2,021 research outputs found
Electric and magnetic fields effects on the excitonic properties of elliptic core-multishell quantum wires
The effect of eccentricity distortions of core-multishell quantum wires on
their electron, hole and exciton states is theoretically investigated. Within
the effective mass approximation, the Schrodinger equation is numerically
solved for electrons and holes in systems with single and double radial
heterostructures, and the exciton binding energy is calculated by means of a
variational approach. We show that the energy spectrum of a core-multishell
heterostructure with eccentricity distortions, as well as its magnetic field
dependence, are very sensitive to the direction of an externally applied
electric field, an effect that can be used to identify the eccentricity of the
system. For a double heterostructure, the eccentricities of the inner and outer
shells play an important role on the excitonic binding energy, specially in the
presence of external magnetic fields, and lead to drastic modifications in the
oscillator strength.Comment: 17 pages, 10 figure
Solubility of amino acids: a group-contribution model involving phase and chemical equilibria
A new model is proposed to represent the solubility behavior of 14 amino acids and 5 small peptides in water. The UNIFAC model is combined with a Debye-Huckel term to describe the activity coefficients of the species present in the biomolecule/water system. New groups have been defined
according to the group-contribution concept, and chemical equilibrium is taken into account simultaneously with the physical equilibrium. To estimate the new interaction parameters, molal activity coefficient data from the literature were used. These parameters, in addition to solubility
data, were the basis for the correlation of the solubility product of the amino acids. Using this approach, satisfactory results were obtained in the representation and prediction of the solubilities
of amino acids in aqueous solutions at different conditions of temperature and pH
Design and implementation of a wireless sensor network applied to motion capture
This paper describes the development of a wireless sensor network prototype and its application in a motion capture system based on inertial and magnetic sensors. The system presents a portable and modular architecture and allows the monitoring of several users at the same time using a single wireless network. The target application requires the wireless sensor network to operate efficiently under high loads, since it generates data intensive traffic and needs to support a high number of sensor modules. Other requirements imposed by the application are real-time operation and reliable data delivery. In order to provide the quality of service required by the application, an enhanced version of the LPRT medium access control protocol was developed and implemented in devices compliant with the IEEE 802.15.4 standard at the physical layer. Simulation results show that the proposed modifications improve the performance of the protocol. The implementation of the protocol is validated through the experimental results presented.Fundação para a Ciência e a Tecnologia (FCT) - projeto
PTDC/EEA-TEL/68625/2006
Trends from the last decade
Publisher Copyright: © 2022 Sociedade Portuguesa de PneumologiaIntroduction and objectives: Nontuberculous mycobacteria (NTM) are opportunistic human pathogens found in the environment. The transmission seems to be associated with inhalation of aerosol droplets, ingestion or trauma events. Recent studies indicate that NTM disease is increasing worldwide, however, the true clinical impact of NTM infections is difficult to determine due to challenges in discriminating between disease and colonization as they are ubiquitous in the environment. In addition, understanding the epidemiology of NTM is difficult and has not yet been established. In this work, we used a country NTM representative collection from the National Reference Laboratory for Tuberculosis (NRL-TB) of the National Institute of Health (INSA), to characterize the circulation trends of NTM species in Portugal and the most affected regions, contributing to a better understanding of the NTM epidemiology. Material and methods: We conducted a nationwide retrospective study where all individuals with positive NTM cultures at the NRL-TB of the INSA from 2014 to December 2020 were included. Positive cultures were identified using GenoType Mycobacterium CM/AS® (Hain Lifescience) according to manufacturer's instructions, or hsp65 DNA sequencing as previously described. Social-demographic data from patients were also analyzed and patients classified into 3 groups according only to microbiological data, “definite NTM disease”, “NTM colonization” and, “possible NTM disease”. Results: In the period 2014-2020, the NRL-TB performed 50397 cultures. Among these, 1118 cultures were NTM positive retrieved from 944. Most of our cases were in patients whose mean age was 64±15.9 years, and no significant differences between gender was observed, although more frequent in male patients. Overall, from the 944 cases, we were able to identified 93 “definite NTM disease” cases and 79 “possible NTM disease”. Mycobacterium avium complex (MAC) (40,8%), Mycobacterium abscessus-chelonae complex (MABC) (9,6%) and Mycobacterium fortuitum (6,3%) were responsible for most of the infections. The geographical distribution of NTM cases varied significantly and was possible to observe that was independent of population density. The region were most cases occurred was Lisbon Metropolitan Area (31,9%), followed by North (25,3%) and Centre (24,4%), however North region has the highest number of “definite NTM disease” cases (n=33). Conclusions: This is the first national wide epidemiological study on this subject, contributing to a better understanding of NTM dynamics in Portugal. MAC was the NTM species responsible for the majority of infections and, LMA the region with the highest number of cases. It was also possible to conclude that the number of NTM isolates is independent of the demography of the region.publishersversionpublishe
Project results presentation (deliverable D18)
This document is a report which collects together the CYCLOPS project results for dissemination to different interested audiences such as Grid communities and Civil Protection agencies. It also reports on national and international initiatives and projects, SMEs, training activities and related projects.
The structure of this document shows the approach used in the project. Following an introduction, it describes a set of related projects, namely grid- based technologies/EGEE, risk management, and GMEs-based services. It then presents the business of Civil Protection and the use cases selected. These highlight the grid requirements for Grid-based CP applications. The research strategies and enhancements needed for the EGEE infra-structure are identified, based on the use cases. Dissemination of training and knowledge to different communities are also key points of the project.FP
Aceite de buriti de la Amazonia: caracterización química y potencial antioxidante
Buriti oil is an example of an Amazonian palm oil of economic importance. The local population uses this oil for the prevention and treatment of different diseases; however, there are few studies in the literature that evaluate its properties. In this study, detailed chemical and antioxidant properties of Buriti oil were determined. The predominant fatty acid was oleic acid (65.6%) and the main triacylglycerol classes were tri-unsaturated (50.0%) and di-unsaturated-mono-saturated (39.3%) triacylglycerols. The positional distribution of the classes of fatty acids on the triacylglycerol backbone indicated a saturated and unsaturated fatty acid relationship similar in the three-triacylglycerol positions. All tocopherol isomers were present, with a total content of 2364.1 mg·kg−1. α-tocopherol constitutes 48% of the total tocopherol content, followed by γ- tocopherol (45%). Total phenolic (107.0 mg gallic acid equivalent·g−1 oil) and β-carotene (781.6 mg·kg−1) were particularly high in this oil. The highest antioxidant activity against the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) was obtained at an oil concentration of 50 mg·mL−1 (73.15%). The antioxidant activity evaluated by the Oxygen Radical Absorbance Capacity (ORAC) was 95.3 μmol Trolox equivalent·g−1 oil. These results serve to present Buriti oil as an Amazonian resource for cosmetic, food and pharmaceuticals purposes672COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação#2012- 22774-5; #2012-22829-4El aceite de Buriti es un ejemplo de aceite de palma amazónica de gran importancia económica. La población local utiliza este aceite para la prevención y el tratamiento de diferentes enfermedades; sin embargo, hay pocos estudios científicos que evalúen sus propiedades. En este estudio, se determinaron las propiedades antioxidantes del aceite de Buriti. El ácido graso predominante fue el oleico (65,6 %) y las principales clases de triglicéridos fueron tri-insaturadas (50,0 %) y Di-insaturados-mono-saturada (39,3 %). La distribución posicional de las clases de ácidos grasos en el esqueleto de triacilglicerol indicó una relación de ácidos grasos saturados e insaturados similar en las tres posiciones del triacilglicerol. Todas las isoformas de tocoferol estaban presentes, con un contenido total de 2364.1 mg·kg−1. El α-tocoferol constituye el 48 % del contenido total de tocoferol, seguido de γ-tocoferol (45 %). El contenido fenólico total (107,0 mg equivalente ácido gálico·g−1 de aceite) y β-caroteno (781,6 mg·kg−1) fueron particularmente altos en este aceite. La mayor actividad antioxidante contra el radical 1,1-difenil-2-picrilhidrazil libre (DPPH) se obtuvo a una concentración de aceite de 50 mg·mL−1 (73,15 %). La actividad antioxidante evaluadas por la capacidad de absorción de radicales de oxígeno (ORAC) fue 95,3 mmol Trolox equivalente·g−1 de aceite. Estos resultados presentan al aceite de Buriti amazónico como buen recurso con fines cosmético, alimenticio y farmacéutic
Química da solução de um gleissolo na várzea do rio Solimões - AM.
Nas várzeas da Amazônia Central predominam os Gleissolos. O entendimento da dinâmica dos elementos nesses solos pode auxiliar no planejamento de épocas adequadas para a prática de plantio. O objetivo do presente estudo foi caracterizar a composição química da solução desses solos em área de várzea do rio Solimões no Amazonas. Foram realizadas sete amostragens da solução do solo, entre os meses de fevereiro a maio de 2011, no qual foram mensurados o pH, condutividade elétrica (CE) e os teores de Ca2+, Mg2+, Na+, K+, Al3+, Fe, Mn, Cu, Zn. Os teores de Ca2+, Mg2+, Na+ e K+ foram maiores em 100 cm de profundidade, indicando que há mobilização de elementos por lixiviação. Os baixos valores de Fe e maiores de Mn apontam para dissolução redutiva desse primeiro elemento. A decomposição da matéria orgânica contribui para a liberação de elementos em solução e acidificação para o meio. O pH e a CE são governados pelo aumento da concentração eletrolítica da solução do solo pelo aporte anual contid
A wireless posture monitoring system for personalized home-based rehabilitation
We live in an aging society, an issue that will be exacerbated in the coming decades, due to low birth
rates and increasing life expectancy. With the decline in physical and cognitive functions with age, it is of the
utmost importance to maintain regular physical activity, in order to preserve an individual’s mobility, motor
capabilities and coordination. Within this context, this paper describes the development of a wireless sensor
network and its application in a human motion capture system based on wearable inertial and magnetic sensors.
The goal is to enable, through continuous real-time monitoring, the creation of a personalized home-based
rehabilitation system for the elderly population and/or injured people. Within this system, the user can benefit
from an assisted mode, in which their movements can be compared to a reference motion model of the same
movements, resulting in visual feedback alerts given by the application. This motion model can be created
previously, in a ‘learning phase’, under supervision of a caregiver.Project “AAL4ALL”, co-financed by the
European Community Fund FEDER through
COMPETE – Programa Operacional Factores de
Competitividade (POFC). This work is funded by
FEDER funds through the COMPETE 2020
Programme and National Funds through FCT -
Portuguese Foundation for Science and Technology
under the projects UID/CTM/50025/2013 and
UID/EEA/04436/2013.info:eu-repo/semantics/publishedVersio
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