5,964 research outputs found

    Transaminase and pyridoxine deficiency

    Get PDF
    This article does not have an abstract

    Solving the time-dependent Schr\"odinger equation with absorbing boundary conditions and source terms in Mathematica 6.0

    Full text link
    In recent decades a lot of research has been done on the numerical solution of the time-dependent Schr\"odinger equation. On the one hand, some of the proposed numerical methods do not need any kind of matrix inversion, but source terms cannot be easily implemented into this schemes; on the other, some methods involving matrix inversion can implement source terms in a natural way, but are not easy to implement into some computational software programs widely used by non-experts in programming (e.g. Mathematica). We present a simple method to solve the time-dependent Schr\"odinger equation by using a standard Crank-Nicholson method together with a Cayley's form for the finite-difference representation of evolution operator. Here, such standard numerical scheme has been simplified by inverting analytically the matrix of the evolution operator in position representation. The analytical inversion of the N x N matrix let us easily and fully implement the numerical method, with or without source terms, into Mathematica or even into any numerical computing language or computational software used for scientific computing.Comment: 15 pages, 7 figure

    Isoprostane in systemic sclerosis: a systematic review and meta-analysis

    Get PDF
    Objectives: To further the knowledge of oxidative stress in systemic sclerosis (SSc), we performed a systematic review and meta-analysis on studies measuring isoprostane, a vasoactive agent deriving from arachidonic acid and implicated in the vasculopathy of SSc. Methods: Systematic search following the PRISMA guidelines in PubMed and EMBASE between January-1990/December-2017 using the terms: oxidative stress, isoprostane, systemic sclerosis and scleroderma. Results: After the screening process, 8 studies including 240 SSc patients and 192 controls were included in the systematic review and meta-analysis, 6 investigating urinary and 2 serum isoprostane: random effect meta-analysis revealed isoprostane overgeneration in SSc (p <.001) with wide heterogeneity (I 2 = 75%). Subgroup analysis on urinary isoprostane favoured excess excretion in SSc (p =.009) with slightly lower heterogeneity (I 2 = 67%); further subgroup analysis according to unit of measurement revealed no increased isoprostane excretion when expressed as pg/mg creatinine but increased when expressed as pmol/mmol creatinine (p =.05) with medium heterogeneity (I 2 = 32%). Subgroup analysis on serum isoprostane favoured overproduction in SSc (p <.0001) with no heterogeneity. Conclusion: There is some evidence for isoprostane overgeneration in SSc that confirms the occurrence of oxidative stress in this setting: further prospective studies with specified outcomes are needed to evaluate the prognostic value of this functional biomarker

    Non-classical symmetries and the singular manifold method: A further two examples

    Full text link
    This paper discusses two equations with the conditional Painleve property. The usefulness of the singular manifold method as a tool for determining the non-classical symmetries that reduce the equations to ordinary differential equations with the Painleve property is confirmed once moreComment: 9 pages (latex), to appear in Journal of Physics

    Academic achievement : the role of praise in motivating students

    Get PDF
    The motivation of students is an important issue in higher education, particularly in the context of the increasing diversity of student populations. A social-cognitive perspective assumes motivation to be dynamic, context-sensitive and changeable, thereby rendering it to be a much more differentiated construct than previously understood. This complexity may be perplexing to tutors who are keen to develop applications to improve academic achievement. One application that is within the control of the tutor, at least to some extent, is the use of praise. Using psychological literature the article argues that in motivating students, the tutor is not well served by relying on simplistic and common sense understandings of the construct of praise and that effective applications of praise are mediated by students' goal orientations, which of themselves may be either additive or interactive composites of different objectives and different contexts

    Antiphospholipid antibodies and renal transplant: a systematic review and meta-analysis

    Get PDF
    Objective: To evaluate the effect of antiphospholipid antibodies (aPL) on renal allograft outcome after kidney transplantation. Methods: A systematic search of EMBASE and PubMed databases from inception to July 2018 was run according to PRISMA guidelines; Peto's odds ratio (OR) for rare events was used for the meta-analysis. Results: Our inclusion/exclusion criteria were met by 22 cohort studies having different outcomes: allograft thrombosis (n = 9) and thromboprophylaxis (n = 3), allograft loss from any cause (n = 9), allograft malfunction (n = 3), duration (n = 2), glomerular filtration rate at 1 year (n = 3) and allograft rejection (n = 5). The pooled prevalence of allograft thrombosis and of thrombotic microangiopathy was greater in aPL+ve than negative recipients (10.4% vs 1.7%, p < 0.0001 and 10.2% vs 0%, p = 0.005, respectively). The pooled prevalence of allograft thrombosis was 75% in patients not taking anticoagulation whereas none of the anticoagulated recipients developed thrombosis (p < 0.0001). The pooled prevalence of allograft loss was greater in aPL+ve recipients (28% vs 18% respectively, p < 0.0001); the pooled prevalence of aPL was greater in allograft loss recipients compared to those who did not lose it (51% vs 33%, p < 0.0001). The pooled prevalence of allograft malfunction and rejection was similar in aPL−ve and aPL+ve recipients (32.2% vs 40.3% and 14.9% vs 14.4%, respectively) but graft duration was shorter in aPL+ve than aPL−ve recipients (p = 0.001) and glomerular filtration rate at 1 year was lower in aPL + ve than aPL−ve recipients (p < 0.0001). Conclusion: APL relate strongly to allograft thrombosis, loss and duration but not to allograft malfunction and rejection. Oral antivitamin K anticoagulants effectively prevent allograft thrombosis in aPL recipients. The debate on the role of aPL in renal transplant is limited by the expression of data as percentage of recipients positive for aPL rather than aPL titres in many studies

    Nonlinear transport of Bose-Einstein condensates through mesoscopic waveguides

    Get PDF
    We study the coherent flow of interacting Bose-condensed atoms in mesoscopic waveguide geometries. Analytical and numerical methods, based on the mean-field description of the condensate, are developed to study both stationary as well as time-dependent propagation processes. We apply these methods to the propagation of a condensate through an atomic quantum dot in a waveguide, discuss the nonlinear transmission spectrum and show that resonant transport is generally suppressed due to an interaction-induced bistability phenomenon. Finally, we establish a link between the nonlinear features of the transmission spectrum and the self-consistent quasi-bound states of the quantum dot.Comment: 23 pages, 16 figure
    • …
    corecore