458 research outputs found

    Determination of polyamines in Arabidopsis thaliana by capillary electrophoresis using salicylaldehyde-5-sulfonate as a derivatizing reagent

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    Herein, we report a novel method for the determination of polyamines in a sample extracted from Arabidopsis thaliana by capillary electrophoresis (CE) using salicylaldehyde-5-sulfonate (SAS) as a derivatizing reagent. An aldehyde group of SAS forms a Schiff base with amino groups of aliphatic polyamines, resulting in an anionic species with an absorption band in the ultraviolet region. The derivatization method was straightforward since the derivatives were formed by mixing a sample with the derivatizing reagent at a neutral pH. In addition, the negative charges induced by SAS led to a high resolution with a short analysis time. This method permitted the separation of five polyamines, which play important roles in plants. However, further improvement in sensitivity was needed for the determination of the polyamines in plant samples. Therefore, the CE method was coupled with solid-phase extraction (SPE) using an ion-pairing formation with sodium dodecyl benzene sulfonate. The SPE method improved the concentration limits of detection to sub-μM levels, which corresponded with a 10-fold enhancement. The calibration curves for cadaverine, putrescine, and spermidine were linear with concentrations that ranged from 1 to 20 μM and correlation coefficients (R2) were greater than 0.998. The proposed method was applied to the determination of spermidine in a plant sample, Arabidopsis thaliana

    Dietary effect of pomegranate seed oil rich in 9cis, 11trans, 13cis conjugated linolenic acid on lipid metabolism in obese, hyperlipidemic OLETF Rats

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    Conjugated fatty acid, the general term of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bonds, has attracted considerable attention because of its potentially beneficial biological effects. In the present study, dietary effect of pomegranate seed oil rich in punicic acid (9cis, 11trans, 13cis-conjugated linolenic acid; 9c, 11t, 13c-CLNA) on lipid metabolism was investigated in obese, hyperlipidemic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. After 2 weeks feeding period, OLETF rats revealed obesity and hyperlipidemia compared with their progenitor LETO rats. Feeding of the diet supplemented with 9% safflower oil and 1% pomegranate seed oil (9c, 11t, 13c-CLNA diet) did not affect abdominal white adipose tissue weights and serum lipid levels compared with the diet supplemented with 10% safflower oil (control diet) in OLETF rats. However, the accumulated hepatic triacylglycerol was markedly decreased by 9c, 11t, 13c-CLNA diet in OLETF rats. Activities of hepatic enzymes related to fatty acid synthesis and fatty acid β-oxidation were not altered by 9c, 11t, 13c-CLNA diet. Levels of monounsaturated fatty acid (MUFA), major storage form of fatty acid, in serum triacylglycerol were markedly higher in obese, hyperlipidemic OLETF rats than in lean LETO rats. In addition, 9c, 11t, 13c-CLNA diet significantly decreased MUFA levels in OLETF rats. This is the first study showing that 9c, 11t, 13c-CLNA suppresses delta-9 desaturation in vivo, and we suggest that the alleviation of hepatic triacylglycerol accumulation by 9c, 11t, 13c-CLNA diet was, at least in part, attributable to the suppression of delta-9 desaturation in OLETF rats

    Three Cases of Struma Ovarii Underwent Laparoscopic Surgery with Definite Preoperative Diagnosis

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    Struma ovarii is a rare neoplasm that accounts for approximately 0.3オ of ovarian tumors. Due to its ultrasound morphology, which is quite similar to that of malignant ovarian carcinoma, most struma ovarii cases are open operated with laparotomy rather than laparoscopy. We present 3 cases of struma ovarii, which were diagnosed preoperatively by imaging studies and removed by laparoscopic surgery. All patients were premenopausal women between ages 31‒50. The magnetic resonance imaging (MRI) findings were complex masses composed of multiple cysts and solid components with T2-hypointense regions as well as multiple T1-hyperintense cystic areas, findings that are typical for struma ovarii. A combination of plain computed tomography (CT), positron emission tomography (PET)-CT, and scintigraphy was useful for diagnosis. Laboratory examination revealed elevated serum thyroglobulin, which led to the diagnosis of struma ovarii. Laparoscopic surgeries were performed without rupturing the tumors. Although it has been difficult to differentiate between struma ovarii and malignant tumors by conventional methods, recently MRI techniques appear make it possible to diagnose struma ovarii preoperatively from the abovementioned imaging characteristic, together with laboratory data. As for treatment, we think laparoscopy could be successful for struma ovarii, but the surgeon must be careful not to rupture the tumor intra-abdominally in order to prevent dissemination, which could lead to malignancy

    Detection and characterization of antibody to liver cell membrane in sera from patients with chronic active liver diseases.

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    Sera from 84 patients with chronic liver disease [CLD] (74 chronic active) and from 53 blood donors were tested immunochemically for anti-liver cell membrane antibody (LMAb). LMAb to rat liver tested by an indirect immunofluorescent technique was positive in 53.3% of CLD patients with positive HB surface antibody (HBsAb) and 40.0% of HBsAb positive blood donors. Pepsin digestion of the sera indicated that the binding between liver cell membrane and IgG was at the Fc site on the immunoglobulin. The sera with positive LMAb from HBsAb positive blood donors had elevated Clq-binding activity (Clq-BA). The LMAb to rat liver was a macro-molecular IgG (19-22S IgG) when assayed by Sephadex G-200 column chromatography and 5-40% sucrose density gradient ultracentrifugation. The results suggest that the LMAb in serum from a patient with chronic active liver disease may be an immune complex which consists of various antigens such as HB virus and its antibodies in serum.</p

    Novel hexagonal structure and ultrahigh strength of magnesium solid solution in the Mg-Zn-Y system

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    A magnesium (Mg) solid solution with a long periodic hexagonal structure was found in a Mg97Zn1Y2 (at.%) alloy in a bulk form prepared by warm extrusion of atomized powders at 573 K. The novel structure has an ABACAB-type six layered packing with lattice parameters of a = 0.322 nm and c = 3 ~ 0.521 nm. The Mg solid solution has fine grain sizes of 100 to 150 nm and contains 0.78 at.% Zn and 1.82 at.% Y. In addition, cubic Mg24Y5 particles with a size of about 7 nm are dispersed at small volume fractions of less than 10% in the Mg matrix. The specific density (ƒÏ) of the extruded bulk Mg-Zn-Y alloy was 1.84 Mg/m3. The tensile yield strength (ƒÐy) and elongation (ƒÂ) are 610 MPa and 5%, respectively, at room temperature, and the specific yield strength defined by the ratio of ƒÐy to ƒÏ is as high as 3.3 ~ 105 Nm/kg. High ƒÐy values exceeding 400 MPa are also maintained at temperatures up to 473 K. It is noticed that the ƒÐy levels are 2.5 to 5 times higher than those for conventional high-strength type Mg-based alloys. The Mg-based alloy also exhibits a high-strain-rate superplasticity with large ƒÂ of 700 to 800% at high strain rates of 0.1 to 0.2 s-1 and 623 K. The excellent mechanical properties are due to the combination of the fine grain size, new long periodic hexagonal solid solution containing Y and Zn, and dispersion of fine Mg24Y5 particles. The new Mg-based alloy is expected to be used in many fields

    Interplay between Stellar Spirals and the ISM in Galactic Disks

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    We propose a new dynamical picture of galactic stellar and gas spirals, based on hydrodynamic simulations in a `live' stellar disk. We focus especially on spiral structures excited in a isolated galactic disk without a stellar bar. Using high-resolution, 3-dimensional N-body/SPH simulations, we found that the spiral features of the gas in galactic disks are formed by essentially different mechanisms from the galactic shock in stellar density waves. The stellar spiral arms and the interstellar matter on average corotate in a galactic potential at any radii. Unlike the stream motions in the galactic shock, the interstellar matter flows into the local potential minima with irregular motions. The flows converge to form dense gas clouds/filaments near the bottom of the stellar spirals, whose global structures resemble dust-lanes seen in late-type spiral galaxies. The stellar arms are non-steady; they are wound and stretched by the galactic shear, and thus local densities of the arm change on a time scale of ~ 100 Myrs, due to bifurcating or merging with other arms. This makes the gas spirals associated with the stellar arms non-steady. The association of dense gas clouds are eventually dissolved into inter-arm regions with non-cirucular motions. Star clusters are formed from the cold, dense gases, whose ages are less than ~30 Myrs, and they are roughly associated with the background stellar arms without a clear spatial offset between gas spiral arms and distribution of young stars.Comment: 13 pages, 12 figures, accepted by ApJ. Higher resolution of ms.pdf is available at http://d.pr/Nvjk A targzipped Supplementary movies is available at http://d.pr/TV6

    Organizing Active Learning Models in Science Classes (2)

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    The purpose of this study is to organize active learning models in science classes. Through classroom practice from elementary school to upper secondary school, we observed the followings: 1) the "reciprocal of internalization and externalization," which means collaborative and cooperative learning, is the key to active learning in science lessons; 2) by creating a "subject skeleton," teachers can gain clarity regarding the promotion of deep learning and organize active learning models in science classes
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