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After intravenous administration of alloxan (50 mg kg-1 liveweight) to lactating ewes, there were triphasic changes in plasma glucose and insulin. Almost immediately, plasma insulin decreased and hyperglycaemia occurred, then, between c. 5-12 h, insulin increased and ewes became hypoglycaemic. Thereafter, insulin decreased and glucose increased from c. 20 h after alloxan and the diabetic state was established. Changes in glucose production and utilization correlated with changes in plasma glucose. Exogenous insulin was administered from 30 h after alloxan, and it took some 2 weeks to stabilize ewes. During this period, when mild hyperglycaemia persisted, milk yields and feed intakes were decreased but milk fat content was elevated. Once ewes were stabilized, plasma glucose, milk yield, feed intake and milk fat content returned to levels prior to alloxan. These observations are consistent with insulin playing a role in the aetiology of the 'low milk fat syndrome' in the ruminant. It appears that the alloxan-treated, insulin-stabilized ewe would be a useful model for studying the role of insulin during lactation, but it is necessary to allow time for animals to overcome effects of administration of alloxan. 相似文献
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Summary This is an ultrastructural study of development of infected cells in nitrogen fixing root nodules ofCasuarina spp. While several aspects of development are similar to those found in many other actinorhizae, unusual aspects of development of the host cell and differentiation of the endophyte inCasuarina are correlated with unusual changes in the wall of the infected cell. Instead of vesicles the endophyte forms atypical hyphae in mature infected cells. These unusual hyphal forms are termed intracellular hyphae. Intracellular hyphae are nonseptate hyphae which originate and terminate within the same host cell, and have a varying diameter and a multidirectional growth and branching pattern. A laminate surface layer previously undescribed on hyphae ofFrankia is a feature common to mostCasuarina endophytic hyphae and is probably similar chemically to the laminae comprising the multilamellate envelope of endophytic vesicles in other actinorhizae.This paper is Florida Agricultural Experiment Station Journal Series No. 7350. 相似文献
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I McDowell 《CMAJ》1987,137(12):1095-1100
The symptoms that a patient presents to the doctor are often not the underlying concern that prompted the consultation. The success of consultations involving a hidden diagnosis depends on how well the patient can express his or her concerns to the doctor and on how skilfully the doctor can encourage this. This study tested the feasibility and acceptability of having patients complete a brief health index questionnaire designed to help them describe their underlying concerns to the doctor. In two family medicine centres 996 patients were asked to complete a questionnaire while waiting to see the doctor; 724 (73%) did so. An evaluation of their responses showed the method to be acceptable to most. The doctors judged that it added valuable information in 41% of all consultations and in 73% of consultations in which the patient presented with psychologic complaints. There was, nevertheless, considerable variation among the physicians in their acceptance of the approach. This variability is discussed in the light of alternative models of how, in practical terms, to treat the psychosocial dimensions of a patient''s complaint. 相似文献
7.
Rod cell outer segments were found to contain a protein phosphatase activity toward phosphoopsin with properties very similar to those of protein phosphatase 1 or 2A. The opsin phosphatase activity was stable to ethanol precipitation, had a Mr of 35,000-38,000 as determined by gel filtration, and was not dependent on divalent cations for activity. The chromatographic properties on DEAE-cellulose of the rod outer segment protein phosphatase were also similar to those reported for protein phosphatase 1 or 2A. In order to distinguish between these two protein phosphatases, we tested homogeneous preparations of protein phosphatases 1 and 2A from skeletal muscle for activity toward phosphoopsin. Protein phosphatase 2A dephosphorylated phosphoopsin at approximately 10% of its rate toward phosphorylase a, whereas protein phosphatase 1 had no activity toward phosphoopsin. We conclude that protein phosphatase 2A is present in the rod cell outer segment and that it is a likely candidate to perform the in vivo dephosphorylation of rhodopsin in the visual cycle. 相似文献
8.
Isabel Walls J. J. Sheridean R. W. Welch D. A. McDowell 《Letters in applied microbiology》1990,10(1):23-26
A new method of separating bacteria from beef mince has been developed, in which an alkaline protease, Alcalase 0.6 L, was used to degrade the meat proteins, leaving micro-organisms in suspension. The organisms were then counted, using a membrane filtration-epifluorescent microscopy technique. A correlation coefficient of 0.97 was obtained between this method and the standard plate count, indicating its suitability for use in quality control. 相似文献
9.
Inhibition of glycoprotein oligosaccharide processing in vitro and in influenza-virus-infected cells by alpha-D-mannopyranosylmethyl-p-nitrophenyltriazene. 下载免费PDF全文
W McDowell A Tlusty R Rott J N BeMiller J A Bohn R W Meyers R T Schwarz 《The Biochemical journal》1988,255(3):991-998
The effects of alpha-D-mannopyranosylmethyl-p-nitrophenyltriazene (MMNT) on mannosidases involved in asparagine-linked oligosaccharide processing were investigated. MMNT was found to inhibit the activity of rat liver Golgi alpha-mannosidase I in a concentration-dependent manner (50% inhibition with 0.18 mM-MMNT), whereas rat liver endoplasmic-reticulum alpha-mannosidase appeared to be resistant (less than 5% inhibition at 1 mM-MMNT). Jack-bean alpha-mannosidase was also sensitive to inhibition by MMNT (50% inhibition with 0.32 mM-MMNT). Treatment of influenza-virus-infected chick-embryo cells with 1 mM-MMNT led to a decrease in the formation of complex-type asparagine-linked oligosaccharides and an accumulation of high-mannose-type oligosaccharides with the composition Man8(GlcNAc)2 and Man7(GlcNAc)2 on the viral glycoproteins. The biological activities of influenza-virus haemagglutinin and neuraminidase synthesized in the presence of 1 mM-MMNT remained unchanged, but the virus was less infectious than the control. 相似文献
10.
Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta
C2), at birth and produce this hemoglobin exclusively during severe anemia.
Sheep that synthesize this juvenile hemoglobin are of the A haplotype.
Other sheep, belonging to a separate group, the B haplotype, do not
synthesize hemoglobin C and during anemia continue to produce their adult
hemoglobin. To understand the basis for this difference we have determined
the structural organization of the beta- globin locus of B-type sheep by
constructing and isolating overlapping genomic clones. These clones have
allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta
I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype.
Thus, B sheep lack four genes, including the BC gene, and have only eight
genes, compared with the 12 found in the goat globin locus. The goat
beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta
C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta
Y-beta F3'. Southern blot analysis of A-type sheep reveals that these
animals have a beta- globin locus similar to that of goat, i.e., 12 globin
genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of
cows and may have retained the duplicated locus of the ancestor of cows and
sheep. Alternatively, the B-sheep locus arrangement may be the result of a
deletion of a four-gene set from the triplicated locus.
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