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161.
Two fluorescent dyes, TO-PRO-1 iodide and 5-CFDA-AM, were evaluated for LIVE/DEAD assessment of unicellular marine algae Brachiomonas submarina and Tetraselmis suecica. Epifluorescence microscopy was used to estimate cell viability in predetermined mixtures of viable and non-viable algal cells and validated using microplate growth assay as reference measurements. On average, 5-CFDA-AM underestimated live cell abundance by ~25% compared with viability estimated by the growth assay, whereas TO-PRO-1 iodide provided accurate viability estimates. Furthermore, viability estimates based on staining with TO-PRO-1 iodide were not affected by a storage period of up to one month in -80°C, making the assay a good candidate for routine assessment of phytoplankton populations in field and laboratory studies. 相似文献
162.
Therése Andersson Kotryna Simonyte Ruth Andrew Magnus Strand Jonas Burén Brian R. Walker Cecilia Mattsson Tommy Olsson 《PloS one》2009,4(12)
With age and menopause there is a shift in adipose distribution from gluteo-femoral to abdominal depots in women. Associated with this redistribution of fat are increased risks of type 2 diabetes and cardiovascular disease. Glucocorticoids influence body composition, and 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) which converts inert cortisone to active cortisol is a putative key mediator of metabolic complications in obesity. Increased 11βHSD1 in adipose tissue may contribute to postmenopausal central obesity. We hypothesized that tissue-specific 11βHSD1 gene expression and activity are up-regulated in the older, postmenopausal women compared to young, premenopausal women. Twenty-three pre- and 23 postmenopausal, healthy, normal weight women were recruited. The participants underwent a urine collection, a subcutaneous adipose tissue biopsy and the hepatic 11βHSD1 activity was estimated by the serum cortisol response after an oral dose of cortisone. Urinary (5α-tetrahydrocortisol+5β-tetrahydrocortisol)/tetrahydrocortisone ratios were higher in postmenopausal women versus premenopausal women in luteal phase (P<0.05), indicating an increased whole-body 11βHSD1 activity. Postmenopausal women had higher 11βHSD1 gene expression in subcutaneous fat (P<0.05). Hepatic first pass conversion of oral cortisone to cortisol was also increased in postmenopausal women versus premenopausal women in follicular phase of the menstrual cycle (P<0.01, at 30 min post cortisone ingestion), suggesting higher hepatic 11βHSD1 activity. In conclusion, our results indicate that postmenopausal normal weight women have increased 11βHSD1 activity in adipose tissue and liver. This may contribute to metabolic dysfunctions with menopause and ageing in women. 相似文献
163.
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165.
Effects of 50-Hz magnetic field exposure on superoxide radical anion formation and HSP70 induction in human K562 cells 总被引:1,自引:0,他引:1
Ann-Christine Mannerling Myrtill Simkó Kjell Hansson Mild Mats-Olof Mattsson 《Radiation and environmental biophysics》2010,49(4):731-741
Epidemiological studies suggest a correlation between exposure to low-level extremely low-frequency (ELF) magnetic fields
(MF) and certain cancers and neurodegenerative diseases. Experimental studies have not provided any mechanism for such effects,
although at flux density levels significantly higher than the ones encountered in epidemiological studies, radical homoeostasis
and levels of stress response proteins can be affected. Here, we report on the influence of MF exposure (50-Hz sine wave;
1 h; 0.025–0.10 mT; vertical or horizontal MF exposure direction) on different cellular parameters (proliferation, cell cycle
distribution, superoxide radical anion, and HSP70 protein levels) in the human leukaemia cell line K562. The positive control
heat treatment (42°C, 1 h) did not affect either cell proliferation or superoxide radical anion production but caused accumulation
of cells in the G2 phase and increased the stress protein HSP70. MF exposure (0.10 mT, 1 h) did not affect either cell cycle
kinetics or proliferation. Both vertical and horizontal MF exposures for 1 h caused significantly and transiently increased
HSP70 levels (>twofold), at several flux densities, compared to sham controls and also compared to heat treatment. This exposure
also increased (30–40%) the levels of the superoxide radical anion, comparable to the positive control PMA. Addition of free
radical scavengers (melatonin or 1,10-phenantroline) inhibited the MF-induced increase in HSP70. In conclusion, an early response
to ELF MF in K562 cells seems to be an increased amount of oxygen radicals, leading to HSP70 induction. Furthermore, the results
suggest that there is a flux density threshold where 50-Hz MF exerts its effects on K562 cells, at or below 0.025 mT, and
also that it is the MF, and not the induced electric field, which is the active parameter. 相似文献
166.
Conifers have a unique small RNA silencing signature 总被引:2,自引:0,他引:2
Dolgosheina EV Morin RD Aksay G Sahinalp SC Magrini V Mardis ER Mattsson J Unrau PJ 《RNA (New York, N.Y.)》2008,14(8):1508-1515
167.
Kallikrein-related peptidase 3 (KLK3, also known as prostate-specific antigen, PSA) is a chymotrypsin-like kallikrein that has anti-angiogenic properties. We have previously shown in a human umbilical vein endothelial cell (HUVEC) model that the anti-angiogenic effect of KLK3 is related to its enzyme activity. However, the mechanism of this effect remains to be clarified. To this end, we used a DNA microarray to study KLK3-induced changes in gene expression associated with reduction of HUVEC tube formation. Among the 41,000 genes studied, 311 were differentially expressed between control and KLK3-treated cells. These changes were enriched in several pathways, including those associated with proteasome, ubiquitin-mediated proteolysis, focal adhesion and regulation of the actin cytoskeleton. Furthermore, the changes were opposite to those previously described to occur during tubulogenesis. In conclusion, our results show that KLK3 induces gene expression changes in HUVECs. Although these changes might be relevant for the mechanism by which KLK3 exerts its anti-angiogenic activity, it cannot be judged from the present results whether they reflect the primary mechanism mediating the effect of KLK3 or are secondary to morphogenic differentiation. 相似文献
168.
Hui Geng Stefan Carlsen Kutty Selva Nandakumar Rikard Holmdahl Anders Aspberg Åke Oldberg Ragnar Mattsson 《Arthritis research & therapy》2008,10(6):R134
Introduction
Cartilage oligomeric matrix protein (COMP) is a homopentameric protein in cartilage. The development of arthritis, like collagen-induced arthritis (CIA), involves cartilage as a target tissue. We have investigated the development of CIA in COMP-deficient mice. 相似文献169.
The genetic basis of vascular differentiation and function isrelatively poorly understood, partly due to the difficulty ofscreening for mutants defective in internal vascular tissues.Here we present an approach based on a predicted increase invascular-related gene expression in response to an auxin transportinhibitor-induced vascular overgrowth. We used microarray analysesto identify 336 genes that were up-regulated 2-fold in shoottissues of Arabidopsis thaliana showing vascular overgrowth.Promoter–marker gene fusions revealed that 38 out of 40genes with 4-fold up-regulation in vascular overgrowth tissueshad vascular-related expression in transgenic Arabidopsis plants.Obtained expression patterns included cambial tissues and differentiatingxylem, phloem and fibers. A total of 15 genes were found tohave vascular-specific expression patterns in the leaves and/orinflorescence stems. This study provides empirical evidenceof the efficiency of the approach and describes for the firsttime the in situ expression patterns of the majority of theassessed genes. 相似文献
170.
The Tec family of cytoplasmic tyrosine kinases: mammalian Btk, Bmx, Itk, Tec, Txk and homologs in other species 总被引:9,自引:0,他引:9
Smith CI Islam TC Mattsson PT Mohamed AJ Nore BF Vihinen M 《BioEssays : news and reviews in molecular, cellular and developmental biology》2001,23(5):436-446
Cytoplasmic protein-tyrosine kinases (PTKs) are enzymes involved in transducing a vast number of signals in metazoans. The importance of the Tec family of kinases was immediately recognized when, in 1993, mutations in the gene encoding Bruton's tyrosine kinase (Btk) were reported to cause the human disease X-linked agammaglobulinemia (XLA). Since then, additional kinases belonging to this family have been isolated, and the availability of full genome sequences allows identification of all members in selected species enabling phylogenetic considerations. Tec kinases are endowed with Pleckstrin homology (PH) and Tec homology (TH) domains and are involved in diverse biological processes related to the control of survival and differentiation fate. Membrane translocation resulting in the activation of Tec kinases with subsequent Ca2+ release seems to be a general feature. However, nuclear translocation may also be of importance. The purpose of this essay is to characterize members of the Tec family and discuss their involvement in signaling. The three-dimensional structure, expression pattern and evolutionary aspects will also be considered. 相似文献