全文获取类型
收费全文 | 322篇 |
免费 | 23篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 20篇 |
2012年 | 24篇 |
2011年 | 21篇 |
2010年 | 20篇 |
2009年 | 12篇 |
2008年 | 17篇 |
2007年 | 30篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有345条查询结果,搜索用时 15 毫秒
71.
Vittorio Sambri Antonella Marangoni Francesca Massaria Aldo Farencena Michelangelo La Placa Roberto Cevenini 《Microbiology and immunology》1995,39(8):623-627
Enriched preparations for mouse polyclonal immunoglobulin G (IgG) antibodies reactive with surface-exposed epitopes (Ab-SEE) of the 22-kDa and 24-kDa membrane lipoproteins of living Borrelia hermsii (HS 1 strain) cells were obtained by an antibody absorption technique using living spirochetes. In vitro, the antibody preparations both inhibited spirochetal growth and were borreliacidal in the presence of complement. The monovalent Fab antibody fragments, prepared from antibody-enriched preparations, did not inhibit the growth of the bacteria, whereas they killed the bacteria in the presence of complement. The two-dimension gel electrophoresis of B. hermsii cells showed that 3H-labeled fatty acids incorporated into the 22-kDa and 24-kDa lipoproteins were resolved into one and three compact spots, respectively. The spots were recognized by the Ab-SEE preparations reactive with the 22-kDa and 24-kDa proteins, by Western blotting. 相似文献
72.
Five peptides containing the amino acids alanine, asparagine, histidine, isoleucine and tryptophan were investigated by partial methanolysis and fast atom bombardment mass spectrometry in order to examine the behaviour of these amino acid residues under the conditions employed in the methanolytic step. The results obtained confirm that partial methanolysis prior to mass analysis increases considerably the content of sequence information in the mass spectra and that no secondary reactions occur in the residues of the amino acids now investigated, with the exception of the esterification of the glutamic acid carboxyl group and partial conversion of the asparagine amide group in the corresponding methyl ester. 相似文献
73.
74.
Juan Antonio Sanchez Michelangelo La Spina Omaththage P. Perera 《Ecology and evolution》2012,2(12):3145-3159
Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) is widely distributed throughout the Palaearctic region. The aim was to explain the current geographic distribution of the species by investigating its genetic population structure. Samples of M. pygmaeus were collected in 15 localities through its range of distribution. A sample from a commercial producer was also analyzed. A total of 367 M. pygmaeus were genotyped for nine microsatellite loci. Isolation by distance was tested by Mantel's test. The molecular structure of M. pygmaeus populations was inferred by UPGMA, AMOVA, Principal component and Bayesian analyses. The average number of alleles per locus per population was 5.5 (range: 3.1–7.8). Istanbul (Turkey) and Nimes (France) had the lowest (0.291) and the highest (0.626) expected heterozygosity (He), respectively. There was an increase in He from the Canary Islands to Nimes, and a progressive decrease thereafter. A significant negative correlation was found between allelic richness and He, and the distance of each population to the easternmost locality (Canary Islands). Significant linkage disequilibrium was observed in the populations from Turkey. FST (0.004–0.334) indicated a high population differentiation, with isolation by distance supported by a high correlation. Bayesian analyses, PCA, and UPGMA pointed to three main clusters: (1) Greece and Turkey, (2) Italy and France, and (3) southern Iberia and the Canary Islands. The recent evolutionary history of M. pygmaeus is inferred from the data as follows: (1) the reduction in the geographic distribution of the species to the Iberian, Italian, and Balkan peninsulas, and possibly southern France, during glaciations and re‐colonization of northern Europe from its southern refuges; (2) the maintenance of high diversity in Iberia and Italy (and possibly southern France) during contraction periods, and bottlenecks in the Balkans; (3) introgression of the Italian–French lineage in northern Spain, naturally or through trade. 相似文献
75.
76.
Sorokin DY Foti M Tindall BJ Muyzer G 《Extremophiles : life under extreme conditions》2007,11(2):363-370
Strain SR 1T was isolated under anaerobic conditions using elemental sulfur as electron acceptor and acetate as carbon and energy source
from the Thiopaq bioreactor in Eerbeek (The Netherlands), which is removing H2S from biogas by oxidation to elemental sulfur under oxygen-limiting and moderately haloalkaline conditions. The bacterium
is obligately anaerobic, using elemental sulfur, nitrate and fumarate as electron acceptors. Elemental sulfur is reduced to
sulfide through intermediate polysulfide, while nitrate is dissimilatory reduced to ammonium. Furthermore, in the presence
of nitrate, strain SR 1T was able to oxidize limited amounts of sulfide to elemental sulfur during anaerobic growth with acetate. The new isolate
is mesophilic and belongs to moderate haloalkaliphiles, with a pH range for growth (on acetate and nitrate) from 7.5 to 10.25
(optimum 9.0), and a salt range from 0.1 to 2.5 M Na+ (optimum 0.4 M). According to phylogenetic analysis, SR 1T is a member of a deep bacterial lineage, distantly related to Chrysiogenes arsenatis (Macy et al. 1996). On the basis of the phenotypic and genetic data, the novel isolate is placed into a new genus and species, Desulfurispirillum alkaliphilum (type strain SRT = DSM 18275 = UNIQEM U250).
Nucleotide sequence accession number: the GenBank/EMBL accession number of the 16S rRNA gene sequence of strain SR 1T is DQ666683. 相似文献
77.
78.
79.
Bravo-Almonacid F Rudoy V Welin B Segretin ME Bedogni MC Stolowicz F Criscuolo M Foti M Gomez M López M Serino G Cabral S Dos Santos C Huarte M Mentaberry A 《Transgenic research》2012,21(5):967-982
Solanum tuberosum ssp. tuberosum (cv. Spunta) was transformed with a chimeric transgene containing the Potato virus Y (PVY) coat protein (CP) sequence. Screening for PVY resistance under greenhouse conditions yielded over 100 independent candidate lines. Successive field testing of selected lines allowed the identification of two genetically stable PVY-resistant lines, SY230 and SY233, which were further evaluated in field trials at different potato-producing regions in Argentina. In total, more than 2,000 individuals from each line were tested along a 6-year period. While no or negligible PVY infection was observed in the transgenic lines, infection rates of control plants were consistently high and reached levels of up to 70-80%. Parallel field studies were performed in virus-free environments to assess the agronomical performance of the selected lines. Tubers collected from these assays exhibited agronomical traits and biochemical compositions indistinguishable from those of the non-transformed Spunta cultivar. In addition, an interspecific out-crossing trial to determine the magnitude of possible natural gene flow between transgenic line SY233 and its wild relative Solanum chacoense was performed. This trial yielded negative results, suggesting an extremely low probability for such an event to occur. 相似文献