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排序方式: 共有110条查询结果,搜索用时 23 毫秒
1.
为探讨珊瑚对生物活饵料的捕食机制,选取美丽鹿角珊瑚(Acropora formosa)和佳丽鹿角珊瑚(Acropora pulchra)为实验对象,以轮虫(SS-type Rotifer)和丰年虫(Artemia salina)无节幼体为生物活饵料进行投喂。通过对投喂饵料量、残余量,以及差值进行统计,从而探讨珊瑚的摄食情况及摄食偏好。结果表明:超小型轮虫平均剩余量8.16×104个,P=0.012(P0.05),实验前后轮虫密度有显著差异。丰年虫无节幼体平均剩余量2.3×103个,P=0.01(P0.05),实验前后丰年虫密度有显著性差异。超小型轮虫和丰年虫无节幼体可以是珊瑚的生物活饵料。 相似文献
2.
[目的]克隆盐藻淀粉磷酸化酶基因,并初步分析其基本性质和表达蛋白。[方法]采用RT-PCR和RACE的方法克隆基因;生物信息学系统分析其性质;构建原核表达载PGS21a-DsSP转化于E.coli BL21表达蛋白,采用GST-SefinoseTMKit和Western Blot分别纯化、检测该融合蛋白。[结果]成功克隆出1种淀粉磷酸化酶(GenBank accession No.KF061044)命名为DsSP;分析得到了其基本性质并预测了该蛋白的亚细胞定位、二级结构和三级结构;该融合蛋白在上清和包涵体中均存在,且对上清蛋白成功纯化;Western Blot检测表明其在E.coli.BL21中成功表达。[结论]为进一步阐明DsSP的功能及作用机制奠定了理论基础。 相似文献
3.
以初始体质量为(13.88±0.28)g的卵形鲳鲹为试验对象,研究不同盐藻添加量(0.0%、0.1%、0.2%、0.4%、0.8%、1.6%)饲料对其体色和生长的影响。每组设3个平行,每个平行饲养20尾鱼,每日饱食投喂2次(8:00;17:00),试验周期为56d。结果显示,盐藻添加量为0.1%~1.6%时,随着饲料中盐藻水平的提高,卵形鲳鲹背部和腹部黄色值(b*)呈显著上升趋势(P0.05),饲料中添加盐藻可明显改善卵形鲳鲹体色;与此同时,卵形鲳鲹质量增加率和特定生长率随饲料盐藻水平的上升呈下降趋势(P0.05),未添加盐藻的对照组具有最高蛋白质效率和最低饲料系数,且与盐藻添加量为0.4%的试验组差异显著(P0.05),饲料中添加盐藻对卵形鲳鲹生长性能和饲料利用没有明显的促进作用;此外饲料盐藻水平对卵形鲳鲹体成分也没有显著影响(P0.05)。 相似文献
4.
为了进一步研究MAPKK激酶的生理功能,利用RT-PCR技术扩增了Ds MAPKKK的开放阅读框序列,并利用T4连接酶与质粒p GS21a连接,构建了原核表达载体p GS21a-Ds MAPKKK。将该重组质粒导入大肠杆菌BL21(DE3)感受态细胞,经IPTG诱导成功表达了融合蛋白。经SDS-PAGE检测,融合蛋白在上清和包涵体中均存在。可溶性蛋白经过GST柱纯化,电泳分析结果表明,在68 k D左右有单一的蛋白条带,说明融合蛋白得到有效纯化。蛋白印迹结果显示在68 k D左右有明显的杂交条带,初步证明纯化的蛋白就是带有GST标签的MAPKK激酶。Ds MAPKKK的成功表达与纯化,为深入探讨Ds MAPKK激酶的性质及功能打下了坚实的基础。 相似文献
5.
Gianluca Pane Gabriele Cacciola Elisabetta Giacco Gian Luigi Mariottini Erika Coppo 《Marine drugs》2015,13(10):6440-6452
External otitis is a diffuse inflammation around the external auditory canal and auricle, which is often occurred by microbial infection. This disease is generally treated using antibiotics, but the frequent occurrence of antibiotic resistance requires the development of new antibiotic agents. In this context, unexplored bioactive natural candidates could be a chance for the production of targeted drugs provided with antimicrobial activity. In this paper, microbial pathogens were isolated from patients with external otitis using ear swabs for over one year, and the antimicrobial activity of the two methanol extracts from selected marine (Dunaliella salina) and freshwater (Pseudokirchneriella subcapitata) microalgae was tested on the isolated pathogens. Totally, 114 bacterial and 11 fungal strains were isolated, of which Staphylococcus spp. (28.8%) and Pseudomonas aeruginosa (P. aeruginosa) (24.8%) were the major pathogens. Only three Staphylococcus aureus (S. aureus) strains and 11 coagulase-negative Staphylococci showed resistance to methicillin. The two algal extracts showed interesting antimicrobial properties, which mostly inhibited the growth of isolated S. aureus, P. aeruginosa, Escherichia coli, and Klebsiella spp. with MICs range of 1.4 × 109 to 2.2 × 1010 cells/mL. These results suggest that the two algae have potential as resources for the development of antimicrobial agents. 相似文献
6.
7.
《Journal of plant nutrition》2013,36(10-11):2197-2210
Abstract The unicellular green alga Dunaliella was previously proposed as a model photosynthetic organism for adaptation to iron deficiency. The purpose of this study was to find out how iron limitation affects the structure and composition of the photosynthetic system of Dunaliella salina. Iron deprivation did not retard proliferation of D. salina cells, but was associated with a decrease in cell volume and chlorophyll content, and with a four‐fold reduction in iron content and a two‐fold increase in Cu content. Electron microscopic analysis revealed shrinkage of the chloroplast and decrease in stacked thylakoid membranes. Measurements of chlorophyll fluorescence induction in the presence of DCMU and of 77 K chlorophyll fluorescence emission spectra indicated gross changes in the photosynthetic efficiency of reaction centers and in the organization of their associated light harvesting antenna. Differential analysis of protein composition led to the identification of a major thylakoid membrane protein (Tidi), that was specifically induced under iron deprivation. Partial sequencing suggests that Tidi is a novel type of a chlorophyll a/b binding protein. These results clearly show that iron limitation is associated with extensive reorganization of the photosynthetic system in Dunaliella. 相似文献
8.
玉米黄质(3,3'-二羟基-β-胡萝卜素)是自然界中常见的一种β-胡萝卜素衍生物,是黄斑和视网膜中最关键的部分.玉米黄质是通过一系列酶作用合成,其中β-胡萝卜素羟化酶(chyb)是关键限速酶,为了研究盐生杜氏藻(Dunaliella salina)中不同胁迫下β-胡萝卜素羟化酶基因的表达及玉米黄质含量的变化.本研究采用RACE方法首次从盐生杜氏藻中扩增出β-胡萝卜素羟化酶基因(Dschyb),并分析强光、葡萄糖等因素对DSchyb表达及玉米黄质含量的影响.结果表明,该基因全长1 433 bp(GenBank登录号:JN118489),包含一个969bp的开放阅读框,编码322个氨基酸,氨基酸的分子量为35.51kD,等电点(PI)为9.01.DsCHYB包含有4个保守的组氨酸基序,与团藻及莱茵衣藻的同源性分别是64%和58%.DsCHYB具有4个跨膜结构及叶绿体导肽,进一步证明该酶定位于叶绿体类囊膜上.系统进化树分析标明,DsCHYB与其他绿藻如团藻(Volvox carteri f.Nagariensis)、莱茵衣藻(Chlamydomonas reinhardtii)的CHYB共处一个进化支,亲缘关系很近.Dschyb基因的表达调控研究显示,在经强光刺激24 h后,Dschyb 基因表达显著上调(P<0.01),在48 h表达最高(P<0.01).在经乙酸钠、硫酸亚铁和强光共同处理6h时,Dschyb表达急剧上升(P<0.01),处理12h后下降;在葡萄糖处理1.5h后,其表达达到最高,6h后表达与对照组无显著性差异;添加放线菌素D后,Dschyb的表达相对对照降低,表明放线菌素D可能对葡萄糖诱导Dschyb表达具有抑制作用.高效液相色谱测定其玉米黄质含量,钠铁、强光及葡萄糖处理均能提高盐生杜氏藻的玉米黄质的含量,其玉米黄质含量比对照组分别增长16%(P<0.05),28%(P<0.05)和53%(P<0.01).本研究结果为玉米黄质合成调控及其在藻类中功能研究提供理论指导. 相似文献
9.
硼铜组合对盐藻生长与物质积累的影响 总被引:1,自引:0,他引:1
为了探索培养盐藻的微量元素条件,设计了室内模拟海洋环境下微量元素硼、铜的不同浓度组合,研究其对盐藻细胞生长与物质积累的影响。结果表明,培养液中适当的硼铜浓度组合对盐藻细胞的生长和物质积累有促进作用,而硼铜浓度过高或过低则对其不利。在试验的9种硼铜浓度组合中,以培养液中4 mg/L的硼和125 μg/L的铜浓度组合对盐藻细胞的生长和物质积累促进作用最好,它可使培养液中的盐藻细胞密度、蛋白质积累量和β-萝卜素积累量都达到最高。培养液中6 mg/L的硼和175 μg/L的铜浓度组合可使单个盐藻细胞中β-萝卜素和蛋白质积累量都最高,但可能仅是在铜、硼过多的逆境条件下,盐藻细胞的适应性反应。 相似文献
10.
Ike Olivotto Chiara Carla Piccinetti Matteo Alessandro Avella Carles Molina Rubio Oliana Carnevali 《Aquaculture Research》2010,41(9):e307-e315
Rotifers and Artemia salina nauplii are the most widely used live prey for newly hatched larvae, but they do not always promote optimal survival and growth. Alternative food sources such as copepods, which bypass these inadequacies and promote adequate growth, are needed and they are viewed with considerable interest by the scientific community. The aim of the present study was to test two different diets [rotifers and A. salina nauplii (group A) and a mixture (group B) of rotifers/Tisbe spp. copepods and A. salina nauplii/copepods] during the larval rearing of the striped blenny Meiacanthus grammistes. The analysis of the survival rate, size (total length and wet weight) and metamorphosis time during the larval phase of this species showed that Tisbe spp. administration can significantly improve larval survival and growth and also reduce the metamorphosis time. The results obtained are related to the fatty acid content of the live prey used and are essential in order to improve the captive production of M. grammistes through a closed system and, in turn, to preserve natural stocks. 相似文献