572 research outputs found

    Structural compliance, misfit strain and stripe nanostructures in cuprate superconductors

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    Structural compliance is the ability of a crystal structure to accommodate variations in local atomic bond-lengths without incurring large strain energies. We show that the structural compliance of cuprates is relatively small, so that short, highly doped, Cu-O-Cu bonds in stripes are subject to a tensile misfit strain. We develop a model to describe the effect of misfit strain on charge ordering in the copper oxygen planes of oxide materials and illustrate some of the low energy stripe nanostructures that can result.Comment: 4 pages 5 figure

    Chemical Pleurodesis For Hepatic Hydrothorax.

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    Ascites can occur after hepatic diseases causing dyspnea, coughing and pain. When associated with pleural effusion it can also increase respiratory distress. In a bibliographic survey hydrothorax has been observed in up to 20% of the patients and the kind of treatment is still being discussed. This case report shows the occurrence of a large volume of ascites and pleural effusion in a cirrhotic patient and his treatment. Report the case of a patient with hepatic cirrhosis due to chronic alcoholism and massive pleural effusion and ascites. He was submitted to several pleural paracenteses without success. Scintigraphy showed the presence of ascites and confirmed a possible pleuroperitoneal communication. The thoracic surgery group was called and after evaluation it was decided to submit the patient to a pulmonary decortication and chemical pleurodesis. These procedures were carried out with success. The pleural effusion was solved and the treatment of ascites was decided upon because the patient did not accept any surgical procedure. This treatment could be applied to patients with hydrothorax who could not be submitted to a liver transplantation.38125-

    Definition of Naturally Processed Peptides Reveals Convergent Presentation of Autoantigenic Topoisomerase I Epitopes in Scleroderma.

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    ObjectiveAutoimmune responses to DNA topoisomerase I (topo I) are found in a subset of scleroderma patients who are at high risk for interstitial lung disease (ILD) and mortality. Anti-topo I antibodies (ATAs) are associated with specific HLA-DRB1 alleles, and the frequency of HLA-DR-restricted topo I-specific CD4+ T cells is associated with the presence, severity, and progression of ILD. Although this strongly implicates the presentation of topo I peptides by HLA-DR in scleroderma pathogenesis, the processing and presentation of topo I has not been studied.MethodsWe developed a natural antigen processing assay (NAPA) to identify putative CD4+ T cell epitopes of topo I presented by monocyte-derived dendritic cells (mo-DCs) from 6 ATA-positive patients with scleroderma. Mo-DCs were pulsed with topo I protein, HLA-DR-peptide complexes were isolated, and eluted peptides were analyzed by mass spectrometry. We then examined the ability of these naturally presented peptides to induce CD4+ T cell activation in 11 ATA-positive and 11 ATA-negative scleroderma patients.ResultsWe found that a common set of 10 topo I epitopes was presented by Mo-DCs from scleroderma patients with diverse HLA-DR variants. Sequence analysis revealed shared peptide-binding motifs within the HLA-DRβ chains of ATA-positive patients and a subset of topo I epitopes with distinct sets of anchor residues capable of binding to multiple different HLA-DR variants. The NAPA-derived epitopes elicited robust CD4+ T cell responses in 73% of ATA-positive patients (8 of 11), and the number of epitopes recognized correlated with ILD severity (P = 0.025).ConclusionThese findings mechanistically implicate the presentation of a convergent set of topo I epitopes in the development of scleroderma

    A systematic review of bilingual experiences, labels, and descriptions in autism spectrum disorder research

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    There is growing research on autism spectrum disorder (ASD) that examines linguistically diverse samples, increasing research generalizability as many individuals with ASD live in bilingual or multilingual communities. However, bilingualism is not a homogenous experience that can be easily categorized. By clarifying participants' language experiences, research findings can be more meaningful for clinicians and practitioners. In this systematic review, we document how the language experiences of samples with and without ASD were described in 103 peer-reviewed journal articles. We observed that language experiences were characterized using a wide range of labels and descriptions. Approximately half of the studies in this review reported participants' language acquisition history, and 64% of the studies defined language proficiency using standardized measures or parental reports. However, <20% of the studies reported daily language exposure and/or usage of the participants. The diversity in how participants' language experiences were characterized in research reflects the complexity of bilingualism. Yet, to further understand how ASD and bilingualism intersect across studies, to facilitate meta-science development, and to balance generalizability with specificity, reporting common characteristics of bilingual experiences is recommended

    The life and death of public organizations: A question of institutional design?

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    FSW – Publicaties zonder aanstelling Universiteit Leide

    Nondestructive residual stress depth profile analysis at the inner surface of small boreholes using energy dispersive diffraction under laboratory conditions

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    Energy dispersive diffraction under both laboratory and synchrotron conditions was applied to study the hoop stress in the near surface region of the inner wall of boreholes with a small diameter of 2 amp; 8197;mm. By use of different X ray beam cross sections for the sin2 amp; 968; measurements, it is demonstrated that the borehole to beam diameter ratio must be considered in the evaluation. A beam cross section which is comparable to the borehole diameter reduces the slope of the dhkl amp; 966; amp; 968; sin2 amp; 968; distributions and thus invalidates the result of stress analysis. A quantitative relationship is applied, which allows the results obtained under the above conditions to be scaled so that they reflect the actual residual stress state at the measurement position. Owing to the small diffraction angles, energy dispersive diffraction proves to be the only suitable experimental technique that allows a nondestructive and depth resolved analysis of the hoop stress component at the inner surface of boreholes with a large length to diameter rati

    African Studies Abstracts Online: number 41, 2013

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    ASA Online provides a quarterly overview of journal articles and edited works on Africa in the field of the social sciences and the humanities available in the ASC library. Issue 41 (2013). African Studies Centre, Leiden.ASC – Publicaties niet-programma gebonde

    African Studies Abstracts Online: number 27, 2009

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    ASA Online provides a quarterly overview of journal articles and edited works on Africa in the field of the social sciences and the humanities available in the ASC library. Issue 27 (2009). African Studies Centre, Leiden.ASC – Publicaties niet-programma gebonde
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