18 research outputs found
Unusual mechanisms in Claisen rearrangements: an ionic fragmentation leading to a meta-selective rearrangement
A mechanistic investigation of the acid-catalysed redox-neutral oxoarylation reaction of ynamides using electrospray ionisation mass-spectrometry (ESI-MS) and quantum chemical calculations (DFT and MP2) is presented. This study reveals the diversity of pathways and products available from an otherwise deceptively simple-looking, classical transformation: fragmentation, an unusual meta-arylation and competing α-carbonyl cation pathways are some of the alternatives unveiled by ESI-MS and mechanistic experiments. Detailed calculations explain the observed trends and rationalise the results.© The Royal Society of Chemistry 201
Developing a programmatic approach to faculty development and scholarship using the ASPIRE criteria: AMEE Guide No. 165
Faculty Development (FD) has become essential in shaping design, delivery and quality assurance of health professions education. The growth of FD worldwide has led to a heightened expectation for quality and organizational integrity in the delivery of FD programmes. To address this, AMEE, An International Association for Health Professions Education, developed quality standards for FD through the development of the AMEE ASPIRE to Excellence criteria. This guide uses the ASPIRE criteria as a framework for health professions educators who wish to establish or expand approaches to FD delivery and scholarship within their institutions
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Landmark Central Venous Catheterization is Effective but Ultrasound Helps Even in Experienced Hands
Evaluation of Extension Reforms in Brazil
To evaluate the impacts of the rural extension policy (PNATER), five territories were selected in three different Brazilian states, including Alto Jequitinhonha (Minas Gerais State), Cantuquiriguaçu (Paraná State), Pontal do Paranapanema (São Paulo State), São Paulo’s Southwestern (São Paulo State), and Vale do Ribeira (Paraná State). An indicator system was elaborated to collect and analyze data from farmers and extension agents in each territory. 12 indicators were proposed to accomplish the desired evaluation. These indicators express the meaningful aspects of the extension reform policy document’s values, principles, and objectives.
Data collection instruments were composed of questionnaires focusing on objective questions, allowing only closed answers to identify the interviewee’s perception of his or her reality. The possibilities for responses were elaborated on a five-point Likert scale—from the least to the greatest—asking respondents to indicate how much they agree or disagree, approve or disapprove, or believe to be true or false. The questionnaire for family farmers was composed of 56 questions, encompassing different indicators, among which three were specific for black rural and indigenous communities. The researchers also added questions from the Brazilian Food Insecurity Scale.
In total researchers conducted 1,000 interviews with farmers and 87 interviews with extensionists (in some territories the goal of 20 interviews with the extensionists in each territory was not achieved due to the difficulty in contacting them or their unavailability in the study period) in the five territories between August 2014 to January 2015.</p
Data underpinning - Fluorine in fragrances: Exploring the difluoromethylene (CF2) group as a conformational constraint in macrocyclic musk lactones.
Dataset for "Predicting Ligand-Free Cell Attachment on Next Generation Cellulose-Chitosan Hydrogels"
There is a growing appreciation that engineered biointerfaces can regulate cell behaviors, or functions. Most systems aim to mimic the cell-friendly extracellular matrix environment and incorporate protein ligands; however, the understanding of how a ligand-free system can achieve this is limited. Cell scaffold materials comprised of interfused chitosan–cellulose hydrogels promote cell attachment in ligand-free systems, and these data were used to demonstrate the role of cellulose molecular weight (MW) and chitosan content and MW in controlling material properties and thus regulating cell attachment. Included are the data used for determining gel shear moduli; data used in cell attachment regression models and for determining average cell attachment; combined DAPI and FITC images of 24 hour cell morphology studies; data used for determining median cell aspect ratio, cell aspect ratio distribution, and median cell area; UV-vis adsorbance data; confocal microscopy data used for calculating chitosan penetration into cellulose gels; FTIR spectra data and fitted curves; scanning probe microscopy data used for determining gel surface roughness and capacitive coupling; and measurements of chitosan MW and gel surface zeta-potential
Dataset for "Predicting Ligand-Free Cell Attachment on Next Generation Cellulose-Chitosan Hydrogels"
There is a growing appreciation that engineered biointerfaces can regulate cell behaviors, or functions. Most systems aim to mimic the cell-friendly extracellular matrix environment and incorporate protein ligands; however, the understanding of how a ligand-free system can achieve this is limited. Cell scaffold materials comprised of interfused chitosan–cellulose hydrogels promote cell attachment in ligand-free systems, and these data were used to demonstrate the role of cellulose molecular weight (MW) and chitosan content and MW in controlling material properties and thus regulating cell attachment. Included are the data used for determining gel shear moduli; data used in cell attachment regression models and for determining average cell attachment; combined DAPI and FITC images of 24 hour cell morphology studies; data used for determining median cell aspect ratio, cell aspect ratio distribution, and median cell area; UV-vis adsorbance data; confocal microscopy data used for calculating chitosan penetration into cellulose gels; FTIR spectra data and fitted curves; scanning probe microscopy data used for determining gel surface roughness and capacitive coupling; and measurements of chitosan MW and gel surface zeta-potential
Supplementary Material for: Development of Gold Standard Ion-Selective Electrode-Based Methods for Fluoride Analysis
Background/Aims: Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research. Methods: A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode. Results: Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies. Conclusion: The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values