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Patterns of Root Colonization in Epacridaceous Plants Collected from Different Sites 总被引:2,自引:0,他引:2
Root colonization was studied in ten species of the Epacridaceaeat three sites in Victoria by morphological and cross-inoculationexperiments. The sites and genera chosen were Cranbourne [Epacrisimpressa Labill. andLeucopogon ericoides(Smith) R. Br.] andRye [L. parviflorus(Andrews) Lindley] on the Mornington Peninsula,and the Grampians[Astroloma conostephioides(Sond.) Benth.,A.humifusum(Cav.) R. Br.,A pinifolium(R. Br.) Benth,Brachylomadaphnoides(Smith) Benth.,E. impressa, E. impressavar.grandifloraBenth.andStyphelia adscendensR. Br.] in western Victoria. For morphologicalstudies, samples of roots from each species at each site werecleared and stained and examined microscopically. For cross-inoculationstudies, cuttings from each site were struck in potting mediuminoculated with soil from the same and other sites. The ericoidmycorrhizae in the roots of plants found at or grown in Cranbourneand Rye soils were similar. Both were significantly differentfrom the internal hyphae found in the roots of plants foundat or grown in Grampians soils, which were three times largerin diameter and formed dense coils which filled the host celland invaded adjacent epidermal cells. This suggests that morethan one fungus is involved in the relationships, that the MorningtonPeninsula sites had a different fungus from the Grampians siteand that host specificity is low. Vesicular structures werealso found commonly on plants at the Grampians site, in contrastwith other sites. Epacridaceae; root; fungus; mycorrhiza; morphology; inoculation 相似文献
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Being able to carry zidovudine (AZT) at known concentrations into CD4+/CD38+ and CD14+ cells permits:
Further studies are necessary in order to:
相似文献
| - to reduce the drug dosage and to increase the interval for administration (until 1 dose I.V. every week); |
| - to modulate the drug concentration into the CD4+/CD38 an CD14+ cells in relation to the in vitro determined HIV sensitiveness; |
| - to eliminate haematological, medullary and general toxicity; |
| - to be able to treat severely hill patients. |
| - To find out the better phase to start the therapy; |
| - To use several drugs with different mechanisms of action in order to slow down as much as possible the presence of resistant viral strains. |
| - As for other drugs which are beginning to be used with artificial vehicles, futher studies are required to improve the selectivity and safety of LIPOAZT for the target cells including macrophages. |
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Piro MC Militello V Leone M Gryczynski Z Smith SV Brinigar WS Cupane A Friedman FK Fronticelli C 《Biochemistry》2001,40(39):11841-11850
The protein folding process of heme proteins entails generation of not only a correct global polypeptide structure, but also a correct, functionally competent heme environment. We employed a variety of spectroscopic approaches to probe the structure and dynamics of the heme pocket of a recombinant sperm whale myoglobin. The conformational characteristics were examined by circular dichroism, time-resolved fluorescence spectroscopy, FTIR spectroscopy, and optical absorption spectroscopy in the temperature range 300-20 K. Each of these spectroscopic probes detected modifications confined exclusively to the heme pocket of the expressed myoglobin relative to the native protein. The functional properties were examined by measuring the kinetics of CO binding after flash-photolysis. The kinetics of the expressed myoglobin were more heterogeneous than those of the native protein. Mild acid exposure of the ferric derivative of the recombinant protein resulted in a protein with "nativelike" spectroscopic properties and homogeneous CO binding kinetics. The heme pocket modifications observed in this recombinant myoglobin do not derive from inverted heme. In contrast, when native apomyoglobin is reconstituted with the heme in vitro, the heme pocket disorder could be attributed exclusively to 180 degrees rotation of the bound heme [La Mar, G. N., Toi, H., and Krishnamoorthi, R. (1984) J. Am. Chem. Soc. 106, 6395-6401; Light, W. R., Rohlfs, R. J., Palmer, G., and Olson, J. S. (1987) J. Biol. Chem. 262, 46-52]. We conclude that exposure to low pH decreases the affinity of globin for the heme and allows an extended conformational sampling or "soft refolding" to a nativelike conformation. 相似文献
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Federica Sinibaldi Barry D. Howes Maria Cristina Piro Fabio Polticelli Cecilia Bombelli Tommaso Ferri Massimo Coletta Giulietta Smulevich Roberto Santucci 《Journal of biological inorganic chemistry》2010,15(5):689-700
Two models have been proposed to explain the interaction of cytochrome c with cardiolipin (CL) vesicles. In one case, an acyl chain of the phospholipid accommodates into a hydrophobic channel of
the protein located close the Asn52 residue, whereas the alternative model considers the insertion of the acyl chain in the
region of the Met80-containing loop. In an attempt to clarify which proposal offers a more appropriate explanation of cytochrome
c–CL binding, we have undertaken a spectroscopic and kinetic study of the wild type and the Asn52Ile mutant of iso-1-cytochrome
c from yeast to investigate the interaction of cytochrome c with CL vesicles, considered here a model for the CL-containing mitochondrial membrane. Replacement of Asn52, an invariant
residue located in a small helix segment of the protein, may provide data useful to gain novel information on which region
of cytochrome c is involved in the binding reaction with CL vesicles. In agreement with our recent results revealing that two distinct transitions
take place in the cytochrome c–CL binding reaction, data obtained here support a model in which two (instead of one, as considered so far) adjacent acyl
chains of the liposome are inserted, one at each of the hydrophobic sites, into the same cytochrome c molecule to form the cytochrome c–CL complex. 相似文献
10.
Andréia S Lessa Bruno D Paredes Juliana V Dias Adriana B Carvalho Luiz Fernando Quintanilha Christina M Takiya Bernardo R Tura Guilherme FM Rezende Antonio C Campos de Carvalho Célia MC Resende Regina CS Goldenberg 《BMC veterinary research》2010,6(1):1-10