Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Orthop Rev (Pavia) ; 14(1): 31843, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38350018

RESUMO

Background: We aimed to systematically review all papers examining floating elbow injuries in adults. Material and Methods: MEDLINE, Cochrane Bone, Joint and Muscle Trauma, PROSPERO, and Scopus databases were searched up to August 31, 2020. Included studies had as a primary or secondary outcome the functional outcomes after a floating elbow injury on patients aged 17 or older. Methodological quality of the included studies was assessed. Results: Thirty-two studies met the inclusion criteria. Patients were male at 73,1%. Median age of the patients was 33,0 years and median time of follow-up was 19,5 months. Articular surfaces were affected at 24,4%, whereas 51,2% of the fractures was open. Approximately, 34,9% of the patients suffered neural injury. Ipsilateral and multiple-system injuries were present in 34,8% and 76,3 % of the cases, respectively. Multivariate analysis showed that intra-articular and nerve damage, open fractures and multi-system injuries affected range of motion, union and complications. Sex, age, vascular damage and ipsilateral injuries of the patient did not adversely impact the outcome. All of the included studies were classified as very-low quality of evidence. Conclusions: The current knowledge regarding the characteristics of floating elbow in adults is limited, albeit we were able to provide possible pre-operative predictor outcomes.

2.
J Mater Sci ; 56(33): 18440-18452, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720179

RESUMO

The microstructural and optical reflectivity response of photonic SiO2/TiO2 nanomultilayers have been investigated as a function of temperature and up to the material system's melting point. The nanomultilayers exhibit high, broadband reflectivities up to 1350 °C with values that exceed 75% for a 1 µm broad wavelength range (600-1600 nm). The optimized nanometer sized, dielectric multilayers undergo phase transformations from anatase TiO2 and amorphous SiO2 to the thermodynamically stable phases, rutile and cristobalite, respectively, that alter their structural morphology from the initial multilayers to that of a scatterer. Nonetheless, they retain their photonic characteristics, when characterized on top of selected substrate foils. The thermal behavior of the nanometer sized multilayers has been investigated by differential thermal analysis (DTA) and compared to that of commercially available, mm-sized, annealed powders. The same melting reactions were observed, but the temperatures were lower for the nm-sized samples. The samples were characterized using X-ray powder diffraction before DTA and after annealing at temperatures of 1350 and 1700 °C. The microstructural evolution and phase compositions were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements. The limited mutual solubility of one material to another, in combination with the preservation of their optical reflectivity response even after annealing, makes them an interesting material system for high-temperature, photonic coatings, such as photovoltaics, aerospace re-entry and gas turbines, where ultra-high temperatures and intense thermal radiation are present. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10853-021-06557-y.

3.
Minerals (Basel) ; 10(4): 348, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32724664

RESUMO

Medicinal earths are an important and yet, so far, little scientifically explored archaeological resource. They are almost always identified by their source locality. Our work over the last few years has focused on their chemical and mineralogical characterization and their testing as anti-bacterials. This paper presents the results of the mineralogical analysis and antibacterial testing of six medicinal earths, bole or Terra Sigillata (stamped earth) of unknown date and provenance in the Pharmacy Museum of the University of Basel. Only one of them, a red (Armenian?) 'bole', was found to be antibacterial against both Gram-positive and Gram-negative bacteria. A yellow powder of Terra Tripolitania was mildly antibacterial and against one pathogen only. We argue that medicinal earths are in a pivotal place to bridge the gap between currently dispersed pieces of information. This information relates to: (a) their nature, attributes, and applications as described in the texts of different periods, (b) the source of their clays and how best to locate them in the field today, and (c) the methods employed for their beneficiation, if known. We propose that work should be focused primarily onto those medicinal earths whose clay sources can be re-discovered, sampled and assessed. From then on, a parallel investigation should be initiated involving both earths and their natural clays (mineralogy at bulk and nano-sized levels, bio-geochemistry, microbiological testing). We argue that the combined study can shed light into the parameters driving antibacterial action in clays and assist in the elucidation of the mechanisms involved.

4.
ACS Appl Mater Interfaces ; 12(8): 9925-9934, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32003964

RESUMO

A simple and thermally stable photonic heterostructure exhibiting high average reflectivity (⟨R⟩ ≈ 88.8%) across a broad wavelength range (920-1450 nm) is presented. The design combines a thin, highly reflective and broadband metallic substrate (Ta) with an optimized dielectric coating (10 layers) to create an enhanced reflector with improved optical and thermal properties compared to its constituents. The heterostructure exhibits temperature-reversible reflective properties up to 1000 °C. In order to take advantage of the high reflectivity and temperature stable properties of this coating, in a wide range of non-photonic composite materials, we have fabricated heterostructure platelets as additives. By impregnating these additives into other types of materials, their response can be photonically enhanced.  Platelets of such a heterostructure have been introduced inside an organic matrix to increase its broadband reflection performance. The platelet-impregnated matrix displays an average reflectivity improvement from 5% to an average of 55% over a 1000 nm range, making it a suitable additive for next generation thermal protection systems (TPS).

5.
Nat Commun ; 6: 7100, 2015 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-25960012

RESUMO

The combination of intense solar radiation and soil desiccation creates a short circuit in the biogeochemical carbon cycle, where soils release significant amounts of CO2 and reactive nitrogen oxides by abiotic oxidation. Here we show that desert soils accumulate metal superoxides and peroxides at higher levels than non-desert soils. We also show the photogeneration of equimolar superoxide and hydroxyl radical in desiccated and aqueous soils, respectively, by a photo-induced electron transfer mechanism supported by their mineralogical composition. Reactivity of desert soils is further supported by the generation of hydroxyl radical via aqueous extracts in the dark. Our findings extend to desert soils the photogeneration of reactive oxygen species by certain mineral oxides and also explain previous studies on desert soil organic oxidant chemistry and microbiology. Similar processes driven by ultraviolet radiation may be operating in the surface soils on Mars.


Assuntos
Processos Fotoquímicos , Espécies Reativas de Oxigênio/química , Solo/química , Clima Desértico , Metais/química , Oxirredução , Peróxidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...