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981.
WF Shen JC Montgomery S Rozenfeld JJ Moskow HJ Lawrence AM Buchberg C Largman 《Canadian Metallurgical Quarterly》1997,17(11):6448-6458
Recent studies show that Hox homeodomain proteins from paralog groups 1 to 10 gain DNA binding specificity and affinity through cooperative binding with the divergent homeodomain protein Pbx1. However, the AbdB-like Hox proteins from paralogs 11, 12, and 13 do not interact with Pbx1a, raising the possibility of different protein partners. The Meis1 homeobox gene has 44% identity to Pbx within the homeodomain and was identified as a common site of viral integration in myeloid leukemias arising in BXH-2 mice. These integrations result in constitutive activation of Meis1. Furthermore, the Hoxa-9 gene is frequently activated by viral integration in the same BXH-2 leukemias, suggesting a biological synergy between these two distinct classes of homeodomain proteins in causing malignant transformation. We now show that the Hoxa-9 protein physically interacts with Meis1 proteins by forming heterodimeric binding complexes on a DNA target containing a Meis1 site (TGACAG) and an AbdB-like Hox site (TTTTACGAC). Hox proteins from the other AbdB-like paralogs, Hoxa-10, Hoxa-11, Hoxd-12, and Hoxb-13, also form DNA binding complexes with Meis1b, while Hox proteins from other paralogs do not appear to interact with Meis1 proteins. DNA binding complexes formed by Meis1 with Hox proteins dissociate much more slowly than DNA complexes with Meis1 alone, suggesting that Hox proteins stabilize the interactions of Meis1 proteins with their DNA targets. 相似文献
982.
Y. K. Shen 《Polymer Engineering and Science》2006,46(12):1797-1803
This paper reports a simple and novel procedure for fabricating the mold insert of microlens arrays. In this paper, an L9 experimental matrix design based on the Taguchi method is constructed to optimize the replication quality of molded microlens arrays. The results of the statistical analysis indicate that the processing temperature is the principal parameter affecting the sag height of the molded microlens array. The 200 × 200 arrays of molded microlens, with a diameter of 150 μm, a pitch of 200 μm and a sag height of 31.51 μm have been successfully fabricated. The average surface roughness of the Ni mold insert is 6.916 nm. The average surface roughness of the molded microlens array is 4.608 nm. The processing temperature is the most important factor for the radius of curvature of molded microlens. POLYM. ENG. SCI. 46:1797–1803, 2006. © 2006 Society of Plastics Engineers. 相似文献
983.
本文分析了给粉机变频器低电压跳闸的原因和解决办法,为解决给粉机变频器低电压跳闸,消除设备隐患提供了经验。 相似文献
984.
Yushi Shen Pamela C Cosman Laurence B Milstein 《IEEE transactions on image processing》2006,15(11):3241-3252
We present an adaptive video transmission scheme for use in a code-division multiple-access network, which incorporates efficient bandwidth allocation among source coding, channel coding, and spreading under a fixed total bandwidth constraint. We derive the statistics of the received signal, as well as a theoretical bound on the packet drop rate at the receiver. Based on these results, a bandwidth allocation algorithm is proposed at the packet level, which incorporates the effects of both the changing channel conditions and the dynamics of the source content. Detailed simulations are done to evaluate the performance of the system, and the sensitivity of the system to estimation error is presented. 相似文献
985.
986.
高能超声处理Al-1Si合金凝固组织分析 总被引:3,自引:2,他引:1
采用高能超声处理Al-1Si合金熔体,借助金相显微镜和电子探针进行组织分析,并测定合金的熔化潜热,分析了熔体中超声空化效应和声流效应影响凝固过程的机理。结果表明,试样晶粒平均尺寸由超声处理前的94μm减小到超声处理后的34μm;合金试样的熔化吸热量由263.90J/g降低为159.81J/g,在熔体中施加高能超声显著改善了合金成分的均匀性并细化了晶粒。 相似文献
987.
988.
The transformation of aluminium species in the processes of coagulation, sedimentation and filtration. 总被引:1,自引:0,他引:1
The aluminium toxicity is closely related to aluminium species. In this work aluminium was fractionated into seven forms: Al(T), Al(Sus), Al(C + S), Al(S), Al(C), Al(O) and Al(I). Four Al-based coagulants and simulated raw water were used in the laboratory to investigate the aluminium transformation in coagulation, sedimentation and filtration processes. It is the use of Al-based coagulants that contributes more to the increase of the residual aluminium for the low-turbidity raw water, while the Al-based coagulants, especially the polymeric aluminium coagulants, work to remove the aluminium from the high-turbidity raw water. In the case of traditional coagulants, the increase of the turbidity or the dissolved organic carbon (DOC) concentration in the raw water results in a high concentration of Al(C + S). The removal rate of aluminium species in the filtration process is not only related to its size: RAl(Sus) > RAl(C+S), RAl(C) > RAl(S), but also to the physicochemical properties of aluminium species and filter. For the kaolin-polyaluminium chloride system, a lower removal rate of aluminium species results is due to the complexation of humic acid and aluminium species. 相似文献
989.
“九华佛茶”是安徽省池州市茶叶主导品牌,是经国家商标总局注册登记的产地证明商标。通过对“九华佛茶”产区、产量、品质标准及生产过程中问题的分析与研究,指出:应尽快制定“九华佛茶”发展规划,加快“九华佛茶”茶园建设;“九华佛茶”的发展要与生态池州的建设、地方经济和茶农的收入及九华山佛教文化相结合;充分发挥茶叶龙头企业和乡镇集体的作用,按安全优质、标准化方式从事“九华佛茶”生产,提高茶叶品质,为“九华佛茶”走出国门、迈向世界打下坚实的基础。 相似文献
990.
Examined the effects of counselor note-taking behavior on participants' impressions of a counselor during a career counseling session. A total of 140 participants (70 men and 70 women) rated 1 of 2 videotapes designed to credibly simulate a real career counseling interview. Note-taking was the independent variable. Results of this study suggest that whether a counselor is observed in a note-taking or non-note-taking condition has no significant effect on perceived counselor expertness, attractiveness, or trustworthiness. However, there was a significantly greater willingness of the participants to see the counselor who refrained from note-taking. Results offer tentative suggestions for those counselors who choose to take notes during a career counseling session. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献