One-step microwave synthesis of palladium-carbon nanotubes hybrids with improved catalytic performance

7 páginas, 7 figuras, 3 tablas.-- El pdf del artículo es la versión pre-print.A fast and easy one-step linker-free approach for the synthesis of palladium nanoparticle/multiwall carbon nanotube (Pd-NP/MWCNT)hybrid materials is described using microwave irradiation for the effective decomposition of Pd2dba3 complex in the presence of MWCNTs. High loadings of Pd nanoparticles (up to 40 wt.%) having sizes between 3 and 5 nm are deposited on the surface of MWCNTs within a time of only 2 minutess. The Pd-NP/MWCNT materials serve as efficient catalysts in C-C coupling as well as in hydrogenation reactions, all characterized by high conversion rates using a small amount of catalysts, high turnover frequency values and good recyclbility.Financial support from the Spanish Ministerio de Ciencia e Innovación (MICINN) and the European Regional Development Fund (ERDF) under projects CTQ2008-01784 and MAT2007-66927-C02-01, and the Gobierno de Aragón (DGAPI086- 08) is gratefully acknowledged. M.C. thanks MICINN for her Grant No. BES-2008-003503.Peer reviewe

Sonographic features differentiating follicular thyroid cancer from follicular adenoma–a meta-analysis

Certain ultrasound features are associated with an increased risk of thyroid malignancy. However, they were studied mainly in papillary thyroid cancers (PTCs); these results cannot be simply extrapolated for the differentiation of follicular thyroid adenomas and cancers (FTAs and FTCs). The aim of our study was to perform a meta-analysis to identify sonographic features sug-gesting malignancy in the case of follicular lesions, potentially differentiating FTA and FTC. We searched thirteen databases from January 2006 to December 2020 to find all relevant, full-text jour-nal articles written in English. Analyses assessed the accuracy of malignancy detection in case of follicular lesions, potentially differentiating FTA and FTC included the odds ratio (OR), sensitivity, specificity, positive and negative predictive values. A random-effects model was used to summarize collected data. Twenty studies describing sonographic features of 10,215 nodules met the inclusion criteria. The highest overall OR

Clinical studies on treatment and follow-up in differentiated thyroid carcinoma

In this thesis several studies on the treatment and follow-up of differentiated thyroid carcinoma are reported. Several results are worth noticing. In this thesis it is shown that administering 40 MBq I-131 before I-131 ablation reduces the success rate of I-131 ablation by half. Furthermore, it is shown that successful ablation is an important indicator of favourable prognosis: recurrence and mortality rates are clearly lower among those in whom the first, ablative I-131 activity is successful in eradicating all disease. It is shown that patients can effectively be considered 'cured' after successful ablation. Another noteworthy results in this thesis concerns the finding that Heterophile antibodies interfere in the measurement of thyroglobulin (a tumour marker used in the follow-up of differentiated thyroid carcinoma) in a significant percentage of patients; so much so that treatment should be changed in nearly 10 percent of patients. The thesis concludes with a discussion on the implications of the current findings as well as a view on the future of differentiated thyroid carcinoma research

Impact assessment of the European biofuel directive on land use and biodiversity

This paper presents an assessment of the potential impact of the EUs biofuel directive on European land use and biodiversity. In a spatially explicit analysis, it is determined which ecologically valuable land use types are likely to be directly replaced by biofuel crops. In addition, it is determined which land use types may be indirectly replaced by biofuel crops through competition over land between biofuel and food crops. Four scenarios of land use change are analyzed for the period 2000-2030 while for each scenario two policy variants are analyzed respectively with and without implementation of the biofuel directive. The results indicate that the area of semi natural vegetation, forest and High Nature Value farmland directly replaced by biofuel crops is small in all scenarios and differs little between policy variants. The direct effects of the directive on European land use and biodiversity therefore are relatively minor. The indirect effects of the directive on European land use and biodiversity are much larger than its direct effects. The area semi natural vegetation is found to be 3-8% smaller in policy variants with the directive as compared to policy variants without the directive. In contrast, little difference is found between the policy variants with respect to the forest area. The results of this study show that the expected indirect effects of the directive on biodiversity are much greater than its direct effects. This suggests that indirect effects need to be taken explicitly into account in assessing the environmental effects of biofuel crop cultivation and designing sustainable pathways for implementing biofuel policies. (C) 2010 Elsevier Ltd. All rights reserved

Translating land use change to landscape change for a scenario study in Europe

The objective of this paper is to translate land use changes (EU 25) into landscape changes. In contrast to land use maps the proposed landscape maps take the neighbourhood of a location into account additionally to solely the land use in a particular cell. Land use categories are reclassified into three main land use types and the dominant land use in a circle around the location is calculated. In addition, land use structure in the surroundings of a location is taken into account by calculating Shannon¿s diversity index and reclassifying this into two categories. By combining these two dataset six landscape types are identified. By comparing the landscape maps for 2000 and 2030 we constructed a landscape change map. The results show a great spatial variety in landscape change within Europe. The relation between land use change and landscape change is non-linear depending on the nature and structure of the initial landscape and land use changes

A phantom assessment of portable imaging and radio-guided surgery systems with technetium-99m and fluorine-18

AIM: To perform a detailed analysis of the performance of mobile intraoperative imaging systems and gamma probes in a phantom set-up, and compare this with a conventional gamma camera. METHODS: Two separate experiments were performed. In the first, a modified Jaszczak phantom equipped with five (99m)Tc-filled hot spheres (0.5-20 ml) was analyzed using Sentinella, declipseSPECT and a conventional gamma camera under three conditions: no background, spheres on the surface of the background activity, and totally immersed spheres (contrast level in both 1: 8). In the second experiment, two phantom spheres (0.5 and 2 ml) filled with (99m)Tc and (18)F (infinite contrast, 1: 4 and 1: 8) were measured using the hand-held probes Navigator and GammaLocator DXI. Data analysis consisted of signal-to-background ratios and determination of the full-width at half-maximum (FWHM). A visual scoring was performed by three nuclear medicine physicians. RESULTS: At infinite contrast, (99m)Tc-filled spheres with volumes of at least 2 ml could be detected adequately with all systems (e.g. 2 ml sphere, FWHM: ECAM 11 mm, declipseSPECT 9 mm, Navigator 13 mm, GammaLocator 12 mm). Under decreased contrast conditions, the results for all systems were impaired and the 0.5 ml phantom sphere filled with either (99m)Tc or (18)F was only detected accurately by the GammaLocator (FWHM range: 13-17 mm). CONCLUSION: All systems are suitable for intraoperative sentinel node detection with nearly infinite signal-to-background contrast. At a lower contrast, the GammaLocator performed best for the detection of small volumes at low-contrast ratios regardless of the radionuclide