1,720,956 research outputs found
Cleaning validation applications using Mid-Infrared quantum cascade laser spectroscopy
No full textAccording to the Recall Root Cause Research (RRCR), an initiative governed by the U.S. Food and Drug Administration (FDA), the contamination of pharmaceutical products is an alarming cause of public concern. During 2015, four hundred and fifty reported recalls were listed for: foods, drugs, pet medicine, biological products, medical devices, cosmetics, and tobacco. Therefore, the importance of developing a quantification method for cleanliness validation of manufacturing devices and vessels using direct and indirect surface sampling is presented. The proposed methodology was established to detect the presence residues of chemicals left as residues after cleaning of surfaces a result of manufacturing processes as well as foraneous microorganisms in the form of biofilms. These contaminants have been detected in real manufacturing substrates with mid-infrared (MIR) spectroscopy. A quantum cascade laser (QCL) aimed at various substrates containing the target residues was employed for developing methodologies for cleaning validation purposes. Stainless steel, TeflonTM and swabs are real substrates that were considered for direct transition of the methodology into a manufacturing environment. The adsorbate residues selected included over-the-counter active ingredients (OTC-AI), microorganisms, detergents and mixtures of these to simulate substrates contamination. This work was directed to assess constraints experienced in process analytical technology at-line or in-line using spectroscopic tools coupled with chemometric statistical methods. Quantitative and qualitative analysis of four microorganisms were evaluated: Bacillus subtilis, Burkholderia cepacia, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Detection limits and quantification limits, before and after chemometric analysis, were calculated for Bacillus subtilis and Burkholderia cepacia. A significant improvement was found with chemometric analysis with a detection limit of 7 and 13 CFU/mL for Burkholderia cepacia and Bacillus subtilis, respectively. The results compare very well to many techniques to quantify microorganisms, including polymerase chain reaction analysis, with quantification limit values of 45 and 20 CFU/mL for Burkholderia cepacia and Bacillus subtilis, respectively.Dado a que los eventos de recolección de productos por contaminación resultan ser costosos para la industria y para los consumidores, se deben establecer métodos de validación de limpieza. La Administración de Drogas y Alimentos de Estados Unidos (US-FDA, por sus siglas en inglés) ha exhortado a las compañías a establecer unas normas a seguir para mejorar la calidad de los productos. En adición a la subjetividad de la inspección visual, la FDA expresa que no es su responsabilidad la de proveer un rango estándar para límites de detección de limpieza. Debido a la alta cantidad de superficies de acero inoxidable que se utiliza en la industria, se propone una iniciativa de investigación. Durante el 2015, cuatrocientos cincuenta eventos de recolección de productos contaminados con microorganismos han ocurrido para comida, drogas, medicinas, dispositivos biológicos y médicos, cosméticos y el tabaco. Por lo tanto, la importancia para el desarrollo de un método de cuantificación directo e indirecto de residuos es vital para evitar contaminación farmacéutica o con microorganismos. Estos contaminantes se han detectado a nivel de trazas con espectroscopía infrarroja media. Para este propósito, se propone el uso de un láser de cascada cuántica acoplado a un sistema o arreglo óptico externo para alcanzar niveles de confiabilidad aceptables. Se utilizaron dos sistemas de láseres de cascada cuántica, uno acoplado a una ventana espectral de 800-1428 cm-1 y otro de 1000-1600 cm-1. Debido a la alta cantidad de superficies de acero inoxidable que se utiliza en la industria, se analizan en este estudio al igual que los hisopos. Los adsorbatos serán residuos seleccionados como ingredientes activos de farmacéuticos no-controlados, microorganismos, detergentes y mezclas para demostrar su viabilidad en eventos de contaminación. Este trabajo se dirige para aplicación bajo el proceso de tecnologías analíticas dentro de una línea o de forma contigua a este. Para este propósito, se utilizan herramientas multivariables de quimiometría acoplados a los análisis. Los análisis cuantitativos se llevaron a cabo para: Bacillus subtilis, Burkholderia cepacia, Staphylococcus aureus, Pseudomonas aeruginosa y Escherichia coli. Como una posible aplicación y prueba conceptual, se analizaron mezclas binarias de algunas bacterias con una de las formulaciones obtenidas donde se logró distinguir la señal y contribución por bacteria. Esto hace posible la determinación inmediata de contaminación de superficies metálicas. En adición, se obtuvieron límites de detección de 7 y 13 unidades formadoras de colonias para B. cepacia y B. subtilis los cuales fueron más bajos que métodos aceptados y estudiados en la literatura. Se obtuvieron límites de cuantificación de 45 y 20 unidades formadoras de colonias para B. cepacia y B. subtilis. Se validaron los parámetros de cuantificación con cromatografía líquida de alta presión acoplado a un arreglo de diodos (HPLC-DAD, por sus siglas en inglés). El límite de detección obtenido y validado por HPLC fue para el ácido salicílico con un valor de 7 μg/cm².U.S. Department of Homeland Security, Science and Technology Directorate, Office of University Programs, under Grant Award 2013-ST-061-ED0001.201
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
Relative quantification of proteins and post-translational modifications in proteomic experiments with shared peptides: a weight-based approach
No full textMotivation Bottom-up mass spectrometry-based proteomics studies changes in protein abundance and structure across conditions. Since the currency of these experiments are peptides, i.e. subsets of protein sequences that carry the quantitative information, conclusions at a different level must be computationally inferred. The inference is particularly challenging in situations where the peptides are shared by multiple proteins or post-translational modifications. While many approaches infer the underlying abundances from unique peptides, there is a need to distinguish the quantitative patterns when peptides are shared.Results We propose a statistical approach for estimating protein abundances, as well as site occupancies of post-translational modifications, based on quantitative information from shared peptides. The approach treats the quantitative patterns of shared peptides as convex combinations of abundances of individual proteins or modification sites, and estimates the abundance of each source in a sample together with the weights of the combination. In simulation-based evaluations, the proposed approach improved the precision of estimated fold changes between conditions. We further demonstrated the practical utility of the approach in experiments with diverse biological objectives, ranging from protein degradation and thermal proteome stability, to changes in protein post-translational modifications.Availability and implementation The approach is implemented in an open-source R package MSstatsWeightedSummary. The package is currently available at https://github.com/Vitek-Lab/MSstatsWeightedSummary (doi: 10.5281/zenodo.14662989). Code required to reproduce the results presented in this article can be found in a repository https://github.com/mstaniak/MWS_reproduction (doi: 10.5281/zenodo.14656053).This work was supported by the National Science Centre, Poland [grant Preludium 2020/37/N/ST6/04070 to M.S.]
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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