全文获取类型
收费全文 | 1705篇 |
免费 | 142篇 |
出版年
2023年 | 4篇 |
2022年 | 17篇 |
2021年 | 36篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 26篇 |
2017年 | 32篇 |
2016年 | 62篇 |
2015年 | 75篇 |
2014年 | 101篇 |
2013年 | 99篇 |
2012年 | 135篇 |
2011年 | 143篇 |
2010年 | 97篇 |
2009年 | 80篇 |
2008年 | 109篇 |
2007年 | 118篇 |
2006年 | 99篇 |
2005年 | 71篇 |
2004年 | 75篇 |
2003年 | 77篇 |
2002年 | 79篇 |
2001年 | 20篇 |
2000年 | 20篇 |
1999年 | 25篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 14篇 |
1992年 | 15篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1971年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有1847条查询结果,搜索用时 15 毫秒
51.
52.
Cassandra De Muynck Catarina S. S. Pereira Myriam Naessens Sofie Parmentier Wim Soetaert Erick J. Vandamme 《Critical reviews in biotechnology》2013,33(3):147-171
ABSTRACTThe genus Gluconobacter comprises some of the most frequently used microorganisms when it comes to biotechnological applications. Not only has it been involved in “historical” production processes, such as vinegar production, but in the last decades many bioconversion routes for special and rare sugars involving Gluconobacter have been developed. Among the most recent are the biotransformations involved in the production of L-ribose and miglitol, both very promising pharmaceutical lead molecules. Most of these processes make use of Gluconobacter's membrane-bound polyol dehydrogenases. However, recently other enzymes have also caught the eye of industrial biotechnology. Among them are dextran dextrinase, capable of transglucosylating substrate molecules, and intracellular NAD-dependent polyol dehydrogenases, of interest for co-enzyme regeneration. As such, Gluconobacter is an important industrial microbial strain, but it also finds use in other fields of biotechnology, such as biosensor-technology. This review aims to give an overview of the myriad of applications for Gluconobacter, with a special focus on some recent developments. 相似文献
53.
Myriam Kruse Sabine Zumbrägel Evert Bakker Eva Spieck Till Eggers André Lipski 《Systematic and applied microbiology》2013
Metabolically-active autotrophic nitrite oxidizers from activated sludge were labeled with 13C-bicarbonate under exposure to different temperatures and nitrite concentrations. The labeled samples were characterized by FAME-SIP (fatty acid methyl ester-stable isotope probing). The compound cis-11-palmitoleic acid, which is the major lipid of the most abundant nitrite oxidizer in activated sludge, Candidatus Nitrospira defluvii, showed 13C-incorporation in all samples exposed to 3 mM nitrite. Subsequently, the lipid cis-7-palmitoleic acid was labeled, and it indicated the activity of a nitrite oxidizer that was different from the known Nitrospira taxa in activated sludge. The highest incorporation of cis-7-palmitoleic acid label was found after incubation with a nitrite concentration of 0.3 mM at 17 and 22 °C. While activity of Nitrobacter populations could not be detected by the FAME-SIP approach, an unknown nitrite oxidizer with the major lipid cis-9 isomer of palmitoleic acid exhibited 13C-incorporation at 28 °C with 30 mM nitrite. These results indicated flexibility of nitrite-oxidizing guilds in a complex community responding to different conditions. Labeled lipids so far not described for activated sludge-associated nitrifiers indicated the presence of unknown nitrite oxidizers in this habitat. The FAME-SIP-based information can be used to define appropriate conditions for the enrichment of nitrite-oxidizing guilds from complex samples. 相似文献
54.
Noëlle Richard-Mercier Myriam Bettane-Casanova Marc Fellous Hélène Charniaux-Cotton 《Invertebrate reproduction & development.》2013,57(3):243-252
Summary The Daudi cell line, a male human line from Burkitt's lymphoma, possesses the peculiarity of releasing H-Y antigen into its culture medium. Daudi-conditioned medium was injected into Colorado potato beetles either during the blastoderm stage, when individualization of the pole cells occurs, or later, during gonadal differentiation. Ovarian and testicular sections examined at hatching showed that only ovarian differentiation was affected by the Daudi conditioned medium, which, irrespective of the day of injection, reduced the number of the terminal filaments of the future lateral ovarioles. Furthermore, in some cases sexual differentiation was blocked altogether. When H-Y antigen was precipitated from the conditioned medium with specific H-Y antisera, the effectiveness of Daudi-conditioned medium was partially destroyed. These results suggest that mammalian H-Y antigen inhibits morphogenetic events leading to ovarian differentiation in the Colorado potato beetle. 相似文献
55.
Myriam M. Ouberai Juan Wang Marcus J. Swann Celine Galvagnion Tim Guilliams Christopher M. Dobson Mark E. Welland 《The Journal of biological chemistry》2013,288(29):20883-20895
There is increasing evidence for the involvement of lipid membranes in both the functional and pathological properties of α-synuclein (α-Syn). Despite many investigations to characterize the binding of α-Syn to membranes, there is still a lack of understanding of the binding mode linking the properties of lipid membranes to α-Syn insertion into these dynamic structures. Using a combination of an optical biosensing technique and in situ atomic force microscopy, we show that the binding strength of α-Syn is related to the specificity of the lipid environment (the lipid chemistry and steric properties within a bilayer structure) and to the ability of the membranes to accommodate and remodel upon the interaction of α-Syn with lipid membranes. We show that this interaction results in the insertion of α-Syn into the region of the headgroups, inducing a lateral expansion of lipid molecules that can progress to further bilayer remodeling, such as membrane thinning and expansion of lipids out of the membrane plane. We provide new insights into the affinity of α-Syn for lipid packing defects found in vesicles of high curvature and in planar membranes with cone-shaped lipids and suggest a comprehensive model of the interaction between α-Syn and lipid bilayers. The ability of α-Syn to sense lipid packing defects and to remodel membrane structure supports its proposed role in vesicle trafficking. 相似文献
56.
57.
Alexis Dereeper Romain Guyot Christine Tranchant-Dubreuil François Anthony Xavier Argout Fabien de Bellis Marie-Christine Combes Frederick Gavory Alexandre de Kochko Dave Kudrna Thierry Leroy Julie Poulain Myriam Rondeau Xiang Song Rod Wing Philippe Lashermes 《Plant molecular biology》2013,83(3):177-189
Coffee is one of the world’s most important agricultural commodities. Coffee belongs to the Rubiaceae family in the euasterid I clade of dicotyledonous plants, to which the Solanaceae family also belongs. Two bacterial artificial chromosome (BAC) libraries of a homozygous doubled haploid plant of Coffea canephora were constructed using two enzymes, HindIII and BstYI. A total of 134,827 high quality BAC-end sequences (BESs) were generated from the 73,728 clones of the two libraries, and 131,412 BESs were conserved for further analysis after elimination of chloroplast and mitochondrial sequences. This corresponded to almost 13 % of the estimated size of the C. canephora genome. 6.7 % of BESs contained simple sequence repeats, the most abundant (47.8 %) being mononucleotide motifs. These sequences allow the development of numerous useful marker sites. Potential transposable elements (TEs) represented 11.9 % of the full length BESs. A difference was observed between the BstYI and HindIII libraries (14.9 vs. 8.8 %). Analysis of BESs against known coding sequences of TEs indicated that 11.9 % of the genome corresponded to known repeat sequences, like for other flowering plants. The number of genes in the coffee genome was estimated at 41,973 which is probably overestimated. Comparative genome mapping revealed that microsynteny was higher between coffee and grapevine than between coffee and tomato or Arabidopsis. BESs constitute valuable resources for the first genome wide survey of coffee and provide new insights into the composition and evolution of the coffee genome. 相似文献
58.
Maria Rosa Buemi Laura De Luca Alba Chimirri Stefania Ferro Rosaria Gitto Julio Alvarez-Builla Ramon Alajarin 《Bioorganic & medicinal chemistry》2013,21(15):4575-4580
Several indole derivatives, that were highly potent ligands of GluN2B-subunit-containing N-methyl-d-aspartate (NMDA) receptor, also demonstrated antioxidant properties in ABTS method. In particular, the 2-(4-benzylpiperidin-1-yl)-1-(5-hydroxy-1H-indol-3-yl)ethanone (1) proved to be a dual-effective neuroprotective agent. With the aim to increase the antioxidant properties we added a catechol moiety onto piperidine moiety. The designed hybrid derivative 3,4-dihydroxy-N-[1-[2-(5-hydroxy-1H-indol-3-yl)-2-oxoethyl]piperidin-4-yl]benzamide (10) was the most effective antioxidant agent (>94.1 ± 0.1% of inhibition at 17 μM) and showed GluN2B/NMDA receptor affinity at low micromolar concentration (IC50 0.66 μM). By means of computational studies we explored the effect of the presence of this antioxidant fragment during the recognition process to binding pocket. 相似文献
59.
Oksana Tehlivets Nermina Malanovic Myriam Visram Tea Pavkov-Keller Walter Keller 《生物化学与生物物理学报:疾病的分子基础》2013,1832(1):204-215
S-adenosyl-L-methionine (AdoMet)-dependent methylation is central to the regulation of many biological processes: more than 50 AdoMet-dependent methyltransferases methylate a broad spectrum of cellular compounds including nucleic acids, proteins and lipids. Common to all AdoMet-dependent methyltransferase reactions is the release of the strong product inhibitor S-adenosyl-L-homocysteine (AdoHcy), as a by-product of the reaction. S-adenosyl-L-homocysteine hydrolase is the only eukaryotic enzyme capable of reversible AdoHcy hydrolysis to adenosine and homocysteine and, thus, relief from AdoHcy inhibition. Impaired S-adenosyl-L-homocysteine hydrolase activity in humans results in AdoHcy accumulation and severe pathological consequences. Hyperhomocysteinemia, which is characterized by elevated levels of homocysteine in blood, also exhibits a similar phenotype of AdoHcy accumulation due to the reversal of the direction of the S-adenosyl-L-homocysteine hydrolase reaction. Inhibition of S-adenosyl-L-homocysteine hydrolase is also linked to antiviral effects. In this review the advantages of yeast as an experimental system to understand pathologies associated with AdoHcy accumulation will be discussed. 相似文献