399 research outputs found

    Mutual Phase Locking of Very Nonidentical Spin Torque Nanooscillators via Spin Wave Interaction

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    In this paper the mutual phase locking theory of very nonidentical spin-torque nanooscillators, which is based on the Slavin-Tiberkevich model, considering the theory of nonlinear oscillations, is developed. Using generalized Adler equation we calculate phase-locking region of the system with spinwave coupling in the parameter plane - distance between nanocontacts and radii difference. We describe trajectories of such a system in the phase space and show the effect of a broadband synchronization. We introduce a generalization of this approach to the ensembles of spin-torque nanooscillatorsComment: 6 pages, 2 figure

    Improvement of nutrient absorption may enhance systemic oxidative stress in cystic fibrosis patients.

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    BACKGROUND: The life expectancy of patients with cystic fibrosis (CF) is largely dependent on the pulmonary disease severity and progress. Malnutrition may be an important complicating factor in active and chronic lung disease. AIMS: The focus of this study was to investigate several inflammatory markers in pancreatic-insufficient CF patients with different enzyme treatment regimens. METHODS: CF patients with pancreatic insufficiency were examined at a time of symptomatic exacerbation of their lung disease. Group A (n = 11) regularly received microspheric enzymes. Group B (n = 8) were treated with enzymes during the hospitalization period only and demonstrated the presence of malnutrition. Inflammatory markers in the sputa (neutrophil elastase activity, interleukin-8 and tumour necrosis factor-alpha levels) and in the peripheral blood (plasma malondialdehyde (MDA), lymphocyte response to PHA, and the cell sensitivity to steroid suppression) have been investigated. RESULTS: During acute lung exacerbation, group B demonstrated reduced levels of lymphocyte proliferation. This parameter was normalized after combined antibiotic and pancreatic enzyme therapy. Simultaneously, plasma MDA in group B markedly increased following treatment. For this group, a significant positive linear association between values of plasma MDA and lymphocyte proliferation has been observed. For group A, neither the same correlation nor changes in MDA levels and lymphocyte proliferation have been found. CONCLUSIONS: Our data indicate that acute lung exacerbation in malnourished CF patients may be associated with alteration in T-lymphocyte activity. Adequate therapy normalizes lymphocyte function but results in systemic oxidative stress

    Towards Integrability of Topological Strings I: Three-forms on Calabi-Yau manifolds

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    The precise relation between Kodaira-Spencer path integral and a particular wave function in seven dimensional quadratic field theory is established. The special properties of three-forms in 6d, as well as Hitchin's action functional, play an important role. The latter defines a quantum field theory similar to Polyakov's formulation of 2d gravity; the curious analogy with world-sheet action of bosonic string is also pointed out.Comment: 31 page

    Anti-inflammatory and immunomodulating effects of clarithromycin in patients with cystic fibrosis lung disease.

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    BACKGROUND AND AIM: Macrolide antibiotics are widely used in the treatment of suppurative lung diseases including cystic fibrosis (CF), the most common inherited fatal disease in the Caucasian population. This condition is characterized by secondary Pseudomonas infection resulting in neutrophil infiltration within the airways. The aim of the study was to investigate the evolution of inflammatory process in CF patients receiving long-term clarithromycin therapy. METHODS: Twenty-seven CF patients (mean age, 12 years) were enrolled into the study. Beside the basic therapy the patients were treated with clarithromycin at a dose of 250 mg every other day orally. All patients were routinely examined every 3 months. Blood and sputum were collected before clarithromycin treatment and then again 3, 6 and 12 months after the drug prescription. Cytokine concentrations (tumor necrosis factor-alpha, interleukin-8, interleukin-4, interferon-gamma) in the sputum and plasma were assayed. Peripheral blood lymphocyte response to phytohemagglutinin was also evaluated. RESULTS: Clarithromycin treatment resulted in a marked reduction of the cytokine levels both in the sputum and plasma specimens. At the same time, the interferon-gamma/interleukin-4 ratio has been significantly elevated. In addition, a sustained increase of peripheral blood lymphocyte response to phytohemagglutinin was demonstrated. These changes were associated with a significant improvement of the lung function. CONCLUSIONS: The beneficial effect of the prolonged treatment of CF patients with a 14-membered ring macrolide antibiotic clarithromycin seems to be associated not only with down-regulation of the inflammatory response, but also with immunological changes including the switch from Th2 to Th1 type response
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