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651.
Intracellular heat shock protein (Hsp) 27 is a potent anti-apoptotic factor that, among other activities, prevents the binding of membrane receptor Fas to its ligand FasL. However, the potential role of extracellular Hsp27 and possibilities to control it have not been clarified. Moreover, there are no data on relations between Hsp27, sFas/sFasL system, matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in patients with chronic kidney disease (CKD)—neither children nor adults. The aim of this study was to evaluate serum concentrations of Hsp27 and their potential regulators (sFas, sFasL, MMP-7, TIMP-1) in children with CKD and on chronic dialysis. Twenty-six CKD children stage 5 still on conservative treatment, 19 patients on hemodialysis (HD), 22 children on automated peritoneal dialysis (APD), and 30 controls were examined. Serum concentrations of Hsp27, sFas, sFasL, MMP-7, and TIMP-1 were assessed by ELISA. Median values of Hsp27 were significantly elevated in all dialyzed patients vs. those in pre-dialysis period and vs. controls, the highest values being observed in subjects on HD. Regression analysis revealed that MMP-7, TIMP-1, sFas, and sFasL were the best predictors of Hsp27 concentrations in dialyzed patients. Children with CKD are prone to Hsp27 dysfunction, aggravated by the dialysis commencement, and more pronounced in patients on hemodialysis. Correlations between Hsp27 and examined parameters suggest the potential role for Hsp27 as a marker of cell damage in the pediatric population on chronic dialysis. 相似文献
652.
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
653.
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
654.
655.
The concentration of airborne Didymella spores has been investigated at two monitoring sites situated along the west–south transect in Poland (Szczecin, Kraków),
i.e. from a height of 100 to 219 m, respectively, above sea level. The aerobiological monitoring of fungal spores was performed
by means of two Lanzoni volumetric spore traps. The high Didymella spore numbers were observed at both cities in June, July and August. Statistically significant correlations have been found
mainly between the Didymella spore concentrations in the air and the minimum air temperature and relative air humidity. The spore count of Didymella is determined by the diversity of local flora and weather conditions, especially by the relative air humidity. The identification
of factors that influence and shape spore concentrations may significantly improve the current methods of allergy prevention. 相似文献
656.
657.
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
658.
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
659.
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
660.