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491.
The affinities and endemism of Kashmir HimalayaRanunculaceae andPaeoniceae reveal some interesting distribution patterns in some taxa. Isoflor maps, revealing the affinities ofAconitum, Aquilegia, Delphinium andRanunculus, are given. A high degree of endemism exists in the study area. About 41% of the total taxa show restricted distribution which is discussed. The floristic relationships of the wides show close links with Central Asia than any other phytogeographical unit. The significance of altitudinal amplitude of some taxa vis-a-vis their distribution pattern is discussed. 相似文献
492.
Cultures of osteoblastlike cells obtained from the endosteal surfaces of rabbit long bones formed and mineralized an extracellular matrix when they were supplied daily with medium containing fresh ascorbate. No matrix formed without this supplementation. The matrix mineralized whether or not beta-glycerophosphate, a substrate of alkaline phosphatase, was added to the medium. The ion-transporting ATPase activities of untreated, ascorbate-treated, and ascorbate plus beta-glycerophosphate-treated cells were measured. Ascorbate-treated and ascorbate plus beta-glycerophosphate-treated cells had similar enzyme activities. The activities of the Ca2+-ATPase; Ca2+,Mg2+-ATPase; and alkaline phosphatase in treated cells were elevated over the activities in untreated cells. Na+,K+-ATPase activity was lower in treated than in untreated cells. HCO3--ATPase activity was not changed by treatment. Alkaline phosphatase activity was 20 times higher in freshly isolated osteoblastlike cells than in cells grown to confluence in primary culture. In addition, subculturing further reduced the activity of this osteoblast-marker enzyme. The activities of the ion-transporting ATPases and alkaline phosphatase in second passage cells were similar to the activities of these enzymes in fresh, noncalcifying tissues. Nevertheless, second passage cells retain the ability to mineralize an extracellular matrix, and their ion-transporting ATPase and alkaline phosphatase activities are altered when the cells mineralize a matrix. 相似文献
493.
494.
Background
This meta-analytic study explored the relationship between the risk of type 2 diabetes mellitus (T2DM) and bisphenol A concentrations.Methods
The Embase and Medline (PubMed) databases were searched, using relevant keywords, for studies published between 1980 and 2018. A total of 16 studies, twelve cross-sectional, two case-control and one prospective, were included in the meta-analysis. The odds ratio (OR) and its 95% confidence interval (CI) were determined across the sixteen studies. The OR and its 95% CI of diabetes associated with bisphenol A were estimated using both fixed-effects and random-effects models.Results
A total of 41,320 subjects were included. Fourteen of the sixteen studies included in the analysis provided measurements of urine bisphenol A levels and two study provided serum bisphenol A levels. Bisphenol A concentrations in human bio-specimens showed positive associations with T2DM risk (OR 1.28, 95% CI 1.14, 1.44). A sensitivity analysis indicated that urine bisphenol A concentrations were positively associated with T2DM risk (OR 1.20, 95% CI 1.09, 1.31).Conclusions
This meta-analysis indicated that Bisphenol A exposure is positively associated with T2DM risk in humans.495.
Hye Jin Yoo Minjoo Kim Minkyung Kim Minsik Kang Keum Ji Jung Se-mi Hwang Sun Ha Jee Jong Ho Lee 《Metabolomics : Official journal of the Metabolomic Society》2018,14(6):85
Introduction
Since blood is in contact with all tissues in the body and is considered to dynamically reflect the body’s pathophysiological status, serum metabolomics changes are important and have diagnostic value in early cancer detection.Objectives
In this prospective study, we investigated the application of metabolomics to differentiate subjects with incident breast cancer (BC) from subjects who remained free of cancer during a mean follow-up period of 7 years with the aim of identifying valuable biomarkers for BC.Methods
Baseline serum samples from 84 female subjects with incident BC (BC group) and 88 cancer-free female subjects (control group) were used. Metabolic alterations associated with BC were investigated via metabolomics analysis of the baseline serum samples using ultra-performance liquid chromatography-linear-trap quadrupole-Orbitrap mass spectrometry.Results
A total of 57 metabolites were identified through the metabolic analysis. Among them, 20 metabolite levels were significantly higher and 22 metabolite levels were significantly lower in the BC group than in the control group at baseline. Ten metabolic pathways, including amino acid metabolism, arachidonic acid (AA) metabolism, fatty acid metabolism, linoleic acid metabolism, and retinol metabolism, showed significant differences between the BC group and the control group. Logistic regression revealed that the incidence of BC was affected by leucine, AA, prostaglandin (PG)J2, PGE2, and γ-linolenic acid (GLA).Conclusions
This prospective study showed the clinical relevance of dysregulation of various metabolisms on the incidence of BC. Additionally, leucine, AA, PGJ2, PGE2, and GLA were identified as independent variables affecting the incidence of BC.496.
Experimental Evidence that Fungi are Dominant Microbes in Carbon Content and Growth Response to Added Soluble Organic Carbon in Moss‐rich Tundra Soil
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O. Roger Anderson Jee Min Lee Krista McGuire 《The Journal of eukaryotic microbiology》2016,63(3):363-366
Global warming significantly affects Arctic tundra, including permafrost thaw and soluble C release that may differentially affect tundra microbial growth. Using laboratory experiments, we report some of the first evidence for the effects of soluble glucose‐C enrichment on tundra soil prokaryotes (bacteria and archaea) and fungi, with comparisons to microbial eukaryotes. Fungal increase in C‐biomass was equivalent to 10% (w/w) of the added glucose‐C, and for prokaryote biomass 2% (w/w), the latter comparable to prior published results. The C‐gain after 14 d was 1.3 mg/g soil for fungi, and ~200 μg/g for prokaryotes. 相似文献
497.
Characterization and developmental expression of single-stranded telomeric DNA-binding proteins from mung bean (Vigna radiata) 总被引:2,自引:0,他引:2
We have identified and characterized protein factors from mung bean (Vigna radiata) nuclear extracts that specifically bind the single-stranded G-rich telomeric DNA repeats. Nuclear extracts were prepared from three different types of plant tissue, radicle, hypocotyl, and root, in order to examine changes in the expression patterns of telomere-binding proteins during the development of mung bean. At least three types of specific complexes (A, B, and C) were detected by gel retardation assays with synthetic telomere and nuclear extract from radicle tissue, whereas the two major faster-migrating complexes (A and B) were formed with nuclear extracts from hypocotyl and root tissues. Gel retardation assays also revealed differences in relative amount of each complex forming activity in radicle, hypocotyl, and root nuclear extracts. These data suggest that the expression of telomere-binding proteins is developmentally regulated in plants, and that the factor involved in the formation of complex C may be required during the early stages of development. The binding factors have properties of proteins and are hence designated as mung bean G-rich telomere-binding proteins (MGBP). MGBPs bind DNA substrates with three or more single-stranded TTTAGGG repeats, while none of them show binding affinity to either double-stranded or single-stranded C-rich telomeric DNA. These proteins have a lower affinity to human telomeric sequences than to plant telomeric sequences and do not exhibit a significant binding activity to Tetrahymena telomeric sequence or mutated plant telomeric sequences, indicating that their binding activities are specific to plant telomere. Furthermore, RNase treatment of the nuclear extracts did not affect the complex formation activities. This result indicates that the single-stranded telomere-binding activities may be attributed to a simple protein but not a ribonucleoprotein. The ability of MGBPs to bind specifically the single-stranded TTTAGGG repeats may suggest their in vivo functions in the chromosome ends of plants. 相似文献
498.
Fluorescence transients were measured in lyophilized maize chloroplasts (suspended in Tris-maleate buffer (pH 6.6)) after extraction with heptane. (The fluorescence characteristics before extraction were qualitatively similar to those in the fresh chloroplasts.) The initial fluorescence level (m) in the (dry) heptane-extracted sample remained the same as in the unextracted material, but the variable fluorescence (Δm) was drastically diminished. A portion of variable fluorescence, however, could be restored by adding Na2S2O4. If the heptane extraction was made in the presence of water (wet), the m level was almost as high as (or higher than) the final level (M) of the unextracted sample, and Δm was reduced. The “jet” of O2 (that measures the pool size of the intersystem intermediate A) and the “microjet” (that measures the pool size of the reaction center complex E), present in the unextracted samples, were absent in both types of extracted samples. Some of the above data may be interpreted in a hypothesis in which two quenchers (Q1 and Q2) control the fluorescence (O → P) of chloroplasts — the reduction of Q1 being responsible for the rapid and that of Q2 for the slow fluorescence rise. 相似文献
499.
Kang Hee Nam Hwa Jee Chung Eo Jin Jeon Mi Kyung Park Yong Hyeon Yim Jang Ryol Liu Jeong Ho Park 《Journal of Plant Biology》2007,50(3):315-320
Strictosidine is a key intermediate in the biosynthesis of the terpenoid indole alkaloid (T1A) pathway. It results from a
condensation reaction, catalyzed by strictosidine synthase (STR), between tryptamine and secologanin. We have now developed
a useful method, based on enzyme-assisted synthesis, to produce strictosidine. Our procedure utilizes leaf extracts from Japanese
honeysuckleLonicera japonica Thunb. as a secologanin source. In these experiments, an enzyme extract was prepared from transgenic yeastSaccharomyces cerevisiae that expresses theCatharanthus roseus STR (CrSTR) coding region. Strictosidine was then isolated with a 38% yield based on the initial amount of tryptamine in the
enzymatic reaction. 相似文献
500.