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101.
The effect of stress factors (small doses of radiation and maximum temperatures in the econiche of the tested plants (tmax)) as well as aging on pea seeds, both acting independently and in combination, is estimated. Here we evaluate the influence of oxidizing stress on pea seeds in the laboratory (gamma-irradiated with 7 cGy at 0.3-19.1 cGy/h, tmax approximately 30-32 degrees C) and on natural plantain seeds collected in a 30-km zone of NPP (radiation exposure approximately 15 R/h, tmax approximately 38-40 degrees C). We have mathematically modeled CAs frequencies in root seedlings meristeme by invoking an enhancing factor transmitted from cell to cell. It is shown under the stress conditions: 1) CA frequency decreases whereas the fraction of inviable seeds (IS) increases, the dependence of IS on CA frequency being inversed; 2) a stimulation of proliferation of cell was observed; 3) a bystander effect appears; 4) antioxidative status (AOS) of seeds influences on adaptation on the all levels of the organization; 5) IS increases up to 73-80% under the combined effect of radiation and heat stresses.  相似文献   
102.
Cationic derivatives of deoxycholic acid with N,N-dimethylenediamine, -aminocaproic acid, and pyridine as polar heads were synthesized. The cationic groups were linked to 3- and 12-hydroxy groups of the steroid moiety through ester or urethane bonds. Liposomal formulations of the compounds synthesized may be used for gene delivery in cells.  相似文献   
103.
The effects of the selective delta-1 (delta(1)) opioid receptor agonist, DPDPE, and the selective delta(2) opioid receptor agonist, DSLET, have been studied on the ventricular fibrillation threshold (VFT) in rats with an experimental post-infarction cardiosclerosis (CS). It has been found that CS induced a significant decrease in VFT. This CS-induced decrease in VFT was significantly reversed by intravenous administration of DPDPE (0.1 mg/kg) 10 min before VFT measurement. On the contrary, intravenous injection of DSLET (0.5 mg/kg) exacerbated the CS-induced cardiac electrical instability. Pretreatment with the selective delta opioid receptor antagonist, ICI 174,864 (0.5 mg/kg), completely abolished the changes in VFT produced by both DPDPE and DSLET. Previous administration of a nonselective peripherally acting opioid receptor antagonist, naloxone methiodide (5 mg/kg) also completely reversed the antifibrillatory action of DPDPE. Naloxone methiodide and ICI 174,864 alone had no effect on VFT. Pretreatment with the nonselective K(ATP) channel blocker, glibenclamide (0.3 mg/kg), or with the mitochondrial selective K(ATP) channel blocker, 5-hydroxydecanoic acid (5-HD, 5 mg/kg), completely abolished the DPDPE-induced increase in cardiac electrical stability. Glibenclamide and 5-HD alone had no effect on VFT. These results demonstrate that the delta opioid receptor plays an important role in the regulation of electrical stability in rats with post-infarction cardiosclerosis. We propose that peripheral delta(1) opioid receptor stimulation reverses CS-induced electrical instability via mitochondrial K(ATP) channels. On the contrary, delta(2) opioid receptor stimulation may exacerbate the CS-induced decrease in VFT. Further studies are necessary to determine the delta opioid receptor subtype which mediates the antifibrillatory effect of DPDPE and pro-fibrillatory effect of DSLET.  相似文献   
104.
It has been found that intravenous administration of nociceptin (0.4 mg/kg) prevents development of aconitine-induced arrhythmias but has no effect on the incidence of occlusion, reperfusion, CaCl2-induced arrhythmias, and exacerbates epinephrine-evoked dysrhythmias. Pretreatment with hexamethonium, atropine, guanethidine and naloxone did not abolish the arrhythmic effect of nociceptin. Intracerebroventricular infusion of orphanin FQ was shown to increase cardiac tolerance of arrhythmogenic influence of aconitine, but this effect is completely abolished by hexamethonium administration. It has been suggested that stimulation of both central and peripheral ORL1 receptors increases cardiac resistance against arrhythmogenic effect of aconitine via different mechanisms.  相似文献   
105.
The results of the determination of radionuclide and chemical (multielement analysis) soil pollution are presented. The data on antioxidant status of plantain (Plantago major L.) in conjunction with the data on radionuclide and chemical pollution are analyzed. The most significant decrease in antioxidant activity of plant seeds was observed in areas situated along the most frequent wind direction in the region in summer 1998. It is suggested that lower antioxidant status is caused by the chronic radionuclide release on the chemically polluted territories.  相似文献   
106.
Apoptosis - In the last 10 years, mortality from acute myocardial infarction (AMI) has not significantly decreased. This situation is associated with the absence in clinical practice of...  相似文献   
107.
108.
A hypothesis of ambivalent foraging is proposed based on ideas about dual treating of the prey by a consumer: the food value attracts while the danger repulses. The foraging strategy of the great tit was investigated experimentally with the use of artificial “food patches” with variable amounts of dangerous prey (live red wood ants) and non-dangerous prey (fly larvae). With non-dangerous prey, the behavior of the birds corresponded to the known marginal value theorem: they proceeded with foraging until the resources were exhausted. We found the threshold amount of dangerous prey that prevents tits from hunting.  相似文献   
109.
The review describes a new method of therapeutic drug monitoring (TDM) based on direct infusion of low-molecular fraction of blood into an electrospray ionization source of mass spectrometer. This technique allows performing TDM of almost all drugs used in clinical practice. Universality and a high-throughput mode of the method significantly simplify wide application of this method. Moreover, the possibility of method application in most cases of drug therapy has been argued as a tool for control of drug doses, rationality of drug therapy, and quality of drugs used. In conclusion, prospects for application of the method as primary means of improving the quality and personalization of drug therapy have been discussed.  相似文献   
110.
The sorts of great minds capable of major scientific breakthroughs often come with oversized and confrontational personalities. Both Ivan Pavlov and Vladimir Bekhterev had such personalities. What started as reasoned contention between two talented scholars grew into a heated rivalry that boiled over into science and public life as outright enmity. Using memoirs of their contemporaries, this article examines Pavlov's and Bekhterev's personal and scientific relationships against the backdrop of Russian science of their day. Pavlov's possible role in the decision not to grant the 1912 Nobel Prize for science is also described.  相似文献   
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