bluuebunny/crossref_metadata_2025 huggingface dataset:
Shuttling Gold Nanoparticles into Tumoral Cells with an Amphipathic Proline‐Rich Peptide
Authors: Pujals Sílvia , Bastús Neus G. , Pereiro Eva , López‐Iglesias Carmen , Puntes Víctor F. , Kogan Marcelo J. , Giralt Ernest
Published: March 2009

Golden bullets: The amphipathic proline‐rich cell‐penetrating peptide sweet arrow peptide (SAP) is able to transport 12 nm gold nanoparticles efficiently into HeLa cells, as observed by three microscopy techniques: transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and transmission X‐ray microscopy (TXM). Multiconjugation to such nanoparticles may provide a convenient method for unifying the key drug properties of high activity, capacity to home onto targets and delivery to therapeutic places of action.

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Cell‐penetrating peptides (CPPs) are a potential tool for intracellular delivery of different kinds of cargoes. Because of their growing use in nanobiomedicine, both for diagnostics and for treatment, metal nanoparticles are an interesting cargo for CPPs. Here, gold nanoparticles (AuNps) and the amphipathic proline‐rich peptide SAP have been used. Conjugation of the peptide onto the AuNps was achieved by addition of a cysteine to the SAP sequence for thiol chemisorption on gold, and the attachment was confirmed by visible spectroscopy, dynamic light scattering (DLS), ζ‐potential (ZP), stability towards ionic strength (as high as 1 M NaCl), X‐ray photoelectron spectroscopy (XPS) and high‐resolution transmission electron microscopy (HR‐TEM) coupled to electron energy loss spectroscopy (EELS). AuNp‐C‐SAP internalization in HeLa cells was observed by three different microscopy techniques—TEM, confocal laser scanning microscopy (CLSM) and transmission X‐ray microscopy (TXM)—and all of them have confirmed the effective intracellular delivery of AuNps by SAP.
Expanding the Scope of Protein Trans‐Splicing to Fragment Ligation of an Integral Membrane Protein: Towards Modulation of Porin‐Based Ion Channels by Chemical Modification
Authors: Brenzel Steffen , Cebi Menekse , Reiß Philipp , Koert Ulrich , Mootz Henning D.
Published: March 2009

It's raining, it's porin: Fragment ligation of OmpF ion channels was achieved by using the split Psp‐GBD Pol intein; this allowed reconstitution of active trimeric porin. In combination with cysteine modification at an internal position, the porin's conductance properties were altered.

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Generating CuII–Oxyl/CuIII–Oxo Species from CuI–α‐Ketocarboxylate Complexes and O2: In Silico Studies on Ligand Effects and CH‐Activation Reactivity
Authors: Huber Stefan M. , Ertem Mehmed Z. , Aquilante Francesco , Gagliardi Laura , Tolman William B. , Cramer Christopher J.
Published: March 2009

Theoretically speaking: The mechanistic details associated with the generation and reaction of [CuO]+ species from CuI–α‐ketocarboxylate complexes, especially with respect to modifications of the ligand supporting the copper center, were investigated (see scheme). Theoretical models were used to characterize the electronic structures of different [CuO]+ species and their reactivity in CH activation and O‐atom transfer reactions.

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A mechanism for the oxygenation of CuI complexes with α‐ketocarboxylate ligands that is based on a combination of density functional theory and multireference second‐order perturbation theory (CASSCF/CASPT2) calculations is elaborated. The reaction proceeds in a manner largely analogous to those of similar FeII–α‐ketocarboxylate systems, that is, by initial attack of a coordinated oxygen molecule on a ketocarboxylate ligand with concomitant decarboxylation. Subsequently, two reactive intermediates may be generated, a Cu–peracid structure and a [CuO]+ species, both of which are capable of oxidizing a phenyl ring component of the supporting ligand. Hydroxylation by the [CuO]+ species is predicted to proceed with a smaller activation free energy. The effects of electronic and steric variations on the oxygenation mechanisms were studied by introducing substituents at several positions of the ligand backbone and by investigating various N‐donor ligands. In general, more electron donation by the N‐donor ligand leads to increased stabilization of the more CuII/CuIII‐like intermediates (oxygen adducts and [CuO]+ species) relative to the more CuI‐like peracid intermediate. For all ligands investigated, the [CuO]+ intermediates are best described as CuIIO⋅− species with triplet ground states. The reactivity of these compounds in CH abstraction reactions decreases with more electron‐donating N‐donor ligands, which also increase the CuO bond strength, although the CuO bond is generally predicted to be rather weak (with a bond order of about 0.5). A comparison of several methods to obtain singlet energies for the reaction intermediates indicates that multireference second‐order perturbation theory is likely more accurate for the initial oxygen adducts, but not necessarily for subsequent reaction intermediates.
Modulating Large‐Area Self‐Assembly at the Solid–Liquid Interface by pH‐Mediated Conformational Switching
Authors: Piot Luc , Meudtner Robert M. , El Malah Tamer , Hecht Stefan , Samorì Paolo
Published: March 2009

Dynamic surfaces: The conformational transition of 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridine (BTP) derivatives, triggered by a change in pH, has been observed with a sub‐nm resolution by STM at the solid–liquid interface. Upon addition of trifluoroacetic acid two different BTP molecules, each forming a highly ordered physisorbed monolayer, underwent significant conformational changes from their “rosette” to their “tetragon” forms, as reflected in dramatically altered 2D self‐assembly over large areas extending over hundreds of nanometers (see graphic).

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Influence of Counteranion on the Chiral Supramolecular Assembly of Alkynylplatinum(II) Terpyridyl Metallogels That Are Stabilised by Pt⋅⋅⋅Pt and π–π Interactions
Authors: Tam Anthony Yiu‐Yan , Wong Keith Man‐Chung , Yam Vivian Wing‐Wah
Published: March 2009

Helical superstructures: A series of luminescent chiral alkynylplatinum(II)–terpyridyl complexes has been successfully synthesised and shown to be capable of forming metallogels that show helical fibrous nanostructures. The chiral supramolecular structure and the spectroscopic properties are found to depend on the extent of aggregation through Pt⋅⋅⋅Pt and π–π interactions in various counteranions, as revealed by UV/Vis, circular dichroism (CD), and luminescence studies (see picture).

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Theoretical analysis of absorption of chlorine in aqueous slurries of calcium hydroxide: Desorption of hypochlorous acid gas
Authors: Mogal M. M. B. , Yadav G. D.
Published: March 2009

A theory has been developed for the absorption of chlorine in aqueous slurries of calcium hydroxide accompanied by a two‐step instantaneous reaction and desorption and simulation is carried out to study the effects of various parameters. The rates of absorption of chlorine and desorption of HOC1 from the aqueous slurry are enhanced when fine particles are present in two diffusion film regions on the liquid side. It is concluded that intensification in the rates of absorption of chlorine and rates of desorption can be realized by using high loading of smaller particle size. An optimum kL must be used to enhance rates of Cl2 absorption and HOG desorption in order to permit the formation of two reaction planes in the diffusion film. Rates can be intensified by an order of magnitude by the proper selection of operating conditions.
Evaluation of the flow rate of an electro‐rheological fluid (corn starch‐kerosene) flowing through a narrow channel formed by a pair of electrodes
Authors: Kobayashi Kazumasa , Okamura Keiji , Sakai Takeshi , Sato Masayuki
Published: March 2009

The flow rate of a com starch‐kerosene ERF through a narrow channel formed by a pair of electrodes has been measured over a range of electric fields between 0 and 2.8 kV/mm. The effect of the entrance shape and various electrode configurations on the flow rate of the ERF has been examined. The relationship between the flow rate and applied voltage is theoretically analysed on the assumption that the ERF is a Bingham fluid and compared with the observed values. It has been illustrated that the theoretically derived relationship is in good agreement with the observed values if a correction term or adjustable parameters are incorporated.
Catalytic methane coupling under periodic operation
Authors: Mortazavi Y. , Hudgins R. R. , Silveston P. L.
Published: March 2009

Composition modulation strategies for improving selectivity to the C2 products in the oxidative coupling of methane were investigated experimentally with Li2O/MgO and CeO/Li2O/MgO catalysts at about 100 kPa pressure and 750°C. Strategies used were 1) “methane cycling” between mixtures with different concentrations of CH4, 2) “oxygen cycling” between mixtures with different concentrations of oxygen, 3) bang‐bang cycling (air‐CH4), and 4) flushing the catalyst with an inert between exposures to reactants.

Experimental C2 yields and ethylene to total C2 ratios showed that composition forcing is better with the Ce/Li/MgO catalyst. Methane cycling proved to be the best strategy explored.
Study of unsteady‐state catalytic oxidation of sulfur dioxide by periodic flow reversal
Authors: Huixiong Wu , Shuzeng Zhang , Chengyue Li
Published: March 2009

A systematic study of catalytic oxidation of sulfur dioxide in a fixed bed reactor operated in flow reversal mode was made. A heterogeneous transient model of the reactor was developed. The global rate equations and the heat transfer parameter correlation were obtained, based on a series of previous experiments. The experiments of unsteady‐state oxidation of low concentration SO2 were conducted in a bench‐scale fixed bed reactor, packed with a domestic commercial catalyst. The model can successfully predict the transient concentration and temperature profiles when a correction factor is introduced to the global rate equations.
Modelling and experimental studies on unsteady‐state SO2 converters
Authors: Xiao Wen‐De , Yuan Wei‐Kang
Published: March 2009

This paper deals with experimentation of the unsteady‐state fixed‐bed reactor with flow reversal for SO2 conversion. A laboratory reactor with compensatory heating coils has been set up, resulting in 96–99% conversion for SO2 = 2.62–9.52 vol%, and u = 0.2 m/s. The results were from agreement with simulation of a really adiabatic unsteady‐state reactor, but agreed well with modelling by considering the radial heat transfer. A three‐stage pilot‐scale converter has also been run with the M‐typed temperature profile produced by heat loss from the chamber between stages. Good agreement was achieved with modelling by taking into account this feature. The results show that, while the adiabatic requirement is difficult to fulfill in the well‐accepted experimental reactors, simulation and modelling are powerful means for compensation.
Modeling of grain drying in continuous cross‐flow sliding bed dryers
Authors: Mayta S. Miguel A. , Massarani Giulio , Pinto José Carlos
Published: March 2009

Two mathematical models were developed in order to describe grain drying in continuous cross‐flow sliding bed dryers: a purely convective model and a diffusive model. It is shown both theoretically and experimentally that diffusion is not fundamental for the proper description of corn and soybean in these dryers at usual operation conditions, in spite of the widespread usage of diffusion‐like models. Particularly, the purely convective model may be easily implemented and used to optimize drying operation at plant site.
Metabolic responses of plant cell culture to hydrodynamic stress
Authors: Takeda Toshiya , Kitagawa Takanori , Takeuchi Yoshikuni , Seki Minoru , Furusaki Shintaro
Published: March 2009

The metabolic responses of eucalyptus and safflower cells to hydrodynamic stress in a 550‐cm3 stirred tank reactor were investigated. At 0.5 — 2.3 m2/s3 of energy dissipation rate, the decreases in respiration rate and ATP content were larger than the decrease in the membrane integrity. Intracellular NAD(P)H was decreased and cytosolic calcium content was increased by agitation. EGTA, verapamil and W‐7 suppressed the decrease in NAD(P)H. These results suggest that the cytosolic calcium, as a second messenger, mediate the signal of the hydrodynamic stress into the metabolism which induces the decrease in respiration rate. Furthermore, a decrease in the filamentous actin content due to agitation was observed.
Newtonian power curve and drop size distributions for vibromixers
Authors: Lo Mei Y. A. , Gierczycki Andrej T. , Titchener‐Hooker Nigel J. , Shamlou Parviz Ayazi
Published: March 2009

Power input data are presented for a twin flat disk up‐and‐down moving (vibromixer) impeller operating in a small vessel with a range of Newtonian liquids. Vibromixer power number and Reynolds number are defined and are used to establish the Newtonian power curve for this type of mixer. Drop size distributions are presented for xylene‐in‐water dispersions under turbulent flow conditions in the vibromixer and are shown to vary with the maximum velocity of the disk (2πAf). The Sauter mean drop diameter of the distribution is related to the vibromixer Weber number, (We =ρ(2πAf)2D/σ), by an equation of the type d32/D = C (We)−3/5 with the coefficient C = 0.37.
Pumping, spraying, and mixing of fluids by electric fields
Authors: Tsouris Costas , Shin Won‐Tae , Yiacoumi Sotira
Published: March 2009

The mechanism of electrostatic spraying of insulating fluids, such as air or organic solvents, into relatively conductive fluids, such as water, is investigated in this work. Experiments with air sprayed into water through an electrified capillary showed that the pressure inside the capillary increases, reaches a maximum, and then decreases as the applied voltage is increased. The initial pressure increase is due to the electric stress on the fluid interface, while the decrease is due to the Coulombic electrohydrodynamic flow generated near the end of the capillary. It is shown that electric fields can cause simultaneous pumping, spraying, and mixing of fluids. This phenomenon is demonstrated for air and kerosene in water.
Etude de l'influence du mode d'anodisation sur la cinétique de croissance des films d'alumine en milieu acide sulfurique
Authors: Azzouz Noureddine , Belmokre Kamel , Taallah Habib , Pagetti Jacques
Published: March 2009

The kinetics of growth of Al2O3 oxide films made by anode oxidation of ALuminium 1050A with two anodization techniques has been investigatedan compared. The first technique is the classical method based on continuous tension during the complete electrlysis duration, and the second one is the modern method ofpulsed tensions, whcih consists of periodically imposing to the material two anodc tensions E1 and E2 (E1 > E2) during time T1 and T2 until the end on anodization. We have shown that the second technique allows the fabrication of films more rapidly for the same electrolysis duraton. Energy and electrolysis time are saved, making it attractive from an economical viewpoint. This advantage arises from the positive effect of excess heat disiption gathered during the imposition of tension, E1, when E2 is imposed thereafter (recovery effect). The logging of in situ transient responses in the case of pulsed anodization is a significant asset to explain the growth film kinetics obtained with this method.
Rheological properties of aqueous α A12O3 suspensions: Influence of dispersant concentration
Authors: Zupančič Andreja , Lapasin Romano , Kristoffersson Annika
Published: March 2009

The effects of concentration of polyacrylic acid as a dispersant on rheological properties of aqueous alumina suspensions have been investigated under steady and oscillatory shear conditions. At solid volume fractions between 0.45 and 0.6, a high degree of particle stabilization is achieved when 0.2 wt% of polyacrylic acid is added. At lower dispersant concentrations, suspensions exhibit pronounced irreversible thixotropic behaviour, whereas at higher dispersant concentrations, time dependent effects on the flow properties are not detectable. When the saturation adsorption limit of the polyelectrolyte on Al2O3 is reached, further addition of the dispersant appreciably changes the flow behaviour, as well as the viscoelastic response of investigated suspensions. The data under steady shear are described by application of the generalized Casson model, and for the analysis of viscoelastic data the generalized Maxwell model is used.
Effects of Thymoquinone–Fatty Acid Conjugates on Cancer Cells
Authors: Breyer Sandra , Effenberger Katharina , Schobert Rainer
Published: March 2009

More than the sum of its parts: The seeds of Nigella sativa have been a traditional herbal remedy for ailments such as asthma, diarrhea, and cancer. Their essential oil is rich in polyunsaturated fatty acids and thymoquinone. By linking them covalently, a tremendous boost in anticancer activity can be achieved in resistant tumor cells.

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4‐Acylhydrazones and 6‐alkyl derivatives of thymoquinone (TQ) were tested for growth inhibition of human HL‐60 leukemia, 518A2 melanoma, KB‐V1/Vbl cervix, and MCF‐7/Topo breast carcinoma cells. Unsaturated side chains conferred greater activities than equally long saturated chains. The number of CC bonds was less decisive than chain length. The 6‐hencosahexaenyl conjugate 3 e was most active in all resistant tumor cells, with IC50 (72 h) values as low as 30 nM in MCF‐7/Topo cells. The conjugates are likely to operate by mechanisms different from that of TQ. For instance, 3 e induced distinct caspase‐independent apoptosis in HL‐60 and 518A2 cells concomitant with a loss of mitochondrial membrane potential and a subsequent rise in the levels of reactive oxygen species.
Synthesis and Biological Evaluation of New Geiparvarin Derivatives
Authors: Chimichi Stefano , Boccalini Marco , Salvador Alessia , Dall'Acqua Francesco , Basso Giuseppe , Viola Giampietro
Published: March 2009

New geiparvarin derivatives modified at the alkenyloxy bridge, where the 3′‐methyl group was replaced by a hydrogen atom, were synthesized and evaluated against a panel of human tumor cell lines in vitro. Compounds (R)‐4 and (R)‐5 show greater inhibitory activity toward cell growth than the parent geiparvarin.

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New geiparvarin derivatives modified at the unsaturated alkenyloxy bridge, where a hydrogen atom replaces the 3′‐methyl group, were synthesized and evaluated against a panel of human tumor cell lines in vitro. These compounds demonstrated an increase in growth inhibitory activity relative to the parent compound, geiparvarin. The activity increased even further in the series of demethylated compounds, with the introduction of a methyl group at the 1′‐position of the alkenyloxy chain. In contrast, a remarkable decrease in activity was observed with the introduction of a methyl group at the 2′‐position. Interestingly, the new derivatives fully inhibited the growth of drug‐resistant cell lines, suggesting that they are not subject to pump‐mediated drug efflux. On the basis of their cytotoxic profiles, the most active compounds (R)‐4 and (R)‐5 were selected for further biological evaluation in comparison with the lead compound. The new derivatives strongly induce apoptosis in a promyelocytic leukemia cell line (HL‐60) mediated by depolarization of mitochondrial transmembrane potential and mitochondrial production of reactive oxygen species (ROS).
Analysis of Non‐Covalent Bioconjugation of Colloidal Nanoparticles by Means of Atomic Force Microscopy and Data Clustering
Authors: Irrgang Jessica , Ksienczyk Jacqueline , Lapiene Vidmantas , Niemeyer Christof M.
Published: March 2009

AFM topography data of non‐covalently assembled biomolecule–nanoparticle hybrids is examined by statistical cluster analysis (see figure). As exemplified for fluorescent‐protein‐modified quantum dots and DNA/protein‐conjugated gold nanoparticles, this analytical approach provides insights into the formation of bioconjugate populations.

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Non‐covalent modification of nanoparticles with biomolecules is frequently applied in the generation of hybrid nanomaterials. Herein, we report on the analysis of non‐covalently assembled hybrid nanoparticles on surfaces, using AFM measurements and examination of the resulting topography data by means of statistical cluster analysis. Two different model systems are investigated. On the one hand, we apply the combined AFM–cluster analysis to CdSe/ZnS core/shell quantum dots, bioconjugated with varying amounts of the hexahistidine‐tagged enhanced yellow fluorescent protein (EYFP). On the other hand, gold nanoparticles modified with single‐stranded DNA oligonucleotides were further functionalized by Watson–Crick base pairing, using complementary DNA oligonucleotides or covalent conjugates of DNA and streptavidin or EYFP. The results clearly indicate that cluster analysis of AFM data allows for the identification of sub‐populations in complex reaction mixtures. Therefore, this analytical approach is useful to elucidate bioconjugate species, formed in the course of non‐covalent synthesis of nanoparticle–biomolecule hybrid systems.
Mediation by any other name would smell as sweet—or would it? The struggle to define mediation and its various approaches
Authors: Charkoudian Lorig , Ritis Cristian De , Buck Ramona , Wilson Carrie L.
Published: March 2009

This article reports on two studies. The analysis of the first study, a survey of 250 mediators, finds four distinct groups of mediator “clusters,” based on self‐reported strategies. These four clusters are described in detail and mediators' self‐defined labels are then correlated with the four clusters. There is little consistency between the labels mediators give their approach and the cluster into which they actually fall in this survey. The analysis of the second study, which involved observation and coding of actual mediations, finds that those mediators who were observed to use any directive strategies tended to use mostly directive strategies and those mediators who were observed to use any elicitive strategies tended to use mostly elicitive strategies throughout the observed mediation case. This challenges the notion that mediators may use both directive and elicitive strategies together in the same mediation.
Building trust with parties: Are mediators overdoing it?
Authors: Stimec Arnaud , Poitras Jean
Published: March 2009

Trust is a key factor in the dynamics of any attempt to settle a conflict. A mediator may be the needed link between the parties, as long as they trust their mediator. But how far should mediators go to win parties' trust? On the basis of questionnaires filled out by participants in employer‐employee mediation, we arrive at a conclusion that differs from the prevailing wisdom. There is a threshold point rather than a linear relationship between the level of trust in the mediator and the degree of conflict resolution. Once the threshold has been reached, additional trust does not necessarily result in a higher level of conflict resolution. Possible explanations are set out and practical implications are discussed.
Shadows, conflict, and the mediator
Authors: McGuigan Richard
Published: March 2009

This article discusses a theory of mediator psychological growth specifically focusing on Carl Jung's concept (1954) of the Shadow. The nature and development of the Shadow are outlined, with particular attention to the mechanism of projection, applied to the perspectives of both the individual and the group. The importance of the mediator uncovering and owning his or her Shadow material is underscored, along with some strategies for doing so. This article responds to Bowling and Hoffman's third stage of mediator development (2003), where the mediator is committed to gaining greater awareness of how personal qualities influence the mediation process.
Research note: Two measures of conflict orientation
Authors: Bresnahan Mary Jiang , Donohue William A. , Shearman Sachiyo M. , Guan Xiaowen
Published: March 2009

This study analyzed the construct validity of two new measures: the Attitude Toward Conflict Scale and the Mediation Scale. Although both of these measures are still being developed, results of two studies (with 557 participants) suggest that these instruments are valid and reliable measures that might be of use to alternative dispute resolution administrators, other mediation practitioners, and university personnel who deal with conflict as a screening device to measure attitude toward conflict and the mediation process.
Temporal and spatial expression of FGF ligands and receptors during Xenopus development
Authors: Lea Robert , Papalopulu Nancy , Amaya Enrique , Dorey Karel
Published: March 2009

Fibroblast growth factor (FGF) signalling plays a major role during early vertebrate development. It is involved in the specification of the mesoderm, control of morphogenetic movements, patterning of the anterior‐posterior axis, and neural induction. In mammals, 22 FGF ligands have been identified, which can be grouped into seven subfamilies according to their sequence homology and function. We have cloned 17 fgf genes from Xenopus tropicalis and have analysed their temporal expression by RT‐PCR and spatial expression by whole mount in situ hybridisation at key developmental stages. It reveals the diverse expression pattern of fgf genes during early embryonic development. Furthermore, our analysis shows the transient nature of expression of several fgfs in a number of embryonic tissues. This study constitutes the most comprehensive description of the temporal and spatial expression pattern of fgf ligands and receptors during vertebrate development to date. Developmental Dynamics 238:1467–1479, 2009. © 2009 Wiley‐Liss, Inc.
Flow cytometry methods for the study of cell‐cycle parameters of planarian stem cells
Authors: Kang Hara , Alvarado Alejandro Sánchez
Published: March 2009

Due to their characteristic inaccessibility and low numbers, little is known about the cell‐cycle dynamics of most stem cells in vivo. A powerful, established methodology to study cell‐cycle dynamics is flow cytometry, which is used routinely to study the cell‐cycle dynamics of proliferating cells in vitro. Its use in heterogeneous mixtures of cells obtained from whole animals, however, is complicated by the relatively low abundance of cycling to non‐cycling cells. We report on flow cytometric methods that take advantage of the abundance of proliferating stem cells in the planarian Schmidtea mediterranea. The optimized protocols allow us to measure cell‐cycle dynamics and follow BrdU‐labeled cells specifically in complex mixtures of cells. These methods expand on the growing toolkit being developed to study stem cell biology in planarians, and open the door to detailed cytometric studies of a collectively totipotent population of adult stem cells in vivo. Developmental Dynamics 238:1111–1117, 2009. © 2009 Wiley‐Liss, Inc.
Penta‐, Hexa‐, and Heptanuclear Organotin–Oxygen Arsonate Clusters Constructed from an Acetate Drum Cluster Precursor and Different Arsonate Anions
Authors: Xie Yun‐Peng , Ma Jian‐Fang , Yang Jin , Liu Ying‐Ying , Ma Ji‐Cheng , Su Min‐Zhong
Published: March 2009

Treatment of the acetate drum [nBuSn(O)O2CMe]6 withdifferent arsonic acids gave seven organotin arsonate clusters: [(nBuSn)5(μ3‐O)(OH)(R′O)3(RAsO3)4(RAsO3H)] [R = 2‐NO2C6H4, R′ = Me (1a and 1b)], [(nBuSn)3(RAsO3)(μ3‐O)(CH3CO2)3(R′O)2]2 [R = 2,4‐(NO2)2C6H3, R′ = Me (2)], [(nBuSn)3(RAsO3)2(RAsO3H)(μ3‐O)(R′O)2]2 [R = 4‐NO2C6H4, R′ = Me (3)], and [(nBuSn)3(RAsO3)3(μ3‐O)(OH)(R′O)2]2Sn [R = C6H5CH2, R′ = Me (4); R = C6H5CH2, R′ = H (5); R = C6H5, R′ = H (6)]. The pentanuclear motif of 1a and 1b, which consists of [Sn3(μ3‐O)(μ2‐OR′)2] and [Sn2(OH)(μ2‐OR′)] units, was firstly found in organotin compounds. The structures of 2 and 3 possess similar organotin–oxygen clusters. However, the structure of 2 presents the first example of a hexanuclear organotin–oxygen cluster that contains both carboxylate and arsonate ligands. The heptanuclear structures of 4–6, which are composed of two [Sn3(μ3‐O)(μ2‐OR′)2] units connected through hydroxy and arsonate ligands to a single tin atom, were firstly obtained by displacement reactions. The syntheses, structures, and structural interrelationship of these diverse organotin–oxygen clusters are also discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Experimental and Theoretical Evidence of π‐d Interactions in Supramolecular Assemblies Based on TTF‐CH=CH‐Py Ligands Tethered to Mo6Xi8 Octahedral Molybdenum Halide Cluster Cores
Authors: Prabusankar Ganesan , Molard Yann , Cordier Stéphane , Golhen Stéphane , Le Gal Yann , Perrin Christiane , Ouahab Lahcène , Kahlal Samia , Halet Jean‐François
Published: March 2009

Synthesis, characterization, and physical properties of [Mo6Xi8(TTF‐CH=CH‐Py)a6]4+ supramolecular assemblies [TTF = tetrathiafulvalene; Py = pyridine; X = Cl (1), Br (2),I (3)] resulting from the reaction between [Mo6Xi8(OSO2CF3)6]2– cluster precursor and TTF‐CH=CH‐Py ligands were investigated. They are based on the association of the strongly delocalized metallic electron [Mo6Xi8]4+ cluster cores with six redox‐active π‐conjugated TTF‐CH=CH‐Py terminal ligands attached to the Mo clusters through the pyridinyl group. Synergetic π‐d interactions between the organic ligands and the cluster core were experimentally evidenced by electrochemistry and absorption measurements, and corroborated by DFT calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Insertion Reactions of an Aminogermylene and Formation of a Single‐Source Precursor for GeTe Thin Films
Authors: Chen Tianniu , Hunks William , Chen Philip S. , Stauf Gregory T. , Cameron Thomas M. , Xu Chongying , DiPasquale Antonio G. , Rheingold Arnold L.
Published: March 2009

Insertion reactions between a liquid germylene 1, and either a carbodiimide or dialkyl telluride lead to the formation of the group‐14‐metal(II) guanidinate complex 2 or the stable group‐14‐metal terminal alkyl tellurolate compound 3, respectively. The complexes 2 and 3 were structurally elucidated by multinuclear NMR and single‐crystal X‐ray crystallography. The use of 3 as a single‐source precursor (SSP) for the MOCVD of GeTe films was demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Iodine‐Promoted Efficient Homocoupling of Arylboronic Acids in PEG‐400 under Aerobic Conditions
Authors: Mao Jincheng , Hua Qiongqiong , Xie Guanlei , Yao Zhigang , Shi Daqing
Published: March 2009

Iodine is able to catalyze the homocoupling of arylboronic acids in moderate to good yields in PEG‐400 under aerobic conditions. This transition‐metal‐free catalytic system is readily available at low cost, which is practical and useful. It is noteworthy that a high activity of our catalytic system could be maintained under mild conditions (100 °C) by addition of water.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Straightforward Synthesis of Chiral Hydroxy Isocyanides
Authors: Bauer Michael , Kazmaier Uli
Published: March 2009

Various types of hydroxy isocyanides have been prepared from the corresponding amino alcohols. These hydroxy isocyanides are interesting building blocks for multicomponent reactions and the synthesis of (hydroxyalkyl)oxazoline ligands. The isocyanides are susceptible to cyclization, giving rise to oxazolines. Therefore, they should be prepared freshly before use or be stored below –30 °C.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Electrochemical Sensor for trans‐Resveratrol Determination Based on Indium Tin Oxide Electrode Modified with Molecularly Imprinted Self‐Assembled Films
Authors: Xiang Hai Yan , Li Wei Guo
Published: March 2009

A voltammetric sensor for sensitive and specific determination of trans‐resveratrol (RES) were prepared based on immobilization of an RES‐imprinted film on the surface of functionalized Indium Tin Oxide (ITO) electrode, which was modified with γ‐methacyloxypropyl trimethoxysilane (γ‐MPS). Cyclic Voltammetry (CV) was presented to extract RES from the molecularly imprinted polymer film and RES were extracted rapidly and completely. The binding performance of the imprinted electrode with the template RES were investigated using differential pulse voltammetry (DPV). The results showed that the imprinted ITO film can give selective recognition to the template RES over that of structurally analogous molecules. A linear response to RES in the concentration range of 2.0×10−6 M to 2.0×10−5 M was observed with a correlation coefficient of 0.992, and the detection limit of the electrochemical sensor was 8.0×10−7 M. Whereas, binding to the reference nonimprinted electrode, made in the same way but without the addition of template RES, there was almost no response to RES.
Prediction of erythemally effective UVB radiation by means of nonlinear regression model
Authors: Láska Kamil , Prošek Pavel , Budík Ladislav , Budíková Marie , Milinevsky Gennadi
Published: March 2009

One of the research programs carried out within the Czech‐Ukrainian scientific co‐operation is the monitoring of global solar and ultraviolet radiation at the Vernadsky Station (formerly the British Faraday Station), Antarctica. Radiation measurements have been made since 2002. Recently, a special attention is devoted to the measurements of the erythemally effective UVB radiation using a broadband Robertson Berger 501 UV‐Biometer (Solar Light Co. Inc., USA). This paper brings some results from modelling the daily sums of erythemally effective UVB radiation intensity in relation to the total ozone content (TOC) in atmosphere and surface intensity of the global solar radiation. Differences between the satellite‐ and ground‐based measurements of the TOC at the Vernadsky Station are taken into consideration. The modelled erythemally effective UVB radiation differed slightly depending on the seasons and sources of the TOC. The model relative prediction error for ground‐ and satellite‐based measurements varied between 9.5% and 9.6% in the period of 2002–2003, while it ranged from 7.4% to 8.8% in the period of 2003–2004. Copyright © 2009 John Wiley & Sons, Ltd.
Experimental fire analysis of steel‐to‐timber connections using dowels and nails
Authors: Frangi Andrea , Erchinger Carsten , Fontana Mario
Published: March 2009

The paper describes and discusses the results of an extensive testing programme on the structural behaviour of timber connections under ISO‐fire. The results of reference tests performed at normal temperature are also presented. From the variety of timber connections multiple shear steel‐to‐timber connections with dowels and slotted‐in steel plates and connections with steel side plates and annular ringed shank nails were experimentally studied. Particular attention was given to the analysis of the efficiency of different strategies in order to increase the fire resistance of the timber connections. The test results showed that unprotected multiple shear steel‐to‐timber connections with dowels designed for normal temperature reached a fire resistance of about 30 min. A reduction of the load level applied during the fire did not lead to a significant increase of the fire resistance. By increasing the side timber members as well as the end distance of the dowels by 40 mm the connections reached a fire resistance of more than 70 min. Connections protected by timber boards or gypsum plasterboards showed a fire resistance of around 60 min. Thus, from a fire design point of view these strategies were favourable in order to increase the fire resistance of the connections significantly. Unprotected connections with steel side plates and annular ringed shank nails failed already after about 12 min due to large deformations of the nails and the steel side plates directly exposed to fire. By protecting the steel side plates using an intumescent paint the fire resistance of the connections was increased to around 30 min. The test results enlarged the experimental background of timber connections in fire significantly. Copyright © 2009 John Wiley & Sons, Ltd.
Direct numerical simulation of low Reynolds number flows in an open‐channel with sidewalls
Authors: Joung Younghoon , Choi Sung‐Uk
Published: March 2009

A direct numerical simulation of low Reynolds number turbulent flows in an open‐channel with sidewalls is presented. Mean flow and turbulence structures are described and compared with both simulated and measured data available from the literature. The simulation results show that secondary flows are generated near the walls and free surface. In particular, at the upper corner of the channel, a small vortex called inner secondary flows is simulated. The results show that the inner secondary flows, counter‐rotating to outer secondary flows away from the sidewall, increase the shear velocity near the free surface. The secondary flows observed in turbulent open‐channel flows are related to the production of Reynolds shear stress. A quadrant analysis shows that sweeps and ejections are dominant in the regions where secondary flows rush in toward the wall and eject from the wall, respectively. A conditional quadrant analysis also reveals that the production of Reynolds shear stress and the secondary flow patterns are determined by the directional tendency of the dominant coherent structures. Copyright © 2009 John Wiley & Sons, Ltd.
Quadratic stochastic estimation of far‐field acoustic pressure with coherent structure events in a 2D compressible plane mixing layer
Authors: Druault Ph. , Yu M. , Sagaut P.
Published: March 2009

Mathematical tools based on cross correlations between aerodynamic quantities of interest inside the shear flow region and the radiated sound pressure are used to investigate noise generation mechanisms in a plane compressible mixing layer. An original methodology relying on an efficient coupling between proper orthogonal decomposition (POD) and stochastic estimation procedures is developed to analyze the main aerodynamic mechanisms that govern noise production. POD is used to split the instantaneous flow fluctuations as the sum of three components: the large‐ and small‐scale coherent structures (LCS and SCS) and the background quasi‐Gaussian fluctuations. Based on this flow partitioning, quadratic stochastic estimation is implemented to estimate the far‐field acoustic pressure associated with each flow component. The far field acoustic pressure associated with both LCS and SCS is then investigated. By analyzing the RMS and temporal spectra of the far‐field acoustic pressure, it is observed that the SCSs, as defined thanks to the POD basis, are responsible for the main part of the noise emission. Copyright © 2009 John Wiley & Sons, Ltd.
New Stilbene, Benzofuran, and Coumarin Glycosides from Morus alba
Authors: Piao Shu‐Juan , Qiu Feng , Chen Li‐Xia , Pan Ya , Dou De‐Qiang
Published: March 2009

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Five new compounds, including three new stilbene‐derived glycosides, one novel arylbenzofuran derivative, and one new coumarin glycoside, along with ten known compounds were isolated from the H2O extract of the bark of Morus alba L. The new compounds were assigned to the structures of 4′‐O‐β‐D‐glucopyranosyl‐2′‐hydroxyresveratrol 3‐(6‐O‐β‐D‐apiofuranosyl‐β‐D‐glucopyranoside) (1), 4′‐O‐β‐D‐glucopyranosyl‐2′‐hydroxyresveratrol 3‐(6‐O‐β‐D‐glucopyranosyl‐β‐D‐glucopyranoside) (2), 3‐O‐β‐D‐glucopyranosyl‐2′‐hydroxyresveratrol 4′‐(6‐O‐β‐D‐glucopyranosyl‐β‐D‐glucopyranoside) (3), moracin M 6‐(β‐D‐glucopyranoside) (4), and 5,7‐dihydroxycoumarin 7‐(6‐O‐β‐D‐apiofuranosyl‐β‐D‐glucopyranoside) (5) by spectroscopic means, and acid and enzymatic hydrolyses. Three compounds, 2′‐hydroxyresveratrol 2′‐(β‐D‐glucopyranoside) (7), moracin M 3′‐(β‐D‐glucopyranoside) (8), and 6,7‐dihydroxycoumarin 7‐(6‐O‐α‐rhamnopyranosyl‐β‐D‐glucopyranoside) (9), were found for the first time in Morus alba.
New Eremophilane Sesquiterpenes from the Roots of Ligularia fischeri
Authors: Deng Meicai , Dong Weiwei , Jiao Wei , Lu Runhua
Published: March 2009

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New eremophilane sesquiterpenes, (3β,6β,8α,10β)‐3‐acetyl‐6,8,10‐trihydroxyeremophil‐7(11)‐eno‐12,8‐lactone (1), (3β,6β,8β,10β)‐3‐acetyl‐8,10‐dihydroxy‐6‐(2‐methyl‐1‐oxobutoxy) eremophil‐7(11)‐eno‐12,8‐lactone (2), (3β,6β,10β)‐ and (3β,6β,10α)‐3‐acetyl‐6,10‐dihydroxyeremophila‐7(11),8‐dieno‐12,8‐lactone (3 and 4, resp.), and a dinoreremophilane derivative, (3aR,4R,5S,7aS)‐2‐acetyl‐3a,4,5,6,7,7a‐hexahydro‐7a‐hydroxy‐1H‐inden‐5‐yl acetate (5), were isolated from the roots of Ligularia fischeri. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR spectra, and the structure of 1 was further confirmed by a single‐crystal X‐ray diffraction experiment. Among the isolated compounds, lactone 1 exhibited inhibitory activity towards PTP1B with an IC50 value of 1.34 μM in vivo. The other compounds were inactive.
[2+2] Cycloadditions of Electron‐Poor Acetylenes to (5Z)‐5‐[(Dimethylamino)methylene]imidazolidine‐2,4‐diones
Authors: Uršič Uroš , Grošelj Uroš , Meden Anton , Svete Jurij , Stanovnik Branko
Published: March 2009

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Microwave‐assisted [2+2] cycloadditions of acetylene mono‐ and acetylenedicarboxylates 2 to (5Z)‐5‐[(dimethylamino)methylene]imidazolidine‐2,4‐dione 4a or to the corresponding thioxo derivative 4b in MeCN furnished the highly functionalized imidazolidine‐2,4‐dione derivatives 5 and 6 or the corresponding thioxo derivatives 5–7 as single isomers or mixtures of two isomers (Schemes 2 and 3, Table 1). When the reaction of (5Z)‐5‐[(dimethylamino)methylene]imidazolidine‐2,4‐dione (4c) with acetylenedicarboxylate 2a was performed in DMF, hydrolysis of the (dimethylamino)methylene group took place to give (2E)‐2‐(2,5‐dioxoimidazolidin‐4‐ylidene)butanedioate 11 (Scheme 5).
Acylated Stilbene Glucosides and Further Constituents from Acanthopanax brachypus
Authors: Hu Hao‐Bin , Zheng Xu‐Dong , Hu Huai‐Sheng , Li Yan
Published: March 2009

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Two new acylated stilbene glucosides, (E)‐3‐O‐methylresveratrol 5‐O‐β‐D‐apiofuranosyl‐(1→6)‐β‐D‐(2″‐vanilloyl)glucopyranoside (1) and (E)‐3‐O‐methylresveratrol 5‐O‐α‐L‐rhamnopyranosyl‐(1→6)‐β‐D‐2″‐[(E)‐feruloyl]glucopyranoside (2), together with five known compounds 2‐methoxyphenyl β‐D‐glucopyranoside, (−)‐syringaresinol‐4,4′‐bis‐O‐β‐D‐glucopyranoside, acantrifoside A, β‐sitosterol, and daucosterol, were isolated from the EtOH extract of Acanthopanax brachypus. Their structures were characterized by means of spectroscopic methods, especially by 1H‐, 13C‐, 2D‐NMR, and HR‐MS, as well as by chemical methods and comparison with literature data.
Cathepsin B Inhibitory Tetraene Lactones from the Fungus Talaromyces wortmannii
Authors: Dong Yuesheng , Lin Jie , Lu Xinhua , Zheng Zhihui , Ren Xiao , Zhang Hua , He Jiangong , Yang Junshan
Published: March 2009

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Wortmannilactones E–H (1–4), four new cathepsin B inhibitors, were produced and isolated from the culture of the soil filamentous fungus Talaromyces wortmannii. Their structures and relative configurations were elucidated on the basis of 1D‐ and 2D‐NMR techniques, three of them (1, 2, and 4) posses an oxabicyclo[2.2.1]heptane moiety. Compounds 1–4 showed inhibitory activities against cathepsin B with IC50 values of 4.3, 6.5, 13.0, and 6.0 μM, respectively.
Access to elective surgery in New Zealand: considering equity and the private and public mix
Authors: Derrett Sarah , Bevin Tui H. , Herbison Peter , Paul Charlotte
Published: March 2009

New Zealand has a two‐tier health system with elective surgery provided by both publicly funded state hospitals and by private hospitals. Issues of equity should be considered across such systems—where the better off can access surgery in private hospitals regardless of relative clinical need. This study evaluated equity of provision of surgery after the introduction of a prioritization system to manage access. Data for people receiving publicly funded elective joint replacement, prostatectomy or cataract surgery between 2000 and 2005 were obtained, as well as most recent data for people receiving privately funded surgery (2001 and 2002). Denominators were derived from the 2001 census for the population of District Health Board regions. NZDep2001, a small‐area deprivation index, was used to identify people in poorest deciles. Despite the introduction of a prioritization system aimed at increased equity and fairness, the provision of elective surgery remains inequitable geographically. High private provision was not associated with better access to publicly funded surgery. Moreover, the argument that private provision for the well off reduces the burden on the public system allowing better access for the poor was not supported. Consequences of two‐tier health systems, as in New Zealand, need more investigation and public discussion. Copyright © 2009 John Wiley & Sons, Ltd.
Fear, worry, and ritualistic behaviour in childhood: developmental trends and interrelations
Authors: Laing Sarah V. , Fernyhough Charles , Turner Michelle , Freeston Mark H.
Published: March 2009

Previous studies of childhood fear, worry, and ritualistic behaviour have been limited by restricted age ranges, narrow ranges of anxiety phenomena, non‐comparable methodologies, and assessment of typical behaviour within a pathological context. Content and intensity of fear, worry, and ritualistic behaviour, and associations among these variables, were assessed through a semi‐structured interview individually administered to 142 children aged 7–16 years. Common themes in the content of fear, worry, and ritualistic behaviour varied predictably with age. Intensity ratings for all three phenomena decreased with age, although this decline was only significant between 7 and 10 years. Levels were higher in girls than boys. Fear and worry were positively related, and the regular performance of rituals was related to anxiety across the age range. Worry was more strongly related than fear to engagement in ritualistic behaviour. We consider implications for the understanding of anxiety and ritualistic behaviour in typical and atypical development. Copyright © 2009 John Wiley & Sons, Ltd.
XRCC1 gene polymorphisms and esophageal squamous cell carcinoma risk in Chinese population: A meta‐analysis of case–control studies
Authors: Dai Liping , Wang Kaijuan , Zhang Jianying , Lv Quanjun , Wu Xiaobing , Wang Yanping
Published: March 2009

Two non‐synonymous polymorphisms Arg194Trp and Arg399Gln in the DNA‐base excision repair gene X‐ray repair cross‐complementing group 1 (XRCC1) have been implicated in risk for esophageal cancer. However, the results from different studies remain controversial. The present meta‐analysis of literatures was performed to clarify these associations in Chinese population. A comprehensive literature search was conducted to identify all case–control studies ofXRCC1polymorphisms Arg194Trp and Arg399Gln and risk for esophageal squamous cell carcinoma (ESCC). A total of 9 eligible studies, including 1,538 ESCC cases and 2,472 controls, were identified to the meta‐analysis. The odds ratio (OR) for the variant homozygous genotype Trp/Trp of the Arg194Trp polymorphism, compared with the wild‐type homozygote Arg/Arg, was 1.59 (p= 0.0007), with 95% confidence interval (95% CI) 1.22–2.09, for ESCC risk without between‐study heterogeneity. However, there was no statistically significant associations of ESCC risk in the dominant model Arg/Trp+Trp/Trp (OR 0.97; 95% CI 0.84–1.12;p= 0.69) and heterozygous genotype Arg/Trp (OR 0.90; 95% CI 0.77–1.04;p= 0.16) when comparing with wild‐type genotype Arg/Arg. For Arg399Gln, there was no effect in dominant modeling (Arg/Gln+Gln/Glnvs.Arg/Arg: OR 0.92; 95% CI 0.80–1.06;p= 0.25), and the variant Gln/Gln homozygote was not associated with ESCC risk (OR 1.29; 95% CI 0.79–2.10;p= 0.31), either. In conclusion, Arg194Trp genetic polymorphism may be associated with an increased risk for developing ESCC and a study with the larger sample size is needed to further evaluate gene–environment interaction onXRCC1polymorphisms and ESCC risk. © 2009 UICC