排序方式: 共有44条查询结果,搜索用时 547 毫秒
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Role of the thymus in tolerance. II. Transfer of specific unresponsiveness to BSA with thymus grafting 总被引:2,自引:0,他引:2
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Sherpa Ang D. Guilfoyle David N. Naik Aditi A. Isakovic Jasmina Irie Fumitoshi Yamaguchi Yu Hrabe Jan Aoki Chiye Hrabetova Sabina 《Neurochemical research》2020,45(1):53-67
Neurochemical Research - Brain white matter is the means of efficient signal propagation in brain and its dysfunction is associated with many neurological disorders. We studied the effect of... 相似文献
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In the nurse plant syndrome, or nurse association, seedlings (beneficiaries) are associated with adult shrubs/trees (benefactors).
This phenomenon has been documented in several regions of the planet. Abiotic stress amelioration (one mechanism of facilitation)
is one of the causes of this association. Most of the studies addressing the nurse syndrome have been conducted on spatial
scales of a few hectares and have focused on only one or a few species. Moreover, there is an almost complete lack of studies
addressing the incidence and characteristics of the nurse phenomenon in the arid Andes of South America. We undertook a first
approximation to the study of facilitation in these ecosystems. The study was conducted at local and regional scales and involved
the assessment of the spatial distribution of juveniles (seedlings and saplings) of 51 populations of 16 shrub and 12 cactus
species in relation to shrub cover at 20 localities of the Prepuna (subtropical Andes of Bolivia and Argentina, 20–26°S).
In terms of spatial distribution, the juveniles of most of the populations of shrubs studied were distributed both under the
shrubs and in open spaces, thereby showing an apparent indifference to microhabitat. Globose and opuntioid cacti were preferentially
distributed below the canopies of shrubs and were usually more associated with the dominant shrub species, which stood out
as better potential nurses. The pattern was consistent throughout the region, including the more mesic and arid localities.
The fact that Prepuna woody species are capable of establishing in open spaces would confer this region a greater resilience.
Our findings further suggest that community dynamics in arid and semi-arid environments are more variable than previously
thought. 相似文献
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Sicking C Brusch M Lindackers A Riedel KU Schubert B Isakovic N Krall C Klipp W Drepper T Schneider K Masepohl B 《Journal of bacteriology》2005,187(1):92-98
Growth of Rhodobacter capsulatus with molecular dinitrogen as the sole N source via the alternative Fe-only nitrogenase requires all seven gene products of the anfHDGK-1-2-3 operon. In contrast to mutant strains carrying lesions in the structural genes of nitrogenase (anfH, anfD, anfG, and anfK), strains defective for either anf1, anf2, or anf3 are still able to reduce the artificial substrate acetylene, although with diminished activity. To obtain further information on the role of Anf1, we screened an R. capsulatus genomic library designed for use in yeast two-hybrid studies with Anf1 as bait. Two genes, which we propose to call ranR and ranT (for genes related to alternative nitrogenase), coding for products that interact with Anf1 were identified. A ranR mutant exhibited a phenotype similar to that of an anf1 mutant strain (no growth with N2 in the absence of molybdenum, but significant reduction of acetylene via the Fe-only nitrogenase), whereas a ranT mutant retained the ability to grow diazotrophically, but growth was clearly delayed compared to the parental strain. In contrast to the situation for anf1, expression of neither ranR nor ranT was regulated by ammonium or molybdenum. A putative role for Anf1, RanR, and RanT in the acquisition and/or processing of iron in connection with the Fe-only nitrogenase system is discussed. 相似文献
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Playing with bone and fat 总被引:15,自引:0,他引:15
Gimble JM Zvonic S Floyd ZE Kassem M Nuttall ME 《Journal of cellular biochemistry》2006,98(2):251-266
The relationship between bone and fat formation within the bone marrow microenvironment is complex and remains an area of active investigation. Classical in vitro and in vivo studies strongly support an inverse relationship between the commitment of bone marrow-derived mesenchymal stem cells or stromal cells to the adipocyte and osteoblast lineage pathways. In this review, we focus on the recent literature exploring the mechanisms underlying these differentiation events and discuss their implications relevant to osteoporosis and regenerative medicine. 相似文献
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Oscar M. Saavedra Ljubomir Isakovic David B. Llewellyn Lijie Zhan Naomy Bernstein Stephen Claridge Franck Raeppel Arkadii Vaisburg Nadine Elowe Andrea J. Petschner Jubrail Rahil Norman Beaulieu A. Robert MacLeod Daniel Delorme Jeffrey M. Besterman Amal Wahhab 《Bioorganic & medicinal chemistry letters》2009,19(10):2747-2751
The inhibitory activity of base-modified SAH analogues and the specificity of inhibiting human DNMT1 and DNMT3b2 enzymes was explored. The 6-amino group was essential while the 7-N of the adenine ring of SAH could be replaced by CH– without loss of activity against both enzymes. The introduction of small groups at the 2-position of the adenine moiety favors DNMT1 over DNMT3b2 inhibition whereas alkylation of the N6-amino moiety favors the inhibition of DNMT3b2 enzyme. 相似文献