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71.
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J.L Beal S.E Tett 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1998,715(2):73
A simple method for the measurement of pindolol enantiomers by HPLC is presented. Alkalinized serum or urine is extracted with ethyl acetate and the residue remaining after evaporation of the organic layer is then derivatised with (S)-(−)-α-methylbenzyl isocyanate. The diastereoisomers of derivatised pindolol and metoprolol (internal standard) are separated by high-performance liquid chromatography (HPLC) using a C18 silica column and detected using fluorescence (excitation λ: 215 nm, emission λ: 320 nm). The assay displays reproducible linearity for pindolol enantiomers with a correlation coefficient of r2≥0.998 over the concentration range 8–100 ng ml−1 for plasma and 0.1–2.5 μg ml−1 for urine. The coefficient of variation for accuracy and precision of the quality control samples for both plasma and urine are consistently <10%. Assay parameters are similar to those of previously published assays for pindolol enantiomers, however this assay is significantly easier and cheaper to run. Clinically relevant concentrations of each pindolol enantiomer can readily be measured. 相似文献
73.
Mamu-B*08-positive macaques control simian immunodeficiency virus replication 总被引:5,自引:2,他引:5 下载免费PDF全文
Loffredo JT Maxwell J Qi Y Glidden CE Borchardt GJ Soma T Bean AT Beal DR Wilson NA Rehrauer WM Lifson JD Carrington M Watkins DI 《Journal of virology》2007,81(16):8827-8832
Certain major histocompatibility complex (MHC) class I alleles are associated with the control of human immunodeficiency virus and simian immunodeficiency virus (SIV) replication. We have designed sequence-specific primers for detection of the rhesus macaque MHC class I allele Mamu-B*08 by PCR and screened a cohort of SIV-infected macaques for this allele. Analysis of 196 SIV(mac)239-infected Indian rhesus macaques revealed that Mamu-B*08 was significantly overrepresented in elite controllers; 38% of elite controllers were Mamu-B*08 positive compared to 3% of progressors (P = 0.00001). Mamu-B*08 was also associated with a 7.34-fold decrease in chronic phase viremia (P = 0.002). Mamu-B*08-positive macaques may, therefore, provide a good model to understand the correlates of MHC class I allele-associated immune protection and viral containment in human elite controllers. 相似文献
74.
Evidence of Increased Oxidative Damage in Both Sporadic and Familial Amyotrophic Lateral Sclerosis 总被引:9,自引:13,他引:9
Robert J. Ferrante Susan E. Browne Leslie A. Shinobu Allen C. Bowling M. Jay Baik Usha MacGarvey Neil W. Kowall †Robert H. Brown Jr. M. Flint Beal 《Journal of neurochemistry》1997,69(5):2064-2074
Abstract: Some cases of autosomal dominant familial amyotrophic lateral sclerosis (FALS) are associated with mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1), suggesting that oxidative damage may play a role in ALS pathogenesis. To further investigate the biochemical features of FALS and sporadic ALS (SALS), we examined markers of oxidative damage to protein, lipids, and DNA in motor cortex (Brodmann area 4), parietal cortex (Brodmann area 40), and cerebellum from control subjects, FALS patients with and without known SOD mutations, SALS patients, and disease controls (Pick's disease, progressive supranuclear palsy, diffuse Lewy body disease). Protein carbonyl and nuclear DNA 8-hydroxy-2'-deoxyguanosine (OH8 dG) levels were increased in SALS motor cortex but not in FALS patients. Malondialdehyde levels showed no significant changes. Immunohistochemical studies showed increased neuronal staining for hemeoxygenase-1, malondialdehyde-modified protein, and OH8 dG in both SALS and FALS spinal cord. These studies therefore provide further evidence that oxidative damage may play a role in the pathogenesis of neuronal degeneration in both SALS and FALS. 相似文献
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The genus Plutella was thought to be represented in Australia by a single introduced species, Plutella xylostella (Linnaeus), the diamondback moth. Its status as a major pest of cruciferous crops, and the difficulty in developing control strategies has motivated broad-ranging studies on its biology. Prior genetic work has generally supported the conclusion that populations of this migratory species are connected by substantial gene flow. However, the present study reveals the presence of two genetically divergent lineages of this taxonin Australia. One shows close genetic and morphological similarity with the nearly cosmopolitan Plutella xylostella. The second lineage possesses a similar external morphology, but marked sequence divergence in the barcode region of the cytochrome c oxidase I gene, coupled with clear differences in genitalia. As a consequence, members of this lineage are described as a new species, Plutella australiana Landry & Hebert, which is broadly distributed in the eastern half of Australia. 相似文献
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M B Bogdanov M F Beal D R McCabe R M Griffin W R Matson 《Free radical biology & medicine》1999,27(5-6):647-666
8-Hydroxy-2'-deoxyguanosine (8OH2'dG) is a principal stable marker of hydroxyl radical damage to DNA. It has been related to a wide variety of disorders and environmental insults, and has been proposed as a useful systematic marker of oxidative stress. Analytic procedures for 8OH2'dG in DNA digests are well established; however, routine measurement of free 8OH2'dG in other body fluids such as urine or plasma has been problematic. This has hindered its evaluation as a general clinical, therapeutic monitoring, or environmental assessment tool. Therefore, we developed a liquid chromatography electrochemical column-switching system based on the use of the unique purine selectivity of porous carbon columns that allows routine accurate measurement of 8OH2'dG in a variety of biologic matrices. This paper describes the rationale of the system design and the protocols developed for 8OH2'dG in urine, plasma, cerebrospinal fluid, tissue, DNA, saliva, sweat, kidney dialysis fluid, foods, feces, culture matrix, and microdialysates. Concentrations in both human and animal body fluids and tissues are reported. The system performance is discussed in the context of a 1-year evaluation of the methods applied to approximately 3600 samples, using internal quality control and external blind testing to determine long-term accuracy. The methods are reliable and accurate, and therefore should prove useful in assessing the role and utility of oxidative DNA damage in aging and human illness. 相似文献
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