bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the non‐covalent complexes between oleanolic acid and cyclodextrins using electrospray ionization tandem mass spectrometry
Authors: Guo Mingquan , Zhang Suoqing , Song Fengrui , Wang Daowu , Liu Zhiqiang , Liu Shuying 
Published: July 2003

AbstractNon‐covalent inclusion complexes formed between an anti‐inflammatory drug, oleanolic acid (OA), and α‐, β‐ and γ‐cyclodextrins (CDs) were investigated by means of solubility studies and electrospray ionization tandem mass spectrometry (ESI‐MSn). The order of calculated association constants (K1 : 1) of complexes between OA and different CDs in solution is in good agreement with the order of their relative peak intensities and the relative CID energies of the complexes under the same ESI‐MSn conditions. These results indicate a direct correlation between the behaviors of solution‐ and gas‐phase complexes. ESI‐MS can thus be used to evaluate solution‐phase non‐covalent complexes successfully. The experimental results show that the most stable 1 : 1 inclusion complexes between three CDs and OA can be formed, but 2 : 1 CD–OA complexes can be formed with β‐ and γ‐CDs. Multi‐component complexes of α‐CD–OA–β‐CD (1 : 1 : 1), α‐CD–OA–γ‐CD (1 : 1 : 1) and β‐CD–OA–γ‐CD (1 : 1 : 1) were found in equimolar CD mixtures with excess OA. The formation of 2 : 1 and multi‐component 1 : 1 : 1 non‐covalent CD–OA complexes indicates that β‐ and γ‐CD are able to form sandwich‐type inclusion non‐covalent complexes with OA. The above results can be partly supported by the relative sizes of OA and CD cavities by molecular modeling calculations. All the complexes allow the detection of gaseous deprotonated CD–OA complexes in the negative ion mode at high abundances. The relative stabilities of the CDs–OA inclusion complexes in the gas phase can be evaluated from the relative CID energies in the ion trap (α‐CD–OA < β‐CD–OA < γ‐CD–OA) in the negative ion mode. Copyright © 2003 John Wiley & Sons, Ltd.
A sensitive and selective liquid chromatographic/electrospray ionization tandem mass spectrometric assay for the simultaneous quantification of α‐,β‐arteether and its metabolite dihydroartemisinin in plasma, useful for pharmacokinetic studies
Authors: Sabarinath S. , Rajanikanth M. , Madhusudanan K. P. , Gupta R. C. 
Published: July 2003

AbstractA sensitive, selective, specific and rapid liquid chromatographic/electrospray ionization tandem mass spectrometric assay method was developed and validated for the simultaneous quantitation of α‐,β‐arteether (α‐,β‐AE) and its metabolite α‐dihydroartemisinin (DHA) in monkey plasma using the propyl ether analogue of β‐arteether (PE) as an internal standard. The method involves a simple two‐step liquid–liquid extraction with hexane. The analytes were chromatographed on a C18 reversed‐phase chromatographic column by isocratic elution with methanol–ammonium acetate buffer (pH 4) (92 : 8, v/v) and analysed by mass spectrometry in the multiple reaction monitoring mode. The chromatographic run time was 7 min and the weighted (1/x2) calibration curves were linear over the range 0.78–200 ng ml−1. The method was validated in terms of accuracy, precision, absolute recovery, freeze–thaw stability, bench‐top stability and re‐injection reproducibility. The limit of detection and lower limit of quantification in monkey plasma were 0.39 and 0.78 ng ml−1 respectively for all the analytes. The intra‐ and inter‐batch precision and accuracy were found to be well within acceptable limits (<15%). All three analytes were stable even after three freeze–thaw cycles (deviation < 15%). The average absolute recoveries of α‐,β‐AE, DHA and PE, used as an internal standard, from spiked plasma samples were 85.85 ± 6.56, 70.10 ± 7.06, 54.37 ± 3.39 and 93.90 ± 6.9%, respectively. The assay method described here could be applied to study the pharmacokinetics of α‐,β‐AE and DHA in rhesus monkeys. Copyright © 2003 John Wiley & Sons, Ltd.
High‐sensitivity quantitation of cabergoline and pergolide using a triple‐quadrupole mass spectrometer with enhanced mass‐resolution capabilities
Authors: Hughes Nicola , Winnik Witold , Dunyach Jean‐Jacques , Amad Ma'an , Splendore Maurizio , Paul Gary 
Published: July 2003

AbstractQuantitative analysis of pharmaceuticals with low systemic plasma levels requires the utmost in sensitivity and selectivity from the analytical method used. A recently introduced triple‐quadrupole mass spectrometer with unique enhanced mass‐resolution capability was evaluated in the analysis of two such drugs, cabergoline and pergolide, in plasma. Liquid chromatographic/electrospray ionization selected reaction monitoring determination of cabergoline in plasma at unit mass‐resolution demonstrated improved sensitivity (50 fg on‐column), coupled with suitable accuracy and precision over a broad linear dynamic range covering five orders of magnitude (50 fg to 5 ng on‐column). Liquid chromatographic/atmospheric pressure chemical ionization selective reaction monitoring determination of pergolide in plasma also attained a high level of sensitivity (500 fg on‐column) at unit mass‐resolution, with accuracy and precision values well within pharmaceutical industry standards. Again, a linear dynamic range covering five orders of magnitude (500 fg to 50 ng on‐column) was achieved for the assay. Utility of the enhanced mass‐resolution feature of the triple‐quadrupole mass spectrometer in the determination of pergolide resulted in an improvement in analyte sensitivity (250 fg on‐column) and linear dynamic range (250 fg to 50 ng on‐column). Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of alkylacyl, alk‐1‐enylacyl and lyso subclasses of glycerophosphocholine by tandem quadrupole mass spectrometry with electrospray ionization
Authors: Hsu Fong‐Fu , Turk John , Thukkani Arun K. , Messner Maria C. , Wildsmith Kristin R. , Ford David A. 
Published: July 2003

AbstractPositive ion tandem quadrupole mass spectrometric methods for structural characterization of the subclasses of sn‐glycero‐3‐phosphocholine (PC), including alkylacyl‐ and alk‐1‐enylacylphosphocholine and lysophosphatidylcholine (LPC), are described. Following collisionally activated dissociation, the [M + Li]+ ions generated by electrospray ionization yield abundant informative fragment ions that permit structural determination, and distinction of regioisomers among lysophosphatidylcholine can be easily achieved. In contrast, structurally informative ions arising from [M + H]+ or [M + Na]+ ions are less prominent. The most abundant ion observed in the product‐ion spectra of the [M + Li]+ ions of plasmenyl‐ and plasmanyl‐PC and of LPC arises from loss of N(CH3)3 ([M + Li − 59]+). This feature permits their distinction from a product‐ion spectrum arising from a diacylphosphatidylcholine, in which the [M + Li − 183]+ ion reflecting loss of phosphocholine is the most prominent. Examples for identification of various subclasses of PC in biological extracts by tandem mass spectrometry applying various constant neutral loss scannings are also shown. Copyright © 2003 John Wiley & Sons, Ltd.
Mass spectrometric methods for the analysis of chlorinated and nitrated isoflavonoids: a novel class of biological metabolites
Authors: Prasain Jeevan K. , Patel Rakesh , Kirk Marion , Wilson Landon , Botting Nigel , Darley‐Usmar Victor M. , Barnes Stephen 
Published: July 2003

AbstractElectrospray ionization combined with tandem mass spectrometry was applied to a study of some representative chlorinated and nitrated isoflavones—potential metabolites of isoflavones in inflammatory cells. Upon collision‐induced dissociation of deprotonated [M − H]− ions of these compounds, a number of structurally characteristic product ions were produced. The product ion analysis of 3′‐ and 8‐chlorodaidzein in the tandom mass spectra led to ready differentiation of these isomers. 3‐Nitro derivatives of both genistein and daidzein have product ions due to the losses of HNO2 and two OH groups. Chlorinated derivatives of isoflavones were detected in cell‐based experiments and their structures were proposed by comparing the tandem mass spectra of their product ions with those of standards. This work provides a suitable analytical basis to aid the characterization of chlorinated and nitrated metabolites in studies in vivo and in vitro. Copyright © 2003 John Wiley & Sons, Ltd.
Two‐laser infrared and ultraviolet matrix‐assisted laser desorption/ionization
Authors: Little Mark W. , Kim Jae‐Kuk , Murray Kermit K. 
Published: July 2003

AbstractMatrix‐assisted laser desorption/ionization (MALDI) was performed using two pulsed lasers with wavelengths in the IR and UV regions. A 10.6 µm pulsed CO2 laser was used to irradiate a MALDI target, followed after an adjustable delay by a 337 nm pulsed nitrogen laser. The sample consisted of a 2,5‐dihydroxybenzoic acid matrix and bovine insulin guest molecule. The pulse energy for both of the lasers was adjusted so that the ion of interest, either the matrix or guest ion, was not produced by either of the lasers alone. The delay time for maximum ion yield occurs at 1 µs for matrix and guest ions and the signal decayed to zero in ∼400 µs. A mechanism is presented for enhanced UV MALDI ion yield following the IR laser pulse based on transient heating. Copyright © 2003 John Wiley & Sons, Ltd.
Direct tissue analysis using matrix‐assisted laser desorption/ionization mass spectrometry: practical aspects of sample preparation
Authors: Schwartz Sarah A. , Reyzer Michelle L. , Caprioli Richard M. 
Published: July 2003

AbstractPractical guidelines for the preparation of tissue sections for direct analysis by matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry are presented. Techniques for proper sample handling including tissue storage, sectioning and mounting are described. Emphasis is placed on optimizing matrix parameters such as the type of matrix molecule used, matrix concentration, and solvent composition. Several different techniques for matrix application are illustrated. Optimal instrument parameters and the necessity for advanced data analysis approaches with regards to direct tissue analysis are also discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Printed dual‐band U‐slotted monopole antenna for WLAN access point
Authors: Su Saou‐Wen , Cheng Yuan‐Tung , Wong Kin‐Lu 
Published: August 2003

AbstractA novel printed U‐slotted monopole antenna suitable for application in 2.4/5.2‐GHz dual‐band wireless local area network (WLAN) access points is presented. The monopole antenna without the U‐shaped slot has a lower or fundamental resonant mode for the 2.4‐GHz WLAN band. When a U‐shaped slot is embedded, an additional smaller monopole is formed, which generates an upper resonant mode for the 5.2‐GHz WLAN band. Experimental results of a constructed prototype are presented. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 436–438, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11083
Novel probe‐feeding architectures for stacked microstrip patch antennas
Authors: Kona Keerti S. , Rahmat‐Samii Yahya 
Published: August 2003

AbstractDual‐band stacked microstrip patch antennas are a popular choice for wireless and other vehicular communication applications. They are also being considered for use in feed arrays for reflector antennas. In this paper, novel center‐feeding schemes to achieve the desired dual‐band response will be presented. Also, novel side‐feeding schemes for a potential application in arrays have been investigated. L‐band frequencies were chosen to test the concept. For the stacked patch configuration, the primary objective was to get the antenna to resonate at two frequencies—1.575 GHz for the upper patch and 1.228 GHz for the lower patch—with a shared aperture and two independent excitations. Return‐loss, isolation, and pattern measurements for several antenna prototypes are presented. The measured results are compared with the simulation results from an FDTD code developed at UCLA. Extension of the concept for dual‐polarization and array configurations has been explored. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 467–475, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11092
Characteristics of Gaussian pulses transmitting in the G.652 fiber with FBG dispersion compensation
Authors: Pei Li , Jian Shuisheng , Yan Fengping , Li Tangjun , Ning Tigang 
Published: August 2003

AbstractThe compression characteristics of a Gaussian pulse with varied chirp and pulse width are obtained by theoretical analysis and experiments. The compensation effects are diverse, even with the same chirped optical fiber Bragg grating (FBG) dispersion compensator, and the optimal dispersion compensation length is related to the position of the FBG. At present, in most of transmission systems, the signal from the lasers are Gaussian pulses, thus an analysis of its broader characteristics, before and after it is reflected from the FBG, will be significant. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 480–484, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11095
Numerical and experimental investigation of the strength of corrugated board packages
Authors: Biancolini M. E. , Brutti C. 
Published: July 2003

AbstractThe buckling behaviour of corrugated paper packages was studied by means of an experimental and theoretical analysis. Mechanical behaviour of paperboard was first evaluated experimentally, then a local geometry FEM model, able to reproduce with a very good accuracy buckling loads obtained experimentally in the standard edge compression test, was developed. In order to investigate the buckling of a complete package, a finite element ‘corrugated board’ was introduced by means of a dedicated homogenization procedure. The FEM model of the package, assembled with this new element, can accurately predict the experimental data of incipient buckling observed during the standard box compression test, despite the few degrees of freedom and the minimal computational effort. Copyright © 2003 John Wiley & Sons, Ltd.
The control of dissolved oxygen content in probiotic yoghurts by alternative packaging materials
Authors: Miller Craig W. , Nguyen Minh H. , Rooney Michael , Kailasapathy Kaila 
Published: July 2003

AbstractProbiotic bacteria, added to yoghurt to impart health benefits, require a low‐oxygen environment for maximum viability. The aim of this experiment was to produce yoghurt with minimal oxygen content using packaging systems. Three packaging systems were evaluated for the effect they exert on the dissolved oxygen content of two types of yoghurt. High‐impact polystyrene (the Australian yoghurt industry's material of choice) was compared with new oxygen‐barrier material and an oxygen‐scavenging active packaging system. Stirred‐type and set‐type yoghurts were observed in each packaging material for dissolved oxygen content, over a normal shelf‐life for yoghurt. Oxygen‐barrier packaging combined with an oxygen‐scavenging material was found to be the most effective system, particularly when used with set‐type yoghurt. Set‐type yoghurt was found to be more conducive to oxygen reduction using packaging methods. Copyright © 2003 John Wiley & Sons, Ltd.
Effect of temperature on the cushioning properties of some foamed plastic materials
Authors: Marcondes Jorge , Hatton Kayo , Graham Jennifer , Schueneman Herb 
Published: July 2003

AbstractFoamed plastics are used to cushion products to protect them from shock and vibration. Design data is in most cases derived from laboratory tests, performed under standard conditions. However, during distribution, most shock and vibration events occur under conditions different from those under which the materials were evaluated. Two commonly used foams in packaging, expanded polyethylene and expanded polystyrene, were used to investigate how changes in temperature affect the performance properties of these materials. The materials were tested for shock and vibration under four different temperatures (−17°C, 3°C, 23°C and 43°C). The results show that the properties of expanded polystyrene were the least influenced and those of expanded polyethylene were the most influenced by changes in temperature. Copyright © 2003 John Wiley & Sons, Ltd.
Simple models for evaluating effects of small leaks on the gas barrier properties of food packages
Authors: Chung Donghwan , Papadakis Spyridon E. , Yam Kit L. 
Published: July 2003

AbstractA detailed theoretical analysis and calculations were made for providing a simple and explicit means to evaluate the effects of small leaks on the barrier properties of food packages. Small leaks, such as pinholes and channel leaks, were approximated as cylindrical pores with diameters of 50–300 μm. The first part of the current study proposes a simple mathematical model based on Fick's law of diffusion, which accounts for both the gas leakage across small leaks and the gas permeation across package walls. The model uses an effective permeability that depends on leak dimensions, type of diffusing gas, type of packaging material and gas conditions around the leak ends. In the second part of the study, three practical cases are presented to illustrate the application of the proposed model in examining the significance of leaks. These demonstrate in a simple and explicit manner that for LDPE packages: (a) leaks affect the oxygen transfer more than the water vapour transfer; (b) leak effects are more significant at lower storage temperatures; and (c) that for high gas barrier packages, the effect of leaks is very important and should not be neglected. The model can be also used to arrive at conclusions about the significance of leaks in other packaging situations (e.g. other than LDPE packaging materials) and to correct the shelf‐life estimation of gas‐ and water vapour‐sensitive foods for errors from package leaks. Copyright © 2003 John Wiley & Sons, Ltd.
History of FDA good laboratory practices
Authors: Baldeshwiler Anne M. 
Published: July 2003

AbstractThe United States Food and Drug Administration (FDA) requires nonclinical studies of new drugs, food additives and chemicals to predict their safety and potential efficacy in humans. The significance of the information gained from these studies requires that they be conducted according to sound scientific principles and with strict attention to quality assurance and quality control. Human health and safety are dependent upon the decisions made from these studies. The discovery of the lack of companies' adherence to these principles led to the development of the good laboratory practice (GLP) regulations, the driving force behind the quality of nonclinical laboratory studies. As the 25th anniversary of the publication of the regulations approaches, a description of the events leading to the proposal of the GLP regulations provides understanding about their significance and the importance of their use in assuring the quality and integrity of nonclinical safety data. Copyright © 2003 John Wiley & Sons, Ltd.
Clinical quality assurance: Auditing phase II trials
Authors: Winchell Terry 
Published: July 2003

AbstractClinical quality assurance (CQA) auditing of Phase II trials may help eliminate potential problems before they occur by providing valuable quality input before pivotal Phase III trials are undertaken. CQA auditing of Phase II trials can affect critical elements of design regarding Phase III protocols, and may be extremely useful in the early evaluation of vendors prior to investing in Phase III research. Copyright © 2003 John Wiley & Sons, Ltd.
Raising the quality of publications: Now we have GPP!
Authors: Wager Elizabeth 
Published: July 2003

AbstractUntil recently, few guidelines were available to assist companies in publishing their clinical trials and, compared to other phases of research, the quality of publications and the processes by which publications are developed have not received much scrutiny. However, guidelines on Good Publication Practice (GPP) for pharmaceutical companies have just been published. These aim to raise the quality of publications and to encourage ethical and responsible publication practices. The GPP guidelines were designed to be used alongside existing guidelines such as those from the International Committee of Medical Journal Editors (ICMJE) and the CONSORT statement. These, and other documents relevant to preparing publications, are reviewed and recommendations for ways in which companies might improve the quality of their publications are proposed. Copyright © 2003 John Wiley & Sons, Ltd.
The quality profession and its role in the world
Authors: Dedhia Navin S. 
Published: July 2003

AbstractThe concept of quality evolved from inspection, measurement, and testing, which had been in practice for many, many years. Long ago, an artist or a sculptor took pride in his work and as a result always tried to excel in what was created. Mass production systems brought the concept of inspection by someone other than the craftsman in the first half of the 20th century. Application of statistical control came later as a result of World War production methods. Quality as a profession and the managerial process associated in the quality function was introduced during the second‐half of the 20th century, and has evolved since then.No other profession has seen as many changes as the quality profession. The quality profession grew from simple control, to engineering, to systems engineering. Quality control activities were predominant in the 1940s, 1950s, and 1960s. The 1970s were an era of quality engineering and the 1990s saw quality systems as an emerging field. Like medicine, accounting, and engineering, quality has achieved status as a recognized profession. Published in 2003 by John Wiley & Sons, Ltd.
Standard operating procedures for clinical research personnel‐‐Part 17
Authors: Bohaychuk Wendy , Ball Graham 
Published: July 2003

AbstractThis is the 17th in a series of articles containing proposals for wording and content of Standard Operating Procedures (SOPs) for clinical research activities conducted by sponsors and Contract Research Organisations (CROs). The procedures include those required by the International Conference on Harmonisation (ICH), the Food and Drug Administration (FDA), many other guidelines and regulations, and 'best practice' observed by the authors. The model forms require modification for actual use. In this article, SOPs are presented for management of study medications/devices: initial request for study medications/devices (SOP 501); labelling and packaging of study medications/devices (SOP 502) and shipment of study medications/devices to study sites (SOP 503). (The full text of all 101 SOPs is available from the authors.) Copyright © 2003 John Wiley & Sons, Ltd.