Peptide bond formation: retraction     

Nitta I  Kamada Y  Noda H  Ueda T  Watanabe K 《Science (New York, N.Y.)》1999,283(5410):2019-2020

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Subaru telescope observations of Deep Impact     

Sugita S  Ootsubo T  Kadono T  Honda M  Sako S  Miyata T  Sakon I  Yamashita T  Kawakita H  Fujiwara H  Fujiyoshi T  Takato N  Fuse T  Watanabe J  Furusho R  Hasegawa S  Kasuga T  Sekiguchi T  Kinoshita D  Meech KJ  Wooden DH  Ip WH  A'Hearn MF 《Science (New York, N.Y.)》2005,310(5746):274-278

The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.  相似文献   

Role for piRNAs and noncoding RNA in de novo DNA methylation of the imprinted mouse Rasgrf1 locus     

Watanabe T  Tomizawa S  Mitsuya K  Totoki Y  Yamamoto Y  Kuramochi-Miyagawa S  Iida N  Hoki Y  Murphy PJ  Toyoda A  Gotoh K  Hiura H  Arima T  Fujiyama A  Sado T  Shibata T  Nakano T  Lin H  Ichiyanagi K  Soloway PD  Sasaki H 《Science (New York, N.Y.)》2011,332(6031):848-852

Genomic imprinting causes parental origin-specific monoallelic gene expression through differential DNA methylation established in the parental germ line. However, the mechanisms underlying how specific sequences are selectively methylated are not fully understood. We have found that the components of the PIWI-interacting RNA (piRNA) pathway are required for de novo methylation of the differentially methylated region (DMR) of the imprinted mouse Rasgrf1 locus, but not other paternally imprinted loci. A retrotransposon sequence within a noncoding RNA spanning the DMR was targeted by piRNAs generated from a different locus. A direct repeat in the DMR, which is required for the methylation and imprinting of Rasgrf1, served as a promoter for this RNA. We propose a model in which piRNAs and a target RNA direct the sequence-specific methylation of Rasgrf1.  相似文献   

Biotechnology. Japanese controversies over transgenic crop regulation     

Watanabe KN  Taeb M  Okusu H 《Science (New York, N.Y.)》2004,305(5690):1572

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Regional focus on GM crop regulation     

Okusu H  Watanabe KN 《Science (New York, N.Y.)》2005,308(5727):1409

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Perceptual learning incepted by decoded fMRI neurofeedback without stimulus presentation     

Shibata K  Watanabe T  Sasaki Y  Kawato M 《Science (New York, N.Y.)》2011,334(6061):1413-1415

It is controversial whether the adult primate early visual cortex is sufficiently plastic to cause visual perceptual learning (VPL). The controversy occurs partially because most VPL studies have examined correlations between behavioral and neural activity changes rather than cause-and-effect relationships. With an online-feedback method that uses decoded functional magnetic resonance imaging (fMRI) signals, we induced activity patterns only in early visual cortex corresponding to an orientation without stimulus presentation or participants' awareness of what was to be learned. The induced activation caused VPL specific to the orientation. These results suggest that early visual areas are so plastic that mere inductions of activity patterns are sufficient to cause VPL. This technique can induce plasticity in a highly selective manner, potentially leading to powerful training and rehabilitative protocols.  相似文献   

Identification and quantification of short oligomeric proanthocyanidins and other polyphenols in boysenberry seeds and juice     

Furuuchi R  Yokoyama T  Watanabe Y  Hirayama M 《Journal of agricultural and food chemistry》2011,59(8):3738-3746

Proanthocyanidins and other polyphenols in the seeds and juice of boysenberry were quantitatively analyzed. Polyphenolic extracts were prepared from the waste seeds and commercial juice by chromatographic fractionation. Compositional analysis revealed that both extracts contained six polyphenolic classes: flavanol monomers, proanthocyanidins, anthocyanins, ellagic acid, ellagitannins, and flavonol glycosides. Ellagitannins were the most abundant polyphenols in both extracts. Proanthocyanidins were present as short oligomers consisting of dimeric and trimeric procyanidins and propelargonidins, with the most abundant component being procyanidin B4 in both extracts. Quantification by high-performance liquid chromatography-mass spectrometry (HPLC-MS) revealed that the seeds contained a 72-fold higher amount of proanthocyanidins than the juice. These results indicate that boysenberry fruits contain short oligomeric proanthocyanidins along with flavanol monomers and the seeds represent a good source of short oligomeric proanthocyanidins.  相似文献   

Differential detection of shrimp and crab for food labeling using polymerase chain reaction     

Taguchi H  Watanabe S  Temmei Y  Hirao T  Akiyama H  Sakai S  Adachi R  Sakata K  Urisu A  Teshima R 《Journal of agricultural and food chemistry》2011,59(8):3510-3519

Shrimp and crab are well-known as allergenic ingredients. According to Japanese food allergy labeling regulations, shrimp species (including prawns, crayfishes, and lobsters) and crab species must be differentially declared when ≥10 ppm (total protein) of an allergenic ingredient is present. However, the commercial ELISA tests for the detection of crustacean proteins cannot differentiate between shrimp and crab. Therefore, two methods were developed to discriminate shrimp and crab: a shrimp-PCR method with postamplification digestion and a crab-PCR method that specifically amplifies a fragment of the 16S rRNA gene. The sensitivity and specificity of both PCR methods were verified by experiments using DNA extracted from 15 shrimp species, 13 crab species, krill, mysid, mantis shrimp, other food samples (cephalopod, shellfish, and fish), incurred foods, and commercial food products. Both PCR methods could detect 5 pg of DNA extracted from target species and 50 ng of genomic DNA extracted from incurred foods containing 10 ppm (μg/g) total protein of shrimp or crab. The two PCR methods were considered to be specific enough to separately detect species belonging to shrimp and crab. Although false-positive and false-negative results were obtained from some nontarget crustacean species, the proposed PCR methods, when used in conjunction with ELISA tests, would be a useful tool for confirmation of the validity of food allergy labeling and management of processed food safety for allergic patients.  相似文献   

Synthesis of morphiceptin (Tyr-Pro-Phe-Pro-NH(2)) by dipeptidyl aminopeptidase IV derived from Aspergillus oryzae     

Ota T  Itoh A  Tachi H  Kudoh K  Watanabe T  Yamamoto Y  Tadokoro T  Maekawa A 《Journal of agricultural and food chemistry》2005,53(15):6112-6116

Morphiceptin (Tyr-Pro-Phe-Pro-NH(2)), tetrapeptide, was synthesized using dipeptidyl aminopeptidase IV (DP IV, EC 3.4.14.5) derived from Aspergillus oryzae RIB 915 as a catalyst. Tyr-Pro-OEt was incubated with Phe-Pro-NH(2) in the presence of DP IV under various conditions of temperature, concentrations of ethylene glycol, pH, reaction time, and others. Morphiceptin was obtained at 40% yield under the optimal reaction conditions: substrate, 4 mM Tyr-Pro-OEt.HCl and 20 mM Phe-Pro-NH(2).HCl; enzyme, DP IV, 0.275 nkat; solvent, 60% ethylene glycol containing 20 mM phosphate buffer at pH 7.0; amine, 4.2 mM diisopropylamine at 4 degrees C for 24 h. Amino group protection was unnecessary for synthesis of morphiceptin by DP IV.  相似文献   

Suppressive effect of saturated acyl L-ascorbate on the oxidation of linoleic acid encapsulated with maltodextrin or gum arabic by spray-drying   总被引：2，自引：0，他引：2  

Watanabe Y  Fang X  Minemoto Y  Adachi S  Matsuno R 《Journal of agricultural and food chemistry》2002,50(14):3984-3987

6-O-Palmitoyl L-ascorbate was added to linoleic acid at various molar ratios of the ascorbate to the acid, the mixtures were emulsified with a maltodextrin or gum arabic solution, and the emulsions were spray-dried to produce microcapsules. At higher molar ratios, the oil droplets in the emulsions were smaller, and the oxidative stabilities of the encapsulated linoleic acid were higher for both the maltodextrin- and gum arabic-based microcapsules. 6-O-Capryloyl, caproyl, and lauroyl L-ascorbates, which were synthesized through lipase-catalyzed condensation in acetone, were also used for the microencapsulation of linoleic acid. Except for capryloyl L-ascorbate, the addition of a saturated acyl ascorbate, especially caproyl ascorbate, to linoleic acid was effective for preparing oil droplets of small particle diameter and for suppressing the oxidation of the encapsulated linoleic acid.  相似文献