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排序方式: 共有414条查询结果,搜索用时 46 毫秒
71.
Ryu YB Jeong HJ Yoon SY Park JY Kim YM Park SJ Rho MC Kim SJ Lee WS 《Journal of agricultural and food chemistry》2011,59(12):6467-6473
Influenza A virus infections continue to pose a major threat to humans and several animal species. Neuraminidase (NA) is one of the most promising targets for the development of drugs against influenza viruses because of its critical role in the viral life cycle. During the course of a search for NA inhibitors from edible natural sources, we found that the ethyl acetate layer of ethanol extracts of Ecklonia cava showed extremely high NA-inhibitory activity (72.1% inhibition at 30 μg/mL). Bioactivity-guided fractionation of the ethyl acetate layer yielded five phlorotannins, identified as phloroglucinol (1), eckol (2), 7-phloroeckol (3), phlorofucofuroeckol (4), and dieckol (5). The inhibitory activities of these compounds (1-5) against NAs from group-1 (A/Bervig_Mission/1/18 [H1N1], A/PR/8/34 [H1N1]) and group-2 (A/Hong Kong/8/68 [H3N2], A/Chicken/Korea/MS96/96 [H9N2]) influenza A were evaluated to determine potencies and kinetic behavior. Analyses using various in vitro influenza A virus NA assays showed that all five phlorotannin derivatives were selective NA inhibitors. Of the phlorotannins, phlorofucofuroeckol (4) exhibited the most potent inhibitory activities toward group-1 NAs (IC?? values, 4.5 and 14.7 μM), whereas dieckol (5) potently inhibited group-2 NAs. Kinetic analyses indicated that compounds 1-5 were all noncompetitive. Notably, these noncompetitive inhibitors synergized with oseltamivir to enhance the NA-inhibitory effects of oseltamivir. 相似文献
72.
Ju Kyoung Oh Jong Pyo Chae Edward Alain B. Pajarillo Sung Hun Kim Min‐Jin Kwak Jong‐Su Eun Seok Woo Chee Kwang‐Youn Whang Sae‐Hun Kim Dae‐Kyung Kang 《Animal Science Journal》2020,91(1)
Gastrointestinal microbiota impact host's biological activities, including digestion of indigestible feed components, energy harvest, and immunity. In this study, fecal microbiota of high body weight (HW) and low body weight (LW) growing pigs at 103 days of age were compared. Principal coordinates analysis separated the HW and LW groups into two clusters, indicating their potential differences between microbial community composition. Although the abundances of two major phyla, Firmicutes and Bacteroidetes, did not significantly differ between the HW and LW groups, some genera showed significant differences. Among them, Peptococcus and Eubacterium exhibited strong positive correlations with body weight (BW) and average daily gain (ADG) (Rho > 0.40), whereas Treponema, Desulfovibrio, Parabacteroides, and Ruminococcaceae_unclassified exhibited strong negative correlations with BW and ADG (Rho < ?0.40). Based on these results, the structure of intestinal microbiota may affect growth traits in pigs through host–microbe interactions. Further in‐depth studies will provide insights into how best to reshape host–microbe interactions in pigs and other animals as well. 相似文献
73.
柑桔爆皮虫(Agrilus auriventris Saunders)及其防治 总被引:4,自引:0,他引:4
柑桔爆皮虫为我国主要柑桔产区的重要害虫,发生已久。在浙江衢县是柑桔上的一种毁灭性害虫,对柑桔生产的影响很大。本文系1958—1960年在浙江衢县桔区結果此虫生活习性和防治的研究。 1.此虫在衢县对衢桔为害最重,广柑、香枹(柚之一种)次之,福桔和有柑为害最輕。一年发生一代,主要以第2—4龄幼虫在树干不同部位越冬,尤以木质部內的第4龄幼虫越冬为主。3月下旬开始化蛹,4月下旬化蛹盛期,同时成虫开始羽化,5月上旬羽化盛期,5月中旬成虫出洞,5月下旬为出洞盛期,以后一直延續到10月间陆續有成虫羽化出洞,但为数不多。 2.成虫产卵有选择性,在已受害的桔树上产卵多,并都在这些桔树树皮的小裂縫內产卵,在地衣、苔蘚內較少。 3.爆皮虫为害桔树主要在幼虫时期,其为害的发展趋势:一是在虫株上从下向上发展,这是主要的;二是横的发展,在同株內从虫干向邻近健干扩散或从被害株向邻近健株扩散,同园内不同桔株是从园边扩散到中間。 4.幼虫有4个龄期,第1—3龄幼虫在韌皮部与形成层内为害,第4龄幼虫在形成层及木质部內为害。 5.用10%二二三乳剂涂刷被害桔树,封閉成虫出洞的效果极好,同时它的残效长,对桔树无药害,是安全有效的防治方法。 相似文献
74.
These days consumers’ various demands are accelerating research on apparel manufacturing system including automatic measurement,
pattern generation, and clothing simulation. Accordingly, methods of reconstructing human body from point-clouds measured
using a three dimensional scanning device are required for apparel CAD system to support these functions. In particular, we
present in this study a human body reconstruction method focused on two issues, which are the decision of the number of control
point for each sectional curve with error bound and the local knot removal for reducing the unusual concentration of control
points. The approximation of sectional curves with error bounds as an approximation criterion leads all sectional curves to
their own particular shapes apart from the number of control points. In addition, the application of the local knot removal
to construction of human body sectional curves reduces the unusual concentration of control points effectively. The results
may be used to produce an apparel CAD system as an automatic pattern generation system and a clothing simulation system through
the low level control of NUBS or NURBS. 相似文献
75.
Shuai ZHANG Xin WU Dandan HAN Yong HOU Jianzhuang TAN Sung Woo KIM Defa LI Yulong YIN Junjun WANG 《农业科学与工程前沿(英文版)》2021,8(1):15
76.
A series of shape memory polyurethane (PU) copolymers synthesized from 1,4-phenyldiisocyanate (PDI), poly(tetramethyleneglycol)
(PTMG), 1,4-butanediol (BD) as a chain extender, and glycerol as a cross-linking agent were tested for the mechanical properties
and the shape memory effect at the temperature 20 °C above melting temperature (T
m), and were compared with other PUs synthesized from 4,4′-methylene-bis-phenyldiisocyanate (MDI), PTMG, and BD. Mechanical
properties and shape memory effect were improved substantially by adopting both PDI and glycerol. Interestingly, enthalpy
of melting and T
m were not affected by the glycerol content. Vibration and shock absorption ability was investigated by measuring both loss
tan δ and storage modulus with dynamic mechanical analyzer (DMA). 相似文献
77.
78.
This paper presents the synthesis of metal complex acid dyes obtained from the reaction of o,o′-dihydroxyazo dyes and chromium and cobalt sulfate. The 1H-NMR, FT-IR and UV/Visible Spectrophotometer, TLC (Thin Layer Chromatography) and ICP (Ion Chromatography) of the intermediates
and the metal complexes were studied and compared. Their properties such as dyeing, fastness and toxicity on nylon were also
assessed according to standard methods. 相似文献
79.
Endosperm-Specific Expression of Serotonin <Emphasis Type="Italic">N</Emphasis>-Hydroxycinnamoyltransferase in Rice 总被引:1,自引:0,他引:1
Lee K Kang K Park M Woo YM Back K 《Plant foods for human nutrition (Dordrecht, Netherlands)》2008,63(2):53-57
Serotonin N-hydroxycinnamoyltransferase (SHT) is a key enzyme in the synthesis of feruloylserotonin (FS) and 4-coumaroylserotonin (CS). These serotonin derivatives show strong antioxidant activity, making them valuable for both nutritional and pharmacological use in humans. Ectopic expression of SHT under the control of the endosperm specific-glutelin and prolamin promoters from rice was produced via Agrobacterium-mediated transformation. SHT expression was confirmed by Southern blot analysis, followed by Northern blotting and SHT enzyme activity analyses using total RNA and protein, respectively, extracted from transgenic seeds. The glutelin A3 (GluA3) promoter produced low SHT mRNA expression in rice seeds, whereas the prolamin promoter expressed high levels of SHT mRNA. In spite of the ectopic expression of SHT in rice seeds, both transgenic genotypes accumulated levels of serotonin derivatives similar to those found in wild-type rice. Furthermore, our data suggest that serotonin, rather than phenylpropanid-CoAs, is the rate-limiting substrate in the biosynthesis of serotonin derivatives in SHT-overexpressing transgenic rice seeds. 相似文献
80.
Toru Taniguchi Yasunori Ohmiya Manabu Kurita Miyoko Tsubomura Teiji Kondo Yong Woo Park Kei’ichi Baba Takahisa Hayashi 《Journal of Wood Science》2008,54(5):408-413
We performed biosafety assessments of transgenic poplars prior to field trials. Constitutive expression of the Aspergillus aculeatus xyloglucanase in Populus alba increased the cellulose content and specific gravity of its stem, the leaves of which were visibly greener, thicker, and
smaller than those of the wild-type plant. Although the young transgenic poplars grew faster than the wild type in a growth
chamber, there was no distinguishable difference in growth between the poplars when they were placed in a special screened
greenhouse. Allelopathic tests showed that the transgenic poplars do not produce harmful substances. Based on all the biosafety
assessments and the scientific literature on poplar species, we came to the conclusion that transgenic poplars probably do
not disturb the biological diversity of the surrounding environment, even when they are submitted to field trials. 相似文献