1,720,955 research outputs found
111In-DTPA-Biotin uptake by Staphilococcus Aureus
No full textThe potential of indium-111 labelled diethylenetriaminepentaacetic acid α,ω-bis(biocytinamide) (In-DTPA-Biotin) as a specific tracer in nuclear medicine imaging of vertebral osteomyelitis has been shown in a large series of consecutive patients. Biocytin is known to serve as a biotin source for a number of different microorganisms and quantitative studies on staphylococci indicated that on a molar basis biocytin seemed to have an activity equal to that of biotin. In this study, we evaluated the possibility of an illicit transport of In-DTPA-Biotin in cultures of Staphylococcus aureus on continued incubation for 24 h. Radiolabelled biocytin was prepared as described earlier and the stability and radiochemical purity was assessed in vitro for 24 h after labelling. Our data seem to demonstrate a passive transport of In-DTPA-Biotin into the cells of the microorganisms
In-111-DTPA-Biotin uptake by Staphylococcus aureus
No full textThe potential of indium-111 labelled diethylenetriaminepentaacetic acid alpha,omega-bis(biocytinamide) (In-111-DTPA-Biotin) as a specific tracer in nuclear medicine imaging of vertebral osteomyelitis has been shown in a large series of consecutive patients. Biocytin is known to serve as a biotin source for a number of different microorganisms and quantitative studies on staphylococci indicated that on a molar basis biocytin seemed to have an activity equal to that of biotin. In this study, we evaluated the possibility of an illicit transport of In-111-DTPA-Biotin in cultures of Staphylococcus aureus on continued incubation for 24 h. Radiolabelled biocytin was prepared as described earlier and the stability and radiochemical purity was assessed in vitro for 24 h after labelling. Our data seem to demonstrate a passive transport of In-111-DTPA-Biotin into the cells of the microrganisms. Nucl Med Commun 31: 994-997 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
CERENKOV LUMINESCENCE IMAGING IN PULMONARY AND HEPATIC METASTASECTOMY
No full textIntroduction
Cerenkov luminescence imaging (CLI) is an optical imaging modality to detect distributions of radiopharmaceuticals. CLI can be used to visualize surgical margins immediately after resection and to refine surgery in a single procedure [1]. We are planning a clinical study to evaluate the impact of CLI during surgery of lung and liver metastasis from various primary tumors with respect to conventional post-operative histology, and we are performing in-vitro simulation measurements to optimize the clinical protocol in terms of patient inclusion criteria, activity to inject, radiation monitoring.
Methods
We analyzed PET/CT data of 15 patients performed with [18F]-FDG in pulmonary and hepatic metastases and with 68Ga-DOTATOC in neuroendocrine tumors (NETs) to determine typical injected activities, lesion volumes, uptakes and time delays between injection and imaging. We are collecting data for typical histological margins. Since the Cerenkov signal depends on the spectrum of the beta particles and on the optical properties of the tissue, we prepared phantoms to measure the minimum detectable activity as a function of the type of radiopharmaceutical, the type of tissue and the source depth in tissue. The phantoms were imaged with a LightPath system with acquisition time acceptable for clinical needs. We used two short-pass filters to discriminate the depth of origin of the detected light.
Results/Discussion
Patient data are summarized in Figure 1. The delay between injection and imaging was ~1 hour. For our clinical study, we expect delays up to 4-5 hours between injection and CLI. The decay-corrected mean uptake values to account for this delay (5-11 kBq/cc) are comparable to the minimum detectable activity level of 8 kBq/cc that we measured for [18F]-FDG [2]. For 68Ga-DOTATOC, the final uptake of 4-7 kBq/cc should be well detectable, because our first tests suggest a 13x signal increase with respect to 18F, but an enhancement up to 22x can be expected [3]. Figure 2a shows a representative phantom image. The attenuation of 68Ga signal in the various animal liver samples is shown in Fig. 2b. Independent data-sets for the same type of tissue suggest good reproducibility. We are finalizing the data analysis to determine the target-to-background ratio in both the patient and phantom data.
Conclusions
Patient data suggests that CLI can be performed with standard clinical activities and 5-minute exposure times. The typical lesion volumes are suitable for LightPath imaging. Phantom data for signal attenuation in biological tissue show good reproducibility. We are collecting additional data for lung phantoms, and we are studying the target-to-background ratio for 18F and 68Ga and a method to extract the source depth from the spectral images
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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