438 research outputs found

    Sentinel Node Detection in Patients with Thyroid Carcinoma: A Meta-analysis

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    Objective: This study was designed to review the diagnostic performance of sentinel node (SN) detection for assessment of the nodal status in thyroid carcinoma patients and to determine the technique (using blue dye or Technetium-99m colloid (99mTc)) that demonstrated the highest success rate with regard to the detection rate and sensitivity. Methods A comprehensive computer literature search of studies published in English language through December 2007 and regarding SN procedures in patients with thyroid disorders was performed in MEDLINE. Pooled values regarding the SN detection rate and the pooled sensitivity values of the SN procedure were presented with a 95% confidence interval (CI) for the different SN detection techniques. Results: Ultimately, we identified 14 studies comprising a total of 457 patients. Of these, ten studies (n = 329 patients) used the blue dye technique with a pooled SN detection of 83% (95% CI, 79–87%). The remaining four studies (n = 128) used 99mTc-colloid with a pooled SN detection of 96% (95% CI, 91–99%; p\0.05 vs. blue dye technique). Conclusion: In patients with suspected thyroid carcinoma, SN biopsy demonstrated a higher SN detection rate when 99mTc was used (96%) instead of the blue dye technique (83%)

    Sentinel Node Detection in Patients with Thyroid Carcinoma: A Meta-analysis

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    Objective: This study was designed to review the diagnostic performance of sentinel node (SN) detection for assessment of the nodal status in thyroid carcinoma patients and to determine the technique (using blue dye or Technetium-99m colloid

    A comparison and accuracy analysis of impedance-based temperature estimation methods for Li-ion batteries

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    In order to guarantee safe and proper use of Lithium-ion batteries during operation, an accurate estimate of the battery temperature is of paramount importance. Electrochemical Impedance Spectroscopy (EIS) can be used to estimate the battery temperature and several EIS-based temperature estimation methods have been proposed in the literature. In this paper, we argue that all existing EIS-based methods implicitly distinguish two steps: experiment design and parameter estimation. The former step consists of choosing the excitation frequency and the latter step consists of estimating the battery temperature based on the measured impedance resulting from the chosen excitation. By distinguishing these steps and by performing Monte-Carlo simulations, all existing methods are compared in terms of accuracy (i.e., mean-square error) of the temperature estimate. The results of the comparison show that, due to different choices in the two steps, significant differences in accuracy of the estimate exist. More importantly, by jointly selecting the parameters of the experiment-design and parameter-estimation step, a more-accurate temperature estimate can be obtained. In case of an unknown State-of-Charge, this novel method estimates the temperature with an average absolute bias of View the MathML sourceC and an average standard deviation of View the MathML sourceC using a single impedance measurement for the battery under consideration

    Cognitive flexibility training has direct and near transfer effects, but no far transfer effects, preschoolers

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    The current project studied the direct, near transfer, and far transfer effects of cognitive flexibility training in two experiments with 117 3-year-olds. In both Experiments 1 and 2, children performed three Dimensional Change Card Sorting (DCCS) tasks in a pre-training/training/post-training design. The training consisted of giving corrective feedback in the training DCCS task. In Experiment 2, in addition, three other executive control tasks were administered during pre-training and post-training. Results showed a direct effect of feedback in the training DCCS task and transfer of this effect to the post-training DCCS task after 1 week with different sorting rules and different stimuli. These findings show that preschoolers learned to switch sorting rules in the context of the DCCS task, independent of the specific sorting rules, and that this effect is not transient. No support was found for transfer to the other executive control tasks. A possible explanation is that the feedback mainly improved rule switching, an ability that is specifically required for performing a cognitive flexibility task but not the other executive control tasks

    Recovery of myocardial perfusion after percutaneous coronary intervention of chronic total occlusions is comparable to hemodynamically significant non-occlusive lesions.

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    BACKGROUND: The benefits of chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) are being questioned. The aim of this study was to assess the effects of CTO PCI on absolute myocardial perfusion, as compared with PCI of hemodynamically significant non-CTO lesions. METHODS: Consecutive patients with a preserved left ventricular ejection fraction (≥50%) and a CTO or non-CTO lesion, in whom [15 O]H2 O positron emission tomography was performed prior and after successful PCI, were included. Change in quantitative (hyperemic) myocardial blood flow (MBF), coronary flow reserve (CFR) and perfusion defect size (in myocardial segments) were compared between CTOs and non-CTO lesions. RESULTS: In total 92 patients with a CTO and 31 patients with a non-CTO lesion were included. CTOs induced larger perfusion defect sizes (4.51 ± 1.69 vs. 3.23 ± 2.38 segments, P < 0.01) with lower hyperemic MBF (1.30 ± 0.37 vs. 1.58 ± 0.62 mL·min-1 ·g-1 , P < 0.01) and similarly impaired CFR (1.66 ± 0.75 vs. 1.89 ± 0.77, P = 0.17) compared with non-CTO lesions. After PCI both hyperemic MBF and CFR increased similarly between groups (P = 0.57 and 0.35) to normal ranges with higher hyperemic MBF values in non-CTO compared with CTO (2.89 ± 0.94 vs. 2.48 ± 0.73 mL·min-1 ·g-1 , P = 0.03). Perfusion defect sizes decreased similarly after CTO PCI and non-CTO PCI (P = 0.14), leading to small residual defect sizes in both groups (1.15 ± 1.44 vs. 0.61 ± 1.45 segments, P = 0.054). CONCLUSIONS: Myocardial perfusion findings are slightly more hampered in patients with a CTO before and after PCI. Percutaneous revascularization of CTOs, however, improves absolute myocardial perfusion similarly to PCI of hemodynamically significant non-CTO lesions, leading to satisfying results

    Unmet care needs of patients with advanced cancer and their relatives:multicentre observational study

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    Objectives: The care needs of patients with advanced cancer and their relatives change throughout the disease trajectory. This study focused on the care-related problems and needs of patients with advanced cancer and their relatives. This was done from the perspective of centres for information and support. Methods: This cross-sectional study used data from the eQuiPe study: an observational cohort study in which 40 Dutch hospitals participated. All adult patients with a diagnosis of a metastasised tumour and their relatives were eligible. Measures included information on the patients' and relatives' care problems and needs, assessed by the short version of the Problems and Needs in Palliative Care questionnaire. Socioeconomic demographics were also collected. Results: 1103 patients with advanced cancer and 831 relatives were included. Both patients (M=60.3, SD=29.0) and relatives (M=59.2, SD=26.6) experienced most problems in the domain of â € psychological issues'. Both patients (M=14.0, SD=24.2) and relatives (M=17.7, SD=25.7) most frequently reported unmet needs within this domain. The most often reported unmet need by patients was â € worrying about the future of my loved ones' (22.0%); for relatives this was â € fear for physical suffering of the patient' (32.8%). There was no clear relationship between socioeconomic demographics and the experienced unmet needs. Conclusions: The most often mentioned unmet needs consisted of fears and worries, followed by a broad range of topics within multiple domains. Centres for information and support may play a role in reducing the unmet needs of (potential) visitors as these centres provide support on a broad range of topics.</p

    Children's Mental Models of Prenatal Development

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    Children's thinking about prenatal development requires reasoning about change that cannot be observed directly. How do children gain knowledge about this topic? Do children have mental models or is their knowledge fragmented? In Experiment 1, results of a forced-choice questionnaire about prenatal development (6- to 13-year-olds; N = 317) indicated that children do have a variety of coherent, grade-related, theories about early shape of the fetus, but not about bodily functions. Coherence of the mental models was enhanced by a preceding generative task. Children's mental models were in agreement with reasoning about natural transformations (Rosengren et al., 1991) and constraints in representational flexibility (Karmiloff-Smith, 1992). In Experiment 2, an open-question interview was administered (6- to 12-year-old children; N = 38). The interview resulted in grade-unrelated, incoherent responses. This study contributes to a deeper understanding of naïve biology and to the effects of different methodologies being used in the area of mental models
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