222 research outputs found

    Correlated Diffuse X-ray Scattering from Periodically Nano-Structured Surfaces

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    Laterally periodic nanostructures were investigated with grazing incidence small angle X-ray scattering. To support an improved reconstruction of nanostructured surface geometries, we investigated the origin of the contributions to the diffuse scattering pattern which is correlated to the surface roughness. Resonant diffuse scattering leads to a palm-like structure of intensity sheets. Dynamic scattering generates the so-called Yoneda band caused by a resonant scatter enhancement at the critical angle of total reflection and higher-order Yoneda bands originating from a subsequent diffraction of the Yoneda enhanced scattering at the grating. Our explanations are supported by modelling using a solver for the time-harmonic Maxwell's equations based on the finite-element method

    Carbohydrate–carbohydrate interaction provides adhesion force and specificity for cellular recognition

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    © 2004 Bucior et al. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. The definitive version was published in Journal of Cell Biology 165 (2004): 529-537, doi:10.1083/jcb.200309005.The adhesion force and specificity in the first experimental evidence for cell–cell recognition in the animal kingdom were assigned to marine sponge cell surface proteoglycans. However, the question whether the specificity resided in a protein or carbohydrate moiety could not yet be resolved. Here, the strength and species specificity of cell–cell recognition could be assigned to a direct carbohydrate–carbohydrate interaction. Atomic force microscopy measurements revealed equally strong adhesion forces between glycan molecules (190–310 piconewtons) as between proteins in antibody–antigen interactions (244 piconewtons). Quantitative measurements of adhesion forces between glycans from identical species versus glycans from different species confirmed the species specificity of the interaction. Glycan-coated beads aggregated according to their species of origin, i.e., the same way as live sponge cells did. Live cells also demonstrated species selective binding to glycans coated on surfaces. These findings confirm for the first time the existence of relatively strong and species-specific recognition between surface glycans, a process that may have significant implications in cellular recognition.This work was supported by the Friedrich Miescher Institute, branch of the Novartis Research Foundation, the M.E. Müller Foundation, and the Swiss National Research Foundatio

    Realizing Change-Driven Consistency for Component Code, Architectural Models, and Contracts in Vitruvius

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    During the development of component-based software systems, it is often impractical or even impossible to include all development information into the source code. Instead, specialized languages are used to describe components and systems on different levels of abstraction or from different viewpoints: Component-based architecture models and contracts, for example, can be used to describe the system on a high level of abstraction, and to formally specify component constraints. Since models, contracts, and code contain redundant information, inconsistencies can occur if they are modified independently. Keeping this information consistent manually can require considerable effort, and can lead to costly errors, for example, when security-relevant components are verified against inconsistent contracts. In this technical report, we present details on realizing an approach for keeping component-based architecture models and contracts specified in the Java Modeling Language (JML) consistent with Java source code. We use change-driven incremental transformations and the Vitruvius framework to automate the consistency preservation where this is possible. Using two case studies, we demonstrate how to detect and propagate changes and refactoring operations to keep models and contracts consistent with the source code

    Proteoglycan mechanics studied by single-molecule force spectroscopy of allotypic cell adhesion glycans

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    Author Posting. © American Society for Biochemistry and Molecular Biology, 2006. This article is posted here by permission of American Society for Biochemistry and Molecular Biology for personal use, not for redistribution. The definitive version was published in Journal of Biological Chemistry 281 (2006): 5992-5999, doi:10.1074/jbc.M507878200.Early Metazoans had to evolve the first cell adhesion system addressed to maintaining stable interactions between cells constituting different individuals. As the oldest extant multicellular animals, sponges are good candidates to have remnants of the molecules responsible for that crucial innovation. Sponge cells associate in a species-specific process through multivalent calcium-dependent interactions of carbohydrate structures on an extracellular membrane-bound proteoglycan termed aggregation factor. Single-molecule force spectroscopy studies of the mechanics of aggregation factor self-binding indicate the existence of intermolecular carbohydrate adhesion domains. A 200-kDa aggregation factor glycan (g200) involved in cell adhesion exhibits interindividual differences in size and epitope content which suggest the existence of allelic variants. We have purified two of these g200 distinct forms from two individuals of the same sponge species. Comparison of allotypic versus isotypic g200 binding forces reveals significant differences. Surface plasmon resonance measurements show that g200 self-adhesion is much stronger than its binding to other unrelated glycans such as chondroitin sulfate. This adhesive specificity through multiple carbohydrate binding domains is a type of cooperative interaction that can contribute to explain some functions of modular proteoglycans in general. From our results it can be deduced that the binding strength/surface area between two aggregation factor molecules is comparable with that of focal contacts in vertebrate cells, indicating that strong carbohydrate-based cell adhesions evolved at the very start of Metazoan history.This work was supported in part by Grants BIO2002-00128 and BIO2005-01591 (both to X. F.-B.) from the Ministerio de Educacio´n y Ciencia, Spain, which included Fondo Europeo de Desarrollo Regional funds

    Emergency treatment of adrenal crisis with prednisone suppositories: a bioequivalence study in female patients with Addison’s disease

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    Objective: Patients with adrenal insufficiency (AI) need to adapt their glucocorticoid replacement under stressful conditions to prevent adrenal crisis s (AC). Prednisone (PN) suppositories are used for emergency treatment. Pharmacokinetics of 100 mg PN suppositories after vaginal or rectal administration was evaluated. Design: Single-center, open-label, sequence-randomized, cross-over, bioequivalence study. Methods: Twelve females with primary AI were included. Comparison of pharmacokinetics after vaginal and rectal administration of 100 mg PN suppositories. Main outcome measures: bioequivalence (Cmax: maximum plasma concentration of prednisolone; AUC0–360: area under the plasma concentration curve of prednisolone from administration to 360 min), adrenocorticotropin (ACTH) levels, safety and tolerability. Comparison of ACTH-suppressive effect with subcutaneous and intramuscular administration of 100 mg hydrocortisone. Results: Vaginal administration of PN suppositories was not bioequivalent to rectal administration: Cmax and AUC0–360 were significantly lower after vaginal compared to rectal administration: 22 ng/mL (109%) vs 161 ng/mL (28%), P 50% of baseline values was observed 149 min (32%) after rectal PN administration; after vaginal PN administration, the maximum decrease within 360 min was only 44%. Adverse events were more frequent after vaginal administration and mainly attributable to the glucocorticoid deficit due to inadequate vaginal absorption. The ACTH-suppressive effect was more pronounced after parenteral hydrocortisone compared to rectal or vaginal PN. Conclusion: Vaginal administration of PN suppositories in the available form is not useful for prevention of AC. Pharmacokinetics after rectal use of PN s how inferiority compared to available data on parenteral glucocorticoids. In adrenal emergencies, hydrocortisone injection should be the first choice

    Change-Driven Consistency for Component Code, Architectural Models, and Contracts

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    During the development of component-based software systems, it is often impractical or even impossible to include all development information into the source code. Instead, specialized languages are used to describe components and systems on different levels of abstraction or from different viewpoints: Component-based architecture models and contracts, for example, can be used to describe the system on a high level of abstraction, and to formally specify component constraints. Since models, contracts, and code contain redundant information, inconsistencies can occur if they are modified independently. Keeping this information consistent manually can require considerable effort, and can lead to costly errors, for example, when security-relevant components are verified against inconsistent contracts. In this technical report, we present details on realizing an approach for keeping component-based architecture models and contracts specified in the Java Modeling Language (JML) consistent with Java source code. We use change-driven incremental transformations and the Vitruvius framework to automate the consistency preservation where this is possible. Using two case studies, we demonstrate how to detect and propagate changes and refactoring operations to keep models and contracts consistent with the source code

    A Central Clearing Clinic to Provide Mental Health Services for Refugees in Germany

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    Objective: To determine migration related distress pattern in refugees and feasibility of a de novo established, central low-threshold outpatient clinic serving more than 80,000 newly arrived refugees in the metropole of Berlin. Methods: In an observational cohort study the relative prevalence of major psychiatric disorders by age, place of living within berlin, language and region of origin were assessed in a refugee cohort from 63 nationalities speaking 36 languages. Findings: Within 18 months, a total of 3,096 cases with a mean age of 29.7 years (11.7) have been referred from all 12 districts and 165 of 182 subdistricts of Berlin to the CCC. 33.7% of the patients were female. The three most frequent diagnoses were unipolar depression (40.4%), posttraumatic stress disorder (24.3%), and adjustment disorder (19.6%). Conclusion: The present data gives insight into the distribution of mental disorders in a large sample of refugees and provides evidence that a CCC is an effective service to quickly and broadly provide psychiatric consultations and thus to overcome classical barriers refugees usually experience in the host communities. In Berlin, Germany, and Europe treatment resources for this population should focus on stress and trauma related disorders
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