419 research outputs found
Hadronic Atoms and Effective Interactions
We examine the problem of hadronic atom energy shifts using the technique of
effective interactions and demonstrate equivalence with the conventional
quantum mechanical approach.Comment: 22 page latex file with 2 figure
Preclinical PET and MR Evaluation of 89Zr- and 68Ga-Labeled Nanodiamonds in Mice over Different Time Scales
Nanodiamonds (NDs) have high potential as a drug carrier and in combination with nitrogen vacancies (NV centers) for highly sensitive MR-imaging after hyperpolarization. However, little remains known about their physiological properties in vivo. PET imaging allows further evaluation due to its quantitative properties and high sensitivity. Thus, we aimed to create a preclinical platform for PET and MR evaluation of surface-modified NDs by radiolabeling with both short- and long-lived radiotracers. Serum albumin coated NDs, functionalized with PEG groups and the chelator deferoxamine, were labeled either with zirconium-89 or gallium-68. Their biodistribution was assessed in two different mouse strains. PET scans were performed at various time points up to 7 d after i.v. injection. Anatomical correlation was provided by additional MRI in a subset of animals. PET results were validated by ex vivo quantification of the excised organs using a gamma counter. Radiolabeled NDs accumulated rapidly in the liver and spleen with a slight increase over time, while rapid washout from the blood pool was observed. Significant differences between the investigated radionuclides were only observed for the spleen (1 h). In summary, we successfully created a preclinical PET and MR imaging platform for the evaluation of the biodistribution of NDs over different time scales
The Galaxy platform for accessible, reproducible and collaborative biomedical analyses: 2018 update
The Galaxy platform for accessible, reproducible and collaborative biomedical analyses: 2018 update
Fusion of Color Doppler and Magnetic Resonance Images of the Heart
This study was designed to establish and analyze color Doppler and magnetic resonance fusion images of the heart, an approach for simultaneous testing of cardiac pathological alterations, performance, and hemodynamics. Ten volunteers were tested in this study. The echocardiographic images were produced by Philips IE33 system and the magnetic resonance images were generated from Philips 3.0-T system. The fusion application was implemented on MATLAB platform utilizing image processing technology. The fusion image was generated from the following steps: (1) color Doppler blood flow segmentation, (2) image registration of color Doppler and magnetic resonance imaging, and (3) image fusion of different image types. The fusion images of color Doppler blood flow and magnetic resonance images were implemented by MATLAB programming in our laboratory. Images and videos were displayed and saved as AVI and JPG. The present study shows that the method we have developed can be used to fuse color flow Doppler and magnetic resonance images of the heart. We believe that the method has the potential to: fill in information missing from the ultrasound or MRI alone, show structures outside the field of view of the ultrasound through MR imaging, and obtain complementary information through the fusion of the two imaging methods (structure from MRI and function from ultrasound)
Finite-size effect on two-particle production in continuous and discrete spectrum
The formalism allowing one to account for the effect of a finite space-time
extent of particle production region is given. Its applications to the lifetime
measurement of hadronic atoms produced by a high-energy beam in a thin target,
as well as to the femtoscopy techniques widely used to measure space-time
characteristics of the production processes, are discussed. Particularly, it is
found that the neglect of the finite-size effect on the pionium lifetime
measurement in the experiment DIRAC at CERN could lead to the lifetime
overestimation comparable with the 10% statistical error. The theoretical
systematic errors arising in the calculation of the finite-size effect due to
the neglect of non-equal emission times in the pair center-of-mass system, the
space-time coherence and the residual charge are shown to be negligible.Comment: LaTeX, 77 pages including 5 tables and 18 figures. Somewhat extended
version to be published in Phys. El. Part. At. Nuc
Descrição dos dados da pesquisa geoespacial: a experiência da Embrapa.
Sob as premissas do acesso aberto, o atual contexto de produção da ciência vem expressando valor ao compartilhamento e abertura dos dados de pesquisa. No Brasil, o Decreto Lei n. 6.666/08, que instituiu a Infraestrutura Nacional de Dados Espaciais (Inde), estabelece-se como um exemplo bem sucedido de iniciativa para a abertura de dados espaciais, tendo influenciado a Embrapa a promover a abertura de seus dados espaciais gerados no âmbito de suas pesquisas. Para a disponibilização do dado de pesquisa, é preciso considerar as questões associadas à representação do dado, ou precisamente, a descrição dos metadados como elemento crucial para que o dado possa disponibilizado. Diante disso, o objetivo deste trabalho é apresentar a experiência da Embrapa em estruturar o processo da organização e representação dos dados espaciais, contextualizando-os sob as considerações da Ciência da Informação e Geociências.Suplemento. Trabalhos apresentados na 8a Conferência Luso Brasileira sobre Acesso Aberto - ConfOA. Na publicação: Davi Oliveira Custódio, Bibiana Teixeira Almeida, Margareth Simões, Gustavo Bayma-Silva
Corporate Social Responsibility/Sustainability Reporting Among the Fortune Global 250: Greenwashing or Green Supply Chain?
The sustainability reporting efforts of MNCs who are members of the Fortune Global 250 (FG250) was investigated. The focus was on sustainability reporting by MNCs of supply chain impacts. The reporting of FG250 MNCs was examined to determine if greenwashing was occurring or whether MNCs had committed to operating a green supply chain. A mixed methodology was used consisting of quantitative analysis of twenty-five MNC CSR/sustainability reports which were randomly selected from the FG250 listing. Qualitative analysis using content analysis was also conducted on the reports. Both methodologies concentrated on the sustainability reporting of the selected MNCs in regard to their supply chain. Findings were mixed as there were great variations among the MNCs in their level of sustainability reporting about their supply chains. Some MNCs did not report on the activities of their supply chain at all (20%), the majority of the MNCs reported on their supply chain impacts at the value and goal level (48%), while the rest reported at the management approach level (32%). A majority of the sampled MNCs could be accused of greenwashing due to the lack of detailed quantitative information provided by the MNCs on the environmental impacts of their supply chai
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