2,403 research outputs found
Low temperature scattering with the R-matrix method: the Morse potential
Experiments are starting to probe collisions and chemical reactions between
atoms and molecules at ultra-low temperatures. We have developed a new
theoretical procedure for studying these collisions using the R-matrix method.
Here this method is tested for the atom -- atom collisions described by a Morse
potential. Analytic solutions for continuum states of the Morse potential are
derived and compared with numerical results computed using an R-matrix method
where the inner region wavefunctions are obtained using a standard nuclear
motion algorithm. Results are given for eigenphases and scattering lengths.
Excellent agreement is obtained in all cases. Progress in developing a general
procedure for treating ultra-low energy reactive and non-reactive collisions is
discussed.Comment: 18 pages, 6 figures, 3 tables, conferenc
La adhesión de las enfermeras al Método Canguro: subvención para la administración del cuidado de enfermería
;;OBJETIVO:;; construir um modelo teórico explicativo acerca da adesão das enfermeiras ao Método Canguru na Unidade de Terapia Intensiva Neonatal, a partir dos significados e interações para a gerência do cuidado.;;;;MÉTODO:;; pesquisa qualitativa, guiada pelo referencial da Grounded Theory. Foram entrevistadas oito enfermeiras de uma Unidade de Terapia Intensiva Neonatal da cidade do Rio de Janeiro. A análise comparativa dos dados percorreu as etapas de codificação aberta, axial e seletiva, sendo construído um modelo teórico do tipo condicional-causal.;;;;RESULTADOS:;; emergiram quatro categorias principais que compuseram o paradigma de análise: Vestindo a camisa do Método Canguru; Trabalhando com a complexidade do Método Canguru; Encontrando (des)motivação para aplicar o Método Canguru; e Deparando-se com os desafios para a adesão e aplicação do Método Canguru.;;;;CONCLUSÕES:;; o fenômeno central revelou que cada enfermeira e profissional da equipe possui um papel de multiplicador de valores e práticas que podem ou não ser construtivas, influenciando potencialmente na (des)continuidade do Método Canguru na Unidade de Terapia Intensiva Neonatal. Os achados podem ser utilizados para o delineamento de estratégias gerenciais que ultrapassem os cursos e treinamentos e garantam o fortalecimento do modelo assistencial.;;;;OBJECTIVE:;; construct an explanatory theoretical model about nurses' adherence to the Kangaroo Care Method at the Neonatal Intensive Care Unit, based on the meanings and interactions for care management.;;;;METHOD:;; qualitative research, based on the reference framework of the Grounded Theory. Eight nurses were interviewed at a Neonatal Intensive Care Unit in the city of Rio de Janeiro. The comparative analysis of the data comprised the phases of open, axial and selective coding. A theoretical conditional-causal model was constructed.;;;;RESULTS:;; four main categories emerged that composed the analytic paradigm: Giving one's best to the Kangaroo Method; Working with the complexity of the Kangaroo Method; Finding (de)motivation to apply the Kangaroo Method; and Facing the challenges for the adherence to and application of the Kangaroo Method.;;;;CONCLUSIONS:;; the central phenomenon revealed that each nurse and team professional has a role of multiplying values and practices that may or may not be constructive, potentially influencing the (dis)continuity of the Kangaroo Method at the Neonatal Intensive Care Unit. The findings can be used to outline management strategies that go beyond the courses and training and guarantee the strengthening of the care model.;;;;OBJETIVO:;; construir un modelo teórico explicativo acerca de la adhesión de las enfermeras al Método Canguro en la Unidad de Terapia Intensiva Neonatal, a partir de los significados e interacciones para la administración del cuidado.;;;;MÉTODO:;; investigación cualitativa, guiada por el referencial de la Grounded Theory. Fueron entrevistadas ocho enfermeras de una Unidad de Terapia Intensiva Neonatal de la ciudad de Rio de Janeiro. El análisis comparativo de los datos recorrió las etapas de codificación abierta, axial y selectiva, siendo construido un modelo teórico del tipo condicional-causal.;;;;RESULTADOS:;; surgieron cuatro categorías principales que compusieron los paradigmas del análisis: Vistiendo la camisa del Método Canguro; Trabajando con la complejidad del Método Canguro; Encontrando (des)motivación para aplicar el Método Canguro; y Encontrando los desafíos para la adhesión y aplicación del Método Canguro.;;;;CONCLUSIONES:;; el fenómeno central reveló que cada enfermera y profesional del equipo posee un papel de multiplicador de valores y prácticas que pueden o no ser constructivas, influenciando potencialmente en la (des)continuidad del Método Canguro en la Unidad de Terapia Intensiva Neonatal. Los hallazgos pueden ser utilizados para el delineamiento de estrategias de administración que sobrepasen los cursos y entrenamientos y garanticen el fortalecimiento del modelo asistencial.;
The All-Data-Based Evolutionary Hypothesis of Ciliated Protists with a Revised Classification of the Phylum Ciliophora (Eukaryota, Alveolata)
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ The file attached is the published version of the article
Counter-current chromatography for the separation of terpenoids: A comprehensive review with respect to the solvent systems employed
Copyright @ 2014 The Authors.This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Natural products extracts are commonly highly complex mixtures of active compounds and consequently their purification becomes a particularly challenging task. The development of a purification protocol to extract a single active component from the many hundreds that are often present in the mixture is something that can take months or even years to achieve, thus it is important for the natural product chemist to have, at their disposal, a broad range of diverse purification techniques. Counter-current chromatography (CCC) is one such separation technique utilising two immiscible phases, one as the stationary phase (retained in a spinning coil by centrifugal forces) and the second as the mobile phase. The method benefits from a number of advantages when compared with the more traditional liquid-solid separation methods, such as no irreversible adsorption, total recovery of the injected sample, minimal tailing of peaks, low risk of sample denaturation, the ability to accept particulates, and a low solvent consumption. The selection of an appropriate two-phase solvent system is critical to the running of CCC since this is both the mobile and the stationary phase of the system. However, this is also by far the most time consuming aspect of the technique and the one that most inhibits its general take-up. In recent years, numerous natural product purifications have been published using CCC from almost every country across the globe. Many of these papers are devoted to terpenoids-one of the most diverse groups. Naturally occurring terpenoids provide opportunities to discover new drugs but many of them are available at very low levels in nature and a huge number of them still remain unexplored. The collective knowledge on performing successful CCC separations of terpenoids has been gathered and reviewed by the authors, in order to create a comprehensive document that will be of great assistance in performing future purifications. © 2014 The Author(s)
The role of enzyme replacement therapy in severe Hunter syndrome—an expert panel consensus
Intravenous enzyme replacement therapy (ERT) with idursulfase for Hunter syndrome has not been demonstrated to and is not predicted to cross the blood–brain barrier. Nearly all published experience with ERT with idursulfase has therefore been in patients without cognitive impairment (attenuated phenotype). Little formal guidance is available on the issues surrounding ERT in cognitively impaired patients with the severe phenotype. An expert panel was therefore convened to provide guidance on these issues. The clinical experience of the panel with 66 patients suggests that somatic improvements (e.g., reduction in liver volume, increased mobility, and reduction in frequency of respiratory infections) may occur in most severe patients. Cognitive benefits have not been seen. It was agreed that, in general, severe patients are candidates for at least a 6–12-month trial of ERT, excluding patients who are severely neurologically impaired, those in a vegetative state, or those who have a condition that may lead to near-term death. It is imperative that the treating physician discuss the goals of treatment, methods of assessment of response, and criteria for discontinuation of treatment with the family before ERT is initiated. Conclusion: The decision to initiate ERT in severe Hunter syndrome should be made by the physician and parents and must be based on realistic expectations of benefits and risks, with the understanding that ERT may be withdrawn in the absence of demonstrable benefits
Structure-Activity Relationship of Cinnamaldehyde Analogs as Inhibitors of AI-2 Based Quorum Sensing and Their Effect on Virulence of Vibrio spp
Background: Many bacteria, including Vibrio spp., regulate virulence gene expression in a cell-density dependent way through a communication process termed quorum sensing (QS). Hence, interfering with QS could be a valuable novel antipathogenic strategy. Cinnamaldehyde has previously been shown to inhibit QS-regulated virulence by decreasing the DNA-binding ability of the QS response regulator LuxR. However, little is known about the structure-activity relationship of cinnamaldehyde analogs. Methodology/Principal Findings: By evaluating the QS inhibitory activity of a series of cinnamaldehyde analogs, structural elements critical for autoinducer-2 QS inhibition were identified. These include an alpha, beta unsaturated acyl group capable of reacting as Michael acceptor connected to a hydrophobic moiety and a partially negative charge. The most active cinnamaldehyde analogs were found to affect the starvation response, biofilm formation, pigment production and protease production in Vibrio spp in vitro, while exhibiting low cytotoxicity. In addition, these compounds significantly increased the survival of the nematode Caenorhabditis elegans infected with Vibrio anguillarum, Vibrio harveyi and Vibrio vulnificus. Conclusions/Significance: Several new and more active cinnamaldehyde analogs were discovered and they were shown to affect Vibrio spp. virulence factor production in vitro and in vivo. Although ligands for LuxR have not been identified so far, the nature of different cinnamaldehyde analogs and their effect on the DNA binding ability of LuxR suggest that these compounds act as LuxR-ligands
Drug Repurposing: Far Beyond New Targets for Old Drugs
Repurposing drugs requires finding novel therapeutic indications compared to the ones for which they were already approved. This is an increasingly utilized strategy for finding novel medicines, one that capitalizes on previous investments while derisking clinical activities. This approach is of interest primarily because we continue to face significant gaps in the drug–target interactions matrix and to accumulate safety and efficacy data during clinical studies. Collecting and making publicly available as much data as possible on the target profile of drugs offer opportunities for drug repurposing, but may limit the commercial applications by patent applications. Certain clinical applications may be more feasible for repurposing than others because of marked differences in side effect tolerance. Other factors that ought to be considered when assessing drug repurposing opportunities include relevance to the disease in question and the intellectual property landscape. These activities go far beyond the identification of new targets for old drugs
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