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排序方式: 共有154条查询结果,搜索用时 31 毫秒
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Cold/Warm stenothermic freshwater macroinvertebrates along altitudinal and latitudinal gradients in Western South America: A modern approach to an old hypothesis with updated data
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Daniel A. Dos Santos Carlos Molineri Carolina Nieto María C. Zuñiga Daniel Emmerich Pablo Fierro Pablo Pessacq Blanca Rios‐Touma Javier Márquez Daniela Gomez Frederico F. Salles Andrea C. Encalada Romina Príncipe Graciela C. Gómez Claudio Valdovinos Zarges Eduardo Domínguez 《Journal of Biogeography》2018,45(7):1571-1581
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Hans-Joachim Emmerich Martin Saft Leonie Schneider Dennis Kock Alfred Batschauer Lars-Oliver Essen 《Nucleic acids research》2020,48(22):12845
Photolyases are ubiquitously occurring flavoproteins for catalyzing photo repair of UV-induced DNA damages. All photolyases described so far have a bilobal architecture with a C-terminal domain comprising flavin adenine dinucleotide (FAD) as catalytic cofactor and an N-terminal domain capable of harboring an additional antenna chromophore. Using sequence-similarity network analysis we discovered a novel subgroup of the photolyase/cryptochrome superfamily (PCSf), the NewPHLs. NewPHL occur in bacteria and have an inverted topology with an N-terminal catalytic domain and a C-terminal domain for sealing the FAD binding site from solvent access. By characterizing two NewPHL we show a photochemistry characteristic of other PCSf members as well as light-dependent repair of CPD lesions. Given their common specificity towards single-stranded DNA many bacterial species use NewPHL as a substitute for DASH-type photolyases. Given their simplified architecture and function we suggest that NewPHL are close to the evolutionary origin of the PCSf. 相似文献
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Preparative separations of plant cell organelles (glyoxysomes, proplastids, mitochondria, and endoplasmic reticulum) in an ordinary refrigerated centrifuge were obtained by sucrose density gradient centrifugation in a zonal rotor loaded and unloaded in the static manner. The quality of the separation which was monitored by marker enzymes and electron microscopy compares to analytical separations in swinging-bucket rotors. Membrane alterations observed in glyoxysomes and mitochondria are traced back to sucrose as a major component of the homogenization and density gradient medium. 相似文献
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Bauer C Dauer M Saraj S Schnurr M Bauernfeind F Sterzik A Junkmann J Jakl V Kiefl R Oduncu F Emmerich B Mayr D Mussack T Bruns C Rüttinger D Conrad C Jauch KW Endres S Eigler A 《Cancer immunology, immunotherapy : CII》2011,60(8):1097-1107
Background and aims
Dendritic cell (DC)-based vaccination can induce antitumor T cell responses in vivo. This clinical pilot study examined feasibility and outcome of DC-based tumor vaccination for patients with advanced pancreatic adenocarcinoma.Methods
Tumor lysate of patients with pancreatic carcinoma was generated by repeated freeze?Cthaw cycles of surgically obtained tissue specimens. Patients were eligible for DC vaccination after recurrence of pancreatic carcinoma or in a primarily palliative situation. DC were generated from peripheral blood mononuclear cells (PBMC), loaded with autologous tumor lysate, stimulated with TNF-?? and PGE2 and injected intradermally. All patients received concomitant chemotherapy with gemcitabine. Disease response was the primary endpoint. Individual immunological responses to DC vaccination were analyzed by T cell-based immunoassays using pre- and post-vaccination samples of non-adherent PBMC.Results
Twelve patients received DC vaccination and concomitant chemotherapy. One patient developed a partial remission, and two patients remained in stable disease. Median survival was 10.5?months. No severe side effects were observed. Tumor-reactive T cells could be detected prior to vaccination. DC vaccination increased the frequency of tumor-reactive cells in all patients tested; however, the degree of this increase varied. To quantify the presence of tumor-reactive T cells, stimulatory indices (SI) were calculated as the ratio of proliferation-inducing capacity of lysate-loaded versus -unloaded DC. The patient with longest overall survival of 56?months had a high SI of 6.49, indicating that the presence of a pre-vaccination antitumor T cell response might be associated with prolonged survival. Five patients survived 1?year or more.Conclusion
DC-based vaccination can stimulate an antitumoral T cell response in patients with advanced or recurrent pancreatic carcinoma receiving concomitant gemcitabine treatment. 相似文献98.
Germain M Saut N Greliche N Dina C Lambert JC Perret C Cohen W Oudot-Mellakh T Antoni G Alessi MC Zelenika D Cambien F Tiret L Bertrand M Dupuy AM Letenneur L Lathrop M Emmerich J Amouyel P Trégouët DA Morange PE 《PloS one》2011,6(9):e25581
Background
Venous Thrombosis (VT) is a common multifactorial disease associated with a major public health burden. Genetics factors are known to contribute to the susceptibility of the disease but how many genes are involved and their contribution to VT risk still remain obscure. We aimed to identify genetic variants associated with VT risk.Methodology/Principal Findings
We conducted a genome-wide association study (GWAS) based on 551,141 SNPs genotyped in 1,542 cases and 1,110 controls. Twelve SNPs reached the genome-wide significance level of 2.0×10−8 and encompassed four known VT-associated loci, ABO, F5, F11 and FGG. By means of haplotype analyses, we also provided novel arguments in favor of a role of HIVEP1, PROCR and STAB2, three loci recently hypothesized to participate in the susceptibility to VT. However, no novel VT-associated loci came out of our GWAS. Using a recently proposed statistical methodology, we also showed that common variants could explain about 35% of the genetic variance underlying VT susceptibility among which 3% could be attributable to the main identified VT loci. This analysis additionally suggested that the common variants left to be identified are not uniformly distributed across the genome and that chromosome 20, itself, could contribute to ∼7% of the total genetic variance.Conclusions/Significance
This study might also provide a valuable source of information to expand our understanding of biological mechanisms regulating quantitative biomarkers for VT. 相似文献99.
Verena S Brauer Maayke Stomp Camillo Rosso Sebastiaan AM van Beusekom Barbara Emmerich Lucas J Stal Jef Huisman 《The ISME journal》2013,7(11):2105-2115
Marine nitrogen-fixing cyanobacteria are largely confined to the tropical and subtropical ocean. It has been argued that their global biogeographical distribution reflects the physiologically feasible temperature range at which they can perform nitrogen fixation. In this study we refine this line of argumentation for the globally important group of unicellular diazotrophic cyanobacteria, and pose the following two hypotheses: (i) nitrogen fixation is limited by nitrogenase activity at low temperature and by oxygen diffusion at high temperature, which is manifested by a shift from strong to weak temperature dependence of nitrogenase activity, and (ii) high respiration rates are required to maintain very low levels of oxygen for nitrogenase, which results in enhanced respiratory cost per molecule of fixed nitrogen at low temperature. We tested these hypotheses in laboratory experiments with the unicellular cyanobacterium Cyanothece sp. . In line with the first hypothesis, the specific growth rate increased strongly with temperature from 18 to 30 °C, but leveled off at higher temperature under nitrogen-fixing conditions. As predicted by the second hypothesis, the respiratory cost of nitrogen fixation and also the cellular C:N ratio rose sharply at temperatures below 21 °C. In addition, we found that low temperature caused a strong delay in the onset of the nocturnal nitrogenase activity, which shortened the remaining nighttime available for nitrogen fixation. Together, these results point at a lower temperature limit for unicellular nitrogen-fixing cyanobacteria, which offers an explanation for their (sub)tropical distribution and suggests expansion of their biogeographical range by global warming. BG043511相似文献
100.
Annie M. Bérard Aurélie Bedel Rémi Le Trequesser Geneviève Freyburger Alan Nurden Sylvie Colomer Viviane Guérin Marie-Christine Vergnes Fran?ois Becker Gabriel Camelot Luc Bressolette Philippe Lacroix Jean-Pierre Cambou Alessandra Bura-Rivière Joseph Emmerich Michel Darmon Anne-Marie Deletraz Samir Mesli Brigitte Colombies Virginie Vanbrugghe Claude Conri Jo?l Constans 《PloS one》2013,8(3)