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691.
XIN LI JIAN‐HUA LI WEI WANG NAI‐ZHI CHEN TONG‐SUO MA YA‐NAN XI XIAO‐LU ZHANG HAI‐FEI LIN YANG BAI SHAN‐JIN HUANG YU‐LING CHEN 《Plant, cell & environment》2014,37(7):1548-1560
Multiple cellular events like dynamic actin reorganization and hydrogen peroxide (H2O2) production were demonstrated to be involved in abscisic acid (ABA)‐induced stomatal closure. However, the relationship between them as well as the underlying mechanisms remains poorly understood. Here, we showed that H2O2 generation is indispensable for ABA induction of actin reorganization in guard cells of Arabidopsis that requires the presence of ARP2/3 complex. H2O2‐induced stomatal closure was delayed in the mutants of arpc4 and arpc5, and the rate of actin reorganization was slowed down in arpc4 and arpc5 in response to H2O2, suggesting that ARP2/3‐mediated actin nucleation is required for H2O2‐induced actin cytoskeleton remodelling. Furthermore, the expression of H2O2 biosynthetic related gene AtrbohD and the accumulation of H2O2 was delayed in response to ABA in arpc4 and arpc5, demonstrating that misregulated actin dynamics affects H2O2 production upon ABA treatment. These results support a possible causal relation between the production of H2O2 and actin dynamics in ABA‐mediated guard cell signalling: ABA triggers H2O2 generation that causes the reorganization of the actin cytoskeleton partially mediated by ARP2/3 complex, and ARP2/3 complex‐mediated actin dynamics may feedback regulate H2O2 production. 相似文献
692.
铝胁迫下黑麦和小麦根尖分泌有机酸的研究 总被引:4,自引:1,他引:3
通过建立的活体根培养及微量根尖分泌物收集系统,对铝胁迫下黑麦和小麦根尖分泌的有机酸进行研究。结果表明:50、100、200、300μmol·L-1 AlCl3处理后黑麦根尖分泌柠檬酸和苹果酸,而铝仅诱导小麦根尖分泌苹果酸。铝处理3h后,根尖分泌的苹果酸显著增加,并在9h内维持较高的分泌速率。铝诱导黑麦根尖分泌柠檬酸有明显的迟缓期,Al(300μmol·L-1)处理后的最初3h,根尖分泌的柠檬酸并不显著增加。在铝溶液中添加的阴离子通道抑制剂A-9-C(20、60、100μmol·L-1)显著抑制根尖分泌有机酸。然而,将黑麦根尖浸泡于含异三聚体G蛋白激活剂霍乱毒素(50ng·mL-1)后,根尖分泌的有机酸显著增加。说明建立的微量根尖分泌物收集系统适合于铝诱导根尖分泌有机酸的研究,小麦和黑麦根尖在铝胁迫下以不同模式通过阴离子通道分泌有机酸,而异三聚体G蛋白可能介导根尖分泌有机酸。 相似文献
693.
Genetic Variations in the Internal Transcribed Spacer and Mitochondrial Small Subunit rRNA Gene of Naegleria spp. 总被引:1,自引:0,他引:1
LING ZHOU RAMA SRIRAM GOVINDA S. VISVESVARA LIHUA XIAO 《The Journal of eukaryotic microbiology》2003,50(S1):522-526
ABSTRACT: Naegleria spp. are widely distributed free-living amebas, but one species in the genus, N. fowleri , causes acute fulminant primary amebic meningoencephalitis in humans and other animals. Thus, it is important to differentiate N. fowleri from the rest in the genus of Naegleria , and to develop tools for the detection of intra-specific genetic variations. In this study, one isolate each of N. australiensis, N. gruberi, N. jadini , and N. lovaniensis and 22 isolates of N. fowleri were characterized at the internal transcribed spacers (ITS) and mitochondrial small subunit rRNA (mtSSU rRNA) gene. The mtSSU rRNA primers designed amplified DNA of all isolates, with distinct sequences obtained from all species examined. In contrast, the ITS primers only amplified DNA from N. lovaniensis and N. fowleri , with minor sequence differences between the two. Three genotypes of N. fowleri were found among the isolates analyzed in both the mtSSU rRNA gene and ITS. The extent of sequence variation was greater in the mtSSU rRNA gene, but the ITS had the advantage of length polymorphism. These data should be useful in the development of molecular tools for rapid species differentiation and genotyping of Naegleria spp. 相似文献
694.
大肠杆菌亮氨酰 tRNA合成酶 (LeuRS)是第 1类氨基酰 tRNA合成酶 ,由 860个氨基酸残基组成 ,催化亮氨酸tRNA的亮氨酰化。研究发现 ,在它的CP1结构域内 3 68和 3 69间的肽键间插入 2 5 3~ 3 68的肽段 ,该插入变种的酶仍具有酶活力 ,取名为LeuRS C。由于这一插入变种的不稳定性 ,构建了His6 LeuRS C的表达质粒 ,用Ni NTA柱亲和层析的方法进行纯化。发现His6 LeuRS C虽然插入了 116个氨基酸残基 ,但仍具有全部的天然LeuRS的活力。测定了His6 LeuRS C的酶学动力学常数 ,比较了它与天然LeuRS的从CD光谱得到的二级结构和热稳定性 相似文献
695.
696.
Unraveling the Distribution and Evolution of miR156 targeted SPLs in Plants by Phylogenetic Analysis
Squamosa promoter binding protein like genes (SPLs) are critical during plant development and mostly regulated by miR156. However, little is known about phylogenetic distribution and evolutionary patterns of miR156 targeted SPLs. In this study, 183 SPLs from nine genome sequenced species representing algae, bryophytes, lycophyte, monocots, and eudicots were computationally analyzed. Our results showed that miR156 responsive elements (MREs) on SPLs were present in land plants but absent from unicellular green algae. Phylogenetic analysis revealed that miR156 targeted SPLs only distributed in group II not group I of land plants, suggesting they originated from a common ancestor. In addition, group II were further divided into seven subgroups (IIa IIg) and miR156 targeted SPLs distributed in some specific members of SPLs from six subgroups except subgroup IId. Such distribution pattern was well elucidated by gene structure evolution of miR156 targeted SPLs based on the correlation of phylogenetic classification and gene structure. They could suffer from the exon loss events combined with MREs loss during evolution. Moreover, gene duplication contributed to the abundance of miR156 targeted SPLs, which had significantly increased after angiosperms and lower plants split. With Arabidopsis as the model species, we found segmental and tandem gene duplications predominated during miR156 targeted SPLs expansion. Taken together, these results provide better insights in understanding the function diversity and evolution of miR156 targeted SPLs in plants. 相似文献
697.
698.
天麻Gastrodia elata种子细小而无胚乳,自然条件下需要石斛小菇Mycena dendrobii等真菌共生来完成种子萌发和生长。为了探讨天麻种子接菌萌发过程中的基因表达变化,本研究利用高通量RNA测序技术,对共生真菌石斛小菇、天麻成熟种子以及接菌萌发后的天麻原球茎进行比较分析,共获得42 263条注释unigenes,并筛选到5 409条差异表达基因。GO分析表明,差异表达基因主要参与代谢、离子结合等生物学通路中。KEGG功能富集分析结果表明,差异基因参与了植物激素信号传导、碳代谢、苯丙素生物合成、淀粉与蔗糖代谢以及氨基酸生物合成中。真菌和植物细胞壁多糖经降解产生的寡糖激发子,可以诱导宿主产生多种防御反应,参与到宿主与真菌互作中。在共生萌发过程中,真菌细胞壁降解相关基因的表达显著提高,如几丁质酶和β-1,3-葡聚糖酶基因表达甚至上调了20倍之多。此外,植物细胞壁木聚糖酶和果胶酶基因表达显著升高。这类基因表达可释放寡糖激发子,在天麻种子对石斛小菇的防御过程中起到重要的作用。本文全面分析天麻种子接菌萌发前后基因表达变化,为进一步研究天麻重要功能基因的功能鉴定提供基础。 相似文献
699.
700.
单增李斯特菌新疆分离株lmo0160基因克隆及序列分析 总被引:1,自引:0,他引:1
【目的】单增李斯特菌是一种重要的食源性致病菌,常引起人和动物致病。其细胞壁表面LPXTG基序蛋白在单增李斯特菌致病过程中发挥重要作用,根据参考株全序列预测的41个LPXTG基序蛋白中仍有部分蛋白功能未知。对单增李斯特菌新疆绵羊脑分离株LM90SB2的LPXTG基序蛋白Lmo0160的基因进行克隆及生物信息学分析,为功能验证提供基础。【方法】根据GenBank中收录的lmo0160序列设计特异性引物,利用PCR方法对新疆分离株的lmo0160基因进行扩增,将扩增产物克隆到pMD 19-T载体,进行PCR、双酶切鉴定及序列测定,并对基因核苷酸序列和蛋白序列进行分析。【结果】分离株LM90SB2的lmo0160序列全长为1 708 bp,包含1 428 bp的开放阅读框,共编码475个氨基酸;LM90SB2株lmo0160核苷酸序列与CFSAN008100株(4b型,美国)、CFSAN023463株(4b型,美国)、J2-064株(4b型,美国)、F2365株(4b型,奶酪,美国)和NTSN株(4b型,绵羊脑,中国扬州)相似性为99.0%-99.1%;与M7株(4a型,牛奶,中国浙江)相似性为97.2%,与Finland1998株(1/2a型,美国)、N53-1株(1/2a型,熟火腿,瑞士)、N1546株(1/2a型,鱼,丹麦)和EGD-e株(1/2a型,美国)相似性为87.2%-91.1%;其推导的氨基酸序列与上述菌株相似性为91.8%-99.4%。系统进化树显示,LM90SB2菌株的lmo0160基因与CFSAN023463、F2365和NSTN菌株亲缘关系较近,处于同一分支上,而与标准株EGD-e菌株亲缘关系较远。蛋白质二级结构预测表明,LM90SB2的Lmo0160蛋白为亲水性蛋白,无信号肽,不形成跨膜结构。蛋白结构域预测表明Lmo0160蛋白含有胶原蛋白结合域和Cna B结构域。【结论】克隆了LM90SB2的lmo0160基因,为进一步研究LM90SB2的lmo0160基因功能奠定了基础。 相似文献