EarlyView Articles

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...

A fatal case involving a caffeine‐containing fat burner

Published: May 9, 2013

Author(s): Ricarda Jantos, Kirsten Marion Stein, Christa Flechtenmacher, Gisela Skopp

Journal: Drug Testing and Analysis

Analytical methods for the detection of undeclared synthetic drugs in traditional herbal medicines as adulterants

Published: May 7, 2013

Author(s): Jamshed Haneef, Mohammad Shaharyar, Asif Husain, Mohd Rashid, Ravinesh Mishra, Nadeem A. Siddique, Manoj Pal

Journal: Drug Testing and Analysis

Traditional herbal medicines (THMs) are gaining popularity worldwide as an alternative approach to prescription drugs for many reasons including a general perception that they are safe. But recently there have been number of reported studies that reveal adulteration of THMs with undeclared synthetic drugs, which may potentially cause serious toxic adverse effects. This paper reviews the various classes of synthetic drugs that were found...

Quantification of conjugated metabolites of drugs in biological matrices after the hydrolysis with β ‐glucuronidase and sufatase: a review of bio‐analytical methods

Published: May 6, 2013

Author(s): Yue Ding, Ming Peng, Tong Zhang, Jian‐Sheng Tao, Zhen‐Zhen Cai, Yong Zhang

Journal: Biomedical Chromatography

ABSTRACT Glucuronidation and sulfation represent two major pathways in phase II drug metabolism in humans and other mammalian species. The great majority of drugs, for example, polyphenols, flavonoids and anthraquinones, could be transformed into sulfated and glucuronidated conjugates simultaneously and extensively in vivo. The pharmacological activities of drug conjugations are normally decreased compared with those of their free forms....

Review of the quantitative analysis of cholesteryl ester transfer protein inhibitors

Published: May 6, 2013

Author(s): Ramesh Mullangi, Nuggehally R. Srinivas

Journal: Biomedical Chromatography

ABSTRACT Clinical investigations of choleteryl ester transfer protein (CETP) inhibitors are still underway owing to its promise of reducing risk factors in patients with cardiovascular disease. Although several CETP inhibitors have reached late phase clinical testing, there is a paucity of publications that describe the determination of various CETP inhibitors in human and/or animal matrices. An attempt is made in this review to...

Measuring anisotropic muscle stiffness properties using elastography

Published: May 3, 2013

Author(s): M. A. Green, G. Geng, E. Qin, R. Sinkus, S. C. Gandevia, L. E. Bilston

Journal: NMR in Biomedicine

Physiological and pathological changes to the anisotropic mechanical properties of skeletal muscle are still largely unknown, with only a few studies quantifying changes in vivo. This study used the noninvasive MR elastography (MRE) technique, in combination with diffusion tensor imaging (DTI), to measure shear modulus anisotropy in the human skeletal muscle in the lower leg. Shear modulus measurements parallel and perpendicular to the...

Metallographic effects of pure aluminum on properties of nanoporous anodic alumina (NPAA)

Published: May 3, 2013

Author(s): Fereshteh Rashidi, Tatsuya Masuda, Hidetaka Asoh, Sachiko Ono

Journal: Surface and Interface Analysis

The microstructure of aluminum substrates was investigated during the quality control of grain sizes determination and crystal orientation analysis before and after preheat (recrystallization) treatment at 500 °C, in relation to the microstructure and heat stability of nanoporous anodic alumina (NPAA) membranes formed on various preheated aluminum substrates and subsequently detached. Depending on the preheating conditions, the average...

Surface treatment of aluminium automotive sheet: Mythology and technology

Published: May 3, 2013

Author(s): G. M. Scamans, P. R. Andrews, C. Butler, A. Hall, G. E. Thompson, Y. Ma, X. Zhou

Journal: Surface and Interface Analysis

The use of aluminium automotive sheet to save weight, fuel and carbon emissions is increasing as EU OEMS strive to reach progressively tougher targets and from the need to avoid fleet average penalty payments. Surface finishing of structural sheet for alloys like AA5754 generally involves cleaning and pretreatment followed by roll coating with a lubricant. For alloys supplied for body panels like AA6016 and its variants, surface...

Assessment of the surface reactivity of AA1050 aluminium alloy

Published: May 1, 2013

Author(s): Malgorzata Witkowska, George Edward Thompson, Teruo Hashimoto, Elena Koroleva

Journal: Surface and Interface Analysis

During processing from cast slab to thin gauge material, the AA1050 aluminium alloy proceeds through various stages of thermomechanical processing, with the conditions at each processing stage influencing the microstructure of the final coil. The reactivity of the material in defined chemical and electrochemical processes has been demonstrated as a useful method to describe variance in the microstructure and surface chemical properties of...

Characterization of aluminum alloys environmentally friendly surface treatments for aircraft and aerospace industry

Published: Apr 30, 2013

Author(s): T. Monetta, A. Acquesta, V. Maresca, R. Signore, F. Bellucci, P. Di Petta, M. Lo Masti

Journal: Surface and Interface Analysis

Due to risk connected to the chromium use, several companies try to find ‘true’ chromium free products to treat aluminum surfaces. Aim of this work was to evaluate and test some treatment systems for avionics applications, in order to replace standard chromate processes based on CrVI. AA2014‐T3 and AA6082‐T6 aluminum alloys were subjected to conversion coating processes based on lithium or zirconium salts. Results were compared to those...

Ratiometric analysis in hyperpolarized NMR (I): test of the two‐site exchange model and the quantification of reaction rate constants

Published: Apr 29, 2013

Author(s): Lin Z. Li, Stephen Kadlececk, He N. Xu, Dania Daye, Benjamin Pullinger, Harrilla Profka, Lewis Chodosh, Rahim Rizi

Journal: NMR in Biomedicine

Conventional methods for the analysis of in vivo hyperpolarized 13C NMR data from the lactate dehydrogenase (LDH) reaction usually make assumptions on the stability of rate constants and/or the validity of the two‐site exchange model. In this study, we developed a framework to test the validity of the assumption of stable reaction rate constants and the two‐site exchange model in vivo via ratiometric fitting of the time courses of the signal ratio...

Looking back into the future: 30 years of metabolomics at TNO

Published: Apr 29, 2013

Author(s): Jan van der Greef, Herman van Wietmarschen, Ben van Ommen, Elwin Verheij

Journal: Mass Spectrometry Reviews

Abstract Metabolites have played an essential role in our understanding of life, health, and disease for thousands of years. This domain became much more important after the concept of metabolism was discovered. In the 1950s, mass spectrometry was coupled to chromatography and made the technique more application‐oriented and allowed the development of new profiling technologies. Since 1980, TNO has performed system‐based metabolic...

Non‐Markovian nature of the fluctuation of the polarizability in molecular liquids by time‐domain and frequency‐domain measurements

Published: Apr 29, 2013

Author(s): Yuji Sakai, Junji Watanabe, Shuichi Kinoshita

Journal: Journal of Raman Spectroscopy

We measured the low‐frequency regions of several molecular liquids at various temperatures using time‐domain and frequency‐domain spectroscopy to investigate the origin of the relaxation mode. We employed high‐resolution light scattering spectroscopy in the frequency domain and femtosecond optical Kerr effect spectroscopy in the time domain. By comparing the light scattering spectra of a relaxation mode with a Lorentzian function fitted...

Micro‐Raman spectroscopy identifies crocidolite and erionite fibers in tissue sections

Published: Apr 28, 2013

Author(s): Alessandro Croce, Maya Musa, Mario Allegrina, Caterina Rinaudo, Y. Izzettin Baris, A. Umran Dogan, Amy Powers, Zeyana Rivera, Pietro Bertino, Haining Yang, Giovanni Gaudino, Michele Carbone

Journal: Journal of Raman Spectroscopy

Exposure to asbestos or erionite is associated with malignant mesothelioma (MM) and other diseases. Micro‐Raman spectroscopy and Variable Pressure Scanning Electron Microscopy/Energy Dispersive Spectroscopy were used to identify mineral fibers in histological sections of various tissues taken from mice injected with crocidolite asbestos and erionite fibers. Routine diagnostic histopathological slides of biopsies from erionite‐exposed MM...

Feasibility of measuring prostate perfusion with arterial spin labeling

Published: Apr 26, 2013

Author(s): Xiufeng Li, Gregory J. Metzger

Journal: NMR in Biomedicine

Accelerating hyperpolarized metabolic imaging of the heart by exploiting spatiotemporal correlations

Published: Apr 25, 2013

Author(s): Kilian Weiss, Andreas Sigfridsson, Lukas Wissmann, Julia Busch, Michael Batel, Marcin Krajewski, Matthias Ernst, Sebastian Kozerke

Journal: NMR in Biomedicine

Hyperpolarized 13C‐labeled pyruvate is a promising tool to investigate cardiac metabolism. It has been shown that changes in substrate metabolism occur following the induction of ischemia. To investigate the metabolic changes that are confined to spatial regions, high spatiotemporal resolution is required. The present work exploits both spatial and temporal correlations using k–t principal component analysis (PCA) to undersample the spatiotemporal...

MRI of tissues with short T2s and T2*s. Wiley ISBN 978‐0‐470‐68835‐9