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排序方式: 共有702条查询结果,搜索用时 15 毫秒
1.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
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In this report, we show that in the human astroglioma cell line D54-MG, both interleukin-1 (IL-1β) and tumor necrosis factor-alpha (TNF-α) enhance C3 gene expression in a time- and dose-dependent manner. Kinetic analysis demonstrates that after 96 h, C3 mRNA levels increase approximately 30-fold and 20-fold in response to IL-1β or TNF-α, respectively. C3 protein production increases proportionally, reaching levels 36-fold and 18-fold higher than untreated controls upon exposure to IL-1β or TNF-α, respectively. D54-MG cells require a minimal 1 h exposure to IL-1β in order to enhance C3 gene expression significantly, while 4 to 8 h are required for TNF-α. Simultaneous treatment of D54-MG cells with IL-1β and interferon-gamma (IFN-γ) resulted in an additive increase in both C3 mRNA and protein expression, a finding not seen with the combination of TNF-α and IFN-γ. Primary rat astrocytes also express increased C3 mRNA levels after 48 h in response to IL-1β (5.3-fold increase) and TNF-α (7-fold increase), while an additive effect was observed upon simultaneous treatment with both IL-1β and IFN-γ. In the central nervous system (CNS), endogenous complement and cytokine production by astrocytes, and enhancement by IFN-γ, a product of activated T cells often seen in the CNS in neural autoimmune disease, may contribute to the pathogenesis of inflammatory demyelinating diseases such as multiple sclerosis. 相似文献
6.
Genotype-phenotype correlation for nucleotide substitutions in the IgII- IgIII linker of FGFR2 总被引:6,自引:3,他引:3
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Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献
9.
A study of the degree of progesterone support required for the maintenance
of various stages of pregnancy was undertaken in mice. Mated females were
ovariectomized at various stages of pregnancy and progesterone and
oestradiol support provided by s.c. Silastic implants with known release
characteristics. In the earliest stages of pregnancy (days 1-5), very low
concentrations of progesterone (<25% of normal physiological values)
were sufficient to maintain pre-implantation stages and allow implantation.
In the immediate post-implantation period (days 5-9), the development of
implantation sites and decidualization required considerably higher
progesterone support. In mid-pregnancy (days 11-14), progesterone alone
could not maintain pregnancy unless present in very high amounts; however,
the presence of oestradiol during this period lowered the progesterone
requirements to well within the physiological range. This effect of
oestradiol started on day 11 but required the level of oestradiol support
to be kept within strictly defined limits, with high concentrations
inducing abortion. Progesterone alone was able to maintain pregnancy from
day 15. These results indicate that the minimal progesterone support
required for pregnancy in mice varies considerably at different stages of
pregnancy and is at least partly modulated by oestradiol.
相似文献
10.
Renal filtration and catabolism of complement protein D 总被引:4,自引:0,他引:4
J E Volanakis S R Barnum M Giddens J H Galla 《The New England journal of medicine》1985,312(7):395-399
Complement protein D, a serine protease participating in the formation of the C3 convertase of the alternative complement pathway, has the lowest molecular weight (23,750) and serum concentration of all complement proteins. In normal serum, D is the rate-limiting protease of the alternative pathway of complement activation. We report that the serum concentrations of D in 20 patients with chronic renal failure (mean +/- S.D., 0.42 +/- 0.28 mg per deciliter) and in 16 patients on long-term dialysis (1.53 +/- 0.39 mg per deciliter) were significantly higher (P less than 0.001) than in 22 healthy adults (0.18 +/- 0.04 mg per deciliter). In chronic renal failure the serum concentration of D correlated with that of creatinine (r = 0.75, P less than 0.001). The serum concentrations of D found in patients with renal failure reached and in some cases exceeded those at which the protease is no longer rate-limiting. Thus, enhanced activity of the alternative pathway of complement should be expected in patients with advanced renal failure. Urinary D was undetectable (less than 0.2 micrograms per deciliter) in 17 normal adults and either undetectable or below the concentration expected from the degree of proteinuria in 10 patients with nephrotic syndrome. However, in a patient with Fanconi's syndrome the urinary concentration of D (1.3 mg per deciliter) was an order of magnitude higher than the serum concentration, representing 0.5 per cent of the total protein. The urinary D in this patient had normal hemolytic activity, antigenicity, and size. These results indicate that D is filtered through the glomerular membrane and is probably catabolized in the proximal renal tubules. 相似文献