477 research outputs found

    Secretory Carcinoma: A Silent Mass Increasing in the Parotid Gland

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    BACKGROUND: Secretory carcinoma (SC) of the salivary gland, also known as mammary analog secretory carcinoma, is a rare tumor in the parotid gland. This kind of tumor is characterized by generally indolent clinical behavior and expression of a break in the ETV6 gene. CASE REPORT: We present a unique case of secretory carcinoma and show its favorable prognoses. CONCLUSION: Secretory carcinoma of the salivary gland is a low-grade carcinoma with a favorable prognosis. It has low regional lymph node and distant metastasis potential. Due to the possibility of misdiagnosis, immunohistochemical studies and FISH are suggested. The most effective treatment is complete surgical excision with negative surgical margins

    THE UPPER LIMB EMG ACTIVITY COMPARISON OF DIFFERENT TABLE TENNIS FOREHAND DRIVES

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    The purpose of this study was to combine dynamics and surface EMG methods to analyze the movements of table tennis forehand drives by Taiwan elite table tennis players performing straight and cross court forehand drives from topspin and backspin serves. The kinematical data were collected by 10 Vicon MX13+ high-speed cameras and one Biovision system was used to record the EMG signal of seven muscles groups on the dominate hand. The results showed that there were significant differences among the four table tennis drives. The players exerted greater muscular activity in the wrist extensors, the biceps and the triceps for the backspin serve forehand drive than when returning the topspin serve forehand drive, not only on the straight but also on the cross court strokes

    Quantum state tomography via non-convex Riemannian gradient descent

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    The recovery of an unknown density matrix of large size requires huge computational resources. The recent Factored Gradient Descent (FGD) algorithm and its variants achieved state-of-the-art performance since they could mitigate the dimensionality barrier by utilizing some of the underlying structures of the density matrix. Despite their theoretical guarantee of a linear convergence rate, the convergence in practical scenarios is still slow because the contracting factor of the FGD algorithms depends on the condition number κ\kappa of the ground truth state. Consequently, the total number of iterations can be as large as O(κln(1ε))O(\sqrt{\kappa}\ln(\frac{1}{\varepsilon})) to achieve the estimation error ε\varepsilon. In this work, we derive a quantum state tomography scheme that improves the dependence on κ\kappa to the logarithmic scale; namely, our algorithm could achieve the approximation error ε\varepsilon in O(ln(1κε))O(\ln(\frac{1}{\kappa\varepsilon})) steps. The improvement comes from the application of the non-convex Riemannian gradient descent (RGD). The contracting factor in our approach is thus a universal constant that is independent of the given state. Our theoretical results of extremely fast convergence and nearly optimal error bounds are corroborated by numerical results.Comment: Comments are welcome

    THE DYNAMICAL ANALYSIS OF TABLE TENNIS FOREHAND AND BACKHAND DRIVES

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    The purpose of this study was to analyze the dynamics parameters of table tennis drives by Taiwan collegiate first class table tennis players when they were performing straight and cross court forehand and backhand drives from receiving topspin and backspin serves. Ten Vicon MX-13+ high-speed cameras (250Hz) and two Kistler force plates (1500 Hz) were used to collect the kinematics and kinetics data. The Wilcoxon matched-pairs signed-rank nonparametric statistical test was to compare the differences between forehand and backhand drives. The results showed that there were significant differences between forehand and backhand drives were in the ball initial velocity and the kinetics variables. The GRF data of the players were different between forehand and backhand drives when they performed four different paths of drive

    Surface Second Harmonic Generation from Topological Dirac Semimetal PdTe2_2

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    Recent experiments and calculations in topological semimetals have observed anomalously strong second-order optical nonlinearity, but yet whether the enhancement also occurs at surfaces of topological semimetals in general remains an open question. In this work, we tackle this problem by measuring polarization-dependent and rotational-anisotropy optical second harmonic generation (SHG) from centrosymmetric type-II Dirac semimetal PdTe2_2. We found the SHG to follow C3v_{3v} surface symmetry with a time-varying intensity dictated by the oxidation kinetics of the material after its surface cleavage, indicating the surface origin of SHG. Quantitative characterization of the surface nonlinear susceptibility indicates a large out-of-plane response of PdTe2_2 with χccc(2)|\chi_{ccc}^{(2)}| up to 25 ×\times 1018^{-18} m2^2/V. Our results support the topological surfaces/interfaces as a new route toward applications of nonlinear optical effects with released symmetry constraints, and demonstrate SHG as a viable means to in situ study of kinetics of topological surfaces

    Risk Analysis of Cargos Damages for Aquatic Products of Refrigerated Containers: Shipping Operators’ Perspective in Taiwan

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    As the development of refrigerated container, transportation of aquatic products is growing rapidly in recent years. It is very important to avoid cargos damages for aquatic products of refrigerated containers, while the shipping operators are running this scope of business. Hence, the risk issue of adopting various improvement strategies would be important for the container shipping operators. In the light of this, the main purpose of this paper is to analyze the risks of cargos damages for aquatic products of refrigerated containers based on the container shipping operators’ perspective in Taiwan. We use four risk assessment procedures - risk identification, risk analysis and evaluation, risk strategies, and risk treatment - as the research method in this paper. The risk factors are generated from literature review and experts interviewing. Then, three dimensions with nineteen risk factors are preliminary identified. We used these risk factors to proceed with the empirical study via questionnaires. Three points of empirical results are presented. At first, the top factor of perceived risk as well as of risk severity is ‘container data setting errors.’ Secondly, the top factor of risk frequency is ‘lack of the goods’ pre-cooling themselves.’ Thirdly, three risk factors are classified into the low-risk area, whereas sixteen risk factors are placed on the medium-risk area. There is no risk factor fix on the high-risk area. Furthermore, three risk strategies - risk prevention, risk reduction, and risk transfer - are suggested to adopt by different risk factors
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