2,866 research outputs found
Structural and functional glycosphingolipidomics by glycoblotting with aminooxy-functionalized gold nanoparticle
Glycosphingolipids (GSLs) synthesized in Golgi apparatus by sequential transfer of sugar residues to a ceramide lipid anchor are ubiquitously distributing on vertebrate plasma membranes. Standardized method allowing for high throughput structural profiling and functional characterization of living cell surface GSLs is of growing importance because they function as crucial signal transduction molecules in various processes of dynamic cellular recognitions. However, methods are not available for amplification of GSLs, while the genomic scale PCR amplification permits large-scale mammalian proteomic analysis. Here we communicate such an approach to a novel "omics", namely glycosphingolipidomics based on the glycoblotting method. The method, which involves selective ozonolysis of the C-C double bond in ceramide moiety and subsequent enrichment of generated GSL-aldehydes by chemical ligation using aminooxy-functionalized gold nanoparticle (aoGNP) should be of widespread utility for identifying and characterizing whole GSLs present in the living cell surfaces. The present protocol using glycoblotting permitted MALDI-TOFMS-based high throughput structural profiling of mouse brain gangliosides such as GM1, GD1a/GD1b, and GT1b for adult or GD3 in case for embryonic mouse. When mouse melanoma B16 cells were subjected to this protocol, it was demonstrated that gangliosides enriched from the plasma membranes are only GM3 bearing microheteogeneity in the structure of N-acyl chain. Surface plasmon resonance analysis revealed that aoGNP displaying whole GSLs blotted from mouse B16 melanoma cell surfaces can be used directly for monitoring specific interaction with self-assembled monolayer (SAM) of Gg3Cer (gangliotriaosylceramide). Our results indicate that GSL-selective enrichment onto aoGNP from living cell surfaces allows for rapid reconstruction of plasma membrane models mimicking intact GSL-microdomain feasible for further structural and functional characterization
Semi-Leptonic B Meson Decays to Excited D Mesons in the Covariant Oscillator Quark Model
The spectra and branching ratios of the weak semi-leptonic B meson decays to
the first excited D mesons are predicted, taking into account the confined
effects of quarks using the covariant oscillator quark model (COQM). In the
COQM the same relation between general weak transition form factors as that in
HQET is derived, and the concrete form of the Isgur-Wise function is given with
no free parameters. Our results are somewhat different from those of other
models. The present experimental data are not sufficient for comparison.Comment: 13 pages, 2 Postscript figure, uses ptptex.st
Determination of Crossarm Installation in Fill Dams by Back Analysis
This paper discusses a numerical model that can be used to optimize the installation in a zoned type and a homogeneous type fill dam. Before installation in a real dam to evaluate dam behavior, numerical model described in this paper is carried out on a prototype dam to check the optimum installation, using cross arm measurements. Three cross arm installations at the upstream, the core and downstream to measure displacements are considered. The installation options considered are three cross arm combinations for best installation to verify the safety of dams and to reduce cost. Finite element method is used for generating the displecement field in a linear elastic numerical model. The generated data is used as an input data in the back analysis to check the adequacy of each installation option
Evaluation of Liquefaction Resistance by In-situ Testing and Its Application to Reliability Design
A calculation method of probability of liquefaction is proposed in this paper. The spatial variability of soil parameters for the dynamic shear strength, i.e., N-values, median grain size, fines contents, and the statistical characteristics of the earthquake frequency are considered in the analysis. The standard penetration test (SPT) is convenient to estimate the spatial variability of the dynamic shear strength and mainly used in this study. Furthermore the determination of dynamic shear strength based on Swedish weight Sounding test also introduced here, because it is the simpler test than SPT. While the statistical model of the earthquake frequency is determined based on the record of historical earthquakes. Using this method the probability of liquefaction is calculated. The sand compaction pile method is considered for the ground improvement against the liquefaction. Finally, the relationship between the sand replacement rate and the probability of liquefaction is clarified
One-dimensional Compression Tests of Sludge Cake from Dredged Sludge
One-dimensional compression tests were performed to investigate compression characteristics of sludge cake used as a construction material. The sludge cake is dewatering product of dredged sludge from the bottom of a lake. The test results show following compression characteristics. (1) For the undisturbed samples, e-log p curves show compressibility of overconsolidated clay ordinatily observed. (2) For the disturbed samples, there observed compressibility close to that of ordinary normally consolidated clay. (3) For the recompressed samples, there observed two turning points on e-log p curve. The compression presures(p(c1) and p(c2)) at those points for the unsubmerged tests have a linear correlation with the recompression pressure(p(s)). The submerged tests give very small values of p(c1) and p(c2) compared with the case of unsubmerged test. (4) For the recompressed samples, the first compression index(C(c1)) after p(c) has a linear correlation with the initial void ratio(e(0)), and the second compression index(C(c2)) shows almost constant value
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