2,577 research outputs found

    Optical contrast in near-field techniques

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    In this paper results of experiments with a scanning near-field optical microscope with shear-force feedback are presented. The setup will be described and the shear-force signal as function of distance is shown. Images of latex spheres and Langmuir- Blodgett layers of pentacosa-acid with about 100 nm lateral resolution are presented which show a true optical contrast due to fluorescence and polarization

    Adding a subjective dimension to an ICF-based disability measure for people with multiple sclerosis: development and use of a measure for perception of disabilities

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    OBJECTIVE: The subjective dimension of disability, the perception of disability, is a dimension missing from the International Classification of Functioning, Disability and Health (ICF), and from health-related quality of life (HRQOL) instruments. However, it is a highly relevant dimension for clinical practice as perceived disability may identify care needs. We therefore developed a measure for this subjective dimension of disability in multiple sclerosis (MS) and examined the contribution of this dimension to QOL. METHOD: A measure named the Multiple Sclerosis Impact Profile-Disability Perception (MSIP-DP) was developed to reflect a person's perception of disabilities reported using the original MSIP-disability (MSIP-D) items. MS patients (n=530) completed both MSIP sections, the medical outcome study short form questionnaire (SF-36), the World Health Organisation Quality Of Life-BREF (WHOQOL-BREF) and questions concerning disease severity. The contribution of disability perception (DP) to QOL in MS was estimated using hierarchical multiple regression analyses after controlling for MS severity. RESULTS: Confirmative factor analysis confirmed the hypothesised disability perception domains that correspond with the related disability domains in the MSIP. DP scales yielded sufficient reliability. DP explained a unique and substantial part of the variance in QOL, particularly the perception of impairments in mental functions. DISCUSSION: Results indicated that the subjective dimension of functioning and health operationalised in the MSIP-DP is a relevant concept in explaining QOL in MS. In clinical practice psychological interventions addressing a patient's perception of disability, particularly of impairments in mental functioning, may contribute to QOL

    Solidification of liquid metal drops during impact

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    Hot liquid metal drops impacting onto a cold substrate solidify during their subsequent spreading. Here we experimentally study the influence of solidification on the outcome of an impact event. Liquid tin drops are impacted onto sapphire substrates of varying temperature. The impact is visualised both from the side and from below, which provides a unique view on the solidification process. During spreading an intriguing pattern of radial ligaments rapidly solidifies from the centre of the drop. This pattern determines the late-time morphology of the splat. A quantitative analysis of the drop spreading and ligament formation is supported by scaling arguments. Finally, a phase diagram for drop bouncing, deposition and splashing as a function of substrate temperature and impact velocity is provided

    Peroxisomes in intestinal and gallbladder epithelial cells of the stickleback, Gasterosteus aculeatus L. (Teleostei)

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    The occurrence of microbodies in the epithelial cells of the intestine and gallbladder of the stickleback, Gasterosteus aculeatus L., is described. In the intestine the organelles are predominantly located in the apical and perinuclear zone of the cells and may contain small crystalline cores. In gallbladder epithelial cells the microbodies are distributed randomly. The latter organdies are characterized by the presence of large crystalloids. Cytochemical and biochemical experiments show that catalase and D-amino acid oxidase are main matrix components of the microbodies in both the intestinal and gallbladder epithelia. These organelles therefore are considered peroxisomes. In addition, in intestinal mucosa but not in gallbladder epithelium a low activity of palmitoyl CoA oxidase was detected biochemically. Urate oxidase and L-α hydroxy acid oxidase activities could not be demonstrated.

    Global cropland and greenhouse gas impacts of UK food supply are increasingly located overseas

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    Funding This work was supported by a University of Aberdeen Environment and Food Security Theme/the James Hutton Institute PhD studentship, and contributes to the Scottish Food Security Alliance-Crops and the Belmont Forum supported DEVIL project (NERC fund UK contribution: NE/M021327/1). J.M. and R.B.M. acknowledge funding from the Rural and Environment Science and Analytical Services, Scottish Government. T.K. acknowledges funding from the European Research Council Grant ERC-263522 (LUISE).Peer reviewedPostprin

    Temperature dependent transport characteristics of graphene/n-Si diodes

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    Realizing an optimal Schottky interface of graphene on Si is challenging, as the electrical transport strongly depends on the graphene quality and the fabrication processes. Such interfaces are of increasing research interest for integration in diverse electronic devices as they are thermally and chemically stable in all environments, unlike standard metal/semiconductor interfaces. We fabricate such interfaces with n-type Si at ambient conditions and find their electrical characteristics to be highly rectifying, with minimal reverse leakage current (<<1010^{-10} A) and rectification of more than 10610^6. We extract Schottky barrier height of 0.69 eV for the exfoliated graphene and 0.83 eV for the CVD graphene devices at room temperature. The temperature dependent electrical characteristics suggest the influence of inhomogeneities at the graphene/n-Si interface. A quantitative analysis of the inhomogeneity in Schottky barrier heights is presented using the potential fluctuation model proposed by Werner and G\"{u}ttler.Comment: 5 pages, 5 figure

    Neuroimaging Biomarkers and Cognitive Function in Non-CNS Cancer and Its Treatment: Current Status and Recommendations for Future Research

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    Cognitive changes in patients undergoing treatment for non-central nervous system (CNS) cancers have been recognized for several decades, yet the underlying mechanisms are not well understood. Structural, functional and molecular neuroimaging has the potential to help clarify the neural bases of these cognitive abnormalities. Structural magnetic resonance imaging (MRI), functional MRI (fMRI), diffusion tensor imaging (DTI), MR spectroscopy (MRS), and positron emission tomography (PET) have all been employed in the study of cognitive effects of cancer treatment, with most studies focusing on breast cancer and changes thought to be induced by chemotherapy. Articles in this special issue of Brain Imaging and Behavior are devoted to neuroimaging studies of cognitive changes in patients with non-CNS cancer and include comprehensive critical reviews and novel research findings. The broad conclusions that can be drawn from past studies and the present body of new research is that there are structural and functional changes associated with cancer and various treatments, particularly systemic cytotoxic chemotherapy, although some cognitive and fMRI studies have identified changes at pre-treatment baseline. Recommendations to accelerate progress include well-powered multicenter neuroimaging studies, a better standardized definition of the cognitive phenotype and extension to other cancers. A systems biology framework incorporating multimodality neuroimaging, genetics and other biomarkers will be highly informative regarding individual differences in risk and protective factors and disease- and treatment-related mechanisms. Studies of interventions targeting cognitive changes are also needed. These next steps are expected to identify novel protective strategies and facilitate a more personalized medicine for cancer patients

    Broadening the scope on health problems among the chronically neurologically ill with the International Classification of Functioning (ICF)

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    Purpose. The aim of this study was to determine ICF items indicating health problems for patients with a chronic neurological disorder such as multiple sclerosis, Parkinson's disease and neuromuscular disease. Method. A Delphi study using three disease-specific panels composed of patients and proxies, medical and non-medical health professionals (N=98). Panels were asked to select items from the International Classification of Functioning, Disability and Health (ICF) reflecting relevant disease-specific health problems. Items appraised as relevant by the panel members were compared with items in established measures namely: the Minimal Record of Disability (MRD) and the Disability and Impact Profile (DIP). Results. Sixty-eight ICF items were considered to be the most relevant, and belonged to four ICF domains. No significant differences were found between the appraisal of items by patients/proxies and health professionals. Agreement across the disease panels appeared to be (very) strong. Differences between the three disease-specific panels were found for the 'Body Functions and Structures' domain: consensus was reached by extension of the inclusion criteria. The ICF-item selection covers almost all items of the established measures. The largest contrast was shown in the item selection for the 'participation' and 'environmental factors' domains. Conclusions. Selected items indicate a broader scope in studying health problems compared with widely used health status measures in neurology, especially for the ICF domains 'Participation' and 'Environmental Factors'

    Accelerated Oxygen Atom Transfer and C−H Bond Oxygenation by Remote Redox Changes in Fe_3Mn-Iodosobenzene Adducts

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    We report the synthesis, characterization, and reactivity of [Lfe_3(PhPz)_3OMn(^sPhIO)][OTf]_x (3: x=2; 4: x=3), where 4 is one of very few examples of iodosobenzene–metal adducts characterized by X-ray crystallography. Access to these rare heterometallic clusters enabled differentiation of the metal centers involved in oxygen atom transfer (Mn) or redox modulation (Fe). Specifically, ^(57)Fe Mössbauer and X-ray absorption spectroscopy provided unique insights into how changes in oxidation state (Fe^(III)_2Fe^(II)Mn^(II) vs. Fe^(III)_3Mn^(II)) influence oxygen atom transfer in tetranuclear Fe_3Mn clusters. In particular, a one-electron redox change at a distal metal site leads to a change in oxygen atom transfer reactivity by ca. two orders of magnitude

    Multifrequency Study of The Radio Galaxy NGC326

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    We present the results of a multi-frequency study of the inversion symmetric radio galaxy NGC326 based on Very Large Array observations at 1.4, 1.6, 4.8, 8.5 and 14.9 GHz. The morphological, spectral and polarization properties of this peculiar object are studied at different levels of spatial resolutions. The interpretation of the data will be discussed in forthcoming papers.Comment: 15 pages, 15 ps figures, accepted by A&
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