1,068 research outputs found
A study of the learning experiences in the eight week period of field instruction in public health nursing from the viewpoint of the student.
Thesis (M.S.)--Boston Universit
Cardiomiopatía mitocondrial de presentación neonatal
La función cardíaca depende principalmente de la producción de energía por parte de las mitocondrias. De allí que casi el 30% de la masa miocárdica corresponde a estas organelas. La cardiomiopatía mitocondrial neonatal o infantil resulta de una disfunción en alguno de los pasos de generación de energía a nivel de esa organela y frecuentemente se presenta con las características de una cardiopatía hipertrófica. En muchas oportunidades la heteroplasmía y heterogeneidad mitocondrial genera confusión para el diagnóstico por lo que el mismo requiere una investigación en forma multidisciplinaria.
Presentamos el caso de un RN con una cardiomiopatía mitocondrial típica cuyo diagnóstico fue corroborado por los hallazgos clínicos, de laboratorio y anátomo-patológico
Mechanochemical Synthesis of Multicomponent Crystals: One Liquid for One Polymorph? A Myth to Dispel
Identifying as many polymorphs as possible for a molecular compound is important in the design of materials with desired properties. In this paper we demonstrate, using a simple experimental procedure, how the amount of liquid present during liquid-assisted mechanochemical reactions can be used to rapidly explore polymorph diversity. Through detailed experimental evidence it is concluded that for the specific (multicomponent) crystal system investigated (caffeine−anthranilic acid) the commonly accepted rule “one liquid for one specific polymorph” is not correct. Additionally we demonstrate that through modification of the amount of added liquid it is possible to form a polymorph previously obtained only by a desolvation reaction. We believe that while the results raise many mechanistic questions the approach is advantageous as a means of rapidly screening for polymorph diversity as well as being a simple screening methodology. While we focus here on a cocrystal system, we believe a similar approach will be advantageous for single component systems.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/acs.cgd.6b0068
A strategy for grouping of nanomaterials based on key physico-chemical descriptors as a basis for safer-by-design NMs
SummaryThere is an urgent need to establish a fundamental understanding of the mechanisms of nanomaterial (NM) interaction with living systems and the environment, in order for regulation of NMs to keep pace with their increasing industrial application. Identification of critical properties (physicochemical descriptors) that confer the ability to induce harm in biological systems is crucial, enabling both prediction of impacts from related NMs (via quantitative nanostructure–activity relationships (QNARs) and read-across approaches) and development of strategies to ensure these features are avoided or minimised in NM production in the future (“safety by design”). A number of challenges to successful implementation of such a strategy exist, including: (i) the lack of widely available systematically varied libraries of NMs to enable generation of sufficiently robust datasets for development and validation of QNARs; (ii) the fact that many physicochemical properties of pristine NMs are inter-related and thus cannot be varied systematically in isolation from others (e.g. increasing surface charge may impact on hydrophobicity, or changing the shape of a NM may introduce defects or alter the atomic configuration of the surface); and (iii) the effect of ageing, transformation and biomolecule coating of NMs under environmental or biological conditions.A novel approach to identify interlinked physicochemical properties, and on this basis identify overarching descriptors (axes or principle components) which can be used to correlate with toxicity is proposed. An example of the approach is provided, using three principle components which we suggest can be utilised to fully describe each NM, these being the intrinsic (inherent) properties of the NM, composition (which we propose as a separate parameter) and extrinsic properties (interaction with media, molecular coronas etc.)
Cellular repair mechanisms triggered by exposure to silver nanoparticles and ionic silver in embryonic zebrafish cells
Quantitative or Qualitative: Selecting the Right Methodological Approach for Credible Evidence
This article provides insight into how an adequate approach to selecting methods can establish credible and actionable evidence. The authors offer strategies to effectively support Extension professionals, including program developers and evaluators, in being more deliberate when selecting appropriate qualitative and quantitative methods. In addition, several examples of commonly used measures are described to help in determining their applicability for evaluating Extension programs. Benefits and challenges of select methods are discussed as well as pitfalls to avoid that can derail the evaluative process. Lastly, a few cases are shared to present how Extension is aiming to establish credible evidence through state efforts and at the national level. The authors discuss the use of practical designs (e.g., common measures) that offer a more uniform way of evaluating programs. Examples are also included to highlight the effective use of Extension reporting systems that aim to streamline data collection, evaluation, and reporting as a means to ensure more credibility
Ariel - Volume 2 Number 8
Editors
Richard J. Bonanno
Robin A. Edwards
Associate Editors
Steven Ager
Stephen Flynn
Shep Dickman
Tom Williams
Lay-out Editor
Eugenia Miller
Contributing Editors
Michael J. Blecker
Milton Packe
James J. Nocon
Lynne Porter
Editors Emeritus
Delvyn C. Case, Jr.
Paul M. Fernhof
Exposure medium and particle ageing moderate the toxicological effects of nanomaterials to Daphnia magna over multiple generations:a case for standard test review?
- …