Mid-Infrared Imaging of NGC 6334 I

We present high-resolution (<0.5") mid-infrared Keck II images of individual sources in the central region of NGC 6334 I. We compare these images to images at a variety of other wavelengths from the near infrared to cm radio continuum and speculate on the nature of the NGC 6334 I sources. We assert that the cometary shape of the UCHII region here, NGC 6334 F, is due to a champagne-like flow from a source on the edge of a molecular clump and not a due to a bow shock caused by the supersonic motion of the UCHII region through the interstellar medium. The mid-infrared emission in concentrated into an arc of dust that define the boundary between the UCHII region and the molecular clump. This dust arc contains a majority of the masers in the region. We discuss the nature of the four near-infrared sources associated with IRS-I 1, and suggest that one of the sources, IRS1E, is responsible for the heating and ionizing of the UCHII region and the mid-infrared dust arc. Infrared source IRS-I 2, which has been thought to be a circumstellar disk associated with a linear distribution of methanol masers, is found not to be directly coincident with the masers and elongated at a much different position angle. IRS-I 3 is found to be a extended source of mid-infrared emission coming from a cluster of young dusty sources seen in the near-infrared.Comment: Accepted for publication by the Astrophysical Journal, 27 pages, 9 figure

Recurrent temporal bone tenosynovial giant cell tumor with chondroid metaplasia: the use of imaging to assess recurrence

Tenosynovial giant cell tumor (TGCT) is a benign proliferative lesion of unclear etiology. It is predominantly monoarticular and involves the synovium of the joint, tendon sheath, and bursa. TGCT of the temporomandibular joint (TMJ) is rare and aggressive resulting in destruction of surrounding structures. The diagnosis may be suggested by imaging, mainly by the MR features and PET/CT, and confirmed by histopathology. We describe the case of a 50-year-old man who presented with right-sided hearing loss, tinnitus and TMJ pain. Pathology revealed tenosynovial giant cell tumor with chondroid metaplasia. Six years later he developed a recurrence, which was documented to our knowledge for the first time with CT, MR and FDG PET/CT imaging

Hierarchical Porous Polybenzimidazole Microsieves: An Efficient Architecture for Anhydrous Proton Transport via Polyionic Liquids

Liquid-induced phase-separation micromolding (LIPSµM) has been successfully used for manufacturing hierarchical porous polybenzimidazole (HPBI) microsieves (42-46% porosity, 30-40 µm thick) with a specific pore architecture (pattern of macropores: ~9 µm in size, perforated, dispersed in a porous matrix with a 50-100 nm pore size). Using these microsieves, proton-exchange membranes were fabricated by the infiltration of a 1H-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide liquid and divinylbenzene (as a cross-linker), followed by in situ UV polymerization. Our approach relies on the separation of the ion conducting function from the structural support function. Thus, the polymeric ionic liquid (PIL) moiety plays the role of a proton conductor, whereas the HPBI microsieve ensures the mechanical resistance of the system. The influence of the porous support architecture on both proton transport performance and mechanical strength has been specifically investigated by means of comparison with straight macroporous (36% porosity) and randomly nanoporous (68% porosity) PBI counterparts. The most attractive results were obtained with the poly[1-(3H-imidazolium)ethylene]bis(trifluoromethanesulfonyl)imide PIL cross-linked with 1% divinylbenzene supported on HPBI membranes with a 21-µm-thick skin layer, achieving conductivity values up to 85 mS cm-1 at 200 °C under anhydrous conditions and in the absence of mineral acids

Cartilage and bone regeneration: how close are we to bedside?

The treatment/regeneration of bone and cartilage diseases or defects, whether induced by rheumatism, joint dysplasia, trauma, or surgery presents great challenges that have not been fully solved by the current therapies. In the last few years, tissue engineering and regenerative medicine have been proposing advanced tools and technologies for bone and cartilage tissue regeneration, and some of which have successfully reached the market. Beyond the source of cells, the creation of superior structures for replacing defective bone and cartilage requires strong research in biomechanical signaling and synthesis of advanced biomaterials to mimic human tissues at the most varied levels. Natural and synthetic polymers, bioresorbable inorganic materials, and composites have been investigated for its potential as scaffolding materials with enhanced mechanical and biological properties. Porous scaffolds, hydrogels, and fibers are the most commonly biomimetic structures used for bone and cartilage tissue engineering. Herein, the concepts and current treatment strategies for bone and cartilage repair, as well as biomimetic strategies for bone and cartilage tissue engineering are overviewed. A global review of the ongoing clinical trials and of the scaffolds commercially available for the repair of osteochondral tissue is also presented.(undefined

Effect of pH of H2O2 solutions on the morphology and wear resistance of human dental enamel: an AFM study

Abstract in proceedings of the Fourth International Congress of CiiEM: Health, Well-Being and Ageing in the 21st Century, held at Egas Moniz’ University Campus in Monte de Caparica, Almada, from 3–5 June 2019.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.info:eu-repo/semantics/publishedVersio

Synthesis and characterization of aryl-substituted BODIPY dyes displaying distinct solvatochromic singlet oxygen photosensitization efficiencies

Three BODIPY derivatives substituted at meso position by aryl (phenyl or N,N-dimethylaminonaphthyl) groups and functionalized at position 2 with electron-withdrawing formyl or electron deficient benzimidazole heterocycle were synthesized and completely characterized by the usual spectroscopic techniques. A comprehensive photophysical study showed a remarkable enhancement of the singlet oxygen sensitization quantum yield for meso-substituted dimethylaminonaphthyl BODIPY with the decrease of the dielectric constant of the solvent (0.02–0.04 for dimethylsulfoxide vs. 0.84 in toluene). In toluene the triplet state formation for the aminonaphthyl substituted BODIPY's was found to be mediated by the intramolecular charge transfer state (ICT), whereas in polar solvents triplet state formation is hindered by fast recombination of the ICT state. Pump-probe transient absorption spectroscopy was used to characterize the photoinduced dynamics of the BODIPY derivatives from the femtosecond to the nanosecond time scale.FCT - Laserlab-Europe(REDE/1517/RMN/2005)This work was supported by the Fundação para a Ciˆencia e a Tec nologia (FCT), Portuguese Agency for Scientific Research, through the Coimbra Chemistry Centre projects UIDB/00313/2020 and UIDP/ 00313/2020 and through the Centro de Química (CQUM), project UID/ QUI/00686/2020. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Reequipment, contract REDE/ 1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT. Raquel C. R. Gonçalves acknowledges FCT for funding (SFRH/BD/ 05278/2020). The research leading to these results has received funding from Laserlab-Europe (grant agreement no. 284464, EC’s Seventh Framework Programme)

Wear of zirconia/leucite glass-ceramics composites: A chewing simulator study

Leucite and zirconia are commonly used in the production of prosthetic dental materials. Leucite presents attractive optical properties but low toughness and wear resistance, which limits its use. Zirconia has much higher toughness, but due to aesthetic reasons and ageing issues, needs to be glass veneered. Chipping of such veneer is usually responsible for the abnormal wear induced on the antagonist teeth. Leucite reinforced with 25% of nano-zirconia is a promising alternative to overcome these issues, allowing the production of dental resto- rations without veneer. This study aims to investigate if leucite-zirconia composites have suitable optical, me- chanical and tribological properties to be used in dental restoration. Samples with different compositions of leucite and/or nano-zirconia were produced by unidirectional compression and characterized concerning den- sity, surface morphology, roughness, hardness, toughness, and translucency. Wear tests were performed in a chewing simulator using human cusps as counterbodies. Tests were also performed in glazed zirconia for com- parison. 25% ZrO2 leads to the lowest wear of the tribological pair among the studied systems, except 100% ZrO2. This can be attributed to the toughening effect of zirconia and reduced size of third body particles. Abrasion was the main wear mechanism observed in this pair. In addition, this was the composite that presented the highest translucency.info:eu-repo/semantics/publishedVersio

Fault systems of Upper Triassic outcrops in Coimbra region

Poster apresentado ao VIII Congresso Nacional de Geologia, em Braga (9-16 de Julho 2010)A partir da análise estrutural dos sistemas de falhas em afloramentos do Triásico Superior localizados na região de Coimbra, na Bacia Lusitânica, foi possível definir famílias e sub-famílias de falhas. Este trabalho permitiu reconhecer que os acidentes tectónicos extensionais que afectaram os depósitos do Triásico nesta região, durante toda a evolução do contexto tectónico do Mesozóico foram sistematicamente reactivados nos regimes compressivos do final do Mesozóico e Cenozóico.From the structural analysis of the fault system in the Upper Triassic outcrops, located in the Coimbra region of the Lusitanian Basin, it was possible to define fault families and subfamilies. This recognizing that the extensional tectonic strutures that affected the Triassic deposits from this region, were systematically reactivated during the Late Mesozoic and Cenozoic compressive regimes