347 research outputs found
Prevention of pressure ulcers in bedridden patient: new evidences
Objetivo: Identificar las mejores medidas para prevención de las úlceras por presión (UPP) relacionadas con superficies de apoyo y cambios posturales, aceite de oliva y ácidos grasos hiperoxigenados, uso profiláctico de apósitos y administración de complementos nutricionales.Método:Se realizó una revisión integradora de la literatura. Las palabras clave fueron úlcera por presión, paciente inmovilizado, prevención primaria. Se consultaron las bases de datos Pubmed, Scielo, Cochrane, Scopus y CINHAL. El límite temporal fue de 5 años.Resultados:Se obtuvieron un total de 833 artículos, de los cuales 793 (95’2%) fueron excluidos. El principal motivo de exclusión fue que el tema de prevención se dirigía hacia otras patologías. Pubmed fue la base de datos con mayor número de artículos con 410 resultados, seguida de CINAHL con 170. Los 40 artículos incluidos fueron clasificados según el tema de los objetivos específicos.Conclusiones: Tanto los colchones que disminuyen la presión como los cambios de posición son buenas medidas de prevención, aunque se precisa más evidencia sobre los tipos de materialesy los tiempos respectivamente. El aceite de oliva se muestra como una alternativa a los ácidos grasos hiperoxigenados para la prevención ya que son igual de eficaces en la prevención. Respecto al uso de apósitos de manera profiláctica, muestran una mayor efectividad los apósitos hidrocoloides y los apósitos transparentes de poliuretano. Se necesita más investigaciones para determinar la efectividad de los complementos nutricionales en la prevención de UPP.Objective: To identify the best measures for the prevention of pressure ulcers (PU) in relation to support surfaces and postural changes, olive oil and hyperoxygenated fatty acids, prophylactic use of dressings and administration of nutritional supplements.
Method: An integrative review of the literature was carried out. Keywords were: pressure ulcer, immobilized patient, and primary prevention. The Pubmed, Scielo, Cochrane, Scopus and CINHAL databases were consulted. There was a 5-year time limit.Results: A total of 833 articles were obtained, of which 793 (95.2%) were excluded. The main reason for exclusion was that the topic of prevention was directed towards other pathologies. Pubmed was the database with the highest number of articles with 410 results, followed by CINAHL with 170. The 40 articles included were classified according to the subject of the specific objectives.Conclusions: Both mattresses that reduce pressure and changes in position are good preventive measures, although more evidence is needed on the types of materials and times respectively. Olive oil is shown as an alternative to hyperoxygenated fatty acids for prevention since they are equally effective in prevention. Regarding the useof dressings prophylactically, hydrocolloid dressings and transparent polyurethane dressings show greater effectiveness. More research is needed to determine the effectiveness of nutritional supplements in the prevention of PU
Chelarctus and Crenarctus (Crustacea: Scyllaridae) from Coral Sea waters, with molecular identification of their larvae
Chelarctus Holthuis, 2002 is widely distributed throughout the Indo-West Pacific, but its biogeographic patterns are unknown because Southern Hemisphere areas, such as the Coral Sea, remained poorly explored. Recent cruises organized by the Muséum national d'Histoire naturelle of Paris and the Australian Institute of Marine Science allowed the molecular identification of Crenarctus crenatus (Whitelegge, 1900), Chelarctus aureus (Holthuis, 1963) and Chelarctus crosnieri Holthuis, 2002 phyllosomae. The Coral Sea C. crenatus larvae are identical to stages IX and X of Scyllarus sp. Z, described in detail by Webber and Booth (2001). Descriptions of phyllosoma stages VI, IX and X of Ch. aureus and stages IX and X of Ch. crosnieri are also presented here. Morphological differences between Crenarctus and Chelarctus larvae are established for the first time and previous misidentifications in the literature are re-assessed
Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib
[EN]
In the current study, 12 Spanish families affected by type-I Usher syndrome, that was previously linked to chromosome 11q, were screened for the presence of mutations in the N-terminal coding portion of the motor domain of the myosin VIIA gene by single-strand conformation polymorphism analysis of the first 14 exons. A mutation (Ala397Asp) segregating with the disease was identified, and several polymorphisms were also detected. It is presumed that the other USH1B mutations in these families could be located in the unscreened regions of the gene.The authors would like to thank the Fondo de Investigaciones Sanitarias (FISS n0 95/1814), the ONCE and the Fundación ONCE for financial support. We acknowledge patients and their family members, as well as the Asociación de retinosis pigmentaria de la Comunidad Valenciana and the FAARPEE, for their help and cooperation.Espinós-Armero, CÁ.; Millán, JM.; Sánchez, F.; Beneyto, M.; Nájera, C. (1998). Ala397Asp Mutation of Myosin VIIA Segregating in a Spanish Family with Usher Syndrome Type Ib. Human Genetics. 102(6):691-694. https://doi.org/10.1007/s004390050763691694102
Advances in the numerical treatment of grain-boundary migration: Coupling with mass transport and mechanics
This work is based upon a coupled, lattice-based continuum formulation that
was previously applied to problems involving strong coupling between mechanics
and mass transport; e.g. diffusional creep and electromigration. Here we
discuss an enhancement of this formulation to account for migrating grain
boundaries. The level set method is used to model grain-boundary migration in
an Eulerian framework where a grain boundary is represented as the zero level
set of an evolving higher-dimensional function. This approach can easily be
generalized to model other problems involving migrating interfaces; e.g. void
evolution and free-surface morphology evolution. The level-set equation is
recast in a remarkably simple form which obviates the need for spatial
stabilization techniques. This simplified level-set formulation makes use of
velocity extension and field re-initialization techniques. In addition, a
least-squares smoothing technique is used to compute the local curvature of a
grain boundary directly from the level-set field without resorting to
higher-order interpolation. A notable feature is that the coupling between mass
transport, mechanics and grain-boundary migration is fully accounted for. The
complexities associated with this coupling are highlighted and the
operator-split algorithm used to solve the coupled equations is described.Comment: 28 pages, 9 figures, LaTeX; Accepted for publication in Computer
Methods in Applied Mechanics and Engineering. [Style and formatting
modifications made, references added.
Review and Comparison of Computational Approaches for Joint Longitudinal and Time‐to‐Event Models
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151312/1/insr12322.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151312/2/insr12322_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151312/3/Supplement_ReviewComputationalJointModels_final.pd
Geometric Integration of Hamiltonian Systems Perturbed by Rayleigh Damping
Explicit and semi-explicit geometric integration schemes for dissipative
perturbations of Hamiltonian systems are analyzed. The dissipation is
characterized by a small parameter , and the schemes under study
preserve the symplectic structure in the case . In the case
the energy dissipation rate is shown to be asymptotically
correct by backward error analysis. Theoretical results on monotone decrease of
the modified Hamiltonian function for small enough step sizes are given.
Further, an analysis proving near conservation of relative equilibria for small
enough step sizes is conducted.
Numerical examples, verifying the analyses, are given for a planar pendulum
and an elastic 3--D pendulum. The results are superior in comparison with a
conventional explicit Runge-Kutta method of the same order
Fronts dynamics in the presence of spatio-temporal structured noises
Front dynamics modeled by a reaction-diffusion equation are studied under the
influence of spatio-temporal structured noises. An effective deterministic
model is analytical derived where the noise parameters, intensity, correlation
time and correlation length appear explicitely. The different effects of these
parameters are discussed for the Ginzburg-Landau and Schl\"ogl models. We
obtain an analytical expression for the front velocity as a function of the
noise parameters. Numerical simulations results are in a good agreement with
the theoretical predictions.Comment: 11 pages, 6 figures; REVTEX; to be published in Phys.Rev.E, july 200
Bayesian analysis of a disability model for lung cancer survival
Bayesian reasoning, survival analysis and multi-state models are used to assess survival times for Stage IV non-small-cell lung cancer patients and the evolution of the disease over time. Bayesian estimation is done using minimum informative priors for the Weibull regression survival model, leading to an automatic inferential procedure. Markov chain Monte Carlo methods have been used for approximating posterior distributions and the Bayesian information criterion has been considered for covariate selection. In particular, the posterior distribution of the transition probabilities, resulting from the multi-state model, constitutes a very interesting tool which could be useful to help oncologists and patients make efficient and effective decisions.This study has been partially supported by the Ministerio de Ciencia e Innovación [grant number MTM2010- 19528], Mutua Madrileña [grant AP75942010], Ministero dell'Istruzione, dell'Universitá e della Ricerca of Italy and the visiting professor program of the Regione Autonoma della Sardegna
Fluctuating "Pulled" Fronts: the Origin and the Effects of a Finite Particle Cutoff
Recently it has been shown that when an equation that allows so-called pulled
fronts in the mean-field limit is modelled with a stochastic model with a
finite number of particles per correlation volume, the convergence to the
speed for is extremely slow -- going only as .
In this paper, we study the front propagation in a simple stochastic lattice
model. A detailed analysis of the microscopic picture of the front dynamics
shows that for the description of the far tip of the front, one has to abandon
the idea of a uniformly translating front solution. The lattice and finite
particle effects lead to a ``stop-and-go'' type dynamics at the far tip of the
front, while the average front behind it ``crosses over'' to a uniformly
translating solution. In this formulation, the effect of stochasticity on the
asymptotic front speed is coded in the probability distribution of the times
required for the advancement of the ``foremost bin''. We derive expressions of
these probability distributions by matching the solution of the far tip with
the uniformly translating solution behind. This matching includes various
correlation effects in a mean-field type approximation. Our results for the
probability distributions compare well to the results of stochastic numerical
simulations. This approach also allows us to deal with much smaller values of
than it is required to have the asymptotics to be valid.Comment: 26 pages, 11 figures, to appear in Phys. rev.
Bayesian estimation of incomplete data using conditionally specified priors
In this paper, a class of conjugate prior for estimating incomplete count data based on a broad class of conjugate prior distributions is presented. The new class of prior distributions arises from a conditional perspective, making use of the conditional specification methodology and can be considered as the generalisation of the form of prior distributions that have been used previously in the estimation of in- complete count data well. Finally, some examples of simulated and real data are given
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