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Bunaciu A.A.,CROMATEC PLUS SRL | Aboul-Enein H.Y.,National Research Center of Egypt | Hoang V.D.,Hanoi University of Pharmacy
Applied Spectroscopy Reviews | Year: 2015

Proteins are essential parts of organisms and participate in virtually every process within cells. Raman spectroscopy can be a powerful tool for the characterization of modified amino acids and proteins. In addition to the potential for quantitative results, it offers the advantage of not requiring any sample preparation. This review focuses on applications for protein analysis, published in the period 2010-2014. Copyright © 2015 Taylor & Francis Group, LLC. Source

Vu D.H.,University of Groningen | Vu D.H.,Hanoi University of Pharmacy | Koster R.A.,University of Groningen | Alffenaar J.W.C.,University of Groningen | And 2 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

Moxifloxacin (MFX) is a potential oral agent use in the treatment of multidrug-resistance tuberculosis (MDR-TB). Due to variability in pharmacokinetics and in vitro susceptibility of causative bacteria, therapeutic drug monitoring (TDM) of MFX is recommended. Conventional plasma sampling for TDM is facing logistical challenges, especially in limited resource areas, and dried blood spots (DBS) sampling may offer a chance to overcome this problem. The objective of this study was to develop a LC-MS/MS method for determination of MFX in dried blood spots (DBS) that is applicable for TDM. The influence of paper type, the hematocrit (Hct) and the blood volume per spot (V b) on the estimated blood volume in a disc (V est) was investigated. The extracts of 8mm diameter discs punched out from DBS were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS) with cyanoimipramin as internal standard. The method was validated with respect to selectivity, linearity, accuracy, precision, sensitivity, recovery and stability. The effect of Hct and V b on LC-MS/MS analytical result was also investigated. The relationship between MFX concentrations in venous and finger prick DBS and those in plasma was clinically explored. V est was highly influenced by Hct while the effect of V b appeared to be different among paper types. Calibration curves were linear in the range of 0.05-6.00mg/L with inter-day and intra-day precisions and biases of less than 11.1%. The recovery was 84.5, 85.1 and 92.6% in response to blood concentration of 0.15, 2.50 and 5.00mg/L, respectively. A matrix effect of less than 11.9% was observed. MFX in DBS was stable for at least 4weeks at room condition (temperature of 25°C and humidity of 50%). A large range of Hct value produced a significant analytical bias and it can be corrected with resulting DBS size. A good correlation between DBS and plasma concentrations was observed and comparable results between venous DBS and finger prick DBS was attained. This fully validated method is suitable for determination of MFX in dried blood spot and applicable for TDM. © 2011 Elsevier B.V. Source

Bunaciu A.A.,CROMATEC PLUS SRL | Aboul-Enein H.Y.,National Research Center of Egypt | Hoang V.D.,Hanoi University of Pharmacy
TrAC - Trends in Analytical Chemistry | Year: 2015

Vibrational spectroscopy includes several techniques, the most important being mid-infrared (MIR), near-IR (NIR) and Raman spectroscopies. Vibrational spectrometry covers a series of well-established analytical methodologies suitable for both qualitative and quantitative purposes. Raman and MIR spectroscopies are complementary techniques and usually both are required to measure the vibrational modes of a molecule completely. In the first part of this review, we focus on theoretical aspects related to vibrational techniques, while, in the second part, we discuss important articles published during the period 2000-14 relating to polymorphic analysis. © 2015 Elsevier B.V. Source

Hoang V.D.,Hanoi University of Pharmacy
TrAC - Trends in Analytical Chemistry | Year: 2014

Wavelets are a topic of pure mathematics. But over the past decade, they have shown great promise and are now being adapted for a vast number of signal-processing applications. One of the main advantages of wavelet analysis is the amount of information that can be extracted from a signal. It has demonstrated unprecedented success in terms of asymptotic optimality, spatial adaptivity and computational efficiency. Applications of wavelet transform and wavelet-packet transform in spectral analysis from 2002 to 2013 are reviewed in this article, clearly stating that wavelet methods significantly outperform other traditional methods of signal processing. © 2014 Elsevier B.V. Source

Dao T.T.H.,Leiden University | Dao T.T.H.,Hanoi University of Pharmacy | Linthorst H.J.M.,Leiden University | Verpoorte R.,Leiden University
Phytochemistry Reviews | Year: 2011

Chalcone synthase (CHS, EC is a key enzyme of the flavonoid/isoflavonoid biosynthesis pathway. Besides being part of the plant developmental program the CHS gene expression is induced in plants under stress conditions such as UV light, bacterial or fungal infection. CHS expression causes accumulation of flavonoid and isoflavonoid phytoalexins and is involved in the salicylic acid defense pathway. This review will discuss CHS and its function in plant resistance. © Springer Science+Business Media B.V. 2011. Source

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