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排序方式: 共有317条查询结果,搜索用时 31 毫秒
311.
Ahlert J Shepard E Lomovskaya N Zazopoulos E Staffa A Bachmann BO Huang K Fonstein L Czisny A Whitwam RE Farnet CM Thorson JS 《Science (New York, N.Y.)》2002,297(5584):1173-1176
The enediynes exemplify nature's ingenuity. We have cloned and characterized the biosynthetic locus coding for perhaps the most notorious member of the nonchromoprotein enediyne family, calicheamicin. This gene cluster contains an unusual polyketide synthase (PKS) that is demonstrated to be essential for enediyne biosynthesis. Comparison of the calicheamicin locus with the locus encoding the chromoprotein enediyne C-1027 reveals that the enediyne PKS is highly conserved among these distinct enediyne families. Contrary to previous hypotheses, this suggests that the chromoprotein and nonchromoprotein enediynes are generated by similar biosynthetic pathways. 相似文献
312.
Vázquez-Carrillo G García-Lara S Salinas-Moreno Y Bergvinson DJ Palacios-Rojas N 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(2):203-208
The maize produced in the highlands of Mexico (>2,400 masl) is generally not accepted by the flour and masa and tortilla industry.
The objective of this work was to evaluate the grain quality and tortilla properties of maize landraces commonly grown in
the highlands of Mexico and compare them with improved germplasm (hybrids). Germplasm analysis included 11 landraces, 32 white
hybrids, and six yellow hybrids. Grain quality was analyzed for a range of physical and chemical factors, as well as for alkaline
cooking quality. Landrace grains tended to be heterogeneous in terms of size, hardness and color. All landraces had soft-intermediate
grains with an average flotation index (FI) of 61%. In contrast, hybrid grains were homogenous in size and color, and harder
than landrace grains, with a FI of 38%. Protein, free sugars, oil and phenolic content in landraces were higher than in the
hybrids. Significant correlations were found between phenolic content and tortilla color (r = −0.60; p < 0.001). Three landraces were identified as appropriate for the masa and tortilla industry, while all the hybrids evaluated
fulfilled the requirements of this industry. 相似文献
313.
314.
Gustavo J. Macchi Marcelo Pjaro María I. Militelli Natalia Radovani Lorena Rivas 《Fisheries Research》2006,80(2-3):345-349
Effects of maternal age–size and condition on oocyte dry weight were analysed for Merluccius hubbsi. Samples of mature females were collected in the Patagonian spawning area during 10 research surveys carried out between 2000 and 2005. Dry weight of 50 hydrated oocytes ranged from 0.80 to 1.90 mg. Relationships of this variable with total length and age were best described by a logarithmic model during the spawning peak. At the beginning and at the end of the reproductive season no significant relationship between these variables was observed, but a decrease in egg dry weight was detected during the spawning period. In general, young spawners (≤5-year-old) showed more variability in egg dry weight, which was associated with a reproductive season shorter than that of old females. Relative condition factor did not shows a significant relationship with oocyte dry weight, and mean values of this index were similar for different months of the spawning seasons analysed. 相似文献
315.
316.
Ji-Min Kim Sung-Chan Shin Yong-Il Cheon Hyung-Sik Kim Gi-Cheol Park Hyoung-Kyu Kim Jin Han Jung-Eun Seol Elena A. Vasileva Natalia P. Mishchenko Sergey A. Fedoreyev Valentin A. Stonik Byung-Joo Lee 《Marine drugs》2022,20(12)
Post-menopausal dry mouth or xerostomia is caused by reduced salivary secretion. This study aimed to investigate the efficacy of echinochrome A (Ech A) in alleviating submandibular gland dysfunctions in ovariectomized rats that mimic menopause. Female rats that were eight-weeks-old were randomly divided into SHAM-6, -12; OVX-6, -12; and ECH-6, -12 groups (consisting of 6- and 12-weeks post-sham-operated, ovariectomized, and Ech A-treated ovariectomized rats, respectively). The ECH groups had lower body weight than OVX but similar food intake and estradiol or estrogen receptor β expression. However, the ECH groups had lower mRNA expression of sterol-regulatory element binding protein-1c (Srebp-1c), acetyl-CoA carboxylase (Acc), fatty acid synthase (Fasn), cluster of differentiation 36 (Cd36), and lipid vacuole deposition than OVX mice. Moreover, reactive oxygen species (ROS), malondialdehyde (MDA), and iron accumulation were lower in the ECH than in the OVX groups. Fibrosis markers, transforming growth factor β (Tgf-βI and Tgf-βII mRNA) increased in the OVX than SHAM groups but decreased in the ECH groups. Aquaporin (Aqp-1 and Aqp-5 mRNA) and mucin expressions were downregulated in the OVX groups but improved with Ech A. In addition, Ech A prevented post-menopausal salivary gland dysfunction by inhibiting lipogenesis and ferroptosis. These findings suggest Ech A as an effective remedy for treating menopausal dry mouth. 相似文献