bluuebunny/crossref_metadata_2025_split huggingface dataset:
A versatile approach to explosion vent design that considers the influence of flame acceleration from congestion
Authors: Herrmann David D. 
Published: January 2010

AbstractCalculations for explosion venting in flammable vapor systems are often done using established methods documented in NFPA 68. It is understood that these equations may under predict vent area where enclosures are congested or the environment in the enclosure is initially turbulent. For new designs, it is helpful for design teams to have the flexibility to choose from a number of potential venting configurations. This article reviews a methodology that was developed and implemented for several projects where computational fluid dynamics was used to evaluate enclosure design parameters for a range of vent configurations. The results of the modeling simulations were then fitted to a lumped parameter model for deflagration venting developed by Molkov et al. The end result is an equation that can be used by the design team as needed to finalize the design minimizing the use of computer modeling resources. © 2010 American Institute of Chemical Engineers Process Saf Prog, 2010
Theoretical investigation on enantioselective Biginelli reaction catalyzed by natural tartaric acid
Authors: Lu Nan , Chen Dezhan , Zhang Guiqiu , Liu Qingjian 
Published: January 2010

AbstractIn this study, enantioselective Biginelli reaction of aldehyde, β‐ketoester, and urea catalyzed by natural (2R, 3R)‐tartaric acid has been investigated using density functional theory calculations. The results indicate that the most favorable pathway involves a protonated imine from aldehyde and urea in the first step. Tartaric acid forms H‐bonds network with substrates enhancing the electrophilicity of protonated imine and the nucleophilicity of β‐ketoester. (R)‐3,4‐Dihydropyrimidin‐2‐(1H)‐ones is preferable for the reaction. The solvent effect is discussed in the prediction of enantiomeric excess (ee) values in ethanol and water. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
First principles investigation on the key factors of broad absorption spectra and electronic properties for oligothiophene and its derivatives for solar cells
Authors: Tang Shanshan , Zhang Jingping 
Published: January 2010

AbstractOn the basis of optimized structures of two kinds thiophene oligomers, we investigated the configuration and conformation dependent optical and electronic properties of α or β substituted oligothiophene (PT) and oligo(thienylenevinylene) (PTV) isomers, respectively, at the TD‐DFT/6‐31+G(d,p)//PBE0/6‐31G(d) level. The corresponding properties of polymers were predicted by extrapolation method. The broad absorption regions for polythiophene and/or poly(thienylenevinylene) can be ascribed to the coexistence of various conformational and/or configurational isomers with similar energies and each corresponding excited state possessing different absorption spectrum and overlapping each other. Furthermore, the reorganization energies for electron (λe) and hole (λh) of α or β substituted PTV and PT indicate them to be potential ambipolar charge transport materials under the proper operating conditions. Therefore, these results are important because they can provide a rational way for the design of multifunctional materials with broad absorption and ambipolar charge transport properties for solar cells devices. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Theoretical estimates of the IR spectrum of formamide intercalated into kaolinite
Authors: Campos Renan Borsoi , Wypych Fernando , Filho Harley Paiva Martins 
Published: January 2010

AbstractCalculations at PM3 and PBE/6‐31G levels of part of the IR spectrum of the formamide‐kaolinite intercalatation compound based on a 110‐atom cluster of kaolinite with one formamide molecule are reported. Frequencies and intensities for the formamide vibrations and stretchings of four cluster hydroxyls were calculated through partial hessian matrices and polar tensors obtained by numerical differentiation of energy gradients and dipole moment. The formamide molecule attaches to the kaolinite inner surfaces in multiple conformations with its CN bond vector parallel to the surfaces. Hydrogen bonds are formed between the formamide hydrogen atoms (both from NH2 or CH groups) and the siloxane surface and between the formamide oxygen and nitrogen atoms and the aluminol hydroxyls. The general features of the experimental assignment of the spectrum are confirmed, but the observed splitting of formamide bands is attributed to vibrations from differently attached molecules. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
The Pauli potential from the differential virial theorem
Authors: Nagy Á. 
Published: January 2010

AbstractRecently, a first‐order differential equation for the functional derivative of the kinetic energy functional is derived for spherically symmetric systems using the differential virial theorem of Nagy and March. Here, a more general first‐order differential equation for the Pauli potential (valid not only for spherically symmetric systems) is derived by applying the differential virial theorem of Holas and March. The solution of the equation can be given by quantities capable of fully determining every property of a Coulomb system. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Surface and interface study of ZnO nanoparticles modified by octadecanol phosphate
Authors: Chen Xue , Li Minggang , Zhu Yanchao , Zhou Bing , Zhao Xu , Gao Xiaoyan , Ma Yuejia , Wang Lili , Wang Zichen 
Published: January 2010

AbstractIn this paper, we describe an effective method in which ZnO nanoparticles were prepared through the rapid precipitation transformation reaction in aqueous solution of ZnSO4 and NaOH with octadecanol phosphate (ODP) as a modifying agent. From the study on the surface and the interface, ZnO nanoparticles modified by ODP exhibited small size, pore structure, good dispersion, and hydrophobicity. The wide variety of surface wettability can be achieved by changing the preparation parameters. The research offers a simple and effective approach to prepare ZnO filler in mild condition and enhances interfacial compatibility between ZnO powders and matrixes by treating the surface with certain capping molecules. Copyright © 2010 John Wiley & Sons, Ltd.
Static SIMS–VAMAS interlaboratory study for intensity repeatability, mass scale accuracy and relative quantification
Authors: Green F. M. , Gilmore I. S. , Lee J. L. S. , Spencer S. J. , Seah M. P. 
Published: January 2010

AbstractAn interlaboratory study involving 19 time‐of‐flight static secondary ion mass spectrometer (TOF‐SSIMS) instruments from 12 countries has been conducted. Analysts were supplied, by the National Physical Laboratory, with a protocol for analysis together with three reference materials: poly(tetrafluoroethylene), a thin layer of polycarbonate on a silicon wafer and a patterned sample with different amounts of Irganox 1010 in each of four quadrants on a silicon wafer. The objectives of the study are (i) to determine the repeatability and constancy of the relative intensity scale achievable using the draft ISO standard (DIS 23830), (ii) to evaluate the effectiveness of mass scale calibration and optimisation procedure and (iii) to evaluate the current capability of relative quantification using SSIMS. The results of this study show that the constancy of the relative intensity scale has an approximate scatter standard deviation of only 5%. This is excellent and demonstrates that SSIMS measurements are significantly more stable than often thought by analysts. The draft ISO standard (DIS) CD 13084 for calibration of the mass scale in TOF‐SIMS was evaluated and found to be consistent with our previous study. Four laboratories optimised the instrument mass calibration accuracy using this procedure leading to improvements in mass scale calibration by factors of 1.8, 2.2, 2.3 and 8.6. Using a novel patterned Irganox sample it is shown that the precision of relative quantification may be as good as a standard deviation of only 5% for 16 instruments—this is a remarkable result. Further work is required to develop more robust reference materials. © Crown copyright 2010. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Ultrasonic Alloying of Preformed Gold and Silver Nanoparticles
Authors: Radziuk Darya V. , Zhang Wei , Shchukin Dmitry , Möhwald Helmuth 
Published: January 2010

AbstractAlloyed gold/silver nanoparticles with a core/shell structure are produced from preformed gold and silver nanoparticles during ultrasonic treatment at different intensities in water and in the presence of surface‐active species. Preformed gold nanoparticles with an average diameter of 15 ± 5 nm are prepared by the citrate reduction of chloroauric acid in water, and silver nanoparticles (38 ± 7 nm) are formed after reduction of silver nitrate by sodium borohydride. Bare binary gold/silver nanoparticles with a core/shell structure are formed in aqueous solution after 1 h of sonication at high ultrasonic intensity. Cationic‐surfactant‐coated preformed gold and silver nanoparticles become gold/silver‐alloy nanoparticles after 3 h of sonication in water at 55 W cm−2, whereas only fusion of isolated gold and silver nanoparticles is observed after ultrasonic treatment in the presence of an anionic surfactant. As the X‐ray diffraction profile of alloyed gold/silver nanoparticles reveals split, shifted, and disappeared peaks, the face‐centered‐cubic crystalline structure of the binary nanoparticles is defect‐enriched by temperatures that can be as high as several thousand Kelvin inside the cavitation bubbles during ultrasonic treatment.
Genome‐wide maps of transcription regulatory elements
Authors: Sakabe Noboru J. , Nobrega Marcelo A. 
Published: January 2010

AbstractExpression of eukaryotic genes with complex spatial‐temporal regulation during development requires finer regulation than that of genes with simpler expression patterns. Given the high degree of conservation of the developmental gene set across distantly related phylogenetic taxa, it is argued that evolutionary variation has occurred by tweaking regulation of expression of developmental genes, rather than by changes in genes themselves. Complex regulation is often achieved through the coordinated action of transcription regulatory elements spread across the genome up to tens of kilobases from the promoters of their target genes. Disruption of regulatory elements has been implicated in several diseases and studies showing associations between disease traits and nonprotein coding variation hint for a role of regulatory elements as cause of diseases. Therefore, the identification and mapping of regulatory elements in genome scale is crucial to understand how gene expression is regulated, how organisms evolve, and to identify sequence variation causing diseases. Previously developed experimental techniques have been adapted to identify regulatory elements in genome scale and high‐throughput, allowing a global view of their biological roles. We review methods as chromatin immunoprecipitation, DNase I hypersensitivity, and computational approaches and how they have been employed to generate maps of histone modifications, open chromatin, nucleosome positioning, and transcription factor binding regions in whole mammalian genomes. Given the importance of non‐promoter elements in gene regulation and the recent explosion in the number of studies devoted to them, we focus on these elements and discuss the insights on gene regulation being obtained by these studies. Copyright © 2010 John Wiley & Sons, Inc.This article is categorized under:

Laboratory Methods and Technologies > Genetic/Genomic Methods
Tetracyanidoborates with Sterically Demanding Phosphonium Cations – Thermally Resistant lonic Liquids
Authors: Flemming Anke , Hoffmann Martina , Köckerling Martin 
Published: January 2010

AbstractThe reaction of K[B(CN)4] with [Ph4P]Cl, [nBu4P]Br, [nBuPh3P]Br, or [EtPh3P]Cl (Ph = phenyl, nBu = n‐butyl, Et = ethyl) affords [Ph4P][B(CN)4] (1), [nBu4P][B(CN)4] (2), [EtPh3P][B(CN)4] (3), and [nBuPh3P][B(CN)4] (4) in high yields. The structures of the compounds 1–3, which contain the tetrahedral [B(CN)4]– ion, were determined by single‐crystal X‐ray diffraction. 1 crystallizes in the tetragonal space group I\bar{4}2d (no. 122), a = 12.948(2), c = 29.382(6) Å, Z = 8, R1(F)/wR2(F2) = 0.0335/0.0953; 2 and 3 with orthorhombic symmetry; 2: space group Pnna (no. 52), a = 18.2187(6), b = 12.0707(3), c = 11.6704(4) Å, Z = 4, R1(F)/wR2(F2) = 0.0489/0.1532; 3: space group Pnma (no. 62), a = 14.1777(3), b = 13.4214(3), c = 12.3199(2) Å, Z = 4, R1(F)/wR2(F2) = 0.0477/0.1505. The IR, Raman, and NMR spectra as well as thermal data derived from DSC and TGA measurements are reported. Depending on the thermal stability of the phosphonium cation some of the tetracyanidoborates are stable up to ~370 °C with the liquid state having a range of up to 300 K. Such salts could be very useful as weakly coordinating reaction media.
Protection by dietary Spirulina platensis against d-galactosamine- and acetaminophen-induced liver injuries
Authors: Lu Jun , Ren Di-Feng , Wang Jian-Zhong , Sanada Hiroo , Egashira Yukari 
Published: January 2010

Increasing attention has been paid to Spirulina for its potential clinical uses. The present study investigated the protection by dietary Spirulina platensis against d-galactosamine (d-GalN)- and acetaminophen (APAP)-induced hepatitis in ICR mice. Mice in each group (n 6) were fed with a standard diet (American Institute of Nutrition (AIN)-93G), a positive control diet containing 0·5 % butylated hydroxytoluene (BHT), or a diet containing 3, 6 or 9 % S. platensis for 1 week. On the last day the mice were treated with d-GalN (300 mg/kg body weight, intraperitoneally) or APAP (150 mg/kg body weight, intraperitoneally) and 24 h later the mice were killed. The doses of both 6 and 9 % S. platensis were found to significantly alleviate the increase of serum glutamate oxaloacetoacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities in d-GalN- or APAP-intoxicated mice. The observation was very similar to that of the positive control groups. Two more experiments were carried out to investigate the involvement of thiobarbituric acid-reactive substances (TBARS) and IL-18 in the suppression of 6 % S. platensis on d-GalN- and APAP-induced hepatitis. The significant increase of GOT and GPT activities was found to be accompanied with the elevation of hepatic TBARS level, IL-18 mRNA expression and serum IL-18 concentration, and was significantly alleviated by supplementation with 6 % S. platensis in diets. These results showed that dietary S. platensis could provide a significant protection against d-GalN- and APAP-induced liver injuries, and IL-18 and lipid peroxidation might be involved in the protective influence of S. platensis.
Relative validity of a semi-quantitative food-frequency questionnaire in an elderly Mediterranean population of Spain
Authors: Fernández-Ballart Joan D. , Piñol Josep Lluís , Zazpe Itziar , Corella Dolores , Carrasco Paula , Toledo Estefanía , Perez-Bauer Manuel , Martínez-González Miguel Ángel , Salas-Salvadó Jorge , Martín-Moreno José M. 
Published: January 2010

The aim of the present study was to assess reproducibility and relative validity of a self-administered FFQ used in the PREDIMED Study, a clinical trial for primary prevention of CVD by Mediterranean diet in a population at high cardiovascular risk. The FFQ was administered twice (FFQ1 and FFQ2) to explore reproducibility at 1 year. Four 3 d dietary records (DR) were used as reference to explore validity; participants therefore recorded their food intake over 12 d in the course of 1 year. The degree of misclassification in the FFQ was also evaluated by a contingency table of quintiles comparing the information from the FFQ2 and the DR. A total of 158 men and women (aged 55–80 years) were asked not to modify their dietary habits during the study period. Reproducibility for food groups, energy and nutrient intake, explored by the Pearson correlation coefficient (r) ranged 0·50–0·82, and the intraclass correlation coefficient (ICC) ranged from 0·63 to 0·90. The FFQ2 tended to report higher energy and nutrient intake than the DR. The validity indices of the FFQ in relation to the DR for food groups and energy and nutrient intake ranged (r) from 0·24 to 0·72, while the range of the ICC was between 0·40 and 0·84. With regard to food groups, 68–83 % of individuals were in the same or adjacent quintile in both methods, a figure which decreased to 55–75 % for energy and nutrient intake. We concluded that FFQ measurements had good reproducibility and a relative validity similar to those of FFQ used in other prospective studies.
A high-fat diet induces lower expression of retinoid receptors and their target genes GAP-43/neuromodulin and RC3/neurogranin in the rat brain
Authors: Buaud Benjamin , Esterle Laure , Vaysse Carole , Alfos Serge , Combe Nicole , Higueret Paul , Pallet Véronique 
Published: January 2010

Numerous studies have reported an association between cognitive impairment in old age and nutritional factors, including dietary fat. Retinoic acid (RA) plays a central role in the maintenance of cognitive processes via its nuclear receptors (NR), retinoic acid receptor (RAR) and retinoid X receptor (RXR), and the control of target genes, e.g. the synaptic plasticity markers GAP-43/neuromodulin and RC3/neurogranin. Given the relationship between RA and the fatty acid signalling pathways mediated by their respective NR (RAR/RXR and PPAR), we investigated the effect of a high-fat diet (HFD) on (1) PUFA status in the plasma and brain, and (2) the expression of RA and fatty acid NR (RARβ, RXRβγ and PPARδ), and synaptic plasticity genes (GAP-43 and RC3), in young male Wistar rats. In the striatum of rats given a HFD for 8 weeks, real-time PCR (RT-PCR) revealed a decrease in mRNA levels of RARβ ( − 14 %) and PPARδ ( − 13 %) along with an increase in RXRβγ (+52 %). Concomitantly, RT-PCR and Western blot analysis revealed (1) a clear reduction in striatal mRNA and protein levels of RC3 ( − 24 and − 26 %, respectively) and GAP-43 ( − 10 and − 42 %, respectively), which was confirmed byin situhybridisation, and (2) decreased hippocampal RC3 and GAP-43 protein levels (approximately 25 %). Additionally, HFD rats exhibited a significant decrease in plasma ( − 59 %) and brain ( − 6 %)n-3 PUFA content, mainly due to the loss of DHA. These results suggest that dietary fat induces neurobiological alterations by modulating the brain RA signalling pathway andn-3 PUFA content, which have been previously correlated with cognitive impairment.
Effect of ground cover vegetation on the abundance and diversity of beneficial arthropods in citrus orchards
Authors: Silva E.B. , Franco J.C. , Vasconcelos T. , Branco M. 
Published: January 2010

AbstractThe effect of ground cover upon the communities of beneficial arthropods established in the canopy of lemon trees was investigated, by comparing three ground-cover management treatments applied: RV, resident vegetation; S, sowed selected species; and BS, bare soil by controlling weeds with herbicide. Over two consecutive years, arthropod communities in the tree canopy were sampled periodically by beating and suction techniques. Significantly higher numbers of beneficial arthropods were found in the RV and S treatments in comparison with bare soil. Spiders and parasitoid wasps were the two most common groups, representing, respectively, 70% and 19% of all catches in beating samples and 33% and 53% in suction samples. For the RV and S treatments, significant seasonal deviations from the bare soil treatment were observed using principal response curves. Similar seasonal patterns were observed over the two years. The RV and S treatments showed significant positive deviations from the BS treatment in late spring and summer, accounted for the higher numbers of parasitoid wasps, coccinelids and lacewings present. By contrast, the seasonal deviations observed for the spider community differed from those of the remaining arthropods. During late winter and early spring, the RV and S treatments presented a higher abundance of spiders in the tree canopy, in comparison with bare soil, whereas in the summer significantly more spiders were found in the bare soil treatment. Spider movements between tree canopy and ground vegetation layers may justify this result.
How does heat shock affect the life history traits of adults and progeny of the aphid parasitoidAphidius avenae(Hymenoptera: Aphidiidae)?
Authors: Roux O. , Le Lann C. , van Alphen J. J. M. , van Baaren J. 
Published: January 2010

AbstractBecause insects are ectotherms, their physiology, behaviour and fitness are influenced by the ambient temperature. Any changes in environmental temperatures may impact the fitness and life history traits of insects and, thus, affect population dynamics. Here, we experimentally tested the impact of heat shock on the fitness and life history traits of adults of the aphid parasitoidAphidius avenaeand on the later repercussions for their progeny. Our results show that short exposure (1 h) to an elevated temperature (36°C), which is frequently experienced by parasitoids during the summer, resulted in high mortality rates in a parasitoid population and strongly affected the fitness of survivors by drastically reducing reproductive output and triggering a sex-dependent effect on lifespan. Heat stress resulted in greater longevity in surviving females and in shorter longevity in surviving males in comparison with untreated individuals. Viability and the developmental rates of progeny were also affected in a sex-dependent manner. These results underline the ecological importance of the thermal stress response of parasitoid species, not only for survival, but also for maintaining reproductive activities.
A bioassay for studying behavioural responses of the common bed bug, Cimex lectularius (Hemiptera: Cimicidae) to bed bug-derived volatiles
Authors: Weeks E.N.I. , Logan J.G. , Gezan S.A. , Woodcock C.M. , Birkett M.A. , Pickett J.A. , Cameron M.M. 
Published: January 2010

AbstractThe common bed bug, Cimex lectularius (Hemiptera: Cimicidae), has recently re-emerged in increasing numbers, distribution and intensity of infestation in many countries. Current control relies on the application of residual pesticides; but, due to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour and physiology modifying chemicals) could be exploited for management of bed bugs. However, in order to identify semiochemicals that can be utilised in monitoring or control, a suitable olfactometer is needed that enables the study of the responses of bed bugs to volatile chemicals. Previous studies have used olfactometers that do not separate olfactory responses from responses to physical contact. In this study, a still-air olfactometer was used to measure behavioural responses to different bed bug-derived volatiles presented in an odour pot. Bed bugs were significantly more likely to visit the area above the odour pot first, and more frequently, in the presence of volatiles from bed bug-exposed paper but not in the presence of volatiles from conspecific bed bugs. Bed bug activity was found to be dependent on the presence of the volatiles from bed bug-exposed paper, the time during the scotophase and the sex of the insect being tested. The still-air olfactometer could be used to test putative semiochemicals, which would allow an understanding of their behavioural role in bed bug ecology. Ultimately, this could lead to the identification of new semiochemical tools for bed bug monitoring and control.