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111.
112.
Thirteen basidiospore-derived isolates of Pleurotus ostreatus f6 strain differing in the level of ligninolytic enzyme production and other characteristics (mycelium extension rate, colony morphology) from the parental strain were cultivated on natural substrates. Under these conditions ligninolytic enzyme activity, loss of organic mass, polycyclic aromatic hydrocarbons (PAHs) degradation and colonization of sterile and nonsterile soil were studied. The activity of ligninolytic enzymes was substantially higher in straw than in liquid culture, although the differences between the isolates were less pronounced on this substrate. Some of the isolates showed a very good ability to decompose the lignocellulosic substrate (straw) and a relatively high loss of organic mass was found after 50 days of cultivation in these strains. The original strain f6 and isolates B13 and B26 successfully degraded all seven tested PAH compounds present in experimental soil samples, but the higher or lower ligninolytic enzyme production of isolates tested had no substantial effect on the extent of the degradation. In our screening, six basidiospore-derivedisolates growing well in nonsterile soil were found, whichcould be suitable for the prospective biotechnological exploitation. 相似文献
113.
The effect of a dominant species, the litter layer, and the moss layer on seedlings and established vegetation was evaluated in two manipulative experiments in an oligotrophic wet meadow (Molinion with some features ofViolion caninae according to phytosociological classification). In the first experiment, the dominant species (Nardus stricta), litter layer, and litter layer together with the moss layer were removed and the response of the established vegetation and seedlings were compared with a control. Results revealed that after one season there was no significant effect of the treatments on established vegetation, but seedling recruitment was significantly affected. The greatest increase of seedling recruitment for many species was observed in the plots with the moss layer removed. In the second experiment, seeds ofSelinum carvifolia were sown into plots subjected to the following treatments: complete vegetation removal, mowing, mowing combined with removal of the moss layer, and an untreated control. The highest number of seedlings was found in plots with the vegetation removed, but the seedling recruitment was nearly as high in plots with the moss layer removed. Low numbers were found in mown plots and the lowest in the untreated control. The results show that seedling recruitment is more sensitive to competition than the established vegetation, at least over one season. This supports the idea of the importance of the regeneration niche for the maintenance of diversity in grassland communities. 相似文献
114.
Ivana Sokolovská Claire Albasi Jean-Pierre Riba Vladimír Báleš 《Bioprocess and biosystems engineering》1998,19(3):179-186
In this study we investigated the influences of aeration, substrate type and concentration on extracellular lipase production in a batch fermentor. The use of air enriched with pure oxygen is the most suitable for the lipase production. Additionally, we found that the presence of fats in the culture broth did not affect the value of the volumetric mass transfer coefficient of oxygen in our system. Olive oil or oleic acid was used as carbon sources. In both cases, the maximal specific rate of growth, μmax, was the same but the highest activity was obtained when 10?g/dm3 of olive oil were used as an initial substrate concentration. 相似文献
115.
In our studies to analyze the structure/function relationships among cytoplasmic and organellar seryl-tRNA synthetases (SerRS), we have characterized a Zea mays cDNA (SerZMm) encoding a protein with significant similarity to prokaryotic SerRS enzymes. To demonstrate the functional identity of SerZMm, the gene sequence encoding the putative mature protein was cloned. This construct complemented in vivo a temperature-sensitive Escherichia coli serS mutant strain. The mature SerZMm protein overexpressed in Escherichia coli efficiently aminoacylated bacterial tRNASer in vitro, while yeast tRNA was a poor substrate. These data identify SerZMm as an organellar maize seryl-tRNA synthetase, the first plant organellar SerRS to be cloned. The analysis of its N-terminal targeting signal suggests a mitochondrial function for the SerZMm protein in maize. 相似文献
116.
Ivana Sirangelo Ettore Bismuto Simona Tavassi G. Irace 《European biophysics journal : EBJ》1998,27(1):27-31
The individual tryptophanyl contributions to the near-ultraviolet circular dichroic activity of apomyoglobin in its native
conformation have been resolved by studying recombinant proteins with single tryptophanyl substitutions. Site-directed mutagenesis
of sperm whale apomyoglobin was performed in order to obtain proteins containing only Trp A-5 or Trp A-12. These amino acid
substitutions have very little effect on the overall globin fold as indicated by comparing the spectroscopic properties of
the mutants with those of the wild type protein. The circular dichroism spectra of the two apomyoglobin mutants in the near
ultraviolet were found to be significantly different, both indole residues having significant activity but of opposite sign.
In particular, Trp A-5 shows the presence of a main positive peak centered near 294 – 295 nm with a marked shoulder at 285
nm, ascribed to the 1LBtransition. The spectrum of the mutant protein containing only Trp A-12 shows a large negative contribution with a minimum
near 283 nm and a marked shoulder at 293 nm. The broadness of the negative contribution exhibited by Trp A-12 suggests that
it may originate mainly from the 1LA transition.
Received: 17 February 1997 / Accepted: 14 August 1997 相似文献
117.
Francesco Taus Marilina B. Santucci Emanuela Greco Matteo Morandi Ivana Palucci Sabrina Mariotti Noemi Poerio Roberto Nisini Giovanni Delogu Maurizio Fraziano 《PloS one》2015,10(5)
A safer and more effective anti-Tuberculosis vaccine is still an urgent need. We probed the effects of monosodium urate crystals (MSU) on innate immunity to improve the Bacille Calmette-Guerin (BCG) vaccination. Results showed that in vitro MSU cause an enduring macrophage stimulation of the anti-mycobacterial response, measured as intracellular killing, ROS production and phagolysosome maturation. The contribution of MSU to anti-mycobacterial activity was also shown in vivo. Mice vaccinated in the presence of MSU showed a lower number of BCG in lymph nodes draining the vaccine inoculation site, in comparison to mice vaccinated without MSU. Lastly, we showed that MSU improved the efficacy of BCG vaccination in mice infected with Mycobacterium tuberculosis (MTB), measured in terms of lung and spleen MTB burden. These results demonstrate that the use of MSU as adjuvant may represent a novel strategy to enhance the efficacy of BCG vaccination. 相似文献
118.
Ivana Cacciatore Mara Di Giulio Erika Fornasari Antonio Di Stefano Laura Serafina Cerasa Lisa Marinelli Hasan Turkez Emanuela Di Campli Soraya Di Bartolomeo Iole Robuffo Luigina Cellini 《PloS one》2015,10(4)
Objective
The increasing prevalence of antibiotic-resistant bacterial infections led to identify alternative strategies for a novel therapeutic approach. In this study, we synthesized ten carvacrol codrugs – obtained linking the carvacrol hydroxyl group to the carboxyl moiety of sulphur-containing amino acids via an ester bond – to develop novel compounds with improved antimicrobial and antibiofilm activities and reduced toxicity respect to carvacrol alone.Method
All carvacrol codrugs were screened against a representative panel of Gram positive (S. aureus and S. epidermidis), Gram negative (E. coli and P. aeruginosa) bacterial strains and C. albicans, using broth microdilution assays.Findings
Results showed that carvacrol codrug 4 possesses the most notable enhancement in the anti-bacterial activity displaying MIC and MBC values equal to 2.5 mg/mL for all bacterial strains, except for P. aeruginosa ATCC 9027 (MIC and MBC values equal to 5 mg/mL and 10 mg/mL, respectively). All carvacrol codrugs 1-10 revealed good antifungal activity against C. albicans ATCC 10231. The cytotoxicity assay showed that the novel carvacrol codrugs did not produce human blood hemolysis at their MIC values except for codrugs 8 and 9. In particular, deepened experiments performed on carvacrol codrug 4 showed an interesting antimicrobial effect on the mature biofilm produced by E. coli ATCC 8739, respect to the carvacrol alone. The antimicrobial effects of carvacrol codrug 4 were also analyzed by TEM evidencing morphological modifications in S. aureus, E. coli, and C. albicans.Conclusion
The current study presents an insight into the use of codrug strategy for developing carvacrol derivatives with antibacterial and antibiofilm potentials, and reduced cytotoxicity. 相似文献119.
Iva Bozic Danijela Savic Danijela Laketa Ivana Bjelobaba Ivan Milenkovic Sanja Pekovic Nadezda Nedeljkovic Irena Lavrnja 《PloS one》2015,10(2)
Microglial cells are resident immune cells of the central nervous system (CNS), recognized as key elements in the regulation of neural homeostasis and the response to injury and repair. As excessive activation of microglia may lead to neurodegeneration, therapeutic strategies targeting its inhibition were shown to improve treatment of most neurodegenerative diseases. Benfotiamine is a synthetic vitamin B1 (thiamine) derivate exerting potentially anti-inflammatory effects. Despite the encouraging results regarding benfotiamine potential to alleviate diabetic microangiopathy, neuropathy and other oxidative stress-induced pathological conditions, its activities and cellular mechanisms during microglial activation have yet to be elucidated. In the present study, the anti-inflammatory effects of benfotiamine were investigated in lipopolysaccharide (LPS)-stimulated murine BV-2 microglia. We determined that benfotiamine remodels activated microglia to acquire the shape that is characteristic of non-stimulated BV-2 cells. In addition, benfotiamine significantly decreased production of pro-inflammatory mediators such as inducible form of nitric oxide synthase (iNOS) and NO; cyclooxygenase-2 (COX-2), heat-shock protein 70 (Hsp70), tumor necrosis factor alpha α (TNF-α), interleukin-6 (IL-6), whereas it increased anti-inflammatory interleukin-10 (IL-10) production in LPS stimulated BV-2 microglia. Moreover, benfotiamine suppressed the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK) and protein kinase B Akt/PKB. Treatment with specific inhibitors revealed that benfotiamine-mediated suppression of NO production was via JNK1/2 and Akt pathway, while the cytokine suppression includes ERK1/2, JNK1/2 and Akt pathways. Finally, the potentially protective effect is mediated by the suppression of translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the nucleus. Therefore, benfotiamine may have therapeutic potential for neurodegenerative diseases by inhibiting inflammatory mediators and enhancing anti-inflammatory factor production in activated microglia. 相似文献
120.
Katja Petzold Diane Poster Fabienne Krauer Katharina Spanaus Gustav Andreisek Thi Dan Linh Nguyen-Kim Ivana Pavik Thien Anh Ho Andreas L. Serra Laura Rotar 《PloS one》2015,10(4)