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61.
Toshihiko Sakurai Maki Horikawa Makoto Takafuji Atsushi Kubo Hirotaka Ihara 《Applied Surface Science》2006,253(2):869-873
An l-glutamic acid-derived lipid with a terminal thiol has been synthesized and its corresponding self-assembled structure on Au(1 1 1) surfaces described. The surface morphology of the lipid self-assembled monolayer (SAM) exhibits nano-order patterning, where the height of the monolayer (approximately 1.5 nm) could be interpreted as due to the monolayer structure estimated from molecular models. The molecular orientation in the monolayer is almost perpendicular to the Au(1 1 1) surface depending on the three-point hydrogen-bonding sites in the molecule. 相似文献
62.
S. Saitoh H. Tanaka A. Ono Y. Furuhama T. Manabe T. Ihara 《International Journal of Infrared and Millimeter Waves》1986,7(6):795-812
The attenuation of 245.52 GHz millimeter wave was measured through a near ground horizontal path in order to study the anomalous water vapor absorption at the window region. The result demonstrates that the attenuation coefficient includes the quadratic dependence on the water vapor density. The quadratic component of the water vapor density in the expression of the attenuation was assumed to arises from the contribution of water dimers alone, then the concentration of water dimers was estimated adopting the published theoretical water dimers absorption coefficient. The obtained concentration was 0.062% of monomers in number when the water vapor density is 7.5 g/m3. This concentration is in agreement with the published result obtained by way of another method. 相似文献
63.
Mingliang Zhang Abul K. Mallik Makoto Takafuji Hirotaka Ihara Hongdeng Qiu 《Analytica chimica acta》2015
Ionic liquids (ILs), a class of unique substances composed purely by cation and anions, are renowned for their fascinating physical and chemical properties, such as negligible volatility, high dissolution power, high thermal stability, tunable structure and miscibility. They are enjoying ever-growing applications in a great diversity of disciplines. 相似文献
64.
Quinolone Analogs 14: Synthesis of Antimalarial 1‐Aryl‐3‐(4‐quinolon‐2‐yl)ureas and Related Compounds 下载免费PDF全文
Yoshihisa Kurasawa Kiminari Yoshida Naoki Yamazaki Kenji Sasaki Yoshito Zamami Zhao Min Atsumi Togi Hideyuki Ito Eisuke Kaji Haruhiko Fukaya 《Journal of heterocyclic chemistry》2014,51(Z1):E241-E248
The 4‐quinolone‐2‐carbohydrazide 6a was converted into 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e , 1‐aryl‐3‐(4‐quinolon‐2‐yl)imidazolidine‐2,4‐diones 9a , 9b , and N‐(4‐quinolon‐2‐yl)carbamates 10a , 10b via 4‐quinolone‐2‐carbonylazide 7a . The 4‐methoxyquinoline‐2‐carbohydrazide 6b was also transformed into 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)ureas 11a , 11b , 11c , 11d , 1‐aryl‐3‐(4‐methoxyquinolin‐2‐yl)imidazolidine‐2,4‐diones 12a , 12b , and N‐(4‐methoxyquinolin‐2‐yl)carbamates 13a , 13b via 4‐methoxyquinoline‐2‐carbonylazide 7b . Some of the 1‐aryl‐3‐(4‐quinolon‐2‐yl)ureas 5a , 5b , 5c , 5d , 5e showed the in vitro antimalarial activity to chloroquine‐resistant Plasmodium falciparum, wherein IC50 was 0.93 to 4.00 μM. 相似文献
65.
Keiichiro Ishikawa Nobuyasu Hanari Yoshitaka Shimizu Toshihide Ihara Akira Nomura Masahiko Numata Takashi Yarita Kenji Kato Koichi Chiba 《Accreditation and quality assurance》2011,16(6):311-322
Purity assay of high-purity materials (HPMs) of phthalic acid esters (PAEs) was carried out by means of a mass balance method.
In this method, chromatographic methods such as gas chromatography-flame ionization detector (GC-FID) and/or high-performance
liquid chromatography (HPLC) in combination with other methods such as Karl-Fischer (KF) titration and vacuum evaporation
(VE) were applied. The sum of the impurities estimated by these methods allowed the estimation of the purity of the main component
by difference. Seven PAEs with varying side chain structures and levels of impurities were analysed on a systematic way in
which impurities were classified into several groups in terms of their abundance, availability of qualitative information
and availability of authentic compounds, etc. The absolute quantity of each impurity was determined by GC-FID and/or HPLC
based on the calibration made by the authentic compounds of impurities whenever available. The purities in mass fraction of
these PAEs were certified at the National Metrology Institute of Japan (NMIJ), and the PAEs were registered as primary reference
materials playing an essential role in linking the metrological traceability of the Japan Calibration Service System (JCSS)
to the International System of Units (SI). 相似文献
66.
The results of and findings from an interlaboratory comparison among laboratories carrying out food testing of pesticide residues
in the APEC (Asia–Pacific Economic Cooperation) region are presented and discussed to show critical roles of chemical metrology
infrastructure in establishing traceability of measurements and in supporting existing measurement capability in safety and
quality of food trade. The study material, which was prepared and certified by Korea Research Institute of Standards and Science
(KRISS), was freeze-dried Chinese cabbage powder fortified with two organophosphorous pesticides (diazinon and chlorpyrifos).
Among 14 participants, 12 laboratories were accredited based on ISO/IEC17025 and one laboratory was under assessment for the
accreditation at the time of this study. Though all participants demonstrated very good intra-day repeatability and inter-day
intermediate precision, many of them showed a large bias from the certified values. It is suggested that in addition to the
accreditation system, economies are encouraged to develop appropriate chemical metrology infrastructure, which could effectively
support laboratories to assure measurement traceability to SI, for which NMIs could play significant roles through their metrological
services recognized in Mutual Recognition Arrangement (MRA) of the International Committee for Weights and Measures (Comité
International des Poids et Mesures, CIPM). 相似文献
67.
Citrin is the hepatic mitochondrial aspartate–glutamate carrier that is encoded by the gene SLC25A13. Citrin deficiency often leads to hyperammonemia, for which the current treatment concept is different from that for primary
hyperammonemias. Metabolite level diagnosis, often referred to as chemical diagnosis, is not always successful in identifying
citrin deficiency immediately or in a timely fashion. We previously made the chemical diagnosis of citrin deficiency in ten
patients from nine families. In order to devise a more rapid and more accurate chemical diagnosis of this disorder than is
currently available, we reinvestigated the gas chromatography/mass spectrometry-based urine metabolome in these patients.
In patients aged 2 to 5 months, prominent biomarkers detected included one or more of the following metabolites: tyrosine,
p-hydroxyphenyllactate, p-hydroxyphenylpyruvate, and N-acetyltyrosine, galactose, galactitol and galactonate, glucose, glucitol, and cystathionine. These biomarkers are less prominent
in older patients, but are not increased in argininosuccinate synthetase deficiency or other hyperammonemias. α-Ketoglutaramate
(KGM), a recently recognized urinary biomarker of primary hyperammonemias associated with defects of the urea cycle, was increased
in most patients with citrin deficiency studied here in spite of normal urinary levels of glutamine (the immediate precursor
of KGM), 5-oxoproline, glutamate, aspartate, and asparagine. Other important urinary biomarkers that should be measured for
differential diagnosis of hyperammonemias, including orotate, uracil, and β-ureidopropionate, were not increased. The presence
of citrulline and citrulline-derived metabolites was noted in all cases. The present study shows that noninvasive urine metabolomics,
together with an analysis of selected metabolites or groups of metabolites, provides a more reliable and rapid chemical diagnosis
of citrin deficiency than was previously available and more readily differentiates this disorder from other hyperammonemic
syndromes. 相似文献
68.
Ito S Tanaka Y Yoshikawa H Ishibashi Y Miyasaka H Masuhara H 《Journal of the American Chemical Society》2011,133(37):14472-14475
Controlling chemical reactions within a small space is a significant issue in chemistry, and methods to induce reactions within a desired position have various potential applications. Here we demonstrate localized, efficient photopolymerization by radiation pressure. We induced a one-photon UV polymerization of liquid acrylate solutions in the optical-trapping potential of a focused near-IR (NIR) laser beam, leading to the confinement of solidification to a minute space with dimensions smaller or equal to one-fifth of the wavelength of the NIR laser. Our approach can produce solidification volumes smaller than those achievable with conventional one-photon polymerization, thus enabling the production of tiny polymeric structures that are smaller than the diffraction limit of the trapping light. This is the first demonstration of a radiation pressure effect on a photochemical reaction. 相似文献
69.
Mallik AK Qiu H Sawada T Takafuji M Ihara H 《Chemical communications (Cambridge, England)》2011,47(37):10341-10343
A molecular gel system was assembled on carrier particles and the integrated effect of weak interaction sites enabled highly efficient separation of the bioactive and shape-constrained isomers of tocopherols, β-carotene, and polycyclic aromatic hydrocarbons (PAHs) by multiple interaction mechanisms. 相似文献
70.
A germacalix‐crown, 25,27‐bis[1‐(3‐trimethylgermylpropyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1a ), and its carbon analog, 25,27‐bis‐[1‐(4,4‐dimethylpentyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1b ), were prepared and their structures were confirmed by elemental analysis and 1H and 13C NMR spectroscopy. A cation transport test indicated that both compounds exhibited much the same cation transport ability, so that the role of the germanium moiety in capturing and transporting counteranions is not yet clear. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献