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1.
Front Res Metr Anal ; 6: 801789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35141462

RESUMO

Addressing sustainability issues requires a radical systemic change across multiple dimensions, including policy, culture, and civil society. This also implies that no blueprints for governing critical sustainability issues both at the local and global levels exist. As a result, rather than imposing decisions, policymakers should engage in a learning process. In this paper, we contend that appropriate policies should be developed and fine-tuned over time through a collective, social endeavour. To support this hypothesis, the study focuses on a shared methodology based on backcasting, a specific type of foresight, to facilitate policy learning (and thus policymaking) within a wide range of territories, regardless of their wealth, geographic characteristics and internal political organisation. This methodology was developed over a three-year period as part of the Territorial Strategies for Innovation (TSI) programme. The overall objective of our assignment was to build capacity and raise awareness within the EU's Overseas Countries and Territories about policymaking and implementation of innovative approaches to development. This innovative approach, which incorporates a systemic innovation perspective, highlights new options and opportunities for adopting and implementing adequate policies to positively impact sustainable development and long-term transformative change. Using empirical examples from Anguilla, Curaçao, and New Caledonia, the paper focuses on the learning processes required to deal with complexity and uncertainty in these remote territories. We conclude by discussing the potential implications of this foresight approach for the sustainable development and transformation of other less-favoured regions and territories.

2.
Skeletal Radiol ; 37(6): 511-7, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18404267

RESUMO

OBJECTIVE: To evaluate the T2 mapping of patellar articular cartilage in patients with osteoarthritis using gradient and spin-echo (GRASE) magnetic resonance (MR) imaging. MATERIALS AND METHODS: After the imaging of a phantom consisting of two sealed 50-ml test objects with different concentrations (30% and 90% weight/volume) of copper sulphate, the T2 mapping of patellar articular cartilage was performed in 35 patients (21 male and 14 female; mean age +/- SD 42+/-17 years) with moderate degree of patellar osteoarthritis. Turbo-spin-echo (TSE) (TR milliseconds/ minimum-maximum TE milliseconds 3,000/15-120; total acquisition time 5 min 52 s) and GRASE (TR milliseconds/ minimum-maximum TE milliseconds 3,000/15-120; total acquisition time 1 min 51 s) were employed. In each patient patellar cartilage was segmented at nine locations (three superior, three central, and three inferior) by manually defined regions of interest. T2 relaxation times were calculated using a linear fit applied to the logarithm of signal intensity decay. RESULTS: In the phantom the T2 values measured by GRASE were similar to those measured by MR spectroscopy (test object 1: 48.1 ms vs 51 ms; test object 2: 66.8 ms vs 71 ms; P>0.05, Wilcoxon test). In patients GRASE and TSE-derived T2 values demonstrated good agreement (mean difference +/- SD, 1.81+/-3.63 ms). The within-patient coefficient of variation was 22% for TSE and 23% for GRASE. CONCLUSION: Fast T2 mapping of the patellar articular cartilage can be performed with GRASE within a third of the time of that of standard sequences.


Assuntos
Cartilagem Articular/patologia , Imageamento por Ressonância Magnética , Osteoartrite do Joelho/patologia , Patela/patologia , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
3.
J Biomed Mater Res A ; 83(2): 345-53, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17450576

RESUMO

Proton nuclear magnetic resonance (NMR) relaxometry can give informations about hydrogel scaffold properties. As these properties can be modified with culture time and conditions according to scaffold biodegradability and new tissue biosynthesis, the aim of this research was to test the efficiency of this noninvasive NMR technique in the follow-up of 3D cultures for tissue engineering. The distributions of proton relaxation times T1 and T2 have been measured on cylindrical gel samples of different types of alginate, in the presence or absence of hyaluronate, in gels or bioconstructs with encapsulated chondrocytes cultured for 30 days in normal or reduced weight conditions. It was found that T2 increases with the mannuronate/guluronate ratio in alginate samples and with the presence of hyaluronate. The distributions of both T1 and T2 result wider for bioconstructs cultured in normal gravity than for those cultured in reduced weight conditions. Neither cell growing nor collagen production but only GAG neosynthesis have been demonstrated in our experimental conditions. In conclusion, T2 is sensitive to the gel properties (possibly to the rigidity of macromolecular components). The homogeneity of bioconstructs can be monitored by the distribution of T1 and T2. We propose that nonspatially resolved NMR relaxometry can efficiently be used in monitoring tissue development in a biodegradable scaffold for tissue engineering.


Assuntos
Alginatos/metabolismo , Materiais Biocompatíveis/metabolismo , Condrócitos/metabolismo , Animais , Condrócitos/citologia , Colágeno/metabolismo , DNA/metabolismo , Ácido Glucurônico/metabolismo , Glicosaminoglicanos/metabolismo , Ácidos Hexurônicos/metabolismo , Espectroscopia de Ressonância Magnética , Prótons , Suínos , Fatores de Tempo
4.
Carbohydr Res ; 340(3): 439-47, 2005 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-15680599

RESUMO

The bacterial species Enterobacter amnigenus was isolated from sugar beets harvested in Finland. It produced an exopolysaccharide rich in l-fucose, which gave viscous water solutions. Its primary structure was determined mainly by NMR spectroscopy and ESIMS of oligosaccharides and a polysaccharide with decreased molecular weight, obtained by Smith degradation of the O-deacetylated native polymer [carbohydrate structure: see text]


Assuntos
Enterobacter/metabolismo , Polissacarídeos Bacterianos/química , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência Molecular , Estrutura Molecular , Oligossacarídeos/química
5.
Spine (Phila Pa 1976) ; 30(2): 174-80, 2005 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-15644752

RESUMO

STUDY DESIGN: Graded endplate injuries were performed in porcine lumbar discs. The effects of such injuries were compared to control animals in which a sham operation was performed. OBJECTIVES: To investigate the effects of endplate injuries on disc tissue. SUMMARY OF BACKGROUND DATA: Studies have shown that injuries of vertebral endplates are frequently found at autopsy. However, little is known on the effects of acute injuries of vertebral endplates in vivo. METHODS: Ten domestic pigs were included in the study group. Under general anesthesia, the lower three discs of the lumbar spine were exposed and randomly submitted to multiple endplate injuries, isolated endplate injury, and no treatment. A sham operation was performed in 5 pigs used as control group. Animals were killed 7 months after surgery and the harvested lumbar spine submitted to MRI investigations, histologic, and biochemical analysis. RESULTS: MRI showed that all but one discs treated with multiple endplate injuries were markedly degenerated while, of the discs treated with an isolated injury, one was markedly degenerated, five slightly degenerated and two were normal (P = 0.01). Histologic analysis showed severe changes in discs treated with multiple injuries. In those who had an isolated injury, changes were less severe and essentially limited to the posterior anulus or the inner anterior anulus. Biochemical analysis showed an inverse correlation between uronate content in the nucleus pulposus and severity of endplate injuries. CONCLUSIONS: Injuries of vertebral endplates in porcine discs were found to cause degenerative changes in the disc tissue on MRI, histologic, and biochemical investigations. The severity of such degenerative changes was related to the severity of endplate injuries. Injuries of vertebral endplate may be one of the pathomechanisms leading to early changes in the disc matrix and eventually to abnormal biomechanical behavior of the whole disc. The present animal model seems to be a suitable experimental model for disc degeneration.


Assuntos
Deslocamento do Disco Intervertebral/patologia , Disco Intervertebral/patologia , Vértebras Lombares/lesões , Sacro/lesões , Fraturas Salter-Harris , Animais , Modelos Animais de Doenças , Lâmina de Crescimento/diagnóstico por imagem , Lâmina de Crescimento/metabolismo , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/metabolismo , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/metabolismo , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/metabolismo , Imageamento por Ressonância Magnética , Radiografia , Sacro/diagnóstico por imagem , Sacro/metabolismo , Suínos
6.
IEEE Trans Biomed Eng ; 50(8): 967-77, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12892324

RESUMO

Magnetic resonance (MR) imaging has recently been proposed for assessing osteoporosis and predicting fracture risks. However, accurate acquisition techniques and image analysis protocols for the determination of the trabecular bone structure are yet to be defined. The aim of this study was to assess the potential of projection reconstruction (PR) MR microscopy in the analysis of the three-dimensional (3-D) architecture of trabecular bone and in the prediction of its biomechanical properties. High-resolution 3-D PR images (41 x 41 x 82 microm3 voxels) of 15 porcine trabecular bone explants were analyzed to determine the trabecular bone volume fraction (Vv), the mean trabecular thickness (Tb.Th), and the mean trabecular separation (Tb.Sp) using the method of directed secants. These parameters were then compared with those derived from 3-D conventional spin-echo microimages. In both cases, segmentation of the high-resolution images into bone and bone marrow was obtained using a spatial adaptive threshold. The contemporary inclusion of Vv, Tb.Th and 1/Tb.Sp in a multiple regression analysis significantly improved the prediction of Young's modulus (YM). The parameters derived from the PR spin-echo images were found to be stronger predictors of YM (R2 = 0.94, p = 0.004) than those derived from conventional spin-echo images (R2 = 0.79, p = 0.051). Our study indicates that projection reconstruction MR microscopy appears to be more accurate than the conventional Fourier transform method in the quantification of trabecular bone structure and in the prediction of its bioimechanical properties. The proposed PR approach should be readily adaptable to the in vivo MRI studies of osteoporosis.


Assuntos
Úmero/citologia , Úmero/fisiologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Animais , Imagem Ecoplanar/métodos , Elasticidade , Aumento da Imagem/métodos , Técnicas In Vitro , Microscopia/métodos , Imagens de Fantasmas , Estresse Mecânico , Suínos , Suporte de Carga/fisiologia
8.
Eur Radiol ; 12(4): 814-23, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11960232

RESUMO

Cartilage degenerative diseases, such as osteoarthritis, affect million of people. Magnetic resonance imaging is presently the most accurate imaging modality in evaluating the state of hyaline cartilage; however, clinical MRI does not accurately reveal early degenerative alterations in cartilage, due mainly to low spatial resolution. Magnetic resonance microscopy (MRM, or microMRI) appears exceptionally well suited to the in vitro or ex vivo study of this heterogeneous tissue, due to its high spatial resolution; however, despite this, further studies are necessary to evaluate the potential of MRM in the detection of early cartilage damage. Herein we briefly review the current applications of MRM in the study of hyaline cartilage. In particular, we review the MR appearance of hyaline cartilage on high-resolution images, the different MRM techniques used to image normal and enzymatically or chemically degraded cartilage and the potential use of contrast agents. The future directions and the relevance of MRM findings for a better understanding of cartilage physiology in health and disease are also discussed.


Assuntos
Cartilagem Articular/patologia , Espectroscopia de Ressonância Magnética , Cartilagem Articular/metabolismo , Meios de Contraste , Humanos , Espectroscopia de Ressonância Magnética/métodos
9.
Biomaterials ; 23(4): 1161-7, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11791920

RESUMO

Structural properties of several cross-linked hyaluronan derivatives, obtained by scanning electron microscopy, monodimensional NMR microscopy and small angle X-ray scattering of synchrotron radiation, are presented and compared with those observed for non-modified hyaluronic acid, used as a reference material. The experimental results, obtained in different media, showed a consistent picture of the synthesized matrices. In particular, the presence of zones of denser polymeric material observed by electron microscopy resulted in a higher transversal relaxation rate of the bulk water protons as well as in a decrease of the diffusion coefficient obtained by NMR microscopy. Moreover, the presence of polymer junction zones gave rise to the appearance of a well-defined correlation peak in the pattern of intensity of the scattered X-radiation.


Assuntos
Materiais Biocompatíveis/química , Ácido Hialurônico/química , Reagentes de Ligações Cruzadas , Espectroscopia de Ressonância Magnética , Teste de Materiais , Microscopia Eletrônica de Varredura , Estrutura Molecular , Espalhamento de Radiação , Raios X
10.
J Gravit Physiol ; 9(1): P173-4, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15002535

RESUMO

A major concern for long-term spaceflight is the effect of microgravity on bone structure and mass as a loss of cortical and trabecular bone volume and density, both of which can lead to decreased bone strength and an increased risk of bone fracture. Detailed analysis of the three-dimensional structure of trabecular bone, and its relation to bone strength has become feasible only recently using high-resolution 3D imaging techniques. In particular, magnetic resonance microscopy (MRM) has proved to be particularly useful for the ex vivo evaluation of the complex architecture of trabecular bone. In this study, we describe the use of two different MRM-based methods for the quantitative evaluation of the three-dimensional structure of trabecular bone explants and for the prediction of their biomechanical properties. The in vivo application of such methods is also discussed.

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