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81.
This paper describes a novel, sensitive detection system for biomolecules (DNA and proteins etc.) that is integrated in a lab-on-a-chip utilizing optical compact discs (CDs) and bio-nanofibers. The new method comprises a microchannel containing CD grating that confines fragments of unique bacterial cellulose fibrils (BC), which have nanometre scale fibers and holes. A maximum of six times higher sensitivity to detect DNA was obtained with this CD and BC system compared to a conventional method. We also demonstrate an effective light-confining effect for biological application with the new method. 相似文献
82.
Martínez-Teipel B Teixidó J Pascual R Mora M Pujolà J Fujimoto T Borrell JI Michelotti EL 《Journal of combinatorial chemistry》2005,7(3):436-448
Heterocyclic demonstration libraries for agrochemical screening were prepared from the common intermediates 2-methoxy-6-oxo-1,4,5,6-tetrahydropyridine-3-carbonitriles (1), using standard solution-phase techniques. A total of 18 screening libraries were prepared in good to excellent yields. Several members of these libraries were active in the first level of agrochemical screening, especially in the fungicide screen. 相似文献
83.
Kim J Birge JR Sharma V Fujimoto JG Kärtner EX Scheuer V Angelow G 《Optics letters》2005,30(12):1569-1571
We present a general design strategy for a broadband thin-film beam splitter with matched group-delay dispersion. By taking the substrate dispersion into account in the coating design, any combination of input and output can show the same dispersion for transmission and reflection. As a specific implementation, an ultrabroadband 50:50 beam splitter from 600 to 1500 nm for femtosecond laser applications was designed, fabricated, and characterized. 相似文献
84.
A new class of molecular beacons were developed in which pyrene fluorophores were connected both at 3' and 5' ends of a single-stranded oligonucleotide. The two pyrene-based fluorophores were synthesized from the same starting material, so that the preparation of the beacons was simplified. The detection strategy of the beacons for target DNAs is based on "excimer-monomer emission switching" of the pyrene fluorophores: excimer emission of the pyrene moieties changed to monomer one when the beacons hybridized with the targets. This type of two-state mode of fluorescence allows unambiguous detection of the target DNAs because strict 1:1 correlation between the nonhybridized and the hybridized beacons can be monitored by the presence of isoemissive points of the fluorescence changes. The beacons can detect target 19-mer DNAs and can discriminate the targets from their single-nucleotide mismatches at 1 nM concentration. Advantages of the excimer-monomer switching molecular beacons were discussed in comparison with conventional ones. 相似文献
85.
Shibata T Fujimoto T Yokota K Takagi K 《Journal of the American Chemical Society》2004,126(27):8382-8383
An asymmetric [2+2+2] cycloaddition of an alpha,omega-diyne, possessing ortho-substituted aryl groups on its terminus, and a monoalkyne with oxygen functionalities gave various axially chiral teraryl compounds. The coupling proceeded with extremely high enantio- (>99.5% ee) and diastereoselectivities (dl/meso = >95/5) when catalyzed by an iridium-chiral phosphine complex. As the products were readily transformed into diol compounds by deprotection without racemization, the present procedure provides access to a new chiral pool of diol compounds with C2 symmetry. 相似文献
86.
Fujimoto H Nakamura E Okuyama E Ishibashi M 《Chemical & pharmaceutical bulletin》2004,52(8):1005-1008
In a screening study on immunomodulatory fungal metabolites, three known anthraquinones, carviolin (roseo-purpurin) (1), 1-O-methylemodin (2), omega-hydroxyemodin (citreorosein) (4), and a new anthraquinone, omega-acetylcarviolin (3), together with a known steroid, ergosta-4,6,8(14),22-tetraen-3-one (5) and a new steroid, 25-hydroxyergosta-4,6,8(14),22-tetraen-3-one (6) were isolated from an Ascomycete, Zopfiella longicaudata, and found to have moderate immunosuppressive activities. The structure-activity relationships of these metabolites are discussed. 相似文献
87.
Chemical investigation of n-butanol extract from the methanol extract of leaves of Grewia damine furnished lupeol, sitosterol beta-D-glucoside, flavone C-glycosides vitexin, isovitexin where as the same extracts from the leaves of Filicium decipiens furnished sitosterol beta-D-glucoside, 3-O-beta-D-glucopyranosyl kaempferol, 3-O-beta-D-glucopyranosylquercetin and 3-O-alpha-L-rhamnopyranosyl(1--> 2)-beta-D-glucopyranosylkaempferol. 相似文献
88.
Antifungal activity-guided fractionation of the n-butanol extract from the methanol extract of the stem bark of Artocarpus nobilis furnished two stilbene derivatives (E)-4-isopentenyl-3,5,2',4'-tetrahydroxystilbene and (E)-4-(3-methyl-E-but-1-enyl)-3,5,2',4'-tetrahydroxystilbene. Both compounds showed strong antifungal activity against Cladosporium cladosporioides and high radical scavenging activity towards the DPPH radical in TLC bio-autography method. 相似文献
89.
Spolenak R Brown WL Tamura N MacDowell AA Celestre RS Padmore HA Valek B Bravman JC Marieb T Fujimoto H Batterman BW Patel JR 《Physical review letters》2003,90(9):096102
Grain-to-grain interactions dominate the plasticity of Al thin films and establish effective length scales smaller than the grain size. We have measured large strain distributions and their changes under plastic strain in 1.5-microm-thick Al 0.5% Cu films using a 0.8-microm-diameter white x-ray probe at the Advanced Light Source. Strain distributions arise not only from the distribution of grain sizes and orientation, but also from the differences in grain shape and from stress environment. Multiple active glide plane domains have been found within single grains. Large grains behave like multiple smaller grains even before a dislocation substructure can evolve. 相似文献
90.
Cho SH Kärtner FX Morgner U Ippen EP Fujimoto JG Cunningham JE Knox WH 《Optics letters》2001,26(8):560-562
We demonstrate the generation of high-energy pulses by using a low-repetition-rate Kerr-lens mode-locked laser. Repetition rates as low as 4 MHz were achieved with a long, multiple-pass cavity and a semiconductor saturable Bragg reflector. The laser generated pulses of 55-fs duration with a pulse energy of 48 nJ when it was mode locked in the net negative dispersion regime. Mode locking in the positive dispersion regime reduces instabilities and enables pulses to have durations of 80 fs and energies as high as 90 nJ. This is, to our knowledge, the highest pulse energy and the lowest repetition rate ever generated directly from a femtosecond laser resonator without cavity dumping. 相似文献