bluuebunny/crossref_metadata_2025_split huggingface dataset:
HPLC‐ELSD analysis of spectinomycin dihydrochloride and its impurities
Authors: Zhou Junyi , Zhang Lin , Wang Yan , Yan Chao 
Published: June 2011

AbstractA simple, rapid and reliable reversed‐phase ion‐pair chromatography method by HPLC coupled to an evaporative light scattering detector (ELSD) has been developed to simultaneously determine chloride, spectinomycin and its related substances in a sample. The column was a TSKgel ODS‐100V. The mobile phase was ACN/aqueous solution of 15 mM ammonium acetate adjusted with TFA to pH 3.0 (2:98 v/v), in an isocratic mode. The drift tube temperature was set at 50°C and the nebulizing gas flow rate of air was 3.5 L/min for ELSD detection. Almost all of the reported degradation compounds of spectinomycin such as actinamine, actinospectinoic acid and biosynthesis intermediates such as dihydrospectinomycin diastereoisomers were baseline separated. MS was utilized for the identification of spectinomycin and its seven related substances. The method for the assay of spectinomycin was successfully validated with respect to accuracy, precision (RSD less than 2%), linearity (throughout the linear range 0.025–3 mg/mL, r=0.9993), sensitivity (LOD: 100 ng on column) and robustness. The experimental results demonstrated that the simultaneous determination of chloride, spectinomycin and related substances is feasible in a single run, which suggests applicability in routine assays.
Analysis of β‐blockers in groundwater using large‐volume injection coupled‐column reversed‐phase liquid chromatography with fluorescence detection and liquid chromatography time‐of‐flight mass spectrometry
Authors: Galera María M. , Vázquez Piedad P. , Vázquez María del Mar P. , García María Dolores G. , Amate Carmen F. 
Published: June 2011

AbstractAtenolol, nadolol, metoprolol, bisoprolol and betaxolol were simultaneously determined in groundwater samples by large‐volume injection coupled‐column reversed‐phase liquid chromatography with fluorescence detection (LVI‐LC‐LC‐FD) and liquid chromatography‐time‐of‐flight mass spectrometry (LC‐TOF‐MS). The LVI‐LC‐LC‐FD method combines analyte isolation, preconcentration and determination into a single step. Significant reductions in costs for sample pre‐treatment (solvent and solid phases for clean up) and method development times are also achieved. Using LC‐TOF‐MS, accurate mass measurements within 3 ppm error were obtained for all of the β‐blockers studied. Empirical formula information can be obtained by this method, allowing the unequivocal identification of the target compounds in the samples. To increase the sensitivity, a solid‐phase extraction step with Oasis MCX cartridge was carried out yielding recoveries of 79–114% (n=5) with RSD 2–7% for the LC‐TOF‐MS method. SPE gives a high purification of β‐blockers compared with the existing methods. A 100% methanol wash was allowed for these compounds with no loss of analytes. Limit of quantification was 1–7 ng/L for LVI‐LC‐LC‐FD and 0.25–5 ng/L for LC‐TOF‐MS. As a result of selective extraction and effective removal of coextractives, no matrix effect was observed in LVI‐LC‐LC‐FD and LC‐TOF‐MS analyses. The methods were applied to detect and quantify β‐blockers in groundwater samples of Almería (Spain).
Global detection and identification of components from crude and processed traditional Chinese medicine by liquid chromatography connected with hybrid ion trap and time‐of‐flight‐mass spectrometry
Authors: Cao Gang , Zhang Chengrong , Zhang Yun , Cong Xiaodong , Cai Hao , Cai Baochang , Li Xiaomeng , Yao Jinting 
Published: June 2011

AbstractWe herein present a chemical profiling method to efficiently process the information acquired by ultra fast liquid chromatography (UFLC)‐electrospray ionization source in combination with hybrid ion trap and high‐resolution time‐of‐flight mass spectrometry (UFLC‐(ESI)‐IT‐TOF/MS), facilitating the structural determination of serial components contained in crude or processed traditional Chinese medicine (TCM). Under the optimized UFLC and IT‐TOF‐MSn conditions, over 39 compounds were separated and detected in crude or processed Fructus corni within 25 min. The components were identified by comparing the mass spectra and retention time with reference compounds, or tentatively assigned by elucidating low‐energy collision‐induced dissociation (CID) fragment ions and matching empirical molecular formula with that of the published compounds. Several factors in the processing procedure were examined. The experimental results demonstrate that the chemical reactions that occurred in the processing procedure can be used to elucidate the processed mechanism of F. corni, which is regularly affected by the processing conditions. This study provides a novel approach and methodology to identify the complicated components from various complex mixtures such as crude TCM, processed TCM, and biological samples. It can be used as a valid analytical method for further understanding the processing mechanism of TCM, along with the intrinsic quality control of TCM and its processed product.
Comparison of different liquid chromatography stationary phases in LC‐HRMS metabolomics for the detection of recombinant growth hormone doping control
Authors: Boyard‐Kieken Fanny , Dervilly‐Pinel Gaud , Garcia Patrice , Paris Anne‐Christelle , Popot Marie‐Agnès , le Bizec Bruno , Bonnaire Yves 
Published: June 2011

AbstractGrowth hormone (GH) is a polypeptide suspected of being used in horse racing to speed up physical performances. Despite scientific advances in the recent years, the control of its administration remains difficult. In order to improve it, a metabolomics study through LC‐high resolution mass spectrometry measurements was recently initiated to assess the metabolic perturbations caused by recombinant equine growth hormone administration. Few tens of ions not identified structurally were highlighted as compounds responsible for the modification of metabolic profiling observed in treated animals. This previous work was based on the use of Uptisphere Strategy NEC as the chromatographic column. In parallel, more and more metabolomics studies showed the interest of the use of new chromatographic supports such as hydrophilic interaction chromatography for the analysis of polar compounds. It is in this context that an investigation was conducted on Uptisphere HDO and Luna hydrophilic interaction chromatography stationary phases to generate and process urinary metabolomics fingerprints, which could allow to establish a comparison with Uptisphere Strategy NEC. The chromatographic column the most adapted for the detection of new biomarkers of GH administration has been used to set up a relevant statistical model based on the analysis of more than hundred biological samples.
Simultaneous determination of aliskiren and hydrochlorothiazide from their pharmaceutical preparations using a validated stability‐indicating MEKC method
Authors: Sangoi Maximiliano S. , Wrasse‐Sangoi Micheli , Oliveira Paulo R. , Rolim Clarice M. B. , Steppe Martin 
Published: June 2011

AbstractA stability‐indicating MEKC method was developed and validated for the simultaneous determination of aliskiren (ALI) and hydrochlorothiazide (HCTZ) in pharmaceutical formulations using ranitidine as an internal standard (IS). Optimal conditions for the separation of ALI, HCTZ and its major impurity chlorothiazide (CTZ), IS and degradation products were investigated. The method employed 47 mM Tris buffer and 47 mM anionic detergent SDS solution at pH 10.2 as the background electrolyte. MEKC method was performed on a fused‐silica capillary (40 cm) at 28°C. Applied voltage was 26 kV (positive polarity) and photodiode array (PDA) detector was set at 217 nm. The method was validated in accordance with the ICH requirements. The method was linear over the concentration range of 5–100 and 60–1200 μg/mL for HCTZ and ALI, respectively (r2>0.9997). The stability‐indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using the PDA detection. Precision and accuracy evaluated by RSD were lower than 2%. The method proved to be robust by a fractional factorial design evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI and HCTZ both individually and in a combined dosage tablet formulation to support the quality control.
Determination of enantiomeric purity of S‐amlodipine by chiral LC with emphasis on reversal of enantiomer elution order
Authors: Dossou Katina S. S. , Edorh Patrick A. , Chiap Patrice , Chankvetadze Bezhan , Servais Anne‐Catherine , Fillet Marianne , Crommen Jacques 
Published: June 2011

AbstractAn LC method was developed and prevalidated for the enantiomeric purity determination of S‐amlodipine in polar organic solvent chromatography using a chlorine‐containing cellulose‐based chiral stationary phase (CSP). The concentration of formic acid (FA) (0.01–0.2%) in the mobile phase containing acetonitrile as the main solvent was found to influence the elution order of amlodipine enantiomers as well as the enantioresolution. A reversal of the enantiomer elution order of amlodipine was only observed with chiral stationary phases with both electron‐withdrawing (chloro) and electron‐donating groups (methyl) on the phenyl moieties of the chiral selector, namely cellulose tris(3‐chloro‐4‐methylphenylcarbamate) and cellulose tris(4‐chloro‐3‐methylphenylcarbamate). The highest enantioresolution (Rs: 4.1) value was obtained at the lowest FA concentration (0.01%) using cellulose tris(4‐chloro‐3‐methylphenylcarbamate) as the chiral selector and the enantiomeric impurity, R‐amlodipine, eluted first under these conditions. Therefore, the mobile phase selected for the prevalidation of the method consisted of ACN/0.1% DEA/0.01% FA and the temperature was set at 25°C. The method was prevalidated by means of the strategy based on the total measurement error and the accuracy profile. The method was found to be selective and the limit of quantification was found to be about 0.05% for R‐amlodipine, while the limit of detection was close to 0.02%.
Sensation‐Seeking Attributes Associated with Storm‐Chasing Tourists: Implications for Future Engagement
Authors: Xu Shuangyu , Barbieri Carla , Stanis Sonja Wilhelm , Market Patrick S. 
Published: June 2011

ABSTRACTThis study explores recreational storm chasing, a new form of niche tourism. In particular, this study examines sensation‐seeking traits associated with participants' socio‐demographics, storm‐chasing involvement and tour satisfaction levels. Results show that recreational storm chasers scored highest on Experience Seeking and lowest on Boredom Susceptibility sensation‐seeking dimensions. Correlation tests showed that several socio‐demographic, storm‐chasing involvement and tour satisfaction indicators are associated with Thrill and Adventure Seeking, Boredom Susceptibility, and Experience Seeking dimensions. Marketing and management implications of study results also are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
SEVERITY OF SALINITY ACCURATELY DETECTED AND CLASSIFIED ON A PADDOCK SCALE WITH HIGH RESOLUTION MULTISPECTRAL SATELLITE IMAGERY
Authors: Setia R. , Lewis M. , Marschner P. , Raja Segaran R. , Summers D. , Chittleborough D. 
Published: June 2011

ABSTRACTWe hypothesised that digital mapping of various forms of salt‐affected soils using high resolution satellite imagery, supported by field studies, would be an efficient method to classify and map salinity, sodicity or both at paddock level, particularly in areas where salt‐affected patches are small and the effort to map these by field‐based soil survey methods alone would be inordinately time consuming. To test this hypothesis, QuickBird satellite data (pan‐sharpened four band multispectral imagery) was used to map various forms of surface‐expressed salinity in an agricultural area of South Australia. Ground‐truthing was performed by collecting 160 soil samples over the study area of 159 km2. Unsupervised classification of the imagery covering the study area allowed differentiation of severity levels of salt‐affected soils, but these levels did not match those based on measured electrical conductivity (EC) and sodium adsorption ratio (SAR) of the soil samples, primarily because the expression of salinity was strongly influenced by paddock‐level variations in crop type, growth and prior land management. Segmentation of the whole image into 450 paddocks and unsupervised classification using a paddock‐by‐paddock approach resulted in a more accurate discrimination of salinity and sodicity levels that was correlated with EC and SAR. Image‐based classes discriminating severity levels of salt‐affected soils were significantly related with EC but not with SAR. Of the spectral bands, bands 2 (green, 520–600 nm) and 4 (near‐infrared, 760–900 nm) explained the majority of the variation (99 per cent) in the spectral values. Thus, paddock‐by‐paddock classification of QuickBird imagery has the potential to accurately delineate salinity at farm level, which will allow more informed decisions about sustainable agricultural management of soils. Copyright © 2011 John Wiley & Sons, Ltd.
Development of Disulfide Core‐Crosslinked Pluronic Nanoparticles as an Effective Anticancer‐Drug‐Delivery System
Authors: Abdullah‐Al‐Nahain  , Lee Haeshin , Lee Young Sun , Lee Kang Dae , Park Sung Young 
Published: June 2011

AbstractThiolated Pluronic (Plu‐SH) nanoparticles are developed as potential articulate, target‐specific anticancer‐drug carriers for intracellular drug release triggered by the difference in redox potential in tumor cells. The cores of the micelles are formed by the disulfide bonds of the functionalized Pluronic F127, when dissolved in an aqueous solution. The nanoparticles are 95.6 ± 18.6 nm in size, and 235.6 ± 63.7 nm after encapsulation of the hydrophobic drug molecules. The drug‐loaded micelles show effective stability in blood‐plasma conditions and the kinetics of micelle stability and drug release are shown. Paclitaxel‐loaded micelles display approximately 39% cell viability in A549 cells. magnified image
Eco‐friendly Poly(butylene 1,4‐cyclohexanedicarboxylate): Relationships Between Stereochemistry and Crystallization Behavior
Authors: Celli Annamaria , Marchese Paola , Sullalti Simone , Berti Corrado , Barbiroli Giancarlo 
Published: June 2011

AbstractPoly(butylene 1,4‐cyclohexanedicarboxylate) (PBCHD) is an environmentally friendly material, as it can be obtained from biomass (although nowadays it is prepared from petroleum resources) and is potentially biodegradable. Moreover, the aliphatic rings along the chains lend interesting characteristics, for example good mechanical properties and resistance to weather for outdoor applications. As many properties, such as biodegradability, strongly depend on crystallinity, a study of the crystallizability of PBCHDs is very meaningful. Equilibrium melting temperatures and crystallization rates are strongly affected by the cis/trans ratio of the 1,4‐cyclohexylene units. Indeed, only the trans isomer can form crystals, whereas the cis isomer is fully excluded from the crystalline phase. All thermal data can be well understood by considering PBCHD as a random copolymer with crystallizable (trans isomer) and noncrystallizable (cis isomer) components, which only differ for the stereochemistry of the aliphatic rings. magnified image
Atom Transfer Radical Dispersion Polymerization of Styrene in the Presence of PEO‐based Macromonomer
Authors: Li Wenwen , Matyjaszewski Krzysztof 
Published: June 2011

AbstractCommercially available poly(ethylene oxide) macromonomers are successfully used as reactive stabilizers for atom transfer radical dispersion/precipitation polymerization of styrene. Polystyrene particles with PEO chains covalently anchored on the surfaces are obtained. Control over both the particle size and polymer chain growth is achieved using a two‐stage technique consisting of an initial free radical polymerization (FRP) for the nucleation followed by a reverse atom transfer radical polymerization (ATRP) for the controlled polymerization process. The limited monomer conversion at the FRP step ensures that the overall polymerization process is mainly controlled by the reverse ATRP step, resulting in the formation of particles containing well‐defined polymer chains. magnified image
Poly(cyclic imino ether)s Beyond 2‐Substituted‐2‐oxazolines
Authors: Bloksma Meta M. , Schubert Ulrich S. , Hoogenboom Richard 
Published: June 2011

Abstract2‐Oxazolines (2‐OZO) are 5‐membered cyclic imino ethers whose cationic ring‐opening polymerization (CROP) mechanism and resulting polymer properties are extensively studied. However, also 6‐ and 7‐membered cyclic imino ethers can be polymerized via CROP. Together with the much less studied 4‐ and 5‐substituted main‐chain chiral poly(2‐oxazoline)s (P‐2‐OZO), these compounds are interesting monomers to enhance the versatility of (co)poly(cyclic imino ether)s. To emphasize the potential of such alternative cyclic imino ether monomers, we provide an overview on the polymerizations of 2‐oxazine (2‐OZI) and chiral 4‐ and 5‐substituted 2‐OZO as well as of selected properties of the resulting polymers. In addition, the hydrolysis of these polymers into the corresponding poly(alkylene imine)s will be addressed. magnified image
Photocatalytically Active Polyelectrolyte/Nanoparticle Films for the Elimination of a Model Odorous Gas
Authors: Dontsova Dariya , Keller Valérie , Keller Nicolas , Steffanut Pascal , Félix Olivier , Decher Gero 
Published: June 2011

AbstractVirtually transparent films of Aeroxide TiO2 P25 were fabricated via layer‐by‐layer assembly with sodium poly(styrene sulfonate). Nanoscale films are formed on model surfaces for characterization or inside of cylindrical reactors for investigating the catalytic properties. Films are fairly homogeneous and smooth over large areas and show different optical interference colors depending on film thickness. The application‐relevant photocatalytic performance of such films toward on‐flow degradation of hydrogen sulfide under UV‐A irradiation was investigated. Scanning electron microscopy reveals a nanoporous structure allowing for the permeation of gas. Consequently, the catalytic efficiency of the films increases with increasing film thickness retaining a considerable activity of the corresponding nanoparticle powder. Scheme 1 depicts in a general way the functionalized reactor and the principle of the measurement.
Application of Poly(3‐hexylthiophene) Functionalized with an Anchoring Group in Dye‐sensitized Solar Cells
Authors: Warnan Julien , Pellegrin Yann , Blart Errol , Odobel Fabrice , Zhang Wei , Liu Bin , Babu Veluru Jagadeesh , Ramakrishna Seeram 
Published: June 2011

AbstractA series of three poly(3‐hexylthiophene) functionalized either with a cyanoacetic acid (CA) or a rhodanine‐3‐acetic acid anchoring groups were synthesized and characterized. The TiO2 based dye‐sensitized solar cells have been fabricated and performances were tested. We show that shorter chain length (15 thiophene units) linked to CA binding group gives good performances as Jsc, Voc, FF and η(%) were 6.93(mA · cm−2), 0.65(V), 0.67 and 3.02%, respectively. A maximum IPCE of ≈50% at 500 nm was recorded with a liquid electrolyte, under AM 1.5 simulated solar irradiance. magnified image
Model Discrimination of Radical Desorption Kinetics in Emulsion Polymerisation
Authors: Fellows Christopher M. , Murison Robert D. , Russell Gregory T. 
Published: June 2011

AbstractAnalysis of published experimental data on monomeric radical diffusion in the emulsion polymerisation of styrene shows that it can be quantitatively described equally well by non‐equilibrium diffusion from particles, where all parameters are derived from properties of the discrete phase, or by steady‐state diffusion where all parameters are derived from properties of the continuous phase. The non‐equilibrium model better describes an observed experimental trend to a reduced desorption rate coefficient at higher weight fraction of polymer in the particles. The theoretical upper bound of the non‐equilibrium model is also higher than the theoretical upper bound of the steady‐state model allowing fits to experimental data which must be discarded as anomalous in the continuous phase model. magnified image
Cortical gray matter changes in primary blepharospasm: A voxel‐based morphometry study
Authors: Martino Davide , Di Giorgio Annabella , D'Ambrosio Enrico , Popolizio Teresa , Macerollo Antonella , Livrea Paolo , Bertolino Alessandro , Defazio Giovanni 
Published: June 2011

AbstractPrevious voxel‐based morphometry studies of patients with primary blepharospasm documented gray matter volumetric differences of the striatum, cerebellum, thalamus, and parietal lobe areas. However, these results were inconsistent across studies, which recruited relatively small samples and did not always provide detailed clinical information on patients with blepharospasm. The objective of this study was to analyze whole‐brain gray matter volume in a larger sample of patients with blepharospasm and to expand on previous works by evaluating whether clinical features of blepharospasm correlate to whole‐brain gray matter changes. Voxel‐based morphometry was performed on 25 patients with primary adult‐onset blepharospasm and 24 healthy subjects (controls) matched for age, sex, and handedness. Clinical data were collected through a standardized interview. Severity of blepharospasm was measured using the Jankovic Rating Scale. Patients with blepharospasm had greater gray matter volume than controls in the right middle frontal gyrus, whereas patients with blepharospasm had smaller gray matter volume than controls in the left postcentral gyrus and left superior temporal gyrus. Spearman correlation analysis with Bonferroni correction failed to show significant correlations between gray matter volume and the explored clinical variables, comprising age at onset, disease duration, blepharospasm severity, presence of an effective geste antagoniste, and dose and duration of botulinum toxin treatment. Patients with blepharospasm exhibited gray matter volume differences exclusively in cortical regions highly relevant to sensory processing and cognitive modulation of motor behavior. Gray matter changes in the primary sensory cortex may represent a common trait of primary dystonias, including blepharospasm. © 2011 Movement Disorder Society