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Micron or submicron spatial resolution for x-ray microfluorescence analysis has been pursued using various x-ray point focusing methods,1-4 such as transmission zone plates, tapered capillaries, and Bragg Fresnel lenses. Point focusing using bent crystals does not seem to be a desirable means for achieving a microbeam size, although it is a traditional technique which utilizes perfectly curved crystal surfaces to focus x rays emanating from the source. It is known that point focusing can only be achieved by bending a crystal two dimensionally, which normally introduces imperfections to the crystal since the crystal is an undevelopable surface. Unavoidably, the introduced imperfections will broaden the reflection curve (rocking curve) of the crystal and, in turn, broadens the focal spot size.
Background: Central neuropathic pain syndromes are a result of central nervous system injury, most commonly related to stroke, traumatic spinal cord injury, or multiple sclerosis. These syndromes are distinctly less common than peripheral neuropathic pain, and less is known regarding the underlying pathophysiology, appropriate pharmacotherapy, and long-term outcomes. The objective of this study was to determine the long-term clinical effectiveness of the management of central neuropathic pain relative to peripheral neuropathic pain at tertiary pain centers. Methods: Patients diagnosed with central (n=79) and peripheral (n=710) neuropathic pain were identified for analysis from a prospective observational cohort study of patients with chronic neuropathic pain recruited from seven Canadian tertiary pain centers. Data regarding patient characteristics, analgesic use, and patient-reported outcomes were collected at baseline and 12-month follow-up. The primary outcome measure was the composite of a reduction in average pain intensity and pain interference. Secondary outcome measures included assessments of function, mood, quality of life, catastrophizing, and patient satisfaction. Results: At 12-month follow-up, 13.5% (95% confidence interval [CI], 5.6-25.8) of patients with central neuropathic pain and complete data sets (n=52) achieved a ≥30% reduction in pain, whereas 38.5% (95% CI, 25.3-53.0) achieved a reduction of at least 1 point on the Pain Interference Scale. The proportion of patients with central neuropathic pain achieving both these measures, and thus the primary outcome, was 9.6% (95% CI, 3.2-21.0). Patients with peripheral neuropathic pain and complete data sets (n=463) were more likely to achieve this primary outcome at 12 months (25.3% of patients; 95% CI, 21.4-29.5) (p=0.012). Conclusion: Patients with central neuropathic pain syndromes managed in tertiary care centers were less likely to achieve a meaningful improvement in pain and function compared with patients with peripheral neuropathic pain at 12-month follow-up.
Increased mass losses from the Greenland ice sheet and inferred contributions to sea-level rise have heightened the need for hydrologic observations of meltwater exiting the ice sheet. We explore whether temporal variations in ice-sheet surface hydrology can be linked to the development of a downstream sediment plume in Kangerlussuaq Fjord by comparing: (1) plume area and suspended sediment concentration from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and field data; (2) ice-sheet melt extent from Special Sensor Microwave/Imager (SSM/I) passive microwave data; and (3) supraglacial lake drainage events from MODIS. Results confirm that the origin of the sediment plume is meltwater release from the ice sheet. Interannual variations in plume area reflect interannual variations in surface melting. Plumes appear almost immediately with seasonal surface-melt onset, provided the estuary is free of landfast sea ice. A seasonal hysteresis between melt extent and plume area suggests late-season exhaustion in sediment supply. Analysis of plume sensitivity to supraglacial events is less conclusive, with 69% of melt pulses and 38% of lake drainage events triggering an increase in plume area. We conclude that remote sensing of sediment plume behavior offers a novel tool for detecting the presence, timing and interannual variability of meltwater release from the ice sheet.
Despite containing only 14% of the Greenland ice sheet by area, the southeastern sector has the highest accumulation rates, and hence receives ∼30% of the total snow accumulation. We present accumulation rates obtained during our 2010 Arctic Circle Traverse derived from three 50 m firn cores dated using geochemical analysis. We tracked continuous internal reflection horizons between the firn cores using a 400 MHz ground-penetrating radar (GPR). GPR data combined with depth-age scales from the firn cores provide accumulation rates along a 70 km transect. We followed an elevation gradient from ∼2350 to ∼1830m to understand how progressive surface melt may affect the ability to chemically date the firn cores and trace the internal layers with GPR. From the firn cores, we find a 52% (∼0.43 m w.e. a-1) increase in average snow accumulation and greater interannual variability at the lower site than the upper site. The GPR profiling reveals that accumulation rates are influenced by topographic undulations on the surface, with up to 23% variability over 7 km. These measurements confirm the presence of high accumulation rates in the southeast as predicted by the calibrated regional climate model Polar MM5.
Background: Painful diabetic neuropathy (PDN) is a frequent complication of diabetes mellitus. Current treatment recommendations are based on short-term trials, generally of ≤3 months’ duration. Limited data are available on the long-term outcomes of this chronic disease. The objective of this study was to determine the long-term clinical effectiveness of the management of chronic PDN at tertiary pain centres. Methods: From a prospective observational cohort study of patients with chronic neuropathic non-cancer pain recruited from seven Canadian tertiary pain centres, 60 patients diagnosed with PDN were identified for analysis. Data were collected according to Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials guidelines including the Brief Pain Inventory. Results: At 12-month follow-up, 37.2% (95% confidence interval [CI], 23.0-53.3) of 43 patients with complete data achieved pain reduction of ≥30%, 51.2% (95% CI, 35.5-66.7) achieved functional improvement with a reduction of ≥1 on the Pain Interference Scale (0-10, Brief Pain Inventory) and 30.2% (95% CI, 17.2-46.1) had achieved both these measures. Symptom management included at least two medication classes in 55.3% and three medication classes in 25.5% (opioids, antidepressants, anticonvulsants). Conclusions: Almost one-third of patients being managed for PDN in a tertiary care setting achieve meaningful improvements in pain and function in the long term. Polypharmacy including analgesic antidepressants and anticonvulsants were the mainstays of effective symptom management.
Common beans (Phaseolus vulgaris L.) are a nutrient-dense, low glycemic index food that supports healthy weight management in people and was examined for dogs. The objectives of this study were to evaluate the apparent total tract digestibility (ATTD) and nutrient utilisation of navy (NB) and black (BB) bean-based diets in overweight or obese companion dogs undergoing a weight loss intervention. A nutritionally complete, dry extruded dog food was used as the control (CON) diet and two isocaloric, nutrient matched bean diets, containing either 25% w/w cooked BB or NB powder formed the test diets. Diets were fed to adult, overweight companion dogs for either four weeks (short-term study, n = 30) or for twenty-six weeks (long-term study, n = 15) at 60% of maintenance calories for ideal weight. Apparent weight loss increased over time in both the short- and long-term studies (p < 0.001) but was not different between the three study groups: apparent weight loss was between 4.05% – 6.14% for the short-term study and 14.0% – 17.9% in the long-term study. The ATTD was within expected ranges for all groups, whereby total dry matter and crude protein ATTD was 7–8% higher in the BB diet compared to CON (P < 0.05), crude fat ATTD was similar across all diets, and nitrogen free extract ATTD was 5–6% higher in both BB and NB compared to CON (P < 0.05). Metabolisable energy was similar for all diets, and ranged from 3,434–3,632 kcal/kg. At the end of each study period, dogs had haemoglobin levels ≥12 g/dl, packed cell volume ≥36%, albumin ≥2.4 g/dl, ALP ≤ 300 IU/l and all median values for each group were within defined limits for nutritional adequacy. This investigation demonstrated that BB and NB diets were safe, digestible, and supported weight loss in calorically restricted, overweight or obese, adult companion dogs.
Based on new spectra spanning wavelengths from 0.8 to 2.4μm, we study the properties of bright near-IR clusters in M82. We focus on age and extinction, which are critical parameters when one uses dynamical masses to constrain the stellar IMF. The modelling of red supergiant evolution by various authors leads to very significant differences in synthetic cluster spectra. Near-IR fluxes alone therefore do not rule out a normal IMF for cluster F, previously found to be deficient in low mass stars. Combined optical and near-IR studies are being undertaken.
Dietary assessment in older adults can be challenging. The Novel Assessment of Nutrition and Ageing (NANA) method is a touch-screen computer-based food record that enables older adults to record their dietary intakes. The objective of the present study was to assess the relative validity of the NANA method for dietary assessment in older adults. For this purpose, three studies were conducted in which a total of ninety-four older adults (aged 65–89 years) used the NANA method of dietary assessment. On a separate occasion, participants completed a 4 d estimated food diary. Blood and 24 h urine samples were also collected from seventy-six of the volunteers for the analysis of biomarkers of nutrient intake. The results from all the three studies were combined, and nutrient intake data collected using the NANA method were compared against the 4 d estimated food diary and biomarkers of nutrient intake. Bland–Altman analysis showed a reasonable agreement between the dietary assessment methods for energy and macronutrient intake; however, there were small, but significant, differences for energy and protein intake, reflecting the tendency for the NANA method to record marginally lower energy intakes. Significant positive correlations were observed between urinary urea and dietary protein intake using both the NANA and the 4 d estimated food diary methods, and between plasma ascorbic acid and dietary vitamin C intake using the NANA method. The results demonstrate the feasibility of computer-based dietary assessment in older adults, and suggest that the NANA method is comparable to the 4 d estimated food diary, and could be used as an alternative to the food diary for the short-term assessment of an individual's dietary intake.
We present the KMOS (K-band Multi-Object Spectrograph) Cluster and VIRIAL (VLT IRIFU Absorption Line) Guaranteed Time Observation (GTO) programs. KMOS provides 24 arms each feeding an integral field unit (14×14 spaxels of 0.2″ pixels) for IZ, YJ, H and K band near infrared (NIR) medium resolution spectroscopy (R ∼ 3500). Targets are selected from a 7.2′ diameter patrol field. Ultra-deep spectroscopy of ∼ 80 early-type cluster galaxies (∼ 20hr on source) and ∼ 200 (∼ 10hr on source) early-type field galaxies at 1 < z < 2 will dramatically improve the situation at z > 1 for which measurements of stellar velocity dispersions and absorption indices are limited to a few, often relatively young passively evolving galaxies (e.g. Bezanson 2013). In ESO Periods P92 and P93, 15 nights worth of data has been collected for KMOS-Clusters and 6 nights for VIRIAL: this will be supplemented with more data in upcoming semesters. All galaxies have multiband HST imaging including existing or upcoming WFC3 IR imaging, providing stellar mass maps and sizes. Combined with our dispersion measurements, this will allow us to examine the fundamental plane and the dynamical mass of a large sample of z > 1 galaxies for the first time, for both cluster and field galaxies.
We report on experiments aimed at the generation and characterization of solid density plasmas at the free-electron laser FLASH in Hamburg. Aluminum samples were irradiated with XUV pulses at 13.5 nm wavelength (92 eV photon energy). The pulses with duration of a few tens of femtoseconds and pulse energy up to 100 µJ are focused to intensities ranging between 1013 and 1017 W/cm2. We investigate the absorption and temporal evolution of the sample under irradiation by use of XUV and optical spectroscopy. We discuss the origin of saturable absorption, radiative decay, bremsstrahlung and atomic and ionic line emission. Our experimental results are in good agreement with simulations.
Frailty is common in older age, and is associated with important adverse health outcomes, including increased risk of disability and long-term care admission.
This study aims to evaluate whether home-based exercise interventions improve outcomes for frail older people.
We searched systematically for randomized controlled trials (RCTs) and cluster RCTs, with literature searching to February 2010.
All trials that evaluated home-based exercise interventions for frail older people were eligible. Primary outcomes were mobility, quality of life and daily living activities. Secondary outcomes included long-term care admission and hospitalization.
Six RCTs involving 987 participants met the inclusion criteria. Four trials were considered of high quality. One high-quality trial reported improved disability in those with moderate but not severe frailty. Meta-analysis of long-term care admission rates identified a trend towards reduced risk. Inconsistent effects on other primary and secondary outcomes were reported in the other studies.
There is preliminary evidence that home-based exercise interventions may improve disability in older people with moderate, but not severe, frailty. There is considerable uncertainty regarding effects on important outcomes including quality of life and long-term care admission. Home-based exercises are a potentially simple, safe and widely applicable intervention to prevent dependency decline for frail older people.
Silicon carbide layers were grown by solid source molecular beam epitaxy on silicon (111). Prior to the silicon carbide growth different amounts of germanium were predeposited on the silicon surface. Structural and morphological investigations with reflection high energy electron diffraction, x-ray diffraction, atomic force microscopy and spectroscopic ellipsometry revealed an improvement of the surface and interface properties for Ge coverages around and below 1 ML. The improved structural properties of the heterojunction lead to an amendment of the forward and reverse properties of the SiC/Si heterojunction.
The present paper reports on positron lifetime measurements on Ceo/C 70 fullerite powder as a function of temperature and quasi-hydrostatic pressure in order to give an estimate of the positron annihilation site in the fullerite lattice. A single-component positron lifetime of 402 ps is observed which significantly decreases under quasi-hydrostatic pressure. From this and the soft intermolecular properties of the fullerites one can conclude that the positron is annihilated rather in the intermolecular space than inside the fullerene molecules. However, positron trapping at lattice defects, which are observed by high-resolution electron microscopy, cannot be ruled out.
Nonstoichiometric defects in carbides of the Group IV and V transition metals and radiation-induced atomic defects in SiC were studied by positron lifetime measurements before and after low-temperature (80 K) electron irradiation and subsequent thermal annealing up to 1900 K. Agglomeration of radiation-induced atomic defects which strongly depends on the energy of the irradiation electrons and subsequent decay of the agglomerates in SiC is observed.
The objective of this study is to characterize the nanoparticle dispersion and to investigate its effect on the surface mechanical properties of nanoparticle-polymer systems. Two types of TiO2 nanoparticles were chosen to mix in two polymeric matrices: solvent-borne acrylic urethane (AU) and water-borne butyl-acrylic styrene latex (latex) coatings. Nanoparticle dispersion was characterized using laser scanning confocal microscopy. Overall, Particle A (PA, without surface treatment) dispersed better than Particle B (PB, organic treatment) in both systems. The AU-PA system exhibited the best dispersion of the four systems, however PB forms big clusters in both of the matrices. Surface mechanical properties, such as surface modulus at micron and sub-micron length scales were determined from depth sensing indentation equipped with a pyramidal tip or a conical tip. The surface mechanical properties were strongly affected by the dispersion of nanoparticle clusters, and a good correlation was found between dispersion of nanoparticle clusters near surface and the modulus-depth mapping using a pyramid tip.