3,743 research outputs found

    Recent radiopharmaceutical research at the AAEC Research Establishment.

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    During the past few years a large part of the radiochemical research carried out at Lucas Heights has been devoted to the synthesis of ligands capable of forming chelate complexes with technetium-99m as part of a search for tumour-localising radiopharmaceuticals. An account is given of the synthesis and biological evaluation of a range of these compounds and of the investigation of certain biochemical and biological properties affecting the clinical application of both ligands and radiopharmaceuticals. In addition to the search for novel Tc-99m radiopharmaceuticals major research programs on the development of Tc-99m generating systems have been in progress at Lucas Heights for several years. Work on the AAEC's Mark III Tc-99m technetium generator has been brought to a successful conclusion. A new type of Tc-99m generator which uses an insoluble zirconium molybdate gel and provides high yields of pertechnetate by a simple elution technique has also been developed. Studies are in progress on the osmium-iridium generator

    Cooperation, collective action, and the archeology of large-scale societies

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    Archeologists investigating the emergence of large-scale societies in the past have renewed interest in examining the dynamics of cooperation as a means of understanding societal change and organizational variability within human groups over time. Unlike earlier approaches to these issues, which used models designated voluntaristic or managerial, contemporary research articulates more explicitly with frameworks for cooperation and collective action used in other fields, thereby facilitating empirical testing through better definition of the costs, benefits, and social mechanisms associated with success or failure in coordinated group action. Current scholarship is nevertheless bifurcated along lines of epistemology and scale, which is understandable but problematic for forging a broader, more transdisciplinary field of cooperation studies. Here, we point to some areas of potential overlap by reviewing archeological research that places the dynamics of social cooperation and competition in the foreground of the emergence of large-scale societies, which we define as those having larger populations, greater concentrations of political power, and higher degrees of social inequality. We focus on key issues involving the communal-resource management of subsistence and other economic goods, as well as the revenue flows that undergird political institutions. Drawing on archeological cases from across the globe, with greater detail from our area of expertise in Mesoamerica, we offer suggestions for strengthening analytical methods and generating more transdisciplinary research programs that address human societies across scalar and temporal spectra

    A Virtual Reality System for Practicing Conversation Skills for Children with Autism

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    We describe a virtual reality environment, Bob’s Fish Shop, which provides a system where users diagnosed with Autism Spectrum Disorder (ASD) can practice social interactions in a safe and controlled environment. A case study is presented which suggests such an environment can provide the opportunity for users to build the skills necessary to carry out a conversation without the fear of negative social consequences present in the physical world. Through the repetition and analysis of these virtual interactions, users can improve social and conversational understanding

    Studies on 99mTc-pertechnetate from the MEK solvent extraction generator.

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    Analysis by gas chromatography-mass spectrometry and high performance liquid chromatography has revealed organic residues in (99m)Tc-pertechnetate obtained from 99Mo-molybdate by extraction using the organic solvent methylethylketone (MEK). The organic residues have been identified as either (i) low molecular weight carbonyl compounds such as formaldehyde acetaldehyde and acetone presumably caused by the effects of gamma-radiation on MEK or (ii) condensation products resulting from the action of strong alkali on MEK during the extraction process. The quantities of organic residues varied from batch to batch of extracted pertechnetate; up to 40 μg mL -1 was found. When these compounds were tested in rats by addition to a pyrophosphate bone-seeking radiopharmaceutical the tissue distribution was not significantly different from that in the control which contained no added compound. Assay for 99Tc in MEK-derived pertechnetate indicated up to 10 μg mL -1 of 99Tc carrier. An assessment of the biological effect of 99Tc carrier was obtained by (i) red blood cell labelling where 6 ng mL -1 of 99Tc was sufficient to reduce labelling efficiency; and (ii) pyrophosphate tissue distribution where a significant effect was obtained in the presence of 10 μg mL -1 of 99Tc carrier

    A five year programme for radioisotope production at the Research Establishment.

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    This report summarises plans for radioisotope production at Lucas Heights over the period 1966-71 and indicates how these are based on present trends of demand for radioisotopes. The programme is discussed in terms of available staff and facilities; while some small staff increases will be required, the facilities presently being commissioned should be adequate over this period

    Development of a pilot plant for the removal of rhenium from molybdenum trioxide.

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    Reagent grade molybdenum trioxide used as a target material for the preparation of Tc-99m pharmaceuticals contains trace amounts of rhenium. A simple charcoal adsorptions process has been developed to remove rhenium selectively from molybdenum before neutron irradiation. Details are given of the design and operation of a pilot plant in which 17 kg of molybdenum trioxide was produced having a rhenium content of less than 1 x 10 -6 mu g g -1. Although contamination of the Tc-99m by inactive rhenium and 188 Re was effectively eliminated 188 Re resulting from the irradiation of tungsten impurity in the molybdenum trioxide target was still present

    Migration of Apicomplexa Across Biological Barriers: The Toxoplasma and Plasmodium Rides

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    The invasive stages of Apicomplexa parasites, called zoites, have been largely studied in in vitro systems, with a special emphasis on their unique gliding and host cell invasive capacities. In contrast, the means by which these parasites reach their destination in their hosts are still poorly understood. We summarize here our current understanding of the cellular basis of in vivo parasitism by two well-studied Apicomplexa zoites, the Toxoplasma tachyzoite and the Plasmodium sporozoite. Despite being close relatives, these two zoites use different strategies to reach their goal and establish infection

    A Laser/EMAT Concurrent Weld Inspection System

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    A noncontacting ultrasonic sensor system is being developed for online inspection of thick section welds made by a robotic gas metal arc welding (GMAW) system. The sensor system consists of a pulsed laser for generating the ultrasound and an electromagnetic-acoustic transducer (EMAT) for receiving it. The sensor will follow closely behind the weld head and inspect the solidified weld bead for flaws. The main advantage of this technique is that flaws can be found and repaired before they are covered by subsequent welding passes. This is expected to be much simpler and less likely to induce further flaws than current practice since a large amount of otherwise good weld metal need not be removed to reach and repair a flaw. The system also monitors the welding process, i.e., detection of a large number of flaws indicates that the process is no longer operating as planned. In this paper, the technique for detecting incomplete sidewall penetration is demonstrated and methods for improving the system are discussed.</p

    The effectiveness of case management for comorbid diabetes type 2 patients; the CasCo study. Design of a randomized controlled trial

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    BACKGROUND: More than half of the patients with type 2 diabetes (T2DM) patients are diagnosed with one or more comorbid disorders. They can participate in several single-disease oriented disease management programs, which may lead to fragmented care because these programs are not well prepared for coordinating care between programs. Comorbid patients are therefore at risk for suboptimal treatment, unsafe care, inefficient use of health care services and unnecessary costs. Case management is a possible model to counteract fragmented care for comorbid patients. It includes evidence-based optimal care, but is tailored to the individual patients' preferences.The objective of this study is to examine the effectiveness of a case management program, in addition to a diabetes management program, on the quality of care for comorbid T2DM patients. METHODS/DESIGN: The study is a randomized controlled trial among patients with T2DM and at least one comorbid chronic disease (N=230), who already participate in a diabetes management program. Randomization will take place at the level of the patients in general practices. Trained practice nurses (case managers) will apply a case management program in addition to the diabetes management program. The case management intervention is based on the Guided Care model and includes six elements; assessing health care needs, planning care, create access to other care providers and community resources, monitoring, coordinating care and recording of all relevant information. Patients in the control group will continue their participation in the diabetes management program and receive care-as-usual from their general practitioner and other care providers. DISCUSSION: We expect that the case management program, which includes better structured care based on scientific evidence and adjusted to the patients' needs and priorities, will improve the quality of care coordination from both the patients' and caregivers' perspective and will result in less consumption of health care services. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR1847. (aut. ref.
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