269 research outputs found
Effect of Luobuma leaves against oxidation of low-density lipoprotein : a cell culture assay
In a previous study, we observed an improvement in the atherosclerosis index, together with a decrease in blood cholesterol, in rats given Luobuma extract orally and fed a high-cholesterol diet. The present study was designed to examine the function of oxidized low-density lipoprotein (LDL) in atherosclerotic lesions, using cultured cells. When endothelial cells were cultured with LDL in the presence of Cu^, the release of thiobarbituric acid (TBA) -reactive substance and lactic dehydrogenase into the culture medium was increased, with a decrease in cell viability. However, when Luobuma extract was also present in the culture medium, changes in these parameters were more favorable. In another in vitro system using macrophages, the levels of TBA-reactive substance, total cholesterol and esterified cholesterol were all significantly lower in the presence of Luobuma extract than in its absence. There was also morphological evidence that foam cell formation through incorporation of oxidized LDL was suppressed. These findings indicate that Luobuma suppresses the progression of atherosclerosis, in which oxidized LDL is involved. 先に,高コレステロール食投与ラットに羅布麻エキスを経口投与した場合,高コレステロール血症の低下とともに動脈硬化指数の改善作用が認められたので,今回,粥状動脈硬化病変への酸化LDLの機能を細胞を用い検寸寸した。まず内皮細胞にLDLとCu^を添加して培養した場合,培地中へのチオバルビツール酸反応物質,総LDHの放出が増加して,細胞生存率の低下が観察された。しかし羅布麻エキス添加群ではこれらパラメータがいずれも改善し,またマクロファージを用いた系でもチオバルビツール酸反応物質,コレステロールエステル,コレステロールエステル/遊離コレステロール比がいずれも無添加群より有意に低下し,形態学的な変化も酸化LDLのとり込みに伴う泡沫化の形成を抑制する知見が得られた。このことから,羅布麻は酸化LDLが関与する動脈硬化の進展過程を抑制することが明らかとなった
Spectropolarimetry of Extremely Luminous Type Ia Supernova 2009dc: Nearly Spherical Explosion of Super-Chandrasekhar Mass White Dwarf
We present the first spectropolarimetric observations of a candidate of
super-Chandrasekhar mass Type Ia supernova (SN): SN 2009dc. The observations
were performed at 5.6 and 89.5 days after the B-band maximum. The data taken at
the later epoch are used to determine the interstellar polarization. Continuum
polarization is found to be small (<0.3 %), indicating that the explosion is
nearly spherically symmetric. This fact suggests that a very aspherical
explosion is not a likely scenario for SN 2009dc. Polarization at the Si II and
Ca II lines clearly shows a loop in the Q-U plane, indicating a
non-axisymmetric, clumpy distribution of intermediate-mass elements. The degree
of line polarization at the Si and Ca line is moderate (0.5% +- 0.1% and 0.7%
+- 0.1%, respectively), but it is higher than expected from the trend of other
Type Ia SNe. This may suggest that there are thick enough, clumpy Si-rich
layers above the thick 56Ni-rich layers (>~ 1.2 Msun). The observed
spectropolarimetric properties, combined with the photometric and spectroscopic
properties, suggest that the progenitor of SN 2009dc has a super-Chandrasekhar
mass, and that the explosion geometry is globally spherically symmetric, with
clumpy distribution of intermediate-mass elements.Comment: 9 pages, 6 figures, The Astrophysical Journal, in pres
Research for Formation of High-Quality Diamond Epitaxial Thin Layers on the Diamond Substrates and Evaluation of These Layers
We have developed a microwave-plasma CVD apparatus for depositing epitaxial diamond layers on the diamond substrates. We used Ib-type substrates and succeeded in depositing high-quality diamond epitaxial layers on these substrates, confirmed by measuring Raman shift spectra and the electrical characteristics of CVD layers using a Hall effect measuring instrument. However, the surface morphology of the deposited layers is not so good, as ascertained by Atomic Force Microprobe. We also measured impurity profiles in the CVD layers, using Secondary Ion Mass Spectroscopy. Moreover, we found an abrupt concentration difference of N impurity at the interface between the deposited layer and the substrate, showing that the concentration of N impurity is lower in the CVD layer than in the substrate
Establishment of Medium Current Ion Implanter at Kanagawa University
A medium-current-type ion implanter was introduced into Kanagawa University. This machine can be used for various purposes, for example, characteristic changes of various materials such as metals, semiconductors, or insulators. Doping various impurities to many kinds of semiconductors is one of the principal roles of semiconductor industries, to acquire controlled electrical conductivity. These features can be accomplished by irradiating various ion species at various energies for various doses. This implanter can implant ion species from hydrogen to atoms with a mass number around gold. The accelerated ion energy ranges from 5 keV to 200keV. The most peculiar feature of this machine is the structure of the target holder, that is, endstation construction. Targets can be kept during ion implantation at temperatures from -200℃ using a liquid nitrogen cooling system to 1000℃ by heaters. The specification of these features cannot be achieved by any other ion implanter in the world. We sincerely hope that this machine will be widely used in Kanagawa University
Development of Multi-purpose Spectroscopy System
Photo-Luminescence (PL) and Cathode-Luminescence (CL) apparatus were designed and created for measurements of fluorescent light from many kinds of semiconductors and other various high-functional materials. A 375-nm wavelength ultra-violet laser beam focused in ~5 pm diameter at a target surface is used for stimulating target materials in PL measurement. A well-collimated electron beam of several micro amperes at maximum energy of 30-keV is used for stimulating target materials in CL measurement. Luminescences between 200 DM-950 nm wavelengths are introduced into a single crystal Ge detector via the light-fiber. One photon produces one electron via the photoelectric effect in Ge crystal. Thus, according to the number of incident photons, the same number of electrons is produced and emitted from Ge crystal and introduced into a photo-multiplier, which amplifies these electron numbers by about one million. These amplified electrons are introduced into a high- sensitivity current meter. Thus, luminescence intensity is proportional to current intensity. Even one photon can be detected by this analysis system. We successfully observed luminescence from fluorescent oil painted on the Si substrate and luminescence from the GaAs semiconductor substrate
Research into Electorical Activation of Ion-implanteed Diamond Semiconductor Using MeV Ion Beam Irradation : Research into Formation of High-Quality Diamond Epitaxial Thin Layers on the Diamond Substrates and Evaluation of These Layers (2)
We have developed a microwave-plasma CVD apparatus for depositing epitaxial diamond layers on the diamond substrates. We reported in 2006 that high-quality diamond epitaxial layers were successfully deposited on these substrates, however, sharp peaks of points several microns high were also observed by using an Atomic Force Microprobe. We attributed these peaks to carbon nanotubes grown on the diamond substrate, because a high density of contamination atoms for species around iron element was detected by the Rutherford Backscattering analysis on the as-purchased diamond substrates. Therefore, in 2007, we adopted some cleaning processes for the diamond substrate surface before deposition, using acidic liquid. We successfully obtained high-quality diamond epitaxial layers without sharp high peaks, however, we observe a uneven hills. These can be attributed to the very small uneven surfaces of the as-purchased diamond substrates, due to inadequate polishing process at the diamond substrate maker. We are now reexamining the polishing process, including the etching process, to obtain clean and flat surfaces of the as-purchased diamond substrates
Noncrystalline Nanocomposites as a Remedy for the Low Diffusivity of Multivalent Ions in Battery Cathodes
Rechargeable batteries using multivalent metals are among the most promising next-generation battery systems due to their high capacity, high safety, and low cost compared with lithium-ion batteries. However, strong cation−anion interaction degrades diffusion in solid cathodes, an effect that must be mitigated to yield practical multivalent metal batteries. We show that a highly defective iron phosphate−carbon composite prepared by ultracentrifugation serves as a reversible insertion/deinsertion for magnesium ions with, and operates beyond, a 2-V cell voltage at room temperature. A composite of noncrystalline particles that embeds the surrounding carbon structure enhances the magnesium-ion diffusion in the solid phase with stability for cycle life. X-ray absorption spectroscopy, transmission electron microscopy with energy-dispersive X-ray spectroscopy, and high-energy X-ray scattering measurements demonstrate magnesium-ion insertion and extraction in the defective iron phosphate without conversion reactions. This work suggests promising applications for highly defective structures as intercalation hosts for multivalent ions
Factor analysis for construct validity of a trunk impairment scale in Parkinson’s disease: a cross-sectional study
ObjectivesTo investigate the construct validity of the Trunk Impairment Scale (TIS), which was developed to assess trunk impairment in patients with stroke, in patients with Parkinson’s disease (PD).DesignThis retrospective, cross-sectional study enrolled consecutive PD inpatients. Correlation analysis was performed to clarify whether the TIS assessment was related to other balance functions, lower extremity muscle strength, or walking ability. Factor analysis was performed to see how the background factors of TIS differ from balance function, lower limb muscle strength, and walking ability.ResultsExamining the data of 471 patients with PD, there were relationships between TIS and the Mini-Balance Evaluation Systems Test (r = 0.67), Barthel Index (r = 0.57), general lower limb extension torque (r = 0.51), two-minute walk test (r = 0.54), Hoehn and Yahr stage (r = −0.61), and Movement Disorder Society Unified Parkinson’s Disease Rating Scale part III total points (r = −0.59). Factor analysis showed that TIS items were divided into three factors (an abdominal muscles and righting reflex component; a perception and verticality component; and a rotational component), differing from other scales that included clinical assessment items.ConclusionThe TIS can be useful for assessing the underlying trunk impairment as a basis for activities of daily living, gait function, and balance ability in patients with PD
Single-port laparoscopic colectomy versus conventional laparoscopic colectomy for colon cancer: a comparison of surgical results
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