EarlyView Articles

Role of high‐field MR in studies of localized prostate cancer

Published: May 24, 2013

Author(s): Miriam W. Lagemaat, Tom W. J. Scheenen

Journal: NMR in Biomedicine

Magnetic resonance imaging is attracting increasing attention from the uroradiological community as a modality to guide the management of prostate cancer. With the high incidence of prostate cancer it might come as a surprise that for a very long time (and in many places even at present) treatment decisions were being made without the use of detailed anatomical and functional imaging of the prostate gland at hand. Although T2‐weighted MRI...

Determination of salbutamol by direct chiral reversed‐phase HPLC using teicoplanin as stationary phase and its application to natural water analysis

Published: May 24, 2013

Author(s): Noelia Rosales‐Conrado, Margherita Dell'Aica, María Eugenia León‐González, Luis Vicente Pérez‐Arribas, Luis María Polo‐Díez

Journal: Biomedical Chromatography

ABSTRACT A direct chiral LC‐UV method was optimized for the determination of salbutamol (SAL) β2‐agonist in environmental water. Two commercially available columns were evaluated: teicoplanin Chirobiotic‐T™ (150 × 2.1 mm i.d., 5 µm) and vancomycin Chirobiotic‐V™ (150 × 2.1 mm i.d., 5 µm). Finally, teicoplanin chiral stationary phase was selected for SAL enantiomer resolution. In order to preserve its integrity and maintain the column...

Desalkylflurazepam found in patients’ samples after high‐dose midazolam treatment

Published: May 24, 2013

Author(s): Susanne Vogt, Jürgen Kempf, Jürgen Buttler, Volker Auwärter, Wolfgang Weinmann

Journal: Drug Testing and Analysis

Monotopic modifications derived from in vitro glycation of albumin with ribose

Published: May 24, 2013

Author(s): Statis Pataridis, Zdeňka Štastná, Pavla Sedláková, Ivan Mikšík

Journal: ELECTROPHORESIS

Post‐translational modifications are significant reactions that occur to proteins. One of these modifications is a non‐enzymatic reaction between the oxo‐group(s) of sugars and amino‐group(s) of protein – glycation. This reaction plays an important role in the chronic complications of diabetes mellitus, or in the aging process of organisms, that is, it has an important role in the pathophysiology and “normal” physiology of animals. In the...

Self‐assembling behavior of TDPA molecules on inhomogeneous surface of 2024 aluminum alloy

Published: May 23, 2013

Author(s): Jun‐e Qu, Dejian Nie, Cheng Liu, Hairen Wang, Geng Chen

Journal: Surface and Interface Analysis

The self‐assembling behavior of 1‐tetradecylphosphonic acid (TDPA) molecules on the surfaces of 2024 aluminum alloys was studied with an emphasis on the different micro‐structural regions of the alloy surface, specially the alloy matrix and the two main types of intermetallic particles, as well as how the adsorption was effected by changes in water content of the self‐assembly solution. Surface characterization was undertaken with contact...

Effects of exercise‐induced intracellular acidosis on the phosphocreatine recovery kinetics: a ³¹ P MRS study in three muscle groups in humans

Published: May 23, 2013

Author(s): Gwenael Layec, Emil Malucelli, Y. Le Fur, David Manners, Kazuya Yashiro, Claudia Testa, Patrick J. Cozzone, Stefano Iotti, David Bendahan

Journal: NMR in Biomedicine

Little is known about the metabolic differences that exist among different muscle groups within the same subjects. Therefore, we used 31P‐magnetic resonance spectroscopy (31P‐MRS) to investigate muscle oxidative capacity and the potential effects of pH on PCr recovery kinetics between muscles of different phenotypes (quadriceps (Q), finger (FF) and plantar flexors (PF)) in the same cohort of 16 untrained adults. The estimated muscle...

Texture‐based and diffusion‐weighted discrimination of parotid gland lesions on MR images at 3.0 Tesla

Published: May 23, 2013

Author(s): Julia Fruehwald‐Pallamar, Christian Czerny, Laura Holzer‐Fruehwald, Stefan F. Nemec, Christina Mueller‐Mang, Michael Weber, Marius E. Mayerhoefer

Journal: NMR in Biomedicine

The purpose of this study was to evaluate whether texture‐based analysis of standard MRI sequences and diffusion‐weighted imaging can help in the discrimination of parotid gland masses. The MR images of 38 patients with a biopsy‐ or surgery‐proven parotid gland mass were retrospectively analyzed. All patients were examined on the same 3.0 Tesla MR unit, with one standard protocol. The ADC (apparent diffusion...

Concept and role off extreme objects in PCA/SIMCA

Published: May 23, 2013

Author(s): Alexey L. Pomerantsev, Oxana Ye Rodionova

Journal: Journal of Chemometrics

For the construction of a reliable decision area in the soft independent modeling by class analogy (SIMCA) method, it is necessary to analyze calibration data revealing the objects of special types such as extremes and outliers. For this purpose, a thorough statistical analysis of the scores and orthogonal distances is necessary. The distance values should be considered as any data acquired in the experiment, and their distributions are...

A 22‐channel receive array with Helmholtz transmit coil for anesthetized macaque MRI at 3 T

Published: May 23, 2013

Author(s): Thomas Janssens, Boris Keil, Peter Serano, Azma Mareyam, Jennifer A. McNab, Lawrence L. Wald, Wim Vanduffel

Journal: NMR in Biomedicine

The macaque monkey is an important model for cognitive and sensory neuroscience that has been used extensively in behavioral, electrophysiological, molecular and, more recently, neuroimaging studies. However, macaque MRI has unique technical differences relative to human MRI, such as the geometry of highly parallel receive arrays, which must be addressed to optimize imaging performance. A 22‐channel receive coil array was constructed...

Paramagnetic liposomes for molecular MRI and MRI‐guided drug delivery

Published: May 23, 2013

Author(s): Sander Langereis, Tessa Geelen, Holger Grüll, Gustav J. Strijkers, Klaas Nicolay

Journal: NMR in Biomedicine

Liposomes are a versatile class of nanoparticles with tunable properties, and multiple liposomal drug formulations have been clinically approved for cancer treatment. In recent years, an extensive library of gadolinium (Gd)‐containing liposomal MRI contrast agents has been developed for molecular and cellular imaging of disease‐specific markers and for image‐guided drug delivery. This review discusses the advances in the development and...

Effect of mineralogical and microstructural properties on surface roughness and gloss of some ornamental marbles subjected to polishing process

Published: May 23, 2013

Author(s): S. Gürcan, R. M. Goktan, A. Yıldız

Journal: X-Ray Spectrometry

High surface finish quality of the produced slabs is generally desirable in the stone processing industry. This paper presents the results of an experimental investigation into the effects of mineralogical‐petrographical and chemical variables on the surface roughness and glossiness of some selected ornamental marbles subjected to grinding–polishing processes. For this purpose, a series of grinding–polishing procedures were performed on...

Theoretical and experimental study on the angular dependence of scattering processes in X‐ray fluorescence systems

Published: May 23, 2013

Author(s): M. Guerra, M. Manso, S. Pessanha, S. Longelin, M. L. Carvalho

Journal: X-Ray Spectrometry

The role of X‐ray reflectivity, coherent, and incoherent scattering has been studied in light samples. The angular dependence of these processes was evaluated, and the best geometrical settings for X‐ray fluorescence spectrometers was studied both for symmetrical and asymmetrical setups. Emphasis is given to biaxial planar geometry rather than triaxial orthogonal geometry, due to the use of low power X‐ray tubes and non‐cryogenic...

Nitrogen determination by SEM‐EDS and elemental analysis

Published: May 23, 2013

Author(s): M.F. Gazulla, M. Rodrigo, E. Blasco, M. Orduña

Journal: X-Ray Spectrometry

This paper describes a methodology for the analysis of nitrogen by scanning electron microscope with an energy dispersive X‐ray spectrometer (SEM‐EDS). The methodology was developed to have a rapid and accurate alternative method to the elemental analysis by combustion and thermoconductivity detection that does not imply the decomposition of the sample. Two methods by SEM‐EDS were established: a quantitative method...

Applicability of portable XRF systems for screening waste loads on hazardous substances as incoming inspection at waste handling plants

Published: May 23, 2013

Author(s): C. Vanhoof, K. A. Holschbach‐Bussian, B. M. Bussian, R. Cleven, K. Furtmann

Journal: X-Ray Spectrometry

In consequence of several European Union Directives, there is an increasing need for rapid and easy‐to‐handle screening tools to identify hazardous substances or to verify the absence of those substances. A field trial was executed to evaluate the capability of portable/handheld X‐ray fluorescence (XRF) systems for screening waste loads on hazardous substances as incoming inspection at waste handling plants to characterise the waste...

Development of a CZE ‐ ESI ‐ MS assay with a sulfonated capillary for profiling picolinic acid and quinolinic acid formation in multienzyme system

Published: May 23, 2013

Author(s): Xiaochun Wang, Ian Davis, Aimin Liu, Shahab A. Shamsi

Journal: ELECTROPHORESIS

This article describes the development of a reliable CZE‐ESI‐MS method to simultaneously separate and quantitate three specific metabolites (3‐hydroxyanthranilic acid (3‐HAA), quinolinic acid (QA), and picolinic acid (PA)) of the kynurenine pathway (KP) of tryptophan catabolism. Using a covalently bonded sulfonated capillary, the parameters such as pH, type of background electrolyte, type of organic solvent, nebulizer pressure as well as...

Separation of glutathione and its novel analogues and determination of their dissociation constants by capillary electrophoresis

Published: May 23, 2013

Author(s): Jana Kazarjan, Merike Vaher, Riina Mahlapuu, Mats Hansen, Ursel Soomets, Mihkel Kaljurand

Journal: ELECTROPHORESIS

A CE protocol was developed to separate reduced glutathione and its four novel analogues UPF1 (Tyr(Me)‐γ‐Glu‐Cys‐Gly), UPF17 (Tyr(Me)‐α‐Glu‐Cys‐Gly), UPF50 (β‐Ala‐His‐Tyr(Me)‐γ‐Glu‐Cys‐Gly), and UPF51 (β‐Ala‐His‐Tyr(Me)‐α‐Glu‐Cys‐Gly), and their homo‐ and heterodimers by varying the ionic strength and/or pH of different BGEs. For the determination of dissociation constants (pKa) of the above‐mentioned peptides the CE method was used....

Easy peak tracking in CE ‐ UV and CE ‐ UV ‐ ESI ‐ MS by incorporating temperature‐correlated mobility scaling

Published: May 23, 2013

Author(s): Bin Li, Nickolaj J. Petersen, Line H. Andersen, Steen H. Hansen

Journal: ELECTROPHORESIS

A simple data reconstruction technique in CE‐UV‐ESI‐MS (where UV stands for ultraviolet) is presented to overcome the drift in mobilities caused by various factors compromising the reproducibility of such data, for example Joule heating effects and the variation in thermostatic control along the capillary, drift in EOF and the suction effect caused by the nebulizing gas in coaxial CE‐MS interfaces. We present here a method to transform...

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...