53 research outputs found
Laryngeal mask airway in neonatal stabilization and transport: a retrospective study.
Laryngeal mask airway (LMA) may be considered by health caregivers of level IâII hospitals for neonatal resuscitation and stabilization before and during interhospital care, but literature provides little information on this aspect. This study reviewed the use of LMA during stabilization and transport in a large series of neonates. This is a retrospective study evaluating the use of LMA in infants who underwent emergency transport by the Eastern Veneto Neonatal Emergency Transport Service between January 2003 and December 2021. All data were obtained from transport registry, transport forms, and hospital charts. In total, 64/3252 transferred neonates (2%) received positive pressure ventilation with an LMA, with increasing trend over time (pâ=â0.001). Most of these neonates were transferred after birth (97%), due to a respiratory or neurologic disease (95%). LMA was used before the transport (nâ=â60), during the transport (nâ=â1), or both (nâ=â3). No device-related adverse effects were recorded. Sixty-one neonates (95%) survived and were discharged/transferred from the receiving center
Comparison of P-wave dispersion in healthy dogs, dogs with chronic valvular disease and dogs with disturbances of supraventricular conduction
Coupled Systems of Differential-Algebraic and Kinetic Equations with Application to the Mathematical Modelling of Muscle Tissue
We consider a coupled system composed of a linear differential-algebraic
equation (DAE) and a linear large-scale system of ordinary differential
equations where the latter stands for the dynamics of numerous identical
particles. Replacing the discrete particles by a kinetic equation for a
particle density, we obtain in the mean-field limit the new class of partially
kinetic systems. We investigate the influence of constraints on the kinetic
theory of those systems and present necessary adjustments.
We adapt the mean-field limit to the DAE model and show that index reduction
and the mean-field limit commute. As a main result, we prove Dobrushin's
stability estimate for linear systems. The estimate implies convergence of the
mean-field limit and provides a rigorous link between the particle dynamics and
their kinetic description.
Our research is inspired by mathematical models for muscle tissue where the
macroscopic behaviour is governed by the equations of continuum mechanics,
often discretised by the finite element method, and the microscopic muscle
contraction process is described by Huxley's sliding filament theory. The
latter represents a kinetic equation that characterises the state of the
actin-myosin bindings in the muscle filaments. Linear partially kinetic systems
are a simplified version of such models, with focus on the constraints.Comment: 32 pages, 18 figure
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Efeito da adubação nitrogenada de cobertura e do espaçamento sobre a produção de rúcula
Evaluation of bioactive sphingolipids in 4-HPR-resistant leukemia cells
<p>Abstract</p> <p>Background</p> <p><it>N</it>-(4-hydroxyphenyl)retinamide (4-HPR, fenretinide) is a synthetic retinoid with potent pro-apoptotic activity against several types of cancer, but little is known regarding mechanisms leading to chemoresistance. Ceramide and, more recently, other sphingolipid species (e.g., dihydroceramide and dihydrosphingosine) have been implicated in 4-HPR-mediated tumor cell death. Because sphingolipid metabolism has been reported to be altered in drug-resistant tumor cells, we studied the implication of sphingolipids in acquired resistance to 4-HPR based on an acute lymphoblastic leukemia model.</p> <p>Methods</p> <p>CCRF-CEM cell lines resistant to 4-HPR were obtained by gradual selection. Endogenous sphingolipid profiles and in situ enzymatic activities were determined by LC/MS, and resistance to 4-HPR or to alternative treatments was measured using the XTT viability assay and annexin V-FITC/propidium iodide labeling.</p> <p>Results</p> <p>No major crossresistance was observed against other antitumoral compounds (i.e. paclitaxel, cisplatin, doxorubicin hydrochloride) or agents (i.e. ultra violet C, hydrogen peroxide) also described as sphingolipid modulators. CCRF-CEM cell lines resistant to 4-HPR exhibited a distinctive endogenous sphingolipid profile that correlated with inhibition of dihydroceramide desaturase. Cells maintained acquired resistance to 4-HPR after the removal of 4-HPR though the sphingolipid profile returned to control levels. On the other hand, combined treatment with sphingosine kinase inhibitors (unnatural (dihydro)sphingosines ((dh)Sph)) and glucosylceramide synthase inhibitor (PPMP) in the presence or absence of 4-HPR increased cellular (dh)Sph (but not ceramide) levels and were highly toxic for both parental and resistant cells.</p> <p>Conclusions</p> <p>In the leukemia model, acquired resistance to 4-HPR is selective and persists in the absence of sphingolipid profile alteration. Therapeutically, the data demonstrate that alternative sphingolipid-modulating antitumoral strategies are suitable for both 4-HPR-resistant and sensitive leukemia cells. Thus, whereas sphingolipids may not be critical for maintaining resistance to 4-HPR, manipulation of cytotoxic sphingolipids should be considered a viable approach for overcoming resistance.</p
On Landau damping
Going beyond the linearized study has been a longstanding problem in the
theory of Landau damping. In this paper we establish exponential Landau damping
in analytic regularity. The damping phenomenon is reinterpreted in terms of
transfer of regularity between kinetic and spatial variables, rather than
exchanges of energy; phase mixing is the driving mechanism. The analysis
involves new families of analytic norms, measuring regularity by comparison
with solutions of the free transport equation; new functional inequalities; a
control of nonlinear echoes; sharp scattering estimates; and a Newton
approximation scheme. Our results hold for any potential no more singular than
Coulomb or Newton interaction; the limit cases are included with specific
technical effort. As a side result, the stability of homogeneous equilibria of
the nonlinear Vlasov equation is established under sharp assumptions. We point
out the strong analogy with the KAM theory, and discuss physical implications.Comment: News: (1) the main result now covers Coulomb and Newton potentials,
and (2) some classes of Gevrey data; (3) as a corollary this implies new
results of stability of homogeneous nonmonotone equilibria for the
gravitational Vlasov-Poisson equatio
Feeding of Oligosarcus hepsetus (Cuvier, 1829) (Characiformes) in the Serra do Mar State Park - Santa VirgĂnia Unit, SĂŁo Paulo, Brazil
Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma
Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearsonâs chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ¹ 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33â41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, Ď2P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05â5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available
Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run
Peer reviewe
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