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1.
Nature ; 603(7899): 52-57, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35236977

RESUMO

All disc-accreting astrophysical objects produce powerful disc winds. In compact binaries containing neutron stars or black holes, accretion often takes place during violent outbursts. The main disc wind signatures during these eruptions are blue-shifted X-ray absorption lines, which are preferentially seen in disc-dominated 'soft states'1,2. By contrast, optical wind-formed lines have recently been detected in 'hard states', when a hot corona dominates the luminosity3. The relationship between these signatures is unknown, and no erupting system has as yet revealed wind-formed lines between the X-ray and optical bands, despite the many strong resonance transitions in this ultraviolet (UV) region4. Here we report that the transient neutron star binary Swift J1858.6-0814 exhibits wind-formed, blue-shifted absorption lines associated with C IV, N V and He II in time-resolved UV spectroscopy during a luminous hard state, which we interpret as a warm, moderately ionized outflow component in this state. Simultaneously observed optical lines also display transient blue-shifted absorption. Decomposing the UV data into constant and variable components, the blue-shifted absorption is associated with the former. This implies that the outflow is not associated with the luminous flares in the data. The joint presence of UV and optical wind features reveals a multi-phase and/or spatially stratified evaporative outflow from the outer disc5. This type of persistent mass loss across all accretion states has been predicted by radiation-hydrodynamic simulations6 and helps to explain the shorter-than-expected duration of outbursts7.

2.
Rehabilitacion (Madr) ; 55(4): 273-281, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-33771381

RESUMO

INTRODUCTION: Equinus in children produces a pattern of unsteady gait and inefficient and inadequate positioning in the wheelchair. Treatment with a serial casting cycle maintains range of motion and facilitates the development of normal movement patterns. Its use in combination with botulinum toxin has proven benefits, but there is a lack of guidance on the optimal management protocol. OBJECTIVE: The aim of this study were to describe the characteristics of the population with equinus of diverse aetiology and to determine the effectiveness of treatment with serial casting. We also aimed to assess its use in conjunction with botulinum toxin in patients with spastic cerebral palsy. MATERIAL AND METHOD: This longitudinal retrospective study included a sample of 95 Achilles tendons of children attended in a children's rehabilitation clinic between 2012 and 2018, with ankle dorsal flexion less than 10°, treated by a cycle of serial casts with or without botulinum toxin. The variables analysed were sex, year when treatment started, age, BMI, diagnosis, previous and/or later treatment, spasticity (modified Ashworth), laterality, active and passive joint range of dorsal and plantar flexion along with R1 (Tardieu). Measurements were carried out with a mechanical inclinometer prior to the first, second and third cast, after the third cast and at 2, 8 and 14 months. The statistical analysis was performed with SPSS®. RESULTS: There was a statistically significant improvement of 10.02° between passive dorsal flexion prior to the first cast and after the third cast, which remained at 6.66° (P=.02) between the former and after 14 months. CONCLUSIONS: Serial casting is an effective method in the management of equinus of any aetiology and has a minimal complication rate.


Assuntos
Toxinas Botulínicas Tipo A , Fármacos Neuromusculares , Moldes Cirúrgicos , Criança , Humanos , Espasticidade Muscular , Estudos Retrospectivos
3.
Rehabilitacion (Madr) ; 55(3): 233-237, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-33248716

RESUMO

Os subtibiale is a low prevalence accessory bone of the ankle. This bone is located in the posterior colliculus of the tibial medial malleolus, both in paediatric and adult ages. It can cause pain, redness and/or swelling, which can lead to a mistaken diagnosis of avulsion fracture. Adequate anatomical knowledge is crucial. First, we present the case of a school-aged boy, seen at the outpatient clinic for a 2-month history of pain in both inner ankles after an injury. Second, we present the case of an adult patient with a 3-day history of right medial ankle pain, with no previous injury, evaluated at the Emergency Department. Accurate history-taking and physical examination are essential. The diagnosis is given by conventional radiology of both ankles, in antero-posterior and lateral load views. The initial treatment is conservative (splint or orthesis) to establish and maintain the function of the foot during loading activities. If there is no recovery after 6 months, surgical treatment can be considered.


Assuntos
Fraturas do Tornozelo , Ossos do Tarso , Adulto , Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/diagnóstico por imagem , Fraturas do Tornozelo/cirurgia , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Artralgia/diagnóstico , Artralgia/etiologia , Criança , Humanos , Masculino
4.
Nanomaterials (Basel) ; 10(12)2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33255714

RESUMO

Pathogenic bacteria have the ability to develop antibiotic resistance mechanisms. Their action consists mainly in the production of bacterial enzymes that inactivate antibiotics or the appearance of modifications that prevent the arrival of the drug at the target point or the alteration of the target point itself, becoming a growing problem for health systems. Chitosan-gold nanoparticles (Cs-AuNPs) have been shown as effective bactericidal materials avoiding damage to human cells. In this work, Cs-AuNPs were synthesized using chitosan as the reducing agent, and a systematic analysis of the influence of the synthesis parameters on the size and zeta potential of the Cs-AuNPs and their UV-vis spectra was carried out. We used a simulation model to characterize the interaction of chitosan with bacterial membranes, using a symmetric charged bilayer and two different chitosan models with different degrees of the chitosan amine protonation as a function of pH, with the aim to elucidate the antibacterial mechanism involving the cell wall disruption. The Cs-AuNP antibacterial activity was evaluated to check the simulation model.

6.
Rev Neurol ; 64(10): 459-470, 2017 May 16.
Artigo em Espanhol | MEDLINE | ID: mdl-28497442

RESUMO

INTRODUCTION: Spasticity is a medical problem with a high incidence that significantly impact on the quality of life of patients and their families. AIM: To analyze and to answer different questions about the use of botulinum toxin type A (BTA) in our clinical practice. DEVELOPMENT: A group of experts in neurology develop a list of topics related with the use of BTA. Two big groups were considered: spasticity in adults and in children with cerebral palsy. A literature search at PubMed for English, French, and Spanish language articles published up to June 2016 was performed. The manuscript was structured as a questionnaire that includes those questions that, according to the panel opinion, could generate more controversy or doubt. The initial draft was reviewed by the expert panel members to allow for modifications, and after subsequent revisions for achieving the highest degree of consensus, the final text was then validated. Different questions about diverse aspects of spasticity in adults, such as methods for evaluating spasticity, infiltration techniques, doses, number of infiltration points, etc. Regarding spasticity in children with cerebral palsy, the document included questions about minimum age of infiltration, methods of analgesia, etc. CONCLUSIONS: This review is a tool for continuous training for neurologist and rehabilitation specialist and residents of both specialties, about different specific areas of the management of BTA.


TITLE: Mitos y evidencias en el empleo de la toxina botulinica: espasticidad del adulto y del nintilde;o con paralisis cerebral.Introduccion. La espasticidad es un problema medico frecuente que impacta de forma significativa en la calidad de vida de los pacientes y sus familias. Objetivo. Analizar y dar respuesta a diferentes cuestiones en el uso de la toxina botulinica tipo A (TBA) en nuestra practica clinica habitual. Desarrollo. Un grupo de expertos en neurologia elaboro una lista de temas relacionados con el uso de la TBA. Se consideraron dos grandes bloques: espasticidad del adulto y del nintilde;o con paralisis cerebral. Se realizo una revision de la bibliografia que incluyo los diferentes articulos publicados en espantilde;ol, ingles y frances hasta junio de 2016. El documento se estructuro como un cuestionario que incluyo las preguntas que, segun el criterio del panel, podrian generar mayor controversia o duda. El borrador inicial del documento fue revisado por los miembros del panel y se realizaron las modificaciones necesarias hasta alcanzar el mayor grado de consenso. A continuacion, el texto final fue validado. Se incluyeron diferentes preguntas sobre diferentes aspectos de la espasticidad en adultos: evaluacion de la espasticidad, tecnicas de infiltracion, dosis, numero de puntos, etc. En cuanto a la espasticidad en los nintilde;os con paralisis cerebral, se analizaron preguntas como: edad minima de infiltracion, metodos de sedoanalgesia, etc. Conclusiones. Esta revision constituye una herramienta para neurologos, medicos rehabilitadores y residentes de ambas especialidades, dentro de diferentes ambitos especificos del manejo de la TBA.


Assuntos
Toxinas Botulínicas Tipo A/uso terapêutico , Paralisia Cerebral/tratamento farmacológico , Fármacos Neuromusculares/uso terapêutico , Adolescente , Adulto , Toxinas Botulínicas Tipo A/administração & dosagem , Toxinas Botulínicas Tipo A/efeitos adversos , Paralisia Cerebral/reabilitação , Paralisia Cerebral/terapia , Criança , Pré-Escolar , Terapia Combinada , Consenso , Gerenciamento Clínico , Feminino , Objetivos , Humanos , Lactente , Masculino , Esclerose Múltipla/complicações , Esclerose Múltipla/tratamento farmacológico , Espasticidade Muscular/tratamento farmacológico , Espasticidade Muscular/terapia , Fármacos Neuromusculares/administração & dosagem , Fármacos Neuromusculares/efeitos adversos , Modalidades de Fisioterapia , Inquéritos e Questionários , Avaliação de Sintomas , Adulto Jovem
7.
Nature ; 534(7605): 75-8, 2016 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-27251277

RESUMO

Accretion of matter onto black holes is universally associated with strong radiative feedback and powerful outflows. In particular, black-hole transients have outflows whose properties are strongly coupled to those of the accretion flow. This includes X-ray winds of ionized material, expelled from the accretion disk encircling the black hole, and collimated radio jets. Very recently, a distinct optical variability pattern has been reported in the transient stellar-mass black hole V404 Cygni, and interpreted as disrupted mass flow into the inner regions of its large accretion disk. Here we report observations of a sustained outer accretion disk wind in V404 Cyg, which is unlike any seen hitherto. We find that the outflowing wind is neutral, has a large covering factor, expands at one per cent of the speed of light and triggers a nebular phase once accretion drops sharply and the ejecta become optically thin. The large expelled mass (>10(-8) solar masses) indicates that the outburst was prematurely ended when a sizeable fraction of the outer disk was depleted by the wind, detaching the inner regions from the rest of the disk. The luminous, but brief, accretion phases shown by transients with large accretion disks imply that this outflow is probably a fundamental ingredient in regulating mass accretion onto black holes.

8.
Chem Commun (Camb) ; 52(23): 4305-8, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26960420

RESUMO

The mechanism of Ph/X exchange in reactions involving SnPh(n)Bu3 and [AuXL] complexes switches dramatically from the usual concerted mechanism involving Ar/X mixed bridges when X = Cl, to an unexpected oxidative addition/reductive elimination pathway via an Au(III) intermediate when X = vinyl.

9.
Nature ; 505(7483): 378-81, 2014 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-24429635

RESUMO

Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary evolution models also predict the existence of black holes accreting from the equatorial envelope of rapidly spinning Be-type stars (stars of the Be type are hot blue irregular variables showing characteristic spectral emission lines of hydrogen). Of the approximately 80 Be X-ray binaries known in the Galaxy, however, only pulsating neutron stars have been found as companions. A black hole was formally allowed as a solution for the companion to the Be star MWC 656 (ref. 5; also known as HD 215227), although that conclusion was based on a single radial velocity curve of the Be star, a mistaken spectral classification and rough estimates of the inclination angle. Here we report observations of an accretion disk line mirroring the orbit of MWC 656. This, together with an improved radial velocity curve of the Be star through fitting sharp Fe II profiles from the equatorial disk, and a refined Be classification (to that of a B1.5-B2 III star), indicates that a black hole of 3.8 to 6.9 solar masses orbits MWC 656, the candidate counterpart of the γ-ray source AGL J2241+4454 (refs 5, 6). The black hole is X-ray quiescent and fed by a radiatively inefficient accretion flow giving a luminosity less than 1.6 × 10(-7) times the Eddington luminosity. This implies that Be binaries with black-hole companions are difficult to detect in conventional X-ray surveys.

10.
Science ; 339(6123): 1048-51, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23449588

RESUMO

Stellar-mass black holes (BHs) are mostly found in x-ray transients, a subclass of x-ray binaries that exhibit violent outbursts. None of the 50 galactic BHs known show eclipses, which is surprising for a random distribution of inclinations. Swift J1357.2-093313 is a very faint x-ray transient detected in 2011. On the basis of spectroscopic evidence, we show that it contains a BH in a 2.8-hour orbital period. Further, high-time-resolution optical light curves display profound dips without x-ray counterparts. The observed properties are best explained by the presence of an obscuring toroidal structure moving outward in the inner disk, seen at very high inclination. This observational feature should play a key role in models of inner accretion flows and jet collimation mechanisms in stellar-mass BHs.

12.
Early Hum Dev ; 89(6): 401-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23312396

RESUMO

BACKGROUND: Previous studies indicate that VLBW preterm children obtain significantly lower scores than full-term children in all the NBAS clusters. However the samples studied usually presented additional medical complications. AIMS: The present study aims to compare the results obtained by low-risk preterm and full term children in the NBAS, and relate possible differences to biological and contextual factors. METHOD: Early neurobehavioral development of 150 preterm (PR) children is compared to that of 49 full term children (FT). The children were assessed at the age of 15 days (corrected age for preterm children) with the NBAS. Biological and environmental variables were collected through an extended interview with the mothers as well as medical data. RESULTS: Significant differences were found between preterm and full term children in the following areas: motor, range of state, and regulation of state. Differences were also found in relation to birth weight in these same three areas, following a parallel pattern. These differences between the two groups were not, however, necessarily more favorable for the FT group; the PR group had higher results in the motor and range of state areas, and lower results in the regulation of state area. The mothers' smoking habit had a negative effect on infants' regulation and orientation. CONCLUSIONS: No general maturation delay in this particular sample of preterm children was found.


Assuntos
Desenvolvimento Infantil , Meio Ambiente , Recém-Nascido Prematuro/crescimento & desenvolvimento , Adulto , Estudos de Casos e Controles , Deficiências do Desenvolvimento/epidemiologia , Deficiências do Desenvolvimento/etiologia , Feminino , Humanos , Recém-Nascido , Masculino , Mães , Transtornos Psicomotores/epidemiologia , Transtornos Psicomotores/etiologia , Fumar
13.
Environ Sci Pollut Res Int ; 20(5): 2924-36, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23054768

RESUMO

In summer, high levels of ozone (O3) are frequently measured at both Galicia and Northern Portugal air quality monitoring stations, even exceeding the limit values imposed by legislation. This work aims to investigate the origin of these high O3 concentrations by the application of a chemical transport modelling system over the northwestern area of the Iberian Peninsula. The WRF-CHIMERE modelling system was applied with high resolution to simulate the selected air pollution episodes that occurred simultaneously in Galicia and North Portugal and in order to study both the contribution of local emission sources and the influence of transboundary pollution. Emission inputs have been prepared based on the development of the Portuguese and Galician emission inventories. The obtained results for O3 have been evaluated and validated against observations. Modelling results show possible contribution of the transboundary transport over the border of two neighbour regions/countries, indicating that the O3 episode starts over the urban and industrialised area of North coast of Portugal, reaching the maximum peaks over this region; at the same time, O3 levels increased over Galicia region, where lower concentrations, but still high, were observed. These results pointed out that air quality management should not be driven by political boundaries and highlight the importance of joining efforts between neighbouring countries.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Ozônio/análise , Modelos Teóricos , Portugal , Estações do Ano , Espanha
14.
Chemosphere ; 90(9): 2428-34, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23177003

RESUMO

Persistent organic pollutants (POPs) are within the most dangerous pollutants released into the environment by human activities. Due to their resistance to degradation (chemical, biological or photolytic), it is critical to assess the fate and environmental hazards of the exchange of POPs between different environmental media. System Dynamics enables to represent complex systems and analyze their dynamic behavior. It provides a highly visual representation of the structure of the system and the existing relationships between the several parameters and variables, facilitating the understanding of the behavior of the system. In the present study the fate of γ-hexachlorocyclohexane (lindane) in a contaminated soil was modeled using the Vensim® simulation software. Results show a gradual decrease in the lindane content in the soil during a simulation period of 10 years. The most important route affecting the concentrations of the contaminant was the biochemical degradation, followed by infiltration and hydrodynamic dispersion. The model appeared to be highly sensitive to the half-life of the pollutant, which value depends on environmental conditions and directly affects the biochemical degradation.


Assuntos
Monitoramento Ambiental/métodos , Modelos Químicos , Poluentes do Solo/análise , Solo/química , Hexaclorocicloexano/análise , Hexaclorocicloexano/química , Poluentes do Solo/química
15.
Sci Total Environ ; 441: 97-110, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23137974

RESUMO

High levels of ozone are frequently measured at the Galicia (NW Iberian Peninsula) air quality monitoring stations from March to October. However, there have been very few studies on surface ozone in the northwestern Iberian Peninsula, most likely because the climate of this region is not favourable to photochemical ozone generation. The occurrence of these episodes may be related to either local-scale photochemical pollution or regional-scale transport from other polluted regions. In addition, high ozone episodes usually are developed under specific synoptic conditions. The main purposes of this study are to characterise the atmospheric conditions that lead to the ozone episodes in this region and to identify possible advection paths of ozone and precursors. A surface hourly ozone dataset (2002-2007) measured at rural sites in Galicia was analysed to identify high ozone episodes together with their associated synoptic patterns using a subjective classification with 23 different synoptic types. The synoptic weather patterns revealed that most of the episodes occur with high surface pressures centred over the British Isles and/or Central Europe while a high-altitude anticyclonic ridge crosses the Peninsula from North Africa, causing easterly or southeasterly winds. This analysis was completed with 3-day backward air mass trajectories obtained with HYSPLIT to assess the contribution of long-range transport, resulting in the following main routes: Mediterranean-Peninsular, South Atlantic-Portuguese, local and French-Cantabric.

16.
ScientificWorldJournal ; 2012: 603034, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22649298

RESUMO

Tropospheric ozone levels around urban and suburban areas at Europe and North America had increased during 80's-90's, until the application of NO(x) reduction strategies. However, as it was expected, this ozone depletion was not proportional to the emissions reduction. On the other hand, rural ozone levels show different trends, with peaks reduction and average increments; this different evolution could be explained by either emission changes or climate variability in a region. In this work, trends of tropospheric ozone episodes at rural sites in the northwest of the Iberian Peninsula were analyzed and compared to others observed in different regions of the Atlantic European coast. Special interest was focused on the air quality sites characterization, in order to guarantee their rural character in terms of air quality. Both episodic local meteorological and air quality measurements along five years were considered, in order to study possible meteorological influences in ozone levels, different to other European Atlantic regions.


Assuntos
Ozônio , Poluentes Atmosféricos , Clima , Geografia , População Rural , Estações do Ano
17.
Environ Pollut ; 162: 176-89, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22243863

RESUMO

A very high ozone episode with observed hourly values above 350 µg m(-3) occurred in July 2005 at the Lamas d'Olo air quality monitoring station, located in a mountainous area in the north of Portugal. Aiming to identify the origin and formation of this ozone-rich episode, a statistical analysis and a modelling approach were applied. A cross-spectrum analysis in the frequency domain and a synoptic analysis of the meteorological and air quality time series were performed. In order to go further in this analysis, a numerical modelling approach was applied. The results indicate that the transport of ozone and its precursors is the main responsible for the high ozone concentrations. Together with the local mountain breeze and subsidence conditions, the sea-breeze circulation transporting pollutants from the coastal urban and industrialized areas that reach the site during late afternoon turn out to be the driving forces for the ozone peaks.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Ozônio/análise , Portugal , População Rural , Estações do Ano
19.
Water Sci Technol ; 59(10): 2017-27, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19474497

RESUMO

This study offers a solution for reducing the environmental effect of wastewaters generated by the olive-oil industry. Olive-oil companies produce variable quantities of wastewaters, which require treatment for disposal or reuse. Today, regulations are becoming increasingly strict regarding the parameters measured in these effluents. In Spain, the resolution by the president of the Hydrographical Confederation of the Guadalquivir on water use 2004 set parameter limits as follows: pH = 6.0-9.0, total suspended solid = 500 mg/L; and COD and BOD(5) (20)=1,500 mg O(2)/L. For the year 2006, maximum values for COD and BOD(5) (20) were fixed at 1,000 mg O(2)/L. To solve this problem, a study has been made to derive irrigation water from the above-mentioned effluents through chemical oxidation based on the Fenton's process. This would be first step towards using a closed-circuit system in olive-oil mills to treat and reuse effluents.


Assuntos
Óleos de Plantas , Eliminação de Resíduos Líquidos/métodos , Cloretos , Compostos Férricos , Indústria Alimentícia , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Cinética , Minerais/análise , Testes de Neutralização , Azeite de Oliva , Oxirredução , Oxigênio/análise , Espanha , Temperatura
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