3,474 research outputs found

    CV3 chondrites: How oxidised or reduced?

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    Biophotonic Tools in Cell and Tissue Diagnostics.

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    In order to maintain the rapid advance of biophotonics in the U.S. and enhance our competitiveness worldwide, key measurement tools must be in place. As part of a wide-reaching effort to improve the U.S. technology base, the National Institute of Standards and Technology sponsored a workshop titled "Biophotonic tools for cell and tissue diagnostics." The workshop focused on diagnostic techniques involving the interaction between biological systems and photons. Through invited presentations by industry representatives and panel discussion, near- and far-term measurement needs were evaluated. As a result of this workshop, this document has been prepared on the measurement tools needed for biophotonic cell and tissue diagnostics. This will become a part of the larger measurement road-mapping effort to be presented to the Nation as an assessment of the U.S. Measurement System. The information will be used to highlight measurement needs to the community and to facilitate solutions

    Atypical features in pleomorphic adenoma--a clinicopathologic study and implications for management.

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    Pleomorphic adenoma is the most common salivary gland neoplasm and infrequently undergoes malignant transformation. Carcinoma ex pleomorphic adenoma is typically an infiltrative neoplasm with features of cellular pleomorphism, high mitotic activity, peri-neural and vascular invasion. More recently, sub-groups of pleomorphic adenoma have been described exhibiting vascular invasion and features of malignancy without evidence of extra-capsular extension. There is little information in the literature regarding how these different histological variants influence clinical presentation and outcome following primary treatment. Following a review of 100 consecutive pleomorphic adenomas removed from the major salivary glands, 4 cases with atypical histological features were found. Three tumours exhibited features of dysplasia/carcinoma without evidence of extra-capsular invasion and a further case demonstrated benign vascular invasion. There were no clinical features suggestive of the atypical nature of these neoplasms, though fine needle aspiration cytology (FNAC) was suspicious of a malignancy in 2 cases and CT scan in 1 case. Patients underwent a superficial parotidectomy or submandibular gland excision based on the location of the lesion. All lesions were completely excised and there were no recurrences in this series

    The efficacy of playing a virtual reality game in modulating pain for children with acute burn injuries: A randomized controlled trial [ISRCTN87413556]

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    BACKGROUND: The management of burn injuries is reported as painful, distressing and a cause of anxiety in children and their parents. Child's and parents' pain and anxiety, often contributes to extended time required for burns management procedures, in particular the process of changing dressings. The traditional method of pharmacologic analgesia is often insufficient to cover the burnt child's pain, and it can have deleterious side effects [1,2]. Intervention with Virtual Reality (VR) games is based on distraction or interruption in the way current thoughts, including pain, are processed by the brain. Research on adults supports the hypothesis that virtual reality has a positive influence on burns pain modulation. METHODS: This study investigates whether playing a virtual reality game, decreases procedural pain in children aged 5–18 years with acute burn injuries. The paper reports on the findings of a pilot study, a randomised trial, in which seven children acted as their own controls though a series of 11 trials. Outcomes were pain measured using the self-report Faces Scale and findings of interviews with parent/carer and nurses. RESULTS: The average pain scores (from the Faces Scale) for pharmacological analgesia only was, 4.1 (SD 2.9), while VR coupled with pharmacological analgesia, the average pain score was 1.3 (SD 1.8) CONCLUSION: The study provides strong evidence supporting VR based games in providing analgesia with minimal side effects and little impact on the physical hospital environment, as well as its reusability and versatility, suggesting another option in the management of children's acute pain

    A computational model of open-irrigated radiofrequency catheter ablation accounting for mechanical properties of the cardiac tissue

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    Radiofrequency catheter ablation (RFCA) is an effective treatment for cardiac arrhythmias. Although generally safe, it is not completely exempt from the risk of complications. The great flexibility of computational models can be a major asset in optimizing interventional strategies, if they can produce sufficiently precise estimations of the generated lesion for a given ablation protocol. This requires an accurate description of the catheter tip and the cardiac tissue. In particular, the deformation of the tissue under the catheter pressure during the ablation is an important aspect that is overlooked in the existing literature, that resorts to a sharp insertion of the catheter into an undeformed geometry. As the lesion size depends on the power dissipated in the tissue, and the latter depends on the percentage of the electrode surface in contact with the tissue itself, the sharp insertion geometry has the tendency to overestimate the lesion obtained, especially when a larger force is applied to the catheter. In this paper we introduce a full 3D computational model that takes into account the tissue elasticity, and is able to capture the tissue deformation and realistic power dissipation in the tissue. Numerical results in FEniCS-HPC are provided to validate the model against experimental data, and to compare the lesions obtained with the new model and with the classical ones featuring a sharp electrode insertion in the tissue.La Caixa 2016 PhD grant to M. Leoni, and Abbott non-conditional grant to J.M. Guerra Ramo

    Geodesics and the competition interface for the corner growth model

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    We study the directed last-passage percolation model on the planar square lattice with nearest-neighbor steps and general i.i.d. weights on the vertices, out- side of the class of exactly solvable models. Stationary cocycles are constructed for this percolation model from queueing fixed points. These cocycles serve as bound- ary conditions for stationary last-passage percolation, solve variational formulas that characterize limit shapes, and yield existence of Busemann functions in directions where the shape has some regularity. In a sequel to this paper the cocycles are used to prove results about semi-infinite geodesics and the competition interface
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