bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energetic Nitrogen‐Rich Salts of 1‐(2‐Hydroxyethyl)‐5‐nitriminotetrazole
Authors: Fischer Niko , Klapötke Thomas M. , Stierstorfer Jörg 
Published: September 2011

Abstract1‐(2‐Hydroxyethyl)‐5‐nitriminotetrazole (2) was formed by the reaction of 5‐amino‐1‐(2‐hydroxyethyl)tetrazole (1) and 100 % HNO3. Compound 1 was obtained by alkylation of 5‐amino‐1H‐tetrazole with 2‐chloroethanol. Nitrogen‐rich salts such as the ammonium (3), hydroxylammonium (4), guanidinium (5), aminoguanidinium (6), diaminoguanidinium (7), triaminoguanidinium (8), azidoformamidinium (9), and diaminouronium (10) 1‐(2‐hydroxyethyl)‐5‐nitriminotetrazolate were prepared by deprotonation or metathesis reactions. Compounds 3–10 were fully characterized by single‐crystal X‐ray diffraction (except for 9 and 10), vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC) measurements. The heats of formation of 4–10 were calculated by the atomization method based on CBS‐4M enthalpies. With these values and the X‐ray densities, several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. In addition their sensitivities towards impact, friction, and electrical discharge were tested using a BAM drophammer, a friction tester, and a small‐scale electrical discharge device.
Development of Decarboxylative Coupling Processes for the Synthesis of Azomethines and Ketones
Authors: Collet Florence , Song Bingrui , Rudolphi Felix , Gooßen Lukas J. 
Published: September 2011

AbstractA bimetallic catalyst system has been developed that allows the synthesis of azomethines by a one‐pot three‐component decarboxylative coupling, starting from simple, nontoxic precursors, i.e. potassium α‐oxo carboxylates, aryl halides and primary amines. In the presence of 15 mol‐% copper/phenanthroline and 1 mol‐% Pd/dppf, a wide range of valuable imines is conveniently accessible in high yields at 100 °C, an unprecedentedly low temperature for redox‐neutral decarboxylative cross‐coupling reactions. Hydrogenation of the azomethine products leads to secondary amines. Alternatively, they can be hydrolyzed in situ to aryl ketones. The resulting ketone synthesis via azomethine intermediates is also of interest as it gives higher yields at much lower temperatures than the direct decarboxylative coupling of α‐oxo carboxylates with aryl halides.
Interaction of Mitomycin C with DNA Immobilized onto Single‐walled Carbon Nanotube/Polymer Modified Pencil Graphite Electrode
Authors: Canavar Ece , Kuralay Filiz , Erdem Arzum 
Published: September 2011

AbstractThe electrochemical investigation of the interaction between the anticancer drug mitomycin C (MC) and DNA was described using a single‐walled carbon nanotube (SWCNT)/poly(vinylferrocenium) (PVF+) modified pencil graphite electrode (PGE). The electrochemical oxidation signals of guanine were monitored before and after the interaction between MC and DNA by using differential pulse voltammetry. The effects of DNA and MC concentration and MC interaction time were examined based on the electrode response. Cyclic voltammetry and electrochemical impedance spectroscopy were used for the characterization of SWCNT/PVF+ modified and PVF+ modified PGEs. The detection limit corresponded to 625 ng/mL for MC using calf thymus double‐stranded DNA immobilized SWCNT/PVF+ modified PGE.
A Third‐Generation Hydrogen Peroxide Biosensor Based on Horseradish Peroxidase Immobilized in Carbon Nanotubes/ SBA‐15 Film
Authors: Fang Zheng‐Hui , Lu Li‐Min , Zhang Xiao‐Bing , Li Hong‐Bo , Yang Bin , Shen Guo‐Li , Yu Ru‐Qin 
Published: September 2011

AbstractA new third‐generation biosensor for H2O2 assay was developed on the basis of the immobilization of horseradish peroxidase (HRP) in a nanocomposite film of carbon nanotubes (CNTs)‐SBA‐15 modified gold electrode. The biological activity of HRP immobilizing in the composite film was characterized by UV‐vis spectra. The HRP immobilized in the nanocomposite matrix displayed excellent electrocatalytic activity to the reduction of H2O2. The effects of the experimental variables such as solution pH and working potential were investigated using steady‐state amperometry. Under the optimal conditions, the resulting biosensor showed a linear range from 1 µM to 7 mM and a detection limit of 0.5 µM (S/N=3). Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.
In Situ Self Assembly of Thiolated ortho‐Quinone Capped Electrocatalysts for Bioanalytical Applications
Authors: Wendland Tom R. , Muntean Brian S. , Kaur Jaskiran , Mukherjee Jhindan , Chen Jie , Tan Xinxuan , Attygalle Dinesh , Collins Robert W. , Kirchhoff Jon R. , Tillekeratne L. M. Viranga 
Published: September 2011

AbstractThiolated o‐quinone‐capped electrocatalysts modeled on the naturally occurring o‐quinone cofactor pyrroloquinoline quinone (PQQ) were designed and synthesized for the development of biosensor devices. The o‐quinone‐capped electrocatalysts self assembled on gold electrodes through a thiolated phenyleneethynylene linkage to form a monolayer less than 2 nm in thickness. Cyclic voltammetric measurements demonstrated reversible electrochemical properties between the quinone and hydroquinone forms of the head group. In an amperometric sensing mode, the modified electrodes reproducibly detected ethanethiol at micromolar levels demonstrating their robust electrocatalytic activity toward thiols. Their redox cycling and electrocatalytic properties show promise for detection of biologically important thiols and other nucleophiles.
Stage-dependent susceptibility to copper in Rhinella arenarum embryos and larvae
Authors: Aronzon Carolina M , Sandoval Maria Teresa , Herkovits Jorge , PérezColl Cristina S 
Published: September 2011

Abstract
Copper toxicity in different embryonic and larval stages of the common South American toad Rhinella arenarum was evaluated by means of continuous and 24-h pulse treatments in 12 different developmental stages. Lethal concentrations (LC) of 10, 50, and 90% of continuous treatment with Cu from early blastula (S.4), complete operculum (S.25), and hind limb bud (S.28) stages were plotted from 24 to 168 h, resulting from S.4 in a 24-h LC50 of 137 µg Cu2+/L and a 168-h LC50 of 19.5 µg Cu2+/L. This result was in agreement with pulse treatments that showed a high resistance to Cu at blastula and gastrula stages, whereas the organogenic period, between muscular response (S.18) and open mouth (S.21), was very susceptible to this metal. Continuous treatments from S.25 showed no significant differences along exposure time (168-h LC50 = 51 µg Cu2+/L), but in the case of S.28 toxicity increased slightly from a 24-h LC50 of 138.6 µg Cu2+/L to a 168-h LC50 of 104 µg Cu2+/L, pointing out that, although the larval period was significantly more resistant to Cu, there was also a remarkable stage-dependent susceptibility to this metal. Copper teratogenic potential was approximately two, and main adverse effects were reduced body size, axial flexure, microcephaly, acephaly, mouth malformations, agenesis of or underdeveloped gills, agenesis of or underdeveloped tail, and hydropsy. The results are discussed considering Cu toxicity mechanisms, an evolutionary perspective, and environmental protection. Environ. Toxicol. Chem. 2011;30:2771–2777. © 2011 SETAC
Database of published retention factors for immobilized artificial membrane HPLC and an assessment of the effect of experimental variability
Authors: Ledbetter M.R , Gutsell S , Hodges G , Madden J.C , O'Connor S , Cronin M.T.D 
Published: September 2011

Abstract
A database was collated of published experimental logarithmic values for the relative retention factors (log kIAM) measured using an immobilized artificial membrane column and high-performance liquid chromatography (IAM HPLC). Log kIAM is an alternative measure of hydrophobicity to the octanol/water partition coefficient (log KOW). While there are several accepted methods to measure log KOW, no standardized method exists to determine log kIAM. The database of collated log kIAM values includes 13 key experimental parameters and contains 1,686 values for 555 compounds, which are predominantly polar organic compounds and include drug molecules and surfactants. These compounds are acidic, basic, and neutral and both ionized and un-ionized under the conditions of analysis. The data compiled demonstrated experimental variability for each experimental parameter considered, including column stationary phase, pH, temperature, and mobile phase. Reducing the experimental variability allowed for greater consistency in the datasets. Environ. Toxicol. Chem. 2011;30:2701–2708. © 2011 SETAC
Anisotropic mesh adaptation driven by a recovery‐based error estimator for shallow water flow modeling
Authors: Porta G. M. , Perotto S. , Ballio F. 
Published: September 2011

SUMMARYThe aim of this paper is to propose an effective anisotropic mesh adaptation procedure for the solution of the shallow water equations. The hyperbolic partial differential equation system is solved via the streamline diffusion FEM, suitably modified by a shock‐capturing correction. The proposed adaptation procedure relies on a recovery‐based error estimator. In particular, we look for an anisotropic error estimator able to select not only the size but also the shape and the orientation of the mesh elements, with the aim of optimizing the computational advantages yielded by a standard isotropic mesh adaptation strategy. The robustness of the proposed estimator is assessed when either a single physical quantity, meaningful for the problem at hand, or a combination of all the shallow water system components drives the adaptation procedure. For this purpose, steady shallow water problems as well as unsteady configurations are considered. Copyright © 2011 John Wiley & Sons, Ltd.
A one‐pot efficient four‐component reaction for the synthesis of 2‐(arylamino)‐2‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)propyl benzoate (or acetate) derivatives
Authors: Ramazani Ali , Ahmadi Yavar , Malekzadeh Asemeh Mashhadi , Rezaei Aram 
Published: September 2011

AbstractReactions of (N‐isocyanimino) triphenylphosphorane with 2‐oxopropylbenzoate (or acetate) in the presence of aromatic carboxylic acids and primary amines proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4‐oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions, and no side reactions were observed. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:692–698, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20735
WHAT FACTORS INFLUENCE THE EARNINGS OF GENERAL PRACTITIONERS AND MEDICAL SPECIALISTS? EVIDENCE FROM THE MEDICINE IN AUSTRALIA: BALANCING EMPLOYMENT AND LIFE SURVEY
Authors: Cheng Terence Chai , Scott Anthony , Jeon Sung‐Hee , Kalb Guyonne , Humphreys John , Joyce Catherine 
Published: September 2011

SUMMARYTo date, there has been little data or empirical research on the determinants of doctors' earnings despite earnings having an important role in influencing the cost of health care, decisions on workforce participation and labour supply. This paper examines the determinants of annual earnings of general practitioners (GPs) and specialists using the first wave of the Medicine in Australia: Balancing Employment and Life, a new longitudinal survey of doctors. For both GPs and specialists, earnings are higher for men, for those who are self‐employed and for those who do after‐hours or on‐call work. GPs have higher earnings if they work in larger practices, in outer regional or rural areas, and in areas with lower GP density, whereas specialists earn more if they have more working experience, spend more time in clinical work and have less complex patients. Decomposition analysis shows that the mean earnings of GPs are lower than that of specialists because GPs work fewer hours, are more likely to be female, are less likely to undertake after‐hours or on‐call work, and have lower returns to experience. Roughly 50% of the income gap between GPs and specialists is explained by differences in unobserved characteristics and returns to those characteristics. Copyright © 2011 John Wiley & Sons, Ltd.
Elucidating the Function of Complex‐Type Oligosaccharides by Use of Chemical Synthesis of Homogeneous Glycoproteins
Authors: Kajihara Yasuhiro , Izumi Masayuki , Hirano Kiriko , Murase Takefumi , Macmillan Derek , Okamoto Ryo 
Published: September 2011

AbstractProtein glycosylation is a major post‐translational modification. To elucidate the effect of this modification on protein function, homogeneous glycoproteins are required. Because glycoproteins isolated from biological sources contain glycoforms, a mixture of a single protein chain with several different oligosaccharides appended, homogeneous glycoproteins obtained through chemical synthesis offer a better solution. In this review, several methods used by our group for the chemical synthesis of homogeneous glycoproteins are addressed. First, preparation of sufficient amounts of oligosaccharides with the desired structures was achieved using a combination of chemical protection and enzymatic digestion. Then glycopeptide‐αthioesters were prepared by incorporation of oligosaccharides onto the side chains of cysteine residues in peptide‐αthioesters. Finally, biologically active homogeneous glycoproteins were prepared through native chemical ligation of glycopeptide‐αthioesters and subsequent oxidative folding.
CH bond activation of methane in aqueous solution: A hybrid quantum mechanical/effective fragment potential study
Authors: Da Silva Júlio C. S. , Rocha Willian R. 
Published: September 2011

AbstractIn this study, we investigated the CH bond activation of methane catalyzed by the complex [PtCl4]2−, using the hybrid quantum mechanical/effective fragment potential (EFP) approach. We analyzed the structures, energetic properties, and reaction mechanism involved in the elementary steps that compose the catalytic cycle of the Shilov reaction. Our B3LYP/SBKJC/cc‐pVDZ/EFP results show that the methane activation may proceed through two pathways: (i) electrophilic addition or (ii) direct oxidative addition of the CH bond of the alkane. The electrophilic addition pathway proceeds in two steps with formation of a σ‐methane complex, with a Gibbs free energy barrier of 24.6 kcal mol−1, followed by the cleavage of the CH bond, with an energy barrier of 4.3 kcal mol−1. The activation Gibbs free energy, calculated for the methane uptake step was 24.6 kcal mol−1, which is in good agreement with experimental value of 23.1 kcal mol−1 obtained for a related system. The results shows that the activation of the CH bond promoted by the [PtCl4]2− catalyst in aqueous solution occurs through a direct oxidative addition of the CH bond, in a single step, with an activation free energy of 25.2 kcal mol−1, as the electrophilic addition pathway leads to the formation of a σ‐methane intermediate that rapidly undergoes decomposition. The inclusion of long‐range solvent effects with polarizable continuum model does not change the activation energies computed at the B3LYP/SBKJC/cc‐pVDZ/EFP level of theory significantly, indicating that the large EFP water cluster used, obtained from Monte Carlo simulations and analysis of the center‐of‐mass radial pair distribution function, captures the most important solvent effects. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
A TD‐DFT study on the hydrogen bonding of three esculetin complexes in electronically excited states: Strengthening and weakening
Authors: Liu Yu‐Fang , Yang Da‐Peng , Shi De‐Heng , Sun Jin‐Feng 
Published: September 2011

AbstractTime‐dependent density functional theory (TD‐DFT) method was used to study the excited‐state hydrogen bonding of three esculetin complexes formed with aprotic solvents. The geometric structures, molecular orbitals (MOs), electronic spectra and the infrared (IR) spectra of the three doubly hydrogen‐bonded complexes formed by esculetin and aprotic solvents dimethylsulfoxide (DMSO), tetrahyrofuran (THF) and acetonitrile (ACN) in both ground state S0 and the first singlet excited state S1 were calculated by the combined DFT and TD‐DFT methods with the COSMO solvation model. Two intermolecular hydrogen bonds can be formed between esculetin and the aprotic solvent in each hydrogen‐bonded complex. Based on the calculated bond lengths of the hydrogen bonds and the groups involved in the formation of the intermolecular hydrogen bonds in different electronic states, it is demonstrated that one of the two hydrogen bonds formed in each hydrogen‐bonded complex is strengthened while the other one is weakened upon photoexcitation. Furthermore, it is found that the strength of the intermolecular hydrogen bonds formed in the three complexes becomes weaker as the solvents change from DMSO, via THF, to ACN, which is suggested to be due to the decrease of the hydrogen bond accepting (HBA) ability of the solvents. The spectral shifts of the calculated IR spectra further confirm the strengthening and weakening of the intermolecular hydrogen bonds upon the electronic excitation. The variations of the intermolecular hydrogen bond strengths in both S0 and S1 states are proposed to be the main reasons for the gradual spectral shifts in the absorption and fluorescence spectra both theoretically and experimentally. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
No person is an island: The effects of group characteristics on individual trait expression
Authors: Schmidt Joseph A. , Ogunfowora Babatunde , Bourdage Joshua S. 
Published: September 2011

SummaryAlthough most researchers now espouse a person‐by‐situation interactionist approach, there remains much work to be carried out to fully understand how different features of the environment interact with personality to influence behavior. Thus, this study sought to examine the moderating effects of three group‐level constructs on the relationships between two personality traits (conscientiousness and extraversion) and individual performance and counterproductive behaviors. Specifically, using trait activation theory as an organizing framework, we considered the moderating effects of the following: (i) a previously unexamined construct called core group evaluations (CGEs); (ii) group conscientiousness composition; and (iii) group extraversion composition. Data were obtained from a sample of university football players (N = 225–252 from 40 groups). The results indicated that CGEs moderated the relationships between individual conscientiousness and both performance (subjective) and counterproductive behaviors. Group conscientiousness composition also moderated the relationships between individual conscientiousness and both performance (objective and subjective) and counterproductive behaviors. Lastly, group extraversion composition moderated the relationship between individual extraversion and counterproductive behaviors. These findings highlight the importance of considering a team's CGEs, as well as the personality composition of team members when investigating the effects of conscientiousness and extraversion on individual performance and counterproductive behaviors. Copyright © 2011 John Wiley & Sons, Ltd.
Reduction of diazinon and dimethoate in apple juice by pulsed electric field treatment
Authors: Zhang Yuanyuan , Hou Yaxi , Zhang Yan , Chen Jie , Chen Fang , Liao Xiaojun , Hu Xiaosong 
Published: September 2011

AbstractBACKGROUND: Organophosphorus pesticides (OPPs) are widely used in agricultural production in China, and residues of OPPs in agro‐products and foods have become a public health concern. Chronic exposure to OPPs can result in potential immunosuppressive effects, cytotoxicity and mutagenicity. Pulsed electric fields (PEFs) have the potential to be used as an alternative to conventional techniques of food production. The aim of the present study was to investigate the influence of PEFs on the degradation of diazinon and dimethoate added to apple juice.RESULTS: PEF treatment significantly promoted the degradation of both pesticides (P < 0.05). The extent of degradation was strongly influenced by the electric field strength and treatment time, and maximum degradation of both diazinon (47.6%) and dimethoate (34.7%) was achieved by treatment at 20 kV cm−1 for 260 µs. The degradation behaviour of the pesticides was described by Weibull and Hülsheger models, both of which successfully fitted the degradation of diazinon and dimethoate. In addition, the decline in the toxicity of samples was observed with a photobacterium bioassay.CONCLUSION: PEF treatment was effective in eliminating residues of diazinon and dimethoate spiked in apple juice and in mitigating sample toxicity. Copyright © 2011 Society of Chemical Industry
Automatic filtration and filter flush for robust online solid‐phase extraction liquid chromatography
Authors: Svendsen Kristin O. , Larsen Hanne R. , Pedersen Siri A. , Brenna Ida , Lundanes Elsa , Wilson Steven R. 
Published: September 2011

AbstractOnline solid‐phase extraction‐liquid chromatography (SPE‐LC) with microbore or capillary columns was significantly improved regarding robustness, as an easily installed automatic filtration and filter flushing (AFFL) procedure was added to avoid system clogging. Specifically, an injected sample is passed through a union containing a stainless steel filter prior to SPE trapping. The filter stops any particulate matter from reaching the SPE. When the SPE is subsequently connected to the LC column by column switching, a separate pump backflushes the filter‐union, removing the particulate matter off the filter after each injection. This feature greatly reduced backpressure buildup over the entire system.
Synthesis of Branched Polymers under Continuous‐Flow Microprocess: An Improvement of the Control of Macromolecular Architectures
Authors: Bally Florence , Serra Christophe A. , Brochon Cyril , Hadziioannou Georges 
Published: September 2011

AbstractPolymerization reactions can benefit from continuous‐flow microprocess in terms of kinetics control, reactants mixing or simply efficiency when high‐throughput screening experiments are carried out. In this work, we perform for the first time the synthesis of branched macromolecular architecture through a controlled/‘living' polymerization technique, in tubular microreactor. Just by tuning process parameters, such as flow rates of the reactants, we manage to generate a library of polymers with various macromolecular characteristics.Compared to conventional batch process, polymerization kinetics shows a faster initiation step and more interestingly an improved branching efficiency. Due to reduced diffusion pathway, a characteristic of microsystems, it is thus possible to reach branched polymers exhibiting a denser architecture, and potentially a higher functionality for later applications.
Facile One‐Pot Synthesis of Functional Gold Nanoparticle–Polymer Hybrids Using Ionic Block Copolymers as a Nanoreactor
Authors: Ahn Hyungmin , Park Moon Jeong 
Published: September 2011

AbstractA highly versatile approach to fabricate functional gold nanoparticle (AuNP)‐polymer hybrids is demonstrated by employing sulfonated block copolymers. The 3–5 nm sized ionic domain of the sulfonated poly(styrene‐block‐methylbutylene) (SnMBm) copolymers can be utilized as a nanoreactor where the Au ions can be selectively sequestered and reduced to AuNPs using a simple photochemical method. The size of the AuNPs can be adjusted in fine‐steps from 2.0 ± 0.3 to 3.9 ± 0.5 nm by changing the sulfonation levels of the SnMBm copolymers. Remarkably, significantly improved methanol oxidation properties are achieved with the hybrid materials owing to the ion conducting–SO3H groups and the interconnected network of AuNPs confined within the self‐assembled microstructures, which provides electronic conductivity.