bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Supramolecular Polymerization
Authors: De Greef Tom F. A. , Smulders Maarten M. J. , Wolffs Martin , Schenning Albert P. H. J. , Sijbesma Rint P. , Meijer E. W. 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Mechanistic Evaluation of Metal‐Catalyzed Hydrogen Transfer Processes: The Shvo Catalyst as an Example of Computational Unravelling
Authors: Comas‐Vives Aleix , Ujaque Gregori , Lledos Agusti 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Principles and Progress in Ultrafast Multidimensional Nuclear Magnetic Resonance
Authors: Mishkovsky Mor , Frydman Lucio 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Electron Paramagnetic Resonance Spectroscopy in the Liquid Phase
Authors: Gescheidt Georg 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: 13C High‐Resolution Solid‐State NMR for Structural Elucidation of Archaeological Woods
Authors: Bardet M. , Gerbaud G. , Giffard M. , Doan C. , Hediger S. , Pape L. Le 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Metabolite Detection by Proton Magnetic Resonance Spectroscopy Using PRESS
Authors: Yahya Atiyah 
Published: February 2010

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Functional roles of VASP phosphorylation in the regulation of chemotaxis and osmotic stress response
Authors: Lin Wan‐Hsin , Nelson Sharon E. , Hollingsworth Ryan J. , Chung Chang Y. 
Published: February 2010

AbstractVasodilator‐stimulated phosphoprotein (VASP) plays crucial roles in controlling F‐actin‐driven processes and growing evidence indicates that VASP function is modulated by phosphorylation at multiple sites. However, the complexity of mammalian system prevents the clear understanding of the role of VASP phosphorylation. In this study, we took advantage of Dictyostelium which possesses only one member of the Ena/VASP family to investigate the functional roles of VASP phosphorylation. Our results demonstrated that hyperosmotic stress and cAMP stimulation cause VASP phosphorylation. VASP phosphorylation plays a negative role for the early steps of filopodia/microspikes formation. VASP phosphorylation appears to modulate VASP localization at the membrane cortex and its interactions with WASP and WIPa. Analysis of chemotaxis of cells expressing VASP mutants showed that VASP phosphorylation is required for the establishment of cell polarity under a cAMP gradient. © 2010 Wiley‐Liss, Inc.
Febrile temperature but not proinflammatory cytokines promotes phosphatidylserine expression on Plasmodium falciparum malaria‐infected red blood cells during parasite maturation
Authors: Pattanapanyasat Kovit , Sratongno Panudda , Chimma Pattamawan , Chitjamnongchai Supapart , Polsrila Korakot , Chotivanich Kesinee 
Published: February 2010

AbstractIntraerythrocytic maturation of the malaria parasite Plasmodium falciparum is associated with profound changes in the asymmetry of phospholipids in the lipid bilayer of the parasitized red blood cells (pRBCs). These changes may contribute to adherence of pRBCs to endothelial cells. This study investigates the effect of febrile temperature and proinflammatory cytokines on phosphatidylserine (PS) expression on the exofacial surface of pRBCs during parasite maturation. The expression of PS on the pRBCs was determined by flow cytometry using fluorescein‐labeled annexin V, which specifically binds to PS and a vital nucleic acid fluorochrome for parasite staining. The results showed that PS expression on the surface of pRBCs increased in association with parasite maturation, especially at the late parasite stage. Furthermore, the growth of P. falciparum also accelerated senescence of the uninfected RBCs in parasite cultures. Exposure to febrile temperature led to significant increases in the expression of PS on the surface of pRBCs, particularly at the late parasite stage associated with the virulence strain of the parasite. In contrast, proinflammatory cytokines had no detectable effect on PS expression on pRBCs. These data suggest that PS molecule expression is more dependent on fever, parasitemia, parasite strain, and virulence than on cytokine exposure. These findings contribute to our understanding of the factors that are involved in malaria pathogenesis. © 2010 International Society for Advancement of Cytometry
Spectrophotometric determination of isopropamide Iodide and trifluoperazine hydrochloride in presence of trifluoperazine oxidative degradate
Authors: Abbas Samah S. , Zaazaa Hala E. , Abdelkawy M. , Abdelrahman Maha M. 
Published: February 2010

AbstractFour sensitive, selective and precise stability indicating methods for the determination of isopropamide iodide (ISO) and trifluoperazine hydrochloride (TPZ) in their binary mixture and in presence of trifluoperazine oxidative degradate (OXD). Method A is a derivative spectrophotometric one, where ISO was determined by first derivative (D1) at 226.4 nm while TPZ was determined by second derivative (D2) at 270.2 nm. Method B is the first derivative of the ratio spectra (DD1) spectrophotometric method, ISO can be determined by measuring the peak amplitude at 227.4 nm using 5 µg mL−1of OXD as a divisor, while TPZ can be determined by measuring the peak amplitude at 249.2 and 261.4 nm using 15 µg mL−1of ISO as a divisor. Method C is the isoabsorptive spectrophotometric method. This method allows determination of ISO and TPZ in their binary mixture by measuring total concentration of ISO and TPZ at their isoabsorptive point at λ229.8nm (Aiso1) while TPZ concentration alone can be determined at λmax311.2 nm, then ISO concentration can be determined by subtraction. On the same basis TPZ can be determined in presence of ISO and OXD, where OXD concentration alone was determined by measuring the peak amplitude at λ281.6and λ309.4nm while total concentration of TPZ and OXD was determined at their isoabsorptive points at (Aiso2= 270.2 nm), (Aiso3= 310.6 nm) and (Aiso4= 331.8 nm) then TPZ concentration was determined by subtraction. Method D is the multivariate calibration techniques [the classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS)], using the information contained in the absorption spectra of ISO, TPZ and OXD mixtures. The selectivity of the proposed methods was checked using laboratory prepared mixtures. The proposed methods have been successfully applied to the analysis of ISO and TPZ in pharmaceutical dosage form without interference from other dosage form additives and the results were statistically compared with the reported method. Copyright © 2010 John Wiley & Sons, Ltd.
Identification of the growth‐hormone‐releasing peptide‐2 (GHRP‐2) in a nutritional supplement
Authors: Thomas Andreas , Kohler Maxie , Mester Joachim , Geyer Hans , Schänzer Wilhelm , Petrou Michael , Thevis Mario 
Published: February 2010

AbstractBlack market products of a pharmaceutical nature and nutritional supplements have received substantial and increasing attention because of potential performance enhancement in elite and non‐professional sports. In addition, improved general health is claimed for non‐competing individuals. The risks and foreseeable dangers of the uncontrolled use of highly potent and non‐approved pharmaceutical compounds in healthy individuals are of considerable concern. In the present case report, the emerging drug candidate GHRP‐2 with verified growth‐hormone‐releasing properties was identified and quantified in tablets offered as an over‐the‐counter nutritional supplement. The impact of this orally active peptide on the hGH/IGF‐axis has been established for several years and its illicit use in elite sports has been assumed. As a releasing factor for hGH, GHRP‐2 belongs to the list of substances prohibited by the World Anti‐Doping Agency (WADA). Unfortunately, to date there is no routinely performed assay for the determination of these peptides potentially occurring in biological fluids of competing athletes, but the present data will facilitate the implementation by providing principle analytical information on liquid chromatographic and mass spectrometric behaviour. Qualitative identification of the target analyte after extraction from the tablet matrix was performed by high resolution/high accuracy mass spectrometry after liquid chromatographic separation under consideration of the accurate masses and the ratios of the protonated molecules and their fragment ions derived from their collisionally induced dissociation. Quantitative results were obtained by means of liquid chromatography coupled to a triple quadrupole mass spectrometer and linear regression using an external calibration curve (with GHRP‐2 reference compound) adjusted via internal standard (Hexarelin). Hereby, the content of GHRP‐2 was determined with approximately 50 µg per tablet. Copyright © 2010 John Wiley & Sons, Ltd.
Modeling the electrophoretic behavior of quinolones in aqueous and hydroorganic media
Authors: Benavente Fernando , Giménez Estela , Barrón Dolores , Barbosa José , Sanz‐Nebot Victoria 
Published: February 2010

AbstractThe applicability of the classical semiempirical relationships between the electrophoretic mobility and charge‐to‐mass ratio (me versus q/Mα) has been investigated to describe migration behavior of a series of quinolones in aqueous and hydroorganic media. The Stoke's law (α=1/3), the classical polymer model (α=1/2) and the Offord's surface law (α=2/3) were evaluated in the pH range comprised between 2 and 11 in ACN–water mixtures of 0, 10 and 30% m/m ACN. As accurate acidity constant values were available for charge calculations, correlations were excellent. The results obtained using the Offord's surface law were slightly better and the plots of q/M2/3 against the separation electrolyte pH were used to select the optimum pH values for separation of a quinolone mixture. The electropherograms simulated considering the accurate charge‐to‐mass ratio of each quinolone at the selected pH values were in good agreement with the experimental results. The ability of these relationships to predict the separation of the studied quinolones at a certain pH value in methanol–water and THF–water mixtures was also demonstrated.
Electrophoretic collision of a DNA molecule with a small elliptical obstacle
Authors: Cho Jaeseol , Kumar Satish , Dorfman Kevin D. 
Published: February 2010

AbstractWe present a Brownian dynamics study of the collision and unhooking of a λ‐DNA molecule with an elliptical obstacle. The semi‐major and semi‐minor axes of the obstacle are comparable to the radius of gyration of the DNA, and the field is sufficiently strong to cause frequent hairpin formation upon collision. We focus on how the dynamics of a head‐on collision (impact parameter of zero) are affected by the angle between the major axis of the ellipse and the direction of the electric field far from the elliptical surface. When this orientation angle breaks the symmetry of the system, we find that the collision dynamics are considerably more complicated than the cylindrical obstacle case. In particular, a higher strain rate at the stagnation point on an elliptical surface does not always lead to a higher hooking probability. As a result, elliptical obstacles should be less effective than cylindrical obstacles for DNA separations based on hairpin formation.
Ionic strength effects on electrophoretic focusing and separations
Authors: Bahga Supreet S. , Bercovici Moran , Santiago Juan G. 
Published: February 2010

AbstractWe present a numerical and experimental study of the effects of ionic strength on electrophoretic focusing and separations. We review the development of ionic strength models for electrophoretic mobility and chemical activity and highlight their differences in the context of electrophoretic separation and focusing simulations. We couple a fast numerical solver for electrophoretic transport with the Onsager–Fuoss model for actual ionic mobility and the extended Debye–Huckle theory for correction of ionic activity. Model predictions for fluorescein mobility as a function of ionic strength and pH compare well with data from CZE experiments. Simulation predictions of preconcentration factors in peak mode ITP also compare well with the published experimental data. We performed ITP experiments to study the effect of ionic strength on the simultaneous focusing and separation. Our comparisons of the latter data with simulation results at 10 and 250 mM ionic strength show the model is able to capture the observed qualitative differences in ITP analyte zone shape and order. Finally, we present simulations of CZE experiments where changes in the ionic strength result in significant change in selectivity and order of analyte peaks. Our simulations of ionic strength effects in capillary electrophoresis compare well with the published experimental data.
Electric field‐enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis
Authors: Kubáň Pavel , Šlampová Andrea , Boček Petr 
Published: February 2010

AbstractSeparation techniques, such as electrodialysis, electroextraction, electro‐membrane extraction and extraction across phase interfaces, are reviewed and discussed as methods for sample cleanup and preconcentration. This survey clearly shows that electromigration of ionic species across phase interfaces, especially across supported liquid membranes, may be very selective and is strongly dependent on the chemical composition of these interfaces. Thus, electric field‐enhanced transport across chemically tailored liquid membranes may open new perspectives in preparative analytical chemistry. This review offers comprehensive survey of related literature and discussion of the topic, which may stimulate interest of experts and practitioners in bioanalysis.
Nonlinear Smoluchowski velocity for electroosmosis of Power‐law fluids over a surface with arbitrary zeta potentials
Authors: Zhao Cunlu , Yang Chun 
Published: February 2010

AbstractElectroosmotic flow of Power‐law fluids over a surface with arbitrary zeta potentials is analyzed. The governing equations including the nonlinear Poisson–Boltzmann equation, the Cauchy momentum equation and the continuity equation are solved to seek exact solutions for the electroosmotic velocity, shear stress, and dynamic viscosity distributions inside the electric double layer. Specifically, an expression for the general Smoluchowski velocity is obtained for electroosmosis of Power‐law fluids in a fashion similar to the classic Smoluchowski velocity for Newtonian fluids. The existing Smoluchowski slip velocities under two special cases, (i) for Newtonian fluids with arbitrary zeta potentials and (ii) for Power‐law fluids with small zeta potentials, can be recovered from our derived formula. It is interesting to note that the general Smoluchowski velocity for non‐Newtonian Power‐law fluids is a nonlinear function of the electric field strength and surface zeta potentials; this is due to the coupling electrostatics and non‐Newtonian fluid behavior, which is different from its counterpart for Newtonian fluids. This general Smoluchowski velocity is of practical significance in determining the flow rates in microfluidic devices involving non‐Newtonian Power‐law fluids.
Advances in the theory and application of MEEKC
Authors: Ryan Richie , Donegan Sheila , Power Joe , Altria Kevin 
Published: February 2010

AbstractMEEKC is an electrodriven separation technique, which utilises the unique properties of a microemulsion (ME) as a background electrolyte to achieve separation of a diverse range of solutes. MEs are composed of nanometre‐sized oil droplets suspended in aqueous buffer, which is commonly referred to as an oil‐in‐water ME. The droplets are stabilised by the presence of a surfactant and co‐surfactant. The use of water‐in‐oil MEs in MEEKC has also been investigated. This review details the advances in MEEKC‐based separations from the period 2008 to 2009. Areas covered include online sample concentration, suppressed electroosmosis MEEKC, chiral separation, MEEKC‐MS, and structure–migration relationships. The review also includes a fundamental introduction to MEEKC, along with the presentation of recent applications.
Destabilization of Pickering emulsions using external electric fields
Authors: Hwang Kyuho , Singh Pushpendra , Aubry Nadine 
Published: February 2010

AbstractIt is known that emulsions can be stabilized by the presence of particles that get trapped at fluid–fluid interfaces and prevent adjacent drops from coalescing with one another. We show here that such emulsions, or Pickering emulsions, can be destabilized by applying external electric fields. This is demonstrated experimentally by studying water drops in decane and silicone oil drops in corn oil in the presence of micro‐sized particles. It is shown that the primary phenomenon responsible for the destabilization is the motion of particles on the surface of drops in the presence of a uniform electric field. Although there should be no electrostatic forces acting on neutral particles in a uniform electric field, the presence of the drop itself introduces nonuniformity, which leads to dielectrophoretic forces acting on the particles and is thus responsible for particle motions along the drop surface. Particles translate to either the poles or the equator of the drop, depending on the relative dielectric constants of the particles, the surrounding fluid and the fluid within the drop. Such motions break the particle barrier, thus allowing for drops to merge with one another and therefore destabilizing the emulsion.
The dependence of the electrophoretic mobility of small organic ions on ionic strength and complex formation
Authors: Allison Stuart A. , Pei Hongxia , Baek Saerom , Brown Jocelyn , Lee Min Y. , Nguyen Vu , Twahir Umar T. , Wu Hengfu 
Published: February 2010

AbstractThe ionic strength dependence of the electrophoretic mobility of small organic anions with valencies up to −3 is investigated in this study. Provided the anions are not too aspherical, it is argued that shape and charge distribution have little influence on mobility. To a good approximation, the electrophoretic mobility of a small particle should be equal to that of a model sphere with the same hydrodynamic radius and same net charge. For small ions, the relaxation effect (distortion of the ion atmosphere from equilibrium due to external electric and flow fields) is significant even for monovalent ions. Alternative procedures of accounting for the relaxation effect are examined. In order to account for the ionic strength dependence of a specific set of nonaromatic and aromatic anions in aqueous solution, it is necessary to include complex formation between the anion with species in the BGE. A number of possible complexes are considered. When the BGE is Tris‐acetate, the most important of these involves the complex formed between anion and Tris, the principle cation in the BGE. When the BGE is sodium borate, an anion–anion (borate) complex appears to be important, at least when the organic anion is monovalent. An algorithm is developed to analyze the ionic strength dependence of the electrophoretic mobility. This algorithm is applied to two sets of organic anions from two independent research groups.
Analysis of fullerene-C60 and kinetic measurements for its accumulation and depuration in Daphnia magna
Authors: Tervonen Kukka , Waissi Greta , Petersen Elijah J. , Akkanen Jarkko , Kukkonen Jussi V.K. 
Published: February 2010

Abstract
A simple method for analyzing masses of water suspended fullerenes (nC60) in Daphnia magna by extracting to toluene and measuring by ultraviolet-vis spectrophotometry was developed. This method was used to assess bioaccumulation and depuration rates by daphnia after nC60 exposure in artificial freshwater. Accumulation was rapid during the first few hours, and based on accumulation modeling, 90% of the steady-state concentration was reached in 21 h. After exposure for 24 h to a 2 mg/L fullerene solution, the daphnia accumulated 4.5 ± 0.7 g/kg wet weight, or 0.45% of the organism wet mass. Daphnids exposed to 2 mg/L fullerenes for 24 h eliminated 46 and 74% of the accumulated fullerenes after depuration in clean water for 24 and 48 h, respectively. Transmission electron microscopy revealed that the majority of the fullerenes present in the gut of daphnids were large agglomerates. The significant fullerene uptake and relatively slow depuration suggest that D. magna may play a role as a carrier of fullerene from one trophic level to another. Additionally, D. magna may impact the fate of suspended fullerene particles in aquatic ecosystems by their ability to pack fullerene agglomerates into larger particles than were found in the exposure water, and then excrete agglomerates that are not stable in water, causing them to settle out of solution. This process decreases fullerene exposure to other aquatic organisms in the water column but may increase exposure to benthic organisms in the sediment. Environ. Toxicol. Chem. 2010;29:1072–1078. © 2010 SETAC