13 research outputs found
Challenges and opportunities in high-precision Be-10 measurements at CAMS
We determined the overall efficiency for 10Be of the high-intensity LLNL modified Middleton cesium sputter source in combination with the CAMS FN mass spectrometer. BeOâ ionization efficiency is >3%. Charge exchange efficiency including transmission through the tandem for 7.5 MeV Be+3 is âŒ34%, resulting in a total system efficiency of just over 1%. At this efficiency and with very low backgrounds, we estimate our detection limit to be âŒ1000 10Be atoms. Cathodes prepared with only âŒ80 ÎŒg of 9Be show only an âŒ33% reduction in 9Be beam current compared to a sample with âŒ200 ÎŒg. These same samples, prepared from 07KNSTD1032 standard material, contained 1 Ă 107 and 5 Ă 10610Be atoms and exhibited similar ionization and total system efficiency. These results demonstrate the feasibility of pursuing applications that require precise measurement of samples with low 10Be concentrations and/or small sample size
Patients with adolescent idiopathic scoliosis perceive positive improvements regardless of change in the Cobb angle â Results from a randomized controlled trial comparing a 6-month Schroth intervention added to standard care and standard care alone. SOSORT 2018 Award winner
Abstract
Background
The Cobb angle is proposed as the âdisease processâ outcome for scoliosis research because therapies aim to correct or stop curve progression. While the Scoliosis Research Society recommends the Cobb angle as the primary outcome, the Society on Scoliosis Orthopaedic and Rehabilitation Treatment prioritises, as a general goal, patient related outcomes over Cobb angle progression.
Objective
To determine the threshold of change in the Cobb angle in adolescents with idiopathic scoliosis (AIS) who perceive improvement in a 6-months randomized controlled trial comparing a Schroth exercise intervention added to the standard of care to the standard of care alone.
Methods
This is a secondary analysis of data from a randomized controlled trial of 50 patients with AIS, with curves ranging from 10° to 45°, with or without a brace. Participants with diagnoses other than AIS, surgical candidates or patients who had scoliosis surgery were excluded. The 6-month interventions consisted of Schroth exercises added to standard-of-care (observation or bracing) with daily home exercises and weekly therapy sessions (Schroth) or standard-of-care alone (Control).
The anchor method for estimating the minimal important difference (MID) in the largest Cobb angles (LC) was used. Patient-reported change in back status over the 6-month treatment period was measured using the Global Rating of Change (GRC) scale as anchor varying from ââ7 (âgreat deal worseâ) to +â7 (âgreat deal betterâ). Participants were divided into two groups based on GRC scores: Improved (GRC â„2) or Stable/Not Improved (GRC â€1). MID was defined as the change in the LC that most accurately predicted the GRC classification as per the receiver operating characteristic curve (ROC).
Results
The average age was 13.4â±â1.6âyears and the average LC was 28.5â±â8.8 °s. The average GRC in the control group was ââ0.1â±â1.6, compared to +â4.4â±â2.2 in the Schroth group. The correlation between LC and GRC was adequate (râ=âââ0.34, pâ<â0.05). The MID for the LC was 1.0 °. The area under the ROC was 0.69 (0.52â0.86), suggesting a 70% chance to properly classify a patient as perceiving No Improvement/Stable or Improvement based on the change in the LC.
Conclusion
Patients undergoing Schroth treatment perceived improved status of their backs even if the Cobb angle did not improve beyond the conventionally accepted threshold of 5°. Standard of care aims to slow/stop progression while Schroth exercises aim to improve postural balance, signs and symptoms of scoliosis. Given the very small MID, perceived improvement in back status is likely due to something other than the Cobb angle. This study warrants investigating alternatives to the Cobb angle that might be more relevant to patients.
Trial registration
ClinicalTrials.gov
,
NCT01610908
. Retrospectively registered on April 2, 2012 (first posted on June 4, 2012 -
https://clinicaltrials.gov/ct2/keydates/NCT01610908
Recommended from our members
Female hunters of the early Americas.
Sexual division of labor with females as gatherers and males as hunters is a major empirical regularity of hunter-gatherer ethnography, suggesting an ancestral behavioral pattern. We present an archeological discovery and meta-analysis that challenge the man-the-hunter hypothesis. Excavations at the Andean highland site of Wilamaya Patjxa reveal a 9000-year-old human burial (WMP6) associated with a hunting toolkit of stone projectile points and animal processing tools. Osteological, proteomic, and isotopic analyses indicate that this early hunter was a young adult female who subsisted on terrestrial plants and animals. Analysis of Late Pleistocene and Early Holocene burial practices throughout the Americas situate WMP6 as the earliest and most secure hunter burial in a sample that includes 10 other females in statistical parity with early male hunter burials. The findings are consistent with nongendered labor practices in which early hunter-gatherer females were big-game hunters
Schroth Physiotherapeutic Scoliosis-Specific Exercises Added to the Standard of Care Lead to Better Cobb Angle Outcomes in Adolescents with Idiopathic Scoliosis â an Assessor and Statistician Blinded Randomized Controlled Trial
<div><p>Background</p><p>The North American non-surgical standard of care for adolescent idiopathic scoliosis (AIS) includes observation and bracing, but not exercises. Schroth physiotherapeutic scoliosis-specific exercises (PSSE) showed promise in several studies of suboptimal methodology. The Scoliosis Research Society calls for rigorous studies supporting the role of exercises before including it as a treatment recommendation for scoliosis.</p><p>Objectives</p><p>To determine the effect of a six-month Schroth PSSE intervention added to standard of care (Experimental group) on the Cobb angle compared to standard of care alone (Control group) in patients with AIS.</p><p>Methods</p><p>Fifty patients with AIS aged 10â18 years, with curves of 10°-45° and Risser grade 0â5 were recruited from a single pediatric scoliosis clinic and randomized to the Experimental or Control group. Outcomes included the change in the Cobb angles of the Largest Curve and Sum of Curves from baseline to six months. The intervention consisted of a 30â45 minute daily home program and weekly supervised sessions. Intention-to-treat and per protocol linear mixed effects model analyses are reported.</p><p>Results</p><p>In the intention-to-treat analysis, after six months, the Schroth group had significantly smaller Largest Curve than controls (-3.5°, 95% CI -1.1° to -5.9°, <i>p</i> = 0.006). Likewise, the between-group difference in the square root of the Sum of Curves was -0.40°, (95% CI -0.03° to -0.8°, <i>p</i> = 0.046), suggesting that an average patient with 51.2° at baseline, will have a 49.3° Sum of Curves at six months in the Schroth group, and 55.1° in the control group with the difference between groups increasing with severity. Per protocol analyses produced similar, but larger differences: Largest Curve = -4.1° (95% CI -1.7° to -6.5°, <i>p</i> = 0.002) and (95% CI -0.8 to 0.2, <i>p</i> = 0.006).</p><p>Conclusion</p><p>Schroth PSSE added to the standard of care were superior compared to standard of care alone for reducing the curve severity in patients with AIS.</p><p>Trial Registration</p><p><a href="https://clinicaltrials.gov/ct2/show/NCT01610908" target="_blank">NCT01610908</a></p></div
Baseline characteristics of the study population.
<p>Baseline characteristics of the study population.</p
Number of patients with improved, deteriorated and stable curves using a 5° Cobb angle clinical significance threshold.
<p>Number of patients with improved, deteriorated and stable curves using a 5° Cobb angle clinical significance threshold.</p