bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sample preparation and separation techniques for bioanalysis of morphine and related substances
Authors: Hansen Steen Honoré 
Published: February 2009

AbstractIn present time the use or misuse of morphine and its derivatives are monitored by assaying the presence of the drug and its metabolites in biofluids. In the present review, focus is placed on the sample preparation and on the separation techniques used in the current best practices of bioanalysis of morphine and its major metabolites. However, as methods for testing the misuse of heroin, a morphine derivative, often involve bioanalytical methods that cover a number of other illicit drug substances, such methods are also included in the review. Furthermore, the review also includes bioanalysis in a broader perspective as analysis of plant materials, cell cultures and environmental samples. The review is not intended to cover all publications that include bioanalysis of morphine but is more to be considered a view into the current best practices of bioanalysis of morphine, its metabolites and other related substances.
Nitrite as regulator of hypoxic signaling in mammalian physiology
Authors: van Faassen Ernst E. , Bahrami Soheyl , Feelisch Martin , Hogg Neil , Kelm Malte , Kim‐Shapiro Daniel B. , Kozlov Andrey V. , Li Haitao , Lundberg Jon O. , Mason Ron , Nohl Hans , Rassaf Tienush , Samouilov Alexandre , Slama‐Schwok Anny , Shiva Sruti , Vanin Anatoly F. , Weitzberg Eddie , Zweier Jay , Gladwin Mark T. 
Published: February 2009

AbstractIn this review we consider the effects of endogenous and pharmacological levels of nitrite under conditions of hypoxia. In humans, the nitrite anion has long been considered as metastable intermediate in the oxidation of nitric oxide radicals to the stable metabolite nitrate. This oxidation cascade was thought to be irreversible under physiological conditions. However, a growing body of experimental observations attests that the presence of endogenous nitrite regulates a number of signaling events along the physiological and pathophysiological oxygen gradient. Hypoxic signaling events include vasodilation, modulation of mitochondrial respiration, and cytoprotection following ischemic insult. These phenomena are attributed to the reduction of nitrite anions to nitric oxide if local oxygen levels in tissues decrease. Recent research identified a growing list of enzymatic and nonenzymatic pathways for this endogenous reduction of nitrite. Additional direct signaling events not involving free nitric oxide are proposed. We here discuss the mechanisms and properties of these various pathways and the role played by the local concentration of free oxygen in the affected tissue. © 2009 Wiley Periodicals, Inc. Med Res Rev, 29, No. 5, 683–741, 2009
Panconnectivity and edge‐pancyclicity of k‐ary n‐cubes
Authors: Hsieh Sun‐Yuan , Lin Tsong‐Jie 
Published: February 2009

AbstractIn this article, we study some topological properties of k‐ary n‐cubes Q. We show that each edge in Q lies on a cycle of every length from k to kn. We also show that Q is both bipanconnected and edge‐bipancyclic, where n ≥ 2 is an integer and k ≥ 2 is an even integer. © 2009 Wiley Periodicals, Inc. NETWORKS 2009
A note on the k‐degree Cayley graph
Authors: Tanaka Yuuki , Shibata Yukio 
Published: February 2009

AbstractThe k‐degree Cayley graph has been proposed by Hsieh and Hsiao (Networks 47 (2006), 26–36). They have shown that the k‐degree Cayley graph is actually a Cayley graph. According to their definition, a generating set of that graph was defined implicitly. Therefore, it requires some effort to figure out that such graphs are actually Cayley graphs. In this article, we use the wreath product of groups to show that k‐degree Cayley graphs form a class of Cayley graphs. © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Searching symmetric networks with Utilitarian‐Postman paths
Authors: Alpern Steve , Baston Vic , Gal Shmuel 
Published: February 2009

AbstractWe introduce the notion of a Utilitarian Postman (UP) path on a network Q as one which minimizes the expected time required to find a random (uniformly distributed) point, and show that UP paths must be used in a minimax search of a symmetric network. For any network Q, one may consider the zero‐sum search game Γ(Q) in which the (minimizing) Searcher picks a unit speed path S(t) in Q, the Hider picks a point H in Q, and the payoff is the meeting time T = min{t : S(t) = H}. We show first that if Q is symmetric (edge and vertex transitive), then it is optimal for the Hider to pick H uniformly in Q, so that the Searcher must follow a UP path. We then show that if Q is symmetric of odd degree, with n vertices and m unit length edges, the value V of Γ(Q) satisfies
$ V \geq {m \over 2} + {n^{2}-2n \over 8m} $, with equality if and only if (*): Q has a path P = v1, v2,…,vn−1 of distinct vertices, such that the edge set Q′ = Q−∪(v2i,v2i+1) is connected. In this case, there is a UP path for Q consisting of P followed by an Eulerian path E of Q′. The condition (*) is satisfied by many symmetric graphs, including all complete graphs, complete bipartite graphs, hypercube graphs, high valency graphs, and the Petersen graph. We know of no odd degree symmetric graph not satisfying (*). © 2009 Wiley Periodicals, Inc. NETWORKS, 2009
Nonconstrained length effects on the compressive behavior of thick laminated composites
Authors: Lin Yung‐Kun , Liu Hsien‐Kuang , Kuo Wen‐Shyong , Chen Yu‐Der 
Published: February 2009

AbstractThis study reports the nonconstrained length effects on the properties of thick woven fabric composites under static compression loading. The materials examined were carbon/epoxy composites laminated with 10, 20, and 30 plies of the woven prepreg. A pressure rolling setup was designed and employed in the present materials to compact the laminate and to remove the air possibly trapped in between the plies. To apply the compressive load, an end‐supported, end‐loaded fixture was used. The end‐supported clamps were designed with different heights at both ends for the tested specimens, such that there are various free lengths (14, 26, 38, and 50 mm) in the central portion of the specimen defined as nonconstrained length. The growth of cracks was monitored and recorded in real‐time by picture and video cameras. The continuous monitoring of the failure progression provides detailed information about the onset and growth of cracks in various specimens under different nonconstrained lengths. Compared with the critical test length, various nonconstrained lengths can result in different loading curves with or without postfailure portion. The influence of the nonconstrained length on modulus, strength, the loss of stiffness, and energy absorption density has been examined. Two major modes of failure are fiber kink‐band and buckling, and the appearance of the modes depends on the nonconstrained length. Finally, the relationships among the nonconstrained length, the resulting properties, and the induced failure modes are discussed. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
LC‐MS analysis of 13,28‐epoxy‐oleanane saponins in Maesa spp. extracts with antileishmanial activity
Authors: Foubert Kenn , Vermeersch Marieke , Theunis Mart , Apers Sandra , Cos Paul , Claeys Magda , Van Puyvelde Luc , Pieters Luc , Maes Louis 
Published: February 2009

AbstractIntroductionSaponins are natural products that are well known for a wide range of biological activities. For saponins of Maesa balansae, selective antileishmanial activity has been described.ObjectiveIn view of their pharmacological interest, several Maesa species from the National Botanical Garden of Meise (Belgium) and wild‐grown plants from Vietnam were screened for their antileishmanial potential and saponin content.MethodologyDifferent parts of the plants (mainly leaves and twigs) were collected, dried and extracted. Plant extracts were evaluated by liquid chromatography/mass spectrometry (LC‐MS) using electrospray ionisation in the negative ion mode and their saponin content was compared with those of Maesa balansae (maesabalides) and Maesa lanceolata (maesasaponins).ResultsSeveral Maesa species (M. ambigua, M. argentea, M. brevipaniculata, M. japonica and M. perlarius) showed potent antileishmanial activity (<0.1 µg/mL) and indeed contained known maesasaponins and maesabalides. However the leaves of M. argentea also revealed two new compounds. Two saponins with [M − H]− ions at m/z 1465 and 1477 were characterised. Their mass spectrometric fragmentation pattern revealed a structure that was the same or closely related to maesasaponin V.3 and VI.2, respectively, but had a glycan part with one additional hexose residue.ConclusionSeveral known as well as new saponins from Maesa species active against leishmaniasis were characterised using LC‐MS. Copyright © 2009 John Wiley & Sons, Ltd.
Facile synthesis of one‐to‐one copy of monomer droplet to latex particle via equilibrium stabilized miniemulsion polymerization
Authors: Luo Ying‐Da , Chiu Wen‐Yen , Dai Chi‐An 
Published: February 2009

AbstractMiniemulsion polymerization has been traditionally used to synthesize latex particles with a high homogenization energy to prepare an oil/water miniemulsion followed by further polymerizations. However, the exact copy of monomer droplets to latex particles depends critically on emulsion formulation, homogenization condition as well as the stability of the miniemulsified droplets after homogenization. In this study, we demonstrated experimentally for the first time that one‐to‐one copy of monomer droplets to latex particles can be synthesized via polymerization of a miniemulsion prepared from a less stringent preparation process including formulation without costabilizer and low homogenization energy. The criterion to obtain narrow size distribution of monomer droplets was established by equilibration of a low energy homogenized emulsion for different keeping time and the bulk homogenized emulsion subsequently phase separated into two layers. Top layer is the polydispersed monomer‐rich phase. The bottom layer is the equilibrium‐stabilized monomer droplet emulsion, in which the size distribution of droplets is narrow. The equilibrium‐stabilized emulsion is stable for days and subsequent polymerization exhibits nearly 100% droplet nucleation. Furthermore, the effect of surfactant/costabilizer and initiator on the one‐to‐one feature for the synthesis of latex particles was investigated in details. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Rheological behavior of gel‐filled raw natural rubber and styrene‐butadiene rubber with reference to gel‐matrix intermixing
Authors: Mitra Suman , Chattopadhyay Santanu , Sabharwal Sunil , Bhowmick Anil K. 
Published: February 2009

AbstractNatural rubber (NR) and styrene‐butadiene rubber (SBR) latex gels were prepared by sulfur prevulcanization technique with varying amounts of curing agent and accelerator systems to generate gradient in crosslink density. These gels were characterized by solvent swelling, dynamic light scattering, atomic force microscopy, and mechanical properties. Crosslinked NR gels were intermixed with neat SBR matrix and vice versa. Rheological behavior of chemically crosslinked gel‐filled NR and SBR was studied by capillary rheometry. Intermixing of crosslinked gels in the rubber matrices resulted in a considerable reduction in apparent shear viscosity and die swell values. This behavior was found to be dependent on several factors like gel concentration in the matrix, crosslink density of the gels, their size, and distribution. The effect of temperature on viscosity was studied extensively following the Arrhenious‐Eyring model. A shear rate‐temperature superposition mastercurve was constructed to predict the melt viscosities of the systems as a function of temperature. The change in die swell values was related to the change in first normal stress difference. The scanning electron photomicrographs of the extrudates revealed that presence of gels markedly improved the surface roughness of the raw rubbers. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Protein carbonylation in kidney medulla of the spontaneously hypertensive rat
Authors: Tyther Raymond , Ahmeda Ahmad , Johns Edward , Sheehan David 
Published: February 2009

AbstractEnhanced generation of ROS has been reported in models of hypertension such as the spontaneously hypertensive rat (SHR). Impairment of kidney function has been implicated in development and progression of hypertension, and the renal medulla appears to play an important role in regulating long‐term blood pressure. A key biomarker of oxidative stress is the formation of protein carbonyls, which we set out to characterize in the SHR medulla. We identified 11 proteins that were differentially carbonylated in SHR medulla in comparison to normotensive wistars including enolase 1, catalase, carbonic anhydrase II, transferrin and members of the aldo–keto‐reductase family. This enhanced protein oxidation was not only accompanied by an increase in intracellular iron deposition, but aldo–keto‐reductase activity was also significantly less in SHR medulla than in normotensive Wistars. Oxidative stress appears selectively to target a subset of proteins in SHR kidney and modification of these proteins may in turn contribute to the renopathy associated with hypertension.
Considerations for powering a clinical proteomics study: Normal variability in the human plasma proteome
Authors: Jackson David , Herath Athula , Swinton Jonathan , Bramwell David , Chopra Rajesh , Hughes Andrew , Cheeseman Kevin , Tonge Robert 
Published: February 2009

AbstractProteomics is increasingly being applied to the human plasma proteome to identify biomarkers of disease for use in non‐invasive assays. 2‐D DIGE, simultaneously analysing thousands of protein spots quantitatively and maintaining protein isoform information, is one technique adopted. Sufficient numbers of samples must be analysed to achieve statistical power; however, few reported studies have analysed inherent variability in the plasma proteome by 2‐D DIGE to allow power calculations. This study analysed plasma from 60 healthy volunteers by 2‐D DIGE. Two samples were taken, 7 days apart, allowing estimation of sensitivity of detection of differences in spot intensity between two groups using either a longitudinal (paired) or non‐paired design. Parameters for differences were: two‐fold normalised volume change, α of 0.05 and power of 0.8. Using groups of 20 samples, alterations in 1742 spots could be detected with longitudinal sampling, and in 1206 between non‐paired groups. Interbatch gel variability was small relative to the detection parameters, indicating robustness and reproducibility of 2‐D DIGE for analysing large sample sets. In summary, 20 samples can allow detection of a large number of proteomic alterations by 2‐D DIGE in human plasma, the sensitivity of detecting differences was greatly improved by longitudinal sampling and the technology was robust across batches.
Effects of Fe3O4 underlayer on the annealing temperature of CoFe2O4 thin films
Authors: Zhong Zhiyong , Zhang Huaiwu , Tang Xiaoli , Jing Yulan , Jia Lijun , Liu Shuang 
Published: February 2009

AbstractCoFe2O4 films of 100 nm thickness were deposited on 20 nm, rf magnetron‐sputtered Fe3O4 underlayers on naturally oxidized Si (100) substrates. These films were then annealed, and the magnetic properties and microstructures were investigated as a function of annealing temperature. Results show that the optimum annealing temperature to obtain the maximum coercivity decreases from 700 °C for films without Fe3O4 underlayers to 500 °C for films with underlayers. The decreased annealing temperature corresponds to a phase transformation of the Fe3O4 underlayers at about 400–500 °C, which accelerates the increase in grain size of the cobalt ferrite films. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studies of thin microwires with enhanced magnetic softness and GMI effect
Authors: Zhukov A. , Ipatov M. , Blanco J. M. , Gonzalez J. , Zhukova V. 
Published: February 2009

AbstractIn this paper we studied the hysteresis loop and GMI effect (real component of impedance, Z, and the off‐diagonal impedance tensor ζϕz (Hex)) in ultra‐thin amorphous glass‐coated microwires with nearly‐zero and negative magnetostriction constant with metallic nucleus diameter ranging from 6 μm to 16 μm paying special attention to the effect of the metallic nucleus diameter on the aforementioned properties. Both GMI effect and hysteresis loops of nearly‐zero magnetostrictive Co67.1Fe3.8Ni1.4Si14.5B11.5Mo1.7 microwires exhibit strong sensitivity to the ratio, ρ, the metallic nucleus diameter, d, to the total microwire diameter, D. Selecting the right chemical composition we achieved low coercivity (generally below 15 A/m). The magnetic anisotropy field, Hk, increases when ρ decreases. The shape of the magnetic field dependence of Z is also affected by the ρ ‐ratio. The field dependence of the off‐diagonal voltage response of nearly zero magnetostrictive (λs ≈ –3 × 10–7) Co67.1Fe3.8Ni1.4Si14.5B11.5Mo1.7 microwires with metallic nucleus diameters ranging between 6.0 μm and 16.8 μm exhibits anti‐symmetrical shapes. At certain magnetic field, Hm, the off‐diagonal voltage reaches the maximum value. Between –Hm and Hm at certain field range almost linear dependence of the off‐diagonal voltage on magnetic field has been observed. This linear region of the curve depends on microwires geometry, but in any case is smaller than whole –Hm to Hm range. Joule heating significantly affects the off‐diagonal MI curves of Co67.1Fe3.8Ni1.4Si14.5B11.5Mo1.7 microwires with vanishing magnetostriction constant. Under DC current annealing the Hm decreases.The obtained results allow us to tailor the microwire magnetic properties for applications in magnetic sensors through the selection of their composition and/or thermal treatment conditions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of SiN films for AlGaN/GaN MIS‐HEMTs on Si(111)
Authors: Cordier Y. , Lecotonnec A. , Chenot S. , Baron N. , Nacer F. , Goullet A. , Lhermite H. , Kazzi M. El , Regreny P. , Hollinger G. , Besland M. P. 
Published: February 2009

AbstractIn this work, AlGaN/GaN HEMT structures grown on Si(111) substrates were covered with SiNx dielectric films, in order to realize MIS‐HEMT devices. The dielectric films have been deposited by plasma enhanced chemical vapor deposition using deposition conditions previously optimized for InP based devices. X‐ray photoelectron spectroscopy was used to control the interface formation and characterize the deposited films. Capacitance‐voltage, Hall effect and current‐voltage measurements were carried out on the MIS‐HEMTs and HEMT reference devices and correlated with the dielectric layer quality. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabricating gratings on nitrides grown by MOVPE for DFB lasers
Authors: Nakao Masashi , Kimura Takeshi , Liu Yuhuai , Ji Shi‐Yang , Matsuoka Takashi 
Published: February 2009

AbstractIn an achievement we believe marks a first, we succeeded in fabricating corrugation gratings in indium‐nitride (InN) films grown by metal organic vapor phase epitaxy (MOVPE) for distributed feedback lasers. The resulting temperature‐independent devices are suitable for wavelength demultiplexing and modulation in optical communications systems. The grating periods are in the first‐order wavelength region of 1.55 μm. We also formed gratings in gallium nitride epitaxial layers, applying electron‐beam (EB) lithography to form grating patterns in nitride substrates and inductively‐coupled plasma reactive ion etching (ICP‐RIE) to transfer EB resist patterns to nitrides. The depth of the grating grooves can be controlled by adjusting ICP‐RIE etching times to attain suitable coupling coefficients for forward and backward propagating waves in DFB lasers. We also introduce UV imprinting, a new grating fabrication technique that offers significant promise. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of oxygen supply on MOVPE InN
Authors: Sugita K. , Hashimoto A. , Yamamoto A. 
Published: February 2009

AbstractThis paper reports the effect of oxygen supply on MOVPE InN growth at high temperature (∼650 °C). It is noted that the deterioration occurs near the interface, and InN film becomes porous layer during growth. When we supply oxygen in the reactor (O2/NH3 ratio is 0∼0.018%), atomic hydrogen is reduced by reacting oxygen and the porous layer is decreased. Our study reveals that the porous layer is produced by atomic hydrogen. It is important to reduce the atomic hydrogen in the reactor. The oxygen suppresses the deterioration of the film during growth. The carrier concentration increases with the increase of oxygen supply. However, not only oxygen but also defect density due to oxygen is responsible for a higher carrier concentration. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined Use of PCA and QSAR/QSPR to Predict the Drugs Mechanism of Action. An Application to the NCI ACAM Database
Authors: Lauria Antonino , Ippolito Mario , Almerico Anna Maria 
Published: February 2009

AbstractDuring the years the National Cancer Institute (NCI) accumulated an enormous amount of information through the application of a complex protocol of drugs screening involving several tumor cell lines, grouped into panels according to the disease class. The Anti‐cancer Agent Mechanism (ACAM) database is a set of 122 compounds with anti‐cancer activity and a reasonably well known mechanism of action, for which are available drug screening data that measure their ability to inhibit growth of a panel of 60 human tumor lines, explicitly designed as a training set for neural network and multivariate analysis. The aim of this work is to adapt a methodology (previously developed for the analysis of DNA minor groove binders) for the analysis of NCI ACAM database, using Principal Component Analysis (PCA) and QSAR/QSPR for the prediction of the mechanism of action of anti‐cancer drugs. The entire database was splitted in a training set of 60 structures and a test set of 48 ones, and each set was expressed in form of a matrix on which further procedures were performed. Three statistical parameters were calculated: First Attempt of Prediction (FAP) expresses the percentage of correct predictions at first attempt, Total Attempt of Prediction (TAP) expresses the total percentage of correct predictions across all the three attempts, Non‐Classified (NC) expresses the percentage of compounds whose mechanism of action has failed to be predicted. The predictive ability of this approach is variable, but the results obtained are generally good; using 50% Growth Inhibiting concentration (GI50) values as training data, we were able to assign a correct mechanism of action with a good degree of reliability (more than 79%).