排序方式: 共有112条查询结果,搜索用时 93 毫秒
31.
Recent years have witnessed waves of protests sweeping across countries and continents, in some cases resulting in political and governmental change. Much media attention has been focused on the increasing usage of social media to coordinate and provide instantly available reports on these protests. Here, we investigate whether it is possible to identify protest outbreaks through quantitative analysis of activity on the photo sharing site Flickr. We analyse 25 million photos uploaded to Flickr in 2013 across 244 countries and regions, and determine for each week in each country and region what proportion of the photographs are tagged with the word “protest” in 34 different languages. We find that higher proportions of “protest”-tagged photographs in a given country and region in a given week correspond to greater numbers of reports of protests in that country and region and week in the newspaper The Guardian. Our findings underline the potential value of photographs uploaded to the Internet as a source of global, cheap and rapidly available measurements of human behaviour in the real world. 相似文献
32.
33.
Alamdar Hussain Dara K. Mohammad Manuela O. Gustafsson Merve Uslu Abdulrahman Hamasy Beston F. Nore Abdalla J. Mohamed C. I. Edvard Smith 《The Journal of biological chemistry》2013,288(10):7338-7350
The inducible T cell kinase-spleen tyrosine kinase (ITK-SYK) oncogene consists of the Tec homology-pleckstrin homology domain of ITK and the kinase domain of SYK, and it is believed to be the cause of peripheral T cell lymphoma. We and others have recently demonstrated that this fusion protein is constitutively tyrosine-phosphorylated and is transforming both in vitro and in vivo. To gain a deeper insight into the molecular mechanism(s) underlying its activation and signaling, we mutated a total of eight tyrosines located in the SYK portion of the chimera into either phenylalanine or to the negatively charged glutamic acid. Although mutations in the interdomain-B region affected ITK-SYK kinase activity, they only modestly altered downstream signaling events. In contrast, mutations that were introduced in the kinase domain triggered severe impairment of downstream signaling. Moreover, we show here that SLP-76 is critical for ITK-SYK activation and is particularly required for the ITK-SYK-dependent phosphorylation of SYK activation loop tyrosines. In Jurkat cell lines, we demonstrate that expression of ITK-SYK fusion requires an intact SLP-76 function and significantly induces IL-2 secretion and CD69 expression. Furthermore, the SLP-76-mediated induction of IL-2 and CD69 could be further enhanced by SYK or ZAP-70, but it was independent of their kinase activity. Notably, ITK-SYK expression in SYF cells phosphorylates SLP-76 in the absence of SRC family kinases. Altogether, our data suggest that ITK-SYK exists in the active conformation state and is therefore capable of signaling without SRC family kinases or stimulation of the T cell receptor. 相似文献
34.
35.
Yuce Merve Ozkirimli Elif Sariyar Akbulut Berna Ulgen Kutlu 《International journal of peptide research and therapeutics》2021,27(3):2003-2013
International Journal of Peptide Research and Therapeutics - Cell penetrating peptides (CPPs) are unique molecules with the ability to pass through biological membranes as they carry their cargoes... 相似文献
36.
The cycle of duplication and division, known as the cell cycle, is the essential mechanism by which all living organisms reproduce. This activity allows students to develop an understanding of the main events that occur during the typical eukaryotic cell cycle mostly in the process of mitotic phase that divides the duplicated genetic material creating two genetically identical daughter cells. 相似文献
37.
38.
Kekecoglu Meral Sonmez Emine Acar Merve Kambur Karaoglu Sengul Alpay 《Biology Bulletin》2022,48(3):S145-S145
Biology Bulletin - An Erratum to this paper has been published: https://doi.org/10.1134/S1062359022330019 相似文献
39.
Huseyin Balci Merve Tuzlakoglu Ozturk Tjaard Pijning Saliha Issever Ozturk Fusun Gumusel 《Applied microbiology and biotechnology》2014,98(10):4467-4477
Penicillin G acylase is the key enzyme used in the industrial production of β-lactam antibiotics. This enzyme hydrolyzes penicillin G and related β-lactam antibiotics releasing 6-aminopenicillanic acid, which is an intermediate in the production of semisynthetic penicillins. To improve the enzymatic activity of Escherichia coli penicillin acylase, sequential rounds of error-prone polymerase chain reaction were applied to the E. coli pac gene. After the second round of evolution, the best mutant M2234 with enhanced activity was selected and analyzed. DNA sequence analyses of M2234 revealed that one amino acid residue (K297I), located far from the center of the catalytic pocket, was changed. This mutant (M2234) has a specific activity 4.0 times higher than the parent enzyme and also displayed higher stability at pH 10. 相似文献
40.