bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of chromatographic and free radical scavenging activity fingerprints by thin‐layer chromatography for selected Salvia species
Authors: Cieśla Łukasz , Staszek Dorota , Hajnos Michał , Kowalska Teresa , Waksmundzka‐Hajnos Monika 
Published: August 2010

AbstractIntroduction – Plant‐derived free radical scavengers have become the subject of intensive scientific interest. Recently, the concept of coupling chromatographic fingerprints with biological fingerprinting analysis has gained much attention for the quality control of plant extracts. However, identification of free radical scavenging activity of each single compound in a complex mixture is a difficult task. Thin‐layer chromatography with post‐chromatographic derivatisation with the methanol solution of DPPH can be a valuable tool in such analyses.Objective – Development of chromatographic and free radical scavenging fingerprints of nineteen Salvia species grown and cultivated in Poland.Methodology – Chromatography was performed on the silica gel layers with use of two eluents, one for the resolution of the less polar compounds, and the other one for the resolution of the medium and highly polar ones. The plates were sprayed with the vanillin–sulfuric acid reagent to produce chemical fingerprints, and with DPPH solution to generate free radical scavenging fingerprints.Results – With four Salvia species, it was revealed that their strong free radical scavenging properties are not only due to the presence of polar flavonoids and phenolic acids, but also due to the presence of several free radical scavengers in the less polar fraction. Because of the similarities in both the chromatographic and the free radical scavenging fingerprints, S. triloba can be introduced as a possible equivalent of the pharmacopoeial species, S. officinalis.Conclusion – Fingerprints developed in the experiments proved useful for the analysis of complex extracts of the different Salvia species. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of marker compounds with anti‐platelet aggregation effects in mailuoning injection using platelet binding assay combined with HPLC‐DAD‐ESI‐MS and solid‐phase extraction technique
Authors: Yu Li , Li Yingbin , Fan Hongwei , Duan Jinao , Zhu Quan , Li Shaoping 
Published: August 2010

AbstractIntroduction – Mailuoning is prepared from a traditional formula of Chinese medicines and widely used as an antithrombotic agent. In this study, the platelet binding assay was used as a novel biospecific separation and analysis method to explore its active constituents, which could be considered as marker compounds for quality control.Objective – To establish a rapid and simple method to predict marker compounds in herbal medicine injection and evaluate the effects of those compounds.Material and methods – Platelets were used to bind and separate constituents. Binding constituents were analysed and taken as potential active compounds for further evaluation. Solid‐phase‐extraction was adopted to improve sensitivity. HPLC‐DAD and ESI‐MS were used to determine the binding constituents.Results – Five compounds were extracted through the platelet binding process and identified as neochlorogenic acid, caffeic acid, isochlorogenic acid and their isomers. Caffeic acid was selected for the flow cytometric assay to test its effect on platelets activation, which was determined by CD62P (P‐selectin) expression. The results indicated that caffeic acid could significantly inhibit platelet activation while chlorogenic acid did not.Conclusion – Caffeic acid could be considered as a marker compound of Mailuoning injection due to its anti‐platelet effect. The study also suggested that platelet binding assay combined with some preconcentration technique could be efficiently used to predict anti‐platelet compounds in complicated herbal medicines. Copyright © 2010 John Wiley & Sons, Ltd.
UV‐nano‐imprint lithography technique for the replication of back reflectors for n‐i‐p thin film silicon solar cells
Authors: Söderström K. , Escarré J. , Cubero O. , Haug F.‐J. , Perregaux S. , Ballif C. 
Published: August 2010

AbstractTexturing of interfaces in thin film silicon solar cells is essential to enhance the produced photocurrent and thus the efficiencies. A UV nano‐imprint‐lithography (UV‐NIL) replication process was developed to prepare substrates with textures that are suitable for the growth of n‐i‐p thin film silicon solar cells. Morphological and optical analyses were performed to assess the quality of the replicas. A comparison of single junction amorphous solar cells on the original structures and on their replicas on glass revealed good light trapping and excellent electrical properties on the replicated structures. A tandem amorphous silicon/amorphous silicon (a‐Si/a‐Si) cell deposited on a replica on plastic exhibits a stabilized efficiency of 8.1% and a high yield of 90% of good cells in laboratory conditions. It demonstrates the possibility to obtain appropriate structure on low cost plastic substrate. Copyright © 2010 John Wiley & Sons, Ltd.
Role of hydrogen in the surface passivation of crystalline silicon by sputtered aluminum oxide
Authors: Li Tsu‐Tsung Andrew , Cuevas Andres 
Published: August 2010

AbstractAluminum oxide films can provide excellent surface passivation on both p‐type and n‐type surfaces of silicon wafers and solar cells. Even though radio frequency magnetron sputtering is capable of depositing aluminum oxide with concentrations of negative charges comparable to some of the other deposition methods, the surface passivation has not been as good. In this paper, we compare the composition and bonding of aluminum oxide deposited by thermal atomic layer deposition and sputtering, and find that the interfacial silicon oxide layer and hydrogen concentration can explain the differences in the surface passivation. Copyright © 2010 John Wiley & Sons, Ltd.
Temporal stability of personality traits and disorders within substance dependent patients
Authors: Samuel Douglas B. , Ball Samuel A. 
Published: August 2010

AbstractThe current study evaluated the temporal stability of personality disorders (PD) and traits as assessed by the Schedule for Nonadaptive and Adaptive Personality (SNAP) within a sample being treated for substance dependence in a residential TC. Temporal stability coefficients were similar to the few previous studies with clinical samples and comparable retest intervals; however, the current study extended previous work by examining mean‐level stability of the PD scales. While most SNAP scales remained stable or decreased over 6 months of active psychotherapy, increases on some scales (e.g. workaholism as well as antisocial, narcissistic and obsessive–compulsive PDs) raised compelling questions. These findings suggest additional research on the stability and validity of the SNAP in treatment samples. Copyright © 2010 John Wiley & Sons, Ltd.
Ring inversion process for a series of 3,5‐dialkyl‐1‐oxa‐3,5‐diazacyclohexanes: 1H DNMR study and semiempirical calculations
Authors: DuBray Cecelia M. , Gerber Cody L. , McCulla Ryan D. , Oakland Angie J. , Schwartz Keith D. , Eliason Robert , Brown Jay H. 
Published: August 2010

AbstractThe ring inversion process for a series of 3,5‐dialkyl‐1‐oxa‐3,5‐diazacyclohexanes was studied using proton dynamic nuclear magnetic resonance (1H DNMR) spectroscopy in conjunction with semiempirical calculations. At low temperature, the ring methylene protons decoalesced into two AB spin systems in a 2:1 ratio. Lineshape simulations of the DNMR spectra provided first‐order rate constants for magnetic exchange. The energy barrier for each inversion reaction was calculated from the respective rate constants. In general, as the size of the N‐alkyl group increased, the barrier to ring inversion decreased. A similar trend was seen in semiempirical calculations that modeled the ring inversion process. Copyright © 2010 John Wiley & Sons, Ltd.
Hyperbranched perfluorinated poly(phenylene germanes) obtained by polycondensation of A2B2 and AB3 monomers
Authors: Gasilova Ekaterina R. , Saprykina Natalia N. , Zamyshlyayeva Olga G. , Semchikov Yurij D. , Bochkarev Mihail N. 
Published: August 2010

AbstractA set of new hyperbranched (HB) perfluorinated poly(phenylene germanes) PPGs, whose connectivity is supported by germanium atoms, was synthesized via an activated copolycondensation of AB3, HGe(C6F5)3 and A2B2, H2Ge(C6F5)2 monomers. Light scattering showed that the content of the AB3 and A2B2 reagents and the sequence of their activation affect the molecular mass and the conformation of PPGs. Morphology of the subaggregates, examined with scanning electron microscopy (SEM) at different magnifications, demonstrated their fractal structure. The conformations of individual PPG macromolecules, obtained with light scattering, were in accord with the morphology of the subaggregates observed with SEM. This allowed to conclude that the fractal approach can be applied up to the scale of the self‐assembly of dendrons during the reaction. The branching structure was analyzed with 19F nuclear magnetic resonance (NMR). The chemical shifts of the main‐chain fluorines depended on the proximity of the C6F4 links to the germanium anion because of the redistribution of the germanium anion charge along the branches via σ–π conjugation. The interdendron links are due to the knots originating from the A2B2 monomer, since they contain nonreacted hydrogens. The interdendron links increase the molecular mass of the copolymers with respect to that of the AB3 homopolymer whose molecular mass cut‐off is due to the entrapment of the focal ion pair. Copyright © 2010 John Wiley & Sons, Ltd.
The influence of organic solvent and ionic liquids on the selective formation of 2‐(2‐ethylhexyl)‐3‐phenyl‐1,2‐oxaziridine mediated by lipases
Authors: Bitencourt Thiago Bergler , Nascimento Maria da Graça 
Published: August 2010

AbstractThis paper describes the influence of the addition of ionic liquids (ILs) based on [BMIm][X], where [X] = SCN, Cl, BF4, and PF6, on the chemo‐enzymatic oxidation of N‐benzyliden‐2‐ethylhexylamine to form the corresponding E‐ and Z‐isomers of oxaziridines mediated by Pseudomonas sp. (PSL) and Candida antarctica (CAL‐B) lipases in various organic solvents at room temperature (25 °C) with urea hydrogen peroxide (UHP). The results showed that the use of different organic solvents in the presence of ILs, critically changes the conversions (5–99%) and the isomeric ratio E:Z, (50–100% E‐isomer) of the products formed. Copyright © 2010 John Wiley & Sons, Ltd.
Surface Morphology of Heterogeneous Nanocrystalline Rutile/Amorphous Anatase TiO2 Films Grown by Reactive Pulsed Magnetron Sputtering
Authors: Gago Raúl , Vinnichenko Mykola , Redondo‐Cubero Andrés , Czigány Zsolt , Vázquez Luis 
Published: August 2010

AbstractTitanium dioxide films were grown on unheated substrates by mid‐frequency (100 kHz) reactive pulsed magnetron sputtering at different O2 partial pressures in an Ar/O2 atmosphere. X‐ray diffraction and absorption measurements reveal a transition from amorphous anatase to nanocrystalline rutile with [O2], with a mixture of both phases at intermediate values. Atomic force microscopy shows that the promotion of rutile is accompanied by surface roughening due to the apparition of hollow structures (holes) on the surface, in contrast with the extremely smooth morphology of amorphous anatase films. The number and size of holes increase with [O2] and growth time in such a way that they eventually coalesce and percolate to lead to a rough surface for those growth conditions for which a rutile rich film is obtained. Transmission electron microscopy analysis shows the growth evolution of a heterogeneous phase mixture and provides unambiguous correlation between the hole (smooth) morphology and the underlying rutile (anatase) phase. Therefore, the surface morphology results from the slower local growth rate of nanocrystalline rutile compared to that of the surrounding amorphous anatase flat regions as well as from the fast (slow) lateral (vertical) growth rate of the rutile domains.magnified image
The crystal structure Escherichia coli Spy
Authors: Kwon Eunju , Kim Dong Young , Gross Carol A. , Gross John D. , Kim Kyeong Kyu 
Published: August 2010

AbstractEscherichia coli spheroplast protein y (EcSpy) is a small periplasmic protein that is homologous with CpxP, an inhibitor of the extracytoplasmic stress reponse. Stress conditions such as spheroplast formation induce the expression of Spy via the Cpx or the Bae two‐component systems in E. coli, though the function of Spy is unknown. Here, we report the crystal structure of EcSpy, which reveals a long kinked hairpin‐like structure of four α‐helices that form an antiparallel dimer. The dimer contains a curved oval shape with a highly positively charged concave surface that may function as a ligand binding site. Sequence analysis reveals that Spy is highly conserved over the Enterobacteriaceae family. Notably, three conserved regions that contain identical residues and two LTxxQ motifs are placed at the horizontal end of the dimer structure, stablizing the overall fold. CpxP also contains the conserved sequence motifs and has a predicted secondary structure similar to Spy, suggesting that Spy and CpxP likely share the same fold.
Conductance of functionalized nanotubes, graphene and nanowires: from ab initio to mesoscopic physics
Authors: Blase X. , Adessi C. , Biel B. , Lopez‐Bezanilla A. , Fernández‐Serra M.‐V. , Margine E. R. , Triozon F. , Roche S. 
Published: August 2010

AbstractWe review recent theoretical results aiming at understanding the impact of doping and functionalization on the electronic transport properties of nanotubes, nanowires and graphene ribbons. On the basis of ab initio calculations, the conductance of micrometer long tubes or ribbons randomly doped or grafted can be studied, allowing to extract quantities at mesoscopic length scales such as the elastic mean free path and localization length. While the random modification of a 1D conducting channel leads generaly to a significant loss of conductance, strategies can be found to either exploit or limitate such a detrimental effect. Spin‐filtering in transition metal doped nanotubes, the opening of a mobility gap in graphene ribbons, and the choice of molecules to limitate backscattering in covalently functionalized tubes are examples that will be discussed.magnified image
Symbolic representation of a nanotube filled with Cobalt atoms or clusters with subsequent optimal spinvalve effect (see text).
Multi‐wall carbon nanotubes – a vehicle for targeted Irinotecan drug delivery
Authors: Tripisciano Carla , Rümmeli Mark H. , Chen Xuecheng , Borowiak‐Palen Ewa 
Published: August 2010

AbstractChemotherapeutics, administered to defeat neoplastic disease, generally interfere with the growth of cancer cells, eventually destroying them. Since the growth of normal cells may also be affected, serious adverse effects may occur. In addition, many medications might not be properly delivered to the target area because of susceptibility to precocious enzymatic degradation in the systemic circulation. An attractive method to safely deliver anticancer drugs to targeted tissues is to employ carbon nanotubes (CNTs) as a transport vehicle. Here we present a study on the encapsulation of the antineoplastic agent Irinotecan within multi‐wall carbon nanotubes (MWCNTs). We also study the pH‐dependent release of the guest molecules from the nanotubes cavity to phosphate and acetate buffers.magnified image
Schematic representation of Irinotecan filled MWCNTs.
Functionalization of graphene with transition metals
Authors: Zólyomi V. , Rusznyák Á. , Koltai J. , Kürti J. , Lambert C. J. 
Published: August 2010

AbstractWe study the strength of the binding of 4d and 5d transition metals on a graphene sheet in the limit of low‐ and high‐coverage using first principles density functional theory. A database of the binding energies is presented. Our results show that Mo, Hf, Ta, and W bind strongest to the graphene sheet. We find a charge transfer of ≈0.01 electrons per carbon atom from the transition metal to the graphene sheet.
Band offset and interface chemistry of HfO2/Si (001) prepared by electron‐beam evaporation in ultrahigh vacuum using atomic oxygen
Authors: Run Xu , Minyan Tang , Zhijun Yan , Linjun Wang , Yiben Xia , Fei Xu 
Published: August 2010

AbstractThe band offset and interface chemistry of HfO2 films prepared by ultrahigh‐vacuum electron‐beam evaporation was investigated by synchrotron radiation photon electron spectroscopy (SRPES). A relatively large valence band (VB) offset of the HfO2 film with Si was determined to be 3.56 eV. Both the Hf‐silicate and a small number of HfSi bonds were formed at the interface of HfO2/Si. This HfSi bond, which cannot be prevented completely in an ultrahigh‐vacuum preparation system using the Hf metallic source despite the atomic oxygen source adopted, may be mainly responsible for this large value of VB offset of HfO2/Si(001). This result also suggests that metal–silicon bonds at the interface of high k oxides on Si may generally lead to a larger VB offset than that with all silicon atoms at the interface bonding directly with oxygen.
Unlinking absorption and haze in thin film silicon solar cells front electrodes
Authors: Boccard Mathieu , Cuony Peter , Battaglia Corsin , Despeisse Matthieu , Ballif Christophe 
Published: August 2010

AbstractWe study the respective influence of haze and free carrier absorption (FCA) of transparent front electrodes on the photogenerated current of micromorph thin film silicon solar cells. To decouple the haze and FCA we develop bi‐layer front electrodes: a flat indium tin oxide layer assures conduction and allows us to tune FCA while the haze is adjusted by varying the thickness of a highly transparent rough ZnO layer. We show how a minimum amount of FCA leads only to a few percents absorption for a single light path but to a strong reduction of the cell current in the infrared part of the spectrum. Conversely, a current enhancement is shown with increasing front electrode haze up to a saturation of the current gain. This saturation correlates remarkably well with the haze of the front electrode calculated in silicon. This allows us to clarify the requirements for the front electrodes of micromorph cells. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mixtures of Uncaria and Tabebuia extracts are potentially chemopreventive in CBA/Ca mice: a long‐term experiment
Authors: Budán Ferenc , Szabó István , Varjas Tímea , Nowrasteh Ghodratollah , Dávid Tamás , Gergely Péter , Varga Zsuzsa , Molnár Kornélia , Kádár Balázs , Orsós Zsuzsa , Kiss István , Ember István 
Published: August 2010

AbstractA long‐term experimental animal model was developed by our research group for the evaluation of potential chemopreventive effects. The inhibitory effects of agents on carcinogen (7,12‐dimethylbenz[a]anthracene (DMBA) induced molecular epidemiological biomarkers, in this case the expression of key onco/suppressor genes were investigated.The expression pattern of c‐myc, Ha‐ras, Bcl‐2, K‐ras protooncogene and p53 tumour suppressor gene were studied to elucidate early carcinogenic and potential chemopreventive effects. The consumption of so‐called Claw of Dragon tea (CoD™ tea) containing the bark of Uncaria guianensis, Cat's Claw (Uncaria sp. U. tomentosa) and Palmer trumpet‐tree (Tabebuia sp. T. avellanedae) was able to decrease the DMBA‐induced onco/suppressor gene overexpression in a short‐term animal experiment. In a following study CBA/Ca mice were treated with 20 mg/kg bw DMBA intraperitoneally (i.p.) and the expression patterns of onco/suppressor genes were examined at several time intervals. According to the examined gene expression patterns in this long‐term experiment the chemopreventive effect of CoD™ tea consumption could be confirmed. Copyright © 2010 John Wiley & Sons, Ltd.
Diagnosis and formulation of heterogeneous background‐error covariances at the mesoscale
Authors: Montmerle Thibaut , Berre Loïk 
Published: August 2010

AbstractThis study focuses on diagnosing variations of background‐error covariances between precipitating and non‐precipitating areas, and on presenting a heterogeneous covariance formulation to represent these variations in a variational framework. The context of this work is the assimilation of observations linked to precipitation (radar data especially) in the AROME model, which has been running operationally at Météo‐France since December 2008 over French territory with a 2.5 km horizontal resolution. This system uses multivariate background‐error covariances deduced from an ensemble‐based method. At first, such statistics have been computed for 17 precipitating cases using an ensemble of AROME forecasts coupled with an ALADIN ensemble assimilation. Results, obtained from 3 h forecast differences performed separately for non‐precipitating and precipitating columns, display large discrepancies in error variances, correlation lengths and the correlations between humidity, temperature and divergence errors.These results argue in favour of including heterogeneous background‐error covariances in AROME incremental 3D‐Var, allowing different covariances to be used in regions with different meteorological patterns. Such a method enables us to get increments more adequately structured in those regions, and thus potentially to make better use of observations in a data assimilation system. The implementation consists of expressing the analysis increment as the sum of two terms, one for precipitating areas and the other for non‐precipitating areas, making use of a mask that defines rainy regions. This implies a doubling in the size of the control variable and of the gradient of the cost function. The feasibility of this method is shown through experiments with four isolated observations. Copyright © 2010 Royal Meteorological Society
Tooling adjustment strategy for acceptable product quality in assembly processes
Authors: Kantanyarat Anantanat , Jin Jionghua (Judy) 
Published: August 2010

AbstractThis paper develops an approach to minimize the number of process tooling adjustments and deliver an acceptable fraction of non‐conforming products based on given product quality specification limits in assembly processes. A linear model is developed to describe the relationships between product quality and process tooling locating positions. Based on the model, the process mean shifts of tooling locating positions are estimated for both deterministic and stochastic cases by using the least‐square estimation or linear mixed model estimation, respectively. A simultaneous confidence interval is obtained to construct the estimation region of a process mean shift under the given false alarm rate. Furthermore, a tooling adjustment strategy is proposed to determine when the process adjustment is essentially needed in order to ensure an acceptable fraction of non‐conforming units based on the given product quality specification limits. Finally, a case study is conducted to illustrate the developed methodology by using a real‐world autobody assembly process. Copyright © 2010 John Wiley & Sons, Ltd.