全文获取类型
收费全文 | 175篇 |
免费 | 14篇 |
国内免费 | 18篇 |
专业分类
林业 | 2篇 |
农学 | 16篇 |
基础科学 | 1篇 |
6篇 | |
综合类 | 56篇 |
农作物 | 20篇 |
水产渔业 | 47篇 |
畜牧兽医 | 37篇 |
园艺 | 5篇 |
植物保护 | 17篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 10篇 |
2014年 | 8篇 |
2013年 | 11篇 |
2012年 | 16篇 |
2011年 | 13篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 7篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有207条查询结果,搜索用时 0 毫秒
11.
棉花凝集素的抽提和专一性结合糖的测定 总被引:1,自引:0,他引:1
用pH7.2,0.05mol/LTris-HCL缓冲液从高抗枯萎病棉花品种86-1种子脱脂粉中抽提出棉花凝集素,测定其专一性结合糖。结果表明:棉花凝集素的专一性结合糖是D-半乳糖、N-乙酰-D-氨基葡萄糖、D-葡萄糖,棉花凝集素最适pH为6-8,具有较高的抗热性。 相似文献
12.
13.
在已知香蕉果实特异表达凝集素(BanLec)启动子670 bp序列的基础上,利用染色体步移方法,克隆获得该段序列5′端上游远端序列330 bp,从而得到该启动子1 000 bp序列。通过Promoter predictions、Plant CARE软件分析表明,新获得的BanLec启动子5′端330 bp序列中具有更多组织特异性表达调控元件。构建总长度为1 000 bp的BanLec启动子表达载体,以35 S启动子和原有670 bp长度BanLec启动子表达载体为对照,利用基因枪转化香蕉根、叶和果实,测量GUS基因和GFP基因瞬时表达,结果证明长度为1 000 bp BanLec启动子为果实特异表达启动子,启动活性高于原有的670 bp BanLec启动子和35S启动子。 相似文献
14.
C型凝集素受体(C-type lectin receptor,CTLR)是可以特异性结合糖类病原体相关分子模式(pathogen-associated molecular patterns,PAMPs)的模式识别受体(pattern recognition receptors,PPRs),在先天性免疫中发挥着重要作用。为了揭示硬骨鱼CTLR的生物学功能,本研究以从大黄鱼(Larimichthys crocea)转录组数据库中筛选出的一个CTLR基因—C型凝集素结构域家族4成员E基因(C-type lectin domain family 4 member E gene,Clec4e)为研究对象,研究其分子特征、表达分布和凝集特性。结果显示,LcClec4e cDNA全长1546 bp,开放阅读框(open reading frame,ORF)771 bp,编码254个氨基酸。LcClec4e的N端有一个跨膜区,无信号肽,C端含有一个糖识别结构域(carbohydrate recognition domain,CRD),其中含有糖结合位点EPN和WFD以及6个可形成二硫键的保守半胱氨酸。系统发育分析表明,LcClec4e与多种鲈形目鱼类Clec4e具有较近的亲缘关系。荧光定量PCR结果显示,LcClec4e在所检测的10种组织中呈组成型分布,且在肝脏中表达量最高;LcClec4e在来源于大黄鱼头肾组织的原代巨噬细胞、淋巴细胞和粒细胞中均有表达,且在巨噬细胞中表达量最高;经灭活溶藻弧菌刺激后,LcClec4e在3种免疫细胞中的表达均极显著上调。原核表达的重组LcClec4e胞外段(recombinant LcClec4e-extracellular domain,rLcClec4e-ex)具有Ca2+依赖性的凝集活性,可凝集小鼠、家兔的红细胞,以及嗜水气单胞菌、变形假单胞菌、溶藻弧菌和坎氏弧菌等4种水产常见的革兰氏阴性菌。D-葡萄糖、D-果糖、D-甘露糖、D-麦芽糖、α-乳糖和脂多糖均可抑制rLcClec4e-ex对大黄鱼重要病原菌变形假单胞菌的凝集作用,说明LcClec4e可能与变形假单胞菌表面的糖类物质结合。这些研究结果提示,LcClec4e可能作为一种PPR,通过结合病原菌表面的糖类PAMPs来识别病原,参与大黄鱼抗细菌感染的免疫防御。 相似文献
15.
《Veterinary immunology and immunopathology》2015,163(1-2):23-32
Mannose-binding lectin (MBL) is a key protein in innate immunity. MBL binds to carbohydrates on the surface of pathogens, where it initiates complement activation via the lectin-dependent pathway or facilitates opsonophagocytosis. In vitro studies have shown that human MBL is able to bind to Salmonella, but knowledge in relation to chicken MBL and Salmonella is lacking. In order to study this relation day-old chickens from two selected lines L10H and L10L, differing in MBL serum concentration, were either orally infected with S. Infantis (S.123443) or kept as non-infected controls. The differences between healthy L10H and L10L chicken sublines were more profound than differences caused by the S. Infantis infection. The average daily body weight was higher for L10H than for L10L, regardless of infection, indicating beneficial effects of MBL selection on growth. Salmonella was detected in cloacal swabs and the number of Salmonella positive chickens during the experiment was significantly higher in L10L than L10H, indicating that MBL may affect the magnitude of Salmonella colonisation in day-old chickens. MBL expression was determined in ceca tissue by real-time RT-PCR. L10H chickens showed a significantly higher relative expression than L10L at days 1 and 41 pi, regardless of infection. Finally, flow cytometric analysis of whole blood from infected chickens showed that L10H had a significantly higher count of all assessed leucocyte subsets on day 5 pi, and also a higher count of monocytes on day 12 pi than L10L. No difference was observed between infected and non-infected L10L chicken. 相似文献
16.
A new mannose-binding lectin was purified from plasma of freshwater fish, rohu (Labeo rohita) by ammonium sulphate precipitation followed by DEAE-cellulose ion-exchange chromatography. The hemagglutinating activity
is strong for neuraminidase-treated rabbit erythrocytes. Mannose, glucose and their derivatives inhibit hemagglutination.
The apparent molecular weight was determined to be 210 kDa in native PAGE. Analysed on SDS-PAGE under reducing and non-reducing
conditions, the protein migrated as a single band of mol.wt. 40,000. The lectin is acidic in nature showing a pI of 4.5. It
is a glycoprotein containing complex glycan part as indicated by carbohydrate analysis using high-pressure anion exchange
chromatography with a pulsed amperometric detector. The N-terminal sequence (WLNGIGTQIPMKITT) shows no significant homology
with known proteins. It appears to be a C-type lectin as Ca2+ is essential for carbohydrate-binding activity. Methyl -α- D-mannopyranoside was found to be the most potent inhibitor among
the monosaccharides and disaccharides tested. Purified lectin was found to induce intracellular superoxide production following
opsonization of E. coli by its own macrophages.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
18.
19.
20.