Assessment and comparison of <Emphasis Type="Italic">in vitro</Emphasis> immunoregulatory activity of three astaxanthin stereoisomers     

Weihong Sun  Lihong Xing  Hong Lin  Kailiang Leng  Yuxiu Zhai  Xiaofang Liu 《中国海洋大学学报(英文版)》2016,15(2):283-287

In recent years, the immune-modulatory role of all-trans astaxanthin from different pigment sources has been studied. It was reported that all-trans astaxanthin might exist as three stereoisomers, and the composition of all-trans stereoisomers in natural materials differs from that of synthetic products. However, the different biological effects of various all-trans stereoisomers still remain unclear. In the present study, we evaluated the bioactivity of three astaxanthin stereoisomers, (3S,3’S)-trans-, (3R,3’R)-trans-and meso-trans-astaxanthin, in regulating cell-mediated immune response using mice lymphocytes and peritoneal exudates cells (PECs) systems. After the treatment with three astaxanthin stereoisomers (20 μmol L^?1), the lymphocyte proliferation capacity, neutral red phagocytosis of PECs and natural killer (NK) cell cytotoxic activity were comparatively assessed. The results showed that all three astaxanthin stereoisomers significantly promoted lymphocyte proliferation, phagocytic capacity of PECs, and cytotoxic activity of NK cells. Moreover, the (3S,3’S)-trans-astaxanthin exhibited a much higher response than others.  相似文献   

Extreme hot summers in China in the CMIP5 climate models     

Guoyong Leng  Qiuhong Tang  Shengzhi Huang  Xuejun Zhang 《Climatic change》2016,135(3-4):669-681

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Western Mediterranean climate and environment since Marine Isotope Stage 3: a 50,000-year record from Lake Banyoles,Spain     

Jack H. Lacey  Melanie J. Leng  Nicole Höbig  Jane M. Reed  Blas Valero-Garcés  Klaus Reicherter 《Journal of Paleolimnology》2016,55(2):113-128

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A study on soil basic characteristics,main microbial flora and typical metal fraction surrounding coal gangue dump in Xiangtan Hunan Province,south of China     

Huan He  Fen-Fen Hong  Xiu-Xiang Tao  Guan-Hua Huang  Yun-Wei Leng  Ju-Fang Shao  Yi-dong Zhao 《Environmental Earth Sciences》2016,75(6):488

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夏季南海西部中尺度物理过程对营养盐和叶绿素a分布特征的影响   总被引：1，自引：1，他引：0  

冷晓云  杨阳  孙军  张桂成  徐文喆  冯媛媛  郭术津  陈建芳  王东晓 《海洋学报》2016,38(4):66-75

通过对2014年8月31日-9月26日国家自然科学基金委南海西部综合航次的调查结果分析,发现在中南半岛沿岸海域存在具有低温高盐的冷涡和位于其东南部海域具有高温低盐的暖涡。相对于暖涡和其他海域,冷涡水团含有更高的营养盐,并在50 m、75 m和100 m层增加明显,DIP分别高0.21 μmol/L、0.39 μmol/L和0.23 μmol/L,DIN分别高4.94 μmol/L、7.56 μmol/L和3.76 μmol/L,DSi分别高2.55 μmol/L、5.25 μmol/L和3.46 μmol/L,说明冷涡对提高初级生产力具有明显的营养优势条件和巨大潜力;叶绿素a最大值均出现在50 m层,其中以海南岛近岸海域最大,冷涡在25 m层提高初级生产力明显,主要是受营养盐影响显著;而在75 m、100 m层可能受到冷涡带来的低温环境而导致叶绿素a含量不高。  相似文献   

Abrupt Holocene climate change and potential response to solar forcing in western Canada     

Daniel G. Gavin  Andrew C.G. Henderson  Karlyn S. Westover  Sherilyn C. Fritz  Ian R. Walker  Melanie J. Leng  Feng Sheng Hu 《Quaternary Science Reviews》2011,30(9-10):1243-1255

Several abrupt climate events during the Holocene, including the widely documented oscillation at 8.2 thousand years before present (ka), are attributed to changes in the North Atlantic thermohaline circulation. Additional mechanisms, such as interactions between atmospheric circulation, ice-sheet dynamics, and the influence of solar irradiance, also have been proposed to explain abrupt climatic events, but evidence remains elusive. This study presents evidence from multi-proxy analyses on the Holocene sediments of Eleanor Lake, interior British Columbia. Climatic inferences from our decadal-resolution record of biogenic silica (BSi) abundance are supported by changes in diatom and pollen assemblages from the same core and correlations with existing regional climate records. The BSi record reveals abrupt and persistent climatic shifts at 10.2, 9.3, and 8.5 ka, the latter two of which are coeval with major collapses of the Laurentide Ice Sheet. The record also reveals a short-term cooling at 8.2 ka that is distinct from the 8.5 ka event and similar in magnitude to several other late-Holocene coolings. BSi is correlated with solar-irradiance indices (r = 0.43–0.61), but the correlation is opposite in sign to that expected from direct solar forcing and weakens after 8 ka. Possible mechanisms causing the abrupt and persistent climate changes of the early Holocene include 1) sudden losses of ice and proglacial lake extent, causing a shift in the meridional structure of atmospheric circulation, 2) a possible link between solar minima and El Niño-like conditions that are correlated with warm spring temperature in interior British Columbia, and 3) the influence of solar irradiance variability on the position of the polar jet, possibly via effects on the strength of the glacial anticyclone.  相似文献   

数值试井技术在凝析气藏边界识别中的应用   总被引：1，自引：0，他引：1  

田冷  何顺利  施英 《新疆地质》2009,27(1)

做为一种新兴试井解释技术,数值试井技术在油、气藏复杂边界形态描述方面发挥了重要作用,具有处理非均质、复杂边界油气藏问题的优点.通过对塔中某区块凝析气藏测试资料综合分析评价,探讨了综合运用解析试井及数值试井进行联合分析方法,将测试动态成果和地质静态成果进行对比,相互验证、补充,实现了对油、气藏外部复杂边界形态的精细描述,落实该气藏边界情况,为该区块凝析气藏下一步开发提供可靠依据.  相似文献   

北方干旱区水地球化学方法应用效果   总被引：1，自引：0，他引：1  

冷福荣  苏美霞  郭利军  张兴龙  何志国 《内蒙古地质》1997,(2)

北方干旱区由于雨水稀少，地下水多以井水（或泉水）的形式分布。取样宜于同一季节，以旱季最佳，该季节的地下水中元素含量相对较高。水中微量元素含量很低，多为10－9级，野外取水样时多采用元素预富集技术，如共沉淀技术和聚氨脂泡塑吸附技术等，分析测试主要采用光谱定量分析。水地球化学异常解释时必须紧密结合地质特征和水文地质条件，对异常作出正确解释和恰当评价。通过几个已知点试验研究，并扩大调查面积，对铜铅锌等有色金属矿、金银等贵金属矿、放射性铀矿以及地热等矿产资源，均取得了明显的应用效果，指出了试验区外围具有普查找矿价值的异常多处，特别在厚层疏松复盖层地区开展水地球化学调查应用效果尤为独特。水地球化学方法一般适用于区域普查阶段。  相似文献   

华北地台北缘海西期花岗岩类地球化学特征及构造环境探讨   总被引：6，自引：0，他引：6  

冷福荣  刘旺盛  苏英 《内蒙古地质》1996,(Z1)

本文论述了华北地台北缘多条海西期花岗岩带的常量元素、微量元素和稀土元素分布特征，由北带至南带花岗岩类具有成分空间变化规律，微量元素特征类似于同碰撞花岗岩中微量元素分布特征。从而论述了在晚古生代期间蒙古洋壳继续俯冲消减在华北增生板块之下，多条海西期花岗岩带继承了早古生代岛弧环境成分极性空间变化规律，同时又具有同碰撞花岗岩的特征，探讨了古生代期间蒙古洋壳和华北陆壳板块运动发展历史。  相似文献   

A new approach to detecting vegetation and land-use change using high-resolution lipid biomarker records in stalagmites   总被引：2，自引：0，他引：2  

Alison J. Blyth  Asfawossen Asrat  Andy Baker  Pauline Gulliver  Melanie J. Leng  Dominique Genty 《Quaternary Research》2007,68(3):314-324

A hundred-year stalagmite lipid biomarker record from Mechara, southeastern Ethiopia, is presented. The record has been recovered at a 10-yr temporal resolution, marking the first time this has been achieved in stalagmite biomarker work and providing the first opportunity to investigate the relationship between stalagmite lipid records and hydrological transport lags, a vital issue in interpreting palaeoenvironmental signals. Preserved plant-derived n-alkanes and n-alkanols show clear changes in composition over time, relating to known land-use changes in the area, particularly the expansion of agriculture in the early twentieth century. The level of environmental detail provided by this technique, combined with the long-term chronological framework offered by stalagmites, holds significant promise for the investigation of early human environments and their associated climatic and anthropogenic controls.  相似文献