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61.
Cellular immune competence of spleen bursa and thymus cells 总被引:1,自引:0,他引:1
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X. J. Musacchia M. Jellinek Th. Cooper 《Cellular and molecular life sciences : CMLS》1963,19(8):418-419
Zusammenfassung 20 h nach Bestrahlung mit letaler Röntgenstrahlendosis (2000 r) zeigten winterschlafendeCitellus tridecemlineatus Herabsetzung der Konzentration von Catecholaminen in Leber und Niere. Werden Veränderungen des Wassergehaltes im Gewebe mitberücksichtigt, so erscheint der Gehalt an myokardialen Catecholaminen unverändert.
Acknowledgments. This research was aided by Grants HE-06312, USPHS; and Ns G-271-62, NASA. The authors are grateful to DoctorD. E. Smith, Division of Biological and Medical Research, Argonne National Laboratory, for providing the ground squirrels and the facilities for their hibernation and radiation. 相似文献
Acknowledgments. This research was aided by Grants HE-06312, USPHS; and Ns G-271-62, NASA. The authors are grateful to DoctorD. E. Smith, Division of Biological and Medical Research, Argonne National Laboratory, for providing the ground squirrels and the facilities for their hibernation and radiation. 相似文献
65.
Patched acts catalytically to suppress the activity of Smoothened 总被引:22,自引:0,他引:22
Mutations affecting the transmembrane proteins Patched (Ptc) or Smoothened (Smo) that trigger ligand-independent activity of the Hedgehog (Hh) signalling pathway are associated with human tumours such as basal cell carcinoma (BCC) and medulloblastoma. Despite extensive genetic studies demonstrating the importance of these receptor components in embryonic patterning and cancer, the mechanism by which Ptc regulates Smo is not understood. Here we report that Ptc and Smo are not significantly associated within Hh-responsive cells. Furthermore, we show that free Ptc (unbound by Hh) acts sub-stoichiometrically to suppress Smo activity and thus is critical in specifying the level of pathway activity. Patched is a twelve-transmembrane protein with homology to bacterial proton-driven transmembrane molecular transporters; we demonstrate that the function of Ptc is impaired by alterations of residues that are conserved in and required for function of these bacterial transporters. These results suggest that the Ptc tumour suppressor functions normally as a transmembrane molecular transporter, which acts indirectly to inhibit Smo activity, possibly through changes in distribution or concentration of a small molecule. 相似文献
66.
Neanderthal DNA. Not just old but old and cold? 总被引:9,自引:0,他引:9
67.
Sahin E Colla S Liesa M Moslehi J Müller FL Guo M Cooper M Kotton D Fabian AJ Walkey C Maser RS Tonon G Foerster F Xiong R Wang YA Shukla SA Jaskelioff M Martin ES Heffernan TP Protopopov A Ivanova E Mahoney JE Kost-Alimova M Perry SR Bronson R Liao R Mulligan R Shirihai OS Chin L DePinho RA 《Nature》2011,470(7334):359-365
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Immunoglobulin heavy-chain switching in pre-B leukaemias 总被引:3,自引:0,他引:3
70.
S I Foundling J Cooper F E Watson A Cleasby L H Pearl B L Sibanda A Hemmings S P Wood T L Blundell M J Valler 《Nature》1987,327(6120):349-352
Inhibitors of the conversion of angiotensinogen to the vasoconstrictor angiotensin II have considerable value as antihypertensive agents. For example, captopril and enalapril are clinically useful as inhibitors of angiotensin-converting enzyme. This has encouraged intense activity in the development of inhibitors of kidney renin, which is a very specific aspartic proteinase catalysing the first and rate limiting step in the conversion of angiotensinogen to angiotensin II. The most effective inhibitors such as H-142 and L-363,564 have used non-hydrolysable analogues of the proposed transition state, and partial sequences of angiotensinogen (Table 1). H-142 is effective in lowering blood pressure in humans but has no significant effect on other aspartic proteinases such as pepsin in the human body (Table 1). At present there are no crystal structures available for human or mouse renins although three-dimensional models demonstrate close structural similarity to other spartic proteinases. We have therefore determined by X-ray analysis the three-dimensional structures of H-142 and L-363,564 complexed with the aspartic proteinase endothiapepsin, which binds these inhibitors with affinities not greatly different from those measured against human renin (Table 1). The structures of these complexes and of that between endothiapepsin and the general aspartic proteinase inhibitor, H-256 (Table 1) define the common hydrogen bonding schemes that allow subtle differences in side-chain orientations and in the positions of the transition state analogues with respect to the active-site aspartates. 相似文献