232 research outputs found

    Energetics of hydrogen impurities in aluminum and their effect on mechanical properties

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    The effects of hydrogen impurities in the bulk and on the surface of aluminum are theoretically investigated. Within the framework of density functional theory, we have obtained the dependence on H concentration of the stacking fault energy, the cleavage energy, the Al/H surface energy and the Al/H/Al interface formation energy. The results indicate a strong dependence of the slip energy barrier in the [2ˉ11][\bar 211] direction the cleavage energy in the [111] direction and the Al/H/Al interface formation energy, on H concentration and on tension. The dependence of the Al/H surface energy on H coverage is less pronounced, while the optimal H coverage is 0.25\leq 0.25 monolayer. The calculated activation energy for diffusion between high symmetry sites in the bulk and on the surface is practically the same, 0.167 eV. From these results, we draw conclusions about the possible effect of H impurities on mechanical properties, and in particular on their role in embrittlement of Al.Comment: 9 pages, 5 figure

    Reliability and validity of cutaneous sarcoidosis outcome instruments among dermatologists, pulmonologists, and rheumatologists

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    IMPORTANCE: Dermatologists, pulmonologists, and rheumatologists study and treat patients with sarcoidosis with cutaneous manifestations. The validity of cutaneous sarcoidosis outcome instruments for use across medical specialties remains unknown. OBJECTIVE: To assess the reliability and validity of cutaneous sarcoidosis outcome instruments for use by dermatologists and nondermatologists treating sarcoidosis. DESIGN, SETTING, AND PARTICIPANTS: We performed a cross-sectional study evaluating the use of the Cutaneous Sarcoidosis Activity and Morphology Instrument (CSAMI) and Sarcoidosis Activity and Severity Index (SASI) to assess cutaneous sarcoidosis disease severity and the Physician's Global Assessment (PGA) as a reference instrument. Four dermatologists, 3 pulmonologists, and 4 rheumatologists evaluated facial cutaneous sarcoidosis in 13 patients treated at a cutaneous sarcoidosis clinic in a 1-day study on October 24, 2014; data analysis was performed from November through December 2014. MAIN OUTCOMES AND MEASURES: Interrater and intrarater reliability and convergent validity, with correlation with quality-of-life measures as the secondary outcome. RESULTS: All instruments demonstrated excellent intrarater reliability. Interrater reliability (reported as intraclass correlation coefficient [95% CI]) was good for the CSAMI Activity scale (0.69 [0.51-0.87]) and PGA (0.66 [0.47-0.85]), weak for the CSAMI Damage scale (0.26 [0.11-0.52]), and excellent for the modified Facial SASI (0.78 [0.63-0.91]). The CSAMI Activity scale and modified Facial SASI showed moderate correlations (95% CI) with the PGA (0.67 [0.57-0.75] and 0.57 [0.45-0.66], respectively). The CSAMI Activity scale but not the modified Facial SASI showed significant correlations (95% CI) with quality-of-life instruments, such as the Dermatology Life Quality Index (Spearman rank correlation, 0.70 [0.25-0.90]) and the Skin Stigma raw score of the Sarcoidosis Assessment Tool (Pearson product moment correlation, 0.56 [0.01-0.85]). CONCLUSIONS AND RELEVANCE: The CSAMI and SASI were reliable and valid in assessing cutaneous sarcoidosis among our diverse group of specialists. The CSAMI Activity score also correlated with quality-of-life measures and suggested construct validity. These results lend credibility to expand the use of the CSAMI and SASI by dermatologists and nondermatologists in assessing cutaneous sarcoidosis disease activity

    Targeting breast cancer stem cells: fishing season open!

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    Studies describing the tumor as a hierarchically organized cell population have changed the classical oncogenesis view and propose new therapeutic strategies. Cancer stem cells (CSCs) are thought to sustain tumor initiation/maintenance, therapy resistance, and systemic metastases. Targeting this tumor cell population is crucial to achieve a true cancer cure. A large research effort is now aiming to develop drugs targeting CSCs, based either on a priori understanding of key pathways regulating CSC biology or on high-throughput screening to identify novel targets and compounds

    Observation of collective excitation of two individual atoms in the Rydberg blockade regime

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    The dipole blockade between Rydberg atoms has been proposed as a basic tool in quantum information processing with neutral atoms. Here we demonstrate experimentally the Rydberg blockade of two individual atoms separated by 4 μ\mum. Moreover, we show that, in this regime, the single atom excitation is enhanced by a collective two-atom behavior associated with the excitation of an entangled state. This observation is a crucial step towards the deterministic manipulation of entanglement of two or more atoms using the Rydberg dipole interaction.Comment: 5 pages, 4 figure

    2010 Rheumatoid arthritis classification criteria: An American College of Rheumatology/European League Against Rheumatism collaborative initiative

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    Objective The 1987 American College of Rheumatology (ACR; formerly, the American Rheumatism Association) classification criteria for rheumatoid arthritis (RA) have been criticized for their lack of sensitivity in early disease. This work was undertaken to develop new classification criteria for RA. Methods A joint working group from the ACR and the European League Against Rheumatism developed, in 3 phases, a new approach to classifying RA. The work focused on identifying, among patients newly presenting with undifferentiated inflammatory synovitis, factors that best discriminated between those who were and those who were not at high risk for persistent and/or erosive disease—this being the appropriate current paradigm underlying the disease construct “rheumatoid arthritis.” Results In the new criteria set, classification as “definite RA” is based on the confirmed presence of synovitis in at least 1 joint, absence of an alternative diagnosis that better explains the synovitis, and achievement of a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains: number and site of involved joints (score range 0–5), serologic abnormality (score range 0–3), elevated acute-phase response (score range 0–1), and symptom duration (2 levels; range 0–1). Conclusion This new classification system redefines the current paradigm of RA by focusing on features at earlier stages of disease that are associated with persistent and/or erosive disease, rather than defining the disease by its late-stage features. This will refocus attention on the important need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent or minimize the occurrence of the undesirable sequelae that currently comprise the paradigm underlying the disease construct “rheumatoid arthritis.”Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78045/1/27584_ftp.pd

    Association of GATA3, P53, Ki67 status and vascular peritumoral invasion are strongly prognostic in luminal breast cancer

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    International audienceIntroduction: Breast cancers are traditionally divided into hormone-receptor positive and negative cases. This classification helps to guide patient management. However, a subgroup of hormone-receptor positive patients relapse irrespective of hormonal therapy. Gene expression profiling has classified breast tumours into five major subtypes with significant different outcome. The two luminal subtypes, A and B, show high expression of ESR1, GATA3 and FOXA1 genes. Prognostic biomarkers for oestrogen receptor (ER)-positive cases include progesterone receptor (PR) and androgen receptor (AR), and proteins related to proliferation or apoptotic resistance. The aim of this study was to identify the best predictors of success of hormonal therapy.Methods: By immunohistochemistry we studied 10 markers in a consecutive series of 832 cases of breast carcinoma treated at the Paoli-Calmettes Institute from 1990 to 2002 and deposited onto tissue microarrays (TMA). These markers were luminal-related markers ER, PR, AR, FOXA1 and GATA3 transcription factors, proliferation-related Ki67 and CCND1, ERBB2, anti-apoptotic BCL2 and P53. We also measured vascular peritumoural invasion (VPI), size, grade and lymph node involvement. For 143 cases, gene expression profiles were available. Adjuvant chemotherapy and hormonal therapy were given to high- and low-risk patients, respectively. The 162 events observed and taken into account were metastases.Results: Molecular expression of the 10 parameters and subtype with ER status were strongly correlated. Of the 67 luminal A cases of this series, 63 were ER-positive. Multivariate analyses showed the highly significant prognostic value of VPI (hazard ratio (HR) = 2.47), Ki67 (HR = 2.9), P53 (HR = 2.9) and GATA3 (HR = 0.5) for the 240 patients who received hormonal therapy.Conclusions: A panel of three antibodies (Ki67, P53 and GATA3) associated with VPI can significantly improve the traditional prognosticators in predicting outcome for ER-positive breast cancer patients receiving hormonal therapy

    MURC/Cavin-4 and cavin family members form tissue-specific caveolar complexes

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    Polymerase I and transcript release factor (PTRF)/Cavin is a cytoplasmic protein whose expression is obligatory for caveola formation. Using biochemistry and fluorescence resonance energy transfer–based approaches, we now show that a family of related proteins, PTRF/Cavin-1, serum deprivation response (SDR)/Cavin-2, SDR-related gene product that binds to C kinase (SRBC)/Cavin-3, and muscle-restricted coiled-coil protein (MURC)/Cavin-4, forms a multiprotein complex that associates with caveolae. This complex can constitutively assemble in the cytosol and associate with caveolin at plasma membrane caveolae. Cavin-1, but not other cavins, can induce caveola formation in a heterologous system and is required for the recruitment of the cavin complex to caveolae. The tissue-restricted expression of cavins suggests that caveolae may perform tissue-specific functions regulated by the composition of the cavin complex. Cavin-4 is expressed predominantly in muscle, and its distribution is perturbed in human muscle disease associated with Caveolin-3 dysfunction, identifying Cavin-4 as a novel muscle disease candidate caveolar protein

    The 2010 American College of Rheumatology/European League Against Rheumatism classification criteria for rheumatoid arthritis: Phase 2 methodological report

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    Objective The American College of Rheumatology and the European League Against Rheumatism have developed new classification criteria for rheumatoid arthritis (RA). The aim of Phase 2 of the development process was to achieve expert consensus on the clinical and laboratory variables that should contribute to the final criteria set. Methods Twenty-four expert RA clinicians (12 from Europe and 12 from North America) participated in Phase 2. A consensus-based decision analysis approach was used to identify factors (and their relative weights) that influence the probability of “developing RA,” complemented by data from the Phase 1 study. Patient case scenarios were used to identify and reach consensus on factors important in determining the probability of RA development. Decision analytic software was used to derive the relative weights for each of the factors and their categories, using choice-based conjoint analysis. Results The expert panel agreed that the new classification criteria should be applied to individuals with undifferentiated inflammatory arthritis in whom at least 1 joint is deemed by an expert assessor to be swollen, indicating definite synovitis. In this clinical setting, they identified 4 additional criteria as being important: number of joints involved and site of involvement, serologic abnormality, acute-phase response, and duration of symptoms in the involved joints. These criteria were consistent with those identified in the Phase 1 data-driven approach. Conclusion The consensus-based, decision analysis approach used in Phase 2 complemented the Phase 1 efforts. The 4 criteria and their relative weights form the basis of the final criteria set.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78048/1/27580_ftp.pd

    A whole-genome sequence and transcriptome perspective on HER2-positive breast cancers

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    HER2-positive breast cancer has long proven to be a clinically distinct class of breast cancers for which several targeted therapies are now available. However, resistance to the treatment associated with specific gene expressions or mutations has been observed, revealing the underlying diversity of these cancers. Therefore, understanding the full extent of the HER2-positive disease heterogeneity still remains challenging. Here we carry out an in-depth genomic characterization of 64 HER2-positive breast tumour genomes that exhibit four subgroups, based on the expression data, with distinctive genomic features in terms of somatic mutations, copy-number changes or structural variations. The results suggest that, despite being clinically defined by a specific gene amplification, HER2-positive tumours melt into the whole luminal-basal breast cancer spectrum rather than standing apart. The results also lead to a refined ERBB2 amplicon of 106 kb and show that several cases of amplifications are compatible with a breakage-fusion-bridge mechanism
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