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71.
Patrick Jung Michael Schermer Laura Briegel‐Williams Karen Baumann Peter Leinweber Ulf Karsten Lukas Lehnert Sebastian Achilles Jrg Bendix Burkhard Büdel 《Journal of phycology》2019,55(6):1306-1318
In the Atacama Desert, cyanobacteria grow on various substrates such as soils (edaphic) and quartz or granitoid stones (lithic). Both edaphic and lithic cyanobacterial communities have been described but no comparison between both communities of the same locality has yet been undertaken. In the present study, we compared both cyanobacterial communities along a precipitation gradient ranging from the arid National Park Pan de Azúcar (PA), which resembles a large fog oasis in the Atacama Desert extending to the semiarid Santa Gracia Natural Reserve (SG) further south, as well as along a precipitation gradient within PA. Various microscopic techniques, as well as culturing and partial 16S rRNA sequencing, were applied to identify 21 cyanobacterial species; the diversity was found to decline as precipitation levels decreased. Additionally, under increasing xeric stress, lithic community species composition showed higher divergence from the surrounding edaphic community, resulting in indigenous hypolithic and chasmoendolithic cyanobacterial communities. We conclude that rain and fog water, respectively, cause contrasting trends regarding cyanobacterial species richness in the edaphic and lithic microhabitats. 相似文献
72.
Claassens Anders Rose Michael T. Van Zwieten Lukas Weng Zhe Rose Terry J. 《Plant and Soil》2019,439(1-2):393-404
Plant and Soil - Some studies have shown that an increasing atmospheric CO2 concentration reduces plant transpiration while others have demonstrated that it interacts with nutrients in soil to... 相似文献
73.
Agatha A. van der Klaauw Sophie Croizier Edson Mendes de Oliveira Lukas K.J. Stadler Soyoung Park Youxin Kong Matthew C. Banton Panna Tandon Audrey E. Hendricks Julia M. Keogh Susanna E. Riley Sofia Papadia Elana Henning Rebecca Bounds Elena G. Bochukova Vanisha Mistry Stephen O’Rahilly Richard B. Simerly I. Sadaf Farooqi 《Cell》2019,176(4):729-742.e18
74.
75.
Pathways governing G1/S transition and their response to DNA damage 总被引:21,自引:0,他引:21
The ability to self-replicate is a fundamental feature of life, reflected at the cellular level by a highly regulated process initiated in G1 phase via commitment to a round of DNA replication and cell division. Here we briefly highlight recent advances in understanding the molecular pathways which govern the decision of mammalian somatic cells to enter S phase, and the so-called cell cycle checkpoints which guard the G1/S transition and S phase progression against potentially deleterious effects of genotoxic stress. Particular emphasis is put on the emerging parallel yet cooperative pathways of retinoblastoma protein (pRB)–E2F and Myc, their convergence to control the activity of the cyclin-dependent kinase 2 (Cdk2) at the G1/S boundary, as well as the two waves of checkpoint responses at G1/S: the rapid pathway(s) leading to Cdc25A degradation, and the delayed p53–p21 cascade, both silencing the Cdk2 activity upon DNA damage. 相似文献
76.
77.
Gormann R Schreiber L Kolodziej H 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(9-10):631-635
Bignoniaceae, Newbouldia laevis, Markhamia acuminata, Spathodea campanulata and Kigelia africana were analysed by GC-MS. The principal constituents were represented by a homologous series of n-alkanes (C23-C33), n-alcohols (C18-C30) and related carboxylic acids (C16-C36). For N. laevis and M. acuminata, ursolic and oleanolic acid were the most abundant wax components (52 and 60%, respectively), followed by the C29, the C31 and the C33 n-alkanes. The predominant components of S. campanulata were n-alcohols (35%), with octacosanol and triacontanol as the most abundant ones, while K. africana is distinguished from these three members by the conspicuous absence of triterpenoic acids and the predominance of n-alkanes (70%) with hentriacontane and tritriacontane as the main representatives. Other notable constituents were sterols, albeit present in trace amounts. The wax profiles are discussed in terms of taxonomic characters. 相似文献
78.
Vrba J Modrianský M 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2004,148(2):141-144
In this study we examined whether microtubules and heat shock protein 90 (Hsp90) are involved in phorbol myristate acetate (PMA) and N-formyl-Met-Leu-Phe (fMLP)-induced oxidative burst in DMSO-differentiated HL-60 cells. Our results showed that microtubule interfering agents, paclitaxel (1-5 microM), colchicine (1-100 microM), nocodazole (1-20 microM), and vincristine (1-50 microM), did not affect either PMA or fMLP-induced oxidative burst. In contrast, radicicol, an inhibitor of Hsp90, inhibited fMLP-induced oxidative burst in time and concentration-dependent manner where IC50 value for 30 min pre-incubation was 16.5 +/- 3.5 microM radicicol. We conclude that both PMA and fMLP-induced oxidative burst in DMSO-differentiated HL-60 cells is microtubule-independent while the latter requires Hsp90 activity. 相似文献
79.
Lymphocytic choriomeningitis virus (LCMV) represents a useful experimental model of murine infection with a non-cytopathic virus, bearing resemblance to HIV and hepatitis C virus (HCV) infections in humans. Recent data from the LCMV model indicate that the humoral immune response that is induced by non-cytopathic viruses is far more complex than previously appreciated. LCMV-induced IgG production is largely polyclonal, with more than 90% of the antibody repertoire constituting non-relevant specificities. A delayed virus-neutralizing antibody response is induced, including specificities directed not only against the parental LCMV-strain present in the host but also cross-specifically against LCMV-variants isolated from other hosts. These findings provide novel insights to aid our understanding of clinically relevant observations that are recorded following human infection with HIV, HCV and dengue viruses. 相似文献
80.
Novak V Yang AC Lepicovsky L Goldberger AL Lipsitz LA Peng CK 《Biomedical engineering online》2004,3(1):39