1,721,127 research outputs found
Meta-analysis: the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication.
No full textContains fulltext :
48800.pdf (Publisher’s version ) (Open Access)BACKGROUND: There is much debate about the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication. The few studies investigating the influence of pre-treatment on triple and quadruple therapies did not find differences in eradication rates. However, the high eradication rates make it difficult to study factors associated with therapy failure in small populations. In order to overcome this problem we performed a meta-analysis. METHODS: The literature was searched in order to identify randomized clinical trials comparing modern triple/quadruple therapies for H. pylori eradication without pre-treatment with a proton pump inhibitor with exactly the same regimen with pre-treatment. The overall risk difference (with - without pre-treatment) was calculated by pooling the risk differences of the individual studies weighted by the inverse of their variances. RESULTS: Nine studies, investigating a total of 773 patients, were identified. There was considerable variation regarding therapy regimen and duration. Pooled eradication rates were 81.3% (312 of 384) for patients with pre-treatment and 81.2% (316 of 389) for patients without pre-treatment. The (weighted) overall risk difference was 0.1% (95% CI: -5%; 5%). CONCLUSION: Pre-treatment with a proton pump inhibitor does not influence H. pylori eradication
Drug-Checking and Monitoring New Psychoactive Substances: Identification of the U-48800 Synthetic Opioid Using Mass Spectrometry, Nuclear Magnetic Resonance Spectroscopy, and Bioinformatic Tools
No full textThe misuse of opioids and opiates has remained a persistent issue since the 19th century. The recent resurgence of non-fentanyl synthetic opioids, such as U-type opioids and nitazenes, has further exacerbated the ongoing crisis. Identifying these synthetic opioids presents many challenges, including the emergence of new substances, the lack of standards, and the presence of structural isomers. This highlights the need for a robust structural characterisation strategy in forensic laboratories. To address these challenges, we developed a methodology to identify a U-type opioid sample received by Kosmicare from the European Union-funded SCANNER project, which was suspected to be either U-48800 or U-51754. Our innovative approach combined gas chromatography coupled with mass spectrometry (GC-MS), nuclear magnetic resonance spectroscopy (NMR), and molecular dynamics to characterise the questioned sample unequivocally. While the GC-MS analysis suggested a potential match with the mass spectrum of U-51754 and its structural isomer U-48800, NMR analysis confirmed the presence of U-48800 in the sample, which was further validated through molecular dynamics experiments. These experiments provided additional insights, confirming the structural features underlying the obtained NMR profile. The presented methodology offers a valuable solution for cases involving the identification of isomers, which are currently one of the most significant challenges in identifying new psychoactive substances
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Toxicokinetics and analytical toxicology of the abused opioid U‐48800 — in vitro metabolism, metabolic stability, isozyme mapping, and plasma protein binding
Get PDFDue to the risk of new synthetic opioids (NSOs) for human health, the knowledge of their toxicokinetic characteristics is important for clinical and forensic toxicology. U‐48800 is an NSO structurally non‐related to classical opioids such as morphine or fentanyl and offered for abuse. As toxicokinetic data of U‐48800 is not currently available, the aims of this study were to identify the in vitro metabolites of U‐48800 in pooled human liver S9 fraction (pS9), to map the isozymes involved in the initial metabolic steps, and to determine further toxicokinetic data such as metabolic stability, including the in vitro half‐life (t1/2), and the intrinsic (CLint) and hepatic clearance (CLh). Furthermore, drug detectability studies in rat urine should be done using hyphenated mass spectrometry. In total, 13 phase I metabolites and one phase II metabolite were identified. N‐Dealkylation, hydroxylation, and their combinations were the predominant metabolic reactions. The isozymes CYP2C19 and CYP3A4 were mainly involved in these initial steps. CYP2C19 poor metabolizers may suffer from an increased U‐48800 toxicity. The in vitro t1/2 and CLint could be rated as moderate, compared to structural related compounds. After administration of an assumed consumer dose to rats, the unchanged parent compound was found only in very low abundance but three metabolites were detected additionally. Due to species differences, metabolites found in rats might be different from those in humans. However, phase I metabolites found in rat urine, the parent compound, and additionally the N‐demethyl metabolite should be used as main targets in toxicological urine screening approaches
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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
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