523 research outputs found
Genomic and Expression Alterations of Tumor Suppressor Genes in Meningioma Development, Progression and Recurrence
The twin paradox in compact spaces
Twins travelling at constant relative velocity will each see the other's time
dilate leading to the apparent paradox that each twin believes the other ages
more slowly. In a finite space, the twins can both be on inertial, periodic
orbits so that they have the opportunity to compare their ages when their paths
cross. As we show, they will agree on their respective ages and avoid the
paradox. The resolution relies on the selection of a preferred frame singled
out by the topology of the space.Comment: to be published in PRA, 3 page
Exploración posturográfica de pacientes simuladores
Introduction: An aphysiological pattern in computerized
dynamic posturography (CDP) may be produced by numerous
causes. We analyze the results obtained in this test
by a group of malingering patients.
Patients and method: This study analyzes a particular
group of 7 malingerers, ie patients simulating a false and
unreal equilibrium disorder, without any a priori awareness
of the gain expected from a pathological report. The condition
can only be identified with the very complex postural
disorder known as “continuous imbalance.” We analyze the
results of the dynamic posturography test following the
diagnostic criteria described by other authors.
Results: Of the criteria analyzed, we found Cevette’s to be
the most frequently positive for our study group.
Conclusions: The wide diversity in the criteria used makes
it necessary to apply them together, assuming a high level
of suspicion and great care in the diagnostic process
Resultados de la autotransfusión postoperatoria en artroplastia total de rodilla
Introducción. El propósito es evaluar si la utilización de los drenajes autotransfusores en la artroplastia
total de rodilla primaria minimiza la caída de la hemoglobina en el postoperatorio, así como la necesidad
de transfusiones sanguíneas alogénicas. Material y métodos. Estudio retrospectivo, analítico observacional que
incluyó 100 pacientes intervenidos de artroplastia de rodilla entre enero 2014 y enero 2015 en el Hospital Dr.
Peset. Compara tanto los parámetros analíticos de sangrado (hemoglobina y hematocrito) como la necesidad de
transfusión sanguínea entre pacientes reinfundidos y no reinfundidos. Resultados. Se reinfundieron 50 pacientes
con un volumen medio de 505 ml. La necesidad de transfusión sanguínea alogénica en los reinfundidos fue de
4% mientras que en los no reinfundidos fue de 24%. La caída media de hemoglobina postquirúrgica fue 1,12 g/
dl menor en el grupo reinfundido. Conclusiones. El redón autotransfusor es una técnica segura que mejora el
rendimiento analítico postransfusional y, por consiguiente, reduce el número de transfusiones alogénicas.Introduction. The purpose is to evaluate the use of autotransfusors drains in total knee arthroplasty
primary minimizes the drop in hemoglobin in the postoperative period, and the need for allogeneic blood
transfusions. Material and methods. A retrospective, analitic and observational study, have been included 100
patients undergoing knee arthroplasty between January 2014 and January 2015 at the Dr. Peset Hospital. Compare
the analytical parameters of bleeding (hemoglobin and hematocrit) and the need for blood transfusion among
patients and not reinfused reinfused. Results. Fifty patients with Total Knee Arthroplasty (TKA) were reinfused
with a mean volume of 505 ml. The need for allogenic blood transfusions was 4%, while in patients not reinfused
was 24%. The average drop in postoperative hemoglobin was 1.12 g / dl lower in the group reinfused. Conclusions.
The autotransfusion drain is a safe technique which improves post-transfusional values and therefore
reduces the number of allogenic blood transfusions
Estudio baropodométrico en pacientes tratados mediante artroplastia total de rodilla
La patología artrósica de la rodilla condiciona una disminución de la carga del miembro afecto y
un patrón de apoyo con predominio generalmente del arco externo. El propósito de este estudio es determinar si
existe una modificación significativa de este patrón tras la implantación de una artroplastia total de rodilla (ATR)
primaria, recogiendo las presiones plantares de ambos pies mediante baropodometría electrónica previamente y 4
meses tras la cirugía, tanto en estática como en dinámica. Así, se analizan las presiones plantares de 30 pacientes,
21 mujeres y 9 hombres, intervenidos de ATR primaria en el Hospital Universitario Doctor Peset entre los años
2013 y 2015. También se ha determinado si existe una corrección del eje anatómico tras la cirugía. Utilizando test
no paramétricos (test de Wilcoxon para datos apareados, U de Mann-Whitney), observamos una modificación
significativa de dicho ángulo desde valores medianos de 1.2º de varo a 4.9º de valgo en el postoperatorio, una
disminución mediana de la presión plantar en ambos pies y una redistribución de la carga axial, aumentando en
el miembro intervenido. Concluimos que, 4 meses tras la cirugía, se produce una tendencia a la “normalización”
de la pisada en pacientes en los que se ha implantado una ATR, condicionado tanto por la mejora del dolor y la
funcionalidad como por la realineación del eje.Knee osteoarthritis determines a decrease of the load of the affected limb and a pattern usually
dominance of external support plantar arc. The purpose of this study is to determine whether a significant change
in this pattern is? after implantation of a primary total knee arthroplasty (TKA), measuring plantar pressures
in both feet by electronic baropodometry previously and 4 months after surgery, in static and dynamic. Plantar
pressures of 30 patients are analyzed, who underwent primary TKA at the University Hospital Doctor Peset
between 2013 and 2015. In addition, it has also been determined if there is a correction on the anatomical axis
after surgery. Using nonparametric test (Wilcoxon test for paired data, U Mann Whitney), we observed a significant
change in the angle from median values of 1.2º varus to 4.9º valgus postoperatively, a median decrease of
plantar pressure in both feet and a redistribution of axial load, increasing in the operated limb. We conclude that,
4 months after surgery, there is a tendency to “normalization” of the tread in patients undergoing TKA. This is
conditioned by improving pain and function as axis realignment occurs
Brane Decay and Death of Open Strings
We show how open strings cease to propagate when unstable D-branes decay. The
information on the propagation is encoded in BSFT two-point functions for
arbitrary profiles of open string excitations. We evaluate them in tachyon
condensation backgrounds corresponding to (i) static spatial tachyon kink (=
lower dimensional BPS D-brane) and (ii) homogeneous rolling tachyon. For (i)
the propagation is restricted to the directions along the tachyon kink, while
for (ii) all the open string excitations cease to propagate at late time and
are subject to a collapsed light cone characterized by Carrollian contraction
of Lorentz group.Comment: 19 pages, published version (typos corrected, a reference added
Sialoendoscopia: una nueva alternativa en el tratamiento de la patología salival. Nuestra experiencia
Objectives: Sialoendoscopy is a procedure used to visualize
the salivary ducts and their pathology. It can be used either
as a diagnostic method to rule out inflammatory processes
in the parotid and submandibular glands (diagnostic
sialoendoscopy) or to treat pathological areas (stenosis,
extract foreign bodies or sialolithiasis) through the use of appropriate
instruments (interventionist sialoendoscopy). We
attempt to prove a declining rate of salivary gland excision.
Patients and method: Sialoendoscopy was performed in
8 patients.
Results: Of these, 50 % of patients were diagnosed as having
sialolithiasis and the other 50 % had chronic sialoadenitis. In
patients with sialolithiasis, sialoendoscopy allowed the
extraction of the calculus in two patients (50 %). In the remainder,
sialoendoscopy provided confirmation of the
diagnosis in all cases.
Conclusions: Sialoendoscopy is a new technique for use in
the diagnosis, treatment and post-operative management
of sialolithiasis, sialoadenitis and other salivary gland
pathologies
Optimal behavior of viscoelastic flow at resonant frequencies
The global entropy generation rate in the zero-mean oscillatory flow of a
Maxwell fluid in a pipe is analyzed with the aim at determining its behavior at
resonant flow conditions. This quantity is calculated explicitly using the
analytic expression for the velocity field and assuming isothermal conditions.
The global entropy generation rate shows well-defined peaks at the resonant
frequencies where the flow displays maximum velocities. It was found that
resonant frequencies can be considered optimal in the sense that they maximize
the power transmitted to the pulsating flow at the expense of maximum
dissipation.Comment: Paper accepted to be published in Phys. Rev.
Rolling of Modulated Tachyon with Gauge Flux and Emergent Fundamental String
We investigate real-time tachyon dynamics of unstable D-brane carrying
fundamental string charge. We construct the boundary state relevant for rolling
of modulated tachyon with gauge fields excited on the world-volume, and study
spatial distribution of the fundamental string charge and current as the
D-brane decays. We find that, in contrast to homogeneous tachyon rolling,
spatial modulation of the tachyon field triggers density wave of strings when
electric field is turned on, and of string anti-string pairs when magnetic
field is turned on. We show that the energy density and the fundamental string
charge density are locked together, and evolve into a localized delta-function
array (instead of evolving into a string fluid) until a critical time set by
initial condition of rolling tachyon. When the gauge fields approach the
critical limit, the fundamental strings produced become BPS-like. We also study
the dynamics via effective field theory, and find agreement.Comment: 28 pages, Latex, 7 .eps figures v2: stability discussion update
Observables and Correlators in Nonrelativistic ABJM Theory
Non-relativistic ABJM theory is defined by Galilean limit of mass-deformed
N=6 Chern-Simons theory. Holographic string theory dual to the theory is not
known yet. To understand features candidate gravity dual might exhibit, we
examine local and nonlocal physical observables and their correlations in the
non-relativistic ABJM theory. We show that gauge invariant local observables
correspond to zero-norm states and that correlation functions among them are
trivial. We also show that a particular class of nonlocal observables, Wilson
loops, are topological in the sense that their correlation functions coincide
with those of pure Chern-Simons theory. We argue that the theory is
nevertheless physical and illustrate several physical observables whose
correlation functions are nontrivial. We also study quantum aspects. We show
that Chern-Simons level is finitely renormalized and that dilatation operator
acting on spin chain is trivial at planar limit. These results all point to
string scale geometry of gravity dual and to intriguing topological and
tensionless nature of dual string defined on it.Comment: 1+30 pages, no figure, v2. typos fixed and references adde
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