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991.
Lo?c?VillierEmail author Daniel?B.?Blake John?W.?M.?Jagt Manfred?Kutscher 《Pal?ontologische Zeitschrift》2004,78(2):281-299
The Pterasteridae comprises a diversified group of extant largely deep-sea starfishes. Generic diagnoses have been based classically
on soft tissue characters and skeletal architecture. A preliminary phylogeny of sixteen extant species is here worked out
by cladistic analysis. The resulting tree suggests monophyly of extant genera and the validity of dissociated plates for identification
of genera. Fossil remains of Pterasteridae are here described for the first time. By comparison with extant species, all the
skeletal remains from the lower Upper Campanian of Belgium and from the lower Maastrichtian of Germany are tentatively assigned
to the genusPteraster. The fossil record of starfishes is poor, but the present Late Cretaceous pterasterids provide one more piece of evidence
of the high diversity of starfishes during the Mesozoic. Known Late Cretaceous and Paleogene fossils are broadly similar,
which suggests the end-Cretaceous extinction event did not cause major turnover in asteroid faunal composition. As suggested
for other starfish groups, both the fossil record of deep-sea Pterasteridae in shelf settings and tree topology imply an onshore-offshore
evolutionary trend.
相似文献
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994.
Simultaneous determination of ketamine and xylazine in canine plasma by liquid chromatography with ultraviolet absorbance detection 总被引:2,自引:0,他引:2
Niedorf F Bohr HH Kietzmann M 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,791(1-2):421-426
An isocratic reversed-phase high-performance liquid chromatographic method for the simultaneous determination of ketamine and xylazine in canine plasma is described. Plasma samples (500 microl) are cleaned up via liquid-liquid extraction. The analytes and the internal standard clonidine are separated on a cyano (CN) column using a mobile phase containing acetonitrile-0.005 M phosphate buffer adjusted to pH 5.5 (3:2) at a detection wavelength of 215 nm. The method was validated according to specificity, sensitivity, accuracy and reproducibility and was used to determine the plasma concentrations of both compounds in dogs after intramuscular injection. 相似文献
995.
Krol J Sato S Rettenberger P Assfalg-Machleidt I Schmitt M Magdolen V Magdolen U 《Biological chemistry》2003,384(7):1085-1096
Serine proteases, cysteine proteases, and matrix metalloproteinases (MMPs) are involved in cancer cell invasion and metastasis. Recently, a recombinant bifunctional inhibitor (chCys-uPA19-31) directed against cysteine proteases and the urokinase-type plasminogen activator (uPA)/plasmin serine protease system was generated by introducing the uPA receptor (uPAR)-binding site of uPA into chicken cystatin (chCysWT). In the present study, we designed and recombinantly produced multifunctional inhibitors also targeting MMPs. The inhibitors comprise the N-terminal inhibitory domain of human TIMP-1 (tissue inhibitor of matrix metalloproteinase-1) or TIMP-3, fused to chCys-uPA19-31 or chCysWT. As demonstrated by various techniques, these fusion proteins effectively interfere with all three targeted protease systems. In in vitro Matrigel invasion assays, the addition of recombinant inhibitors strongly reduced invasion of ovarian cancer cells (OV-MZ-6#8). Additionally, OV-MZ-6#8 cells were stably transfected with expression plasmids encoding the various inhibitors. Synthesis and secretion of the inhibitors was verified by a newly developed ELISA, which selectively detects the recombinant proteins. Invasive capacity of inhibitor-producing cells was significantly reduced compared to vector-transfected control cells. Thus, these novel, compact, and small-size inhibitors directed against up to three different tumor-associated proteolytic systems may represent promising agents for prevention of tumor cell migration and metastasis. 相似文献
996.
Separation of proteins by two-dimensional gel electrophoresis (2-DE) coupled with identification of proteins through peptide
mass fingerprinting (PMF) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is
the widely used technique for proteomic analysis. This approach relies, however, on the presence of the proteins studied in
public-accessible protein databases or the availability of annotated genome sequences of an organism. In this work, we investigated
the reliability of using raw genome sequences for identifying proteins by PMF without the need of additional information such
as amino acid sequences. The method is demonstrated for proteomic analysis of Klebsiella pneumoniae grown anaerobically on glycerol. For 197 spots excised from 2-DE gels and submitted for mass spectrometric analysis 164 spots
were clearly identified as 122 individual proteins. 95% of the 164 spots can be successfully identified merely by using peptide
mass fingerprints and a strain-specific protein database (ProtKpn) constructed from the raw genome sequences of K. pneumoniae. Cross-species protein searching in the public databases mainly resulted in the identification of 57% of the 66 high expressed
protein spots in comparison to 97% by using the ProtKpn database. 10 dha regulon related proteins that are essential for the initial enzymatic steps of anaerobic glycerol metabolism were successfully
identified using the ProtKpn database, whereas none of them could be identified by cross-species searching. In conclusion,
the use of strain-specific protein database constructed from raw genome sequences makes it possible to reliably identify most
of the proteins from 2-DE analysis simply through peptide mass fingerprinting. 相似文献
997.
Water microdrops of about 50 microm in diameter, generated by an ink-jet system, have been used to hydrate fragments of Pogonophora tubes. In situ X-ray microdiffraction with a beam size of 10 microm was used to follow the structural transformations that affected the crystalline beta-chitin part of the specimens. Starting from anhydrous chitin, the formation of a full beta-chitin dihydrate was observed within about 90 s. A disordered intermediate phase with variable d-spacing that could be due to a mixture of anhydrous and hydrated beta-chitin layers was also detected. 相似文献
998.
999.
Ploski R Wozniak M Pawlowski R Monies DM Branicki W Kupiec T Kloosterman A Dobosz T Bosch E Nowak M Lessig R Jobling MA Roewer L Kayser M 《Human genetics》2002,110(6):592-600
Different regional populations from Poland were studied in order to assess the genetic heterogeneity within Poland, investigate the genetic relationships with other European populations and provide a population-specific reference database for anthropological and forensic studies. Nine Y-chromosomal microsatellites were analysed in a total of 919 unrelated males from six regions of Poland and in 1,273 male individuals from nine other European populations. AMOVA revealed that all of the molecular variation in the Polish dataset is due to variation within populations, and no variation was detected among populations of different regions of Poland. However, in the non-Polish European dataset 9.3% ( P<0.0001) of the total variation was due to differences among populations. Consequently, differences in R(ST)-values between all possible pairs of Polish populations were not statistically significant, whereas significant differences were observed in nearly all comparisons of Polish and non-Polish European populations. Phylogenetic analyses demonstrated tight clustering of Polish populations separated from non-Polish groups. Population clustering based on Y-STR haplotypes generally correlates well with the geography and history of the region. Thus, our data are consistent with the assumption of homogeneity of present-day paternal lineages within Poland and their distinctiveness from other parts of Europe, at least in respect to their Y-STR haplotypes. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00439-002-0728-0. 相似文献
1000.
Juvenile polyposis: massive gastric polyposis is more common in MADH4 mutation carriers than in BMPR1A mutation carriers 总被引:4,自引:0,他引:4
Friedl W Uhlhaas S Schulmann K Stolte M Loff S Back W Mangold E Stern M Knaebel HP Sutter C Weber RG Pistorius S Burger B Propping P 《Human genetics》2002,111(1):108-111
Juvenile polyposis syndrome (JPS) is an autosomal dominant predisposition to multiple juvenile polyps in the gastrointestinal tract. Germline mutations in the MADH4 or BMPR1A genes have been found to be causative of the disease in a subset of JPS patients. So far, no genotype-phenotype correlation has been reported. We examined 29 patients with the clinical diagnosis of JPS for germline mutations in the MADH4 or BMPR1A genes and identified MADH4 mutations in seven (24%) and BMPR1A mutations in five patients (17%). A remarkable prevalence of massive gastric polyposis was observed in patients with MADH4 mutations when compared with patients with BMPR1A mutations or without identified mutations. This is the first genotype-phenotype correlation observed in JPS. 相似文献