Cholecystectomy is considered the treatment of choice for symptomatic gallstone disease. Some patients abstain from surgery and provide the opportunity to study the natural history of cholelithiasis. ...The aim of the present study was to examine the feasibility and safety of observation after extended long-term follow-up in a randomized controlled trial.
A total of 137 patients (40.5% of those assessed) were randomized to observation or cholecystectomy and followed up for 14 years. The prevalence of symptomatic events or major complications after treatment was the primary end point. A secondary end point was completion of randomized treatment.
There were no differences in outcome between the observation group and the surgical group (p = 0.298). Virtually no cholecystectomy was performed after 5 years of follow-up, and no clear escalation in the severity of the disease was observed. A total of 50.7% of patients from the observation group and 88.2% from the surgical group underwent surgery. The group randomized to surgery completed their designated treatment significantly more often (p < 0.001), especially among patients younger than 70 years of age (p = 0.005).
Cholecystectomy was the preferred treatment after extended long-term follow-up, but conservative management for symptomatic gallstone disease is an alternative to surgery in the elderly.
Wireless control systems for factory automation (FA) applications are subject to coexistence impairments, especially in license-free spectrum bands. Evaluating the coexistence impact requires the ...knowledge of appropriate characteristic parameters and the usage of a suitable simulation method. In this paper we propose an integral approach for the event-based simulation of wireless coexisting close-loop networked control systems (NCSs) for mutual impact evaluations based upon the integration of an ordinary differential equation resolving library within an event-based wireless network simulation framework. The approach is evaluated within a harsh FA scenario of two identical closed-loop NCS with two coexisting wireless technologies IEEE 802.11 and PNO WSAN-FA.
A fully differential all-pass filter is designed in 250 nm BiCMOS technology with an over three decades tunable corner frequency from 50 kHz to 50 MHz. The filter provides a coarse tuning section by ...switching a capacitive network. Fine tuning is realized by adjusting the bias current of two operational transconductance amplifiers (OTAs) in the signal path. The overall SNDR is between 44 dB to 58 dB depending on the operational mode. Power consumption does not exceed 11.68 mW.
We have developed organic photodetectors based on two complementary wedge layers made of CuPc and C60 and observed a strong spatial dependence of the spectral response on the position of the incident ...light spot. Photocurrent measurements are correlated with atomic force microscopy (AFM), micro-Raman and ellipsometry maps in order to provide insights into the local donor/acceptor concentration, layer thickness and nature of the donor-acceptor interface along the direction of the thickness gradient. Deviations in spatial dependence between experimental photocurrent values and those predicted with a model assuming a sharp and well defined organic-organic interface are discussed in terms of inter-diffusion layers.
O presente trabalho discute a localização de pacientes em ambientes hospi- talares e contém as seguintes partes principais: em primeiro lugar, é intro- duzido o estado de arte sobre técnicas de ...localização de modo à fornecer ao leitor os conhecimentos básicos para os capitulos seguintes. Em se gundo lugar, é efectuada uma avaliação do estado de arte tendo em conta os requisitos necessários para ambientes hospitalares. Em terceiro lugar, é especificado um sistema de localização de pacientes com enfoque na sua arquitectura. A quarta e última parte contém uma proposta de imple- mentação de um sistema de localização, fazendo referencia à investigação actual, sendo também descrito o software do servidor de localização que foi desenvolvido durante a tese.
Atom interferometry represents a quantum leap in the technology for the ultra-precise monitoring of accelerations and rotations and, therefore, for the science that relies on these quantities. These ...sensors evolved from a new kind of optics based on matter-waves rather than light-waves and might result in an advancement of the fundamental detection limits by several orders of magnitude. This paper describes the current status of the Space Atom Interferometer project (SAI), funded by the European Space Agency. In a multi-pronged approach, SAI aims to investigate both experimentally and theoretically the various aspects of placing atom interferometers in space: the equipment needs, the realistically expected performance limits and potential scientific applications in a micro-gravity environment considering all aspects of quantum, relativistic and metrological sciences. A drop-tower compatible atom interferometry acceleration sensor prototype has been designed, and the manufacturing of its subsystems has been started. A compact modular laser system for cooling and trapping rubidium atoms has been assembled. A compact Raman laser module, featuring outstandingly low phase noise, has been realized. Possible schemes to implement coherent atomic sources in the atom interferometer have been experimentally demonstrated.
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