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661.
In order to know the characteristics of circadian rhythms in core temperature in tropical inhabitants, we measured rectal temperatures every 10 min for 50 h in 6 Vietnamese, 20-22 years old (5 males and 1 female) under natural conditions. Ambient temperatures ranged from 33 to 36°C. These data obtained in tropical inhabitants were compared with those in Polish inhabitants. The participants in both groups were usually sitting during wakefulness and lying in bed during sleep. The results obtained are summarized as follows: (1) The average maximum value was 37.7°C, which was significantly higher than in the Europeans; (2) The average minimum value was 36.2°C, which was lower; (3) A range of oscillation was 1.5°C, which was clearly greater than in the Europeans. The higher maximum value of core temperature, which was actively regulated under warm temperature, seemed of adaptive significance in order to reduce water consumption. A greater rage of oscillation in tropical Vietnamese people might have ecological significance for efficient acclimatization in the warm environment, suggesting that the setpoint of core temperature could show a greater range of oscillation. 相似文献
662.
Agnieszka Malinska Bartlomiej Perek Piotr Buczkowski Katarzyna Kowalska Danuta Ostalska-Nowicka Wojciech Witkiewicz Michal Nowicki 《Histochemistry and cell biology》2013,140(2):183-188
Atherosclerosis commonly affects the arteries harvested from patients 70 years of age or older. Saphenous vein grafts appear to maintain a higher patency rate after coronary artery bypass grafting in these subjects. The infiltration of macrophages is an early step in saphenous vein graft atherosclerosis; however, little is known regarding the underlying mechanisms of infiltration. The objective of the present report is to evaluate the presence of CD68-positive cells in the saphenous vein wall and correlate initial CD68-positive infiltration to specific clinical and biochemical parameters and the graft patency rate as estimated in patients undergoing coronary artery bypass grafting. A total of 309 patients were allocated into two groups: A1 patients, who were between 50 and 70 years of age, and A2 patients, who were 70 years or older at the time of vein harvesting. CD68 expression was evaluated by immunohistochemistry. There were no significant differences between A1 and A2 patients regarding macrophage expression within any of the analyzed vascular regions. Saphenous vein macrophages were never present in the tunica intima unless they were also expressed in the media or the adventitia. The patients with CD68-positive cells in the tunica intima had a significantly higher number of bypass stenoses when compared with the subjects who did not have CD68-positive cells in this layer. These findings suggest that the CD68-positive cells (those that have not yet developed into foam cells) present in the intima of saphenous vein grafts might serve as a very early marker of graft occlusion. 相似文献
663.
664.
Saponins as cytotoxic agents: a review 总被引:1,自引:0,他引:1
Saponins are natural glycosides which possess a wide range of pharmacological properties including cytotoxic activity. In
this review, the recent studies (2005–2009) concerning the cytotoxic activity of saponins have been summarized. The correlations
between the structure and the cytotoxicity of both steroid and triterpenoid saponins have been described as well as the most
common mechanisms of action. 相似文献
665.
Paul V. Bernhardt Gregory J. Wilson Philip C. Sharpe Danuta S. Kalinowski Des R. Richardson 《Journal of biological inorganic chemistry》2008,13(1):107-119
2-Pyridinecarbaldehyde isonicotinoyl hydrazone (HPCIH) and di-2-pyridylketone isonicotinoyl hydrazone (HPKIH) are two Fe chelators
with contrasting biological behavior. HPCIH is a well-tolerated Fe chelator with limited antiproliferative activity that has
potential applications in the treatment of Fe-overload disease. In contrast, the structurally related HPKIH ligand possesses
significant antiproliferative activity against cancer cells. The current work has focused on understanding the mechanisms
of the Fe mobilization and antiproliferative activity of these hydrazone chelators by synthesizing new analogs (based on 2-acetylpyridine
and 2-benzoylpyridine) that resemble both series and examining their Fe coordination and redox chemistry. The Fe mobilization
activity of these compounds is strongly dependent on the hydrophobicity and solution isomeric form of the hydrazone (E or Z). Also, the antiproliferative activity of the hydrazone ligands was shown to be influenced by the redox properties of the
Fe complexes. This indicated that toxic Fenton-derived free radicals are important for the antiproliferative activity for
some hydrazone chelators. In fact, we show that any substitution of the H atom present at the imine C atom of the parent HPCIH
analogs leads to an increase in antiproliferative efficacy owing to an increase in redox activity. These substituents may
deactivate the imine R–C=N–Fe (R is Me, Ph, pyridyl) bond relative to when a H atom is present at this position preventing
nucleophilic attack of hydroxide anion, leading to a reversible redox couple. This investigation describes novel structure–activity
relationships of aroylhydrazone chelators that will be useful in designing new ligands or fine-tuning the activity of others.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
666.
The growth of root, hypocotyl and cotyledons was measured in apple seedlings cultured for nine days from embryos isolated from seeds after various periods of after-ripening. Greening of the cotyledons was taken into account and the chlorophyll content determined as well. Embryonal dormancy results in anomalies already appearing in the early stage of development. They are manifested by differentiated greening and uneven growth of cotyledons, as well as by hypotrophy of root or hypocotyl. The frequency of those anomalies in the population decreases during the removal of dormancy, and therefore it may be accepted as the criterion of its depth. 相似文献
667.
Further genetic characteristics of methionine mutants and their suppressors in Aspergillus nidulans 总被引:1,自引:0,他引:1
Alexandra Putrament Joanna Guzewska Danuta Pieniazek 《Molecular & general genetics : MGG》1970,109(3):209-218
Summary At least eight methF55 suppressor loci have been identified (Tables 1-4). All suppressors tested were effective towards methA, methB and methG mutants, while some of them were effective also towards methD10, methH2 and probably methE53 mutants (Tables 5 and 6).In the progenies of non-leaky methionine mutants leaky segregants were found (Table 7).Double mutant strains carrying methE31 and methA34 or methF55 or methD10 mutants reverted with approximately the same frequencies as did strains carrying a single methE31 mutant (Table 8).The possible implications of these findings, together with the other data on methionine mutants and their suppressors in A. nidulans, are discussed. 相似文献
668.
Summary In this paper the literature data on the structure-activity relationship for the series of tuftsin analogs are summarized. Among others, the questions of the substitution of particular amino acid residues in different positions of the peptide chain, as well as the questions of shortening and lengthening of the peptide chain of tuftsin, are reviewed. The existing models of the biologically active conformation of tuftsin are also summarized. 相似文献
669.
670.