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51.
Members of the Bcl-2 family include pro- and antiapoptotic proteins that regulate programmed cell death of developing tissues and death in response to cellular damage. In developing mice, the antiapoptotic Bcl-xL is necessary for survival of neural and hematopoietic cells, and consequently, bcl-x–deficient mice die around Day 13.5 of embryogenesis. Furthermore, adult bcl-x+/− heterozygous male mice have reduced fertility because of testicular degeneration. Bax, a multi-BH (Bcl-2 homology) domain proapoptotic member of the Bcl-2 family, is regulated by Bcl-xL and is required for the neuropathological abnormalities seen in bcl-x–deficient embryos. The BH3 domain only subgroup of the Bcl-2 family includes proapoptotic members that are essential for the initiation of apoptotic signaling. In this study, we investigated the role for Bim, a BH3 domain only protein, in the embryonic lethality and increased developmental cell death in bcl-x–deficient animals and the perturbed testicular function in bcl-x+/− adults. Our studies show that bim deficiency attenuates hematopoietic cell death in the fetal liver of bcl-x–deficient animals, indicating that Bim contributes to programmed cell death in this cell population. In addition, we found that testicular degeneration of adult bcl-x+/− males was rescued by concomitant Bim deficiency. However, concomitant Bim deficiency had no effect on the embryonic lethality and widespread nervous system abnormalities caused by bcl-x deficiency. Our work identifies Bim as an important regulator of bcl-x deficiency–induced cell death during hematopoiesis and testicular development. (J Histochem Cytochem 56:921–927, 2008)  相似文献   
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Synchrotron-radiation-based computer microtomography (SRμCT) was applied to three biomineralised objects First, embryonic snails of the freshwater snail Biomphalaria glabrata, second, rhopalia (complex sense organs) of the medusa Aurelia aurita, and third, human teeth. The high absorption contrast between the soft tissue and mineralised tissues, i.e. the shell in the first case (consisting of calcium carbonate) and the statoliths in the second case (consisting of calcium sulphate hemihydrate), makes this method ideal for the study of biomineralised tissues. The objects can be non-destructively studied on a micrometre scale, and quantitative parameters like the thickness of a forming a snail shell or statolith crystal sizes can be obtained on a length scale of 1–2 μm. Using SRμCT, the dentin–enamel border can be clearly identified in X-ray dense teeth.  相似文献   
53.
The first part of this study was a cross-sectional analysis of the impact of 29 management factors on udder health in organic dairy farms in Switzerland. All 77 farms joined the extension program 'pro-Q'. As a measure of udder health the theoretical bulk milk somatic cell count (TBMSCC) calculated by the monthly cow composite somatic cell count over a time period of 1 year was chosen. The basic udder health of the farms was determined by TBMSCC during the year prior to the start of the project (mean for all farms = 176 460 cells/ml). In the multivariable analysis, the five factors 'swiss brown breed', 'alpine summer pasturing', 'calf feeding with milk from mastitis diseased cows', 'hard bedding' and 'no post-milking' remained as significant risk factors on udder health. In the second part of the study, the development of management factors and the udder health situation affected by an extension program after 1 year was investigated. A partial improvement of the management factors on the farms but no overall improvement on udder health and no association between management changes and udder health changes were found. Improvement of udder health was more likely in farms with higher basic TBMSCC than in those farms with less udder health problems at the beginning of the project.  相似文献   
54.
The procedure for genetic transformation of two spring and one winter rapeseed cultivars was developed. No-paline strains of Agrobacterium tumefaciens GV3101 and EHA105 were shown to be preferable for gene transfer, as compared to the octopine strain GV2260. With two types of plant explants, the segments of hypocotyls and cotyledons, transformation was successful; however, its efficiency was somewhat higher with the fragments of hypocotyls. Analysis of regenerated plants by PCR and Southern blotting confirmed the presence of the nptII and nisA genes in transformants. RNA analysis by Northern blotting showed expression of the nisA gene in transformed shoots. The transgenes were inherited in T2 as Mendelian traits. The effect of biotic and abiotic factors on the efficiency of genetic transformation in rapeseed is discussed.  相似文献   
55.
Plasmodium berghei ANKA (PbA) infection of C57BL/6 mice leads to experimental cerebral malaria (ECM) that is commonly associated with serious T cell mediated damage. In other parasitic infection models, inflammatory monocytes have been shown to regulate Th1 responses but their role in ECM remains poorly defined, whereas neutrophils are reported to contribute to ECM immune pathology. Making use of the recent development of specific monoclonal antibodies (mAb), we depleted in vivo Ly6Chi inflammatory monocytes (by anti-CCR2), Ly6G+ neutrophils (by anti-Ly6G) or both cell types (by anti-Gr1) during infection with Ovalbumin-transgenic PbA parasites (PbTg). Notably, the application of anti-Gr1 or anti-CCR2 but not anti-Ly6G antibodies into PbTg-infected mice prevented ECM development. In addition, depletion of Ly6Chi inflammatory monocytes but not neutrophils led to decreased IFNγ levels and IFNγ+CD8+ T effector cells in the brain. Importantly, anti-CCR2 mAb injection did not prevent the generation of PbTg-specific T cell responses in the periphery, whereas anti-Gr1 mAb injection strongly diminished T cell frequencies and CTL responses. In conclusion, the specific depletion of Ly6Chi inflammatory monocytes attenuated brain inflammation and immune cell recruitment to the CNS, which prevented ECM following Plasmodium infection, pointing out a substantial role of Ly6C+ monocytes in ECM inflammatory processes.  相似文献   
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Microbial communities in biogas batch fermentations, using straw and hay as co-substrates, were analyzed at the gene and protein level by metagenomic and metaproteomic approaches. The analysis of metagenomic data revealed that the Clostridiales and Bacteroidales orders were prevalent in the community. However, the number of sequences assigned to the Clostridiales order decreased during fermentation, whereas the number of sequences assigned to the Bacteroidales order increased. In addition, changes at the functional level were monitored and the metaproteomic analyses detected transporter proteins and flagellins, which were expressed mainly by members of the Bacteroidetes and Firmicutes phyla. A high number of sugar transporters, expressed by members of the Bacteroidetes, proved their potential to take up various glycans efficiently. Metagenome data also showed that methanogenic organisms represented less than 4% of the community, while 20–30% of the identified proteins were of archeal origin. These data suggested that methanogens were disproportionally active.  相似文献   
58.

Introduction  

Recent evidence suggests that uric acid (UA), regardless of crystal deposition, may play a direct pathogenic role in renal disease. We have shown that UA is an independent predictor of hypertension and cardiovascular disease (CVD), and that CVD risk factors associate with renal dysfunction, in patients with rheumatoid arthritis (RA). In this study we investigated whether UA associates with renal dysfunction in patients with RA and whether such an association is independent or mediated through other comorbidities or risk factors for renal impairment.  相似文献   
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In spite of the importance of sperm motility to fertility in the stallion, little is known about the signaling pathways that regulate motility in this species. In other mammals, calcium/calmodulin signaling and the cyclic AMP/protein kinase-A pathway are involved in sperm motility regulation. We hypothesized that these pathways also were involved in the regulation of sperm motility in the stallion. Using immunoblotting, calmodulin and the calmodulin-dependent protein kinase II β were shown to be present in stallion sperm and with indirect immunofluorescence calmodulin was localized to the acrosome and flagellar principal piece. Additionally, inhibition of either calmodulin or protein kinase-A significantly reduced sperm motility without affecting viability. Following inhibition of calmodulin, motility was not restored with agonists of the cyclic AMP/protein kinase-A pathway. These data suggest that calcium/calmodulin and cyclic AMP/protein kinase-A pathways are involved in the regulation of stallion sperm motility. The failure of cyclic AMP/protein kinase-A agonists to restore motility of calmodulin inhibited sperm suggests that both pathways may be required to support normal motility.  相似文献   
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