Pressure, Temperature and Dwell Time Effects on Fatigue Life in 304 Stainless Steel Using a R5-based Mechanistic Fatigue Model

AbstractThis paper aims to evaluate the effects of pressure, temperature, pipe wall thickness and dwell time on fatigue life in 304 stainless steel. For a given dwell time and temperature-internal pressure combination, fatigue life is calculated using the mechanistic fatigue model (MFM) presented. In addition, the influence of pipe wall thickness is also examined. The MFM uses Tresca strain range for initiation and Rankine strain range to account for crack growth rate up to a crack limiting length. The results showed that fatigue life was generally lower for a given load combination in the thinner pipe considered given its smaller surface area compared to the thicker pipe. This led to higher plastic strains and consequently, faster crack growth rates. Also, dwell time influences fatigue life with longer dwell times found to be more damaging. However, the influence of dwell time is tightly coupled with pipe wall thickness as it determines the nature of the thermal gradients developed

Interval training normalizes cCardiomyocyte function, diastolic Ca²⁺ control, and SR Ca²⁺ release synchronicity in a mouse model of diabetic cardiomyopathy

In the present study we explored the mechanisms behind excitation-contraction (EC)-coupling defects in cardiomyocytes from mice with type-2 diabetes (db/db), and determined whether 13-weeks of aerobic interval training could restore cardiomyocyte Ca2+ cycling and EC-coupling. Reduced contractility in cardiomyocytes isolated from sedentary db/db was associated with increased diastolic sarcoplasmic reticulum (SR)-Ca2+ leak, reduced synchrony of Ca2+ release, reduced transverse (T)-tubule density, and lower peak systolic and diastolic Ca2+ and caffeine-induced Ca2+ release. Additionally, the rate of SR Ca2+ ATPase (SERCA2a)-mediated Ca2+ uptake during diastole was reduced, whereas a faster recovery from caffeine-induced Ca2+ release indicated increased Na+/Ca2+- exchanger (NCX) activity. The increased SR-Ca2+ leak was attributed to increased Ca2+-calmodulindependent protein kinase (CaMKIIδ) phosphorylation, supported by the normalization of SR-Ca2+ leak upon inhibition of CaMKIIδ (AIP). Exercise training restored contractile function associated with restored SR Ca2+ release synchronicity, T-tubule density, twitch Ca2+ amplitude, SERCA2a and NCX activities, and SR-Ca2+ leak. The latter was associated with reduced phosphorylation of cytosolic CaMKIIδ. Despite normal contractile function and Ca2+ handling after the training period, phospholamban was hyperphosphorylated at Serine-16. Protein kinase A (PKA) inhibition (H-89) in cardiomyocytes from the exercised db/db group abolished the differences in SR-Ca2+ load when compared with the sedentary db/db mice. EC-coupling changes were observed without changes in serum insulin or glucose levels, suggesting that the exercise training-induced effects are not via normalization of the diabetic condition. These data demonstrate that aerobic interval training almost completely restored the contractile function of the diabetic cardiomyocyte to levels close to sedentary wild type (WT)

The Norwich Patellar Instability Score:validity, internal consistency and responsiveness for people conservatively-managed following first-time patellar dislocation

Background: This paper assessed the validity, internal consistency, responsiveness and floor-ceiling effects of the Norwich Patellar Instability (NPI) Score for a cohort of conservatively managed people following first-time patellar dislocation (FTPD).  Methods: Fifty patients were recruited, providing 130 completed datasets over 12 months. The NPI Score, Lysholm Knee Score, Tegner Level of Activity Score and isometric knee extension strength were assessed at baseline, six weeks, six and 12 months post-injury.  Results: There was high convergent validity with a statistically significant correlation between the NPI Score and the Lysholm Knee Score (p < 0.001), Tegner Level of Activity Score (p < 0.001) and isometric knee extension strength (p < 0.002). Principal component analysis revealed that the NPI Score demonstrated good concurrent validity with four components account for 70.4% of the variability. Whilst the NPI Score demonstrated a flooring-effect for 13 of the 19 items, no ceiling effect was reported. There was high internal consistency with a Cronbach Alpha value of 0.93 (95% CI: 0.91 to 0.93). The NPI Score was responsive to change over the 12 months period with an effect size of 1.04 from baseline to 12 months post-injury.  Conclusions: The NPI Score is a valid tool to assess patellar instability symptoms in people conservatively managed following FTPD.  Level of evidence: Level I

Does anticholinergics drug burden relate to global neuro-disability outcome measures and length of hospital stay?

Primary objective: To assess the relationship between disability, length of stay (LOS) and anticholinergic burden (ACB) with people following acquired brain or spinal cord injury. Research design: A retrospective case note review assessed total rehabilitation unit admission. Methods and procedures: Assessment of 52 consecutive patients with acquired brain/spinal injury and neuropathy in an in-patient neuro-rehabilitation unit of a UK university hospital. Data analysed included: Northwick Park Dependency Score (NPDS), Rehabilitation complexity Scale (RCS), Functional Independence Measure and Functional Assessment Measure FIM-FAM (UK version 2.2), LOS and ACB. Outcome was different in RCS, NPDS and FIM-FAM between admission and discharge. Main outcomes and results: A positive change was reported in ACB results in a positive change in NPDS, with no significant effect on FIM-FAM, either Motor or Cognitive, or on the RCS. Change in ACB correlated to the length of hospital stay (regression correlation = −6.64; SE = 3.89). There was a significant harmful impact of increase in ACB score during hospital stay, from low to high ACB on NPDS (OR = 9.65; 95% CI = 1.36–68.64) and FIM-FAM Total scores (OR = 0.03; 95% CI = 0.002–0.35). Conclusions: There was a statistically significant correlation of ACB and neuro-disability measures and LOS amongst this patient cohort

Smoking and alcohol behaviours in people following hip and knee arthroplasty: data from the Osteoarthritis Initiative

Background: Smoking and alcohol consumption have a negative effect on overall health. Limited evidence has been presented as to how these health behaviours may change between pre- and postoperative intervals in the initial 12 months post-arthroplasty. The purpose of this study was to address this uncertainty.  Hypothesis: Smoking and alcohol consumption differs between pre- and post-THA/TKA and is differs between non-arthroplasty cohorts.  Materials and Methods: Data from the Osteoarthritis Initiative (OAI), a population-based observational study in the USA, was gathered. In total, data from 287 people who had undergone THA or TKA from baseline to Month 48 OAI follow-up assessments were analysed. Data on this cohort were compared to 287 age- and gender-matched people with osteoarthritis. Mean change from pre- to post-arthroplasty, and differences between arthroplasty and non-arthroplasty participants for smoking and alcohol consumption were assessed descriptively and through Wilcoxin-matched pairs test and Student t-tests (as appropriate),.  Results: The life-time prevalence of smoking was high for people who received THA (99%) and TKA (96%). Prevalence of current smoking significantly decreased from 5% to 3% across the THA and TKA cohort in the initial 12 months post-arthroplasty (p<0.05). Similarly, there was a statistically significant decrease in weekly alcohol consumption post-arthroplasty for people who underwent THA and TKA (p<0.01), although the mean difference was only by 0.9 alcoholic drinks. The only statistically significant difference in smoking and alcohol consumption for arthroplasty to non-arthroplasty participants was in weekly alcohol consumption, which was higher by 0.3 drinks in the non-arthroplasty cohort (p=0.04).  Conclusions: Smoking and alcohol consumption decreased in the initial 12 months post-THA and TKA. This was not significantly different to an age- and gender-matched non-arthroplasty cohort. Whilst this is positive, a small group of patients still present with unhealthy lifestyle choices in relation to these behaviours post-arthroplasty

Conceptual framework for an episode of rehabilitative care after hip fracture surgery

Researchers face a challenge when evaluating the effectiveness of rehabilitation after hip fracture surgery. Reported outcomes of rehabilitation will vary depending on the endpoint of the episode of care. Evaluation at an inappropriate endpoint may suggest a lack of effectiveness leading to the underuse of rehabilitation that could improve outcomes. The purpose of this paper is to describe a conceptual framework for a continuum-care-episode of rehabilitation after hip fracture surgery. We propose definitions for the index event, endpoint, and service scope of the episode. We discuss challenges in defining the episode of care, operationalizing the episode, and next steps for researchers. The episode described is intended to apply to all patients eligible for entry to rehabilitation after hip fracture and includes most functional recovery endpoints. This framework will provide a guide for rehabilitation researchers when designing and interpreting evaluations of the effectiveness of rehabilitation after hip fracture. Evaluation of all potential care episodes facilitates transparency in reporting of outcomes enabling researchers to determine the true effectiveness of rehabilitation after hip fracture surgery

Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State

Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II detector we have observed a narrow resonance in the Ds*+pi0 final state, with a mass near 2.46 GeV. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new state, designated as the DsJ(2463)+. Because of the similar dM values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences = 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and = 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+ state. We have also searched, but find no evidence, for decays of the two states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels respectively, are consistent with their interpretations as (c anti-strange) mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical Review D; minor modifications and fixes to typographical errors, plus an added section on production properties. The main results are unchanged; they supersede those reported in hep-ex/030501

Measurement of the Charge Asymmetry in B→K∗(892)±π∓B\to K^* (892)^{\pm}\pi^{\mp}

We report on a search for a CP-violating asymmetry in the charmless hadronic decay B -> K*(892)+- pi-+, using 9.12 fb^-1 of integrated luminosity produced at \sqrt{s}=10.58 GeV and collected with the CLEO detector. We find A_{CP}(B -> K*(892)+- pi-+) = 0.26+0.33-0.34(stat.)+0.10-0.08(syst.), giving an allowed interval of [-0.31,0.78] at the 90% confidence level.Comment: 7 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

Study of the q^2-Dependence of B --> pi ell nu and B --> rho(omega)ell nu Decay and Extraction of |V_ub|

We report on determinations of |Vub| resulting from studies of the branching fraction and q^2 distributions in exclusive semileptonic B decays that proceed via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson pairs collected at the Y(4S) resonance with the CLEO II detector. We measure B(B0 -> pi- l+ nu) = (1.33 +- 0.18 +- 0.11 +- 0.01 +- 0.07)x10^{-4} and B(B0 -> rho- l+ nu) = (2.17 +- 0.34 +0.47/-0.54 +- 0.41 +- 0.01)x10^{-4}, where the errors are statistical, experimental systematic, systematic due to residual form-factor uncertainties in the signal, and systematic due to residual form-factor uncertainties in the cross-feed modes, respectively. We also find B(B+ -> eta l+ nu) = (0.84 +- 0.31 +- 0.16 +- 0.09)x10^{-4}, consistent with what is expected from the B -> pi l nu mode and quark model symmetries. We extract |Vub| using Light-Cone Sum Rules (LCSR) for 0<= q^2<16 GeV^2 and Lattice QCD (LQCD) for 16 GeV^2 <= q^2 < q^2_max. Combining both intervals yields |Vub| = (3.24 +- 0.22 +- 0.13 +0.55/-0.39 +- 0.09)x10^{-3}$ for pi l nu, and |Vub| = (3.00 +- 0.21 +0.29/-0.35 +0.49/-0.38 +-0.28)x10^{-3} for rho l nu, where the errors are statistical, experimental systematic, theoretical, and signal form-factor shape, respectively. Our combined value from both decay modes is |Vub| = (3.17 +- 0.17 +0.16/-0.17 +0.53/-0.39 +-0.03)x10^{-3}.Comment: 45 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

Search for CP Violation in D^0--> K_S^0 pi^+pi^-

We report on a search for CP violation in the decay of D0 and D0B to Kshort pi+pi-. The data come from an integrated luminosity of 9.0 1/fb of e+e- collisions at sqrt(s) ~ 10 GeV recorded with the CLEO II.V detector. The resonance substructure of this decay is well described by ten quasi-two-body decay channels (K*-pi+, K*0(1430)-pi+, K*2(1430)-pi+, K*(1680)-pi+, Kshort rho, Kshort omega, Kshort f0(980), Kshort f2(1270), Kshort f0(1370), and the ``wrong sign'' K*+ pi-) plus a small non-resonant component. We observe no evidence for CP violation in the amplitudes and phases that describe the decay D0 to K_S^0 pi+pi-.Comment: 10 pages, 3 figures, also available at http://w4.lns.cornell.edu/public/CLNS/, submitted to PR