1,288 research outputs found
A Study on Intrinsic Localized Modes in a Macro-mechanical Cantilever Array with Tunable on-site Nonlinearity
AbstractA macro-mechanical cantilever array with tunable on-site nonlinearity is proposed for experimental study on dynamics of intrinsic localized mode (ILM). In this paper, the cantilever array is first introduced and the equation of motion is derived. An experimentally excited ILM is shown and compared with the corresponding ILM obtained numerically. In addition, an unstable ILM is also shown with its waveform and Floquet multipliers
Replacement of the Catalytic Nucleophile Aspartyl Residue of Dextran Glucosidase by Cysteine Sulfinate Enhances Transglycosylation Activity
Dextran glucosidase from Streptococcus mutans (SmDG) catalyzes the hydrolysis of an α-1,6-glucosidic linkage at the nonreducing end of isomaltooligosaccharides and dextran. This enzyme has an Asp-194 catalytic nucleophile and two catalytically unrelated Cys residues, Cys-129 and Cys-532. Cys-free SmDG was constructed by replacement with Ser (C129S/C532S (2CS), the activity of which was the same as that of the wild type, SmDG). The nucleophile mutant of 2CS was generated by substitution of Asp-194 with Cys (D194C-2CS). The hydrolytic activity of D194C-2CS was 8.1 × 10⁻⁴ % of 2CS. KI-associated oxidation of D194C-2CS increased the activity up to 0.27% of 2CS, which was 330 times higher than D194C-2CS. Peptide-mapping mass analysis of the oxidized D194C-2CS (Ox-D194C-2CS) revealed that Cys-194 was converted into cysteine sulfinate. Ox-D194C-2CS and 2CS shared the same properties (optimum pH, pI, and substrate specificity), whereas Ox-D194C-2CS had much higher transglucosylation activity than 2CS. This is the first study indicating that a more acidic nucleophile (-SOO−) enhances transglycosylation. The introduction of cysteine sulfinate as a catalytic nucleophile could be a novel approach to enhance transglycosylation
Impartial comparative analysis of measurement of leukocyte telomere length/DNA content by Southern blots and qPCR.
Telomere length/DNA content has been measured in epidemiological/clinical settings with the goal of testing a host of hypotheses related to the biology of human aging, but often the conclusions of these studies have been inconsistent. These inconsistencies may stem from various reasons, including the use of different telomere length measurement techniques. Here, we report the first impartial evaluation of measurements of leukocyte telomere length by Southern blot of the terminal restriction fragments and quantitative PCR (qPCR) of telomere DNA content, expressed as the ratio of telomeric product (T)/single copy gene (S) product. Blind measurements on the same samples from 50 donors were performed in two independent laboratories on two different occasions. Both the qPCR and Southern blots displayed highly reproducible results as shown by r values > 0.9 for the correlations between results obtained by either method on two occasions. The inter-assay CV measurement for the qPCR was 6.45%, while that of the Southern blots was 1.74%. The relation between the results generated by Southern blots versus those generated by qPCR deviated from linearity. We discuss the ramifications of these findings with regard to measurements of telomere length/DNA content in epidemiological/clinical circumstances
Fashion-Specific Attributes Interpretation via Dual Gaussian Visual-Semantic Embedding
Several techniques to map various types of components, such as words,
attributes, and images, into the embedded space have been studied. Most of them
estimate the embedded representation of target entity as a point in the
projective space. Some models, such as Word2Gauss, assume a probability
distribution behind the embedded representation, which enables the spread or
variance of the meaning of embedded target components to be captured and
considered in more detail. We examine the method of estimating embedded
representations as probability distributions for the interpretation of
fashion-specific abstract and difficult-to-understand terms. Terms, such as
"casual," "adult-casual,'' "beauty-casual," and "formal," are extremely
subjective and abstract and are difficult for both experts and non-experts to
understand, which discourages users from trying new fashion. We propose an
end-to-end model called dual Gaussian visual-semantic embedding, which maps
images and attributes in the same projective space and enables the
interpretation of the meaning of these terms by its broad applications. We
demonstrate the effectiveness of the proposed method through multifaceted
experiments involving image and attribute mapping, image retrieval and
re-ordering techniques, and a detailed theoretical/analytical discussion of the
distance measure included in the loss function
Macrophage Migration Inhibitory Factor as an Emerging Drug Target to Regulate Antioxidant Response Element System
Oxidative stress is involved in pathophysiology and pathological conditions of numerous human diseases. Thus, understanding the mechanisms underlying the redox homeostasis in cells and organs is valuable for discovery of therapeutic drugs for oxidative stress-related diseases. Recently, by applying chemical biology approach with an ARE activator, BTZO-1, we found macrophage migration inhibitory factor (MIF) as a new regulator of antioxidant response element- (ARE-) mediated gene transcription. BTZO-1 and its active derivatives bound to MIF and protected cells and organs from oxidative insults via ARE activation in animal models with oxidative stress such as ischemia/reperfusion injury, inflammatory bowel diseases, and septic shock. In this review, we briefly highlight key findings in understanding the MIF-ARE system
Pterobreathers in a model for a layered crystal with realistic potentials: Exact moving breathers in a moving frame
In this article we perform a thorough analysis of breathers in a one-dimensional model for a layered silicate for which there exists fossil and experimental evidence of moving excitations along the close-packed lines of the K+ layers. Some of these excitations are likely breathers with a small energy of about 0.2 eV as the numerically obtained breathers described in the present model. Moving breathers as exact solutions of the dynamical equations are obtained at the price of being generically associated with a plane wave, a wing, with finite amplitude, although this amplitude can be very small. We call them pterobreathers. For some frequencies the wings disappear and the solutions become exact moving breathers with no wings, showing the phenomenon of supertransmission of energy. We perform a theoretical analysis of pterobreathers in systems with substrate potential and show that they are characterized by a single frequency in the moving frame plus the frequency of the wings. We have also studied high-energy stationary breathers which transform into single and double kinks and stable multibreathers with very strong localization.Ministerio de Economía y competitividad, FIS2015-65998- C2-2-PMinisterio de Ciencia e Innovación, PRX18/00360Junta de Andalucía, 2017/FQM-280Japan Society for the Promotion of Science, 16K05041Kyoto University Foundation and CASIO Science Promotion Foundation, H29-1
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