34 research outputs found

    Solutions for certain classes of Riccati differential equation

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    We derive some analytic closed-form solutions for a class of Riccati equation y'(x)-\lambda_0(x)y(x)\pm y^2(x)=\pm s_0(x), where \lambda_0(x), s_0(x) are C^{\infty}-functions. We show that if \delta_n=\lambda_n s_{n-1}-\lambda_{n-1}s_n=0, where \lambda_{n}= \lambda_{n-1}^\prime+s_{n-1}+\lambda_0\lambda_{n-1} and s_{n}=s_{n-1}^\prime+s_0\lambda_{k-1}, n=1,2,..., then The Riccati equation has a solution given by y(x)=\mp s_{n-1}(x)/\lambda_{n-1}(x). Extension to the generalized Riccati equation y'(x)+P(x)y(x)+Q(x)y^2(x)=R(x) is also investigated.Comment: 10 page

    CD28null CD4 T-cell expansions in autoimmune disease suggest a link with cytomegalovirus infection

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    Immunosenescence is thought to contribute to the increase of autoimmune diseases in older people. Immunosenescence is often associated with the presence of an expanded population of CD4 T cells lacking expression of CD28 (CD28null). These highly cytotoxic CD4 T cells were isolated from disease-affected tissues in patients with rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, or other chronic inflammatory diseases and their numbers appeared to be linked to disease severity. However, we recently demonstrated that the common herpes virus, cytomegalovirus (CMV), not ageing, is the major driver of this subset of cytotoxic T cells. In this review, we discuss how CMV might potentiate and exacerbate autoimmune disease through the expansion of CD28null CD4 T cells

    Molecular Analysis of Tn1546-Like Elements in Vancomycin-Resistant Enterococci Isolated from Patients in Europe Shows Geographic Transposon Type Clustering

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    Resistance mechanism relatedness was studied in 18 clinical, European vanA vancomycin-resistant enterococci. Molecular analysis revealed 10 Tn1546-like elements, suggesting two evolutionary lineages. Lineage I dominated the European mainland, and lineage II dominated the United Kingdom and Israel. Geographic clustering reflected different types of meat consumption between countries, since each lineage is associated with colonization of different animals
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