bluuebunny/crossref_metadata_2025_split huggingface dataset:
A high‐performance liquid chromatographic method for saikosaponin a quantification in rat plasma
Authors: Tang Yi‐hong , Zhang Yuan‐yuan , Zhu Hai‐yan , Huang Cheng‐gang 
Published: March 2007

AbstractA high‐performance liquid chromatographic method with UV detection has been developed for the determination of saikosaponin a in rat plasma. Saikosaponin a and internal standard jujuboside A were isolated from plasma samples by solid‐phase extraction. The chromatographic separation was achieved on a reversed‐phase C18 column with the mobile phase of acetonitrile–water (35:65, v/v) at a flow rate of 1 mL/min and UV detection was set at 205 nm. The standard curve for saikosaponin a was linear over the concentration range 0.25–10 µg/mL and the limit of detection was 0.05 µg/mL. The absolute recovery was greater than 82%. The precision and accuracy ranged from 3.05 to 9.59% and 95.61 to 110.00%, respectively. The validated method was used to determine saikosaponin a in plasma samples in a pharmacokinetic study of saikosaponin a administered to Sprague–Dawley rats. Copyright © 2007 John Wiley & Sons, Ltd.
LC‐MS characterization of efficacy substances in serum of experimental animals treated with Sophora flavescens extracts
Authors: Ye Guan , Zhu Hai‐Yan , Li Zhi‐Xiong , Ma Chun‐Hui , Fan Ming‐Song , Sun Zhao‐Lin , Huang Cheng‐Gang 
Published: March 2007

AbstractAnti‐DHBV (duck hepatitis B virus) activity was found in the aqueous extracts of Sophora flavescens Ait. in vivo. Liquid chromatography/electrospray ionization ion trap mass spectrometry was applied to characterize the components in duck serum after oral administration of S. flavescens extract. Oxymatrine (1), sophoranol (2), sophoridine (3) and matrine (4) were identified in the serum. Further research on the four compounds was evaluated for their antiviral activity against HBV (hepatitis B virus) in cell culture. The results suggested that oxymatrine, sophoranol and matrine were the efficacy substances for anti‐HBV activity in aqueous extracts of S. flavescens Ait. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous determination and pharmacokinetic studies of aloe emodin and chrysophanol in rats after oral administration of Da‐Cheng‐Qi decoction by high‐performance liquid chromatography
Authors: Tang Wen‐Fu , Yu Qin , Wan Mei‐Hua , Qin Feng , Wang Yong‐Gang , Chen Guang‐Yuan , Liang Mao‐Zhi , Huang Xi 
Published: March 2007

AbstractA validated high‐performance liquid chromatography (HPLC) method was developed for simultaneous determination and pharmacokinetic study of aloe emodin and chrysophanol in rats. It was performed on a reverse‐phase C18 column and a mobile phase made up of methanol and 0.2% acetic acid (83:17, v/v). The ultraviolet detection was 254 nm. 1,8‐dihydroxyanthraquinone was used as the internal standard. The assay was linear over the range 28–2800 ng/mL (r2 = 0.9993) for aloe emodin and 25.6–2560 ng/mL (r2 = 0.9991) for chrysophanol. The average percentage recoveries of three spiked plasmas were 98.8–104.8% and 97.7–103.2% for aloe emodin and chrysophanol, respectively. Their RSD of intra‐day and inter‐day precision at concentrations of 56, 280 and 1400 ng/mL for aloe emodin and 51.6, 258 and 1290 ng/mL for chrysophanol were less than 3.5%. This method was applied for the first time to simultaneously determinate aloe emodin and chrysophanol in rats following oral administration of traditional Chinese medicine of Da‐Cheng‐Qi decoction. The pharmacokinetic parameters showed that chrysophanol was better absorbed with higher concentrations in plasma than aloe emodin did. They both eliminated slowly in male rats. The assay is suitable for identifying the plasma and tissue levels of aloe emodin and chrysophanol in preclinical investigations. Copyright © 2007 John Wiley & Sons, Ltd.
Kinetic release of triptolide after injection of renal‐targeting 14‐succinyl triptolide‐lysozyme in a rat kidney study by liquid chromatography/mass spectrometry
Authors: Zheng Qiang , Ye Limin , Gao Rong , Han Jing , Xiong Meijin , Zhao Dong , Gong Tao , Zhang Zhirong 
Published: March 2007

AbstractTriptolide (TP) is one of the most important biologically active components of the Chinese herb Tripterygium wilfordii Hook f (TWHf). A novel high‐performance liquid chromatography/mass spectrometry (LC/MS) method was developed to study the kinetic release of TP after intravenous injection of the newly synthesized 14‐succinyl triptolide‐lysozyme (TPS–LZM). The method was validated in terms of selectivity, linearity, precision, accuracy, stability, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve was linear over the concentration range 0.5–400.0 ng/g. The mean recovery of triptolide from spiked samples, in a concentration range of 0.5–400.0 ng/g, was 91.84% (RSD = 3.69%, n = 3). The intra‐ and inter‐assay coefficients of variation were less than 6.38%. The method with simple sample pretreatment and being highly specific and precise, can be used for analysis of triptolide release in rat kidney after intravenous injection of renal‐targeting TPS–LZM conjugate. The results showed that, as compared with free TP, TPS–LZM could significantly increase the concentration and prolong the action time of TP in the kidney. Copyright © 2007 John Wiley & Sons, Ltd.
Quaternary Ammonium Zinc Phthalocyanine: Inhibiting Telomerase by Stabilizing G quadruplexes and Inducing G‐Quadruplex Structure Transition and Formation
Authors: Ren Lige , Zhang Anming , Huang Jing , Wang Ping , Weng Xiaocheng , Zhang Lixia , Liang Feng , Tan Zheng , Zhou Xiang 
Published: March 2007

AbstractWater‐soluble, octacationic zinc phthalocyanine (ZnPc) was found to be a very good G‐quadruplex DNA stabilizer by using UV‐melting studies and DNA polymerase stop assays, and a potent telomerase inhibitor by using the telomeric repeat amplification protocol (TRAP) assay. The compound’s DNA‐binding properties were also studied by surface plasmon resonance (SPR). Furthermore, CD experiments demonstrated that ZnPc could induce intramolecular G‐quadruplex structure transition from the antiparallel to parallel form. More importantly, ZnPc was found to induce parallel structure formation in cation‐deficient conditions. The stability of the induced structure was determined with CD melting assays.
High‐Density Storage of H2 in Microporous Crystalline Silica at Ambient Conditions
Authors: van den Berg Annemieke W. C. , Pescarmona Paolo P. , Schoonman Joop , Jansen Jacobus C. 
Published: March 2007

AbstractMolecular hydrogen was encapsulated in the cages of clathrasil decadodecasil 3R (DD3R) during the hydrothermal synthesis of this microporous silicate. The crystalline structure of DD3R facilitates high‐density hydrogen storage at ambient conditions. Prompt gamma activation analysis (PGAA) revealed that on average about one molecule of H2 is trapped in each (512) cage of DD3R. The presence of molecular hydrogen inside the DD3R framework was confirmed by solid‐state 1H NMR spectroscopy. Temperature‐programmed decomposition (TPD) in combination with mass spectrometry showed that the encapsulated hydrogen is released upon decomposition of the clathrasil structure. This release can be promoted by the presence of water.
Functional protofilament numbering of ciliary, flagellar, and centriolar microtubules
Authors: Linck Richard W. , Stephens Raymond E. 
Published: March 2007

AbstractThis article discusses the current state of knowledge about the evolutionarily conserved structure of ciliary, flagellar and centriolar microtubules, and formally proposes a functional numbering convention for their protofilaments. Cell Motil. Cytoskeleton 2007. © 2007 Wiley‐Liss, Inc.
Prediction of Tyrosinase Inhibition Activity Using Atom‐Based Bilinear Indices
Authors: Marrero‐Ponce Yovani , Khan Mahmud Tareq Hassan , Casañola Martín Gerardo M. , Ather Arjumand , Sultankhodzhaev Mukhlis N. , Torrens Francisco , Rotondo Richard 
Published: March 2007

AbstractA set of novel atom‐based molecular fingerprints is proposed based on a bilinear map similar to that defined in linear algebra. These molecular descriptors (MDs) are proposed as a new means of molecular parametrization easily calculated from 2D molecular information. The nonstochastic and stochastic molecular indices match molecular structure provided by molecular topology by using the kth nonstochastic and stochastic graph‐theoretical electronic‐density matrices, Mk and Sk, respectively. Thus, the kth nonstochastic and stochastic bilinear indices are calculated using Mk and Sk as matrix operators of bilinear transformations. Chemical information is coded by using different pair combinations of atomic weightings (mass, polarizability, vdW volume, and electronegativity). The results of QSAR studies of tyrosinase inhibitors using the new MDs and linear discriminant analysis (LDA) demonstrate the ability of the bilinear indices in testing biological properties. A database of 246 structurally diverse tyrosinase inhibitors was assembled. An inactive set of 412 drugs with other clinical uses was used; both active and inactive sets were processed by hierarchical and partitional cluster analyses to design training and predicting sets. Twelve LDA‐based QSAR models were obtained, the first six using the nonstochastic total and local bilinear indices and the last six with the stochastic MDs. The discriminant models were applied; globally good classifications of 99.58 and 89.96 % were observed for the best nonstochastic and stochastic bilinear indices models in the training set along with high Matthews correlation coefficients (C) of 0.99 and 0.79, respectively, in the learning set. External prediction sets used to validate the models obtained were correctly classified, with accuracies of 100 and 87.78 %, respectively, yielding C values of 1.00 and 0.73. This subset contains 180 active and inactive compounds not considered to fit the models. A simulated virtual screen demonstrated this approach in searching tyrosinase inhibitors from compounds never considered in either training or predicting series. These fitted models permitted the selection of new cycloartane compounds isolated from herbal plants as new tyrosinase inhibitors. A good correspondence between theoretical and experimental inhibitory effects on tyrosinase was observed; compound CA6 (IC50=1.32 μM) showed higher activity than the reference compounds kojic acid (IC50=16.67 μM) and L‐mimosine (IC50=3.68 μM).
Effect of Gramicidin on Phospholipid‐Modified Monolayers and on Ion Transfer at a Liquid–Liquid Interface
Authors: Santos Hélder A. , Carlsson Sanna , Murtomäki Lasse , Kontturi Kyösti 
Published: March 2007

AbstractThe interaction of hybrid lipid/gramicidin A (gA) monolayers with dextran sulfate (DS) and the effect of this interaction on ion transfer at a liquid–liquid interface is reported. The interfacial and physicochemical properties are studied with Langmuir–Blodgett (LB) and electrochemical techniques. The results obtained from compression isotherms demonstrate that the interactions between the different species in the hybrid monolayer vary according to the chemical nature of the lipid (hydrocarbon region and charge of the head group). Interfacial capacitance measured with AC voltammetry indicates that the DS chains form a rather flat and compact layer when adsorbed to either zwitterionic or negatively charged phospholipid monolayers, and that calcium, even at low concentrations, interacts with the monolayers. These results are successfully described by a model based on the solution of the Poisson–Boltzmann equation in the interfacial region. Ion transfer and interactions with the lipid/gA/DS‐modified monolayers were also studied with electrochemical techniques. Admittance data show that although the studied ions are not using gA channels for the transfer through the lipid membranes, the incorporation of gA in the lipid domain and the adsorption of DS at the interface have a significant effect on ion transfer across the monolayers. This effect can be explained as a consequence of the modified surface charge and of the compactness of the lipid domain due to its interaction with gA and to calcium and DS adsorption at the interface. The ion‐transfer rate, therefore, depends on the composition of the monolayer and the chemical nature of the ion.
Contribution of Charge‐Transfer Mechanisms to Surface‐Enhanced Raman Scattering with Near‐IR Excitation
Authors: Zhou Qun , Chao Yanwen , Li Yan , Xu Wei , Wu Ying , Zheng Junwei 
Published: March 2007

AbstractSurface‐enhanced Raman scattering under near‐IR excitation is investigated for p‐aminothiophenol (PATP) molecules that are either adsorbed on an electrochemically roughened silver electrode or embedded in an Au/PATP/Ag molecular junction assembled on an indium‐doped tin oxide electrode. The contribution from chemical enhancement can be amplified relative to the contribution from electromagnetic enhancement, because the energy of the near‐IR excitation is far from the surface plasmon resonance of the nanosized metal particles. The energy required for the charge‐transfer process for the Au/PATP/Ag molecular junction is much lower than that of the PATP molecules adsorbed on the electrochemically roughened silver electrode. Coadsorption of chloride ions on the metal nanoparticles may result in an alteration of the local Fermi level of the metal nanoparticles, thus leading to better energy matching between the energy level of the interconnecting PATP molecules and the Fermi level of the metal nanoparticles.
A practical method to determine the amount of tissue to analyze using laser scanning cytometry
Authors: Wijsman John A. , Obert Leslie A. , Paulissen Jerome , Garrido Rosario , Toy Katherine A. , Dunstan Robert W. 
Published: March 2007

AbstractBackground:Laser scanning cytometry (LSC) is a new technology similar to flow cytometry but generates data from analysis of successive microscopic fields. Unlike its use in other applications, LSC‐generated data are not random when used for tissue sections, but are dependent on the microanatomy of the tissue and the distribution and expression of the protein under investigation. For valid LSC analysis, the data generated requires the evaluation of a sufficient tissue area to ensure an accurate representation of expression within the tissue of interest.Methods:In this report, we describe a simple and common sense method for determining the area of tissue required for sound LSC analysis by tracking the variation in the measure of target expression with increasing number of fields until it approaches zero.Results:This approach was used to evaluate the expression of immunohistochemical markers with differing tissue distributions in liver (PMP70, CYP1A2, and Ki67 positive macrophages) and a colorectal adenocarcinoma (activated caspase‐3 positive cells), which exhibited diffuse, regional (centrilobular), random, and irregular distribution patterns respectively.Conclusions:Analyses of these markers demonstrated that the amount of tissue area required to reach a steady measure of a parameter increased with increasing variability of the tissue distribution. © 2007 International Society for Analytical Cytology
Outcomes of eating disorders: A systematic review of the literature
Authors: Berkman Nancy D. , Lohr Kathleen N. , Bulik Cynthia M. 
Published: March 2007

AbstractObjective:The RTI International‐University of North Carolina at Chapel Hill Evidence‐based Practice Center systematically reviewed evidence on factors associated with outcomes among individuals with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) and whether outcomes differed by sociodemographic characteristics.Method:We searched electronic databases including MEDLINE and reviewed studies published from 1980 to September, 2005, in all languages against a priori inclusion/exclusion criteria and focused on eating, psychiatric or psychological, or biomarker outcomes.Results:At followup, individuals with AN were more likely than comparisons to be depressed, have Asperger's syndrome and autism spectrum disorders, and suffer from anxiety disorders including obsessive‐compulsive disorders. Mortality risk was significantly higher than what would be expected in the population and the risk of suicide was particularly pronounced. The only consistent factor across studies relating to worse BN outcomes was depression. A substantial proportion of individuals continue to suffer from eating disorders over time but BN was not associated with increased mortality risk. Data were insufficient to draw conclusions concerning factors associated with BED outcomes. Across disorders, little to no data were available to compare results based on sociodemographic characteristics.Conclusion:The strength of the bodies of literature was moderate for factors associated with AN and BN outcomes and weak for BED. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
Binge eating disorder treatment: A systematic review of randomized controlled trials
Authors: Brownley Kimberly A. , Berkman Nancy D. , Sedway Jan A. , Lohr Kathleen N. , Bulik Cynthia M. 
Published: March 2007

AbstractObjective:The Research Triangle Institute‐University of North Carolina Evidence Based Practice Center (RTI‐EPC) systematically reviewed evidence on efficacy of treatment for binge eating disorder (BED), harms associated with treatments, factors associated with treatment efficacy, and differential outcome by sociodemographic characteristics.Method:We searched six major databases for studies on the treatment of BED published from 1980 to September, 2005, in all languages against a priori inclusion/exclusion criteria and focused on eating, psychiatric or psychological, or biomarker outcomes.Results:Twenty‐six studies, including medication‐only, medication plus behavioral intervention, and behavioral intervention only designs, met inclusion criteria. The strength of the evidence for medication and behavioral interventions was moderate, for self‐help and other interventions was weak, for treatment‐related harms was strong, for factors associated with efficacy of treatment was weak, and for differential outcome by sociodemographic factors was nonexistent. Individual or group CBT reduces binge eating and improves abstinence rates for up to 4 months after treatment but does not lead to weight loss. Medications may play a role in treating BED patients.Conclusion:The literature regarding treatment efficacy for BED is variable. Future directions include the identification of optimal interventions that are associated with both sustained abstinence from binge eating and permanent weight loss. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2007
Construction of 1D and 2D Copper(I) Coordination Polymers Assembled by PhS(CH2)nSPh (n = 1, 2) Dithioether Ligands: Surprising Effect of the Spacer Length on the Dimensionality, Cluster Nuclearity and the Fluorescence Properties of the Metal–Organic Framework
Authors: Peindy Harmel N. , Guyon Fabrice , Khatyr Abderrahim , Knorr Michael , Strohmann Carsten 
Published: March 2007

AbstractTreatment of CuI with PhSCH2SPh in MeCN solution affords, by a self‐assembly reaction, the monodimensional metal–organic coordination polymer [Cu4I4{μ‐PhS2CH2SPh}2]n (1), in which Cu4(μ3‐I)4 cluster units are linked by the dithioether ligand in a 1D necklace structure. In contrast, the reaction of PhSCH2CH2SPh with CuI results in the formation of the metallopolymer [(CuI)2{μ‐PhS(CH2)2SPh}2]n (2). The 2D network of 2 is built from dimeric Cu2I2 units which are connected by 1,2‐bis(phenylthio)ethane bridging ligands. The solid‐state luminescence spectrum of 1 exhibits a strong emission around 532 nm, whereas a weak emission centred at 413 nm is observed in the case of 2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis and Optical Properties of β‐BaB2O4 Network‐Like Nanostructures
Authors: Zhao Qingrui , Zhu Xi , Bai Xue , Fan Haihua , Xie Yi 
Published: March 2007

AbstractNetwork‐like nanostructures made from the nonlinear optical material beta barium metaborate (β‐BaB2O4, β‐BBO) have been successfully synthesized from a BBO gel precursor by a sol–gel method. The homogeneous BBO gel precursor is prepared by the hydrolysis and condensation of barium acetate, sorbitol, and boric acid in a mixture of polyethylene glycol (PEG200) and water. We have also demonstrated that the morphology of the synthesized β‐BaB2O4 materials exerts a significant influence on the second harmonic generation (SHG) efficiency. Importantly, the preparation and second‐order nonlinear optical studies with different shapes will offer great opportunities to explore the dependence of a material's second‐order nonlinear optical properties on its morphology and is essential for the manufacture of potential nanoscale optoelectronic and nonlinear optical devices.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
DFT Study of the Nucleophilic Addition of Water to Ketenes
Authors: Rodríguez‐Otero Jesús , Hermida‐Ramón Jose M. , Cabaleiro‐Lago Enrique M. 
Published: March 2007

AbstractThe geometries of the different stationary points of reactants, products, and transition states of the nucleophilic addition of water to cyanoketene and methylcarboxyketene have been identified by optimizing every degree of freedom by density functional theory at the B3LYP/6‐31++G** level of theory. The computational results for methylcarboxyketene in both the gas and solvated phase agree with the explanation based on experimental data, according to which the nucleophilic addition of water or alcohols to ketenes obtained from malonates (in our case represented by methylcarboxyketene) occurs by a concerted pseudopericyclic mechanism. The results of the calculations also agree with the experimental data for addition to cyanoketene. This reaction occurs through a zwitterionic intermediate, but in contrast to the previous reaction the solvent is essential for the process to occur.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Selectivity in 1,3‐Dipolar Cycloadditions of β‐Substituted Captodative Olefins – An Experimental and DFT Transition State Study
Authors: Herrera Rafael , Mendoza Jorge A. , Morales Miguel A. , Méndez Francisco , Jiménez‐Vázquez Hugo A. , Delgado Francisco , Tamariz Joaquín 
Published: March 2007

AbstractCaptodative olefins 1‐acetylvinyl carboxylates substituted with alkyl groups at theposition, 12, strongly modified the regioselectivity of 1,3‐dipolar cycloadditions with respect to the behavior observed for their unsubstituted analogs, 1. When the reaction of 12 was carried out with diphenyl nitrone (7a), the corresponding C‐4 disubstituted isoxazolidines were obtained as a mixture or as single stereoisomers, in contrast to the isomeric C‐5 disubstituted heterocycles yielded by olefins 1. Nevertheless, olefins 12 reacted with benzonitrile oxide (2a) to give the C‐5 acetyl isoxazoles, as observed with dipolarophiles 1. This intricate behavior of the reactions between 1,3‐dipoles and β‐substituted captodative olefins was rationalized on the basis of DFT calculations [B3LYP/6‐31(d)] of the transition states (TSs) for nitrone 7a and olefin 12a. Thus, the observed C‐4 and endo regio‐ and stereoselectivities agreed with the most stable TSs, which are mainly stabilized by dipolar and electrostatic interactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)