573 research outputs found
Traitement de l’incontinence urinaire post-opératoire de l’homme par bandelette sous urétrale: A propos de 16 cas
Objectif: Evaluer les résultats préliminaires de la mise en place d’une bandelette sous urétrale pour le traitement d’incontinence urinaire suite à une chirurgie prostatique chez l’homme selon la technique de Comiter modifiée (sans vissage osseux). Patients et méthodes: Entre janvier 2005 et décembre 2006, 16 patients ont été pris en charge pour incontinence urinaire qui apparut après chirurgie prostatique. Une bandelette de polypropylène fixée sur le périoste des branches ischio-pubiennes par des fils de nylon et comprimant l’urètre bulbaire a été mise en place. L’évaluation pré et post-opératoire a été basée sur l’examen clinique et le nombre de protections utilisées par jour. Les patients ont été revus à un mois post-opératoire, puis tous les trois mois. Résultats: Avec un recul moyen de 18 mois, 11 patients sont continents ne nécessitant pas deprotection et 3 patients sont nettement améliorés. Un échec a été noté chez un patient qui avait présenté initialement une incontinence sévère. Un autre patient a développé une infection de la bandelette nécessitant son retrait et a été exclus de la série pour l’évaluation fonctionnelle. Nousn’avons pas constaté de douleurs périnéales persistantes ni d’érosion urétrale ni d’ostéite. Conclusion: Notre modification de la technique selon Comiter semble avoir des résultats satisfaisants comparables avec la technique originale. Elle présente un avantage économique certain par rapport à d’autres kits du marché
Towards surface quantum optics with Bose-Einstein condensates in evanescent waves
We present a surface trap which allows for studying the coherent interaction
of ultracold atoms with evanescent waves. The trap combines a magnetic Joffe
trap with a repulsive evanescent dipole potential. The position of the magnetic
trap can be controlled with high precision which makes it possible to move
ultracold atoms to the surface of a glass prism in a controlled way. The
optical potential of the evanescent wave compensates for the strong attractive
van der Waals forces and generates a potential barrier at only a few hundred
nanometers from the surface. The trap is tested with Rb Bose-Einstein
condensates (BEC), which are stably positioned at distances from the surfaces
below one micrometer
Negative Effect of Smoking on the Performance of the QuantiFERON TB Gold in Tube Test.
False negative and indeterminate Interferon Gamma Release Assay (IGRA) results are a well documented problem. Cigarette smoking is known to increase the risk of tuberculosis (TB) and to impair Interferon-gamma (IFN-γ) responses to antigenic challenge, but the impact of smoking on IGRA performance is not known. The aim of this study was to evaluate the effect of smoking on IGRA performance in TB patients in a low and high TB prevalence setting respectively. Patients with confirmed TB from Denmark (DK, n = 34; 20 smokers) and Tanzania (TZ, n = 172; 23 smokers) were tested with the QuantiFERON-TB Gold In tube (QFT). Median IFN-γ level in smokers and non smokers were compared and smoking was analysed as a risk factor for false negative and indeterminate QFT results. Smokers from both DK and TZ had lower IFN-γ antigen responses (median 0.9 vs. 4.2 IU/ml, p = 0.04 and 0.4 vs. 1.6, p < 0.01), less positive (50 vs. 86%, p = 0.03 and 48 vs. 75%, p < 0.01) and more false negative (45 vs. 0%, p < 0.01 and 26 vs. 11%, p = 0.04) QFT results. In Tanzanian patients, logistic regression analysis adjusted for sex, age, HIV and alcohol consumption showed an association of smoking with false negative (OR 17.1, CI: 3.0-99.1, p < 0.01) and indeterminate QFT results (OR 5.1, CI: 1.2-21.3, p = 0.02). Cigarette smoking was associated with false negative and indeterminate IGRA results in both a high and a low TB endemic setting independent of HIV status
Fast cavity-enhanced atom detection with low noise and high fidelity
Cavity quantum electrodynamics describes the fundamental interactions between
light and matter, and how they can be controlled by shaping the local
environment. For example, optical microcavities allow high-efficiency detection
and manipulation of single atoms. In this regime fluctuations of atom number
are on the order of the mean number, which can lead to signal fluctuations in
excess of the noise on the incident probe field. Conversely, we demonstrate
that nonlinearities and multi-atom statistics can together serve to suppress
the effects of atomic fluctuations when making local density measurements on
clouds of cold atoms. We measure atom densities below 1 per cavity mode volume
near the photon shot-noise limit. This is in direct contrast to previous
experiments where fluctuations in atom number contribute significantly to the
noise. Atom detection is shown to be fast and efficient, reaching fidelities in
excess of 97% after 10 us and 99.9% after 30 us.Comment: 7 pages, 4 figures, 1 table; extensive changes to format and
discussion according to referee comments; published in Nature Communications
with open acces
Opto-mechanical measurement of micro-trap via nonlinear cavity enhanced Raman scattering spectrum
High-gain resonant nonlinear Raman scattering on trapped cold atoms within a
high-fineness ring optical cavity is simply explained under a nonlinear
opto-mechanical mechanism, and a proposal using it to detect frequency of
micro-trap on atom chip is presented. The enhancement of scattering spectrum is
due to a coherent Raman conversion between two different cavity modes mediated
by collective vibrations of atoms through nonlinear opto-mechanical couplings.
The physical conditions of this technique are roughly estimated on Rubidium
atoms, and a simple quantum analysis as well as a multi-body semiclassical
simulation on this nonlinear Raman process is conducted.Comment: 7 pages, 2 figure
A systematic comparison of linear regression-based statistical methods to assess exposome-health associations
BACKGROUND: The exposome constitutes a promising framework to better understand the effect of environmental exposures on health by explicitly considering multiple testing and avoiding selective reporting. However, exposome studies are challenged by the simultaneous consideration of many correlated exposures. OBJECTIVES: We compared the performances of linear regression-based statistical methods in assessing exposome-health associations. METHODS: In a simulation study, we generated 237 exposure covariates with a realistic correlation structure, and a health outcome linearly related to 0 to 25 of these covariates. Statistical methods were compared primarily in terms of false discovery proportion (FDP) and sensitivity. RESULTS: On average over all simulation settings, the elastic net and sparse partial least-squares regression showed a sensitivity of 76% and a FDP of 44%; Graphical Unit Evolutionary Stochastic Search (GUESS) and the deletion/substitution/addition (DSA) algorithm a sensitivity of 80% and a FDP of 33%. The environment-wide association study (EWAS) underperformed these methods in terms of FDP (average FDP, 86%), despite a higher sensitivity. Performances decreased considerably when assuming an exposome exposure matrix with high levels of correlation between covariates. CONCLUSIONS: Correlation between exposures is a challenge for exposome research, and the statistical methods investigated in this study are limited in their ability to efficiently differentiate true predictors from correlated covariates in a realistic exposome context. While GUESS and DSA provided a marginally better balance between sensitivity and FDP, they did not outperform the other multivariate methods across all scenarios and properties examined, and computational complexity and flexibility should also be considered when choosing between these methods
The first experience of ex-vivo lung perfusion (EVLP) in Iran: An effective method to increase suitable lung for transplantation
Background: Although lung transplantation is a well-accepted treatment for end-stage lung diseases patients, only 15-20 of the brain-dead donors' lungs are usable for transplantation. This results in high mortality of candidates on waiting lists. Ex-vivo lung perfusion (EVLP) is a novel method for better evaluation of a potential lung for transplantation. Objective: To report the first experience of EVLP in Iran. Methods: The study included a pig in Vienna Medical University, Vienna, Austria, and 4 humans in Masih Daneshvari Hospital, Tehran, Iran. All brain-dead donors from 2013 to 2015 in Tehran were evaluated for EVLP. Donors without signs of severe chest trauma or pneumonia, with poor oxygenation were included. Results: An increasing trend in difference between the pulmonary arterial pO2 and left atrial pO2, an increasing pattern in dynamic lung compliance, and a decreasing trend in the pulmonary vascular resistance, were observed. Conclusion: The initial experience of EVLP in Iran was successful in terms of important/critical parameters. The results emphasize on some important considerations such as precisely following standard lung harvesting and monitoring temperature and pressure. EVLP technique may not be a cost-effective option for low-income countries at first glance. However, because this is the only therapeutic treatment for end-stage lung disease, it is advisable to continue working on this method to find alternatives with lesser costs
Dynamical Coupling between a Bose-Einstein Condensate and a Cavity Optical Lattice
A Bose-Einstein condensate is dispersively coupled to a single mode of an
ultra-high finesse optical cavity. The system is governed by strong
interactions between the atomic motion and the light field even at the level of
single quanta. While coherently pumping the cavity mode the condensate is
subject to the cavity optical lattice potential whose depth depends nonlinearly
on the atomic density distribution. We observe bistability already below the
single photon level and strong back-action dynamics which tunes the system
periodically out of resonance.Comment: 5 pages, 4 figure
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