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Transgenic mice carrying the 3-hydroxy-3-methylglutarylCoA reductase (HMG) promoter driving theEscherichia coli -galactosidase (lacZ) gene did not display the expected ubiquitous and constitutive expression inHMG-lacZ transgenic mice. The same promoter is however able to drive ubiquitous expression of the chloramphenicol acetyltransferase (cat) gene. Two lines of doubleHMG-lacZ andHMG-cat transgenic mice were obtained in which the two constructs were integrated at the same genomic sites. These mice expressed both reporter genes, but exclusively in the testes. These results suggest that thelacZ sequence might interfere negatively with the expression of the adjacentHMG-cat transgene. 相似文献
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Targeted disruption of Aldh1a1 (Raldh1) provides evidence for a complex mechanism of retinoic acid synthesis in the developing retina 下载免费PDF全文
Fan X Molotkov A Manabe S Donmoyer CM Deltour L Foglio MH Cuenca AE Blaner WS Lipton SA Duester G 《Molecular and cellular biology》2003,23(13):4637-4648
Genetic studies have shown that retinoic acid (RA) signaling is required for mouse retina development, controlled in part by an RA-generating aldehyde dehydrogenase encoded by Aldh1a2 (Raldh2) expressed transiently in the optic vesicles. We examined the function of a related gene, Aldh1a1 (Raldh1), expressed throughout development in the dorsal retina. Raldh1(-/-) mice are viable and exhibit apparently normal retinal morphology despite a complete absence of Raldh1 protein in the dorsal neural retina. RA signaling in the optic cup, detected by using a RARE-lacZ transgene, is not significantly altered in Raldh1(-/-) embryos at embryonic day 10.5, possibly due to normal expression of Aldh1a3 (Raldh3) in dorsal retinal pigment epithelium and ventral neural retina. However, at E16.5 when Raldh3 is expressed ventrally but not dorsally, Raldh1(-/-) embryos lack RARE-lacZ expression in the dorsal retina and its retinocollicular axonal projections, whereas normal RARE-lacZ expression is detected in the ventral retina and its axonal projections. Retrograde labeling of adult Raldh1(-/-) retinal ganglion cells indicated that dorsal retinal axons project to the superior colliculus, and electroretinography revealed no defect of adult visual function, suggesting that dorsal RA signaling is unnecessary for retinal ganglion cell axonal outgrowth. We observed that RA synthesis in liver of Raldh1(-/-) mice was greatly reduced, thus showing that Raldh1 indeed participates in RA synthesis in vivo. Our findings suggest that RA signaling may be necessary only during early stages of retina development and that if RA synthesis is needed in dorsal retina, it is catalyzed by multiple enzymes, including Raldh1. 相似文献
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Generalized relative risk models, with adjustments to the relative risk for time after exposure and age at exposure and incorporating
a linear-quadratic dose response, were fitted to the latest (Life Span Study Report 12) Japanese atomic bomb survivor cancer
mortality data using Bayesian Markov Chain Monte Carlo methods, taking account of random errors in the DS86 dose estimates.
The resulting uncertainty distributions in the relative risk model parameters were used to derive uncertainties in population
cancer risks for a current UK population. Following an assumed administered dose of 1 Sv, leukaemia mortality risks were estimated
to be 1.93×10–2 Sv–1 (95% CI 1.14, 3.38), or 0.44 years of life lost Sv–1 (95% CI 0.22, 0.94). Following an assumed administered dose of 1 Sv, solid cancer mortality risks were calculated to be 10.36×10–2 Sv–1 (95% CI 8.41, 12.42), or 1.38 years of life lost Sv–1 (95% CI 1.11, 1.68). In general, solid cancer risks were very similar to those predicted by classical likelihood-based methods;
however, leukaemia risks were somewhat higher, by 10–35%, than those predicted by classical likelihood-based methods. This
is so in both cases, irrespective of whether or not adjustments are made in these likelihood-based fits for the effects of
measurement errors, and the discrepancy for leukaemia tends to be greater at higher doses. Overall, cancer risks predicted
by Bayesian Markov Chain Monte Carlo methods are similar to those derived by classical likelihood-based methods and which
form the basis of established estimates of radiation-induced cancer risk.
Received: 28 September 1999 / Accepted: 21 August 2000 相似文献
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Lambé Pascal Mutambel Hity S.N. Deltour Roger Dinant Monique 《Plant Cell, Tissue and Organ Culture》1998,55(1):23-29
Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somatic embryogenesis and regeneration.
Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were
used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison
with immature zygotic embryos. Moreover, differences between genotypes were minimal when using shoot apices. Friable embryogenic
calli (type II) developed on the initial nodular calli after 1 to 3 months of culture. The frequency of type II callus is
related to the composition of the maintenance medium and they were more often found in ageing cultures. The transfer of embryogenic
calli onto auxin-free medium was sufficient for inducing somatic embryo development in short-term culture (3 months) while
a progressive loss in regeneration potential was observed with increasing time of subcultures. Maturation of embryogenic calli
on medium supplemented with activated charcoal, followed by germination of somatic embryos on medium supplemented with gibberellic
acid, restored regeneration in long-term cultures.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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An acetylation/deacetylation-SUMOylation switch through a phylogenetically conserved psiKXEP motif in the tumor suppressor HIC1 regulates transcriptional repression activity 下载免费PDF全文
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Deltour I Wiart J Taki M Wake K Varsier N Mann S Schüz J Cardis E 《Bioelectromagnetics》2011,32(8):634-643
The three‐dimensional distribution of the specific absorption rate of energy (SAR) in phantom models was analysed to detect clusters of mobile phones producing similar spatial deposition of energy in the head. The clusters' characteristics were described from the phones external features, frequency band and communication protocol. Compliance measurements with phones in cheek and tilt positions, and on the left and right side of a physical phantom were used. Phones used the Personal Digital Cellular (PDC), Code division multiple access One (CdmaOne), Global System for Mobile Communications (GSM) and Nordic Mobile Telephony (NMT) communication systems, in the 800, 900, 1500 and 1800 MHz bands. Each phone's measurements were summarised by the half‐ellipsoid in which the SAR values were above half the maximum value. Cluster analysis used the Partitioning Around Medoids algorithm. The dissimilarity measure was based on the overlap of the ellipsoids, and the Manhattan distance was used for robustness analysis. Within the 800 MHz frequency band, and in part within the 900 MHz and the 1800 MHz frequency bands, weak clustering was obtained for the handset shape (bar phone, flip with top and flip with central antennas), but only in specific positions (tilt or cheek). On measurements of 120 phones, the three‐dimensional distribution of SAR in phantom models did not appear to be related to particular external phone characteristics or measurement characteristics, which could be used for refining the assessment of exposure to radiofrequency energy within the brain in epidemiological studies such as the Interphone. Bioelectromagnetics. Bioelectromagnetics 32:634–643, 2011. © 2011 Wiley Periodicals, Inc. 相似文献
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Targeting of mouse alcohol dehydrogenase genes Adh1, Adh3, and Adh4 resulted in null mutant mice that all developed and reproduced apparently normally but differed markedly in clearance of ethanol and formaldehyde plus metabolism of retinol to the signaling molecule retinoic acid. Following administration of an intoxicating dose of ethanol, Adh1 -/- mice, and to a lesser extent Adh4 -/- mice, but not Adh3 -/- mice, displayed significant reductions in blood ethanol clearance. Ethanol-induced sleep was significantly longer only in Adh1 -/- mice. The incidence of embryonic resorption following ethanol administration was increased 3-fold in Adh1 -/- mice and 1.5-fold in Adh4 -/- mice but was unchanged in Adh3 -/- mice. Formaldehyde toxicity studies revealed that only Adh3 -/- mice had a significantly reduced LD50 value. Retinoic acid production following retinol administration was reduced 4.8-fold in Adh1 -/- mice and 8.5-fold in Adh4 -/- mice. Thus, Adh1 and Adh4 demonstrate overlapping functions in ethanol and retinol metabolism in vivo, whereas Adh3 plays no role with these substrates but instead functions in formaldehyde metabolism. Redundant roles for Adh1 and Adh4 in retinoic acid production may explain the apparent normal development of mutant mice. 相似文献