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151.
A miniaturized FIA system for the determination of residual chlorine in environmental water samples.
Jiye Jin Yasutada Suzuki Naoyoshi Ishikawa Toyohide Takeuchi 《Analytical sciences》2004,20(1):205-207
The present study was aimed at developing a portable miniaturized FIA system with a two-electrode based amperometric detector for on-site monitoring of residual chlorine in environmental samples. The electrode potential control and current data collection were conducted with a home-designed potentiostat with a size of 150 x 100 x 40 mm and the weight of 350 g. It was confirmed that the amperometric response increased in proportion to the chlorine concentration up to 5 microg/ml, and the detection limit for chlorine was 0.05 microg/ml. Besides a drastic reduction in the size of the analytical system, such miniaturization achieved the advantages of increased speed, minimal mobile-phase consumption, and high sensitivity. The proposed method was successfully applied to the determination of residual chlorine in samples of pool water and tap water. The results were well agreed with those obtained by the N,N-diethyl-p-phenylenediamine (DPD) photometric method. 相似文献
152.
153.
It was found that rhenium complex is an effective catalyst for the reaction of carbonyl compounds with ketene silyl acetals. A wide range of β-silyloxy esters is obtained by the treatment of carbonyl compounds with ketene silyl acetals in the presence of a catalytic amount of ReBr(CO)5 in moderate to good yields. 相似文献
154.
K Yagi T Seto M Terakado F Umeda T Doi T Imanishi Y Miura 《Chemical & pharmaceutical bulletin》1992,40(12):3292-3296
The nucleotide sequences of membrane-bound hydrogenase small (hupS) and large (hupL) subunit genes of hydrogen bacterium Alcaligenes hydrogenophilus were determined. The hupS and hupL genes encoded polypeptides of 363 and 619 amino acids, respectively. The hupS was located upstream of hupL with 35bp of intergenic region. The consensus ribosome-binding sequences were identified upstream of the start codons of hupS and hupL. Amino acid sequence of hupS is very similar to that of Rhodobacter capsulatus, Bradyrhizobium japonicum, and Azotobacter vinelandii at amino acid levels of 82%, 77%, and 81%, respectively. Similarly, amino acid sequence of HupL is similar to that of R. capsulatus, B. japonicum, and A. vinelandii at amino acid levels of 63%, 65%, and 68%, respectively. Northern hybridization analysis showed that hupS and hupL were co-transcribed, and addition of fructose to the culture medium remarkably decreased the amount of mRNA transcribed from hupS and hupL. 相似文献
155.
Tomoya Fujiwara Kazuki Hashimoto Masanori Umeda Saki Murayama Yuki Ohno Bo Liu Hisanori Nambu Takayuki Yakura 《Tetrahedron》2018,74(35):4578-4591
The divergent synthesis of penaresidin B and its straight side chain analogue was accomplished by constructing an azetidine ring via SN2 type cyclization of protected 2,3-syn-3,4-syn-4-amino-1,3-dihydroxyhept-6-en-2-yl mesylate and late-stage introduction of an alkyl side chain via olefin cross-metathesis of 4-allylazetidine with readily available terminal alkenes. This synthetic route would be useful to synthesize penaresidin side chain analogues. 相似文献
156.
Rui Umeda Toshifumi Jikyo Kazuki Toda Issey Osaka Yutaka Nishiyama 《Tetrahedron letters》2018,59(12):1121-1124
The coupling reactions of allylic and benzylic alcohols and allyltrimethylsilane are efficiently catalyzed by a rhenium complex to give the corresponding 1,5-dienes and alkenes in moderate to good yields. Similarly, alcohols were coupled with ketene silyl acetals to form the corresponding esters. 相似文献
157.
158.
Partially supported by NSF grant #DMS-8807336 相似文献
159.
A simple direct radioimmunoassay for 11-deoxycortisol in serum is described. A new type of bridge heterologous 125I labeled 11-deoxycortisol was prepared and was applied to the direct radioimmunoassay. Low and high levels of 11-deoxycortisol in serum were sensitively determined by the direct radioimmunoassay. 相似文献
160.
Hayakawa T Iwamoto N Shizuma T Kajino T Umeda H Nomoto K 《Physical review letters》2004,93(16):161102
Analyzing the solar system abundance, we find two universal scaling laws concerning the p and s nuclei. They indicate that the gamma process in supernova (SN) explosions is the most probable origin of the p nuclei that has been discussed with many possible nuclear reactions and sites in about 50 years. In addition, the scalings lead to new concepts: a universality of the gamma process and a new nuclear cosmochronometer. We carry out gamma-process nucleosynthesis calculations for typical core-collapse SN explosion models, and the results satisfy the observed scalings. 相似文献