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Sample records for large-head metal-on-metal total

  1. Early failures in large head metal-on-metal total hip arthroplasty.

    PubMed

    Althuizen, Martje N R; V Hooff, Miranda L; v d Berg-v Erp, Saskia H M; V Limbeek, Jacques; Nijhof, Marc W

    2012-01-01

    Concerns have recently been raised about large head metal-on-metal total hip arthroplasties (LDH THA). Metal ion release due to wear may cause osteolysis, pseudotumours and necrosis. In addition, fixation of certain acetabular components is thought to be suboptimal. We present the short term outcome of the Durom LDH THA. Retrospectively, a consecutive series of 64 implants in 60 patients was analysed with a mean follow-up of 37 months. Clinical and radiological evaluation was performed on a regular basis, followed by additional evaluations when indicated. The 10-year revision percentage was calculated and compared with National Institute for Health and Clinical Excellence (NICE) standards. Six patients (six hips) underwent cup revision (9%). Four of these cups showed no or minimal bone fixation. Three patients had a pseudotumour. In two revision cases, ALVAL (aseptic lymphocyte-dominated vasculitis-associated lesion) was present. Lack of bone ingrowth and the presence of ARMD (adverse reaction to metal debris) seem to contribute to a high failure rate of the Durom LDH THA. The predicted ten-year revision rate of 14.2% (95% CI 5.6-22.8) is, given the broad confidence interval, not significantly outside NICE recommended standards. However, it is not clear which factors, if any, predict implant failure. Therefore, we do not advocate the use of this implant. PMID:23233178

  2. Large-head metal-on-metal total hip arthroplasty using the Durom acetabular component at minimum 1-year interval.

    PubMed

    Illgen, Richard L; Heiner, John P; Squire, Matthew W; Conrad, David N

    2010-09-01

    Large-head metal-on-metal total hip arthroplasty represents novel technology, and outcome data are lacking. We prospectively compared the performance of a nonmodular metal-on-metal acetabular component (Durom; Zimmer, Warsaw, IN) with a modular titanium component (Trilogy, Zimmer). All Durom components placed at our institution with minimum 1-year follow up (n = 63) were compared with an age- and sex-matched Trilogy control group (n = 100). Failure defined as revision or persistent moderate/severe groin pain was significantly higher for the Durom (11.1%) compared with the Trilogy group (0%) (P = .002). Although all acetabular components in both groups appeared radiographically stable, no significant bone ingrowth was noted at the time of Durom revisions. We could not identify any patient/surgical-related factors predictive of failure. Further study is needed to determine the scientific basis for these observations. PMID:20570096

  3. No association between serum metal ions and implant fixation in large-head metal-on-metal total hip arthroplasty

    PubMed Central

    Søballe, Kjeld; Jakobsen, Stig Storgaard; Lorenzen, Nina Dyrberg; Mechlenburg, Inger; Stilling, Maiken

    2014-01-01

    Background The mechanism of failure of metal-on-metal (MoM) total hip arthroplasty (THA) has been related to a high rate of metal wear debris, which is partly generated from the head-trunnion interface. However, it is not known whether implant fixation is affected by metal wear debris. Patients and methods 49 cases of MoM THA in 41 patients (10 women) with a mean age of 52 (28–68) years were followed with stereoradiographs after surgery and at 1, 2, and 5 years to analyze implant migration by radiostereometric analysis (RSA). Patients also participated in a 5- to 7-year follow-up with measurement of serum metal ions, questionnaires (Oxford hip score (OHS) and Harris hip score (HHS)), and measurement of cup and stem positions and systemic bone mineral density. Results At 1–2 years, mean total translation (TT) was 0.04 mm (95% CI: –0.07 to 0.14; p = 0.5) for the stems; at 2–5 years, mean TT was 0.13 mm (95% CI: –0.25 to –0.01; p = 0.03), but within the precision limit of the method. For the cups, there was no statistically significant TT or total rotation (TR) at 1–2 and 2–5 years. At 2–5 years, we found 4 cups and 5 stems with TT migrations exceeding the precision limit of the method. There was an association between cup migration and total OHS < 40 (4 patients, 4 hips; p = 0.04), but there were no statistically significant associations between cup or stem migration and T-scores < –1 (n = 10), cup and stem positions, or elevated serum metal ion levels (> 7µg/L (4 patients, 6 hips)). Interpretation Most cups and stems were well-fixed at 1–5 years. However, at 2–5 years, 4 cups and 5 stems had TT migrations above the precision limits, but these patients had serum metal ion levels similar to those of patients without measurable migrations, and they were pain-free. Patients with serum metal ion levels > 7 µg/L had migrations similar to those in patients with serum metal ion levels < 7 µg/L. Metal wear debris does not appear to influence the fixation of hip components in large-head MoM articulations at medium-term follow-up. PMID:24847790

  4. Does bearing size influence metal ion levels in large-head metal-on-metal total hip arthroplasty? A comparison of three total hip systems

    PubMed Central

    2014-01-01

    Background The purpose of the study was twofold: first, to determine whether there is a statistically significant difference in the metal ion levels among three different large-head metal-on-metal (MOM) total hip systems. The second objective was to assess whether position of the implanted prostheses, patient demographics or factors such as activity levels influence overall blood metal ion levels and whether there is a difference in the functional outcomes between the systems. Methods In a cross-sectional cohort study, three different metal-on-metal total hip systems were assessed: two monoblock heads, the Durom socket (Zimmer, Warsaw, IN, USA) and the Birmingham socket (Smith and Nephew, Memphis, TN, USA), and one modular metal-on-metal total hip system (Pinnacle, Depuy Orthopedics, Warsaw, IN, USA). Fifty-four patients were recruited, with a mean age of 59.7 years and a mean follow-up time of 41 months (12 to 60). Patients were evaluated clinically, radiologically and biochemically. Statistical analysis was performed on all collected data to assess any differences between the three groups in terms of overall blood metal ion levels and also to identify whether there was any other factor within the group demographics and outcomes that could influence the mean levels of Co and Cr. Results Although the functional outcome scores were similar in all three groups, the blood metal ion levels in the larger monoblock large heads (Durom, Birmingham sockets) were significantly raised compared with those of the Pinnacle group. In addition, the metal ion levels were not found to have a statistically significant relationship to the anteversion or abduction angles as measured on the radiographs. Conclusions When considering a MOM THR, the use of a monoblock large-head system leads to higher elevations in whole blood metal ions and offers no advantage over a smaller head modular system. PMID:24472283

  5. Pseudotumour incidence, cobalt levels and clinical outcome after large head metal-on-metal and conventional metal-on-polyethylene total hip arthroplasty: mid-term results of a randomised controlled trial.

    PubMed

    van der Veen, H C; Reininga, I H F; Zijlstra, W P; Boomsma, M F; Bulstra, S K; van Raay, J J A M

    2015-11-01

    We compared the incidence of pseudotumours after large head metal-on-metal (MoM) total hip arthroplasty (THA) with that after conventional metal-on-polyethylene (MoP) THA and assessed the predisposing factors to pseudotumour formation. From a previous randomised controlled trial which compared large head (38 mm to 60 mm) cementless MoM THA with conventional head (28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males, 20 females, mean age of 64 years, standard deviation (sd) 4) and 55 MoP (25 males, 30 females, mean age of 65 years, sd 5) were recruited after a mean follow-up of 50 months (36 to 64). The incidence of pseudotumours, measured using a standardised CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP THA. Women with a MoM THA were more likely to develop a pseudotumour than those with a MoP THA (15 vs 7, odds ratio (OR) = 13.4, p < 0.001). There was a similar incidence of pseudotumours in men with MoM THAs and those with MoP THAs (7 vs 5, OR = 2.1, p = 0.30). Elevated cobalt levels (? 5 microgram/L) were only associated with pseudotumours in women with a MoM THA. There was no difference in mean Oxford and Harris hip scores between patients with a pseudotumour and those without. Contrary to popular belief, pseudotumours occur frequently around MoP THAs. Women with a MoM THA and an elevated cobalt level are at greatest risk. In this study, pseudotumours had no effect on the functional outcome after either large head MoM or conventional MoP THA. Cite this article: Bone Joint J 2015;97-B:1481-7. PMID:26530649

  6. Shorter, rough trunnion surfaces are associated with higher taper wear rates than longer, smooth trunnion surfaces in a contemporary large head metal-on-metal total hip arthroplasty system.

    PubMed

    Brock, Timothy M; Sidaginamale, Raghavendra; Rushton, Steven; Nargol, Antoni V F; Bowsher, John G; Savisaar, Christina; Joyce, Tom J; Deehan, David J; Lord, James K; Langton, David J

    2015-12-01

    Taper wear at the head-neck junction is a possible cause of early failure in large head metal-on-metal (LH-MoM) hip replacements. We hypothesized that: (i) taper wear may be more pronounced in certain product designs; and (ii) an increased abductor moment arm may be protective. The tapers of 104 explanted LH-MoM hip replacements revised for adverse reaction to metal debris (ARMD) from a single manufacturer were analyzed for linear and volumetric wear using a co-ordinate measuring machine. The mated stem was a shorter 12/14, threaded trunnion (n?=?72) or a longer, smooth 11/13 trunnion (n?=?32). The abductor moment arm was calculated from pre-revision radiographs. Independent predictors of linear and volumetric wear included taper angle, stem type, and the horizontal moment arm. Tapers mated with the threaded 12/14 trunnion had significantly higher rates of volumetric wear (0.402?mm(3) /yr vs. 0.123?mm(3) /yr [t?=?-2.145, p?=?0.035]). There was a trend to larger abductor moment arms being protective (p?=?0.055). Design variation appears to play an important role in taper-trunnion junction failure. We recommend that surgeons bear these findings in mind when considering the use of a short, threaded trunnion with a cobalt-chromium head. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1868-1874, 2015. PMID:26135357

  7. Metal-on-Metal Total Hip Resurfacing Arthroplasty

    PubMed Central

    2006-01-01

    Executive Summary Objective The objective of this review was to assess the safety and effectiveness of metal on metal (MOM) hip resurfacing arthroplasty for young patients compared with that of total hip replacement (THR) in the same population. Clinical Need Total hip replacement has proved to be very effective for late middle-aged and elderly patients with severe degenerative diseases of the hips. As indications for THR began to include younger patients and those with a more active life style, the longevity of the implant became a concern. Evidence suggests that these patients experience relatively higher rates of early implant failure and the need for revision. The Swedish hip registry, for example, has demonstrated a survival rate in excess of 80% at 20 years for those aged over 65 years, whereas this figure was 33% by 16 years in those aged under 55 years. Hip resurfacing arthroplasty is a bone-conserving alternative to THR that restores normal joint biomechanics and load transfer. The technique has been used around the world for more than 10 years, specifically in the United Kingdom and other European countries. The Technology Metal-on-metal hip resurfacing arthroplasty is an alternative procedure to conventional THR in younger patients. Hip resurfacing arthroplasty is less invasive than THR and addresses the problem of preserving femoral bone stock at the initial operation. This means that future hip revisions are possible with THR if the initial MOM arthroplasty becomes less effective with time in these younger patients. The procedure involves the removal and replacement of the surface of the femoral head with a hollow metal hemisphere, which fits into a metal acetabular cup. Hip resurfacing arthroplasty is a technically more demanding procedure than is conventional THR. In hip resurfacing, the femoral head is retained, which makes it much more difficult to access the acetabular cup. However, hip resurfacing arthroplasty has several advantages over a conventional THR with a small (28 mm) ball. First, the large femoral head reduces the chance of dislocation, so that rates of dislocation are less than those with conventional THR. Second, the range of motion with hip resurfacing arthroplasty is higher than that achieved with conventional THR. A variety of MOM hip resurfacing implants are used in clinical practice. Six MOM hip resurfacing implants have been issued licences in Canada. Review Strategy A search of electronic bibliographies (OVID Medline, Medline In-Process and Other Non-Indexed Citations, Embase, Cochrane CENTRAL and DSR, INAHTA) was undertaken to identify evidence published from Jan 1, 1997 to October 27, 2005. The search was limited to English-language articles and human studies. The literature search yielded 245 citations. Of these, 11 met inclusion criteria (9 for effectiveness, 2 for safety). The result of the only reported randomized controlled trial on MOM hip resurfacing arthroplasty could not be included in this assessment, because it used a cemented acetabular component, whereas in the new generation of implants, a cementless acetabular component is used. After omitting this publication, only case series remained. Summary of Findings   Health Outcomes The Harris hip score and SF-12 are 2 measures commonly used to report health outcomes in MOM hip resurfacing arthroplasty studies. Other scales used are the Oxford hip score and the University of California Los Angeles hip score. The case series showed that the mean revision rate of MOM hip resurfacing arthroplasty is 1.5% and the incidence of femoral neck fracture is 0.67%. Across all studies, 2 cases of osteonecrosis were reported. Four studies reported improvement in Harris hip scores. However, only 1 study reported a statistically significant improvement. Three studies reported improvement in SF-12 scores, of which 2 reported a significant improvement. One study reported significant improvement in UCLA hip score. Two studies reported postoperative Oxford hip scores, but no preoperative values were reported. None of the reviewed studies r

  8. The Clinical Performance of Metal-on-Metal as an Articulation Surface in Total Hip Replacement

    PubMed Central

    Long, William T

    2005-01-01

    The metal-on-metal articulations in total hip arthroplasty (THA) were widely used between 1960 and 1975. The McKee-Farrar and other first-generation prostheses failed at a high rate because impingement caused early component loosening. The problem of early component loosening was corrected by improved component design and better manufacturing quality. Second-generation metal-on-metal total hip replacements have experienced short and medium-term success as assessed by Harris Hip Scores and patient selfassessment. The combined annual linear wear of the metal-on-metal femoral head and acetabular insert is less than 10 mm and osteolysis has only rarely been observed in association with well-fixed metal-on-metal total hip replacements. Hypersensitivity is not a common cause of loosening with second-generation hip replacements and remains to be proven as a definitive diagnosis in unusual cases of unexplained pain. More than 40 years of use has demonstrated no increase in the incidence of renal failure or cancer in patients with metal-on-metal total hip replacements. The scientific evidence of the results using the metal-on-metal articulations would recommend its continued use in any patient who does not have compromised renal function. PMID:16089065

  9. Short-term results with the Zweymueller-SL metal-on-metal total hip arthroplasty.

    PubMed

    Korovessis, Panagiotis; Petsinis, Georgios; Repanti, Maria; Papazisis, Zisis; Iliopoulos, Panagiotis; Soucacos, Panagiotis N

    2002-01-01

    In a prospective study we followed 266 consecutive patients who received 350 Zweymueller-SL uncemented total hip replacements with metal-on-metal articulation for osteoarthritis. Mean follow-up was 52 (range 37-92) months. Patient age at the time of surgery was 55±9 (25-70) years. Pre-operative Harris score of 45±19 was increased post-operatively to 96±4. Pre-operative invalidity was significantly improved post-operatively (P<0.001), and 97% of the patients were either satisfied or very satisfied with the results. There was no aseptic loosening of either component. Revision was made in six hips (1.8%) because of either septic loosening (five, 1.5%) or technical error (one, 0.3%). At revision, surgical microscopic evidence for metalosis (Mirra grades 1 and 2) was shown in all revised hips. The reasons for early loosening were unrelated to the metal-on-metal bearing but rather were the result of either low-grade deep infection or inadequate surgical technique. Survival rate for Zweymueller screw socket and stem 7.6 years after implantation was 99.4% and 96.8% respectively. There was no evidence that metal-on-metal articulation gives rise to new problems or complications. PMID:24570158

  10. Complications Related to Metal-on-Metal Articulation in Trapeziometacarpal Joint Total Joint Arthroplasty.

    PubMed

    Frølich, Christina; Hansen, Torben Bæk

    2015-01-01

    Adverse reactions to metal-on-metal (MoM) prostheses are well known from total hip joint resurfacing arthroplasty with elevated serum chrome or cobalt, pain and pseudo tumor formation. It may, however, also be seen after total joint replacement of the trapeziometacarpal joint using MoM articulation, and we present two cases of failure of MoM prostheses due to elevated metal-serum levels in one case and pseudo tumor formation in another case. Furthermore, we suggest a diagnostic algorithm for joint pain after MoM trapeziometacarpal joint replacement based on published experiences from MoM hip prostheses and adverse reactions to metal. PMID:26020592

  11. Metal-on-Metal Total Hip Arthroplasty: Patient Evaluation and Treatment.

    PubMed

    Bolognesi, Michael P; Ledford, Cameron K

    2015-12-01

    Metal-on-metal (MoM) hip articulations were thought to represent a biologic and biomechanically favorable alternative to conventional metal-on-polyethylene total hip arthroplasty implants. However, concerns emerged when registry data reported significantly higher failure rates associated with MoM implants compared with other contemporary hip implants. These high implant failure rates have been attributed to the release of metal particles into the periprosthetic space, creating macroscopic necrosis; corrosive osteolysis; large, sterile hip effusions; and periprosthetic solid and cystic masses (ie, pseudotumors)-a spectrum of findings termed adverse reaction to metal debris. A thorough clinical history and physical examination, along with laboratory data and imaging surveillance of these patients, is critical for appropriate diagnosis and treatment. The decision to perform revision hip arthroplasty of a metal-on-metal implant is multifactorial and should be based on documented, objective clinical indications. A systematic and objective approach to this evaluation and treatment is essential to optimize the care of patients who undergo total hip arthroplasty with MoM implants. PMID:26493972

  12. Friction in metal-on-metal total disc arthroplasty: effect of ball radius.

    PubMed

    Moghadas, Parshia; Mahomed, Aziza; Hukins, David W L; Shepherd, Duncan E T

    2012-02-01

    Total disc arthroplasty (TDA) can be used to replace a degenerated intervertebral disc in the spine. There are different designs of prosthetic discs, but one of the most common is a ball-and-socket combination. Contact between the bearing surfaces can result in high frictional torque, which can then result in wear and implant loosening. This study was designed to determine the effects of ball radius on friction. Generic models of metal-on-metal TDA were manufactured with ball radii of 10, 12, 14 and 16 mm, with a radial clearance of 0.015 mm. A simulator was used to test each sample in flexion-extension, lateral bending and axial rotation at frequencies of 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2 Hz under loads of 50, 600, 1200 and 2000 N, in new born calf serum. Frictional torque was measured and Stribeck curves were plotted to illustrate the lubrication regime in each case. It was observed that implants with a smaller ball radius showed lower friction and showed boundary and mixed lubrication regimes, whereas implants with larger ball radius showed boundary lubrication only. This study suggests designing metal-on-metal TDAs with ball radius of 10 or 12 mm, in order to reduce wear and implant loosening. PMID:22177670

  13. A finite element method comparison of wear in two metal-on-metal total hip prostheses.

    PubMed

    Cosmi, F; Hoglievina, M; Fancellu, G; Martinelli, B

    2006-11-01

    The contact mechanics of two metal-on-metal (MOM) total hip prostheses was studied by means of the finite element method (FEM). The purpose of the work was to compare two total hip replacements (Durom and Metasul) with regard to the amount of wear debris released. Wear on the bearing surfaces was evaluated following Reye hypotheses from the pressure distribution, computed by means of three-dimensional FEM models; an approximate analytical model based on Hertz contact theory has also been developed and discussed. The results show that in the dry friction condition the Durom joint releases almost twice as much wear volume as produced by the Metasul joint. Therefore, while Durom implants can improve hip stability by increasing the prosthetic impingement-free range of motion (PIF-ROM), Metasul prostheses can be a valuable solution whenever wear represents a critical choice factor. PMID:17236520

  14. Metal on metal total hip arthroplasty and a large groin mass: Not always adverse reaction to metallic debris

    PubMed Central

    Krishnan, Harry; Magnussen, Alex; Sharma, Aadhar; Skinner, John

    2014-01-01

    Due to their improved wear rates, Metal-on-metal bearings have been increasingly used in the past decade by orthopaedic surgeons carrying out total hip arthroplasty. However there is increasing evidence that there are significant complications associated with such implants. One well documented complication is that of metallic debris leading to pseudotumour formation, however there is less known about associations with other tumours within the pelvis. We present two cases where an intra-pelvic mass in patients with metal-on-metal implants were diagnosed as being of a different aetiology. This highlights the need for careful assessment of such patients in order to guide appropriate management. PMID:25560054

  15. Large diameter metal on metal total hip replacement for femoral neck fractures with neurological conditions

    PubMed Central

    Li, Jia; Zheng, Wei; Zhao, Jinzhu; Liu, Denghui; Xu, Weidong

    2014-01-01

    Background: Patients with Parkinson's disease and poliomyelitis can have a femoral neck fracture; yet, the optimal methods of treatment for these hips remains controversial. Many constrained or semi-constrained prostheses, using constrained liners (CLs) with a locking mechanism to capture the femoral head, were used to treat femoral neck fractures in patients with neurological disorders. We retrospectively studied a group of patients with Parkinson's disease and poliomyelitis who sustained femoral neck fractures and were treated by total hip arthroplasty using an L-MoM prosthesis. Materials and Methods: We retrospectively reviewed 12 hips in 12 patients who underwent large-diameter metal-on-metal (L-MoM) total hip replacement between May 2007 and October 2009. Eight of the 12 patients (8 hips; 66.7%) had Parkinson's disease and 4 patients (4 hips; 33.3%) were affected with poliomyelitis. Results: The followup time was 5.2 years (range 3.6-6.0 years). At the latest followup, all the patients showed satisfactory clinical and radiographic results, with pain relief. No complications, such as dislocation or aseptic loosening occurred. Conclusion: We believe the use of L-MoM can diminish the rate of instability or dislocation, after operation. The L-MoM is an option for patients with Parkinson's disease and poliomyelitis with femoral neck fracture. PMID:25404774

  16. Utility of synovial fluid aspirations in failed metal-on-metal total hip arthroplasty.

    PubMed

    Wyles, Cody C; Larson, Dirk R; Houdek, Matthew T; Sierra, Rafael J; Trousdale, Robert T

    2013-05-01

    White blood cell (WBC) count and neutrophil percentage from preoperative synovial fluid aspirations are used to help determine the presence or absence of periprosthetic joint infection (PJI) in failed total hip arthroplasty (THA). The clinical levels indicative of infection have not been delineated in metal-on-metal (MoM) bearings. We identified 39 patients who received a preoperative synovial fluid aspiration prior to MoM revision. Thirty-five of 39 cases were culture negative and 4 of 39 were culture positive. WBC count >3000 cells/?L was 100% sensitive and 57.1% specific. Neutrophil percentage >80% was 100% sensitive and 97.1% specific. Both CRP and ESR >8.0mg/L and >22 mm/h, respectively were 75.0% sensitive and 67.6% specific. Our data suggest that synovial WBC count and serum ESR and CRP have poor predictive value in diagnosing PJI for failed MoM THA, whereas synovial neutrophil percentage is a highly accurate marker for diagnosing infection in this patient population. PMID:23499404

  17. Metallic debris from metal-on-metal total hip arthroplasty regulates periprosthetic tissues

    PubMed Central

    Lohmann, Christoph H; Singh, Gurpal; Willert, Hans-Georg; Buchhorn, Gottfried H

    2014-01-01

    The era of metal-on-metal (MoM) total hip arthroplasty has left the orthopaedic community with valuable insights and lessons on periprosthetic tissue reactions to metallic debris. Various terms have been used to describe the tissue reactions. Sometimes the nomenclature can be confusing. We present a review of the concepts introduced by Willert and Semlitsch in 1977, along with further developments made in the understanding of periprosthetic tissue reactions to metallic debris. We propose that periprosthetic tissue reactions be thought of as (1) gross (metallosis, necrosis, cyst formation and pseudotumour); (2) histological (macrophage-dominated, lymphocyte-dominated or mixed); and (3) molecular (expression of inflammatory mediators and cytokines such as interleukin-6 and tumor necrosis factor-alpha). Taper corrosion and modularity are discussed, along with future research directions to elucidate the antigen-presenting pathways and material-specific biomarkers which may allow early detection and intervention in a patient with adverse periprosthetic tissue reactions to metal wear debris. PMID:25405095

  18. Metal-on-metal total hip arthroplasty - five- to 11-year follow-up.

    PubMed

    Nikolaou, Vassilios S; Petit, Alain; Debiparshad, Kevin; Huk, Olga L; Zukor, David J; Antoniou, John

    2011-01-01

    Metal-on-metal (MoM) total hip arthroplasty (THA) has been introduced in an attempt to reduce the wear rate and the consequent osteolysis around implants. The aim of this study was to present the intermediate to long-term clinical and radiological outcomes and to investigate the metal ion levels in the blood of patients who had undergone primary uncemented MoM THA in our institution. Between July 1997 and November 2003, 166 patients (193 hips), with a mean age of 50 years (range, 18-65 years), underwent primary MoM THA. Clinical data, radiographs, and blood samples were obtained at regular follow-up visits. Cobalt (Co), chromium (Cr), and molybdenum (Mo) ions were measured by inductively coupled plasma-mass spectrometry (ICP-MS) from the patient's whole blood. All patients were prospectively followed for a minimum of 5 years (mean, 7 years; range, 5-11 years). The mean Harris hip score (HHS) and the University of California at Los Angeles (UCLA) activity score at the latest follow-up was 88 ± 11 and 7 ± 1.8 points, respectively. Thirteen hips have been revised. Ten acetabular components had early failure, due to factory manufacturing problems. All other implants have been found stable, with no signs of aseptic loosening. The probability of survival at 11 years, if the hips that were revised due to manufacturing problems were excluded, was 98.4%. The Co and Cr metal ion levels, after increasing significantly during the first 4 to 5 years post-surgery, remained stable, with a tendency to decrease thereafter, but not significantly. During the same follow-up period, Mo ion levels remained stable. In this 5-to-11 year follow-up study of MoM THA patients, excellent survivorship, with low complications rates, was found. Results of longer follow-up studies are necessary to clarify the possible long-term effects of metal ion release. PMID:22035490

  19. Increased risk of revision of cementless stemmed total hip arthroplasty with metal-on-metal bearings

    PubMed Central

    Pedersen, Alma B; Mäkelä, Keijo; Eskelinen, Antti; Havelin, Leif Ivar; Furnes, Ove; Kärrholm, Johan; Garellick, Göran; Overgaard, Søren

    2015-01-01

    Background and purpose Data from the national joint registries in Australia and England and Wales have revealed inferior medium-term survivorship for metal-on-metal (MoM) total hip arthroplasty (THA) than for metal-on-polyethylene (MoP) THA. Based on data from the Nordic Arthroplasty Register Association (NARA), we compared the revision risk of cementless stemmed THA with MoM and MoP bearings and we also compared MoM THA to each other. Patients and methods We identified 32,678 patients who were operated from 2002 through 2010 with cementless stemmed THA with either MoM bearings (11,567 patients, 35%) or MoP bearings (21,111 patients, 65%). The patients were followed until revision, death, emigration, or the end of the study period (December 31, 2011), and median follow-up was 3.6 (interquartile range (IQR): 2.4–4.8) years for MoM bearings and 3.4 (IQR: 2.0–5.8) years for MoP bearings. Multivariable regression in the presence of competing risk of death was used to assess the relative risk (RR) of revision for any reason (with 95% confidence interval (CI)). Results The cumulative incidence of revision at 8 years of follow-up was 7.0% (CI: 6.0–8.1) for MoM bearings and 5.1% (CI: 4.7–5.6) for MoP bearings. At 6 years of follow-up, the RR of revision for any reason was 1.5 (CI: 1.3–1.7) for MoM bearings compared to MoP bearings. The RR of revision for any reason was higher for the ASR (adjusted RR = 6.4, CI: 5.0–8.1), the Conserve Plus (adjusted RR = 1.7, CI: 1.1–2.5) and “other” acetabular components (adjusted RR = 2.4, CI: 1.5–3.9) than for MoP THA at 6 years of follow-up. Interpretation At medium-term follow-up, the survivorship for cementless stemmed MoM THA was inferior to that for MoP THA, and metal-related problems may cause higher revision rates for MoM bearings with longer follow-up. PMID:25715878

  20. Understanding the differences between the wear of metal-on-metal and ceramic-on-metal total hip replacements.

    PubMed

    Figueiredo-Pina, C G; Yan, Y; Neville, A; Fisher, J

    2008-04-01

    Hip simulator studies have been carried out extensively to understand and test artificial hip implants in vitro as an efficient alternative to obtaining long-term results in vivo. Recent studies have shown that a ceramic-on-metal material combination lowers the wear by up to 100 times in comparison with a typical metal-on-metal design. The reason for this reduction remains unclear and for this reason this study has undertaken simple tribometer tests to understand the fundamental material loss mechanisms in two material combinations: metal-on-metal and ceramic-on-ceramic. A simple-configuration reciprocating pin-on-plate wear study was performed under open-circuit potential (OCP) and with applied cathodic protection (CP) in a serum solution using two tribological couples: firstly, cobalt-chromium (Co-Cr) pins against Co-Cr plates; secondly, Co-Cr pins against alumina (Al2O3) plates. The pin and plate surfaces prior to and after testing were examined by profilometry and scanning electron microscopy. The results showed a marked reduction in wear when CP was applied, indicating that total material degradation under the OCP condition was attributed to corrosion processes. The substitution of the Co-Cr pin with an Al2O3 plate also resulted in a dramatic reduction in wear, probably due to the reduction in the corrosion-wear interactions between the tribological pair. PMID:18491698

  1. Acetabular bone density and metal ions after metal-on-metal versus metal-on-polyethylene total hip arthroplasty; short-term results.

    PubMed

    Zijlstra, Wierd P; van der Veen, Hugo C; van den Akker-Scheek, Inge; Zee, Mark J M; Bulstra, Sjoerd K; van Raay, Jos J A M

    2014-01-01

    Information on periprosthetic acetabular bone density is lacking for metal-on-metal total hip arthroplasties. These bearings use cobalt-chromium instead of titanium acetabular components, which could lead to stress shielding and hence periprosthetic bone loss. Cobalt and chromium ions have detrimental effects on bone. It is unknown whether serum metal ion levels affect bone density clinically. We compared cementless large femoral head (mean 48 mm) metal-on-metal total hip arthroplasties (M2a-Magnum, Biomet) to cementless 28 mm metal-on-polyethylene total hip arthroplasties (Mallory-Head, Biomet) in a randomised clinical trial. We evaluated periprosthetic acetabular bone density and serum metal ion levels at 1 year postoperatively. Acetabular bone density was analyzed with dual energy x-ray absorptiometry in four horizontal regions of interest in 70 patients. After one year, acetabular bone density decreased (-3.5% to -7.8%) in three of four regions of interest in metal-on-polyethylene patients, but was retained in metal-on-metal patients. Bone density preservation was most pronounced superior to the metal-on-metal cup (+1% versus -3.7%). Serum cobalt, chromium and titanium ion levels were not related to bone density, nor to acetabular inclination or femoral head size. Oxford and Harris hip scores were similar in both groups. Contrary to our hypothesis, acetabular bone density was retained with metal-on-metal total hip arthroplasty, compared to metal-on-polyethylene arthroplasty. Bone preservation was most pronounced in the area superior to the cup. This could be a benefit during future revision surgery. PMID:24186673

  2. The Latest Lessons Learned from Retrieval Analyses of Ultra-High Molecular Weight Polyethylene, Metal-on-Metal, and Alternative Bearing Total Disc Replacements

    PubMed Central

    Kurtz, Steven M.; Toth, Jeffrey M.; Siskey, Ryan; Ciccarelli, Lauren; MacDonald, Dan; Isaza, Jorge; Lanman, Todd; Punt, Ilona; Steinbeck, Marla; Goffin, Jan; van Ooij, André

    2012-01-01

    Knowledge regarding the in vivo performance and periposthetic tissue response of cervical and lumbar total disc replacements (TDRs) continues to expand. This review addresses the following four main questions: 1) What are the latest lessons learned from polyethylene in large joints and how are they relevant to current TDRs? 2) What are the latest lessons learned regarding adverse local tissue reactions from metal-on-metal, CoCr bearings in large joints and how are they relevant to current TDRs? 3) What advancements have been made in understanding the in vivo performance of alternative biomaterials, such as stainless steel and polycarbonate urethane, for TDRs in the past five years? 4) How has retrieval analysis of all these various artificial disc bearing technologies advanced the state of the art in preclinical testing of TDRs? The study of explanted artificial discs and their associated tissues can help inform bearing selection as well as the design of future generations of disc arthroplasty. Analyzing retrieved artificial discs is also essential for validating preclinical test methods. PMID:22904606

  3. The Latest Lessons Learned from Retrieval Analyses of Ultra-High Molecular Weight Polyethylene, Metal-on-Metal, and Alternative Bearing Total Disc Replacements.

    PubMed

    Kurtz, Steven M; Toth, Jeffrey M; Siskey, Ryan; Ciccarelli, Lauren; Macdonald, Dan; Isaza, Jorge; Lanman, Todd; Punt, Ilona; Steinbeck, Marla; Goffin, Jan; van Ooij, André

    2012-03-01

    Knowledge regarding the in vivo performance and periposthetic tissue response of cervical and lumbar total disc replacements (TDRs) continues to expand. This review addresses the following four main questions: 1) What are the latest lessons learned from polyethylene in large joints and how are they relevant to current TDRs? 2) What are the latest lessons learned regarding adverse local tissue reactions from metal-on-metal, CoCr bearings in large joints and how are they relevant to current TDRs? 3) What advancements have been made in understanding the in vivo performance of alternative biomaterials, such as stainless steel and polycarbonate urethane, for TDRs in the past five years? 4) How has retrieval analysis of all these various artificial disc bearing technologies advanced the state of the art in preclinical testing of TDRs? The study of explanted artificial discs and their associated tissues can help inform bearing selection as well as the design of future generations of disc arthroplasty. Analyzing retrieved artificial discs is also essential for validating preclinical test methods. PMID:22904606

  4. A longitudinal study of MARS MRI scanning of soft-tissue lesions around metal-on-metal total hip arthroplasties and disease progression.

    PubMed

    Briant-Evans, T W; Lyle, N; Barbur, S; Hauptfleisch, J; Amess, R; Pearce, A R; Conn, K S; Stranks, G J; Britton, J M

    2015-10-01

    We investigated the changes seen on serial metal artefact reduction magnetic resonance imaging scans (MARS-MRI) of metal-on-metal total hip arthroplasties (MoM THAs). In total 155 THAs, in 35 male and 100 female patients (mean age 70.4 years, 42 to 91), underwent at least two MRI scans at a mean interval of 14.6 months (2.6 to 57.1), at a mean of 48.2 months (3.5 to 93.3) after primary hip surgery. Scans were graded using a modification of the Oxford classification. Progression of disease was defined as an increase in grade or a minimum 10% increase in fluid lesion volume at second scan. A total of 16 hips (30%) initially classified as 'normal' developed an abnormality on the second scan. Of those with 'isolated trochanteric fluid' 9 (47%) underwent disease progression, as did 7 (58%) of 'effusions'. A total of 54 (77%) of hips initially classified as showing adverse reactions to metal debris (ARMD) progressed, with higher rates of progression in higher grades. Disease progression was associated with high blood cobalt levels or an irregular pseudocapsule lining at the initial scan. There was no association with changes in functional scores. Adverse reactions to metal debris in MoM THAs may not be as benign as previous reports have suggested. Close radiological follow-up is recommended, particularly in high-risk groups. Cite this article: Bone Joint J 2015;97-B:1328-37. PMID:26430006

  5. Changes in early serum metal ion levels and impact on liver, kidney, and immune markers following metal-on-metal total hip arthroplasty.

    PubMed

    Chen, Zhefeng; Wang, Zhen; Wang, Qing; Cui, Weiding; Liu, Feng; Fan, Weimin

    2014-03-01

    We retrospectively studied 32 consecutive patients (32 hips) who underwent THA with a Durom large-head, MOM articulation between January 2008 and December 2010. Of the patients who underwent THA using a Trilogy metal on polyethylene prosthesis during the same period, 32 were chosen to form the Trilogy group. 32 volunteers were chosen to form the control group. At the last follow-up, serum metal ion levels, liver and kidney function and host immunologic immune responses were evaluated. The mean Co and Cr levels in the Durom group were 4.33- and 1.95-fold higher than those in the Trilogy group. CD3+, CD4+ and CD8+ cell levels in the Durom group were significantly decreased. The INF-? level in the Durom group was significantly higher than that in the Trilogy and control groups. PMID:23993737

  6. Similar incidence of periprosthetic fluid collections after ceramic-on-polyethylene total hip arthroplasties and metal-on-metal resurfacing arthroplasties: results of a screening metal artefact reduction sequence-MRI study.

    PubMed

    Bisseling, P; de Wit, B W K; Hol, A M; van Gorp, M J; van Kampen, A; van Susante, J L C

    2015-09-01

    Patients from a randomised trial on resurfacing hip arthroplasty (RHA) (n = 36, 19 males; median age 57 years, 24 to 65) comparing a conventional 28 mm metal-on-metal total hip arthroplasty (MoM THA) (n = 28, 17 males; median age 59 years, 37 to 65) and a matched control group of asymptomatic patients with a 32 mm ceramic-on-polyethylene (CoP) THA (n = 33, 18 males; median age 63 years, 38 to 71) were cross-sectionally screened with metal artefact reducing sequence-MRI (MARS-MRI) for pseudotumour formation at a median of 55 months (23 to 72) post-operatively. MRIs were scored by consensus according to three different classification systems for pseudotumour formation. Clinical scores were available for all patients and metal ion levels for MoM bearing patients. Periprosthetic lesions with a median volume of 16 mL (1.5 to 35.9) were diagnosed in six patients in the RHA group (17%), one in the MoM THA group (4%) and six in the CoP group (18%). The classification systems revealed no clear differences between the groups. Solid lesions (n = 3) were exclusively encountered in the RHA group. Two patients in the RHA group and one in the MoM THA group underwent a revision for pseudotumour formation. There was no statistically significant relationship between clinical scoring, metal ion levels and periprosthetic lesions in any of the groups. Periprosthetic fluid collections are seen on MARS-MRI after conventional CoP THA and RHA and may reflect a soft-tissue collection or effusion. Currently available MRI classification systems seem to score these collections as pseudotumours, causing an-overestimatation of the incidence of pseudotumours. PMID:26330582

  7. Edge loading in metal-on-metal hips: low clearance is a new risk factor

    PubMed Central

    Zografos, Angelos; Sayles, Ritchie S; Hart, Alister; Cann, Philippa

    2012-01-01

    The revision rate of large head metal-on-metal and resurfacing hips are significantly higher than conventional total hip replacements. The revision of these components has been linked to high wear caused by edge loading; which occurs when the head–cup contact patch extends over the cup rim. There are two current explanations for this; first, there is loss of entrainment of synovial fluid resulting in breakdown of the lubricating film and second, edge loading results in a large local increase in contact pressure and consequent film thickness reduction at the cup rim, which causes an increase in wear. This paper develops a method to calculate the distance between the joint reaction force vector and the cup rim – the contact patch centre to rim (CPCR) distance. However, the critical distance for the risk of edge loading is the distance from the contact patch edge to rim (CPER) distance. An analysis of explanted hip components, divided into edge worn and non-edge-worn components showed that there was no statistical difference in CPCR values, but the CPER value was significantly lower for edge worn hips. Low clearance hips, which have a more conformal contact, have a larger diameter contact patch and thus are more at risk of edge loading for similarly positioned hips. PMID:22558836

  8. Metal-on-Metal Hip Resurfacing Arthroplasty

    PubMed Central

    Sehatzadeh, S; Kaulback, K; Levin, L

    2012-01-01

    Background Metal-on-metal (MOM) hip resurfacing arthroplasty (HRA) is in clinical use as an appropriate alternative to total hip arthroplasty in young patients. In this technique, a metal cap is placed on the femoral head to cover the damaged surface of the bone and a metal cup is placed in the acetabulum. Objectives The primary objective of this analysis was to compare the revision rates of MOM HRA using different implants with the benchmark set by the National Institute of Clinical Excellence (NICE). The secondary objective of this analysis was to review the literature regarding adverse biological effects associated with implant material. Review Methods A literature search was performed on February 13, 2012, to identify studies published from January 1, 2009, to February 13, 2012. Results The revision rates for MOM HRA using 6 different implants were reviewed. The revision rates for MOM HRA with 3 implants met the NICE criteria, i.e., a revision rate of 10% or less at 10 years. Two implants had short-term follow-ups and MOM HRA with one of the implants failed to meet the NICE criteria. Adverse tissue reactions resulting in failure of the implants have been reported by several studies. With a better understanding of the factors that influence the wear rate of the implants, adverse tissue reactions and subsequent implant failure can be minimized. Many authors have suggested that patient selection and surgical technique affect the wear rate and the risk of tissue reactions. The biological effects of high metal ion levels in the blood and urine of patients with MOM HRA implants are not known. Studies have shown an increase in chromosomal aberrations in patients with MOM articulations, but the clinical implications and long-term consequences of this increase are still unknown. Epidemiological studies have shown that patients with MOM HRA implants did not have an overall increase in mortality or risk of cancer. There is insufficient clinical data to confirm the teratogenicity of MOM implants in humans. Conclusions Metal-on-metal HRA can be beneficial for appropriately selected patients, provided the surgeon has the surgical skills required for performing this procedure. Plain Language Summary There are many young patients with hip diseases who need to have hip replacement surgery. Although a traditional hip replacement is an acceptable procedure for these patients, some surgeons prefer using a newer technique in young patients called hip resurfacing. In this technique, instead of removing the head of the femoral bone, a metal cap is placed on the femoral head to cover the damaged surface of the bone and a metal cup is placed in the hip socket, similar to the cups used in traditional hip replacement. The analysis of the revision rates (i.e., how soon and in how many patients the surgery needs to be redone) and safety of resurfacing implants showed that generally these implants can last 10 years or more for the majority of young people. Good outcomes can be expected when skilled surgeons perform the surgery in properly selected patients. However, since these implants are made of metal (cobalt and chromium alloy), there is concern about excess metal debris production due to friction between the 2 metal components leading to high levels of metal ions in the blood and urine of patients. The production of metal debris may result in inflammation in the joint or development of a benign soft tissue mass leading to implant failure. However, it has been shown that this risk can be reduced by proper positioning of the implant and the careful selection of patients for this procedure. Little is known about the long-term biological effects of high levels of metal ions in the blood and urine of patients who have received metal implants. There is concern about potential increases in the risk of cancer and the risk of fetal abnormalities, but these effects have not been established yet. However, since cobalt and chromium can pass the placental barrier, implants that are not metal-on-metal are recommended for women at childbearing ages if they

  9. The minimal invasive direct anterior approach in combination with large heads in total hip arthroplasty - is dislocation still a major issue? a case control study

    PubMed Central

    2014-01-01

    Background There have been increasing numbers of publications in recent years on minimally invasive surgery (MIS) for total hip arthroplasty (THA), reporting results with the use of different head sizes, tribologic and functional outcomes. This study presents the results and early complication rates after THA using the direct anterior approach (DAA) in combination with head sizes???36 mm. Methods A total of 113 patients with THA were included in the study. The Harris Hip Score (HHS) was determined, a radiographic evaluation was carried out, and complications were recorded. The minimum follow-up period was 2 years (means 35?±?7 months). Results The HHS improved from 43.6 (± 12) to 88.2 (± 14; P?large heads is associated with good to very good functional results in the majority of cases. The complication rates are not increased. The rate of dislocation mainly as an complication of the first two years can be markedly reduced in particular. PMID:24621189

  10. Metal-on-metal: history, state of the art (2010)

    PubMed Central

    2011-01-01

    The history of metal-on-metal bearing began with K. Mc Kee. Several "episodes" have marked the history of metal-on-metal articulations, and each has contributed to a better understanding of this type of tribology. But to date the indications for this bearing are debated and are subject to reservations because of the existence of permanently elevated levels of circulating metal ions. It therefore appears that the monitoring of our patients, the documentation of our revisions and the collaboration with our industry partners as well as communicating with our biology and pathology colleagues is necessary to help us solve these problems. PMID:21234564

  11. Taper junction failure in large-diameter metal-on-metal bearings

    PubMed Central

    Langton, D. J.; Sidaginamale, R.; Lord, J. K.; Nargol, A. V. F.; Joyce, T. J.

    2012-01-01

    Objectives An ongoing prospective study to investigate failing metal-on-metal hip prostheses was commenced at our centre in 2008. We report on the results of the analysis of the first consecutive 126 failed mated total hip prostheses from a single manufacturer. Methods Analysis was carried out using highly accurate coordinate measuring to calculate volumetric and linear rates of the articular bearing surfaces and also the surfaces of the taper junctions. The relationship between taper wear rates and a number of variables, including bearing diameter and orientation of the acetabular component, was investigated. Results The measured rates of wear and distribution of material loss from the taper surfaces appeared to show that the primary factor leading to taper failure is the increased lever arm acting on this junction in contemporary large-diameter metal-on-metal hip replacements. Conclusions Our analysis suggests that varus stems, laterally engaging taper systems and larger head diameters all contribute to taper failure. PMID:23610672

  12. Graphitic Tribological Layers in Metal-on-Metal Hip Replacements

    NASA Astrophysics Data System (ADS)

    Liao, Y.; Pourzal, R.; Wimmer, M. A.; Jacobs, J. J.; Fischer, A.; Marks, L. D.

    2011-12-01

    Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.

  13. Graphitic tribological layers in metal-on-metal hip replacements.

    PubMed

    Liao, Y; Pourzal, R; Wimmer, M A; Jacobs, J J; Fischer, A; Marks, L D

    2011-12-23

    Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris. PMID:22194573

  14. Tribological performance of various CoCr microstructures in metal-on-metal bearings: the development of a more physiological protocol in vitro.

    PubMed

    Kamali, A; Hussain, A; Li, C; Pamu, J; Daniel, J; Ziaee, H; Daniel, J; McMinn, D J W

    2010-05-01

    Hip simulators have been used for ten years to determine the tribological performance of large-head metal-on-metal devices using traditional test conditions. However, the hip simulator protocols were originally developed to test metal-on-polyethylene devices. We have used patient activity data to develop a more physiologically relevant test protocol for metal-on-metal devices. This includes stop/start motion, a more appropriate walking frequency, and alternating kinetic and kinematic profiles. There has been considerable discussion about the effect of heat treatments on the wear of metal-on-metal cobalt chromium molybdenum (CoCrMo) devices. Clinical studies have shown a higher rate of wear, levels of metal ions and rates of failure for the heat-treated metal compared to the as-cast metal CoCrMo devices. However, hip simulator studies in vitro under traditional testing conditions have thus far not been able to demonstrate a difference between the wear performance of these implants. Using a physiologically relevant test protocol, we have shown that heat treatment of metal-on-metal CoCrMo devices adversely affects their wear performance and generates significantly higher wear rates and levels of metal ions than in as-cast metal implants. PMID:20436012

  15. CoCrMo Metal-on-Metal Hip Replacements

    PubMed Central

    Liao, Yifeng; Hoffman, Emily; Wimmer, Markus; Fischer, Alfons; Jacobs, Joshua; Marks, Laurence

    2012-01-01

    After the rapid growth in the use of CoCrMo metal-on-metal hip replacements since the second generation was introduced circa 1990, metal-on-metal hip replacements have experienced a sharp decline in the last two years due to biocompatibility issues related to wear and corrosion products. Despite some excellent clinical results, the release of wear and corrosion debris and the adverse response of local tissues have been of great concern. There are many unknowns regarding how CoCrMo metal bearings interact with the human body. This perspective article is intended to outline some recent progresses in understanding wear and corrosion of metal-on-metal hip replacement both in-vivo and in-vitro. The materials, mechanical deformation, corrosion, wear-assisted corrosion, and wear products will be discussed. Possible adverse health effects caused by wear products will be briefly addressed, as well as some of the many open questions such as the detailed chemistry of corrosion, tribochemical reactions and the formation of graphitic layers. Nowadays we design almost routinely for high performance materials and lubricants for automobiles; humans are at least as important. It is worth remembering that a hip implant is often the difference between walking and leading a relatively normal life, and a wheelchair. PMID:23196425

  16. CoCrMo metal-on-metal hip replacements.

    PubMed

    Liao, Yifeng; Hoffman, Emily; Wimmer, Markus; Fischer, Alfons; Jacobs, Joshua; Marks, Laurence

    2013-01-21

    After the rapid growth in the use of CoCrMo metal-on-metal hip replacements since the second generation was introduced circa 1990, metal-on-metal hip replacements have experienced a sharp decline in the last two years due to biocompatibility issues related to wear and corrosion products. Despite some excellent clinical results, the release of wear and corrosion debris and the adverse response of local tissues have been of great concern. There are many unknowns regarding how CoCrMo metal bearings interact with the human body. This perspective article is intended to outline some recent progresses in understanding wear and corrosion of metal-on-metal hip replacement both in vivo and in vitro. The materials, mechanical deformation, corrosion, wear-assisted corrosion, and wear products will be discussed. Possible adverse health effects caused by wear products will be briefly addressed, as well as some of the many open questions such as the detailed chemistry of corrosion, tribochemical reactions and the formation of graphitic layers. Nowadays we design almost routinely for high performance materials and lubricants for automobiles; humans are at least as important. It is worth remembering that a hip implant is often the difference between walking and leading a relatively normal life, and a wheelchair. PMID:23196425

  17. Information for Patients Who Have Metal-on-Metal Hip Implants

    MedlinePLUS

    ... Metal Hip Implants Information for Patients Who Have Metal-on-Metal Hip Implants Share Tweet Linkedin Pin it More ... How do I know if I have a metal-on-metal hip implant? Patients are usually told ...

  18. Independent predictors of revision following metal-on-metal hip resurfacing: a retrospective cohort study using National Joint Registry data.

    PubMed

    Jameson, S S; Baker, P N; Mason, J; Porter, M L; Deehan, D J; Reed, M R

    2012-06-01

    Modern metal-on-metal hip resurfacing has been widely performed in the United Kingdom for over a decade. However, the literature reports conflicting views of the benefits: excellent medium- to long-term results with some brands in specific subgroups, but high failure rates and local soft-tissue reactions in others. The National Joint Registry for England and Wales (NJR) has collected data on all hip resurfacings performed since 2003. This retrospective cohort study recorded survival time to revision from a resurfacing procedure, exploring risk factors independently associated with failure. All patients with a primary diagnosis of osteoarthritis who underwent resurfacing between 2003 and 2010 were included in the analyses. Cox's proportional hazard models were used to analyse the extent to which the risk of revision was related to patient, surgeon and implant covariates. A total of 27 971 hip resurfacings were performed during the study period, of which 1003 (3.59%) underwent revision surgery. In the final adjusted model, we found that women were at greater risk of revision than men (hazard ratio (HR) = 1.30, p = 0.007), but the risk of revision was independent of age. Of the implant-specific predictors, five brands had a significantly greater risk of revision than the Birmingham Hip Resurfacing (BHR) (ASR: HR = 2.82, p < 0.001, Conserve: HR = 2.03, p < 0.001, Cormet: HR = 1.43, p = 0.001, Durom: HR = 1.67, p < 0.001, Recap: HR = 1.58, p = 0.007). Smaller femoral head components were also significantly more likely to require revision (? 44 mm: HR = 2.14, p < 0.001, 45 to 47 mm: HR = 1.48, p = 0.001) than medium or large heads, as were operations performed by low-volume surgeons (HR = 1.36, p < 0.001). Once these influences had been removed, in 4873 male patients < 60 years old undergoing resurfacing with a BHR, the five-year estimated risk of revision was 1.59%. In summary, after adjustment for a range of covariates we found that there were significant differences in the rate of failure between brands and component sizes. Younger male patients had good five-year implant survival when the BHR was used. PMID:22628587

  19. Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

    PubMed Central

    Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

    2013-01-01

    Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip resurfacing arthroplasty. Patients with implanted MoM-bearing should receive regular and standardized monitoring of metal ion concentrations. Further research is indicated especially with regard to potential systemic reactions due to accumulation of metal products. PMID:23950923

  20. Muscle atrophy and metal-on-metal hip implants

    PubMed Central

    Berber, Reshid; Khoo, Michael; Cook, Erica; Guppy, Andrew; Hua, Jia; Miles, Jonathan; Carrington, Richard; Skinner, John; Hart, Alister

    2015-01-01

    Background and purpose Muscle atrophy is seen in patients with metal-on-metal (MOM) hip implants, probably because of inflammatory destruction of the musculo-tendon junction. However, like pseudotumors, it is unclear when atrophy occurs and whether it progresses with time. Our objective was to determine whether muscle atrophy associated with MOM hip implants progresses with time. Patients and methods We retrospectively reviewed 74 hips in 56 patients (32 of them women) using serial MRI. Median age was 59 (23–83) years. The median time post-implantation was 83 (35–142) months, and the median interval between scans was 11 months. Hip muscles were scored using the Pfirrmann system. The mean scores for muscle atrophy were compared between the first and second MRI scans. Blood cobalt and chromium concentrations were determined. Results The median blood cobalt was 6.84 (0.24–90) ppb and median chromium level was 4.42 (0.20–45) ppb. The median Oxford hip score was 34 (5–48). The change in the gluteus minimus mean atrophy score between first and second MRI was 0.12 (p = 0.002). Mean change in the gluteus medius posterior portion (unaffected by surgical approach) was 0.08 (p = 0.01) and mean change in the inferior portion was 0.10 (p = 0.05). Mean pseudotumor grade increased by 0.18 (p = 0.02). Interpretation Worsening muscle atrophy and worsening pseudotumor grade occur over a 1-year period in a substantial proportion of patients with MOM hip implants. Serial MRI helps to identify those patients who are at risk of developing worsening soft-tissue pathology. These patients should be considered for revision surgery before irreversible muscle destruction occurs. PMID:25588091

  1. Assessing the material loss of the modular taper interface in retrieved metal-on-metal hip replacements

    NASA Astrophysics Data System (ADS)

    Bills, Paul J.; Racasan, R.; Tessier, P.; Blunt, L. A.

    2015-06-01

    Measuring the amount of material loss in the case of revised hip replacements is considered to be a prerequisite of understanding and assessing the true in vivo performance of the implant. This paper outlines a method developed by the authors for quantifying taper material loss as well as more general taper interface parameters. Previous studies have mostly relied on visual inspection to assess the material loss at the taper interface, whereas this method aims to characterize any surface and form changes through the use of an out-of-roundness measurement machine. Along with assessing the volumetric wear, maximum linear penetration and taper contact length can also be determined. The method was applied to retrieved large head metal-on-metal femoral heads in order to quantify the material loss at this junction. Material loss from the female femoral head taper can be characterized as a localized area that is in contact with the stem taper surface. The study showed that this method has good repeatability and a low level of interoperability variation between operators.

  2. Metal-on-metal hip resurfacing arthroplasty: a review of periprosthetic biological reactions.

    PubMed

    Mabilleau, Guillaume; Kwon, Young-Min; Pandit, Hemant; Murray, David W; Sabokbar, Afsie

    2008-12-01

    Metal-on-metal hip resurfacing arthroplasty has undergone a recent resurgence as an alternative treatment option for young and active patients with significant osteoarthritis. The claimed advantages of metal-on-metal hip resurfacing arthroplasty include lower wear rate, preservation of bone stock for subsequent revision procedures, restoration of anatomic hip mechanics, and enhanced stability due to the larger diameter of articulation. A disadvantage, however, is that the metal-on-metal resurfacing releases large amounts of very small wear particles and metal ions. The long-term biological consequences of the exposure to these Co-Cr particles and ions remain largely unknown. The purpose of this review is to provide an overview of the current literature on the adverse periprosthetic biological reactions associated with metal-on-metal hip resurfacing arthroplasty. PMID:19085489

  3. Tribolayer Formation in a Metal-on-Metal (MoM) Hip Joint: An Electrochemical Investigation

    PubMed Central

    Mathew, MT; Nagelli, C; Pourzal, R; Fischer, A; Laurent, MP; Jacobs, JJ; Wimmer, MA

    2013-01-01

    The demand for total hip replacement (THR) surgery is increasing in the younger population due to faster rehabilitation and more complete restoration of function. Up to 2009, metal-on-metal (MoM) hip joint bearings were a popular choice due to their design flexibility, post-operative stability and relatively low wear rates. The main wear mechanisms that occur along the bearing surface of MoM joints are tribochemical reactions that deposit a mixture of wear debris, metal ions and organic matrix of decomposed proteins known as a tribolayer. No in-depth electrochemical studies have been reported on the structure and characteristics of this tribolayer or about the parameters involved in its formation. In this study, we conducted an electrochemical investigation of different surfaces (bulk-like: control, nano-crystalline: new implant and tribolayer surface: retrieved implant) made out of two commonly used hip CoCrMo alloys (high-carbon and low-carbon). As per ASTM standard, cyclic polarization tests and electrochemical impedance spectroscopy tests were conducted. The results obtained from electrochemical parameters for different surfaces clearly indicated a reduction in corrosion for the tribolayer surface (Icorr: 0.76 ?A/cm2). Further, polarization resistance (Rp:2.39±0.60M?/cm2) and capacitance (Cdl:15.20±0.75 ?F/cm2) indicated variation in corrosion kinetics for the tribolayer surface, that attributed to its structure and stability in a simulated body environment. PMID:24099949

  4. The Durom large diameter head acetabular component: early results with a large-diameter metal-on-metal bearing.

    PubMed

    Berton, C; Girard, J; Krantz, N; Migaud, H

    2010-02-01

    Implantation of a large-diameter femoral head prosthesis with a metal-on-metal bearing surface reduces the risk of dislocation, increases the range of movement, minimises the risk of impingement and, in theory, results in little wear. Between February 2004 and March 2007 we implanted 100 consecutive total hip replacements with a metal-on-metal bearing and a large femoral head into 92 patients. There were 51 men and 41 women with a mean age of 50 years (18 to 70) at the time of surgery. Outcome was assessed using the Western Ontario McMaster University osteoarthritis index and the Harris hip score as well as the Devane activity score. These all improved significantly (p < 0.0001). At the last follow-up there were no cases of dislocation, no impingement, a good range of movement and no osteolysis, but seven revisions, two for infection and five for aseptic loosening. The probability of groin pain increased if the other acetabular component inclination exceeded 50 degrees (p = 0.0007). At 4.8 years of follow-up, the projected survival of the Durom acetabular component, with revision for any reason, was 92.4% (sd 2.8) (95% confidence interval 89.6 to 95.2). The design of the component made it difficult both to orientate and seat, which when combined with a poor porous coating, produced unpredictable fixation and a low survival at five years. PMID:20130309

  5. Does Ion Release Differ Between Hip Resurfacing and Metal-on-metal THA?

    PubMed Central

    Moroni, Antonio; Cadossi, Matteo; Baldini, Nicola; Giannini, Sandro

    2008-01-01

    Modern metal-on-metal hip resurfacing was introduced as a bone-preserving method of joint reconstruction for young and active patients; however, the large diameter of the bearing surfaces is of concern for potential increased metal ion release. We hypothesized there were no differences in serum concentrations of chromium, cobalt, and molybdenum between patients who had metal-on-metal hip resurfacing (Group A; average head diameter, 48 mm; median followup, 24 months) and patients who had 28-mm metal-on-metal THA (Group B; median followup, 25 months). Serum concentrations also were compared with concentrations in healthy subjects. We identified no differences in ion levels between Groups A and B. A distinction was made according to gender. Women showed a higher chromium release in Group A whereas men had a higher cobalt release in Group B. Values obtained from Group A were higher than those of the control subjects. Our data suggest metal-on-metal bearings for THA should not be rejected because of concern regarding potential increased metal ion release; however, patients with elevated ion levels, even without loosening or toxicity, could be at higher risk and should be followed up periodically. Level of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196364

  6. Effects of metal-on-metal wear on the host immune system and infection in hip arthroplasty

    PubMed Central

    2010-01-01

    Background and purpose Joint replacement with metal-on-metal (MOM) bearings have gained popularity in the last decades in young and active patients. However, the possible effects of MOM wear debris and its corrosion products are still the subject of debate. Alongside the potential disadvantages such as toxicity, the influences of metal particles and metal ions on infection risk are unclear. Methods We reviewed the available literature on the influence of degradation products of MOM bearings in total hip arthroplasties on infection risk. Results Wear products were found to influence the risk of infection by hampering the immune system, by inhibiting or accelerating bacterial growth, and by a possible antibiotic resistance and heavy metal co-selection mechanism. Interpretation Whether or not the combined effects of MOM wear products make MOM bearings less or more prone to infection requires investigation in the near future. PMID:20860450

  7. Metal-on-Metal Hip Prostheses and Systemic Health: A Cross-Sectional Association Study 8 Years after Implantation

    PubMed Central

    Prentice, Jennifer R.; Clark, Matthew J.; Hoggard, Nigel; Morton, Allison C.; Tooth, Claire; Paley, Martyn N.; Stockley, Ian; Hadjivassiliou, Marios; Wilkinson, J. Mark

    2013-01-01

    There is public concern over the long term systemic health effects of metal released from hip replacement prostheses that use large-diameter metal-on-metal bearings. However, to date there has been no systematic study to determine which organs may be at risk, or the magnitude of any effect. We undertook a detailed cross-sectional health screen at a mean of 8 years after surgery in 35 asymptomatic patients who had previously received a metal-on-metal hip resurfacing (MoMHR) versus 35 individually age and sex matched asymptomatic patients who had received a conventional hip replacement. Total body bone mineral density was 5% higher (mean difference 0.05 g/cm2, P?=?0.02) and bone turnover was 14% lower (TRAP 5b, mean difference ?0.56IU/L, P?=?0.006; osteocalcin, mean difference ?3.08 ng/mL, P?=?0.03) in the hip resurfacing versus conventional hip replacement group. Cardiac ejection fraction was 7% lower (mean absolute difference ?5%, P?=?0.04) and left ventricular end-diastolic diameter was 6% larger (mean difference 2.7 mm, P?=?0.007) in the hip resurfacing group versus those patients who received a conventional hip replacement. The urinary fractional excretion of metal was low (cobalt 5%, chromium 1.5%) in patients with MoMHR, but creatinine clearance was normal. Diuretic prescription was associated with a 40% increase in the fractional excretion of chromium (mean difference 0.5%, P?=?0.03). There was no evidence of difference in neuropsychological, renal tubular, hepatic or endocrine function between groups (P>0.05). Our findings of differences in bone and cardiac function between patient groups suggest that chronic exposure to low elevated metal concentrations in patients with well-functioning MoMHR prostheses may have systemic effects. Long-term epidemiological studies in patients with well-functioning metal on metal hip prostheses should include musculoskeletal and cardiac endpoints to quantitate the risk of clinical disease. PMID:23762480

  8. A retrieval analysis of explanted Durom metal-on-metal hip arthroplasties.

    PubMed

    Matthies, Ashley K; Henckel, Johann; Skinner, John A; Hart, Alister J

    2011-01-01

    Given the recent reports of high failure rates, an improved understanding of the mechanism of failure of large diameter metal-on-metal hip arthroplasties is essential. We present clinical data and tribological analysis of a consecutive series of 74 failed large diameter metal-on-metal hips, comparing the Durom (Zimmer) with the Birmingham hip resurfacing (BHR) (Smith and Nephew). We retrospectively analysed pre-, intra-, and post-operative clinical data and measured the linear wear and component form of the explanted components using a roundness measuring machine. A significantly higher proportion of hips in the Durom group failed as a result of acetabular loosening (p=0.001) and this was supported by evidence of reduced bone in-growth on the backside of the cup. Comparison of roundness measurement revealed that the Durom hip was significantly lower wearing than the BHR (p<0.05) but the Durom femoral components were subject to significantly greater form errors (p<0.001), the pole of the head being flattened by up to 31 microns. Although the Durom hip is low wearing, reduced sphericity of the femoral component may have resulted in equatorial bearing, leading to an increased frictional torque at the cup-bone interface, preventing bone in-growth, and culminating in acetabular loosening. This supports recent clinical findings of high revision rates as a result of acetabular loosening for the Durom metal-on-metal hip system. PMID:22144337

  9. Revision of metal-on-metal hip arthroplasty in a tertiary center

    PubMed Central

    2013-01-01

    Background and purpose Operative findings during revision of metal-on-metal hip arthroplasty (MOMHA) vary widely and can involve massive soft tissue and bone disruption. As a result, planning of theater time and resources is difficult, surgery is challenging, and outcomes are often poor. We describe our experience with revision of MOMHA and provide recommendations for management. Patients and methods We present the findings and outcomes of 39 consecutive MOMHAs (in 35 patients) revised in a tertiary unit (median follow-up time 30 (12–54) months). The patients underwent a preoperative work-up including CT, metal artifact reduction sequence (MARS) MRI, and blood metal ion levels. Results We determined 5 categories of failure. 8 of 39 hips had conventional failure mechanisms including infection and impingement. Of the other 31 hips, 14 showed synovitis without significant disruption of soft tissue; 6 had a cystic pseudotumor with significant soft tissue disruption; 7 had significant osteolysis; and 4 had a solid pseudotumor. Each category of failure had specific surgical hazards that could be addressed preoperatively. There were 2 reoperations and 1 patient (2 hips) died of an unrelated cause. Median Oxford hip score (OHS) was 37 (9–48); median change (?OHS) was 17 (–10 to 41) points. ?OHS was similar in all groups—except those patients with solid pseudotumors and those revised to metal-on-metal bearings, who fared worse. Interpretation Planning in revision MOMHA is aided by knowledge of the different categories of failure to enable choice of appropriate personnel, theater time, and equipment. With this knowledge, satisfactory outcomes can be achieved in revision of metal-on-metal hip arthroplasty. PMID:23621810

  10. Analysis of elastohydrodynamic lubrication in McKee-Farrar metal-on-metal hip joint replacement.

    PubMed

    Yew, A; Udofia, I; Jagatia, M; Jin, Z M

    2004-01-01

    An elastohydrodynamic lubrication (EHL) analysis was carried out in this study for a typical McKee-Farrar metal-on-metal hip prosthesis under a simple steady state rotation. The finite element method was used initially to investigate the effect of the cement and bone on the predicted contact pressure distribution between the two articulating surfaces under dry conditions, and subsequently to determine the elastic deformation of both the femoral and the acetabular components required for the lubrication analysis. Both Reynolds equation and the elasticity equation were coupled and solved numerically using the finite difference method. Important features in reducing contact stresses and promoting fluid-film lubrication associated with the McKee-Farrar metal-on-metal hip implant were identified as the large femoral head and the thin acetabular cup. For the typical McKee-Farrar metal-on-metal hip prosthesis considered under typical walking conditions, an increase in the femoral head radius from 14 to 17.4 mm (for a fixed radial clearance of 79 microm) was shown to result in a 25 per cent decrease in the maximum dry contact pressure and a 60 per cent increase in the predicted minimum film thickness. Furthermore, the predicted maximum contact pressure considering both the cement and the bone was found to be decreased by about 80 per cent, while the minimum film thickness was predicted to be increased by 50 per cent. Despite a significant increase in the predicted minimum lubricating film thickness due to the large femoral head and the thin acetabular cup, a mixed lubrication regime was predicted for the McKee-Farrar metal-on-metal hip implant under estimated in vivo steady state walking conditions, depending on the surface roughness of the bearing surfaces. This clearly demonstrated the important influences of the material, design and manufacturing parameters on the tribological performance of these hard-on-hard hip prostheses. Furthermore, in the present contact mechanics analysis, the significant increase in the elasticity due to the relatively thin acetabular cup was not found to cause equatorial contact and gripping of the ball. PMID:14982343

  11. Metal-on-Metal Hip Arthroplasty: A Review of Adverse Reactions and Patient Management

    PubMed Central

    Drummond, James; Tran, Phong; Fary, Camdon

    2015-01-01

    Recent alarming joint registry data highlighting increased revision rates has prompted further research into the area of metal-on-metal hip replacements and resurfacings. This review article examines the latest literature on the topic of adverse reactions to metal debris and summarises the most up-to-date guidelines on patient management. Adverse reactions to metal debris can cause significant damage to soft tissue and bone if not diagnosed early. Furthermore, not every patient with an adverse reaction to metal debris will be symptomatic. As such, clinicians must remain vigilant when assessing and investigating these patients in order to detect failing implants and initiate appropriate management. PMID:26132653

  12. Formation of molten metal films during metal-on-metal slip under extreme interfacial conditions

    NASA Astrophysics Data System (ADS)

    Liou, Nai-Shang; Okada, Makoto; Prakash, Vikas

    2004-09-01

    The present paper describes results of plate-impact pressure-shear friction experiments conducted to study time-resolved growth of molten metal films during dry metal-on-metal slip under extreme interfacial conditions. By employing tribo-pairs comprising hard tool-steel against relatively low melt-point metals such as 7075-T6 aluminum alloys, interfacial friction stress ranging from 100 to 400 MPa and slip speeds of approximately 100 m/ s have been generated. These relatively high levels of friction stress combined with high slip-speeds generate conditions conducive for interfacial temperatures to approach the melting point of the lower melt point metal (Al alloy) comprising the tribo-pair. A Lagrangian finite element code is developed to understand the evolution of the thermo-mechanical fields and their relationship to the observed slip response. The code accounts for dynamic effects, heat conduction, contact with friction, and full thermo-mechanical coupling. At temperatures below the melting point the material is described as an isotropic thermally softening elastic-viscoplastic solid. For material elements with temperatures in excess of the melt point a purely Newtonian fluid constitutive model is employed. The results of the hybrid experimental-computational study provides new insights into the thermoelastic-plastic interactions during high speed metal-on-metal slip under extreme interfacial conditions. During the early part of frictional slip the coefficient of kinetic friction is observed to decrease with increasing slip velocity. During the later part transition in interfacial slip occurs from dry metal-on-metal sliding to the formation of molten Al films at the tribo-pair interface. Under these conditions the interfacial resistance approaches the shear strength of the molten aluminum alloy under normal pressures of approximately 1- 3 GPa and shear strain rates of ˜10 7 s-1. The results of the study indicate that under these extreme conditions molten aluminum films maintain a shearing resistance as high as 100 MPa. Scanning electron microscopy of the slip surfaces reveal molten aluminum to be smeared on the tribo-pair interface. Knoop hardness measurements in 7075-T6 Al alloy at various depths from the slip interface indicate that the hardness increases approximately linearly with depth and reaches a plateau at approximately 40 ?m from the surface.

  13. Effects of CoCr metal wear debris generated from metal-on-metal hip implants and Co ions on human monocyte-like U937 cells.

    PubMed

    Posada, Olga M; Tate, Rothwelle J; Grant, M Helen

    2015-03-01

    Hip resurfacing with cobalt-chromium (CoCr) alloy was developed as a surgical alternative to total hip replacement. However, the biological effects of nanoparticles generated by wear at the metal-on-metal articulating surfaces has limited the success of such implants. The aim of this study was to investigate the effects of the combined exposure to CoCr nanoparticles and cobalt ions released from a resurfacing implant on monocytes (U937 cells) and whether these resulted in morphology changes, proliferation alterations, toxicity and cytokine release. The interaction between prior exposure to Co ions and the cellular response to nanoparticulate debris was determined to simulate the situation in patients with metal-on-metal implants receiving a second implant. Effects on U937 cells were mainly seen after 120h of treatment. Prior exposure to Co ions increased the toxic effects induced by the debris, and by Co ions themselves, suggesting the potential for interaction in vivo. Increased TNF-? secretion by resting cells exposed to nanoparticles could contribute to osteolysis processes in vivo, while increased IFN-? production by activated cells could represent cellular protection against tissue damage. Data suggest that interactions between Co ions and CoCr nanoparticles would occur in vivo, and could threaten the survival of a CoCr metal implant. PMID:25433333

  14. Elastohydrodynamic lubrication analysis of metal-on-metal hip-resurfacing prostheses.

    PubMed

    Udofia, I J; Jin, Z M

    2003-04-01

    The elastohydrodynamic lubrication analysis was carried out in this study for a typical metal-on-metal hip-resurfacing prosthesis under a simple steady-state rotation. Both the Reynolds equation and the elasticity equation were coupled and solved numerically by the finite difference method. The finite element method was used to determine the elastic deformation of both the femoral and the acetabular components required for the lubrication analysis. The effect of the radial clearance between the femoral head and the acetabular cup on the predicted film thickness and pressure distribution was investigated. The predicted minimum lubricating film thickness was found to compare favourably with the prediction using the Hamrock and Dowson [J. Lubrication Technol. 100 (1978) 236] formula based on the assumption of ball-on-plane semi-infinite solids. This implies that the non-metallic materials such as bone and cement underlying the metallic components have a small effect on the predicted lubrication performance for the particular metal-on-metal hip-resurfacing prosthesis considered in this study. Under realistic physiological walking conditions, a decrease in the radial clearance from 150 to 50 microm resulted in a 137% increase in the predicted minimum film thickness from 19 to 45 nm. Consequently, given a surface roughness of 0.01 microm for both the metallic femoral and acetabular bearing surfaces, the predicted mixed lubrication regime for the larger clearance was changed to a full fluid film lubrication regime for the smaller clearance. This clearly highlighted the importance of the design and manufacturing parameters on the tribological performance of these hard-on-hard hip prostheses. PMID:12600344

  15. Fast growing pseudotumour in a hairdresser after metal-on-metal hip resurfacing: a case report.

    PubMed

    Cadossi, M; Chiarello, E; Savarino, L; Mazzotti, A; Tedesco, G; Greco, M; Giannini, S

    2014-01-01

    A 44-year-old female hairdresser who underwent metal-on-metal hip resurfacing (MOMHR) for hip osteoarthritis developed a benign pelvic pseudotumour. Elevated levels of chromium and cobalt ions were detected in the blood. Patch testing after pseudotumor formation, showed positive skin reactions to cobalt and nickel. Marked hypereosinophilia was noted, as well as the presence of eosinophils in the pseudotumor mass. A revision to a ceramic-on-ceramic implant was performed. Radiographs showed no implant loosening or bone resorption. We hypothesized that a steep cup positioning as well as hypersensitivity response to the metal nanoparticles and ion release may have induced pseudotumour development. Currently there is no evidence that negative patch testing reduces the probability to develop an adverse reaction to metal debris therefore we suggest to carefully investigate patient medical history regarding occupation exposure and daily contact with jewellery, beauty and cleaning products before implanting MOMHR. The main challenge is to identify a sensitive patient candidate to MOMHR never suspected to be. PMID:24825038

  16. Wear of metal-on-metal hip bearings: metallurgical considerations after hip simulator studies.

    PubMed

    Affatato, Saverio; Traina, Francesco; Ruggeri, Oddone; Toni, Aldo

    2011-12-01

    Metal-on-metal hip-bearing components with different percentages of carbon content (low and high carbon) were tested in 6 different configurations using a hip joint simulator. The aim of this study was to characterize metallurgical and tribological events occurring at the articulating surfaces of these articulations. Also, ion release was evaluated and correlated with wear. After the test, for the high-carbon components, carbides were observed below the matrix surface. In the low-carbon content components, most carbides were "carbide-free", while a minority were worn below the matrix surface with increased test cycles. In the cast alloy components, some carbides were pulled out resulting in micropits. Scanning microscope electron characterization of the tested specimens showed scratches and holes. The surface showed a dominant severe wear mechanism due to third-body particles. A greater amount of ions was released in the lubricant used during the wear test for the smaller diameter compared with the bigger one. This study showed that the metallurgical and tribological events taking place at the articulating surfaces of metal-metal hip implants are numerous and complex. The surface morphology after the test showed the effect of more critical working conditions with smaller diameters. PMID:22198601

  17. Prevalence of Pseudotumor in Patients After Metal-On-Metal Hip Arthroplasty Evaluated with Metal Ion Analysis and MARS-MRI.

    PubMed

    Sutphen, Sean A; MacLaughlin, Lewis H; Madsen, Adam A; Russell, Jackie H; McShane, Michael A

    2016-01-01

    The purpose of this study is to quantify the prevalence of pseudotumors in patients with well-functioning and painful metal-on-metal total hip arthroplasty, to characterize the pseudotumor with the use of MARS-MRI, and to assess the relationship between pseudotumors and metal ions. We retrospectively reviewed 102 single surgeon patients. The results showed that 68.6% developed pseudotumor with 60.9% of the asymptomatic group developing pseudotumor. The symptomatic group had a higher proportion of patients with elevated serum cobalt levels (P=0.035). There was no difference found with elevated metal ions and prevalence of pseudotumor, but elevated cobalt levels were associated with larger pseudotumor size (P=0.001). The available evidence indicated that most patients that develop pseudotumors are asymptomatic, and that elevated serum cobalt levels may be associated with symptoms and pseudotumor size. PMID:26253484

  18. Novel method for characterization and compensation for canopy distortion over a large head box

    NASA Astrophysics Data System (ADS)

    Atac, Robert; Fischler, Mark

    2013-05-01

    Thales Visionix, a wholly owned subsidiary of Thales Communications, Inc., has developed a novel method for characterization of canopy distortion for a large head box. Canopy distortion occurs when the user is looking through any curved transparency. Any helmet mounted display system must either compensate for this distortion, or add canopy distortion error to its total error budget. To date, canopies have been characterized for only a few discrete locations in the cockpit. This results in a dilution of canopy distortion compensation as the pilot will rarely sit in one of the few defined locations. The method described herein allows for canopy distortion characterization and compensation for the entire HMD head-box.

  19. Metal presence in hair after metal-on-metal resurfacing arthroplasty.

    PubMed

    Rodríguez de la Flor, María; Hernández-Vaquero, Daniel; Fernández-Carreira, José Manuel

    2013-12-01

    The elevation of metal levels in serum and urine during post-operative follow-up is a frequent find following the implantation of certain models of metal-on-metal hip prostheses. Among 45 patients with the same resurfacing prostheses, chromium (Cr) and cobalt (Co) levels in serum and urine were determined at 3, 4, 5, and 6 years after surgery. In the same period, levels of Cr, Co and molibdene (Mo) in scalp hair were also measured. Mean Cr and Co levels in serum were 8.29 µg/L (SD 17.97) and 8.38 µg/L (SD 21.97), respectively, whereas in urine levels were 16.20 µg/L (SD SD 32.55) and 75.40 µg/L (SD 190.86), respectively. In hair, mean Cr level were 163.27 µg/g (SD 300.62), mean Co level 61.98 µg/g (SD 126.48), and Mo 31.36 µg/g (SD 37.86). A high concordance was observed between chromium-urine and chromium-serum and between cobalt-urine and cobalt-hair. A moderate concordance was present between cobalt-urine and cobalt-serum, and between cobalt-hair and cobalt-serum. Eleven patients required revision surgery, five of them due to metallosis and periarticular cyst. At 1 year after reintervention, analytics were performed again and the following decrease rates were found: 42.8% in Cr levels, 51.1% in Mo levels, and 90.3% in Co levels. PMID:23893786

  20. Changes in blood ion levels after removal of metal-on-metal hip replacements

    PubMed Central

    Durrani, Salim K; Sampson, Barry; Panetta, Therese; Liddle, Alexander D; Sabah, Shiraz A; Chan, Newton K; Skinner, John A; Hart, Alister J

    2014-01-01

    Background and purpose In patients with metal-on-metal (MoM) hip prostheses, pain and joint effusions may be associated with elevated blood levels of cobalt and chromium ions. Since little is known about the kinetics of metal ion clearance from the body and the rate of resolution of elevated blood ion levels, we examined the time course of cobalt and chromium ion levels after revision of MoM hip replacements. Patients and methods We included 16 patients (13 female) who underwent revision of a painful MoM hip (large diameter, modern bearing) without fracture or infection, and who had a minimum of 4 blood metal ion measurements over an average period of 6.1 (0–12) months after revision. Results Average blood ion concentrations at the time of revision were 22 ppb for chromium and 43 ppb for cobalt. The change in ion levels after revision surgery varied extensively between patients. In many cases, over the second and third months after revision surgery ion levels decreased to 50% of the values measured at revision. Decay of chromium levels occurred more slowly than decay of cobalt levels, with a 9% lag in return to normal levels. The rate of decay of both metals followed second-order (exponential) kinetics more closely than first-order (linear) kinetics. Interpretation The elimination of cobalt and chromium from the blood of patients who have undergone revision of painful MoM hip arthroplasties follows an exponential decay curve with a half-life of approximately 50 days. Elevated blood levels of cobalt and chromium ions can persist for at least 1 year after revision, especially in patients with high levels of exposure. PMID:24758321

  1. Analysis of elastohydrodynamic lubrication in a novel metal-on-metal hip joint replacement.

    PubMed

    Jagatia, M; Jin, Z M

    2002-01-01

    Elastohydrodynamic lubrication (EHL) analysis was carried out in this study for a novel metal-on-metal hip prosthesis, which consists of a cobalt-chrome alloy femoral head articulating against a cobalt-chrome alloy acetabular insert connected to a titanium fixation shell through a taper. Finite element models were developed to investigate the effect of the pelvic bone and the load on the predicted contact pressure distribution between the two bearing surfaces under dry conditions. The finite element method was used to develop elasticity models for both the femoral and the acetabular components; it was found that the elastic deformation of the acetabular insert was mainly dependent on the load, rather than the detailed pressure distribution. A modified solution methodology was accordingly developed to couple the elasticity models for both the femoral and the acetabular surfaces with the Reynolds equation and to solve these numerically by the finite difference method. It was found that a load increase from 500 to 2500 N had a negligible effect on the predicted maximum contact pressure and the minimum film thickness, due to the relatively flexible and accommodating structure of the acetabular insert. Furthermore, the predicted minimum film thickness was shown to be significantly greater than the simple estimation based on the assumption of semi-infinite solids (mono-block design) using the Hamrock and Dowson formula. The effects of the viscosity of the lubricant and the radial clearance between the femoral and the acetabular components on the predicted lubricating film thickness were investigated under both in vitro simulator testing and in vivo walking conditions. PMID:12137285

  2. Cross-sectional imaging of metal-on-metal hip arthroplasties

    PubMed Central

    Robinson, Elizabeth; Henckel, Johann; Sabah, Shiraz; Satchithananda, Keshthra; Skinner, John; Hart, Alister

    2014-01-01

    Background and purpose — Metal artifact reduction sequence (MARS) MRI is widely advocated for surveillance of metal-on-metal hip arthroplasties (MOM-HAs). However, its use is limited by susceptibility artifact at the prosthesis-bone interface, local availability, patient compliance, and cost (Hayter et al. 2011a). We wanted to determine whether CT is a suitable substitute for MARS MRI in evaluation of the painful MOM-HA. Patients and methods — 50 MOM-HA patients (30 female) with unexplained painful prostheses underwent MARS MRI and CT imaging. 2 observers who were blind regarding the clinical data objectively reported the following outcomes: soft tissue lesions (pseudotumors), muscle atrophy, and acetabular and femoral osteolysis. Diagnostic test characteristics were calculated. Results — Pseudotumor was diagnosed in 25 of 50 hips by MARS MRI and in 11 of 50 by CT. Pseudotumors were classified as type 1 (n = 2), type 2A (n = 17), type 2B (n = 4), and type 3 (n = 2) by MARS MRI. CT did not permit pseudotumor classification. The sensitivity of CT for diagnosis of pseudotumor was 44% (95% CI: 25–65). CT had “slight” agreement with MARS MRI for quantification of muscle atrophy (? = 0.23, CI: 0.16–0.29; p < 0.01). Osteolysis was identified in 15 of 50 patients by CT. 4 of these lesions were identified by MARS MRI. Interpretation — CT was found to be superior to MRI for detection of osteolysis adjacent to MOM-HA, and should be incorporated into diagnostic algorithms. CT was unable to classify and failed to detect many pseudotumors, and it was unreliable for assessment of muscle atrophy. Where MARS MRI is contraindicated or unavailable, CT would be an unsuitable substitute and other modalities such as ultrasound should be considered PMID:25267500

  3. Metal ion release from bearing wear and corrosion with 28 mm and large-diameter metal-on-metal bearing articulations: a follow-up study.

    PubMed

    Vendittoli, P-A; Roy, A; Mottard, S; Girard, J; Lusignan, D; Lavigne, M

    2010-01-01

    We have updated our previous randomised controlled trial comparing release of chromium (Cr) and cobalt (Co) ions and included levels of titanium (Ti) ions. We have compared the findings from 28 mm metal-on-metal total hip replacement, performed using titanium CLS/Spotorno femoral components and titanium AlloFit acetabular components with Metasul bearings, with Durom hip resurfacing using a Metasul articulation or bearing and a titanium plasma-sprayed coating for fixation of the acetabular component. Although significantly higher blood ion levels of Cr and Co were observed at three months in the resurfaced group than in total hip replacement, no significant difference was found at two years post-operatively for Cr, 1.58 microg/L and 1.62 microg/L respectively (p = 0.819) and for Co, 0.67 microg/L and 0.94 microg/L respectively (p = 0.207). A steady state was reached at one year in the resurfaced group and after three months in the total hip replacement group. Interestingly, Ti, which is not part of the bearing surfaces with its release resulting from metal corrosion, had significantly elevated ion levels after implantation in both groups. The hip resurfacing group had significantly higher Ti levels than the total hip replacement group for all periods of follow-up. At two years the mean blood levels of Ti ions were 1.87 microg/L in hip resurfacing and and 1.30 microg/L in total hip replacement (p = 0.001). The study confirms even with different bearing diameters and clearances, hip replacement and 28 mm metal-on-metal total hip replacement produced similar Cr and Co metal ion levels in this randomised controlled trial study design, but apart from wear on bearing surfaces, passive corrosion of exposed metallic surfaces is a factor which influences ion concentrations. Ti plasma spray coating the acetabular components for hip resurfacing produces significantly higher release of Ti than Ti grit-blasted surfaces in total hip replacement. PMID:20044673

  4. Blood metal ion testing is an effective screening tool to identify poorly performing metal-on-metal bearing surfaces

    PubMed Central

    Sidaginamale, R. P.; Joyce, T. J.; Lord, J. K.; Jefferson, R.; Blain, P. G.; Nargol, A. V. F.; Langton, D. J.

    2013-01-01

    Objectives The aims of this piece of work were to: 1) record the background concentrations of blood chromium (Cr) and cobalt (Co) concentrations in a large group of subjects; 2) to compare blood/serum Cr and Co concentrations with retrieved metal-on-metal (MoM) hip resurfacings; 3) to examine the distribution of Co and Cr in the serum and whole blood of patients with MoM hip arthroplasties; and 4) to further understand the partitioning of metal ions between the serum and whole blood fractions. Methods A total of 3042 blood samples donated to the local transfusion centre were analysed to record Co and Cr concentrations. Also, 91 hip resurfacing devices from patients who had given pre-revision blood/serum samples for metal ion analysis underwent volumetric wear assessment using a coordinate measuring machine. Linear regression analysis was carried out and receiver operating characteristic curves were constructed to assess the reliability of metal ions to identify abnormally wearing implants. The relationship between serum and whole blood concentrations of Cr and Co in 1048 patients was analysed using Bland-Altman charts. This relationship was further investigated in an in vitro study during which human blood was spiked with trivalent and hexavalent Cr, the serum then separated and the fractions analysed. Results Only one patient in the transfusion group was found to have a blood Co > 2 µg/l. Blood/Serum Cr and Co concentrations were reliable indicators of abnormal wear. Blood Co appeared to be the most useful clinical test, with a concentration of 4.5 µg/l showing sensitivity and specificity for the detection of abnormal wear of 94% and 95%, respectively. Generated metal ions tended to fill the serum compartment preferentially in vivo and this was replicated in the in vitro study when blood was spiked with trivalent Cr and bivalent Co. Conclusions Blood/serum metal ion concentrations are reliable indicators of abnormal wear processes. Important differences exist however between elements and the blood fraction under study. Future guidelines must take these differences into account. PMID:23836464

  5. Analysis of contact mechanics in McKee-farrar metal-on-metal hip implants.

    PubMed

    Yew, A; Jagatia, M; Ensaff, H; Jin, Z M

    2003-01-01

    Contact mechanics analysis for a typical McKee-Farrar metal-on-metal hip implant was carried out in this study. The finite element method was used to predict the contact area and the contact pressure distribution at the bearing surfaces. The study investigated the effects of the cement and underlying bone, the geometrical parameters such as the radial clearance between the acetabular cup and the femoral head, and the acetabular cup thickness, as well as other geometrical features on the acetabular cup such as lip and studs. For all the cases considered, the predicted contact pressure distribution was found to be significantly different from that based upon the classical Hertz contact theory, with the maximum value being away from the centre of the contact region. The lip on the cup was found to have a negligible effect on the predicted contact pressure distribution. The presence of the studs on the outside of the cup caused a significant increase in the local contact pressure distribution, and a slight decrease in the contact region. Reasonably good agreement of the predicted contact pressure distribution was found between a three-dimensional anatomical model and a simple two-dimensional axisymmetric model. The interfacial boundary condition between the acetabular cup and the underlying cement, modelled as perfectly fixed or perfectly unbonded, had a negligible effect on the predicted contact parameters. For a given radial clearance of 0.079 mm, the decrease in the thickness of the acetabular cup from 4.5 to 1.5 mm resulted in an increase in the contact half angle from 15 degrees to 26 degrees, and a decrease in the maximum contact pressure from 55 to 20 MPa. For a given acetabular cup thickness of 1.5 mm, a decrease in the radial clearance from 0.158 to 0.0395 mm led to an increase in the contact half-angle from 20 degrees to 30 degrees, and a decrease in the maximum contact pressure from 30 to 10 MPa. For zero clearance, although the contact pressure was significantly reduced over most of the contact area, the whole acetabular cup came into contact with the femoral head, leading to stress concentration at the edge of the cup. Design optimization of the geometrical parameters, in terms of the acetabular cup thickness and the radial clearance, is important, not only to minimize the contact stress at the bearing surfaces, but also to avoid equatorial and edge contact. PMID:14558645

  6. Combined Vascular and Orthopaedic Approach for a Pseudotumor Causing Deep Vein Thrombosis after Metal-on-Metal Hip Resurfacing Arthroplasty

    PubMed Central

    Abdel-Hamid, Hossam; Miles, Jonathan; Carrington, Richard W. J.; Hart, Alister; Loh, Alex; Skinner, John A.

    2015-01-01

    Introduction. Metal-on-metal (MoM) hip resurfacings have been associated with a variety of complications resulting from adverse reaction to metal debris. Pseudotumors have rarely been reported to cause deep venous thrombosis (DVT). Study Design. A case report and a review of the literature. Case Presentation. A 75-year-old female who had left metal-on-metal hip resurfacing 6 years ago presented with left groin pain associated with unilateral lower limb edema and swelling. By duplex and MRI studies, our patient had an extensive soft tissue necrosis associated with a large pelvic mass causing extensive DVT of the lower limb secondary to mechanical compression of the left iliac vein. Results. Our case was initially treated for DVT followed by dual surgical approach. The pseudotumor was excised through a separate iliofemoral approach and revision of the hip implant was undertaken through a posterior approach in the same setting. An inferior vena cava (IVC) filter was inserted to minimise the perioperative risks of handling the iliac veins. Conclusion. A combined approach with vascular surgeons is required. Combined resection of the pseudotumor and revision of the metal bearing surfaces is essential, in order to achieve a good surgical outcome in this rare complication. PMID:26457216

  7. How Should We Follow-Up Asymptomatic Metal-on-Metal Hip Resurfacing Patients? A Prospective Longitudinal Cohort Study.

    PubMed

    Low, Adrian K; Matharu, Gulraj S; Ostlere, Simon J; Murray, David W; Pandit, Hemant G

    2016-01-01

    Current surveillance for metal-on-metal hip resurfacing (MoMHR) patients is not evidence based. This study established changes that occurred in 152 asymptomatic MoMHRs using repeat ultrasound and patient-reported outcomes. Factors associated with (1) ultrasound progression and (2) developing new pseudotumors were analyzed. Patients underwent repeat assessments 4.3 years later. Ultrasound progression was observed in 19% (n = 29), with 10% (n = 15) developing new pseudotumors. Key predictors of ultrasound progression included high blood cobalt (P = .00013) and chromium (P = .00065), and high initial ultrasound grade (P = .003) and volume (P = .036). No asymptomatic MoMHRs with initially normal metal ions (<2 ?g/L) and normal ultrasounds (33% of cohort) developed new pseudotumors. This patient subgroup does not require repeat follow-up within 5 years. PMID:26439179

  8. MRI findings following metal on metal hip arthroplasty and their relationship with metal ion levels and acetabular inclination angles.

    PubMed

    Fox, Ciara M; Bergin, Karen M; Kelly, Gabrielle E; McCoy, Gerry F; Ryan, Anthony G; Quinlan, John F

    2014-08-01

    Following the global recall of all ASR metal on metal hip products, our aim was to correlate MRI findings with acetabular inclination angles and metal ion levels in patients with these implants. Both cobalt and chromium levels were significantly higher in the presence of a periprosthetic fluid collection. There was no association between the presence of a periprosthetic mass, bone marrow oedema, trochanteric bursitis or greater levels of abductor muscle destruction for cobalt or chromium. There was no association between the level of periprosthetic tissue reaction and the acetabular inclination angle with any of the pathologies identified on MRI. The relationship between MRI pathology, metal ion levels and acetabular inclination angles in patients with ASR implants remains unclear adding to the complexity of managing patients. PMID:24793890

  9. A randomised controlled trial of cemented and cementless femoral components for metal-on-metal hip resurfacing: a bone mineral density study.

    PubMed

    Tice, A; Kim, P; Dinh, L; Ryu, J J; Beaulé, P E

    2015-12-01

    The primary purpose of this study of metal-on-metal (MoM) hip resurfacing was to compare the effect of using a cementless or cemented femoral component on the subsequent bone mineral density (BMD) of the femoral neck. This was a single-centre, prospective, double-blinded control trial which randomised 120 patients (105 men and 15 women) with a mean age of 49.4 years (21 to 68) to receive either a cemented or cementless femoral component. Follow-up was to two years. Outcome measures included total and six-point region-of-interest BMD of the femoral neck, radiological measurements of acetabular inclination, neck-shaft and stem-shaft angles, and functional outcome scores including the Harris hip score, the Western Ontario and McMaster Universities Osteoarthritis Index and the University of California at Los Angeles activity scale. In total, 17 patients were lost to follow-up leaving 103 patients at two years. There were no revisions in the cementless group and three revisions (5%) in the cemented group (two because of hip pain and one for pseudotumour). The total BMD was significantly higher in the cementless group at six months (p < 0.001) and one year (p = 0.01) than in the cemented group, although there was a loss of statistical significance in the difference at two years (p = 0.155). All patient outcomes improved significantly: there were no significant differences between the two groups. The results show better preservation of femoral neck BMD with a cementless femoral component after two years of follow-up. Further investigation is needed to establish whether this translates into improved survivorship. Cite this article: Bone Joint J 2015;97-B:1608-14. PMID:26637673

  10. Wear of surface-engineered metal-on-metal bearings for hip prostheses under adverse conditions with the head loading on the rim of the cup.

    PubMed

    Leslie, Ian; Williams, Sophie; Isaac, Graham; Hatto, Peter; Ingham, Eileen; Fisher, John

    2013-04-01

    Clinical studies have found high wear rates, elevated ion levels and high revision rates of large-diameter metal-on-metal surface replacement bearings in some patients, which have been associated with edge loading of the head on the rim of the cup. We have simulated increased wear and ion levels in metal-on-metal bearings in vitro by introducing variations in translational and rotational positioning of the components, which reproduces stripe wear on the femoral head, cup rim wear and clinically relevant large as well as small wear particles. There is interest in technologies such as surface engineering, which might reduce metal wear and the release of wear particles and ions. Reduced wear with surface-engineered surface replacements compared to metal-on-metal controls has been reported under standard walking conditions with correctly aligned and concentric components. In this in vitro study, the wear of chromium nitride surface-engineered metal-on-metal bearings under conditions of microseparation associated with translational and rotational malpositioning of the components was investigated and the results were compared with a previously reported study of metal-on-metal bearings under the same conditions. Simulations were conducted using our unique hip simulation microseparation methodologies, which reproduce accelerated wear in metal-on-metal bearings and have previously been clinically validated with ceramic-on-ceramic bearings. Four of the six surface-engineered bearings had evidence of head contact on the rim of the cup, which produced stripe wear on the femoral head. Four of the six surface-engineered bearings (two without stripe and two with stripe wear) had lower wear than the previously reported high wearing metal-on-metal bearings. At 2 million cycles, two of the surface-engineered bearings had substantially increased wear rates, four times higher than the high wear rates previously reported for metal-on-metal bearings under the same conditions. There was wear through and cohesive failure of the thick atomic emission physical vapour deposition (AEPVD) chromium nitride (CrN) coating. At this point, the study was stopped to investigate the failure mode. This study highlights the need to pre-clinically investigate the tribology of new bearings under a wide set of clinical conditions as demonstrated by our stratified approach for enhanced reliability (SAFER) simulation methods. In adopting this SAFER approach to pre-clinical simulation testing of new bearings, it is important to communicate the failures as well as successes of technologies arising from the research, in order that the wider community can benefit from the analysis of the pre-clinical failure modes. PMID:23637209

  11. Early failure of the Durom prosthesis in metal-on-metal hip resurfacing in Chinese patients.

    PubMed

    Li, Jia; He, Chongru; Li, Dahe; Zheng, Wei; Liu, Denghui; Xu, Weidong

    2013-12-01

    Hip resurfacing (HR) is being used increasingly as an alterative to total hip arthroplasty in osteonecrosis (ON) and ankylosing spondylitis (AS) of the hip. We performed 141 consecutive HR arthroplasties in 111 patients comprising 3 etiology groups: ON, AS, and osteoarthritis (OA). After retrospective study of retrieved components, we hypothesized that the main reason for revision was femoral loosening in the ON group (4 of 46 hips; 8.7%) and femoral-neck fracture in the AS group (3 of 58 hips; 5.2%). Necrotic areas were seen on femoral heads retrieved from patients with femoral loosening, whereas femoral heads were fixed tightly to components in patients with femoral-neck fractures. Etiology may be an important risk factor for postoperative complications. PMID:23831082

  12. Comparison of in vivo and simulator-retrieved metal-on-metal cervical disc replacements

    PubMed Central

    Kurtz, Steven M.; Ciccarelli, Lauren; Harper, Megan L.; Siskey, Ryan; Shorez, Jacob; Chan, Frank W.

    2012-01-01

    Background Cervical disc arthroplasty is regarded as a promising treatment for myelopathy and radiculopathy as an alternative to cervical spine fusion. On the basis of 2-year clinical data for the PRESTIGE® Cervical Disc (Medtronic, Memphis, Tennessee), the Food and Drug Administration recommended conditional approval in September 2006 and final approval in July 2007; however, relatively little is known about its wear and damage modes in vivo. The main objective was to analyze the tribological findings of the PRESTIGE® Cervical Disc. This study characterized the in vivo wear patterns of retrieved cervical discs and tested the hypothesis that the total disc replacements exhibited similar surface morphology and wear patterns in vitro as in vivo. Methods Ten explanted total disc replacements (PRESTIGE®, PRESTIGE® I, and PRESTIGE® II) from 10 patients retrieved after a mean of 1.8 years (range, 0.3–4.1 years) were analyzed. Wear testing included coupled lateral bending ( ±4.7°) and axial rotation ( ±3.8°) with a 49 N axial load for 5 million cycles followed by 10 million cycles of flexion-extension ( ±9.7°) with 148 N. Implant surfaces were characterized by the use of white-light interferometry, scanning electron microscopy, and energy dispersive spectroscopy. Results The explants generally exhibited a slightly discolored, elliptic wear region of varying dimension centered in the bearing center, with the long axis oriented in the medial-lateral direction. Abrasive wear was the dominant in vivo wear mechanism, with microscopic scratches generally oriented in the medial-lateral direction. Wear testing resulted in severe abrasive wear in a curvilinear fashion oriented primarily in the medial-lateral direction. All retrievals showed evidence of an abrasive wear mechanism. Conclusions This study documented important similarity between the wear mechanisms of components tested in vitro and explanted PRESTIGE® Cervical Discs; however, the severity of wear was much greater during the in vitro test compared with the retrievals. PMID:25694884

  13. Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement.

    PubMed

    Reito, Aleksi; Elo, Petra; Nieminen, Jyrki; Puolakka, Timo; Eskelinen, Antti

    2016-02-01

    Background and purpose - There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors. Patients and methods - 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles. Results - The prevalance of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (>?5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that "preoperative diagnosis other than osteoarthrosis" was the strongest predictor of the presence of fatty atrophy. Interpretation - Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach. PMID:26427902

  14. The chemical form of metallic debris in tissues surrounding metal-on-metal hips with unexplained failure.

    PubMed

    Hart, Alister J; Quinn, Paul D; Sampson, Barry; Sandison, Ann; Atkinson, Kirk D; Skinner, John A; Powell, Jonathan J; Mosselmans, J Fred W

    2010-11-01

    Implant-derived material from metal-on-metal (MOM) hip arthroplasties may be responsible for an unexplained tissue inflammatory response. The chemical form of the metal species in the tissues is predominantly chromium (Cr), but the currently used techniques have not been able to determine whether this is Cr(III) phosphate or Cr(III) oxide. The analytical challenge must overcome the fact that the metal in the tissues is at a relatively low concentration and tissue preparation or the microscopy beam used can affect the results. Microfocus X-ray spectroscopy using a synchrotron beam is useful in addressing both these issues. Using this technique we compared tissue from failed MOM hips with: (1) tissue from metal-on-polyethylene (MOP) hips; (2) chemical standards; (3) metal discs cut from MOM hips. The most abundant implant-related species in all MOM hip tissues contained Cr. Comparison with standards revealed the chemical form was Cr(III) phosphate, which did not vary with manufacturer type (four types analysed) or level of blood metal ions. Cobalt (Co) and molybdenum (Mo) were occasionally present in areas of high Cr. Co was normally found in a metallic state in the tissue, while Mo was found in an oxidized state. The variety of metallic species may have arisen from corrosion, wear or a combination of both. No evidence of Cr(VI) was seen in the tissues examined. PMID:20541630

  15. Clinical usefulness of blood metal measurements to assess the failure of metal-on-metal hip implants

    PubMed Central

    Sampson, Barry; Hart, Alister

    2012-01-01

    In April 2010, a Medicines and Healthcare Products Regulatory Agency safety alert concerning all metal-on-metal (MOM) hip replacements recommended measuring chromium and cobalt concentrations when managing patients with painful prostheses. The need for this review is illustrated by the recent surge in requests for these blood tests from orthopaedic surgeons following this alert. The aim is to provide guidance to laboratories in assessing these requests and advising clinicians on interpretation. First, we summarize the basic terminology regarding the types of hip replacements, with emphasis on the MOM type. Second, we describe the clinical concerns over implant-derived wear debris in the local tissues and distant sites. Analytical aspects of the measurement of the relevant metal ions and what factors affect the levels measured are discussed. The application of inductively coupled plasma mass spectrometry techniques to the measurement of these metals is considered in detail. The biological effects of metal wear products are summarized with local toxicity and systemic biological effects considered, including carcinogenicity, genotoxicity and systemic toxicity. Clinical cases are used to illustrate pertinent points. PMID:22155921

  16. A comparison of the diagnostic accuracy of MARS MRI and ultrasound of the painful metal-on-metal hip arthroplasty

    PubMed Central

    Siddiqui, Imran A; Sabah, Shiraz A; Satchithananda, Keshthra; Lim, Adrian K; Cro, Suzie; Henckel, Johann; Skinner, John A

    2014-01-01

    Background and purpose Metal artifact reduction sequence (MARS) MRI and ultrasound scanning (USS) can both be used to detect pseudotumors, abductor muscle atrophy, and tendinous pathology in patients with painful metal-on-metal (MOM) hip arthroplasty. We wanted to determine the diagnostic test characteristics of USS using MARS MRI as a reference for detection of pseudotumors and muscle atrophy. Patients and methods We performed a prospective cohort study to compare MARS MRI and USS findings in 19 consecutive patients with unilateral MOM hips. Protocolized USS was performed by consultant musculoskeletal radiologists who were blinded regarding clinical details. Reports were independently compared with MARS MRI, the imaging gold standard, to calculate predictive values. Results The prevalence of pseudotumors on MARS MRI was 68% (95% CI: 43–87) and on USS it was 53% (CI: 29–76). The sensitivity of USS in detecting pseudotumors was 69% (CI 39–91) and the specificity was 83% (CI: 36–97). The sensitivity of detection of abductor muscle atrophy was 47% (CI: 24–71). In addition, joint effusion was detected in 10 cases by USS and none were seen by MARS MRI. Interpretation We found a poor agreement between USS and MARS MRI. USS was inferior to MARS MRI for detection of pseudotumors and muscle atrophy, but it was superior for detection of joint effusion and tendinous pathologies. MARS MRI is more advantageous than USS for practical reasons, including preoperative planning and longitudinal comparison. PMID:24694273

  17. Chromium and cobalt ion concentrations in blood and serum following various types of metal-on-metal hip arthroplasties

    PubMed Central

    2013-01-01

    Background and purpose Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties. Methods Studies were searched for in the Medline database, Embase, and the Cochrane Database of Systematic Reviews. Highest mean or median ion concentrations of Cr and Co after a minimum of 1 year of follow-up were extracted and grouped according to sample- and articulation type, and average values were calculated. Results 43 studies were included and 16 different MoM implants were identified. For the different types of bearings, average ion concentrations and range were calculated from the mean or median ion concentration. The average Cr concentration ranged between 0.5 and 2.5 ?g/L in blood and between 0.8 and 5.1 ?g/L in serum. For Co, the range was 0.7–3.4 ?g/L in blood and 0.3–7.5 ?g/L in serum. Interpretation When the average blood ion concentrations calculated for the different implants, together with the concentrations measured in the individual studies, were compared with the upper acceptable limit for Cr and Co in blood, no clear pattern was recognized. Furthermore, we were unable to detect any clear difference in ion concentrations between different types of implants (THA and resurfacing). PMID:23594249

  18. Good sensitivity and specificity of ultrasound for detecting pseudotumors in 83 failed metal-on-metal hip replacements

    PubMed Central

    Lainiala, Olli; Elo, Petra; Reito, Aleksi; Pajamäki, Jorma; Puolakka, Timo; Eskelinen, Antti

    2015-01-01

    Background and purpose Ultrasound is used for imaging of pseudotumors associated with metal-on-metal (MoM) hips. Ultrasound has been compared with magnetic resonance imaging, but to date there have been no studies comparing ultrasound findings and revision findings. Methods We evaluated the sensitivity and specificity of preoperative ultrasound for detecting pseudotumors in 82 patients with MoM hip replacement (82 hips). Ultrasound examinations were performed by 1 of 3 musculoskeletal radiologists, and pseudotumors seen by ultrasound were retrospectively classified as fluid-filled, mixed-type, or solid. Findings at revision surgery were retrieved from surgical notes and graded according to the same system as used for ultrasound findings. Results Ultrasound had a sensitivity of 83% (95% CI: 63–93) and a specificity of 92% (CI: 82–96) for detecting trochanteric region pseudotumors, and a sensitivity of 79% (CI: 62–89) and a specificity of 94% (CI: 83–98) for detecting iliopsoas-region pseudotumors. Type misclassification of pseudotumors found at revision occurred in 8 of 23 hips in the trochanteric region and in 19 of 33 hips in the iliopsoas region. Interpretation Despite the discrepancy in type classification between ultrasound and revision findings, the presence of pseudotumors was predicted well with ultrasound in our cohort of failed MoM hip replacements. PMID:25582840

  19. Metal ion levels and revision rates in metal-on-metal hip resurfacing arthroplasty: a comparative study.

    PubMed

    Robinson, Patrick G; Wilkinson, Andrew J; Meek, Robert M D

    2014-01-01

    Metal-on-metal (MoM) bearings in hip surgery are related to increased blood levels of metal ions. The nature of the relationship between ion levels and failure is still not fully understood. This study compares three cohorts of patients, 120 patients in each cohort, treated with a hip resurfacing arthroplasty, grouped by brand and diameter of femoral component on average four years postoperatively: Birmingham Hip Resurfacing ?50 mm, Durom resurfacing ?50 mm and Durom resurfacing <50 mm. The median blood ion levels of cobalt and chromium were significantly lower in the cohort with the large Durom resurfacing than the other two cohorts (P<0.05). The large BHR and large Durom HRA had revision rates of 3.3%. The small Durom HRA had a revision rate of 8.3%. Elevated blood ion levels can indicate a failing MoM bearing. The large BHR and large Durom HRA have similar revision rates yet the large Durom HRA had significantly lower metal ion levels. When similar ion levels were reported for BHR and small Durom the latter had significantly higher revision rates. This suggests ion levels do not absolutely predict the rate of HRA failure. Since MoM generation of metal ions is not the sole reason of failure, regular clinical and radiographic follow-up should also be in place for patients with these joints. PMID:24500833

  20. A simulator study of adverse wear with metal and cement debris contamination in metal-on-metal hip bearings

    PubMed Central

    Halim, T.; Clarke, I. C.; Burgett-Moreno, M. D.; Donaldson, T. K.; Savisaar, C.; Bowsher, J. G.

    2015-01-01

    Objectives Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt–chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA). Methods Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range 5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments (5 mg) were inserted at ten intervals during the five million cycle (5 Mc) test. Results In a clean test phase (0 Mc to 0.8 Mc), lubricants retained their yellow colour. Addition of metal particles at 0.8 Mc turned lubricants black within the first hour of the test and remained so for the duration, while PMMA particles did not change the colour of the lubricant. Rates of wear with PMMA, CoCr and Ti6Al4V debris averaged 0.3 mm3/Mc, 4.1 mm3/Mc and 6.4 mm3/Mc, respectively. Conclusions Metal particles turned simulator lubricants black with rates of wear of MOM bearings an order of magnitude higher than with control PMMA particles. This appeared to model the findings of black, periarticular joint tissues and high CoCr wear in failed MOM replacements. The amount of wear debris produced during a 500 000-cycle interval of gait was 30 to 50 times greater than the weight of triggering particle allotment, indicating that MOM bearings were extremely sensitive to third-body wear. Cite this article: Bone Joint Res 2015;4:29–37. PMID:25736072

  1. Genetic alterations in periprosthetic soft-tissue masses from patients with metal-on-metal hip replacement.

    PubMed

    Sarhadi, Virinder Kaur; Parkkinen, Jyrki; Reito, Aleksi; Nieminen, Jyrki; Porkka, Noora; Wirtanen, Tiina; Laitinen, Minna; Eskelinen, Antti; Knuutila, Sakari

    2015-11-01

    Adverse soft tissue reactions in patients with metal-on-metal (MoM) hip replacement are associated with cobalt (Co) and chromium (Cr) particles released from the implant. Exposing the patients to long periods of increased metal ions concentrations resulting from the wear of these implants poses an increased risk of genotoxicity/mutagenicity. A variable proportion of patients develop periprosthetic soft-tissue masses or pseudotumors at the site of the implant. There is a concern that exposure to increased metal ions could increase the risk of cancer. In order to investigate whether the periprosthetic soft-tissue mass harbours any cancer- related genetic alterations, we studied DNA isolated from periprosthetic tissues of 20 patients with MoM hip replacement, for copy number alterations and mutations in hotspot regions of 50 cancer genes using aCGH and amplicon-based next generation sequencing. Our results showed copy number gains at 12q14.3 and 21q21.1in tumour from patient diagnosed with liposarcoma. Copy number alterations in periprosthetic tissues were seen in three other patients, one had a region of gain at 9q24.1 affecting JAK2 and INSL6, and two patients had region of gain at 6p21.1, affecting RUNX2. Mutation analysis showed V1578del mutation in NOTCH1 in two patients. The copy number alterations and mutations seen in periprosthetic soft-tissue masses are earlier reported in either haematological malignancies or in osteoblast related bone dysplasia. The presence of genetic anomalies was associated with longer in-situ time of the implant. Our findings warrant the need of similar studies in larger patient cohorts to evaluate the risk of development of neoplastic alterations in periprosthetic tissues of patients with MoM hip replacement. PMID:26355908

  2. Effect of microseparation on contact mechanics in metal-on-metal hip replacements-A finite element analysis.

    PubMed

    Liu, Feng; Williams, Sophie; Fisher, John

    2015-08-01

    Some early failures of metal-on-metal (MoM) hip replacements associated with elevated wear have caused concerns for the use of this bearing combination. Simulator studies have shown that microseparation and its associated rim contact and edge loading may produce the most severe wear in MoM bearings. It is generally recognized that this high wear can be attributed to the high contact stress of the head on the rim of the cup. In this study, an improved finite element contact model that incorporates an elastic-perfectly plastic material property for cobalt-chrome alloy of the metal bearing was developed in an attempt to provide an accurate prediction of the stress and strain for the rim contact. The effects of the microseparation displacement (0.1-2 mm), cup inclination angle (25-65°) and cup rim radius (0.5-4 mm) on the contact stress/strain were investigated. The results show that a translational displacement >0.1 mm under a load >0.5 kN can produce a highly concentrated contact stress at the surface of the cup rim which can lead to plastic deformation. This study also suggests that the magnitude of translational displacement was the major factor that determined the severity of the contact conditions and level of stress and strain under microseparation conditions. Future studies will address the effect of surgical translational and rotational malposition and component design on the magnitude of microseparation, contact stress and strain and severity of wear. PMID:25370809

  3. A Two Centre Study to Assess the Long-term Performance of the Pinnacle™ Cup With a Metal-on-Metal Bearing in Primary Total Hip Replacement

    ClinicalTrials.gov

    2014-04-29

    Rheumatoid Arthritis; Osteoarthritis; Post-traumatic Arthritis; Collagen Disorders; Avascular Necrosis; Traumatic Femoral Fractures; Nonunion of Femoral Fractures; Congenital Hip Dysplasia; Slipped Capital Femoral Epiphysis

  4. 'Severe' wear challenge to 'as-cast' and 'double heat-treated' large-diameter metal-on-metal hip bearings.

    PubMed

    Bowsher, J G; Nevelos, J; Williams, P A; Shelton, J C

    2006-02-01

    The wear generation of double-heat-treated and as-cast large-diameter metal-on-metal (MOM) hip bearings was investigated using standard- and 'severe'-gait simulations. The test hypothesis was that double heat treatment would change MOM hip wear compared with the as-cast condition. Two groups of high-carbon MOM bearings of 40 mm diameter were manufactured and subjected to either hot isostatic pressing (HIP) and solution annealing (SA) or no heat treatment (as cast). The results showed no statistical difference between the two groups under both running-in and steady state conditions. Even under the most 'severe'-gait simulation published to date, the mean volumetric wear rates were 2.9 and 3.9 mm3 per 10(6) cycles for the HIP-SA and as-cast bearings respectively, showing a ten-fold increase in wear compared with walking. These differences were not statistically different; therefore our hypothesis was negated. Changes in alloy microstructure do not appear to influence the wear behaviour of high-carbon cast MOM articulations with similar chemical compositions. This is in sharp contrast with the published significance of bearing diameter and radial clearance on the wear of MOM hip bearings. PMID:16669382

  5. Influence of head size on the development of metallic wear and on the characteristics of carbon layers in metal-on-metal hip joints

    PubMed Central

    Sprecher, Christoph M; Wimmer, Markus A; Milz, Stefan; Taeger, Georg

    2009-01-01

    Background and purpose Particles originating from the articulating surfaces of hip endoprostheses often induce an inflammatory response, which can be related to implant failure. We therefore analyzed the metal content in capsular tissue from 44 McKee-Farrar metal-on-metal hip prostheses (with 3 different head sizes) and we also analyzed the morphological structure of layers located on articulating surfaces. Methods Atomic absorption spectrometry (AAS) was used to analyze the metal content in capsular tissue. Visually detectable carbon layers located on the articulating surfaces were evaluated using scanning electron microscopy (SEM), energy-dispersive Xray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). Results Metallic debris was detected in all capsular tissue samples but no statistically significant differences in metal content were found in relation to implant head size. The morphological characteristics of the different layer zones allowed an exact analysis of contact and non-contact areas. Furthermore, surface layers appear to have a protective function because they can prevent sharp-edged particles from damaging the prostheses surface. Interpretation The implant head size does not appear to influence the amount of metallic debris. The layers obviously act like a lubricating agent because the protection function does not occur in regions without layers where the metal surface often shows numerous scratches. As layers are not generated immediately after the implantation of hip prostheses, these findings may at least partially explain the high amount of wear early after implantation. PMID:19421914

  6. Chromium and cobalt ion release following the Durom high carbon content, forged metal-on-metal surface replacement of the hip.

    PubMed

    Vendittoli, P-A; Mottard, S; Roy, A G; Dupont, C; Lavigne, M

    2007-04-01

    We evaluated the concentrations of chromium and cobalt ions in blood after metal-on-metal surface replacement arthroplasty using a wrought-forged, high carbon content chromium-cobalt alloy implant in 64 patients. At one year, mean whole blood ion levels were 1.61 microg/L (0.4 to 5.5) for chromium and 0.67 microg/L (0.23 to 2.09) for cobalt. The pre-operative ion levels, component size, female gender and the inclination of the acetabular component were inversely proportional to the values of chromium and/or cobalt ions at one year postoperatively. Other factors, such as age and level of activity, did not correlate with the levels of metal ions. We found that the levels of the ions in the serum were 1.39 and 1.37 times higher for chromium and cobalt respectively than those in the whole blood. The levels of metal ions obtained may be specific to the hip resurfacing implant and reflect its manufacturing process. PMID:17463109

  7. Peri-acetabular bone mineral density in total hip replacement

    PubMed Central

    Gauthier, L.; Dinh, L.; Beaulé, P. E.

    2013-01-01

    Objectives To quantify and compare peri-acetabular bone mineral density (BMD) between a monoblock acetabular component using a metal-on-metal (MoM) bearing and a modular titanium shell with a polyethylene (PE) insert. The secondary outcome was to measure patient-reported clinical function. Methods A total of 50 patients (25 per group) were randomised to MoM or metal-on-polyethlene (MoP). There were 27 women (11 MoM) and 23 men (14 MoM) with a mean age of 61.6 years (47.7 to 73.2). Measurements of peri-prosthetic acetabular and contralateral hip (covariate) BMD were performed at baseline and at one and two years’ follow-up. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC), University of California, Los Angeles (UCLA) activity score, Harris hip score, and RAND-36 were also completed at these intervals. Results At two years, only zone 1 showed a loss in BMD (-2.5%) in MoM group compared with a gain in the MoP group (+2.2%). Zone 2 showed loss in both groups (-2.2% for MoM; -3.9% for MoP) and zones 3 and 4 a gain in both groups (+0.1% for MoM; +3.3% for MoP). No other between-group differences were detected. When adjusting for BMD of the contralateral hip, no differences in BMD were observed. The only significant differences in functional scores at two years were higher UCLA activity (7.3 (sd 1.2) vs 6.1 (sd 1.5); p = 0.01) and RAND-36 physical function (82.1 (sd 13.0) vs 64.5 (sd 26.4); p = 0.02) for MoM bearings versus MoP. One revision was performed in the MoM group, for aseptic acetabular loosening at 11 months. Conclusions When controlling for systemic BMD, there were no significant differences between MoM and MoP groups in peri-acetabular BMD. However, increasing reports of adverse tissue reactions with large head MoM THR have restricted the use of the monoblock acetabular component to resurfacing only. PMID:23913361

  8. Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident-Accolade total hip replacement.

    PubMed

    Craig, P; Bancroft, G; Burton, A; Collier, S; Shaylor, P; Sinha, A

    2014-01-01

    The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ? 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components. PMID:24395309

  9. Effect of femoral head size on risk of revision for dislocation after total hip arthroplasty

    PubMed Central

    Kostensalo, Inari; Junnila, Mika; Virolainen, Petri; Remes, Ville; Matilainen, Markus; Vahlberg, Tero; Pulkkinen, Pekka; Eskelinen, Antti; Mäkelä, Keijo T

    2013-01-01

    Background and purpose Previous population-based registry studies have shown that larger femoral head size is associated with reduced risk of revision for dislocation. However, the previous data have not included large numbers of hip resurfacing arthroplasties or large metal-on-metal (> 36-mm) femoral head arthroplasties. We evaluated the association between femoral component head size and the risk of revision for dislocation after THA by using Finnish Arthroplasty Register data. Patients and methods 42,379 patients who were operated during 1996–2010 fulfilled our criteria. 18 different cup/stem combinations were included. The head-size groups studied (numbers of cases) were 28 mm (23,800), 32 mm (4,815), 36 mm (3,320), and > 36 mm (10,444). Other risk factors studied were sex, age group (18–49 years, 50–59 years, 60–69 years, 70–79 years, and > 80 years), and time period of operation (1996–2000, 2001–2005, 2006–2010). Results The adjusted risk ratio in the Cox model for a revision operation due to dislocation was 0.40 (95% CI: 0.26–0.62) for 32-mm head size, 0.41 (0.24–0.70) for 36-mm head size, and 0.09 (0.05–0.17) for > 36-mm head size compared to implants with a head size of 28 mm. Interpretation Larger femoral heads clearly reduce the risk of dislocation. The difference in using heads of > 36 mm as opposed to 28-mm heads for the overall revision rate at 10 years follow-up is about 2%. Thus, although attractive from a mechanical point of view, based on recent less favorable clinical outcome data on these large heads, consisting mainly of metal-on-metal prostheses, one should be cautious using these implants. PMID:23799348

  10. Biomaterial Hypersensitivity: Is It Real? Supportive Evidence and Approach Considerations for Metal Allergic Patients following Total Knee Arthroplasty

    PubMed Central

    Mihalko, William M.; Grupp, Thomas M.; Manning, Blaine T.; Dennis, Douglas A.; Goodman, Stuart B.; Saleh, Khaled J.

    2015-01-01

    The prospect of biomaterial hypersensitivity developing in response to joint implant materials was first presented more than 30 years ago. Many studies have established probable causation between first-generation metal-on-metal hip implants and hypersensitivity reactions. In a limited patient population, implant failure may ultimately be related to metal hypersensitivity. The examination of hypersensitivity reactions in current-generation metal-on-metal knee implants is comparatively limited. The purpose of this study is to summarize all available literature regarding biomaterial hypersensitivity after total knee arthroplasty, elucidate overall trends about this topic in the current literature, and provide a foundation for clinical approach considerations when biomaterial hypersensitivity is suspected. PMID:25883940

  11. Prediction of Impact Shock Vibrations at Tennis Player's Wrist Joint: Comparison between Conventional Weight Racket and Light Weight Racket with Super Large Head Size

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Takeda, Yukihiro; Nakagawa, Masamichi; Casolo, Federico; Tomosue, Ryoso; Yoshinari, Keiko

    The lightweight racket with handle-light configuration and large head size is recent tendency of high-tech tennis rackets, increasing power or post-impact ball velocity with an increasing racket swing speed. This paper investigated the performance of lightweight tennis racket with super-large head size in terms of feel or comfort. It predicted the effect of the mass and mass distribution of super-large sized rackets on the impact shock vibrations of the racket handle and the player's wrist joint when a player hits a flat forehand drive. The prediction is based on the identification of the racket characteristics, the damping of the racket-arm system, equivalent mass of the player's arm system and the approximate nonlinear impact analysis in tennis. A super-light weight balanced racket (mass: 292 g, the center of gravity LG: 363 mm from the butt end) and a conventional weight and weight balanced racket (349 g, LG: 323 mm) are selected as representatives. They are the super-large sized rackets made of carbon graphite with a head size of 120 square inches and the same geometry. The result showed that the shock vibration of the super-light weight balanced racket with super-large sized head is much larger than that of the conventional weight balanced type racket. It also showed that the sweet area of the former in terms of the shock vibration shifts from the center to the topside on the racket face compared to the latter. This is because the location of the grip on the racket handle is further from the location of the node on the handle of the first mode of super-light racket than that of the conventional weight racket.

  12. A novel bradykinin-related dodecapeptide (RVALPPGFTPLR) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis) exhibiting unusual structural and functional features.

    PubMed

    Shi, Daning; Luo, Yu; Du, Qiang; Wang, Lei; Zhou, Mei; Ma, Jie; Li, Renjie; Chen, Tianbao; Shaw, Chris

    2014-10-01

    Bradykinin-related peptides (BRPs) are significant components of the defensive skin secretions of many anuran amphibians, and these secretions represent the source of the most diverse spectrum of such peptides so far encountered in nature. Of the many families of bioactive peptides that have been identified from this source, the BRPs uniquely appear to represent homologues of counterparts that have specific distributions and receptor targets within discrete vertebrate taxa, ranging from fishes through mammals. Their broad spectra of actions, including pain and inflammation induction and smooth muscle effects, make these peptides ideal weapons in predator deterrence. Here, we describe a novel 12-mer BRP (RVALPPGFTPLR-RVAL-(L¹, T?, L?)-bradykinin) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis). The C-terminal 9 residues of this BRP (-LPPGFTPLR) exhibit three amino acid substitutions (L/R at Position 1, T/S at Position 6 and L/F at Position 8) when compared to canonical mammalian bradykinin (BK), but are identical to the kinin sequence present within the cloned kininogen-2 from the Chinese soft-shelled turtle (Pelodiscus sinensis) and differ from that encoded by kininogen-2 of the Tibetan ground tit (Pseudopodoces humilis) at just a single site (F/L at Position 8). These data would imply that the novel BRP is an amphibian defensive agent against predation by sympatric turtles and also that the primary structure of the avian BK, ornithokinin (RPPGFTPLR), is not invariant within this taxon. Synthetic RVAL-(L¹, T?, L?)-bradykinin was found to be an antagonist of BK-induced rat tail artery smooth muscle relaxation acting via the B2-receptor. PMID:25268979

  13. A Novel Bradykinin-Related Dodecapeptide (RVALPPGFTPLR) from the Skin Secretion of the Fujian Large-Headed Frog (Limnonectes fujianensis) Exhibiting Unusual Structural and Functional Features

    PubMed Central

    Shi, Daning; Luo, Yu; Du, Qiang; Wang, Lei; Zhou, Mei; Ma, Jie; Li, Renjie; Chen, Tianbao; Shaw, Chris

    2014-01-01

    Bradykinin-related peptides (BRPs) are significant components of the defensive skin secretions of many anuran amphibians, and these secretions represent the source of the most diverse spectrum of such peptides so far encountered in nature. Of the many families of bioactive peptides that have been identified from this source, the BRPs uniquely appear to represent homologues of counterparts that have specific distributions and receptor targets within discrete vertebrate taxa, ranging from fishes through mammals. Their broad spectra of actions, including pain and inflammation induction and smooth muscle effects, make these peptides ideal weapons in predator deterrence. Here, we describe a novel 12-mer BRP (RVALPPGFTPLR-RVAL-(L1, T6, L8)-bradykinin) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis). The C-terminal 9 residues of this BRP (-LPPGFTPLR) exhibit three amino acid substitutions (L/R at Position 1, T/S at Position 6 and L/F at Position 8) when compared to canonical mammalian bradykinin (BK), but are identical to the kinin sequence present within the cloned kininogen-2 from the Chinese soft-shelled turtle (Pelodiscus sinensis) and differ from that encoded by kininogen-2 of the Tibetan ground tit (Pseudopodoces humilis) at just a single site (F/L at Position 8). These data would imply that the novel BRP is an amphibian defensive agent against predation by sympatric turtles and also that the primary structure of the avian BK, ornithokinin (RPPGFTPLR), is not invariant within this taxon. Synthetic RVAL-(L1, T6, L8)-bradykinin was found to be an antagonist of BK-induced rat tail artery smooth muscle relaxation acting via the B2-receptor. PMID:25268979

  14. Making A Noble-Metal-On-Metal-Oxide Catalyst

    NASA Technical Reports Server (NTRS)

    Miller, Irvin M.; Davis, Patricia P.; Upchurch, Billy T.

    1989-01-01

    Catalyst exhibits superior performance in oxidation of CO in CO2 lasers. Two-step process developed for preparing platinum- or palladium-on-tin-oxide catalyst for recombination of CO and O2, decomposition products that occur in high-voltage discharge region of closed-cycle CO2 laser. Process also applicable to other noble-metal/metal-oxide combinations.

  15. Total Knee Arthroplasty Failure Induced by Metal Hypersensitivity

    PubMed Central

    Gupta, Ryan; Phan, Duy; Schwarzkopf, Ran

    2015-01-01

    Patient: Female, 70 Final Diagnosis: Metal hypersensitivity Symptoms: Joint pain • swelling • instability Medication: — Clinical Procedure: Revision total knee arthroplasty Specialty: Orthopedics and Traumatology Objective: Unusual clinical course Background: Metal hypersensitivity is an uncommon complication after total knee arthroplasty (TKA) that can lead to significant functional impairment and aseptic prosthesis failure. Case Report: We describe a 70-year-old patient who presented with persistent pain, swelling, and instability 2 years after a primary TKA. The patient had a history of metal hypersensitivity following bilateral metal-on-metal total hip arthroplasty (THA) that was revised to ceramic-on-polyethylene implants. Knee radiographs showed severe osteolysis with implant loosening. Serum cobalt was elevated and serum chromium was significantly elevated, while joint aspiration and inflammatory marker levels ruled out a periprosthetic infection. Revision TKA was performed, with intraoperative tissue pathology and postoperative leukocyte transformation testing confirming metal hypersensitivity as the cause for aseptic implant failure. Conclusions: This case report demonstrates the clinical and laboratory signs that suggest metal hypersensitivity in total knee arthroplasty and the potential for joint function restoration with revision surgery. PMID:26278890

  16. Total protein

    MedlinePLUS

    The total protein test measures the total amount of two classes of proteins found in the fluid portion of your blood. These are albumin and globulin. Proteins are important parts of all cells and tissues. ...

  17. Presence of corrosion products and hypersensitivity-associated reactions in periprosthetic tissue after aseptic loosening of total hip replacements with metal bearing surfaces.

    PubMed

    Huber, Monika; Reinisch, Georg; Trettenhahn, Günter; Zweymüller, Karl; Lintner, Felix

    2009-01-01

    Aseptic loosening of articular implants is frequently associated with tissue reactions to wear particles. Some patients, who had received metal-on-metal articulations, present early symptoms including persistent pain and implant failure. These symptoms raise the suspicion about the development of an immunological response. Furthermore, the generation of rare corrosion products in association with metallic implants has been observed. Corrosion products are known to enhance third-body wear and contribute to the loss of the implant. The purpose of this study was to investigate periprosthetic tissue containing solid corrosion products after aseptic loosening of second-generation metal-on-metal total hip replacements made of low-carbon cobalt-chromium-molybdenum alloy for the presence of immunologically determined tissue changes. Periprosthetic tissue of 11 cases containing uncommon solid deposits was investigated by light microscopy. In order to confirm the presence of corrosion products, additional methods including scanning electron microscopy (SEM) investigation, energy dispersive X-ray (EDX) and Fourier transform infrared microspectroscopy (FTIR) analysis were used. All investigated cases revealed solid chromium orthophosphate corrosion products as well as metallic wear particles to a various extent. Moreover, various intense tissue reactions characteristic of immune response were observed in all cases. The simultaneous presence of corrosion products and hypersensitivity-associated tissue reaction indicates that a relationship between corrosion development and implant-related hypersensitivity may exist. PMID:18725188

  18. Totally James

    ERIC Educational Resources Information Center

    Owens, Tom

    2006-01-01

    This article presents an interview with James Howe, author of "The Misfits" and "Totally Joe". In this interview, Howe discusses tolerance, diversity and the parallels between his own life and his literature. Howe's four books in addition to "The Misfits" and "Totally Joe" and his list of recommended books with lesbian, gay, bisexual, transgender,…

  19. Early surveillance of ceramic-on-metal total hip arthroplasty.

    PubMed

    Hill, J C; Diamond, O J; O'Brien, S; Boldt, J G; Stevenson, M; Beverland, D E

    2015-03-01

    Ceramic-on-metal (CoM) is a relatively new bearing combination for total hip arthroplasty (THA) with few reported outcomes. A total of 287 CoM THAs were carried out in 271 patients (mean age 55.6 years (20 to 77), 150 THAs in female patients, 137 in male) under the care of a single surgeon between October 2007 and October 2009. With the issues surrounding metal-on-metal bearings the decision was taken to review these patients between March and November 2011, at a mean follow-up of 34 months (23 to 45) and to record pain, outcome scores, radiological analysis and blood ion levels. The mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268 hips (95%) had mild/very mild/no pain, the mean angle of inclination of the acetabular component was 44.8(o) (28(o) to 63(o)), 82 stems (29%) had evidence of radiolucent lines of > 1 mm in at least one Gruen zone and the median levels of cobalt and chromium ions in the blood were 0.83 ?g/L (0.24 ?g/L to 27.56 ?g/L) and 0.78 ?g/L (0.21 ?g/L to 8.84 ?g/L), respectively. The five-year survival rate is 96.9% (95% confidence interval 94.7% to 99%). Due to the presence of radiolucent lines and the higher than expected levels of metal ions in the blood, we would not recommend the use of CoM THA without further long-term follow-up. We plan to monitor all these patients regularly. PMID:25737511

  20. 78 FR 24426 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

    ...metal-on-metal (cobalt chrome molybdenum alloy) cervical total disc replacement device. The Kineflex/C is indicated...metal-on-metal (cobalt chrome molybdenum alloy) lumbar total disc replacement device. The Kineflex Lumbar...

  1. Serum metal ion concentrations in paediatric patients following total knee arthroplasty using megaprostheses.

    PubMed

    Friesenbichler, Jörg; Sadoghi, Patrick; Maurer-Ertl, Werner; Szkandera, Joanna; Glehr, Mathias; Ogris, Kathrin; Wolf, Matthias; Weger, Christian; Leithner, Andreas

    2014-01-01

    The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P = 0.002 and P < 0.001) and preoperative controls (P < 0.001). On the other hand, the serum levels of patients following MoM THA or rotating hinge arthroplasty using megaprostheses were higher. Therefore, periodic long-term follow-ups are recommended due to the rising concerns about systemic metal ion exposure in the literature. Upon the occurrence of adverse reactions to metal debris the revision of the fixed hinge implant should be considered. PMID:25276819

  2. Serum Metal Ion Concentrations in Paediatric Patients following Total Knee Arthroplasty Using Megaprostheses

    PubMed Central

    Friesenbichler, Jörg; Sadoghi, Patrick; Maurer-Ertl, Werner; Szkandera, Joanna; Glehr, Mathias; Ogris, Kathrin; Wolf, Matthias; Weger, Christian; Leithner, Andreas

    2014-01-01

    The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device (P = 0.002 and P < 0.001) and preoperative controls (P < 0.001). On the other hand, the serum levels of patients following MoM THA or rotating hinge arthroplasty using megaprostheses were higher. Therefore, periodic long-term follow-ups are recommended due to the rising concerns about systemic metal ion exposure in the literature. Upon the occurrence of adverse reactions to metal debris the revision of the fixed hinge implant should be considered. PMID:25276819

  3. Local and systemic toxicity of nanoscale debris particles in total hip arthroplasty.

    PubMed

    Polyzois, Ioannis; Nikolopoulos, Dimitrios; Michos, Ioannis; Patsouris, Efstratios; Theocharis, Stamatios

    2012-04-01

    Over the past 30?years joint replacement prostheses have been developed and refined to enhance durability and reproducibility. Total hip joint arthroplasty is being performed in an increasing number of younger patients; therefore orthopaedic surgeons seek implants with a longer life span. With regards to the progress of mechanical behaviour of the biomaterials used in an arthroplasty, little is known about the long-term biological effects of wear debris. Owing to the composition of the prostheses currently in use, systemic exposure to chromium (Cr), cobalt (Co), nickel (Ni) and aluminium (Al) alloys occurs as a result of the formation of metal wear nano-particles that are released both from metal-on-metal and polyethylene-on-metal bearings, resulting in a postoperative increase in metal ion levels at different organ sites. These particles circulate both locally and systemically, penetrate cell plasma membranes, bind to cellular proteins and enzymes and modulate cytokine expression. Their physiologic effects are poorly understood and their potential toxicity, hypersensitivity and carcinogenicity remain a cause for concern. In this article we will address the issue of whether these nanoscale degradation products are associated with adverse, clinically significant local or systemic toxicologic sequelae. PMID:22328167

  4. Total Artificial Heart

    MedlinePLUS

    ... NHLBI on Twitter. What Is a Total Artificial Heart? A total artificial heart (TAH) is a device ... the chest to an outside power source. Normal Heart and CardioWest Total Artificial Heart Figure A shows ...

  5. Supporting Online Material for Graphitic Tribological Layers in Metal-on-Metal Hip Replacements

    E-print Network

    Marks, Laurence D.

    . The replacements were rinsed to remove blood and placed in 10% formalin for sterilization and storage. Note were rinsed to remove blood and placed in 10% formalin for sterilization and storage. TEM specimen that the effects of the electron beam on the graphitic material was minor. Raman Raman spectra from the pole

  6. New Insights into Hard Phases of CoCrMo Metal-on-Metal Hip Replacements

    PubMed Central

    Liao, Y.; Pourzal, R.; Stemmer, P.; Wimmer, M.A.; Jacobs, J.J.; Fischer, A.; Marks, L. D.

    2012-01-01

    The microstructural and mechanical properties of the hard phases in CoCrMo prosthetic alloys in both cast and wrought conditions were examined using transmission electron microscopy and nanoindentation. Besides the known carbides of M23C6-type (M=Cr, Mo, Co) and M6C-type which are formed by either eutectic solidification or precipitation, a new mixed-phase hard constituent has been found in the cast alloys, which is composed of ~100 nm fine grains. The nanosized grains were identified to be mostly of M23C6 type using nano-beam precession electron diffraction, and the chemical composition varied from grain to grain being either Cr- or Co-rich. In contrast, the carbides within the wrought alloy having the same M23C6 structure were homogeneous, which can be attributed to the repeated heating and deformation steps. Nanoindentation measurements showed that the hardness of the hard phase mixture in the cast specimen was ~15.7 GPa, while the M23C6 carbides in the wrought alloy were twice as hard (~30.7 GPa). The origin of the nanostructured hard phase mixture was found to be related to slow cooling during casting. Mixed hard phases were produced at a cooling rate of 0.2 °C/s, whereas single phase carbides were formed at a cooling rate of 50 °C/s. This is consistent with sluggish kinetics and rationalizes different and partly conflicting microstructural results in the literature, and could be a source of variations in the performance of prosthetic devices in-vivo. PMID:22659365

  7. Origin of Compact Triangular Islands in Metal-on-Metal Growth

    SciTech Connect

    Bogicevic, Alexander; Lundqvist, Bengt I.; Ovesson, Staffan

    1999-07-12

    The microscopic origin of compact triangular islands on close-packed surfaces is identified using kinetic Monte Carlo simulations with energy barriers obtained from density-functional calculations. In contrast to earlier accounts, corner diffusion anisotropy is found to control the shape of compact islands at intermediate temperatures. We rationalize the correlation between the orientation of dendrites grown at low temperatures and triangular islands grown at higher temperatures, and explain why in some systems dendrites grow fat before turning compact.

  8. Enhanced wear and corrosion in modular tapers in total hip replacement is associated with the contact area and surface topography.

    PubMed

    Panagiotidou, Anna; Meswania, Jay; Hua, Jia; Muirhead-Allwood, Sarah; Hart, Alister; Blunn, Gordon

    2013-12-01

    Widespread concern exists about adverse tissue reactions after metal-on-metal (MoM) total hip replacement (THR). Concerns have also been expressed with wear and corrosion of taper junctions in THR. We report the effect of surface finish and contact area associated with a single combination of materials of modular tapers. In an in vitro test, we investigated the head/neck (CoCrMo/Ti) interface of modular THRs using commercially available heads. Wear and corrosion of taper surfaces was compared following a 10 million loading cycle. Surface parameters and profiles were measured before and after testing. Electrochemical static and dynamic corrosion tests were performed under loaded and non-loaded conditions. After the load test, the surface roughness parameters on the head taper were significantly increased where the head/neck contact area was reduced. Similarly, the surface roughness parameters on the head taper were significantly increased where rough neck tapers were used. Corrosion testing showed breaching of the passive film on the rough but not the smooth neck tapers. Thus, surface area and surface finish are important factors in wear and corrosion at modular interfaces. PMID:23966288

  9. Total Parenteral Nutrition

    MedlinePLUS

    ... Print This Page Email This Page Total Parenteral Nutrition Brand Name(s): TPN WHY is this medicine prescribed? Your doctor has ordered total parenteral nutrition (TPN) for you. TPN will drip through a ...

  10. Ceramic-on-metal for total hip replacement: mixing and matching can lead to high wear.

    PubMed

    Affatato, Saverio; Spinelli, Michele; Zavalloni, Mara; Traina, Francesco; Carmignato, Simone; Toni, Aldo

    2010-04-01

    Ceramic-on-ceramic and metal-on-metal bearing surfaces are often employed for total hip replacement because of their resistance to wear. However, they have some limits: brittleness is a major concern for ceramic, and ion release is a drawback for metal. To reduce the effect of these limitations, a hybrid coupling of ceramic-on-metal has been proposed. The theoretical advantage of this new coupling might lead orthopedic surgeons to use it indiscriminately. We asked whether the wear rate of this innovative solution was comparable with that of ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. In a hip simulator study, we tested the wear pattern of a hybrid ceramic-on-metal coupling supplied by the same distributor; in particular, three different configurations were tested for 5 million cycles: 36-mm ceramic-on-ceramic, 32-mm and 36-mm ceramic-on-metal. These combinations were gravimetrically and geometrically evaluated. After 5 million cycles, the volumetric loss for the metal acetabular cups (Phi 36-mm) was 20-fold greater than that of the ceramic cups of the same size (Phi 36-mm); a volumetric loss of 4.35 mm(3) and 0.26 mm(3) was observed, respectively, for ceramic-on-metal and ceramic-on-ceramic combinations. Significant statistical differences were observed between all 36-mm different combinations (P < 0.0001). The increased diameter of the 36-mm ceramic-on-metal configuration resulted in a lower volumetric loss compared with that of the 32-mm ceramic-on-metal configuration. Our findings showed an increase in wear for the proposed hybrid specimens with respect to that of the ceramic-on-ceramic ones. This confirms that even in the case of ceramic-on-metal bearings, mixing and matching could not prove effective wear behavior, not even comparable with that of the ceramic-on-ceramic gold standard. PMID:20420614

  11. Mixing of components from different manufacturers in total hip arthroplasty: prevalence and comparative outcomes.

    PubMed

    Tucker, Keith; Pickford, Martin; Newell, Claire; Howard, Peter; Hunt, Linda P; Blom, Ashley W

    2015-12-01

    Background and purpose - There have recently been highly publicized examples of suboptimal outcomes with some newer implant designs used for total hip replacement. This has led to calls for tighter regulation. However, surgeons do not always adhere to the regulations already in place and often use implants from different manufacturers together to replace a hip, which is against the recommendations of the Medicines and Healthcare Products Regulatory Agency (MHRA) and the directions of the manufacturers. Patients and methods - We used data from the National Joint Registry of England and Wales (NJR) to investigate this practice. Results - Mixing of components was common, and we identified over 90,000 cases recorded between 2003 and 2013. In the majority of these cases (48,156), stems and heads from one manufacturer were mixed with polyethylene cemented cups from another manufacturer. When using a cemented stem and a polyethylene cup, mixing of stems from one manufacturer with cups from another was associated with a lower revision rate. At 8 years, the cumulative percentage of revisions was 1.9% (95% CI: 1.7-2.1) in the mixed group as compared to 2.4% (2.3-2.5) in the matched group (p = 0.001). Mixing of heads from one manufacturer with stems from another was associated with a higher revision rate (p < 0.001). In hip replacements with ceramic-on-ceramic or metal-on-metal bearings, mixing of stems, heads, and cups from different manufacturers was associated with similar revision rates (p > 0.05). Interpretation - Mixing of components from different manufacturers is a common practice, despite the fact that it goes against regulatory guidance. However, it is not associated with increased revision rates unless heads and stems from different manufacturers are used together. PMID:26201845

  12. Estonian total ozone climatology

    NASA Astrophysics Data System (ADS)

    Eerme, K.; Veismann, U.; Koppel, R.

    2002-02-01

    The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS) data are discussed. The mean annual cycle during 1979 2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO) corrected systematic decrease of total ozone from February April was 3 +/- 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of +/- 20 DU and phase lag of 20 months. Between 1987 1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April May) and summer (June August) total ozone have the best correlation (coefficient 0.7) in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

  13. Parallel Total Energy

    Energy Science and Technology Software Center (ESTSC)

    2004-10-21

    This is a total energy electronic structure code using Local Density Approximation (LDA) of the density funtional theory. It uses the plane wave as the wave function basis set. It can sue both the norm conserving pseudopotentials and the ultra soft pseudopotentials. It can relax the atomic positions according to the total energy. It is a parallel code using MP1.

  14. Total Quality Leadership

    NASA Technical Reports Server (NTRS)

    1991-01-01

    More than 750 NASA, government, contractor, and academic representatives attended the Seventh Annual NASA/Contractors Conference on Quality and Productivity. The panel presentations and Keynote speeches revolving around the theme of total quality leadership provided a solid base of understanding of the importance, benefits, and principles of total quality management (TQM). The presentations from the conference are summarized.

  15. Total Synthesis of (?)-Himandrine

    E-print Network

    Movassaghi, Mohammad

    We describe the first total synthesis of (?)-himandrine, a member of the class II galbulimima alkaloids. Noteworthy features of this chemistry include a diastereoselective Diels?Alder reaction in the rapid synthesis of the ...

  16. TOTAL ANNUAL Rent / Mortgage $

    E-print Network

    Snider, Barry B.

    EXPENSES TOTAL ANNUAL AMOUNT Rent / Mortgage $ Food / Clothing $ Household (Utilities, Laundry, etc/loss Business, Rental, Royalties, estate, trust income $ Housing or Food Allowances (military, clergy etc $ Contributions to tax deferred plans(401K) $ Non Educational Veterans' Benefits $ Unemployment Compensation

  17. Total Water Management - slides

    EPA Science Inventory

    Total Water Management (TWM) examines urban water systems in an interconnected manner. It encompasses reducing water demands, increasing water recycling and reuse, creating water supply assets from stormwater management, matching water quality to end-use needs, and achieving envi...

  18. NAME: Date: = Total Velocity

    E-print Network

    Lega, Joceline

    NAME: Date: = Total Velocity = Vertical Velocity = Horizontal Velocity Instructions: Fire your horizontal velocity. My average rate is________________________ #12;To find the average vertical velocity the ground, given an initial vertical velocity v. My average vertical velocity

  19. Total parenteral nutrition - infants

    MedlinePLUS

    IV fluids - infants; TPN - infants; Intravenous fluids - infants; Hyperalimentation - infants ... Total parenteral nutrition (TPN) is a method of feeding that bypasses the gastrointestinal tract. Fluids are given into a ...

  20. Convex Total Least Squares

    E-print Network

    Slavov, Nikolai

    We study the total least squares (TLS) problem that generalizes least squares regression by allowing measurement errors in both dependent and independent variables. TLS is widely used in applied fields including computer ...

  1. Total lymphoid irradiation

    SciTech Connect

    Sutherland, D.E.; Ferguson, R.M.; Simmons, R.L.; Kim, T.H.; Slavin, S.; Najarian, J.S.

    1983-05-01

    Total lymphoid irradiation by itself can produce sufficient immunosuppression to prolong the survival of a variety of organ allografts in experimental animals. The degree of prolongation is dose-dependent and is limited by the toxicity that occurs with higher doses. Total lymphoid irradiation is more effective before transplantation than after, but when used after transplantation can be combined with pharmacologic immunosuppression to achieve a positive effect. In some animal models, total lymphoid irradiation induces an environment in which fully allogeneic bone marrow will engraft and induce permanent chimerism in the recipients who are then tolerant to organ allografts from the donor strain. If total lymphoid irradiation is ever to have clinical applicability on a large scale, it would seem that it would have to be under circumstances in which tolerance can be induced. However, in some animal models graft-versus-host disease occurs following bone marrow transplantation, and methods to obviate its occurrence probably will be needed if this approach is to be applied clinically. In recent years, patient and graft survival rates in renal allograft recipients treated with conventional immunosuppression have improved considerably, and thus the impetus to utilize total lymphoid irradiation for its immunosuppressive effect alone is less compelling. The future of total lymphoid irradiation probably lies in devising protocols in which maintenance immunosuppression can be eliminated, or nearly eliminated, altogether. Such protocols are effective in rodents. Whether they can be applied to clinical transplantation remains to be seen.

  2. Head size and dislocation rate in primary total hip arthroplasty

    PubMed Central

    Singh, Somesh P; Bhalodiya, Haresh P

    2013-01-01

    Background: Dislocation after total hip arthroplasty (THA) has a multifactorial etiology with variables such as surgical approach, component orientation and position, type of cup, stem and head size. Review of the literature regarding the relationship of head size and dislocation rate in THA is suggestive that large femoral head size is associated with lower dislocation rate after THA. However, limited data is available as a proof of this hypothesis. The purpose of this study was to determine that the use of large head size would lead to a decreased incidence of dislocations following THA. Materials and Methods: 317 primary THAs were performed using the posterolateral approach with posterior soft-tissue repair between January 2006 and December 2009. Cases were divided into two groups (A and B). Femoral head diameter size 36 mm was used in 163 THA in group A and 28 mm in 154 THA in group B. Average period of followup being 2 years (6 month to 4 years). Patients were routinely followed at definite intervals and were specifically assessed for dislocation. Results: One or more dislocations occurred in 11 out of 317 hips with the overall rate of dislocation being 3.47%. Dislocation rate was 0.6% in 36 mm head size and 6.49% with 28 mm head size (P value is 0.0107). Keeping the stem design variable as a constant, the difference in the rate of dislocation between the two groups was again found to be statistically significant for both un-cemented and cemented stem. Conclusion: Dislocation rate decreased significantly as the size of the head increased in primary THA. However, longer followup is necessary as rate of dislocation or in vivo highly cross linked poly failure or fracture may increase in future affecting the rate of dislocations in primary THA. PMID:24133302

  3. Total Energy Monitor

    SciTech Connect

    Friedrich, S

    2008-08-11

    The total energy monitor (TE) is a thermal sensor that determines the total energy of each FEL pulse based on the temperature rise induced in a silicon wafer upon absorption of the FEL. The TE provides a destructive measurement of the FEL pulse energy in real-time on a pulse-by-pulse basis. As a thermal detector, the TE is expected to suffer least from ultra-fast non-linear effects and to be easy to calibrate. It will therefore primarily be used to cross-calibrate other detectors such as the Gas Detector or the Direct Imager during LCLS commissioning. This document describes the design of the TE and summarizes the considerations and calculations that have led to it. This document summarizes the physics behind the operation of the Total Energy Monitor at LCLS and derives associated engineering specifications.

  4. Total synthesis of (+)-iresin.

    PubMed

    Wang, Bian-Lin; Gao, Hai-Tao; Li, Wei-Dong Z

    2015-05-15

    The first asymmetric total synthesis of (+)-iresin (4), an historically important ent-Drimane sesquiterpene lactone, was realized from aldehyde 3 via cyclic orthoester 6 in 5 steps. Notable transformations in this synthesis include a tandem trifluoroperacetic acid (TFPAA)-mediated Baeyer-Villiger oxidation-olefin epoxidation-epoxy ester cyclization, regioselective Burgess dehydration, and regioselective Fétizon oxidative lactonization. PMID:25906145

  5. TOTAL DIET STUDY

    EPA Science Inventory

    The Total Diet Study (TDS), sometimes called the Market Basket Study, is an ongoing FDA program that determines levels of various pesticide residues, contaminants, and nutrients in foods, for the purpose of estimating intakes of these substances in representative diets of specifi...

  6. CSF total protein

    MedlinePLUS

    CSF total protein is a test to determine the amount of protein in your spinal fluid, also called cerebrospinal fluid (CSF). ... The normal protein range varies from lab to lab, but is typically about 15 to 60 mg/dL. Note: mg/dL = ...

  7. Total Water Management - Report

    EPA Science Inventory

    There is a growing need for urban water managers to take a more holistic view of their water resource systems as population growth, urbanization, and current operations put different stresses on the environment and urban infrastructure. Total Water Management (TWM) is an approac...

  8. Total Water Management

    EPA Science Inventory

    This project will investigate total water management (TWM) as a way of improving water resource management and reducing waste streams. This project will also improve management of potable water, wastewater and wet-weather flow through combined management, reuse and recycling wil...

  9. Total Precipitable Water

    SciTech Connect

    2012-01-01

    The simulation was performed on 64K cores of Intrepid, running at 0.25 simulated-years-per-day and taking 25 million core-hours. This is the first simulation using both the CAM5 physics and the highly scalable spectral element dynamical core. The animation of Total Precipitable Water clearly shows hurricanes developing in the Atlantic and Pacific.

  10. Total Immersion Camping.

    ERIC Educational Resources Information Center

    Conklin, Mildred; Murphy, Stephen

    A total immersion program at North Rose-Wolcott High School, Wolcott, New York, involves speaking in the target language over a period of hours or days, the assistance of at least one fluent speaker for each six students, and a planned schedule of activities. Programs have varied from activities at the home of a teacher, all-day interaction at…

  11. Total Quality Management Seminar.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. The booklet contains seven sections that cover the following topics: (1) meaning of total quality management (TQM); (2) the customer; (3) the organization's culture; (4) comparison of management…

  12. Total Quality Management Simplified.

    ERIC Educational Resources Information Center

    Arias, Pam

    1995-01-01

    Maintains that Total Quality Management (TQM) is one method that helps to monitor and improve the quality of child care. Lists four steps for a child-care center to design and implement its own TQM program. Suggests that quality assurance in child-care settings is an ongoing process, and that TQM programs help in providing consistent, high-quality…

  13. Estuarine Total Ecosystem Metabolism

    EPA Science Inventory

    Total ecosystem metabolism (TEM), both as discrete measurements and as a theoretical concept, has an important history in ecosystem ecology, particularly in estuaries. Some of the earliest ecological studies were developed to determine how energy flowed through an ecosystem and w...

  14. "Total Deposition (TDEP) Maps"

    EPA Science Inventory

    The presentation provides an update on the use of a hybrid methodology that relies on measured values from national monitoring networks and modeled values from CMAQ to produce of maps of total deposition for use in critical loads and other ecological assessments. Additionally, c...

  15. The clinical and radiological outcomes of hip resurfacing versus total hip arthroplasty: a meta-analysis and systematic review

    PubMed Central

    2010-01-01

    Background and purpose Hip resurfacing (HRS) procedures have gained increasing popularity for younger, higher-demand patients with degenerative hip pathologies. However, with concerns regarding revision rates and possible adverse metal hypersensitivity reactions with metal-on-metal articulations, some authors have questioned the hypothesized superiority of hip resurfacing over total hip arthroplasty (THA). In this meta-analysis, we compared the clinical and radiological outcomes and complication rates of these 2 procedures. Methods A systematic review was undertaken of all published (Medline, CINAHL, AMED, EMBASE) and unpublished or gray literature research databases up to January 2010. Clinical and radiological outcomes as well as complications of HRS were compared to those of THA using risk ratio, mean difference, and standardized mean difference statistics. Studies were critically appraised using the CASP appraisal tool. Results 46 studies were identified from 1,124 citations. These included 3,799 HRSs and 3,282 THAs. On meta-analysis, functional outcomes for subjects following HRS were better than or the same as for subjects with a THA, but there were statistically significantly greater incidences of heterotopic ossification, aseptic loosening, and revision surgery with HRS compared to THA. The evidence base showed a number of methodological inadequacies such as the limited use of power calculations and poor or absent blinding of both patients and assessors, possibly giving rise to assessor bias. Interpretation On the basis of the current evidence base, HRS may have better functional outcomes than THA, but the increased risks of heterotopic ossification, aseptic loosening, and revision surgery following HRS indicate that THA is superior in terms of implant survival. PMID:21067432

  16. Total synthesis of clostrubin

    PubMed Central

    Yang, Ming; Li, Jian; Li, Ang

    2015-01-01

    Clostrubin is a potent antibiotic against methicillin- and vancomycin-resistant bacteria that was isolated from a strictly anaerobic bacterium Clostridium beijerinckii in 2014. This polyphenol possesses a fully substituted arene moiety on its pentacyclic scaffold, which poses a considerable challenge for chemical synthesis. Here we report the first total synthesis of clostrubin in nine steps (the longest linear sequence). A desymmetrization strategy is exploited based on the inherent structural feature of the natural product. Barton–Kellogg olefination forges the two segments together to form a tetrasubstituted alkene. A photo-induced 6? electrocyclization followed by spontaneous aromatization constructs the hexasubstituted B ring at a late stage. In total, 200?mg of clostrubin are delivered through this approach. PMID:25759087

  17. Totally parallel multilevel algorithms

    NASA Technical Reports Server (NTRS)

    Frederickson, Paul O.

    1988-01-01

    Four totally parallel algorithms for the solution of a sparse linear system have common characteristics which become quite apparent when they are implemented on a highly parallel hypercube such as the CM2. These four algorithms are Parallel Superconvergent Multigrid (PSMG) of Frederickson and McBryan, Robust Multigrid (RMG) of Hackbusch, the FFT based Spectral Algorithm, and Parallel Cyclic Reduction. In fact, all four can be formulated as particular cases of the same totally parallel multilevel algorithm, which are referred to as TPMA. In certain cases the spectral radius of TPMA is zero, and it is recognized to be a direct algorithm. In many other cases the spectral radius, although not zero, is small enough that a single iteration per timestep keeps the local error within the required tolerance.

  18. The Total Library *

    PubMed Central

    Annan, Gertrude L.

    1968-01-01

    Changing functions and techniques of today's libraries have led to questioning the very substance of the library of the future. Ralph Shaw points out that the total library must be “a living force for the enrichment of mankind.” The Medical Research Library of Brooklyn at its very inauguration is uniquely prepared and equipped to work toward that goal. It imaginatively serves the needs of the immediate area by generous sharing of resources, use of its computerized program, and participation in a state-wide system. The large collection of the Academy of Medicine of Brooklyn offers thousands of volumes for the historian, both great works as highlights of medical achievements and more modest contributions of both early and recent date. The total library must serve as an intellectual resource, as well as a mechanism for the rapid transfer of current information. PMID:5644795

  19. Physician Update: Total Health

    PubMed Central

    Tuso, Phillip

    2014-01-01

    As an integrated prepaid health care system, Kaiser Permanente (KP) is in a unique position to demonstrate that affordability in health care can be achieved by disease prevention. During the past decade, KP has significantly improved the quality care outcomes of its members with preventable diseases. However, because of an increase in the incidence of preventable disease, and the potential long-term and short-term costs associated with the treatment of preventable disease, KP has developed a new strategy called Total Health to meet the current and future needs of its patients. Total Health means healthy people in healthy communities. KP’s strategic vision is to be a leader in Total Health by making lives better. KP hopes to make lives better by 1) measuring vital signs of health, 2) promoting healthy behaviors, 3) monitoring disease incidence, 4) spreading leading practices, and 5) creating healthy environments with our community partners. Best practices, spread to the communities we serve, will make health care more affordable, prevent preventable diseases, and save lives. PMID:24694316

  20. Total Synthesis of (-)-Isoschizogamine.

    PubMed

    Takada, Akihiro; Fujiwara, Hiroaki; Sugimoto, Kenji; Ueda, Hirofumi; Tokuyama, Hidetoshi

    2015-11-01

    The total synthesis of (-)-isoschizogamine was accomplished, featuring the construction of the quaternary carbon center by the modified Johnson-Claisen rearrangement in basic media and the facile assembly of the key tetracyclic quinolone intermediate through a cascade cyclization. The characteristic cyclic aminal was constructed by late-stage C?H functionalization at the position adjacent to the lactam nitrogen using a combination of CrO3 and nBu4 NIO4 and subsequent Bi(OTf)3 -mediated cyclization. PMID:26424406

  1. Total photoabsorption in nuclei

    SciTech Connect

    Bianchi, N.

    1992-06-01

    The Frascati-Genova collaboration proposes to measure the total photonuclear cross section on a wide range of nuclei between 500 MeV and 2 GeV, to obtain informations on the interaction of baryon resonances with nucleons and on the onset of the shadowing effect. The experiment could be performed in the Hall B as soon as the tagging facility will be ready and before the end of the installation of the CLAS spectrometer. The requirements for the photon beam, like maximum energy, intensity and beam definition, are not so strong so that the experiment would also be a good first test of the tagged photon facility.

  2. Postoperative total parenteral nutrition.

    PubMed

    Waitzberg, D L; Plopper, C; Terra, R M

    1999-06-01

    Surgical trauma induces complex physiologic changes that lead to catabolism and loss of body cell mass. This reaction is usually mild but can be exacerbated by previous malnutrition and postoperative complications. To avoid severe metabolic distress, nutritional therapy may be prescribed, using the enteral route whenever possible. Postoperative total parenteral nutrition (TPN) is indicated for patients already receiving TPN preoperatively, those severely malnourished prior to major surgery, those unable to eat satisfactorily for 7 days, or patients presenting with severe complications. Postoperative TPN should last for at least 7 days. The total energy requirements are between 30 and 35 kcal/kg/day. About 50% to 70% should be provided in the form of carbohydrates, and 20% to 30% in the form of lipids. The optimal input rates for glucose and lipids are 4 to 5 g/kg/day and 80 mg/kg/hr, respectively. The ideal nitrogen administration is 250 to 300 mg/kg/day, and the optimal calorie/nitrogen ratio is 150 to 200. Some specific amino acids can be added as intravenous dipeptides. An adequate follow-up must include clinical and biochemical parameters. Several trials evaluated the impact of TPN in postoperative patients, but further well designed, controlled clinical trials are still necessary to address a great number of unanswered questions. PMID:10227924

  3. Anisotropic Total Variation Filtering

    SciTech Connect

    Grasmair, Markus; Lenzen, Frank

    2010-12-15

    Total variation regularization and anisotropic filtering have been established as standard methods for image denoising because of their ability to detect and keep prominent edges in the data. Both methods, however, introduce artifacts: In the case of anisotropic filtering, the preservation of edges comes at the cost of the creation of additional structures out of noise; total variation regularization, on the other hand, suffers from the stair-casing effect, which leads to gradual contrast changes in homogeneous objects, especially near curved edges and corners. In order to circumvent these drawbacks, we propose to combine the two regularization techniques. To that end we replace the isotropic TV semi-norm by an anisotropic term that mirrors the directional structure of either the noisy original data or the smoothed image. We provide a detailed existence theory for our regularization method by using the concept of relaxation. The numerical examples concluding the paper show that the proposed introduction of an anisotropy to TV regularization indeed leads to improved denoising: the stair-casing effect is reduced while at the same time the creation of artifacts is suppressed.

  4. TOTAL user manual

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C.; Boerschlein, David P.

    1994-01-01

    Semi-Markov models can be used to analyze the reliability of virtually any fault-tolerant system. However, the process of delineating all of the states and transitions in the model of a complex system can be devastatingly tedious and error-prone. Even with tools such as the Abstract Semi-Markov Specification Interface to the SURE Tool (ASSIST), the user must describe a system by specifying the rules governing the behavior of the system in order to generate the model. With the Table Oriented Translator to the ASSIST Language (TOTAL), the user can specify the components of a typical system and their attributes in the form of a table. The conditions that lead to system failure are also listed in a tabular form. The user can also abstractly specify dependencies with causes and effects. The level of information required is appropriate for system designers with little or no background in the details of reliability calculations. A menu-driven interface guides the user through the system description process, and the program updates the tables as new information is entered. The TOTAL program automatically generates an ASSIST input description to match the system description.

  5. Total organic carbon analyzer

    NASA Technical Reports Server (NTRS)

    Godec, Richard G.; Kosenka, Paul P.; Smith, Brian D.; Hutte, Richard S.; Webb, Johanna V.; Sauer, Richard L.

    1991-01-01

    The development and testing of a breadboard version of a highly sensitive total-organic-carbon (TOC) analyzer are reported. Attention is given to the system components including the CO2 sensor, oxidation reactor, acidification module, and the sample-inlet system. Research is reported for an experimental reagentless oxidation reactor, and good results are reported for linearity, sensitivity, and selectivity in the CO2 sensor. The TOC analyzer is developed with gravity-independent components and is designed for minimal additions of chemical reagents. The reagentless oxidation reactor is based on electrolysis and UV photolysis and is shown to be potentially useful. The stability of the breadboard instrument is shown to be good on a day-to-day basis, and the analyzer is capable of 5 sample analyses per day for a period of about 80 days. The instrument can provide accurate TOC and TIC measurements over a concentration range of 20 ppb to 50 ppm C.

  6. On total disc replacement.

    PubMed

    Berg, Svante

    2011-02-01

    Low back pain consumes a large part of the community's resources dedicated to health care and sick leave. Back disorders also negatively affect the individual leading to pain suffering, decreased quality-of-life and disability. Chronic low back pain (CLBP) due to degenerative disc disease (DDD) is today often treated with fusion when conservative treatment has failed and symptoms are severe. This treatment is as successful as arthroplasty is for hip arthritis in restoring the patient's quality of life and reducing disability. Even so, there are some problems with this treatment, one of these being recurrent CLBP from an adjacent segment (ASD) after primarily successful surgery. This has led to the development of alternative surgical treatments and devices that maintain or restore mobility, in order to reduce the risk for ASD. Of these new devices, the most frequently used are the disc prostheses used in Total Disc Replacement (TDR). This thesis is based on four studies comparing total disc replacement with posterior fusion. The studies are all based on a material of 152 patients with DDD in one or two segments, aged 20-55 years that were randomly treated with either posterior fusion or TDR. The first study concerned clinical outcome and complications. Follow-up was 100% at both one and two years. It revealed that both treatment groups had a clear benefit from treatment and that patients with TDR were better in almost all outcome scores at one-year follow-up. Fusion patients continued to improve during the second year. At two-year follow-up there was a remaining difference in favour of TDR for back pain. 73% in the TDR group and 63% in the fusion group were much better or totally pain-free (n.s.), while twice as many patients in the TDR group were totally pain free (30%) compared to the fusion group (15%). Time of surgery and total time in hospital were shorter in the TDR group. There was no difference in complications and reoperations, except that seventeen of the patients in the fusion group were re-operated for removal of their implants. The second study concerned sex life and sexual function. TDR is performed via an anterior approach, an approach that has been used for a long time for various procedures on the lumbar spine. A frequent complication reported in males when this approach is used is persistent retrograde ejaculation. The TDR group in this material was operated via an extra-peritoneal approach to the retroperitoneal space, and there were no cases of persistent retrograde ejaculation. There was a surprisingly high frequency of men in the fusion group reporting deterioration in ability to have an orgasm postoperatively. Preoperative sex life was severely hampered in the majority of patients in the entire material, but sex life underwent a marked improvement in both treatment groups by the two-year follow-up that correlated with reduction in back pain. The third study was on mobility in the lumbar spinal segments, where X-rays were taken in full extension and flexion prior to surgery and at two-year follow-up. Analysis of the films showed that 78% of the patients in the fusion group reached the surgical goal (non-mobility) and that 89% of the TDR patients maintained mobility. Preoperative disc height was lower than in a normative database in both groups, and remained lower in the fusion group, while it became higher in the TDR group. Mobility in the operated segment increased in the TDR group postoperatively. Mobility at the rest of the lumbar spine increased in both treatment groups. Mobility in adjacent segments was within the norm postoperatively, but slightly larger in the fusion group. In the fourth study the health economics of TDR vs Fusion was analysed. The hospital costs for the procedure were higher for patients in the fusion group compared to the TDR group, and the TDR patients were on sick-leave two months less. In all, these studies showed that the results in the TDR group were as good as in the fusion group. Patients are more likely to be totally pain-free when treated with TDR compared to fusion

  7. Total Energy CMR Production

    SciTech Connect

    Friedrich, S; Kolagani, R M

    2008-08-11

    The following outlines the optimized pulsed laser deposition (PLD) procedure used to prepare Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} (NSMO) temperature sensors at Towson University (Prof. Rajeswari Kolagani) for the LCLS XTOD Total Energy Monitor. The samples have a sharp metal/insulator transition at T {approx} 200 K and are optimized for operation at T {approx} 180 K, where their sensitivity is the highest. These samples are epitaxial multilayer structures of Si/YSZ/CeO/NSMO, where these abbreviations are defined in table 1. In this heterostructure, YSZ serves as a buffer layer to prevent deleterious chemical reactions, and also serves to de-oxygenate the amorphous SiO{sub 2} surface layer to generate a crystalline template for epitaxy. CeO and BTO serve as template layers to minimize the effects of thermal and lattice mismatch strains, respectively. More details on the buffer and template layer scheme are included in the attached manuscript accepted for publication in Sensor Letters (G. Yong et al., 2008).

  8. Determination of Total Petroleum Hydrocarbons (TPH) Using Total Carbon Analysis

    SciTech Connect

    Ekechukwu, A.A.

    2002-05-10

    Several methods have been proposed to replace the Freon(TM)-extraction method to determine total petroleum hydrocarbon (TPH) content. For reasons of cost, sensitivity, precision, or simplicity, none of the replacement methods are feasible for analysis of radioactive samples at our facility. We have developed a method to measure total petroleum hydrocarbon content in aqueous sample matrixes using total organic carbon (total carbon) determination. The total carbon content (TC1) of the sample is measured using a total organic carbon analyzer. The sample is then contacted with a small volume of non-pokar solvent to extract the total petroleum hydrocarbons. The total carbon content of the resultant aqueous phase of the extracted sample (TC2) is measured. Total petroleum hydrocarbon content is calculated (TPH = TC1-TC2). The resultant data are consistent with results obtained using Freon(TM) extraction followed by infrared absorbance.

  9. Total Knee Replacement

    PubMed Central

    2005-01-01

    Executive Summary Objective The aim of this review was to assess the effectiveness, in terms of pain reduction and functional improvement, and costing of total knee replacement (TKR) for people with osteoarthritis for whom less invasive treatments (such as physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids, hyaluronic acids, and arthroscopic surgery) have failed. Clinical Need Osteoarthritis affects an estimated 10% to 12% of Canadian adults. The therapeutic goals of osteoarthritis treatment are to improve joint mobility and reduce pain. Stepwise treatment options include exercise, weight loss, physiotherapy, analgesics, anti-inflammatory drugs, intra-articular steroids and hyaluronic acids, arthroscopic surgery, and, in severe cases, total joint replacement with follow-up rehabilitation. These treatments are delivered by a range of health care professionals, including physiotherapists, occupational therapists, family physicians, internists, rheumatologists, and orthopedic surgeons. TKR is an end-of-line treatment for patients with severe pain and functional limitations. More women than men undergo knee replacement, and most patients are between 55 and 84 years old. The Technology TKR is a surgical procedure in which an artificial joint or prosthesis replaces a damaged knee joint. The primary indication for TKR is pain, followed by functional limitation. Usually, a person’s daily activities must be substantially affected by pain and functional limitations for him or her to be considered a candidate for TKR. There are 3 different types of knee replacement prostheses. Non-constrained prostheses use the patient’s ligaments and muscles to provide the stability for the prosthesis. Semi-constrained prostheses provide some stability for the knee and do not rely entirely on the patient’s ligaments and muscles to provide the stability. Constrained prostheses are for patients whose ligaments and muscles are not able to provide stability for the knee prosthesis. The most common risks and complications associated with TKR are deep venous thrombosis, infection, stiffness, loosening, and osteolysis. To prevent deep venous thrombosis, patients are treated with heparin prophylactically and/or given support stockings to wear. Patients are also given antibiotics for 24 hours after surgery to minimize the risk of infection. Stiffness is another associated complication. In most patients, it can be avoided by keeping the knee moving in the days and weeks following surgery. The National Institutes of Health in the United States concluded that the indications for TKR should include the following: radiological evidence of joint damage, moderate to severe persistent pain that is not adequately relieved by nonsurgical management, and clinically significant functional limitation resulting in diminished quality of life. Review Strategy In March 2005, the following databases were searched: Cochrane Library International Agency for Health Technology Assessment (first quarter 2005), Cochrane Database of Systematic Reviews (first quarter 2005), Cochrane Central Register of Controlled Trials (first quarter 2005), MEDLINE (1966 to March 2005), MEDLINE In-Process and Other Non-indexed Citations (1966 to March 14, 2005), and EMBASE (1980 to 2005 week 9). The Medical Advisory Secretariat also searched Medscape on the Internet for recent reports on trials that were unpublished but that were presented at international conferences. In addition, the Web site Current Controlled Trials (www.controlled-trials.com) was searched for ongoing trials investigating TKR or unicompartmental knee replacement. No studies were identified that compared TKR to an alternative treatment. Several studies have been reported that compare preoperative measurement scores on targeted measures of functioning and pain to postoperative measurement scores in patients undergoing various TKR procedures. In order for the Medical Advisory Secretariat to measure the effectiveness of TKR and to compare the effectiveness of TKR across studies, effec

  10. Combinatorial aspects of total positivity

    E-print Network

    Williams, Lauren Kiyomi

    2005-01-01

    In this thesis I study combinatorial aspects of an emerging field known as total positivity. The classical theory of total positivity concerns matrices in which all minors are nonnegative. While this theory was pioneered ...

  11. Recommended Amounts of Total dairy

    Cancer.gov

    Recommended Amounts of Total dairy Table B15. Total dairy: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting recommendation (SE) % with intake above

  12. Recommended Amounts of Total fruits

    Cancer.gov

    Recommended Amounts of Total fruits Table B1. Total fruits: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting recommendation (SE) % with intake above

  13. Recommended Amounts of Total seafood

    Cancer.gov

    Recommended Amounts of Total seafood Table B12. Total seafood: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting recommendation (SE) % with intake

  14. Recommended Amounts of Total grains

    Cancer.gov

    Recommended Amounts of Total grains Table B8. Total grains: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting recommendation (SE) % with intake above

  15. MUJERES ( * ) TOTAL BIOLOGA 16 22

    E-print Network

    Autonoma de Madrid, Universidad

    PREVENTIVA Y SALUD PÚBLICA Y MICROBIOLOGÍA 3 6 OBSTETRICIA Y GINECOLOGÍA 2 3 ORGANIZACIÓN DE EMPRESAS 1 1 SALUD 4 9 PSICOLOGÍA EVOLUTIVA Y DE LA EDUCACIÓN 0 2 PSICOLOGÍA SOCIAL Y METODOLOGÍA 2 3 TOTAL Terapéutica 16 12 TOTAL MEDICINA 87 65 Psicología Biológica y de la Salud 2 2 TOTAL PSICOLOGÍA 2 2 2 2 285 243

  16. Total Quality and Organization Development. Total Quality Series.

    ERIC Educational Resources Information Center

    Lindsay, William M.; Petrick, Joseph A.

    As the global business environment becomes more turbulent, quality management seems more indispensable. This book offers strategies for integrating the theory and practice of Total Quality Management (TQM) with organizational-development (OD) theory at all organizational levels. Chapter 1 answers the question "Why Total Quality Management and…

  17. Usual Intake of Total seafood

    Cancer.gov

    Usual Intake of Total seafood Table A27. Total seafood: Means, percentiles and standard errors of usual intake, 2007-2010 Age (Years) N1 oz equivalents3 Mean (SE)2 5% (SE) 10% (SE) 25% (SE) 50% (SE) 75% (SE) 90% (SE) 95% (SE) Males 1-3 774 0.1 (0.02) 0.0

  18. TOWARDS ESTIMATING TOTAL ECONOMIC VALUE

    E-print Network

    Bateman, Ian J.

    TOWARDS ESTIMATING TOTAL ECONOMIC VALUE OF FORESTS IN MEXICO by Neil Adger Katrina Brown Raffaello Cervigni Dominic Moran CSERGE Working Paper GEC 94-21 #12;TOWARDS ESTIMATING TOTAL ECONOMIC VALUE and Economic Research on the Global Environment, University of East Anglia amd University College London

  19. Usual Intake of Total grains

    Cancer.gov

    Usual Intake of Total grains Table A17. Total grains: Means, percentiles and standard errors of usual intake, 2007-2010 Age (Years) N1 oz equivalents3 Mean (SE)2 5% (SE) 10% (SE) 25% (SE) 50% (SE) 75% (SE) 90% (SE) 95% (SE) Males 1-3 774 4.1 (0.10) 2.2

  20. MUJERES ( * ) TOTAL BIOLOGA 10 19

    E-print Network

    Autonoma de Madrid, Universidad

    CC POLÍTICAS Y RR II 4 6 DERECHO PRIVADO SOCIAL Y ECONÓMICO 1 2 DERECHO PÚBLICO Y FILOSOFÍA JURÍDICA 1 2 TOTAL DERECHO 6 10 INGENIERÍA INFORMÁTICA 2 11 TOTAL ESCUELA POLITÉCNICA SUPERIOR 2 11 UAM CIENCIAS CIENCIAS ECONÓMICAS Y EMPRESARIALES DERECHO ESCUELA POLITÉCNICA SUPERIOR Nº de tesis

  1. MUJERES ( * ) TOTAL BIOLOGA 18 22

    E-print Network

    Autonoma de Madrid, Universidad

    PREVENTIVA Y SALUD PÚBLICA Y MICROBIOLOGÍA 4 7 OBSTETRICIA Y GINECOLOGÍA 0 1 PEDIATRÍA 4 6 PSIQUIATRÍA 12 19 TOTAL MEDICINA 86 142 PSICOLOGÍA BÁSICA 3 6 PSICOLOGÍA BIOLÓGICA Y DE LA SALUD 5 10 PSICOLOGÍA EVOLUTIVA de la Salud 2 2 TOTAL PSICOLOGÍA 2 2 2 2 302 238 Fecha de referencia: 25 de julio de 2012; Fuente

  2. Usual Intake of Total fruit

    Cancer.gov

    Usual Intake of Total fruit Table A1. Total fruit: Means, percentiles and standard errors of usual intake, 2007-2010 Age (Years) N1 cup equivalents3 Mean (SE)2 5% (SE) 10% (SE) 25% (SE) 50% (SE) 75% (SE) 90% (SE) 95% (SE) Males 1-3 774 1.5 (0.07) 0.6

  3. The total charm cross section

    SciTech Connect

    Vogt, R

    2007-09-14

    We assess the theoretical uncertainties on the total charm cross section. We discuss the importance of the quark mass, the scale choice and the parton densities on the estimate of the uncertainty. We conclude that the uncertainty on the total charm cross section is difficult to quantify.

  4. Usual Intake of Total dairy

    Cancer.gov

    Usual Intake of Total dairy Table A33. Total dairy: Means, percentiles and standard errors of usual intake, 2007-2010 Age (Years) N1 cup equivalents3 Mean (SE)2 5% (SE) 10% (SE) 25% (SE) 50% (SE) 75% (SE) 90% (SE) 95% (SE) Males 1-3 774 2.5 (0.07) 1.0

  5. Total anomalous pulmonary venous return

    MedlinePLUS

    TAPVR; Total veins ... lungs. It then returns through the pulmonary (lung) veins to the left side of the heart, which ... lungs to the right atrium or to a vein flowing into the right atrium, instead of the ...

  6. 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 ...

  7. MUJERES TOTAL BIOLOGIA 16 27

    E-print Network

    Autonoma de Madrid, Universidad

    MUJERES TOTAL BIOLOGIA 16 27 BIOLOGIA MOLECULAR 43 74 ECOLOGIA 1 7 FISICA APLICADA 3 9 FISICA DE LA: Servicio de Investigación de la UAM #12;Solicitados En vigor Biología Molecular 85 48 Biología 12 7 Física

  8. MUJERES TOTAL BIOLOGIA 16 24

    E-print Network

    Autonoma de Madrid, Universidad

    MUJERES TOTAL BIOLOGIA 16 24 BIOLOGIA MOLECULAR 50 85 ECOLOGIA 4 7 FISICA APLICADA 1 8 FISICA DE LA Biología Molecular 76 44 Biología 11 6 Física de Materiales 17 15 Física Aplicada 25 17 Física de la

  9. MUJERES TOTAL BIOLOGIA 21 32

    E-print Network

    Autonoma de Madrid, Universidad

    MUJERES TOTAL BIOLOGIA 21 32 BIOLOGIA MOLECULAR 60 96 ECOLOGIA 1 2 FISICA APLICADA 5 9 FISICA DE LA Contents ( Bases de datos del ISI) #12;Solicitados En vigor Biología Molecular 90 46 Biología 12 6 Física

  10. MUJERES TOTAL BIOLOGIA 14 28

    E-print Network

    Autonoma de Madrid, Universidad

    MUJERES TOTAL BIOLOGIA 14 28 BIOLOGIA MOLECULAR 64 105 ECOLOGIA 5 10 FISICA APLICADA 17 29 FISICA Current Contents ( Bases de datos del ISI) #12;Solicitados En vigor Biología Molecular 90 51 Biología 12 6

  11. Mujeres Hombres Total Hombres Total 16 5 21 0 10

    E-print Network

    Autonoma de Madrid, Universidad

    VOLUNTARIADO LOCAL 9 Enseñanzas Técnicas 0 Ciencias de la Salud 3 No estudiante de UAM 0 #12;Año Mujeres Jurídicas 7 Enseñanzas Técnicas 2 Ciencias de la Salud 0 4 1 5 3 9 4 Número de voluntarios/as: mujeres/as: hombres, mujeres y totales. 2.1. Servicio de Voluntariado Europeo (SVE) Ciencias de la Salud 0 Humanidades

  12. Total body water and total body potassium in anorexia nervosa

    SciTech Connect

    Dempsey, D.T.; Crosby, L.O.; Lusk, E.; Oberlander, J.L.; Pertschuk, M.J.; Mullen, J.L.

    1984-08-01

    In the ill hospitalized patient with clinically relevant malnutrition, there is a measurable decrease in the ratio of the total body potassium to total body water (TBK/TBW) and a detectable increase in the ratio of total exchangeable sodium to total exchangeable potassium (Nae/Ke). To evaluate body composition analyses in anorexia nervosa patients with chronic uncomplicated semistarvation, TBK and TBW were measured by whole body K40 counting and deuterium oxide dilution in 10 females with stable anorexia nervosa and 10 age-matched female controls. The ratio of TBK/TBW was significantly (p less than 0.05) higher in anorexia nervosa patients than controls. The close inverse correlation found in published studies between TBK/TBW and Nae/Ke together with our results suggest that in anorexia nervosa, Nae/Ke may be low or normal. A decreased TBK/TBW is not a good indicator of malnutrition in the anorexia nervosa patient. The use of a decreased TBK/TBW ratio or an elevated Nae/Ke ratio as a definition of malnutrition may result in inappropriate nutritional management in the patient with severe nonstressed chronic semistarvation.

  13. Total Quality Management Is Total at Fox Valley Technical College.

    ERIC Educational Resources Information Center

    Tyler, Carol R.

    1993-01-01

    At Fox Valley Technical College (Wisconsin), application of Total Quality Management (TQM) brought positive outcomes and other effects. Areas in which TQM was used are considered, including admissions, employee safety, customer focus, policy formation, management performance appraisal, student services, creation of a self-managing class, TQM for…

  14. Total eclipses of the sun.

    PubMed

    Zirker, J B

    1980-12-19

    Total eclipses of the sun offer research opportunities in a variety of sciences. Some of the advances in solar physics resulting from eclipse observations are discussed. Experiments at the total eclipse of 16 February 1980 in India are also described. These included a test of general relativity, studies in coronal physics, investigations of solar prominences, diameter measurements, a search for interplanetary dust, a study of the gravity waves in the earth's atmosphere, and experiments on the biological effects on animals and humans. PMID:17817829

  15. Total synthesis of (+/-)-merrilactone A.

    PubMed

    He, Wei; Huang, Jie; Sun, Xiufeng; Frontier, Alison J

    2008-01-01

    The total synthesis of racemic merrilactone A (a neurotrophic agent) is described, featuring simultaneous and stereospecific creation of the C4 and C5 stereocenters via a notable silyloxyfuran Nazarov cyclization. Full details of the successful synthetic strategy are given, as well as several examples of the interesting reactivity of intermediates that were prepared and studied during the execution of the total synthesis. A detailed investigation of the Lewis acid-catalyzed Nazarov cyclization of silyloxyfurans was conducted, including a systematic study of substrate scope and limitations. In addition, experiments were conducted that suggest the participation of Lewis acidic silicon species in the Nazarov cyclization. PMID:18067294

  16. Total Synthesis of Propolisbenzofuran B†

    PubMed Central

    Jones, Brian T.; Avetta, Christopher T.; Thomson, Regan J.

    2014-01-01

    The first total synthesis of propolisbenzofuran B, a bioactive natural product isolated from honeybee propolis resin, is reported. The convergent synthesis makes use of a silicon-tether controlled oxidative ketone–ketone cross-coupling and a novel benzofuran-generating cascade reaction to deliver the core structure of the natural product from readily prepared precursors. PMID:24976944

  17. TOTAL MUJERES TOTAL MUJERES TOTAL MUJERES MUJERES % MUJERES TOTAL AFGANISTN 12 5 0 0 0 0 5 42% 12

    E-print Network

    Autonoma de Madrid, Universidad

    estudiantes: distribución de los estudiantes extranjeros por nacionalidad, ciclo y sexo (2009/10) PAÍS 1er y 2 nacionalidad, ciclo y sexo (2009/10) PAÍS 1er y 2º CICLO 3er CICLO PROGRAMAS INTERNACIONALE TOTAL JAPÓN 3 3 3 3

  18. Total Library Computerization for Windows.

    ERIC Educational Resources Information Center

    Combs, Joseph, Jr.

    1999-01-01

    Presents a general review of features of version 2.1 of Total Library Computerization (TLC) for Windows from On Point, Inc. Includes information about pricing, hardware and operating systems, modules/functions available, user interface, security, on-line catalog functions, circulation, cataloging, and documentation and online help. A table…

  19. Total Synthesis of (-)-Enigmazole A.

    PubMed

    Ai, Yanran; Kozytska, Mariya V; Zou, Yike; Khartulyari, Anton S; Smith, Amos B

    2015-12-16

    A highly convergent, stereocontrolled total synthesis of the architecturally complex marine sponge metabolite (-)-enigmazole A has been achieved. Highlights include an unprecedented late-stage large-fragment Petasis-Ferrier union/rearrangement, a multicomponent Type I Anion Relay Chemistry (ARC) tactic, and a dithiane-epoxide union in conjunction with an oxazole-directed stereoselective reduction. PMID:26632969

  20. Total Phenolics and Total Flavonoids in Selected Indian Medicinal Plants

    PubMed Central

    Sulaiman, C. T.; Balachandran, Indira

    2012-01-01

    Plant phenolics and flavonoids have a powerful biological activity, which outlines the necessity of their determination. The phenolics and flavonoids content of 20 medicinal plants were determined in the present investigation. The phenolic content was determined by using Folin-Ciocalteu assay. The total flavonoids were measured spectrophotometrically by using the aluminium chloride colorimetric assay. The results showed that the family Mimosaceae is the richest source of phenolics, (Acacia nilotica: 80.63 mg gallic acid equivalents, Acacia catechu 78.12 mg gallic acid equivalents, Albizia lebbeck 66.23 mg gallic acid equivalents). The highest total flavonoid content was revealed in Senna tora which belongs to the family Caesalpiniaceae. The present study also shows the ratio of flavonoids to the phenolics in each sample for their specificity. PMID:23439764

  1. Total Synthesis of (+)-Rubriflordilactone A

    PubMed Central

    Goh, Shermin S; Chaubet, Guilhem; Gockel, Birgit; Cordonnier, Marie-Caroline A; Baars, Hannah; Phillips, Andrew W; Anderson, Edward A

    2015-01-01

    Two enantioselective total syntheses of the nortriterpenoid natural product rubriflordilactone A are described, which use palladium- or cobalt-catalyzed cyclizations to form the CDE rings, and converge on a late-stage synthetic intermediate. These key processes are set up through the convergent coupling of a common diyne component with appropriate AB-ring aldehydes, a strategy that sets the stage for the synthetic exploration of other members of this family of natural products. PMID:26337920

  2. Total Pancreatectomy With Islet Autotransplantation

    PubMed Central

    Bellin, Melena D.; Gelrud, Andres; Arreaza-Rubin, Guillermo; Dunn, Ty B.; Humar, Abhinav; Morgan, Katherine A.; Naziruddin, Bashoo; Rastellini, Cristiana; Rickels, Michael R.; Schwarzenberg, Sarah J.; Andersen, Dana K.

    2015-01-01

    A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis. The session was held on July 23, 2014 and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, GI complications in this population, and unique features of children with chronic pancreatitis considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of chronic pancreatitis and total pancreatectomy outcomes and postsurgical diabetes outcomes was repeatedly emphasized. PMID:25599324

  3. Deformation of the Durom Acetabular Component and Its Impact on Tribology in a Cadaveric Model—A Simulator Study

    PubMed Central

    Gu, Yanqing; Wang, Qing; Cui, Weiding; Fan, Weimin

    2012-01-01

    Background Recent studies have shown that the acetabular component frequently becomes deformed during press-fit insertion. The aim of this study was to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the Durom large head metal-on-metal (MOM) total hips in simulators. Methods Six Durom cups impacted into reamed acetabula of fresh cadavers were used as the experimental group and another 6 size-paired intact Durom cups constituted the control group. All 12 Durom MOM total hips were put through a 3 million cycle (MC) wear test in simulators. Results The 6 cups in the experimental group were all deformed, with a mean deformation of 41.78±8.86 µm. The average volumetric wear rate in the experimental group and in the control group in the first million cycle was 6.65±0.29 mm3/MC and 0.89±0.04 mm3/MC (t?=?48.43, p?=?0.000). The ion levels of Cr and Co in the experimental group were also higher than those in the control group before 2.0 MC. However there was no difference in the ion levels between 2.0 and 3.0 MC. Conclusions This finding implies that the non-modular acetabular component of Durom total hip prosthesis is likely to become deformed during press-fit insertion, and that the deformation will result in increased volumetric wear and increased ion release. Clinical Relevance This study was determined to explore the deformation of the Durom cup after implantation and to clarify the impact of deformation on wear and ion release of the prosthesis. Deformation of the cup after implantation increases the wear of MOM bearings and the resulting ion levels. The clinical use of the Durom large head prosthesis should be with great care. PMID:23144694

  4. Total synthesis of heronapyrrole C.

    PubMed

    Ding, Xiao-Bo; Furkert, Daniel P; Capon, Robert J; Brimble, Margaret A

    2014-01-17

    A flexible total synthesis of the 2-nitropyrrole-derived marine natural product, (+)-heronapyrrole C, is reported. The approach is based on regioselective access to key building blocks containing the rare 4-substituted 2-nitropyrrole motif. Sharpless asymmetric epoxidation and dihydroxylation and a Shi epoxidation were used to introduce the five stereogenic centers of the bis-THF-diol side chain. The N-benzoyloxymethyl (Boz) protecting group was crucial for functionalization of the 2-nitropyrrole moiety and enabling final deprotection under mild conditions. PMID:24351092

  5. Total synthesis of (±)-antroquinonol d.

    PubMed

    Sulake, Rohidas S; Jiang, Yan-Feng; Lin, Hsiao-Han; Chen, Chinpiao

    2014-11-21

    Total synthesis of (±)-antroquinonol D, which is isolated from very expensive and rarely found Antrodia camphorata and which has potential anticancer properties, was achieved from 4-methoxyphenol. In addition, a Michael addition to dimethoxy cyclohexadienones was studied. The main step involved chelation and substrate-controlled diastereoselective reduction of cyclohexenone and lactonization. Lactone synthesis facilitated the diastereoselective reduction of ketone, which help control the desired stereochemistry at the crucial stereogenic center in the natural product. Other key reactions in the synthesis involved a Michael addition of dimethyl malonate on cyclohexadienone, dihydroxylation, and Wittig olefination. A sesquiterpene side chain was synthesized through coupling with geranyl phenyl sulfide and Bouveault-Blanc reduction. PMID:25375772

  6. Antarctic total ozone in 1958

    SciTech Connect

    Newman, P.A. )

    1994-04-22

    The Antarctic ozone hole results from catalytic destruction of ozone by chlorine radicals. The hole develops in August, reaches its full depth in early October, and is gone by early December of each year. Extremely low total ozone measurements were made at the Antarctic Dumont d'Urville station in 1958. These measurements were derived from spectrographic plates of the blue sky, the moon, and two stars. These Dumont plate data are inconsistent with 1958 Dobson spectrophotometer ozone measurements, inconsistent with present-day Antarctic observations, and inconsistent with meteorological and theoretical information. There is no credible evidence for an ozone hole in 1958.

  7. Total quality in health care.

    PubMed

    Brannan, K M

    1998-05-01

    Quality is at the top of American consumers' demand list, and consequently American manufacturing companies have been forced to assign priority to the development of high-quality products. To improve the quality of what they offer, many manufacturers use the management philosophy known as total quality management (TQM), and now the service sector is following in their footsteps. The health care industry is a good example of a service industry that can benefit greatly from TQM, and it is the purpose of this article to show how a health care provider can implement TQM and evaluate its effects. PMID:10178544

  8. Formal total synthesis of (+)-neopeltolide.

    PubMed

    Athe, Sudhakar; Chandrasekhar, Balla; Roy, Saumya; Pradhan, Tapan Kumar; Ghosh, Subhash

    2012-11-01

    This paper describes the formal total synthesis of (+)-neopeltolide, a cytotoxic macrolide isolated from the marine sponge Neopeltidae. The key features of the synthesis include an asymmetric Evans alkylation to fix the C9-methyl center, Jacobsen hydrolytic kinetic resolution of terminal epoxides followed by their regioselective opening to fix the stereocenters at the C11 and C13 positions, respectively, a Pd-catalyzed oxa-Michael reaction to construct the tetrahydropyran ring, and Yamaguchi macrolactonization to form the macrocyclic core of the molecule. PMID:23039136

  9. Total ozone trend over Cairo

    NASA Technical Reports Server (NTRS)

    Hassan, G. K. Y.

    1994-01-01

    A world wide interest in protecting ozone layer against manmade effects is now increasing. Assessment of the ozone depletion due to these activities depends on how successfully we can separate the natural variabilities from the data. The monthly mean values of total ozone over Cairo (30 05N) for the period 1968-1988, have been analyzed using the power spectral analysis technique. The technique used in this analysis does not depend on a pre-understanding of the natural fluctuations in the ozone data. The method depends on increasing the resolution of the spectral peaks in order to obtain the more accurate sinusoidal fluctuations with wavelength equal to or less than record length. Also it handles the possible sinusoidal fluctuations with wavelength equal to or less than record length. The results show that it is possible to detect some of the well known national fluctuations in the ozone record such as annual, semiannual, quasi-biennial and quasi-quadrennial oscillations. After separating the natural fluctuations from the ozone record, the trend analysis of total ozone over Cairo showed that a decrease of about -1.2% per decade has occurred since 1979.

  10. Solar total energy project Shenandoah

    SciTech Connect

    1980-01-10

    This document presents the description of the final design for the Solar Total Energy System (STES) to be installed at the Shenandoah, Georgia, site for utilization by the Bleyle knitwear plant. The system is a fully cascaded total energy system design featuring high temperature paraboloidal dish solar collectors with a 235 concentration ratio, a steam Rankine cycle power conversion system capable of supplying 100 to 400 kW(e) output with an intermediate process steam take-off point, and a back pressure condenser for heating and cooling. The design also includes an integrated control system employing the supervisory control concept to allow maximum experimental flexibility. The system design criteria and requirements are presented including the performance criteria and operating requirements, environmental conditions of operation; interface requirements with the Bleyle plant and the Georgia Power Company lines; maintenance, reliability, and testing requirements; health and safety requirements; and other applicable ordinances and codes. The major subsystems of the STES are described including the Solar Collection Subysystem (SCS), the Power Conversion Subsystem (PCS), the Thermal Utilization Subsystem (TUS), the Control and Instrumentation Subsystem (CAIS), and the Electrical Subsystem (ES). Each of these sections include design criteria and operational requirements specific to the subsystem, including interface requirements with the other subsystems, maintenance and reliability requirements, and testing and acceptance criteria. (WHK)

  11. Locked Intramedullary Total Wrist Arthrodesis

    PubMed Central

    Orbay, Jorge L.; Feliciano, Eric; Orbay, Carolina

    2012-01-01

    Total wrist arthrodesis is commonly performed using fixation plates, which can produce soft tissue irritation, often require removal, and limit the ability to position the hand in space. The Skeletal Dynamics IMPLATE is an intramedullary total wrist fusion device designed to provide stable fixation while avoiding the problems associated with plates. Radial and metacarpal locked intramedullary nails are inserted and joined by a connector. Desired hand placement is achieved by selecting the proper connector length and angle, then orienting it appropriately. Fusion mass compression is obtained by virtue of longitudinal threads on the radial nail that allow for length adjustment. Seven wrists in three men and four women were treated with this device and followed for a minimum of 24 weeks. In all cases, local cancellous bone graft was used and the third carpometacarpal (CMC) joint incorporated into the fusion. The median age was 49 (range, 28–71) years. Indications for fusion were two posttraumatic arthritides, three rheumatoid arthritides, one spastic deformity, and one infection. Patients were evaluated before surgery and at final follow-up using the Fernandez pain score and grip strength measurements using a hand-held dynamometer. All patients improved their grip strength and decreased their pain scores. All fusions united, and none of the patients presented dorsal soft tissue problems or required implant removal. One rheumatoid patient required secondary surgery for removal of a retained palmar osteophyte. This device delivers stable fixation, facilitates hand placement, and does not require removal. PMID:24179725

  12. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    MedlinePLUS

    ... a state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On ... I get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August ...

  13. Total quality management implementation guidelines

    SciTech Connect

    Not Available

    1993-12-01

    These Guidelines were designed by the Energy Quality Council to help managers and supervisors in the Department of Energy Complex bring Total Quality Management to their organizations. Because the Department is composed of a rich mixture of diverse organizations, each with its own distinctive culture and quality history, these Guidelines are intended to be adapted by users to meet the particular needs of their organizations. For example, for organizations that are well along on their quality journeys and may already have achieved quality results, these Guidelines will provide a consistent methodology and terminology reference to foster their alignment with the overall Energy quality initiative. For organizations that are just beginning their quality journeys, these Guidelines will serve as a startup manual on quality principles applied in the Energy context.

  14. Total synthesis of maoecrystal V.

    PubMed

    Zhang, Wei-Bin; Lin, Guang; Shao, Wen-Bin; Gong, Jian-Xian; Yang, Zhen

    2015-04-01

    Maoecrystal V (1) is a novel diterpenoid, which was originally isolated from the leaves of the Chinese medicinal herb Isodon eriocalyx in 2004 by Sun et?al.1 It has been found to be selectively cytotoxic towards HeLa cells, with an IC50 value of 20?ng?mL(-1) . Significant research efforts have been devoted to the synthesis of maoecrystal V because of its intriguing biological properties, rarity in nature, and complex structural features. Herein, we describe our recent investigations, which have culminated in the total synthesis of (±)-maoecrystal V. The current strategy involved three key steps for the successful construction of the key tetrahydrofuran oxa-bridge skeleton, including a Wessely oxidative dearomatization, a novel intramolecular Diels-Alder reaction, and a Rh(II) -catalyzed O - H insertion reaction. PMID:25504983

  15. Total quality management program planning

    SciTech Connect

    Thornton, P.T.; Spence, K.

    1994-05-01

    As government funding grows scarce, competition between the national laboratories is increasing dramatically. In this era of tougher competition, there is no for resistance to change. There must instead be a uniform commitment to improving the overall quality of our products (research and technology) and an increased focus on our customers` needs. There has been an ongoing effort to bring the principles of total quality management (TQM) to all Energy Systems employees to help them better prepare for future changes while responding to the pressures on federal budgets. The need exists for instituting a vigorous program of education and training to an understanding of the techniques needed to improve and initiate a change in organizational culture. The TQM facilitator is responsible for educating the work force on the benefits of self-managed work teams, designing a program of instruction for implementation, and thus getting TQM off the ground at the worker and first-line supervisory levels so that the benefits can flow back up. This program plan presents a conceptual model for TQM in the form of a hot air balloon. In this model, there are numerous factors which can individually and collectively impede the progress of TQM within the division and the Laboratory. When these factors are addressed and corrected, the benefits of TQM become more visible. As this occurs, it is hoped that workers and management alike will grasp the ``total quality`` concept as an acceptable agent for change and continual improvement. TQM can then rise to the occasion and take its rightful place as an integral and valid step in the Laboratory`s formula for survival.

  16. Conversion total hip arthroplasty: Primary or revision total hip arthroplasty.

    PubMed

    Schwarzkopf, Ran; Baghoolizadeh, Mahta

    2015-11-18

    Total hip arthroplasty (THA) is an increasingly common procedure among elderly individuals. Although conversion THA is currently bundled in a diagnosis related group (DRG) with primary THA, there is a lack of literature supporting this classification and it has yet to be identified whether conversion THA better resembles primary or revision THA. This editorial analyzed the intraoperative and postoperative factors and functional outcomes following conversion THA, primary THA, and revision THA to understand whether the characteristics of conversion THA resemble one procedure or the other, or are possibly somewhere in between. The analysis revealed that conversion THA requires more resources both intraoperatively and postoperatively than primary THA. Furthermore, patients undergoing conversion THA present with poorer functional outcomes in the long run. Patients undergoing conversion THA better resemble revision THA patients than primary THA patients. As such, patients undergoing conversion THA should not be likened to patients undergoing primary THA when determining risk stratification and reimbursement rates. Conversion THA procedures should be planned accordingly with proper anticipation of the greater needs both in the operating room, and for in-patient and follow-up care. We suggest that conversion THA be reclassified in the same DRG with revision THA as opposed to primary THA as a step towards better allocation of healthcare resources for conversion hip arthroplasties. PMID:26601055

  17. Conversion total hip arthroplasty: Primary or revision total hip arthroplasty

    PubMed Central

    Schwarzkopf, Ran; Baghoolizadeh, Mahta

    2015-01-01

    Total hip arthroplasty (THA) is an increasingly common procedure among elderly individuals. Although conversion THA is currently bundled in a diagnosis related group (DRG) with primary THA, there is a lack of literature supporting this classification and it has yet to be identified whether conversion THA better resembles primary or revision THA. This editorial analyzed the intraoperative and postoperative factors and functional outcomes following conversion THA, primary THA, and revision THA to understand whether the characteristics of conversion THA resemble one procedure or the other, or are possibly somewhere in between. The analysis revealed that conversion THA requires more resources both intraoperatively and postoperatively than primary THA. Furthermore, patients undergoing conversion THA present with poorer functional outcomes in the long run. Patients undergoing conversion THA better resemble revision THA patients than primary THA patients. As such, patients undergoing conversion THA should not be likened to patients undergoing primary THA when determining risk stratification and reimbursement rates. Conversion THA procedures should be planned accordingly with proper anticipation of the greater needs both in the operating room, and for in-patient and follow-up care. We suggest that conversion THA be reclassified in the same DRG with revision THA as opposed to primary THA as a step towards better allocation of healthcare resources for conversion hip arthroplasties. PMID:26601055

  18. Dynaflex prosthesis in total phalloplasty.

    PubMed

    Hage, J J

    1997-02-01

    Because of the high rate of complications and because voiding while standing is a priority for most female-to-male transsexuals, until recently, I have refrained from implantation of a rigidity prosthesis in total phalloplasty. However, promising results have been obtained with self-contained Dynaflex hydraulic penile implants. The results and complications observed in my first five cases are reported in order to help prevent failure in future cases. I advocate implantation as a secondary procedure after the neophallus has gained sensitivity. The penile prosthesis should be covered by a Dacron prosthesis to ensure optimal encapsulation and collagen ingrowth. Since the neophallus girth will not allow for two prostheses to be implanted, and because properly serviceable crus penis is lacking in female-to-male transsexuals, I further advocate fixation of the one cylinder to the pubic symphysis. For insertion, the neoscrotal approach is superior. I maintain that combination of a neourethra and a rigidity prosthesis in one neophallus remains a challenge, both to the patient and to the surgeon. PMID:9030158

  19. Total hydrocarbon analyzer evaluation study

    SciTech Connect

    Shamat, N. ); Crumpler, E. ); Roddan, A. )

    1991-10-01

    Measuring and controlling organic emissions from incineration processes has become a major environmental concern in recent years. The US Environmental Protection Agency (EPA) recently proposed a regulation for sewage sludge incinerators under section 405(d) of the Clean Water Act that will require all sludge incinerators to monitor total hydrocarbon emissions (THCs) on a continuous basis. Such a requirement would be part of National Pollutant Discharge Elimination (NPDES) permits and site-specific THC limits would be established for facilities based on a risk assessment of organic emissions. Before EPA can finalize the proposed requirement, THC monitoring must be successfully conducted in a plant environment and the system required by any final regulation must be kept in operation so that facilities can comply with their permits. The Metropolitan Waste Control Commission (MWCC) in St. Paul, Minn., and Rosemount Analytical Division in La Habre, Calif., entered into a joint agreement with EPA to demonstrate a hot' THC monitoring system to detect THCs in stack gases. The objectives of the study are to determine the feasibility of THC monitoring of sludge incinerator emissions; evaluate the long term reliability, cost of operation, and consistency of a continuous THC monitoring system in an incinerator environment; and determine the correlation of THC stack concentration to incinerator and scrubber operating conditions, carbon monoxide concentration, and specific VOC emissions.

  20. ARIZONA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  1. NEVADA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  2. CALIFORNIA CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  3. HAWAII CITIES WITH 1990 & 2000 POPULATION TOTALS

    EPA Science Inventory

    Point locations represent cities with Census 2000 population totals and 1990 Census population totals. Cities represent Census Designated Place (CDP) as classified by the US Bureau of the Census. CDP comprise densely settled concentrations of population that are identifiable by...

  4. Recommended Amounts of Total starchy vegetables

    Cancer.gov

    Recommended Amounts of Total starchy vegetables Table B6. Total starchy vegetables: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting recommendation

  5. The Total Quality Movement in Education.

    ERIC Educational Resources Information Center

    Leuenberger, John A.; Whitaker, Sheldon V., Jr.

    The total quality movement began as a result of the desire of W. Edwards Deming, an American statistician, to permit the economic system to maintain its edge in a growing global market. The 14 points Deming listed as essential to "total quality management" have recently been adapted to the field of education. The success of the total quality…

  6. Wear mechanisms and improvements of wear resistance in cobalt-chromium alloy femoral components in artificial total knee joints

    NASA Astrophysics Data System (ADS)

    Que, Like

    Wear is one of the major causes of artificial total knee arthroplasty (TKA) failure. Wear debris can cause adverse reactions to the surrounding tissue which can ultimately lead to loosening of the prosthesis. The wear behavior of UHMWPE tibial components have been studied extensively, but relatively little attention has been paid to the CoCrMo femoral component. The goal of the present study was to investigate the wear mechanisms of CoCrMo femoral components, to study the effect of CoCrMo alloy surface roughness on the wear of UHMWPE, and to determine the effect of heat treatments on the wear resistance of the CoCrMo implant alloys. The surface roughness of twenty-seven retrieved CoCrMo femoral components was analyzed. A multiple station wear testing machine and a wear fixture attached to an MTS 858 bionix system were built and used for in vitro wear studies of the CoCrMo/UHMWPE bearing couple. Solution and aging treatments were applied to the CoCrMo alloys. A white light interference surface profilometer (WLISP) and a scanning electron microscope (SEM) were used to measure the surface roughness and to study wear mechanisms of CoCrMo alloy. An optical microscope was used for alloy microstructure study. X-ray diffraction tests were performed to identify alloy phase transformation after aging. The micro-structure, hardness, and wear resistance of the alloys were studied. Surface roughness was used to quantify alloy wear, and the minimum number of surface roughness measurements required to obtain a reliable and repeatable characterization of surface roughness for a worn alloy surface was determined. The surfaces of the retrieved CoCrMo femoral components appeared to be damaged by metal particles embedded in the UHMWPE tibial component and metal-on-metal wear due to UHMWPE tibial component through-wear. Surface roughness of the femoral components was not correlated with patient age, weight, sex, or length of implantation. In vitro wear tests showed that when the CoCrMo alloy surface roughness was higher than 0.022 mum Ra (surface roughness average), UHMWPE wear increased with increasing CoCrMo alloy surface roughness. Bone and poly(methyl methacrylate) (PMMA) bone cement abrasive particles created scratches on the alloy via a ploughing mechanism, and resulted in significantly rougher surfaces than controls without particles (P < 0.01). Solution treatments at 1230sp°C and 1245sp°C reduced the hardness and wear resistance of the as-cast F75 CoCrMo alloy. Aging at 700sp°C caused recrystallization of the forged F799 alloy and improved wear resistance. Thermo-mechanical treatments have the potential to increase the lifetime of artificial joints by increasing the wear resistance of CoCrMo components.

  7. Prosthetic Design in Total Wrist Arthroplasty.

    PubMed

    Kennedy, Colin D; Huang, Jerry I

    2016-01-01

    Total wrist arthroplasty (TWA) provides a motion-preserving alternative to total wrist arthrodesis for low-demand patients with debilitating pancarpal arthritis. The earlier generation total wrist implants had high complication and failure rates. Advances in prosthetic design have contributed to improved clinical outcomes and implant survivorship. The current fourth-generation implants allow for expansion of indications for TWA. Careful patient selection remains critical; patients with high-demand lifestyles and poor bone stock may not be candidates. Long-term studies on implant survival and patient outcomes are critical for the current generation total wrist implants in assessing their long-term value compared with total wrist arthrodesis. PMID:26614934

  8. Trends in total column ozone measurements

    NASA Technical Reports Server (NTRS)

    Rowland, F. S.; Angell, J.; Attmannspacher, W.; Bloomfield, P.; Bojkov, R. D.; Harris, N.; Komhyr, W.; Mcfarland, M.; Mcpeters, R.; Stolarski, R. S.

    1989-01-01

    It is important to ensure the best available data are used in any determination of possible trends in total ozone in order to have the most accurate estimates of any trends and the associated uncertainties. Accordingly, the existing total ozone records were examined in considerable detail. Once the best data set has been produced, the statistical analysis must examine the data for any effects that might indicate changes in the behavior of global total ozone. The changes at any individual measuring station could be local in nature, and herein, particular attention was paid to the seasonal and latitudinal variations of total ozone, because two dimensional photochemical models indicate that any changes in total ozone would be most pronounced at high latitudes during the winter months. The conclusions derived from this detailed examination of available total ozone can be split into two categories, one concerning the quality and the other the statistical analysis of the total ozone record.

  9. Total solar eclipse of 3 November 1994

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1993-01-01

    A total eclipse of the Sun will be visible from the southern half of the Western Hemisphere on 3 November 1994. The path of the Moon's shadow passes through Peru, Chile, Bolivia, Paraguay, and Brazil. Detailed predictions for this event are presented and include tables of geographic coordinates of the path of totality, local circumstances for hundreds of cities, maps of the path of total and partial eclipse, weather prospects, and the lunar limb profile.

  10. Total quality management in American industry.

    PubMed

    Widtfeldt, A K; Widtfeldt, J R

    1992-07-01

    The definition of total quality management is conformance to customer requirements and specifications, fitness for use, buyer satisfaction, and value at an affordable price. The three individuals who have developed the total quality management concepts in the United States are W.E. Deming, J.M. Juran, and Philip Crosby. The universal principles of total quality management are (a) a customer focus, (b) management commitment, (c) training, (d) process capability and control, and (e) measurement through quality improvement tools. Results from the National Demonstration Project on Quality Improvement in Health Care showed the principles of total quality management could be applied to healthcare. PMID:1616505

  11. Computation of orbits using total energy

    NASA Technical Reports Server (NTRS)

    Bond, Victor R.; Mulcihy, David D.

    1988-01-01

    The computation of orbits can be done more efficiently by the use of any of several new formulations of the perturbed two body problem which consider the total energy of the orbital system as one of the dependent variables. The total energy is the osculating two body energy plus the potential energy due to perturbing masses. The use of the total energy as the dependent variable instead of the two body energy is a relatively new idea. The advantage of using total energy arises from the fact that the more perturbing potential energy that is accounted for in the total energy variable, the more nearly constant is the total energy. In fact, except for dissipative forces such as drag, the only reason for the total energy not being constant is the rotation or revolution of the perturbing mass. This near constancy of the total energy has the effect of inhibiting error growth during numerical solution. This paper will present the results of an application of total energy formulation to the problem of the precise computation of orbits.

  12. Total Quality Management in Education. Second Edition.

    ERIC Educational Resources Information Center

    Sallis, Edward

    Quality is at the top of most agendas, and improving quality is probably the most important task facing any institution. In addition, quality is difficult to define or measure. This book, the second edition of "Total Quality Management in Education," introduces the key concepts of Total Quality Management (TQM) and demonstrates how they can be put…

  13. Multicomponent Reactions in Total Synthesis Kevin Allan

    E-print Network

    Stoltz, Brian M.

    Multicomponent Reactions in Total Synthesis Kevin Allan Stoltz Group Literature Meeting Monday Ph Ph PhO N N H Ph Ph Ph Ph N HN Ph Ph 3-CR 4-CR 5-CR #12;Multicomponent Reactions in Total Synthesis / Petasis (Boronic Acid Mannich) Reaction · Biginelli Dihydropyrimidinone Synthesis · Passerini Reaction

  14. EVALUATION OF TOTAL ORGANIC EMISSIONS ANALYSIS METHODS

    EPA Science Inventory

    The rationale and supporting experimental data for revising EPA's 1996 "Guidance for Total Organics" are summarized in this document. It reports the results of reseach and investigation of improvements to the Total Organic Emissions (TOE) guidance used by EPA to measure recovera...

  15. Custom total occlusal convergence angle sticker fabrication.

    PubMed

    Cho, Seok-Hwan; Nagy, William W

    2015-09-01

    This article describes a method of fabricating a custom total occlusal convergence angle sticker with photo editing software and label stickers. The custom total occlusal convergence angle sticker can help clinicians achieve an accurate degree of taper during axial wall reduction of tooth preparation. PMID:26013073

  16. Seasonal persistence of midlatitude total ozone anomalies

    E-print Network

    Wirosoetisno, Djoko

    Seasonal persistence of midlatitude total ozone anomalies Article Published Version Fioletov, V. E. and Shepherd, T. G. (2003) Seasonal persistence of midlatitude total ozone anomalies. Geophysical Research.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading #12;Reading's research outputs online #12;Seasonal

  17. Total natural radioactivity, Tuscany, Italy Ivan Callegaria

    E-print Network

    Roma "La Sapienza", Università di

    SCIENCE Total natural radioactivity, Tuscany, Italy Ivan Callegaria , Gian Pietro Bezzonb , Carlo radioactive content of rocks of the Tuscany Region (Italy): this permitted the first total natural radioactivity map of the region. The sampling was planned using the geological map of Tuscany at scale 1

  18. TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION

    E-print Network

    Skogestad, Sigurd

    TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION BERND WITTGENS, RAJAB LITTO, EVA S RENSEN a generalization of previously proposed batch distillation schemes. A simple feedback control strategy for total re verify the simulations. INTRODUCTION Although batch distillation generally is less energy e cient than

  19. DENSITY ESTIMATION BY TOTAL VARIATION REGULARIZATION

    E-print Network

    Mizera, Ivan

    DENSITY ESTIMATION BY TOTAL VARIATION REGULARIZATION ROGER KOENKER AND IVAN MIZERA Abstract. L1 based on total variation of the estimated density, its square root, and its logarithm ­ and their derivatives ­ in the context of univariate and bivariate density estimation, and compare the results to some

  20. 'Total disability' and the wrongness of killing.

    PubMed

    Omelianchuk, Adam

    2015-08-01

    Walter Sinnott-Armstrong and Franklin G Miller recently argued that the wrongness of killing is best explained by the harm that comes to the victim, and that 'total disability' best explains the nature of this harm. Hence, killing patients who are already totally disabled is not wrong. I maintain that their notion of total disability is ambiguous and that they beg the question with respect to whether there are abilities left over that remain relevant for the goods of personhood and human worth. If these goods remain, then something more is lost in death than in 'total disability,' and their explanation of what makes killing wrong comes up short. But if total disability is equivalent with death, then their argument is an interesting one. PMID:25323315

  1. Ultra-low wear rates for rigid-on-rigid bearings in total hip replacements.

    PubMed

    Clarke, I C; Good, V; Williams, P; Schroeder, D; Anissian, L; Stark, A; Oonishi, H; Schuldies, J; Gustafson, G

    2000-01-01

    With the increased clinical interest in metal-on-metal and ceramic-on-ceramic total-hip replacements (THRs), the objective of this hip simulator study was to identify the relative wear ranking of three bearing systems, namely CoCr-polyethylene (M-PE), CoCr-CoCr (M-M) and ceramic-on-ceramic (C-C). Volumetric wear rates were used as the method of comparison. The seven THR groupings included one M-PE study, two M-M studies and four C-C studies. Special emphasis was given to defining the 'run-in' phase of accelerated wear that rigid-on-rigid bearings generally exhibit. The hypothesis was that characterization of the run-in and steady state wear phases would clarify not only the tribological performance in vitro but also help correlate these in vitro wear rates with the 'average' wear rates measured on retrieved implants. The implant systems were studied on multichannel hip simulators using the Paul gait cycle and bovine serum as the lubricant. With 28 mm CoCr heads, the PE (2.5 Mrad/N2) wear rates averaged 13 mm3/10(6) cycles duration. This was considered a low value compared with the clinical model of 74 mm3/year (for 28 mm heads). Our later studies established that this low laboratory value was a consequence of the serum parameters then in use. The mating CoCr heads (with PE cups) wore at the steady state rate of 0.028 mm3/10(6) cycles. The concurrently run Metasul M-M THRs wore at the steady state rate of 0.119 mm3/10(6) cycles with high-protein serum. In the second Metasul M-M study with low-protein serum, the THR run-in rate was 2.681 mm3/10(6) cycles and steady state was 0.977 mm3/10(6) cycles. At 10 years, these data would predict a 70-fold reduction in M-M wear debris compared with the clinical PE wear model. All M-M implants exhibited biphasic wear trends, with the transition point at 0.5 x 10(6) cycles between run-in and steady state phases, the latter averaging a 3-fold decrease in wear rate. White surface coatings on implants (coming from the serum solution) were a confounding factor but did not obscure the two orders of magnitude wear performance improvement for CoCr over PE cups. The liners in the alumina head-alumina cup combination wore at the steady state rate of 0.004 mm3/10(6) cycles over 14 x 10(6) cycles duration (high-protein serum). The zirconia head-alumina cup THR combination wore at 0.174 and 0.014 mm3/10(6) cycles for run-in and steady state rates respectively (low-protein serum). The zirconia head and cup THR combination wore slightly higher initially with 0.342 and 0.013 mm3/10(6) cycles for run-in and steady state rates respectively. Other wear studies have generally predicted catastrophic wear for such zirconia-ceramic combinations. It was noted that the zirconia wear trends were frequently masked by the effects of tenacious white surface coatings. It was possible that these coatings protected the zirconia surfaces somewhat in this simulator study. The experimental ceramic Crystaloy THR had the highest ceramic run-in wear at 0.681 mm3/10(6) cycles and typical 0.016 mm3/10(6) cycles for steady state. Since these implants represented the first Crystaloy THR sets made, it was likely that the surface conditions of this high-strength ceramic could be improved in the future. Overall, the ceramic THRs demonstrated three orders of magnitude wear performance improvement over PE cups. With zirconia implants, while the cup wear was sometimes measurable, head wear was seldom discernible. Therefore, we have to be cautious in interpreting such zirconia wear data. Identifying the run-in and steady state wear rates was a valuable step in processing the ceramic wear data and assessing its reliability. Thus, the M-M and C-C THRs have demonstrated two to three orders of reduction in volumetric wear in the laboratory compared with the PE wear standard, which helps to explain the excellent wear performance and minimal osteolysis seen with such implants at retrieval operations. PMID:10997055

  2. The total bondage number of grid graphs

    E-print Network

    Hu, Fu-Tao; Xu, Jun-Ming

    2011-01-01

    The total domination number of a graph $G$ without isolated vertices is the minimum number of vertices that dominate all vertices in $G$. The total bondage number $b_t(G)$ of $G$ is the minimum number of edges whose removal enlarges the total domination number. This paper considers grid graphs. An $(n,m)$-grid graph $G_{n,m}$ is defined as the cartesian product of two paths $P_n$ and $P_m$. This paper determines the exact values of $b_t(G_{n,2})$ and $b_t(G_{n,3})$, and establishes some upper bounds of $b_t(G_{n,4})$.

  3. Total to withdraw from Qatar methanol - MTBE?

    SciTech Connect

    1996-05-01

    Total is rumored to be withdrawing from the $700-million methanol and methyl tert-butyl ether (MTBE) Qatar Fuel Additives Co., (Qafac) project. The French company has a 12.5% stake in the project. Similar equity is held by three other foreign investors: Canada`s International Octane, Taiwan`s Chinese Petroleum Corp., and Lee Change Yung Chemical Industrial Corp. Total is said to want Qafac to concentrate on methanol only. The project involves plant unit sizes of 610,000 m.t./year of MTBE and 825,000 m.t./year of methanol. Total declines to comment.

  4. Total solar eclipse of 1995 October 24

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1994-01-01

    A total eclipse of the sun will be visible from Asia and the Pacific Ocean on 24 Oct. 1995. The path of the moon's shadow begins in the Middle East and sweeps across India, Southeast Asia, and the waters of the Indonesian archipelago before ending at sunset in the Pacific. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality.

  5. Total body calcium analysis. [neutron irradiation

    NASA Technical Reports Server (NTRS)

    Lewellen, T. K.; Nelp, W. B.

    1974-01-01

    A technique to quantitate total body calcium in humans is developed. Total body neutron irradiation is utilized to produce argon 37. The radio argon, which diffuses into the blood stream and is excreted through the lungs, is recovered from the exhaled breath and counted inside a proportional detector. Emphasis is placed on: (1) measurement of the rate of excretion of radio argon following total body neutron irradiation; (2) the development of the radio argon collection, purification, and counting systems; and (3) development of a patient irradiation facility using a 14 MeV neutron generator. Results and applications are discussed in detail.

  6. Total synthesis of cyclotryptamine and diketopiperazine alkaloids

    E-print Network

    Kim, Justin, Ph. D. Massachusetts Institute of Technology

    2013-01-01

    I. Total Synthesis of the (+)-12,12'-Dideoxyverticillin A The fungal metabolite (+)-12,12'-dideoxyverticillin A, a cytotoxic alkaloid isolated from a marine Penicillium sp., belongs to a fascinating family of densely ...

  7. UNDERSTANDING CHILDREN'S TOTAL DIETARY EXPOSURE TO PESTICIDES

    EPA Science Inventory

    Recent residential monitoring studies have demonstrated that significant portion of total exposure of infants and children to environmental contaminants can result from contamination of food in the home. Children's foods become contaminated through handling and contact with surf...

  8. Total synthesis and study of myrmicarin alkaloids

    E-print Network

    Ondrus, Alison Evelynn, 1981-

    2009-01-01

    I. Enantioselective Total Synthesis of Tricyclic Myrmicarin Alkaloids An enantioselective gram-scale synthesis of a key dihydroindolizine intermediate for the preparation of myrmicarin alkaloids is described. Key transformations ...

  9. ANTHROPOLOGY MAJOR REQUIREMENTS Total Credits: 31

    E-print Network

    Suri, Manil

    ANTHROPOLOGY MAJOR REQUIREMENTS Total Credits: 31 This must include at least 16 ANTH credits taken in Anthropology; Recommended: completion of ANTH 400 with a C or better Elective requirements: · 6 courses (18

  10. Patient Matched Instruments and Total Knee System

    MedlinePLUS Videos and Cool Tools

    Smith & Nephew Technologies: VISIONAIRE™ Patient Matched Instruments and LEGION™ Total Knee System You must have Javascript enabled in your web browser. View Program Transcript Click Here to view the OR-Live, Inc. Privacy Policy and Legal ...

  11. Total Enterprise Simulation Performance and Participant Learning.

    ERIC Educational Resources Information Center

    Washbush, John B.; Gosen, Jerry

    1998-01-01

    A series of evaluations of total enterprise simulation in business capstone courses found no direct positive relationship between performance in the management game and learning outcomes. Ability to play the game did not correlate to learning. (SK)

  12. Total Solar Eclipse--A Caribbean Adventure.

    ERIC Educational Resources Information Center

    Green, Steven; Tunstall, Louisa; Tunstall, Neil

    1999-01-01

    Describes the experiences of two high school students who traveled to the Caribbean island of Curacao to view a total solar eclipse and prepare methods for teaching classmates about the eclipse the following school year. (Author/WRM)

  13. Total lymphoid irradiation in alloimmunity and autoimmunity

    SciTech Connect

    Strober, S.

    1987-12-01

    Total lymphoid irradiation has been used as an immunosuppressive regimen in autoimmune disease and organ transplantation. The rationale for its use originated from studies of patients with Hodgkin disease, in whom this radiotherapy regimen was noted to induce profound and long-lasting immune suppression and yet was well tolerated, with few long-term side effects. Total lymphoid irradiation is a unique immunosuppressive regimen that produces a selective (and long-lasting) reduction in the number and function of helper T cells and certain subsets of B cells. Conventional immunosuppressive drugs show little selectivity, and their effects are short-lived. The most important aspect of total lymphoid irradiation is the potential for achieving transplantation tolerance and permanent remissions in autoimmune disease in laboratory animals. Attempts are being made to achieve similar goals in humans given total lymphoid irradiation, so that immunosuppressive drugs can be ultimately withdrawn from transplant recipients and patients with lupus nephritis. 28 references.

  14. Enantioselective Total Synthesis of (?)-Acylfulvene and (?)- Irofulven

    E-print Network

    Movassaghi, Mohammad

    We report our full account of the enantioselective total synthesis of (?)-acylfulvene (1) and (?)-irofulven (2), which features metathesis reactions for the rapid assembly of the molecular framework of these antitumor ...

  15. TECAB - Totally Endoscopic Coronary Artery Bypass

    MedlinePLUS Videos and Cool Tools

    ... completely endoscopic coronary artery bypass grafting procedure using robotics. We call this operation a “TECAB,” “Totally Endoscopic ... scrub nurse, also a lot of experience with robotics now. And Dr. Atiq Rahman, fellow here for ...

  16. TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION

    E-print Network

    Skogestad, Sigurd

    TOTAL REFLUX OPERATION OF MULTIVESSEL BATCH DISTILLATION BERND WITTGENS, RAJAB LITTO, EVA SØRENSEN in this paper provides a generalization of previously proposed batch distillation schemes. A simple feedback been built and the experiments verify the simulations. INTRODUCTION Although batch distillation

  17. Effects of xenobiotics on total antioxidant capacity.

    PubMed

    Ferrari, Carlos Kusano Bucalen

    2012-09-01

    The objective of this article was to review the effects of xenobiotics on total antioxidant capacity (TAC). Measurement of TAC is appropriate for evaluation of the total antioxidant defenses of blood, cells, and different kinds of tissues and organs. TAC is reduced by alcoholism, smoking, and exposure to radiation, herbicides, carbon monoxide, carbon tetrachloride, lead, arsenic, mercury, cadmium, aluminum, and other toxic elements. The test is also an important tool in evaluating environmental and occupational exposure. PMID:23554550

  18. Total antioxidant capacity of the Korean diet

    PubMed Central

    Han, Jeong-Hwa; Lee, Hye-Jin; Cho, Mi Ran; Chang, Namsoo; Kim, Yuri; Oh, Se-Young

    2014-01-01

    BACKGROUND/OBJECTIVES The objective of this study was to measure and/or estimate the total antioxidant capacity of the Korean diet. MATERIALS/METHODS Eighty-one plant foods that were expected to exhibit rather high antioxidant activities were selected from the Korean diet using the Fifth Korean National Health and Nutrition Survey (KNHANES V). These foods were categorized into 11 food groups: cereals, potatoes, legumes, nuts, vegetables, kimchies, mushrooms, fruits, fruit juices, sea weeds, and oils. The foods were mixed in the proportions specified in traditional Korean recipes and analyzed. The measured indicators for antioxidant capacities were total phenolics, 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC). RESULTS Total phenolics were high in the fruit juices, nuts, vegetables, and fruits; and the average DPPH, ORAC, and TEAC values were high in the vegetables, fruits, fruit juices, and nuts. The correlation coefficient between the content of total phenolics of each food and the in vitro antioxidant capacity was relatively high at 0.851. The intake of total phenolics per capita per day in the Republic of Korea was estimated to be 127 mg. The total dietary antioxidant capacity (TDAC) values, which were obtained from the total antioxidant capacity of each food, taking into account the intake of each food, were 20,763, 54,335, and 876.4 µmol of Trolox equivalents using the DPPH, ORAC, and TEAC methods, respectively. The food group that contributed the most to the Korean TDAC was cereals at 39.7%, followed by fruits and vegetables at 27.8% and 13.9%, respectively. The contribution of legumes, nuts, fruit juices, and mushrooms was quite minimal at less than 2% each. CONCLUSIONS The content of total phenolics and the antioxidant capacity of the Korean diet are significantly correlated and the high contributing food groups are cereals, fruits, and vegetables. PMID:24741403

  19. Total Acquired Vulval Synechia: An Unusual Presentation

    PubMed Central

    2015-01-01

    An unusual case of Acquired Total vulval synechia due to vulvar Lichen planus is reported in an 18-year-old girl, which is an extremely rare condition. It has a potential for producing extensive scarring and narrowing of introitus resulting in dyspareunia and rarely carcinoma of vulva. Successful surgical management of total vulvar synechiae in patient suffering from Lichen Planus is being reported. PMID:26023590

  20. Total synthesis of leucosceptroids A and B.

    PubMed

    Guo, Sheng; Liu, Jie; Ma, Dawei

    2015-01-19

    Leucosceptroids?A and B are sesterterpenoids with potent antifeedant and antifungal activities. A more efficient gram-scale total synthesis of leucosceptroid?B and the first total synthesis of leucosceptroid?A are presented. The key transformations include an aldol reaction between a substituted dihydrofuranone and an (S)-citronellal-derived aldehyde, a SmI2-mediated intramolecular ketyl-olefin radical cyclization, and final-stage alcohol oxidation. PMID:25470240

  1. Effects of xenobiotics on total antioxidant capacity

    PubMed Central

    2012-01-01

    The objective of this article was to review the effects of xenobiotics on total antioxidant capacity (TAC). Measurement of TAC is appropriate for evaluation of the total antioxidant defenses of blood, cells, and different kinds of tissues and organs. TAC is reduced by alcoholism, smoking, and exposure to radiation, herbicides, carbon monoxide, carbon tetrachloride, lead, arsenic, mercury, cadmium, aluminum, and other toxic elements. The test is also an important tool in evaluating environmental and occupational exposure. PMID:23554550

  2. Total lymphoid irradiation and discordant cardiac xenografts

    SciTech Connect

    Kaplan, E.; Dresdale, A.R.; Diehl, J.T.; Katzen, N.A.; Aronovitz, M.J.; Konstam, M.A.; Payne, D.D.; Cleveland, R.J. )

    1990-01-01

    Total lymphoid irradiation can prolong concordant cardiac xenografts. The effects of total lymphoid irradiation in a discordant xenograft model (guinea pig to rat) were studied with and without adjuvant pharmacologic immunosuppression. Inbred Lewis rats were randomly allocated to one of four groups. Group 1 (n = 6) served as a control group and rats received no immunosuppression. Group 2 (n = 5) received triple-drug therapy that consisted of intraperitoneal azathioprine (2 mg/kg), cyclosporine (20 mg/kg), and methylprednisolone (1 mg/kg) for 1 week before transplantation. Group 3 animals (n = 5) received 15 Gy of total lymphoid irradiation in 12 divided doses over a 3-week period. Group 4 (n = 6) received both triple-drug therapy and total lymphoid irradiation as described for groups 2 and 3. Complement-dependent cytotoxicity assay was performed to determine if a correlation between complement-dependent cytotoxicity and rejection-free interval existed. Rejection was defined as cessation of graft pulsation and was confirmed by histologic test results. Only groups 1 and 2 showed a difference in survival (group 1, 6.9 +/- 1.0 minutes; group 2, 14.2 +/- 2.7 minutes, p = 0.02). Although total lymphoid irradiation did decrease complement-dependent cytotoxicity, linear regression revealed no correlation between complement-dependent cytotoxicity and graft survival (coefficient of correlation, 0.30). Unlike concordant cardiac xenografts, total lymphoid irradiation with or without triple-drug therapy does not prolong graft survival.

  3. Risk assessment tools used to predict outcomes of total hip and total knee arthroplasty.

    PubMed

    Konopka, Joseph F; Hansen, Viktor J; Rubash, Harry E; Freiberg, Andrew A

    2015-07-01

    This article reviews recently proposed clinical tools for predicting risks and outcomes in total hip arthroplasty and total knee arthroplasty patients. Additionally, we share the Massachusetts General Hospital experience with using the Risk Assessment and Prediction Tool to predict the need for an extended care facility after total joint arthroplasty. PMID:26043049

  4. 38 CFR 3.340 - Total and permanent total ratings and unemployability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Total and permanent total ratings and unemployability. 3.340 Section 3.340 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... are met. (3) Ratings of total disability on history. In the case of disabilities which have...

  5. A high performance totally ordered multicast protocol

    NASA Technical Reports Server (NTRS)

    Montgomery, Todd; Whetten, Brian; Kaplan, Simon

    1995-01-01

    This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears un undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered delivery, to K-resilient, majority resilient, and totally resilient atomic delivery. These QoS guarantees are selectable on a per packet basis. RMP provides many communication options, including virtual synchrony, a publisher/subscriber model of message delivery, an implicit naming service, mutually exclusive handlers for messages, and mutually exclusive locks. It has commonly been held that a large performance penalty must be paid in order to implement total ordering -- RMP discounts this. On SparcStation 10's on a 1250 KB/sec Ethernet, RMP provides totally ordered packet delivery to one destination at 842 KB/sec throughput and with 3.1 ms packet latency. The performance stays roughly constant independent of the number of destinations. For two or more destinations on a LAN, RMP provides higher throughput than any protocol that does not use multicast or broadcast.

  6. COMPONENT VERSION IN MODULAR TOTAL HIP REVISION

    PubMed Central

    Kopec, Michael A.; Pemberton, Aaron; Milbrandt, Joseph C.; Allan, Gordon

    2009-01-01

    Morphologic changes of the proximal femur make revision total hip arthroplasty challenging. Metaphyseal retroversion and diaphyseal varus are common in this scenario. Twenty-one total hip revisions using a modular femoral prosthesis were examined by obtaining three radiographs (A/P, surgical lateral, and true lateral of the femur) to assemble CAD models for determining the range of modular component positioning. An average of femoral neck anteversion was observed. Seventeen of 21 cases (81%) had retroverted metaphyseal segments (?23.2°+/?17.4°) and/or varus stems (?32.1°+/?13.0°). Neck anteversion averaged 21.4°(+/?10.0°). One of 21 cases (5%) resulted in component orientation similar to a non-modular prosthesis. Modular components provide options to accommodate proximal femoral remodeling not afforded by monobloc stems in total hip revision surgery. PMID:19742077

  7. The adjacent vertex distinguishing total chromatic number

    E-print Network

    Johannson, Karen

    2010-01-01

    A well-studied concept is that of the total chromatic number. A proper total colouring of a graph is a colouring of both vertices and edges so that every pair of adjacent vertices receive different colours, every pair of adjacent edges receive different colours and every vertex and incident edge receive different colours. This paper considers a strengthening of this condition and examines the minimum number of colours required for a total colouring with the additional property that for any adjacent vertices $u$ and $v$, the sets of colours incident to $u$ is different from the set of colours incident to $v$. It is shown that there is a constant $C$ so that for any graph $G$, there exists such a colouring using at most $\\Delta(G) + C$ colours.

  8. Uncommon Indications for Reverse Total Shoulder Arthroplasty

    PubMed Central

    Hyun, Yoon Suk; Huri, Gazi; Garbis, Nickolas G.

    2013-01-01

    Total shoulder arthroplasty and shoulder hemiarthroplasty have been the traditional method for treating a variety of shoulder conditions, including arthritis, cuff tear arthropathy, and some fracture types. However, these procedures did not provide consistently good results for patients with torn rotator cuffs. The development of the reverse prosthesis by Grammont in the late 20th century revolutionized the treatment of the rotator-cuff-deficient shoulder with arthritis. The main indication for the reverse prosthesis remains the patient with cuff tear arthropathy who has pain and loss of motion. Because the reverse total shoulder arthroplasty produced such good results in these patients, the indications for the reverse prosthesis have expanded to include other shoulder conditions that have previously been difficult to treat successfully and predictably. This review discusses and critically reviews these newer indications for the reverse total shoulder arthroplasty. PMID:24340143

  9. The US 2017 Total Solar Eclipse Workshops

    NASA Astrophysics Data System (ADS)

    Arndt, Martina B.; Habbal, S. R.; Wind Sherpas, Solar

    2012-05-01

    In preparation for the Total Solar Eclipse that will span across the United States in 2017, multiple eclipse workshops are being planned to bring together professional and amateur researchers, educators, and imagers. Our ultimate goal with these workshops is to maximize the amount and quality of data we can collect during the eclipse as well as to leverage this exciting event to educate and inspire people of all ages. Part of the workshops will be dedicated to discussing the science that can be learned from observing total solar eclipses, and part of the workshops will be dedicated to strategizing about how to mobilize and prepare communities in the path of totality. In this poster, we will share our preliminary results from the inaugural workshop in Maryland, April 2012.

  10. Total artificial hearts: past, present, and future.

    PubMed

    Cohn, William E; Timms, Daniel L; Frazier, O H

    2015-10-01

    A practical artificial heart has been sought for >50 years. An increasing number of people succumb to heart disease each year, but the number of hearts available for transplantation remains small. Early total artificial hearts mimicked the pumping action of the native heart. These positive-displacement pumps could provide adequate haemodynamic support and maintain the human circulation for short periods, but large size and limited durability adversely affected recipients' quality of life. Subsequent research into left ventricular assist devices led to the use of continuous-flow blood pumps with rotating impellers. Researchers have attempted to integrate this technology into modern total artificial hearts with moderate clinical success. The importance of pulsatile circulation remains unclear. Future research is, therefore, needed into positive-displacement and rotary total artificial hearts. PMID:26031698

  11. Total Solar Eclipse of 1999 August 11

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1997-01-01

    On 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon's umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India, where it ends at sunset in the Bay of Bengal. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, all of Europe, northern Africa, and the western half of Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 1400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  12. Total Solar Eclipse of 2008 August 01

    NASA Technical Reports Server (NTRS)

    Espenak, F.; Anderson, J.

    2007-01-01

    On 2008 August 01, a total eclipse of the Sun is visible from within a narrow corridor that traverses half the Earth. The path of the Moon's umbral shadow begins in northern Canada and extends across Greenland, the Arctic, central Russia, Mongolia, and China. A partial eclipse is seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, most of Europe and Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 308 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  13. Total Solar Eclipse of 2001 June 21

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1999-01-01

    On 2001 June 21, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Southern Hemisphere. The path of the Moon's umbral shadow begins in the South Atlantic, crosses southern Africa and Madagascar, and ends at sunset in the Indian Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern South America and the southern two thirds of Africa. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  14. Total Solar Eclipse of 1997 March 9

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    1995-01-01

    A total eclipse of the Sun will be visible from Asia and the Pacific Ocean on 1997 March 9. The path of the Moon's umbral shadow begins in eastern Kazakhstan and travels through Mongolia and eastern Siberia, where it swings northward to end at sunset in the Arctic Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern Asia, the northern Pacific, and the northwest corner of North America. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 280 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  15. Total Solar Eclipse of 2002 December 04

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, Jay

    2001-01-01

    On 2002 December 04, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Southern Hemisphere. The path of the Moon's umbral shadow begins in the South Atlantic, crosses southern Africa and the Indian Ocean, and ends at sunset in southern Australia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the southern two thirds of Africa, Antarctica, Indian Ocean and Australia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 400 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  16. Total Solar Eclipse of 2006 March 29

    NASA Technical Reports Server (NTRS)

    Espenak, F.; Anderson, J.

    2004-01-01

    On 2006 March 29, a total eclipse of the Sun will be visible from within a narrow corridor which traverses half the Earth. The path of the Moon's umbral shadow begins in Brazil and extends across the Atlantic, northern Africa, and central Asia where it ends at sunset in western Mongolia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the northern two thirds of Africa, Europe, and central Asia.Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  17. An Operational Perspective of Total Lightning Information

    NASA Technical Reports Server (NTRS)

    Nadler, David J.; Darden, Christopher B.; Stano, Geoffrey; Buechler, Dennis E.

    2009-01-01

    The close and productive collaborations between the NWS Warning and Forecast Office, the Short Term Prediction and Research Transition Center at NASA Marshall Space Flight Center and the University of Alabama in Huntsville have provided a unique opportunity for science sharing and technology transfer. One significant technology transfer that has provided immediate benefits to NWS forecast and warning operations is the use of data from the North Alabama Lightning Mapping Array. This network consists of ten VHF receivers deployed across northern Alabama and a base station located at the National Space Science and Technology Center. Preliminary investigations done at WFO Huntsville, along with other similar total lightning networks across the country, have shown distinct correlations between the time rate-of-change of total lightning and trends in intensity/severity of the parent convective cell. Since May 2003 when WFO HUN began receiving these data - in conjunction with other more traditional remotely sensed data (radar, satellite, and surface observations) -- have improved the situational awareness of the WFO staff. The use of total lightning information, either from current ground based systems or future space borne instrumentation, may substantially contribute to the NWS mission, by enhancing severe weather warning and decision-making processes. Operational use of the data has been maximized at WFO Huntsville through a process that includes forecaster training, product implementation, and post event analysis and assessments. Since receiving these data, over 50 surveys have been completed highlighting the use of total lightning information during significant events across the Tennessee Valley. In addition, around 150 specific cases of interest have been archived for collaborative post storm analysis. From these datasets, detailed trending information from radar and total lightning can be compared to corresponding damage reports. This presentation will emphasize the effective use of total lightning information in warning decision making along with best practices for implementation of new technologies into operations.

  18. Total Knee Arthroplasty Considerations in Rheumatoid Arthritis

    PubMed Central

    Danoff, Jonathan R.; Geller, Jeffrey A.

    2013-01-01

    The definitive treatment for advanced joint destruction in the late stages of rheumatoid arthritis can be successfully treated with total joint arthroplasty. Total knee arthroplasty has been shown to be a well-proven modality that can provide pain relief and restoration of mobility for those with debilitating knee arthritis. It is important for rheumatologists and orthopedic surgeons alike to share an understanding of the special considerations that must be addressed in this unique population of patients to ensure success in the immediate perioperative and postoperative periods including specific modalities to maximize success. PMID:24151549

  19. Measuring Total and Germinable Spore Populations

    NASA Technical Reports Server (NTRS)

    Noell, A.C.; Yung, P.T.; Yang, W.; Lee, C.; Ponce, A.

    2011-01-01

    It has been shown that bacterial endospores can be enumerated using a microscopy based assay that images the luminescent halos from terbium ions bound to dipicolinic acid, a spore specific chemical marker released upon spore germination. Further development of the instrument has simplified it towards automation while at the same time improving image quality. Enumeration of total spore populations has also been developed allowing measurement of the percentage of viable spores in any population by comparing the germinable/culturable spores to the total. Percentage viability will allow a more quantitative comparison of the ability of spores to survive across a wide range of extreme environments.

  20. [Rehabilitation following total hip and knee replacement].

    PubMed

    Heisel, J

    2008-12-01

    For the more than 330.000 patients/year with primary total hip replacement (THR) or total knee replacement (TKR) in Germany alone, postoperative rehabilitation either on an inpatient or follow-up outpatient basis is largely accepted as standard, despite limited financial resources. The present article discusses the necessary diagnostic and therapeutic measures in the immediate postoperative phase in the hospital or clinic, the so-called post-inpatient phase in a rehabilitation clinic or centre, as well as the subsequent outpatient phase with consistent and regular specialist follow-up. PMID:19089406

  1. Nucleon-Nucleon Total Cross Section

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2008-01-01

    The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

  2. Recurrent hemarthrosis after total knee arthroplasty

    PubMed Central

    Rukavina, Alexander; Schneider, Philipp; Kuster, Markus S.

    2010-01-01

    This report describes a case of spontaneous recurrent hemarthrosis of the knee that presented 4 weeks after total knee arthroplasty. Femoral arteriography showed a false aneurysm of a branch of the inferior lateral geniculate artery. Therapeutic embolization of the arterial branch was performed using three platinum coils with good clinical result and good knee joint function. Hemarthrosis has not recurred since embolization. PMID:20076944

  3. The Leica TCRA1105 Reflectorless Total Station

    SciTech Connect

    Gaudreault, F.

    2005-09-06

    This poster provides an overview of SLAC's TCRA1105 reflectorless total station for the Alignment Engineering Group. This instrument has shown itself to be very useful for planning new construction and providing quick measurements to difficult to reach or inaccessible surfaces.

  4. TOTAL ENERGY CONSUMPTION FOR MUNICIPAL WASTEWATER TREATMENT

    EPA Science Inventory

    Quantities of all forms of energy consumed for collection and treatment of municipal wastewater are estimated. Heat energy is equated to electrical energy by a conversion factor of 10,500 Btu/kwh. Total energy consumption, expressed as kwh/mg of wastewater treated, ranges from 23...

  5. Implications of Total Quality Management in Education.

    ERIC Educational Resources Information Center

    Wiedmer, Terry L.; Harris, Vicki L.

    1997-01-01

    Total Quality Management in Education is a systems model that involves internal and external stakeholders in developing practices, establishing partnership teams, enhancing individual growth, and increasing communication. Walk the Talk in Texas is an example of successful application of the model. (SK)

  6. Total Energy Management for Minnesota Schools.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Energy, Planning and Development, St. Paul.

    Total Energy Management (TEM) is a unified, planned approach to reducing the energy use and costs of an individual school or school district. The program increases energy awareness and improves school energy efficiency through: (1) careful energy accounting; (2) changes in operations and maintenance procedures; (3) modifications in the building…

  7. Revitalizing Space Operations through Total Quality Management

    NASA Technical Reports Server (NTRS)

    Baylis, William T.

    1995-01-01

    The purpose of this paper is to show the reader what total quality management (TQM) is and how to apply TQM in the space systems and management arena. TQM is easily understood, can be implemented in any type of business organization, and works.

  8. Application of Total Quality Management in Education

    ERIC Educational Resources Information Center

    Farooq, M. S.; Akhtar, M. S.; Ullah, S. Zia; Memon, R. A.

    2007-01-01

    The purpose of the paper is to analyzing thoughts of the modern management paradigm "Total Quality Management" (TQM), and its application in the field of education. The basic theme of TQM is participatory approach to address the question(s) of quality in business aswell as in the field of education. Reviewing fresh literature from the internet …

  9. Coordinating Council. Ninth Meeting: Total Quality Management

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This report summarizes the 9th meeting of the STI Coordinating Council. The council listened to the speakers' understanding of Total Quality Management (TQM) principles and heard stories of successful applications of these principles. Definitions of quality stated were focused on customer satisfaction. Reports presented by the speakers are also included.

  10. Total Quality Management: Institutional Research Applications.

    ERIC Educational Resources Information Center

    Heverly, Mary Ann

    Total Quality Management (TQM), a technique traditionally reserved for the manufacturing sector, has recently spread to service companies, government agencies, and educational institutions. TQM places responsibility for quality problems with management rather than on the workers. A principal concept of TQM is the management of Process Variation,…

  11. How to calculate total purchase cost.

    PubMed

    Harding, M L

    1998-05-01

    Companies wanting to implement a total cost-based supplier selection process often stumble over how to include nonmonetary issues such as delivery and quality performance, lead time, services, and social policies. This article describes a process that allows a company to include any issue it deems relevant and to determine its cost factor. PMID:10178553

  12. PROCEDURE FOR ESTIMATING PERMANENT TOTAL ENCLOSURE COSTS

    EPA Science Inventory

    The paper discusses a procedure for estimating permanent total enclosure (PTE) costs. (NOTE: Industries that use add-on control devices must adequately capture emissions before delivering them to the control device. One way to capture emissions is to use PTEs, enclosures that mee...

  13. Total Quality Management: The Emperor's Tailor.

    ERIC Educational Resources Information Center

    Alexander, Gary C.; Keeler, Carolyn M.

    Conversations among educators, business leaders, legislators, and educational reformers have generated support for the application of Total Quality Management (TQM) to education. This paper considers whether TQM is indeed the solution to education's problems. After a brief explanation of TQM theory, the paper is organized around four broad issues…

  14. Courses Credit Hours Total Credit Hours

    E-print Network

    Mohaghegh, Shahab

    Courses Credit Hours Total Credit Hours Hrs Attempted Hrs Completed Semester GPA Overall GPA Date are requesting to register for more than 20 credit hours during the fall/spring and more than 14 credit hours and approval from the Assistant/Associate Dean. For requests to register for more than 21 credit hours during

  15. Total Quality Management: Implications for Higher Education.

    ERIC Educational Resources Information Center

    Hoffman, Allan M., Ed.; Julius, Daniel J., Ed.

    This book contains 19 papers describing the implementation of Total Quality Management in a variety of higher education settings. Following a Foreword by Peter Likins and a Preface by Daniel J. Julius, the chapter titles and authors are: (1) "TQM: Implications for Higher Education--A Look Back to the Future" (Allan M. Hoffman and Randall Summers);…

  16. Total Quality Management. ERIC Digest, Number 73.

    ERIC Educational Resources Information Center

    Weaver, Tyler

    The Japanese success story has made W. Edwards Deming's Total Quality Management (TQM) theory increasingly popular among American managers, from car manufacturers to educational leaders. TQM is based on two tenets: the primacy of customer satisfaction and the necessity of tapping nontraditional sources (especially employee ideas) to institute…

  17. In-situ measurements of total carbon

    NASA Astrophysics Data System (ADS)

    Smythe, W.; Boryta, M.; Nelson, R.

    2009-04-01

    Quantitative assessment of the equilibration of biotic and pre-biotic materials and of the mechanisms leading to their presence in a planetary context requires knowledge of the relative concentrations of the organic species within a sample. The measurement of these relative concentrations is not practical for many remote sensing and in-situ techniques because of the large number of potential compounds having high variance in (for example) volatility, spectral response and/or molecular weight. One approach is to compare the concentration of identified materials to the total carbon and total organic carbon in a sample. The traditional two-stage approach for this measurement is acidification to convert "inorganic" carbon to CO2 and pyrolysis to convert the remaining "organic" carbon and carbon-based compounds the CO2. Measurement of the evolved CO2 provides a measure of organic and total carbon in the sample. These measurements are relatively successful in a laboratory context, but are difficult to implement robotically, particularly in challenging environments. A variety of alternative approaches for achieving total carbon measurements with acceptable accuracy are examined for feasibility of use in a field or robotic environment, with particular emphasis on soils on Mars.

  18. Curriculum Transformation through Total Quality Management.

    ERIC Educational Resources Information Center

    Edwards, Barbara; Algozzine, Bob

    1995-01-01

    Describes a massive cultural transformation project at two Charlotte, North Carolina, elementary schools that used Deming's total quality management principles to restructure curricula according to Boyer's eight commonalities of learning. Shows how the FADE (focus, analyze, develop, and execute) model was used to develop a well-coordinated,…

  19. Total Quality Management in Higher Education.

    ERIC Educational Resources Information Center

    Sherr, Lawrence A.; Lozier, G. Gredgory

    1991-01-01

    Total Quality Management, based on theories of W. Edward Deming and others, is a style of management using continuous process improvement characterized by mission and customer focus, a systematic approach to operations, vigorous development of human resources, long-term thinking, and a commitment to ensuring quality. The values espoused by this…

  20. Total main rotor isolation system analysis

    NASA Technical Reports Server (NTRS)

    Halwes, D. R.

    1981-01-01

    The requirements for a preliminary design study and verification procedure for a total main rotor isolation system at n/rev are established. The system is developed and analyzed, and predesign drawings are created for an isolation system that achieves over 95 percent isolation of all six degrees of freedom.

  1. 2 CFR 170.330 - Total compensation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Total compensation. 170.330 Section 170.330 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS Reserved REPORTING SUBAWARD...

  2. 2 CFR 170.330 - Total compensation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Total compensation. 170.330 Section 170.330 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS NATIONAL POLICY...

  3. 2 CFR 170.330 - Total compensation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Total compensation. 170.330 Section 170.330 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS REPORTING SUBAWARD AND...

  4. Total Quality Management in Libraries: A Sourcebook.

    ERIC Educational Resources Information Center

    O'Neil, Rosanna M., Comp.

    Total Quality Management (TQM) brings together the best aspects of organizational excellence by driving out fear, offering customer-driven products and services, doing it right the first time by eliminating error, and maintaining inventory control without waste. Libraries are service organizations which are constantly trying to improve service.…

  5. Total Quality Management (TQM) in Higher Education.

    ERIC Educational Resources Information Center

    Sullivan, Michael F.

    This document consists largely of paper versions of the transparencies used by the author to give his conference paper on Total Quality Management (TQM) in the college and university setting. An introduction lists a series of definitional phrases, a list of what TQM is not, and 11 fundamental principles describing what TQM is. The three major…

  6. A GENUINELY HIGH ORDER TOTAL VARIATION DIMINISHING ...

    E-print Network

    where the total variation is measured by (1.2), necessarily degenerate to first order ... volume schemes we develop in this paper are (k+1)-th order accurate in the ..... where rj(x) is either a polynomial or a (possibly discontinuous) two-piece poly ...

  7. The technology behind Colgate Total Advanced Fresh.

    PubMed

    Williams, Malcolm I; Cummins, Diane

    2003-09-01

    In the early 1990s, a breakthrough toothpaste, Colgate Total, was launched with documented long-lasting activity against plaque, gingivitis, calculus, tooth decay, and bad breath. The technology behind this toothpaste is the combination of triclosan, a polyvinylmethylether/maleic acid copolymer, and sodium fluoride. The copolymer ensures maximal oral retention and subsequent release of the antibacterial triclosan. Effective levels of triclosan have been observed in the oral cavity 12 hours after brushing the teeth, allowing prolonged control of oral bacteria that may cause the most common dental problems, including bad breath. Similarly, the enhanced retention of triclosan to oral surfaces after using this revolutionary toothpaste for up to 2 years has led to significantly reduced incremental coronal caries compared to an American Dental Association-Approved anticavity fluoride toothpaste. Furthermore, significantly less calcium remained in dental plaque after brushing the teeth with the triclosan/copolymer toothpaste, resulting in the formation of less tartar. In keeping with the multiple oral health benefits provided by Colgate Total, consumers are now offered a new dentifrice, Colgate Total Advanced Fresh, which provides the numerous therapeutic and esthetic benefits that are the hallmark of Colgate Total. The new dentifrice, which contains an impactful breath-freshening flavor, has been documented to provide sustained control of bad breath over 12 hours. PMID:14692205

  8. Mineral Analysis of Whole Grain Total Cereal

    ERIC Educational Resources Information Center

    Hooker, Paul

    2005-01-01

    The quantitative analysis of elemental iron in Whole Grain Total Cereal using visible spectroscopy is suitable for a general chemistry course for science or nonscience majors. The more extensive mineral analysis, specifically for the elements iron, calcium and zinc, is suitable for an instrumental or quantitative analysis chemistry course.

  9. The Total Solar Eclipse, March 1970

    ERIC Educational Resources Information Center

    Glenn, William H.

    1970-01-01

    Describes the circumstances of the total and partial solar eclipse of March 7, 1970 in certain American cities. Also discussed are (1) a classroom demonstration of the cause of solar eclipses, (2) techniques for safely observing the eclipse, and (3) what to observe during the eclipse. Bibliography. (LC)

  10. Applying Total Quality Management to Business Education.

    ERIC Educational Resources Information Center

    Brown, Daniel J.; Koenig, Harold F.

    1993-01-01

    Responses from 390 business school alumni (60%) show that students want educators to consider their opinions about their overall educational experience and what happens after graduation. A total quality management approach can help discover customer/student needs, establish a focus on improvement, and implement a process orientation. (SK)

  11. Forecasting Total Risk Greg Anderson y

    E-print Network

    Forecasting Total Risk #3; Greg Anderson y Barra, Inc. Lisa Goldberg y Barra, Inc. Alec N. Kercheval z Florida State University Guy Miller y Barra, Inc. Kathy Sorge y Barra, Inc. May 1, 2003 x, optimization. y Barra, Inc., 2100 Milvia Street, Berkeley, CA 94704 USA z Department of Mathematics, Florida

  12. A Campus Is a Total Community.

    ERIC Educational Resources Information Center

    Hunt, Robert E.

    1979-01-01

    Described are the various components of the total college or university community and their associated environmental health and safety problems. Included are food service, insect and rodent control, multi-use athletic facilities, housing, laboratory animal facilities, laboratory biosafety, radiological health, fire protection, and emergency…

  13. Total ozone variations at Reykjavik since 1957

    SciTech Connect

    Bjarnason, G.G.; Rognvaldsson, O.E.; Sigfusson, T.I.; Jakobsson, T.; Thorkelsson, B. |

    1993-12-01

    Total ozone measurements using a Dobson spectrophotometer have been performed on a regular basis at Reykjavik (65 deg 08 min N, 21 deg 54 min W), Iceland, since 1957. The data set for the entire period of observations has been critically examined. Due to problems related to the calibration of the instrument the data record of ozone observations is divided into two periods in the following analysis (1957-1977 and 1977-1990). A statistical model was developed to fit the data and estimate long-term changes in total ozone. The model includes seasonal variations, solar cycle influences, quasi-biennial oscillation (QBO) effects, and linear trends. Some variants of the model are applied to investigate to what extent the estimated trends depend on the form of the model. Trend analysis of the revised data reveals a statistically significant linear decrease of 0.11 +/- 0.07% per year in the annual total ozone amount during the earlier period and 0.30 +/- 0.11% during the latter. The annual total ozone decline since 1977 is caused by a 0.47 +/- 0.14% decrease per year during the summer with no significant change during the winter or fall. On an annual basis, ozone varies by 3.5 +/- 0.8% over a solar cycle and by 2.1 +/- 0.6% over a QBO for the whole observation period. The effect of the 11-year solar cycle is particularly strong in the data during the early months of the year and in the westerly phase of the QBO. The data also suggest a strong response of total ozone to major solar proton events.

  14. The total momentum of quantum fluids

    NASA Astrophysics Data System (ADS)

    Süt?, András

    2015-08-01

    The probability distribution of the total momentum P is studied in N-particle interacting homogeneous quantum systems at positive temperatures. Using Galilean invariance we prove that in one dimension, the asymptotic distribution of P / ?{ N } is normal at all temperatures and densities, and in two dimensions, the tail distribution of P / ?{ N } is normal. We introduce the notion of the density matrix reduced to the center of mass and show that its eigenvalues are N times the probabilities of the different eigenvalues of P. A series of results is presented for the limit of sequences of positive definite atomic probability measures, relevant for the probability distribution of both the single-particle and the total momentum. The P = 0 ensemble is shown to be equivalent to the canonical ensemble. Through some conjectures we associate the properties of the asymptotic distribution of the total momentum with the characteristics of fluid, solid, and superfluid phases. Our main suggestion is that in interacting quantum systems above one dimension, in infinite space, the total momentum is finite with a nonzero probability at all temperatures and densities. In solids, this probability is 1, and in a crystal, it is distributed on a lattice. Since it is less than 1 in two dimensions, we conclude that a 2D system is always in a fluid phase, so if the hexatic phase existed classically, it would be destroyed by quantum fluctuations. For a superfluid, we conjecture that the total momentum is zero with a nonzero probability and otherwise its distribution is continuous. We define a macroscopic wave function based on the density matrix reduced to the center of mass. We discuss how dissipation can give rise to a critical velocity, predict the temperature dependence of the latter, and argue that Landau's criterion cannot explain superfluidity and its breakdown at positive temperatures. We also comment on the relation between superfluidity and Bose-Einstein condensation.

  15. The total momentum of quantum fluids

    E-print Network

    Andras Suto

    2015-11-10

    The probability distribution of the total momentum P is studied in N-particle interacting homogeneous quantum systems at positive temperatures. Using Galilean invariance we prove that in one dimension the asymptotic distribution of P/\\sqrt{N} is normal at all temperatures and densities, and in two dimensions the tail distribution of P/\\sqrt{N} is normal. We introduce the notion of the density matrix reduced to the center of mass, and show that its eigenvalues are N times the probabilities of the different eigenvalues of \\P. A series of results is presented for the limit of sequences of positive definite atomic probability measures, relevant for the probability distribution of both the single-particle and the total momentum. The P=0 ensemble is shown to be equivalent to the canonical ensemble. Through some conjectures we associate the properties of the asymptotic distribution of the total momentum with the characteristics of fluid, solid, and superfluid phases. Our main suggestion is that in interacting quantum systems above one dimension, in infinite space, the total momentum is finite with a nonzero probability at all temperatures and densities. In solids this probability is 1, and in a crystal it is distributed on a lattice. Since it is less than 1 in two dimensions, we conclude that a 2D system is always in a fluid phase. For a superfluid we conjecture that the total momentum is zero with a nonzero probability and otherwise its distribution is continuous. We define a macroscopic wave function based on the density matrix reduced to the center of mass. We discuss how dissipation can give rise to a critical velocity, predict the temperature dependence of the latter, and prove that Landau's criterion cannot explain superfluidity and its breakdown in a dissipative flow. We also comment on the relation between superfluidity and Bose-Einstein condensation.

  16. The importance of the anterior longitudinal ligament in lumbar disc arthroplasty: 36-Month follow-up experience in extreme lateral total disc replacement

    PubMed Central

    Marchi, Luis; Oliveira, Leonardo; Coutinho, Etevaldo; Pimenta, Luiz

    2012-01-01

    Background Current total disc replacement (TDR) for lumbar spine requires an anterior approach for implantation but presents inherent limitations, including risks to the abdominal structures, as well as resection of the anterior longitudinal ligament. By approaching the spine laterally, it is possible to preserve the stabilizing ligaments, which are a natural restraint to excessive rotations and translations, and thereby help to minimize facet stresses. This less invasive approach also offers a biomechanical advantage of placement of the device over the ring apophysis bilaterally; importantly, it also offers a greater opportunity for safer revision surgery, if necessary, by avoiding scarring of the anterior vasculature. We present the clinical and radiologic results of a lateral TDR device from a prospective single-center study. Methods A new metal-on-metal TDR device designed for implantation through a true lateral, retroperitoneal, transpsoatic approach (extreme lateral interbody fusion) was implanted in 36 patients with discography-confirmed 1- or 2-level degenerative disc disease. Clinical (pain and function) and radiographic (range of motion) outcome assessments were prospectively collected preoperatively, postoperatively, and serially up to a minimum of 36 months’ follow-up. Results Between December 2005 and December 2006, 36 surgeries were performed in 16 men and 20 women (mean age, 42.6 years). These included 15 single-level TDR procedures at L3-4 or L4-5, 3 2-level TDR procedures spanning L3-4 and L4-5, and 18 hybrid procedures (anterior lumbar interbody fusion) at L5-S1 and TDR at L4-5 (17) or L3-4 (1). Operative time averaged 130 minutes, with mean blood loss of 60 mL and no intraoperative complications. Postoperative X-rays showed good device placement, with restoration of disc height, foraminal volume, and sagittal balance. All patients were up and walking within 12 hours of surgery, and all but 9 were discharged the next day (7 of those 9 were hybrid TDR–anterior lumbar interbody fusion cases). Postoperatively, 5 of 36 patients (13.8%) had psoas weakness and 3 of 36 (8.3%) had anterior thigh numbness, with both symptoms resolving within 2 weeks. Of the 36 patients, 4 (11%) had postoperative facet joint pain, all in hybrid cases. Visual analog scale pain scores and Oswestry Disability Index scores improved by 74.5% and 69.2%, respectively, from preoperatively to 3-year follow-up. Range of motion at 3 years postoperatively averaged 8.1°. Signals of heterotopic ossification were present in 5 patients (13.9%), and 2 patients (5.5%) were considered to have fusion after 36 months. Conclusions The clinical and radiographic results of a laterally placed TDR have shown maintenance of pain relief and functional improvement over a long-term follow-up period. The benefits of the lateral access—minimal morbidity, avoidance of mobilization of the great vessels, preservation of the anterior longitudinal ligament, biomechanically stable orientation, and broader revision options—promote a new option for motion-preservation procedures. PMID:25694866

  17. Early Predictors of Hypocalcemia After Total Thyroidectomy

    PubMed Central

    Noureldine, Salem I.; Genther, Dane J.; Lopez, Michael; Agrawal, Nishant; Tufano, Ralph P.

    2015-01-01

    IMPORTANCE Postoperative hypocalcemia is common after total thyroidectomy, and perioperative monitoring of serum calcium levels is arguably the primary reason for overnight hospitalization. Confidently predicting which patients will not develop significant hypocalcemia may allow for a safe earlier discharge. OBJECTIVE To examine associations of patient characteristics with hypocalcemia, duration of hospitalization, and postoperative intact parathyroid hormone (IPTH) level after total thyroidectomy. DESIGN, SETTING, AND PARTICIPANTS Retrospective study of consecutive patients who underwent total thyroidectomy by a single high-volume surgeon between February 1, 2010, and November 30, 2012. Postoperative serum 25-hydroxyvitamin D (vitamin D), calcium, and IPTH levels were tested within 6 to 8 hours after surgery. Mild hypocalcemia was defined as any postoperative serum calcium level of less than 8.4 to 8.0 mg/dL. Significant hypocalcemia was defined as any postoperative serum calcium level of less than 8.0 mg/dL or the development of hypocalcemia-related symptoms. INTERVENTIONS Total thyroidectomy. MAIN OUTCOMES AND MEASURES Associations of patient demographic and clinical characteristics and laboratory values with postoperative mild and significant hypocalcemia were examined using univariate analysis, and independent predictors of hypocalcemia, duration of hospitalization, and IPTH level were determined using multivariate analysis. RESULTS Overall, 304 total thyroidectomies were performed. Mild and significant hypocalcemia occurred in 68 (22.4%) and 91 (29.9%) patients, respectively, of which the majority were female (P = .003). The development of significant hypocalcemia was associated with postoperative IPTH level (P < .001). On multivariate analysis, males had a decreased risk of developing mild (odds ratio, 0.37 [95% CI, 0.16–0.85]) and significant (odds ratio, 0.57 [95% CI, 0.09–0.78]) hypocalcemia. Every 10-pg/mL increase in postoperative IPTH level predicted a 43% decreased risk of significant hypocalcemia (P < .001) and an 18% decreased risk of hospitalization beyond 24 hours (P = .03). Presence of malignant neoplasm carried a 27% risk of mild hypocalcemia (P = .02). There was a progressively increasing risk of lower IPTH levels for each parathyroid gland inadvertently resected or autotransplanted. Male sex and African American race were independently predictive of higher IPTH levels. CONCLUSIONS AND RELEVANCE Low postoperative IPTH level, female sex, and presence of malignant neoplasm are all significant, independent predictors of hypocalcemia after total thyroidectomy. Clinicians should consider these variables when deciding how to best manage or prevent postoperative hypocalcemia. PMID:25321339

  18. Fluorogenic membrane overlays to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and seawater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three assays were developed to enumerate total coliforms, Escherichia coli, and total Vibrionaceae in shellfish and other foods and in seawater and other environmental samples. Assays involve membrane overlays of overnight colonies on non-selective agar plates to detect ß-glucuronidase and lysyl am...

  19. Observation of the total solar eclipsis. L'observation des eclipses totales solaires

    SciTech Connect

    Koutchmy, S.

    1987-03-01

    A brief historical account of the solar-total-eclipses events is presented to show their importance, including their use for the scientific analysis of the solar corona, since 1848. The main parameters and a schema of the eclipses are given. Several examples of investigations performed during a solar total eclipse are discussed.

  20. Gravitation experiments during the total solar eclipse

    SciTech Connect

    Kuusela, T.; Jaeykkae, J.; Kiukas, J.; Multamaeki, T.; Ropo, M.; Vilja, I.

    2006-12-15

    The variations of the apparent vertical direction of the gravity field were measured with horizontal gravimeters acting as tilt meters during the total solar eclipse in Turkey in March 29, 2006. Three separated locations within the path of totality were chosen for observations, two spaced apart along the center line, and one off the center line. No anomaly was observed at the furthest location from the center line. Aperiodic oscillations in tilt were recorded at the two locations on the center line. These may be related to the eclipse phenomenon. The average tilt amplitude deviation during the eclipse over all locations and in all directions was 150 nrad, which can be regarded as a mean upper limit for the eclipse related changes in the tilt.

  1. Frustrated total internal reflection acoustic field sensor

    DOEpatents

    Kallman, Jeffrey S. (Pleasanton, CA)

    2000-01-01

    A frustrated total internal reflection acoustic field sensor which allows the acquisition of the acoustic field over an entire plane, all at once. The sensor finds use in acoustic holography and acoustic diffraction tomography. For example, the sensor may be produced by a transparent plate with transparent support members tall enough to support one or more flexible membranes at an appropriate height for frustrated total internal reflection to occur. An acoustic wave causes the membrane to deflect away from its quiescent position and thus changes the amount of light that tunnels through the gap formed by the support members and into the membrane, and so changes the amount of light reflected by the membrane. The sensor(s) is illuminated by a uniform tight field, and the reflection from the sensor yields acoustic wave amplitude and phase information which can be picked up electronically or otherwise.

  2. Total quality management of cobalt-60 sources

    NASA Astrophysics Data System (ADS)

    Malkoske, G. R.

    1999-06-01

    Total Quality Management of Cobalt-60 sources by a supplier requires a life cycle approach to source management. This covers various aspects, including design, manufacturing, installation, field inspection, source surveillance and return of cobalt-60 sources at the end of their useful life. The Total Quality Management approach demonstrates a strong industry commitment to the beneficial use of gamma technology for industrial irradiation applications in both developed nations and in those nations who are developing their infrastructure and techniques for the beneficial use of this technology. MDS Nordion continues to demonstrate its support and commitment to the industry by developing and implementing state-of-the-art standards for the safe use of cobalt-60 sources.

  3. Increasing productivity through Total Reuse Management (TRM)

    NASA Technical Reports Server (NTRS)

    Schuler, M. P.

    1991-01-01

    Total Reuse Management (TRM) is a new concept currently being promoted by the NASA Langley Software Engineering and Ada Lab (SEAL). It uses concepts similar to those promoted in Total Quality Management (TQM). Both technical and management personnel are continually encouraged to think in terms of reuse. Reuse is not something that is aimed for after a product is completed, but rather it is built into the product from inception through development. Lowering software development costs, reducing risk, and increasing code reliability are the more prominent goals of TRM. Procedures and methods used to adopt and apply TRM are described. Reuse is frequently thought of as only being applicable to code. However, reuse can apply to all products and all phases of the software life cycle. These products include management and quality assurance plans, designs, and testing procedures. Specific examples of successfully reused products are given and future goals are discussed.

  4. Generalized Higher Degree Total Variation (HDTV) Regularization

    PubMed Central

    Hu, Yue; Ongie, Greg; Ramani, Sathish; Jacob, Mathews

    2015-01-01

    We introduce a family of novel image regularization penalties called generalized higher degree total variation (HDTV). These penalties further extend our previously introduced HDTV penalties, which generalize the popular total variation (TV) penalty to incorporate higher degree image derivatives. We show that many of the proposed second degree extensions of TV are special cases or are closely approximated by a generalized HDTV penalty. Additionally, we propose a novel fast alternating minimization algorithm for solving image recovery problems with HDTV and generalized HDTV regularization. The new algorithm enjoys a ten-fold speed up compared to the iteratively reweighted majorize minimize algorithm proposed in a previous work. Numerical experiments on 3D magnetic resonance images and 3D microscopy images show that HDTV and generalized HDTV improve the image quality significantly compared with TV. PMID:24710832

  5. Total positive curvature of circular DNA

    NASA Astrophysics Data System (ADS)

    Bohr, Jakob; Olsen, Kasper W.

    2013-11-01

    The properties of double-stranded DNA and other chiral molecules depend on the local geometry, i.e., on curvature and torsion, yet the paths of closed chain molecules are globally restricted by topology. When both of these characteristics are to be incorporated in the description of circular chain molecules, e.g., plasmids, it is shown to have implications for the total positive curvature integral. For small circular micro-DNAs it follows as a consequence of Fenchel's inequality that there must exist a minimum length for the circular plasmids to be double stranded. It also follows that all circular micro-DNAs longer than the minimum length must be concave, a result that is consistent with typical atomic force microscopy images of plasmids. Predictions for the total positive curvature of circular micro-DNAs are given as a function of length, and comparisons with circular DNAs from the literature are presented.

  6. Total synthesis of palau'amine

    PubMed Central

    Namba, Kosuke; Takeuchi, Kohei; Kaihara, Yukari; Oda, Masataka; Nakayama, Akira; Nakayama, Atsushi; Yoshida, Masahiro; Tanino, Keiji

    2015-01-01

    Palau'amine has received a great deal of attention in the past two decades as an attractive synthetic target by virtue of its intriguing molecular architecture and significant immunosuppressive activity. Here we report the total synthesis of palau'amine characterized by the construction of an ABDE tetracyclic ring core including a trans-bicylo[3.3.0]octane skeleton at a middle stage of total synthesis. The ABDE tetracyclic ring core is constructed by a cascade reaction of a cleavage of the N–N bond, including simultaneous formation of imine, the addition of amide anion to the resulting imine (D-ring formation) and the condensation of pyrrole with methyl ester (B-ring formation) in a single step. The synthetic palau'amine is confirmed to exhibit excellent immunosuppressive activity. The present synthetic route has the potential to help elucidate a pharmacophore as well as the mechanistic details of immunosuppressive activity. PMID:26530707

  7. Total synthesis of panicein A2

    PubMed Central

    Yeung, Lili; Pilkington, Lisa I; Cadelis, Melissa M; Copp, Brent R

    2015-01-01

    Summary The first total synthesis of the unusual aromatic sesquiterpene panicein A2 is reported and the structure of the natural product has been confirmed. When tested by the NCI against a range of human cancer cell lines, it was found that panicein A2 exhibits very little antiproliferative activity at 10 ?M – an observation that is at odds with the earlier report that stated panicein A2 exhibits in vitro cytotoxicity against a number of tumour cell lines. PMID:26664619

  8. Total Synthesis of Oridamycins A and B.

    PubMed

    Trotta, Adam H

    2015-07-01

    The total synthesis of both oridamycin A and oridamycin B was accomplished starting from a common synthetic intermediate readily prepared from geranyl acetate. The sequence utilizes an oxidative radical cyclization to construct the trans-decalin ring system, setting three of four contiguous stereocenters in one operation. The carbazole nucleus was forged through a one-pot process entailing acid-promoted dehydration followed by 6?-electrocyclization/aromatization. PMID:26069989

  9. Total Synthesis of (+)-Rubriflordilactone?A.

    PubMed

    Goh, Shermin S; Chaubet, Guilhem; Gockel, Birgit; Cordonnier, Marie-Caroline A; Baars, Hannah; Phillips, Andrew W; Anderson, Edward A

    2015-10-19

    Two enantioselective total syntheses of the nortriterpenoid natural product rubriflordilactone?A are described, which use palladium- or cobalt-catalyzed cyclizations to form the CDE rings, and converge on a late-stage synthetic intermediate. These key processes are set up through the convergent coupling of a common diyne component with appropriate AB-ring aldehydes, a strategy that sets the stage for the synthetic exploration of other members of this family of natural products. PMID:26337920

  10. Total synthesis of hapalindoles J and U.

    PubMed

    Rafferty, Ryan J; Williams, Robert M

    2012-01-01

    The total synthesis of D,L-hapalindoles J and U has been accomplished. Hapalindole J was prepared in 11% overall yield over 11 synthetic steps and hapalindole U was prepared in 25% overall yield over 13 synthetic steps from commercially available materials. The route employs a novel silyl ether-based strategy for accessing the 6:5:6:6 ring system of the hapalindoles rapidly and in good yields. PMID:22126131

  11. Measurement of total organic concentration in water

    NASA Technical Reports Server (NTRS)

    Winkler, E.

    1978-01-01

    Instrument for determining total organic concentration in water uses no corrosive reagents or gases. Instead continuous ultraviolet photolysis process converts organic compounds to carbon dioxide (CO2). CO2 electrode is used to measure CO2 content. Only reagent necessary is oxygen, generated in situ by electrolyzing some water. In addition to application in aerospace industry, system has potential uses in pollution monitoring and in laboratory analyses.

  12. Total synthesis of (+)-antroquinonol and (+)-antroquinonol D.

    PubMed

    Sulake, Rohidas S; Chen, Chinpiao

    2015-03-01

    The first total synthesis of (+)-antroquinonol and (+)-antroquinonol D, two structurally unique quinonols with a sesquiterpene side chain, is described. The route features an iridium-catalyzed olefin isomerization-Claisen rearrangement reaction (ICR), lactonization, and Grubbs olefin metathesis. The requisite ?,?-unsaturation was achieved via the selenylation/oxidation protocol and elimination of ?-methoxy group to provide two natural products from a common intermediate. PMID:25679542

  13. Total Synthesis of Hapalindoles J and U

    PubMed Central

    Rafferty, Ryan J.; Williams, Robert M.

    2011-01-01

    The total synthesis of D,L-hapalindoles J and U has been accomplished. Hapalindole J was prepared in 11% overall yield over eleven synthetic steps and hapalindole U was prepared in 25% overall yield over thirteen synthetic steps from commercially available materials. The route employs a novel silyl ether-based strategy for accessing the 6:5:6:6 ring system of the hapalindoles rapidly and in good yields. PMID:22126131

  14. Nonlinear identification of the total baroreflex arc.

    PubMed

    Moslehpour, Mohsen; Kawada, Toru; Sunagawa, Kenji; Sugimachi, Masaru; Mukkamala, Ramakrishna

    2015-12-15

    The total baroreflex arc [the open-loop system relating carotid sinus pressure (CSP) to arterial pressure (AP)] is known to exhibit nonlinear behaviors. However, few studies have quantitatively characterized its nonlinear dynamics. The aim of this study was to develop a nonlinear model of the sympathetically mediated total arc without assuming any model form. Normal rats were studied under anesthesia. The vagal and aortic depressor nerves were sectioned, the carotid sinus regions were isolated and attached to a servo-controlled piston pump, and the AP and sympathetic nerve activity (SNA) were measured. CSP was perturbed using a Gaussian white noise signal. A second-order Volterra model was developed by applying nonparametric identification to the measurements. The second-order kernel was mainly diagonal, but the diagonal differed in shape from the first-order kernel. Hence, a reduced second-order model was similarly developed comprising a linear dynamic system in parallel with a squaring system in cascade with a slower linear dynamic system. This "Uryson" model predicted AP changes 12% better (P < 0.01) than a linear model in response to new Gaussian white noise CSP. The model also predicted nonlinear behaviors, including thresholding and mean responses to CSP changes about the mean. Models of the neural arc (the system relating CSP to SNA) and peripheral arc (the system relating SNA to AP) were likewise developed and tested. However, these models of subsystems of the total arc showed approximately linear behaviors. In conclusion, the validated nonlinear model of the total arc revealed that the system takes on an Uryson structure. PMID:26354845

  15. NASA total quality management 1989 accomplishments report

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Described here are the accomplishments of NASA as a result of the use of Total Quality Management (TQM). The principles in practice which led to these process refinements are important cultural elements to any organization's productivity and quality efforts. The categories of TQM discussed here are top management leadership and support, strategic planning, focus on the customer, employee training and recognition, employee empowerment and teamwork, measurement and analysis, and quality assurance.

  16. Assessing Operational Total Lightning Visualization Products

    NASA Technical Reports Server (NTRS)

    Stano, Geoffrey T.; Darden, Christopher B.; Nadler, David J.

    2010-01-01

    In May 2003, NASA's Short-term Prediction Research and Transition (SPoRT) program successfully provided total lightning data from the North Alabama Lightning Mapping Array (NALMA) to the National Weather Service (NWS) office in Huntsville, Alabama. The major accomplishment was providing the observations in real-time to the NWS in the native Advanced Weather Interactive Processing System (AWIPS) decision support system. Within days, the NALMA data were used to issue a tornado warning initiating seven years of ongoing support to the NWS' severe weather and situational awareness operations. With this success, SPoRT now provides real-time NALMA data to five forecast offices as well as working to transition data from total lightning networks at Kennedy Space Center and the White Sands Missile Range to the surrounding NWS offices. The only NALMA product that has been transitioned to SPoRT's partner NWS offices is the source density product, available at a 2 km resolution in 2 min intervals. However, discussions with users of total lightning data from other networks have shown that other products are available, ranging from spatial and temporal variations of the source density product to the creation of a flash extent density. SPoRT and the Huntsville, Alabama NWS are evaluating the utility of these variations as this has not been addressed since the initial transition in 2003. This preliminary analysis will focus on what products will best support the operational warning decision process. Data from 19 April 2009 are analyzed. On this day, severe thunderstorms formed ahead of an approaching cold front. Widespread severe weather was observed, primarily south of the Tennessee River with multiple, weak tornadoes, numerous severe hail reports, and wind. This preliminary analysis is the first step in evaluation which product(s) are best suited for operations. The ultimate goal is selecting a single product for use with all total lightning networks to streamline training and science sharing.

  17. The benefits of total quality management.

    PubMed

    Geraedts, H P; Montenarie, R; van Rijk, P P

    2001-01-01

    In this article, we will review the implementation of the ISO 9000 quality system in the Department of Nuclear Medicine. We will also discuss the benefits of working with the ISO 9000 standards and explain why we have shifted our focus from ISO 9000 towards the EFQM model. After an introduction concerning Total Quality Management and the EFQM model, we will describe how we have used the EFQM model to date and how we intend to implement TQM in the future. PMID:11137800

  18. Economics of a total maintenance coatings program

    SciTech Connect

    Poncio, S.; Adkison, P. )

    1994-08-01

    Coating costs are escalating due to increased awareness of the environment and safety and health issues. Owners can reduce the overall cost of maintenance painting projects through the implementation of a total quality program. This program should encompass project pre-planning, evaluation of safety and quality assurance programs, and analysis of employee absenteeism and turnover. The information presented is a case history of one utility's experience managing a maintenance painting program during a five-year period.

  19. 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.

  20. Cogeneration Plant is Designed for Total Energy 

    E-print Network

    Howell, H. D.; Vera, R. L.

    1987-01-01

    was reached with Houston Lighting and Power (HL&P). It was the first capacity contract signed under the Texas Public Utility Commission's guide lines for cogeneration. Once the type of cogeneration plant cycle was de cided upon, and the permits... requirements. 2. Capability to control total cogeneration plant generation automatically when limitations are placed by the utility on the export of power because of electrical grid operating conditions. 3. Automatic load management to maintain...

  1. NASA total quality management 1990 accomplishments report

    NASA Technical Reports Server (NTRS)

    1991-01-01

    NASA's efforts in Total Quality Management are based on continuous improvement and serve as a foundation for NASA's present and future endeavors. Given here are numerous examples of quality strategies that have proven effective and efficient in a time when cost reduction is critical. These accomplishment benefit our Agency and help to achieve our primary goal, keeping American in the forefront of the aerospace industry.

  2. Measured flexion following total knee arthroplasty.

    PubMed

    Mai, Kenny T; Verioti, Christopher A; Hardwick, Mary E; Ezzet, Kace A; Copp, Steven N; Colwell, Clifford W

    2012-10-01

    Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners.At a mean follow-up of 2.7 years (range, 1-5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant (P<.05). These findings demonstrate the importance of describing how flexion is measured in studies and understanding how the method of measurement can affect the findings. PMID:23027482

  3. Surgical navigation in canine total knee replacement

    E-print Network

    Peters, Kaleigh M.; Hutter, Erin; Siston, Robert A.; Bertran, Judith

    2015-06-16

    knee surgical total 384 replacement. CVRMed-MRCAS ‘97: First Joint Conference Computer Vision, Virtual 385 Reality and Robotics in Medicine and Medical Robotics and Computer-Assisted Surgery, 386 Springer, Grenoble, France (1997), pp. 627–638 387... have turned to the use of 74 computer-assisted surgical navigation systems that use three-dimensional motion 75 capture and optical tracking technologies to collect real-time data on bone and joint 76 alignment in the operating room. 77 78...

  4. Advanced lymphosarcoma treated by total body irradiation.

    PubMed Central

    Chaffey, J. T.; Rosenthal, D. S.; Pinkus, F.; Hellman, S.

    1975-01-01

    Twenty-five cases of clinical Stage III and Stage IV lymphosarcoma primarily treated by total body irradiation (TBI) are reported. Fifteen cases demonstrated nodular histology and 10 demonstrated diffuse histology by the Rappaport criteria. Treatments were 15 rad given twice weekly, calculated to midpelvis, to a total dose of 150 rad. Toxicity was confined to thrombocytopenia, one-third of patients requiring interruptions in the treatment course to allow platelet count recovery. Five patients had additional local irradiation. Complete responses were seen in 80% of patients and partial responses in 20%. Sixteen patients (64%) have been in continuous, unmaintained remission since treatments for variable periods to 39 months. Of 9 patients with clinically recurrent disease, 3 received further TBI and are in remission, 3 are in remission on chemotherapy, one patient has died, failing on all therapy, and 2 have not been treated. One patient died of pneumonia at 12 months, without clinical evidence of disease. Overall, actuarial survival is 87% at 2 years and compares well with survival in a sequential combination drug treated group of patients matched for age, sex, and histology, though differences are not statistically significant in these small groups. Total body irradiation is an effective systemic agent in the management of advanced lymphosarcoma and should be considered in treating this disease. PMID:810155

  5. Climate Change and Tropical Total Lightning

    NASA Technical Reports Server (NTRS)

    Albrecht, R.; Petersen, W.; Buechler, D.; Goodman, S.; Blakeslee, R.; Christian, H.

    2009-01-01

    While global warming is regarded as a fact by many in the scientific community, its future impact remains a challenge to be determined and measured. The International Panel on Climate Change (IPCC) assessment report (IPCC, 2007) shows inconclusive answers on global rainfall trends and general agreement on a future drier climate with increased global warming. The relationship between temperature, humidity and convection is not linear and is strongly dependent on regional scale features, such as topography and land cover. Furthermore, the relationship between convective lightning production (thunderstorms) and temperature is even more complicated, being subjected to the cloud dynamics and microphysics. Total lightning (intracloud and cloud-to-ground) monitoring is a relatively new field of observation. Global and tropical total lightning began to be more extensively measured by satellites in the mid 90s. In this scope, the Lightning Imaging Sensor (LIS) onboard of the Tropical Rainfall Measurement Mission (TRMM) has been operational for over 11 years. Here we address total lightning trends observed by LIS from 1998 to 2008 in different temporal (annual and seasonal) and spatial (large and regional) scales. The observed 11-year trends are then associate to different predicted/hypothesized climate change scenarios.

  6. 257 Incidental Appendectomies During Total Laparoscopic Hysterectomy

    PubMed Central

    Fisher, Deidre T.; O'Holleran, Michael S.

    2007-01-01

    Objective: This retrospective observational report analyzes the demographics, blood loss, length of surgical duration, number of days in the hospital, and complications for 821 consecutive patients undergoing total laparoscopic hysterectomy over a 11-year period stratified by incidental appendectomy. Methods: A retrospective chart abstraction was performed. ANOVA and chi-square tests were performed with significance preset at P<0.05. Results: Of 821 consecutive patients undergoing total laparoscopic hysterectomy, 257 underwent elective appendectomy with the ultrasonic scalpel, either as part of their staging, treatment for pelvic pain, or prophylaxis against appendicitis. Comparing the 2 groups, no difference existed in mean age of 50±10 years or mean BMI of 27.6±6.7. Both groups had a similar mean blood loss of 130 mL. Surgery took less time (137 vs 118 minutes, P<0.0012) and the hospital stay was shorter in the appendectomy group (1.5 vs 1.2, P<0.0001) possibly because it was performed incidentally in most cases. No complications were attributable to the appendectomy, and complication types and rates in both groups were similar. Though all appendicies appeared normal, pathology was documented in 9%, including 3 carcinoid tumors. Conclusions: Incidental appendectomy during total laparoscopic hysterectomy is not associated with significant risk and can be routinely offered to patients planning elective gynecologic laparoscopic procedures, as is standard for open procedures. PMID:18237505

  7. Bacteriology swabs in primary total knee arthroplasty

    PubMed Central

    Haenle, Maximilian; Podbielski, Andreas; Ellenrieder, Martin; Mundt, Andreas; Krentz, Helga; Mittelmeier, Wolfram; Skripitz, Ralf

    2013-01-01

    Objective: An early detection of possible periprosthetic infection may lead to an earlier and potentially less invasive treatment of infected total knee arthroplasty TKA). The purpose of the present study was to evaluate retrospectively our current, affordable clinical practice of intra-operative swab taking during primary TKA. Methods: A total of 206 primary TKA were analysed retrospectively for intra-operative bacteriology swabs and subsequent periprosthetic infection. All bacteriology swabs were obtained in a standardized manner including a tissue sample. Data was statistically evaluated concerning standard descriptive statistics and using the chi-square test. Results: Bacteria were identified in 43.4% with coagulase-negative staphylococci being the most frequently isolated pathogens (52.2%). Regarding the contingency tables and chi-squared tests, generally no association was found between positive intra-operative swabs and subsequent periprosthetic infection as well as all other parameters investigated (timing of the antibiotic prophylaxis and pre-operative laboratory results). Conclusions: Bacteriology swabs during primary total knee arthroplasty are no adequate measure to predict subsequent periprosthetic infections, even if augmented with a tissue sample. PMID:23967388

  8. Total quality management -- Remedial actions planning program

    SciTech Connect

    Petty, J.L.; Horne, T.E.

    1989-01-01

    This paper describes the management approach being taken within the Hazardous Waste Remedial Actions Program (HAZWRAP) Support Contractor Office (SCO) to ensure quality of services in a highly competitive waste management environment. An overview is presented of the contractor support role assigned to Martin Marietta Energy Systems, Inc., by the Department of Energy (DOE) national program for managing hazardous waste. The HAZWRAP SCO mission, organizational structure, and major programs are outlined, with emphasis on waste management planning for the DOE Work for Others (WFO) Program. The HAZWRAP SCO provides waste management technical support, via interagency agreements between DOE and various Department of Defense (DOD) agencies for DOD sponsors planning remedial response actions. The remainder of the paper focuses on how the concept of Total Quality Management is applied to the HAZWRAP Remedial Actions Planning (RAP) Program. The management challenge is to achieve quality on a ''system'' basis where all functional elements of program management synergistically contribute to the total quality of the effort. The quality assurance (QA) program requirements applied to the RAP Program and its subcontractors are discussed. The application of management principles in the areas of program management, procurement, and QA to achieve total quality is presented. 3 refs.

  9. Total quality in spent fuel pool reracking

    SciTech Connect

    Cranston, J.S.; Taglianetti, J.N.; Schaeffer, D.G.; Bradbury, R.B.; Cacciapouti, R.J.

    1993-12-31

    The nuclear utility environment is one of strict cost control under prescriptive regulations and increasing public scrutiny. This paper presents the results of A Total Quality approach, by a dedicated team, that addresses the need for increased on-site spent fuel storage in this environment. Innovations to spent fuel pool reracking, driven by utilities` specific technical needs and shrinking budgets, have resulted in both product improvements and lower prices. A Total Quality approach to the entire turnkey project is taken, thereby creating synergism and process efficiency in each of the major phases of the project: design and analysis, licensing, fabrication, installation and disposal. Specific technical advances and the proven quality of the team members minimizes risk to the utility and its shareholders and provides a complete, cost effective service. Proper evaluation of spent fuel storage methods and vendors requires a full understanding of currently available customer driven initiatives that reduce cost while improving quality. In all phases of a spent fuel reracking project, from new rack design and analysis through old rack disposal, the integration of diverse experts, at all levels and throughout all phases of a reracking project, better serves utility needs. This Total Quality environment in conjunction with many technical improvements results in a higher quality product at a lower cost.

  10. Total Synthesis of (±)- and (?)-Actinophyllic Acid

    PubMed Central

    Martin, Connor L.; Overman, Larry E.; Rohde, Jason M.

    2010-01-01

    Development of efficient sequences for the total syntheses of (±)-actinophyllic acid (rac-1) and (?)-actinophyllic acid (1) are described. The central step in these syntheses is the aza-Cope/Mannich reaction, which constructs the previously unknown hexacyclic ring system of actinophyllic acid in one step from much simpler tetracyclic precursors. The tetracyclic hexahydro-1,5-methano-1H-azocino[4,3-b]indole ketone rac-37 is assembled from o-nitrophenylacetic acid in four steps, with oxidative cyclization of a dienolate derivative of tricyclic precursor rac-35 being the central step. In the first-generation synthesis, this intermediate is transformed in two steps to homoallyl amine rac-43, whose formaldiminium derivative undergoes efficient aza-Cope/Mannich reaction to give pentacyclic ketone rac-44. In four additional steps, this intermediate is advanced to (±)-actinophyllic acid. The synthesis is streamlined by elaborating ketone rac-37 to ?-hydroxyester intermediate rac-53, which is directly transformed to (±)-actinophyllic acid upon exposure to HCl and paraformaldehyde. This concise second-generation total synthesis of (±)-actinophyllic acid is realized in 22% overall yield from commercially available di-tert-butylmalonate and o-nitrophenylacetic acid by a sequence that proceeds by way of only six isolated intermediates. The first enantioselective total synthesis of (?)-actinophyllic acid (1) is accomplished by this direct sequence from tricyclic keto malonate (S)-35. Catalytic enantioselective reduction of ?,?-unsaturated ketone 66 is the key step in the preparation of intermediate (S)-35 from the commercially available Boc-amino acid 65. Discussed also is the possibility that the aza-Cope/Mannich reaction might be involved in the biosynthesis of (?)-actinophyllic acid. PMID:20218696

  11. The 2012 Total Eclipse Expeditions in Queensland

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.; Babcock, B. A.; Lu, M.; Dantowitz, R.; Lucas, R.; Seiradakis, J. H.; Voulgaris, A.; Gaintatzis, P.; Steele, A.; Sterling, A. C.; Rusin, V.; Saniga, M.

    2013-07-01

    A total eclipse swept across Queensland and other sites in northeastern Australia on the early morning of 14 November 2012, local time. We mounted equipment to observe coronal images and spectra during the approximately 2 minutes of totality, the former for comparison with spacecraft images and to fill in the doughnut of imaging not well covered with space coronagraphs. Matching weather statistics, viewing was spotty, and our best observations were from a last-minute inland site on the Tablelands, with some observations from a helicopter at 9000 feet altitude over our original viewing site at Miallo. Only glimpses of the corona were visible at our Port Douglas and Trinity Beach, Cairns, locations, with totality obscured from our sites at Newell and Miallo, though some holes in the clouds provided coronal views from Palm Cove and elsewhere along the coast. Preliminary analysis of the spectra again shows Fe XIV stronger than Fe X, as in 2010 but not earlier, a sign of solar maximum, as was the coronal shape. An intriguing CME is discernible in the SE. Acknowledgments: We thank Terry Cuttle, Aram Friedman, Michael Kentrianakis, and Nicholas Weber for assistance and collaboration in Australia and Wendy Carlos for image processing. Our expedition was supported in part by NSF grant AGS-1047726 from Solar Terrestrial Research of the Atmospheric and Geospace Sciences Division, and by the Rob Spring Fund and Science Center funds at Williams College. ML was also supported in part by a Grant-In-Aid of Research from the National Academy of Sciences, administered by Sigma Xi, The Scientific Research Society (Grant ID: G20120315159311). VR and MS acknowledge support from projects VEGA 2/0003/13 and NGS-3139-12 of the National Geographic Society. We are grateful to K. Shiota (Japan) for kindly providing us with some of his 2012 eclipse coronal images.

  12. Conformal totally symmetric arbitrary spin fermionic fields

    E-print Network

    R. R. Metsaev

    2012-11-19

    Conformal totally symmetric arbitrary spin fermionic fields in flat space-time of even dimension greater than or equal to four are studied. First-derivative formulation involving Fang-Fronsdal kinetic operator for such fields is developed. Gauge invariant Lagrangian and the corresponding gauge transformations are obtained. Gauge symmetries are realized by involving the Stueckelberg and auxiliary fields. Realization of conformal algebra symmetries on the space of conformal gauge fermionic fields is obtained. On-shell degrees of freedom of the arbitrary spin conformal fermionic field are also discussed.

  13. Enantioselective Total Synthesis of Secalonic Acid E.

    PubMed

    Ganapathy, Dhandapani; Reiner, Johannes R; Löffler, Lorenz E; Ma, Ling; Gnanaprakasam, Boopathy; Niepötter, Benedikt; Koehne, Ingo; Tietze, Lutz F

    2015-11-16

    The first enantioselective synthesis of a secalonic acid containing a dimeric tetrahydroxanthenone skeleton is described, using a Wacker-type cyclization of a methoxyphenolic compound to form a chiral chroman with a quaternary carbon stereogenic center with >99?% ee. Further steps are a Sharpless dihydroxylation and a Dieckmann condensation to give a tetrahydroxanthenone. A late-stage one-pot palladium-catalyzed Suzuki-dimerization reaction leads to the 2,2'-biphenol linkage to complete the enantioselective total synthesis of secalonic acid E in 18?steps with 8?% overall yield. PMID:26447631

  14. Total synthesis of indole alkaloid alsmaphorazine D.

    PubMed

    Zhu, Chenlong; Liu, Zhaobo; Chen, Guanyu; Zhang, Kai; Ding, Hanfeng

    2015-01-12

    A concise total synthesis of rac-alsmaphorazine?D has been described for the first time. The efficient synthetic strategy features four key transformations: 1)?a catalytic intramolecular oxidative cyclization for the ?-lactamindole backbone; 2)?an oxidative cyclic aminal formation for the hexahydropyrrolo[2,3-b]pyrrole framework; 3)?a transannular radical cyclization for the construction of the diazabicyclo[3.3.1]nonane structure; and 4)?a one-pot desilylation/double epimerization reaction that affirms the relative stereochemistry. PMID:25418345

  15. Total Mercury in Six Antarctic Notothenioid Fishes.

    PubMed

    Wintle, Nathan J P; Sleadd, Isaac M; Gundersen, Deke T; Kohl, Kristina; Buckley, Bradley A

    2015-11-01

    We analyzed white muscle samples from six species of Antarctic fish (suborder Notothenioidei) collected in 2011 from McMurdo Sound, Ross Sea, Antarctica, to assess levels of total mercury (THg). Gymnodraco acuticeps and Trematomus bernacchii exhibited the highest concentrations of THg followed by Trematomus pennellii, Trematomus nicolai, Trematomus newnesi and Pagothenia borchgrevinki, (71.3, 53.9 ± 32.1, 45.8 ± 27.3, 37.2 ± 18.6, 35.7 ± 23.6, and 21.9 ± 2.8 ng/g wet weight, respectively). The results from this study suggest that THg has the potential to bioaccumulate from various marine Antarctic ecosystems into biota. PMID:26155962

  16. Biomimetic total synthesis of santalin?Y.

    PubMed

    Strych, Sebastian; Journot, Guillaume; Pemberton, Ryan P; Wang, Selina C; Tantillo, Dean J; Trauner, Dirk

    2015-04-20

    A biomimetic total synthesis of santalin?Y, a structurally complex but racemic natural product, is described. The key step is proposed to be a (3+2)?cycloaddition of a benzylstyrene to a "vinylogous oxidopyrylium", which is followed by an intramolecular Friedel-Crafts reaction. This cascade generates the unique oxafenestrane framework of the target molecule and sets its five stereocenters in one operation. Our work provides rapid access to santalin?Y and clarifies its biosynthetic relationship with other colorants isolated from red sandalwood. PMID:25858797

  17. Total body nitrogen analysis. [neutron activation analysis

    NASA Technical Reports Server (NTRS)

    Palmer, H. E.

    1975-01-01

    Studies of two potential in vivo neutron activation methods for determining total and partial body nitrogen in animals and humans are described. A method using the CO-11 in the expired air as a measure of nitrogen content was found to be adequate for small animals such as rats, but inadequate for human measurements due to a slow excretion rate. Studies on the method of measuring the induced N-13 in the body show that with further development, this method should be adequate for measuring muscle mass changes occurring in animals or humans during space flight.

  18. Enantioselective Total Synthesis of (+)-Lyngbyabellin M

    PubMed Central

    Pirovani, Rodrigo V.; Brito, Gilmar A.; Barcelos, Rosimeire C.; Pilli, Ronaldo A.

    2015-01-01

    Lyngbyabellin M is a non-ribosomal peptide synthetase/polyketide synthase derived metabolite isolated from the cyanobacterium M. bouillonii displaying thiazole rings and a distinct chlorinated octanoic acid chain. Its absolute configuration was proposed based on the comparison of its spectroscopic data with those of other representatives of this family of marine natural products, as well as degradation and derivatization studies. Here the first total synthesis of (+)-lyngbyabellin M is described based on the coupling of three key intermediates: two chiral thiazole moieties and an anti hydroxycarboxylic acid prepared stereoselectively via a boron enolate mediated aldol reaction directed by Masamune’s chiral auxiliary. PMID:26023838

  19. Prenatal diagnosis of total arhinia by MRI.

    PubMed

    Li, Xiaobing; Zhang, Lili; Wang, Feng

    2015-10-01

    Congenital arhinia is the absence of an external nose, nasal cavities and olfactory apparatus, and extremely rare. It occurs during the early gestational stage and may be a result of maldevelopment of the paired nasal placodes embryologically. Total arhinia is often associated with other craniofacial abnormalities. Early detection may be helpful for the parents and physician. However, fewer than 40 patients with arhinia have been reported so far, and most of them were diagnosed after birth. To our knowledge, this is the first case diagnosed by fetal MRI during the second trimester of pregnancy, and confirmed by pathological examination. PMID:26311082

  20. Total-variation regularization with bound constraints

    SciTech Connect

    Chartrand, Rick; Wohlberg, Brendt

    2009-01-01

    We present a new algorithm for bound-constrained total-variation (TV) regularization that in comparison with its predecessors is simple, fast, and flexible. We use a splitting approach to decouple TV minimization from enforcing the constraints. Consequently, existing TV solvers can be employed with minimal alteration. This also makes the approach straightforward to generalize to any situation where TV can be applied. We consider deblurring of images with Gaussian or salt-and-pepper noise, as well as Abel inversion of radiographs with Poisson noise. We incorporate previous iterative reweighting algorithms to solve the TV portion.

  1. Stem length in revision total knee arthroplasty.

    PubMed

    Patel, Anay Rajendra; Barlow, Brian; Ranawat, Amar S

    2015-12-01

    Stems are intramedullary extensions of either the femoral or tibial component of a total knee arthroplasty (TKA) designed to increase the mechanical stability to decrease the risk of aseptic loosening. Biomechanical studies have shown that TKA stems increase the mechanical stability by transferring load over a larger area and thereby reduce strain at the bone-component interface [1-4]. The length of a revision TKA stem is determined by the patient's anatomy and the intended fixation, namely fully cemented or press-fit cortical contact. The advantages and disadvantages of various stem lengths must be weighed against the needs of the patient to achieve an optimal outcome. PMID:26371072

  2. 21 CFR 862.1470 - Lipid (total) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lipid (total) test system. 862.1470 Section 862....1470 Lipid (total) test system. (a) Identification. A lipid (total) test system is a device intended to measure total lipids (fats or fat-like substances) in serum and plasma. Lipid (total) measurements...

  3. MEASUREMENT AND DECOMPOSITION OF TOTAL EXPOSURE USING THE TOTAL-ISOLATED-BY-MICROENVIRONMENT-EXPOSURE (TIME) MONITOR

    EPA Science Inventory

    This paper describes a new, highly compact and lightweight monitor that directly measures personal exposure resolved into four microenvironments. he device is the "Total-Isolated-by-Microenvironment-Exposure (TIME)" monitor. he monitor can identify electronically a subject's micr...

  4. Calculation of the total and total ionization cross sections for positron scattering on atomic hydrogen

    SciTech Connect

    Bray, I. ); Stelbovics, A.T. )

    1994-04-01

    The total and total ionization cross sections for positron scattering on atomic hydrogen are calculated by applying the convergent-close-coupling method to the model where positronium-formation channels are omitted. This model accurately describes the physics of the scattering whenever the positronium formation cross section is negligible, in particular, above 100 eV for this system. The total ionization cross section results in this energy region are in excellent agreement with the recent measurements of Jones [ital et] [ital al]. [J. Phys. B 26, L483 (1993)], and so lie below the earlier measurements of Spicher [Phys. Rev. Lett. 64, 1019 (1990)], and the recent calculations of Acacia [ital et] [ital al]. [Phys. Rev. Lett. (to be published)]. The total cross section is in very good agreement with the recent measurements of Zhou [ital et] [ital al]. (unpublished) down to 30 eV.

  5. Large scale total synthesis of apoptolidinone and progress towards the total synthesis of ammocidin 

    E-print Network

    Liu, Qingsong

    2009-05-15

    transformed with the adenovirus type E1A oncognene, but not normal cells. This dissertation describes the latest studies in understanding of apoptolidin’s biological activity mechanism and previous contributions towards its total synthesis. Synthesizing...

  6. Positron interactions with water–total elastic, total inelastic, and elastic differential cross section measurements

    SciTech Connect

    Tattersall, Wade; Centre for Antimatter-Matter Studies, School of Engineering and Physical Sciences, James Cook University, Townsville, 4810 Queensland ; Chiari, Luca; Machacek, J. R.; Anderson, Emma; Sullivan, James P.; White, Ron D.; Brunger, M. J.; Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur ; Buckman, Stephen J.; Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur ; Garcia, Gustavo; Blanco, Francisco

    2014-01-28

    Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions.

  7. Periprosthetic Fractures Following Total Knee Arthroplasty

    PubMed Central

    Kim, Nam Ki

    2015-01-01

    Periprosthetic fractures after total knee arthroplasty may occur in any part of the femur, tibia and patella, and the most common pattern involves the supracondylar area of the distal femur. Supracondylar periprosthetic fractures frequently occur above a well-fixed prosthesis, and risk factors include anterior femoral cortical notching and use of the rotational constrained implant. Periprosthetic tibial fractures are frequently associated with loose components and malalignment or malposition of implants. Fractures of the patella are much less common and associated with rheumatoid arthritis, use of steroid, osteonecrosis and malalignment of implants. Most patients with periprosthetic fractures around the knee are the elderly with poor bone quality. There are many difficulties and increased risk of nonunion after treatment because reduction and internal fixation is interfered with by preexisting prosthesis and bone cement. Additionally, previous soft tissue injury is another disadvantageous condition for bone healing. Many authors reported good clinical outcomes after non-operative treatment of undisplaced or minimally displaced periprosthetic fractures; however, open reduction or revision arthroplasty was required in displaced fractures or fractures with unstable prosthesis. Periprosthetic fractures around the knee should be prevented by appropriate technique during total knee arthroplasty. Nevertheless, if a periprosthetic fracture occurs, an appropriate treatment method should be selected considering the stability of the prosthesis, displacement of fracture and bone quality. PMID:25750888

  8. Methods development for total organic carbon accountability

    NASA Technical Reports Server (NTRS)

    Benson, Brian L.; Kilgore, Melvin V., Jr.

    1991-01-01

    This report describes the efforts completed during the contract period beginning November 1, 1990 and ending April 30, 1991. Samples of product hygiene and potable water from WRT 3A were supplied by NASA/MSFC prior to contract award on July 24, 1990. Humidity condensate samples were supplied on August 3, 1990. During the course of this contract chemical analyses were performed on these samples to qualitatively determine specific components comprising, the measured organic carbon concentration. In addition, these samples and known standard solutions were used to identify and develop methodology useful to future comprehensive characterization of similar samples. Standard analyses including pH, conductivity, and total organic carbon (TOC) were conducted. Colorimetric and enzyme linked assays for total protein, bile acid, B-hydroxybutyric acid, methylene blue active substances (MBAS), urea nitrogen, ammonia, and glucose were also performed. Gas chromatographic procedures for non-volatile fatty acids and EPA priority pollutants were also performed. Liquid chromatography was used to screen for non-volatile, water soluble compounds not amenable to GC techniques. Methods development efforts were initiated to separate and quantitate certain chemical classes not classically analyzed in water and wastewater samples. These included carbohydrates, organic acids, and amino acids. Finally, efforts were initiated to identify useful concentration techniques to enhance detection limits and recovery of non-volatile, water soluble compounds.

  9. Annular and Total Solar Eclipses of 2010

    NASA Technical Reports Server (NTRS)

    Espenak, Fred; Anderson, J.

    2008-01-01

    While most NASA eclipse bulletins cover a single eclipse, this publication presents predictions for two solar eclipses during 2010. This has required a different organization of the material into the following sections. Section 1 -- Eclipse Predictions: The section consists of a general discussion about the eclipse path maps, Besselian elements, shadow contacts, eclipse path tables, local circumstances tables, and the lunar limb profile. Section 2 -- Annular Solar Eclipse of 2010 Ja n 15: The section covers predictions and weather prospects for the annular eclipse. Section 3 -- Total Solar Eclipse of 2010 Jul 11: The se ction covers predictions and weather prospects for the total eclipse. Section 4 -- Observing Eclipses: The section provides information on eye safety, solar filters, eclipse photography, and making contact timings from the path limits. Section 5 -- Eclipse Resources: The final section contains a number of resources including information on the IAU Working Group on Eclipses, the Solar Eclipse Mailing List, the NASA eclipse bulletins on the Internet, Web sites for the two 2010 eclipses, and a summary identifying the algorithms, ephemerides, and paramete rs used in the eclipse predictions.

  10. Evaluation of the unstable total hip arthroplasty.

    PubMed

    Hamilton, William G; McAuley, James P

    2004-01-01

    Despite advances in total hip arthroplasty, dislocation persists as a troublesome complication for orthopaedic surgeons to manage, second only to prosthetic loosening as a cause of revision. Although this complication has received considerable attention, evaluation and treatment of the unstable total hip arthroplasty remain poorly understood. Therefore, it is important to evaluate such factors as underlying patient comorbidities, the direction of dislocation, soft-tissue tension, surgical technique, implant design, and component position. For recurrent hip instability, a careful history to determine the mechanism of dislocation is necessary, and a review of preoperative imaging studies can help clarify whether gross component malpositioning is present. Examination under anesthesia and intraoperative inspection are also important. Taking the hip through a full range of motion while directly visualizing the anatomy can help diagnose component-to-component impingement, inadequate offset soft-tissue tension, extra-articular impingement, and other possible contributing factors. Even when a seemingly obvious cause of dislocation, such as component malposition, is diagnosed, surgical results have been somewhat disappointing. Therefore, surgical planning should include all possible revision options, and the temptation to find the quick fix should be resisted. Patients should be extensively counseled regarding realistic expectations both before primary hip arthroplasty and in the face of a revision surgery for recurrent dislocations because long-term results are less than optimal. PMID:15116602

  11. Postoperative Autologous Reinfusion in Total Knee Replacement

    PubMed Central

    Crescibene, A.; Martire, F.; Gigliotti, P.; Rende, A.; Candela, M.

    2015-01-01

    Surgeries for total knee replacement (TKR) are increasing and in this context there is a need to develop new protocols for management and use of blood transfusion therapy. Autologous blood reduces the need for allogeneic blood transfusion and the aim of the present study was to verify the safety and the clinical efficacy. An observational retrospective study has been conducted on 124 patients, undergoing cemented total knee prosthesis replacement. Observed population was stratified into two groups: the first group received reinfusion of autologous blood collected in the postoperative surgery and the second group did not receive autologous blood reinfusion. Analysis of data shows that patients undergoing autologous blood reinfusion received less homologous blood bags (10.6% versus 30%; p = 0.08) and reduced days of hospitalization (7.88 ± 0.7 days versus 8.96 ± 2.47 days for the control group; p = 0.03). Microbiological tests were negative in all postoperatively salvaged and reinfused units. Our results emphasize the effectiveness of this procedure and have the characteristics of simplicity, low cost (€97.53 versus €103.79; p < 0.01), and easy reproducibility. Use of autologous drainage system postoperatively is a procedure that allows reducing transfusion of homologous blood bags in patients undergoing TKR. PMID:26442168

  12. [Epiglottic reconstruction after near total laryngectomy].

    PubMed

    Nong, H

    1989-01-01

    Near total laryngectomy results in large defect of the larynx requiring reconstruction. Pedicled composite epiglottic flap containing cartilage and epithelium is an ideal reconstructive tissue. This paper describes our experiences with 15 cases who underwent epiglottic laryngoplasty after near total laryngectomy since 1983. In order to avoid too wide a glottis leading to aspiration and poor voice, the Tucker technique has been modified in two ways: (1) The posterior edge of the epiglottis was sutured separately to the posterior edge of the cricoid opposing the true and false cords rather than the thyroid alar struts; An arytenoid was reformed. (2) Bilateral edge of the epiglottis was lowered. Anew pseudocord was formed. (3) The anterior epiglottic flap was manipulated to simulate the shape of anterior commissure. These modified reconstructive techniques resulted in decreasing in the transverse diameter and increasing slightly in the anterior-posterior length of the glottis, the functions of deglutition, phonation and respiration were improved significantly None had developed local recurrence and distant metastasis in more than 2-4 years. PMID:2485464

  13. Previous gastric bypass surgery complicating total thyroidectomy.

    PubMed

    Alfonso, Bianca; Jacobson, Adam S; Alon, Eran E; Via, Michael A

    2015-03-01

    Hypocalcemia is a well-known complication of total thyroidectomy. Patients who have previously undergone gastric bypass surgery may be at increased risk of hypocalcemia due to gastrointestinal malabsorption, secondary hyperparathyroidism, and an underlying vitamin D deficiency. We present the case of a 58-year-old woman who underwent a total thyroidectomy for the follicular variant of papillary thyroid carcinoma. Her history included Roux-en-Y gastric bypass surgery. Following the thyroid surgery, she developed postoperative hypocalcemia that required large doses of oral calcium carbonate (7.5 g/day), oral calcitriol (up to 4 ?g/day), intravenous calcium gluconate (2.0 g/day), calcium citrate (2.0 g/day), and ergocalciferol (50,000 IU/day). Her serum calcium levels remained normal on this regimen after hospital discharge despite persistent hypoparathyroidism. Bariatric surgery patients who undergo thyroid surgery require aggressive supplementation to maintain normal serum calcium levels. Preoperative supplementation with calcium and vitamin D is strongly recommended. PMID:25738720

  14. Total mass of the Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Vinogradova, T. A.; Chernetenko, Yu. A.

    2015-12-01

    The total mass of the Jupiter Trojans is estimated at (0.30 ± 0.19) × 10-10 M Sun using all available physical characteristics of these asteroids. The mass of asteroids in the L4 swarm ((0.19 ± 0.11) × 10-10 M Sun) is higher than that in the L5 swarm ((0.11 ± 0.07) × 10-10 M Sun) by a factor of 1.7. The obtained estimates include the hidden mass of asteroids that are not discovered yet. This hidden component constitutes 7% of the total mass. The number of Trojans with diameters larger than 1 km is estimated at 6 × 105. The number of such asteroids at the L4 Lagrangian point ( N L4 = 4 × 105) is two times higher than that at the L5 Lagrangian point ( N L5 = 2 × 105). It is found that the N L4/ N L5 ratio is increased at smaller asteroid sizes or higher absolute magnitudes H. This ratio equals just 1.3 for asteroids with H <11m (i.e., asteroids with diameters D > 30 km). The effect of gravitational perturbations from Trojans on the motion of Hildian asteroids and centaurs is evaluated. This effect turned out to be at the limit of accuracy of modern observations.

  15. Total Internal Reflection Fluorescence Flow Cytometry

    PubMed Central

    Wang, Jun; Bao, Ning; Paris, Leela L.; Geahlen, Robert L.; Lu, Chang

    2009-01-01

    Total internal reflection fluorescence microscopy (TIRFM) has been widely used to explore biological events that are close to the cell membrane by illuminating fluorescent molecules using the evanescent wave. However, TIRFM is typically limited to the examination of a low number of cells and the results do not reveal potential heterogeneity in the cell population. In this report, we develop an analytical tool referred to as total internal reflection fluorescence flow cytometry (TIRF-FC) to examine the region of the cell membrane with a throughput of ~100–150 cells/s and single cell resolution. We use an elastomeric valve that is partially closed to force flowing cells in contact with the glass surface where the evanescent field resides. We demonstrate that TIRF-FC is able to detect the differences in the subcellular location of an intracellular fluorescent protein. Proper data processing and analysis allows TIRF-FC to be quantitative. With the high throughput, TIRF-FC will be a very useful tool for generating information on cell populations with events and dynamics close to the cell surface. PMID:19007249

  16. 21 CFR 862.1175 - Cholesterol (total) test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Cholesterol (total) test system. 862.1175...Chemistry Test Systems § 862.1175 Cholesterol (total) test system. (a) Identification. A cholesterol (total) test system is a device...

  17. 21 CFR 862.1175 - Cholesterol (total) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Cholesterol (total) test system. 862.1175...Chemistry Test Systems § 862.1175 Cholesterol (total) test system. (a) Identification. A cholesterol (total) test system is a device...

  18. 21 CFR 862.1175 - Cholesterol (total) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Cholesterol (total) test system. 862.1175...Chemistry Test Systems § 862.1175 Cholesterol (total) test system. (a) Identification. A cholesterol (total) test system is a device...

  19. 21 CFR 862.1175 - Cholesterol (total) test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Cholesterol (total) test system. 862.1175...Chemistry Test Systems § 862.1175 Cholesterol (total) test system. (a) Identification. A cholesterol (total) test system is a device...

  20. 21 CFR 862.1175 - Cholesterol (total) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Cholesterol (total) test system. 862.1175...Chemistry Test Systems § 862.1175 Cholesterol (total) test system. (a) Identification. A cholesterol (total) test system is a device...

  1. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Operational standard-total hydrocarbons. 503.44 Section 503.44 Protection...503.44 Operational standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a...

  2. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Operational standard-total hydrocarbons. 503.44 Section 503.44 Protection...503.44 Operational standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a...

  3. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Operational standard-total hydrocarbons. 503.44 Section 503.44 Protection...503.44 Operational standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a...

  4. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Operational standard-total hydrocarbons. 503.44 Section 503.44 Protection...503.44 Operational standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a...

  5. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Operational standard-total hydrocarbons. 503.44 Section 503.44 Protection...503.44 Operational standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a...

  6. AN UNCOUNTABLY INFINITE NUMBER OF INDECOMPOSABLE TOTALLY REFLEXIVE MODULES

    E-print Network

    Takahashi, Ryo

    AN UNCOUNTABLY INFINITE NUMBER OF INDECOMPOSABLE TOTALLY REFLEXIVE MODULES RYO TAKAHASHI Abstract- tain totally reflexive module implies the existence of an uncountably infinite number of isomorphism classes of indecomposable totally reflexive modules. 1. Introduction Throughout the present paper, we

  7. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Total protein test system. 862.1635 Section 862...Chemistry Test Systems § 862.1635 Total protein test system. (a) Identification. A total protein test system is a device intended to...

  8. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Total protein test system. 862.1635 Section 862...Chemistry Test Systems § 862.1635 Total protein test system. (a) Identification. A total protein test system is a device intended to...

  9. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Total protein test system. 862.1635 Section 862...Chemistry Test Systems § 862.1635 Total protein test system. (a) Identification. A total protein test system is a device intended to...

  10. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Total protein test system. 862.1635 Section 862...Chemistry Test Systems § 862.1635 Total protein test system. (a) Identification. A total protein test system is a device intended to...

  11. Zooplankton and the total phosphorus chlorophyll a relationship: hierarchical Bayesian

    E-print Network

    Notre Dame, University of

    Zooplankton and the total phosphorus ­ chlorophyll a relationship: hierarchical Bayesian analysis: Zooplankton grazing is important in resolving residual variation around the total phosphorus ­ chlorophyll found consistent effects of total zooplankton biomass, but not zooplankton length, on chlorophyll a

  12. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Total temporomandibular joint prosthesis. 872.3940 Section 872...872.3940 Total temporomandibular joint prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is...

  13. Tracer monitored titrations: measurement of total alkalinity.

    PubMed

    Martz, Todd R; Dickson, Andrew G; DeGrandpre, Michael D

    2006-03-15

    We introduce a new titration methodology, tracer monitored titration (TMT), in which analyses are free of volumetric and gravimetric measurements and insensitive to pump precision and reproducibility. Spectrophotometric monitoring of titrant dilution, rather than volume increment, lays the burden of analytical performance solely on the spectrophotometer. In the method described here, the titrant is a standardized mixture of acid-base indicator and strong acid. Dilution of a pulse of titrant in a titration vessel is tracked using the total indicator concentration measured spectrophotometrically. The concentrations of reacted and unreacted indicator species, derived from Beer's law, are used to calculate the relative proportions of titrant and sample in addition to the equilibrium position (pH) of the titration mixture. Because the method does not require volumetric or gravimetric additions of titrant, simple low-precision pumps can be used. Here, we demonstrate application of TMT for analysis of total alkalinity (A(T)). High-precision, high-accuracy seawater A(T) measurements are crucial for understanding, for example, the marine CaCO3 budget and saturation state, anthropogenic CO2 penetration into the oceans, calcareous phytoplankton blooms, and coral reef dynamics. We present data from 286 titrations on three types of total alkalinity standards: Na2CO3 in 0.7 mol kg x soln(-1) NaCl, NaOH in 0.7 mol kg x soln(-1) NaCl, and a seawater Certified Reference Material (CRM). Based on Na2CO3 standards, the accuracy and precision are +/-0.2 and +/-0.1% (4 and 2 micromol kg x soln(-1) for A(T) approximately 2100-2500 micromol kg x soln(-1), n = 242), using low-precision solenoid pumps to introduce sample and titrant. Similar accuracy and precision were found for analyses run 42 days after the initial experiments. Excellent performance is achieved by optimizing the spectrophotometric detection system and relying upon basic chemical thermodynamics for calculating the equivalence point. Although applied to acid-base titrations in this paper, the approach should be generally applicable to other types of titrations. PMID:16536416

  14. Image-guided total marrow and total lymphatic irradiation using helical tomotherapy

    SciTech Connect

    Schultheiss, Timothy E. . E-mail: Schultheiss@coh.org; Wong, Jeffrey; Liu, An; Olivera, Gustavo; Somlo, George

    2007-03-15

    Purpose: To develop a treatment technique to spare normal tissue and allow dose escalation in total body irradiation (TBI). We have developed intensity-modulated radiotherapy techniques for the total marrow irradiation (TMI), total lymphatic irradiation, or total bone marrow plus lymphatic irradiation using helical tomotherapy. Methods and Materials: For TBI, we typically use 12 Gy in 10 fractions delivered at an extended source-to-surface distance (SSD). Using helical tomotherapy, it is possible to deliver equally effective doses to the bone marrow and lymphatics while sparing normal organs to a significant degree. In the TMI patients, whole body skeletal bone, including the ribs and sternum, comprise the treatment target. In the total lymphatic irradiation, the target is expanded to include the spleen and major lymph node areas. Sanctuary sites for disease (brain and testes) are included when clinically indicated. Spared organs include the lungs, esophagus, parotid glands, eyes, oral cavity, liver, kidneys, stomach, small and large intestine, bladder, and ovaries. Results: With TBI, all normal organs received the TBI dose; with TMI, total lymphatic irradiation, and total bone marrow plus lymphatic irradiation, the visceral organs are spared. For the first 6 patients treated with TMI, the median dose to organs at risk averaged 51% lower than would be achieved with TBI. By putting greater weight on the avoidance of specific organs, greater sparing was possible. Conclusion: Sparing of normal tissues and dose escalation is possible using helical tomotherapy. Late effects such as radiation pneumonitis, veno-occlusive disease, cataracts, neurocognitive effects, and the development of second tumors should be diminished in severity and frequency according to the dose reduction realized for the organs at risk.

  15. Total synthesis of Class II and Class III Galbulimima Alkaloids

    E-print Network

    Tjandra, Meiliana

    2010-01-01

    I. Total Synthesis of All Class III Galbulimima Alkaloids We describe the total synthesis of (+)- and (-)-galbulimima alkaloid 13, (-)-himgaline anad (-)-himbadine. The absolute stereochemistry of natural (-)-galbulimima ...

  16. Enantioselective total syntheses of acylfulvene, irofulven, and the agelastatins

    E-print Network

    Siegel, Dustin S. (Dustin Scott), 1980-

    2010-01-01

    I. Enantioselective Total Synthesis of (-)-Acylfulvene, and (-)-Irofulven We report the enantioselective total synthesis of (-)-acylfulvene and (-)-irofulven, which features metathesis reactions for the rapid assembly of ...

  17. Modeling total expenditure on warranty claims

    E-print Network

    Mitra, Abhimanyu

    2010-01-01

    We approximate the distribution of total expenditure of a retail company over warranty claims incurred in a fixed period [0, T], say the following quarter. We consider two kinds of warranty policies, namely, the non-renewing free replacement warranty policy and the non-renewing pro-rata warranty policy. Our approximation holds under modest assumptions on the distribution of the sales process of the warranted item and the nature of arrivals of warranty claims. We propose a method of using historical data to statistically estimate the parameters of the approximate distribution. Our methodology is applied to the warranty claims data from a large car manufacturer for a single car model and model year.

  18. Shenandoah Solar Total-Energy Project

    SciTech Connect

    Leonard, J.A.; Hunke, R.W.

    1982-12-01

    The design and construction of the world's first solar total-energy plant in the private sector has been completed and checkout is underway. During its operational phase, the solar plant will furnish electrical power, process steam, and other thermal energy to a nearby knitwear factory. The solar system consists of a collector field containing 114 parabolic-dish collectors which supply thermal energy at 400/sup 0/C to drive a 400 kW multi-stage Rankine-cycle turbine generator. Some steam is extracted from the turbine and supplied to the knitwear manufacturing processes. The system will be grid-connected. Presented are: (1) a description of the system and components being installed; (2) a summary of performance testing of the extraction turbine and of four prototype parabolic-dish collectors; and (3) a discussion of design considerations and insights which have general applicability to solar-thermal-system designs.

  19. Total synthesis of the Daphniphyllum alkaloid daphenylline

    NASA Astrophysics Data System (ADS)

    Lu, Zhaoyong; Li, Yong; Deng, Jun; Li, Ang

    2013-08-01

    The Daphniphyllum alkaloids are a large class of natural products isolated from a genus of evergreen plants widely used in Chinese herbal medicine. They display a remarkable range of biological activities, including anticancer, antioxidant, and vasorelaxation properties as well as elevation of nerve growth factor. Daphenylline is a structurally unique member among the predominately aliphatic Daphniphyllum alkaloids, and contains a tetrasubstituted arene moiety mounted on a sterically compact hexacyclic scaffold. Herein, we describe the first total synthesis of daphenylline. A gold-catalysed 6-exo-dig cyclization reaction and a subsequent intramolecular Michael addition reaction, inspired by Dixon's seminal work, were exploited to construct the bridged 6,6,5-tricyclic motif of the natural product at an early stage, and the aromatic moiety was forged through a photoinduced olefin isomerization/6?-electrocyclization cascade followed by an oxidative aromatization process.

  20. Doppler tomography by total variation minimization

    NASA Astrophysics Data System (ADS)

    Uemura, Makoto; Kato, Taichi; Nogami, Daisaku; Mennickent, Ronald

    2015-04-01

    We have developed a new model of Doppler tomography using total variation minimization (DTTVM). This method can reconstruct localized and nonaxisymmetric profiles with sharp edges in the Doppler map. This characteristic is emphasized in the case where input data are small in number. We apply this model to natural data for the dwarf nova WZ Sge in superoutburst and TU Men in quiescence. We confirm that DTTVM can reproduce the observed spectra with high precision. Compared with the models based on the maximum entropy method, our new model can provide Doppler maps that little depend on the hyperparameter and on the presence of the absorption core. We also introduce a cross-validation method of estimating reasonable values of a hyperparameter in the model from the data themselves.

  1. Total Quality Management and Cost of Quality

    NASA Astrophysics Data System (ADS)

    Hadjicostas, Evsevios

    Before we start analysing the philosophy of Total Quality Management it is worthwhile going back to the early days of quality and the quality movement. In fact, the quality concept dates back to the creation of Adam and Eve: “And God saw every thing that he had made, and, behold, it was very good”. (Genesis A 31). It is remarkable that at the end of each day, looking at his creations God was saying, “This is good”. However, at the end of the sixth day, after he finished the creation of human beings, he said, “This is very good”. It is amazing that he did not say, “This is excellent”. This is because excellence is something that we gain after tireless effort. God left room for improvement in order to challenge us and make our life more attractive, which has really happened!

  2. UPRE method for total variation parameter selection

    SciTech Connect

    Wohlberg, Brendt; Lin, Youzuo

    2008-01-01

    Total Variation (TV) Regularization is an important method for solving a wide variety of inverse problems in image processing. In order to optimize the reconstructed image, it is important to choose the optimal regularization parameter. The Unbiased Predictive Risk Estimator (UPRE) has been shown to give a very good estimate of this parameter for Tikhonov Regularization. In this paper we propose an approach to extend UPRE method to the TV problem. However, applying the extended UPRE is impractical in the case of inverse problems such as de blurring, due to the large scale of the associated linear problem. We also propose an approach to reducing the large scale problem to a small problem, significantly reducing computational requirements while providing a good approximation to the original problem.

  3. Radiological evaluation of painful total hip replacement

    SciTech Connect

    Jamshid, T.; Schneider, R.; Freiberger, R.H.

    1981-11-01

    Ninety-four cases of clinically failed, cemented, total hip prostheses requiring surgery were reviewed to determine the accuracy of preoperative plain radiography, culture of aspirated fluid, arthrography, and bone scanning. When radiopaque cement had been used to embed the prosthesis, plain radiography was highly accurate in detecting a loose femoral component, less so in detecting a loose acetabular component. Culture of aspirated fluid was accurate in diagnosing infection. A positive arthrogram identified loosening with good accuracy; however, a negative arthrogram did not reliably exclude loosening. /sup 99/mTc bone scans frequently differentiated loosening from loosening with infection. The suggested sequence of diagnostic tests is plain radiography followed by bone scanning. If the bone scan shows diffuse augmented uptake, culture of aspirated fluid followed by arthrography is indicated.

  4. Radiological evaluation of painful total hip replacement

    SciTech Connect

    Tehranzadeh, J.; Schneider, R.; Freiberger, R.H.

    1981-01-01

    Ninety-four cases of clinically failed, cemented, total hip prostheses requiring surgery were reviewed to determine the accuracy of preoperative plain radiography, culture of aspirated fluid, arthrography, and bone scanning. When radiopaque cement had been used to embed the prosthesis, plain radiography was highly accurate in detecting a loose femoral component, less so in detecting a loose acetabular component. Culture of aspirated fluid was accurate in diagnosing infection. A positive arthrogram identified loosening with good accuracy; however, a negative arthrogram did not reliably exclude loosening. /sup 99/mTc bone scans frequently differentiated loosening from loosening with infection. The suggested sequence of diagnostic tests is plain radiography followed by bone scanning. If the bone scan shows diffuse augmented uptake, culture of aspirated fluid followed by arthrography is indicated.

  5. Total Ore Processing Integration and Management

    SciTech Connect

    Leslie Gertsch; Richard Gertsch

    2006-01-30

    This report outlines the technical progress achieved for project DE-FC26-03NT41785 (Total Ore Processing Integration and Management) during the period 01 July through 30 September of 2005. This ninth quarterly report discusses the activities of the project team during the period 1 July through 30 September 2005. Richard Gertsch's unexpected death due to natural causes while in Minnesota to work on this project has temporarily slowed progress. Statistical analysis of the Minntac Mine data set for late 2004 is continuing. Preliminary results raised several questions that could be amenable to further study. Detailed geotechnical characterization is being applied to improve the predictability of mill and agglomerator performance at Hibtac Mine.

  6. Cementless total knee arthroplasty: a review.

    PubMed

    Cherian, Jeffrey J; Banerjee, Samik; Kapadia, Bhaveen H; Jauregui, Julio J; Harwin, Steven F; Mont, Michael A

    2014-06-01

    There is ongoing debate over the use of cementless fixation in total knee arthroplasty (TKA). Previous generation prostheses resulted in less than optimal outcomes which was somewhat attributed to design issues. As the demand for TKA is continuously increasing and the current U.S. age population is getting younger, cemented fixation may not provide adequate long-term outcomes due to failure of fixation. Thus, there has been a reemergence of the development and use of cementless TKA. Recent short-term trials have demonstrated that modern cementless TKA has comparable survivorship and functional outcomes as cemented prostheses. However, more prospective, randomized trials are needed to clearly delineate any differences between these two fixation options. PMID:24764231

  7. 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

  8. Subwavelength total acoustic absorption with degenerate resonators

    NASA Astrophysics Data System (ADS)

    Yang, Min; Meng, Chong; Fu, Caixing; Li, Yong; Yang, Zhiyu; Sheng, Ping

    2015-09-01

    We report the experimental realization of perfect sound absorption by sub-wavelength monopole and dipole resonators that exhibit degenerate resonant frequencies. This is achieved through the destructive interference of two resonators' transmission responses, while the matching of their averaged impedances to that of air implies no backscattering, thereby leading to total absorption. Two examples, both using decorated membrane resonators (DMRs) as the basic units, are presented. The first is a flat panel comprising a DMR and a pair of coupled DMRs, while the second one is a ventilated short tube containing a DMR in conjunction with a sidewall DMR backed by a cavity. In both examples, near perfect absorption, up to 99.7%, has been observed with the airborne wavelength up to 1.2 m, which is at least an order of magnitude larger than the composite absorber. Excellent agreement between theory and experiment is obtained.

  9. NASA total quality management 1989 accomplishments report

    NASA Technical Reports Server (NTRS)

    Tai, Betty P. (editor); Stewart, Lynne M. (editor)

    1990-01-01

    NASA and contractor employees achieved many notable improvements in 1989. The highlights of those improvements, described in this seventh annual Accomplishments Report, demonstrate that the people who support NASA's activities are getting more involved in quality and continuous improvement efforts. Their gains solidly support NASA's and this Nation's goal to remain a leader in space exploration and in world-wide market competition, and, when communicated to others through avenues such as this report, foster improvement efforts across government and industry. The principles in practice which led to these process refinements are important cultural elements to any organization's productivity and quality efforts. The categories in this report reflect NASA principles set forth in the 1980's and are more commonly known today as Total Quality Management (TQM): top management leadership and support; strategic planning; focus on the customer; employee training and recognition; employee empowerment and teamwork; measurement and analysis; and quality assurance.

  10. Total parenteral nutrition: potion or poison?

    PubMed

    Jeejeebhoy, K N

    2001-08-01

    The role of nutritional support in clinical care has burgeoned over the past 40 y. Initially, total parenteral nutri-tion (TPN) was considered to be the standard of care. Later, the concept that enteral nutrition (EN) promoted gut function and prevented the translocation of intestinal bacteria resulted in EN becoming the standard of care. Furthermore, TPN was consid-ered to be a dangerous form of therapy. Critical review of the data suggests that, in humans, TPN does not cause mucosal atrophy or increase bacterial translocation. Increased sepsis with TPN can be ascribed to overfeeding; the dangers of TPN-induced complications have been exaggerated. TPN is an equally effective alternative to EN when a risk of malnutrition is present and EN is not tolerated or when gut failure is present. PMID:11470715

  11. The total parenteral nutrition service: an update.

    PubMed Central

    Clarke, P. J.; Ball, M. J.; Tunbridge, A.; Kettlewell, M. G.

    1988-01-01

    A total parenteral nutrition (TPN) service was established in Oxford in 1978 and the results of the first 3 years were published in 1983. Since then the service has provided intravenous nutritional support to an increasing number of patients, representing a considerable and increasing financial burden on the constrained hospital budget. To assess whether this expansion is justified, and whether regular review has improved the care given to patients, a further audit has been performed for the period 1983 to 1986. Despite an increase of approximately 60% in the numbers of patients parenterally fed, line associated morbidity was less and there were no serious metabolic problems or deaths. Patient selection has improved, as judged by fewer patients fed for periods less than a week. Regular audit appears to improve the selection and treatment of patients but there remains a need to identify subgroups of patients for whom this costly form of nutrition is essential. PMID:3142330

  12. 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. PMID:26523281

  13. Recognizing the pitfalls of total quality management

    SciTech Connect

    Laza, R.W.; Wheaton, P.L.

    1990-04-12

    Should utilities be interested in total quality management (TQM) After all, the argument that better quality products should increase the sales and result in higher profits does not readily apply to a public utility operating in a monopolistic environment. Yet, utilities in the US are moving toward a more competitive environment; FPL's success with its TQM programs is forcing most utilities to look at TQM so as not to risk future competitive disadvantage. A few regulatory commissions have already started to inquire as to what steps utilities under their jurisdiction are taking to pursue the benefits of TQM. This article will address two facets of this issue. First, it will define what TQM is and identify the pitfalls that might keep a utility from attaining the full benefits of a well-executed TQM program. Second, it will lay out a simple, straightforward approach that a utility can use to determine whether and how to utilize this new management tool.

  14. Total quality management issues in managed care.

    PubMed

    McLaughlin, C P; Kaluzny, A D

    1997-01-01

    The implementation of total quality management (TQM) in health care has gone on in parallel with the growth of managed care. What is the interaction between the two? Key issues are the ascendance of cost control over quality in many areas, erosion of employee commitment and loyalty, and a short-run orientation. Associated with this is an emphasis on organizational learning rather than learning by autonomous professionals. Both TQM and managed care acknowledge the dynamic nature of clinical processes and the ability and responsibility of both institutions and clinicians to improve their processes. Both are consistent with efforts to identify and implement best practices. However, these similarities should not mask fundamental differences. Continuous improvement must shift its focus from avoiding unnecessary variation to facilitating rapid organizational learning and institutionalizing mass customization into the delivery of health services. PMID:9327355

  15. Total quality management in clinical virology laboratories.

    PubMed

    Tibbets, M W; Gomez, R; Kannangai, R; Sridharan, G

    2006-10-01

    The diagnostic laboratories in India are progressively promoting higher standards and are moving towards accreditation and international acceptance. Hence, the concept of "Quality" will need to be understood and implemented. Total quality management (TQM) in a laboratory is an integrated program involving all laboratory staff and management. TQM is a framework to operate and it is aiming for integration, consistency, increase in efficiency and a continuous drive for improvement. A well structured clinical virology service will include serology setup, cell culture facility and capacity for molecular diagnosis. The quality of results from the laboratory is significantly influenced by many pre-analytical and post-analytical factors which needed attention. The end goal of the TQM should be to provide the best care possible for the patient. PMID:17185843

  16. Changes in total body water during spaceflight

    NASA Technical Reports Server (NTRS)

    Leach, Carolyn S.; Inners, L. D.; Charles, John B.

    1991-01-01

    Total body water (TBW) changes occurring in humans as a consequence of prolonged exposure to microgravity were measured in five male crewmembers of Space Shuttle missions STS-61C and STS-26. It was found that the inflight mean TBW values were significantly different from the preflight and postflight values, while the preflight TBW values were not significantly different from the postflight values. It was also found that individuals may differ in the rate at which they respond to weightlessness. Of the three crewmen who reported experiencing no symptoms of space motion sickness (SMS), two had not exhibited a decrease of TBW at the time of measurements (24 hrs after launch), while the two crewmen who reported SMS of intermediate severity showed a decrease of several kg by 24 hrs, suggesting that dehydration might be an important factor affecting the rate of TBW decrease.

  17. Totally Asymmetric Simple Exclusion Process on Networks

    NASA Astrophysics Data System (ADS)

    Neri, Izaak; Kern, Norbert; Parmeggiani, Andrea

    2011-08-01

    We study the totally asymmetric simple exclusion process (TASEP) on complex networks, as a paradigmatic model for transport subject to excluded volume interactions. Building on TASEP phenomenology on a single segment and borrowing ideas from random networks we investigate the effect of connectivity on transport. In particular, we argue that the presence of disorder in the topology of vertices crucially modifies the transport features of a network: irregular networks involve homogeneous segments and have a bimodal distribution of edge densities, whereas regular networks are dominated by shocks leading to a unimodal density distribution. The proposed numerical approach of solving for mean-field transport on networks provides a general framework for studying TASEP on large networks, and is expected to generalize to other transport processes.

  18. Totally asymmetric simple exclusion process on networks.

    PubMed

    Neri, Izaak; Kern, Norbert; Parmeggiani, Andrea

    2011-08-01

    We study the totally asymmetric simple exclusion process (TASEP) on complex networks, as a paradigmatic model for transport subject to excluded volume interactions. Building on TASEP phenomenology on a single segment and borrowing ideas from random networks we investigate the effect of connectivity on transport. In particular, we argue that the presence of disorder in the topology of vertices crucially modifies the transport features of a network: irregular networks involve homogeneous segments and have a bimodal distribution of edge densities, whereas regular networks are dominated by shocks leading to a unimodal density distribution. The proposed numerical approach of solving for mean-field transport on networks provides a general framework for studying TASEP on large networks, and is expected to generalize to other transport processes. PMID:21902376

  19. Total chemical management in photographic processing

    USGS Publications Warehouse

    Luden, Charles; Schultz, Ronald

    1985-01-01

    The mission of the U. S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center is to produce high-quality photographs of the earth taken from aircraft and Landsat satellite. In order to meet the criteria of producing research-quality photographs, while at the same time meeting strict environmental restrictions, a total photographic chemical management system was installed. This involved a three-part operation consisting of the design of a modern chemical analysis laboratory, the implementation of a chemical regeneration system, and the installation of a waste treatment system, including in-plant pretreatment and outside secondary waste treatment. Over the last ten years the result of this program has yielded high-quality photographs while saving approximately 30,000 per year and meeting all Environmental Protection Agency (EPA) restrictions.

  20. The total synthesis of Isodon diterpenes.

    PubMed

    Lazarski, Kiel E; Moritz, Benjamin J; Thomson, Regan J

    2014-09-26

    Families of structurally related molecules often provide stimulating targets for organic chemists that are engaged in the development of new methods and strategies for natural product synthesis. While typically focused on specific molecules, these synthetic investigations often lead to generalizable concepts and significant opportunities for learning in a greater sense. Historically well-investigated families of natural products, such as the prostanoids, indole alkaloids, and macrolide antibiotics, provide ample evidence for the enduring value of these collective activities. In this Minireview, we turn our attention to the polycyclic family of diterpenes isolated from the Isodon genus of plants and provide an account of the recent methods and strategies utilized for their total synthesis. PMID:25159338

  1. Total Sleep Time Severely Drops during Adolescence

    PubMed Central

    Leger, Damien; Beck, François; Richard, Jean-Baptiste; Godeau, Emmanuelle

    2012-01-01

    Restricted sleep duration among young adults and adolescents has been shown to increase the risk of morbidities such as obesity, diabetes or accidents. However there are few epidemiological studies on normal total sleep time (TST) in representative groups of teen-agers which allow to get normative data. Purpose To explore perceived total sleep time on schooldays (TSTS) and non schooldays (TSTN) and the prevalence of sleep initiating insomnia among a nationally representative sample of teenagers. Methods Data from 9,251 children aged 11 to 15 years-old, 50.7% of which were boys, as part of the cross-national study 2011 HBSC were analyzed. Self-completion questionnaires were administered in classrooms. An estimate of TSTS and TSTN (week-ends and vacations) was calculated based on specifically designed sleep habits report. Sleep deprivation was estimated by a TSTN – TSTS difference >2 hours. Sleep initiating nsomnia was assessed according to International classification of sleep disorders (ICSD 2). Children who reported sleeping 7 hours or less per night were considered as short sleepers. Results A serious drop of TST was observed between 11 yo and 15 yo, both during the schooldays (9 hours 26 minutes vs. 7 h 55 min.; p<0.001) and at a lesser extent during week-ends (10 h 17 min. vs. 9 h 44 min.; p<0.001). Sleep deprivation concerned 16.0% of chidren aged of 11 yo vs. 40.5% of those of 15 yo (p<0.001). Too short sleep was reported by 2.6% of the 11 yo vs. 24.6% of the 15 yo (p<0.001). Conclusion Despite the obvious need for sleep in adolescence, TST drastically decreases with age among children from 11 to 15 yo which creates significant sleep debt increasing with age. PMID:23082111

  2. Minimally invasive total hip arthroplasty: in opposition.

    PubMed

    Hungerford, David S

    2004-06-01

    At the Knee Society Winter Meeting in 2003, Seth Greenwald and I debated about whether there should be new standards (ie, regulations) applied to the release of information to the public on "new developments." I argued for the public's "right to know" prior to the publication of peer-reviewed literature. He argued for regulatory constraint or "proving by peer-reviewed publication" before alerting the public. It is not a contradiction for me to currently argue against the public advertising of minimally invasive (MIS) total hip arthroplasty as not yet being in the best interest of the public. It is hard to remember a concept that has so captured both the public's and the surgical community's fancy as MIS. Patients are "demanding" MIS without knowing why. Surgeons are offering it as the next best, greatest thing without having developed the skill and experience to avoid the surgery's risks. If you put "minimally invasive hip replacement" into the Google search engine (http://www.google.com), you get 5,170 matches. If you put the same words in PubMed (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi), referencing the National Library of Medicine database, you get SEVENTEEN; none is really a peer-reviewed article. Most are 1 page papers in orthopedics from medical education meetings. On the other hand, there are over 6,000 peer-reviewed articles on total hip arthroplasty. Dr. Thomas Sculco, my couterpart in this debate, wrote an insightful editorial in the American Journal of Orthopedic Surgery in which he stated: "Although these procedures have generated incredible interest and enthusiasm, I am concerned that they may be performed to the detriment of our patients." I couldn't agree with him more. Smaller is not necessarily better and, when it is worse, it will be the "smaller" that is held accountable. PMID:15190556

  3. Total Percutaneous Aortic Repair: Midterm Outcomes

    SciTech Connect

    Bent, Clare L. Fotiadis, Nikolas; Renfrew, Ian; Walsh, Michael; Brohi, Karim; Kyriakides, Constantinos; Matson, Matthew

    2009-05-15

    The purpose of this study was to examine the immediate and midterm outcomes of percutaneous endovascular repair of thoracic and abdominal aortic pathology. Between December 2003 and June 2005, 21 patients (mean age: 60.4 {+-} 17.1 years; 15 males, 6 females) underwent endovascular stent-graft insertion for thoracic (n = 13) or abdominal aortic (n = 8) pathology. Preprocedural computed tomographic angiography (CTA) was performed to assess the suitability of aorto-iliac and common femoral artery (CFA) anatomy, including the degree of CFA calcification, for total percutaneous aortic stent-graft repair. Percutaneous access was used for the introduction of 18- to 26-Fr delivery devices. A 'preclose' closure technique using two Perclose suture devices (Perclose A-T; Abbott Vascular) was used in all cases. Data were prospectively collected. Each CFA puncture site was assessed via clinical examination and CTA at 1, 6, and 12 months, followed by annual review thereafter. Minimum follow-up was 36 months. Outcome measures evaluated were rates of technical success, conversion to open surgical repair, complications, and late incidence of arterial stenosis at the site of Perclose suture deployment. A total of 58 Perclose devices were used to close 29 femoral arteriotomies. Outer diameters of stent-graft delivery devices used were 18 Fr (n = 5), 20 Fr (n = 3), 22 Fr (n = 4), 24 Fr (n = 15), and 26 Fr (n = 2). Percutaneous closure was successful in 96.6% (28/29) of arteriotomies. Conversion to surgical repair was required at one access site (3.4%). Mean follow-up was 50 {+-} 8 months. No late complications were observed. By CT criteria, no patient developed a >50% reduction in CFA caliber at the site of Perclose deployment during the study period. In conclusion, percutaneous aortic stent-graft insertion can be safely performed, with a low risk of both immediate and midterm access-related complications.

  4. Total N losses in managed grassland systems

    NASA Astrophysics Data System (ADS)

    Neftel, A.; Felber, R.; Jocher, M.; Conen, F.; Schibig, M.

    2009-04-01

    Total N losses in managed grassland systems Losses of nitrogen as N2 constitutes a major fraction of the N-turnover in managed grassland systems and might be in the order of 30% of the applied N (van der Salm et al., 2007). Consequently this loss path is limiting the N efficiency. In the framework of the EU IP project NitroEurope we aim to comprehensibly determine the nitrogen flows in a managed grassland system under a cut regime (i.e. no grazing). A major effort is devoted to establish an operational technique to determine total N-losses on 30 cm soil core using the acetylene inhibition technique. In a recent review by Groffman et al. (2006) the acetylene inhibition technique is considered as a robust technique for soils with a high inorganic nitrogen supply despite its serious limitations. Soil cores are isothermally transported in the laboratory within less than three hours and then measured within the next 24 hours without and with addition of acetylene. The experimental systems allows to measure up to eight samples in parallel. The detection limit of the system is 10 ng N2O - N m-2s-1. An estimate of the range of annual losses is presented with a discussion of potential biases. References: Groffman P. et al. (2006): Methods for measuring denitrification: diverse approaches for a difficult problem. Ecological Applications 16(6) 2091-2122 Van der Salm C. et al. (2007): Estimation of nitrogen losses via denitrificatrion from a heavy clay soil under grass. Agriculture, Ecosystems and Environment, 311-319

  5. Development of a totally implantable artificial heart.

    PubMed

    Rowles, J R; Khanwilkar, P S; Diegel, P D; Hansen, A C; Bearnson, G B; Smith, K D; Tatsumi, E; Olsen, D B

    1992-01-01

    The first generation of an integrated, totally implantable electrohydraulic total artificial heart was designed for long-term cardiac replacement. The system consists of an elliptical blood pump with an interatrial shunt, Medtronic-Hall 27 mm and 25 mm inflow and outflow valves, respectively, an energy converter consisting of an axial-flow, hydraulic pump driven by a brushless DC motor, and an electronics system with transcutaneous energy transmission and telemetry. Energy is supplied by internal nickel-cadmium rechargeable batteries that supply power for 20 min and external silver-zinc batteries that are designed to supply energy to run the system for 5 hr. The blood pump consists of a single layer diaphragm cast from Biolon, with joined right and left ventricles sharing a common base. The dynamic stroke volume is 84 ml, and maximum cardiac output is 9.2 L/min at a heart rate of 110 beats/min on the mock circulation. A 4.3 mm diameter interatrial shunt is used to balance the volumetrically coupled ventricles. The energy converter pumps hydraulic fluid alternately between ventricles, with controlled, active filling in one ventricle during the systolic phase of the other ventricle. Internal or external controllers adjust the heart rate and motor speed to maintain normal atrial filling pressures and full stroke. Electromagnetic induction is used to transfer energy through the skin and a bidirectional infrared data link incorporated within the transcutaneous energy transmission coils is used to transmit information. The entire system is being assembled and refined for long-term animal implant studies. PMID:1457955

  6. Efficient oil palm total RNA extraction with a total RNA extraction kit.

    PubMed

    Habib, S H; Saud, H M; Kausar, H

    2014-01-01

    Oil palm tissues are rich in polyphenols, polysaccharides and secondary metabolites; these can co-precipitate with RNA, causing problems for downstream applications. We compared two different methods (one conventional and a kit-based method - Easy-Blue(TM) Total RNA Extraction Kit) to isolate total RNA from leaves, roots and shoot apical meristems of tissue culture derived truncated leaf syndrome somaclonal oil palm seedlings. The quality and quantity of total RNA were compared through spectrophotometry and formaldehyde gel electrophoresis. The specificity and applicability of the protocols were evaluated for downstream applications, including cDNA synthesis and RT-PCR analysis. We found that the conventional method gave higher yields of RNA but took longer, and it was contaminated with genomic DNA. This method required extra genomic DNA removal steps that further reduced the RNA yield. The kit-based method, on the other hand, produced good yields as well as well as good quality RNA, within a very short period of time from a small amount of starting material. Moreover, the RNA from the kit-based method was more suitable for synthesizing cDNA and RT-PCR amplification than the conventional method. Therefore, we conclude that the Easy-BlueTM Total RNA Extraction Kit method is suitable and superior for isolation of total RNA from oil palm leaf, root and shoot apical meristem. PMID:24781991

  7. Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples

    DOEpatents

    Caldwell, John T. (Los Alamos, NM); Kunz, Walter E. (Santa Fe, NM); Cates, Michael R. (Oak Ridge, TN); Franks, Larry A. (Santa Barbara, CA)

    1985-01-01

    Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for .sup.239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

  8. Positron interactions with water-total elastic, total inelastic, and elastic differential cross section measurements.

    PubMed

    Tattersall, Wade; Chiari, Luca; Machacek, J R; Anderson, Emma; White, Ron D; Brunger, M J; Buckman, Stephen J; Garcia, Gustavo; Blanco, Francisco; Sullivan, James P

    2014-01-28

    Utilising a high-resolution, trap-based positron beam, we have measured both elastic and inelastic scattering of positrons from water vapour. The measurements comprise differential elastic, total elastic, and total inelastic (not including positronium formation) absolute cross sections. The energy range investigated is from 1 eV to 60 eV. Comparison with theory is made with both R-Matrix and distorted wave calculations, and with our own application of the Independent Atom Model for positron interactions. PMID:25669536

  9. Coronal Dynamics at Recent Total Solar Eclipses

    NASA Astrophysics Data System (ADS)

    Pasachoff, J. M.; Lu, M.; Davis, A. B.; Demianski, M.; Rusin, V.; Saniga, M.; Seaton, D. B.; Lucas, R.; Babcock, B. A.; Dantowitz, R.; Gaintatzis, P.; Seeger, C. H.; Malamut, C.; Steele, A.

    2014-12-01

    Our composite images of the solar corona based on extensive imaging at the total solar eclipses of 2010 (Easter Island), 2012 (Australia), and 2013 (Gabon) reveal several coronal mass ejections and other changes in coronal streamers and in polar plumes. Our resultant spatial resolution is finer than that available in imaging from spacecraft, including that from SOHO/LASCO or STEREO. We trace the eruptions back to their footpoints on the sun using imaging from SDO and SWAP, and follow them upwards through the corona, measuring velocities. The high-resolution computer compositing by Miloslav Druckmüller and Hana Druckmüllerová (2010 and 2013) and Pavlos Gaintatzis (2012) allows comparison of our images with those taken at intervals of minutes or hours along the totality path. Williams College's 2013 eclipse expedition was supported in part by grant 9327-13 from National Geographic Society/Committee for Research and Exploration. Our work on the 2012 eclipse is supported in part by grant AGS-1047726 from Solar Terrestrial Research/NSF AGS. V.R. and M.S. were partially supported by the VEGA grant agency project 2/0098/10 and 2/0003/13 (Slovak Academy of Sciences) and Grant 0139-12 from NG/CRE, and Hana Druckmüllerová by grant 205/09/1469 of the Czech Science Foundation. M.L. was supported by Sigma Xi. C.M. was a Keck Northeast Astronomy Consortium Summer Fellow, supported at Williams College by REU/NSF grant AST-1005024. Partial support was provided by U.S. Department of Defense's ASSURE program. J.M.P. thanks Caltech's Planetary Sciences Department for hospitality. Support for D.B.S. and SWAP came from PRODEX grant C90345 managed by ESA in collaboration with the Belgian Federal Science Policy Office (BELSPO) in support of the PROBA2/SWAP mission, and from the EC's Seventh Framework Programme (FP7/2007-2013) under grant 218816 (SOTERIA project, www.soteria-space.eu). SWAP is a project of the Centre Spatial de Liège and the Royal Observatory of Belgium funded by BELSPO.

  10. Two-level total lumbar disc replacement

    PubMed Central

    Bakaloudis, Georgios; Lolli, Francesco; Vommaro, Francesco; Parisini, Patrizio

    2009-01-01

    Total lumbar disc replacement (TDR) has been widely used as a treatment option for 2-level symptomatic degenerative disc disease. However, recent studies have presented conflicting results and some authors concluded that outcome deteriorated when disc replacement was performed bisegmentally, with an increase of complications for bisegmental replacements in comparison with monosegmental disc arthroplasty. The goal of the present retrospective study is to investigate results in a group of patients who have received bisegmental TDR with SB Charitè III artificial disc for degenerative disc disease with a minimum follow-up of 3 years, and to compare the results of 2-level disc replacement versus 1-level patients treated with the same prosthesis. A total of 32 patients had at least 3-years follow-up and were reviewed. The average age of the patients was 38.5 years. There were 11 males and 21 females. About 16 patients received 2-level TDR (SB Charitè III) and 16 received 1-level TDR (SB Charitè III). Both radiographic and functional outcome analysis, including patient’s satisfaction, was performed. There were no signs of degenerative changes of the adjacent segments in any case of the 2- or 1-level TDR. There was no statistically significant difference between 2- and 1-level TDR both at 12 months and at 3-years follow-up on functional outcome scores. There was a statistically insignificant difference concerning the patients satisfaction between 1- and 2-level surgeries at the last follow-up (P = 0.46). In the 2-level TDR patients, there were 5 minor complications (31.25%), whereas major complications occurred in 4 more patients (25%) and required a new surgery in 2 cases (12.5%). In the 1-level cases there were 2 minor complications (12.5%) and 2 major complications (12.5%) and a new revision surgery was required in 1 patient (6.25%). In conclusion, the use of 2-level disc replacement at last follow-up presented a higher incidence of complications than in cases with 1-level replacement. At the same time it was impossible to delineate a clear difference in evaluating the questionnaires between the follow-up results of patients receiving 2- and 1-level TDR: the 2-level group presented slightly lower scores at follow-up, but none was statistically significant. PMID:19399536

  11. Total intravenous anesthesia for major burn surgery

    PubMed Central

    Cancio, Leopoldo C; Cuenca, Phillip B; Walker, Stephen C; Shepherd, John M

    2013-01-01

    Total intravenous anesthesia (TIVA) is frequently used for major operations requiring general anesthesia in critically ill burn patients. We reviewed our experience with this approach. Methods: During a 22-month period, 547 major burn surgeries were performed in this center’s operating room and were staffed by full-time burn anesthesiologists. The records of all 123 TIVA cases were reviewed; 112 records were complete and were included. For comparison, 75 cases were selected at random from a total of 414 non-TIVA general anesthetics. Some patients had more than one operation during the study: as appropriate for the analysis in question, each operation or each patient was entered as an individual case. For inter-patient analysis, exposure to 1 or more TIVAs was used to categorize a patient as member of the TIVA group. Results: Excision and grafting comprised 78.2% of the operations. 14 TIVA regimens were used, employing combinations of 4 i.v. drugs: ketamine (K, 91 cases); i.v. methadone (M, 62); fentanyl (F, 58); and propofol (P, 21). The most common regimens were KM (34 cases); KF (26); KMF (16); and K alone (8). Doses used often exceeded those used in non-burn patients. TIVA was preferred for those patients who were more critically ill prior to surgery, with a higher ASA score (3.87 vs. 3.11). Consistent with this, inhalation injury (26.7 vs. 1.6%), burn size (TBSA, 36.3 vs. 15.8%), and full-thickness burn size (FULL, 19.8 vs. 6.5%) were higher in TIVA than in non-TIVA patients. Despite this, intraoperative pressor use was as common in TIVA as in non-TIVA cases (23.9 vs. 22.7%). Conclusions: TIVA was used in patients whose inhalation injury rate and TBSA were greater than those of non-TIVA patients. TIVA cases were not associated with increased hemodynamic instability. TIVA is a viable approach to general anesthesia in critically ill burn patients. PMID:23638329

  12. Calibration of the Total Irradiance Monitor

    NASA Astrophysics Data System (ADS)

    Kopp, G.; Lawrence, G.; Rottman, G.

    2001-05-01

    We present an overview of the calibrations of the Total Irradiance Monitor (TIM), a total solar irradiance (TSI) instrument designed to achieve a relative standard uncertainty (1 ? accuracy) of 100 parts per million (ppm) and a precision and long-term uncertainty of 10 ppm/year. This instrument is one of four on the Solar Radiation and Climate Experiment (SORCE, http://lasp.colorado.edu/sorce), a satellite mission scheduled for launch in July of 2002. The TIM will report four TSI measurements daily, continuing a 22-year record of solar irradiance through SORCE's goal 5-year mission life. Precision detection of TSI by the TIM follows the basic concepts of electrical substitution radiometry, but employs state-of-the-art electronics and materials. The instrument uses four electrical substitution radiometers (ESRs), each behind a precision aperture, to measure TSI while providing instrument redundancy and sensor degradation detection. The absorptive cavities are used in pairs, one as the active sensor and the other providing a thermal reference. The black absorbing surfaces of diffuse nickel phosphorous (NiP) provide good thermal conductivity, robustness against hard radiation, and low intrinsic outgassing. A shutter modulates incident sunlight to the active ESR, while electrical heater power maintains constant cavity temperature despite the fluctuations in absorbed sunlight. Phase-sensitive detection of the electrical power supplied to the active cavity at the shutter frequency determines cavity absorption and hence TSI. Additionally, this DSP-controlled phase-sensitive detection and thermal control reduces sensitivity to thermal drifts and noise, enabling the instrument's high precision. The TIM's ability to achieve the desired relative standard uncertainty results from component-level calibrations and characterizations to better than 100 ppm. NIST measured the precision apertures to stated accuracies of 25 ppm. LASP measured the ESR reflectances at several wavelengths spanning the visible and near infrared, and selected the flight ESRs based on their low ( ~100 ppm) and stable reflectances. We have recorded the resistances of all ESR electrical leads to the needed 2 ppm uncertainty level. Additionally, we report on system-level measurements indicating instrument reproducibility and relative accuracy.

  13. 21 CFR 862.1275 - Estrogens (total, nonpregnancy) test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Estrogens (total, nonpregnancy) test system. 862... Test Systems § 862.1275 Estrogens (total, nonpregnancy) test system. (a) Identification. As estrogens (total, nonpregnancy) test system is a device intended to measure the level of estrogens (total...

  14. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  15. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  16. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  17. 21 CFR 862.1635 - Total protein test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Total protein test system. 862.1635 Section 862....1635 Total protein test system. (a) Identification. A total protein test system is a device intended to measure total protein(s) in serum or plasma. Measurements obtained by this device are used in...

  18. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Total disability-speech. 8.18 Section 8.18 Pensions, Bonuses...Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under...

  19. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Total disability-speech. 8.18 Section 8.18 Pensions, Bonuses...Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under...

  20. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Total disability-speech. 8.18 Section 8.18 Pensions, Bonuses...Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under...

  1. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Total disability-speech. 8.18 Section 8.18 Pensions, Bonuses...Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under...

  2. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Total disability-speech. 8.18 Section 8.18 Pensions, Bonuses...Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under...

  3. 12 CFR 932.2 - Total capital requirement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...FINANCE BOARD FEDERAL HOME LOAN BANK RISK MANAGEMENT AND CAPITAL STANDARDS FEDERAL HOME...total assets; and (2) A leverage ratio of total capital to total assets of...For purposes of determining the leverage ratio, total capital shall be computed...

  4. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Total disability-speech... SERVICE LIFE INSURANCE Premium Waivers and Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under National Service Life...

  5. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Total disability-speech... SERVICE LIFE INSURANCE Premium Waivers and Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under National Service Life...

  6. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Total disability-speech... SERVICE LIFE INSURANCE Premium Waivers and Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under National Service Life...

  7. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Total disability-speech... SERVICE LIFE INSURANCE Premium Waivers and Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under National Service Life...

  8. 38 CFR 8.18 - Total disability-speech.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Total disability-speech... SERVICE LIFE INSURANCE Premium Waivers and Total Disability § 8.18 Total disability—speech. The organic loss of speech shall be deemed to be total disability under National Service Life...

  9. Total Knee Arthroplasty in Hemophilic Arthropathy.

    PubMed

    Rodríguez-Merchán, E Carlos

    2015-12-01

    Hemophilic arthropathy of the knee is common among patients with hemophilia and is a major cause of severe joint pain and functional disability requiring total knee arthroplasty (TKA). We evaluated TKA outcomes and complications with a special focus on prosthetic survival and infection. We retrospectively reviewed the medical records of 74 patients with chronic hemophilic arthropathy of the knee treated with TKA (N = 88) over a 13-year period. The same type of implant was used in all cases. Fourteen patients had 2-stage bilateral TKAs. Mean patient age was 38.2 years (range, 24-73 years). Fourteen patients were positive for human immunodeficiency virus, and 32 for hepatitis C virus. Mean follow-up was 8 years (range, 1-13 years). The prosthetic survival rate with implant removal for any reason regarded as final endpoint was 92%. Causes of TKA failure were prosthetic joint infection (6.8%) and aseptic loosening (2.2%). Clinical outcomes of the primary TKAs in this series were good prosthetic survival and excellent pain relief. TKA infection continues to be a major concern for patients with hemophilia relative to patients without hemophilia. PMID:26665252

  10. Effectiveness of total worker health interventions.

    PubMed

    Anger, W Kent; Elliot, Diane L; Bodner, Todd; Olson, Ryan; Rohlman, Diane S; Truxillo, Donald M; Kuehl, Kerry S; Hammer, Leslie B; Montgomery, Dede

    2015-04-01

    Total Worker Health (TWH) was introduced and the term was trademarked in 2011 by the National Institute for Occupational Safety and Health (NIOSH) to formally signal the expansion of traditional occupational safety and health (OSH) to include wellness and well-being. We searched PubMed, PsycINFO, and other databases using keywords TWH, health promotion, health protection, and variants for articles meeting the criteria of (a) employing both occupational safety and/or health (OSH, or health protection) and wellness and/or well-being (health promotion, or HP) in the same intervention study, and (b) reporting both OSH and HP outcomes. Only 17 published studies met these criteria. All but 1 of the 17 TWH interventions improved risk factors for injuries and/or chronic illnesses, and 4 improved 10 or more risk factors. Several TWH interventions reported sustained improvements for over a year, although only 1 is readily available for dissemination. These results suggest that TWH interventions that address both injuries and chronic diseases can improve workforce health effectively and more rapidly than the alternative of separately employing more narrowly focused programs to change the same outcomes in serial fashion. These 17 articles provide useful examples of how TWH interventions can be structured. The promise of simultaneous improvements in safety, health, and well-being leads to the call to pursue TWH research to identify and disseminate best practices. PMID:25528687

  11. Total gluon shadowing due to fluctuation effects

    E-print Network

    Misha Kozlov; Arif I. Shoshi; Bo-Wen Xiao

    2007-05-02

    We show a new physical phenomenon expected for the ratio R_{pA} of the unintegrated gluon distribution of a nucleus over the unintegrated gluon distribution of a proton scaled up by the atomic factor A^{1/3} in the fluctuation-dominated (diffusive scaling) region at high energy. We calculate the dependence of R_{pA} on the atomic number A, the rapidity Y and the transverse gluon momentum k_{\\perp}. We find that R_{pA} exhibits an increasing gluon shadowing with growing rapidity, approaching 1/A^{1/3} at asymptotic rapidities which means total gluon shadowing, due to the effect of gluon number fluctuations or Pomeron loops. The increase of R_{pA} with rising gluon momentum decreases as the rapidity grows. In contrast, in the geometric scaling region where the effect of fluctuations is negligible, the ratio R_{pA} shows only partial gluon shadowing in the fixed-coupling case, basically independent on the rapidity and the gluon momentum.

  12. 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

  13. Total Electron Content forecast model over Australia

    NASA Astrophysics Data System (ADS)

    Bouya, Zahra; Terkildsen, Michael; Francis, Matthew

    Ionospheric perturbations can cause serious propagation errors in modern radio systems such as Global Navigation Satellite Systems (GNSS). Forecasting ionospheric parameters is helpful to estimate potential degradation of the performance of these systems. Our purpose is to establish an Australian Regional Total Electron Content (TEC) forecast model at IPS. In this work we present an approach based on the combined use of the Principal Component Analysis (PCA) and Artificial Neural Network (ANN) to predict future TEC values. PCA is used to reduce the dimensionality of the original TEC data by mapping it into its eigen-space. In this process the top- 5 eigenvectors are chosen to reflect the directions of the maximum variability. An ANN approach was then used for the multicomponent prediction. We outline the design of the ANN model with its parameters. A number of activation functions along with different spectral ranges and different numbers of Principal Components (PCs) were tested to find the PCA-ANN models reaching the best results. Keywords: GNSS, Space Weather, Regional, Forecast, PCA, ANN.

  14. Metabolic consequences of (regional) total pancreatectomy.

    PubMed Central

    Dresler, C M; Fortner, J G; McDermott, K; Bajorunas, D R

    1991-01-01

    Little information has been reported on the metabolic characteristics of the totally pancreatectomized patient or the efficacy of medical management after radical pancreatic surgery. The prospective evaluation of 49 such patients, with 31% followed for 48 or more months, forms the basis of this report. The major immediate postoperative challenge is control of diarrhea and weight stabilization. Chronically patients have an increased daily caloric requirement (mean +/- SE, 56 +/- 1 kcal/kg), not wholly explained by moderate steatorrhea (fecal fat excretion, 16% +/- 2% of unrestricted fat intake). Despite persistent malabsorption, deficiencies in fat-soluble vitamin, magnesium, and trace element serum levels can be prevented in most patients. Pancreatogenic diabetes is characterized by (1) absence of the major glucoregulatory hormones insulin and glucagon, (2) instability, and (3) frequent hypoglycemia, with the latter parameters improving with rigorous home glucose monitoring. No patient has developed clinically overt diabetic micro- or macrovascular disease. Performance status in long-term survivors has been reasonable. However adverse chronic sequelae of the operation occur and include an unusual frequency of liver disease, characterized by accelerated fatty infiltration, and osteopenia, with an 18% reduction in radial bone mineral content noted in pancreatectomized patients studied more than 5 years after surgery. Images Fig. 3. PMID:1867520

  15. Totally Corrective Boosting with Cardinality Penalization

    E-print Network

    Vasil S. Denchev; Nan Ding; Shin Matsushima; S. V. N. Vishwanathan; Hartmut Neven

    2015-04-07

    We propose a totally corrective boosting algorithm with explicit cardinality regularization. The resulting combinatorial optimization problems are not known to be efficiently solvable with existing classical methods, but emerging quantum optimization technology gives hope for achieving sparser models in practice. In order to demonstrate the utility of our algorithm, we use a distributed classical heuristic optimizer as a stand-in for quantum hardware. Even though this evaluation methodology incurs large time and resource costs on classical computing machinery, it allows us to gauge the potential gains in generalization performance and sparsity of the resulting boosted ensembles. Our experimental results on public data sets commonly used for benchmarking of boosting algorithms decidedly demonstrate the existence of such advantages. If actual quantum optimization were to be used with this algorithm in the future, we would expect equivalent or superior results at much smaller time and energy costs during training. Moreover, studying cardinality-penalized boosting also sheds light on why unregularized boosting algorithms with early stopping often yield better results than their counterparts with explicit convex regularization: Early stopping performs suboptimal cardinality regularization. The results that we present here indicate it is beneficial to explicitly solve the combinatorial problem still left open at early termination.

  16. Total Operators and Inhomogeneous Proper Values Equations

    E-print Network

    Jose G. Vargas

    2015-07-09

    Kaehler's two-sided angular momentum operator, K + 1, is neither vector-valued nor bivector-valued. It is total in the sense that it involves terms for all three dimensions. Constant idempotents that are "proper functions" of K+1's components are not proper functions of K+1. They rather satisfy "inhomogeneous proper-value equations", i.e. of the form (K + 1)U = {\\mu}U + {\\pi}, where {\\pi} is a scalar. We consider an equation of that type with K+1 replaced with operators T that comprise K + 1 as a factor, but also containing factors for both space and spacetime translations. We study the action of those T's on linear combinations of constant idempotents, so that only the algebraic (spin) part of K +1 has to be considered. {\\pi} is now, in general, a non-scalar member of a Kaehler algebra. We develop the system of equations to be satisfied by the combinations of those idempotents for which {\\pi} becomes a scalar. We solve for its solutions with {\\mu} = 0, which actually also makes {\\pi} = 0: The solutions with {\\mu} = {\\pi} = 0 all have three constituent parts, 36 of them being different in the ensemble of all such solutions. That set of different constituents is structured in such a way that we might as well be speaking of an algebraic representation of quarks. In this paper, however, we refrain from pursuing this identification in order to emphasize the purely mathematical nature of the argument.

  17. Total least squares for anomalous change detection

    SciTech Connect

    Theiler, James P; Matsekh, Anna M

    2010-01-01

    A family of difference-based anomalous change detection algorithms is derived from a total least squares (TLSQ) framework. This provides an alternative to the well-known chronochrome algorithm, which is derived from ordinary least squares. In both cases, the most anomalous changes are identified with the pixels that exhibit the largest residuals with respect to the regression of the two images against each other. The family of TLSQ-based anomalous change detectors is shown to be equivalent to the subspace RX formulation for straight anomaly detection, but applied to the stacked space. However, this family is not invariant to linear coordinate transforms. On the other hand, whitened TLSQ is coordinate invariant, and furthermore it is shown to be equivalent to the optimized covariance equalization algorithm. What whitened TLSQ offers, in addition to connecting with a common language the derivations of two of the most popular anomalous change detection algorithms - chronochrome and covariance equalization - is a generalization of these algorithms with the potential for better performance.

  18. 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

  19. Muscular strength after total hip arthroplasty.

    PubMed

    Winther, Siri B; Husby, Vigdis S; Foss, Olav A; Wik, Tina S; Svenningsen, Svein; Engdal, Monika; Haugan, Kristin; Husby, Otto S

    2016-02-01

    Background and purpose - Minimizing the decrease in muscular strength after total hip arthroplasty (THA) might allow patients to recover faster. We evaluated muscular strength in patients who were operated on using 3 surgical approaches. Patients and methods - In a prospective cohort study, 60 patients scheduled for primary THA were allocated to the direct lateral, posterior, or anterior approach. Leg press and abduction strength were evaluated 2 weeks or less preoperatively, 2 and 8 days postoperatively, and at 6-week and 3-month follow-up. Results - Differences in maximal strength change were greatest after 2 and 8 days. The posterior and anterior approaches produced less decrease in muscular strength than the direct lateral approach. 6 weeks postoperatively, the posterior approach produced greater increase in muscular strength than the direct lateral approach, and resulted in a greater increase in abduction strength than the anterior approach. At 3-month follow-up, no statistically significant differences between the groups were found. The operated legs were 18% weaker in leg press and 15% weaker in abduction than the unoperated legs, and the results were similar between groups. Interpretation - The posterior and anterior approaches appeared to have the least negative effect on abduction and leg press muscular strength in the first postoperative week; the posterior approach had the least negative effect, even up to 6 weeks postoperatively. THA patients have reduced muscle strength in the operated leg (compared to the unoperated leg) 3 months after surgery. PMID:26141371

  20. SynCardia: the total artificial heart

    PubMed Central

    Anyanwu, Anelechi; Zucchetta, Fabio; Gerosa, Gino

    2014-01-01

    The SynCardia total artificial heart (TAH) currently provides the most definitive option for patients with biventricular failure who are not candidates for isolated left ventricular (LV) assist device placement. The techniques for implantation are adaptable to almost all patients with advanced heart failure, including those with severe biventricular cardiomyopathy, complex congenital heart disease, failed LV assist devices, failed transplantations, and acquired structural heart defects that have failed or are not amenable to conventional surgical treatment. Over the years, the implantation technique has evolved in order to minimize the surgical invasiveness of the procedure, in anticipation of additional future surgery. Meticulous hemostasis with double layer sutures, use of Gore-Tex sheets around the TAH and the pericardial cavity, and use of tissue expanders to avoid contraction of pericardial cavity around the device are discussed in detail in the following report. Additionally, we will provide our experience with implantation of TAH in various challenging scenarios, such as patients with a small chest cavity, congenital heart defects, and simultaneous use of extracorporeal membrane oxygenation (ECMO). PMID:25512904

  1. Chronic Knee Dislocation After Total Knee Arthroplasty.

    PubMed

    Ross, John P; Brown, Nicholas M; Levine, Brett R

    2015-12-01

    Knee dislocation after total knee arthroplasty (TKA), although rare, is a dangerous injury that can lead to neurovascular compromise and permanent disability. Chronic dislocation after TKA is even less common and is defined as dislocation that is present for 4 weeks or more. There are few reports of its management. Chronic dislocation may be complicated further by concomitant extensor mechanism disruption, ligamentous instability, and/or capsular contracture. This article describes 3 cases of chronically dislocated TKAs and the challenges encountered in treating this difficult problem. A higher level of constraint was required to maintain knee stability, and an extensor mechanism allograft was needed in 2 of the 3 reported patients. The preferred technique at the authors' institution is a complete allograft composite, tensioned in full extension. In the setting of a chronically dislocated TKA, the authors now recommend revision surgery with an enhanced measure of constraint (constrained condylar device or hinged knee prosthesis), reconstruction of the extensor mechanism when necessary, and restoration of the joint while compensating for concomitant bony defects. Even when surgeons follow these principles, it is important to inform the patient that long-term outcomes will likely be inferior to those of revision surgery for other causes. [Orthopedics. 2015; 38(12):e1155-e1159.]. PMID:26652339

  2. [Total quality management in laboratory medicine].

    PubMed

    Vogt, W

    1998-12-01

    The German Public Health will be continuously challenged in the future. It has to be assumed that modified managed care will not only take place sporadically. Thus, quality aspects of services gain more and more significance. Only suppliers will be successful who can offer services of highest quality at lowest prices. Quality in a comprehensive sense has to be substantiated in the near future. It is recommended to apply industry proven models also in public health service. Medical laboratories can be pioneers in this field as they have been already in the past. All previously proposed procedures can not describe quality of results comprehensively. They are based to a high degree on external control. Total quality management, however, represents a comprehensive approach. Principles are zero-defect approach, customer orientation and system management. Quality is given in the sense of TQM if the customer is permanently satisfied with the service of the supplier. In such a way, the customer defines quality of service. A customer is everyone who receives products or services. TQM overcomes the drawbacks of quality management systems, which are strongly formal and oriented by external control, as accreditation (EN 45,000) or certification (ISO 9000). Competition between hospitals is a declared goal of German health politics because usually quality is increased and cost decreased as a consequence. Competition means also comparison of services. TQM emphasizes benchmarking especially among the best suppliers. PMID:10028601

  3. The Helmholtz Total Artificial Heart Labtype.

    PubMed

    Kaufmann, R; Reul, H; Rau, G

    1994-07-01

    To perform the first experimental tests for validation of a new gear unit concept, the pump chamber, diaphragm, and pusher plate design of an orthotopic electromechanical total artificial heart (TAH) (Helmholtz Labtype) was manufactured. In its early stage of development, it provides some of the most important features of the conceptual final artificial heart. The new gear unit transforms a uniform unidirectional rotational motor movement into translatory pusher plate movements, with resting phase in the end-diastolic position, and the angled pump chamber orientation determines the available space for the motor and gear unit. Furthermore, this labtype provides flexibility with regard to use of different types of structural parts for experimental investigations. The first in vitro test results, obtained with specially designed circulatory mockloops that simulate physiological preload and afterload conditions, are presented. They comprise pressure and flow generation, motor performance, efficiency, and energy consumption. The results prove the feasibility of the new gear unit concept for an electromechanical artificial heart and allow a reliable determination of the necessary performance of the future brushless DC motor for the first in vivo TAH model. PMID:7980100

  4. Total parenteral nutrition in diabetic rats

    SciTech Connect

    Norcross, E.D.; Stein, T.P.

    1986-03-01

    Parenteral Nutrition with hypertonic glucose is frequently given to diabetic patients. Large amounts of insulin can be required. The purpose of this investigation was to develop a totally parenterally nourished diabetic rat model. 200 g Female Sprague Dawley rats were made diabetic by i.v. injection of streptozotocin (50 mg/kg). Rats were then allowed to recover for at least 1 week before undergoing surgical insertion of a central venous catheter for parenteral feeding. TPN was begun 3 days after surgery. Prior to this they were allowed unlimited access to food and water. Control (non-streptozotocin treated) rats were run at the same time. Protein turnover was investigated by using /sup 15/N glycine. Preliminary results: diabetic rats given mostly fat as a calorie source survived well in the absence of exogenous insulin whereas those that were given glucose only as their non-protein calorie source showed poor survival even with exogenous insulin. N balance and protein turnover in the lipid treated diabetic rats were comparable to the non-diabetic control rats.

  5. Laparoscopic totally extraperitoneal repair without suprapubic port: comparison with conventional totally extraperitoneal repair

    PubMed Central

    Kwon, Ki-Hwak; Han, Won-Kon

    2011-01-01

    Purpose We have treated 24 patients through laparoscopic totally extraperitoneal (TEP) repair without suprapubic port by using reliability and reducing the invasiveness of two surgery. This study is aimed to assess the safety and feasibility of the TEP repair without suprapubic port compared to conventional TEP repair. Methods From September 2007 to 11 May 2010, we compared two groups that suffer from inguinal hernias. One is comprised of 24 patients who were treated without suprapubic port laparoscopic totally extraperitoneal repair (Group A), and the other is comprised of 100 patients who were treated with conventional laparoscopic totally extraperitoneal repair (Group B). Data regarding patient demographics (sex, age, site of hernia, and the type of hernia), operating time, postoperative hospital stay, the use of analgesics, and complications were prospectively collected. Results There was no significant difference noted between two groups in relation to sex, age, site, and the type of hernia. The mean operating time and postoperative hospital stay was longer for the Group B (62.9 minutes, 3.55 days) than for the Group A (59.0 minutes, 2.54 days) (P = 0.389, P < 0.001). Postoperative urinary retention, seroma, wound infection were respectively 4.2%, 8.3%, 0% in Group A, and 12.0%, 8.0%, 7% in group B. There was difference between the two groups, but not statistical significance. Group B used more analgesics than Group A (0.33 vs. 0.48), but it wasn't significant statistically (P = 0.234). Conclusion Although prospective randomized studies with long-term follow-up evaluation are needed to confirm our study between laparoscopic totally extraperitoneal repair without suprapubic-port and conventional laparoscopic totally extraperitoneal repair, our method have some advantages in postoperative pain, urinary retention, operating time, postoperative hospital stay, and cosmetic effect. PMID:22066055

  6. Infection after primary total hip arthroplasty.

    PubMed

    Lindeque, Bennie; Hartman, Zach; Noshchenko, Andriy; Cruse, Margaret

    2014-04-01

    The number of primary total hip arthroplasties (THAs) performed in the United States each year continues to climb, as does the incidence of infectious complications. The changing profile of antibiotic-resistant bacteria has made preventing and treating primary THA infections increasingly complex. The goal of this review was to summarize (1) the published data concerning the risk of surgical site infection (SSI) after primary THA by type of bacteria and (2) the effect of potentially modifying factors. The Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, EMBASE, Web of Science, and PubMed were searched. Studies dated between 2001 and 2011 examining primary THA in adults were included. Meta-analysis of the collected data was performed. The pooled SSI rate was 2.5% (95% confidence interval [Cl], 1.4%-4.4%; P<.001; n=28,883). The pooled deep prosthetic joint infection (PJI) rate was 0.9% (95% Cl, 0.4%-2.2%; P<.001; n=28,883). The pooled rate of methicillin-resistant Staphylococcus aureus SSI was 0.5% (95% Cl, 0.2%-1.5%; P<.001; n=26,703). This is approximately 20% of all SSI cases. The pooled rate of intraoperative bacterial wound contamination was 16.9% (95% Cl, 6.6%-36.8%; P=.003; n=2180). All these results had significant heterogeneity. The postoperative risk of SSI was significantly associated with intraoperative bacterial surgical wound contamination (pooled rate ratio, 2.5; 95% Cl, 1.4%-4.6%; P=.001; n=19,049). PMID:24762833

  7. Backside Wear in Modern Total Knee Designs

    PubMed Central

    Jayabalan, Prakash; Furman, Bridgette D.; Cottrell, Jocelyn M.

    2006-01-01

    Although modularity affords various options to the orthopedic surgeon, these benefits come at a price. The unintended bearing surface between the back surface of the tibial insert and the metallic tray results in micromotion leading to polyethylene wear debris. The objective of this study was to examine the backside wear of tibial inserts from three modern total knee designs with very different locking mechanisms: Insall-Burstein II® (IB II®), Optetrak®, and Advance®. A random sample of 71 inserts were obtained from our institution’s retrieval collection and examined to assess the extent of wear, depth of wear, and wear damage modes. Patient records were also obtained to determine patient age, body mass index, length of implantation, and reason for revision. Modes of wear damage (abrasion, burnishing, scratching, delamination, third body debris, surface deformation, and pitting) were then scored in each zone from 0 to 3 (0?=?0%, 1?=?0–10%, 2?=?10–50%, and 3?=?>50%). The depth of wear was subjectively identified as removal of manufacturing identification markings stamped onto the inferior surface of the polyethylene. Both Advance® and IB II® polyethylene inserts showed significantly higher scores for backside wear than the Optetrak® inserts. All IB II® and Advance® implants showed evidence of backside wear, whereas 17% (5 out of 30) of the retrieved Optetrak® implants had no observable wear. There were no significant differences when comparing the depth of wear score between designs. The locking mechanism greatly affects the propensity for wear and should be considered when choosing a knee implant system. PMID:18751767

  8. [Robotic total mesorectal excision for rectal cancer].

    PubMed

    Rossi, Gustavo; Alvarez, Fernando A; Mentz, Ricardo; Vaccaro, Carlos A; Im, Víctor; Quintana, Guillermo Ojea

    2013-06-01

    Laparoscopic total mesorectal excision (TME) has proven to be feasible and safe. However, it represents a major technical challenge, since it involves the dissection of the rectum in a confined space such as the bony pelvis using un-ergonomic surgical devices. This difficulty is accentuated in patients with distal tumors and high body mass index (BMI), in which the surgical margins and the hypogastric nerves may be affected. Therefore, robotic surgery aims to overcome these limitations that conspire against the mininvasive surgical approach of rectal cancer. We present an obese (BMI = 32 kg/m2) 82-year-old man with a history of smoking and prostate cancer that was recently diagnosed with a middle rectal adenocarcinoma at 9 cm from the anal verge. Rectal examination evidenced a mobile lesion. Computed tomography scan ruled out metastases and at the local staging by MRI, the tumor was considered as T3-N0 with free circumferential margins. Surgical treatment was decided and a hybrid technique was used combining an initial laparoscopic approach followed by the robotic TME. The patient had a full recovery and was discharged three days after surgery without complications. Pathological examination revealed a low-grade adenocarcinoma with mesorectal invasion, free circumferential and distal margins, and 24 negative lymph nodes (pT3-pN0-pM0/Stage II). Robotic TME was performed safely in an obese patient. It facilitated dissection maneuvers in a confined space with proper identification and preservation of the hypogastric nerves, allowing retrieving an intact mesorectum. Prospective randomized trials will define the role of this new technology. PMID:23940915

  9. Total lymphoid irradiation for multiple sclerosis

    SciTech Connect

    Devereux, C.K.; Vidaver, R.; Hafstein, M.P.; Zito, G.; Troiano, R.; Dowling, P.C.; Cook, S.D.

    1988-01-01

    Although chemical immunosuppression has been shown to benefit patients with chronic progressive multiple sclerosis (MS), it appears that chemotherapy has an appreciable oncogenic potential in patients with multiple sclerosis. Accordingly, we developed a modified total lymphoid irradiation (TLI) regimen designed to reduce toxicity and applied it to a randomized double blind trial of TLI or sham irradiation in MS. Standard TLI regimens were modified to reduce dose to 1,980 rad, lowering the superior mantle margin to midway between the thyroid cartilage and angle of the mandible (to avert xerostomia) and the lower margin of the mantle field to the inferior margin of L1 (to reduce gastrointestinal toxicity by dividing abdominal radiation between mantle and inverted Y), limiting spinal cord dose to 1,000 rad by custom-made spine blocks in the mantle and upper 2 cm of inverted Y fields, and also protecting the left kidney even if part of the spleen were shielded. Clinical efficacy was documented by the less frequent functional scale deterioration of 20 TLI treated patients with chronic progressive MS compared to to 20 sham-irradiated progressive MS patients after 12 months (16% versus 55%, p less than 0.03), 18 months (28% versus 63%, p less than 0.03), and 24 months (44% versus 74%, N.S.). Therapeutic benefit during 3 years follow-up was related to the reduction in lymphocyte count 3 months post-irradiation (p less than 0.02). Toxicity was generally mild and transient, with no instance of xerostomia, pericarditis, herpes zoster, or need to terminate treatment in TLI patients. However, menopause was induced in 2 patients and staphylococcal pneumonia in one.

  10. Periprosthetic Bone Remodelling in Total Knee Arthroplasty

    PubMed Central

    GEORGEANU, Vlad; ATASIEI, Tudor; GRUIONU, Lucian

    2014-01-01

    Introduction: The clinical studies have shown that the displacement of the prosthesis components, especially of the tibial one is higher during the first year, after which it reaches an equilibrum position compatible with a good long term functioning. This displacement takes place due to bone remodelling close to the implant secondary to different loading concentrations over different areas of bone. Material and Method: Our study implies a simulation on a computational model using the finite element analysis. The simulation started taking into account arbitrary points because of non-linear conditions of bone-prosthesis interface and it was iterative.. A hundred consecutive situations corresponding to intermediate bone remodelling phases have been calculated according to given loadings. Bone remodelling was appreciated as a function of time and bone density for each constitutive element of the computational model created by finite element method. For each constitutive element a medium value of stress during the walking cycle was applied. Results: Analyse of proximal epiphysis-prosthesis complex slices showed that bone density increase is maintained all over the stem in the immediately post-operative period. At 10 months, the moment considered to be the end of bone remodelling, areas with increased bone density are fewer and smaller. Meanwhile, their distribution with a concentration toward the internal compartment in the distal metaphysis is preserved. Conclusions: After the total knee arthroplasty the tibial bone suffered a process of remodelling adapted to the new stress conditions. This bone remodelling can influence, sometimes negatively, especially in the cases with tibial component varus malposition, the fixation, respectively the survival of the prosthesis. This process has been demonstrated both by clinical trials and by simulation, using the finite elements method of periprosthetic bone remodelling. PMID:25553127

  11. Antioxidant activity, total phenolic and total flavonoid contents of whole plant extracts Torilis leptophylla L

    PubMed Central

    2012-01-01

    Background The aim of this study was to screen various solvent extracts of whole plant of Torilis leptophylla to display potent antioxidant activity in vitro and in vivo, total phenolic and flavonoid contents in order to find possible sources for future novel antioxidants in food and pharmaceutical formulations. Material and methods A detailed study was performed on the antioxidant activity of the methanol extract of whole plant of Torilis leptophylla (TLM) and its derived fractions {n-hexane (TLH), chloroform (TLC) ethyl acetate (TLE) n-butanol (TLB) and residual aqueous fraction (TLA)} by in vitro chemical analyses and carbon tetrachloride (CCl4) induced hepatic injuries (lipid peroxidation and glutathione contents) in male Sprague-Dawley rat. The total yield, total phenolic (TPC) and total flavonoid contents (TFC) of all the fractions were also determined. TLM was also subjected to preliminary phytochemical screening test for various constituents. Results The total phenolic contents (TPC) (121.9±3.1 mg GAE/g extract) of TLM while total flavonoid contents (TFC) of TLE (60.9 ±2.2 mg RTE/g extract) were found significantly higher as compared to other solvent fractions. Phytochemical screening of TLM revealed the presence of alkaloids, anthraquinones, cardiac glycosides, coumarins, flavonoids, saponins, phlobatannins, tannins and terpenoids. The EC50 values based on the DPPH (41.0±1 ?g/ml), ABTS (10.0±0.9 ?g/ml) and phosphomolybdate (10.7±2 ?g/ml) for TLB, hydroxyl radicals (8.0±1 ?g/ml) for TLC, superoxide radicals (57.0±0.3 ?g/ml) for TLM and hydrogen peroxide radicals (68.0±2 ?g/ml) for TLE were generally lower showing potential antioxidant properties. A significant but marginal positive correlation was found between TPC and EC50 values for DPPH, hydroxyl, phosphomolybdate and ABTS, whereas another weak and positive correlation was determined between TFC and EC50 values for superoxide anion and hydroxyl radicals. Results of in vivo experiment revealed that administration of CCl4 caused a significant increase in lipid peroxidation (TBARS) while decrease in GSH contents of liver. In contrast, TLM (200 mg/kg bw) and silymarin (50 mg/kg bw) co-treatment effectively prevented these alterations and maintained the antioxidant status. Conclusion Data from present results revealed that Torilis leptophylla act as an antioxidant agent due to its free radical scavenging and cytoprotective activity. PMID:23153304

  12. Isolated Total Rupture of Extraocular Muscles

    PubMed Central

    Chen, Jingchang; Kang, Ying; Deng, Daming; Shen, Tao; Yan, Jianhua

    2015-01-01

    Abstract Total rupture of extraocular muscles is an infrequent clinical finding. Here we conducted this retrospective study to evaluate their causes of injury, clinical features, imaging, surgical management, and final outcomes in cases of isolated extraocular muscle rupture at a tertiary center in China. Thirty-six patients were identified (24 men and 12 women). Mean age was 34 years (range 2–60). The right eye was involved in 21 patients and the left 1 in 15. A sharp object or metal hook was the cause of this lesion in 16 patients, sinus surgery in 14 patients, traffic accident in 3 patients, orbital surgery in 2 patients, and conjunctive tumor surgery in 1 patient. The most commonly involved muscles were medial (18 patients) and inferior rectus muscles (13 patients). The function of the ruptured muscles revealed a scale of ?3 to ?4 defect of ocular motility and the amount of deviation in primary position varied from 10 to 140 PD (prism diopter). Computerized tomography (CT) confirmed the presence of ruptured muscles. An end-to-end muscle anastomosis was performed and 3 to 5?mm of muscle was resected in 23 patients. When the posterior border of the injured muscle could not be identified (13 patients), a partial tendon transposition was performed, together with recession of the antagonist in most patients, whereas a recession of the antagonist muscle plus a resection of the involved muscle with or without nasal periosteal fixation was performed in the remaining patients. After an average of 16.42 months of follow-up an excellent result was achieved in 23 patients and results of 13 patients were considered as a failure. In most patients, the posterior border of the ruptured muscle can be identified and an early surgery can be performed to restore function. Alternatively, a partial tendon transposition should be performed. When muscular rupture is suspected, an early orbital CT is required to confirm this possibility, which can then verify the necessity for an early surgical intervention. PMID:26426604

  13. Solar total irradiance in cycle 23

    NASA Astrophysics Data System (ADS)

    Krivova, N. A.; Solanki, S. K.; Schmutz, W.

    2011-05-01

    Context. The most recent minimum of solar activity was deeper and longer than the previous two minima as indicated by different proxies of solar activity. This is also true for the total solar irradiance (TSI) according to the PMOD composite. Aims: The apparently unusual behaviour of the TSI has been interpreted as evidence against solar surface magnetism as the main driver of the secular change in the TSI. We test claims that the evolution of the solar surface magnetic field does not reproduce the observed TSI in cycle 23. Methods: We use sensitive, 60-min averaged MDI magnetograms and quasi-simultaneous continuum images as an input to our SATIRE-S model and calculate the TSI variation over cycle 23, sampled roughly every two weeks. The computed TSI is then compared with the PMOD composite of TSI measurements and with the data from two individual instruments, SORCE/TIM and UARS/ACRIM II, that monitored the TSI during the declining phase of cycle 23 and over the previous minimum in 1996, respectively. Results: Excellent agreement is found between the trends shown by the model and almost all sets of measurements. The only exception is the early, i.e. 1996 to 1998, PMOD data. Whereas the agreement between the model and the PMOD composite over the period 1999-2009 is almost perfect, the modelled TSI shows a steeper increase between 1996 and 1999 than implied by the PMOD composite. On the other hand, the steeper trend in the model agrees remarkably well with the ACRIM II data. A closer look at the VIRGO data, which are the basis of the PMOD composite after 1996, reveals that only one of the two VIRGO instruments, the PMO6V, shows the shallower trend present in the composite, whereas the DIARAD measurements indicate a steeper trend. Conclusions: Based on these results, we conclude that (1) the sensitivity changes of the PMO6V radiometers within VIRGO during the first two years have very likely not been correctly evaluated; and that (2) the TSI variations over cycle 23 and the change in the TSI levels between the minima in 1996 and 2008 are consistent with the solar surface magnetism mechanism.

  14. T.Q.M.: Total Quality Management or total quackery and mismanagement

    SciTech Connect

    Stallard, T.F.

    1996-12-31

    The concept of total quality management (TQM) is outlined. The basic idea of TQM is that quality products and services will lead a company to greater financial success than will mass quantities of inferior products. The following topics are outlined: standard labs and TQM;TQM benefits to be gained by standard labs; TQM at standard labs is quality improvement system (QIS), TQM, reduces of attitude. QIS team leader training agenda; and the safety connection.

  15. Total ozone during the 88-89 Northern Hemisphere winter

    NASA Technical Reports Server (NTRS)

    Newman, Paul; Stolarski, Richard; Schoeberl, Mark; Lait, Leslie R.; Krueger, Arlin

    1990-01-01

    Total ozone values measured by the Total Ozone Mapping Spectrometer during January, February, and March 1989 are analyzed. During this period, polar total ozone values did not reveal clear depletions, although average winter total ozone values indicate that a 2-6 percent ozone reduction has occurred in northern mid to high latitudes over the last 10 years. Rapid total ozone increases were seen during mid-February, resulting from a wave 2 major stratospheric warming. In order to track polar air over the warming period, total ozone trends are further analyzed using Ertel's potential vorticity.

  16. Total ozone during the 88-89 northern hemisphere winter

    SciTech Connect

    Newman, P.; Stolarski, R.; Schoeberl, M.; Lait, L.R.; Krueger, A. )

    1990-03-01

    Total ozone values measured by the Total Ozone Mapping Spectrometer (TOMS) during January, February and March 1989 are analyzed. During this period, polar total ozone values did not reveal clear depletions, although average winter total ozone values indicate that a 2-6% ozone reduction has occurred in northern mid to high latitudes over the last years. Rapid total ozone increases were seen during mid-February, resulting from a wave 2 major stratospheric warming. In order to track polar air over the warming period, total ozone trends are further analyzed using Ertel's potential vorticity.

  17. 21 CFR 862.1700 - Total thyroxine test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid...

  18. 21 CFR 862.1700 - Total thyroxine test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid...

  19. 21 CFR 862.1700 - Total thyroxine test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid...

  20. 21 CFR 862.1700 - Total thyroxine test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Identification. A total thyroxine test system is a device intended to measure total (free and protein bound) thyroxine (thyroid hormone) in serum and plasma. Measurements obtained by this device are used in the diagnosis and treatment of thyroid...

  1. 21 CFR 874.3495 - Total ossicular replacement prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3495 Total ossicular replacement prosthesis...ossicular replacement prosthesis is a device intended to be implanted for the total functional reconstruction of the...

  2. 21 CFR 874.3495 - Total ossicular replacement prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3495 Total ossicular replacement prosthesis...ossicular replacement prosthesis is a device intended to be implanted for the total functional reconstruction of the...

  3. 12 CFR 932.2 - Total capital requirement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Total capital requirement. 932.2 Section 932.2 Banks...CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL REQUIREMENTS § 932.2 Total capital requirement. (a) Each Bank shall maintain...

  4. 20 CFR 410.422 - Determining total disability: General criteria.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Total Disability or Death Due to Pneumoconiosis § 410.422 Determining total...

  5. Total Protein and Albumin/Globulin Ratio Test

    MedlinePLUS

    ... limited. Home Visit Global Sites Search Help? Total Protein and A/G Ratio Share this page: Was ... as: TP; Albumin/Globulin Ratio Formal name: Total Protein; Albumin to Globulin Ratio Related tests: Albumin ; Liver ...

  6. 20 CFR 410.412 - “Total disability” defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Total Disability or Death Due to Pneumoconiosis § 410.412 “Total disability” defined....

  7. 24 CFR 886.308 - Maximum total annual contract commitment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false Maximum total annual contract commitment. 886.308 Section 886.308 ...308 Maximum total annual contract commitment. (a) Number of units assisted...by which the maximum annual contract commitment per year exceeds amounts paid...

  8. Recommended Amounts of Total red and orange vegetables

    Cancer.gov

    Recommended Amounts of Total red and orange vegetables Table B4. Total red and orange vegetables: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) % with intake meeting

  9. Joint Line Reconstruction in Navigated Total Knee Arthroplasty Revision

    ClinicalTrials.gov

    2012-05-16

    Revision Total Knee Arthroplasty Because of; Loosening; Instability; Impingement; or Other Reasons Accepted as Indications for TKA Exchange.; The Focus is to Determine the Precision of Joint Line Restoration in Navigated vs. Conventional Revision Total Knee Arthroplasty

  10. Recommended Amounts of Total protein foods excluding beans and peas

    Cancer.gov

    Recommended Amounts of Total protein foods excluding beans and peas Table B11. Total protein foods excluding beans and peas: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation

  11. Recommended Amounts of Total vegetables including beans and peas

    Cancer.gov

    Recommended Amounts of Total vegetables including beans and peas Table B2. Total vegetables including beans and peas: Estimated percentage of persons below, at, or above recommendation1 Age (years) N Mean (SE) % with intake below recommendation (SE) %

  12. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  13. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  14. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  15. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  16. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total...

  17. Total Lightning as an Indicator of Mesocyclone Behavior

    NASA Technical Reports Server (NTRS)

    Stough, Sarah M.; Carey, Lawrence D.; Schultz, Christopher J.

    2014-01-01

    Apparent relationship between total lightning (in-cloud and cloud to ground) and severe weather suggests its operational utility. Goal of fusion of total lightning with proven tools (i.e., radar lightning algorithms. Preliminary work here investigates circulation from Weather Suveilance Radar- 1988 Doppler (WSR-88D) coupled with total lightning data from Lightning Mapping Arrays.

  18. Fluorescence-based Total Protein Determination using the Compound CBQCA

    E-print Network

    Raizada, Manish N.

    Fluorescence-based Total Protein Determination using the Compound CBQCA Total protein content solutions at 280 nm (A280) can be performed, but are subject to interference from any nucleic acid absorbance-based methods to measure total protein content. Here we describe the use of 3-(4-carboxybenzoyl

  19. Total Recall: Are Privacy Changes Inevitable? William C. Cheng

    E-print Network

    Kay, David G.

    Total Recall: Are Privacy Changes Inevitable? William C. Cheng Computer Science Dept. & IMSC of Information and Computer Sciences University of California, Irvine ABSTRACT Total Recall in a pair of glasses or a camera in a necklace. There are many applications of Total Recall ­ patients

  20. Total Enrollment Last 10 Years Honors College Students

    E-print Network

    Rock, Chris

    Financial Aid Top Declared Majors* Total Enrollment by Gender Enrollment by Geographic Origin Degrees English 37 Curriculum & Instruction 36 Clinical Psychology 35 Counseling Psychology 35 Marriage & Family Total Total Year Change By Gender Female 10,355 1,880 309 12,544 45.50% 11,869 5.69% Male 12,408 2

  1. ON THE NUMBER OF INDECOMPOSABLE TOTALLY REFLEXIVE MODULES

    E-print Network

    Takahashi, Ryo

    ON THE NUMBER OF INDECOMPOSABLE TOTALLY REFLEXIVE MODULES RYO TAKAHASHI Abstract. In this note isomorphism classes of indecomposable totally reflexive modules, if there is a nonfree cyclic totally reflexive module. 1. Introduction Throughout this note, we assume that all rings are commutative

  2. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Total temporomandibular joint prosthesis. 872.3940... prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is intended to be... and Drug Administration on or before March 30, 1999, for any total temporomandibular joint...

  3. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Total temporomandibular joint prosthesis. 872.3940... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3940 Total temporomandibular joint prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is intended to...

  4. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Total temporomandibular joint prosthesis. 872.3940... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3940 Total temporomandibular joint prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is intended to...

  5. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Total temporomandibular joint prosthesis. 872.3940... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3940 Total temporomandibular joint prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is intended to...

  6. 21 CFR 872.3940 - Total temporomandibular joint prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Total temporomandibular joint prosthesis. 872.3940... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3940 Total temporomandibular joint prosthesis. (a) Identification. A total temporomandibular joint prosthesis is a device that is intended to...

  7. 12 CFR 932.2 - Total capital requirement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Total capital requirement. 932.2 Section 932.2 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK RISK MANAGEMENT AND CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL REQUIREMENTS § 932.2 Total capital requirement. (a) Each Bank shall maintain at all times: (1) Total...

  8. Diabetic Neuropathy: What is a Total Contact Cast?

    MedlinePLUS

    MENU Return to Web version Diabetic Neuropathy | What is a Total Contact Cast? What is a total contact cast? A total contact cast is a cast used to treat ulcers (serious, deep sores) on a person’s foot. It consists of a fiberglass shell that fits around your leg and foot very ...

  9. Concentration and flux of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids for monitored tributaries of Lake Champlain, 1990-2012

    USGS Publications Warehouse

    Medalie, Laura

    2014-01-01

    Annual and daily concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids were estimated for 18 monitored tributaries to Lake Champlain by using the Weighted Regressions on Time, Discharge, and Seasons regression model. Estimates were made for 21 or 23 years, depending on data availability, for the purpose of providing timely and accessible summary reports as stipulated in the 2010 update to the Lake Champlain “Opportunities for Action” management plan. Estimates of concentration and flux were provided for each tributary based on (1) observed daily discharges and (2) a flow-normalizing procedure, which removed the random fluctuations of climate-related variability. The flux bias statistic, an indicator of the ability of the Weighted Regressions on Time, Discharge, and Season regression models to provide accurate representations of flux, showed acceptable bias (less than ±10 percent) for 68 out of 72 models for total and dissolved phosphorus, total nitrogen, and chloride. Six out of 18 models for total suspended solids had moderate bias (between 10 and 30 percent), an expected result given the frequently nonlinear relation between total suspended solids and discharge. One model for total suspended solids with a very high bias was influenced by a single extreme value; however, removal of that value, although reducing the bias substantially, had little effect on annual fluxes.

  10. Results of a multimodal analgesic trial involving patients with total hip or total knee arthroplasty.

    PubMed

    Skinner, Harry B; Shintani, Ellen Y

    2004-02-01

    The mainstays for pain relief after total hip arthroplasty (THA) and total knee arthroplasty (TKA) have been the opioids, but these medications, though excellent analgesics, have problems limiting their effectiveness. Alternative analgesics have been considered too mild for the pain caused by THA and TKA. These medications have been used in combination, but only in pairs and not in a "stacked modality." Here we report a trial of around-the-clock acetaminophen, rofecoxib, tramadol, and dexamethasone combined with bupivicaine pain pumps and on-demand opioid use (patient-controlled analgesia with morphine). Patients (48 with THA, 54 with TKA) were divided into pain protocol (PP) groups and conventional pain-therapy groups. Important variables were recorded from a chart review. In the PP groups, reductions in opioid use, length of hospital stay (TKA, P=.012), and time on patient-controlled analgesia were significant, as were improvements in pain scores for TKA. In addition, there was a trend in improved pain scores for the PP group with THA. Minor adverse events were similar for the groups, but major medical complications were fewer in the PP group. Preemptive analgesia with multiple non-narcotic medications used in a stacked modality can significantly reduce postoperative pain. PMID:15005598

  11. Predictions for the total solar eclipse of 1991

    NASA Technical Reports Server (NTRS)

    Espenak, Fred

    1989-01-01

    A total eclipse of the sun will be widely visible from the Western Hemisphere on July 11, 1991. Detailed predictions for this event are presented which include tables of geographic coordinates for the northern limit, southern limit and center line of the path of totality, local circumstances on the center line and for 95 cities within the partial and total eclipse paths, maps depicting the path of totality, the sky during totality and the lunar limb profile. The author discusses the general characteristics of the eclipse including local circumstances from various points along the central path, the Saros series history and effects caused by the lunar limb profile.

  12. Total anthocyanins, total carotenoids, hydrophilic- and lipophilic-ORAC levels in diverse clones and breeding lines over six field environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven specialty clones were grown in six field locations and tuber samples were analyzed for total carotenoids, total anthocyanins, hydrophilic_Oxygen Radical Absorbance Capacity (ORAC), and lipophilic (ORAC). Four of the genotypes had red or purple pigmented flesh. The highest total anthocyanins ...

  13. Distribution and biogeochemical control of total CO 2 and total alkalinity in the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Beldowski, J.; Löffler, A.; Schneider, B.; Joensuu, L.

    2010-05-01

    The distributions of total CO 2 ( CT) and total alkalinity ( AT) were determined in the Baltic Sea in summer 2008 and winter 2009, respectively. The cruises covered all major basins between the Kattegat, the north of the Gulf of Bothnia and the east of the Gulf of Finland. A CT-salinity diagram indicated that the surface water CT was mainly controlled by AT. Except for the Gulf of Riga, AT decreased with decreasing salinity and resulted in a strong CT gradient in the surface water between the Kattegat to the northern regions of the Baltic Sea. Whereas the biologically induced modulations of the AT-controlled CT distribution were relatively small in the surface layer, the effect of the organic matter decomposition on the CT levels in the below-halocline water was large. The CT fraction generated by mineralization ( minCT) in the deeper water layers was determined from the difference between the measured CT and the preformed CT. The preformed CT was estimated on the basis of the CO 2 partial pressure and the AT which the considered deep water mass had during its last contact with the atmosphere. The minCT accumulation was largest in the deep basins of the central Baltic Sea where maximum values of up to 450 µmol kg - 1 were found in the bottom water of the Gotland Sea. This was attributed to long-lasting stagnation periods and to an intense organic matter input. Considerably lower minCT (factors 4-5) were obtained for the Gulf of Bothnia due to both a more frequent deep water renewal and a reduced organic matter flux.

  14. Total carbon and nitrogen abundances in lunar samples.

    PubMed

    Moore, C B; Lewis, C F; Gibson, E K; Nichiporuk, W

    1970-01-30

    Total carbon and nitrogen abundances were determined by using combustion-gas chromatographic techlniques. Weighited mean analyses for butlk fines were 225 and 140 ppm total carbon and 150 anid 100 ppm total nitrogen. Total carbon in fine breccia was 230 ppm; in coarse breccia, 100 ppmn; in fine-grained rock, 70 ppm; and in mediumn-grained rock, 64 ppm. The finest sieved fraction had the highest carbon content. Total nitrogen in fine breccia was 125 ppm; in coarse breccia, 100 ppm; in fine-grained rock, 115 ppm; and in medium-grained rock, 30 ppm. The total carbon and nitrogen finies appeat to be mixtuires of indigenous lunar material togetheer with meteoritic and solar wind components. PMID:17781467

  15. Modelling ash extractable Total Phosphorous and Total Sulphur distribution after a forest fire

    NASA Astrophysics Data System (ADS)

    Pereira, P.; Ubeda, X.

    2012-04-01

    The ash distribution in the immediate period after the fire assumes an extreme importance and this depends especially of fire severity. Due the different conditions of combustion, the fire severity can be very heterogeneous, even in small scale distances. Different fire severities produced ash with different physical and chemical properties. One of the main effects of this is the complex and very heterogenic disposition of ash nutrients that will play an important role on plant recuperation. Spatial models help to have a better picture of ash properties distribution. However, it is important to find the best model that interpolate with best accuracy the studied the variable. In this work we test several interpolation methods, namely Inverse Distance to a Weight (IDW) (with the power of 1,2,3,4 and 5), Local Polynomial with the first and second polynomial order, Polynomial Regression (PR), Radial Basis Functions (RBF) as Multilog (MTG), Natural Cubic Spline (NCS), Multiquadratic (MTQ), Inverse Multiquadratic (IMTQ) and Thin plate Spline (TPS) and Ordinary Kriging, in order to identify the best spatial predictor for Total Phosphorous (TP) and Total Sulphur (TS) after a forest fire in Portugal. Inside the burned area we designed a small plot (27x9 m) and we collected a total of 40 samples of ash. Interpolation accuracy was observed with the cross-validation method that is achieved by taking each observation in turn out of the sample and estimating from the remaining ones. The errors produced in each interpolation allowed us to calculate the Root Mean Square Error (RMSE). The results showed that on average ash extractable TP were 92.42 (±77.34) mg/l, with a Coefficient of variation (CV%) of 83.68. The distribution was positively skewed and non-normal distributed. This previously to modelling we transformed it with a neperian logarithm, in order to respect the normality assumptions. From all the tested methods the best predictor for TP was the IDW 1 and the less precise the NCS. This shows the heterogenic character of TP distribution, since IDW 1 is more accurate to interpolate variables with small distance variability. The distribution of TP was heterogenic and did not respond to a specific spatial pattern, with some higher values in the northwest and southwest parts of the plot. TS presented on average 1690 (±468.72), with CV% of 27.73%. In this case the variable distribution was normally distributed and no transformation was needed previous to data modelling. As TP the most precise interpolator was IDW 1 and the less accurate was also NCS. This reflects also the heterogenic distribution of TS, however small than TP, due the reduced CV%. The models presented showed important differences among interpolation tests, in both variables, and this shown that the test of interpolation methods is fundamental to have a correct evaluation of the spatial distribution of the variables. Keywords: Ash, fire severity, interpolation methods, heterogenic distribution

  16. The Association between Diabetic Retinopathy and Levels of Ischemia-Modified Albumin, Total Thiol, Total Antioxidant Capacity, and Total Oxidative Stress in Serum and Aqueous Humor

    PubMed Central

    Kirboga, Kadir; Ozec, Ayse V.; Kosker, Mustafa; Dursun, Ayhan; Toker, Mustafa I.; Aydin, Huseyin; Erdogan, Haydar; Topalkara, Aysen; Arici, Mustafa K.

    2014-01-01

    Purpose. To investigate the oxidant and antioxidant status of patients with type 2 diabetes mellitus and nonproliferative diabetic retinopathy (DRP). Methods. Forty-four patients who had cataract surgery were enrolled in the study. We included 22 patients with DRP in one group and 22 patients in the control group. Samples of aqueous humor and serum were taken from all patients. Serum and aqueous ischemia-modified albumin (IMA), total thiol, total antioxidant capacity (TAC), and total oxidative stress (TOS) levels were compared in two groups. Results. Median serum IMA levels were 44.80 absorbance units in the DRP group and 40.15 absorbance units in the control group (P = 0.031). Median serum total thiol levels in the DRP group were significantly less than those in the control group (3051.13 and 3910.12, resp., P = 0.004). Mean TOS levels in the serum were 2.93 ± 0.19 in the DRP group and 2.61 ± 0.26 in the control group (P = 0.039). The differences in mean total thiol, TAC, and TOS levels in the aqueous humor and mean TAC levels in the serum were not statistically significant. Conclusion. IMA, total thiol, and TOS levels in the serum might be useful markers in monitoring the risk of DRP development. PMID:25580282

  17. On total correlations in a bipartite quantum joint probability distribution

    E-print Network

    C. Jebarathinam

    2014-12-16

    We discuss the problem of separating the total correlations in a given quantum joint probability distribution into nonlocality, contextuality and classical correlations. Bell discord and Mermin discord which qunatify nonlocality and contextuality of quantum correlations are interpreted as distance measures in the nonsignaling polytope. A measure of total correlations is introduced to divide the total amount of correlations into a purely nonclassical part and a classical part. We show that quantum correlations satisfy additivity relations among these three measures.

  18. Delayed sciatic nerve palsy following resurfacing hip arthroplasty caused by metal debris

    PubMed Central

    Kayani, Babar; Rahman, Jeeshan; Hanna, Sammy A; Cannon, Stephen R; Aston, William J; Miles, Jonathan

    2012-01-01

    The rapid rise in the incidence of failed metal-on-metal hip articulations in recent years has led to many patients requiring complex revision surgery. These failed metal prostheses may produce local metallic debris, which promotes both local and systemic adverse effects. We report an unusual case of failed metal-on-metal resurfacing hip arthroplasty presenting with ipsilateral buttock pain and foot drop 6?months after surgery. After thorough investigations, the metal-on-metal bearing was revised to a metal-on-polyethylene total hip replacement. This resulted in marked improvement in the systemic symptoms, inflammatory marke and metal ion levels postoperatively. However, neither clinical nor neurophysiological sciatic nerve recovery followed. The patient eventually required tendon transfer surgery for her persistent foot drop. PMID:23152177

  19. Predictions for the total solar eclipse of 1988

    NASA Technical Reports Server (NTRS)

    Espenak, Fred

    1987-01-01

    A total eclipse of the sun will be widely visible from the East Indies on March 18, 1988. Detailed predictions for this event are presented which include tables of geographic coordinates for the northern limit, center line and southern limit of the path of totality, local circumstances for 40 cities within the total and partial eclipse paths, the lunar-limb profile, and maps depicting the path of totality. The author discusses the general characteristics of the eclipse, local circumstances from various points along the central path and the Saros-series history.

  20. 21 CFR 862.1700 - Total thyroxine test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1700 Total thyroxine test system. (a)...