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91.
Cytogenetic tests are effective tools for monitoring the health status of livestock and improving their genetic value. Cytogenetic screening allows for the detection of animals carrying chromosomal aberrations and to avoid using them as breeders. Progress in karyotype monitoring, with new molecular probes and automation, has greatly increased the productivity of this procedure. Several genotoxicity tests are available to detect the possible presence and effects of pollutants or drugs. Among these, the micronucleus test and the Comet assay are the most convenient in terms of costs and benefits. Finally, analysis of telomeres, the end of chromosomes and markers of genomic instability, may be developed into a new marker of stress and genetic value. 相似文献
92.
Soltani F Mosaffa F Iranshahi M Karimi G Malekaneh M Haghighi F Behravan J 《Cell biology and toxicology》2009,25(3):291-296
The protective properties of a prenylated coumarin, umbelliprenin (UMB), on the human lymphocytes DNA lesions were tested.
Lymphocytes were isolated from blood samples taken from healthy volunteers. DNA breaks and resistance to H2O2-induced damage were measured using a single-cell microgel electrophoresis technique under alkaline conditions (comet assay).
Human lymphocytes were incubated in UMB (10, 25, 50, 100, 200, and 400 μM) alone or a combination of different concentrations
of UMB (10, 25, 50, 100, 200, and 400 μM) and 25 μM H2O2. Untreated cells, ascorbic acid (AA; 25, 50, 100, 200, and 400 μM) and H2O2 (25 μM) were considered as negative control, positive control, and the standard antioxidant agent for our study, respectively.
Single cells were analyzed with “TriTek Cometscore version 1.5” software. The DNA damage was expressed as percent tail DNA.
UMB exhibited a concentration-dependent increase in protection activity against DNA damage induced by 25 μM H2O2 (from 67.28% to 39.17%). The antigenotoxic activity of AA, in the range 0–50 μM, was greater than that of UMB. However, no
significant difference (p > 0.05) in the protective activity was found between UMB and AA at concentrations of approximately higher than 50 μM. 相似文献
93.
Hervé Poras Sophie DuquesnoyMarie-Claude Fournié-Zaluski Céline Ratinaud-GiraudBernard P. Roques Tanja Ouimet 《Analytical biochemistry》2013,441(2):152-161
Leukotriene A4 hydrolase (LTA4H) is a bifunctional zinc-dependent metalloprotease bearing both an epoxide hydrolase, producing the pro-inflammatory LTB4 leukotriene, and an aminopeptidase activity, whose physiological relevance has long been ignored. Distinct substrates are commonly used for each activity, although none is completely satisfactory; LTA4, substrate for the hydrolase activity, is unstable and inactivates the enzyme, whereas aminoacids β-naphthylamide and para-nitroanilide, used as aminopeptidase substrates, are poor and nonselective. Based on the three-dimensional structure of LTA4H, we describe a new, specific, and high-affinity fluorigenic substrate, PL553 [l-(4-benzoyl)phenylalanyl-β-naphthylamide], with both in vitro and in vivo applications. PL553 possesses a catalytic efficiency (kcat/Km) of 3.8 ± 0.5 × 104 M−1 s−1 using human recombinant LTA4H and a limit of detection and quantification of less than 1 to 2 ng. The PL553 assay was validated by measuring the inhibitory potency of known LTA4H inhibitors and used to characterize new specific amino-phosphinic inhibitors. The LTA4H inhibition measured with PL553 in mouse tissues, after intravenous administration of inhibitors, was also correlated with a reduction in LTB4 levels. This authenticates the assay as the first allowing the easy measurement of endogenous LTA4H activity and in vitro specific screening of new LTA4H inhibitors. 相似文献
94.
J. R. Ryan K. Dave E. Emmerich L. Garcia L. Yi R. E. Coleman J. Sattabongkot R. F. Dunton A. S. T. Chan R. A. Wirtz 《Medical and veterinary entomology》2001,15(2):225-230
Malaria remains the most serious vector-borne disease, affecting some 300-500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme-linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one-step procedure using a 'dipstick' wicking test strip. In laboratory assessment, dipsticks identified 1 ng/ mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors. 相似文献
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Microtopography is one of several strategies used by marine organisms to inhibit colonization by fouling organisms. While replicates of natural microtextures discourage settlement, details of larval interactions with the structured surfaces remain scarce. Close-range microscopy was used to quantify the exploration of cyprids of Amphibalanus amphitrite on cylindrical micropillars with heights of 5 and 30 μm and diameters ranging from 5 to 100 μm. While 5 μm-high structures had little impact, 30 μm-high pillars significantly influenced cyprid exploration. An observed step length decrease and step duration increase on 5 μm diameter pillars is attributed to the small dimensions of the voids excluding the cyprid's attachment disc and consequently reducing the area of adhesive contact. When exploring larger diameter pillars, cyprids preferred using the voids to form temporary attachment points. This may enhance their resistance to flow. No-choice assay settlement patterns mirrored this exploration behaviour, albeit in a pattern counter to what was predicted. 相似文献
98.
Galileo is a DNA transposon responsible for the generation of several chromosomal inversions in Drosophila. In contrast to other members of the P-element superfamily, it has unusually long terminal inverted-repeats (TIRs) that resemble those of Foldback elements. To investigate the function of the long TIRs we derived consensus and ancestral sequences for the Galileo transposase in three species of Drosophilids. Following gene synthesis, we expressed and purified their constituent THAP domains and tested their binding activity towards the respective Galileo TIRs. DNase I footprinting located the most proximal DNA binding site about 70 bp from the transposon end. Using this sequence we identified further binding sites in the tandem repeats that are found within the long TIRs. This suggests that the synaptic complex between Galileo ends may be a complicated structure containing higher-order multimers of the transposase. We also attempted to reconstitute Galileo transposition in Drosophila embryos but no events were detected. Thus, although the limited numbers of Galileo copies in each genome were sufficient to provide functional consensus sequences for the THAP domains, they do not specify a fully active transposase. Since the THAP recognition sequence is short, and will occur many times in a large genome, it seems likely that the multiple binding sites within the long, internally repetitive, TIRs of Galileo and other Foldback-like elements may provide the transposase with its binding specificity. 相似文献
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