625 research outputs found

    Bone imaging in prostate cancer: the evolving roles of nuclear medicine and radiology

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    The bone scan continues to be recommended for both the staging and therapy response assessment of skeletal metastases from prostate cancer. However, it is widely recognised that bone scans have limited sensitivity for disease detection and is both insensitive and non-specific for determining treatment response, at an early enough time point to be clinically useful. We, therefore, review the evolving roles of nuclear medicine and radiology for this application. We have reviewed the published literature reporting recent developments in imaging bone metastases in prostate cancer, and provide a balanced synopsis of the state of the art. The development of single-photon emission computed tomography combined with computed tomography has improved detection sensitivity and specificity but has not yet been shown to lead to improvements in monitoring therapy. A number of bone-specific and tumour-specific tracers for positron emission tomography/computed tomography (PET/CT) are now available for advanced prostate cancer that show promise in both clinical settings. At the same time, the development of whole-body magnetic resonance imaging (WB-MRI) that incorporates diffusion-weighted imaging also offers significant improvements for detection and therapy response assessment. There are emerging data showing comparative SPECT/CT, PET/CT, and WB-MRI test performance for disease detection, but no compelling data on the usefulness of these technologies in response assessment have yet emerged

    The Clustering of Financial Services in London*

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    This paper reports a one-year study which investigated the clustering of financial services activity in London. A questionnaire asking about the advantages and disadvantages of a London location was sent to a stratified sample of 1,500 firms and institutions. In addition, thirty-nine on-site interviews with firms, professional institutions, government bodies and other related agencies were conducted. The study finds that banking, including investment banking, forms the cluster’s hub with most other companies depending on relationships with this sub-sector. Generally, the cluster confers many advantages to its incumbents including enhanced reputation, the ability to tap into large, specialized labor pool and customer proximity. The localized nature of relationships between skilled labor, customers and suppliers is a critical factor which helps firms achieve innovative solutions, develop new markets and attain more efficient ways to deliver services and products. Particularly important are the personal relationships which are enhanced by the on-going face-to-face contact that is possible in a compact geographical space. Many of the cluster’s advantages are dynamic in that they become stronger as agglomeration increases. The study also finds important disadvantages in the cluster which threaten its future growth and prosperity. These include the poor quality and reliability of transport, particularly the state of the London Underground and links to airports, increasing levels of regulation and government policy that is not co-ordinated with the whole of the cluster in mind. Key words: Industrial clustering, agglomeration, financial services.

    Multitracer Guided PET Image Reconstruction

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    The isotope bone scan: we can do better

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    Telehealth Services to Improve Nonadherence: A Placebo-Controlled Study

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    This is the publisher's version, also available electronically from http://online.liebertpub.com/doi/abs/10.1089/tmj.2006.12.289.The objective of this study was to test whether a telehealth intervention could improve the compliance with continuous positive airway pressure (CPAP) by patients with sleep apnea. These patients had been nonadherent for the initial 3 months of therapy even after receiving the initial standard and then supplemental audiotaped/videotaped patient education for adhering to CPAP nightly. The materials and methods included a randomized testing of experimental and placebo interventions. Interventions were delivered by nurses to two groups in their homes by telehealth over a 12-week period. The placebo intervention was used to control for Hawthorne effect, time and attention influences and the novelty of having telehealth in the home. Results following the telehealth interventions were that significantly more patients in the experimental group 1 (n = 10) than the placebo group 2 (n = 9) were adhering nightly to CPAP (χ2 = 4.55, p = 0.033). Group 1 patients reported greater satisfaction with their intervention. However, both groups rated telehealth delivery positively. The mean cost of each 20-minute telehealth visit was 30whilethetotalcostofthetelehealthinterventionforeachpatientwas30 while the total cost of the telehealth intervention for each patient was 420. These costs included telehealth equipment, initial installation, longdistance telephone charges, nurse salary, and intervention materials. Conclusions are that telehealth interventions are a potentially cost-effective service for increasing adherence to prescribed medical treatments. Replication studies with large samples and in other clinical groups are recommended

    Cultural and economic complementarities of spatial agglomeration in the British television broadcasting industry: Some explorations.

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    This paper considers the processes supporting agglomeration in the British television broadcasting industry. It compares and contrasts the insights offered by the cultural turn in geography and more conventionally economic approaches. It finds that culture and institutions are fundamental to the constitution of production and exchange relationships and also that they solve fundamental economic problems of coordinating resources under conditions of uncertainty and limited information. Processes at a range of spatial scales are important, from highly local to global, and conventional economics casts some light on which firms are most active and successful

    Insights Into the Feeding Behaviors and Biomechanics of \u3ci\u3eVarroa destructor\u3c/i\u3e Mites on Honey Bee Pupae Using Electropenetrography and Histology

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    Feeding behaviors and biomechanics of female Varroa destructor mites are revealed from AC-DC electropenetrography (EPG) recordings of mites feeding from Apis mellifera honey bee pupae and histology of mite internal ingestion apparatus. EPG signals characteristic of arthropod suction feeding (ingestion) were identified for mites that fed on pupae during overnight recordings. Ingestion by these mites was confirmed afterwards by observing internally fluorescent microbeads previously injected into their hosts. Micrographs of internal ingestion apparatus illustrate the connection between a gnathosomal tube and a pharyngeal lumen, which is surrounded by alternating dilator and constrictor muscles. Inspection of EPG signals showed the muscularized mite pharyngeal pump operates at a mean repetition rate of 4.5 cycles/s to ingest host fluids. Separate feeding events observed for mites numbered between 23 and 33 over approximately 16 h of recording, with each event lasting ~10 s. Feeding events were each separated by ~2 min. Consecutive feeding events separated by either locomotion or prolonged periods of quiescence were grouped into feeding bouts, which ranged in number from one to six. Statistical analyses of EPG data revealed that feeding events were prolonged for mites having lower pharyngeal pump frequencies, and mites having prolonged feeding events went unfed for significantly more time between feeding events. These results suggest that mites may adjust behaviors to meet limitations of their feeding apparatus to acquire similar amounts of food. Data reported here help to provide a more robust view of Varroa mite feeding than those previously reported and are both reminiscent of, as well as distinct from, some other acarines and fluid-feeding insects

    Harvesting Single Ferroelectric Domain Stressed Nanoparticles for Optical and Ferroic Applications

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    We describe techniques to selectively harvest single ferroelectric domain nanoparticles of BaTiO3 as small as 9 nm from a plethora of nanoparticles produced by mechanical grinding. High resolution transmission electron microscopy imaging shows the unidomain atomic structure of the nanoparticles and reveals compressive and tensile surface strains which are attributed to the preservation of ferroelectric behavior in these particles. We demonstrate the positive benefits of using harvested nanoparticles in disparate liquid crystal systems

    Time Dynamics of Self-Pumped Reflection Gratings in a Photorefractive Polymer

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    The time dynamics of self-pumped reflection gratings in a commonly used photorefractive polymer PDCST:PVK:ECZ-BBP:C60 with no additional electron sources or traps is investigated. While holes are normally the mobile charges and responsible for grating formation, our experimental observations, analyzed using multi-exponential fitting curves, show evidence of electrons in addition to holes as charge carriers, particularly above an applied field of 40 V/μm. The dependence of effective carrier mobilities on the applied electric field, deduced from experimental results, show stronger field dependence of electron mobility at high electric fields. At an applied field of 70 V/μm, electron and hole mobilities become approximately equal, and the contribution of electrons on grating formation becomes significant
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