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11.
Characteristic aroma components of water dropwort (Oenanthe javanica DC.) were evaluated by aroma extract dilution analysis and solid-phase microextraction-gas chromatography-olfactometry. Alpha-Terpinolene (plastic/cucumber-like) was the most intense aroma-active compound in water dropwort. Other potent aroma-active compounds included p-cymene (kerosene-like), alpha-terpinene (lemon), (E)-caryophyllene (woody), (Z,E)-alpha-farnesene (woody), hexanal (green), (Z)-3-hexenol (green), phenylacetaldehyde (honey), (E)-2-nonenal (cucumber), bornyl acetate (cooked vegetable), and gamma-terpinene (lemon). Of these, p-cymene was believed to be primarily responsible for the distinct kerosene-like aroma note of water dropwort. The aroma property of p-cymene was dependent on its concentration and was described as kerosene-like at relatively high concentrations but changed to citrus and green aroma notes at low concentrations. 相似文献
12.
Abelson JF Kwan KY O'Roak BJ Baek DY Stillman AA Morgan TM Mathews CA Pauls DL Rasin MR Gunel M Davis NR Ercan-Sencicek AG Guez DH Spertus JA Leckman JF Dure LS Kurlan R Singer HS Gilbert DL Farhi A Louvi A Lifton RP Sestan N State MW 《Science (New York, N.Y.)》2005,310(5746):317-320
Tourette's syndrome (TS) is a genetically influenced developmental neuropsychiatric disorder characterized by chronic vocal and motor tics. We studied Slit and Trk-like 1 (SLITRK1) as a candidate gene on chromosome 13q31.1 because of its proximity to a de novo chromosomal inversion in a child with TS. Among 174 unrelated probands, we identified a frameshift mutation and two independent occurrences of the identical variant in the binding site for microRNA hsa-miR-189. These variants were absent from 3600 control chromosomes. SLITRK1 mRNA and hsa-miR-189 showed an overlapping expression pattern in brain regions previously implicated in TS. Wild-type SLITRK1, but not the frameshift mutant, enhanced dendritic growth in primary neuronal cultures. Collectively, these findings support the association of rare SLITRK1 sequence variants with TS. 相似文献
13.
Giant piezoelectricity on Si for hyperactive MEMS 总被引:1,自引:0,他引:1
Baek SH Park J Kim DM Aksyuk VA Das RR Bu SD Felker DA Lettieri J Vaithyanathan V Bharadwaja SS Bassiri-Gharb N Chen YB Sun HP Folkman CM Jang HW Kreft DJ Streiffer SK Ramesh R Pan XQ Trolier-McKinstry S Schlom DG Rzchowski MS Blick RH Eom CB 《Science (New York, N.Y.)》2011,334(6058):958-961
Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting. 相似文献
14.
Park HG Kim SH Kwon SH Ju YG Yang JK Baek JH Kim SB Lee YH 《Science (New York, N.Y.)》2004,305(5689):1444-1447
We report the experimental demonstration of an electrically driven, single-mode, low threshold current (approximately 260 microA) photonic band gap laser operating at room temperature. The electrical current pulse is injected through a sub-micrometer-sized semiconductor wire at the center of the mode with minimal degradation of the quality factor. The actual mode of interest operates in a nondegenerate monopole mode, as evidenced through the comparison of the measurement with the computation based on the actual fabricated structural parameters. As a small step toward a thresholdless laser or a single photon source, this wavelength-size photonic crystal laser may be of interest to photonic crystals, cavity quantum electrodynamics, and quantum information communities. 相似文献
15.
Min‐Jung GU Md. Jahangir ALAM Seon‐Ho KIM Che‐Ok JEON Moon‐Baek CHANG Young‐Kyoon OH Sang‐Cheol LEE Sang‐Suk LEE 《Animal Science Journal》2011,82(5):663-672
Molecular diversity of methanogens in the rumen of Korean black goats was investigated with 16S rRNA gene clone libraries using methanogen‐specific primers. The libraries were composed of rumen fluid‐associated methanogens (FAM) and rumen particle‐associated methanogens (PAM) from rumen‐fistulated Korean black goats. Among the 141 clones of the FAM library, the sequences were mostly related to two phyla, the Methanobacteriaceae family (77.3%) and the Thermoplasmatales family (22.7%); and among the 68 clones of the PAM library, sequences were also mainly clustered in the two phyla, the Thermoplasmatales family (63.24%) and the Methanobacteriaceae family (35.29%). Most of the sequenced clones in the two libraries were closely related to uncultured methanogenic archaeon. Quantitative real‐time PCR revealed that PAM (8.97 log 10) had significantly higher (P < 0.01) density of methanogens by the methanogenic 16S rRNA gene copies than FAM (7.57 log 10). The two clone libraries also showed difference in Shannon index (FAM library 1.70 and PAM library 1.59) and Chao 1 estimator (FAM library 18 and PAM library 17 operational taxonomic units). Apparent differences found in the microbial community from the two 16S rRNA gene libraries could be a result of such factors as the chemical and physical nature of the target material surface, types or component of diets, the interaction between the methanogens and other microbes, and age of the experimental goats. 相似文献
16.
Glycoalkaloids and metabolites inhibit the growth of human colon (HT29) and liver (HepG2) cancer cells 总被引:4,自引:0,他引:4
Lee KR Kozukue N Han JS Park JH Chang EY Baek EJ Chang JS Friedman M 《Journal of agricultural and food chemistry》2004,52(10):2832-2839
As part of an effort to improve plant-derived foods such as potatoes, eggplants, and tomatoes, the antiproliferative activities against human colon (HT29) and liver (HepG2) cancer cells of a series of structurally related individual compounds were examined using a microculture tetrazolium (MTT) assay. The objective was to assess the roles of the carbohydrate side chain and aglycon part of Solanum glycosides in influencing inhibitory activities of these compounds. Evaluations were carried out with four concentrations each (0.1, 1, 10, and 100 microg/mL) of the the potato trisaccharide glycoalkaloids alpha-chaconine and alpha-solanine; the disaccharides beta(1)-chaconine, beta(2)-chaconine, and beta(2)-solanine; the monosaccharide gamma-chaconine and their common aglycon solanidine; the tetrasaccharide potato glycoalkaloid dehydrocommersonine; the potato aglycon demissidine; the tetrasaccharide tomato glycoalkaloid alpha-tomatine, the trisaccharide beta(1)-tomatine, the disaccharide gamma-tomatine, the monosaccharide delta-tomatine, and their common aglycon tomatidine; the eggplant glycoalkaloids solamargine and solasonine and their common aglycon solasodine; and the nonsteroidal alkaloid jervine. All compounds were active in the assay, with the glycoalkaloids being the most active and the hydrolysis products less so. The effectiveness against the liver cells was greater than against the colon cells. Potencies of alpha-tomatine and alpha-chaconine at a concentration of 1 microg/mL against the liver carcinoma cells were higher than those observed with the anticancer drugs doxorubicin and camptothecin. Because alpha-chaconine, alpha-solanine, and alpha-tomatine also inhibited normal human liver HeLa (Chang) cells, safety considerations should guide the use of these compounds as preventative or therapeutic treatments against carcinomas. 相似文献
17.
Woo Duck Seo Jun Young Kim You-Chun Song Jun-Hyun Cho Ki Chang Jang Sang-Ik Han Ji-Eun Ra Seong-Hwan Oh Hyeon-Jung Kang Byung-Joo Kim Nam-In Baek Rak-Hun Jeong Min Hee Nam 《Journal of Crop Science and Biotechnology》2013,16(1):63-68
The main objectives of this study were to investigate physicochemicals and antioxidant activities of new red rice (Oryza sativa cv. Gunganghongmi (GH)) by comparing normal brown (Nampyeongbyeo, NB) and reported red rice (Jukjinjubyeo, JB) in Korea. The nutritional constituents, including protein, oil, sugar, fatty acid, GABA, and γ-oryzanol were not significantly different between normal brown and colored rice. However, the ethanol extract of GH showed the highest phenolic content (24.7 ± 1.3 mg g?1). The ethanol extracts of GH showed higher scavenging activities against DPPH (0.2 mg mL?1 = 62.1 ± 2.5%) and ABTS (0.2 mg mL?1 = 63.2 ± 3.5%) radicals. Moreover, GH more inhibited LPS-induced nitric oxide (NO) production (13.2 ± 1.4 μM) than JB (18.3 ± 2.3 μM) and NB (22.1 ± 1.4 μM) at the same concentration (0.2 mg mL?1) without cytotoxicity. These results suggest that new red rice (GH) would be considered to be new functional rice due to its anti-oxidative effect and high nutrition. 相似文献
18.
Young-Hee Lee Eun-Kyung Hwang Young-Mee Baek Mee-Sung Lee Dong-Jin Lee Young-Jin Jung Han-Do Kim 《Fibers and Polymers》2013,14(9):1445-1453
Natural dye extracts were obtained by extraction from Punica granatum L. using water as an extractant at 90 °C for 90 min with various liquor ratios (solid Punica granatum L.(wt.): solvent water(wt.); 1:100–1:5). Dyeing was carried out using a 1:50 dyeing bath ratio at 80 °C for 60 min by exhaustion method. This study focused on the effect of liquor ratio on dyeing properties and deodorizing/antibacterial performance of various fabrics (cotton, silk and wool) dyed with Punica granatum L. extract without mordants. The optimum liquor ratio was found to be 1:10. By IR, UV-visible spectroscopies and HPLC analysis, the main component in Punica granatum L. extract and the yellow colorant component were found to be ellagic acid. By GC/MS analysis, the major volatile components of pristine Punica granatum L. powder were found to be acetic acid (area: 25.84 %), ethanol (area: 17.97 %), acetoin (area: 13.11 %), acetaldehyde (area: 8.96 %), isobutanal (area: 4.90 %). All dyed fabrics (cotton, silk and wool fabrics) displayed outstanding deodorizing performance (99 %) against ammonia gas and excellent antibacterial performance (bacteriostatic reduction rate: 99.9 %) against Staphylococcu aureus and Klebsiella pneumoniae. 相似文献
19.
This study was undertaken to identify and characterize amino acid substitutions in gyrA and parC related with quinolone resistance of 27 nalidixic acid-resistant (NaR) Salmonella isolates collected in poultry slaughterhouses in Korea. A total of 51 Salmonella isolates were detected from 44.8% (47/105) of the total samples from 15 poultry slaughterhouses examined, among which 27 (52.9%) NaR isolates were detected while ciprofloxacin (Cip) resistance was not present in the isolates. These 27 NaR isolates of DNA sequencing revealed that it contained three types of gyrA mutations in only D87 codon. Mutations in the D87 codon resulted in substitutions to G in most of the isolates, but D87Y and D87N exchanges were also detected. Although Cip resistance was absent, reduced susceptibility characterized by mutations in gyrA was apparent among Salmonella isolates from poultry slaughterhouses in Korea. 相似文献
20.
Static equilibrium was established between the gas phase (headspace) and an unstirred aqueous phase in a sealed vessel. The headspace was then diluted with air to mimic the situation when a container of food is opened and the volatiles are diluted by the surrounding air. Because this first volatile signal can influence overall flavor perception, the parameters controlling volatile release under these conditions are of interest. A mechanistic model was developed and validated experimentally. Release of compounds depended on the air-water partition coefficient (K(aw)) and the mass transport in both phases. For compounds with K(aw) values <10(-)(3), K(aw) was the factor determining release rate. When K(aw) was >10(-)(3), mass transport in the gas phase became significant and the Reynolds number played a role. Because release from packaged foods occurs at low Reynolds numbers, whereas most experiments are conducted at medium to high Reynolds numbers, the experimentally defined profile may not reflect the real situation. 相似文献