70 research outputs found

    How much and for how long does the neonatal myocardium suffer from mild perinatal asphyxia?

    Get PDF
    Cardiac troponins can be useful in monitoring cardiac injury following perinatal distress. We report here an increase of cardiac troponin I (cTnI) to 2.84 microg/l at 3 weeks (age-related median: 0.07 microg/l) followed by normalization in a newborn with an uneventful clinical course after resuscitation at birth. Serial echocardiographs showed normal cardiac function. Such a time course of cTnI, not previously reported, could be due to either a greater sensitivity of biochemical markers than of instrumental tools or birth asphyxia. Larger studies are neede

    Integrable systems without the Painlev\'e property

    Full text link
    We examine whether the Painlev\'e property is a necessary condition for the integrability of nonlinear ordinary differential equations. We show that for a large class of linearisable systems this is not the case. In the discrete domain, we investigate whether the singularity confinement property is satisfied for the discrete analogues of the non-Painlev\'e continuous linearisable systems. We find that while these discrete systems are themselves linearisable, they possess nonconfined singularities

    On positive solutions and the Omega limit set for a class of delay differential equations

    Full text link
    This paper studies the positive solutions of a class of delay differential equations with two delays. These equations originate from the modeling of hematopoietic cell populations. We give a sufficient condition on the initial function for t≤0t\leq 0 such that the solution is positive for all time t>0t>0. The condition is "optimal". We also discuss the long time behavior of these positive solutions through a dynamical system on the space of continuous functions. We give a characteristic description of the ω\omega limit set of this dynamical system, which can provide informations about the long time behavior of positive solutions of the delay differential equation.Comment: 15 pages, 2 figure

    A list of all integrable 2D homogeneous polynomial potentials with a polynomial integral of order at most 4 in the momenta

    Full text link
    We searched integrable 2D homogeneous polynomial potential with a polynomial first integral by using the so-called direct method of searching for first integrals. We proved that there exist no polynomial first integrals which are genuinely cubic or quartic in the momenta if the degree of homogeneous polynomial potentials is greater than 4.Comment: 22 pages, no figures, to appear in J. Phys. A: Math. Ge

    Trimester-specific reference intervals for thyroid function parameters in pregnant Caucasian women using Roche platforms: a prospective study

    Get PDF
    Background: Standard thyroid function parameters reference intervals (RI) are unsuitable during pregnancy, potentially resulting in incongruous treatments that may cause adverse effects on pregnancy outcomes. We aimed at defining trimester-specific TSH, FT4 and FT3 RI, using samples longitudinally collected from healthy Caucasian women. Materials and methods: Blood samples from 150 healthy Caucasian women, who had a physiological gestation and a healthy newborn at term, were collected in each trimester and at around six months post-partum. They showed mild iodine deficiency. After excluding women with overt TSH abnormalities (> 10 mU/L) and/or TPO antibodies, data from 139 pregnant women were analyzed by means of widely used Roche platforms, and TSH, FT4 and FT3 trimester-specific RI were calculated. Post-partum data were available for 55 subjects. Results: Serum TSH RI were 0.34-3.81 mU/L in the first trimester, and changed slightly to 0.68-4.07 U/L and 0.63-4.00 mU/L in the second and third trimester, respectively. Conversely, both FT4 and FT3 concentrations progressively decreased during pregnancy, the median values in the third trimester being 14.8% and 13.2% lower, respectively, than in the first trimester. Thyroid function parameters in the first trimester were similar to those measured after the end of pregnancy. Conclusions: This study calculates trimester-specific RI for thyroid function parameters in pregnancy, and proposes the reference limits that should be adopted when using Roche platforms in Caucasian women

    On the Floquet Theory of Delay Differential Equations

    Full text link
    We present an analytical approach to deal with nonlinear delay differential equations close to instabilities of time periodic reference states. To this end we start with approximately determining such reference states by extending the Poincar'e Lindstedt and the Shohat expansions which were originally developed for ordinary differential equations. Then we systematically elaborate a linear stability analysis around a time periodic reference state. This allows to approximately calculate the Floquet eigenvalues and their corresponding eigensolutions by using matrix valued continued fractions

    On bi-integrable natural Hamiltonian systems on the Riemannian manifolds

    Full text link
    We introduce the concept of natural Poisson bivectors, which generalizes the Benenti approach to construction of natural integrable systems on the Riemannian manifolds and allows us to consider almost the whole known zoo of integrable systems in framework of bi-hamiltonian geometry.Comment: 24 pages, LaTeX with AMSfonts (some new references were added

    Molecular Characterization of the Gastrula in the Turtle Emys orbicularis: An Evolutionary Perspective on Gastrulation

    Get PDF
    Due to the presence of a blastopore as in amphibians, the turtle has been suggested to exemplify a transition form from an amphibian- to an avian-type gastrulation pattern. In order to test this hypothesis and gain insight into the emergence of the unique characteristics of amniotes during gastrulation, we have performed the first molecular characterization of the gastrula in a reptile, the turtle Emys orbicularis. The study of Brachyury, Lim1, Otx2 and Otx5 expression patterns points to a highly conserved dynamic of expression with amniote model organisms and makes it possible to identify the site of mesoderm internalization, which is a long-standing issue in reptiles. Analysis of Brachyury expression also highlights the presence of two distinct phases, less easily recognizable in model organisms and respectively characterized by an early ring-shaped and a later bilateral symmetrical territory. Systematic comparisons with tetrapod model organisms lead to new insights into the relationships of the blastopore/blastoporal plate system shared by all reptiles, with the blastopore of amphibians and the primitive streak of birds and mammals. The biphasic Brachyury expression pattern is also consistent with recent models of emergence of bilateral symmetry, which raises the question of its evolutionary significance

    Diagnostic and prognostic value of procalcitonin among febrile critically ill patients with prolonged ICU stay

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Procalcitonin (PCT) has been proposed as a diagnostic and prognostic sepsis marker, but has never been validated in febrile patients with prolonged ICU stay.</p> <p>Methods</p> <p>Patients were included in the study provided they were hospitalised in the ICU for > 10 days, were free of infection and presented a new episode of SIRS, with fever >38°C being obligatory. Fifty patients fulfilled the above criteria. PCT was measured daily during the ICU stay. The primary outcome was proven infection.</p> <p>Results</p> <p>Twenty-seven out of 50 patients were diagnosed with infection. Median PCT on the day of fever was 1.18 and 0.17 ng/ml for patients with and without proven infections (p < 0.001). The area under the curve for PCT was 0.85 (95% CI; 0.71-0.93), for CRP 0.65 (0.46-0.78) and for WBC 0.68 (0.49-0.81). A PCT level of 1 ng/mL yielded a negative predictive value of 72% for the presence of infection, while a PCT of 1.16 had a specificity of 100%. A two-fold increase of PCT between fever onset and the previous day was associated with proven infection (p 0.001) (OR = 8.55; 2.4-31.1), whereas a four-fold increase of PCT of any of the 6 preceding days was associated with a positive predictive value exceeding 69.65%. A PCT value less than 0.5 ng/ml on the third day after the advent of fever was associated with favorable survival (p 0.01).</p> <p>Conclusion</p> <p>The reported data support that serial serum PCT may be a valuable diagnostic and prognostic marker in febrile chronic critically ill patients.</p
    • …
    corecore