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Molecular cloning of an amino acid-regulated mRNA (amino acid starvation-induced) in rat hepatoma cells 总被引:1,自引:0,他引:1
Using the combination of a subtracted library and differential hybridization, a 409-base pair cDNA was identified that corresponds to a mRNA that is induced 2-3-fold when rat Fao hepatoma cells are subjected to amino acid starvation for 12 h. While this mRNA species was induced during starvation, others such as beta-actin, Cu-Zn superoxide dismutase, glyceraldehyde-3-P, and histone H4 were decreased in abundance to 25-50% of their original levels. The induction of the amino acid starvation-induced (ASI) mRNA was repressed when starved cells were returned to a medium supplemented with amino acids. Tissue distribution analysis showed the ASI mRNA, approximately 650 base pairs in length, to be present in every rat tissue tested. The cDNA clone has been sequenced and appears to correspond to the 3'-most end of the mRNA. The cDNA sequence includes the poly(A) tail, two potential polyadenylation signal sequences, and an open reading frame that we presume to be a portion of the coding sequence. The ASI cDNA will be used to investigate the molecular mechanisms for amino acid-dependent regulation of protein expression by mammalian cells. 相似文献
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A. Klockow-Beck A. Nick St. Geisshuesler D. Schaufelberger 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1998,720(1-2):141-151
A capillary electrophoresis (CE) method has been developed as an alternative method for the determination of the inorganic degradation products sulfate and sulfamate in topiramate drug product and drug substance, currently performed by ion chromatography. The anions are separated in a background electrolyte containing potassium chromate and boric acid, followed by indirect UV detection. By adding tetradecyltrimethylammonium bromide to the electrolyte, analysis is performed under co-electroosmotic flow conditions. Variations in injection volumes and migration times are compensated for by use of an internal standard. The validation of the method, which was performed according to ICH guidelines (International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use) [1], comprises specificity, accuracy, linearity, precision, sensitivity and robustness. In addition, the results of an actual tablet sample analysis obtained by this CE method are statistically shown to be in close agreement with those obtained by an ion chromatographic method. 相似文献
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Wei Zhang Nick Bansback Annelies Boonen Adam Young Amitabh Singh Aslam H Anis 《Arthritis research & therapy》2010,12(5):R177
Introduction
The Work Productivity and Activity Impairment (WPAI) questionnaire is a well validated instrument to measure impairments in work and activities. However, its validation among patients with rheumatoid arthritis (RA) has not been well established. The present study's purpose is to evaluate the construct validity of the WPAI-general health version among RA patients and its ability to differentiate between RA patients with varying health status. 相似文献9.
We have addressed the role of the F-box helicase 1 (Fbh1) protein during genome maintenance in mammalian cells. For this, we generated two mouse embryonic stem cell lines deficient for Fbh1: one with a homozygous deletion of the N-terminal F-box domain (Fbh1f/f), and the other with a homozygous disruption (Fbh1?/?). Consistent with previous reports of Fbh1-deficiency in vertebrate cells, we found that Fbh1?/? cells show a moderate increase in Rad51 localization to DNA damage, but no clear defect in chromosome break repair. In contrast, we found that Fbh1f/f cells show a decrease in Rad51 localization to DNA damage and increased cytoplasmic localization of Rad51. However, these Fbh1f/f cells show no clear defects in chromosome break repair. Since some Rad51 partners and F-box-associated proteins (Skp1-Cul1) have been implicated in progression through mitosis, we considered whether Fbh1 might play a role in this process. To test this hypothesis, we disrupted mitosis using catalytic topoisomerase II inhibitors (bisdioxopiperazines), which inhibit chromosome decatenation. We found that both Fbh1f/f and Fbh1?/? cells show hypersensitivity to topoisomerase II catalytic inhibitors, even though the degree of decatenation stress was not affected. Furthermore, following topoisomerase II catalytic inhibition, both Fbh1-deficient cell lines show substantial defects in anaphase separation of chromosomes. These results indicate that Fbh1 is important for restoration of normal mitotic progression following decatenation stress. 相似文献
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Ronald G. Iacocca Nick Toltl M. Allgeier B. Bustard Xia Dong M. Foubert J. Hofer S. Peoples T. Shelbourn 《AAPS PharmSciTech》2010,11(3):1340-1349
Delamination, or the generation of glass flakes in vials used to contain parenteral drug products, continues to be a persistent
problem in the pharmaceutical industry. To understand all of the factors that might contribute to delamination, a statistical
design of experiments was implemented to describe this loss of chemical integrity for glass vials. Phase I of this study focused
on the effects of thermal exposure (prior to product filling) on the surface chemistry of glass vials. Even though such temperatures
are below the glass transition temperature for the glass, and parenteral compounds are injected directly into the body, data
must be collected to show that the glass was not phase separating. Phase II of these studies examined the combined effects
of thermal exposure, glass chemistry, and exposure to pharmaceutically relevant molecules on glass delamination. A variety
of tools was used to examine the glass and the solution contained in the vial including: scanning electron microscopy and
dynamic secondary ion mass spectroscopy for the glass; and visual examination, pH measurements, laser particle counting, and
inductively coupled plasma–optical emission spectrometry for the analysis of the solution. The combined results of phase I
and II showed depyrogenation does not play a significant role in delamination. Terminal sterilization, glass chemistry, and
solution chemistry are the key factors in the generation of glass flakes. Dissolution of silica may be an effective indicator
that delamination will occur with a given liquid stored in glass. Finally, delamination should not be defined by the appearance
of visible glass particulates. There is a mechanical component in the delamination process whereby the flakes must break away
from the interior vial surface. Delamination should be defined by the observation of flakes on the interior surface of the
vial, which can be detected by several other analytical techniques. 相似文献