1,721,221 research outputs found
32P-postlabelling analysis of complex DNA adducts in human tissues
No full textComplex DNA adducts in humans originate from exogenous and endogenous sources. Polycyclic aromatic hydrocarbons (PAHs) are a large group of chemicals including many potent carcinogens. PAHs are ubiquitously present in the environment and PAH-DNA adducts have been extensively studied in humans. Endogenous processes such as lipid peroxidation are known to produce adduct-forming agents. The characteristics of many human adducts have not been identified. This thesis study focused on the analysis of these human adducts by the 32P-postlabelling technique.In order to detect the effects of air pollution resulted from engine exhaust on the aromatic adduct levels, PAH-DNA adducts were analysed in peripheral blood lymphocytes (PBL) of 53 newspaper vendors working at high and low traffic areas. No difference in adduct levels was found between the high and low exposed group. In west European cities, the airborne benzo[a]pyrene concentrations are usually 2-3 times higher in high traffic areas than in low traffic areas. Our results suggested that the effects of low-level air pollution could approach the limit that can be detected by the 32P-postlabelling assay. DNA samples isolated from PBL of 317 smoking and nonsmoking lung cancer patients and controls were analysed for the aromatic adducts in a case-control study. A significantly higher adduct level was observed in current smokers compared to never- or ex-smokers and there appeared to be a decreasing trend in adduct level with increasing time since last smoking. A slight decrease of adduct level with increasing age was shown in the entire study population, whereas a slight increase of adduct level with age was shown in current smokers. The increase was much stronger among current smoking patients. These results showed a clear effect of smoking on the lymphocytic aromatic adduct level and implied an interaction between smoking and genetic host factors. A 32P-postlabelling/HPLC (high-performance liquid chromatography) method using both nuclease P1 treatment and butanol extraction was developed and applied to the analysis of the lipophilic adducts in human tissues. Abundant adducts were detected in lung, colon, breast, skin and endometrial tissues and lymphocytes. These adducts exhibited tissue-specific and, in some tissues, complex patterns. In lung tissues, the lipophilic adduct levels were about 20 times higher than the aromatic adduct levels determined by a 32P-postlabelling/TLC (thin-layer chromatography) assay. The adduct levels in lymphocytes were shown not to be associated with smoking and occupational exposure to PAIL The adduct levels of two HPLC fractions in lymphocytes were found to be age-dependent. An adduct in lung tissue DNA was identified as a putative 2,3-epoxy-4-hydroxynonanal-induced adduct. These results suggested that at least part of the lipophilic adducts were of endogenous origin. When analysing the whole spectrum of DNA adducts which were resistant to nuclease P1 treatment in human tissues by a 32P-postlabelling/HPLC assay not using butanol extraction, more abundant DNA adducts were detected in the early eluting fractions. In these fractions, acrolein- and crotonaldehyde-induced endogenous DNA adducts were detected in human lymphocytes, and lung and colon tissues. These abundant adducts were also analysed in tumor and tumor-adjacent tissues from breast cancer patients and in the normal breast tissues of the controls. The tumor and tumor-adjacent tissues showed higher adduct levels than the normal tissues, with significance detected in three HPLC fractions. Adduct levels of three HPLC fractions were found to correlate significantly with age.</p
Supplemental Material - C1q/TNF-related protein-2 improved angiogenesis to protect myocardial function during ischaemia‒reperfusion
No full textSupplemental Material for C1q/TNF-related protein-2 improved angiogenesis to protect myocardial function during ischaemia‒reperfusion by Mingfang Ye, Qi-Hong Wu, Ke Yang, Yukun Luo in Diabetes and Vascular Disease Research</p
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
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
Surporting_Information-20190716 – Supplemental material for Synthesis and crystal structure of trifluoromethyl-containing bendamustine hydrochloride
No full textSupplemental material, Surporting_Information-20190716 for Synthesis and crystal structure of trifluoromethyl-containing bendamustine hydrochloride by Yue Yin, Huailiang Liu, Tangxin Xiao, Xiaoqiang Sun, Ke Yang and Zhengyi Li in Journal of Chemical Research</p
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