101,908 research outputs found
Advanced quantitative proteomics to evaluate molecular effects of low-molecular-weight hyaluronic acid in human dermal fibroblasts
Hyaluronic acid (HA) is physiologically synthesized by several human cells types but it is also a widespread ingredient of commercial products, from pharmaceuticals to cosmetics. Despite its extended use, the precise intra- and extra-cellular effects of HA at low-molecular-weight (LWM-HA) are currently unclear. At this regard, the aim of this study is to in-depth identify and quantify proteome's changes in normal human dermal fibroblasts after 24 h treatment with 0.125, 0.25 and 0.50 % LMW-HA (20−50 kDa) respectively, vs controls. To do this, a label-free quantitative proteomic approach based on high-resolution mass spectrometry was used. Overall, 2328 proteins were identified of which 39 significantly altered by 0.125 %, 149 by 0.25 % and 496 by 0.50 % LMW-HA. Protein networking studies indicated that the biological effects involve the enhancement of intracellular activity at all concentrations, as well as the extracellular matrix reorganization, proteoglycans and collagen biosynthesis. Moreover, the cell's wellness was confirmed, although mild inflammatory and immune responses were induced at the highest concentration. The more complete comprehension of intra- and extra-cellular effects of LMW-HA here provided by an advanced analytical approach and protein networking will be useful to further exploit its features and improve current formulations
ATMOSPHERIC-PRESSURE IONIZATION MASS-SPECTROMETRIC ANALYSIS OF NEW ANIONIC SURFACTANTS - THE ALKYLPOLYGLUCOSIDE ESTERS
Atmospheric-pressure ionization mass spectrometry has been successfully applied to characterization of a new class of anionic surfactants, the alkylpolyglucoside esters of sulfosuccic, citric and tartaric acid. Complex mixtures of final and intermediate products were injected directly into the ion source without prior chromatographic separation. The constituents were identified on the basis of quasi-molecular ions: cationized ions or solute-solute cluster ions in positive-ion mode, and deprotonated ions in negative-ion mode. The mass-spectrometric data show that all three final products contain one nonionic and two different types of anionic surfactants. The ''real time,'' highly sensitive mass-spectrometric approach proposed here is well suited for quality control testing of tensides, to ensure the safety of the final product, and far the validation of the manufacturing process, because it is able to identify the individual components of the mixture
[Regeneration of endogenous antioxidants, ascorbic acid, alpha tocopherol, by the oligomeric procyanide fraction of Vitus vinifera L.:ESR study]
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
Dieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
We 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
sj-pdf-1-imr-10.1177_03000605221101970 - Supplemental material for Programmed multi-level ventilation in COVID-19-related acute respiratory distress syndrome: a multi-center retrospective observational study
Supplemental material, sj-pdf-1-imr-10.1177_03000605221101970 for Programmed multi-level ventilation in COVID-19-related acute respiratory distress syndrome: a multi-center retrospective observational study by Filip Depta, Pavol Török, Andrew G. Miller, Peter Firment, Jozef Leškanič, Adam Porubän, Pavol Halaš, Stanislav Mandinec, Vladimír Filka, Henryk Zajac, Michael A. Gentile and Marko Zdravkovic: the DBDS Genomic Consortium in Journal of International Medical Research</p
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3346: Samuel G. Freedman, author, 2013
Photograph of author Samuel G. Freedman, at NT Daily Slash meeting in the Mayborn School of Journalism at UNT
DEM-Based Approach for the Modeling of Gelation and Its Application to Alginate
The gelation of biopolymers is of great interest in the material science community and has gained increasing relevance in the past few decades, especially in the context of aerogels-lightweight open nanoporous materials. Understanding the underlying gel structure and influence of process parameters is of great importance to predict material properties such as mechanical strength. In order to improve understanding of the gelation mechanism in aqueous solution, this work presents a novel approach based on the discrete element method for the mesoscale for modeling gelation of hydrogels, similarly to an extremely coarse-grained molecular dynamics (MD) approach. For this, polymer chains are abstracted as dimer units connected by flexible bonds and interactions between units and with the environment, that is, diffusion in implicit water, are described. The model is based on Langevin dynamics and includes an implicit probabilistic ion model to capture the effects of ion availability during ion-mediated gelation. The model components are fully derived and parameterized using literature data and theoretical considerations based on a simplified representation of atomistic processes. The presented model enables investigations of the higher-scale network formation during gelation on the micrometer and millisecond scale, which are beyond classical modeling approaches such as MD. As a model system, calcium-mediated alginate gelation is investigated including the influence of ion concentration, polymer composition, polymer concentration, and molecular weight. The model is verified against numerous literature data as well as own experimental results for the corresponding Ca-alginate hydrogels using nitrogen porosimetry, NMR cryoporometry, and small-angle neutron scattering. The model reproduces both bundle size and pore size distribution in a reasonable agreement with the experiments. Overall, the modeling approach paves the way to physically motivated design of alginate gels
The Right to Strike under the United States Constitution: Theory, Practice, and Possible Implications for Canada
Answering critics of the Canadian Supreme Court's judgment in B.C. Health, the author argues that the Court laid the foundation for a principled and durable doctrine protecting constitutional labour rights, one that goes directly to the heart of the matter — the inequality of workers’ power in the employment relation. In the author’s view, two paths could lead from B.C. Health to the recognition of Charter protec- tion for a right to strike: one that treats the right as an accessory to col- lective bargaining, and one that upholds the right directly on the basis of the Charter values of equality and participation. The author supports the latter approach, contending that constitutional rights should be defined in relation to fundamental values, in a way that is not contingent on time-bound or fact-sensitive assessments about the role of strikes within a particular collective bargaining regime. Although a Charter right to strike may involve the courts in difficult choices about when to defer to legislative policy decisions, and courts may lack the institutional capac- ity to deal effectively with labour law issues, the author points out that judges can look to ILO standards for expert guidance. Noting that the U.S. experience in this area might be of considerable use to Canadians, the author concludes by providing an overview of American case law concerning a constitutional right to strike.Peer reviewe
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