2,449 research outputs found
Magnification in undergraduate endodontics teaching in the UK and Ireland: a survey of teaching leads in Endodontology
Aim:
To investigate the use of magnification in undergraduate endodontic teaching in dental schools within the UK and Ireland and identify factors that may impact on levels of adoption.
Methodology:
An electronic questionnaire was distributed to teaching leads in undergraduate endodontics in all UK and Ireland dental schools.
Results:
Completed questionnaires were received from 15 of 18 course leads. The study revealed magnification is not universally embedded within the undergraduate curricula and the majority of schools had no expectation for students to use magnification, although it was encouraged. The study provided insight into teaching staff factors, student factors and institutional factors that impact upon the adoption of magnification in undergraduate endodontic teaching. Although course leads utilised magnification in their own practice, this did not translate into institutional expectation for students to use magnification. Barriers to adoption of such an institutional expectation included cost and lack of staff training.
Conclusions:
Magnification has become viewed as an essential part of endodontic practice. The dental operating microscope has the most significant impact on endodontic visualisation, however, the use of dental loupes in non‐surgical endodontics could be considered the minimum standard. The pedagogical dilemma faced by dental educators training undergraduates to behave in a manner that they themselves would not, cannot be rationalised on the basis of cost and lack of staff training. It is proposed that although significant, these barriers are not insurmountable and dental loupe use should become an expectation in undergraduate training in the UK and Ireland
MHD models of Pulsar Wind Nebulae
Pulsar Wind Nebulae (PWNe) are bubbles or relativistic plasma that form when
the pulsar wind is confined by the SNR or the ISM. Recent observations have
shown a richness of emission features that has driven a renewed interest in the
theoretical modeling of these objects. In recent years a MHD paradigm has been
developed, capable of reproducing almost all of the observed properties of
PWNe, shedding new light on many old issues. Given that PWNe are perhaps the
nearest systems where processes related to relativistic dynamics can be
investigated with high accuracy, a reliable model of their behavior is
paramount for a correct understanding of high energy astrophysics in general. I
will review the present status of MHD models: what are the key ingredients,
their successes, and open questions that still need further investigation.Comment: 18 pages, 5 figures, Invited Review, Proceedings of the "ICREA
Workshop on The High-Energy Emission from Pulsars and their Systems", Sant
Cugat, Spain, April 12-16, 201
A model of impairment and functional limitation in rheumatoid arthritis
BACKGROUND: We have previously proposed a theoretical model for studying physical disability and other outcomes in rheumatoid arthritis (RA). The purpose of this paper is to test a model of impairment and functional limitation in (RA), using empirical data from a sample of RA patients. We based the model on the disablement process framework. METHODS: We posited two distinct types of impairment in RA: 1) Joint inflammation, measured by the tender, painful and swollen joint counts; and 2) Joint deformity, measured by the deformed joint count. We hypothesized direct paths from the two impairments to functional limitation, measured by the shirt-button speed, grip strength and walking velocity. We used structural equation modeling to test the hypothetical relationships, using empirical data from a sample of RA patients recruited from six rheumatology clinics. RESULTS: The RA sample was comprised of 779 RA patients. In the structural equation model, the joint inflammation impairment displayed a strong significant path toward the measured variables of joint pain, tenderness and swelling (standardized regression coefficients 0.758, 0.872 and 0.512, P ≤ 0.001 for each). The joint deformity impairment likewise displayed significant paths toward the measured upper limb, lower limb, and other deformed joint counts (standardized regression coefficients 0.849, 0.785, 0.308, P ≤ 0.001 for each). Both the joint inflammation and joint deformity impairments displayed strong direct paths toward functional limitation (standardized regression coefficients of -0.576 and -0.564, respectively, P ≤ 0.001 for each), and explained 65% of its variance. Model fit to data was fair to good, as evidenced by a comparative fit index of 0.975, and the root mean square error of approximation = 0.058. CONCLUSION: This evidence supports the occurrence of two distinct impairments in RA, joint inflammation and joint deformity, that together, contribute strongly to functional limitations in this disease. These findings may have implications for investigators aiming to measure outcome in RA
Microvascular function is preserved in newly diagnosed rheumatoid arthritis and low systemic inflammatory activity
Rheumatoid arthritis (RA) is associated with increased cardiovascular morbidity and mortality. Microvascular function has been linked to several risk factors for cardiovascular disease and may be affected in RA. It is, however, presently unknown at what point in the disease course the abnormalities in microvascular function occur. We determined whether microvascular function is already disturbed in early disease-modifying antirheumatic drugs (DMARD)-naive RA patients with low systemic inflammation. Fifteen consecutive RA patients with a median symptom duration of 5 months, a C-reactive protein level of ≤20 mg/l and without a history of cardiovascular disease, and age 15 and sex-matched healthy controls were recruited. Endothelium-dependent and endothelium-independent vasodilatation in skin was evaluated with laser Doppler fluxmetry after iontophoresis of acetylcholine and sodium nitroprusside, respectively. Videomicroscopy was used to measure recruitment of skin capillaries after arterial occlusion. CRP and ESR levels were mildly, but significantly elevated in patients compared to controls. No differences in both endothelium-dependent vasodilatation and capillary recruitment were observed between groups [709% (95% CI, 457–961%) vs 797% (95% CI, 556–1,037%), P = 0.59 and 37% (95% CI, 26–47%) vs 41% (95% CI, 31–50%), P = 0.59, respectively]. Skin microvascular function is preserved in early, DMARD-naive RA patients with moderately active RA but low systemic inflammatory activity. Both the extent of the systemic inflammation and disease duration, therefore, may be important determinants of microvascular dysfunction and subsequent increased risk for cardiovascular disease
Carotid artery plaque in women with rheumatoid arthritis and low estimated cardiovascular disease risk: a cross-sectional study
INTRODUCTION:
We previously reported that most patients with rheumatoid arthritis (RA) and moderate cardiovascular disease (CVD) risk according to the Systematic COronary Evaluation score (SCORE) experience carotid artery plaque. In this study, we aimed to identify patient characteristics that can potentially predict carotid plaque presence in women with RA and a concurrent low CVD risk according to the SCORE.
METHODS:
A cohort of 144 women with an evaluated low risk of CVD (SCORE value of zero) was assembled amongst 550 consecutive patients with RA that underwent CVD risk factor recording and carotid artery ultrasound. Participants had no established CVD, moderate or severe chronic kidney disease, or diabetes. We assessed carotid plaque(s) presence and its associated patient characteristics.
RESULTS:
Carotid artery plaque was present in 35 (24.3%) of women with RA. Age, the number of synthetic disease-modifying agents (DMARDs) and total cholesterol concentrations were independently associated with plaque in multivariable stepwise backward regression analysis (odds ratio (95% confidence interval)=1.15 (1.07 to 1.24), P49.5 years or/and total cholesterol concentration of >5.4 mmol/l, respectively, compared to only 7.8% in those (n=64; 44.4%) with age≤49.5 years or/and total cholesterol concentration of ≤5.4 mmol/l, respectively.
CONCLUSIONS:
Approximately one-third of women with RA who experience a low SCORE value and are aged >49.5 years or/and have a total cholesterol concentration of >5.4 mmol/l, experience high-risk atherosclerosis, which requires intensive CVD risk management
Carglumic acid enhances rapid ammonia detoxification in classical organic acidurias with a favourable risk-benefit profile: A retrospective observational study
BACKGROUND: Isovaleric aciduria (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) are inherited organic acidurias (OAs) in which impaired organic acid metabolism induces hyperammonaemia arising partly from secondary deficiency of N-acetylglutamate (NAG) synthase. Rapid reduction in plasma ammonia is required to prevent neurological complications. This retrospective, multicentre, open-label, uncontrolled, phase IIIb study evaluated the efficacy and safety of carglumic acid, a synthetic structural analogue of NAG, for treating hyperammonaemia during OA decompensation. METHODS: Eligible patients had confirmed OA and hyperammonaemia (plasma NH3 > 60 μmol/L) in ≥1 decompensation episode treated with carglumic acid (dose discretionary, mean (SD) first dose 96.3 (73.8) mg/kg). The primary outcome was change in plasma ammonia from baseline to endpoint (last available ammonia measurement at ≤18 hours after the last carglumic acid administration, or on Day 15) for each episode. Secondary outcomes included clinical response and safety. RESULTS: The efficacy population (received ≥1 dose of study drug and had post-baseline measurements) comprised 41 patients (MMA: 21, PA: 16, IVA: 4) with 48 decompensation episodes (MMA: 25, PA: 19, IVA: 4). Mean baseline plasma ammonia concentration was 468.3 (±365.3) μmol/L in neonates (29 episodes) and 171.3 (±75.7) μmol/L in non-neonates (19 episodes). At endpoint the mean plasma NH3 concentration was 60.7 (±36.5) μmol/L in neonates and 55.2 (±21.8) μmol/L in non-neonates. Median time to normalise ammonaemia was 38.4 hours in neonates vs 28.3 hours in non-neonates and was similar between OA subgroups (MMA: 37.5 hours, PA: 36.0 hours, IVA: 40.5 hours). Median time to ammonia normalisation was 1.5 and 1.6 days in patients receiving and not receiving concomitant scavenger therapy, respectively. Although patients receiving carglumic acid with scavengers had a greater reduction in plasma ammonia, the endpoint ammonia levels were similar with or without scavenger therapy. Clinical symptoms improved with therapy. Twenty-five of 57 patients in the safety population (67 episodes) experienced AEs, most of which were not drug-related. Overall, carglumic acid seems to have a good safety profile for treating hyperammonaemia during OA decompensation. CONCLUSION: Carglumic acid when used with or without ammonia scavengers, is an effective treatment for restoration of normal plasma ammonia concentrations in hyperammonaemic episodes in OA patients
Tumor markers in breast cancer - European Group on Tumor Markers recommendations
Recommendations are presented for the routine clinical use of serum and tissue-based markers in the diagnosis and management of patients with breast cancer. Their low sensitivity and specificity preclude the use of serum markers such as the MUC-1 mucin glycoproteins ( CA 15.3, BR 27.29) and carcinoembryonic antigen in the diagnosis of early breast cancer. However, serial measurement of these markers can result in the early detection of recurrent disease as well as indicate the efficacy of therapy. Of the tissue-based markers, measurement of estrogen and progesterone receptors is mandatory in the selection of patients for treatment with hormone therapy, while HER-2 is essential in selecting patients with advanced breast cancer for treatment with Herceptin ( trastuzumab). Urokinase plasminogen activator and plasminogen activator inhibitor 1 are recently validated prognostic markers for lymph node-negative breast cancer patients and thus may be of value in selecting node-negative patients that do not require adjuvant chemotherapy. Copyright (C) 2005 S. Karger AG, Basel
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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