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991.
Behavioral and physiological effects of chronic 2,450-MHz microwave irradiation of the rat at 0.5 mW/cm2 总被引:2,自引:0,他引:2
J A D'Andrea J R DeWitt O P Gandhi S Stensaas J L Lords H C Nielson 《Bioelectromagnetics》1986,7(1):45-56
Adult male Long-Evans rats were intermittently exposed to 2450 MHz CW microwaves at an average power density of 0.5 mW/cm2 for 90 days. The resulting SAR was 0.14 W/kg (range 0.11 to 0.18 W/kg). The animals were exposed 7 h/day, 7 days/wk, for a total of 630 h in a monopole-above-ground radiation chamber while housed in Plexiglas holding cages. Daily measures of body mass and food and water intake indicated no statistically significant effects of microwave exposure. Monthly assessment of reactivity to electric footshock, levels of cholinesterase and sulfhydryl groups in blood, and 17-ketosteroids in urine revealed no reliable differences between 14 sham-exposed and 14 microwave-exposed rats. After the 90 days of exposure, seven rats, randomly chosen from each group, were assessed for open-field behavior, shuttlebox performance, and schedule-controlled (IRT schedule) lever pressing for food pellets. Statistically significant differences between microwave-exposed and sham-exposed rats were observed in shuttlebox performances and lever pressing. Post mortem measures of mass of several organs and microscopic examination of adrenal tissue revealed no differences between the two groups of animals. 相似文献
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993.
Yan-Hong He Guo-Gui Ning Ya-Lin Sun Yan Hu Xing-Yu Zhao Man-Zhu Bao 《Molecular breeding : new strategies in plant improvement》2010,26(1):19-29
A male sterile line was isolated in marigold (Tagetes erecta L.) and cytological analysis determined this to be a novel genic male sterility trait (Tems). Through the use of amplified fragment length polymorphisms (AFLPs) and bulked segregant analysis (BSA), tightly linked
markers of Tems were identified with a view towards a map-based cloning strategy. It was found that spontaneous homeotic conversion of floral
organs was the underlying cause of the male sterility in this marigold line. Thus, petals of male sterile plants resembled
sepal-like structures and the stamens were partially converted to styles, although without the full characteristics or function
of the true style organs. We have constructed a fine marker-based map for the Tems gene. This is intended to provide a tool for marker assisted selection (MAS) strategies in hybrid breeding and map-based
cloning strategies for the male sterility locus. We discuss the significance of this spontaneously derived genic male sterility
trait relating to the homeotic conversion of floral organs in marigold. 相似文献
994.
A. N. Malyan 《Biochemistry. Biokhimii?a》2010,75(1):81-84
An analysis of amino acid sequences and 3D structures of chloroplast, mitochondrial, and bacterial F1-ATPases revealed that in their α- and β-chains there are short highly conserved segments linking in pairs the catalytic and
noncatalytic sites. The analysis was based on the reported effect of directed mutagenesis of amino acids forming these segments
on catalytic properties of the F1-ATPases. It is proposed that one of these segments is responsible for transduction of a conformation signal from the noncatalytic
to catalytic site upon ADP-for-ATP substitution at the noncatalytic site. At the catalytic site, this signal changes position
of the terminal amino acid residue with respect to the adenine part of the molecule and results in a lower tightness of MgADP
binding and its dissociation followed by enzyme activation. Mutagenesis of amino acids comprised by the two other segments
was shown to produce an effect on the rate of cooperative catalysis, whereas the rate of single-site catalysis remained unaffected.
This suggests that these segments are responsible for the cooperative mode of enzyme functioning. 相似文献
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Andrew Leask 《Journal of cell communication and signaling》2010,4(2):109-110
The role of CCN proteins in vivo is only just becoming understood. A prototypical member of the CCN family, CCN3 suppresses proliferation. In a study in press, Shimoyama and colleagues show that mice lacking CCN3 have a hyperproliferative response to vascular injury. These data, along with other recent observations, suggest that CCN3 may represent a novel therapy for hyperproliferative diseases. 相似文献