80 resultados para 502


Relevância:

10.00% 10.00%

Publicador:

Resumo:

河西走廊地区草原生态环境,棘豆等毒草泛滥成灾,导致大量牲畜中毒死亡。棘豆毒草导致的牲畜中毒症状与历史上马可波罗记载的古代肃州牲畜毒草中毒症状及其相似。为了确定马可波罗所记载的肃州牲畜毒草中毒是否与硒有关,本项研究对河西走廊地区主要草原畜牧区肃南县草原发育的棘豆属植物及其土壤中的硒进行了测定,测定结果表明:土壤硒含量平均值为0.205±0.173mg/kg,与世界平均土壤硒含量相近。棘豆属植物小花棘豆根、茎叶的硒平均含量分别为0.112±0.038mg/kg(0.052~0.174mg/kg),0.102±0.027mg/kg(0.066~0.158 mg/kg);黄花棘豆全株硒平均含量为0.066±0.009mg/kg(0.058~0.078mg/kg),种子硒:0.107mg/kg。可见该区棘豆属毒草硒含量远低于能导致一般动物中毒的3mg/kg植物硒含量。根据肃南县棘豆毒草发育的地理位置、牲畜中毒症状调查及其硒含量测定的结果,本文认为马可波罗所记载的中国西部肃州牲畜毒草中毒是棘豆属毒草中毒,其主要毒素成分不是硒。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

国家自然科学基金(编号:40573014;40373030);中国科学院“百人计划”项目

Relevância:

10.00% 10.00%

Publicador:

Resumo:

研究角砾岩的目的是把它作为一个"窗口",进而研究已知角砾岩体与成矿的关系,研究它们的产出条件和地质背景,以其为类比对象而进行成矿预测.预测的对象和空间范围不完全局限于仅由角砾岩体揭示出的某些地段,也包括分析推断而有利于和(或)相当于角砾岩产出的某些地段(史明魁和苟月明,2000).研究安徽月山矿田三叠系月山组角砾岩与成矿的关系旨在为第二轮找矿预测提供依据.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fibrosis caused by the host response to long-term transplanted microcapsules and the limitation of traditional L929 cell model for biocompatibility testing inspire the development of an assay of biocompatibility based on macrophage behavior. In this paper, the human monocytic cell line THP-1 was utilized for biocompatibility evaluation of microcapsule materials. The cell viability and secretion of nitric oxide (NO) and cytokines served as index of biocompatibility were assayed. It was found that the evaluated microcapsule materials had no effect on the stimulation of NO and cytokines secretion, which meant that these materials were biocompatible. Furthermore, it suggests the THP-1 cell a convenient in vitro experimental model that might be useful for long-term predictions of material biocompatibility.