全文获取类型
收费全文 | 186篇 |
免费 | 12篇 |
专业分类
198篇 |
出版年
2023年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 9篇 |
2007年 | 6篇 |
2006年 | 13篇 |
2005年 | 8篇 |
2004年 | 16篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1936年 | 1篇 |
排序方式: 共有198条查询结果,搜索用时 15 毫秒
191.
Fiorenzo Battaini Stefano Govoni Angelo Mauri Luigi Civelli Marco Trabucchi 《Life sciences》1987,40(26):2505-2509
The binding of 3H-oubain to human erythrocytes was analyzed in a population of hospitalized male ethanol addicted patients under long term digitalis treatment. In the non-alcoholic patient group the long term digitalis treatment induced an increase in Bmax and Kd values; such modification was not observed in the alcoholic patients. Chronic alcohol intake itself induced an increase in 3H-ouabain kinetic parameters. These observations confirm that ouabain binding to human erythrocytes is subject to pharmacological and toxicological regulation and that adaptive changes in peripheral tissues can be useful in predicting possible parallel modifications in other less accessible tissues. 相似文献
192.
J Albani 《Archives of biochemistry and biophysics》1985,243(1):292-297
The binding of cytochrome c to the cytochrome b2 core, both extracted from the yeast, Hansenula anomala, has been studied. Cytochrome b2 core heme is extracted and replaced by the fluorescent probe, 2-p-toluidinylnaphthalene-6-sulfonate (TNS). A dissociation constant in the range of 85 microM is found for the TNS-apoprotein complex with a stoichiometry of 1:1. The interaction between the two proteins is followed by monitoring changes in the TNS fluorescence. We find the interaction between the cytochrome c and the apocytochrome b2 core to be dependent upon the ionic strength. The dissociation constant of this complex at 20 mM ionic strength is 6 +/- 2 microM with a 1:1 stoichiometry. This dissociation constant is similar to that estimated, by other researchers, for the dimer Zn cytochrome c-cytochrome b2 core complex. 相似文献
193.
194.
Fiorenzo Facchini 《Human Evolution》2006,21(1):51-57
Human behaviour, in addition to morphology, is essential to identify man. The characteristics of cultural behaviour are expressed by planning in tool making and territorial organization and by their meaning in the context of life. Cultural behaviour enriched the adaptive strategies of the human species and took on significance in the definition of the genus Homo since H. habilis/H. rudolfensis. Culture probably played a double role in the process of human speciation: (1) in isolation and differentiation from other groups of hominids that did not had such behaviour; and (2) in adaptation to the environment and in communication between groups that had the same cultural behaviour, thus slowing down or preventing the conditions of isolation that lead to new species. 相似文献
195.
Q-mode cluster analysis has been applied to a foraminiferal fauna from Pitt Water, N.S.W. (Australia), in order to define biotopes and their geographic extent. By successive elimination of the less commonly occurring species several biotope pattenrs have been obtained and mapped.These different sub-populations indicate that a large population has to be taken into consideration before cluster analysis can be successfully used.The biotopes determined show a meaningful relationship with the bottom topography and with the other environmental parameters. 相似文献
196.
J Albani 《Biophysical chemistry》1992,44(2):129-137
Dynamics studies on tryptophan residues of human alpha 1-acid glycoprotein (orosomucoid) and of 2-p-toluidinylnaphthalene-6-sulfonate bound to the protein are performed. Excitation at the red edge of the absorption spectrum of the tryptophan does not lead to a shift of the fluorescence emission maximum of the fluorophore. This reveals that Trp residues present motions with respect to their microenvironment. This is confirmed by polarization studies as a function of temperature. Excitation at the red edge of the absorption spectrum of TNS leads to an important shift (15 nm) of the fluorescence emission maximum of the probe. This reveals that emission of TNS occurs before relaxation of the amino-acids dipole occurs. Emission from a non-relaxed state means that TNS molecules are bound tightly to the protein, a result confirmed by polarization studies. 相似文献
197.
Fast aiming movements were measured in a choice reaction paradigm in a healthy control group and in Parkinsonian patients.
The patients were tested without (‘off ’) and with 3,4-dihydroxyphenylalanine (‘on’) (L-dopa) medication. The movement trajectories were used to estimate the parameters of a dynamic linear model. The model is
based on the functional structure of the basal ganglia-thalamocortical circuit with direct and indirect pathways linking the
putamen to the basal ganglia output nuclei (Albin et al. 1989). The output of the circuit is connected to a model for the
motor neuron-musculo-skeletal system. The gain k
d for the direct pathway and the gain k
i for the indirect pathway were estimated. They were found to be significantly decreased for Parkinsonian patients in ‘off ’
compared with the control group. L-dopa therapy in Parkinsonian patients increased the gains of the direct and the indirect pathway almost to normal values
which implies that the long-term dopamine level in the striatum was excitatory for the direct and for the indirect pathway.
This result is restricted to movements of correct size. For movements of diminished size, which are typical for Parkinsonian
patients, the model predicts that the dopamine level in the striatum is excitatory for the direct pathway but inhibitory for
the indirect pathway. The simulated values for neuronal activities are in agreement with expected values according to the
experimental data. The proposed model of the ‘motor’ basal ganglia thalamocortical circuit implies that information about
biomechanical properties of the musculo-skeletal system is stored in the ‘motor’ basal ganglia-thalamocortical circuit, and
that the basal ganglia are involved in computation of the desired movement amplitude.
Received: 24 April 1996/Accepted in revised form: 25 February 1997 相似文献
198.
A Conforti L M Albani A Modesti S Leopardi L Felici 《Virchows Archiv. B, Cell pathology including molecular pathology》1978,28(4):301-308
Human lymphocytes were separated by centrifugation and grown for 48--72 h in TC 199 medium. Synchronous cells, obtained by the addition of colchicine, were treated with arabinosylcytosine (Ara-C), an antimitotic substance which is known to produce nuclear changes in vivo and in vitro. In this case, alterations in the nuclear envelope closely resembling the malignancy associated changes described in human leukaemic cells were observed. The results allow us to suggest that such alterations may be due to a cellular derangement involving the renewal of the nuclear envelope in th G1 phase of the mitotic cycle. 相似文献