2,861 research outputs found

    On the Csorgo-RƩvƩsz increments of finite dimensional Gaussian random fields

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    In this paper, we establish some limit theorems on the combined Csorgo-RƩvƩsz increments with moduli of continuity for finite dimensional Gaussian random fields under mild conditions, via estimating upper bounds of large deviation probabilities on suprema of the finite dimensional Gaussian random fields.Csorgo-RƩvƩsz increment; Gaussian process; random field; modulus of continuity; quasi-increasing; regularly varying function; large deviation probability.

    Pseudo-Differential Neural Operator: Generalized Fourier Neural Operator for Learning Solution Operators of Partial Differential Equations

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    Learning the mapping between two function spaces has garnered considerable research attention. However, learning the solution operator of partial differential equations (PDEs) remains a challenge in scientific computing. Fourier neural operator (FNO) was recently proposed to learn solution operators, and it achieved an excellent performance. In this study, we propose a novel \textit{pseudo-differential integral operator} (PDIO) to analyze and generalize the Fourier integral operator in FNO. PDIO is inspired by a pseudo-differential operator, which is a generalized differential operator characterized by a certain symbol. We parameterize this symbol using a neural network and demonstrate that the neural network-based symbol is contained in a smooth symbol class. Subsequently, we verify that the PDIO is a bounded linear operator, and thus is continuous in the Sobolev space. We combine the PDIO with the neural operator to develop a \textit{pseudo-differential neural operator} (PDNO) and learn the nonlinear solution operator of PDEs. We experimentally validate the effectiveness of the proposed model by utilizing Darcy flow and the Navier-Stokes equation. The obtained results indicate that the proposed PDNO outperforms the existing neural operator approaches in most experiments.Comment: 23 pages, 13 figure

    Pyridoxine induced neuropathy by subcutaneous administration in dogs

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    To construct a sensory neuropathy model, excess pyridoxine (150 mg/kg s.i.d.) was injected subcutaneously in dogs over a period of 7 days. During the administrations period, the dogs experienced body weight reduction and proprioceptive loss involving the hindquarters. After pyridoxine administration was completed, electrophysiological recordings showed that the M wave remained at a normal state, but the H-reflex of the treated dogs disappeared at 7 days. The dorsal funiculus of L4 was disrupted irregularly in the axons and myelin with vacuolation. The dorsal root ganglia of L4, and sciatic and tibial nerves showed degenerative changes and vacuolation. However, the lateral and ventral funiculi of L4 showed a normal histopathologic pattern. Although this subcutaneous administration method did not cause systemic toxicity and effectively induced sensory neuropathy, this study confirmed the possibility of producing a pyridoxine-induced sensory neuropathy model in dogs with short-term administration

    Bright color optical switching device by polymer network liquid crystal with a specular reflector

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    The color optical switching device by polymer network liquid crystal (PNLC) with color filter on a specular reflector shows excellent performance; white reflectance of 22%, color gamut of 32%, and contrast ratio up to 50:1 in reflective mode measurement. The view-angle dependence of the reflectance can be adjusted by changing the PNLC thickness. The color chromaticity shown by the device is close to the limit value of color filters, and its value nearly remains with respect to the operating voltage. These optical properties of the device can be explained from the prediction based on multiple interactions between the light and the droplets of liquid crystal. The high reflectance, vivid color image, and moderate responds time allow the PNLC device to drive good color moving image. It can widely extend the applications of the reflective device. Ā© 2011 Optical Society of America.1

    Carriage of Cytochrome 2C19 Polymorphism Is Associated With Risk of High Post-Treatment Platelet Reactivity on High Maintenance-Dose Clopidogrel of 150 mg/day Results of the ACCEL-DOUBLE (Accelerated Platelet Inhibition by a Double Dose of Clopidogrel According to Gene Polymorphism) Study

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    ObjectivesThis study sought to determine the impact of gene polymorphisms on platelet reactivity (PR) after clopidogrel 150 mg/day in patients treated with percutaneous coronary intervention (PCI).BackgroundAlthough high maintenance-dose (MD) clopidogrel reduces PR, it is unknown whether gene polymorphisms are related with the risk of high post-treatment PR (HPPR) after high-MD clopidogrel.MethodsWe included mostly patients receiving high-MD clopidogrel after PCI from previously registered Gyeongsang National University Hospital data. A total of 126 PCI-treated patients receiving high-MD clopidogrel were enrolled. Platelet reactivity was assessed with conventional aggregometry and VerifyNow (Accumetrics Inc., San Diego, California) after receiving clopidogrel 150 mg/day for at least 1 month. CYP3A5, CYP2C19, and ABCB1 genotyping was performed. We defined HPPR as 5 Ī¼mol/l adenosine diphosphate (ADP)ā€“induced maximal PR (PRmax) >50%.ResultsCYP3A5 and ABCB1 polymorphisms did not influence PR. Carriers of CYP2C19 variant (*2 or *3) (n = 80) had significantly higher 5 and 20 Ī¼mol/l ADP-induced PRmax than did noncarriers (n = 46) (40.7 Ā± 16.8% vs. 30.3 Ā± 12.6%, p < 0.001; 54.2 Ā± 16.2% vs. 40.5 Ā± 15.8%, p < 0.001, respectively). Late PR and VerifyNow results indicated consistently greater measures in carriers versus noncarriers of CYP2C19 variant. All platelet measures proportionally increased according to the number of CYP2C19 variant alleles. Twenty-seven (21.4%) patients met the criteria for HPPR. Prevalence of HPPR was 8.7%, 21.7%, and 50.0% in carriers of 0, 1, and 2 CYP2C19 variant alleles, respectively (p < 0.001). By multivariate analysis, carriage of CYP2C19 variant was a significant predictor of HPPR (odds ratio: 5.525, 95% confidence interval: 1.333 to 23.256, p = 0.018).ConclusionsAmong PCI-treated patients receiving high-MD clopidogrel, carriage of CYP2C19 variant relates to increased PR and predicts risk of HPPR. (Adjunctive Cilostazol Versus High Maintenance-dose ClopidogrEL in Acute Myocardial Infarction [AMI] Patients According to CYP2C19 Polymorphism [ACCELAMI2C19]; NCT00915733; and Comparison of Platelet Inhibition With Adjunctive Cilostazol Versus High Maintenance-Dose Clopidogrel According to Hepatic Cytochrome 2C19 Allele (CYP2C19) Polymorphism [ACCEL2C19]; NCT00891670)

    Hepatitis C Virus NS5B Protein Is a Membrane-Associated Phosphoprotein with a Predominantly Perinuclear Localization

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    AbstractHepatitis C virus NS5B protein is an RNA-dependent RNA polymerase. To investigate the properties and function of this protein, we have expressed the NS5B protein in insect and mammalian cells. NS5B was found to be present as fine speckles in the cytoplasm, particularly concentrated in the perinuclear region, suggesting its association with the nuclear membrane, the endoplasmic reticulum, or the Golgi complex. This conclusion was supported by the biochemical demonstration that NS5B was associated with the membranes in the cells. Furthermore, it was shown that NS5B protein is a phosphoprotein. These properties may be related to its function as an RNA polymerase
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