5,416 research outputs found
Adeno-tonsillectomy and rapid maxillary distraction in pre-pubertal children: a pilot study
Introduction When both narrow maxilla and moderately
enlarged tonsils are present in children with obstructive
sleep apnea, the decision of which treatment to do first is
unclear. A preliminary randomized study was done to
perform a power analysis and determine the number of
subjects necessary to have an appropriate response. Thirtyone
children, 14 boys, diagnosed with OSA based on
clinical symptoms and polysomnography (PSG) findings
had presence of both narrow maxillary complex and
enlarged tonsils. They were scheduled to have both
adeno-tonsillectomy and RME for which the order of
treatment was randomized: group 1 received surgery
followed by orthodontics, while group 2 received
orthodontics followed by surgery. Each child was seen
by an ENT, an orthodontist, and a sleep medicine
specialist. The validated pediatric sleep questionnaire
and PSG were done at entry and after each treatment
phase at time of PSG. Statistical analyses were ANOVA
repeated measures and t tests.
Results The mean age of the children at entry was 6.5±
0.2 years (mean ± SEM). Overall, even if children
presented improvement of both clinical symptoms and
PSG findings, none of the children presented normal
results after treatment 1, at the exception of one case.
There was no significant difference in the amount of
improvement noted independently of the first treatment
approach. Thirty children underwent treatment 2, with an
overall significant improvement shown for PSG findings
compared to baseline and compared to treatment 1,
without any group differences.
Conclusion This preliminary study emphasizes the need to
have more than subjective clinical scales for determination
of sequence of treatments
Acute life-threatening extrinsic allergic alveolitis in a paint controller
Background Occupational diisocyanate-induced extrinsic allergic alveolitis (EAA) is a rare and probably underestimated diagnosis. Two acute occupational EAA cases have been described in this context, but neither of them concerned hexamethylene diisocyanate (HDI) exposure. Aims To investigate the cause of a life-threatening EAA arising at work in a healthy 30-year-old female paint quality controller. Methods Occupational medical assessment, workplace evaluation, airborne and biological monitoring and immunodermatological tests. Results Diagnosis of EAA relied on congruent clinical and radiological information, confirmed occupational HDI exposure and positive IgG antibodies and patch tests. The patient worked in a small laboratory for 7 years, only occasionally using HDI-containing hardeners. While working with HDI for 6 h, she developed breathlessness, rapidly progressing to severe respiratory failure. Workplace HDI airborne exposure values ranged from undetectable levels to 4.25 p.p.b. Biological monitoring of urinary hexamethylene diamine in co-workers ranged from <1.0 to 15.4 μg/g creatinine. Patch tests 8 months later showed delayed skin reaction to HDI at 48 h. Subsequent skin biopsy showed spongiotic dermatitis with infiltration of CD4+ and CD8+ T cells. Conclusions We believe this is the first reported case of acute life-threatening EAA following exposure to HDI. Low concentrations of airborne HDI and relatively high urinary hexamethylene diamine suggest significant skin absorption of HDI could have significantly contributed to the development of this acute occupational EA
Heat flow and calculus on metric measure spaces with Ricci curvature bounded below - the compact case
We provide a quick overview of various calculus tools and of the main results
concerning the heat flow on compact metric measure spaces, with applications to
spaces with lower Ricci curvature bounds.
Topics include the Hopf-Lax semigroup and the Hamilton-Jacobi equation in
metric spaces, a new approach to differentiation and to the theory of Sobolev
spaces over metric measure spaces, the equivalence of the L^2-gradient flow of
a suitably defined "Dirichlet energy" and the Wasserstein gradient flow of the
relative entropy functional, a metric version of Brenier's Theorem, and a new
(stronger) definition of Ricci curvature bound from below for metric measure
spaces. This new notion is stable w.r.t. measured Gromov-Hausdorff convergence
and it is strictly connected with the linearity of the heat flow.Comment: To the memory of Enrico Magenes, whose exemplar life, research and
teaching shaped generations of mathematician
A weighted reduced basis method for parabolic PDEs with random data
This work considers a weighted POD-greedy method to estimate statistical
outputs parabolic PDE problems with parametrized random data. The key idea of
weighted reduced basis methods is to weight the parameter-dependent error
estimate according to a probability measure in the set-up of the reduced space.
The error of stochastic finite element solutions is usually measured in a root
mean square sense regarding their dependence on the stochastic input
parameters. An orthogonal projection of a snapshot set onto a corresponding POD
basis defines an optimum reduced approximation in terms of a Monte Carlo
discretization of the root mean square error. The errors of a weighted
POD-greedy Galerkin solution are compared against an orthogonal projection of
the underlying snapshots onto a POD basis for a numerical example involving
thermal conduction. In particular, it is assessed whether a weighted POD-greedy
solutions is able to come significantly closer to the optimum than a
non-weighted equivalent. Additionally, the performance of a weighted POD-greedy
Galerkin solution is considered with respect to the mean absolute error of an
adjoint-corrected functional of the reduced solution.Comment: 15 pages, 4 figure
Early complications after living donor nephrectomy: analysis of the Swiss Organ Living Donor Health Registry.
We evaluated the prospectively collected data about the incidence of early peri- and postoperative complications, and potential risk factors for adverse outcomes after living kidney donation in Switzerland.
Peri- and postoperative events were prospectively recorded on a questionnaire by the local transplant teams of all Swiss transplant centres and evaluated by the Swiss Organ Living Donor Health Registry. Complications were classified according to the Clavien grading system. A total of 1649 consecutive donors between 1998 and 2015 were included in the analysis.
There was no perioperative mortality observed. The overall complication rate was 13.5%. Major complications defined as Clavien ≥3 occurred in 2.1% of donors. Obesity was not associated with any complications. Donor age >70years was associated with major complications (odds ratio [OR] 3.99) and genitourinary complications (urinary tract infection OR 5.85; urinary retention OR 6.61). There were more major complications observed in donors with laparoscopic surgery versus open surgery (p = 0.048), but an equal overall complication rate (p = 0.094).
We found a low rate of major and minor complications, independent of surgical technique, after living donor nephrectomy. There was no elevated complication rate in obese donors. In contrast, elderly donors >70 years had an elevated risk for perioperative complications
Paediatric patient safety and the need for aviation black box thinking to learn from and prevent medication errors
Since the publication of To Err Is Human: Building a Safer Health System in 1999, there has been much research conducted into the epidemiology, nature and causes of medication errors in children, from prescribing and supply to administration. It is reassuring to see growing evidence of improving medication safety in children; however, based on media reports, it can be seen that serious and fatal medication errors still occur. This critical opinion article examines the problem of medication errors in children and provides recommendations for research, training of healthcare professionals and a culture shift towards dealing with medication errors. There are three factors that we need to consider to unravel what is missing and why fatal medication errors still occur. (1) Who is involved and affected by the medication error? (2) What factors hinder staff and organisations from learning from mistakes? Does the fear of litigation and criminal charges deter healthcare professionals from voluntarily reporting medication errors? (3) What are the educational needs required to prevent medication errors? It is important to educate future healthcare professionals about medication errors and human factors to prevent these from happening. Further research is required to apply aviation’s ‘black box’ principles in healthcare to record and learn from near misses and errors to prevent future events. There is an urgent need for the black box investigations to be published and made public for the benefit of other organisations that may have similar potential risks for adverse events. International sharing of investigations and learning is also needed
Structural insights on TRPV5 gating by endogenous modulators.
TRPV5 is a transient receptor potential channel involved in calcium reabsorption. Here we investigate the interaction of two endogenous modulators with TRPV5. Both phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and calmodulin (CaM) have been shown to directly bind to TRPV5 and activate or inactivate the channel, respectively. Using cryo-electron microscopy (cryo-EM), we determined TRPV5 structures in the presence of dioctanoyl PI(4,5)P2 and CaM. The PI(4,5)P2 structure reveals a binding site between the N-linker, S4-S5 linker and S6 helix of TRPV5. These interactions with PI(4,5)P2 induce conformational rearrangements in the lower gate, opening the channel. The CaM structure reveals two TRPV5 C-terminal peptides anchoring a single CaM molecule and that calcium inhibition is mediated through a cation-π interaction between Lys116 on the C-lobe of calcium-activated CaM and Trp583 at the intracellular gate of TRPV5. Overall, this investigation provides insight into the endogenous modulation of TRPV5, which has the potential to guide drug discovery
The lowest eigenvalue of Jacobi random matrix ensembles and Painlev\'e VI
We present two complementary methods, each applicable in a different range,
to evaluate the distribution of the lowest eigenvalue of random matrices in a
Jacobi ensemble. The first method solves an associated Painleve VI nonlinear
differential equation numerically, with suitable initial conditions that we
determine. The second method proceeds via constructing the power-series
expansion of the Painleve VI function. Our results are applied in a forthcoming
paper in which we model the distribution of the first zero above the central
point of elliptic curve L-function families of finite conductor and of
conjecturally orthogonal symmetry.Comment: 30 pages, 2 figure
The ATLAS Survey of the CDFS and ELAIS-S1 Fields
The first phase of the ATLAS (Australia Telescope Large Area Survey) project
surveyed a total 7 square degrees down to 30 micro Jy rms at 1.4 GHz and is the
largest sensitive radio survey ever attempted. We report on the scientific
achievements of ATLAS to date and plans to extend the project as a path finder
for the proposed EMU (Evolutionary map of the Universe) project which has been
designed to use ASKAP (Australian Square Kilometre Array Pathfinder).Comment: 4 pages, 3 figure
Quartic scaling of sound attenuation with frequency in vitreous silica
Several theoretical approaches to disordered media predict that acoustic
waves should undergo a quartic increase in their attenuation coefficient with
increasing frequency in the sub-terahertz region. Such Rayleigh-type scattering
would be related to the anomalous low-temperature plateau in the thermal
conductivity and to the so-called boson peak, i.e. an excess of vibrational
modes above the Debye density of states at around 1 THz. Brillouin scattering
of light allows the measurement of sound absorption and velocity dispersion up
to about 0.1 THz while inelastic x-ray scattering is limited to frequencies
larger than about 1 THz. We take advantage of the advent of ultrafast optical
techniques to explore the acoustical properties of amorphous SiO2 layers in the
difficult but crucial frequency region within this gap. A quartic scaling law
with frequency is clearly revealed between 0.2 and 0.9 THz, which is further
shown to be independent of temperature. This strongly damped regime is
accompanied by a decrease in the sound velocity already starting from about 0.5
THz, in line with theories. Our study assists to clarify the anomalous
acoustical properties in glasses at frequencies entering the boson peak region.Comment: 4 figures, 11 page
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