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101.
A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation 11p;16q is described. Clinical findings are compared with similar case reports from the literature. 相似文献
102.
Ricardo A. Margni 《Glycoconjugate journal》1984,1(1):59-66
IgG asymmetric antibodies are synthesized by the same cellular clones as the symmetric ones but appear in the immune response in different proportions. The evidence suggests that they are caused by asymmetric glycosylation on some IgG molecules in the Fab region. The cause of this is unknown but it could be speculated that there are cellular factors that induce glycosyl transferases or cause the molecule to be more accessible to glycosylation. The production of asymmetric antibodies can be modified by the physical status (soluble or particulate) of the antigen used as immunogen by the number and frequency of stimulation, and by physiological factors such as the ones secreted by the placenta and by lymphocytes that express progesterone receptors in response to hormone. An increase of these antibodies can be beneficial or harmful to the host, depending on the situation in which they act and the character of self or non-self of the antigens recognized.
Editors note—Many of the ideas proposed in this article are very speculative, but it was thought appropriate to publish it in order to stimulate further discussion of the subject. It is an interesting role for Fab glycosylation that is proposed by Professor Margni. The ideas discussed are not necessarily those held by the Editorial Board or the reviewers, who felt that the evidence for many of the deductions made was very limited. It was also emphasized by the reviewers that the author's case would be substantially improved if more corroborative evidence was available from other groups. The Editors would welcome any comments on the subject for publication in future issues of the journal. 相似文献
103.
Ricardo A. Godoy 《Human ecology: an interdisciplinary journal》1984,12(4):359-383
Andean cultural ecologists have made two claims in recent years: ecological decomposition is absent due to effective indigenous management of communal resources, and agricultural intensification is inversely related to altitude. Drawing on material from the Jukumani Indians of Northern Potosi, Bolivia, these assertions are challenged. First, there is little evidence to prove or disprove ecological degradation. Second, the location of agricultural intensification, as the Jukumani data suggests, is influenced by altitude as well as by the presence of market.Fieldwork in Bolivia was carried out between January 1979 and May 1981. This essay was originally presented at a conference entitled, How Communities Resolve Common Property Problems, sponsored by the Harvard Institute for International Development and the Center for Population Studies of Harvard University in the spring semester of 1983. 相似文献
104.
The long-acting opiate antagonist naltrexone hydrochloride was administered by intraperitoneal injection, in a dose response protocol, to adult rats. The drug was used to observe effects of opiate receptor blockade on cells of the pituitary gland and adjacent hypothalamus. At higher drug doses (5mg/kg or 10mg/kg), neurites directly innervating pars intermedia cells contained swollen vesicles and disrupted membranous elements. Fibers within the median eminence of the hypothalamus appeared swollen, and contained myelin figures. Despite the consistent degenerative changes appearing in neurites, measurements of levels of dopamine, norepinephrine, and epinephrine in striatum, and hypothalamus did not differ significantly between naltrexone-treated or control animals, although there was a significant elevation of norepinephrine in the pituitary after drug treatment. At all drug dose levels administered, supraependymal neuron-like cells appeared atop the ependyma of the third ventricle above the median eminence. These observations suggest that naltrexone produces specific neurotoxic effects on neurites of the tuberoinfundibular system, and may induce changes in the ventricular environment which stimulate the appearance of supraependymal neurons. 相似文献
105.
Fuensanta Reyes M.I. Perez-Leblic M.J. Martinez R. Lahoz 《FEMS microbiology letters》1984,24(2-3):281-283
Abstract Production of protoplasts in different genera of filamentous fungi with their own lytic enzymes obtained from autolyzed cultures, as well as the regeneration of these protoplasts, has been studied. The results support the idea that the use of these autolytic enzymes could be a general method of production of protoplasts from filamentous fungi. 相似文献
106.
107.
The lipid composition of muscle cells during development 总被引:3,自引:0,他引:3
Developmental changes in the phospholipid, cholesterol, and fatty acid composition of chicken pectoralis muscle cells were analyzed during development in vivo and in tissue culture. The phospholipid composition of muscle cells showed only minor changes during in vivo or in vitro development but there were significant alterations in fatty acid composition. During in vivo development between the 12th and 22nd days the concentration of palmitate and arachidonate decreased with increase in linoleate. In cultured muscle cells the fatty acid composition changes with surprising plasticity depending on the fatty acid supply. Compensatory changes were observed in the chain length and unsaturation of several fatty acids, aimed presumably at maintaining the physical properties of the lipid phase relatively constant. 相似文献
108.
109.
Summary Male and female siblings demonstrated similar facial features and had seizures from birth. Neurologic development, which was delayed, began to deteriorate at 1 year. Sudden death occurred at 2 8/12 and 2 3/12 years of age associated with respiratory infections. Tanning of the skin was noted 2 months before death in the first child. In the second child, blood cortisol levels failed to increase after intravenous ACTH administration, and computerized axial tomography (CAT) scans were normal.At autopsy both patients demonstrated adrenal atrophy and degenerative changes of the white matter throughout the neuraxis. We propose that these siblings have a new form of adrenoleukodystrophy that can be distinguished from the X-linked form by onset at birth, clinical appearance, and pattern of inheritance.A comparison of these cases with a second disorder, Zellweger's syndrome, suggests that a distinctive phenotype is associated with intrauterine degeneration of white matter. 相似文献
110.
Changes in the activity of -N-acetylglucosaminidase, chitinase, invertase, esterases, glucanases and phosphatases liberated into the culture fluid were followed during the autolytic phase of growth of Aspergillus niger on media with various initial levels of the carbon source. The general pattern was of an accumulation of these lytic enzymes in the culture fluid during autolysis, but some enzymes reached maximum activity and then declined. The initial level of the carbon source affected the enzyme pattern during autolysis. Maximum activity for the various enzymes was always observed either for the lowest initial level of carbon or the highest (3.5 mM glucose, 111 mM glucose). The highest specific activities were those for exopolygalacturonidase (500 mU/mg at 3.45 mM glucose), and for -amylase (about 500 mU/mg at 3.45 mM glucose). Cellulase, chitinase and esterase showed the weakest activity. Acid phosphatase was most active (about 200 mU/mg) at 3.45 mM initial glucose, whereas alkaline phosphatase was most active (45 mU/mg) at 111 mM glucose, both during the autolytic phase of growth. 相似文献