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排序方式: 共有141条查询结果,搜索用时 203 毫秒
91.
Ruben Bartali Alessandro Vaccari Victor Micheli Gloria Gottardi Rajesh Pandiyan Amos Collini Paolo Lori Gianni Coser Nadhira Laidani 《自然科学进展(英文版)》2014,24(3):287-290
The thin film hardness estimation by nanoindentation is influenced by substrate beyond a critical relative indentation depth(CRID). In this study we developed a methodology to identify the CRID in amorphous carbon film. Three types of amorphous carbon film deposited on silicon have been studied. The nanoindentation tests were carried out applying a 0.1–10 mN load range on a Berkovich diamond tip, leading to penetration depth-to-film thickness ratios of 8–100%. The work regained during unloading(We) and the work performed during loading(Wt) was estimated for each indentation. The trend of unload-to-load ratio(We/Wt) data as a function of depth has been studied. We/Wtdepth profiles showed a sigmoid trend and the data were fitted by means of a Hill sigmoid equation. Using Hill sigmoid fit and a simple analytical method it is possible to estimate CRID of carbon based films. 相似文献
92.
93.
Evolution of genes and genomes on the Drosophila phylogeny 总被引:2,自引:0,他引:2
Drosophila Genomes Consortium Clark AG Eisen MB Smith DR Bergman CM Oliver B Markow TA Kaufman TC Kellis M Gelbart W Iyer VN Pollard DA Sackton TB Larracuente AM Singh ND Abad JP Abt DN Adryan B Aguade M Akashi H Anderson WW Aquadro CF Ardell DH Arguello R Artieri CG Barbash DA Barker D Barsanti P Batterham P Batzoglou S Begun D Bhutkar A Blanco E Bosak SA Bradley RK Brand AD Brent MR Brooks AN Brown RH Butlin RK Caggese C Calvi BR Bernardo de Carvalho A Caspi A Castrezana S Celniker SE 《Nature》2007,450(7167):203-218
Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species. 相似文献
94.
Jun Su Hao Zhang Zhihong Li Paolo Ventura Yunju Li Ertao Li Chen Chen Yangping Shen Gang Lian Bing Guo Xinyue Li Liyong Zhang Jianjun He Yaode Sheng Yinji Chen Luohuan Wang Long Zhang Fuqiang Cao Wei Nan Weike Nan Gexing Li Na Song Baoqun Cui Lihua Chen Ruigang Ma Zhicheng Zhang Taoyu Jiao Bingshui Gao Xiaodong Tang Qi Wu Jiaqing Li Liangting Sun Shuo Wang Shengquan Yan Junhui Liao Youbao Wang Sheng Zeng Ding Nan Qiwen Fan Ningchun Qi Wenliang Sun Xuyuan Guo Peng Zhang Yunhua Chen Yong Zhou Jifang Zhou Jinrong He Changsong Shang Mingchuan Li Jianping Cheng Weiping Liu JUNA Collaboration 《科学通报(英文版)》2022,(2):125-132
The 25Mg(p,γ)26Al reaction plays an important role in the study of cosmic 1.809 MeV γ-ray as a signature of ongoing nucleosynthesis in the Galaxy.At astrophysic... 相似文献
95.
Lukas Trixl Thomas Amort Alexandra Wille Manuela Zinni Susanne Ebner Clara Hechenberger Felix Eichin Hanna Gabriel Ines Schoberleitner Anming Huang Paolo Piatti Roxana Nat Jakob Troppmair Alexandra Lusser 《Cellular and molecular life sciences : CMLS》2018,75(8):1483-1497
Chemical modifications of RNA have been attracting increasing interest because of their impact on RNA fate and function. Therefore, the characterization of enzymes catalyzing such modifications is of great importance. The RNA cytosine methyltransferase NSUN3 was recently shown to generate 5-methylcytosine in the anticodon loop of mitochondrial tRNAMet. Further oxidation of this position is required for normal mitochondrial translation and function in human somatic cells. Because embryonic stem cells (ESCs) are less dependent on oxidative phosphorylation than somatic cells, we examined the effects of catalytic inactivation of Nsun3 on self-renewal and differentiation potential of murine ESCs. We demonstrate that Nsun3-mutant cells show strongly reduced mt-tRNAMet methylation and formylation as well as reduced mitochondrial translation and respiration. Despite the lower dependence of ESCs on mitochondrial activity, proliferation of mutant cells was reduced, while pluripotency marker gene expression was not affected. By contrast, ESC differentiation was skewed towards the meso- and endoderm lineages at the expense of neuroectoderm. Wnt3 was overexpressed in early differentiating mutant embryoid bodies and in ESCs, suggesting that impaired mitochondrial function disturbs normal differentiation programs by interfering with cellular signalling pathways. Interestingly, basal levels of reactive oxygen species (ROS) were not altered in ESCs, but Nsun3 inactivation attenuated induction of mitochondrial ROS upon stress, which may affect gene expression programs upon differentiation. Our findings not only characterize Nsun3 as an important regulator of stem cell fate but also provide a model system to study the still incompletely understood interplay of mitochondrial function with stem cell pluripotency and differentiation. 相似文献
96.
Marieke Rienks Anna Papageorgiou Kristiaan Wouters Wouter Verhesen Rick van Leeuwen Paolo Carai Georg Summer Dirk Westermann Stephane Heymans 《Cellular and molecular life sciences : CMLS》2017,74(8):1511-1525
Background
Viral myocarditis can severely damage the myocardium through excessive infiltration of immune cells. Osteoglycin (OGN) is part of the small leucine-rich repeat proteoglycan (SLRP) family. SLRP’s may affect inflammatory and fibrotic processes, but the implication of OGN in cardiac inflammation and the resulting injury upon viral myocarditis is unknown.Methods and results
This study uncovered a previously unidentified 72-kDa variant of OGN that is predominant in cardiac human and mouse samples of viral myocarditis. Its absence in mice significantly decreased cardiac inflammation and injury in Coxsackievirus-B3-induced myocarditis. It also delayed mortality in lipopolysaccharide-induced endotoxemia going along with a reduced systemic production of pro-inflammatory cytokines. This 72-kDa OGN is expressed in the cell membrane of circulating and resident cardiac macrophages and neutrophils. Co-immunoprecipitation and OGN siRNA experiments revealed that this 72-kDa variant activates the toll-like receptor-4 (TLR4) with a concomitant increase in IL-6, TNF-α, IL-1β, and IL-12 expression. This immune cell activation by OGN occurred via MyD88 and increased phosphorylation of c-jun. Finally, the 72-kDa chondroitin sulfate is the result of O-linked glycosylation of the 32-kDa protein core of OGN. In contrast, the 34-kDa dermatan sulfate-OGN, involved in collagen cross linking, was also the result of O-linked glycosylation.Conclusion
The current study discovered a novel 72-kDa chondroitin sulfate-OGN that is specific for innate immune cells. This variant is able to bind and activate TLR4. The absence of OGN decreases cytokine production by both circulating and cardiac leukocytes upon (systemic) LPS exposure, and reduces cardiac inflammation and injury in viral myocarditis.97.
Qiao H He X Schymura D Ban L Field L Dani FR Michelucci E Caputo B della Torre A Iatrou K Zhou JJ Krieger J Pelosi P 《Cellular and molecular life sciences : CMLS》2011,68(10):1799-1813
To understand olfactory discrimination in Anopheles gambiae, we made six purified recombinant OBPs and investigated their ligand-binding properties. All OBPs were expressed in bacteria with additional production of OBP47 in the yeast Kluveromyces lactis. Ligand-binding experiments, performed with a diverse set of organic compounds, revealed marked differences between the OBPs. Using the fluorescent probe N-phenyl-1-naphthylamine, we also measured the binding curves for binary mixtures of OBPs and obtained, in some cases, unexpected behaviour, which could only be explained by the OBPs forming heterodimers with binding characteristics different from those of the component proteins. This shows that OBPs in mosquitoes can form complexes with novel ligand specificities, thus amplifying the repertoire of OBPs and the number of semiochemicals that can be discriminated. Confirmation of the likely role of heterodimers was demonstrated by in situ hybridisation, suggesting that OBP1 and OBP4 are co-expressed in some antennal sensilla of A. gambiae. 相似文献
98.
Anna Maria Frassanito Laura Barsanti Vincenzo Passarelli Valtere Evangelista Paolo Gualtieri 《Cellular and molecular life sciences : CMLS》2010,67(6):965-971
Here, we report the DNA sequence of the rhodopsin gene in the alga Cyanophora paradoxa (Glaucophyta). The primers were designed according to the conserved regions of prokaryotic and eukaryotic rhodopsin-like
proteins deposited in the GenBank. The sequence consists of 1,272 bp comprised of 5 introns. The correspondent protein, named
Cyanophopsin, showed high identity to rhodopsin-like proteins of Archea, Bacteria, Fungi, and Algae. At the N-terminal, the
protein is characterized by a region with no transmembrane α-helices (80 aa), followed by a region with 7α-helices (219 aa)
and a shorter 35-aa C-terminal region. The DNA sequence of the N-terminal region was expressed in E. coli and the recombinant purified peptide was used as antigen in hens to obtain polyclonal antibodies. Indirect immunofluorescence
in C. paradoxa cells showed a marked labeling of the muroplast (aka cyanelle) membrane. 相似文献
99.
Rothman N Garcia-Closas M Chatterjee N Malats N Wu X Figueroa JD Real FX Van Den Berg D Matullo G Baris D Thun M Kiemeney LA Vineis P De Vivo I Albanes D Purdue MP Rafnar T Hildebrandt MA Kiltie AE Cussenot O Golka K Kumar R Taylor JA Mayordomo JI Jacobs KB Kogevinas M Hutchinson A Wang Z Fu YP Prokunina-Olsson L Burdett L Yeager M Wheeler W Tardón A Serra C Carrato A García-Closas R Lloreta J Johnson A Schwenn M Karagas MR Schned A Andriole G Grubb R Black A Jacobs EJ Diver WR Gapstur SM 《Nature genetics》2010,42(11):978-984
We conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1: rs1014971, (P = 8 × 10?12) maps to a non-genic region of chromosome 22q13.1, rs8102137 (P = 2 × 10?11) on 19q12 maps to CCNE1 and rs11892031 (P = 1 × 10??) maps to the UGT1A cluster on 2q37.1. We confirmed four previously identified genome-wide associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P = 4 × 10?11) and a tag SNP for NAT2 acetylation status (P = 4 × 10?11), and found interactions with smoking in both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into the mechanisms of carcinogenesis. 相似文献
100.
A functional variant of SUMO4, a new I kappa B alpha modifier, is associated with type 1 diabetes 总被引:23,自引:0,他引:23