4,049 research outputs found

    Using affinity set on mining the necessity of computed tomography scanning

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    Computed tomography (CT) is a medical imaging method of tomography. Digital geometry processing is used to generate a three-dimensional image of the inside of a patient from a large series of two-dimensional X-ray images taken around a single axis of rotation. The scanning ofCT has become an important tool in medical imaging to supplement X-rays and medical ultrasonography. Although it is expensive, it is the best tool to diagnose a large number of different disease entities; especially, for the trauma patients in emergency room. In this study, the trauma patients, who were treated by the CT scanning are collected in order to discover the critical knowledge; that is, what characteristics of trauma patients would lead to the necessity of CT scanning? The data mining model of affinity set and neural network (NN) are both used for resolution and comparison. Finally, studying results show that he affinity model performs better than the NN model, but the collected data lacks the explanatory power in practices. Thus, a further research is necessary

    Traceable GISAXS measurements for pitch determination of a 25 nm self-assembled polymer grating

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    The feature sizes of only a few nanometers in modern nanotechnology and next-generation microelectronics continually increase the demand for suitable nanometrology tools. Grazing incidence small-angle X-ray scattering (GISAXS) is a versatile technique to measure lateral and vertical sizes in the nm-range, but the traceability of the obtained parameters, which is a prerequisite for any metrological measurement, has not been demonstrated so far. In this work, the first traceable GISAXS measurements, demonstrated with a self-assembled block copolymer grating structure with a nominal pitch of 25 nm, are reported. The different uncertainty contributions to the obtained pitch value of 24.83(9) nm are discussed individually. The main uncertainty contribution results from the sample-detector distance and the pixel size measurement, whereas the intrinsic asymmetry of the scattering features is of minor relevance for the investigated grating structure. The uncertainty analysis provides a basis for the evaluation of the uncertainty of GISAXS data in a more general context, for example in numerical data modeling.Comment: 9 pages, 6 figures; submitted to Journal of Applied Crystallograph

    Gene expression in early and progression phases of autosomal dominant polycystic kidney disease

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    <p>Abstract</p> <p>Background</p> <p>Little is known about the genes involved in the initial cyst formation and disease progression in autosomal dominant polycystic kidney disease (ADPKD); however, such knowledge is necessary to explore therapeutic avenues for this common inherited kidney disease.</p> <p>Findings</p> <p>To uncover the genetic determinants and molecular mechanisms of ADPKD, we analyzed 4-point time-series DNA microarrays from <it>Pkd1</it><sup><it>L</it>3/<it>L</it>3 </sup>mice to generate high resolution gene expression profiles at different stages of disease progression. We found different characteristic gene expression signatures in the kidneys of <it>Pkd1</it><sup><it>L</it>3/<it>L</it>3 </sup>mice compared to age-matched controls during the initial phase of the disease. By postnatal week 1, the <it>Pkd1</it><sup><it>L</it>3/<it>L</it>3 </sup>kidney already had a distinctive gene expression pattern different from the corresponding normal controls.</p> <p>Conclusion</p> <p>The genes differentially expressed, either induced or repressed, in ADPKD are important in immune defense, cell structure and motility, cellular proliferation, apoptosis and metabolic processes, and include members of three pathways (Wnt, Notch, and BMP) involved in morphogenetic signaling. Further analysis of the gene expression profiles from the early stage of cystogenesis to end stage disease identified a possible gene network involved in the pathogenesis of ADPKD.</p

    On the Mass-Period Distributions and Correlations of Extrasolar Planets

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    In addition to fitting the data of 233 extra-solar planets with power laws, we construct a correlated mass-period distribution function of extrasolar planets, as the first time in this field. The algorithm to generate a pair of positively correlated beta-distributed random variables is introduced and used for the construction of correlated distribution functions. We investigate the mass-period correlations of extrasolar planets both in the linear and logarithm spaces, determine the confidence intervals of the correlation coefficients, and confirm that there is a positive mass-period correlation for the extrasolar planets. In addition to the paucity of massive close-in planets, which makes the main contribution on this correlation, there are other fine structures for the data in the mass-period plane.Comment: to be published in AJ, tentatively in December 200

    Controlled Heterogeneous Nucleation and Growth of Germanium Quantum Dots on Nanopatterned Silicon Dioxide and Silicon Nitride Substrates

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    Controlled heterogeneous nucleation and growth of Ge quantum dots (QDs) are demonstrated on SiO_2/Si_3N_4 substrates by means of a novel fabrication process of thermally oxidizing nanopatterned SiGe layers. The otherwise random self-assembly process for QDs is shown to be strongly influenced by the nanopatterning in determining both the location and size of the QDs. Ostwald ripening processes are observed under further annealing at the oxidation temperature. Both nanopattern oxidation and Ostwald ripening offer additional mechanisms for lithography for controlling the size and placement of the QDs

    Sodium vanadate combined with l-ascorbic acid delays disease progression, enhances motor performance, and ameliorates muscle atrophy and weakness in mice with spinal muscular atrophy

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    BACKGROUND: Proximal spinal muscular atrophy (SMA), a neurodegenerative disorder that causes infant mortality, has no effective treatment. Sodium vanadate has shown potential for the treatment of SMA; however, vanadate-induced toxicity in vivo remains an obstacle for its clinical application. We evaluated the therapeutic potential of sodium vanadate combined with a vanadium detoxification agent, L-ascorbic acid, in a SMA mouse model. METHODS: Sodium vanadate (200 ฮผM), L-ascorbic acid (400 ฮผM), or sodium vanadate combined with L-ascorbic acid (combined treatment) were applied to motor neuron-like NSC34 cells and fibroblasts derived from a healthy donor and a type II SMA patient to evaluate the cellular viability and the efficacy of each treatment in vitro. For the in vivo studies, sodium vanadate (20 mg/kg once daily) and L-ascorbic acid (40 mg/kg once daily) alone or in combination were orally administered daily on postnatal days 1 to 30. Motor performance, pathological studies, and the effects of each treatment (vehicle, L-ascorbic acid, sodium vanadate, and combined treatment) were assessed and compared on postnatal days (PNDs) 30 and 90. The Kaplan-Meier method was used to evaluate the survival rate, with P < 0.05 indicating significance. For other studies, one-way analysis of variance (ANOVA) and Student's t test for paired variables were used to measure significant differences (P < 0.05) between values. RESULTS: Combined treatment protected cells against vanadate-induced cell death with decreasing B cell lymphoma 2-associated X protein (Bax) levels. A month of combined treatment in mice with late-onset SMA beginning on postnatal day 1 delayed disease progression, improved motor performance in adulthood, enhanced survival motor neuron (SMN) levels and motor neuron numbers, reduced muscle atrophy, and decreased Bax levels in the spinal cord. Most importantly, combined treatment preserved hepatic and renal function and substantially decreased vanadium accumulation in these organs. CONCLUSIONS: Combined treatment beginning at birth and continuing for 1 month conferred protection against neuromuscular damage in mice with milder types of SMA. Further, these mice exhibited enhanced motor performance in adulthood. Therefore, combined treatment could present a feasible treatment option for patients with late-onset SMA
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