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841.
Since ceramides (CERs) play roles in signal transduction and cell regulation, CERs of human hair might be responsible for
apoptosis during keratinization, in addition to their structural barrier and water-holding functions. Although, we previously
developed a method for comprehensive profiling of the CERs in hair, that method was too insensitive to quantitatively characterize
the CERs in a small amount of hair samples. The aim of this study was to develop a novel method for the highly sensitive determination
of the diverse CERs. The method developed is negative ion electrospray ionization mass spectrometry (ESI-MS) coupled to reversed-phase
high-performance liquid chromatography (RP-HPLC) using methanol containing 10 mM ammonium acetate as a mobile phase. By this
method, 48 peaks derived from 73 kinds of CERs were simultaneously determined in selected ion monitoring measurement using
one calibration line of the standard N-palmitoyl dihydrosphigosine, based on extremely small differences in the molar responses among different species of CERs,
followed by the calculation of the actual levels using corrections for 13C and 2H effects. This method had extremely high sensitivity as indicated in the limit of quantification being in the femtomolar
range. Other quantitative validation data, such as reproducibility, linearity and recoveries, were all sufficient. The quantitative
levels of CERs determined by RP-HPLC–ESI-MS were comparable with those determined by thin-layer chromatography. This method
was successfully applied to the characterization of levels of CERs in only 1-mm pieces derived from a single hair fiber and
revealed the presence of interindividual and intraindividual variations of the CER composition. This RP-HPLC–ESI-MS method
can be a powerful tool for future research on physicochemical and physiological roles of CERs in hair. 相似文献
842.
843.
844.
Yoshinori Sato Hikaru Nishizaka Shunichi Sawano Atsushi Yoshinaka Kazutaka Hirano Shinji Hashiguchi Takayuki Arie Seiji Akita Go Yamamoto Toshiyuki Hashida Hisamichi Kimura Kenichi Motomiya Kazuyuki Tohji 《Carbon》2012,50(1):34-39
We prepared and characterized multi-walled carbon nanotube (MWCNT) solids by de-fluorination of fluorinated MWCNTs using spark plasma sintering. In order to investigate the influence of the structure of MWCNT on the mechanical strength of the resulting solids, MWCNTs used in this experiment were as-defected MWCNTs modified by nitric acid and as-purified ones as non-defected nanotubes by comparison. The bend strength and modulus of the resulting solids were lower than those of de-fluorinated MWCNT solids derived from as-purified MWCNTs. The mechanical properties of the resulting MWCNT solids were found to be strongly dependent on the structure of the MWCNT. 相似文献
845.
Yamamoto H Kouno M Muguruma S Hayasaki Y Nagai Y Shimizu Y Nishida N 《Applied optics》2002,41(32):6907-6919
In a stereoscopic full-color LED display by use of a parallax barrier, we discuss optimization of the viewing area, which depends on the width of the black regions between LEDs. Although conventional stereoscopic displays use a parallax barrier to permit the viewer to view stereoscopic images without any special glasses, their viewing area is restricted by crosstalk and the disappearing of pixels. Widening of the viewing area is examined by use of full-color panels with black regions having different widths. The optimum aperture ratio of the parallax barrier is obtained by analyzing the viewing area. An enlarged viewing area has been demonstrated by use of a 3-in-1 chip LED panel that has wider black regions than ordinary LED lamp cluster panels. 相似文献
846.
Nobihiro Kumada Yoshinori Yonesaki Takahiro Takei Nobukazu Kinomura Satoshi Wada 《Materials Research Bulletin》2009,44(6):1298-3456
Single crystals of a new tin titanate containing Sn2+, Sn2TiO4 was prepared by high temperature reaction in an evacuated quartz tube and its crystal structure was determined by single crystal X-ray diffraction data. The tin titanate crystallizes in the tetragonal space group P42/mbc with a = 8.490(2) and c = 5.923(3) Å, Z = 4 and the final R factors are R = 0.0497 and Rw = 0.0676 for 354 unique reflections. This tin titanate is isostructural with the low temperature form of Pb3O4(Pb22+Pb4+O4). This compound was oxidized above 600 °C accompanying the mass gain and finally changed to rutile-type solid solution (Sn,Ti)O2. 相似文献
847.
The identification of appropriate reaction models is very helpful for developing chemical vapor deposition (CVD) processes. In this study, we have developed an automatic system to model reaction mechanisms in the CVD processes by analyzing the experimental results, which are cross-sectional shapes of the deposited films on substrates with micrometer- or nanometer-sized trenches. We designed the inference engine to model the reaction mechanism in the system by the use of real-coded genetic algorithms (RCGAs). We studied the dependence of the system performance on two methods using simple genetic algorithms (SGAs) and the RCGAs; the one involves the conventional GA operators and the other involves the blend crossover operator (BLX-alpha). Although we demonstrated that the systems using both the methods could successfully model the reaction mechanisms, the RCGAs showed the better performance with respect to the accuracy and the calculation cost for identifying the models. 相似文献
848.
Current‐Induced Nucleation and Annihilation of Magnetic Skyrmions at Room Temperature in a Chiral Magnet 下载免费PDF全文
Xiuzhen Yu Daisuke Morikawa Yusuke Tokunaga Takashi Kurumaji Hiroshi Oike Masao Nakamura Fumitaka Kagawa Yasujiro Taguchi Taka‐hisa Arima Masashi Kawasaki Yoshinori Tokura 《Advanced materials (Deerfield Beach, Fla.)》2017,29(21)
A magnetic skyrmion is a nanometer‐scale magnetic vortex carrying an integer topological charge. Skyrmions show a promise for potential application in low‐power‐consumption and high‐density memory devices. To promote their use in applications, it is attempted to control the existence of skyrmions using low electric currents at room temperature (RT). This study presents real‐space observations for the current‐induced formation and annihilation of a skyrmion lattice (SkL) as well as isolated skyrmions in a microdevice composed of a thin chiral magnet Co8Zn9Mn3 with a Curie temperature, T C ≈ 325 K, above RT. It is found that the critical current for the manipulation of Bloch‐type skyrmions is on the order of 108 A m?2, approximately three orders of magnitude lower than that needed for the creation and drive of ferromagnetic (FM) domain walls in thin FM films. The in situ real‐space imaging also demonstrates the dynamical topological transition from a helical or conical structure to a SkL induced by the flow of DC current, thus paving the way for the electrical control of magnetic skyrmions. 相似文献
849.
Tokura Y Kida N 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2011,369(1951):3679-3694
Multiferroics with coexistent ferroelectric and magnetic orders can provide an interesting laboratory to test unprecedented magnetoelectric (ME) responses and their possible applications. One such example is the dynamical and/or resonant coupling between magnetic and electric dipoles in a solid. As examples of such dynamical ME effects, (i)?the multiferroic domain wall dynamics and (ii)?the electric dipole active magnetic responses are discussed with an overview of recent experimental observations. 相似文献
850.
Takahashi T Fukui N Arakawa M Funatsu K Ema Y 《Journal of nanoscience and nanotechnology》2011,11(9):8004-8008
We have developed an automatic modeling system for calculation processes of the simulator to reproduce experimental results of chemical vapor deposition (CVD), in order to decrease the calculation cost of the simulator. Replacing the simulator by the mathematical models proposed by the system will contribute towards decreasing the calculation costs for predicting the experimental results. The system consists of a mobile agent and two software resources in computer networks, that is, generalized modeling software and a simulator reproducing cross-sections of the deposited films on the substrates with the micrometer- or nanometer-sized trenches. The mobile agent autonomously creates appropriate models by moving to and then operating the software resources. The models are calculated by partial least squares regression (PLS), quadratic PLS (QPLS) and error back propagation (BP) methods using artificial neural networks (ANN) and expresses by mathematical formulas to reproduce the calculated results of the simulator. The models show good reproducibility and predictability both for uniformity and filling properties of the films calculated by the simulator. The models using the BP method yield the best performance. The filling property data are more suitable to modeling than film uniformity. 相似文献