisting and longitudinal movements of the left ventricle. Methods Using CMR phase contrast velocity mapping (also called Tissue Phase Mapping) regional wall motion patterns and longitudinally and circumferentially directed movements of the left ventricle were studied using a high temporal resolution technique in healthy male subjects (n = 14, age 23 ± 3 years). Results Previously undescribed systolic and diastolic motion patterns were obtained for left ventricular segments (based on the AHA segmental) and for basal, mid and apical segments. The summation of segmental motion results in a complex pattern of ventricular twisting and longitudinal motion in the normal human heart which underlies systolic and diastolic function. As viewed from the apex, the entire LV initially rotates in a counter-clockwise direction at the beginning of ventricular systole, followed by opposing clockwise rotation of the base and counter-clockwise rotation at the apex, resulting in ventricular torsion. Simultaneously, as the entire LV moves in an apical direction during systole, the base and apex move towards each other, with little net apical displacement. The reverse of these motion patterns occur in diastole. Conclusion Left ventricular function may be a consequence of the relative orientations and moments of torque of the sub-epicardial relative to the sub-endocardial myocyte layers, with influence from tethering of the heart to adjacent structures and the directional forces associated with blood flow. Understanding the complex mechanics of the left ventricle is vital to enable these techniques to be used for the evaluation of cardiac pathology. PMID:20716369

  10. Differential effects of inhaled methacholine on circumferential wall and vascular smooth muscle of third-generation airways in awake sheep.

    PubMed

    McLeod, Damian; Parsons, Gibbe; Gunther, Robert; Quail, Anthony; Cottee, David; White, Saxon

    2012-10-15

    Evolution and natural selection ensure that specific mechanisms exist for selective airway absorption of inhaled atmospheric molecules. Indeed, nebulized cholinoceptor agonists used in asthma-challenge tests may or may not enter the systemic circulation. We examined the hypothesis that inhaled cholinoceptor agonists have selective access. Six sheep were instrumented under general anesthesia (propofol 5 mg/kg iv, 2-3% isoflurane-oxygen), each with pulsed-Doppler blood flow transducers mounted on the single bronchial artery and sonomicrometer probes mounted on the intrapulmonary third-generation lingula lobe bronchus. Continuous measurements were made of bronchial blood flow (Q(br)), Q(br) conductance (C(br)), bronchial hemicircumference (CIRC(br)), and bronchial wall thickness (WALL TH(br)) in recovered, standing, awake sheep. Methacholine (MCh; 0.125-2.0 μg/kg iv), at the highest dose, caused a 233% rise in Q(br) (P < 0.05) and a 286% rise in C(br) (P < 0.05). CIRC(br) fell to 90% (P < 0.05); WALL TH(br) did not change. In contrast, nebulized MCh (1-32 mg/ml), inhaled through a mask at the highest dose, caused a rise in ventilation and a rise in Q(br) proportional to aortic pressure without change in C(br). CIRC(br) fell to 91% (P < 0.01), and WALL TH(br) did not change. Thus inhaled MCh has access to cholinoceptors of bronchial circumferential smooth muscle to cause airway lumen narrowing but effectively not to those of the systemic bronchovascular circulation. It is speculated that the mechanism is selective neuroparacrine inhibition of muscarinic acetylcholine receptors (M3 bronchovascular cholinoceptors) by prostanoids released by intense MCh activation of epithelial and mucosal cells lining the airway. PMID:22898550

  11. Sparing Sphincters and Laparoscopic Resection Improve Survival by Optimizing the Circumferential Resection Margin in Rectal Cancer Patients

    PubMed Central

    Keskin, Metin; Bayraktar, Adem; Sivirikoz, Emre; Yegen, Gülcin; Karip, Bora; Saglam, Esra; Bulut, Mehmet Türker; Balik, Emre

    2016-01-01

    Abstract The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors. Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann–Whitney U test and the Mantel–Cox log-rank sum test. A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics or surgical treatment between the patients who had positive CRM and who had negative CRM, but a higher positive CRM rate was observed in patients undergone abdominoperineal resection (APR) (P < 0.001). Advanced T-stage (P < 0.001), lymph node invasion (P = 0.001) and incomplete mesorectum (P = 0.007) were encountered significantly more often in patients with positive CRM status. Logistic regression analysis revealed that APR (P < 0.001) and open resection (P = 0.046) were independent predictors of positive CRM status. Moreover, positive CRM was associated with decreased 5-year overall and disease-free survival (P = 0.002 and P = 0.004, respectively). This large single-institution series demonstrated that APR and open resection were independent predictive factors for positive CRM status in rectal cancer. Positive CRM independently decreased the 5-year overall and disease-free survival rates. PMID:26844498

  12. Sparing Sphincters and Laparoscopic Resection Improve Survival by Optimizing the Circumferential Resection Margin in Rectal Cancer Patients.

    PubMed

    Keskin, Metin; Bayraktar, Adem; Sivirikoz, Emre; Yegen, Gülcin; Karip, Bora; Saglam, Esra; Bulut, Mehmet Türker; Balik, Emre

    2016-02-01

    The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors.Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann-Whitney U test and the Mantel-Cox log-rank sum test.A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics or surgical treatment between the patients who had positive CRM and who had negative CRM, but a higher positive CRM rate was observed in patients undergone abdominoperineal resection (APR) (P < 0.001). Advanced T-stage (P < 0.001), lymph node invasion (P = 0.001) and incomplete mesorectum (P = 0.007) were encountered significantly more often in patients with positive CRM status. Logistic regression analysis revealed that APR (P < 0.001) and open resection (P = 0.046) were independent predictors of positive CRM status. Moreover, positive CRM was associated with decreased 5-year overall and disease-free survival (P = 0.002 and P = 0.004, respectively).This large single-institution series demonstrated that APR and open resection were independent predictive factors for positive CRM status in rectal cancer. Positive CRM independently decreased the 5-year overall and disease-free survival rates.

  13. Molecular replacement: tricks and treats

    SciTech Connect

    Abergel, Chantal

    2013-11-01

    To be successful, molecular replacement relies on the quality of the model and of the crystallographic data. Some tricks that could be applied to the models or to the crystal to increase the success rate of MR are discussed here. Molecular replacement is the method of choice for X-ray crystallographic structure determination provided that suitable structural homologues are available in the PDB. Presently, there are ∼80 000 structures in the PDB (8074 were deposited in the year 2012 alone), of which ∼70% have been solved by molecular replacement. For successful molecular replacement the model must cover at least 50% of the total structure and the C{sub α} r.m.s.d. between the core model and the structure to be solved must be less than 2 Å. Here, an approach originally implemented in the CaspR server (http://www.igs.cnrs-mrs.fr/Caspr2/index.cgi) based on homology modelling to search for a molecular-replacement solution is discussed. How the use of as much information as possible from different sources can improve the model(s) is briefly described. The combination of structural information with distantly related sequences is crucial to optimize the multiple alignment that will define the boundaries of the core domains. PDB clusters (sequences with ≥30% identical residues) can also provide information on the eventual changes in conformation and will help to explore the relative orientations assumed by protein subdomains. Normal-mode analysis can also help in generating series of conformational models in the search for a molecular-replacement solution. Of course, finding a correct solution is only the first step and the accuracy of the identified solution is as important as the data quality to proceed through refinement. Here, some possible reasons for failure are discussed and solutions are proposed using a set of successful examples.

  14. 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.

  15. Improved circumferential shaft seal

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    Comparative tests of modified and unmodified carbon ring seals showed that addition of helical grooves to conventional segmented carbon ring seals reduced leakage significantly. Modified seal was insensitive to shaft runout and to flooding by lubricant.

  16. 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.

  17. Testing of Replacement Bag Material

    SciTech Connect

    Laurinat, J.E.

    1998-11-03

    Recently, the FB-Line bagout material was changed to simplify the processing of sand, slag, and crucible.The results of the strength tests and the outgassing measurements and calculations demonstrate that the proposed replacement nylon bag materials (HRMP and orange anti-static material) are acceptable substitutes for LDPE and the original nylon with respect to mechanical properties.

  18. 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.

  19. [Organ replacement therapy - renal replacement therapy in intensive care medicine].

    PubMed

    Kraus, Daniel; Wanner, Christoph

    2016-09-01

    Critically ill patients who are treated in an intensive care unit are at increased risk of developing acute renal failure. Every episode of renal failure decreases life expectancy. However, acute renal failure is no longer an immediate cause of death because renal function can be substituted medically and mechanically, by the use of renal replacement therapy. Hemodialysis and hemofiltration are the 2 fundamental modalities of renal replacement therapy and may be performed intermittently or continuously. The decision for one particular therapy has to be made for each patient individually. Peritoneal dialysis is an alternative treatment for acute renal failure, but is not available for immediate use in most centers. Contrast media and rhabdomyolysis are 2 common causes of toxic renal failure in the intensive care unit. However, they cannot be prevented by hemodialysis. PMID:27631449

  20. [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.

  1. Hurricane intensity and eyewall replacement.

    PubMed

    Houze, Robert A; Chen, Shuyi S; Smull, Bradley F; Lee, Wen-Chau; Bell, Michael M

    2007-03-01

    Observations made during the historic 2005 hurricane season document a case of "eyewall replacement." Clouds outside the hurricane eyewall coalesce to form a new eyewall at a greater radius from the storm center, and the old eyewall dies. The winds in the new eyewall are initially weaker than those in the original eyewall, but as the new eyewall contracts, the storm reintensifies. Understanding this replacement mechanism is vital to forecasting variations in hurricane intensity. Processes in the "moat" region between the new and old eyewall have been particularly unclear. Aircraft data now show that the moat becomes dynamically similar to the eye and thus is converted into a region inimical to survival of the inner eyewall. We suggest that targeting aircraft to key parts of the storm to gain crucial input to high-resolution numerical models can lead to improvements in forecasting hurricane intensity.

  2. Replacement element for automobile thermostat

    SciTech Connect

    Ferrari, W.

    1988-06-07

    This patent describes a thermostat replacement element for use in a cooling system in which a continuous stream of coolant normally flows from a radiator through a thermostat to an engine. The thermostat is mounted within a mounting cavity and permits maximum flow of coolant through the cooling system when in an open position. The replacement element comprises a disc-shaped member having a diameter substantially corresponding to the diameter of the mounting cavity. The member is provided with apertures of a predetermined size to permit flow of coolant therethrough at a rate generally corresponding to the rate of flow of coolant through the thermostat when the thermostat is in an open position.

  3. 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

  4. Nicotine Replacement Therapy: An Overview.

    PubMed

    Wadgave, Umesh; Nagesh, L

    2016-07-01

    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.

  5. Nicotine Replacement Therapy: An Overview.

    PubMed

    Wadgave, Umesh; Nagesh, L

    2016-07-01

    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

  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.

  7. 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. PMID:24877582

  8. 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

  9. Total disc replacement surgery for symptomatic degenerative lumbar disc disease: a systematic review of the literature

    PubMed Central

    van den Eerenbeemt, Karin D.; van Royen, Barend J.; Peul, Wilco C.; van Tulder, Maurits W.

    2010-01-01

    The objective of this study is to evaluate the effectiveness and safety of total disc replacement surgery compared with spinal fusion in patients with symptomatic lumbar disc degeneration. Low back pain (LBP), a major health problem in Western countries, can be caused by a variety of pathologies, one of which is degenerative disc disease (DDD). When conservative treatment fails, surgery might be considered. For a long time, lumbar fusion has been the “gold standard” of surgical treatment for DDD. Total disc replacement (TDR) has increased in popularity as an alternative for lumbar fusion. A comprehensive systematic literature search was performed up to October 2008. Two reviewers independently checked all retrieved titles and abstracts, and relevant full text articles for inclusion. Two reviewers independently assessed the risk of bias of included studies and extracted relevant data and outcomes. Three randomized controlled trials and 16 prospective cohort studies were identified. In all three trials, the total disc replacement was compared with lumbar fusion techniques. The Charité trial (designed as a non-inferiority trail) was considered to have a low risk of bias for the 2-year follow up, but a high risk of bias for the 5-year follow up. The Charité artificial disc was non-inferior to the BAK® Interbody Fusion System on a composite outcome of “clinical success” (57.1 vs. 46.5%, for the 2-year follow up; 57.8 vs. 51.2% for the 5-year follow up). There were no statistically significant differences in mean pain and physical function scores. The Prodisc artificial disc (also designed as a non-inferiority trail) was found to be statistically significant more effective when compared with the lumbar circumferential fusion on the composite outcome of “clinical success” (53.4 vs. 40.8%), but the risk of bias of this study was high. Moreover, there were no statistically significant differences in mean pain and physical function scores. The Flexicore trial

  10. 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

  11. Anesthesia for bone replacement surgery

    PubMed Central

    Singh, Sunil; Singh, Shri Prakash; Agarwal, Jitendra K

    2012-01-01

    Advances in clinical medicine, improved understanding of pathophysiology, and the extensive application of medical technology have projected hitherto high risk and poor outcome surgical procedures into the category of routine and relatively good outcome surgeries. Bone replacement surgery is one amongst these and is wrought with a multitude of perioperative complexities. An understanding of these goes a long way in assisting in the final outcome for the patient. Here we present a review of the literature covering various issues involved during the different stages of the perioperative period. PMID:22557736

  12. Patellofemoral replacement: the third compartment.

    PubMed

    Hofmann, A A; McCandless, J B; Shaeffer, J F; Magee, T H

    2013-11-01

    Isolated patellofemoral arthritis is a common condition and there are varying opinions on the most effective treatments. Non-operative and operative treatments have failed to demonstrate effective long-term treatment for those in an advanced stage of the condition. Newer designs and increased technology in patellofemoral replacement (PFR) have produced more consistent outcomes. This has led to a renewed enthusiasm for this procedure. Newer PFR prostheses have addressed the patellar maltracking issues plaguing some of the older designs. Short-term results with contemporary prostheses and new technology are described here.

  13. Advances in testosterone replacement therapy.

    PubMed

    Gooren, Louis J G

    2009-01-01

    The major goal of androgen substitution is to replace testosterone at levels as close to physiological concentrations as is possible. The mainstay of testosterone susbstitution are parenteral testosterone esters (enanthate and cypionate) to be administered every 2-3 weeks. A major disadvantage is the strongly fluctuating levels of plasma testosterone which are at least 50% of the time not in the physiological range. A significant improvement is parenteral testosterone undecanoate producing normal plasma testosterone for 12 weeks. Subcutaneous testosterone implants provide the patient, depending on the dose of implants, with normal plasma testosterone for 3-6 months. Its use is, however, not widespread. Oral testosterone undecanoate dissolved in oil bypasses the liver via its lymphatic absorption, but resulting plasma levels are erratic. Transdermal testosterone preparations have already been available for two decades. Transdermal testosterone gel produces attractive pharmocokinetic serum testosterone profiles and offers greater flexibility in dosing. Transdermal gel has been recommended in elderly males. In case of complications its use can be discontinued immediately. Oromucosal testosterone preparations are being developed. Testosterone replacement is usually of long duration, and patient compliance is of utmost importance. Therefore, the patient must be involved in the selection of the type of testosterone preparation. PMID:19011287

  14. The future of nicotine replacement.

    PubMed

    Russell, M A

    1991-05-01

    Following in the wake of progress forged by nicotine chewing gum, a new generation of nicotine replacement products will soon be available as aids to giving up smoking. These range from nicotine skin patches, which take 6-8 hrs to give very flat steady-state peak blood levels, to nicotine vapour inhalers which mimic the transient high-nicotine boli that follow within a few seconds of each inhaled puff of cigarette smoke. Other products undergoing clinical trials include a nasal nicotine spray and nicotine lozenges. It is argued here that it is not so much the efficacy of new nicotine delivery systems as temporary aids to cessation, but their potential as long-term alternatives to tobacco that makes the virtual elimination of tobacco a realistic future target. Their relative safety compared with tobacco is discussed. A case is advanced for selected nicotine replacement products to be made as palatable and acceptable as possible and actively promoted on the open market to enable them to compete with tobacco products. They will also need health authority endorsement, tax advantages and support from the anti-smoking movement if tobacco use is to be gradually phased out altogether.

  15. Raised replacement heifers: some economic considerations.

    PubMed

    Hughes, Harlan

    2013-11-01

    This article lays out the recommended procedure for determining the economic cost of developing a proposed set of replacement heifers. In particular, a 6-step process that calculates the economic cost of developing a raised pregnant replacement heifer is described.

  16. 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.

  17. Cardiac valve replacement: Experience in 2400 patients

    PubMed Central

    Papo, Isidor; Albreht, Mis̆a; Martinović, Nebojs̆a; Sokolić, Josip; Marenović, Tomislav

    1981-01-01

    In the series described here, 2400 patients over a 15-year period underwent surgery for correction of acquired valvular heart disease. Of these, 1586 patients had single valve replacement, 714 had double valve replacement, and 100 had triple valve replacement. Concomitant surgery for associated congenital and acquired lesions was done in 114 patients. The hospital mortality was 9.16%. PMID:15216220

  18. 25 CFR 700.53 - Dwelling, replacement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Dwelling, replacement. 700.53 Section 700.53 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means...

  19. 25 CFR 700.53 - Dwelling, replacement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Dwelling, replacement. 700.53 Section 700.53 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means...

  20. 25 CFR 700.53 - Dwelling, replacement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Dwelling, replacement. 700.53 Section 700.53 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means...

  1. 25 CFR 700.53 - Dwelling, replacement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Dwelling, replacement. 700.53 Section 700.53 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.53 Dwelling, replacement. The term replacement dwelling means...

  2. 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 ( ...

  3. 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 ( ...

  4. Estrogen Replacement Therapy for Stroke

    PubMed Central

    Pabon, Mibel; Tamboli, Cyrus; Tamboli, Sarosh; Acosta, Sandra; De La Pena, Ike; Sanberg, Paul R.; Tajiri, Naoki; Kaneko, Yuji; Borlongan, Cesar V.

    2014-01-01

    Stroke is the third most common cause of death and severe disability among Western populations. Overall, the incidence of stroke is uniformly higher in men than in women. Stroke is rare in women during the reproductive years and rapidly increases after menopause, strongly suggesting that estrogen (E2) plays an important role in the prevention of stroke. Ongoing studies are currently evaluating both the benefits and the risks associated with E2 replacement therapy and hormone replacement therapy in stroke. Equally important is the role of E2 receptor (ER), as studies indicate that ER populations in several tissue sites may significantly change during stress and aging. Such changes may affect the patient’s susceptibility to neurological disorders including stroke and greatly affect the response to selective E2 receptor modulators (SERMs). Replacement therapies may be inefficient with low ER levels. The goal of this review paper is to discuss an animal model that will allow investigations of the potential therapeutic effects of E2 and its derivatives in stroke. We hypothesize that E2 neuroprotection is, in part, receptor mediated. This hypothesis is a proof-of-principle approach to demonstrate a role for specific ER subtypes in E2 neuroprotection. To accomplish this, we use a retroviral-mediated gene transfer strategy that expresses subtypes of the ER gene in regions of the rat brain most susceptible to neuronal damage, namely, the striatum and the cortex. The animal model is exposed to experimental stroke conditions involving middle cerebral artery occlusion (MCAo) method, and eventually the extent of neuronal damage will be evaluated. A reduction in neuronal damage is expected when E2 is administered with specific ER subtypes. From this animal model, an optimal E2 dose and treatment regimen can be determined. The animal model can help identify potential E2-like therapeutics in stroke and screen for beneficial or toxic additives present in commercial E2

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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. PMID:20120606

  11. 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. PMID:26715998

  12. 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.

  13. 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

  14. 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.

  15. Delivery of testosterone replacement therapy.

    PubMed

    Hameed, Asjad; Brothwood, Theresa; Bouloux, Pierre

    2003-10-01

    Optimal testosterone replacement therapy remains a considerable challenge for the estimated five out of 1000 men in the general community with androgen deficiency. Oral delivery is not possible due to rapid first pass metabolism and short half-life. Testosterone derivatives have been developed to enhance intrinsic androgenic potency, prolong duration of action, or improve oral bioavailability of synthetic androgens. Structural modification of testosterone include 17 beta-esterification, 17 alpha-alkylation, 1-methylation, addition of a 19-normethyl group, and 7 alpha-methylation. Currently, oral (testosterone undecanoate), transcutaneous (Andropatch, Virormone, Testoderm (ALZA Corp), Testogel), sublingual (testosterone cyclodextrin), intramuscular (Sustanon, Primoteston Depot), and fused crystalline testosterone pellet preparations are available for clinical use. Transbuccal testosterone systems have also been developed for clinical use and require twice daily application. Suspensions of biodegradable microspheres consisting of a polyglycolide-lactide matrix laden with testosterone can deliver stable, physiological levels of testosterone for 2 to 3 months. Micronized testosterone has low oral bioavailability requiring high daily doses. 7 alpha-Methyl 19-nortestosterone, a potent, synthetic androgen free of hepatotoxicity, has tissue-specific selectivity, being susceptible to aromatization but not 5 alpha-reduction, thereby potentially avoiding intraprostatic androgen amplification. PMID:14649214

  16. Autologous tracheal replacement for cancer.

    PubMed

    Fabre, Dominique; Fadel, Elie; Mussot, Sacha; Kolb, Frederic; Leymarie, Nicolas; Mercier, Olaf; Le Chevalier, Thierry; Dartevelle, Philippe G

    2015-12-01

    Surgical research has failed during fifty years to find an ideal substitute for the trachea after extended resection. All the prostheses could erode the adjacent structures or lead to infection or obstructive issues. Innovation in surgery development has been improved using novel techniques of plastic surgery. During the last ten years, we have developed a technique using free fasciocutaneous flaps. This allows us to construct tubes for tracheal replacement. The most accurate flap used for this technique is the forearm free flap (FFF). Reinforcement of the flap with autologous strips of cartilage harvested from the last ribs offers sufficient resistance to respiratory pressure. This technique is also completely autologous without any stent in the tracheal lumen. From 2004 to 2015 we have already reconstructed the trachea of 16 patients for 12 primary tracheal neoplasms [including 9 adenoid cystic carcinoma (ACC) and 3 squamous cell carcinoma (SCC)], 3 secondary tracheal Neoplasms and one for benign lesion. This article describes the indications, determination of resectability, patient selection, subheading for surgery, postoperative management and results of this technique. PMID:26730758

  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

    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.

  18. 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

  19. 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

  20. Microcrystalline cellulose replacement in cakes and biscuits.

    PubMed

    Brys, K D; Zabik, M E

    1976-07-01

    Sensory and physical characteristics of cakes and biscuits with up to 60 per cent of flour replaced, volume for volume, with microcrystalline cellulose were compared with those of the respective controls. High quality products were obtained at replacement levels of 40 and 20 per cent, respectively, in lean-formula cakes and in biscuits. At these replacement levels, caloric density was reduced by 12 and 10 per cent, respectively, in the cakes and biscuits.

  1. 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. PMID:9601410

  2. 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.

  3. Reoperations Following Cervical Disc Replacement.

    PubMed

    Skovrlj, Branko; Lee, Dong-Ho; Caridi, John Michael; Cho, Samuel Kang-Wook

    2015-06-01

    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

  4. The unstable total hip replacement

    PubMed Central

    D'Angelo, F; Murena, L; Zatti, G; Cherubino, P

    2008-01-01

    Background: Dislocation is one of the most common complications of total hip arthroplasty with a reported dislocation rate of 3.2%. Despite increased experience with hip replacement, the overall rate has not yet changed. The aim of this paper is to review the most recent literature published on this topic and indexed in Medline, in order to clarify the main risk factors, and to standardize a treatment protocol of such an important complication of prosthetic surgery. Materials and Methods: Medline database was searched using key words: “hip dislocation”, “hip instability” from 1980-2007. Studies were eligible for review and included if they met the following criteria: (1) publication in English, (2) clinical trials (3) review papers. Results: The risk of first-time dislocation as a function of time after the surgery is not well understood. Most, but not all, series have demonstrated that the risk of dislocation is highest during the first few months after hip arthroplasty; however, first-time late dislocation can also occur many years after the procedure. Several risk factors were described, including the surgical approach, the diameter of the head, impingement, component malposition, insufficient abductor musculature. In addition, there are also many treatment options, such as long-term bracing after closed reduction, component reorientation, capsulorraphy, trochanteric advancement, increasing offset, exchange of the modular head and the polyethylene liner, insertion of constrained liner. Conclusion: Preventing hip dislocation is obviously the best strategy. Surgeons must take into account patient and surgical risk factors. For patients at high risk for dislocation the surgeon should accurately restore leg length and femoral offset; the use of larger femoral heads, posterior transosseous repair of the capsulotendinous envelope if posterior approach is chosen or the use of a lateral approach should be considered. Proper patient education and postoperative

  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. 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…

  8. 47 CFR 13.17 - Replacement license.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Replacement license. 13.17 Section 13.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS General § 13.17 Replacement license. (a) Each licensee or permittee whose original document is lost, mutilated, or destroyed...

  9. Insect biotechnology: controllable replacement of disease vectors.

    PubMed

    Wimmer, Ernst A

    2013-05-20

    To fight human vector-borne diseases, first releases of sterile transgenic mosquitoes have been performed. Someday, disease-refractory mosquitoes will replace wild types to stop transmission. For such population replacements, gene drive mechanisms must be established that allow local confinement and reversibility.

  10. 30 CFR 823.14 - Soil replacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as...

  11. 30 CFR 823.14 - Soil replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as...

  12. 30 CFR 823.14 - Soil replacement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as...

  13. 30 CFR 823.14 - Soil replacement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as...

  14. 30 CFR 823.14 - Soil replacement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Soil replacement. 823.14 Section 823.14 Mineral... Soil replacement. (a) Soil reconstruction specifications established by the U.S. Soil Conservation Service shall be based upon the standards of the National Cooperative Soil Survey and shall include, as...

  15. Condylar hyperplasia following unilateral temporomandibular joint replacement.

    PubMed

    Machon, V; Levorova, J; Hirjak, D; Foltan, R

    2015-06-01

    Total joint replacement of the temporomandibular joint (TJR) can be associated with intraoperative and postoperative complications. We report herein the occurrence of a postoperative open bite malocclusion, the result of condylar hyperplasia affecting the non-operated joint at 1 year after unilateral total joint replacement. PMID:25662429

  16. Conservative treatment planning in veneer replacement.

    PubMed

    Guzmán-Armstrong, Sandra; Maia, Rodrigo Rocha

    2016-04-01

    This clinical report describes a conservative treatment in veneer replacement where diastemas, malalignment, and midline shift were the main modifying factors. When replacement veneers are indicated, the definitive results can only be accurately predicted after an esthetic reanalysis of the existing restorations. PMID:26602148

  17. 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

  18. 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... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than...

  19. 25 CFR 700.189 - Expenditure of replacement home benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Expenditure of replacement home benefits. 700.189 Section... PROCEDURES Replacement Housing Payments § 700.189 Expenditure of replacement home benefits. Replacement home... maximum replacement home benefit. (b) All replacement home benefits shall be expended not later than...

  20. 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

  1. 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.

  2. Porous surface replacement of the hip with chamfered-cylinder component.

    PubMed

    Amstutz, H; Kilgus, D; Kabo, M; Dorey, F

    1988-01-01

    One hundred porous surface replacements (PSR) were performed in 92 patients (63 men and 29 women) with a mean age of 53 (range 17-76). Follow-up times range from 1 to 4 years, with 48 patients having a follow-up of at least 2 years. Preoperative diagnoses were osteoarthritis (OA) 63, osteonecrosis (ON) 13, dysplasia 9, rheumatoid-ankylosing spondylitis 6, and other 9. Seventeen hips had metal-backed acrylic-fixed THARIES acetabular sockets, nine hips had a porous cobalt chrome hemispheric beaded acetabular component with adjuvant fixation screws and externally protruding screw hubs, and 74 hips had a porous chamfered cylinder-design acetabulum. Pain relief had been immediate and more complete than with acrylic-fixed or biologic-ingrowth stem-type replacement with comparable walking and function improvements. There have been no major systemic complications, sepsis, or loosening. There have been two transient peroneal nerve palsies and three trochanteric fibrous unions. There have been three reoperations, one for subluxation, one for "metalosis" due to mesh pad loosening, and one femoral neck fracture. Examination of one removed femoral surface component which has been histologically sectioned revealed excellent (90%) bone in-growth. Circumferential progressive radiolucencies developed at the bone-cement interface by 1 year in all of the 17 acrylic-fixed acetabular components. Reaming or seating defects were noted in 25% of the ingrowth components on postoperative radiographs. Radiographic analysis of immediate postoperative films of the chamfered cylinder design acetabular components frequently demonstrated bone-component interface radiolucencies which represented component seating defects. These initial interface radiolucencies became progressively more narrow over the first six months postoperatively suggesting "healing" of the reamed bone-component interface with trabecular bone around the chamfered cylinder acetabular components. Partial healing of initial

  3. Older Person's Guide to Joint Replacement

    MedlinePlus

    ... he or she will refer you to an orthopedic surgeon who does hip and knee replacement surgery. ... The Arthritis Foundation Web The American Academy of Orthopedic Surgeons ' The American Association of Knee and Hip ...

  4. 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.

  5. 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.

  6. Three-dimensional imaging of collagen fibril organization in rat circumferential lamellar bone using a dual beam electron microscope reveals ordered and disordered sub-lamellar structures.

    PubMed

    Reznikov, Natalie; Almany-Magal, Rotem; Shahar, Ron; Weiner, Steve

    2013-02-01

    Lamellar bone is a major component of most mammalian skeletons. A prominent component of individual lamellae are parallel arrays of mineralized type I collagen fibrils, organized in a plywood like motif. Here we use a dual beam microscope and the serial surface view (SSV) method to investigate the three dimensional collagen organization of circumferential lamellar bone from rat tibiae after demineralization and osmium staining. Fast Fourier transform analysis is used to quantitatively identify the mean collagen array orientations and local collagen fibril dispersion. Based on collagen fibril array orientations and variations in fibril dispersion, we identify 3 distinct sub-lamellar structural motifs: a plywood-like fanning sub-lamella, a unidirectional sub-lamella and a disordered sub-lamella. We also show that the disordered sub-lamella is less mineralized than the other sub-lamellae. The hubs and junctions of the canalicular network, which connect radially oriented canaliculi, are intimately associated with the disordered sub-lamella. We also note considerable variations in the proportions of these 3 sub-lamellar structural elements among different lamellae. This new application of Serial Surface View opens the way to quantitatively compare lamellar bone from different sources, and to clarify the 3-dimensional structures of other bone types, as well as other biological structural materials. PMID:23153959

  7. Mechanical buckling of a functionally graded cylindrical shell with axial and circumferential stiffeners using the third-order shear deformation theory

    NASA Astrophysics Data System (ADS)

    Farahani, Hossein; Azarafza, Reza; Barati, Farzan

    2014-09-01

    This paper deals with an analytical approach of the buckling behavior of a functionally graded circular cylindrical shell under axial pressure with external axial and circumferential stiffeners. The shell properties are assumed to vary continuously through the thickness direction. Fundamental relations and equilibrium and stability equations are derived using the third-order shear deformation theory. The resulting equations are employed to obtain the closed-form solution for the critical buckling loads. A simply supported boundary condition is considered for both edges of the shell. The comparison of the results of this study with those in the literature validates the present analysis. The effects of material composition (volume fraction exponent), of the number of stiffeners and of shell geometry parameters on the characteristics of the critical buckling load are described. The analytical results are compared and validated using the finite-element method. The results show that the inhomogeneity parameter, the geometry of the shell and the number of stiffeners considerably affect the critical buckling loads.

  8. Bioceramics in ossicular replacement prostheses: a review.

    PubMed

    Wongwiwat, Plawut; Boonma, Apichart; Lee, Yuan-Shin; Narayan, Roger J

    2011-01-01

    For many decades, bioceramic materials have been used in a variety of biomedical applications due to their biocompatibility, hardness, wear resistance and compressive strength properties. Bioceramic materials, including Bioglass, glass ceramic materials, and hydroxyapatite, have used to create total ossicular replacement prostheses and partial ossicular replacement prostheses. This review describes design factors associated with middle ear implants as well as clinical use of bioceramic materials in middle ear implants.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Adaptive Replacement Strategies for MOEA/D.

    PubMed

    Wang, Zhenkun; Zhang, Qingfu; Zhou, Aimin; Gong, Maoguo; Jiao, Licheng

    2016-02-01

    Multiobjective evolutionary algorithms based on decomposition (MOEA/D) decompose a multiobjective optimization problem into a set of simple optimization subproblems and solve them in a collaborative manner. A replacement scheme, which assigns a new solution to a subproblem, plays a key role in balancing diversity and convergence in MOEA/D. This paper proposes a global replacement scheme which assigns a new solution to its most suitable subproblems. We demonstrate that the replacement neighborhood size is critical for population diversity and convergence, and develop an approach for adjusting this size dynamically. A steady-state algorithm and a generational one with this approach have been designed and experimentally studied. The experimental results on a number of test problems have shown that the proposed algorithms have some advantages. PMID:25826813

  14. 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.

  15. 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.

  16. [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.

  17. 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.

  18. 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. PMID:19547086

  19. A localizing circumferential compression device delayed death after artificial eastern diamondback rattlesnake envenomation to the torso of an animal model in a pilot study.

    PubMed

    Hack, Jason B; Orogbemi, Babatunde; Deguzman, Jocelyn M; Brewer, Kori L; Meggs, William J; O'Rourke, Dorcas

    2010-06-01

    Nearly all prior studies to delay onset of systemic toxicity and death after snake bite use a model of distal extremity envenomation. In the first of a series of planned studies using snake venoms with different toxicity profiles, the application of a novel device in a new model of torso envenomation in the setting of Eastern Coral Snake (Micrurus fulvius) venom (a potent neurotoxin) envenomation showed promise by delaying systemic intoxication. In this pilot study, we investigated this novel localizing circumferential compression (LoCC) device's ability to delay onset of life threatening systemic toxicity after Eastern Diamondback Rattlesnake (Crotalus adamanteus) envenomation, a potent hemotoxic and myotoxic venom. With university approval, four juvenile female pigs (22-25 kg) were anesthetized, sedated, and intubated but not paralyzed to allow for spontaneous respirations. Each animal was injected subcutaneously with 50 mg of C. adamanteus venom in identical preselected areas of the trunk. After 1 min, two treatment animals had the LoCC device applied; two control animals had no intervention. Vital signs were recorded every 10 min for the first 2 h and every 30 min thereafter. Endpoints included cardiovascular collapse (fatal arrhythmia, loss of mean arterial pressure, or pulse) or respiratory arrest (<3 breaths/min, saturation < 80%) or survival to 7 h. The pigs in the treatment group reached an endpoint at an average time of 355 (+/-65) min compared with control 32 (+/-3.5) min (p < 0.04). In this pilot study, the LoCC device significantly delayed onset of systemic symptoms and death after torso envenomation with Eastern Diamondback Rattlesnake venom in this model.

  20. 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.

  1. 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

  2. WEIGHT LOSS WITH MEAL REPLACEMENT AND MEAL REPLACEMENT PLUS SNACKS: A RANDOMIZED TRIAL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: To evaluate whether snacking would improve weight loss and weight maintenance in overweight individuals within the context of a structured meal replacement (MR) weight loss program. A prospective 24 week, 2 (snacking vs nonsnacking) x 2 (MR vs meal replacement augmented with snacks (MRPS)...

  3. 48 CFR 8.715 - Replacement commodities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Replacement commodities. 8.715 Section 8.715 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition From Nonprofit Agencies Employing People...

  4. A Helix Replacement Mechanism Directs Metavinculin Functions

    SciTech Connect

    Rangarajan, Erumbi S.; Lee, Jun Hyuck; Yogesha, S.D.; Izard, Tina

    2010-10-11

    Cells require distinct adhesion complexes to form contacts with their neighbors or the extracellular matrix, and vinculin links these complexes to the actin cytoskeleton. Metavinculin, an isoform of vinculin that harbors a unique 68-residue insert in its tail domain, has distinct actin bundling and oligomerization properties and plays essential roles in muscle development and homeostasis. Moreover, patients with sporadic or familial mutations in the metavinculin-specific insert invariably develop fatal cardiomyopathies. Here we report the high resolution crystal structure of the metavinculin tail domain, as well as the crystal structures of full-length human native metavinculin (1,134 residues) and of the full-length cardiomyopathy-associated {Delta}Leu954 metavinculin deletion mutant. These structures reveal that an {alpha}-helix (H1{prime}) and extended coil of the metavinculin insert replace {alpha}-helix H1 and its preceding extended coil found in the N-terminal region of the vinculin tail domain to form a new five-helix bundle tail domain. Further, biochemical analyses demonstrate that this helix replacement directs the distinct actin bundling and oligomerization properties of metavinculin. Finally, the cardiomyopathy associated {Delta}Leu954 and Arg975Trp metavinculin mutants reside on the replaced extended coil and the H1{prime} {alpha}-helix, respectively. Thus, a helix replacement mechanism directs metavinculin's unique functions.

  5. [Exoprosthetic Replacement of the Upper Extremity].

    PubMed

    Salminger, S; Mayer, J A; Sturma, A; Riedl, O; Bergmeister, K D; Aszmann, O C

    2016-08-01

    During the last years, the prosthetic replacement in upper limb amputees has undergone different developments. The use of new nerve surgical concepts improved the control strategies tremendously, especially for high-level amputees. Technological innovation in the field of pattern recognition enables the control of multifunctional myoelectric hand prostheses in a natural and intuitive manner. However, the different levels of amputation pose different challenges for the therapeutic team which concern not only the prosthetic attachment; also the expected functional outcome of prosthetic limb replacement differs greatly between the individual levels of amputation. Therefore, especially in partial hand amputations the indication for prosthetic fitting has to be evaluated critically, as these patients may benefit more from biologic reconstructive concepts. The value of the upper extremity, in particular of the hand, is undisputable and, as such represents the driving force for the technological and surgical developments within the exoprosthetic replacement. This article discusses the possibilities and limitations of exoprosthetic limb replacement on the different amputation levels and explores new developments. PMID:27547980

  6. 30 CFR 57.19122 - Replacement parts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 57.19122 Replacement parts. Parts used to repair hoists shall have...

  7. 30 CFR 56.19122 - Replacement parts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 56.19122 Replacement parts. Parts used to repair hoists shall have...

  8. 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...

  9. Retrograde replacement of the thoracic aorta.

    PubMed Central

    Cooley, D A

    1995-01-01

    A technique is described for replacement of the entire thoracic aorta. In this "pull-through" technique, which utilizes hypothermic circulatory arrest, the graft is implanted in a retrograde fashion, thus providing protection for the spinal cord and brain and avoiding injury to the vagus and phrenic nerves. PMID:7647599

  10. 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…

  11. Do Formal Supports Replace Informal Supports?

    ERIC Educational Resources Information Center

    Barer, Barbara M.; And Others

    Health policy researchers have long been interested in the extent to which the provision of formal supports replaces or undermines the informal support system. This study examined the linkages between the formal and informal support system as they are mediated by a health care setting which readily provides patients with access to social services.…

  12. 30 CFR 56.19122 - Replacement parts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 56.19122 Replacement parts. Parts used to repair hoists shall have...

  13. 30 CFR 56.19122 - Replacement parts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 56.19122 Replacement parts. Parts used to repair hoists shall have...

  14. 30 CFR 57.19122 - Replacement parts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 57.19122 Replacement parts. Parts used to repair hoists shall have...

  15. 30 CFR 57.19122 - Replacement parts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel Hoisting Inspection and Maintenance § 57.19122 Replacement parts. Parts used to repair hoists shall have...

  16. 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…

  17. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... HPG funds; (3) Must meet all applicable requirements of 7 CFR 3550.57; and (4) May not be sold within... 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...

  18. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... HPG funds; (3) Must meet all applicable requirements of 7 CFR 3550.57; and (4) May not be sold within... 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...

  19. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... HPG funds; (3) Must meet all applicable requirements of 7 CFR 3550.57; and (4) May not be sold within... 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...

  20. 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-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED)...

  1. 7 CFR 1944.659 - Replacement housing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... HPG funds; (3) Must meet all applicable requirements of 7 CFR 3550.57; and (4) May not be sold within... 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...

  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. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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

  10. Long-term radiographic follow-up of total hip replacements.

    PubMed

    Collis, D K

    1982-01-01

    This report relates the long-term clinical result with the serial radiologic findings of 350 consecutive total hip replacements done by the author. Thirteen femoral components and one acetabular component have been revised, and 12 of the 14 components had shown radiologic changes in the surrounding cement prior to the need for revision. Available roentgenograms at 6 weeks, 1 year, 5 years, and 8 to 10 years after surgery made radiologic assessment possible in 129 hips. Heterotopic bone formation, calcar resorption and distal cortical hypertrophy all appeared to be primarily radiologic findings with little effect on clinical results. A variety of changes seen in the cement or bone-cement interface were noted on the femoral component side of 13.6% of the hips. None of these patients had any symptoms or functional limitations. These radiologic femoral cement mantle changes showed a high correlation with apparently inadequate initial cementing techniques and were usually already seen on the 1- and 5-year postoperative roentgenogram. Only one acetabular cup was identified as radiologically loose and one as migrated. Radiolucent lines at the bone-cement interface on the acetabular side showed vascillating increases and decreases on the serial roentgenograms. Since the lucent lines on the acetabular component side improved as often as they increased in size, these lucencies did not seem to be of similar predictive value as those on the femoral side. Of the hips followed 8 to 10 years only 2 circumferential and 10 lucencies greater than 2 mm could be found. I could not correlate these with inadequate cup position or inadequate cement mantle on the initial radiograph. The 29 patients in this series who were under 50 years of age did not have a revision rate or radiologic change different from the group as a whole.

  11. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with the replacement standards prescribed in 41 CFR 102-34.270 and 109-38.402. (b) The Heads of Contracting... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Replacement of...

  12. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with the replacement standards prescribed in FPMR 41 CFR 101-38.9 and DOE-PMR 41 CFR 109-38.9. (b) The... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Replacement of...

  13. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with the replacement standards prescribed in 41 CFR 102-34.270 and 109-38.402. (b) The Heads of Contracting... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Replacement of...

  14. 25 CFR 700.189 - Expenditure of replacement home benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 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...

  15. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with the replacement standards prescribed in FPMR 41 CFR 101-38.9 and DOE-PMR 41 CFR 109-38.9. (b) The... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Replacement of...

  16. 48 CFR 908.7101-4 - Replacement of motor vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ....7101-4 Replacement of motor vehicles. (a) The replacement of motor vehicles shall be in accordance with the replacement standards prescribed in FPMR 41 CFR 101-38.9 and DOE-PMR 41 CFR 109-38.9. (b) The... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Replacement of...

  17. 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... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement...

  18. 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... PROCEDURES Replacement Housing Payments § 700.187 Utilization of replacement home benefits. The Commission... to the head of household as provided in these regulations for the acquisition of a replacement...

  19. 41 CFR 109-38.402 - Replacement standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., AND MOTOR VEHICLES 38-MOTOR EQUIPMENT MANAGEMENT 38.4-Use and Replacement Standards § 109-38.402 Replacement standards. (a) (b) Motor vehicles may be replaced without regard to the replacement standards in 41 CFR 101-38.402 only after certification by the Director of Administrative Services or the Head...

  20. Mitochondrial replacement therapy in reproductive medicine.

    PubMed

    Wolf, Don P; Mitalipov, Nargiz; Mitalipov, Shoukhrat

    2015-02-01

    Mitochondrial dysfunction is implicated in disease and age-related infertility. Mitochondrial replacement therapies (MRT) in oocytes or zygotes, such as pronuclear (PNT), spindle (ST), or polar body (PBT) transfer, could prevent second-generation transmission of mitochondrial DNA (mtDNA) defects. PNT, associated with high levels of mtDNA carryover in mice but low levels in human embryos, carries ethical issues secondary to donor embryo destruction. ST, developed in primates, supports normal development to adults and low mtDNA carryover. PBT in mice, coupled with PN or ST, may increase the yield of reconstructed embryos with low mtDNA carryover. MRT also offers replacement of the deficient cytoplasm in oocytes from older patients, with the expectation of high pregnancy rates following in vitro fertilization. PMID:25573721

  1. Mitochondrial Replacement Therapy in Reproductive Medicine

    PubMed Central

    Wolf, Don P.; Mitalipov, Nargiz; Mitalipov, Shoukhrat

    2015-01-01

    Mitochondrial dysfunction is implicated in disease and in age-related infertility. Mitochondrial replacement therapies (MRT) in oocytes or zygotes such as pronuclear (PNT), spindle (ST) or polar body (PBT) transfer could prevent second generation transmission of mitochondrial DNA (mtDNA) defects. PNT, associated with high levels of mtDNA carryover in mice but low levels in human embryos, carries ethical issues secondary to donor embryo destruction. ST, developed in primates, supports normal development to adults and low mtDNA carryover. PBT in mice, coupled with PN or ST, may increase the yield of reconstructed embryos with low mtDNA carryover. MRT also offers replacement of the deficient cytoplasm in oocytes from older patients, with the expectation of high pregnancy rates following in vitro fertilization. PMID:25573721

  2. Enzyme replacement in Tay-Sachs disease.

    PubMed

    von Specht, B U; Geiger, B; Arnon, R; Passwell, J; Keren, G; Goldman, B; Padeh, B

    1979-06-01

    Enzyme replacement therapy was attempted with two Tay-Sachs-diseased individuals--a 14-month-old child and a 7-week-old infant. Treatment consisted of repeated weekly intrathecal injections of pure hexosaminidase A. Injection of this enzyme resulted in almost complete disappearance of GM2 from the serum, but did not bring about dissolution of the GM2 membranous cytoplasmic bodies in the brain, as detected by electronmicroscopy. Both patients tolerated the treatment without apparent clinical complications, but no clear-cut improvement was noted as a result of prolonged injections of hexosaminidase A. Since this treatment was initiated in both an advanced stage and a very early stage of the disease, we conclude that enzyme replacement treatment by this route is not beneficial for patients with Tay-Sachs disease. PMID:572006

  3. BALBES: a molecular-replacement pipeline

    SciTech Connect

    Long, Fei; Vagin, Alexei A.; Young, Paul; Murshudov, Garib N.

    2008-01-01

    The fully automated pipeline, BALBES, integrates a redesigned hierarchical database of protein structures with their domains and multimeric organization, and solves molecular-replacement problems using only input X-ray and sequence data. The number of macromolecular structures solved and deposited in the Protein Data Bank (PDB) is higher than 40 000. Using this information in macromolecular crystallography (MX) should in principle increase the efficiency of MX structure solution. This paper describes a molecular-replacement pipeline, BALBES, that makes extensive use of this repository. It uses a reorganized database taken from the PDB with multimeric as well as domain organization. A system manager written in Python controls the workflow of the process. Testing the current version of the pipeline using entries from the PDB has shown that this approach has huge potential and that around 75% of structures can be solved automatically without user intervention.

  4. 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.

  5. 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

  6. Challenges after the first decade of transcatheter aortic valve replacement: focus on vascular complications, stroke, and paravalvular leak.

    PubMed

    Reidy, Christopher; Sophocles, Aris; Ramakrishna, Harish; Ghadimi, Kamrouz; Patel, Prakash A; Augoustides, John G T

    2013-02-01

    Transcatheter aortic valve replacement (TAVR) is entering its second decade. Three major clinical challenges have emerged from the first decade of experience: vascular complications, stroke, and paravalvular leak (PVL). Major vascular complications remain common and independently predict major bleeding, transfusion, renal failure, and mortality. Although women are more prone to vascular complications, overall they have better survival than men. Further predictors of major vascular complications include heavily diseased femoral arteries and operator experience. Strategies to minimize vascular complications include a multimodal approach and sleeker delivery systems. Although cerebral embolism is very common during TAVR, it mostly is asymptomatic. Major stroke independently predicts prolonged recovery and increased mortality. Identified stroke predictors include functional disability, previous stroke, a transapical approach, and atrial fibrillation. Embolic protection devices are in development to mitigate the risk of embolic stroke after TAVR. PVL is common and significantly decreases survival. Undersizing of the valve prosthesis can be minimized with 3-dimensional imaging by computed tomography or echocardiography to describe the elliptic aortic annulus accurately. The formal grading of PVL severity in TAVR is based on its percentage of the circumferential extent of the aortic valve annulus. Further emerging management strategies for PVL include a repositionable valve prosthesis and transcatheter plugging. The first decade of TAVR has ushered in a new paradigm for the multidisciplinary management of valvular heart disease. The second decade likely will build on this wave of initial success with further significant innovations.

  7. 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.

  8. The Anterior Approach for Total Hip Replacement.

    PubMed

    Hochfelder, Jason P; Davidovitch, Roy I

    2016-03-01

    The anterior approach for total hip replacements has recently gained popularity. Some authors report faster recoveries and decreased dislocation rated with no increased risk of complications. However others claim no difference in outcomes when compared to other approaches yet an increase in complication rates. This paper provides a brief history of the approach, discusses various indications and contraindications, preoperative considerations, surgical techniques, and postoperative protocols. PMID:26977549

  9. VH replacement in primary immunoglobulin repertoire diversification.

    PubMed

    Sun, Amy; Novobrantseva, Tatiana I; Coffre, Maryaline; Hewitt, Susannah L; Jensen, Kari; Skok, Jane A; Rajewsky, Klaus; Koralov, Sergei B

    2015-02-01

    The genes encoding the variable (V) region of the B-cell antigen receptor (BCR) are assembled from V, D (diversity), and J (joining) elements through a RAG-mediated recombination process that relies on the recognition of recombination signal sequences (RSSs) flanking the individual elements. Secondary V(D)J rearrangement modifies the original Ig rearrangement if a nonproductive original joint is formed, as a response to inappropriate signaling from a self-reactive BCR, or as part of a stochastic mechanism to further diversify the Ig repertoire. VH replacement represents a RAG-mediated secondary rearrangement in which an upstream VH element recombines with a rearranged VHDHJH joint to generate a new BCR specificity. The rearrangement occurs between the cryptic RSS of the original VH element and the conventional RSS of the invading VH gene, leaving behind a footprint of up to five base pairs (bps) of the original VH gene that is often further obscured by exonuclease activity and N-nucleotide addition. We have previously demonstrated that VH replacement can efficiently rescue the development of B cells that have acquired two nonproductive heavy chain (IgH) rearrangements. Here we describe a novel knock-in mouse model in which the prerearranged IgH locus resembles an endogenously rearranged productive VHDHJH allele. Using this mouse model, we characterized the role of VH replacement in the diversification of the primary Ig repertoire through the modification of productive VHDHJH rearrangements. Our results indicate that VH replacement occurs before Ig light chain rearrangement and thus is not involved in the editing of self-reactive antibodies.

  10. Risks of testosterone replacement therapy in men

    PubMed Central

    Osterberg, E. Charles; Bernie, Aaron M.; Ramasamy, Ranjith

    2014-01-01

    Testosterone replacement therapy (TRT) is a widely used treatment for men with symptomatic hypogonadism. The benefits seen with TRT, such as increased libido and energy level, beneficial effects on bone density, strength and muscle as well as cardioprotective effects, have been well-documented. TRT is contraindicated in men with untreated prostate and breast cancer. Men on TRT should be monitored for side-effects such as polycythemia, peripheral edema, cardiac and hepatic dysfunction. PMID:24497673

  11. Femoral Bone Plug in Total Knee Replacement.

    PubMed

    Vulcano, Ettore; Regazzola, Gianmarco M V; Murena, Luigi; Ronga, Mario; Cherubino, Paolo; Surace, Michele F

    2015-10-01

    The intramedullary alignment guides used in total knee replacement disrupt the intramedullary vessels, resulting in greater postoperative blood loss. The use of an autologous bone plug to seal the intramedullary femoral canal has been shown to be effective in reducing postoperative bleeding. The authors present a simple technique to create a bone plug from the anterior chamfer femoral cut to perfectly seal the intramedullary canal of the femur. PMID:26488774

  12. Biosurfactants: a sustainable replacement for chemical surfactants?

    PubMed

    Marchant, Roger; Banat, Ibrahim M

    2012-09-01

    Glycolipid biosurfactants produced by bacteria and yeasts provide significant opportunities to replace chemical surfactants with sustainable biologically produced alternatives in bulk commercial products such as laundry detergents and surface cleaners. Sophorolipids are already available in sufficient yield to make their use feasible while rhamnolipids and mannosylerythritol lipids require further development. The ability to tailor the biosurfactant produced to the specific needs of the product formulation will be an important future step. PMID:22618240

  13. Mortality after total hip replacement surgery

    PubMed Central

    Berstock, J. R.; Beswick, A. D.; Lenguerrand, E.; Whitehouse, M. R.; Blom, A. W.

    2014-01-01

    Total hip replacement causes a short-term increase in the risk of mortality. It is important to quantify this and to identify modifiable risk factors so that the risk of post-operative mortality can be minimised. We performed a systematic review and critical evaluation of the current literature on the topic. We identified 32 studies published over the last 10 years which provide either 30-day or 90-day mortality data. We estimate the pooled incidence of mortality during the first 30 and 90 days following hip replacement to be 0.30% (95% CI 0.22 to 0.38) and 0.65% (95% CI 0.50 to 0.81), respectively. We found strong evidence of a temporal trend towards reducing mortality rates despite increasingly co-morbid patients. The risk factors for early mortality most commonly identified are increasing age, male gender and co-morbid conditions, particularly cardiovascular disease. Cardiovascular complications appear to have overtaken fatal pulmonary emboli as the leading cause of death after hip replacement. Cite this article: Bone Joint Res 2014;3:175–82. PMID:24894596

  14. Experimental replacement of an obligate insect symbiont.

    PubMed

    Moran, Nancy A; Yun, Yueli

    2015-02-17

    Symbiosis, the close association of unrelated organisms, has been pivotal in biological diversification. In the obligate symbioses found in many insect hosts, organisms that were once independent are permanently and intimately associated, resulting in expanded ecological capabilities. The primary model for this kind of symbiosis is the association between the bacterium Buchnera and the pea aphid (Acyrthosiphon pisum). A longstanding obstacle to efforts to illuminate genetic changes underlying obligate symbioses has been the inability to experimentally disrupt and reconstitute symbiont-host partnerships. Our experiments show that Buchnera can be experimentally transferred between aphid matrilines and, furthermore, that Buchnera replacement has a massive effect on host fitness. Using a recipient pea aphid matriline containing Buchnera that are heat sensitive because of an allele eliminating the heat shock response of a small chaperone, we reduced native Buchnera through heat exposure and introduced a genetically distinct Buchnera from another matriline, achieving complete replacement and stable inheritance. This transfer disrupted 100 million years (∼ 1 billion generations) of continuous maternal transmission of Buchnera in its host aphids. Furthermore, aphids with the Buchnera replacement enjoyed a dramatic increase in heat tolerance, directly demonstrating a strong effect of symbiont genotype on host ecology.

  15. Experimental replacement of an obligate insect symbiont.

    PubMed

    Moran, Nancy A; Yun, Yueli

    2015-02-17

    Symbiosis, the close association of unrelated organisms, has been pivotal in biological diversification. In the obligate symbioses found in many insect hosts, organisms that were once independent are permanently and intimately associated, resulting in expanded ecological capabilities. The primary model for this kind of symbiosis is the association between the bacterium Buchnera and the pea aphid (Acyrthosiphon pisum). A longstanding obstacle to efforts to illuminate genetic changes underlying obligate symbioses has been the inability to experimentally disrupt and reconstitute symbiont-host partnerships. Our experiments show that Buchnera can be experimentally transferred between aphid matrilines and, furthermore, that Buchnera replacement has a massive effect on host fitness. Using a recipient pea aphid matriline containing Buchnera that are heat sensitive because of an allele eliminating the heat shock response of a small chaperone, we reduced native Buchnera through heat exposure and introduced a genetically distinct Buchnera from another matriline, achieving complete replacement and stable inheritance. This transfer disrupted 100 million years (∼ 1 billion generations) of continuous maternal transmission of Buchnera in its host aphids. Furthermore, aphids with the Buchnera replacement enjoyed a dramatic increase in heat tolerance, directly demonstrating a strong effect of symbiont genotype on host ecology. PMID:25561531

  16. Renal function after elective total hip replacement.

    PubMed

    Perregaard, Helene; Damholt, Mette B; Solgaard, Søren; Petersen, Morten B

    2016-06-01

    Background and purpose - Acute kidney injury (AKI) is associated with increased short-term and long-term mortality in intensive care populations and in several surgical specialties, but there are very few data concerning orthopedic populations. We have studied the incidence of AKI and the prevalence of chronic kidney disease (CKD) in an elective population of orthopedic patients undergoing primary total hip replacement, hypothesizing that chronic kidney disease predisposes to AKI. Patients and methods - This was a single-center, population-based, retrospective, registry-based cohort study involving all primary elective total hip replacements performed from January 2003 through December 2012. Patient demographics and creatinine values were registered. We evaluated the presence of CKD and AKI according to the international guidelines for kidney disease (KDIGO Acute Kidney Injury Workgroup 2013 ). Results - 3,416 patients were included (2,064 females (60%)). AKI (according to KDIGO criteria) was seen in 75 patients (2.2%, 95% CI: 1.7-2.7) in the course of primary total hip replacement. Of these, 26 had pre-existing CKD of class 3-5. Pre-existing CKD of class 3-5, indicating moderately to severely reduced kidney function, was seen in 374 individuals (11%). Interpretation - Development of acute kidney injury appears to be a substantial problem compared to other complications related to elective total hip arthroplasty, i.e. luxation and infection. Patients with pre-existing chronic kidney disease may be especially vulnerable. The clinical impact of acute kidney injury in an elective orthopedic population remains to be elucidated. PMID:26937782

  17. 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.

  18. Trials and Tribulations with VH Replacement.

    PubMed

    Meng, Wenzhao; Jayaraman, Sahana; Zhang, Bochao; Schwartz, Gregory W; Daber, Robert D; Hershberg, Uri; Garfall, Alfred L; Carlson, Christopher S; Luning Prak, Eline T

    2014-01-01

    VH replacement (VHR) is a type of antibody gene rearrangement in which an upstream heavy chain variable gene segment (VH) invades a pre-existing rearrangement (VDJ). In this Hypothesis and Theory article, we begin by reviewing the mechanism of VHR, its developmental timing and its potential biological consequences. Then we explore the hypothesis that specific sequence motifs called footprints reflect VHR versus other processes. We provide a compilation of footprint sequences from different regions of the antibody heavy chain, and include data from the literature and from a high throughput sequencing experiment to evaluate the significance of footprint sequences. We conclude by discussing the difficulties of attributing footprints to VHR.

  19. Alternatives to testosterone replacement: testosterone restoration

    PubMed Central

    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. PMID:25578932

  20. The befores and afters of molecular replacement

    PubMed Central

    Dodson, Eleanor

    2008-01-01

    This review addresses the essential questions to consider when attempting to phase a new crystal structure using molecular replacement. Sequence matching can suggest whether there is a suitable three-dimensional model available, but it is also important to analyse the model in order to find its likely oligomeric state and to establish whether there are likely to be domain movements. Once a solution has been found it must be refined, which can be challenging for low-homology models. There is a detailed discussion of structures used as examples for CCP4 tutorials. PMID:18094463

  1. Soft tissue balancing in total shoulder replacement.

    PubMed

    Mueller, Maike; Hoy, Gregory

    2014-03-01

    Total shoulder arthroplasty is now capable of recreating near anatomic reproduction of native bony shoulder anatomy, but the function and longevity of anatomic shoulder replacement is dependent on a competent soft tissue envelope and adequate motoring of all musculo-tendinous units about the shoulder. Balancing the soft tissues requires understanding of the anatomy and pathology, as well as technical skills. The advent of reverse shoulder biomechanics has brought with it special requirements of understanding of the soft tissue elements still left in the shoulder despite major rotator cuff deficiency.

  2. Aortic Annular Enlargement during Aortic Valve Replacement

    PubMed Central

    Dumani, Selman; Likaj, Ermal; Dibra, Laureta; Llazo, Stavri; Refatllari, Ali

    2016-01-01

    In the surgery of aortic valve replacement is always attempted, as much as possible, to implant the larger prosthesis with the mains goals to enhance the potential benefits, to minimise transvalvular gradient, decrease left ventricular size and avoid the phenomenon of patient-prosthesis mismatch. Implantation of an ideal prosthesis often it is not possible, due to a small aortic annulus. A variety of aortic annulus enlargement techniques is reported to avoid patient-prosthesis mismatch. We present the case that has submitted four three times open heart surgery. We used Manouguian technique to enlarge aortic anulus with excellent results during the fourth time of surgery. PMID:27703574

  3. Current status of valve replacement in children.

    PubMed

    Schaff, H V; Danielson, G K

    1986-01-01

    Management of valve diseases in children demands an eclectic approach by the surgeon. Whenever possible, valve function should be restored by repair rather than prosthetic replacement. Recent evidence firmly demonstrates that there are accelerated calcification and degeneration of porcine heterografts in children, especially in the aortic and mitral positions. For this reason, we reserve the use of heterograft prostheses for the right atrioventricular position and for conduits from the right ventricle to the pulmonary artery. Such patients are observed carefully for signs of valve degeneration. Long-term followup of the Starr-Edwards prosthesis in children demonstrates excellent durability and a thromboembolic rate that is equal to or lower than that found in adult patients. Hemodynamic properties of the Starr-Edwards valve are adequate even in the smallest size used in infants and have allowed children to reach early adolescence at which time valve re-replacement with an adult-sized prosthesis is possible. Intermediate-term experience with the Bjork-Shiley valve in children has also been favorable. At present we continue to use systemic anticoagulation with warfarin in all children with mechanical prostheses. PMID:3742534

  4. Limitations to fluid replacement during exercise.

    PubMed

    Maughan, R J; Leiper, J B

    1999-04-01

    Fluid replacement during exercise is essential for endurance exercise performance and reducing the risk of heat illness. Fluids supply water, which ameliorates dehydration, and also substrate for the working muscles. Absorption of water and nutrients occurs in the upper part of the small intestine, and replacement may be limited by the rate at which fluid is emptied from the stomach or absorbed in the intestine. Gastric emptying of liquids is influenced primarily by the volume of fluid in the stomach and by its energy density. Increasing the volume will speed emptying, but increasing the nutrient content will slow emptying. Osmolality, temperature, and pH of drinks, as well as exercise intensity, are of minor importance. Intestinal water absorption is a passive process: water follows osmotic gradients but will also follow the active absorption of nutrients, especially glucose, which is actively co-transported with sodium. Water transport is maximised by the presence in the intestine of hypotonic solutions of glucose and sodium. Hypertonic solutions promote net water secretion into the intestinal lumen, resulting in a temporary net loss of water from the body. The amount of fluid ingested by athletes is normally much less than can be tolerated, therefore issues such as palatability and practising drinking during training are important.

  5. Recombinant Enzyme Replacement Therapy in Hypophosphatasia.

    PubMed

    Hofmann, Christine; Jakob, Franz; Seefried, Lothar; Mentrup, Birgit; Graser, Stephanie; Plotkin, Horacio; Girschick, Hermann J; Liese, Johannes

    2015-01-01

    Hypophosphatasia (HPP) is a rare monogenetic and multisystemic disease with involvement of different organs, including bone, muscle, kidney, lung, gastrointestinal tract and the nervous system. The exact metabolic mechanisms of the effects of TNAP deficiency in different tissues are not understood in detail. There is no approved specific treatment for HPP; therefore symptomatic treatment in order to improve the clinical features is of major interest. Enzyme replacement therapy (ERT) is a relatively new type of treatment based on the principle of administering a medical treatment replacing a defective or absent enzyme. Recently ERT with a bone targeted recombinant human TNAP molecule has been reported to be efficient in ten severely affected patients and improved survival of life threatening forms. These results are very promising especially with regard to the skeletal phenotype but it is unclear whether ERT also has beneficial effects for craniosynostosis and in other affected tissues in HPP such as brain and kidney. Long-term data are not yet available and further systematic clinical trials are needed. It is also necessary to establish therapeutic approaches to help patients who are affected by less severe forms of HPP but also suffer from a significant reduction in quality of life. Further basic research on TNAP function and role in different tissues and on its physiological substrates is critical to gain a better insight in the pathogenesis in HPP. This and further experiences in new therapeutic strategies may improve the prognosis and quality of life of patients with all forms of HPP.

  6. Hypoparathyroidism: Replacement Therapy with Parathyroid Hormone

    PubMed Central

    Underbjerg, Line; Sikjaer, Tanja

    2015-01-01

    Hypoparathyroidism (HypoPT) is characterized by low serum calcium levels caused by an insufficient secretion of parathyroid hormone (PTH). Despite normalization of serum calcium levels by treatment with activated vitamin D analogues and calcium supplementation, patients are suffering from impaired quality of life (QoL) and are at increased risk of a number of comorbidities. Thus, despite normalization of calcium levels in response to conventional therapy, this should only be considered as an apparent normalization, as patients are suffering from a number of complications and calcium-phosphate homeostasis is not normalized in a physiological manner. In a number of recent studies, replacement therapy with recombinant human PTH (rhPTH(1-84)) as well as therapy with the N-terminal PTH fragment (rhPTH(1-34)) have been investigated. Both drugs have been shown to normalize serum calcium while reducing needs for activated vitamin D and calcium supplements. However, once a day injections cause large fluctuations in serum calcium. Twice a day injections diminish fluctuations, but don't restore the normal physiology of calcium homeostasis. Recent studies using pump-delivery have shown promising results on maintaining normocalcemia with minimal fluctuations in calcium levels. Further studies are needed to determine whether this may improve QoL and lower risk of complications. Such data are needed before replacement with the missing hormone can be recommended as standard therapy. PMID:26394728

  7. Limitations to fluid replacement during exercise.

    PubMed

    Maughan, R J; Leiper, J B

    1999-04-01

    Fluid replacement during exercise is essential for endurance exercise performance and reducing the risk of heat illness. Fluids supply water, which ameliorates dehydration, and also substrate for the working muscles. Absorption of water and nutrients occurs in the upper part of the small intestine, and replacement may be limited by the rate at which fluid is emptied from the stomach or absorbed in the intestine. Gastric emptying of liquids is influenced primarily by the volume of fluid in the stomach and by its energy density. Increasing the volume will speed emptying, but increasing the nutrient content will slow emptying. Osmolality, temperature, and pH of drinks, as well as exercise intensity, are of minor importance. Intestinal water absorption is a passive process: water follows osmotic gradients but will also follow the active absorption of nutrients, especially glucose, which is actively co-transported with sodium. Water transport is maximised by the presence in the intestine of hypotonic solutions of glucose and sodium. Hypertonic solutions promote net water secretion into the intestinal lumen, resulting in a temporary net loss of water from the body. The amount of fluid ingested by athletes is normally much less than can be tolerated, therefore issues such as palatability and practising drinking during training are important. PMID:10198143

  8. 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

  9. New replacement name Kuznetsoviella (Ostracoda): a correction.

    PubMed

    Doweld, Alexander B

    2016-01-01

    Recently it was found (Doweld 2016) that the generic name Aenigma Kuznetsova (1957: 68; type species A. jucunda Kuznetsova, by original designation) of fossil Ostracoda from the Lower Cretaceous (Barremian) of Tegchaj, North-Eastern Azerbaijan, former USSR (Transcaucasia), is already preoccupied by a marine gastropod molluscan generic name Aenigma Newman (1836: 499), which is in active current use in zoology (Coleoptera: Carabidae), along with a few other known homonyms, Aenigma Amsel (1956: 288) [Lepidoptera], Aenigma Koch (in Martini & Chemnitz 1846: 1, unpaginated) [Mollusca], Aenigma Karsch (1878: 825) [Arachnida], Aenigma Strecker (1876: 122) [Lepidoptera]. Therefore, a new replacement name was proposed, Kuznetsovia Doweld (2016: 68). However, it was overlooked that this generic name is already preoccupied by Kuznetsovia Kammerer (2006: 269) [Arthropoda], escaped from Nomenclator Zoologicus and Zoobank. In this connection, to resolve unexpected homonymy with an arthropod generic name, in accordance with article 60 of the International Code of Zoological Nomenclature (1999), a new replacement name is proposed for the fossil Ostracoda genus:. PMID:27470720

  10. Aortic valve replacement with combined myocardial revascularisation.

    PubMed Central

    Jones, M; Schofield, P M; Brooks, N H; Dark, J F; Moussalli, H; Deiraniya, A K; Lawson, R A; Rahman, A N

    1989-01-01

    Early and late outcome was studied in 630 patients who underwent aortic valve replacement between 1974 and 1982. Group 1 (506 patients) did not have important coronary artery disease, group 2 (69 patients) had coronary artery disease and underwent coronary artery bypass grafting, and group 3 (55 patients) had coronary artery disease but did not undergo myocardial revascularisation. Early mortality (within 30 days of operation) was significantly lower for group 1 (6%) than for group 2 (13%) and for group 3 (16%). Operative mortality in all three groups was lower in patients operated on more recently. The three year survival of patients in group 1 (83%) was significantly higher than that of patients in group 3 (62%) but not than that of patients in group 2 (76%). The findings of this study suggest that the presence of coronary artery disease increases the risk of aortic valve replacement whether or not coronary artery grafting is performed. Myocardial revascularisation, however, seems to return patients with aortic valve and coronary artery disease to a survival curve similar to that of patients with isolated aortic valve disease. PMID:2788003

  11. 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

  12. Hypoparathyroidism: Replacement Therapy with Parathyroid Hormone.

    PubMed

    Rejnmark, Lars; Underbjerg, Line; Sikjaer, Tanja

    2015-12-01

    Hypoparathyroidism (HypoPT) is characterized by low serum calcium levels caused by an insufficient secretion of parathyroid hormone (PTH). Despite normalization of serum calcium levels by treatment with activated vitamin D analogues and calcium supplementation, patients are suffering from impaired quality of life (QoL) and are at increased risk of a number of comorbidities. Thus, despite normalization of calcium levels in response to conventional therapy, this should only be considered as an apparent normalization, as patients are suffering from a number of complications and calcium-phosphate homeostasis is not normalized in a physiological manner. In a number of recent studies, replacement therapy with recombinant human PTH (rhPTH(1-84)) as well as therapy with the N-terminal PTH fragment (rhPTH(1-34)) have been investigated. Both drugs have been shown to normalize serum calcium while reducing needs for activated vitamin D and calcium supplements. However, once a day injections cause large fluctuations in serum calcium. Twice a day injections diminish fluctuations, but don't restore the normal physiology of calcium homeostasis. Recent studies using pump-delivery have shown promising results on maintaining normocalcemia with minimal fluctuations in calcium levels. Further studies are needed to determine whether this may improve QoL and lower risk of complications. Such data are needed before replacement with the missing hormone can be recommended as standard therapy. PMID:26394728

  13. 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.

  14. Transdermal testosterone replacement therapy in men

    PubMed Central

    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. PMID:24470750

  15. Prospective evaluation of Foley catheter as a replacement gastrostomy tube.

    PubMed

    Kadakia, S C; Cassaday, M; Shaffer, R T

    1992-11-01

    Percutaneous endoscopic gastrostomy provides a nonsurgical alternative to enteral feeding. However, the percutaneous endoscopic gastrostomy tube may deteriorate, malfunction, or be accidentally expelled from the stomach, requiring replacement. This prospective study was performed to evaluate the use of an all silicone Foley catheter (Foley) as a replacement feeding gastrostomy in 28 patients requiring replacement gastrostomy. A plastic ring and a retention disc were always placed over the Foley prior to replacement. Foley functioned well without replacement in 19 (68%) patients for a mean of 167 days. It needed to be replaced in nine (32%) patients due to malfunction after a mean of 138 days. Lack of migration of Foley was the most striking finding of our study, in contrast to case reports in the literature. These data suggest that Foley can be safely used as replacement gastrostomy tube. A randomized controlled trial comparing the Foley catheter as a replacement tube with other commercially available devices is needed.

  16. The effect of fat replacers on batter and cake properties.

    PubMed

    Psimouli, Vassiliki; Oreopoulou, Vassiliki

    2013-10-01

    Fat was replaced at 35% to 100% in cakes by maltodextrin (dextrose equivalent = 3), inulin (high performance and granulated), oligofructose, citrus pectin, and microparticulated protein. Fat replacement by 35% did not induce significant differences in general. Above 65% fat replacement resulted in statistically significant (P < 0.05) decreased viscosity (except for pectin) that was followed by statistically significant decrease in air incorporation and broader bubble size distribution. The starch gelatinization temperature showed a statistically significant increase when fat was replaced by fructose oligosaccharides. The cakes presented statistically significant increase of hardness, elasticity, and decrease of volume development as fat replacement increased above 65%. Also cakes with increased fat replacement received lower scores on taste and flavor, whereas at total fat replacement they were evaluated as not acceptable. Nevertheless, at 65% fat replacement, the samples presented acceptable textural, physical, and sensorial attributes.

  17. Protein Replacement Therapy Shows Promise in Treating Rare Skin Disorder

    MedlinePlus

    ... 1999 Spotlight on Research 2014 February 2014 (historical) Protein Replacement Therapy Shows Promise in Treating Rare Skin Disorder Replacing a protein that is crucial to ensuring that the skin’s ...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 21 CFR 870.3925 - Replacement heart valve.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  14. 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...

  15. 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...

  16. 21 CFR 870.3710 - Pacemaker repair or replacement material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  17. 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...

  18. 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...

  19. 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...

  20. 30 CFR 75.1438 - 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. 75.1438 Section 75.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn....

  1. 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...

  2. 25 CFR 700.183 - Determination of replacement housing benefit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Determination of replacement housing benefit. 700.183 Section 700.183 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit....

  3. 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 Section 700.183 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit....

  4. 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...

  5. 25 CFR 700.95 - Replacement housing funds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 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...

  6. 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...

  7. 25 CFR 700.183 - Determination of replacement housing benefit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Determination of replacement housing benefit. 700.183 Section 700.183 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit....

  8. 25 CFR 700.183 - Determination of replacement housing benefit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Determination of replacement housing benefit. 700.183 Section 700.183 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Replacement Housing Payments § 700.183 Determination of replacement housing benefit....

  9. 30 CFR 56.12036 - Fuse removal or replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fuse removal or replacement. 56.12036 Section 56.12036 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... § 56.12036 Fuse removal or replacement. Fuses shall not be removed or replaced by hand in an...

  10. 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 system must meet all conditions of initial approval of a mechanized claims processing and information retrieval system. (b) The agency must submit a APD that includes— (1) The date the replacement system...

  11. 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....404 Replacement housing of last resort. (a) Determination to provide replacement housing of last resort. Whenever a program or project cannot proceed on a timely basis because comparable...

  12. 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

  13. 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.

  14. 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

  15. Emergent double valve replacement in Austrian syndrome.

    PubMed

    Shokoohi, Hamid; Haywood, Yolanda; Najam, Farzad; Taheri, M Reza

    2015-02-01

    Bi-valvular pneumococcal endocarditis in Austrian syndrome, which includes a triad of pneumococcal endocarditis, pneumonia, and meningitis, is a rare but life-threatening disease. We present a case of a woman found to have Austrian syndrome who presented to the emergency department (ED) with dehydration and radiographical signs of lobar pneumonia and quickly deteriorated to fulminant cardiogenic shock in less than four hours. An early echocardiogram in the ED confirmed a diagnosis of bi-valvular endocarditis with severe aortic and mitral valve insufficiency and large vegetations on the valve leaflets requiring emergent surgical intervention with double valve replacement. Assumed meningitis as a part of the triad of Austrian syndrome was confirmed by imaging the day after hospital admission. Early diagnosis of endocarditis by obtaining the echocardiogram in the ED along with emergent surgical intervention allowed for a favorable outcome for the patient.

  16. Artificial cells for cell and organ replacements.

    PubMed

    Chang, Thomas Ming Swi

    2004-03-01

    The artificial cell is a Canadian invention (Chang, Science, 1964). This principle is being actively investigated for use in cell and organ replacements. The earliest routine clinical use of artificial cells is in the form of coated activated charcoal for hemoperfusion for use in the removal of drugs, and toxins and waste in uremia and liver failure. Encapsulated cells are being studied for the treatment of diabetes, liver failure, and kidney failure, and the use of encapsulated genetically-engineered cells is being investigated for gene therapy. Blood substitutes based on modified hemoglobin are already in Phase III clinical trials in patients, with as much as 20 units being infused into each patient during trauma surgery. Artificial cells containing enzymes are being developed for clinical trial in hereditary enzyme deficiency diseases and other diseases. The artificial cell is also being investigated for drug delivery and for other uses in biotechnology, chemical engineering, and medicine.

  17. The cost of standing strong for replacement.

    PubMed

    Brown, Katy

    2015-03-01

    The testimonies of these individuals largely speak for themselves. The responses point to the importance of specific institutions or research groups that focus on the development and use of alternatives, and these should, of course, be better supported. Those who find themselves outside such institutions or teams, are more likely to feel stranded and isolated. Then again, Liz did have the support of a research group dedicated to replacement, but she has still had a significant struggle to find funding. The interviews with some of these particular young researchers indeed pointed toward a tangible ‘cost’ in terms of having to steer their career on the often difficult path toward the use of non-animal based methods.

  18. 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.

  19. 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.

  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. 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

  2. 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

  3. Allograft Replacement for Absent Native Tissue

    PubMed Central

    Chaudhury, Salma; Wanivenhaus, Florian; Fox, Alice J.; Warren, Russell F.; Doyle, Maureen; Rodeo, Scott A.

    2013-01-01

    Context: Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports. Traditionally, allografts were employed to reinforce weakened tissue. However, they can also be employed to substitute deficient or functionally absent tissue, particularly in the sports medicine setting. Objective: This article presents a series of 6 cases that utilized allografts to restore functionally deficient anatomic architecture, rather than just simply augmenting the degenerated or damaged native tissue. Detailed discussions are presented of the use of allografts as a successful treatment strategy to replace functionally weakened tissue, often after failed primary repairs. PMID:24427387

  4. Hormone replacement therapy: dilemmas in 2002.

    PubMed Central

    Moore, Anne

    2003-01-01

    About 6 million women in the United States are prescribed a combined estrogen-progestin regimen during and after the menopause. The immediate benefits of hormone replacement therapy (HRT) are relief of menopausal symptoms. Doctors and their patients have long presumed that the benefits on cardiovascular disease and osteoporosis outweigh the possible increased risk of breast cancer or venous thrombosis. The Women's Health Initiative, a National Institutes of Health program, is the first study to compare HRT to placebo in healthy women. The July 2002 report of increased cardiovascular events as well as increased breast cancer diagnosis in women on the HRT arm of the study brought widespread media coverage and has led to distress and confusion among women taking HRT. Women with a personal or family history of breast cancer pose a particular challenge to their physicians when they ask for advice about HRT. PMID:12813923

  5. Mechanical versus biological aortic valve replacement strategies.

    PubMed

    Reineke, D; Gisler, F; Englberger, L; Carrel, T

    2016-01-01

    Aortic valve replacement (AVR) is the most frequently performed procedure in valve surgery. The controversy about the optimal choice of the prosthetic valve is as old as the technique itself. Currently there is no perfect valve substitute available. The main challenge is to choose between mechanical and biological prosthetic valves. Biological valves include pericardial (bovine, porcine or equine) and native porcine bioprostheses designed in stented, stentless and sutureless versions. Homografts and pulmonary autografts are reserved for special indications and will not be discussed in detail in this review. We will focus on the decision making between artificial biological and mechanical prostheses, respectively. The first part of this article reviews guideline recommendations concerning the choice of aortic prostheses in different clinical situations while the second part is focused on novel strategies in the treatment of patients with aortic valve pathology. PMID:26678683

  6. 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. PMID:26436487

  7. Material Science in Cervical Total Disc Replacement.

    PubMed

    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.

  8. 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

  9. 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. PMID:26069515

  10. 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.

  11. 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.

  12. Doripenem Treatment during Continuous Renal Replacement Therapy

    PubMed Central

    Wenisch, J. M.; Maier-Salamon, A.; Fritsch, A.; Saria, K.; Zuba, C.; Jilch, S.; Lemmerer, R.; Unger, M.; Jaehde, U.; Jäger, W.; Thalhammer, F.

    2015-01-01

    Doripenem is a broad-spectrum parenteral carbapenem with enhanced activity against Pseudomonas aeruginosa. While the initial dosing recommendation for renally competent patients and patients undergoing continuous renal replacement therapy (cRRT) was 500 mg every 8 h (q8h), the dose for renally competent patients was updated to 1 g q8h in June 2012. There are no updated data for the dosing of patients on continuous renal replacement therapy. The original dosing regimen for cRRT patients was based on nonseptic patients, while newer publications chose comparatively low target concentrations for a carbapenem. Thus, there is an urgent need for updated recommendations for dosing during cRRT. In the trial presented here, we included 13 oliguric septic patients undergoing cRRT in an intensive care setting. Five patients each were treated with hemodiafiltration or hemodialysis, while three patients received hemofiltration treatment. All patients received 1 g doripenem every 8 h. Doripenem concentrations in the plasma and ultrafiltrate were measured over 48 h. The mean hemofilter clearance was 36.53 ml/min, and the mean volume of distribution was 59.26 liters. The steady-state trough levels were found at 8.5 mg/liter, with no considerable accumulation. Based on pharmacokinetic and pharmacodynamic considerations, we propose a regimen of 1 g q8h, which may be combined with a loading dose of 1.5 to 2 g for critically ill patients. (This study has been registered with EudraCT under registration no. 2009-018010-18 and at ClinicalTrials.gov under registration no. NCT02018939.) PMID:26711775

  13. An improved general amino acid replacement matrix.

    PubMed

    Le, Si Quang; Gascuel, Olivier

    2008-07-01

    Amino acid replacement matrices are an essential basis of protein phylogenetics. They are used to compute substitution probabilities along phylogeny branches and thus the likelihood of the data. They are also essential in protein alignment. A number of replacement matrices and methods to estimate these matrices from protein alignments have been proposed since the seminal work of Dayhoff et al. (1972). An important advance was achieved by Whelan and Goldman (2001) and their WAG matrix, thanks to an efficient maximum likelihood estimation approach that accounts for the phylogenies of sequences within each training alignment. We further refine this method by incorporating the variability of evolutionary rates across sites in the matrix estimation and using a much larger and diverse database than BRKALN, which was used to estimate WAG. To estimate our new matrix (called LG after the authors), we use an adaptation of the XRATE software and 3,912 alignments from Pfam, comprising approximately 50,000 sequences and approximately 6.5 million residues overall. To evaluate the LG performance, we use an independent sample consisting of 59 alignments from TreeBase and randomly divide Pfam alignments into 3,412 training and 500 test alignments. The comparison with WAG and JTT shows a clear likelihood improvement. With TreeBase, we find that 1) the average Akaike information criterion gain per site is 0.25 and 0.42, when compared with WAG and JTT, respectively; 2) LG is significantly better than WAG for 38 alignments (among 59), and significantly worse with 2 alignments only; and 3) tree topologies inferred with LG, WAG, and JTT frequently differ, indicating that using LG impacts not only the likelihood value but also the output tree. Results with the test alignments from Pfam are analogous. LG and a PHYML implementation can be downloaded from http://atgc.lirmm.fr/LG.

  14. Hormone replacement therapy and the endometrium

    PubMed Central

    Feeley, K; Wells, M

    2001-01-01

    Modern hormone replacement therapy (HRT) regimens contain oestrogen and progestogen, given either in a cyclical or continuous combined manner. Most endometrial biopsies from women on sequential HRT show weak secretory features. Approximately 15% show proliferative activity, although this figure may be less if more than nine days of progestogen is given in each cycle. A small proportion will show an inactive or atrophic endometrium. Up to 50% of biopsies from women on continuous combined HRT contain minimal endometrial tissue for histopathological analysis: this correlates well with an atrophic endometrium with no appreciable pathology. Of the 50% with more substantial material, approximately one half will show endometrial atrophy, and one half will show weak secretory features. Proliferative, menstrual, and pseudodecidual changes are rare. Approximately 20% of women given unopposed oestrogen for one year develop endometrial hyperplasia. The relative risk of endometrial carcinoma is two to three. This is dramatically reduced by the addition of progestogen to the regimen, but cyclical progestogen as part of a sequential HRT regimen does not completely eliminate the risk of carcinoma. The prevalence of endometrial hyperplasia associated with sequential HRT is 5.4%, and that of atypical hyperplasia (endometrial intraepithelial neoplasia) is 0.7%. Continuous combined HRT is not associated with the development of hyperplasia or carcinoma, and may normalise the endometrium of women who have developed complex hyperplasia on sequential HRT. The probability of a histopathologist finding clinically relevant pathology in an endometrial biopsy specimen of a patient on HRT is low and is more likely to be a manifestation of pre-existing disease. Key Words: endometrium • hormone replacement therapy • endometrial hyperplasia • endometrial carcinoma PMID:11376015

  15. 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.

  16. 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.

  17. 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

  18. Systolic and diastolic myocardial mechanics in hypertrophic cardiomyopathy and their link to the extent of hypertrophy, replacement fibrosis and interstitial fibrosis.

    PubMed

    Nucifora, Gaetano; Muser, Daniele; Gianfagna, Pasquale; Morocutti, Giorgio; Proclemer, Alessandro

    2015-12-01

    Aim of the present study was to investigate the relations between myocardial mechanics and the extent of hypertrophy and fibrosis in hypertrophic cardiomyopathy (HCM). Forty-five consecutive patients with HCM and 15 subjects without structural heart disease were included. Cardiac magnetic resonance with late gadolinium enhancement (LGE) imaging was performed to evaluate biventricular function, LV mass index and presence/extent of LGE, expression of replacement fibrosis. Myocardial T1 relaxation, a surrogate of interstitial fibrosis, was measured from Look-Locker sequence. Feature-tracking analysis was applied to LV basal, mid and apical short-axis images to assess systolic and diastolic global LV circumferential strain (CS) and strain rate (CSr). Peak systolic CS and CSr were significantly higher among HCM patients as compared to control subjects (p = 0.015 and p = 0.007, respectively). The ratio of peak CSr during early filling to peak systolic CSr was significantly lower among HCM patients (p = 0.002). At multivariate linear regression analysis, LV mass index (p < 0.001) and %LV LGE (p = 0.011) were significantly and independently related to peak systolic CS; LV mass index (p < 0.001) and %LV LGE (p = 0.023) were significantly and independently related to peak systolic CSr; %LV LGE (p = 0.021) and T1 ratio (p = 0.006) were significantly and independently related to the ratio of peak CSr during early filling to peak systolic CSr. LV systolic mechanics are enhanced and LV diastolic mechanics are impaired in HCM. Extent of hypertrophy and replacement fibrosis influence the LV systolic mechanics while extent of replacement fibrosis and interstitial fibrosis influence the LV diastolic mechanics.

  19. Stentless aortic valve replacement: an update

    PubMed Central

    Kobayashi, Junjiro

    2011-01-01

    Although porcine aortic valves or pericardial tissue mounted on a stent have made implantation techniques easier, these valves sacrifice orifice area and increase stress at the attachment of the stent, which causes primary tissue failure. Optimizing hemodynamics to prevent patient–prosthetic mismatch and improve durability, stentless bioprostheses use was revived in the early 1990s. The purpose of this review is to provide a current overview of stentless valves in the aortic position. Retrospective and prospective randomized controlled studies showed similar operative mortality and morbidity in stented and stentless aortic valve replacement (AVR), though stentless AVR required longer cross-clamp and cardiopulmonary bypass time. Several cohort studies showed improved survival after stentless AVR, probably due to better hemodynamic performance and earlier left ventricular (LV) mass regression compared with stented AVR. However, there was a bias of operation age and nonrandomization. A randomized trial supported an improved 8-year survival of patients with the Freestyle or Toronto valves compared with Carpentier–Edwards porcine valves. On the contrary, another randomized study did not show improved clinical outcomes up to 12 years. Freedom from reoperation at 12 years in Toronto stentless porcine valves ranged from 69% to 75%, which is much lower than for Carpentier–Edwards Perimount valves. Cusp tear with consequent aortic regurgitation was the most common cause of structural valve deterioration. Cryolife O’Brien valves also have shorter durability compared with stent valves. Actuarial freedom from reoperation was 44% at 10 years. Early prosthetic valve failure was also reported in patients who underwent root replacement with Shelhigh stentless composite grafts. There was no level I or IIa evidence of more effective orifice area, mean pressure gradient, LV mass regression, surgical risk, durability, and late outcomes in stentless bioprostheses. There is no

  20. 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

  1. 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

  2. Surfactant replacement therapy--economic impact.

    PubMed

    Pejaver, R K; al Hifzi, I; Aldussari, S

    2001-06-01

    Surfactant replacement is an effective treatment for neonatal respiratory distress syndrome. (RDS). As widespread use of surfactant is becoming a reality, it is important to assess the economic implications of this new form of therapy. A comparison study was carried out at the Neonatal Intensive Care Unit (NICU) of Northwest Armed Forces Hospital, Saudi Arabia. Among 75 infants who received surfactant for RDS and similar number who were managed during time period just before the surfactant was available, but by set criteria would have made them eligible for surfactant. All other management modalities except surfactant were the same for all these babies. Based on the intensity of monitoring and nursing care required by the baby, the level of care was divided as: Level IIIA, IIIB, Level II, Level I. The cost per day per bed for each level was calculated, taking into account the use of hospital immovable equipment, personal salaries of nursing, medical, ancillary staff, overheads and maintenance, depreciation and replacement costs. Medications used, procedures done, TPN, oxygen, were all added to individual patient's total expenditure. 75 infants in the Surfactant group had 62 survivors. They spent a total of 4300 days in hospital. (av 69.35) Out of which 970 d (av 15.65 per patient) were ventilated days. There were 56 survivors in the non-surfactant group of 75. They had spent a total of 5023 days in the hospital (av 89.69/patient) out of which 1490 were ventilated days (av 26.60 d). Including the cost of surfactant (two doses), cost of hospital stay for each infant taking the average figures of stay would be SR 118, 009.75 per surfactant treated baby and SR 164, 070.70 per non-surfactant treated baby. The difference of 46,061 SR is 39.03% more in non-surfactant group. One Saudi rial = 8 Rs (approx at the time study was carried out.) Medical care cost varies from place to place. However, it is definitely cost-effective where surfactant is concerned. Quality adjusted

  3. Comparison of Foley catheter as a replacement gastrostomy tube with commercial replacement gastrostomy tube: a prospective randomized trial.

    PubMed

    Kadakia, S C; Cassaday, M; Shaffer, R T

    1994-01-01

    Percutaneous endoscopic gastrostomy (PEG) provides a non-surgical alternative to long-term enteral feeding. The gastrostomy tube, however, may deteriorate, malfunction, or be accidentally expelled, requiring replacement. A commercial gastrostomy tube is commonly used for replacement. However, a commercial replacement gastrostomy tube is many times more expensive than a Foley catheter, and the two have never been compared. We compared the efficacy and safety of an all-silicone Foley catheter used as a replacement feeding gastrostomy tube with the effectiveness of a commercial replacement gastrostomy tube in 46 patients undergoing long-term enteral feedings per gastrostomy. Twenty-four patients were randomized to the Foley group and 22 patients to the commercial replacement gastrostomy tube group. The Foley catheter functioned well without need for replacement in 16 (66%) patients for 27.4 +/- 14.8 (mean +/- SD) weeks; the commercial replacement gastrostomy tube functioned in 13 (59%) patients for 24.5 +/- 13.6 weeks (p > 0.05, NS). The Foley catheter needed to be replaced because of malfunction in 8 (34%) patients and the commercial replacement gastrostomy tube in 9 (41%) patients after 21.6 +/- 11.5 weeks and 19.3 +/- 9.3 weeks, respectively (p > 0.05, NS). Neither the Foley catheter nor the commercial replacement gastrostomy tube migrated; this was the most striking finding, in contrast to case reports in the literature. Our data suggest that the Foley catheter can be safely used as a replacement gastrostomy tube; it is considerably cheaper than the commercial replacement gastrostomy tube, and its efficacy and complication rates are similar to those of the commercial replacement gastrostomy tube.

  4. 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.

  5. Hypernatraemic dehydration following tricuspid valve replacement.

    PubMed

    Taylor, K M; Morgan, H G; Thomson, R M; Turner, M A; Lawrie, T D; Bain, W H

    1978-01-01

    The development of abnormally high plasma sodium and plasma osmolality levels is described in 5 patients following open-heart surgery involving prosthetic replacement of the tricuspid valve. These biochemical abnormalities developed in the early post-operative period and were associated with an excessive diuresis during the first 3 to 4 days after operation. Biochemical correction required a prolonged, high volume intravenous water load, and was paralleled by progressive clinical improvement, notably in peripheral circulation, tissue turgor and cerebral function. Plasma sodium and osmolality levels and observed fluid balance in 20 patients undergoing similar surgical procedures for tricuspid valve lesions fail to show this hypernatraemic, hyperosmolar state, and indicate that the majority of such patients have a markedly positive observed fluid balance in the early post-operative period. These differences are statistically highly significant (p less than 0.001). Consideration of urine/plasma osmolality levels reveals a transient but highly significant impairment of renal concentration in the hypernatraemic patients (p less than 0.001).

  6. 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.

  7. Physical training after heart valve replacement.

    PubMed Central

    Newell, J P; Kappagoda, C T; Stoker, J B; Deverall, P B; Watson, D A; Linden, R J

    1980-01-01

    A controlled trial was undertaken to examine the efficacy of physical training in patients recovering from the replacement of a single heart valve. Patients were allocated to a test or control group two weeks after operation. Each patient performed a submaximal exercise test at entry, and 12 and 24 weeks after this test. The Canadian Air Force exercise programme was undertaken by the test group, while the control group continued normal activities for the 24 weeks between the first and last exercise group. A regression line of submaximal heart rate on oxygen consumption was calculated from the data of each exercise test in each patient. Alterations in this line were used as an "index" of changes in "cardiorespiratory fitness". The individual results showed a consistent improvement in "cardiorespiratory fitness" over the first 12 weeks in both groups. Only patients in the test group continued to improve between 12 and 24 weeks. Thus the exercise programme modified the recovery of "cardiorespiratory fitness" after operation. Results in patients who developed clinical complications, and were excluded from the trial, predicted a deteriorating clinical condition. This finding suggested that sequential exercise tests are of value after cardiac surgery. PMID:7459147

  8. 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

  9. Current concepts in total femoral replacement

    PubMed Central

    Ramanathan, Deepak; Siqueira, Marcelo BP; Klika, Alison K; Higuera, Carlos A; Barsoum, Wael K; Joyce, Michael J

    2015-01-01

    Total femoral replacement (TFR) is a salvage arthroplasty procedure used as an alternative to lower limb amputation. Since its initial description in the mid-20th century, this procedure has been used in a variety of oncologic and non-oncologic indications. The most compelling advantage of TFR is the achievement of immediate fixation which permits early mobilization. It is anticipated that TFR will be increasingly performed as the rate of revision arthroplasty rises worldwide. The existing literature is mainly composed of a rather heterogeneous mix of retrospective case series and a wide assortment of case reports. Numerous TFR prostheses are currently available and the surgeon must understand the unique implications of each implant design. Long-term functional outcomes are dependent on adherence to proper technique and an appropriate physical therapy program for postoperative rehabilitation. Revision TFR is mainly performed for periprosthetic infection and the severe femoral bone loss associated with aseptic revisions. Depending on the likelihood of attaining infection clearance, it may sometimes be advisable to proceed directly to hip disarticulation without attempting salvage of the TFR. Other reported complications of TFR include hip joint instability, limb length discrepancy, device failure, component loosening, patellar maltracking and delayed wound healing. Further research is needed to better characterize the long-term functional outcomes and complications associated with this complex procedure. PMID:26716087

  10. 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

  11. Maryland striped bass: recruitment declining below replacement

    SciTech Connect

    Goodyear, C.P.; Cohen, J.E.; Christensen, S.W.

    1985-01-01

    A mathematical technique was developed to examined interrelationships among first-year survival rates, adult fecundity, and adult survival of striped bass Morone saxatilis based on indices of year-class strength. Application of this technique to striped bass in Maryland waters of the Chesapeake Bay provided evidence for reduced survival in the life cycle. If adult fecundity and survival have remained constant, first-year survival declined significantly from 1969 to 1983, and averaged less than that needed for replacement for the last 10 years. Treatment of the individual spawning grounds separately indicated that the downward trend in survival for the pooled data was the result of declines in the upper bay and, to a lesser extent, in the Choptank River. Alternatively, if first-year survival and adult fecundity were assumed to have remained constant, an annual decline of about 1.9% in adult survival would have been required to produce the observed trend in the pooled year-class data. This would be consistent with increased fishing mortality and implies declining recruitment because of declining stock size. Continuing declines in first-year or adult survival would eliminate the Maryland striped bass stock and the fishery it supports. Conversely, an increase in adult survival could offset of the unknown factor or factors responsible for the apparent decline in first-year survival. 25 references, 1 figure, 1 table.

  12. Nicotine replacement products: poisoning in children.

    PubMed

    2014-05-01

    Nicotine is widely used in smoking cessation aids. They are marketed in many forms, including: chewing gum, sublingual tablets, lozenges, transdermal patches, cartridges for oral inhalation, and mouth spray. French poison control and toxico-vigilance centres identified 318 cases of exposure to nicotine replacement products in children under the age of 10 years between 2000 and 2010. The exposure provoked symptoms in 62 of these children, about two-thirds of whom were under the age of 4 years. A U.S. analysis identified 1768 cases of poisoning in children under the age of 6 years involving smokeless tobacco products, reported between 2006 and 2008.84% of these cases occurred in children under the age of 3 years. The first signs of nicotine poisoning are gastrointestinal (vomiting, diarrhoea), cardiovascular (tachycardia, hypertension) and neuropsychological (tremor of the extremities). With higher doses, these effects are rapidly followed by loss of consciousness, convulsions or respiratory failure. In children, poisoning can occur after ingestion of 1 mg of nicotine per kilogram of body weight. A dose of this magnitude is sometimes fatal in adults. Most cases of poisoning involving transdermal patches occur when a child finds an unused patch, or a used patch that an adult has discarded in a bin without taking proper precautions. Sometimes they involve patches that have become detached from an adult's skin. In practice, it is important to warn adults using smoking cessation aids containing nicotine that these products are dangerous

  13. Pancreatic enzyme replacement therapy during pancreatic insufficiency.

    PubMed

    Berry, Amy J

    2014-06-01

    Pancreatic stimulation and therefore digestion is a tightly controlled and hormonally mediated process. Any alterations affecting any of the systematic steps for successful digestion and absorption to occur will impair appropriate pancreatic enzymatic secretion, entry into the bowel lumen, functionality once inside the lumen, and thus appropriate mixing with foods and nutrients. Many causes of pancreatic insufficiency may require the initiation of pancreatic enzyme therapy, including but not limited to cystic fibrosis, pancreatic cancer, acute and chronic pancreatitis, and pancreatic surgery. This purpose of this article is to help clarify the conditions that cause pancreatic insufficiency, how to determine if the patient is malabsorbing, and the best use of pancreatic enzyme replacement therapy for treatment in these conditions. The first step in determining if pancreatic enzyme therapy is appropriate is to determine if the patient is malabsorbing specifically due to pancreatic exocrine insufficiency. An overview of the methods used to determine pancreatic insufficiency is provided, as well as appropriate treatment methods. Recent Food and Drug Administration regulations require a more thorough process, including randomized controlled trials to prove the safety and efficacy of pancreatic enzymes, to approve them for use. The studies used to verify efficacy also are examined. Last, dosing guidelines and some unconventional ways to administer pancreatic enzymes, such as during enteral feedings, are reviewed.

  14. Toward beta cell replacement for diabetes.

    PubMed

    Johannesson, Bjarki; Sui, Lina; Freytes, Donald O; Creusot, Remi J; Egli, Dieter

    2015-04-01

    The discovery of insulin more than 90 years ago introduced a life-saving treatment for patients with type 1 diabetes, and since then, significant progress has been made in clinical care for all forms of diabetes. However, no method of insulin delivery matches the ability of the human pancreas to reliably and automatically maintain glucose levels within a tight range. Transplantation of human islets or of an intact pancreas can in principle cure diabetes, but this approach is generally reserved for cases with simultaneous transplantation of a kidney, where immunosuppression is already a requirement. Recent advances in cell reprogramming and beta cell differentiation now allow the generation of personalized stem cells, providing an unlimited source of beta cells for research and for developing autologous cell therapies. In this review, we will discuss the utility of stem cell-derived beta cells to investigate the mechanisms of beta cell failure in diabetes, and the challenges to develop beta cell replacement therapies. These challenges include appropriate quality controls of the cells being used, the ability to generate beta cell grafts of stable cellular composition, and in the case of type 1 diabetes, protecting implanted cells from autoimmune destruction without compromising other aspects of the immune system or the functionality of the graft. Such novel treatments will need to match or exceed the relative safety and efficacy of available care for diabetes.

  15. Individualizing factor replacement therapy in severe hemophilia.

    PubMed

    Carcao, Manuel D; Iorio, Alfonso

    2015-11-01

    Prophylactic replacement of factor concentrate is the established optimal treatment to avoid or minimize joint disease in severe hemophilia patients, thus ultimately improving their life expectancy and quality of life toward values matching those in the normal population. Where uncertainty still exists is around the optimal regimen to be prescribed for prophylaxis, and more and more treaters and patients are showing interest in patient tailored approaches to prophylaxis, aiming at matching the prophylaxis regimen to the specific needs of the patient. The rationale behind tailoring the prophylaxis regimen to the individual patient is based on the significant variability that exists between patients (all with the same label of severe hemophilia) with respect to their bleeding phenotype, their pharmacokinetic handling of factor, their levels of physical activity, and a variety of other characteristics that contribute to differential prophylaxis needs of patients. Of course, any form of tailoring of prophylaxis needs to take into consideration the economic resources of the country; for many countries very intense prophylaxis regimens are just not possible. This article will review different concerns and strategies when tailoring prophylaxis, and will address how these issues will apply to the new longer acting factor concentrates in development.

  16. Process optimized minimally invasive total hip replacement.

    PubMed

    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

  17. Total ankle replacement for posttraumatic arthritis

    PubMed Central

    Weme, Rebecca A Nieuwe; van Solinge, Guido; N Doornberg, Job; Sierevelt, Inger; Haverkamp, Daniël; Doets, H Cornelis

    2015-01-01

    Background and purpose Most studies on total ankle replacement (TAR) have used a case mix of patients. We evaluated the outcome of TAR performed for end-stage arthritis either because of fracture or ligamentous injury. Patients and methods We prospectively followed 88 consecutive patients (50 postfracture ankles and 40 ankles with instability arthritis (2 bilateral)) who underwent TAR between 2001 and 2009. Mean follow-up for both groups was 5 years. Results Preoperative varus deformity of 10° or more was present in 23 ankles in the instability group. At 6 years, survival with revision or salvage fusion as an endpoint was 87% (95% CI: 74–99) in the postfracture group and 79% (95% CI: 63–94) in the instability group. Progressive periprosthetic osteolysis was seen in 23 ankles, and required salvage fusion in 6. The number of reoperations was similar in both groups. Clinical outcome, as assessed with 2 ankle scores and 2 questionnaires, showed good results and was similar at the latest follow-up. Interpretation The outcome was similar in the postfracture and instability groups and also similar to that reported in series including a case mix of patients. In contrast to earlier reports, preoperative frontal plane deformity in this series was not identified as a risk factor for failure. PMID:25772269

  18. TOTAL ANKLE REPLACEMENT: WHY, WHEN AND HOW?

    PubMed Central

    Bonasia, Davide Edoardo; Dettoni, Federico; Femino, John E; Phisitkul, Phinit; Germano, Margherita; Amendola, Annunziato

    2010-01-01

    Total ankle replacement (TAR) was first attempted in the 1970s, but poor results led to its being considered inferior to ankle fusion until the late 1980s and early 1990s. By that time, newer designs which more closely replicated the natural anatomy of the ankle, showed improved clinical outcomes.1 Currently, even though controversy still exists about the effectiveness of TAR compared to ankle fusion, TAR has shown promising mid-term results and should no longer be considered an experimental procedure. Factors related to improved TAR outcomes include: 1) better patient selection, 2) more precise knowledge and replication of ankle biomechanics, 3) the introduction of less-constrained designs with reduced bone resection and no need for cementation, and 4) greater awareness of soft-tissue balance and component alignment. When TAR is performed, a thorough knowledge of ankle anatomy, pathologic anatomy and biomechanics is needed along with a careful pre-operative plan. These are fundamental in obtaining durable and predictable outcomes. The aim of this paper is to outline these aspects through a literature review. PMID:21045984

  19. Avascular necrosis of bone complicating corticosteroid replacement therapy.

    PubMed Central

    Williams, P L; Corbett, M

    1983-01-01

    Two patients who developed widespread severe avascular necrosis of bone while on steroid replacement therapy are described. One, a diabetic, underwent yttrium-90 pituitary ablation for retinopathy and developed avascular necrosis within 18 months of starting prednisolone. The other, who had Addison's disease, developed avascular necrosis within 14 months of starting cortisol replacement therapy. Both cases came to bilateral total hip replacement. Images PMID:6859959

  20. Replacing fallow by cover crops: economic sustainability

    NASA Astrophysics Data System (ADS)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  1. Patient injuries in primary total hip replacement.

    PubMed

    Helkamaa, Teemu; Hirvensalo, Eero; Huhtala, Heini; Remes, Ville

    2016-06-01

    Background and purpose - Although the results of primary total hip replacements (THRs) are generally excellent, sometimes serious complications arise. Some of these severe complications are considered to be patient injuries. We analyzed primary THR-related patient injuries in a nationwide setting. Patients and methods - We evaluated all the primary THR-related patient injury claims in Finland between 2008 and 2010. We used the original medical records and 2 nationwide registries, the Care Register for Social Welfare and Health Care and the Patient Injury Claim Register. Results - We identified 563 claims, 44% of which were compensated (n = 250). Of these 250 compensated claims, 79% were considered to be avoidable (treatment injuries) and 21% were severe unexpected infections (with a preoperative infection risk of less than 2%). The most common type of technical error was cup malposition (31%). High-volume hospitals (with an annual primary THR volume ≥ 400) had a lower patient injury rate. In lower-volume hospitals (with an annual primary THR volume of < 400), the relative risks (RRs) of patient injury for any reason, due to technical errors, or because of cup malposition were 2-fold (95% CI: 1.6-3.1), 4-fold (95% CI: 2.3-6.2), and 9-fold (95% CI: 3-28), respectively, compared to high-volume hospitals. Interpretation - Our study provides the first comprehensive nationwide data on THR-related patient injury types. Hospital volume was associated with the quality and quantity of errors detected. An annual hospital volume of ≥ 400 primary THRs was established as a protective factor against patient injuries. PMID:26808350

  2. Patient injuries in primary total hip replacement

    PubMed Central

    Helkamaa, Teemu; Hirvensalo, Eero; Huhtala, Heini; Remes, Ville

    2016-01-01

    Background and purpose Although the results of primary total hip replacements (THRs) are generally excellent, sometimes serious complications arise. Some of these severe complications are considered to be patient injuries. We analyzed primary THR-related patient injuries in a nationwide setting. Patients and methods We evaluated all the primary THR-related patient injury claims in Finland between 2008 and 2010. We used the original medical records and 2 nationwide registries, the Care Register for Social Welfare and Health Care and the Patient Injury Claim Register. Results We identified 563 claims, 44% of which were compensated (n = 250). Of these 250 compensated claims, 79% were considered to be avoidable (treatment injuries) and 21% were severe unexpected infections (with a preoperative infection risk of less than 2%). The most common type of technical error was cup malposition (31%). High-volume hospitals (with an annual primary THR volume ≥ 400) had a lower patient injury rate. In lower-volume hospitals (with an annual primary THR volume of < 400), the relative risks (RRs) of patient injury for any reason, due to technical errors, or because of cup malposition were 2-fold (95% CI: 1.6–3.1), 4-fold (95% CI: 2.3–6.2), and 9-fold (95% CI: 3–28), respectively, compared to high-volume hospitals. Interpretation Our study provides the first comprehensive nationwide data on THR-related patient injury types. Hospital volume was associated with the quality and quantity of errors detected. An annual hospital volume of ≥ 400 primary THRs was established as a protective factor against patient injuries. PMID:26808350

  3. Activation of Complement Following Total Hip Replacement.

    PubMed

    Thordardottir, S; Vikingsdottir, T; Bjarnadottir, H; Jonsson, H; Gudbjornsson, B

    2016-03-01

    The aim of this study was to investigate whether complement activation, via the classical and alternative pathways, occurs following a cemented total hip replacement (THR) surgery due to osteoarthritis. Blood samples were collected systematically from 12 patients - six male and six women, with a median age of 75 (range: 59-90 years) - preoperatively, 6 h post-operatively and on the first, second and third post-operative day. Total function of classical (CH50) and alternative pathways (AH50) was evaluated, along with the determination of serum concentrations of the complement proteins C3, C4, C3d, the soluble terminal complement complex (sTCC) sC5b-9, as well as C-reactive protein (CRP) and albumin. Measurements of CRP and albumin levels elucidated a marked inflammatory response following the operation. The CH50, AH50 and C3 and C4 levels were significantly lower 6 h after the surgery compared with the preoperative levels, but elevated above the preoperative levels during the following 3 days. The complement activation product C3d levels increased continually during the whole observation period, from 13.5 AU/ml (range: 8-19 AU/ml) preoperative to 20 AU/ml (range: 12-34 AU/ml) on the third post-operative day. Furthermore, we observed an increase in the sC5b-9 levels between the preoperative and the third post-operative day. These results demonstrate a significant activation of the complement system following cemented THR. Further studies are needed to elucidate the time frame and the pathogenic role of this observed complement activation.

  4. Celestite replacements of evaporites in the Salina Group

    NASA Astrophysics Data System (ADS)

    Carlson, Ernest H.

    1987-09-01

    Replacements of evaporites by celestite were discovered recently at three sites in northwestern Ohio. These replacements are more durable than the original evaporites and provide new paleoenvironmental data for the upper Silurian rocks of the region. The occurrences are situated along the western margin of the Ohio (Cayugan) Basin and appear in the Greenfield Dolomite and in undifferentiated Salina dolostones. The replacements include: lenticular and prismatic crystals of gypsum, nodules of anhydrite and laminar evaporites. The lenticular crystals contain inclusions of carbonate and anhydrite, and are believed to have altered to anhydrite prior to replacement. The prismatic crystals are exceptionally well-preserved, with euhedral, deeply embayed outlines and internally zoned growth bands containing large numbers of inclusions of dolostone and anhydrite. Optical data for the latter crystals indicate that they are oriented replacements of gypsum, and suggest that the original gypsum was unchanged prior to replacement. The nodular and laminar occurrences display features such as chicken-wire and enterolithic structures, and were comprised of anhydrite prior to replacement. Replacement postdates the dolomitization and cementation of the Salina sediments enclosing the evaporites, but occurred prior to deep burial. The rocks hosting the replacements, therefore, did not provide the strontium. The strontium may have been released from dolomitization of the underlying Lockport (Niagaran) beds or from dissolution of subaerially exposed Salina gypsum prior to the middle Devonian.

  5. [Octreotide acetate for persistent cylothorax after descending aorta replacement].

    PubMed

    Naganuma, Hirokuni; Kawahito, Koji; Matsumura, Yoko; Nakamura, Ken; Haijima, Norimasa

    2010-12-01

    Cylothorax is one of a hazardous complication after thoracic aorta replacement. In this paper, we report effectiveness of octreotide acetate for postoperative persistent cylothorax. A 59-year-old female was referred to our hospital for chest pain. Previously she underwent arch reconstruction following aortic root replacement due to aortic dissection. Computed tomography (CT) revealed acute dissection on dissected descending aorta. Urgent descending aorta replacement was performed. After surgery, massive chylothoracic pleural fluid was drainaged. Although conventional medical treatment was not effective, drainage of chylothoracic pleural fluid significantly decreased after administration of octreotide acetate. Although mechanism has not been fully investigated, octreotide acetate was effective for persistent cylothorax after descending aorta replacement.

  6. Mitochondrial replacement techniques: egg donation, genealogy and eugenics.

    PubMed

    Palacios-González, César

    2016-03-01

    Several objections against the morality of researching or employing mitochondrial replacement techniques have been advanced recently. In this paper, I examine three of these objections and show that they are found wanting. First I examine whether mitochondrial replacement techniques, research and clinical practice, should not be carried out because of possible harms to egg donors. Next I assess whether mitochondrial replacement techniques should be banned because they could affect the study of genealogical ancestry. Finally, I examine the claim that mitochondrial replacement techniques are not transferring mitochondrial DNA but nuclear DNA, and that this should be prohibited on ethical grounds.

  7. Mitochondrial replacement techniques: egg donation, genealogy and eugenics.

    PubMed

    Palacios-González, César

    2016-03-01

    Several objections against the morality of researching or employing mitochondrial replacement techniques have been advanced recently. In this paper, I examine three of these objections and show that they are found wanting. First I examine whether mitochondrial replacement techniques, research and clinical practice, should not be carried out because of possible harms to egg donors. Next I assess whether mitochondrial replacement techniques should be banned because they could affect the study of genealogical ancestry. Finally, I examine the claim that mitochondrial replacement techniques are not transferring mitochondrial DNA but nuclear DNA, and that this should be prohibited on ethical grounds. PMID:27468863

  8. Arthroscopic Management of Complications Following Total Ankle Replacement.

    PubMed

    Lui, Tun Hing; Roukis, Thomas S

    2015-10-01

    There is great potential of managing the complications of total ankle replacement arthroscopically and endoscopically, and these procedures can be summarized into 3 groups. Group 1 includes procedures of the ankle joint proper with close proximity to the articular components of the total ankle replacement. Group 2 includes procedures of the tibia and talus with close proximity to the nonarticular parts of the total ankle replacement. Group 3 includes procedures that are away from the total ankle replacement. However, these remain master arthroscopist procedures and should be performed by foot and ankle surgeons who perform them with regularity.

  9. An objective replacement method for censored geochemical data

    USGS Publications Warehouse

    Sanford, R.F.; Pierson, C.T.; Crovelli, R.A.

    1993-01-01

    Geochemical data are commonly censored, that is, concentrations for some samples are reported as "less than" or "greater than" some value. Censored data hampers statistical analysis because certain computational techniques used in statistical analysis require a complete set of uncensored data. We show that the simple substitution method for creating an uncensored dataset, e.g., replacement by 3/4 times the detection limit, has serious flaws, and we present an objective method to determine the replacement value. Our basic premise is that the replacement value should equal the mean of the actual values represented by the qualified data. We adapt the maximum likelihood approach (Cohen, 1961) to estimate this mean. This method reproduces the mean and skewness as well or better than a simple substitution method using 3/4 of the lower detection limit or 3/4 of the upper detection limit. For a small proportion of "less than" substitutions, a simple-substitution replacement factor of 0.55 is preferable to 3/4; for a small proportion of "greater than" substitutions, a simple-substitution replacement factor of 1.7 is preferable to 4/3, provided the resulting replacement value does not exceed 100%. For more than 10% replacement, a mean empirical factor may be used. However, empirically determined simple-substitution replacement factors usually vary among different data sets and are less reliable with more replacements. Therefore, a maximum likelihood method is superior in general. Theoretical and empirical analyses show that true replacement factors for "less thans" decrease in magnitude with more replacements and larger standard deviation; those for "greater thans" increase in magnitude with more replacements and larger standard deviation. In contrast to any simple substitution method, the maximum likelihood method reproduces these variations. Using the maximum likelihood method for replacing "less thans" in our sample data set, correlation coefficients were reasonably

  10. Electric field replaces gravity in laboratory

    NASA Astrophysics Data System (ADS)

    Gorgolewski, S.

    For several years experiments in physical laboratories and in the fitotron have shown that one can replace gravitational field with electrical fields for plants. First obvious experiments in strong electrical fields in the MV/m regi on show that any materials and living plants respond immediately to Coulomb forces. Such fields are found in nature during thunderstorms. One has to be very careful in handling such strong fields for safety reasons. The fair weather global electrical field is about 20,000 times weaker. The coulomb forces are proportional to the square of the field strength and are thus 400 milion times weaker for a field of the order of 100 V/m.Yet it was found that some plants respond to such "weak" fields. We must remember that the electrical field is a factor of 10 38 times stronger than gravitational interaction. In plants we have dissociated in water mineral salts and the ions are subject to such ernormous forces. It was shown and published that the positive charges in the air in fields of the order of 3kV/m enhance lettuce growth by a factor of four relative to fields about 30 times weaker (100V/m). Reversal of the field polarity reverses the direction of plant growth and retards the plant's growth. Such fields overpower the gravitropism in the laboratory. More so horizontal electrical field is othogonal to gravity, now the fields do not see each other. Lettuce now growth horizontally ignoring the gravitational field. We can thus select the plants whose electrotropism even in the laboratory overwhelms gravity. This is important for the long space flights that we must grow vegetarian food for the crew. The successful harvesting of wheat in orbit does not contradict our experimental findings because wheat is not electrotropic like all plants from the grass family. The results of fitotron experiments with kV/m electrical fields are richly illustrated with colour digital photographs. We also subjected the candle flame to very strong horizontal

  11. Management of Gaucher disease: enzyme replacement therapy.

    PubMed

    Zimran, Ari; Elstein, Deborah

    2014-09-01

    Starting in 1994, 3 years after the first approval of the placental-derived enzyme replacement therapy (ERT) with alglucerase, the recombinant form imiglucerase was the introduced and became the standard of care for the visceral symptoms of Gaucher disease. For patients with non-neuronopathic (type 1) Gaucher disease, ERT is safe, with few adverse/side events, and effective in reducing hepatosplenomegaly, improving hematological parameters such as anemia and thrombocytopenia, and to a lesser degree, ameliorating lung- and bone-referred disease. Dosage differences are appreciated mainly as differences in the initial slope in achieving improvements before plateauing. Because ERT does not pass the blood-brain barrier, for patients with the acute neuronopathic form (type 2), there is no substantial change in the life-threatening neurological parameters and hence ERT is not seen as efficacious; but for patients with sub-acute neuronopathic forms (type 3), ERT for the often devastating visceral symptoms, improved quality of life, and longevity make ERT part of the standard care. Due to a world-wide reduction in imiglucerase availability mid-2009 that was not resolved quickly, patients were ERT-stopped or dose-reduced, re-invigorated the movement to provide additional therapeutic options. Early access programs of two new ERTs, then at the pre-license stage, were initiated at regulatory authorities' request for patients requiring ERT. At that point, velaglucerase alfa which has the native-enzyme sequence produced in a (proprietary) human cell line, and taliglucerase alfa, which is plant-cell-derived and produced in an inexpensive platform, were completing Phase 3 clinical trials. Velaglucerase alfa was FDA-approved in February 2010 while taliglucerase alfo was approved in May 2012. Marketing of these ERTs has also targeted the extraordinarily high cost of imiglucerase. However, with > 20 years' experience with infusible ERTs, many patients are eager to consider oral

  12. 10 CFR 490.8 - Replacement fuel production goal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in...

  13. 10 CFR 490.8 - Replacement fuel production goal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in...

  14. 10 CFR 490.8 - Replacement fuel production goal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in...

  15. 10 CFR 490.8 - Replacement fuel production goal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in...

  16. 10 CFR 490.8 - Replacement fuel production goal.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Replacement fuel production goal. 490.8 Section 490.8 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM General... sufficient to replace, on an energy equivalent basis, at least 30 percent of motor fuel consumption in...

  17. Cable cleaning solvents; Environmental issues and effective replacements

    SciTech Connect

    Wilcox, D.P.; Hunder, D.N. )

    1992-04-01

    This paper presents the sequence of events used in selecting potential candidates as effective replacements for currently used chlorinated solvents. It also discusses the health and environmental issues that surround the use of chlorinated solvents and the test criteria used to determine the final selection of one such replacement.

  18. 48 CFR 908.7112 - Materials handling equipment replacement standards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Materials handling equipment replacement standards. 908.7112 Section 908.7112 Federal Acquisition Regulations System DEPARTMENT... shall be purchased for replacement purposes in accordance with the standards in FPMR 41 CFR...

  19. 48 CFR 908.7112 - Materials handling equipment replacement standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Materials handling equipment replacement standards. 908.7112 Section 908.7112 Federal Acquisition Regulations System DEPARTMENT... shall be purchased for replacement purposes in accordance with the standards in FPMR 41 CFR...

  20. Functionality of Inulin as a Sucrose Replacer in Cookie Baking

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inulin was evaluated as a sucrose replacer for healthy cookie production with benefits of low glycemic impact and prebiotic soluble fiber. Sucrose (as a reference) and three inulin products of different concentrations (as soluble fibers) were used to explore the effects of sugar-replacer type on so...

  1. 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... valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any of the heart's natural valves. This device includes valves constructed of prosthetic...

  2. 21 CFR 870.3925 - Replacement heart valve.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Replacement heart valve. 870.3925 Section 870.3925... valve. (a) Identification. A replacement heart valve is a device intended to perform the function of any of the heart's natural valves. This device includes valves constructed of prosthetic...

  3. The development and replacement of teeth in viviparous caecilians.

    PubMed

    Wake, M H

    1976-01-01

    Tooth development and replacement in fetal and adult viviparous caecilians (Amphibia: Gymnophiona) are described and analyzed according to current theories of tooth succession. The fetal dentition differs from that of the adult in morphology, position, and function. Teeth are used by fetuses to scrape the oviducal epithelium, thus stimulating the secretion of a nutrient substance. Fetal dentitions vary in morphology and position in different species. The ontogeny of teeth of several species is described and the patterns of addition of loci and of replacement are analyzed. Loci are added both posteriorly along the jaw and between existing loci as the jaw grows prior to ossification; subsequently addition is restricted to the posterior part of the jaw. Tooth replacement is alternate. The several rows and patches of teeth are the result of retention of replacement series on the dentigerous elements. Tooth development and replacement in a series of juveniles and adults of different sizes in a single species are also considered. Post-fetal patterns of development and replacement are similar to those seen in larvae and adults of oviparous species. Variation in numbers of teeth and proportions of teeth at particular stages occurs ontogenetically and among individuals of the same size, though proportions occur in a similar pattern throughout the series. The general pattern of tooth replacement in fetuses and adults can be explained by either Edmund's Zahnreihen theory or by Osborn's Tooth Family theory, but replacement in fetal tooth patches and the fetal-adult dentitional transition are explained by neither.

  4. 75 FR 50777 - Minidoka Dam Spillway Replacement, Minidoka County, ID

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... on December 11, 2009 (74 FR 65783) with a public comment period ending on February 5, 2010. The Final... Bureau of Reclamation Minidoka Dam Spillway Replacement, Minidoka County, ID AGENCY: Bureau of... proposed Minidoka Dam Spillway Replacement. The U.S. Fish and Wildlife Service (Department of Interior)...

  5. 49 CFR 541.6 - Requirements for replacement parts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Requirements for replacement parts. 541.6 Section 541.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE THEFT PREVENTION STANDARD § 541.6 Requirements for replacement parts....

  6. 9 CFR 82.15 - Replacement birds and poultry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Replacement birds and poultry. 82.15... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS EXOTIC NEWCASTLE DIS- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry....

  7. 9 CFR 82.15 - Replacement birds and poultry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Replacement birds and poultry. 82.15... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS EXOTIC NEWCASTLE DIS- EASE (END) AND CHLAMYDIOSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and poultry....

  8. 9 CFR 82.15 - Replacement birds and poultry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Replacement birds and poultry. 82.15... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS EXOTIC NEWCASTLE DISEASE (END) AND CHLAMYDI-OSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and...

  9. 9 CFR 82.15 - Replacement birds and poultry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Replacement birds and poultry. 82.15... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS EXOTIC NEWCASTLE DISEASE (END) AND CHLAMYDI-OSIS Exotic Newcastle Disease (END) § 82.15 Replacement birds and...

  10. 9 CFR 82.15 - Replacement birds and poultry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Replacement birds and poultry. 82.15... AGRICULTURE INTERSTATE TRANSPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS NEWCASTLE DISEASE AND CHLAMYDIOSIS Newcastle Disease § 82.15 Replacement birds and poultry. Birds and poultry that have...

  11. 7 CFR 4280.138 - Replacement of document.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Replacement of document. 4280.138 Section 4280.138 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.138 Replacement of document....

  12. 7 CFR 4280.138 - Replacement of document.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Replacement of document. 4280.138 Section 4280.138 Agriculture Regulations of the Department of Agriculture (Continued) RURAL BUSINESS-COOPERATIVE SERVICE AND... Efficiency Improvements Program Section B. Guaranteed Loans § 4280.138 Replacement of document....

  13. 30 CFR 77.1438 - 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. 77.1438 Section 77.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... Personnel Hoisting Wire Ropes § 77.1438 End attachment replacement. Wire rope attachments shall be...

  14. 41 CFR 51-6.14 - Replacement services.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Replacement services. 51... § 51-6.14 Replacement services. If a service is on the Procurement List to meet the needs of a Government entity at a specific location and the entity moves to another location, the service at the...

  15. 30 CFR 57.12036 - Fuse removal or replacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fuse removal or replacement. 57.12036 Section 57.12036 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Electricity Surface and Underground § 57.12036 Fuse removal or replacement. Fuses shall not be removed...

  16. 40 CFR 141.84 - Lead service line replacement requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap...

  17. 40 CFR 141.84 - Lead service line replacement requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap...

  18. 40 CFR 141.84 - Lead service line replacement requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap...

  19. 40 CFR 141.84 - Lead service line replacement requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap...

  20. 40 CFR 141.84 - Lead service line replacement requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Lead service line replacement... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Control of Lead and Copper § 141.84 Lead service line replacement requirements. (a) Systems that fail to meet the lead action level in tap...