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排序方式: 共有1583条查询结果,搜索用时 218 毫秒
51.
Altered nucleosome structure containing DNA sequences complementary to 19S and 26S ribosomal RNA in Physarum polycephalum. 总被引:10,自引:0,他引:10
E M Johnson V G Allfrey E M Bradbury H R Matthews 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(3):1116-1120
The localization of DNA sequences coding for ribosomal RNA was studied by hybridization of purified ribosomal RNA to DNA from chromatin fragments prepared by limited digestion of Physarum nuclei with staphylococcal nuclease. The 32P-labeled 19S and 26S RNA hybridized to DNA from nucleosome monomers, dimers, trimers, and higher oligomers, separated by sucrose gradient centrifugation, although the level of hybridization to DNA from nucleosome fractions was less than the level of hybridization to undigested nuclear DNA. The distribution of 19S and 26S rDNA sequences in the nucleosome fractions differed from the distribution of bulk DNA in that the rDNA sequences were recovered primarily in two fractions containing monomer-sized DNA lengths (140-160 base pairs). The percentage of DNA hybridizing to 19S plus 26S RNA was greater in peak A, the more slowly sedimenting monomer peak, than in any other chromatin fraction at all stages of digestion. Peak A and monomer particles differed in protein content and distribution. The presence of ribosomal cistrons in an altered nucleosome configuration may be related to changes in functional states of rDNA chromatin. 相似文献
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Nguyen Teresa P. Karney Benjamin R. Kennedy David P. Bradbury Thomas N. 《Cognitive therapy and research》2021,45(3):529-541
Cognitive Therapy and Research - Theoretical and clinical perspectives argue that couples’ maladaptive attributions for marital problems lead to marital distress and that these attributions... 相似文献
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Sara D'Angelo Flavio Mignone Cecilia Deantonio Roberto Di Niro Roberta Bordoni Roberto Marzari Gianluca De Bellis Tarcisio Not Fortunato Ferrara Andrew Bradbury Claudio Santoro Daniele Sblattero 《Clinical immunology (Orlando, Fla.)》2013,148(1):99-109
The aim of this study was to dissect the autoantibody response in celiac disease (CD) that remains largely unknown, with the goal of identifying the disease-specific autoantigenic protein pattern or the so called epitome. Sera from CD patients were used to select immunoreactive antigens from a cDNA phage-display library. Candidate genes were identified, the corresponding proteins produced and their immunoreactivity validated with sera from CD patients and controls. Thirteen CD-specific antigens were identified and further validated by protein microarray. The specificity for 6 of these antigens was confirmed by ELISA. Furthermore we showed that this antibody response was not abolished on a gluten free diet and was not shared with other autoimmune diseases. These antigens appear to be CD specific and independent of gluten induction. The utility of this panel extends beyond its diagnostic value and it may drive the attention to new targets for unbiased screens in autoimmunity research. 相似文献
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Successful Transplantation of Kidneys From Elderly Circulatory Death Donors by Using Microscopic and Macroscopic Characteristics to Guide Single or Dual Implantation
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D. H. Mallon G. E. Riddiough D. M. Summers A. J. Butler C. J. Callaghan L. L. Bradbury V. Bardsley V. Broecker K. Saeb‐Parsy N. Torpey J. A. Bradley G. J. Pettigrew 《American journal of transplantation》2015,15(11):2931-2939
Most kidneys from potential elderly circulatory death (DCD) donors are declined. We report single center outcomes for kidneys transplanted from DCD donors over 70 years old, using preimplantation biopsy Remuzzi grading to inform implantation as single or dual transplants. Between 2009 and 2012, 43 single transplants and 12 dual transplants were performed from elderly DCD donors. Remuzzi scores were higher for dual than single implants (4.4 vs. 3.4, p < 0.001), indicating more severe baseline injury. Donor and recipient characteristics for both groups were otherwise similar. Early graft loss from renal vein thrombosis occurred in two singly implanted kidneys, and in one dual‐implanted kidney; its pair continued to function satisfactorily. Death‐censored graft survival at 3 years was comparable for the two groups (single 94%; dual 100%), as was 1 year eGFR. Delayed graft function occurred less frequently in the dual‐implant group (25% vs. 65%, p = 0.010). Using this approach, we performed proportionally more kidney transplants from elderly DCD donors (23.4%) than the rest of the United Kingdom (7.3%, p < 0.001), with graft outcomes comparable to those achieved nationally for all deceased‐donor kidney transplants. Preimplantation biopsy analysis is associated with acceptable transplant outcomes for elderly DCD kidneys and may increase transplant numbers from an underutilized donor pool. 相似文献
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Protected areas facilitate species' range expansions 总被引:1,自引:0,他引:1
CD Thomas PK Gillingham RB Bradbury DB Roy BJ Anderson JM Baxter NA Bourn HQ Crick RA Findon R Fox JA Hodgson AR Holt MD Morecroft NJ O'Hanlon TH Oliver JW Pearce-Higgins DA Procter JA Thomas KJ Walker CA Walmsley RJ Wilson JK Hill 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(35):14063-14068
The benefits of protected areas (PAs) for biodiversity have been questioned in the context of climate change because PAs are static, whereas the distributions of species are dynamic. Current PAs may, however, continue to be important if they provide suitable locations for species to colonize at their leading-edge range boundaries, thereby enabling spread into new regions. Here, we present an empirical assessment of the role of PAs as targets for colonization during recent range expansions. Records from intensive surveys revealed that seven bird and butterfly species have colonized PAs 4.2 (median) times more frequently than expected from the availability of PAs in the landscapes colonized. Records of an additional 256 invertebrate species with less-intensive surveys supported these findings and showed that 98% of species are disproportionately associated with PAs in newly colonized parts of their ranges. Although colonizing species favor PAs in general, species vary greatly in their reliance on PAs, reflecting differences in the dependence of individual species on particular habitats and other conditions that are available only in PAs. These findings highlight the importance of current PAs for facilitating range expansions and show that a small subset of the landscape receives a high proportion of colonizations by range-expanding species. 相似文献
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