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901.
Hang J Sundaram AK Zhu P Shelton DR Karns JS Martin PA Li S Amstutz P Tang CM 《Journal of microbiological methods》2008,73(3):242-246
Bacillus anthracis is considered a major threat as an agent of bioterrorism. B. anthracis spores are readily dispersed as aerosols, are very persistent, and are resistant to normal disinfection treatments. Immunoassays have been developed to rapidly detect B. anthracis spores at high concentrations. However, detection of B. anthracis spores at lower concentrations is problematic due to the fact that closely related Bacillus species (e.g., B. thuringiensis) can cross-react with anti-B. anthracis antibodies, resulting in false positive detections. Subsequent polymerase chain reaction (PCR) analysis is required to differentiate virulent strains. We report here on a protocol for the rapid, sensitive detection of B. anthracis spore using the Integrating Waveguide Biosensor followed by a method for the rapid release and germination of immunocaptured spores. A detection limit of ca. 103 spores was achieved by incubating spores simultaneously with capture and detection antibodies (“liquid-phase” assay) prior to capture on capillary tubes/waveguides. Subsequent incubation with BHI broth directly in capillary tubes allowed for rapid germination, outgrowth, and release of spores, resulting in vegetative cells for PCR analysis. 相似文献
902.
Background
Methanogenesis is the sole means of energy production in methanogenic Archaea. H2-forming methylenetetrahydromethanopterin dehydrogenase (Hmd) catalyzes a step in the hydrogenotrophic methanogenesis pathway in class I methanogens. At least one hmd paralog has been identified in nine of the eleven complete genome sequences of class I hydrogenotrophic methanogens. The products of these paralog genes have thus far eluded any detailed functional characterization. 相似文献903.
S Y Tamura E A Goldman P W Bergum J E Semple 《Bioorganic & medicinal chemistry letters》1999,9(17):2573-2578
Rigid benzolactam P3-P2 dipeptide mimics were designed and prepared as potential inhibitors of blood coagulation factor Xa. Methoxy substitution of the tetrahydrobenzazepinone scaffold led to potent and selective inhibitors. The synthesis and biological activities of these derivatives are reported herein. 相似文献
904.
Naked mole-rats live in large colonies and exhibit a strict reproductive hierarchy. Each colony has one breeding female and one to three breeding males; all other individuals are nonreproductive subordinates. Subordinates show a remarkable lack of sex differences in behavior and anatomy, but can become reproductive if removed from the colony. We recently reported that the striated perineal muscles and their innervating motoneurons, which are sexually dimorphic in all other mammals examined to date, are not dimorphic in subordinate naked mole-rats. Here we asked whether sexual differentiation of this neuromuscular system occurs when a subordinate becomes a breeder. The size and number of cells within Onuf's nucleus (homologue of the rat spinal nucleus of the bulbocavernosus) as well as perineal muscle volume were examined in subordinate and breeding naked mole-rats of both sexes. Sex differences in perineal motoneurons were not observed, regardless of social status. To our surprise, however, counts of motoneurons in Onuf's nucleus were increased approximately 30% in breeders of both sexes. This was accompanied by a reciprocal decrease in cells in Onuf's nucleus that were characterized by small soma size, and lacked a clear nucleus or nucleolus. Although not exhibiting typical motoneuron morphology, some of these small cells were positive for the motoneuron marker, SMI-32. The neuronal changes correlate with increased perineal muscle volumes in breeders. We propose that small, relatively undifferentiated cells are recruited to the pool of large Onuf's nucleus motoneurons when subordinate naked mole-rats become breeders. 相似文献
905.
An immunoreceptor tyrosine activation motif in the mouse mammary tumor virus envelope protein plays a role in virus-induced mammary tumors
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Ross SR Schmidt JW Katz E Cappelli L Hultine S Gimotty P Monroe JG 《Journal of virology》2006,80(18):9000-9008
Mouse mammary tumor virus (MMTV) induces breast cancer with almost 100% efficiency in susceptible strains through insertional activation of protooncogenes, such as members of the wnt and fibroblast growth factor (fgf) families. We previously showed that expression of the MMTV envelope protein (Env) in normal immortalized mammary epithelial cells grown in three-dimensional cultures caused their morphological transformation, and that this phenotype depended on an immunoreceptor tyrosine-based activation motif (ITAM) present in Env and signaling through the Syk tyrosine kinase (E. Katz, M. H. Lareef, J. C. Rassa, S. M. Grande, L. B. King, J. Russo, S. R. Ross, and J. G. Monroe, J. Exp. Med. 201:431-439, 2005). Here, we examined the role of the Env protein in virus-induced mammary tumorigenesis in vivo. Similar to the effect seen in vitro, Env expression in the mammary glands of transgenic mice bearing either full-length wild-type provirus or only Env transgenes showed increased lobuloalveolar budding. Introduction of the ITAM mutation into the env of an infectious, replication-competent MMTV or into MMTV/murine leukemia virus pseudotypes had no effect on incorporation of Env into virus particles or on in vitro infectivity. Moreover, replication-competent MMTV bearing the ITAM mutation in Env infected lymphoid and mammary tissue at the same level as wild-type MMTV and was transmitted through milk. However, mammary tumor induction was greatly attenuated, and the pattern of oncogene activation was altered. Taken together, these studies indicate that the MMTV Env protein participates in mammary epithelial cell transformation in vivo and that this requires a functional ITAM in the envelope protein. 相似文献
906.
Salgueiro J Leonardi N Segal M Shapira N Shafran N Carasso Y Zubillaga M Goldman C Barrado A Janjetic M Boccio J 《Biological trace element research》2006,109(1):91-96
In this research, we measure the iron bioavailability of micronized ferric orthophosphate when it is used to fortify low-fat
fluid milk enriched with calcium and petit suisse cheese using the prophylactic-preventive method in rats. Four groups of
male weaned rats received a basal diet (control diet; 6.5 ppm Fe), a reference standard diet (SO4Fe; 18.2 ppm Fe), a basal diet using iron-fortified fluid milk as the iron source (milk diet; Fe ppm 17.9), and a basal diet
using iron-fortified petit suisse cheese as the iron source (cheese diet; 18.0 ppm Fe) for 22 d. The iron bioavailability
of the different sources was calculated as the ratio between the mass of iron incorporated into hemoglobin during the experiment
and the total iron intake per animal. The relative biological values with regard to the reference standard (RBV%) were 61%
and 69% for the milk and cheese diet, respectively. These results show that according to this method, the iron bioavailability
in both fortified foods can be considered as medium bioavailability rates. 相似文献
907.
Sawers RJ Viney J Farmer PR Bussey RR Olsefski G Anufrikova K Hunter CN Brutnell TP 《Plant molecular biology》2006,60(1):95-106
Semi-dominant Oil yellow1 (Oy1) mutants of maize (Zea mays) are deficient in the conversion of protoporphyrin IX to magnesium protoporphyrin IX, the first committed step of chlorophyll
biosynthesis. Using a candidate gene approach, a cDNA clone was isolated that was predicted to encode the I subunit of magnesium
chelatase (ZmCHLI) and mapped to the same genetic interval as Oy1. Allelic variation was identified at ZmCHLI between wild-type plants and plants carrying semi-dominant alleles of Oy1. These differences revealed putative amino acid substitutions that could account for the alterations in protein function.
Candidate lesions were tested by introduction of homologous changes into the Synechocystis magnesium chelatase I gene (SschlI) and characterization of the activity of mutant protein variants in an in vitro enzyme activity assay. The results of these analyses suggest that SsChlI protein variants containing the substitutions identified
in the dominant Oy1 maize alleles lack activity necessary for magnesium chelation and confer a semi-dominant phenotype via competitive inhibition
of wild-type SsChlI. 相似文献
908.
Beth Bennett Phyllis J. Carosone-Link Lu Lu Elissa J. Chesler Thomas E. Johnson 《Mammalian genome》2005,16(10):764-774
This is the first phenotypic analysis of 75 new recombinant inbred (RI) strains derived from ILS and ISS progenitors. We analyzed
body weight in two independent cohorts of female mice at various ages and in males at 60 days. Body weight is a complex trait
which has been mapped in numerous crosses in rodents. The LXS RI strains displayed a large range of weights, transgressing
those of the inbred progenitors, supporting the utility of this large panel for mapping traits not selected in the progenitors.
Numerous QTLs for body weight mapped in single- and multilocus scans. We assessed replication between these and previously
reported QTLs based on overlapping confidence intervals of published QTLs for body weight at 60 days and used meta-analyses
to determine combined p values for three QTL regions located on Chromosomes 4, 5, and 11. Strain distribution patterns of microsatellite marker genotypes,
weight, and other phenotypes are available on WebQTL () and allow genetic mapping of any heritable quantitative phenotype measured in these strains. We report one such analysis,
correlating brain and body weights. Large reference panels of RI strains, such as the LXS, are invaluable for identifying
genetic correlations, GXE (Gene X Environment) interactions, and replicating previously identified QTLs.
Electronic Supplementary Material Electronic Supplementary material is available for this article at
and accessible for authorised users. 相似文献
909.
Löytynoja A Goldman N 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2008,363(1512):3913-3919
We have developed a phylogeny-aware progressive alignment method that recognizes insertions and deletions as distinct evolutionary events and thus avoids systematic errors created by traditional alignment methods. We now extend this method to simultaneously model regional heterogeneity and evolution. This novel method can be flexibly adapted to alignment of nucleotide or amino acid sequences evolving under processes that vary over genomic regions and, being fully probabilistic, provides an estimate of regional heterogeneity of the evolutionary process along the alignment and a measure of local reliability of the solution. Furthermore, the evolutionary modelling of substitution process permits adjusting the sensitivity and specificity of the alignment and, if high specificity is aimed at, leaving sequences unaligned when their divergence is beyond a meaningful detection of homology. 相似文献
910.
Watanabe MA Bhalodia R Lundequam EJ Domitrovich PP Steinmeyer BC Stein PK Freedland KE Duntley SP Carney RM 《Indian pacing and electrophysiology journal》2008,8(4):258-267