1,720,964 research outputs found
CRISPR/Cas9 as a tool for the study of the interactions between viruses and host
No full textCRISPR/Cas9 in virolog
Development of new edited cell models to analyze pros and cons of the CRISPR/Cas9 technique
Full text linkThe CRISPR/Cas9 system is a powerful genome-editing tool and its great potential is thoroughly recognized. CRISPR/Cas9 has been applied in several fields, such as plant engineering, development of new cell lines, and animal models. CRISPR/Cas9 exploits a small single guide RNA to direct the Cas9 endonuclease activity against a specific genome sequence, where it introduces a double strand break. The DNA damage is then repaired by the non-homologous and joining or the homology direct repair processes. While the first one allows a gene knock out, the homology direct repair bases its activity on a repair template, thus allowing the introduction of specific modification within a gene target. In the present work, we aimed to analyze the pros and cons of the CRISPR/Cas9 system by developing new edited cell models, that will be useful to study the involvement of specific factors in different human diseases. Particularly, viral infections, cancer diseases, and neurodegenerative disorders represent a major issue for public health. The CRISPR/Cas9 system was fundamental to develop new cell lines useful to study host-retrovirus interaction, the involvement of specific proteins in tumorigenesis and cancer progression, and the importance of particular proteins in the onset of neurodegenerative disorders. Retroviral infection: host-virus interaction HIV-1 and HTLV-1 represent the two major human retroviruses. To assess how specific host proteins modulate HIV-1 infection, different 293T packaging cell lines were developed. Specifically, CRISPR/Cas9 was used to produce 293T ACOT8, HDAC6 ΔBUZ, and HLA-C KO cell lines. To investigate the involvement of TRAF3 in the deregulation of the NF-kB pathway mediated by the HTLV protein Tax1, a TRAF3 KO cell model was developed. Cancer diseases Malignant melanoma and pancreatic cancer are two of the most frequent morbidities. To analyze the oncogenic potential of RUNX2 in the development and progression of malignant melanoma, the Mel-HO RUNX2 KO melanoma cell line was developed through CRISPR/Cas9. To clarify the role of GNA15 in the molecular mechanisms leading to pancreatic adenocarcinoma, CRISPR/Cas9 was employed to generate PT45 GNA15 KO adenocarcinoma cells. Neurodegenerative diseases Neurodegenerative disorders are becoming even more frequent especially due to the increase in the average age of the population. Nowadays no effective cures are available. To understand the molecular mechanism by which GPR3 induces amyloid β deposition in Alzheimer’s disease, CRISPR/Cas9 was used to develop H4 Swe GPR3 KO neuroglioma cells. To fully investigate the involvement of the palmitoyl-protein thioesterase 1 PPT1, in the neuronal ceroid lipofuscinoses neurological disorder, SH-SY5Y PPT1 KO neuroblastoma cell line was developed. The CRISPR/Cas9 pros and cons are analyzed for a full technique understanding, with particular regard to its potential limits, such as off-targets, in vitro genome manipulation, delivery systems, and editing screening. As any technology revolution, CRISPR/Cas9 represents the linchpin of fierce debates involving many scientists and researchers to regulate its employment for gene therapy, germline, and human embryos manipulation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
CRISPR/Cas9 mediated knock-out of RUNX2 in melanoma cells
No full textIncidence of MM has increased considerably in consequence of lifestyle and environmental changes. The mortality rate for MM is very high as it is highly invasive and also genetically resistant to chemotherapeutic treatments. It has been reported that mutation rate and gene modulation in melanoma are higher than in other solid malignancies. In addition, transcription factors by acting on gene expression can affect cellular process. In particular a higher expression of RUNX2 in melanoma than in normal melanocytes have been shown. RUNX2 is overexpressed in several tumor tissues, including pancreatic cancer , breast cancer, ovarian epithelial cancer , prostate cancer , lung cancer and osteosarcoma. As no direct RUNX2 inhibitor is available and experiments performed with RNA interference were scarcely reproducible we applied Crisp/cas 9 technology to knockout the RUNT domain of RUNX2 in melanoma cell line. Crisp/Cas 9 tecnology was able to delete, partially, the RUNT domain. The deleted clone showed a reduced proliferation, reduced EMT features, reduced migration ability, suggesting the involvement of RUNT in different pathway of MM. In addition, the deleted clone showed a reduction of genes involved in migration ability and an increased expression of SSBP1 gene suggesting RUNT as oncotarget in MM
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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