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931.
Heidi Rudi Knut‐Erik Gylder Odd Arne Rognli 《Preparative biochemistry & biotechnology》2013,43(3):253-257
Abstract Determining haplotype‐specific DNA sequence information is very important in a wide range of research fields. However, no simple and robust approaches are currently available for determining haplotype‐specific sequence information. We have addressed this problem by developing a very simple and robust haplotype‐specific sequencing approach. We utilise the fact that DNA sequencing polymerases are sensitive to 3′end mismatches in the sequencing primer. By using two sequencing primers with 3′end corresponding to the two alleles in a given SNP locus, we are able to obtain allele‐specific DNA sequences from both alleles. We evaluated this direct haplotype‐specific approach by determining haplotypes within the intron 2 sequence of the fructan‐6‐fructosyltransferase (6‐ft) gene in Lolium perenne L. We obtained reliable haplotype‐specific sequences for all primers and genotypes evaluated. We conclude that the haplotype‐specific sequencing is robust, and that the approach has a potentially very wide application range for any diploid organism. 相似文献
932.
Lars Snipen Dirk Repsilber Ludvig Nyquist Andreas Ziegler ?got Aakra Are Aastveit 《BMC bioinformatics》2006,7(1):181
Background
Array-based comparative genome hybridization (aCGH) is a tool for rapid comparison of genomes from different bacterial strains. The purpose of such analysis is to detect highly divergent or absent genes in a sample strain compared to an index strain. Development of methods for analyzing aCGH data has primarily focused on copy number abberations in cancer research. In microbial aCGH analyses, genes are typically ranked by log-ratios, and classification into divergent or present is done by choosing a cutoff log-ratio, either manually or by statistics calculated from the log-ratio distribution. As experimental settings vary considerably, it is not possible to develop a classical discriminant or statistical learning approach. 相似文献933.
Centrosomal ALIX regulates mitotic spindle orientation by modulating astral microtubule dynamics 下载免费PDF全文
Lene Malerød Åsmund Husabø Eikenes Andreas Brech Knut Liestøl Harald Stenmark Kaisa Haglund 《The EMBO journal》2018,37(13)
The orientation of the mitotic spindle (MS) is tightly regulated, but the molecular mechanisms are incompletely understood. Here we report a novel role for the multifunctional adaptor protein ALG‐2‐interacting protein X (ALIX) in regulating MS orientation in addition to its well‐established role in cytokinesis. We show that ALIX is recruited to the pericentriolar material (PCM) of the centrosomes and promotes correct orientation of the MS in asymmetrically dividing Drosophila stem cells and epithelial cells, and symmetrically dividing Drosophila and human epithelial cells. ALIX‐deprived cells display defective formation of astral microtubules (MTs), which results in abnormal MS orientation. Specifically, ALIX is recruited to the PCM via Drosophila Spindle defective 2 (DSpd‐2)/Cep192, where ALIX promotes accumulation of γ‐tubulin and thus facilitates efficient nucleation of astral MTs. In addition, ALIX promotes MT stability by recruiting microtubule‐associated protein 1S (MAP1S), which stabilizes newly formed MTs. Altogether, our results demonstrate a novel evolutionarily conserved role of ALIX in providing robustness to the orientation of the MS by promoting astral MT formation during asymmetric and symmetric cell division. 相似文献
934.
Characterization of unknown genetic modifications using high throughput sequencing and computational subtraction 总被引:1,自引:0,他引:1
935.
During exponential growth ofStreptococcus faecalis, the distribution of cell arrangements remains constant, but depends on the growth rate. The predominant cell arrangements
are diplococci (about 60–80% of total cells) the amount of which varies only little with the growth rate. A clear correlation
exists for cells growing as chains; the amount decreases from about 20% at μ=2.0 to about 6% at μ=0.45. After cessation of
growth in the stationary phase, the number of diplococci and chains decreases and the number of monococci increases; after
10 h in the stationary phase, more than 50% of the cells have become monococci. The dry weight of 2.5×10−10 mg/cell remains constant at different growth rates, while cell size shows small differences on different growth media. Treatment
of exponentially growing cultures with crystal violet or nitrofurantoin results in faster sedimentation on sucrose gradients
of treated cultures compared to untreated cultures. While crystal violet effects an increased chain formation, treatment with
nitrofurantoin results in an increase of the size of the individual cell. 相似文献
936.
Are Halvor Aastveit 《Biometrical journal. Biometrische Zeitschrift》1983,25(2):129-153
Correlation between adjacent plots in field experiments are common. In this paper the effect of correlation on the usual analysis of variance in a randomized block design is studied. A generalised analysis of variance where correlation is taken into consideration, and the analysis of covariance where the residuals of the neighbouring plots are used as covariates, is discussed. Uniformity trials are used as a basis of a Monte-Carlo study. The generalised analysis improved the power of the tests. The analysis of covariance method was not better than the usual analysis of variance method. 相似文献
937.
Marte I. Flydal Tonje C. Mohn Angel L. Pey Jessica Siltberg-Liberles Knut Teigen Aurora Martinez 《Amino acids》2010,39(5):1463-1475
Phenylalanine hydroxylase (PAH) catalyzes the hydroxylation of L-Phe to L-Tyr. Dysfunctional PAH results in phenylketonuria and mammalian PAH is therefore highly regulated and displays positive cooperativity
for L-Phe (Hill coefficient (h) = 2). L-Phe does not bind to the regulatory ACT domain in full-length tetrameric human PAH and cooperativity is elicited by homotropic
binding to the catalytic site (Thórólfsson et al. in Biochemistry 41:7573–7585, 2002). PAH from Caenorhabditis elegans (cePAH) is devoid of cooperativity for L-Phe (h = 0.9), and, as shown in this work, structural analysis reveal an additional L-Phe binding site at the regulatory domain of full-length cePAH. This site involves the GA(S)L/ISRP motifs, which are also
found in ACT domains of other L-Phe binding proteins, such as prephenate dehydratase. Isothermal titration calorimetry further demonstrated 2 binding sites
per subunit for cePAH versus ~1 for hPAH. Steric occlusion of the regulatory site, notably by residues Lys215/Tyr216 from
the adjacent catalytic domain, appears to hinder regulatory binding in full-length hPAH. Accordingly, the humanized mutant
Q215K/N216Y of cePAH binds ~1.4 L-Phe/subunit. This mutant also displays high catalytic activity and certain positive cooperativity for L-Phe (h = 1.4). Our results support that the acquisition of positive cooperativity in mammalian forms of PAH is accompanied by a
closure of the regulatory L-Phe binding site. Concomitantly, the function of the regulatory ACT domain appears to be adapted from amino acid binding
to serving the communication of conformational changes among catalytic subunits. 相似文献
938.
Knut J. Børve Vidar R. Jensen Tor Karlsen Jon Andreas Støvneng Ole Swang 《Journal of molecular modeling》1997,3(4):193-202
The PM3(tm) method has been applied to several systems of relevance to catalytic polymerization of olefins, for catalysts containing Ti, Zr or Cr. With some exceptions, PM3(tm) calculations reproduce experimental geometries of stable, closed-shell, precursors well. For stationary points along the path of monomer insertion into a metal-alkyl bond, the comparison is made to structures obtained by optimization using various first-principle methods. Large errors are uncovered for the transient structures, in particular pertaining to metal-ethylene coordination and agostic interactions. The energy profiles for four insertion reactions are computed by gradient-corrected density functional (DFTG) methods, using molecular structures taken from PM3(tm) and first-principle geometry optimizations, respectively. The chromium case is promising, giving values for the barrier to monomer insertion of 11 and 9 kcal/mol based on PM3(tm) and DFTG geometries, respectively. The Ti- and Zr-based systems are predicted to proceed downhill based on PM3(tm) structures, whereas small barriers are found when using first-principle structures. A hybrid PM3(tm)-DFTG procedure is suggested for geometry optimization, which facilitates an accurate estimate of the barrier when applied to one of the zirconium systems. 相似文献
939.
Staffan Knut Holmgren 《International Review of Hydrobiology》1984,69(6):781-817
Based on 500 quantitative algal analyses from 1971–1980 the seasonal variations of phytoplankton biomass and species diversity have been evaluated in one natural and three fertilized subarctic lakes. Enrichment with P alone did not cause any biomass increase and inhibited dinoflagellates and Dinobryon. Enrichment with N alone stimulated Uroglena and Gymnodinium and the biomass increased. No species were inhibited. Enrichment with both N and P made the biomass increase 50–60 times and the stimulated genera were: Chlorella, Choricystis, Chromulina, Chrysochromulina, Gymnodinium, Monoraphidium, Ochromonas, Spiniferomonas, Rhodomonas and Uroglena. In all fertilized lakes monocultures of chlorococcal green algae finally developed. 相似文献