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991.
Huang HP Shih YW Chang YC Hung CN Wang CJ 《Journal of agricultural and food chemistry》2008,56(19):9286-9293
Anthocyanins richly exist in mulberry plants and have been well characterized to have various bioactive properties. However, the antimetastasis properties of mulberry anthocyanins (MACs) remain unclear. The objectives of this study were to investigate the inhibitory effects of MACs on the metastasis of B16-F1 cells under noncytotoxic concentrations. Further investigation revealed that the antimetastatic effect of MACs was also evident in a C57BL/6 mice model. First, MACs exhibited an inhibitory effect on the migration ability by wound healing assay and Boyden chamber assay. In the cancer cell metastasis process, matrix degrading proteinases are required. B16-F1 cells treated with MACs at various concentrations showed reduced extracellular matrix (ECM) proteinases including matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) by gelatin zymography assay. The results of the Western blotting assay demonstrated that the expression levels of Ras, phosphoinositide 3-kinase (PI3K), phospho-Akt, and nuclear factor kappa B (NF-kappaB) in the MACs-treated B16-F1 cells were reduced. Therefore, it was suggested that MACs could mediate B16-F1 cell metastasis by reduction of MMP-2 and MMP-9 activities involving the suppression of the Ras/PI3K signaling pathway. Besides, B16-F1 melanoma cells were also injected into the right groin of the C57BL/6 mice, and the mice were fed with MACs at the same time. The hematoxylin-eosin stain (H&E stain) and immunohistochemistry stain showed that the MACs inhibited the mtastasis of B16-F1 cells in vivo. Taken together, the findings proved the inhibitory effect of MACs on the growth and metastasis of B16-F1 cells. These results indicated that MACs might be offered for future application as an antimetastatic agent. 相似文献
992.
Cheng HL Huang HK Chang CI Tsai CP Chou CH 《Journal of agricultural and food chemistry》2008,56(16):6835-6843
Treatment of insulin resistance is a critical strategy in the prevention and management of type 2 diabetes. The crude extracts from all parts of Momordica charantia L. have been reported by many studies for the effective treatment of diabetes and related complications. However, the exact ingredients responsible for the hypoglycemic effect and the underlying mechanism of their actions have not been well characterized because of the lack of a proper assay and screening system. A new cell-based, nonradioactive, and nonfluorescent screening method was demonstrated in this study to screen for natural products from the stem of M. charantia, aiming to identify hypoglycemic components that can overcome cellular insulin resistance. The results suggest triterpenoids being potential hypoglycemic components of the plant and the mechanism underlying their action involving AMP-activated protein kinase. 相似文献
993.
A simple and rapid procedure for the separation and determination of inorganic, methyl, and ethyl mercury compounds was described using liquid chromatography (LC) followed by vapor generation inductively coupled plasma-mass spectrometry (VG-ICP-MS). Well resolved chromatograms were obtained within 5 min by reversed-phase liquid chromatography with a C8 column as the stationary phase and a pH 4.7 solution containing 0.5% v/v 2-mercaptoethanol and 5% v/v methanol as the mobile phase. The separated mercury compounds were converted to mercury vapors by an in situ nebulizer/vapor generation system for their introduction into ICP. The concentrations of NaBH4 and HNO3 required for vapor generation were also optimized. The method was applied for the speciation of mercury in reference materials NIST SRM 1568a Rice Flour and NIST SRM 1567a Wheat Flour and also rice flour and wheat flour samples purchased locally. The accuracy of the procedure was verified by analyzing the certified reference material NRCC DOLT-3 Dogfish Liver for methyl mercury. Precision between sample replicates was better than 13% for all the determinations. The detection limits of the mercury compounds studied were in the range 0.003-0.006 ng Hg mL(-1) in the injected solutions, which correspond to 0.02-0.06 ng g(-1) in original flour samples. A microwave-assisted extraction procedure was adopted for the extraction of mercury compounds from rice flour, wheat flour, and fish samples using a mobile phase solution. 相似文献
994.
Zhao Y Mao C Li Y Zhang P Huang Z Bi F Huang R Wang Q 《Journal of agricultural and food chemistry》2008,56(16):7326-7332
Two series of novel N-alkyloxyoxalyl derivatives of 2-arylpyrrole were synthesized, and their structures were characterized by (1)H NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction analysis. The insecticidal activities of the new compounds were evaluated. The results of bioassays indicated that some of these title compounds exhibited excellent insecticidal activities, and their insecticidal activities against oriental armyworm, mosquito, and spider mite are comparable to those of the commercialized Chlorfenapyr. 相似文献
995.
996.
Zhao Q Shang J Huang Z Wang K Bi F Huang R Wang Q 《Journal of agricultural and food chemistry》2008,56(13):5254-5259
A series of novel N-substituted phenoxysulfenyl- N'- tert-butyl- N, N'-diacylhydrazines were designed and synthesized as insect growth regulators via the key intermediates N-chlorosulfenyl- N'- tert-butyl- N, N'-diacylhydrazines. Compared to the parent compounds, these N-substituted phenoxysulfenyl derivatives displayed better solubility and improved hydrophobicities. The insecticidal activities of the new compounds were evaluated. The results of bioassays showed that the title compounds possessed a combination of strong stomach as well as contact poison property higher than the corresponding parent compounds. In particular, N-(4-chlorophenoxy)sulfenyl -N'- tert-butyl- N-4-ethylbenzoyl- N'-3,5-dimethylbenzoylhydrazide ( IIIi) as a field testing candidate has higher stomach toxicities against oriental armyworm and tobacco cutworm than the corresponding parent compound RH-5992. Furthermore, the compound IIIi exhibits higher contact activities against Asian corn borer, tobacco cutworm, and cotton bollworm than RH-5992. 相似文献
997.
998.
砀山县丰产农机服务专业合作社位于安徽省宿州市砀山县朱楼镇朱楼村,成立于2015年5月13日。合作社目前占地1.33 hm^2(20余亩),拥有成员200余人,拖拉机40多台,收割机18台,灌溉机械14套,植保飞机80多架,烘干机6组,配套农具230多台(套),机械资产达到1 200余万元。 相似文献
999.
Comparative functional responses of native and high‐impacting invasive fishes: impact predictions for native prey populations 下载免费PDF全文
Zhiqiang Guo Danny Sheath Fatima Amat Trigo J. Robert Britton 《Ecology of Freshwater Fish》2017,26(4):533-540
Comparative functional responses (FRs) can predict impacts of invasive species, including piscivorous fishes, via quantifying their depletion of native food resources as a function of prey density. The utility of FRs for predicting impacts on prey populations by invasive fishes of different trophic guilds was tested here by comparing the FRs of the invaders Cyprinus carpio and Carassius auratus, with three native, trophically analogous fishes, Barbus barbus, Squalius cephalus and Tinca tinca. Chironomid larvae and Gammarus pulex were used as prey items. Predictions, developed from studies on the foraging of C. carpio and C. auratus in the literature, were that the invaders would have significantly higher consumption rates for chironomids than the native fishes, but not for G. pulex. Mean consumption rates for chironomids were significantly lower for both invaders than B. barbus and S. cephalus, but were similar to T. tinca. Barbus barbus had a significantly lower consumption rate of G. pulex than both invaders, but there were no significant differences between S. cephalus, T. tinca and the invaders. All FRs were type II, with FR curves for the invaders preying upon chironomids never being significantly higher than the native fishes, contrary to predictions. For G. pulex, some significant differences were apparent between the invaders and native fishes, but again were contrary to predictions. These results indicated that when predation impacts of invasive fishes could also be a function of their population density and body sizes, these parameters should be incorporated into FR models to improve impact predictions. 相似文献
1000.
针对冬小麦因播期推迟造成产量损失的问题,以2个不同分蘖能力的冬小麦品种中麦8号和航麦501为供试材料,研究苗期覆膜和补施氮肥对晚播小麦产量及氮素利用的影响。试验设置3个播期:10月5日适期播种(S0,对照)、10月15日适当晚播(S1)和10月25日过晚播(S2)。结果表明:随着播期推迟,小麦产量逐渐降低。晚播条件下,苗期覆膜和补施氮肥可调控冬小麦产量构成因素、农艺性状、茎蘖生长、成穗率以及氮素的吸收利用。综合而言,晚播条件下,覆膜和补施氮肥有利于提高小麦穗长、总小穗数及冬前群体数量;同时,覆膜可显著提高2个品种晚播条件下的分蘖成穗率和过晚播条件下的植株氮素积累量(PNA)及氮肥偏生产力(PFP),增幅分别为46.4%~89.1%、12.7%~26.5%和19.5%~20.1%;补施氮肥在过晚播条件下有利于成穗率的提高,增幅为18.5%~34.7%。2种调控措施均有利于增加晚播小麦产量,增幅达1.4%~19.5%。但不同分蘖力的小麦对2种调控措施的响应存在差异。综合考虑产量及氮素利用等各方面因素,在晚播条件下,相比于补施氮肥,苗期覆膜更有利于提高晚播小麦产量,弥补晚播造成的产量损失,但在实际操作和节约生产成本方面,前者优于后者。 相似文献