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11.
A laser-induced fluorescence detection system coupled with a highly sensitive silicon-intensified target (SIT) camera is successfully applied to the imaging of a band for DNA fragment labeling by fluorescence dye in a microchannel, and to the visualizing of the separation process on a microfabricated chip. We demonstrated that an only 6 mm separation channel is sufficient for the separation of triplet repeat DNA fragment and DNA molecular marker within only 12 s. The separation using the microfabricated capillary electrophoresis device is confirmed to be at least 18 times faster than the same separation carried out by conventional capillary electrophoresis with 24.5 cm effective length. The use of a short capillary with 8.5 cm effective length is also efficient for fast separation of DNA; however, the microchip technology is even faster than capillary electrophoresis using a short capillary. 相似文献
12.
Biju V Makita Y Nagase T Yamaoka Y Yokoyama H Baba Y Ishikawa M 《The journal of physical chemistry. B》2005,109(30):14350-14355
Photoluminescence (PL) intermittency characteristics are examined for single quantum dots (QDs) in a CdSe QD sample synthesized at a slow rate at 75 degrees C. Although the PL quantum efficiency was relatively low ( approximately 0.25), we noticed that the PL intensity of single CdSe QDs fluctuated on a subsecond time scale with short-lived "on" and "off" states. The subsecond PL intensity fluctuations of CdSe QDs are different from "on" and "off" PL blinking generally observed for QDs fluctuating on a millisecond to minute time scale. We characterized single QDs by identifying polarized excitations, topographic imaging using atomic force microscopy (AFM), and transmission electron microscopy (TEM). From analysis of the PL intensity trajectories from >100 single CdSe QDs, the average intermittency time was 213 ms. From the PL quantum efficiency, slow growth of QDs, intensity trajectory analyses, and previous reports relating surface trap states and PL properties of QDs, we attribute the subsecond PL intensity fluctuations of single CdSe QDs and short-lived "on" and "off" states to a high-density distribution of homogeneous surface trap states. 相似文献
13.
Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF2C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields. 相似文献
14.
Y Inamori M Ogawa H Tsujibo K Baba M Kozawa H Nakamura 《Chemical & pharmaceutical bulletin》1991,39(12):3353-3354
3,3',4,5'-Tetrahydroxystilbene (I) and 3,3',4,5'-tetrahydroxybibenzyl (II), isolated from the heartwood of Cassia garrettiana Craib (Leguminosae), showed inhibitory effects on antigen-induced histamine release from rat peritoneal mast cells in vitro. The inhibitory effect of I (IC50 = 30.2 microM) was much stronger than that of II (greater than 100 microM). Compound II, as well as I (IC50 = 7.3 microM) reported previously, also inhibited the histamine release from human peripheral basophils induced by anti-immunoglobulin E (IgE) in vitro, and its IC50-value was 68.0 microM. These results suggest that the trans-olefin structure in the molecule may be necessary for I to have an inhibitory effect on histamine release. Considering that disodium cromoglycate did not show any significant inhibitory effect on anti-IgE-induced histamine release from human basophils, the strong inhibitory effects of I in both tests are of considerable interest. 相似文献
15.
Mehrdad Nikravech Kamal Baba Bernard Leneindre Frédéric Rousseau 《Chemical Papers》2012,66(5):502-510
Processing the aerosol of metal salts in non-equilibrium plasma represents a promising technique that combines the advantages
of spray pyrolysis with the high reactivity of plasmas at nearlaboratory temperature in order to produce mixed-oxides and
perovskite materials. The aim of this paper is to describe the principles of this new technique and to present the various
applications and latest developments. This technique’s capacity to deposit various mixed metal oxides with precise stoichiometry
is demonstrated. It is shown that oxidant plasma species play a key role in the chemical transformation of starting materials
into oxides at laboratory temperature, while the configuration of the reactor determines the morphology and texture of the
deposited layers. Two different reactor configurations are presented. The porous layers of La
x
Sr1−x
MnO3 as the cathode for fuel cells were synthesised in a wave shock reactor configuration, while nanostructured ZnO-Al layers
to form a transparent conductive cathode for photovoltaic cells were deposited in the spray plasma reactor of the latest generation
for this technique. The experimental results emphasise the role of plasma species in the rate of chemical reactions and in
the chemical composition of the deposited layers. 相似文献
16.
Abstract The present author investigated the structure-reactivity correlation in the reactions of amines with P-O-P bridged phosphonylating agent 1, diphosphonate. 相似文献
17.
Norimasa Yoza Hisanobu Hirano Yoshinobu Baba Shigeru Ohashi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4):605-608
Abstract Inorganic pyrophosphatase (EC 3. 6. 1. 1) drived the reaction of uridine 5′-triphosphate with glucose 1-monophosphate in the direction of uridine 5′-diphosphoglucose formation. 相似文献
18.
Yutaka Kubota Yuri Kaneda Kazuhiro Haraguchi Mirei Mizuno Hiroshi Abe Satoshi Shuto Takayuki Hamasaki Masanori Baba Hiromichi Tanaka 《Tetrahedron》2013
The key glycosyl donor for the target molecule 12 was prepared by two-step sequences; (1) acetalization of tert-butyldimethylsilyloxyacetaldehyde with 3-bromopropanediol, (2) DBN-initiated β-elimination of the resulting 2-(tert-butyldimethylsilyloxy)methyl-4-bromomethyl-1,3-dioxolane 11. Electrophilic glycosidation between 12 and silylated pyrimidine nucleobase proceeded efficiently to provide a mixture of β- and α-anomers of the respective glycosides 14 and 15. Tin radical-mediated reduction of the bromomethyl functional group of 14 and 15 gave protected 4′-C-methyl-dioxorane uracil- 16 and thymine nucleoside 17. The respective cytosine nucleoside 18 was synthesized from 16. De-silylation of 4′-methyl-1′,3′-dioxolane pyrimidine nucleosides 16–18 gave the target molecules. Evaluation of the anti-HIV-1 activity of the β- and α-anomers of the novel 4′-C-methyl-1′,3′-dioxolane nucleosides 22β,α–24β,α revealed that none of the nucleoside derivatives possess anti-viral activity against HIV-1 and show cytotoxicity against MT-4 cells at 100 μM. 相似文献
19.
F. Ditrói F. Tárkányi S. Takács A. Hermanne H. Yamazaki M. Baba A. Mohammadi 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(2):853-865
As a part of our series of studies on charged particle induced reactions on various target materials, proton induced excitation functions on natural cobalt have been determined by using the stacked-foil technique. In these measurements the radionuclides 55,56,57,58Co, 51Cr, 52,54,56Mn and 56,57Ni have been identified. For the above mentioned nuclides the cross-sections were derived from the measured activities and were compared with the literature data and with the results of EMPIRE code calculations and tabulated values in the TENDL 2011 library (based on TALYS code calculations). The agreement with previous measurements and with theoretical values was acceptable. 相似文献