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991.
Background aimsBecause of the inflammatory nature and extensive stromal compartment in pancreatic tumors, we investigated the role of mesenchymal stromal cells (MSC) to engraft selectively in pancreatic carcinomas and serve as anti-tumor drug delivery vehicles to control pancreatic cancer progression.MethodsHuman pancreatic carcinoma cells, PANC-1, expressing renilla luciferase were orthotopically implanted into SCID mice and allowed to develop for 10 days. Firefly luciferase-transduced MSC or MSC expressing interferon (IFN)-β were then injected intraperitoneally weekly for 3 weeks. Mice were monitored by bioluminescent imaging for expression of renilla (PANC-1) and firefly (MSC) luciferase.ResultsMSC selectively homed to sites of primary and metastatic pancreatic tumors and inhibited tumor growth (P = 0.032). The production of IFN-β within the tumor site by MSC–IFN-β further suppressed tumor growth (P = 0.0000083). Prior studies indicated that MSC home to sites of inflammation; therefore, we sought to alter the tumor microenvironment through treatment with a potent anti-inflammatory agent. After treatment, inflammation-associated mediators were effectively down-regulated, including NFκB, vascular endothelial growth factor (VEGF) and interleukin (IL)-6 as well as chemokines involved in MSC migration (CCL3 and CCL25). Treatment with the anti-inflammatory agent CDDO-Me before and after MSC–IFN-β injections resulted in reduction of MSC in the tumors and reversed the positive effect of tumor inhibition by MSC–IFN-β alone (P = 0.041).ConclusionsThese results suggest that MSC exhibit innate anti-tumor effects against PANC-1 cells and can serve as delivery vehicles for IFN-β for the treatment of pancreatic cancer. However, these beneficial effects may be lost in therapies combining MSC with anti-inflammatory agents.  相似文献   
992.
Soil nematodes play crucial roles in the soil food web and are a suitable indicator for assessing soil environments and ecosystems. Previous nematode community analyses based on nematode morphology classification have been shown to be useful for assessing various soil environments. Here we have conducted DNA barcode analysis for soil nematode community analyses in Japanese soils. We isolated nematodes from two different environmental soils of an unmanaged flowerbed and an agricultural field using the improved flotation-sieving method. Small subunit (SSU) rDNA fragments were directly amplified from each of 68 (flowerbed samples) and 48 (field samples) isolated nematodes to determine the nucleotide sequence. Sixteen and thirteen operational taxonomic units (OTUs) were obtained by multiple sequence alignment from the flowerbed and agricultural field nematodes, respectively. All 29 SSU rDNA-derived OTUs (rOTUs) were further mapped onto a phylogenetic tree with 107 known nematode species. Interestingly, the two nematode communities examined were clearly distinct from each other in terms of trophic groups: Animal predators and plant feeders were markedly abundant in the flowerbed soils, in contrast, bacterial feeders were dominantly observed in the agricultural field soils. The data from the flowerbed nematodes suggests a possible food web among two different trophic nematode groups and plants (weeds) in the closed soil environment. Finally, DNA sequences derived from the mitochondrial cytochrome oxidase c subunit 1 (COI) gene were determined as a DNA barcode from 43 agricultural field soil nematodes. These nematodes were assigned to 13 rDNA-derived OTUs, but in the COI gene analysis were assigned to 23 COI gene-derived OTUs (cOTUs), indicating that COI gene-based barcoding may provide higher taxonomic resolution than conventional SSU rDNA-barcoding in soil nematode community analysis.  相似文献   
993.
In rodents, forced activation of hepatic peroxisome proliferator-activated receptor α (PPARα) by administration of exogenous PPARα activators during lactation leads to a reduction of milk triacylglycerol (TAG) production. Herein, we investigated whether a negative energy balance (NEB) induced by feed restriction (about 18% lower feed and energy intake) during lactation by increasing the release of fatty acids, which act as PPARα agonists, causes a disruption of hepatic lipid metabolism and thereby impairs milk TAG production in sows. Nutrient and energy content of the milk on day 20 of lactation and gains of litters during the first 14 d and the whole 21 d suckling period did not differ between Control and feed-restricted sows. The mRNA concentrations of several sterol regulatory element-binding protein target genes involved in lipid synthesis in the liver and the plasma concentration of TAG were reduced in the feed-restricted sows, whereas the mRNA concentrations of PPARα target genes involved in fatty acid oxidation in liver and skeletal muscle were not different between groups. In conclusion, it was shown that an NEB during lactation does not adversely affect milk composition and gains of litters, despite inhibiting hepatic expression of genes involved in lipid synthesis and reducing plasma TAG concentration. The finding that PPARα target genes involved in fatty acid utilisation in liver and muscle of sows are not induced by the NEB during lactation may explain that fatty acid availability in the mammary gland is sufficient to maintain milk TAG production and to allow normal litter gain.  相似文献   
994.
Objective: Measurement of salivary IgA antibody (PAc‐peptide antibody, PPA) to amino acid residues 361–386 of Streptococcus mutans PAc, which possess a multiple binding motif to various HLA‐DR molecules and a B‐cell epitope that recognises the inhibiting antibody to S. mutans, is an indicator for the population numbers of mutans streptococci (MS) in human saliva. The purpose of this study was to clarify the role of PPA in infection control of MS after professional oral hygiene care. Materials and methods: Thirty‐nine dependently living institutionalised elderly subjects (75.9 ± 7.5 years; 10 males, 29 females) participated in the study. The measurements of PPA, MS, total streptococci (TS) and lactobacilli (LB) were performed by ELISA and culture techniques from saliva, plaque and tongue samples from the elderly. Results: After treatment using professional oral care, the numbers of MS decreased significantly at 6 months in saliva and tongue samples from the group not having PPA in comparison with the primary data; whereas in the PPA‐detected group, a significant decrease in MS number was shown immediately following professional care at 1–12 months in all samples. There was little difference in the numbers of LB at any of the time points. The numbers of TS decreased rapidly in PPA‐not detected group in comparison with the PPA‐detected group. Conclusion: PPA may be more effective for controlling MS number in the oral cavity after professional treatment. The measurement of PPA may be used for preventive instruction to dental caries at the chair side in the clinical setting.  相似文献   
995.
996.
In the search for new antioxidants, flavan structures called our attention, as substructures of many important natural compounds, including catechins (flavan-3-ols), simple and dimeric proanthocyanidins, and condensed tannins. In this work the conformational space of the Z-isomers of (4α→6′′, 2α→O→1′′)-phenylflavans substituted with R = H, OH and OCH3 was scanned in aqueous solution, simulating the solvent by the polarizable continuum model (PCM). Geometry optimizations were performed at B3LYP/6-31 G** level. Electronic distributions were analyzed at a better calculation level, thus improving the basis set (6-311++G**). A topological study based on Bader′s theory (atoms in molecules) and natural bond orbital (NBO) framework was performed. Furthermore, molecular electrostatic potential maps (MEPs) were obtained and thoroughly analyzed. The stereochemistry was discussed, and the effect of the solvent was addressed. Moreover, intrinsic properties were identified, focusing on factors that may be related to their antioxidant properties. Hyperconjugative and inductive effects were described. The coordinated NBO/AIM analysis allowed us to rationalize the changes of MEPs in a polar solvent. To investigate the molecular and structural properties of these compounds in biological media, the polarizabilities and dipolar moments were predicted which were further used to enlighten stability and reactivity properties. All conformers were taken into account. Relevant stereoelectronic aspects were described for understanding the stabilization and antioxidant function of these structures.  相似文献   
997.
The complete genome of EcoM-GJ1, a lytic phage that attacks porcine enterotoxigenic Escherichia coli of serotype O149:H10:F4, was sequenced and analyzed. The morphology of the phage and the identity of the structural proteins were also determined. The genome consisted of 52,975 bp with a G+C content of 44% and was terminally redundant and circularly permuted. Seventy-five potential open reading frames (ORFs) were identified and annotated, but only 29 possessed homologs. The proteins of five ORFs showed homology with proteins of phages of the family Myoviridae, nine with proteins of phages of the family Podoviridae, and six with proteins of phages of the family Siphoviridae. ORF 1 encoded a T7-like single-subunit RNA polymerase and was preceded by a putative E. coli σ70-like promoter. Nine putative phage promoters were detected throughout the genome. The genome included a tRNA gene of 95 bp that had a putative 18-bp intron. The phage morphology was typical of phages of the family Myoviridae, with an icosahedral head, a neck, and a long contractile tail with tail fibers. The analysis shows that EcoM-GJ1 is unique, having the morphology of the Myoviridae, a gene for RNA polymerase, which is characteristic of phages of the T7 group of the Podoviridae, and several genes that encode proteins with homology to proteins of phages of the family Siphoviridae.  相似文献   
998.
Urease pre-treatment of urine has been utilized since the early 1960s to remove high levels of urea from samples prior to further processing and analysis by gas chromatography–mass spectrometry (GC–MS). Aside from the obvious depletion or elimination of urea, the effect, if any, of urease pre-treatment on the urinary metabolome has not been studied in detail. Here, we report the results of three separate but related experiments that were designed to assess possible indirect effects of urease pre-treatment on the urinary metabolome as measured by GC–MS. In total, 235 GC–MS analyses were performed and over 106 identified and 200 unidentified metabolites were quantified across the three experiments. The results showed that data from urease pre-treated samples (1) had the same or lower coefficients of variance among reproducibly detected metabolites, (2) more accurately reflected quantitative differences and the expected ratios among different urine volumes, and (3) increased the number of metabolite identifications. Overall, we observed no negative consequences of urease pre-treatment. In contrast, urease pre-treatment enhanced the ability to distinguish between volume-based and biological sample types compared to no treatment. Taken together, these results show that urease pre-treatment of urine offers multiple beneficial effects that outweigh any artifacts that may be introduced to the data in urinary metabolomics analyses.  相似文献   
999.
Aim Native plant communities are susceptible to climate anomalies, which would favour the invasion of non‐native species. However, climate anomalies may also provide opportunities for detecting non‐native plants at a regional scale using remote sensing. Based on this mechanism, we propose a direct and effective remote sensing approach to map the abundance of South African Eragrostis lehmanniana Nees (Lehmann lovegrass), a highly invasive, non‐native plant in the desert grasslands of southwestern North America. Location The desert grassland of Fort Huachuca Military Reservation (31°34′N, 110°26′W) in southern Arizona, USA. Methods Simple linear regression models were used to examine the relationships between additional (comparing to the normal level) remotely sensed greenness (delta Enhanced Vegetation Index (ΔEVI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS)), and field actual (g m?2) and percentage (%) biomass of E. lehmanniana in an abnormal wet, cool period in October 2000. Results There was a strong and positive agreement (P < 0.005) between ΔEVI and field observations (R2 = 0.72 and 0.64 for actual and percentage biomass of E. lehmanniana, respectively). These relationships allowed us to estimate the abundance of E. lehmanniana in the desert grassland. Main conclusions Phenology of native grass communities is quite similar to systems dominated by E. lehmanniana but responses differ when there are substantial amounts of precipitation in cool seasons. Eragrostis lehmanniana can produce significant amount of new tissues and seeds with sufficient cool season moisture, while native grasses are still in senescence or dormancy. Therefore, amplitude of ΔEVI during wet, cool seasons would indicate the abundance of E. lehmanniana. Long‐term climate records denote an amplification of cool season precipitation in the southwestern USA. This regional climatic trend should allow us to monitor E. lehmanniana and possibly other non‐native species frequently in this vast arid region.  相似文献   
1000.
Abstract. The spatial relationships between the protein constituents of two junctional structures, adhaerens junctions and desmosomes, were determined by double immunofluorescence microscopy using marker proteins specific for these structures. Adhaerens junctions were visualized by immunofluorescent labeling for the membrane-associated protein vinculin and by their association with actin filaments. Desmosomal components were identified by labeling with anti-bodies to a group of minor desmosomal plaque proteins (DP1 antigens) and their association with filaments stained by cytokeratin antibodies. Double immunofluorescence microscopy of these components was performed in several tissues and cultured cells, including intact intestine, dissociated intestinal cells, and two morphologically different types of epithelial cells, cultured bovine kidney (MDBK), and mammary gland (BMGE) epithelial cells. This allowed the direct demonstration that each filament system is associated exclusively with its specific membrane-bound junctional protein. Vinculin and DP1-protein were found in distinct sites in the subapical intercellular junctional complex of intestinal epithelium and MDBK cells. Cell-substrate focal contacts contained vinculin and actin and showed no apparent relationships to the tonofilament system whereas intercellular contacts of BMGE cells were characterized by positive staining for DP1-protein and associated cytokeratin filaments. Immunolabeling of the cultured cells at different intervals after plating for the cytoskeletal elements and their membrane anchorage proteins was used to determine the temporal sequence of their organization. We propose that this approach may be used for the molecular definition and identification of cellular contacts and junctions as well as for studies of junction topology, dynamics of junction-cytoskeleton interactions, and junction biogenesis.  相似文献   
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