1,082 research outputs found
Cateterização venosa central guiada por ultrassom --- abordagem ‘‘Syringe-Free’’
Background and objectives
Central venous catheterization of the internal jugular vein is a commonly performed invasive procedure associated with a significant morbidity and even mortality. Ultrasound-guided methods have shown to significantly improve the success of the technique and are recommended by various scientific societies, including the American Society of Anesthesiologists. The aim of this report is to describe an innovative ultrasound-guided central line placement of the internal jugular vein.
Technique
The authors describe an innovative ultrasound-guided central line placement of the internal jugular vein based on an oblique approach – the “Syringe-Free” approach. This technique allows immediate progression of the guide wire in the venous lumen, while maintaining a real-time continuous ultrasound image.
Conclusions
The described method adds to the traditional oblique technique the possibility of achieving a continuous real-time ultrasound-guided venipuncture and a guide wire insertion that does not need removing the probe from the puncture field, while having a single operator performing the whole procedure
A Novel Biomanufacturing System to Produce Multi-Material Scaffolds for Tissue Engineering: Concept and Preliminary Results
This research work aims to validate a new system that enables the fabrication of multimaterial 3D structures using poly(e-caprolactone) and sodium alginate for potential use in Tissue Engineering applications. To produce multi-material scaffolds for Tissue Engineering, accurate techniques are needed to obtain three-dimensional constructs with clinically appropriate size and structural integrity. This paper presents a novel biomanufacturing system which can fabricate 3D scaffolds with precise shape and porosity, through the control of all fabrication modules by an integrated computational platform. The incorporation of a clean flow unit and a camera makes it possible to produce scaffolds in a clean environment and provides a monitoring tool to analyse
constructs during the production, respectively.info:eu-repo/semantics/publishedVersio
A selective journey: enantioselective biphasic systems for the resolution of propranolol
Enantiomers may have different biological properties, leading to complications when using racemates for the treatment of diseases. Considering the difficulty in the synthesis of pure enantiomers, the synthesis of racemates followed by their chiral resolution is deemed as a simpler and cheaper alternative. Enantioselective liquid-liquid extraction (ELLE) is a promising separation process. ELLE is composed of two immiscible phases that enable the optimization of enantioseparation through the addition of a chiral selector, such as chiral ionic liquids (CIL) or tartaric acid derivatives. Upon their introduction in ELLE, these chiral selectors may help increase the selectivity of the system, contributing to high performant extraction/separation approaches. In this work, CILs and tartaric acid derivatives were used in biphasic systems as chiral selectors, aiming to separate R/S-propranolol (R/S-PRP) enantiomers. The most promising system was applied in centrifugal partition chromatography to further improve the enantiomeric purification rates.publishe
Design of a liquid-liquid extraction platform for the resolution of chiral pharmaceuticals
Enantiomers have different pharmacological properties, which can hinder the treatment of pathologies using racemic drugs. Racemates represent around 90 % of the commercialized chiral drugs, raising concerns by the FDA (Food and Drug Administration of United States) and EMA (European Medicines Agency). Therefore, the commercialization of the therapeutically active isomer should be preferential. Obtaining the pure enantiomer relies on direct synthesis or resolution of the existing racemates. Resolution is often considered a simpler and cheaper alternative. Enantioselective liquid-liquid extraction (LLE) is a promising separation process that can be operated in a continuous mode. LLE are composed of two tunable immiscible phases that allow the optimization of enantioseparation by the addition of a chiral selector, which is responsible for the chiral recognition. If the two immiscible phases are composed mainly of water, then the system is an aqueous biphasic system (ABS). Since the majority component of ABS is water, they are considered green, economical and reliable systems. A major advantage of LLE is that it can comprise both enantiomeric recognition and solvent extraction on a single technique. Ionic liquids are alternative solvents with great structural diversity, allowing the design of task-specific solvents, including chiral ionic liquids (CILs). The introduction of CILs in LLE may contribute to high performant extraction/separation systems. Another promising class of green chiral selectors is the tartaric acid esters family which in conjugation with boric acid appear as promising adjuvants for the LLE systems. In this work, two different approaches were explored for the purification of propranolol enantiomers using LLE and ABS. In the first one, CILs and tartaric acid esters were used in LLE systems as chiral selectors, and in the second one, CILs and tartaric acid esters were used as chiral selectors in polymer-polymer-based ABS. The best outcome was scaled-up resorting to centrifugal partition chromatography (CPC).publishe
Value of systolic pulmonary arterial pressure as a prognostic factor of death in the systemic sclerosis EUSTAR population.
The aim of this study was to assess the prognostic value of systolic pulmonary artery pressure (sPAP) estimated by echocardiography in the multinational European League Against Rheumatism Scleroderma Trial and Research (EUSTAR) cohort.Data for patients with echocardiography documented between 1 January 2005 and 31 December 2011 were extracted from the EUSTAR database. Stepwise forward multivariable statistical Cox pulmonary hypertension analysis was used to examine the independent effect on survival of selected variables.Based on our selection criteria, 1476 patients were included in the analysis; 87\% of patients were female, with a mean age of 56.3 years (s.d. 13.5) and 31\% had diffuse SSc. The mean duration of follow-up was 2.0 years (s.d. 1.2, median 1.9). Taking index sPAP of 50 mmHg. In a multivariable Cox model, sPAP and the diffusing capacity for carbon monoxide (DLCO) were independently associated with the risk of death [HR 1.833 (95\% CI 1.035, 3.247) and HR 0.973 (95\% CI 0.955, 0.991), respectively]. sPAP was an independent risk factor for death with a HR of 3.02 (95\% CI 1.91, 4.78) for sPAP ≥36 mmHg.An estimated sPAP >36 mmHg at baseline echocardiography was significantly and independently associated with reduced survival, regardless of the presence of pulmonary hypertension based on right heart catheterization
The role of biomass elemental composition and ion-exchange in metal sorption by algae
The use of macroalgae, microalgae and cyanobacteria for metal sorption has been widely reported. Still, there are no studies allowing a direct comparison of the performance of these biomasses, especially while evaluating metal competition. The simultaneous sorption of Co2+, Cu2+, Ni2+ and Zn2+ present in a multi-elemental solution by six macroalgae, two microalgae and three cyanobacteria was evaluated. Brown macroalgae were shown to be the most promising biosorbent, with Undaria pinnatifida having a total metal sorption capacity of 0.6 mmol g-1. Overall, macroalgae performed better than microalgae, followed by cyanobacteria. Carboxyl groups were identified as being the main functional groups involved in metal sorption, and all biomass samples were found to be selective to Cu2+. This was linked not only to its higher complexation constant value with relevant functional groups when compared to the remaining metals, but also the Irving-Williams series. The release of K+ and Ca2+ to the aqueous solution during the metal sorption was followed. The obtained results suggest they are readily exchanged with metals in the solution, indicating the occurrence of an ion-exchange mechanism in metal sorption by most biomass. Red macroalgae are an exception to the reported trends, suggesting that their metal sorption mechanism may differ from the other biomass types.publishe
First results from the Very Small Array -- IV. Cosmological parameter estimation
We investigate the constraints on basic cosmological parameters set by the
first compact-configuration observations of the Very Small Array (VSA), and
other cosmological data sets, in the standard inflationary LambdaCDM model.
Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the
VSA and COBE_DMR data alone produce the constraints Omega_tot =
1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 =
0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent
confidence level. Adding in the type Ia supernovae constraints, we additionally
find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}.
These constraints are consistent with those found by the BOOMERanG, DASI and
MAXIMA experiments. We also find that, by combining all the recent CMB
experiments and assuming the HST key project limits for H_0 (for which the
X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the
tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda=
0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those
obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres
Efeitos da associação do farelo de aveia e barra de soja no perfil lipídico de indivíduos dislipidêmicos.
Nascente termal do Poço Quente (Granjão–Caldas do Moledo, Norte de Portugal): morfoestrutura, geoquímica e hidrogeologia
High-Dimensional Similarity Search with Quantum-Assisted Variational Autoencoder
Recent progress in quantum algorithms and hardware indicates the potential
importance of quantum computing in the near future. However, finding suitable
application areas remains an active area of research. Quantum machine learning
is touted as a potential approach to demonstrate quantum advantage within both
the gate-model and the adiabatic schemes. For instance, the Quantum-assisted
Variational Autoencoder has been proposed as a quantum enhancement to the
discrete VAE. We extend on previous work and study the real-world applicability
of a QVAE by presenting a proof-of-concept for similarity search in large-scale
high-dimensional datasets. While exact and fast similarity search algorithms
are available for low dimensional datasets, scaling to high-dimensional data is
non-trivial. We show how to construct a space-efficient search index based on
the latent space representation of a QVAE. Our experiments show a correlation
between the Hamming distance in the embedded space and the Euclidean distance
in the original space on the Moderate Resolution Imaging Spectroradiometer
(MODIS) dataset. Further, we find real-world speedups compared to linear search
and demonstrate memory-efficient scaling to half a billion data points
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