bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical and optical studies of furan and thieno[3,2‐b]thiophene end capped benzotriazole derivatives
Authors: Akbaşoğlu Naime , Balan Abidin , Baran Derya , Cirpan Ali , Toppare Levent 
Published: October 2010

AbstractTwo new 2‐dodecyl benzotriazole (BTz) based donor‐acceptor‐donor (DAD) type polymers were synthesized and characterized in terms of their electrochemical and spectral properties. These DAD type polymers were synthesized electrochemically from furan or thieno[3,2‐b]thiophene (TT) end‐capped BTz monomers. Furan based and thieno[3,2‐b]thiophene based monomers showed monomer oxidations at 1.15 and 1.25 V, respectively, which eased the formation of conducting polymer films without overoxidation. Cyclic voltammetry and spectroelectrochemistry studies showed that both materials are multicolored electrochromic polymers. Results and comparison with properties of other BTz based DAD type polymers are highlighted in detail. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Recognition of Smac‐mimetic compounds by the BIR domain of cIAP1
Authors: Cossu Federica , Malvezzi Francesca , Canevari Giulia , Mastrangelo Eloise , Lecis Daniele , Delia Domenico , Seneci Pierfausto , Scolastico Carlo , Bolognesi Martino , Milani Mario 
Published: October 2010

AbstractInhibitor of apoptosis proteins (IAPs) are negative regulators of apoptosis. As IAPs are overexpressed in many tumors, where they confer chemoresistance, small molecules inactivating IAPs have been proposed as anticancer agents. Accordingly, a number of IAP‐binding pro‐apoptotic compounds that mimic the sequence corresponding to the N‐terminal tetrapeptide of Smac/DIABLO, the natural endogenous IAPs inhibitor, have been developed. Here, we report the crystal structures of the BIR3 domain of cIAP1 in complex with Smac037, a Smac‐mimetic known to bind potently to the XIAP‐BIR3 domain and to induce degradation of cIAP1, and in complex with the novel Smac‐mimetic compound Smac066. Thermal stability and fluorescence polarization assays show the stabilizing effect and the high affinity of both Smac037 and Smac066 for cIAP1‐ and cIAP2‐BIR3 domains.
Enzyme–ligand interactions that drive active site rearrangements in the Helicobacter pylori 5′‐methylthioadenosine/S‐adenosylhomocysteine nucleosidase
Authors: Ronning Donald R. , Iacopelli Natalie M. , Mishra Vidhi 
Published: October 2010

AbstractThe bacterial enzyme 5′‐methylthioadenosine/S‐adenosylhomocysteine nucleosidase (MTAN) plays a central role in three essential metabolic pathways in bacteria: methionine salvage, purine salvage, and polyamine biosynthesis. Recently, its role in the pathway that leads to the production of autoinducer II, an important component in quorum‐sensing, has garnered much interest. Because of this variety of roles, MTAN is an attractive target for developing new classes of inhibitors that influence bacterial virulence and biofilm formation. To gain insight toward the development of new classes of MTAN inhibitors, the interactions between the Helicobacter pylori‐encoded MTAN and its substrates and substrate analogs were probed using X‐ray crystallography. The structures of MTAN, an MTAN‐Formycin A complex, and an adenine bound form were solved by molecular replacement and refined to 1.7, 1.8, and 1.6 Å, respectively. The ribose‐binding site in the MTAN and MTAN‐adenine cocrystal structures contain a tris[hydroxymethyl]aminomethane molecule that stabilizes the closed form of the enzyme and displaces a nucleophilic water molecule necessary for catalysis. This research gives insight to the interactions between MTAN and bound ligands that promote closing of the enzyme active site and highlights the potential for designing new classes of MTAN inhibitors using a link/grow or ligand assembly development strategy based on the described H. pylori MTAN crystal structures.
Homology modeling and deletion mutants of human nicotinamide mononucleotide adenylyltransferase isozyme 2: New insights on structure and function relationship
Authors: Brunetti Lucia , Di Stefano Michele , Ruggieri Silverio , Cimadamore Flavio , Magni Giulio 
Published: October 2010

AbstractNicotinamide mononucleotide adenylyltransferase (NMNAT) catalyzes the formation of NAD by means of nucleophilic attack by 5′‐phosphoryl of NMN on the α‐phosphoryl group of ATP. Humans possess three NMNAT isozymes (NMNAT1, NMNAT2, and NMNAT3) that differ in size and sequence, gene expression pattern, subcellular localization, oligomeric state and catalytic properties. Of these, NMNAT2, the least abundant isozyme, is the only one whose much‐needed crystal structure has not been solved as yet. To fill this gap, we used the crystal structures of human NMNAT1 and NMNAT3 as templates for homology‐based structural modeling of NMNAT2, and the resulting raw structure was then refined by molecular dynamics simulations in a water box to obtain a model of the final folded structure. We investigated the importance of NMNAT2's central domain, which we postulated to be dispensable for catalytic activity, instead representing an isozyme‐specific control domain within the overall architecture of NMNAT2. Indeed, we experimentally confirmed that removal of different‐length fragments from this central domain did not compromise the enzyme's catalytic activity or the overall tridimensional structure of the active site.
Protein folding pathways and state transitions described by classical equations of motion of an elastic network model
Authors: Williams Gareth , Toon Andrew J. 
Published: October 2010

AbstractProtein topology defined by the matrix of residue contacts has proved to be a fruitful basis for the study of protein dynamics. The widely implemented coarse‐grained elastic network model of backbone fluctuations has been used to describe crystallographic temperature factors, allosteric couplings, and some aspects of the folding pathway. In the present study, we develop a model of protein dynamics based on the classical equations of motion of a damped network model (DNM) that describes the folding path from a completely unfolded state to the native conformation through a single‐well potential derived purely from the native conformation. The kinetic energy gained through the collapse of the protein chain is dissipated through a friction term in the equations of motion that models the water bath. This approach is completely general and sufficiently fast that it can be applied to large proteins. Folding pathways for various proteins of different classes are described and shown to correlate with experimental observations and molecular dynamics and Monte Carlo simulations. Allosteric transitions between alternative protein structures are also modeled within the DNM through an asymmetric double‐well potential.
Exploring the trigger sequence of the GCN4 coiled‐coil: Biased molecular dynamics resolves apparent inconsistencies in NMR measurements
Authors: Missimer John H. , Dolenc Jožica , Steinmetz Michel O. , van Gunsteren Wilfred F. 
Published: October 2010

AbstractTrigger sequences are indispensable elements for coiled‐coil formation. The monomeric helical trigger sequence of the yeast transcriptional activator GCN4 has been investigated recently using several solution NMR observables including nuclear Overhauser enhancement (NOE) intensities and 3J(HN,HCα)‐coupling constants, and a set of 20 model structures was proposed. Constrained to satisfy the NOE‐derived distance bounds, the NMR model structures do not appear to reproduce all the measured 3J(HN‐HCα)‐coupling constant values, indicating that the α‐helical propensity is not uniform along the GCN4 trigger sequence. A recent methodological study of unrestrained and restrained molecular dynamics (MD) simulations of the GCN4 trigger sequence in solution showed that only MD simulations incorporating time‐averaged NOE distance restraints and instantaneous or local‐elevation 3J‐coupling restraints could satisfy the entire set of the experimental data. In this report, we assess by means of cluster analyses the model structures characteristic of the two simulations that are compatible with the measured data and compare them with the proposed 20 NMR model structures. Striking characteristics of the MD model structures are the variability of the simulated configurations and the indication of entropic stability mediated by the aromatic N‐terminal residues 17Tyr and 18His, which are absent in the set of NMR model structures.
Critical analysis of simultaneous blockage of histone deacetylase and multiple receptor tyrosine kinase in the treatment of prostate cancer
Authors: Wedel Steffen , Hudak Lukasz , Seibel Jens‐Michael , Juengel Eva , Oppermann Elsie , Haferkamp Axel , Blaheta Roman A. 
Published: October 2010

AbstractBACKGROUNDThe concept of molecular tumor targeting might be an innovative option to treat advanced prostate cancer. We analyzed the effect of combining the multiple receptor tyrosine kinase inhibitor AEE788 and the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on adhesion and growth properties of prostate cancer cell lines.METHODSPC‐3, DU‐145, and LNCaP cells were treated with AEE788, VPA or with an AEE788–VPA combination, and cell cycle progression investigated. Furthermore, tumor cell adhesion to vascular endothelium or to immobilized extracellular matrix proteins was evaluated, and integrin α and β subtypes were analyzed. Finally, effects of drug treatment on cell signaling pathways were determined.RESULTSAEE788 moderately and VPA strongly reduced tumor cell adhesion and growth. VPA impaired cell cycle progression and altered the expression level of the cell cycle regulating proteins cdk1, cdk2, cdk4, cyclin B, D1, cyclin E, p21, and p27. VPA also acted on the membranous, cytoplasmic, and gene expression pattern of various integrin α and β subtypes. AEE788 acted likewise, but more moderately. Combining AEE788 and VPA did not result in an additive anti‐tumor effect. Signaling analysis revealed that the EGFr downstream target Akt was similarly modified in the presence of VPA or the VPA–AEE788 combination, but not influenced by AEE788 alone.CONCLUSIONSThe AEE788–VPA combination has no advantage over VPA monotreatment in vitro. The non‐responsiveness of Akt towards AEE788 might be one reason for this phenomenon. Prostate 71:722–735, 2011. © 2010 Wiley‐Liss, Inc.
Exposure risk assessment and evaluation of the best management practice for controlling pesticide runoff from paddy fields. Part 2: Model simulation for the herbicide pretilachlor
Authors: Phong Thai Khanh , Vu Son Hong , Ishihara Satoru , Hiramatsu Kazuaki , Watanabe Hirozumi 
Published: October 2010

AbstractBACKGROUND: Monitoring studies revealed high concentrations of pesticides in the drainage canal of paddy fields. It is important to have a way to predict these concentrations in different management scenarios as an assessment tool. A simulation model for predicting the pesticide concentration in a paddy block (PCPF‐B) was evaluated and then used to assess the effect of water management practices for controlling pesticide runoff from paddy fields.RESULTS: The PCPF‐B model achieved an acceptable performance. The model was applied to a constrained probabilistic approach using the Monte Carlo technique to evaluate the best management practices for reducing runoff of pretilachlor into the canal. The probabilistic model predictions using actual data of pesticide use and hydrological data in the canal showed that the water holding period (WHP) and the excess water storage depth (EWSD) effectively reduced the loss and concentration of pretilachlor from paddy fields to the drainage canal. The WHP also reduced the timespan of pesticide exposure in the drainage canal.CONCLUSIONS: It is recommended that: (1) the WHP be applied for as long as possible, but for at least 7 days, depending on the pesticide and field conditions; (2) an EWSD greater than 2 cm be maintained to store substantial rainfall in order to prevent paddy runoff, especially during the WHP. Copyright © 2010 Society of Chemical Industry
Responses of Rhynchophorus ferrugineus adults to selected synthetic palm esters: electroantennographic studies and trap catches in an urban environment
Authors: Guarino Salvatore , Bue Paolo Lo , Peri Ezio , Colazza Stefano 
Published: October 2010

AbstractBACKGROUND: The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, accidentally introduced into the European countries facing the Mediterranean basin, is becoming the most serious pest for ornamental palms in the urban environment. In the present work, tests were conducted on the electroantennogram (EAG) and behavioural responses of RPW adults to five selected synthetic palm esters, ethyl propionate, ethyl butyrate, ethyl isobutyrate, ethyl lactate and ethyl acetate, to assess the application of a mass trapping technique in an urban environment.RESULTS: In the laboratory, EAG bioassays on RPW adults with the synthetic palm esters showed: (1) positive dose‐dependent responses; (2) differences among the treatments; (3) a greater response to ethyl propionate; (4) a higher sensitivity of female antennae compared with male antennae. In the urban environment, RPW behavioural responses, evaluated over six biweekly observations on pheromone‐ and molasses‐ baited traps, showed that more adults were caught by traps supplemented with ethyl propionate and ethyl acetate than by traps supplemented with only ethyl propionate. Similar catches were recorded in the traps supplemented with ethyl propionate or ethyl acetate.CONCLUSION: This study supports the application of the mass trapping implemented with synthetic palm esters as a potential tool for the management of RPW populations to protect ornamental palms in urban environments. Copyright © 2010 Society of Chemical Industry
Transition towards homeownership among foreign‐born immigrants in Spain from a life‐course approach
Authors: Vono‐de‐Vilhena Daniela , Bayona‐Carrasco Jordi 
Published: October 2010

AbstractThe objective of this paper is to analyse immigrants' transition to homeownership in Spain from a life‐course approach, utilising homeownership as an indicator of the integration process. We use data from the National Immigrant Survey that allows for a longitudinal analysis of this transition in Spain. Results have shown strong differences in homeownership depending on immigrant's country of birth. The length of stay in Spain, marriage and transnational ties with the country of origin were also demonstrated to be relevant factors in the analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Why return migrants return: survey evidence on motives for internal return migration in Sweden
Authors: Niedomysl Thomas , Amcoff Jan 
Published: October 2010

AbstractInternal return migration has received limited attention in most western countries, despite studies attesting to its potential for helping understand population redistribution. This paper compares differences in self‐reported motives for migration between return and non‐return migrants. Particular attention is paid to differences in individual characteristics and in the types of places these two migrant groups seek. The large‐scale Swedish survey data employed in this study make it the most exhaustive on the subject to date, enabling the exploration of different perspectives on migrant motivations. The results indicate significant differences in motivation between return and non‐return migrants, even after controlling for differences in individual characteristics and migration patterns. In particular, return migrants are much more likely to move for social reasons and much less likely to move for educational reasons. The evidence is less clear‐cut regarding the other motives investigated in this study: although there are indications that employment factors may facilitate return migration, return migration is largely driven by social considerations. Copyright © 2010 John Wiley & Sons, Ltd.
Novel etch process to tune crater size on magnetron sputtered ZnO:Al
Authors: Owen Jorj I. , Hüpkes Jürgen , Zhu Hongbing , Bunte Eerke , Pust Sascha E. 
Published: October 2010

AbstractMagnetron sputtered aluminum‐doped zinc oxide (ZnO:Al) is used as a window layer in silicon‐based thin‐film solar cells due to its high transparency, high conductivity, and ability to provide effective light trapping after etching in a dilute HCl solution. A challenge with this method is the strong influence of sputtering conditions on the density and shape of the ZnO:Al etch features. Here we present a novel chemical etch process based on HF that enables the modification of surface features through the etch process itself, thus allowing the separate optimization of ZnO:Al deposition and texturization. The different etch characteristics of HCl and HF are studied on single crystal ZnO. Using the different etch characteristics of HF we effectively texturize polycrystalline ZnO:Al films which previously exhibited only poor light trapping in silicon thin‐film solar cells. The light trapping improvement is seen by an 18% increase in short circuit current density when used in microcrystalline silicon solar cells. Additionally, using mixtures of HCl and HF we are able to tune the feature size and shape on a given ZnO:Al sample.magnified image
Scanning electron microscope images of high‐rate deposited ZnO:Al etched in HCl and HF.
Fullerene sensitized silicon for near‐ to mid‐infrared light detection
Authors: Matt G. J. , Fromherz T. , Bednorz M. , Neugebauer H. , Sariciftci N. S. , Bauer G. 
Published: October 2010

AbstractHere, we report on a novel light sensing scheme based on a silicon/fullerene‐derivative (methano‐fullerene [6,6] phenyl‐C61 butyric acid methyl ester – PCBM) heterojunction that allows the realization of optoelectronic devices for the detection of near‐ to mid‐IR light. Despite the absent absorption of silicon and the fullerene‐derivative in the IR a heterojunction of these materials absorbes and generates a photocurrentin the spectral range from 1.1 to 0.55 eV. Besides its scientific relevance, the simple fabrication process of the heterojunction (e.g., the fullerene‐derivative is deposited by spin coating on Si) as well as its compatibility with the established complementary metaloxide semiconductor (CMOS) technology makes the presented hybrid approach a promising candidate for widespread applications.
On the choice of the test structure for the electrical characterization of dielectrics for silicon solar cells
Authors: Loozen X. , O'Sullivan B. J. , Rothschild A. , Vermang B. , John J. , Gordon I. 
Published: October 2010

AbstractSurface passivation of Si solar cells is typically achieved by deposition of a dielectric layer. Via the investigation of Al2O3 passivation layers, we show that care must be taken when performing capacitance–voltage (C –V) measurements in order to obtain results that are meaningful at solar cell level. The passivation properties of a dielectric are not only affected by post‐deposition treatments but also by the presence and the nature of a metal covering the dielectric. Consequently, this Letter emphasizes how important it is to perform C –V measurements on a device structure that resembles as closely as possible that of the finished solar cell, using the same metal, deposition technique and thermal budget. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetism and electronic correlations in the iron aluminides R Fe2Al10 (R = Y, Yb)
Authors: Strydom A. M. , Peratheepan P. 
Published: October 2010

AbstractYFe2Al10 and YbFe2Al10 are new additions to the currently investigated rare‐earth (R) series of compounds RT2Al10 in which T is Fe, Ru, or Os. Unusual physical properties are drawing considerable attention to this group of compounds. Intriguingly, very small moments order in CeRu2Al10 at as high as 27 K, whereas CeFe2Al10 is a Kondo insulator with very strong hybridization of the Ce magnetic moments and no magnetic ordering at all. Here we present the first results of two further iron‐based compounds YFe2Al10 and YbFe2Al10 as a timely contribution to the knowledge of the physics at work in this system. In YFe2Al10 we find signatures of correlated electrons and the low‐temperature results of specific heat, magnetic susceptibility and electrical resistivity are indicative of ferromagnetic quantum criticality. In YbFe2Al10 localized f‐electron spins of Yb become involved in correlations with a moderately enhanced electronic specific heat that classifies it as a non‐ordered heavy‐fermion compound. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Life cycle inventory of HDPE bottle‐based liquid milk packaging systems
Authors: Singh Jay , Krasowski Aric , Singh S. Paul 
Published: October 2010

AbstractThis study aims at providing a relatively straightforward methodology to serve as a decision‐making tool when more than one packaging solution could be available to a user. It involves a life cycle inventory (LCI) analysis and comparison of three currently available 3.79 l (1 gallon) packaging systems for liquid milk. Two of the primary container types studied use reusable plastic crates (RPCs) for stacking and shipping, while the third type is a heavier duty container that does not require secondary shipping containers. The three primary containers studied are identified as original, cube and stackable throughout this paper. The study shows that the use of RPCs for controlled environment distribution reduces the material requirements of the primary containers and therefore reduces the overall CO2 emissions. It was also found that though the transportation‐related emissions varied between the packaging systems for the two end‐of‐life scenarios considered, it had the lowest overall effect on the CO2 emissions and use of energy. The study concludes that transportation weight limits must be considered as a limiting factor in package design for liquid products, as trailers ‘weigh out’ before they ‘cube out.’ As related to the LCI impacts, this study found that the original and cube container‐based packaging systems have better overall per functional unit performance in comparison with the stackable design. It was also noted that scorecards based on the Wal‐Mart format do not accurately define the environmental impacts posed by packaging systems. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of composition on structure and barrier properties of active PET films for food packaging applications
Authors: Galdi Maria Rosaria , Incarnato Loredana 
Published: October 2010

AbstractA very attractive solution in food packaging technology is the functionalization of packaging materials by incorporating an active phase into polymeric matrices. Nowadays, the applications of active substances into flexible packaging are very limited due to difficulties in realizing performing films by common manufactory processes.This work is focused on the production and characterization of monolayer poly(ethylene terephtalate) (PET) active films at different concentrations of an oxygen scavenger by cast extrusion process.Rheological, thermal, morphological analyses and oxygen absorption measurements were carried out on the produced samples to investigate the structure of active PET films and to determine their scavenging properties.Overall migration analyses were performed on active films to asses their safety in use with foodstuff, and finally the produced films were used to package fresh banana slices for evaluating their capability in quality foods preservation. Copyright © 2010 John Wiley & Sons, Ltd.