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1.
Foods ; 12(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36673485

RESUMO

The establishment of operation protocols for olive oil (OO) extraction at non-industrial scale is crucial for research purposes. Thus, the present study proposes a simple and cost-effective method for OO extraction at the laboratory scale (LS) level. To validate the proposed methodology, industrial OO extraction (IS) was performed in parallel, using the same cultivars 'Galega vulgar' (GV), 'Cobrançosa' (COB) and 'Arbequina' (ARB) collected from the same orchards, within the same period. Obtained results showed highest extractability for COB and ARB, of about 53%, while GAL showed 50%. All produced OO showed values lower than the regulated limits for the physicochemical parameters (acidity, K232, K268 and ΔK), classifying them as extra virgin OO (EVOO). Highest total phenolic content was observed for COB, with no significant differences (p-value > 0.05) between extraction methods. Regarding fatty acid composition, oleic acid (C18:1) showed the lowest percentage for ARB, with about 66% and 68%, for LS and IS, respectively, and the highest for GV with about 72% for both LS and IS. Furthermore, all samples from both extraction methods were compared to the European Community Regulation, with fatty acid composition within the regulated levels for EVOO. This work showed promising results regarding extraction yields and OO extractability, as well as its quality parameters.

2.
Sci Rep ; 12(1): 17273, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241676

RESUMO

Arthropod declines have been linked to agricultural intensification. However, information about the impacts of intensification is still limited for many crops, as is our understanding of the responses of different arthropod taxa and trophic groups, thus hindering the development of effective mitigation measures. We investigated the impacts of olive farming intensification on canopy-dwelling arthropods in the Mediterranean region. Intensification involves the increased use of agrochemicals, mechanisation and irrigation, but also structural changes from traditional orchards with low densities of large and old trees, to intensive and superintensive orchards with high to very high densities of smaller and younger trees, respectively. Canopy arthropods were vacuum-sampled at 53 sites representing the three orchard intensification levels, in spring, summer and autumn 2017. We evaluated how the arthropod community varied across intensification levels, and in response to orchard structure, management and landscape context. We found no changes in the diversity of arthropod taxa across intensification levels after correcting for sample coverage, but arthropod abundance declined markedly along the intensification gradient. Decreased abundance was associated with changes in orchard structure, lower herbaceous cover, and higher herbicide and insecticide use. The abundance of a specialized olive pest was lower in landscapes with higher woodland cover. The negative effects of intensification were stronger in spring and summer than in autumn, and parasitoids and predators were particularly affected. Overall, results suggest that retaining herbaceous cover, reducing agrochemical inputs and preserving natural woody elements in the landscape, may contribute to mitigate impacts of olive farming intensification on canopy arthropods, particularly on beneficial species.


Assuntos
Artrópodes , Herbicidas , Inseticidas , Olea , Agricultura/métodos , Animais , Artrópodes/fisiologia , Ecossistema , Florestas , Herbicidas/farmacologia , Inseticidas/farmacologia
3.
Sensors (Basel) ; 22(16)2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-36015867

RESUMO

The information about where crops are distributed is useful for agri-environmental assessments, but is chiefly important for food security and agricultural policy managers. The quickness with which this information becomes available, especially over large areas, is important for decision makers. Methodologies have been proposed for the study of crops. Most of them require field survey for ground truth data and a single crop map is generated for the whole season at the end of the crop cycle and for the next crop cycle a new field survey is necessary. Here, we present models for recognizing maize (Zea mays L.), beans (Phaseolus vulgaris L.), and alfalfa (Medicago sativa L.) before the crop cycle ends without current-year field survey for ground truth data. The models were trained with an exhaustive field survey at plot level in a previous crop cycle. The field surveys begin since days before the emergence of crops to maturity. The algorithms used for classification were support vector machine (SVM) and bagged tree (BT), and the spectral information captured in the visible, red-edge, near infrared, and shortwave infrared regions bands of Sentinel 2 images was used. The models were validated within the next crop cycle each fifteen days before the mid-season. The overall accuracies range from 71.9% (38 days after the begin of cycle) to 87.5% (81 days after the begin cycle) and a kappa coefficient ranging from 0.53 at the beginning to 0.74 at mid-season.


Assuntos
Produtos Agrícolas , Zea mays , Agricultura , Algoritmos , Aprendizado de Máquina , Medicago sativa
4.
Trends Plant Sci ; 27(7): 637-645, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35039247

RESUMO

The growing demand for timber and the boom in massive tree-planting programs could mean the spreading of mismanaged tree plantations worldwide. Here, we apply the concept of ecological intensification to forestry systems as a viable biodiversity-focused strategy that could be critical to develop productive, yet sustainable, tree plantations. Tree plantations can be highly productive if tree species are properly combined to complement their ecological functions. Simultaneously considering soil biodiversity and animal-mediated biocontrol will be critical to minimize the reliance on external inputs. Integrating genetic, functional, and demographic diversity across heterogeneous landscapes should improve resilience under climate change. Designing ecologically intensified plantations will mean breaking the timber productivity versus conservation dichotomy and assuring the maintenance of key ecosystem services at safe levels.


Assuntos
Ecossistema , Árvores , Animais , Biodiversidade , Conservação dos Recursos Naturais , Agricultura Florestal , Florestas
5.
Sci Rep ; 11(1): 23662, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34880280

RESUMO

Pest control services provided by naturally occurring species (the so-called biocontrol services) are widely recognized to provide key incentives for biodiversity conservation. This is particularly relevant for vertebrate-mediated biocontrol services as many vertebrate species are of conservation concern, with most of their decline associated to landscape modification for agricultural purposes. Yet, we still lack rigorous approaches evaluating landscape-level correlates of biocontrol potential by vertebrates over broad spatial extents to better inform land-use and management decisions. We performed a spatially-explicit interaction-based assessment of potential biocontrol services in Portugal, using 1853 pairwise trophic interactions between 78 flying vertebrate species (birds and bats) and 53 insect pests associated to two widespread and economically valuable crops in the Euro-Mediterranean region, olive groves (Olea europaea subsp. europaea) and vineyards (Vitis vinifera subsp. vinifera). The study area was framed using 1004 square cells, each 10 × 10 km in size. Potential biocontrol services were determined at all those 10 × 10 km grid-cells in which each crop was present as the proportion of the realized out of all potential pairwise interactions between vertebrates and pests. Landscape correlates of biocontrol potential were also explored. Our work suggests that both birds and bats can effectively provide biocontrol services in olive groves and vineyards as they prey many insect pest species associated to both crops. Moreover, it demonstrates that these potential services are impacted by landscape-scale features and that this impact is consistent when evaluated over broad spatial extents. Thus, biocontrol potential by vertebrates significantly increases with increasing amount of natural area, while decreases with increasing area devoted to target crops, particularly olive groves. Overall, our study highlights the suitability of our interaction-based approach to perform spatially-explicit assessments of potential biocontrol services by vertebrates at local spatial scales and suggest its utility for integrating biodiversity and ecosystem services in conservation planning over broad spatial extents.


Assuntos
Aves/fisiologia , Quirópteros/fisiologia , Cadeia Alimentar , Insetos , Controle Biológico de Vetores/métodos , Animais , Biodiversidade , Produtos Agrícolas , Ecossistema , Portugal , Comportamento Predatório
6.
Micromachines (Basel) ; 12(5)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069654

RESUMO

Micro/nanomachines (MNMs) correspond to human-made devices with motion in aqueous solutions. There are different routes for powering these devices. Light-driven MNMs are gaining increasing attention as fuel-free devices. On the other hand, Plasmonic nanoparticles (NPs) and their photocatalytic activity have shown great potential for photochemistry reactions. Here we review several photocatalyst nanosystems, with a special emphasis in Plasmon induced photocatalytic reactions, as a novel proposal to be explored by the MNMs community in order to extend the light-driven motion of MNMs harnessing the visible and near-infrared (NIR) light spectrum.

7.
Nanoscale ; 13(3): 1738-1744, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33428700

RESUMO

Plasmonic reversible gas sensors are of paramount importance for the monitoring of indoor environments. Herein, we design and engineer a plasmonic foam, with a high surface area, confined inside a capillary glass tube for the live monitoring of carbon monoxide (CO) in closed environments using surface-enhanced resonance Raman scattering. The illumination of the sensor with light during the flow of air allows the live monitoring of the concentration of atmospheric CO through surface-enhanced resonance Raman scattering. The sensor was prepared with a detection range from 10 to 40 ppm, due to health needs. The results show a sensitive, selective, reversible and robust sensor applicable to the monitoring of CO levels but also to other gas species upon appropriate functionalization.

8.
Semin Arthritis Rheum ; 50(6): 1299-1306, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33065425

RESUMO

BACKGROUND: Non-infectious non-anterior uveitis (NINA) is a sight-threatening condition that often requires immunomodulatory drugs (IMDs) for its management. OBJECTIVES: To evaluate the published evidence regarding the use of IMDs in adult patients with NINA uveitis including intermediate (IU) and posterior uveitis (PU), panuveitis (PanU) and macular edema (ME). METHODS: We performed a systematic literature review. Search strategies were designed for Medline, Embase, and Cochrane Libraries for articles up to 2019 to evaluate the efficacy and safety of the IMDs. A quality assessment was performed using the Jadad Scale. RESULTS: Nineteen randomized clinical trials were selected from the 1,103 articles retrieved. Characteristics of patients, treatment dosages and outcome measures were heterogeneous. The outcomes most frequently analyzed were visual acuity (VA), macular thickness and vitreous haze (VH). Different IMDs were used at their usual dosages. Methotrexate (MTX), micophenolate mofetil, cyclosporine A (CsA), tacrolimus, adalimumab and sarilumab were effective in NINA uveitis. Rituximab combined with MTX was effective in PU. Interferon-ß was superior to MTX, albeit with more adverse events in IU with ME. CsA was similar to cyclophosphamide (Cyc) in Behçet uveitis. Tacrolimus was safer and similar to CsA. Cyc was effective in serpiginoid choroiditis, but when combined with azathioprine in PU, but did not improve VA. Secukinumab did not prevent NINA uveitis recurrences, although intravenously it showed a higher response rate than when used subcutaneously. Daclizumab did not show any benefits in Behçet NINA uveitis. CONCLUSION: Several IMDs and their combinations can be useful in treating NINA uveitis. The available studies were heterogeneous regarding patient characteristics and outcomes.


Assuntos
Edema Macular , Pan-Uveíte , Preparações Farmacêuticas , Uveíte Posterior , Uveíte , Adulto , Humanos , Edema Macular/tratamento farmacológico , Resultado do Tratamento , Uveíte/tratamento farmacológico , Uveíte Posterior/tratamento farmacológico
9.
Int J Qual Health Care ; 32(6): 356-363, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32427320

RESUMO

OBJECTIVE: The aim was to develop a clinical guideline for managing generalised anxiety disorder in Primary Health Care and Mental Health, using guideline adaptation methods. DESIGN: A clinical guideline was developed, following the methods of the ADAPTE group, and implemented in a Primary Health Care District and in Mental Health Services in Spain. SETTING: Regional University Hospital of Málaga and District of Primary Health Care Málaga-Guadalhorce (Spain). PARTICIPANTS: The participants were family physicians, psychiatrists and clinical psychologists. The phases of the process included definition of clinical scenarios, literature search and guidelines appraisal, elaboration of recommendations, conducting focus groups with users diagnosed with generalised anxiety disorder, linking the testimonials of users with recommendations, external review and implementation by multifaceted interventions. RESULTS: The final release included 49 Recommendations, of which 47 are from the 2011 NICE guidance for GAD and 2 of the 2011 NICE guideline for common mental disorder. Finally, seven recommendations needed to be adapted to the Spanish health care context, and three recommendations were excluded. CONCLUSIONS: A guideline aimed to improve the quality and effectiveness of the care provided to people with generalised anxiety disorder has been released. The use of adaptation methods has simplified the use of resources and time. This guideline and the process designed for its implementation constitute a suitable collection of resources for the improvement on detection and treatment of GAD in primary health care. Adaptation methods play a key role in the knowledge translation continuum.


Assuntos
Transtornos de Ansiedade/terapia , Guias de Prática Clínica como Assunto , Transtornos de Ansiedade/diagnóstico , Medicina Baseada em Evidências , Hospitais de Ensino , Humanos , Serviços de Saúde Mental , Atenção Primária à Saúde/normas , Qualidade da Assistência à Saúde , Espanha
10.
J Environ Manage ; 258: 110033, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929068

RESUMO

Roads disrupt landscape connectivity for many terrestrial mammals. These infrastructures can be barriers to movement thereby threatening population persistence. Nonetheless, small mammals may use road verges as habitat or corridor, thus increasing migration across intensively managed landscapes. However, in well-preserved habitats where road verges show a similar vegetation structure to surrounding areas, their role is still unknown. Road verges would have an important role as fine-scale connectivity providers for small mammals in a well-preserved habitat depending on land management on road surroundings. We aimed to quantify the effects of road verges and paved lanes on the fine-scale landscape connectivity for the wood mouse (Apodemus sylvaticus) in a well-preserved Mediterranean woodland. Additionally, we assessed the impact on connectivity of vegetation cutting on verges and of management in surrounding areas (i.e. firebreaks, grazing, ploughing and cork stripping). We quantified connectivity using graph theory based on two years of capture-recapture data. We compared a set of connectivity metrics (derived from the probability of connectivity index) in a road area and in a virtual roadless scenario. We found that the presence of the road reduced overall fine-scale landscape connectivity, acting as a partial barrier for wood mice movement. However, verges had a key role in promoting movement on road surroundings. Vegetation cutting on verges, and land ploughing in the surrounding landscape were the only management activities compromising connectivity. Our study supports the already known role of road verges as habitat corridors for small mammals. However, it goes beyond existing knowledge by quantifying the connectivity enhancement provided by road verges and demonstrating that this role is highly relevant even in well-preserved landscapes. Therefore, our findings emphasize the critical role of road verges and suggest important management options to enhance landscape connectivity for small mammals.


Assuntos
Ecossistema , Mamíferos , Animais , Florestas , Camundongos , Murinae
12.
Nanoscale ; 11(6): 2829-2839, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30676594

RESUMO

Herein, a series of N-doped carbon nanotube (CNx) samples were obtained by modifying the synthesis temperature. Consequently, the proportion of graphitic nitrogen (Ngraph) in the samples was systematically increased as a function of temperature. This allowed evaluation of the role of the CNx graphitic nitrogen in the oxygen reduction reaction (ORR). A correlation between the Ngraph content and the ORR onset potential was observed, which shifted to more positive potentials with an increase in kinetic current density (jk); this showed that Ngraph played a significant catalytic role in the ORR. The samples with high Ngraph content favored the two-electron pathway for the ORR not only in basic media (pH = 13) but also in neutral media (pH = 7), representing an attractive alternative for wastewater remediation through the on-site generation of H2O2. The energetic calculations showed that the formation of H2O2 must be favorable in the presence of graphitic nitrogen sites. Finally, the performance of the buckypaper arrangement was evaluated, and the CNx buckypaper showed a higher cathodic current peak as compared to CNx traditional ink dispersions. Overall, this study not only sheds light on the role of Ngraph in the ORR, but also demonstrates that CNx buckypaper is an efficient 3D electrode for electrocatalytic applications.

13.
PLoS One ; 13(4): e0194848, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29641610

RESUMO

Managing landscape connectivity is a widely recognized overarching strategy for conserving biodiversity in human-impacted landscapes. However, planning the conservation and management of landscape connectivity of multiple and ecologically distinct species is still challenging. Here we provide a spatially-explicit framework which identifies and prioritizes connectivity conservation and restoration actions for species with distinct habitat affinities. Specifically, our study system comprised three groups of common bird species, forest-specialists, farmland-specialists, and generalists, populating a highly heterogeneous agricultural countryside in the southwestern Iberian Peninsula. We first performed a comprehensive analysis of the environmental variables underlying the distributional patterns of each bird species to reveal generalities in their guild-specific responses to landscape structure. Then, we identified sites which could be considered pivotal in maintaining current levels of landscape connectivity for the three bird guilds simultaneously, as well as the number and location of sites that need to be restored to maximize connectivity levels. Interestingly, we found that a small number of sites defined the shortest connectivity paths for the three bird guilds simultaneously, and were therefore considered key for conservation. Moreover, an even smaller number of sites were identified as critical to expand the landscape connectivity at maximum for the regional bird assemblage as a whole. Our spatially-explicit framework can provide valuable decision-making support to conservation practitioners aiming to identify key connectivity and restoration sites, a particularly urgent task in rapidly changing landscapes such as agroecosystems.


Assuntos
Aves/fisiologia , Conservação dos Recursos Naturais , Ecossistema , Agricultura , Animais , Biodiversidade , Tomada de Decisões , Ecologia , Feminino , Florestas , Geografia , Masculino , Orientação Espacial , Portugal , Reprodutibilidade dos Testes , Espanha , Especificidade da Espécie
14.
Psychiatr Serv ; 68(8): 759-761, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28669282

RESUMO

Depression is the most frequent psychiatric disorder in primary health care, and the evidence shows that there is suboptimal management by primary care practitioners, perhaps owing to difficulties in decision making. Because clinical guidelines can improve decision making and management, a clinical guideline to manage depression in primary health care was developed in adherence to the ADAPTE method and was implemented in the Málaga Primary Health Care District in Spain. This column reports on the guideline development process, which produced a set of resources to improve the quality of primary health care-based depression care in Spain.


Assuntos
Tomada de Decisão Clínica , Depressão/terapia , Transtorno Depressivo/terapia , Guias de Prática Clínica como Assunto/normas , Atenção Primária à Saúde/normas , Humanos , Espanha
15.
Langmuir ; 32(27): 6815-24, 2016 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-27322018

RESUMO

The effect of a surrounding, dielectric, liquid environment on the dynamics of a suddenly electrified liquid drop is investigated both numerically and experimentally. The onset of stability of the droplet is naturally dictated by a threshold value of the applied electric field. While below that threshold the droplet retains its integrity, reaching to a new equilibrium state through damped oscillations (subcritical regime), above it electrical disruption takes place (supercritical regime). In contrast to the oscillation regime, the dynamics of the electric droplet disruption in the supercritical regime reveals a variety of modes. Depending on the operating parameters and fluid properties, a drop in the supercritical regime may result in the well-known tip streaming mode (with and without whipping instability), in droplet splitting (splitting mode), or in the development of a steep shoulder at the elongating front of the droplet that expands radially in a sort of "splashing" (splashing mode). In both splitting and splashing modes, the sizes of the progeny droplets, generated after the breakup of the mother droplet, are comparable to that of the mother droplet. Furthermore, the development in the emission process of the shoulder leading to the splashing mode is described as a parametrical bifurcation, and the parameter governing that bifurcation has been identified. Physical analysis confirms the unexpected experimental finding that the viscosity of the dynamically active environment is absent in the governing parameter. However, the appearance of the splitting mode is determined by the viscosity of the outer environment, when that viscosity overcomes a certain large value. These facts point to the highly nonlinear character of the drop fission process as a function of the droplet volume, inner and outer liquid viscosities, and applied electric field. These observations may have direct implications in systems where precise control of the droplet size is critical, such as in analytical chemistry and "drop-on-demand" processes driven by electric fields.

16.
Sensors (Basel) ; 15(12): 30539-44, 2015 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-26690158

RESUMO

Low concentrations of hazardous gases are difficult to detect with common gas sensors. Using semiconductor nanostructures as a sensor element is an alternative. Single ZnO nanowire gas sensor devices were fabricated by manipulation and connection of a single nanowire into a four-electrode aluminum probe in situ in a dual-beam scanning electron microscope-focused ion beam with a manipulator and a gas injection system in/column. The electrical response of the manufactured devices shows response times up to 29 s for a 121 ppm of H2 pulse, with a variation in the nanowire resistance appreciable at room temperature and at 373.15 K of approximately 8% and 14% respectively, showing that ZnO nanowires are good candidates to detect low concentrations of H2.

17.
Oecologia ; 173(4): 1649-60, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23852029

RESUMO

Widespread alterations in species distribution and abundance as a result of global environmental change include upwards and polewards shifts driven by local extinctions in the south or at lower elevations and colonizations of newly available habitat elements in the north or at higher elevations. Although cumulative changes on patterns of community composition are also expected, studies following a community-level approach are still scarce. Here, we estimate changes in abundance and distribution of bumblebee (Bombus spp.) species over two decades along an elevational gradient to test whether these changes entailed concomitant alterations on patterns of community composition. Bumblebee species showed an overall trend to shift uphill their upper- or lower-elevational boundaries, resulting in narrower elevational ranges from one period to another, coincident with a regional warming of ca. 0.9 °C. Changes in elevational ranges were, however, mainly related to retractions of the lower limit of species distribution, rather than to variations in their upper elevational limit. Species turnover was associated with colonization and extinction events and also with variability in the relative abundance of short-, medium- and long-tongued species along the elevational gradient. Extinctions were especially relevant at medium elevations, while only communities at higher elevations had a positive net outcome between colonization and extinction events. The combination of these effects resulted in the homogenization of bumblebee assemblages, especially between medium and upper elevations. The changes reported in our study strongly match with predictions of global change driving elevational shifts in species distribution and provide the first evidence of elevational changes in bumblebees at both species and community level.


Assuntos
Altitude , Abelhas/classificação , Ecossistema , Animais , Espanha
18.
Injury ; 44(9): 1191-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23294894

RESUMO

OBJECTIVE: To report the clinical and radiological characteristics, management and outcomes of traumatic ascending aorta and aortic arch injuries. METHODS: Historic cohort multicentre study including 17 major trauma patients with traumatic aortic injury from January 2000 to January 2011. RESULTS: The most common mechanism of blunt trauma was motor-vehicle crash (47%) followed by motorcycle crash (41%). Patients sustaining traumatic ascending aorta or aortic arch injuries presented a high proportion of myocardial contusion (41%); moderate or greater aortic valve regurgitation (12%); haemopericardium (35%); severe head injuries (65%) and spinal cord injury (23%). The 58.8% of the patients presented a high degree aortic injury (types III and IV). Expected in-hospital mortality was over 50% as defined by mean TRISS 59.7 (SD 38.6) and mean ISS 48.2 (SD 21.6) on admission. Observed in-hospital mortality was 53%. The cause of death was directly related to the ATAI in 45% of cases, head and abdominal injuries being the cause of death in the remaining 55% cases. Long-term survival was 46% at 1 year, 39% at 5 years, and 19% at 10 years. CONCLUSIONS: Traumatic aortic injuries of the ascending aorta/arch should be considered in any major thoracic trauma patient presenting cardiac tamponade, aortic valve regurgitation and/or myocardial contusion. These aortic injuries are also associated with a high incidence of neurological injuries, which can be just as lethal as the aortic injury, so treatment priorities should be modulated on an individual basis.


Assuntos
Acidentes de Trânsito , Aorta Torácica/lesões , Aorta/lesões , Traumatismo Múltiplo/mortalidade , Ferimentos não Penetrantes/complicações , Adulto , Idoso , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Veículos Automotores , Motocicletas , Traumatismo Múltiplo/complicações , Traumatismo Múltiplo/terapia , Prognóstico , Ferimentos não Penetrantes/epidemiologia , Ferimentos não Penetrantes/mortalidade , Ferimentos Penetrantes/complicações , Ferimentos Penetrantes/epidemiologia , Ferimentos Penetrantes/mortalidade
20.
Sci Rep ; 2: 363, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22509463

RESUMO

The establishment of covalent junctions between carbon nanotubes (CNTs) and the modification of their straight tubular morphology are two strategies needed to successfully synthesize nanotube-based three-dimensional (3D) frameworks exhibiting superior material properties. Engineering such 3D structures in scalable synthetic processes still remains a challenge. This work pioneers the bulk synthesis of 3D macroscale nanotube elastic solids directly via a boron-doping strategy during chemical vapour deposition, which influences the formation of atomic-scale "elbow" junctions and nanotube covalent interconnections. Detailed elemental analysis revealed that the "elbow" junctions are preferred sites for excess boron atoms, indicating the role of boron and curvature in the junction formation mechanism, in agreement with our first principle theoretical calculations. Exploiting this material's ultra-light weight, super-hydrophobicity, high porosity, thermal stability, and mechanical flexibility, the strongly oleophilic sponge-like solids are demonstrated as unique reusable sorbent scaffolds able to efficiently remove oil from contaminated seawater even after repeated use.

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