1,721,057 research outputs found
Particulate air pollution on London Underground: health effects
No full textCOMEAP statement on the evidence of health effects on the travelling public from exposure to particulate matter in the London Underground
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
Histone Acetylation and Chemoresistance in Colorectal Cancer: an Opportunity for Effective Personalized Treatment
Full text linkColorectal cancer (CRC) is the most common cause of deaths in the West. Despite many therapeutic opportunities, drug resistance or recurrence has significant rates among patients. Nearly 50% of CRC patients develop metastases. Therefore, sensitive biomarker and effective treatments with minimal toxicity are needed. Genetic and epigenetic alterations play major roles in initiation, development, and chemoresistance of CRC. Histone deacetylase2 (HDAC2) over-expression is well-known in CRC. Many studies have associated HDAC2 over-expression and TP53 mutations with late stages of metastatic CRC (mCRC). However, the relationship between HDAC2 expression level and TP53 status and mCRC drug resistance is unclear. Here, I have investigated HDAC2 role in drug resistance and assessed the synergistic effects of DNA chemotherapeutics agents and HDAC inhibitors (HDACIs) on TP53 status in mCRC cell lines. I have shown for the first time that in mutated p53 mCRC cells (Sw480 and HT-29) the steady-state level of HDAC2 is low compared to wild-type p53 cells (HCT116 p53+/+). I have also found that increase in HDAC2 expression level in the highly resistant cell line HT-29 enhances drug resistance and its depletion by shRNA sensitises HT-29 to 5Fluorouracil (5FU) or Oxaliplatin (Oxa). The combined treatment of suberoylanilide hydroxamic acid (SAHA)/5FU and SAHA/Oxa was able to reduced HDAC2 expression level and induced mitotic cell death. However, SAHA/Doxorubicin combined treatment induced cell death in wild-type p53 (HCT116 p53+/+), null p53 (HCT116 p53-/-), and SW480 cell lines. This cell death associated with decrease in HDAC2 level. I have shown the association between sensitivity to treatment and reduction of HDAC2 level via bioluminescence imaging in combination with liposomal-encapsulated SAHA/Doxorubicin delivery to monitor tumour growth. I have observed a significant decrease in tumour growth and HADC2 level. Therefore, I suggest that unlike mutated p53, HDAC2 could be an epigenetic prognostic biomarker to predict therapeutic response in mCRC
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
Metabolism and interactions of pesticides in human and animal <em>in vitro</em> hepatic models
No full textAbstractRisk assessment of chemicals needs reliable scientific information and one source of information is the characterization of the metabolic fate and toxicokinetics of a chemical. Metabolism is often the most important factor contributing to toxicokinetics. Cytochrome P450 (CYP) enzymes are a superfamily of microsomal proteins playing a pivotal role in xenobiotic metabolism. In the present study, pesticides were used as representative xenobiotics since exposure to pesticides is a global challenge to risk assessment. Human and animal in vitro hepatic models were applied with the advantage of novel analytical techniques (LC/TOF-MS and LC/MS-MS) to elucidate the in vitro metabolism and interaction of selected pesticides. The results of these studies demonstrate that CYP enzymes catalyze the bioactivation of profenofos, diuron and carbosulfan into their more toxic metabolites desthiopropylprofenofos, N-demethyldiuron and carbofuran, respectively. The suspected carcinogenic metabolite of metalaxyl, 2,6-dimethylaniline, was not detected. CYP3A4 and CYP2C19 activities may be important in determining the toxicity arising from exposure to profenofos and carbosulfan. Individuals with high CYP1A2 and CYP2C19 activities might be more susceptible to diuron toxicity. Qualitative results of in vitro metabolism were generally in agreement with the results obtained from the published in vivo data, at least for the active chemical moiety and major metabolites. Considerable differences in the quantities of the metabolites produced within the species, as well as in the ratios of the metabolites among the species, were observed. These findings illustrate that in vitro screening of qualitative and quantitative differences are needed to provide a firm basis for interspecies and in vitro-in vivo extrapolations. Based on our findings, in vitro-in vivo extrapolation based on the elucidation of the in vitro metabolic pattern of pesticides in human and animal hepatic models could be a good model for understanding and extending the results of pesticides metabolism studies to human health risk assessment. Academic dissertation to be presented with the assent of the Faculty of Medicine of the University of Oulu for public defence in the Auditorium of the Department of Pharmacology and Toxicology (Aapistie 5 B), on 26 November 2010, at 12 noonAbstract
Risk assessment of chemicals needs reliable scientific information and one source of information is the characterization of the metabolic fate and toxicokinetics of a chemical. Metabolism is often the most important factor contributing to toxicokinetics. Cytochrome P450 (CYP) enzymes are a superfamily of microsomal proteins playing a pivotal role in xenobiotic metabolism.
In the present study, pesticides were used as representative xenobiotics since exposure to pesticides is a global challenge to risk assessment. Human and animal in vitro hepatic models were applied with the advantage of novel analytical techniques (LC/TOF-MS and LC/MS-MS) to elucidate the in vitro metabolism and interaction of selected pesticides.
The results of these studies demonstrate that CYP enzymes catalyze the bioactivation of profenofos, diuron and carbosulfan into their more toxic metabolites desthiopropylprofenofos, N-demethyldiuron and carbofuran, respectively. The suspected carcinogenic metabolite of metalaxyl, 2,6-dimethylaniline, was not detected. CYP3A4 and CYP2C19 activities may be important in determining the toxicity arising from exposure to profenofos and carbosulfan. Individuals with high CYP1A2 and CYP2C19 activities might be more susceptible to diuron toxicity.
Qualitative results of in vitro metabolism were generally in agreement with the results obtained from the published in vivo data, at least for the active chemical moiety and major metabolites. Considerable differences in the quantities of the metabolites produced within the species, as well as in the ratios of the metabolites among the species, were observed.
These findings illustrate that in vitro screening of qualitative and quantitative differences are needed to provide a firm basis for interspecies and in vitro-in vivo extrapolations. Based on our findings, in vitro-in vivo extrapolation based on the elucidation of the in vitro metabolic pattern of pesticides in human and animal hepatic models could be a good model for understanding and extending the results of pesticides metabolism studies to human health risk assessment
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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