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排序方式: 共有419条查询结果,搜索用时 625 毫秒
71.
Masanori Kawakami Yutaka Abe Akiko Kaneko Yuji Yamamoto Koji Hasegawa 《Microgravity science and technology》2010,22(2):145-150
Under the microgravity environment, new and high quality materials with a homogeneous crystal structure are expected to be
manufactured by undercooling solidification, since the material manufacturing under the microgravity environment is more static
than that under the normal gravity. However, the temperature change on the interface of the material in space can affect on
the material processing. The purpose of the present study is to investigate effect of the temperature change of interface
on the large levitated droplet interface. A water droplet levitated by the acoustic standing wave is heated by YAG laser.
In order to heat the water droplet by the laser heating, rhodamine 6G is solved in it to achieve high absorbance of the laser.
The droplet diameter is from 4 to 5.5 mm. The deformation of the droplet interface is observed by high speed video camera.
The temperature of droplet is measured by the radiation thermometer. It is noticed that the larger droplet under the higher
sound pressure tends to oscillate remarkably by the laser heating. 相似文献
72.
Akiko Hayashi Dr. Ken-ichi Haruna Haruna Sato Dr. Kenichiro Ito Dr. Chisato Makino Dr. Takuhiro Ito Dr. Kensaku Sakamoto 《Chembiochem : a European journal of chemical biology》2021,22(1):120-123
Expansion of the amino-acid repertoire with synthetic derivatives introduces novel structures and functionalities into proteins. In this study, we improved the antigen binding of antibodies by incorporating halogenated tyrosines at multiple selective sites. Tyrosines in the Fab fragment of an anti-EGF-receptor antibody 059–152 were systematically replaced with 3-bromo- and 3-chlorotyrosines, and simultaneous replacements at four specific sites were found to cause a tenfold increase in the affinity toward the antigen. Structure modeling suggested that this effect was due to enhanced shape complementarity between the antigen and antibody molecules. On the other hand, we showed that chlorination in the constant domain, far from the binding interface, of Rituximab Fab also increased the affinity significantly (up to 17-fold). Our results showed that antigen binding is tunable with the halogenation in and out of the binding motifs. 相似文献
73.
During embryo implantation, apoptosis is observed morphologically at the implantation site of endometrium. The objectives of this study were to demonstrate biochemical evidence of apoptosis and quantitative assessment of DNA fragmentation in uterine epithelial cells using a mouse implantation model, and to investigate the autocrine/paracrine regulation of apoptosis in uterine epithelial cells during blastocyst outgrowth. Blastocysts from day 4 pregnant mice were cultured on uterine epithelial cells for 96 h. Uterine epithelial cells dislodged by trophoblasts in endometrium-trophoblast unit demonstrated morphological features of apoptosis by Acridine Orange staining. Electrophoresis demonstrated DNA ladder and DNA fragmentation by enzyme-linked immunosorbent assay markedly increased after 48 h period of incubation. Apoptosis increased in an exponential way in accordance with trophoblast outgrowth. In addition, DNA fragmentation was shown in the epithelial cells by adding embryo-conditioned medium (CM) and the effect of embryo CM on apoptosis was significantly inhibited by anti-transforming growth factor (TGF)-beta antibody. Delayed outgrowth was observed after 48 h of incubation in the blastocysts cultured with anti-TGF-beta antibody. These results suggest there is autocrine/paracrine regulation of apoptosis in uterine epithelial cells at mouse embryo implantation and that TGF-beta might play an important role in the occurrence of apoptosis in the endometrium-trophoblast unit. 相似文献
74.
Recent advances in biomaterial technology have made alloplastic bone substitutes more predictable when used with the proper clinical methodology in carefully selected patients. In this animal study, early bone formation using a novel resorbable bioactive glass in the repair of surgically created bony defects in the rat mandible was investigated. Biopsies taken from the implanted sites after 1, 2, 3, 4, 8, and 16 weeks were examined histologically by means of standard cell-staining techniques. In addition, an electron probe microanalyzer was used to determine the presence and distribution of specific elements in samples taken after 16 weeks. Results indicated the early stage of osteoconductive bone growth after approximately 4 weeks. After 16 weeks, electron probe micro-analyzer scans indicated the formation of a calcium-phosphate shell formed in situ and the resorption of silica to background levels. 相似文献
75.
Hisashi Sugiyama Keisuke Ebata Akiko Mizushima Kazuo Nate 《Polymer Engineering and Science》1989,29(13):863-867
A new class of alkali-developable positive excimer laser (KrF) resists is described. Novel α-diazoacetoacetates derived from aliphatic polyfunctional alcohols were synthesized. These compounds undergo photolysis upon deep UV exposure to yield carboxylic acids, and exhibit excellent bleaching effects. Some of them, especially those having steroid skeletons, act as effective dissolution inhibitors. The composites prepared from these compounds and poly(p-hydroxybenzylsilsesquioxane) were used as alkali-developable positive deep UV resists, whose sensitivities depend on the number of photoactive groups in one photoactive molecule. Imaging results of KrF excimer laser projection printing are presented. 相似文献
76.
Shoko Hira Akiko Matsumoto Ken Kihara Sakuichi Ohtsuka 《Journal of the Society for Information Display》2019,27(7):409-426
The mutual understanding of color‐normal observers (CNOs) and color‐defective observers (CDOs) is now essential because personal color information display environments have been widely adopted. However, existing tools for CDOs offer only color discrimination; they fail to support color impression (ie, saturation and contrast). Therefore, we need a novel tool that offers help in distinguishing opponent colors, while preserving color saturation. We introduce two key techniques for realizing this difficult goal. The former is the repeated sequential display of the original and processed images to support the formation of unified correct percepts that provide discrimination of both red‐green and yellow‐blue opponent colors. One image, ie, original, exhibits correct yellow‐blue but distorted red‐green information for CDOs while the other, ie, processed, provides synthesized distinguishable red‐green but confusable yellow‐blue information for CDOs; here, hue rotation (HR) is useful for advanced users whereas hue blending (HB) is suitable for general. The latter is realized by the real‐time video processing available on smartphones; our algorithms support direct processing of the digital component video signal formats (eg, Y, CR, and CB). Subjective tests suggest that the two above‐mentioned algorithms will, along with embedding a lightweight real‐time dichromatic simulation facility for CNOs, greatly help the mutual understanding of CNOs and CDOs. 相似文献
77.
78.
Electrochemical reduction of acetone in aqueous H2SO4 solution was studied on Hg electrode by galvanostatic, potentiodynamic and polarographic methods. Electrocapillary curves show that acetone molecule adsorbs to a monolayer at concentrations larger than 0·5 M in a potential range of 0 > V > ? 1·0 V (nhe). It orients with the positive end of the dipole toward electrode surface and extends an attractive interaction to its neighbours.Kinetics oberved by galvanostatic pulse method and polarography leads the following conclusions; (1) adsorbed acetone molecule undergoes elecrochemical reduction at potentials more negative than ?1·0 V (nhe), (2) reaction rate is the first and second order with respect to the amount of adsorbed acetone and proton activity, and (3) one electron transfer step determines the reaction rate (Tafel slope is 0·12 V). Reaction intermediate is concluded from the potentiodynamic study to be isopropanol radical, (CH3)2??OH, whose amount is proportional to that of adsorbed acetone and to aH+. From the above results, the rate of the electrochemical reduction of acetone is H2SO4 solution is concluded as determined by the step, (CH3)2?OH(a) + H+ + e? → (CH3)2CHOH. 相似文献
79.
Tomokazu Umeyama Kensuke Naka Mia D. Bravo Akiko Nakahashi Yoshiki Chujo 《Polymer Bulletin》2004,52(3-4):191-199
Summary
Cross-linked poly(vinylene-arsine)s (4) were synthesized by a free-radical terpolymerization of phenylacetylene (2), hexaphenylcyclohexaarsine (l), and p- or m-diethynylbenzene (p- or m-3) at different compositions in the presence of a catalytic amount of AIBN. The number-average molecular weights of the resulting polymers were a few thousands estimated by gel permeation chromatography (GPC) analysis. By gas chromatography (GC) analysis p-3 was found to be more reactive during the polymerization than m-3 and the resulting cross-linked polymer (p-4) showed lower solubility than that of m-4. The cross-linked poly(vinylene-arsine)s showed higher glass transition temperature in the measurement of differential scanning calorimetry (DSC) and more red-shifted emission in chloroform solution than that of the linear poly(vinylene-arsine). These properties could be tuned by varying the monomer feed ratio. 相似文献
80.
Masahiro Utsumi Kazuya Nagata Masahiko Suzuki Akiko Mori Itsuo Sakuramoto Yuuichi Torigoe Toshiaki Kaneeda Hideshige Moriya 《应用聚合物科学杂志》2003,87(10):1602-1609
The effects of calcium stearate addition in molding of ultrahigh molecular weight polyethylene (UHMWPE) were investigated by tensile testing, scanning electron microscope (SEM), Fourier transform infrared (FT‐IR) spectroscopy, and elemental analysis. Four types of UHMWPE specimens with varying contents of calcium stearate (<5, 50, 100, and 1000 ppm) were used in this study. SEM observation revealed that calcium stearate added specimens have smoother and more homogeneous microstructures. After accelerated aging, subsurface oxidative degeneration was observed in all specimens; however, calcium stearate added specimens had less oxidative degeneration in comparison with specimens without additives. Specimens showed better mechanical properties with increasing content of calcium stearate. Though all specimens aggravated their mechanical properties due to oxidation after accelerated aging, the specimens of 100 ppm of calcium stearate showed better properties at 3.7 MPa larger yield strength and four times larger value of elongation at fracture than the specimens without additives. These results indicate that calcium stearate addition produces dense packing of UHMWPE particles, which brings about stronger fusion among the particles and fewer structural defects, and results in better mechanical properties and better resistance to oxidative degeneration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1602–1609, 2003 相似文献