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The mechanism of chromosome 14 inversion in a human T cell lymphoma 总被引:16,自引:0,他引:16
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E Songu-Mize R W Caldwell P G Baer 《Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)》1987,186(3):280-287
Studies of renal and other tissues suggest that chronic elevation or reduction of dietary potassium intake could affect vascular smooth muscle sodium pump (Na-pump) activity. To examine this possibility, the effects of 3 weeks of low (LK: 4 mmole KCl/kg chow), normal (NK; 162 mmole/kg), and high (HK; 1350 mmole/kg) dietary potassium intake on Na-pump activity, the Na-pump activity response to changes in extracellular potassium concentration, and Na-pump site density were determined in tail arteries of rats. Plasma potassium concentration was elevated by 21% in HK rats and reduced by 45% in LK rats. When incubated in autologous plasma, compared to arteries from NK rats, Na-pump activity was decreased in the tail arteries from LK rats but not altered in those from HK rats. When arteries from NK and LK rats were incubated in autologous plasma with the potassium concentration increased to equal that of the HK rats, Na-pump activity exceeded that of HK rat arteries: Na-pump activity of arteries incubated in autologous plasma did not differ from that of arteries incubated in Krebs-Henseleit buffer with the potassium concentration adjusted to equal that of the plasma. Tail artery Na-pump activity for all three dietary potassium groups increased as potassium concentration of the incubation medium was increased from 1 to 12 mM; Na-pump activity was similar for the NK and LK rats at all potassium concentrations, but Na-pump activity of HK rat arteries was less than that of NK arteries at high extracellular potassium concentrations. Na-pump site density was not altered by either HK or LK diet. It is concluded that in tail arteries of rats fed the LK diet, chronically decreased extracellular potassium results in chronically decreased Na-pump activity. In contrast, an adaptive change occurs in tail arteries of rats fed HK diet, such that Na-pump activity remains at normal levels despite elevated extracellular potassium; this adaptive response to chronically increased dietary potassium does not appear to be the result of decreased Na-pump site density. 相似文献
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J Hadidian S R Jenkins D H Johnston P J Savarie V F Nettles D Manski G M Baer 《Journal of wildlife diseases》1989,25(1):1-9
In summer 1986, a study was conducted to evaluate raccoon (Procyon lotor) acceptance of oral baits that could be used for rabies vaccination. One thousand wax-coated sponge bait cubes were filled with 5 mg of a seromarker (iophenoxic acid), placed in polyethylene bags, and hand-distributed in an 80 ha area within an urban National Park in Washington, D. C. (USA). After 3 wk, target and nontarget animals were trapped and blood samples collected to evaluate bait uptake. Thirty-three of 52 (63%) raccoons had elevated blood iodine levels indicating they had eaten at least one bait, 13 (25%) were negative, and six (12%) had marginal values. These results indicate that sponge baits hand-placed at a density of 12.4/ha can reach a significant proportion of an urban raccoon population. Implications for oral rabies vaccination of raccoons are discussed. 相似文献
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R Fathi-Afshar T M Allen C A Krueger D A Cook A S Clanachan R Vriend H P Baer C E Cass 《Canadian journal of physiology and pharmacology》1989,67(4):276-281
Agelasimine A and agelasimine B, two novel compounds related to adenine, have been isolated from the orange sponge, Agelas mauritiana, and have been tested for a variety of biological activities. Both compounds inhibited proliferation of cultured L1210 leukemia cells at nanomolar concentrations with accumulation in the G1 stage of the cell cycle. However, no prolongation of life was observed in mice bearing P388 leukemia treated with these compounds. In the rat isolated aorta, micromolar concentrations of agelasimines were very effective in inhibiting contractions elicited by potassium chloride but had little or no effect on responses for prostaglandin F2 alpha and had modest effects on the responses to noradrenaline and significant effects on 5-hydroxytryptamine. Agelsamines A and B appeared to be equipotent in causing relaxation in rabbit jejunum and bovine coronary artery, and they also inhibited nucleoside transport into rabbit erythrocytes in micromolar concentrations. 相似文献
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Industrial yeast strain improvement: construction of strains having the killer character and capable of utilizing starch 总被引:1,自引:0,他引:1
Adela Bortol Clara Nudel Ana M. Giulietti J. F. T. Spencer D. M. Spencer 《Applied microbiology and biotechnology》1988,28(6):577-579
Summary A hybrid of Saccharomyces cerevisiae with the ability to utilize starch and to produce the killer toxin was constructed by the protoplast fusion technique. The hybrid was obtained in two steps. In the first, a wild killer strain was fused with a laboratory strain (S. cerevisiae STA2). A fusion product which carried the killer factor and the ability to grow on starch was selected. In the second step, this hybrid was fused with a baker's yeast. 相似文献
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Farkas G. A.; Baer R. E.; Estenne M.; De Troyer A. 《Journal of applied physiology》1988,64(3):1060-1067
To examine the mechanical effects of the abdominal and triangularis sterni expiratory recruitment that occurs when anesthetized dogs are tilted head up, we measured both before and after cervical vagotomy the end-expiratory length of the costal and crural diaphragmatic segments and the end-expiratory lung volume (FRC) in eight spontaneously breathing animals during postural changes from supine (0 degree) to 80 degrees head up. Tilting the animals from 0 degree to 80 degrees head up in both conditions was associated with a gradual decrease in end-expiratory costal and crural diaphragmatic length and with a progressive increase in FRC. All these changes, however, were considerably larger (P less than 0.005 or less) postvagotomy when the expiratory muscles were no longer recruited with tilting. Alterations in the elastic properties of the lung could not account for the effects of vagotomy on the postural changes. We conclude therefore that 1) by contracting during expiration, the canine expiratory muscles minimize the shortening of the diaphragm and the increase in FRC that the action of gravity would otherwise introduce, and 2) the end-expiratory diaphragmatic length and FRC in upright dogs are thus actively determined. The present data also indicate that by relaxing at end expiration, the expiratory muscles make a substantial contribution to tidal volume in upright dogs; in the 80 degrees head-up posture, this contribution would amount to approximately 60% of tidal volume. 相似文献
10.
M Fekadu J H Shaddock J W Sumner D W Sanderlin J C Knight J J Esposito G M Baer 《Journal of wildlife diseases》1991,27(4):681-684
Twenty nine skunks (Mephitis mephitis) were vaccinated orally with raccoon poxvirus (RCN) recombinants: 10 with a recombinant expressing the rabies virus glycoprotein (RCNRG), 10 with RCNRG mixed with a recombinant expressing the rabies virus nucleoprotein (RCNRN) and nine with RCN alone. Rabies virus neutralizing antibodies were detected in six of the 20 skunks; five skunks (three given RCNRG, two given a mixture of recombinants) survived a rabies challenge that was lethal for nine skunks vaccinated with RCN alone. 相似文献