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961.
962.
应用RT-PCR技术从分泌抗人黑色素瘤单克隆抗体的杂交瘤细胞HB8760中克隆了抗体轻、重链可变区基因,然后用(Gly4Ser)3连接肽基因将VH、VL连接成ScFv基因,并进行了序列测定.计算机分析表明VH,VL均符合小鼠抗体可变区的特征,为功能性重排的抗体可变区基因.VH、VL、linker拼接正确.ScFv基因全长729bp,其中VH基因长360bp,编码120个氨基酸,VL基因长324bp,编码108个氨基酸.在噬菌粒表达载体pCANTAB5E中表达了可溶性的ScFv蛋白,表达产物经流式细胞仪检测可特异地与黑色素瘤细胞结合,不与肝癌、胃癌及良性黑痣细胞结合 相似文献
963.
Mai Brigid Margetts Ian George Barr Elizabeth Ann Webb 《Protein expression and purification》2000,18(3):262
This paper describes the overexpression of the Rgp-1 (arginine) protease domain from Porphyromonas gingivalis. This protease and the related Kgp (lysine) protease, both of which display trypsin-like specificity, have been implicated as major virulence factors and may play a significant role in the etiology of periodontal disease. Both Rgp-1 and Kgp are initially translated as polyproteins, each containing a protease domain and multiple adhesin domains. The Rgp-1 protease domain was expressed in E. coli, purified, refolded, and assayed for activity. These expression studies demonstrated that prior to the formation of inclusion bodies in the E. coli cytoplasm, the protease was proteolytically active and could hydrolyze a specific synthetic substrate. When the Rgp-1 protease domain was purified from inclusion bodies and refolded, it was found to be autolytically active and displayed specific catalytic activity. This is the first report on the expression and purification of active Rgp-1 from E. coli. Polyclonal antisera raised against recombinant protein recognized the native form of the protease in the P. gingivalis strain W50, indicating that the recombinant protein contained some of the antigenic determinants of the native protease. 相似文献
964.
Two exo-β-glucanases (LP-ExoI, 83 kDa and LP-ExoII, 71 kDa) were extracted and partially purified from the cell wall of Lilium longiflorum pollen tubes. Both LP-ExoI and LP-ExoII hydrolyzed laminarin (1,3-β-glucan). These enzymes also exhibited some activity toward
1,3:1,4-β-glucans of Hordeum vulgare and Cetraria islandica and the 1,6-β-glucan of Umbilicaria papullosa. The pH for optimum activity for both exo-β-glucanases was 5.5. Methylation analysis of the reaction products revealed that
purified LP-ExoI decreased both 1,3- and 1,4-glucosyl linkages in hemicellulosic polysaccharides isolated from the cell wall
of lily pollen tubes. D-gluconolactone and nojirimycin, inhibitors of glucosidase, inhibited activities of both exo-β-glucanases,
as well as growth of the lily pollen tubes. These results disclosed that the wall-bound exo-β-glucanases play an important
role in the regulation of lily pollen tube growth.
Received: 3 January 2000 / Revision accepted: 8 March 2000 相似文献
965.
Masatake Araki Mai Nakahara Mayumi Muta Miharu Itou Chika Yanai Fumika Yamazoe Mikiko Miyake Ayaka Morita Miyuki Araki Yoshiyuki Okamoto Naomi Nakagata Kumiko Yoshinobu Ken‐ichi Yamamura Kimi Araki 《Development, growth & differentiation》2014,56(2):161-174
Gene trapping in embryonic stem (ES) cells is a proven method for large‐scale random insertional mutagenesis in the mouse genome. We have established an exchangeable gene trap system, in which a reporter gene can be exchanged for any other DNA of interest through Cre/mutant lox‐mediated recombination. We isolated trap clones, analyzed trapped genes, and constructed the database for Exchangeable Gene Trap Clones (EGTC) [ http://egtc.jp ]. The number of registered ES cell lines was 1162 on 31 August 2013. We also established 454 mouse lines from trap ES clones and deposited them in the mouse embryo bank at the Center for Animal Resources and Development, Kumamoto University, Japan. The EGTC database is the most extensive academic resource for gene‐trap mouse lines. Because we used a promoter‐trap strategy, all trapped genes were expressed in ES cells. To understand the general characteristics of the trapped genes in the EGTC library, we used Kyoto Encyclopedia of Genes and Genomes (KEGG) for pathway analysis and found that the EGTC ES clones covered a broad range of pathways. We also used Gene Ontology (GO) classification data provided by Mouse Genome Informatics (MGI) to compare the functional distribution of genes in each GO term between trapped genes in the EGTC mouse lines and total genes annotated in MGI. We found the functional distributions for the trapped genes in the EGTC mouse lines and for the RefSeq genes for the whole mouse genome were similar, indicating that the EGTC mouse lines had trapped a wide range of mouse genes. 相似文献
966.
967.
968.
太阳辐射减弱对冬小麦旗叶光合速率的影响 总被引:2,自引:0,他引:2
以冬小麦扬麦13号为供试材料,设计了15%(T15)、20%(T20)、40%(T40)、60%(T60)和100%(CK)自然光5个处理,在大田条件下研究了模拟太阳辐射减弱对
冬小麦旗叶光合速率日变化及其影响因素的影响.结果表明:太阳辐射减弱显著提高了冬小麦叶绿素和叶黄素含量,降低了光合速率(Pn).不同辐射减弱条件下冬小麦Pn日变化差异较大,日最高值表现为CK>60%自然光>40%自然光>20%自然光>15%自然光,其中CK呈双峰曲线变化,有明显的“午休”现象,其他各处理均呈单峰型曲线变化,“午休”现象不明显,但峰值出现时间滞后.相关分析表明,太阳辐射减弱是影响Pn日变化的主导因子,但其他因子也显著影响Pn.与CK相比,60%和40%自然光处理中光合有效辐射(PAR)、叶温(Tl)、气孔导度(Gs)和蒸腾速率(Tr)与Pn均呈显著正相关,表明上述因子对Pn有正效应;冬小麦叶片胞间二氧化碳浓度(Ci)和气孔导度限制值(Ls)在60%和40%自然光处理中与Pn呈显著负相关,但在20%和15%自然光处理中与Pn呈显著正相关,说明太阳辐射强度高于40%自然光时Ci和Ls对Pn有负效应,太阳辐射强度低于40%自然光时则为正效应. 相似文献
969.
970.
在大田试验条件下研究了不同pH模拟酸雨对冬小麦籽粒氨基酸、蛋白质、可溶性糖、还原糖、淀粉以及总酸度的胁迫效应,以期为防治我国农作物的酸雨灾害提供基础理论依据。结果表明,pH≤4.5酸雨处理会抑制总游离氨基酸的合成,且酸度越强,抑制越明显。蛋白质(可溶性蛋白质、总蛋白)含量随着酸雨酸度的增强逐步下降,且在极酸性条件下降低较明显。pH≤4.5酸雨处理对可溶性糖的合成会有较强的抑制作用。pH≤2.5时还原糖的合成明显受抑。随着酸雨酸度的增强,总酸度和酸糖比均表现出先增加后下降的变化趋势,且在pH=3.5处达到最大值。pH≤3.5酸雨处理显著抑制淀粉的合成,且对支链淀粉的影响较明显,致使淀粉支/直比下降。 相似文献