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11.
Calorimetric studies have been made on the complex formation of cyclodextrins with triiodide ion or p-nitrophenolate anion in aqueous solutions by using microcalorimeter. The heats of complex formation of α-, β-, and γ-dextrin, respectively with both the guest compounds were obtained and marked differences in magnitude of the reaction heats were observed for the three dextrins. The association process of the dextrins with the guest compounds in aqueous solutions was briefly discussed with respect to the points of stoichiometry and thermodynamics. 相似文献
12.
Masanori Ono Natsumi Toyoda Kyosuke Kagami Takashi Hosono Takeo Matsumoto Shin-ichi Horike Rena Yamazaki Mitsuhiro Nakamura Yasunari Mizumoto Tomoko Fujiwara Hitoshi Ando Hiroshi Fujiwara Takiko Daikoku 《International journal of molecular sciences》2022,23(14)
Recently, it was demonstrated that the expression of BMAL1 was decreased in the endometrium of women suffering from recurrent spontaneous abortion. To investigate the pathological roles of uterine clock genes during pregnancy, we produced conditional deletion of uterine Bmal1 (cKO) mice and found that cKO mice could receive embryo implantation but not sustain pregnancy. Gene ontology analysis of microarray suggested that uterine NK (uNK) cell function was suppressed in cKO mice. Histological examination revealed the poor formation of maternal vascular spaces in the placenta. In contrast to WT mice, uNK cells in the spongiotrophoblast layer, where maternal uNK cells are directly in contact with fetal trophoblast, hardly expressed an immunosuppressive NK marker, CD161, in cKO mice. By progesterone supplementation, pregnancy could be sustained until the end of pregnancy in some cKO mice. Although this treatment did not improve the structural abnormalities of the placenta, it recruited CD161-positive NK cells into the spongiotrophoblast layer in cKO mice. These findings indicate that the uterine clock system may be critical for pregnancy maintenance after embryo implantation. 相似文献
13.
The title compound was prepared by a reaction sequence comprising methylation of heptakis (6-bromo-6-deoxy)-β-cyclodextrin by the Kuhn procedure, regeneration of the primary hydroxyl groups from the resulting heptakis(2-O-methyl-6-bromo-6-deoxy)-β-dextrin via the 6-O-benzoate ester by benzoate exchange and subsequent deesterification. It was proved that the methyl groups in the tetradeca-O-methyl ether of β-dextrin are located 0–2 and 0–6 of the D-glucose residues. 相似文献
14.
Hot acetylation of maltotriose with acetic anhydride and sodium acetate led to the formation of an anomerically unsubstituted maltotriose decaacetate (2.8% yield) in amorphous form in addition to the principal product, β-maltotriose hendecaacetate (80% yield). The structure of the decaacetate was elucidated by chemical reactions and n.m.r. spectroscopy. α-Maltotriose hendecaacetate and deca-O-acetyl-α-maltotriosyl chloride were prepared to facilitate the structural assignment. From measurement of the optical rotation, it was assumed that the decaacetate is a mixture of both anomers in a constant proportion. The decaacetate was also obtained either by treatment of the β-hendecaacetate with hydrogen bromide in acetic acid followed by warm aqueous sodium acetate or by the reaction of the β-hendecaacetate with piperidine in tetrahydrofuran. 相似文献
15.
A specimen heating holder equipped with a gas injector and an evaporator has been developed for use with conventional transmission electron microscopes (TEMs). The developed specimen holder allows both synthesis of metal oxide support and deposition of catalyst nano-particles in situ. Since the holder is designed to be used in small gapped high-resolution objective lens pole-piece, all the procedure from the synthesis of support material to the deposition of catalyst as well as the behavior of the catalyst nano-particles on the support can be observed at near atomic resolution. The developed specimen holder was applied to the study of AuPd catalyst. First, air was injected onto heated aluminum particles via a gas injector to synthesize Al(2)O(3) support. Then, nano-particles of AuPd were deposited on the Al(2)O(3) support. After the deposition, the synthesized Al(2)O(3) support was heated and air was injected again to observe behaviors of the deposited AuPd nano-particles at elevated temperatures in the aerial environment. Behaviors of the AuPd nano-particles such as coalescence, segmentation and diffusion to the Al(2)O(3) support were dynamically observed at atomic level high resolution. 相似文献
16.
Masatomo Yamagiwa Takayuki Ogawa Takeo Minamikawa Dahi Ghareab Abdelsalam Kyosuke Okabe Noriaki Tsurumachi Yasuhiro Mizutani Testuo Iwata Hirotsugu Yamamoto Takeshi Yasui 《Journal of Infrared, Millimeter and Terahertz Waves》2018,39(6):561-572
Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials. 相似文献
17.
The ethylamine contents of tea shoots and made teas were derived with o-phthalaldehyde and 2-mercaptoethanol, and quantified by high performance liquid chromatography. The coefficient of variation of this method was 1.97% from eight analyses. The levels of ethylamine in tea shoots declined markedly during growth and senescence after plucking; they also declined in the extracts of fresh tea during the incubation at 37°C, but this decrease was completely inhibited by amine oxidase inhibitors. The content of ethylamine in high grade green teas was higher than in low grade teas, but was almost identical in high and low grade black tea. The mean contents of ethylamine in 22 green teas and 17 black teas were 6.76±3.07 μmol g?1 and 6.40±1.82 μmol g?1, respectively. 相似文献
18.
Tadakazu Takeo 《Journal of the science of food and agriculture》1984,35(1):84-87
The amount and composition of volatile compounds in the volatile oils were compared between non-withered tea and withered tea. Important differences in the aroma constituents were found in the amounts of E-2-hexenal, Z-3-hexanol ester, linalool and its oxides, and methylsalcylate. In withered teas, the amounts of Z-3-hexenol ester, linalool and its oxides, and methylsalcylate were much greater than in non-withered tea, but the E-2-hexenal content was higher in non-withered tea. From the results it was thought that the withering process has an important role in the formation of volatile compounds in tea shoots during black tea fermentation. 相似文献
19.
Kazuhisa Okamoto Mai Ohta Kei Inage Takeo Fujii Masayuki Ariyoshi 《Analog Integrated Circuits and Signal Processing》2012,73(2):503-516
Because of the rapid development of cognitive radio technologies, research on sharing frequency resources allocated to primary users with secondary users has attracted much attention. If a frequency band is unused by the primary users, multiple secondary users are expected to share the spectrum in a future wireless communication network. To efficiently share the spectrum among secondary systems, we propose a novel channel allocation method that uses a frequency priority table generated based on the location of the secondary system. By using this method, the interference with other systems is autonomously reduced by selecting channels. Moreover, a power control method is also proposed for protecting the secondary systems that are allocated to the channels with higher priority. 相似文献
20.
Kamino T Yaguchi T Kuroda Y Ohnishi T Ishitani T Miyahara Y Horita Z 《Journal of electron microscopy》2004,53(5):459-463
Transmission electron microscopy (TEM) samples of an Mg-Al alloy has been prepared using a Ga-focused ion beam (FIB) milling at two different operating voltages of 10 kV and 40 kV to investigate the influence of the FIB energy on the sample quality. The fine structures of the samples have been studied using a high resolution TEM, and the concentration of the implanted Ga was analysed using an energy dispersive X-ray (EDX) analysis. The result of the TEM observation revealed that point defects were introduced to the sample finally milled at 40 kV but not at 10 kV. However, crystal lattice images and electron diffraction patterns were clearly observed on both the samples. The typical influence of the FIB energy was indicated in the elemental analysis. The relative Ga concentration in the thin sample finally milled at 10 kV was 1.0-2.0 at% that is less than half of 4.0-6.0 at% of the Ga concentration in the sample finally milled at 40 kV. A comparison between the experimental results of the Ga concentration measurement with simulation was also discussed. 相似文献