EarlyView Articles

Unedited in vivo detection and quantification of γ‐aminobutyric acid in the occipital cortex using short‐TE MRS at 3 T

Published: May 22, 2013

Author(s): Jamie Near, Jesper Andersson, Eduard Maron, Ralf Mekle, Rolf Gruetter, Philip Cowen, Peter Jezzard

Journal: NMR in Biomedicine

Short‐TE MRS has been proposed recently as a method for the in vivo detection and quantification of γ‐aminobutyric acid (GABA) in the human brain at 3 T. In this study, we investigated the accuracy and reproducibility of short‐TE MRS measurements of GABA at 3 T using both simulations and experiments. LCModel analysis was performed on a large number of simulated spectra with known metabolite input concentrations. Simulated spectra were generated ...

An embedded four‐channel receive‐only RF coil array for fMRI experiments of the somatosensory pathway in conscious awake marmosets

Published: May 22, 2013

Author(s): Daniel Papoti, Cecil Chern‐Chyi Yen, Julie B. Mackel, Hellmut Merkle, Afonso C. Silva

Journal: NMR in Biomedicine

fMRI has established itself as the main research tool in neuroscience and brain cognitive research. The common marmoset (Callithrix jacchus) is a non‐human primate model of increasing interest in biomedical research. However, commercial MRI coils for marmosets are not generally available. The present work describes the design and construction of a four‐channel receive‐only surface RF coil array with excellent signal‐to‐noise ratio (SNR) specifically...

Antioxidant activity, lipophilicity and extractability of polyphenols from pig skin – development of analytical methods for skin permeation studies

Published: May 22, 2013

Author(s): Olesya V. Zillich, Ute Schweiggert‐Weisz, Katrin Hasenkopf, Peter Eisner, Martina Kerscher

Journal: Biomedical Chromatography

ABSTRACT Permeation of polyphenols through the stratum corneum barrier is a precondition for the protective action of polyphenols against oxidative skin damage. Prior to in vitro skin permeation experiments, we developed a method for the quantification of polyphenols in pig skin, including organic solvent extraction and HPLC analysis. Catechine hydrate, epigallocatechin gallate, trans‐resveratrol, quercetin, rutin and protocatechuic acid were...

The chiral bioconversion and preclinical pharmacokinetic analysis of ( R )‐(+)‐rabeprazole in beagle dogs by HPLC and HPLC‐MS/MS

Published: May 22, 2013

Author(s): Yan‐hui Gao, Jia‐xing Xu, Zhong‐xue Su, Li Song, Hong‐xiang Lou

Journal: Biomedical Chromatography

ABSTRACT In order to accurately investigate the preclinical pharmacokinetics of (R)‐(+)‐rabeprazole sodium injection, a reliable high‐performance liquid chromatography (HPLC) method was developed using a Chiral‐AGP column to prove that there is no chiral bioconversion of (R)‐(+)‐rabeprazole to (S)‐(−)‐rabeprazole in beagle dogs after single intravenous administration of (R)‐(+)‐rabeprazole sodium injection. An HPLC–tandem mass spectrometry (HPLC‐MS/MS)...

Simultaneous measurements of fuel vapor concentration and temperature in a flash‐boiling propane jet using laser‐induced gratings

Published: May 22, 2013

Author(s): B. Roshani, A. Flügel, I. Schmitz, D. N. Kozlov, T. Seeger, L. Zigan, J. Kiefer, A. Leipertz

Journal: Journal of Raman Spectroscopy

To enhance the efficiency of direct injection engines, the understanding of the combustible mixture formation after a liquid fuel spray is injected is crucial; hence, the need is readily apparent for experimental methods that allow determining characteristic parameters such as fuel/air ratio and gas temperature. The paper demonstrates the potential of the laser‐induced grating technique to determine simultaneously the local vapor phase...

Analysis of 1,3 dimethylamylamine concentrations in Geraniaceae , geranium oil and dietary supplements

Published: May 22, 2013

Author(s): Krista G. Austin, John Travis, Gerry Pace, Harris R. Lieberman

Journal: Drug Testing and Analysis

1,3‐Dimethylamylamine (DMAA) is a sympathomimetic compound currently incorporated into some dietary supplements. Significant controversy exists regarding the ‘natural’ origin of DMAA, as claimed by manufacturers of supplements. Manufacturers often refer to its presence by the name Geranamine® implying that DMAA is found in the plant species Geranium and Pelargonium known collectively as Geraniaceae. This study determined whether DMAA is present in...

Quantification of curcumin, demethoxycurcumin, and bisdemethoxycurcumin in rodent brain by UHPLC/ESI‐Q‐TOF‐MS/MS after intra‐nasal administration of curcuminoids loaded PNIPAM nanoparticles

Published: May 22, 2013

Author(s): Niyaz Ahmad, Musarrat Husain Warsi, Zeenat Iqbal, Mohd Samim, Farhan Jalees Ahmad

Journal: Drug Testing and Analysis

An ultra high performance liquid chromatography‐electrospray ionization‐synapt mass spectrometric method (UHPLC/ESI‐QTOF‐MS/MS) for the analysis of curcumin (Cur), demethoxycurcumin (DMC), bisdemethoxycurcumin (BDMC) in Wistar rat brain homogenate was developed and validated. The chromatographic separation was achieved on a Waters ACQUITY UPLC™ BEH C18 (2.1mm × 100 mm; 1.7μm) column using isocratic mobile phase, consisting of...

Aluminium alloy corrosion inhibition by chromate‐free composition of zinc phosphate and ion‐exchanged zeolite

Published: May 21, 2013

Author(s): V. I. Pokhmurskii, I. M. Zin, L. M. Bily, V. A. Vynar, Ya I. Zin

Journal: Surface and Interface Analysis

Corrosion inhibition of aluminium alloy D16T by natural and calcium and zinc ion‐exchanged zeolites and their compositions with phosphate pigment was studied. Clinoptilolite, a natural zeolite from Sokyrnytsia deposit (Transcarpathian region, Ukraine), has been used in this study as a basic component. Protective properties of polyurethane coatings containing ion‐exchanged zeolites were investigated in acid rain solution. Direct current...

In vivo metabolism study of bergenin in rats by HPLC‐QTOF mass spectrometry

Published: May 20, 2013

Author(s): Haojing Song, Jin Wang, Rui Zhang, Xiaoyan Liu, Guiyan Yuan, Chunmin Wei, Wenjing Zhao, Rong Li, Benjie Wang, Ruichen Guo

Journal: Biomedical Chromatography

ABSTRACT Bergenin is the major component of Ardisia creanta sims and Rodgersia sambucifolia hemsl with many biological activities. Although bergenin has been used to treat human diseases in China for man years, there is no report regarding its metabolism. This is the first report to separate and identify the metabolites of bergenin in vivo. In the study, HPLC/Q‐TOF‐MS/MS was used to investigate the metabolites of bergenin in vivo by analyzing the rat body...

Acute intoxication by synthetic cannabinoids – Four case reports

Published: May 20, 2013

Author(s): Maren Hermanns‐Clausen, Stefan Kneisel, Melanie Hutter, Bela Szabo, Volker Auwärter

Journal: Drug Testing and Analysis

Body fluid and tissue analysis using filter paper sampling support prior to LC‐MS/MS: Application to fatal overdose with colchicine

Published: May 16, 2013

Author(s): Estelle Lauer, Christèle Widmer, François Versace, Christian Staub, Patrice Mangin, Sara Sabatasso, Marc Augsburger, Julien Déglon

Journal: Drug Testing and Analysis

Because of the various matrices available for forensic investigations, the development of versatile analytical approaches allowing the simultaneous determination of drugs is challenging. The aim of this work was to assess a liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) platform allowing the rapid quantification of colchicine in body fluids and tissues collected in the context of a fatal overdose. For this purpose, filter paper...

Nurse induced respiratory depression by succinylcholine – the ‘hero syndrome’

Published: May 15, 2013

Author(s): F. Musshoff, U. Kuepper, B. Madea

Journal: Drug Testing and Analysis

A nurse administered the neuromuscular blocking agent succinylcholine (SUX) to at least one patient and gave first aid in the therapy of unexpected respiratory depression. SUX is regarded as an undetectable and thus perfect poison due to its short half‐life and degradation to the endogenous compounds choline and succinic acid. However, SUX and especially its metabolite succinylmonocholine (SMC) were found in plasma and urine a few hours...

Cross‐reactivity of designer drugs, including cathinone derivatives, in commercial enzyme‐linked immunosorbent assays

Published: May 15, 2013

Author(s): Madeleine J. Swortwood, W. Lee Hearn, Anthony P. DeCaprio

Journal: Drug Testing and Analysis

Since the introduction of synthetic heroin, designer drugs have been increasing in prevalence in the United States drug market over the past few decades. Recently, ‘legal highs’ sold as ‘bath salts’ have become a household term for one such class of designer drugs. While a number of federal and state bans have been enacted, the abuse of these designer drugs still continues. Few assays have been developed for the comprehensive detection of...

Polarization‐ and time‐resolved DFWM spectroscopy of the A ² Σ ⁺ − X ² Π (0,0) band transitions of nascent OH radicals generated by 266 nm laser photolysis of H ₂ O ₂

Published: May 15, 2013

Author(s): P. Maksyutenko, P. P. Radi, D. N. Kozlov, A. P. Kouzov

Journal: Journal of Raman Spectroscopy

The potential of a non‐linear spectroscopic technique – degenerate four‐wave mixing (DFWM) spectroscopy – for photo‐dissociation studies is investigated. By applying a carefully considered control of the input beam polarizations, the technique is used to measure the line shapes of specific rovibrational transitions in the A 2Σ+ − X 2Π (0,0) band of nascent OH radicals upon pulsed photo‐dissociation of H2O2. The photofragmentation is performed by...

2D‐IR spectroscopy: an additional dimension to investigate ultrafast structural dynamics

Published: May 15, 2013

Author(s): Manuela Lima, Marco Candelaresi, Paolo Foggi

Journal: Journal of Raman Spectroscopy

We describe the theory, some experimental details and the data analysis procedures of two‐dimensional infrared (2D‐IR) spectroscopy. A brief description of an application of the technique to the study of a dipeptide in solution is also reported. Like multi‐dimensional NMR spectroscopy, 2D‐IR can provide additional pieces of information hidden in the inhomogenously broadened bands observed in linear IR spectra. In addition, the presence of...

DTI of human skeletal muscle: the effects of diffusion encoding parameters, signal‐to‐noise ratio and T ₂ on tensor indices and fiber tracts

Published: May 14, 2013

Author(s): Martijn Froeling, Aart J. Nederveen, Klaas Nicolay, Gustav J. Strijkers

Journal: NMR in Biomedicine

In this study, we have performed simulations to address the effects of diffusion encoding parameters, signal‐to‐noise ratio (SNR) and T2 on skeletal muscle diffusion tensor indices and fiber tracts. Where appropriate, simulations were corroborated and validated by in vivo diffusion tensor imaging (DTI) of human skeletal muscle. Specifically, we have addressed: (i) the accuracy and precision of the diffusion parameters and eigenvectors at...

Mammalian cell metabolomics: Experimental design and sample preparation

Published: May 13, 2013

Author(s): Zacarías León, Juan C. García‐Cañaveras, María Teresa Donato, Agustín Lahoz

Journal: ELECTROPHORESIS

Metabolomics represents the global assessment of metabolites in a biological sample and reports the closest information to the phenotype of the biological system under study. Mammalian cell metabolomics has emerged as a promising tool with potential applications in many biotechnology and research areas. Metabolomics workflow includes experimental design, sampling, sample processing, metabolite analysis, and data processing. Given their...

UPLC‐PDA‐TOF/MS coupled with multivariate statistical analysis to rapidly analyze and evaluate Ginkgo biloba leaves from different origin

Published: May 10, 2013

Author(s): Xin Yao, Guisheng Zhou, Yuping Tang, Sheng Guo, Yefei Qian, Chun Jin, Yong Qin, Dawei Qian, Jin‐ao Duan

Journal: Drug Testing and Analysis

In the present study, an ultra performance liquid chromatography coupled with photodiode array detector and time‐of‐flight mass spectrometry (UPLC‐PDA‐TOF/MS) was proposed and validated for rapidly analyzing and evaluating Ginkgo biloba leaves from different origins by using multivariate statistical analysis. Batches of these kinds of G. biloba leaves were subjected to UPLC‐PDA‐TOF/MS analysis, the datasets of retention time (RT)‐m/z pairs, ion intensities and...

Preparation of sulfur reference materials that reproduce atmospheric particulate matter sample characteristics for XRF calibration

Published: May 9, 2013

Author(s): H. Indresand, W. H. White, K. Trzepla, A. M. Dillner

Journal: X-Ray Spectrometry

Energy‐dispersive X‐ray fluorescence (XRF) is an important tool used in routine elemental analysis of atmospheric particulate matter (PM) samples collected on polytetrafluoroethylene (PTFE) membrane filters. The method requires calibration against thin‐film standards of known elemental masses commonly obtained from commercial suppliers. These standards serve as a convenient and widely accepted interlaboratory reference but can differ...

Effect of microstructure on the corrosion behaviour of extruded heat exchanger aluminium alloys

Published: May 9, 2013

Author(s): A. Laferrere, N. Parson, X. Zhou, G. Thompson

Journal: Surface and Interface Analysis

Aluminium extrusions used for heat transfer applications are exposed to corrosive environments, which can eventually lead to perforation of the tube by pitting. In this study, the effect of microstructure on the corrosion behaviour of extruded AA3XXX series alloys has been investigated. It was revealed that pits developed were purely crystallographic and a drop testing procedure was developed to simulate the seawater acetic acid test in a...