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Quick Screening (quick + screening)

Distribution by Scientific Domains
Chemistry60%
Medical Sciences40%

Selected Abstracts

Quick Screening of Crystal Methamphetamine/Methyl Sulfone Exhibits by Raman Spectroscopy

JOURNAL OF FORENSIC SCIENCES, Issue 4 2010
Robert G. Weston M.Sc.
Abstract:, The analysis of mixtures of "crystal meth" (usually comprised of methyl sulfone [MS] and methamphetamine [MA]) by gas chromatography-mass spectrometry (GCMS) is routine in many forensic drug laboratories. The utilization of Raman spectroscopy for the identification of such mixtures quickly and without the need for a separation technique is discussed. Samples were dissolved in water and Raman spectra of the resulting aqueous solutions were collected. By comparing these spectra to spectra of methylsulfone and MA mixtures of known composition, an indication of the composition of the sample can be obtained in only a few minutes. This spectral comparison also can be used as a semi-quantitative analysis of MA concentrations in such exhibits. [source]

The Brief Kingston Standardized Cognitive Assessment,Revised

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 3 2005
Robert W. Hopkins
Abstract Objectives The Kingston Standardized Cognitive Assessment,Revised (KSCA-R) was designed to be a cognitive screening tool available to health professionals who were not trained in specialized cognitive assessment techniques. It was introduced to bridge the gap between brief, narrowly focused rating scales, and intensive, expensive, full neuropsychological assessments. We now present the Brief Kingston Standardized Cognitive Assessment,Revised (BriefKSCA-R). Methods Groups of Alzheimer's disease patients, patients suffering from other dementias, and a group of normal community dwelling elderly were assessed using the BriefKSCA-R. Results This shortened version of the full Kingston Standardized Cognitive Assessment,Revised can be given in half the time while retaining most of the full KSCA-R's effectiveness. Conclusions Suitable for a quick screening, or follow-up of patients already more fully assessed. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Rational design of shape selective separations and catalysis: Lattice relaxation and effective aperture size

AICHE JOURNAL, Issue 3 2010
Chrysanthos E. Gounaris
Abstract Gounaris et al. presented a computational method that can be used for the quick screening of zeolite structures and provide predictions regarding which of them have the potential to exhibit high selectivity among a set of molecules of interest. This article builds upon this earlier work and furthers our understanding of diffusion processes in zeolites and other microporous metal oxides. We first present an augmented formulation to account for the flexibility of the zeolitic portal and conduct an analysis to assess the effect of varying the parameters of the associated quadratic potential. We then introduce a methodology to map the energetic landscape, identify all locally optimal conformations, and probabilistically account for the multiplicity of conformers. Finally, we conduct sensitivity analysis on the effective size of the aperture, and show how the methodology can be fine,tuned through experimental observations. A comprehensive database of 290 molecules of industrial interest and a total of 123 different zeolite structures were used in this study. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

Screening of Plant Extracts for Antioxidant Activity: a Comparative Study on Three Testing Methods

PHYTOCHEMICAL ANALYSIS, Issue 1 2002
Irina I. Koleva
Abstract Three methods widely employed in the evaluation of antioxidant activity, namely 2,2,-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and ,-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Can We Increase the Estimative Value of Semen Assessment?*

REPRODUCTION IN DOMESTIC ANIMALS, Issue 2006
H Rodríguez-Martínez
Contents Estimating the fertility of a semen sample or of the male from where it has been collected by simple assessment of in vitro sperm characteristics is still difficult, owing to the variable correlations that laboratory results achieve with in vivo fertility. A major reason behind these variations is the fact that the ejaculate and the artificial insemination (AI)-doses it generates are composed of a diverse sperm population. Such heterogeneity is reflected both in differences of intactness of attributes needed for fertilization, such as motility or morphology, but also in the relative ability of spermatozoa to prevail fertile over time, handling and exposure to different stimuli, all of which account for innate variations in fertilizing ability among doses, ejaculates and sires. However, methods are already available to select sub-populations of intact spermatozoa which can be tested for their degree of competence for fertilization and whose estimative power is promising, allowing the elimination of cases of sub-fertility, particularly in bovine. Examples of these methods are the separation of viable spermatozoa by swim-up or discontinuous gradient centrifugation, followed by testing the ability of the selected spermatozoa to dose-response/time sustain capacitation and acrosome reaction induction. Finding how large a sperm population with non-compensable attributes for fertilization and ability to display and sustain stimuli is, perhaps by a quick screening of membrane integrity and stability by multi-parametric methods, would allow, provided the particular male produces this sub-population in a repeatable manner, for a better estimation of fertility. [source]