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101.
102.
Spirov A. V. Levchenko V. F. Sabirov M. A. Grigorev I. P. Korzhevskii D. E. Evsyukova I. I. Lunichkin A. M. Zhukovskaya M. I. Gorshkova O. P. Silkin Yu. A. Silkina E. N. Silkin M. Yu. Ravaeva M. Yu. Chuyan E. N. Cheretaev I. V. Mironyuk I. S. Grishina T. V. Pushchina E. V. Kapustyanov I. A. Shamshurina E. V. Varaksin A. A. Fedorova I. M. Tikhonov D. B. Prutskova N. P. Seliverstova E. V. Hernandez-Cortes P. Ünüvar S. Gürsoy Ş. Berk A. Kaymaz B. İlhan N. Aktay G. El-Kafoury B. M. A. Saad R. A. Ismail E. G. M. Abdel-Hady E. A. Lobov G. I. Ivanova G. T. Plekanchuk V. S. Ryazanova M. A. Pogorelova T. N. Gunko V. O. Nikashina A. A. Alliluev I. A. 《Journal of Evolutionary Biochemistry and Physiology》2021,57(2):424-428
Journal of Evolutionary Biochemistry and Physiology - A Correction to this paper has been published: https://doi.org/10.1134/S0022093021020216 相似文献
103.
V. V. Tikhonov D. S. Orlov O. V. Lisovitskaya Yu. A. Zavgorodnyaya B. A. Byzov V. V. Demin 《Microbiology》2013,82(6):707-712
Capacity for sorption of humic acid (HA) from water solutions was shown for 38 bacterial strains. Isotherms of HA sorption were determined for the cells of 10 strains. The bonding strength between the cells and HA (k) and the terminal adsorption (Q max) determined from the Langmuir equation for gram-positive and gram-negative bacteria were reliably different. Gram-positive bacteria sorbed greater amounts of HA than gram-negative ones (Q max = 23 ± 10 and 5.6 ± 1.2 mg/m2, respectively). The bonding strength between HA and the cells was higher in gram-negative bacteria than in gram-positive: k = 9 ± 5 and 3.3 ± 1.1 mL/mg, respectively. 相似文献
104.
Kuvykin IV Ptushenko VV Vershubskii AV Tikhonov AN 《Biochimica et biophysica acta》2011,1807(3):336-347
In this work, we have investigated the effects of atmospheric CO(2) and O(2) on induction events in Hibiscus rosa-sinensis leaves. These effects manifest themselves as multiphase kinetics of P(700) redox transitions and non-monotonous changes in chlorophyll fluorescence. Depletion of CO(2) and O(2) in air causes a decrease in linear electron flux (LEF) and dramatic lowering of P(700)(+) level. This is explained by the impediment to electron efflux from photosystem 1 (PS1) at low acceptor capacity. With the release of the acceptor deficit, the rate of LEF significantly increases. We have found that oxygen promotes the outflow of electrons from PS1, providing the rise of P(700)(+) level. The effect of oxygen as an alternative electron acceptor becomes apparent at low and ambient concentrations of atmospheric CO(2) < or = 0.06-0.07%). A decrease in LEF at low CO(2) is accompanied by a significant (about 3-fold) rise of non-photochemical quenching (NPQ) of chlorophyll fluorescence. Such an increase in NPQ can be explained by more significant acidification of the thylakoid lumen. This occurs due to lessening the proton flux through the ATP synthases caused by a decrease in the ATP consumption in the Bassham-Benson-Calvin (BBC) cycle. pH-dependent mechanisms of electron transport control have been described within the frames of our mathematical model. The model describes the reciprocal changes in LEF and NPQ and predicts the redistribution of electron fluxes on the acceptor side of PS1. In particular, the contribution of cyclic electron flow around PS1 (CEF1) and water-water cycle gradually decays during the induction phase. This result is consistent with experimental data indicating that under the steady-state conditions the contribution of CEF1 to photosynthetic electron transport in Hibiscus rosa-sinensis is insignificant (< or = 10%). 相似文献
105.
Nerea Abrego Tomas Roslin Tea Huotari Ayco J. M. Tack Bjrn D. Lindahl Gleb Tikhonov Panu Somervuo Niels Martin Schmidt Otso Ovaskainen 《Molecular ecology》2020,29(14):2736-2746
Understanding the role of interspecific interactions in shaping ecological communities is one of the central goals in community ecology. In fungal communities, measuring interspecific interactions directly is challenging because these communities are composed of large numbers of species, many of which are unculturable. An indirect way of assessing the role of interspecific interactions in determining community structure is to identify the species co‐occurrences that are not constrained by environmental conditions. In this study, we investigated co‐occurrences among root‐associated fungi, asking whether fungi co‐occur more or less strongly than expected based on the environmental conditions and the host plant species examined. We generated molecular data on root‐associated fungi of five plant species evenly sampled along an elevational gradient at a high arctic site. We analysed the data using a joint species distribution modelling approach that allowed us to identify those co‐occurrences that could be explained by the environmental conditions and the host plant species, as well as those co‐occurrences that remained unexplained and thus more probably reflect interactive associations. Our results indicate that not only negative but also positive interactions play an important role in shaping microbial communities in arctic plant roots. In particular, we found that mycorrhizal fungi are especially prone to positively co‐occur with other fungal species. Our results bring new understanding to the structure of arctic interaction networks by suggesting that interactions among root‐associated fungi are predominantly positive. 相似文献
106.
Nerea Abrego Tea Huotari Ayco J. M. Tack Bjrn D. Lindahl Gleb Tikhonov Panu Somervuo Niels Martin Schmidt Otso Ovaskainen Tomas Roslin 《Ecology and evolution》2020,10(16):8989-9002
How community‐level specialization differs among groups of organisms, and changes along environmental gradients, is fundamental to understanding the mechanisms influencing ecological communities. In this paper, we investigate the specialization of root‐associated fungi for plant species, asking whether the level of specialization varies with elevation. For this, we applied DNA barcoding based on the ITS region to root samples of five plant species equivalently sampled along an elevational gradient at a high arctic site. To assess whether the level of specialization changed with elevation and whether the observed patterns varied between mycorrhizal and endophytic fungi, we applied a joint species distribution modeling approach. Our results show that host plant specialization is not environmentally constrained in arctic root‐associated fungal communities, since there was no evidence for changing specialization with elevation, even if the composition of root‐associated fungal communities changed substantially. However, the level of specialization for particular plant species differed among fungal groups, root‐associated endophytic fungal communities being highly specialized on particular host species, and mycorrhizal fungi showing almost no signs of specialization. Our results suggest that plant identity affects associated mycorrhizal and endophytic fungi differently, highlighting the need of considering both endophytic and mycorrhizal fungi when studying specialization in root‐associated fungal communities. 相似文献
107.
D. B. Tikhonov 《Journal of Evolutionary Biochemistry and Physiology》2011,47(5):499-501
Jubilee Dates
Aleksandr Ivanovich Krivchenko (To the 70th Anniversary) 相似文献108.
A I Sinopal'nikov O V Fesenko Iu G Tikhonov V K Duganov 《Antibiotiki i khimioterapii͡a》2001,46(6):6-11
A complex microbiological (sputum, protected brush biopsy of the bronchial mucosa) and immunological examination of 40 male patients (the average age of 55.4 +/- 8.8 years) with severe community-acquired pneumonia (risk classes III-V according to Fine M.J. et al., 1997) revealed the disease etiology in 52.5 per cent of the cases. The leading pathogen was Streptococcus pneumoniae. It was detected in 61.6 per cent of the cases of the etiologically verified pneumonia. Staphylococcus aureus and Klebsiella pneumoniae were also among the actual pathogens (14.3 and 14.3 per cent respectively). The Legionnaires infection was not confirmed in any of the patients (enzyme-linked immunological analysis of urine for the serotype 1-6 Legionella pneumophila antigen). In the absolute majority of the patients the isolated pneumococci were susceptible (E-test) to benzylpenicillin. Only in 1 patients with severe pneumonia and secondary bacteriemia the pneumococcal isolates were moderately resistant to benzylpenicillin (the MIC of 0.125 mg/ml). Still, they were susceptible to ceftriaxone (the MIC of 0.023 mg/ml). The data are useful in the development of a national (regional) programme for empirical antibacterial therapy of severe community-acquired pneumonia. 相似文献
109.
Lymphotactin is a potent chemotactic cytokine (chemokine) that is produced by and also attracts T and natural killer (NK) cells. We are studying whether chemokines that affect mainly T cells might also regulate immune responses by preferentially recruiting individual subsets or by affecting cytokine or other chemokine responses. In order to pursue these questions, we need to learn more about the mechanisms regulating lymphotactin production and the cell types capable of releasing this factor. We used new monoclonal antibodies against human lymphotactin to develop a sensitive antigen-capture enzyme linked immunoabsorbent assay (ELISA) that measures chemokine levels in culture fluids. Using this capture ELISA, we showed that lymphotactin could be produced by CD4+ and CD8+ T cells, but only after T cell-receptor-dependent stimulation using bacterial superantigens and not after treatment by inflammatory cytokines or lipopolysaccharide (LPS). Our data show that lymphotactin production responds mainly to T cell-receptor signals in CD4+ and CD8+ T cells, and suggests a mechanism whereby this chemokine could help to regulate T cell immune responses. 相似文献
110.
Tikhonov DB 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2007,93(5):531-543
The voltage-gated sodium channels play a key role in the generation of action potential in excitable cells. Sodium channels are targeted by a number of modulating ligands. Despite numerous studies, the mechanisms of action of many ligands are still unknown. The main cause of the problem is the absence of the channel structure. Sodium channels belong to the superfamily of P-loop channels that also the data abowt includes potassium and calcium channels and the channels of ionotropic glutamate receptors. Crystallization of several potassium channels has opened a possibility to analyze the structure of other members of the superfamily using the homology modeling approach. The present study summarizes the results of several recent modelling studies of such sodium channel ligands as tetrodotoxin, batrachotoxin and local anesthetics. Comparison of available experimental data with X-ray structures of potassium channels has provided a new level of understanding of the mechanisms of action of sodium channel ligands and has allowed proposing several testable hypotheses. 相似文献