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41.
Solvent extraction of platinum(IV) and palladium(II) with tri-n-octylamine(TOA) in o-xylene from 4.0M (Na,H)(Cl, HSO4) has been investigated at 298K in order to compare with similar extraction by trioctylphosphine oxide(TOPO). The dependence of the distribution ratio of platinum(IV) and pal 1adium(II) on TOA, hydrogen ion and chloride ion concentrations suggests the dominant extracted species of these metals would be 2:1 for proto-nated amine : chlorocomplex anion and the extraction should be essentially anion exchange reaction. The extraction constants (Kex = D[H+(T0A)C1 ] 2[C1 ]2), were evaluated as 106-3 and 105.8 for platinum(IV) and pal ladium(II), respectively. The anion exchange with protonated TOPO salt represented by H(T0P0)2 +C1 is less than that with protonated TOA salt by a factor of one order. 相似文献
42.
43.
Sachiko Sakura 《Electrochimica acta》1992,37(15):2731-2735
Electrochemiluminescence (ECL) was used to detect tryptophan in aqueous solutions in the presence of a brominating agent. Using platinum and glassy carbon electrodes, the ECL mechanism of tryptophan was studied. Tryptophan was oxidized at 0.78 V vs. sce in 0.1 M NaOH aqueous solution to the excited intermediate at a platinum electrode (0.44 V at a glassy carbon electrode). The intermediate was further oxidized and emitted light. The ECL signal was clearly observed when the applied potential was enough to oxidize the tryptophan. The ECL spectrum was measured, showing maximum emission peaks at 544 nm, 434 nm and 404 nm. Above 1.0 V, the brominating agent was oxidized which results in suppression of the ECL signal. A weak ECL signal was observed at an applied potential below 0.5 V, which indicates that this reaction is chemiluminescence (CL), enhanced by the applied potential. This method cannot be used for routine analysis because of the high detection limit of tryptophan (1.0 μmol), but can be used to obtain emission mechanism information. 相似文献
44.
Whole soybeans were exposed to microwave roasting for 6, 12, and 20 min at a frequency of 2,450 MHz and were studied not only
for phospholipid composition but also for positional distribution of the fatty acids. During microwave roasting, the greatest
rate of phospholipid losses (P<0.05) was observed in phosphatidylethanolamine (PE), followed by phosphatidylcholine (PC) and phosphatidylinositol (PI),
respectively. Therefore, the effects of microwave roasting on the composition and positional distribution of the fatty acids
are likely clearer in PE than in PC or PI. However, the principal characteristics for the positional distribution of fatty
acids are still retained during microwave roasting: unsaturated fatty acids, especially linoleic, are predominantly concentrated
in the 2-position, and saturated fatty acids, especially palmitic, primarily occupy the 1-position after 12 or 20 min of roasting.
The results suggest that unsaturated fatty acids located in the 2-position are significantly protected from microwave roasting. 相似文献
45.
ABSTRACT: The morphological change of silicon macropore arrays formed by metal-assisted chemical etching using shape-controlled Au thin film arrays was investigated during anisotropic chemical etching in tetramethylammonium hydroxide (TMAH) aqueous solution. After the deposition of Au as the etching catalyst on (111) silicon through a honeycomb mask prepared by sphere lithography, the specimens were etched in a mixed solution of HF and H2O2 at room temperature, resulting in the formation of ordered macropores in silicon along the [111] direction, which is not achievable by conventional chemical etching without a catalyst. In the anisotropic etching in TMAH, the macropores changed from being circular to being hexagonal and finally to being triangular owing to the difference in etching rate between the crystal planes. 相似文献
46.
Masanori Iwata Sachiko Komiya Kouji Nakamura Masakazu Kiuchi Noriko Andoh Fumiki Hirahara Yoshie Maitani Kozo Takayama 《Drug development and industrial pharmacy》2001,27(10):1039-1045
The mechanism of drug release from progesterone suppositories that consist of two types of hard fat (Witepsol® W35 and Witepsol® E85) was investigated. The strength, the thermodynamic characteristics, the surface structures, the drug release property, methylene blue penetration into suppositories, and change of surface structure after the dissolution test were employed for detecting characteristics of progesterone suppositories. The formulation with a mixing ratio of Witepsol W35 and Witepsol E85 at a 1:1 ratio showed the maximum strength value. The peak temperature of the suppositories showed a tendency to increase with increases in the ratio of Witepsol E85. The maximum height of the profiles measured with laser microscopy, from 20.8 μm to 29.2 μm, reached a maximum after 3 h of the dissolution test. When the suppositories were immersed in pH 7.4 phosphate buffer containing 0.5% methylene blue at 37°C, the penetrating area increased with time. The weight of the suppositories also increased with time. According to these findings, it was suggested that the release of drug from a mixed type of suppository containing progesterone was via the matrix and pores. 相似文献
47.
The authors argue that perception is Bayesian inference based on accumulation of noisy evidence and that, in masked priming, the perceptual system is tricked into treating the prime and the target as a single object. Of the 2 algorithms considered for formalizing how the evidence sampled from a prime and target is combined, only 1 was shown to be consistent with the existing data from the visual word recognition literature. This algorithm was incorporated into the Bayesian Reader model (D. Norris, 2006), and its predictions were confirmed in 3 experiments. The experiments showed that the pattern of masked priming is not a fixed function of the relations between the prime and the target but can be changed radically by changing the task from lexical decision to a same-different judgment. Implications of the Bayesian framework of masked priming for unconscious cognition and visual masking are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
48.
This paper introduces a framework for whole-body motion generation integrating operator's control and robot's autonomous functions during online control of humanoid robots. Humanoid robots are biped machines that usually possess multiple degrees of freedom (DOF). The complexity of their structure and the difficulty in maintaining postural stability make the whole-body control of humanoid robots fundamentally different from fixed-base manipulators. Getting hints from human conscious and subconscious motion generations, the authors propose a method of generating whole-body motions that integrates the operator's command input and the robot's autonomous functions. Instead of giving commands to all the joints all the time, the operator selects only the necessary points of the humanoid robot's body for manipulation. This paper first explains the concept of the system and the framework for integrating operator's command and autonomous functions in whole-body motion generation. Using the framework, autonomous functions were constructed for maintaining postural stability constraint while satisfying the desired trajectory of operation points, including the feet, while interacting with the environment. Finally, this paper reports on the implementation of the proposed method to teleoperate two 30-DOF humanoid robots, HRP-1S and HRP-2, by using only two 3-DOF joysticks. Experiments teleoperating the two robots are reported to verify the effectiveness of the proposed method. 相似文献
49.
Megumi Miyabe Nobuhisa Nakamura Tomokazu Saiki Satoru Miyabe Mizuho Ito Sachiko Sasajima Tomomi Minato Tatsuaki Matsubara Keiko Naruse 《International journal of molecular sciences》2023,24(1)
Atherosclerosis is a major cause of mortality worldwide. The initial change in atherosclerosis is intimal thickening due to muscle cell proliferation and migration. A correlation has been observed between periodontal disease and atherosclerosis. Here, we investigated the proliferation and migration of human aortic smooth muscle cells (HASMCs) using Porphyromonas gingivalis-derived LPS (Pg-LPS). To elucidate intracellular signaling, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) of HASMCs were knocked down, and the role of these molecules in Pg-LPS-stimulated proliferation and migration was examined. The role of mitogen-activated protein kinase (MAPK) in HASMC proliferation and migration was further elucidated by MAPK inhibition. Pg-LPS stimulation increased the proliferation and migration of HASMCs and activated the TLR4/MyD88 pathway. TLR4 knockdown inhibited Pg-LPS stimulated HASMCs proliferation and migration. Pg-LPS stimulation led to the phosphorylation of P38 MAPK, JNK, and ERK, and MyD88 knockdown inhibited the phosphorylation of P38 MAPK and JNK but not ERK. P38 MAPK and SAPK/JNK inhibition did not suppress the proliferation of HASMCs upon Pg-LPS stimulation, but ERK inhibition significantly inhibited proliferation. SAPK/JNK and ERK inhibition suppressed Pg-LPS-stimulated migration of HASMCs. In conclusion, our findings suggest that Pg-LPS may promote atherosclerosis via the activation of MAPK through TLR4. 相似文献
50.
Distribution of storage proteins in low-glutelin rice seed determined using a fluorescent antibody 总被引:4,自引:0,他引:4
Furukawa S Mizuma T Kiyokawa Y Masumura T Tanaka K Wakai Y 《Journal of Bioscience and Bioengineering》2003,96(5):467-473
To compare the distribution of storage proteins in low-glutelin rice seed with that in other cultivars having normal protein compositions, immunofluorescence labeling with specific antibodies was applied to visualize the distribution of storage proteins in endosperm tissues. The endosperm tissues from five cultivars were reacted with anti-prolamin and anti-glutelin antibodies, and then observed by light microscopy and confocal laser scanning microscopy (CLSM). In low-glutelin rice, using microscopic analysis, a large proportion of storage proteins was observed in the endosperm tissue of 70% polished rice. To determine the localization of two types of protein bodies in endosperm tissues, images of the distribution of the type I protein body (PB-I) and the type II protein body (PB-II) were obtained by CLSM. The CLSM images showed that, in low-glutelin rice, prolamin which accumulates in PB-I remains in the center of 70% polished rice grains despite the elimination of 30% of the outer layer of brown rice grains. However, the other cultivars mostly contained glutelin which accumulates in PB-II and is distributed throughout the endosperm tissues. This shows that low-glutelin rice differs from the other cultivars not only in the major storage protein composition but also in the distribution of storage proteins in endosperm tissues. 相似文献