等度高效液相色谱测定食品中色素流动相条件研究

本文通过对等度液相色谱测定食品中色素流动相条件的研究,得出了等度液相色谱测定食品中色素流动相的最佳条件。经试验发现,测定胭脂红流动相甲醇与乙酸铵比例为30∶70,流速为0.8ml/min时,加标回收率,保留时间,相对标准偏差准确可靠,方法稳定。     

5G NSA网络关键性能研究与优化

5G NSA网络结构复杂,5G与4G在接入网级互通互连,建网初期,一些基础性的关键指标对网络影响大。本文从NSA网络初始接入信令流程、5G原理等方面入手,对网络的接入、保持和移动性进行分析,找出每个节点异常的原因,结合日常优化的实例总结出一套问题分析处理的思路,以保证网络的基本性能——能接入、不掉线,可移动。     

儿童酱油:重口味,不营养

正儿童酱油,不仅完全是炒作忽悠的营销噱头,而且对于孩子的健康有害无益。如果家里还有,那么还是留给大人吃吧商品营销中有句格言"女人和孩子的钱最好赚",中国父母对孩子的投入更是到了"不多花钱不舒服"的地步,于是各种"儿童专用"的产品也应运而生,"儿童酱油"就是其中的一种奇葩。儿童酱油的广告宣称"专为儿童健康研制的酿造低盐淡口酱油","适合拌饭、清蒸食物等,一则起到开胃的     

Clustered spikelets 4, encoding a putative cytochrome P450 protein CYP724B1, is essential for rice panicle development

Rice （Oryza sativa L.） inflorescence （panicle） architecture is an important agronomic trait, serving as one of the determinants of rice yield. A number of genes related to panicle development have been cloned and functionally characterized so far. However, more information is needed for fully understanding of the mechanism underlying the panicle development. In the present study, we identified a clustered spikelets 4 （cl4） mutant in the 93-11 genetic background. Compared to its wild-type 93-11, cl4 mutant has a typical clustered spikelets phenotype with all primary branches clustered on the base of the main rachis and 2-3 abnormal spikelets clustered on the primary branches. Moreover, cl4 mutant also shows shorter plant height than that of the wild type. Map-based cloning strategy is per- formed to clone the CL4 gene. As a result, CL4 is demonstrated to encode a putative cytochrome P450 protein CYP724B1, which is involved in brassinosteroid biosynthesis. To confirm our mapping result, the CL4 RNAi transgenic plants are generated. And the transgenic plants also show similar phenotype as the cl4 mutant. These results provide strong evidence that CL4 plays an important role in rice panicle development as well as plant height regulation.     

COX-2与CYPlBl在人乳腺癌中的表达及意义

目的探讨人乳腺癌组织中COX-2和CYPlBl的表达规律及与临床病理特征的关系，对认识其在乳腺癌发生发展中的作用奠定初步病理学基础。方法应用免疫组织化学方法检测42例乳腺癌组织中COX-2和CYPlBl的表达情况，结合临床病理指标进行研究分析。结果在乳腺癌中COX-2和CYPIBl表达阳性率分别为78．6％和73．8％。COX-2的阳性表达与乳腺癌淋巴结转移、组织学分级显著相关（P〈0．05）；CYPlBI的阳性表达与组织学分级、ER表达显著相关（P〈0．05）。乳腺癌COX-2与CYPlBI表达呈正相关（r=0．481，P〈0．01）。结论人乳腺癌组织存在COX-2与CYPlBl的共同阳性表达，COX-2可能促进CYPlBl表达，共同作用参与乳腺癌的发生发展。     

肤色的秘密

剃掉一只黑猩猩的毛．你会发现它的皮肤是白色的。千百年来，人类的皮肤就是黑色的。对于人类皮肤为何变化．学者各执己见。其中一种解释是黑色素通过吸收紫外线来防止皮肤癌的发生：自种人搬去热带．罹患皮肤癌的风险会变大。     

活性白土柱层析法分离提纯姜黄素

分别用乙醇、乙酸乙酯、丙酮提取姜黄粉中的姜黄素,通过正交实验确定最佳提取溶剂为丙酮．采取逆向思维,将活性白土用于姜黄色素脱油脂进行提纯,并建立了高效液相色谱外标法用于分析姜黄素的含量．实验表明：用丙酮提取的,提取率最高,可达94.57%．丙酮提取液流经活性白土层析柱后,测得活性白土对姜黄素的吸附容量为7.34%,分别采用碱性水、碱性乙醇、碱性丙酮洗脱被吸附的姜黄素．通过单因素实验确定最佳吸附和洗脱条件．最终可得到高纯度、不吸潮的精制姜黄素产品．实验结果显示,色素的产率为2.36%,产品纯度为94.29%,色素总收率达80.71%．     

DNA barcoding of 18 species of Bovidae

Genetic divergences of mitochondrial cytochrome c oxidase subunit I genes, known as DNA barcodes, have been used in species identification in the animal kingdom. Barcodes can assist field workers and taxonomists to determine groups in need of taxa analysis, and facilitate the recognition of appropriate populations and scales for conservation planning. In this study, 18 species of Bovidae were selected to evaluate the effectiveness of DNA barcoding for species differentiation. The results showed that all but 2 species had unique DNA barcodes. The mean intraspecific variation was 0.63%, yielding a threshold of 6.3% for flagging putative species. The results supported the inference that barcode variation within species of mammals is somewhat higher than within other animal groups. The present study validated the effectiveness of barcoding for the identification of bovid species.     

基于哈达玛变换的LTE辅同步信号检测方法实现研究

针对LTE系统中辅同步信号检测算法复杂度大的问题,根据辅同步信号的特点,提出了基于哈达玛变换的检测方法。详细推导了该方法的理论依据,并对其实现复杂度与常规检测方法进行分析比较,得出本方法能够降低90%计算量的结论。通过MATLAB仿真,验证了本方法在白噪声环境下能够和常规检测方法获得相同的检测性能。     

微藻色素及其提取研究

微藻是地球上最早的生物物种,它们能十分有效地利用太阳能将H2O、CO2和无机盐类转化为有机资源,是地球有机资源的最初级生产力,藻类不仅富含蛋白质、脂肪和碳水化合物这三大类人类所必需的要素,而且还含有多种色素等生物活性物质,是人类向海洋索取食品、药品、燃料、生化试剂、精细化工产品以及其他重要材料的一种方式。