Search results for "FAILURE"

Loup-assisted technique to create arterio-venous fistulas in elderly. A single centre experience

2019

AIMS: The radio-cephalic arteriovenous fistula (RCAVF) is the first choice treatment in end-stage renal disease patients. In the last few years, the hemodialysis population has shown a high percentage of elderly patients (> 65 year old) with comorbidities, mainly vascular diseases, which may adversely affect their vascular access success. The aim of this study was to evaluate the effectiveness of a loup-assisted technique to create RCAVFs in over 65 patients. PATIENTS AND METHODS: 98 consecutive patients with renal failure were prospectively observed. The patient were divided in relation to their age (> 65 year old; < 65 year old). In both groups, a microsurgical distal RCAVF was c…

Urea Cycle Metabolites and Atrial Fibrillation or Heart Failure Risk: Two Case-Control Studies in the PREDIMED Trial

2021

OBJECTIVES: To prospectively analyze the associations between urea cycle metabolites and incident atrial fibrillation (AF) or heart failure (HF), and to evaluate the effect of a Mediterranean diet (MD) intervention on such associations. METHODS: We designed two nested case-control studies within the PREDIMED trial, a randomized controlled trial aimed to evaluate the effect of two MD interventions, supplemented with either extra virgin olive oil (EVOO) or nuts, on cardiovascular disease (CVD). Fasting blood samples were collected at baseline and urea cycle metabolites (arginine, citrulline, and ornithine) and methylarginines (asymmetric dimethylarginine/symmetric dimethylarginine ratio (ADMA…

Insuficiencia cardiaca con fracción de eyección preservada. Tenue luz al final del túnel

2019

The Significance of Treasure Hunting: Past and Present

2012

It is certainly insufficient to explain treasure hunting as a reaction to poverty or a form of greed and avarice.1 Avarice has been seen as a part of the human condition and thus as a non-historical, that is, a quasi-anthropological constant. Anthropological constants hardly ever help to explain the behaviour of historical people. In our case, an alleged human tendency to accumulate material wealth does not explain why some people engaged in treasure hunting whereas others did not. Why did people look for treasure? Why did they talk about treasure? Why were they willing to suffer the repeated failure of treasure hunts and continue to look for hidden riches?

Practical strategies for stable operation of HFF-QCM in continuous air flow

2013

Currently there are a few fields of application using quartz crystal microbalances (QCM). Because of environmental conditions and insufficient resolution of the microbalance, chemical sensing of volatile organic compounds in an open system was as yet not possible. In this study we present strategies on how to use 195 MHz fundamental quartz resonators for a mobile sensor platform to detect airborne analytes. Commonly the use of devices with a resonant frequency of about 10 MHz is standard. By increasing the frequency to 195 MHz the frequency shift increases by a factor of almost 400. Unfortunately, such kinds of quartz crystals tend to exhibit some challenges to obtain a reasonable signal-to…

DEVELOPMENT AND APPLICATIONS OF A VIRTUAL HYBRID PLATFORM FOR MULTISCALE ANALYSIS OF ADVANCED STRUCTURES OF AIRCRAFT (DEVISU)

2022

This paper outlines the main findings of the project “DEvelopment and applications of a VIrtual hybrid platform for multiscale analysis of advanced StructUres of aircraft” (DEVISU), which deals with failure of composite structures and noise/vibration reduction, along with investigation of new materials for aerospace applications.

Waveguiding properties of a photonic crystal fiber with a solid core surrounded by four large air holes

2009

The polarization-dependent guiding properties of a hexagonal-lattice photonic crystal fiber with a solid-core surrounded by four large air holes are investigated. The appearance of a polarization dependent cutoff frequency, together with several parameters as the birefringence, the modal effective area, the group velocity dispersion and the polarization dependent loss are analyzed. A collection of fibers with different structural parameters were fabricated and characterized. An effective anti-guide structure from at least 450 nm to 1750 nm, a polarizing fiber with a polarization dependent loss of 16 dB/m at 1550 nm, and an endlessly singlemode polarization-maintaining fiber with group biref…

A Refractive Index Sensor Based on the Resonant Coupling to Cladding Modes in a Fiber Loop

2013

We report an easy-to-build, compact, and low-cost optical fiber refractive index sensor. It consists of a single fiber loop whose transmission spectra exhibit a series of notches produced by the resonant coupling between the fundamental mode and the cladding modes in a uniformly bent fiber. The wavelength of the notches, distributed in a wavelength span from 1,400 to 1,700 nm, can be tuned by adjusting the diameter of the fiber loop and are sensitive to refractive index changes of the external medium. Sensitivities of 170 and 800 nm per refractive index unit for water solutions and for the refractive index interval 1.40-1.442, respectively, are demonstrated. We estimate a long range resolut…

Multioctave midinfrared supercontinuum generation in suspended-core chalcogenide fibers

2014

An As2S3 fiber-based supercontinuum source that covers 3500 nm, extending from near visible to the midinfrared, is successfully reported by using a 200-fs-pulsed pump with nJ-level energy at 2.5 μm. The main features of our fiber-based source are two-fold. On the one hand, a low-loss As2S3 microstructured optical fiber has been fabricated, with typical attenuation below 2 dB/m in the 1-4 μm wavelength range. On the other hand, a 20-mm-long microstructured fiber sample is sufficient to enable a spectral broadening, spreading from 0.6 to 4.1 μm in a 40 dB dynamic range.

Microstructured chalcogenide optical fibers from As2S3 glass: towards new IR broadband sources

2010

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