bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐step separation of bioactive flavonol glucosides from Osteomeles schwerinae by high‐speed counter‐current chromatography
Authors: Lee Jun , Jang Dae Sik , Yoo Nam Hee , Lee Yun Mi , Kim Joo‐Hwan , Kim Jin Sook 
Published: February 2010

AbstractTwo bioactive flavonol glucosides, hyperoside and quercitrin, were successfully isolated in one step from the phytochemically unknown medicinal plant Osteomeles schwerinae by high‐speed counter‐current chromatography using a two‐phase solvent system composed of n‐hexane–ethyl acetate–methanol–water (0.5:5.5:1.5:4.5 v/v). From 160 mg of crude extract, 2.1 mg of hyperoside (98.6% purity, 83.3% recovery) and 4.5 mg of quercitrin (99.2% purity, 81.7% recovery) were separated and then their chemical structures were identified by 1H and 13C NMR analysis. In addition, the isolates were subjected to an in vitro bioassay to evaluate their inhibitory activity on rat lens aldose reductase. Both quercitrin and hyperoside showed excellent inhibitory activities toward rat lens aldose reductase with the IC50 values of 0.16 and 4.33 μM, respectively, as compared with positive control, 3,3‐tetramethyleneglutaric acid (28.7 μM). So far, chemical constituents and biological activities of O. schwerinae have never been reported. This is the first report on the chemical constituents and biological activity of this plant using semi‐preparative high‐speed counter‐current chromatography separation technique.
Circulating cell‐free DNA levels increase variably following chorionic villus sampling
Authors: Vora Neeta L. , Johnson Kirby L. , Peter Inga , Tighiouart Hocine , Ralston Steven J. , Craigo Sabrina D. , Bianchi Diana W. 
Published: February 2010

AbstractObjectiveCell‐free fetal DNA (cffDNA) in maternal plasma results from degradation of fetal and/or placental cells. Our objective was to determine if chorionic villus sampling (CVS) causes increased release of fetal and/or maternal DNA.MethodsFifty‐two pregnant women were recruited prior to CVS, performed for clinical indications, at 10 5/7 to 13 2/7 weeks. Maternal blood was collected before and within 15 min after CVS. cffDNA was extracted from plasma. Real‐time polymerase chain reaction (PCR) amplification of glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and the Y chromosome sequence DYS1 were used as measures of total and fetal DNA, respectively. All samples were analyzed in triplicate without knowledge of fetal gender.ResultsSensitivity of DYS1 detection in male fetuses was 100% (n = 30); specificity in female fetuses was 100% (n = 22). While a majority of women had > 50% post‐procedure increases in both fetal and total DNA, some showed post‐procedure decreases. However, overall median proportional increases were not statistically significant. Gestational age (GA), placental location, and individual CVS operator did not correlate with changes in DNA levels.ConclusionsWhile there were no statistically significant overall changes in DNA levels after CVS, as‐yet undiscovered variables may influence the extent of post‐procedure release of cell‐free DNA in the circulation of pregnant women. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of organo‐modifier on the structure and properties of poly[ethylene–(vinyl alcohol)]/organo‐modified montmorillonite composites
Authors: Franco‐Urquiza Edgar , Gamez Perez José , Sánchez‐Soto Miguel , Santana Orlando O , Maspoch Maria L 
Published: February 2010

AbstractEthylene–(vinyl alcohol) (EVOH)/organo‐modified montmorillonite clay (OMMT) composites were prepared using commercial OMMTs with two different organo‐modifiers. The first one has polar groups, which interact with EVOH chains, whereas the second one is non‐polar. Composites with a high weight percentage of OMMT were prepared by melt‐extrusion in a twin‐screw extruder. Films were prepared in a cast‐film line in order to evaluate the tensile and fracture parameters. The morphology of the EVOH/OMMT composites was characterized using wide‐angle X‐ray scattering and transmission electron microscopy, complemented by image analysis. The mechanical properties were evaluated using uniaxial tensile tests; the fracture behaviour was analysed using the essential work of fracture (EWF) method. Results show differences in composite morphologies and crystalline fraction, depending on the content and the nature of the organo‐modifier. The mechanical and fracture behaviours are strongly influenced by those parameters, which act in opposite senses. The EWF method is shown to be a useful tool for the analysis of the structure–properties relationships of these composites. Copyright © 2010 Society of Chemical Industry
Two different sides of ‘chemobrain’: determinants and nondeterminants of self‐perceived cognitive dysfunction in a prospective, randomized, multicenter study
Authors: Hermelink Kerstin , Küchenhoff Helmut , Untch Michael , Bauerfeind Ingo , Lux Michael Patrick , Bühner Markus , Manitz Juliane , Fensterer Veronika , Münzel Karin 
Published: February 2010

AbstractObjective: Complaints of cognitive dysfunction are frequent among cancer patients. Many studies have identified neuropsychological compromise associated with cancer and cancer therapy; however, the neuropsychological compromise was not related to self‐reported cognitive dysfunction. In this prospective study, the authors examined if confounding factors masked an underlying association of self‐perceived cognitive function with actual cognitive performance. Determinants of self‐perceived cognitive dysfunction were investigated.Methods: Self‐perceived cognitive function and cognitive performance were assessed before treatment, at the end of treatment, and 1 year after baseline in 101 breast cancer patients randomized to standard versus intensified chemotherapy. Linear mixed‐effects models were applied to test the relationships of performance on neuropsychological tests, patient characteristics, and treatment variables to self‐reported cognitive function. Change of cognitive performance was tested as a predictor of change in self‐reports.Results: Self‐perceived cognitive function deteriorated during chemotherapy and had partially recovered 1 year after diagnosis. The personality trait negative affectivity, current depression, and chemotherapy regimen were consistently related to cognitive self‐reports. No significant associations with performance in any of the 12 cognitive tests emerged. Change of cognitive performance was not reflected in self‐reports of cognitive function.Conclusions: Neuropsychological compromise and self‐perceived cognitive dysfunction are independent phenomena in cancer patients. Generally, cancer‐associated neuropsychological compromise is not noticed by affected patients, but negative affectivity and treatment burden induce pessimistic self‐appraisals of cognitive functioning regardless of the presence of neuropsychological compromise. Clinicians should consider this when determining adequate therapy for patients who complain of ‘chemobrain’. Copyright © 2010 John Wiley & Sons, Ltd.
A web‐based decision support system to enhance IPM programs in Washington tree fruit
Authors: Jones Vincent P , Brunner Jay F , Grove Gary G , Petit Brad , Tangren Gerald V , Jones Wendy E 
Published: February 2010

AbstractBACKGROUND: Integrated pest management (IPM) decision‐making has become more information intensive in Washington State tree crops in response to changes in pesticide availability, the development of new control tactics (such as mating disruption) and the development of new information on pest and natural enemy biology. The time‐sensitive nature of the information means that growers must have constant access to a single source of verified information to guide management decisions.RESULTS: The authors developed a decision support system for Washington tree fruit growers that integrates environmental data [140 Washington State University (WSU) stations plus weather forecasts from NOAA], model predictions (ten insects, four diseases and a horticultural model), management recommendations triggered by model status and a pesticide database that provides information on non‐target impacts on other pests and natural enemies. A user survey in 2008 found that the user base was providing recommendations for most of the orchards and acreage in the state, and that users estimated the value at $ 16 million per year.CONCLUSIONS: The design of the system facilitates education on a range of time‐sensitive topics and will make it possible easily to incorporate other models, new management recommendations or information from new sensors as they are developed. Copyright © 2010 Society of Chemical Industry
Field leaching of pesticides at five test sites in Hawaii: study description and results
Authors: Dusek Jaromir , Sanda Martin , Loo Binh , Ray Chittaranjan 
Published: February 2010

AbstractBACKGROUND: Following the discovery of pesticides in wells, the Hawaii Department of Agriculture (HDOA) supported research to evaluate the likelihood of pesticide leaching to the groundwater in Hawaii. The aim of this study was to evaluate the relative leaching pattern of five pesticides at five different sites on three islands and to compare their leaching behavior with bromide and a reference chemical (atrazine) that is known to leach in Hawaiian conditions. Laboratory measurements of sorption and degradation of the pesticides were made.RESULTS: Most of the applied mass of pesticides was still present in the top 80 cm after the 16 week study period. The aggregated oxisol at Kunia showed the most intensive leaching among the five sites. The revised attenuation factor screening approach used by the HDOA indicated that all chemicals, with the exception of trifloxystrobin, had the potential to leach. Similarly, the groundwater ubiquity score ranked trifloxystrobin as a non‐leacher. The field leaching data, however, suggested that trifloxystrobin was the most mobile compound among the pesticides tested.CONCLUSION: Although the results were variable among the sites, the field and laboratory experiments provided useful information for regulating use of these pesticides in Hawaii. Copyright © 2010 Society of Chemical Industry
Magnetic properties of cobalt‐carbon nanocomposites
Authors: Matsui Denys , Prylutskyy Yuriy , Matzui Ludmila , Zakharenko Mykola , Le Normand François , Derory Alain 
Published: February 2010

AbstractThe paper presents the results of experimental study of the structure and magnetic characteristics of Co‐graphite compounds, which were obtained by metal reduction of metal chlorides in graphite intercalated compound (GIC) by C8K. The obtained materials were shown to have heterogeneous structure consisting of nanographite matrix in which nanoclusters of Co‐GIC are distributed. Magnetic field was applied either along or perpendicularly to the C‐axis. It was shown that magnetism of this compound is determined mainly by nanoclusters of Co‐GIC for which high anisotropy of magnetic characteristic were observed. ZFC and FC temperature dependences of magnetic susceptibility indicate the formation spin glass state below ∼20 K. It was also shown that experimental dependences of magnetization contain the contribution due to antiferromagnetic sublattice and magnetizationdue to uncompensated magnetic moments (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production of high quality carbon nanotubes for less than $1 per gram
Authors: Smajda R. , Mionic M. , Duchamp M. , Andresen J. C. , Forró L. , Magrez A. 
Published: February 2010

AbstractIn this article, we report on the mass production of carbon nanotubes using a continuous production system based on a rotary tube furnace. At first, we have optimized the composition of the metallic nanoparticles. Bimetallic Fe2Ni and Fe2Co alloys exhibit higher catalytic activity than pure Fe, Co or Ni. Then, catalyst production process has been modified for the preparation of large quantity of catalyst with low aggregation suitable for large scale synthesis of CNTs. A production rate of about 1.2 kg per day has been achieved. This is yielding to a cost production of less than $1 per gram. Finally, we show that the CNTs growth can also be obtained on naturally occurring calcite support for further cost reduction of the synthesis. Quality of the CNTs produced has been established by measuring their mechanical properties using AFM. Young's modulus of the CNTs can be as high as the ideal value of 1 TPa. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Concentration‐dependent effect of (−) epicatechin in hypertensive patients
Authors: Kumar Navneet , Kant Ruchi , Maurya Pawan Kumar 
Published: February 2010

AbstractNon‐vitamin polyphenolic compounds are ubiquitous in food plants and therefore potentially present in human plasma in a diet‐dependent concentration. The aim of this study was to evaluate the concentration‐dependent effect of (−) epicatechin, a polyphenol present in green tea with antioxidant activity, on various biomarkers of oxidative stress. The current study examined the in vitro concentration‐dependent (10−4 M to 10−7 M) effects of (−) epicatechin on biomarkers of oxidative stress viz. malondialdehyde (MDA), reduced glutathione (GSH), membrane sulfhydryl (‐SH) group and protein carbonyl content in hypertensive patients and normal ones. This effect seems to be due to ability of (−) epicatechin to reduce MDA and protein carbonyl content while increase in GSH and membrane ‐SH group in hypertensive patients. It can be concluded that (‐) epicatechin exerts an antioxidant action inside the cell, responsible for the observed modulation of cellular response to oxidative challenges. Copyright © 2010 John Wiley & Sons, Ltd.
Stability of the Rydberg atom in the crossed magnetic and electric fields
Authors: Guirao Juan L. G. , Vera Juan A. 
Published: February 2010

AbstractThe stability of equilibrium positions of the Rydberg atom exposed to the uniform crossed electric and magnetic fields is analyzed. The dynamics of the system is described by an autonomous Hamiltonian depending on parameters a and f. By the normalization of the quadratic part of the Hamiltonian expansion in the neighborhood of the equilibrium position it is proved that for any f < 0 and ${1 \over 2} < a < {1 \over 2} + {{( - f)^{3/2} } \over {3\sqrt 3 }}$, the equilibrium solution of the equations of motion is stable in Liapunov sense, while for f > 0 and a < 1/2, there is a domain of instability in the plain of parameters Ofa bounded by the curve d3 = 0. In the domain of linear stability, it is proved that there are two curves in the plane Ofa, where the resonance conditions of third (ω1 = 2ω2) and fourth (ω1 = 3ω2) order are fulfilled. Moreover, by the normalization of the third‐ and fourth‐order terms in the Hamiltonian expansion it is proved that in the case of the third‐order resonance, the equilibrium position is unstable for all f > 0 different from f = 0.111572 and f = 0.281144, for which the stability takes place. In the case of the fourth‐order resonance, there are two intervals of parameters for which the equilibrium position is unstable. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Theoretical study of mechanism of cycloaddition reaction between dichloro‐germylene carbene (Cl2GeC:) and aldehyde
Authors: Lu Xiu Hui , Che Xin , Shi Le Yi , Han Jun Feng , Lian Zhen Xia 
Published: February 2010

AbstractThe mechanism of the cycloaddition reaction between singlet dichloro‐germylene carbene and aldehyde has been investigated with MP2/6‐31G* method, including geometry optimization and vibrational analysis for the involved stationary points on the potential energy surface. The energies of the different conformations are calculated by zero‐point energy and CCSD (T)//MP2/6‐31G* method. From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. The channel (A) consists of four steps: (1) the two reactants (R1, R2) first form an intermediate INT2 through a barrier‐free exothermic reaction of 142.4 kJ/mol; (2) INT2 then isomerizes to a four‐membered ring compound P2 via a transition state TS2 with energy barrier of 8.4 kJ/mol; (3) P2 further reacts with aldehyde (R2) to form an intermediate INT3, which is also a barrier‐free exothermic reaction of 9.2 kJ/mol; (4) INT3 isomerizes to a germanic bis‐heterocyclic product P3 via a transition state TS3 with energy barrier of 4.5 kJ/mol. The process of channel (B) is as follows: (1) the two reactants (R1, R2) first form an intermediate INT4 through a barrier‐free exothermic reaction of 251.5 kJ/mol; (2) INT4 further reacts with aldehyde (R2) to form an intermediate INT5, which is also a barrier‐free exothermic reaction of 173.5 kJ/mol; (3) INT5 then isomerizes to a germanic bis‐heterocyclic product P5 via a transition state TS5 with an energy barrier of 69.4 kJ/mol. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
DFT study of the structure and property of small organic hole‐transporting molecules
Authors: Mi Shizhen , Chen Dezhan , Lu Nan 
Published: February 2010

AbstractIn this article, all calculations are performed at B3LYP/6‐31G** level. For each one of the molecule, including triphenylamine (TPA), N,N′‐diphenyl‐N,N′‐bis(3‐methyllphenyl)‐(1,1′‐biphenyl)‐4,4′‐diamine (TPD), biphenyl (Bp), and their derivatives (TPAs, TPDs, Bps, respectively), the geometry is optimized for both neutral and radical‐cation states. Their reorganization energy is then compared. It seems that it is the monomer, TPAs, and not the central biphenyl moiety that determines the properties of TPDs. However, this is contradictory of some previous results. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Toward a regional quantum description of the positronic systems: Primary considerations
Authors: Nasertayoob Payam , Goli Mohammad , Shahbazian Shant 
Published: February 2010

AbstractThis article presents the foundations of a regional quantum description of the positronic systems; molecules containing positron(s), the antielectron. It is demonstrated that by introducing a novel scalar function, called μ‐field, it is possible to construct a positronic local zero‐flux equation. This equation is the basis of the topological analysis of the quantum structure as well as delineating the boundaries of the positronic subsystems, which are 3D regions with well‐defined regional kinetic energies. Furthermore, the positronic subsystem hypervirial theorem is proposed, which yields the regional quantum theorems for the positronic subsystems. The regional virial, force, and continuity theorems are all derivable from the positronic subsystem hypervirial theorem. The primary computational considerations on LiH,e+illustrate that the positronic zero‐flux equation results to reasonable subsystems; that is, to 3D regions similar to those derived previously in purely electronic systems. The general approach proposed in this study is extendable to other exotic species and pave the way toward a unified regional description of these systems. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Multipole expansions of orbital products about an intermediate center
Authors: Talman James D. 
Published: February 2010

AbstractA numerical method described previously (Talman, Int J Quantum Chem, 2007, 107, 1578) is reviewed and a modified formulation that may be more computationally efficient is presented. Modifications required for the application to real harmonics are described. The method requires the numerical evaluation of a one‐dimensional integral on a finite interval, and an improved method for this is described. The application to the evaluation of electron–electron repulsion four‐center integrals is also discussed. It is indicated that μ H accuracy is obtainable with modest computational effort. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Evidence for the production of NO and N2O in two contrasting subsoils following the addition of synthetic cattle urine
Authors: Dixon E. R. , Laughlin R. J. , Watson C. J. , Hatch D. J. 
Published: February 2010

AbstractNitrogenous materials can be transferred out of the topsoil, either vertically to a greater depth, or in lateral pathways to surface waters, and they may also become transformed, with the potential of generating environmentally active agents. We measured the production of NO and N2O in two contrasting subsoils (70 to 90 cm): one poorly drained and the other freely drained and compared this with the topsoil (0 to 20 cm) of the corresponding soils. The soils were incubated aerobically in jars with subtreatments of either synthetic cattle urine or deionised water and sampled at intervals up to 34 days.15N‐NOwas used to determine the processes responsible for NO and N2O production. The headspace was analysed for the concentrations of N2O, NO and CO2and15N enrichment of N2O. The soil samples were extracted and analysed for NO, NOand NH, and the15N enrichment of the extracts was measured after conversion into N2O and N2.The study demonstrated the potential for NO, N2O and NOto be generated from subsoils in laboratory incubations. Differences in these N dynamics occurred due to subsoil drainage class. In the freely drained subsoil the rates of NO and NOproduction were higher than those observed for the corresponding topsoil, with mean maximum production rates of 3.5 µg NO‐N g−1dry soil on day 16 and 0.12 µg NO‐N g−1dry soil on day 31. The calculated total losses of N2O‐N as percentages of the applied synthetic urine N were 0.37% (freely drained subsoil), 0.24% (poorly drained subsoil), 0.43% (freely drained topsoil) and 2.09% (poorly drained topsoil). The calculated total losses of NO‐N as percentages of the applied synthetic urine N were 1.53% (freely drained subsoil), 0.02% (poorly drained subsoil), 0.25% (freely drained topsoil) and 0.08% (poorly drained topsoil). Copyright © 2010 John Wiley & Sons, Ltd.
Crack‐free sol‐gel coatings for protection of AA1050 aluminium alloy
Authors: Feng Z. , Liu Y. , Thompson G. E. , Skeldon P. 
Published: February 2010

AbstractOrganically modified sol‐gel coatings have been investigated as potential replacements for chromate conversion treatments of an AA1050 aluminium alloy. The coatings were prepared by combination of a completely hydrolysable precursor of tetra‐n‐propoxyzirconium (TPOZ), with a partially hydrolysable precursor of glycidoxypropyltrimethoxysilane (GPTMS). GPTMS contains an organic functional group, which is retained in the sol‐gel coatings after the hydrolysis–condensation process. Different GPTMS/TPOZ ratios and withdrawal speeds were studied. Coatings produced using a low GPTMS/TPOZ ratio and a high withdrawal speed generated significant cracks due to the shrinkage of the coatings, with no corrosion protection of the alloy. It was found that increase of organic moieties reduced the shrinkage of the coatings and the tendency for crack formation. By control of process parameters and ratios of organic and inorganic moieties, crack‐free sol‐gel coatings above 1 µm thick, with improved corrosion protection, can be produced on the alloy surface. Copyright © 2010 John Wiley & Sons, Ltd.