bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability‐indicating chemometric methods for the determination of tazarotene
Authors: Saad Ahmed S. , Darwish Hany W. , Badawy Amr M. , Abd El‐Aleem Abd El‐Aziz B. 
Published: May 2010

AbstractTwo multivariate calibration methods—principal component regression (PCR) and partial least square (PLS)—have been used to determine tazarotene in the presence of its degradation products. Both methods are useful in spectral analysis because of the simultaneous inclusion of many spectral wavelengths instead of the single wavelength used in derivative spectrophotometry. A great improvement in the precision and predictive abilities of these multivariate calibrations was observed. A calibration set was constructed for the mixture and the best model was used to predict the concentration of the selected drug. The proposed methods were applied successfully in the determination of tazarotene in laboratory‐prepared mixtures and in commercial preparations. Tazarotene was analyzed with mean accuracies of 100.006 ± 0.695 and 100.007 ± 0.690 using the PCR and PLS methods, respectively. The validity of the proposed methods was assessed using the standard addition technique. The proposed methods were found to be rapid, simple and required no preliminary separation. They can therefore be used for the routine analysis of tazarotene in quality‐control laboratories. Copyright © 2010 John Wiley & Sons, Ltd.
A tale of two crises: what the global financial crisis means for the global environmental crisis
Authors: Tienhaara Kyla 
Published: May 2010

AbstractHumanity is currently faced with two global crises, one financial and one environmental. Although ostensibly distinct, these crises are in fact interlinked. Unsustainable consumption, at the heart of the environmental crisis, is driven to a large extent by unsustainable debt, which creates financial instability. If these underlying issues are tackled, and investment is directed into environmental initiatives through a ‘green new deal’, then the ultimate outcome of the financial crisis could be the mitigation of the environmental crisis. If, conversely, economic hardship is used as a justification for delaying action on critical environmental issues and economic growth remains at the centre of government policy, then the ultimate outcome of the financial crisis could be the deepening of the environmental crisis. The relationship between the two crises therefore provides both opportunities and threats to achieving long‐term economic and ecological sustainability. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Synthesis, Crystal Structure, DNA Binding, and Hydrolytic Cleavage Activity of a Manganese(II) Complex
Authors: Qian Jing , Ma Xiao‐Fang , Xu Hai‐Zhen , Tian Jin‐Lei , Shang Jing , Zhang Yuan , Yan Shi‐Ping 
Published: May 2010

AbstractA new trinuclear manganese(II) complex {[MnCl(bpma)]2[Mn(μ‐Cl)4(H2O)2]}·CH3CN (1) [bpma = N,N‐bis(2‐pyridylmethyl)methylamine] has been synthesized and structurally characterized by X‐ray crystallography. The variable temperature‐dependent susceptibility measurement (2–300 K) of 1 reveals a weak antiferromagnetic interaction between the manganese ions through the dichlorido bridging ligands, with J = –0.46 cm–1, g = 1.99. The electrospray ionization mass spectrum of 1 in solution indicates that the dinuclear [Mn2(bpma)2Cl2(H2O)(OH)]+ ion is the active species. In the absence of a reducing agent, supercoiled plasmid DNA cleavage by the active species was performed and its hydrolytic mechanism was demonstrated with radical scavengers, anaerobic reaction, and T4 ligase. The pseudo‐Michaelis–Menten kinetic parameters (kcat., KM) were calculated to be 1.11 h–1 and 6.65 × 10–4 M for the dinuclear species.
Dinuclear Complexes of the N2O2 Oxime Chelate Ligand with Zinc(II)–Lanthanide(III) as a Selective Sensitization System for Sm3+
Authors: Akine Shigehisa , Utsuno Fumihiko , Taniguchi Takanori , Nabeshima Tatsuya 
Published: May 2010

AbstractA series of zinc(II)–lanthanide(III) dimetallic complexes have been synthesized by the one‐pot reaction of the oxime‐based N2O2 chelate ligand H2L with zinc(II) acetate and lanthanide(III) salts. The heavier lanthanides (Sm–Lu) producedheterodinuclear complexes [LZnLn]3+ (Ln = Sm–Lu) in which the zinc(II) ion occupies the N2O2 chelate site of H2L and the lanthanide(III) ion is located in the semicircular O4 site. In contrast, the trinuclear complex [(LZn)2La]3+ was obtained by the reaction of H2L with zinc(II) and lanthanum(III) salts. The heterometallic complexes [LZnLn]3+ and [(LZn)2La]3+ were also formed by the reaction of [L2Zn3]2+ with the heavier lanthanides (Sm3+–Lu3+) and La3+, respectively. The dinuclear complex [LZnSm(OAc)3] exhibited a relatively intense red emission due to Sm3+, whereas [LZnEu(OAc)3] gave no detectable emission. The corresponding complexes containing other lanthanides showed only a weak blue emission due to the ligand moiety. Therefore the ligand L2– can selectively sensitize Sm3+ from among Sm3+, Eu3+, Tb3+, and Dy3+, although these complexes would often exhibit f–f luminescence. The deep‐red luminescence from samarium(III) at around 650 nm is potentially useful for a full‐color display. In addition, [LZnYb(OAc)3] exhibited near‐infrared luminescence.
A New Cobalt(II)‐Layered Network Based on Phenyl(carboxymethyl) Phosphinate
Authors: Costantino Ferdinando , Ienco Andrea , Midollini Stefano , Orlandini Annabella , Rossin Andrea , Sorace Lorenzo 
Published: May 2010

AbstractIn the presence of 4,4′‐bipyridine (4,4′‐bipy) and CoII metal ions, a bifunctional phosphinate‐carboxylate ligand, phenyl(carboxymethyl) phosphinate (pcc), forms a new polymeric metal‐organic framework (MOF), [[Co(pcc)(4,4′‐bipy)(H2O)](H2O)1.5]n (1). The structure consists of 2D slabs connected by solvent water molecules with cobalt metal atoms in two different coordination environments. The temperature‐dependent X‐ray powder diffraction analysis of 1 shows the formation of dehydrated phases in the range 120–180 °C. The dehydration–rehydration process is reversible. The overall magnetic behaviour of complex 1 is dominated by single ion effects with only weak exchange coupling interactions, due to the syn/anti conformation of the Co–O–C–O–Co path.
Syntheses at Elevated Temperature and Structures of Lanthanoid/Alkaline Earth Heterobimetallic Derivatives of 2‐Methyl‐8‐hydroxyquinoline
Authors: Deacon Glen B. , Forsyth Craig M. , Junk Peter C. , Urbatsch Aron 
Published: May 2010

AbstractRearrangement reactions between Ln(MQ)3 and AE(MQ)2 (MQ = 8‐quinaldinolate) at 200–300 °C in a 1,2,4,5‐tetramethylbenzene (TMB) flux afforded the homoleptic heterobimetallic complexes [Ln2AE(MQ)8] (Ln = Eu, Gd, Tb, Er with AE = Mg; Ln = La, Eu with AE = Ca) and [Eu3Ba(MQ)11]·2TMB. From an attempt to prepare [La2Mg(MQ)8], [Mg4(MQ)8] was isolated, and it was also obtained with the heterobimetallics from syntheses in which Ln = Eu, Gd, Tb. Surprisingly, [Er3(MQ)7CO3] was isolated from an attempted synthesis of [Er2Ca(MQ)8], and the Eu analogue was prepared from Eu(MQ)3 and CaCO3 in TMB at 210 °C. The [Ln2AE(MQ)8] complexes have a trinuclear structure with a linear or nearly linear Ln–AE–Ln array. Octacoordinate Ln atoms have one terminal chelating (N, O) MQ ligand and three chelating‐bridging MQ ligands that link to AE through the phenolic oxygen atoms, leading to hexacoordination of AE. In [Eu3Ba(MQ)11]·2TMB, an Eu atom is positioned above the Ba–Eu vector of a somewhat bent Eu–Ba–Eu unit. All atoms are octacoordinate, and the structure features μ3‐η2(N,O):η1(O):η1(O) MQ ligands in addition to terminal chelating and chelating‐bridging μ‐η2(N,O):η1(O) MQ groups observed in [Ln2AE(MQ)8] complexes. The three modes of ligation are also observed in [Mg4(MQ)8] where Mg is hexacoordinate but with two different arrays. [Ln3(MQ)7CO3] complexes have a perpendicular Ln–Ln–Ln arrangement with two octacoordinate metal atoms flanking a heptacoordinate one. Carbonate binding features the new η1(O)‐μ3‐η1(O′):η1(O′):η1(O′)‐η1(O″) ligation mode. The carbonate ligand chelates to each of the outer Ln atoms, which are also linked to one chelating and two chelating‐bridging MQ ligands. Attached to the central Ln atom is a carbonate oxygen atom, four oxygen atoms from chelating‐bridging MQ ligands and a terminal MQ chelate.
Palladium‐Catalyzed Synthesis of 4‐Arylcoumarins Using Triarylbismuth Compounds as Atom‐Efficient Multicoupling Organometallic Nucleophiles
Authors: Rao Maddali L. N. , Venkatesh Varadhachari , Jadhav Deepak N. 
Published: May 2010

AbstractTriarylbismuth compounds have been cross‐coupled as atom‐efficient multicoupling organometallic nucleophiles with 4‐bromo‐ and 4‐(trifluoromethylsulfonyloxy)coumarins under palladium catalysis conditions. These reactions afforded an array of 4‐arylcoumarins in high yields. The general palladium protocol has been demonstrated to be efficient for the coupling of both bromide and triflate derivatives of coumarins with triarylbismuth reagents.
A Cyclic Porphyrin Tetramer Linked by Azo and Butadiyne Bridges
Authors: Bašić Bruno , McMurtrie John C. , Arnold Dennis P. 
Published: May 2010

AbstractA soluble cyclic porphyrin oligomer (CPO) consisting of four 5,10‐diarylporphyrins linked by alternating azo and butadiyne bridges has been synthesised via an aminated dinickel(II) butadiyne dimer. This is the first cyclic tetramer that combines both azo and butadiyne bridges and extends the azoporphyrin family, which comprises only a very few examples. The electronic absorption spectrum of the tetramer is more similar to spectra of azoporphyrins than to those of butadiyne‐linked dimers or tetramer, exhibiting a two‐component Soret band with a splitting of 4190 cm–1 and a strongly red‐shifted Q band maximum at 735 nm.
Synthesis of New Sulfoxide‐Containing Diselenides and Unexpected Cyclization Reactions to 2,3‐Dihydro‐1,4‐benzoselenothiine 1‐Oxides
Authors: Freudendahl Diana M. , Iwaoka Michio , Wirth Thomas 
Published: May 2010

AbstractNew chiral sulfoxide‐containing diselenides were prepared and their corresponding selenium electrophiles were used for the stereoselective functionalization of alkenes. The influence of solvents and different nucleophiles on the outcome of the selenenylation reaction was studied. Besides the successful selenenylation reactions, one selenium electrophile showed an unexpected reactivity in forming a six‐membered heterocyclic system upon reaction with alkenes. A mechanism for the formation of these 2,3‐dihydro‐1,4‐benzoselenothiine 1‐oxides is proposed.
Behavioral rebound following stereotype suppression
Authors: Follenfant Alice , Ric François 
Published: May 2010

AbstractAttempts to suppress stereotypes have often been found to result in an increased accessibility of these stereotypes. According to thought suppression literature together with research on prime‐to‐behavior effects, we hypothesized that suppression of stereotype can lead people to subsequently behave in accordance with its content and that these effects are stronger after suppression (rebound) than after a classical priming condition (i.e., no‐suppression condition). Experiment 1 showed that suppression of the stereotype of sportsmen (associated with poor math performance) but not of Italian men (not related to math performance) led participants to subsequently perform worse on a calculus task in comparison to non‐suppressors. These effects were replicated in a second experiment with another stereotype (elderly) and another behavior that does not require self‐regulation (walking speed): Suppressors walked slower than non‐suppressors. These findings are considered in the context of mental control and social stereotyping. Copyright © 2009 John Wiley & Sons, Ltd.
Terminal‐vinyl liquid crystal crown ether‐modified, vinyl‐functionalized hybrid silica monolith for capillary electrochromatography
Authors: Feng Rui , Tian Yun , Chen Hao , Huang Zaifu , Zeng Zhaorui 
Published: May 2010

AbstractA novel terminal‐vinyl liquid crystal crown ether (2‐[4‐(3‐undeceny‐1‐yloxy)‐phenyl]‐2‐[4′‐(4′‐carboxybenzo‐15‐crown‐5)‐phenyl] propane) (LCCE) was synthesized and used to modify hybrid silica‐based monolithic column possessing vinyl ligands for CEC. The monolithic silica matrix containing vinyl functionalities was prepared by in situ co‐condensation of tetramethoxysilane and vinyl‐trimethoxysilane via sol–gel process and chemically modified with LCCE by free radical polymerization procedure using α,α'‐azobisisobutyronitrile as an initiator. Morphology of the monolithic column was examined by SEM and mercury porosimetry and the successful incorporation of terminal‐vinyl LCCE to the vinyl‐hybrid monolith was characterized by infrared spectra. Polycyclic aromatic hydrocarbons, benzenediols, carbamate pesticides and steroids, were successfully separated on the column. The separations were dominated hydrogen bonding supplied by crown ether and hydrophobic interaction offered by the liquid crystal. The effect of ACN concentration on separation performance was studied and the result indicated that RP retention mechanism played an important role. Reproducibilities of migration times for the six selected polycyclic aromatic hydrocarbons were reasonable, with relative standard deviation less than 3.50% for five consecutive within‐column runs and were 8.38–9.11% for column‐to‐column measurements of three columns.
Pressure generation at the junction of two microchannels with different depths
Authors: Yanagisawa Naoki , Dutta Debashis 
Published: May 2010

AbstractIn this study, we report the design of a microchip‐based hydraulic pump that comprises three glass conduits arranged in a T‐geometry, one of which has a 2 mm long segment shallower (0.5–3 μm in depth) than the remaining 15 μm deep microfluidic network. Upon application of an electric field across this microchannel junction, a mismatch in EOF rate is introduced due to a differential in the fluid conductivity across the deep and shallow segments. Using the reported micropump, pressure‐driven velocities up to 3.2 mm/s have been generated in a 15 μm deep separation channel for an applied voltage of 1.75 kV allowing us to operate under separation conditions that yield the minimum plate height. Moreover, we have shown that this flow velocity can be maximized by optimizing the depth in the shallow region of the T‐geometry. Interestingly however, a simple theory accounting for fluid conductivity differences across microchannels of different depths significantly underestimates the pressure‐driven velocities observed in our experiments. The Taylor dispersion coefficient in our system on the other hand compares well with the theoretical predictions reported in the literature. Finally, the functionality of our device has been demonstrated by implementing a reverse‐phase chromatographic separation that was driven by the pressure‐driven flow generated on‐chip.
Interactions of metal cations with anionic groups on the cell wall of the macroalga Vaucheria sp.
Authors: Michalak Izabela , Chojnacka Katarzyna 
Published: May 2010

AbstractThe aim of this article was to investigate the interactions of metal cations in aqueous solutions with the biomass of the freshwater macroalga Vaucheria sp. This problem is important when elaborating new applications of biosorption, e.g. the production of mineral feed additives for livestock from the biomass of algae enriched with microelement ions. Potentiometric titration was applied as a quick and cheap screening test to search for new efficient biosorbents. It revealed a variety of functional groups capable of cation exchange on the macroalgal surface, including carboxyl, phosphate, hydroxyl or amino groups. Fourier transform infrared spectroscopy on natural and chromium‐loaded Vaucheria sp. confirmed that carboxyl groups played a dominant role in the biosorption. The study also showed that Ca(II), Na(I), K(I), and Mg(II) ions were released from the biomass after biosorption of Cu(II), Mn(II), Zn(II), and Co(II) ions, indicating that ion exchange was a key mechanism in the biosorption of metal ions by Vaucheria sp. biomass. It was noticed that the mass of the microelement cations bound by the macroalga was proportional to the total mass of light metal ions [Na(I), K(I), Ca(II), and Mg(II)] released from the biomass.
Convenient, multi‐well plate‐based DNA damage response analysis using DT40 mutants is applicable to a high‐throughput genotoxicity assay with characterization of modes of action
Authors: Ridpath John R. , Takeda Shunichi , Swenberg James A. , Nakamura Jun 
Published: May 2010

AbstractChemists continually synthesize myriad new chemicals (∼2,000/year), some of which make their way into the environment or otherwise pose possible threats to humans who potentially become exposed to the compounds. Regulators must determine whether these, along with the glut (∼80,000) of existing, chemicals are toxic and at what exposure levels. An important component of this determination is to ascertain the mode of action (MOA) of each compound as it relates to the pathway the compound uses to induce genotoxicity. Several assays have traditionally been used to reveal these effects to the genome: the Ames test, tests with yeast and mammalian cell lines, and animal studies. Previously, we described a new multi‐well plate‐based method which makes use of the DT40 isogenic cell line and its dozens of available mutants knocked out in DNA repair and cell cycle pathways and we now provide a detailed protocol of the further improvement of the assay. Although the DT40 line has existed for some time and has been used in numerous studies of DNA repair pathways, little use has been made of this valuable resource for toxicological investigations. Our method introduces the 2,3‐bis (2‐methoxy‐4‐nitro‐5‐sulfophenyl)−5‐[(phenylamino) carbonyl]−2H‐tetrazolium hydroxide dye scheme determination of cell survival in a manner that greatly increases throughput and reduces cost while maintaining reasonable sensitivity. Although this new genotoxicity assay requires validation with many more mutagens before becoming an established, regulatory decision‐making analysis tool, we believe that this method will be very advantageous if eventually added to the repertoire of those investigating MOAs of potentially genotoxic substances. Environ. Mol. Mutagen. 52:153–160, 2011. © 2010 Wiley‐Liss, Inc.
Effect of electro‐Fenton application on azo dyes biodegradability
Authors: Elias B. , Guihard L. , Nicolas S. , Fourcade F. , Amrane A. 
Published: May 2010

AbstractThe aim of this study was to examine the feasibility of combining an electro‐Fenton pre‐treatment and a biological treatment to remove azo dyes from aqueous effluents. The electro‐Fenton reaction was performed in a two‐compartment system involving a reference (saturated calomel electrode), a platinum anode and a graphite felt cathode. For the three considered dyes, high discoloration (in the range 77.1–97.8%) and low mineralization (in the range 7.7–18.8%) after 4‐h reaction were in favor of the hybrid process, which was confirmed during subsequent experiments with methyl red sodium salt (MRSS) as a model dye. When potential‐controlled electrolysis at −0.5 V/SCE was performed with a carbon‐felt cathode surface of 378 cm2 and a catalytic amount of ferric iron of 1 mmol L−1, less than 1‐h reaction was needed for an almost total discoloration (90.5%); while mineralization and oxidation remained low even after 48‐h reaction, 11.1 and 57.2%, respectively. High discoloration level concomitantly to low mineralization and oxidation for MRSS removal which were in favor of a hybrid process, confirmed by the decrease of the COD on DOC ratio (45.1%) and the increase of the average oxidation state AOS (2.1). Final BOD5 on COD ratio of 0.24 and an absence of toxicity of the treated solution (EC50 = 165%) also showed the positive impact of an electro‐Fenton pretreatment. © 2010 American Institute of Chemical Engineers Environ Prog, 2011
A strategy for ranking environmentally occurring chemicals. Part III: Multivariate quantitative structure-activity relationships for halogenated aliphatics
Authors: Eriksson Lennart , Jonsson Jörgen , Hellberg Sven , Lindgren Fredrik , Skagerberg Bert , Sjöström Michael , Wold Svante , Berglind Rune 
Published: May 2010

Abstract
A strategy for systematic analysis and priority ranking of chemical compounds was applied to a class of 58 saturated halogenated aliphatics. By means of a fractional factorial design, a training set consisting of 10 compounds was selected. The training set compounds were subjected to biological testing and their acute oral toxicity to rat and highest nonlethal dose to mouse were determined. Based on the selected training set, two multivariate quantitative structure-activity relationships (QSARs) were developed. It was concluded that both end points needed a multivariate structural description to be modelled. The derived QSARs were used to predict the potential hazards of the remaining compounds in the class.
Effects of lead and pesticides on δ-aminolevulinic acid dehydratase of ring doves(Streptopelia risoria)
Authors: Scheuhammer A. M. , Wilson L. K. 
Published: May 2010

AbstractThe effects of lead (Pb2+) and various pesticides on δ-aminolevulinic acid dehydratase (ALA-d) in avian blood, liver and kidney were studied. In blood, virtually all of the ALA-d activity was localized in the cellular fraction. Complete inhibition of RBC ALA-d occurred at an in vitro Pb2+ concentration of ∼10 μmol/g protein, with an IC50 of ∼0.9 μmol/g protein. Pesticides (carbaryl, carbofuran, chlorpyrifos, diazinon, dieldrin, fenitrothion, hexachlorobenzene) added to blood samples up to 10 mM in vitro had no inhibitory effect on ALA-d, nor did the presence of pesticides greatly modify the response of ALA-d to inhibition by increasing concentrations of Pb2+. Recovery of Pb-inactivated RBC ALA-d activity was accomplished by treatment of blood hemolysates with Zn2+ and an SH-reducing agent such as dithiothreitol (DTT). A combination of Zn2+ (4 mM) and DTT (120 mM) was required to achieve complete recovery of Pb-inhibited enzyme activity. Normal avian ALA-d activity was greatest in blood, followed by liver, then kidney. Unlike blood hemolysates, liver and kidney homogenates contained a fraction of ALA-d activity which was very resistant to inhibition by in vitro Pb2+. In vivo, hepatic ALA-d was unaffected by Pb exposure (2.5 μg Pb2+/g body weight injected intraperitoneally), but renal ALA-d was decreased as a result of greater deposition of Pb in kidney than in liver. Inhibition of ALA-d in avian blood, particularly when expressed as a ratio of fully restored:nonrestored activity (activity ratio), is a highly specific, sensitive indicator of Pb exposure, deposition and corresponding enzyme inhibition in other target organs (kidney).