251 research outputs found

    Surface Activation Treatment of Wood and Its Effect on the Gel Time of Phenol-Formaldehyde Resin

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    Surface activation treatment of wood using hydrogen peroxide, nitric acid, and sodium hydroxide was examined to assess its effect on the gel time of phenol-formaldehyde resin. Four wood species comprising both hardwoods and softwoods, two treatment levels, and two treatment conditions (activation and activation followed by drying) were examined in the study. The effect of surface activation on the gel time of phenol-formaldehyde resin varies for a particular surface activator according to treatment level and treatment condition. Surface activated treated wood decreases the gel time of phenol-formaldehyde resin with hydrogen peroxide treatment having the greatest effect followed by nitric acid and sodium hydroxide treatments

    Noise and dynamical pattern selection

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    In pattern forming systems such as Rayleigh-Benard convection or directional solidification, a large number of linearly stable, patterned steady states exist when the basic, simple steady state is unstable. Which of these steady states will be realized in a given experiment appears to depend on unobservable details of the system's initial conditions. We show, however, that weak, Gaussian white noise drives such a system toward a preferred wave number which depends only on the system parameters and is independent of initial conditions. We give a prescription for calculating this wave number, analytically near the onset of instability and numerically otherwise.Comment: 12 pages, REVTEX, no figures. Submitted to Phys. Rev. Let

    Investigating possible ethnicity and sex bias in clinical examiners: an analysis of data from the MRCP(UK) PACES and nPACES examinations

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    Bias of clinical examiners against some types of candidate, based on characteristics such as sex or ethnicity, would represent a threat to the validity of an examination, since sex or ethnicity are 'construct-irrelevant' characteristics. In this paper we report a novel method for assessing sex and ethnic bias in over 2000 examiners who had taken part in the PACES and nPACES (new PACES) examinations of the MRCP(UK)

    What doesn’t kill you will only make you more risk-loving: early life disasters and CEO behavior

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    The literature on managerial style posits a linear relation between a CEO's past experiences and firm risk. We show that there is a nonmonotonic relation between the intensity of CEOs’ early-life exposure to fatal disasters and corporate risk-taking. CEOs who experience fatal disasters without extremely negative consequences lead firms that behave more aggressively, whereas CEOs who witness the extreme downside of disasters behave more conservatively. These patterns manifest across various corporate policies including leverage, cash holdings, and acquisition activity. Ultimately, the link between CEOs’ disaster experience and corporate policies has real economic consequences on firm riskiness and cost of capital

    Collective Management Organisations, Creativity and Cultural Diversity

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    Glycogen synthase kinase 3 (GSK3) is a central regulator of cellular metabolism, development and growth. GSK3 activity was thought to oppose tumourigenesis, yet recent studies indicate that it may support tumour growth in some cancer types including in non-small cell lung carcinoma (NSCLC). We examined the undefined role of GSK3 protein kinase activity in tissue from human NSCLC.The expression and protein kinase activity of GSK3 was determined in 29 fresh frozen samples of human NSCLC and patient-matched normal lung tissue by quantitative immunoassay and western blotting for the phosphorylation of three distinct GSK3 substrates in situ (glycogen synthase, RelA and CRMP-2). The proliferation and sensitivity to the small-molecule GSK3 inhibitor; CHIR99021, of NSCLC cell lines (Hcc193, H1975, PC9 and A549) and non-neoplastic type II pneumocytes was further assessed in adherent culture.Expression and protein kinase activity of GSK3 was elevated in 41% of human NSCLC samples when compared to patient-matched control tissue. Phosphorylation of GSK3α/β at the inhibitory S21/9 residue was a poor biomarker for activity in tumour samples. The GSK3 inhibitor, CHIR99021 dose-dependently reduced the proliferation of three NSCLC cell lines yet was ineffective against type II pneumocytes.NSCLC tumours with elevated GSK3 protein kinase activity may have evolved dependence on the kinase for sustained growth. Our results provide further important rationale for exploring the use of GSK3 inhibitors in treating NSCLC

    Revision of the Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis Classification Schema for Melanocytic Lesions: A Consensus Statement

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    IMPORTANCE A standardized pathology classification system for melanocytic lesions is needed to aid both pathologists and clinicians in cataloging currently existing diverse terminologies and in the diagnosis and treatment of patients. The Melanocytic Pathology Assessment Tool and Hierarchy for Diagnosis (MPATH-Dx) has been developed for this purpose. OBJECTIVE To revise the MPATH-Dx version 1.0 classification tool, using feedback from dermatopathologists participating in the National Institutes of Health-funded Reducing Errors in Melanocytic Interpretations (REMI) Study and from members of the International Melanoma Pathology Study Group (IMPSG). EVIDENCE REVIEW Practicing dermatopathologists recruited from 40 US states participated in the 2-year REMI study and provided feedback on the MPATH-Dx version 1.0 tool. Independently, member dermatopathologists participating in an IMPSG workshop dedicated to the MPATH-Dx schema provided additional input for refining the MPATH-Dx tool. A reference panel of 3 dermatopathologists, the original authors of the MPATH-Dx version 1.0 tool, integrated all feedback into an updated and refined MPATH-Dx version 2.0. FINDINGS The new MPATH-Dx version 2.0 schema simplifies the original 5-class hierarchy into 4 classes to improve diagnostic concordance and to provide more explicit guidance in the treatment of patients. This new version also has clearly defined histopathological criteria for classification of classes I and II lesions; has specific provisions for the most frequently encountered low-cumulative sun damage pathway of melanoma progression, as well as other, less common World Health Organization pathways to melanoma; provides guidance for classifying intermediate class II tumors vs melanoma; and recognizes a subset of pT1a melanomas with very low risk and possible eventual reclassification as neoplasms lacking criteria for melanoma. CONCLUSIONS AND RELEVANCE The implementation of the newly revised MPATH-Dx version 2.0 schema into clinical practice is anticipated to provide a robust tool and adjunct for standardized diagnostic reporting of melanocytic lesions and management of patients to the benefit of both health care practitioners and patients

    Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas

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    Background: The prognosis for malignant gliomas remains dismal. We addressed the safety, feasibility and preliminary clinical activity of the vaccinations using autologous glioma cells and interleukin (IL)-4 gene transfected fibroblasts. Methods: In University of Pittsburgh Cancer Institute (UPCI) protocol 95-033, adult participants with recurrent glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA) received gross total resection (GTR) of the recurrent tumors, followed by two vaccinations with autologous fibroblasts retrovirally transfected with TFG-IL4-Neo-TK vector admixed with irradiated autologous glioma cells. In UPCI 99-111, adult participants with newly diagnosed GBM or AA, following GTR and radiation therapy, received two intradermal vaccinations with the TFG-IL4-Neo-TK-transfected fibroblasts admixed with type-1 dendritic cells (DC) loaded with autologous tumor lysate. The participants were evaluated for occurrence of adverse events, immune response, and clinical response by radiological imaging. Results and Discussion: In UPCI 95-033, only 2 of 6 participants received the vaccinations. Four other participants were withdrawn from the trial because of tumor progression prior to production of the cellular vaccine. However, both participants who received two vaccinations demonstrated encouraging immunological and clinical responses. Biopsies from the local vaccine sites from one participant displayed IL-4 dose-dependent infiltration of CD4+ as well as CD8+ T cells. Interferon (IFN)-γ Enzyme-Linked Immuno-SPOT (ELISPOT) assay in another human leukocyte antigen (HLA)-A2+ participant demonstrated systemic T-cell responses against an HLA-A2-restricted glioma-associated antigen (GAA) epitope EphA2883-891. Moreover, both participants demonstrated clinical and radiological improvement with no evidence of allergic encephalitis, although both participants eventually succumbed with the tumor recurrence. In 99-111, 5 of 6 enrolled participants received scheduled vaccinations with no incidence of major adverse events. Monocyte-derived DCs produced high levels of IL-12 p70. Treatment was well tolerated; however, we were unable to observe detectable IFN-γ post-vaccine responses or prolonged progression-free survival in these participants. Conclusion: Feasibility challenges inherent in the generation of a patient-specific gene transfection-based vaccine strongly suggests the need for more practical formulations that would allow for the timely administration of vaccines. Nevertheless, successful generation of type-1 DCs and preliminary safety in the current study provide a strong rationale for further efforts to develop novel glioma vaccines. © 2007 Okada et al; licensee BioMed Central Ltd

    The U.S. Environmental Protection Agency Particulate Matter Health Effects Research Centers Program: a midcourse report of status, progress, and plans.

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    In 1998 Congress mandated expanded U.S. Environmental Protection Agency (U.S. EPA) health effects research on ambient air particulate matter (PM) and a National Research Council (NRC) committee to provide research oversight. The U.S. EPA currently supports intramural and extramural PM research, including five academically based PM centers. The PM centers in their first 2.5 years have initiated research directed at critical issues identified by the NRC committee, including collaborative activities, and sponsored scientific workshops in key research areas. Through these activities, there is a better understanding of PM health effects and scientific uncertainties. Future PM centers research will focus on long-term effects associated with chronic PM exposures. This report provides a synopsis of accomplishments to date, short-term goals (during the next 2.5 years) and longer-term goals. It consists of six sections: biological mechanisms, acute effects, chronic effects, dosimetry, exposure assessment, and the specific attributes of a coordinated PM centers program
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