314 research outputs found

    Negative-energy perturbations in cylindrical equilibria with a radial electric field

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    The impact of an equilibrium radial electric field EE on negative-energy perturbations (NEPs) (which are potentially dangerous because they can lead to either linear or nonlinear explosive instabilities) in cylindrical equilibria of magnetically confined plasmas is investigated within the framework of Maxwell-drift kinetic theory. It turns out that for wave vectors with a non-vanishing component parallel to the magnetic field the conditions for the existence of NEPs in equilibria with E=0 [G. N. Throumoulopoulos and D. Pfirsch, Phys. Rev. E 53, 2767 (1996)] remain valid, while the condition for the existence of perpendicular NEPs, which are found to be the most important perturbations, is modified. For eiϕTi|e_i\phi|\approx T_i (ϕ\phi is the electrostatic potential) and Ti/Te>βcP/(B2/8π)T_i/T_e > \beta_c\approx P/(B^2/8\pi) (PP is the total plasma pressure), a case which is of operational interest in magnetic confinement systems, the existence of perpendicular NEPs depends on eνEe_\nu E, where eνe_\nu is the charge of the particle species ν\nu. In this case the electric field can reduce the NEPs activity in the edge region of tokamaklike and stellaratorlike equilibria with identical parabolic pressure profiles, the reduction of electron NEPs being more pronounced than that of ion NEPs.Comment: 30 pages, late

    The influence of different culture microenvironments on the generation of dendritic cells from non-small-cell lung cancer patients

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    This study extends the model developed in Williams and Seaman’s [Williams, J. J. and Seaman, A. E. (2010). Corporate Governance and Mindfulness: The Impact of Management Accounting Systems Change, The Journal of Applied Business Research, Vol. 26, No. 5, pp. 1-17] exploratory paper examining the moderating effects of management accounting systems (MAS) change on the corporate governance/mindfulness relationship for a Canadian sample of 124 top-level accounting professionals. Canonical correlation analysis was applied to the linkage of multiple cognitive processes of mindfulness (Weick and Sutcliffe, 2001; 2007) and the governance dimensions of performance and conformance specified by the International Federation of Accountants (2009), underpinned by the moderating effects of five different components of MAS change, which yielded 13 significant relationships. The latter were subsequently analyzed for important gestalts (i.e., patterns) in the overall relationship, and assessed within the context of aligning professional accounting practices involving systems changes to the IFAC (2009) governance framework. These findings appear to have implications for improved governance structures in practice as well as offering a rich foundation for future research

    Palliative chemotherapy beyond three courses conveys no survival or consistent quality-of-life benefits in advanced non-small-cell lung cancer

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    This randomised multicentre trial was conducted to establish the optimal duration of palliative chemotherapy in advanced non-small-cell lung cancer (NSCLC). We compared a policy of three vs six courses of new-generation platinum-based combination chemotherapy with regard to effects on quality of life (QoL) and survival. Patients with stage IIIB or IV NSCLC and WHO performance status (PS) 0–2 were randomised to receive three (C3) or six (C6) courses of carboplatin (area under the curve (AUC) 4, Chatelut's formula, equivalent to Calvert's AUC 5) on day 1 and vinorelbine 25 mg m−2 on days 1 and 8 of a 3-week cycle. Key end points were QoL at 18 weeks, measured with EORTC Quality of Life Questionnaire (QLQ)-C30 and QLQ-LC13, and overall survival. Secondary end points were progression-free survival and need of palliative radiotherapy. Two hundred and ninety-seven patients were randomised (C3 150, C6 147). Their median age was 65 years, 30% had PS 2 and 76% stage IV disease. Seventy-eight and 54% of C3 and C6 patients, respectively, completed all scheduled chemotherapy courses. Compliance with QoL questionnaires was 88%. There were no significant group differences in global QoL, pain or fatigue up to 26 weeks. The dyspnoea palliation rate was lower in the C3 arm at 18 and 26 weeks (P<0.05), but this finding was inconsistent across different methods of analysis. Median survival in the C3 group was 28 vs 32 weeks in the C6 group (P=0.75, HR 1.04, 95% CI 0.82–1.31). One- and 2-year survival rates were 25 and 9% vs 25 and 5% in the C3 and C6 arm, respectively. Median progression-free survival was 16 and 21 weeks in the C3 and C6 groups, respectively (P=0.21, HR 0.86, 95% CI 0.68–1.08). In conclusion, palliative chemotherapy with carboplatin and vinorelbine beyond three courses conveys no survival or consistent QoL benefits in advanced NSCLC

    Morphological analysis of the sheathed flagellum of Brucella melitensis

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    <p>Abstract</p> <p>Background</p> <p>It was recently shown that <it>B. melitensis </it>is flagellated. However, the flagellar structure remains poorly described.</p> <p>Findings</p> <p>We analyzed the structure of the polar sheathed flagellum of <it>B. melitensis </it>by TEM analysis and demonstrated that the Ryu staining is a good method to quickly visualize the flagellum by optical microscopy. The TEM analysis demonstrated that an extension of the outer membrane surrounds a filament ending by a club-like structure. The Δ<it>ftcR</it>, Δ<it>fliF</it>, Δ<it>flgE </it>and Δ<it>fliC </it>flagellar mutants still produce an empty sheath.</p> <p>Conclusions</p> <p>Our results demonstrate that the flagellum of <it>B. melitensis </it>has the characteristics of the sheathed flagella. Our results also suggest that the flagellar sheath production is not directly linked to the flagellar structure assembly and is not regulated by the FtcR master regulator.</p

    Expression of MAGE-1 and -3 genes and gene products in human hepatocellular carcinoma

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    MAGE gene family encodes peptides recognized by autologous cytotoxic T lymphocytes in a major histocompatibility complex (MHC) class-I restricted fashion. In the present study, we have performed reverse-transcription polymerase chain reaction (RT-PCR) for the genes, as well as immunohistochemical analysis and Western blotting of MAGE-1 and -3 proteins in 33 surgically resected hepatocellular carcinomas (HCCs). MAGE-1 and -3 mRNAs were constitutively expressed exclusively in 78 and 42% of HCCs respectively. On immunohistochemistry with monoclonal antibodies, 77B for MAGE-1 and 57B for MAGE-3, MAGE-1 and -3 proteins were recognized in cytoplasm of only six among 33 (18%) and two of 29 HCCs (7%) respectively. The distribution pattern was mostly focal in HCC nodules. By contrast, the Western blot analysis revealed that the MAGE-1 (46 kDa) and -3 proteins (48 kDa) were expressed in 80 and 60% of 15 HCCs examined respectively. The proteins of MAGE-1 and -3 were also expressed exclusively in HCCs regardless of the histological grading and clinical staging. Our results indicate that the detection of the genes by RT-PCR or the proteins by Western blotting is useful for differentiating early HCCs from non-cancerous lesions, and that the peptides derived from MAGE-1 and -3 proteins might be suitable targets for immunotherapy of human HCC. © 1999 Cancer Research Campaig

    The Duration of Antigen-Stimulation Significantly Alters the Diversity of Multifunctional CD4 T Cells Measured by Intracellular Cytokine Staining

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    The assessment of antigen-specific T cell responses by intracellular cytokine staining (ICS) has become a routine technique in studies of vaccination and immunity. Here, we highlight how the duration of in vitro antigen pre-stimulation, combined with the cytokine accumulation period, are critical parameters of these methods. The effect of varying these parameters upon the diversity and frequency of multifunctional CD4 T cell subsets has been investigated using a murine model of TB vaccination and in cattle naturally infected with Mycobacterium bovis. We demonstrate a substantial influence of the duration of the antigen pre-stimulation period on the repertoire of the antigen-specific CD4 T cell responses. Increasing pre-stimulation from 2 to 6 hours amplified the diversity of the seven potential multifunctional CD4 T cell subsets that secreted any combination of IFN-γ, IL-2 and TNF-α. However, increasing pre-stimulation from 6 to 16 hours markedly altered the multifunctional CD4 T cell repertoire to a dominant IFN-γ+ only response. This was observed in both murine and cattle models

    Patients with Chronic Obstructive Pulmonary Disease harbour a variation of Haemophilus species

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    H. haemolyticus is often misidentified as NTHi due to their close phylogenetic relationship. Differentiating between the two is important for correct identification and appropriate treatment of infective organism and to ensure any role of H. haemolyticus in disease is not being overlooked. Speciation however is not completely reliable by culture and PCR methods due to the loss of haemolysis by H. haemolyticus and the heterogeneity of NTHi. Haemophilus isolates from COPD as part of the AERIS study (ClinicalTrials - NCT01360398) were speciated by analysing sequence data for the presence of molecular markers. Further investigation into the genomic relationship was carried out using average nucleotide identity and phylogeny of allelic and genome alignments. Only 6.3% were identified as H. haemolyticus. Multiple in silico methods were able to distinguish H. haemolyticus from NTHi. However, no single gene target was found to be 100% accurate. A group of omp2 negative NTHi were observed to be phylogenetically divergent from H. haemolyticus and remaining NTHi. The presence of an atypical group from a geographically and disease limited set of isolates supports the theory that the heterogeneity of NTHi may provide a genetic continuum between NTHi and H. haemolyticus
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