217 research outputs found
Inelastic x-ray scattering investigations of lattice dynamics in SmFeAsOF superconductors
We report measurements of the phonon density of states as measured with
inelastic x-ray scattering in SmFeAsOF powders. An unexpected
strong renormalization of phonon branches around 23 meV is observed as fluorine
is substituted for oxygen. Phonon dispersion measurements on
SmFeAsOF single crystals allow us to identify the 21 meV A
in-phase (Sm,As) and the 26 meV B (Fe,O) modes to be responsible for
this renormalization, and may reveal unusual electron-phonon coupling through
the spin channel in iron-based superconductors.Comment: 4 pages, 3 figures, submitted for SNS2010 conference proceeding
The influence of poly (2-methoxyaniline-5-sulfonic acid) on the electrochemical and photochemical properties of a highly luminescent ruthenium complex
Immobilisation of a luminescent material on an electrode surface is well known to substantially modulate its photophysical and electrochemical properties. Here a positively charged ruthenium metal complex ([Ru(bpy)(3)](2+)) is immobilised on all electrode surface by ion paring with a sulfonated conducting polymer poly(2-methoxyaniline-5-sulfonic acid), (PMAS). Significantly, our study reveals that the electron transport between the ruthenium metal centres can be greatly enhanced due to the interaction with the conducting polymer when both are surface confined. Charge transfer diffusion rates in the present system are an order of magnitude faster than those found where the metal centre is immobilised within a non-conducting polymeric matrix. Electron transport appears to be mediated through the PMAS conjugated structure, contrasting with the electron hopping process typically observed in non-conducting metallopolymers. This increased regeneration rate causes the ruthenium-based electrochemiluminescence (ECL) efficiency to be increased. The impact of these observations on the ECL detection of low concentrations of disease biomarkers is discussed. (c) 2007 Published by Elsevier Ltd
Effect of K Doping on Phonons in Ba1-xKxFe2As2
The lattice dynamics of Ba1-xKxFe2As2 (x = 0.00, 0.27) have been studied by
inelastic X-ray scattering measurement at room temperature. K doping induces
the softening and broadening of phonon modes in the energy range E = 10-15 meV.
Analysis with a Born-von Karman force-constant model indicates that the
softening results from reduced interatomic force constants around (Ba,K) sites
following the displacement of divalent Ba by monovalent K. The phonon
broadening may be explained by the local distortions induced by the K
substitution. Extra phonon modes are observed around the wave vector q =
(0.5,0,0) at E = 16.5 meV for the x = 0.27 sample. These modes may arise either
from the local disorder induced by K doping or from electron-phonon coupling.Comment: J. Phys. Soc. Jpn. (in press
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POSTCLOSURE GROUNDWATER REMEDIATION AND MONITORING AT THE SANITARY LANDFILL, SAVANNAH RIVER SITE TRANSITIONING TO MONITORED NATURAL ATTENUATION
Resource Conservation and Recovery Act (RCRA) requirements for hazardous waste facilities include 30 years of post-closure monitoring. The use of an objective-based monitoring strategy allows for a significant reduction in the amount of groundwater monitoring required, as the groundwater remediation transitions from an active biosparging system to monitored natural attenuation. The lifecycle of groundwater activities at the landfill has progressed from detection monitoring and plume characterization, to active groundwater remediation, and now to monitored natural attenuation and postclosure monitoring. Thus, the objectives of the groundwater monitoring have changed accordingly. Characterization monitoring evaluated what biogeochemical natural attenuation processes were occurring and determined that elevated levels of radium were naturally occurring. Process monitoring of the biosparging system required comprehensive sampling network up- and down-gradient of the horizontal wells to verify its effectiveness. Currently, the scope of monitoring and reporting can be significantly reduced as the objective is to demonstrate that the alternate concentration limits (ACL) are being met at the point of compliance wells and the maximum contaminant level (MCL) is being met at the surface water point of exposure. The proposed reduction is estimated to save about $2M over the course of the remaining 25 years of postclosure monitoring
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Mapping Fusarium solani and Aphanomyces euteiches Root Rot Resistance and Root Architecture Quantitative Trait Loci in Common Bean
Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RI mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean with small brown seeds. We evaluated the RR138 RI population beginning in the F₆ generation for resistance to Fusarium solani f. sp. phaseoli (Burk.) root rot in Oregon and Aphanomyces euteiches (Drechsler) root rot in Wisconsin. The population was evaluated for a set of root architecture traits at the Oregon location. Fusarium solani root rot resistance was evaluated in three seasons, whereas A. euteiches resistance was evaluated in two seasons. For each disease, RR6950 was resistant and OSU 5446 was susceptible. The recombinant inbred (RI) population was normally distributed for reaction to both diseases. We assembled a high-density linkage map using 1689 single-nucleotide polymorphisms (SNPs) from an Illumina 6000-SNP BARCbean6K_3 Beadchip. The map spanned 1196 cM over 11 linkage groups at a density of one SNP per 1.4 cM. Three quantitative trait loci (QTL) associated with A. euteiches were identified, each accounting for 5 to 15% of the total genetic variation, and two QTL associated with F. solani resistance accounted for 9 and 22% of the total genetic variation. A QTL for taproot diameter (TD) and one QTL for basal root angle were identified. The QTL for resistance to the two diseases mapped to different genome locations indicating a different genetic control
Effects of shared medical appointments on quality of life and cost-effectiveness for patients with a chronic neuromuscular disease. Study protocol of a randomized controlled trial
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96862.pdf (publisher's version ) (Open Access)BACKGROUND: Shared medical appointments are a series of one-to-one doctor-patient contacts, in presence of a group of 6-10 fellow patients. This group visits substitute the annual control visits of patients with the neurologist. The same items attended to in a one-to-one appointment are addressed. The possible advantages of a shared medical appointment could be an added value to the present management of neuromuscular patients. The currently problem-focused one-to-one out-patient visits often leave little time for the patient's psychosocial needs, patient education, and patient empowerment. METHODS/DESIGN: A randomized, prospective controlled study (RCT) with a follow up of 6 months will be conducted to evaluate the clinical and cost-effectiveness of shared medical appointments compared to usual care for 300 neuromuscular patients and their partners at the Radboud University Nijmegen Medical Center. Every included patient will be randomly allocated to one of the two study arms. This study has been reviewed and approved by the medical ethics committee of the region Arnhem-Nijmegen, The Netherlands. The primary outcome measure is quality of life as measured by the EQ-5D, SF-36 and the Individualized neuromuscular Quality of Life Questionnaire. The primary analysis will be an intention-to-treat analysis on the area under the curve of the quality of life scores. A linear mixed model will be used with random factor group and fixed factors treatment, baseline score and type of neuromuscular disease. For the economic evaluation an incremental cost-effectiveness analysis will be conducted from a societal perspective, relating differences in costs to difference in health outcome. Results are expected in 2012. DISCUSSION: This study will be the first randomized controlled trial which evaluates the effect of shared medical appointments versus usual care for neuromuscular patients. This will enable to determine if there is additional value of shared medical appointments to the current therapeutical spectrum. When this study shows that group visits produce the alleged benefits, this may help to increase the acceptance of this innovative and creative way of using one of the most precious resources in health care more efficiently: time. TRIAL REGISTRATION: DutchTrial Register http://www.trialregister.nlNTR1412
A shift from distal to proximal neoplasia in the colon: a decade of polyps and CRC in Italy
<p>Abstract</p> <p>Background</p> <p>In the last years a trend towards proximalization of colorectal carcinomas (CRC) has been reported. This study aims to evaluate the distribution of CRC and adenomatous polyps (ADP) to establish the presence of proximalization and to assess the potential predictors.</p> <p>Methods</p> <p>We retrieved histology reports of colonic specimens excised during colonoscopy, considering the exams performed between 1997 and 2006 at Cuneo Hospital, Italy. We compared the proportion of proximal lesions in the period 1997-2001 and in the period 2002-2006.</p> <p>Results</p> <p>Neoplastic lesions were detected in 3087 people. Proximal CRC moved from 25.9% (1997-2001) to 30.0% (2002-2006). Adjusting for sex and age, the difference was not significant (OR 1.23; 95% CI: 0,95-1,58). The proximal ADP proportion increased from 19.2% (1997-2001) to 26.0% (2002-2006) (OR: 1.43; 95% CI: 1.17-1.89). The corresponding figures for advanced proximal ADP were 6.6% and 9.5% (OR: 1.48; 95% CI: 1.02-2.17). Adjusting for gender, age, diagnostic period, symptoms and number of polyps the prevalence of proximal advanced ADP was increased among people ≥ 70 years compared to those aged 55-69 years (OR 1.49; 95% CI: 1.032.16). The main predictor of proximal advanced neoplasia was the number of polyps detected per exam (> 1 polyp versus 1 polyp: considering all ADP: OR 2.16; 95% CI: 1.59-2.93; considering advanced ADP OR 1.63; 95% CI: 1.08-2.46). Adjusting for these factors, the difference between the two periods was no longer significant.</p> <p>Conclusions</p> <p>CRC do not proximalize while a trend towards a proximal shift in adenomas was observed among people ≥ 70 years.</p
The influence of contextual information regarding the breakdown of relationships and perpetrator-target sex composition on perceptions of relational stalking
The present study examines the influence of prior relationship (with contextual information regarding the breakdown of the relationship) and perpetrator-target sex composition on perceptions of relational stalking. The study employed an experimental 7 × 2 independent measures design, and the sample comprised 1,260 members of the community residing in Australia, the United Kingdom and the United States. Participants received one of 14 versions of a hypothetical scenario and responded to scale items concerning the situation described. The situation was perceived to be most serious when the perpetrator was a stranger or a physically violent ex-partner and least serious when the perpetrator was an ex-partner of
an unfaithful target. Scenarios involving a male perpetrator and a female victim were also perceived to be more serious than scenarios involving a female perpetrator and a male target. It is apparent therefore that the context of the relationship breakdown and the sex of the perpetrator and target significantly influence perceptions of relational stalking
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