1,340 research outputs found
Dual energy X-ray absorptiometry positioning protocols in assessing body composition: A systematic review of the literature:A systematic review of the literature
OBJECTIVES: To systematically identify and assess methods and protocols used to reduce technical and biological errors in published studies that have investigated reliability of dual energy X-ray absorptiometry (DXA) for assessing body composition. DESIGN: Systematic review. METHODS: Systematic searches of five databases were used to identify studies of DXA reliability. Two independent reviewers used a modified critical appraisal tool to assess their methodological quality. Data was extracted and synthesised using a level of evidence approach. Further analysis was then undertaken of methods used to decrease DXA errors (technical and biological) and so enhance DXA reliability. RESULTS: Twelve studies met eligibility criteria. Four of the articles were deemed high quality. Quality articles considered biological and technical errors when preparing participants for DXA scanning. The Nana positioning protocol was assessed to have a strong level of evidence. The studies providing this evidence indicated very high testâretest reliability (ICC 0.90â1.00 or less than 1% change in mean) of the Nana positioning protocol. The National Health and Nutrition Examination Survey (NHANES) positioning protocol was deemed to have a moderate level of evidence due to lack of high quality studies. However, the available studies found the NHANES positioning protocol had very high testâretest reliability. Evidence is limited and reported reliability has varied in papers where no specific positioning protocol was used or reported. CONCLUSIONS: Due to the strong level of evidence of excellent testâretest reliability that supports use of the Nana positioning protocol, it is recommended as the first choice for clinicians when using DXA to assess body composition
Real-world clinical experience in the ConnectÂź chronic lymphocytic leukaemia registry: a prospective cohort study of 1494 patients across 199 US centres.
The clinical course of chronic lymphocytic leukaemia (CLL) is heterogeneous, and treatment options vary considerably. The ConnectÂź CLL registry is a multicentre, prospective observational cohort study that provides a real-world perspective on the management of, and outcomes for, patients with CLL. Between 2010 and 2014, 1494 patients with CLL and that initiated therapy, were enrolled from 199 centres throughout the USA (179 community-, 17 academic-, and 3 government-based centres). Patients were grouped by line of therapy at enrolment (LOT). We describe the clinical and demographic characteristics of, and practice patterns for, patients with CLL enrolled in this treatment registry, providing patient-level observational data that represent real-world experiences in the USA. Fluorescence in situ hybridization (FISH) analyses were performed on 49·3% of patients at enrolment. The most common genetic abnormalities detected by FISH were del(13q) and trisomy 12 (45·7% and 20·8%, respectively). Differences in disease characteristics and comorbidities were observed between patients enrolled in LOT1 and combined LOT2/â„3 cohorts. Important trends observed include the infrequent use of genetic prognostic testing, and differences in patient characteristics for patients receiving chemoimmunotherapy combinations. These data represent experiences of patients with CLL in the USA, which may inform treatment decisions in everyday practice
Substituting a copper atom modifies the melting of aluminum clusters
ProducciĂłn CientĂficaHeat capacities have been measured for Al(nâ1)Cuâ clusters (n = 49â62) and compared with results for pure Aln+ clusters. Al(nâ1)Cuâ and Aln+ have the same number of atoms and the same number of valence electrons (excluding the copper d electrons). Both clusters show peaks in their heat capacities that can be attributed to melting transitions; however, substitution of an aluminum atom by a copper atom causes significant changes in the melting behavior. The sharp drop in the melting temperature that occurs between n = 55 and 56 for pure aluminum clusters does not occur for the Al(nâ1)Cuâ analogs. First-principles density-functional theory has been used to locate the global minimum energy structures of the doped clusters. The results show that the copper atom substitutes for an interior aluminum atom, preferably one with a local face-centered-cubic environment. Substitution does not substantially change the electronic or geometric structures of the host cluster unless there are several Aln+ isomers close to the ground state. The main structural effect is a contraction of the bond lengths around the copper impurity, which induces both a contraction of the whole cluster and a stress redistribution between the AlâAl bonds. The size dependence of the substitution energy is correlated with the change in the latent heat of melting on substitution
Variable Curvature Slab Molecular Dynamics as a Method to Determine Surface Stress
A thin plate or slab, prepared so that opposite faces have different surface
stresses, will bend as a result of the stress difference. We have developed a
classical molecular dynamics (MD) formulation where (similar in spirit to
constant-pressure MD) the curvature of the slab enters as an additional
dynamical degree of freedom. The equations of motion of the atoms have been
modified according to a variable metric, and an additional equation of motion
for the curvature is introduced. We demonstrate the method to Au surfaces, both
clean and covered with Pb adsorbates, using many-body glue potentials.
Applications to stepped surfaces, deconstruction and other surface phenomena
are under study.Comment: 16 pages, 8 figures, REVTeX, submitted to Physical Review
Exploratory Biomarker Analysis In The Ph 3 Echelonâ1 Study: Worse Outcome With Abvd In Patients With Elevated Baseline Levels Of Scd30 And Tarc
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149507/1/hon99_2630.pd
A New Type of Electron Nuclear-Spin Interaction from Resistively Detected NMR in the Fractional Quantum Hall Effect Regime
Two dimensional electron gases in narrow GaAs quantum wells show huge
longitudinal resistance (HLR) values at certain fractional filling factors.
Applying an RF field with frequencies corresponding to the nuclear spin
splittings of {69}Ga, {71}Ga and {75}As leads to a substantial decreases of the
HLR establishing a novel type of resistively detected NMR. These resonances are
split into four sub lines each. Neither the number of sub lines nor the size of
the splitting can be explained by established interaction mechanisms.Comment: 4 pages, 3 figure
Children's Divergent Thinking Improves When They Understand False Beliefs
This research utilized longitudinal and cross sectional methods to investigate the relation between the development of a representational theory of mind and children's growing ability to search their own minds for appropriate problem solutions. In the first experiment 59 pre-school children were given three false-belief tasks and a divergent thinking task. Those children who passed false-belief tasks produced significantly more items, as well as more original items, in response to divergent thinking questions than those children who failed. This significant association persisted even when chronological age, verbal and nonverbal general ability were partialed out. In a second study 20 children who failed the false-belief tasks in the first experiment were re-tested three months later. Again, those who now passed the false-belief tasks were significantly better at the divergent thinking task than those who continued to fail. The associations between measures of divergent thinking and understanding false-beliefs remained significant when controlling for the covariates. Earlier divergent thinking scores did not predict false-belief understanding three months later. Instead, children who passed false-belief tasks on the second measure improved significantly in relation to their own earlier performance and improved significantly more than children who continued to fail. False-belief task performance was significantly correlated to the amount of intra-individual improvement in divergent thinking even when age, verbal and nonverbal skills were partialed out. These findings suggest that developments in common underlying skills are responsible for the improvement in understanding other minds and searching one's own. Changes in representational and executive skills are discussed as potential causes for the improvement
Fine material in grain
Fine material in grain: an overview / Richard Stroshine -- Factors that affect the costs of fines in the corn export market / Lowell D. Hill, Mack Leath -- Effects of fine material on mold growth in grain / David B. Sauer, Richard A. Meronuck, John Tuite -- Effects of fine material on insect infestation: a review / Paul W. Flinn, William H. McGaughey, Wendell E. Burkholder -- Reducing or controlling damage to grain from handling: a review / Charles R. Martin, George H. Foster -- Evaluating grain for potential production of fine material - breakage susceptibility testing / Steven R. Eckhoff -- Genotypic differences in breakage susceptibility of corn and soybeans -- M. R. Paulsen, L. L. Darrah, R. L. Stroshin
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