首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   29篇
  免费   4篇
  国内免费   2篇
化学   29篇
综合类   3篇
物理学   3篇
  2022年   3篇
  2021年   5篇
  2019年   1篇
  2018年   1篇
  2016年   3篇
  2015年   1篇
  2014年   1篇
  2013年   2篇
  2012年   1篇
  2010年   1篇
  2009年   3篇
  2008年   2篇
  2007年   2篇
  2006年   2篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  1999年   1篇
排序方式: 共有35条查询结果,搜索用时 62 毫秒
21.
Skin is the largest organ of humans. Overexposure to ultraviolet (UV) is the primary environmental factor that causes skin damage. The compound, (-)-loliode, isolated from the brown seaweed Sargassum horneri, showed strong antioxidant and anti-inflammatory activities in in vitro and in vivo models. To further explore the potential of (-)-loliode in cosmetics, in the present study, we investigated the photoprotective effect of (-)-loliode in vitro in skin cells and in vivo in zebrafish. The results indicated that (-)-loliode significantly reduced intracellular reactive oxygen species (ROS) level, improved cell viability, and suppressed apoptosis of UVB-irradiated human keratinocytes. In addition, (-)-loliode remarkably attenuated oxidative damage, improved collagen synthesis, and inhibited matrix metalloproteinases expression in UVB-irradiated human dermal fibroblasts. Furthermore, the in vivo test demonstrated that (-)-loliode effectively and dose-dependently suppressed UVB-induced zebrafish damage displayed in decreasing the levels of ROS, nitric oxide, lipid peroxidation, and cell death in UVB-irradiated zebrafish. These results indicate that (-)-loliode possesses strong photoprotective activities and suggest (-)-loliode may an ideal ingredient in the pharmaceutical and cosmeceutical industries.  相似文献   
22.
羊栖菜多糖对小鼠免疫功能的影响   总被引:4,自引:0,他引:4  
采用从羊栖菜提取物分离获得的 4个组分中选择其中不同分子量 ,且得率较高的F1、f1组分 ,观察它们对小鼠免疫功能的影响 .结果显示按 4 0mg/(kg·d)剂量腹腔注射 7d后 ,对小鼠抗SRBC抗体生成有促进作用 ,同时明显提高小鼠脾指数 ,其中f1组最明显 .对f1组分按不同剂量注射 ,结果显示对小鼠胸腺T淋巴细胞增殖促进作用呈明显量效关系 .  相似文献   
23.
Cultivation of the fungal strain Eurotium cristatum EN‐220, an endophyte obtained from the marine alga Sargassum thunbergii, resulted in the isolation of one new anthraquinone glycoside, 3‐O‐(α‐D ‐ribofuranosyl)questinol ( 1 ) and one new orsellinic acid ester, cristatumside A ( 2 ), together with three known aromatic glycosides, 3‐O‐(α‐D ‐ribofuranosyl)questin ( 3 ), isotorachrysone 6‐Oα‐D ‐ribofuranoside ( 4 ), and asperflavin ribofuranoside ( 5 ), as well as three anthraquinone derivatives, asperflavin ( 6 ), eurorubrin ( 7 ), and (+)‐variecolorquinone A ( 8 ). The structures of these compounds were determined by extensive analysis of their spectroscopic data, as well as by their comparison with those in the literature. Each of the isolated compounds was evaluated for its antimicrobial activity and brine shrimp lethality.  相似文献   
24.
The aim of this study is to elucidate the structure and investigate the hypolipidaemic activity of a fucoidan extracted from brown seaweed Sargassum henslowianum collected at Hai Van–Son Cha peninsula, Hue province, Vietnam by using tandem electrospray ionisation mass spectrometry. The results demonstrated that the fucoidan has α(1 → 3)-linked l-fucopyranose backbone and sulphate groups occupied mostly at C-2, C-4 and sometimes at C-3 position of fucose residues. The results of in vivo bioactivity examination revealed that the fucoidan in the dose of 100 mg/kgP/day by oral administration helped decrease cholesterol, triglyceride and LDL-cholesterol levels on obese mice.  相似文献   
25.
Thealgaeproducedmanyinterestingpharmacologicalandbiologicalactivitymetabolitessuchasantibacterium.antineoplastic.anticancerandantimicrobialactivitiescompound'-'.Moreandmorechemistandbiologistpayattentiontothecollstituentsofthealgae.ThealgaSal'gassunl1)achedcollectedfromtheSouthChinaSeahasbeenstudiedandcompoundIwasisolated.FigureI-shestructureof1Theethanole\tractofalgaSul'gassll))]1)uk'hel/waselutedb}'silicagelusingpetroleunletherx"itllincreasingamountsofethy'lacetateaseluent.Thefractionobt…  相似文献   
26.
This study focuses on the green synthesis of silver and gold nanoparticles using the marine algae extract, Sargassum horneri, as well as the degradation of organic dyes using biosynthesized nanoparticles as catalysts. The phytochemicals of the brown algae Sargassum horneri acted as reducing and capping agents for nanoparticle synthesis. Ultraviolet–visible absorption spectroscopy, dynamic light scattering, high-resolution transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy were used to characterize the biosynthesized nanoparticles. The green-synthesized SH-AgNPs and SH-AuNPs exhibited high catalytic activity for degradation of organic dyes, such as methylene blue, rhodamine B, and methyl orange. The reduction reactions of dyes are based on pseudo-first-order kinetics.  相似文献   
27.
Seasonal variation in elemental composition of Stoechospermum marginatum and Sargassum wightii collected from Mandapam, Gulf of Mannar was studied over a period of 1 year from May 2006 to February 2007 at 3 months interval. The physico-chemical parameters of water such as air temperature (°C), surface water temperature (°C), turbidity (NTU), salinity (‰) and water pH were also made. Significant seasonal variation in the elemental composition of the two species was observed. These were correlated to the seawater chemistry. The accumulation factor of certain ions by the algae is also discussed. Intake of more minerals was accumulated in S. wightii during summer season.  相似文献   
28.
This is the first study to examine the effects of in vitro digestion on biological activities of Sargassum spp., a broadly known brown seaweed for therapeutic potential. Three fractions (F1–F3) were obtained from hexane extract by column chromatography. Under in vitro simulated digestion, the anti-α-amylase capacity of F1 in oral and intestinal phases increases, while it significantly decreases in the gastric phase. The α-amylase inhibition of F2 promotes throughout all digestive stages while the activity of F3 significantly reduces. The cytotoxic activity of F1 against U266 cell-line accelerates over the oral, gastric, and intestinal stages. The fractions F2 and F3 exhibited the declined cytotoxic potentialities in oral and gastric phases, but they were strengthened under intestinal condition. Palmitic acid and fucosterol may play an active role in antidiabetic and cytotoxic activity against multiple myeloma U266 cell line of Sargassum spp. However, the involvement of other phytochemicals in the seaweed should be further investigated.  相似文献   
29.
30.
Recent increased interest in seaweed is motivated by attention generated in their bioactive components that have potential applications in the functional food and nutraceutical industries. In the present study, nutritional composition, metabolite profiles, phytochemical screening and physicochemical properties of freeze-dried brown seaweed, Sargassum polycystum were evaluated. Results showed that the S. polycystum had protein content of 8.65 ± 1.06%, lipid of 3.42 ± 0.01%, carbohydrate of 36.55 ± 1.09% and total dietary fibre content of 2.75 ± 0.58% on dry weight basis. The mineral content of S. polycystum including Na, K, Ca, Mg Fe, Se and Mn were 8876.45 ± 0.47, 1711.05 ± 0.07, 1079.75 ± 0.30, 213.85 ± 0.02, 277.6 ± 0.12, 4.70 ± 0.00 and 4.45 ± 0.00 mg 100/g DW, respectively. Total carotenoid, chlorophyll a and b content in S. polycystum were detected at 45.28 ± 1.77, 141.98 ± 1.18 and 111.29 µg/g respectively. The total amino acid content was 74.90 ± 1.45%. The study revealed various secondary metabolites and major constituents of S. polycystum fibre to include fucose, mannose, galactose, xylose and rhamnose. The metabolites extracted from the seaweeds comprised n-hexadecanoic acid, 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester, benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy- methyl ester, 1-dodecanol, 3,7,11-trimethyl-, which were the most abundant. The physicochemical properties of S. polycystum such as water-holding and swelling capacity were comparable to several commercial fibre-rich products. In conclusion, results of this study indicate that S. polycystum is a potential candidate as functional food sources for human consumption and its cultivation needs to be encouraged.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号