801 research outputs found

    TauDecay: a library to simulate polarized tau decays via FeynRules and MadGraph5

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    TauDecay is a library of helicity amplitudes to simulate polarized tau decays, constructed in the FeynRules and MadGraph5 framework. Together with the leptonic mode, the decay library includes the main hadronic modes, \tau \to \nu_{\tau}+\pi, 2\pi, and 3\pi, which are introduced as effective vertices by using FeynRules. The model file allows us to simulate tau decays when the on-shell tau production is kinematically forbidden. We also demonstrate that all possible correlations among the decay products of pair-produced taus through a Z boson and a scalar/pseudoscalar Higgs boson are produced automatically. The program has been tested carefully by making use of the standard tau decay library Tauola.Comment: 10 pages, 12 figures, 3 tables; v2: typo in Eq.(20b) corrected, references added, version accepted by EPJC. 'Note added' also included for the brief TauDecay instruction in MadGraph5_aMC@NL

    Reduction of exogenous ketones depends upon NADPH generated photosynthetically in cells of the cyanobacterium Synechococcus PCC 7942

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    Effective utilization of photosynthetic microorganisms as potential biocatalysts is favorable for the production of useful biomaterials and the reduction of atmospheric CO2. For example, biocatalytic transformations are used in the synthesis of optically active alcohols. We previously found that ketone reduction in cells of the cyanobacterium Synechococcus PCC 7942 is highly enantioselective and remarkably enhanced under light illumination. In this study, the mechanism of light-enhanced ketone reduction was investigated in detail using several inhibitors of photosynthetic electron transport and of enzymes of the Calvin cycle. It is demonstrated that light intensity and photosynthesis inhibitors significantly affect the ketone reduction activity in Synechococcus. This indicates that the reduction correlates well with photosynthetic activity. Moreover, ketone reduction in Synechococcus specifically depends upon NADPH and not NADH. These results also suggest that cyanobacteria have the potential to be utilized as biocatalytic systems for direct usage of light energy in various applications such as syntheses of useful compounds and remediation of environmental pollutants

    Density Functional Perturbation Theory to Predict Piezoelectric Properties

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    Among the various computational methods in materials science, only first-principles calculation based on the density functional theory has predictability for unknown material. Especially, density functional perturbation theory (DFPT) can effectively calculate the second derivative of the total energy with respect to the atomic displacement. By using DFPT method, we can predict piezoelectric constants, dielectric constants, elastic constants, and phonon dispersion relationship of any given crystal structure. Recently, we established the computational technique to decompose piezoelectric constants into each atomic contribution, which enable us to gain deeper insights to understand the piezoelectricity of material. Therefore, in this chapter, we will introduce the computational framework to predict piezoelectric properties of polar material by means of DFPT and details of decomposition technique of piezoelectric constants. Then, we will show some case studies to predict and discover new piezoelectric material

    Visualization of coronary plaque in type 2 diabetes mellitus patients using a new 40MHz intravascular ultrasound imaging system

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    SummaryBackgroundPrevious epidemiological studies demonstrated plaque vulnerability to be high in diabetic patients. iMap-intravascular ultrasound (IVUS) is a recently developed radiofrequency 40MHz IVUS imaging system for tissue characterization. This study aimed to characterize coronary plaque in target lesions of diabetic patients using iMap-IVUS.MethodsWe studied 175 treated vessels in 146 patients with stable angina pectoris and analyzed plaque components of culprit lesions by iMAP-IVUS. Patients were divided into 2 groups: non-diabetic (non-DM: 112 vessels, 93 patients) and diabetic (DM: 63 vessels, 53 patients).ResultsIn gray-scale IVUS 2D analysis, there were no differences in IVUS parameters. In 3D analysis, the DM group tended to have a larger plaque volume (p=0.07) and plaque burden (p=0.10). At minimum lumen sites, the absolute lipidic and necrotic areas (0.84±0.44mm2 vs. 0.58±0.41mm2, p<0.001, and 2.42±1.65mm2 vs. 1.46±1.76mm2, p<0.001, respectively) and percent lipidic and necrotic areas were significantly greater in the DM than in the non-DM group (8.39±3.38% vs. 5.25±2.30%, p<0.0001, and 23.65±11.54% vs. 12.99±10.71%, p<0.0001, respectively). In addition, the absolute lipidic and necrotic volumes (11.75±10.59mm3 vs. 8.18±6.24mm3, p<0.01, and 29.99±28.90mm3 vs. 19.44±19.35mm3, p<0.01, respectively) and percent lipidic and necrotic volumes were significantly greater in the DM than in the non-DM group (6.27±1.92% vs. 5.13±1.82%, p<0.0001, and 16.54±7.56% vs. 12.08±6.05%, p<0.0001, respectively).ConclusionCharacterization of coronary plaque by iMAP-IVUS in diabetic patients showed increased lipidic amount and necrotic plaque volume relative to subjects without DM

    Relationship between tissue characterization with 40MHz intravascular ultrasound imaging and 64-slice computed tomography

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    AbstractBackgroundIdentification of coronary plaque composition is important for selecting the treatment strategy, and 64-slice computed tomography (CT) is a noninvasive method of characterizing atherosclerotic plaques. However, the correlation between plaque characteristics detected by CT and intravascular ultrasound (IVUS) is not clear. A 40MHz IVUS imaging system (iMap-IVUS) has recently been developed to evaluate plaque composition. The aim of this study was to compare iMap-IVUS with 64-slice CT angiography for the characterization of non-calcified coronary plaques.Methods and resultsBoth 64-slice CT angiography and iMap-IVUS were performed in 19 patients (38 plaques). CT values were measured as Hounsfield units (HU) in circular regions of interest (ROI) drawn on the plaques. The iMap-IVUS system analyzed coronary plaques as fibrotic, lipidic, necrotic, or calcified tissue based on the radiofrequency spectrum.A positive correlation was found between CT values and the percentage of fibrotic plaque (r=0.34, p=0.036) or calcified plaque (r=0.40, p=0.011). Conversely, a negative correlation was found between CT values and the percentage of lipidic plaque (r=−0.41, p=0.01), or necrotic plaque (r=−0.41, p=0.01).ConclusionsGood correlations were observed between the characteristics of non-calcified plaque determined by iMap-IVUS and the CT values of plaque detected by 64-slice CT scanning
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