bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of pentablock and multibranched copolymers bearing poly(ethylene glycol), hyperbranched polyglycidol, and poly(L‐lactide) with biocompatibility for controlled drug release
Authors: Wang Jing , Kim Min Hee , Kang Dong Eun , Suh Hongsuk , Kim Il 
Published: April 2012

AbstractA series of multibranched pentablock copolymer (mBr5BlC), poly(L‐lactide)‐b‐HBP‐b‐poly(ethylene glycol)‐b‐HBP‐b‐poly(L‐lactide) (HBP = hyperbranched polyglycidol), has been synthesized by ring‐opening multibranching polymerization of glycidol using bifunctional poly(ethylene glycol) [PEG; molecular weight (MW) = 1000] as an initiator, followed by ring‐opening polymerization (ROP) of L‐lactide in the presence of stannous octoate. The ROP of different amounts of L‐lactide on HBP‐b‐PEG‐b‐HBP [MW = 2550; polydispersity index (PDI) = 1.08] yielded a series of the targeted mBr5BlCs of the MW range of 4360–15,300 with narrow PDI. All the mBr5BlCs have been well demonstrated to be in possession of good biocompatibility as biomaterials for various applications in biological medicine areas. The mBr5BlCs with tunable MW exhibited promising controllability in self‐assembly into spherical micellar structures with an average diameter range of 59–140 nm, which have no acute and intrinsic cytotoxicity against normal cells and provide a convenient strategy for drug loading. The anticancer drug doxorubicin was demonstrated to have a good affinity with the copolymer system, and its controlled release was performed in various pHs. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Electro‐osmotic flow in nanochannels with voltage‐controlled polyelectrolyte brushes: Dependence on grafting density and normal electric field
Authors: Cao Qianqian , Zuo Chuncheng , Li Lujuan , Zhang Yinhe , Yan Guang 
Published: April 2012

AbstractMolecular dynamics simulations were performed for electro‐osmotic flow (EOF) confined in a polyelectrolyte‐grafted nanochannel under variable grafting density and normal electric field. With decreasing the value of the normal electric field, the brush undergoes a collapse transition, and the ion distribution is changed significantly. The brush thickness increases on increasing the grafting density at positive and weak negative electric fields, whereas a reduced brush thickness is observed at strong negative electric field. Our results further reveal that the flow velocity is not only dependent on conformational transition of the brush but also related to the cation and anion distributions. At low grafting density, the EOF is almost completely quenched at high electric field strength due to strong surface friction between ions and walls. For the case of very dense grafting, the flow velocity is influenced weakly within the brush when varying the grafting density. Additionally, a bidirectional flow occurs at an intermediate electric field. The investigation on fluid flux indicates that the fluid flux is insensitive to the grafting density, when the normal electric field is removed. For nonzero normal electric fields, a significant change in the fluid flux is observed at low grafting densities. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Specific Heat Capacity, Thermal Behavior, and Thermal Hazard of 2,4‐Dinitroanisole
Authors: Xing Xiaoling , Zhao Fengqi , Ma Shunnian , Xu Kangzhen , Xiao Libai , Gao Hongxu , An Ting , Hu Rongzu 
Published: April 2012

AbstractThe thermal hazard of 2,4‐dinitroanisole (2,4‐DNAN) was evaluated by microcalorimetry methods. The specific heat capacity, melting enthalpy, and the solidification heat of 2,4‐DNAN were determined with a Micro‐DSCIII calorimeter. The thermal decomposition behavior of 2,4‐DNAN at four different heating rates was studied by using a C‐500 type calvet microcalorimeter. The kinetic and thermodynamic parameters were obtained from the analysis of the heat flow data. The critical temperature of thermal explosion (Tb) and the initial decomposition temperature (Tp0) were determined to distinctly evaluate the thermal hazard of 2,4‐DNAN.
The Role of Aluminum in the Detonation and Post‐Detonation Expansion of Selected Cast HMX‐Based Explosives
Authors: Manner Virginia W. , Pemberton Steven J. , Gunderson Jake A. , Herrera Tommy J. , Lloyd Joseph M. , Salazar Patrick J. , Rae Philip , Tappan Bryce C. 
Published: April 2012

AbstractIn order to improve understanding of how aluminum contributes in non‐ideal explosive mixtures, cast‐cured formulations have been analyzed in a series of cylinder tests and plate‐pushing experiments. This study describes the contribution of 15 % aluminum (median size of 3.2 μm) vs. lithium fluoride (an inert substitute for aluminum; <5 μm) in cast‐cured HMX formulations in different temporal regimes. Small cylinder tests were performed to analyze the detonation and wall velocities (1–20 μs) for these formulations. Near‐field blast effects of 58 mm diameter spherical charges were measured at 152 mm and 254 mm using steel plate acceleration. Pressure measurements at 1.52 m gave information about free‐field pressure at several milliseconds. While the observed detonation velocities for all formulations were within uncertainty, significantly higher cylinder wall velocities, plate velocities, and pressures were observed for the aluminum formulations at ≥2 μs. Additionally, hydrocode calculations were performed to determine how non‐ideal behavior affected the plate test results. Collectively, this work gives a clearer picture of how aluminum contributes to detonation on timescales from 1 μs to about 2 ms, and how the post‐detonation energy release contributes to wall velocities and blast effects. The experiments indicate that significant aluminum reactions occur after the CJ plane, and continue to contribute to expansion at late times.
Structure and dynamics in solution of the stop codon decoding N‐terminal domain of the human polypeptide chain release factor eRF1
Authors: Polshakov Vladimir I. , Eliseev Boris D. , Birdsall Berry , Frolova Ludmila Yu. 
Published: April 2012

AbstractThe high‐resolution NMR structure of the N‐domain of human eRF1, responsible for stop codon recognition, has been determined in solution. The overall fold of the protein is the same as that found in the crystal structure. However, the structures of several loops, including those participating in stop codon decoding, are different. Analysis of the NMR relaxation data reveals that most of the regions with the highest structural discrepancy between the solution and solid states undergo internal motions on the ps–ns and ms time scales. The NMR data show that the N‐domain of human eRF1 exists in two conformational states. The distribution of the residues having the largest chemical shift differences between the two forms indicates that helices α2 and α3, with the NIKS loop between them, can switch their orientation relative to the β‐core of the protein. Such structural plasticity may be essential for stop codon recognition by human eRF1.
Brane tilings and reflexive polygons
Authors: Hanany A. , Seong R.‐K. 
Published: April 2012

AbstractReflexive polygons have attracted great interest both in mathematics and in physics. This paper discusses a new aspect of the existing study in the context of quiver gauge theories. These theories are 4d supersymmetric worldvolume theories of D3 branes with toric Calabi‐Yau moduli spaces that are conveniently described with brane tilings. We find all 30 theories corresponding to the 16 reflexive polygons, some of the theories being toric (Seiberg) dual to each other. The mesonic generators of the moduli spaces are identified through the Hilbert series. It is shown that the lattice of generators is the dual reflexive polygon of the toric diagram. Thus, the duality forms pairs of quiver gauge theories with the lattice of generators being the toric diagram of the dual and vice versa.
DC‐SCRIPT: AR and VDR regulator lost upon transformation of prostate epithelial cells
Authors: Ansems Marleen , Karthaus Nina , Hontelez Saartje , Aalders Tilly , Looman Maaike W. , Verhaegh Gerald W. , Schalken Jack A. , Adema Gosse J. 
Published: April 2012

AbstractBACKGROUNDNuclear receptors (NR), including the Androgen Receptor (AR) and the Vitamin D Receptor (VDR), play an important role in prostate cancer etiology. We recently found that DC‐SCRIPT is a prognostic marker in breast cancer and a unique NR coregulator differentially regulating different classes of NRs. Here we investigated the importance of DC‐SCRIPT in prostate cancer.METHODSDC‐SCRIPT mRNA expression was measured by qPCR. Immunohistochemistry was used to detect DC‐SCRIPT protein expression. The functional effects of DC‐SCRIPT on the transcriptional activity of AR and VDR were assessed by luciferase reporter assays and qPCR assays on well‐known AR and VDR target genes.RESULTSDC‐SCRIPT mRNA was higher in normal than in corresponding malignant prostate tissue but could not be related to disease stage. DC‐SCRIPT protein was found in morphologically normal prostate glands and in infiltrating immune cells. Strikingly, DC‐SCRIPT protein expression was absent in malignant prostate epithelial tissue and prostate carcinoma cell lines. DC‐SCRIPT protein expression appears to be lost prior to the basal cell marker HMW cytokeratin used in prostate carcinoma diagnostics. In addition, our data demonstrated that DC‐SCRIPT repressed transcription mediated by wild‐type and mutated AR while enhancing VDR mediated transcription. In addition, transient expression of DC‐SCRIPT expression in prostate carcinoma cells strongly repressed cell growth.CONCLUSIONSDC‐SCRIPT is a key regulator of nuclear receptors AR and VDR that play an opposite role in prostate cancer etiology and loss of DC‐SCRIPT may be involved in the onset of prostate cancer. Prostate 72:1708–1717, 2012. © 2012 Wiley Periodicals, Inc.
A dual indicator set to help farms achieve more sustainable crop protection
Authors: Wustenberghs Hilde , Delcour Ilse , D'Haene Karoline , Lauwers Ludwig , Marchand Fleur , Steurbaut Walter , Spanoghe Pieter 
Published: April 2012

AbstractBACKGROUND: Farmers are being called to use plant protection products (PPPs) more consciously and adopt more sustainable crop protection strategies. Indicators will help farmers to monitor their progress towards sustainability and will support their learning process. Talking the indicators through in farmers' discussion groups and the resulting peer encouragement will foster knowledge acquirement and can lead to changes in attitudes, norms, perception and behaviour.RESULTS: Using a participatory approach, a conceptual framework for on‐farm sustainable crop protection practices was created. The same participatory approach was used to design a dual indicator set, which pairs a pesticide impact assessment system (PIAS) with a farm inquiry. The PIAS measures the risk for human health and the environment exerted by chemical crop protection. The inquiry reveals the farmers' response to this risk, both in terms of the actions they take and their knowledge, awareness and attitude.CONCLUSIONS: The dual indicator set allows for implementation in four tiers, each representing increased potential for monitoring and social learning. The indicator set can be adjusted on the basis of new findings, and the participatory approach can be extrapolated to other situations. Copyright © 2012 Society of Chemical Industry
Effects of cycloxaprid, a novel cis‐nitromethylene neonicotinoid insecticide, on the feeding behaviour of Sitobion avenae
Authors: Cui Li , Sun Lina , Yang Daibin , Yan Xiaojing , Yuan Huizhu 
Published: April 2012

AbstractBACKGROUND: Cycloxaprid with cis‐configuration is a novel neonicotinoid insecticide, developed in China, that has good industrialisation prospects for its high activity against imidacloprid‐resistant pests. Studies were carried out to investigate the biological activity of cycloxaprid and its effect on the feeding behaviour of Sitobion avenae.RESULTS: The results demonstrated that cycloxaprid had good contact and root‐systemic activity. The electrical penetration graph (EPG) revealed that cycloxaprid significantly increased the total time of non‐probing periods and greatly inhibited phloem ingestion of treated aphids because it significantly reduced the total time and the frequency of phloem ingestion. Furthermore, cycloxaprid can increase the phloem salivation of treated aphids by comparison with aphids treated with imdacloprid and distilled water. Consequently, a sublethal dose of cycloxaprid impaired aphid ingestion of phloem sap and thereby reduced the weight of aphids. On the other hand, EPG data showed that a sublethal dose of cycloxaprid had no significant effect on xylem sap ingestion, in contrast to imidacloprid.CONCLUSION: All these tests indicated that cycloxaprid had both contact and root‐systemic activity, with sublethal effects resulting in reduction in Sitobion avenae phloem‐feeding behaviour and growth rate. Copyright © 2012 Society of Chemical Industry
Optical investigations of nonpolar homoepitaxial ZnO/(Zn,Mg)O quantum wells
Authors: Béaur L. , Bretagnon T. , Gil B. , Guillet T. , Brimont C. , Tainoff D. , Teisseire M. , Chauveau J.‐M. 
Published: April 2012

AbstractWe report growth of high quality ZnO/(Zn,Mg)O quantum wells, with 20% magnesium content, on M‐plane oriented ZnO substrates. The optical properties are studied by reflectance spectroscopy and continuous wave photoluminescence. The reflectance spectra reveal strong in‐plane optical anisotropies, as predicted by group theory. Signatures of confined excitons analogous to C‐exciton in bulk ZnO, are detected using light polarized along the c‐axis. Experiments performed in orthogonal polarization reveal confined states analogous to A and B bulk excitons. Envelope function calculations including excitonic interaction nicely match the experimental results. The weak Stokes‐shift between reflectance and photoluminescence spectra, and clear reflectance structures, are evidences of good interface morphologies. The independency of intensity of the photoluminescence with the temperature indicates the very small contributions of non‐radiative recombination channels in these samples (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prediction of boron–phosphorous nanographene‐like material
Authors: López‐Castillo Alejandro 
Published: April 2012

AbstractIn this work, nanographene based on Boron–Phosphorous is characterized theoretically by infrared, Raman spectroscopies, and other microscopic properties. Comparative studies among boron–phosphorous nanographene (BPNG), carbon one (CNG), and boron–nitrogen (BNNG) also suggest that it is experimentally possible to obtain the BPNG. There are several electronic similarities among BPNG, CNG, and BNNG. The studied ones have a circulene‐like structure with D6h and D3h symmetries for the carbon and boron compounds, respectively. The HOMO–LUMO gap obtained was compared with several sizes of those nanographenes. Compounds based on BP are expected to present intermediary properties in between the CNG and BNNG due to the electronegativity difference. The BPNG can be a promising material when used to obtain nanodevices, its gap is near the orange/VIS region. © 2012 Wiley Periodicals, Inc.
Some spin and spin‐free aspects of coulomb correlation in molecules
Authors: Luzanov A. V. 
Published: April 2012

AbstractA spin component analysis of the cumulant (irreducible) density matrices is provided. In particular, the spin‐up spin‐down cumulant density matrix, π, is considered as the most general definition of the Coulomb‐hole density matrix. The local atomic cumulants produced from π, turn out to be the most important components of the atomic charge and spin correlators. These spin‐up spin‐down components, vanishing in the restricted Hartree–Fock model, reflect directly an effect of the Coulomb correlation on the generalized Wiberg bond order indices and Penney–Dirac bond orders. A spin‐free algorithm for computing spin correlators and related local spins is proposed. The algorithm is implemented numerically at full configuration interaction (FCI) and simple coupled‐cluster (CC) levels. The presented analysis is exemplified by some FCI and CC doubles computations on small hydrides and typical carbenes and cumulenes. © 2012 Wiley Periodicals, Inc.
Asymptotic enumeration of sparse 2‐connected graphs
Authors: Kemkes Graeme , Sato Cristiane M. , Wormald Nicholas 
Published: April 2012

AbstractWe determine an asymptotic formula for the number of labelled 2‐connected (simple) graphs on n vertices and m edges, provided that m ‐ n →∞ and m = O(nlog n) as n →∞. This is the entire range of m not covered by previous results. The proof involves determining properties of the core and kernel of random graphs with minimum degree at least 2. The case of 2‐edge‐connectedness is treated similarly. We also obtain formulae for the number of 2‐connected graphs with given degree sequence for most (“typical”) sequences. Our main result solves a problem of Wright from 1983. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2013
The impact of an integrated approach to science and literacy in elementary school classrooms
Authors: Cervetti Gina N. , Barber Jacqueline , Dorph Rena , Pearson P. David , Goldschmidt Pete G. 
Published: April 2012

AbstractThis study investigates the efficacy of an integrated science and literacy approach at the upper‐elementary level. Teachers in 94 fourth grade classrooms in one Southern state participated. Half of the teachers taught the treatment unit, an integrated science–literacy unit on light and energy designed using a curriculum model that engages students in reading text, writing notes and reports, conducting firsthand investigations, and frequent discussion of key concepts and processes to acquire inquiry skills and knowledge about science concepts, while the other half of the teachers taught a content‐comparable science‐only unit on light and energy (using materials provided by their districts) and provided their regular literacy instruction. Students in the treatment group made significantly greater gains on measures of science understanding, science vocabulary, and science writing. Students in both groups made comparable gains in science reading comprehension. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 631–658, 2012
High performance hard carbon coatings (diamond‐like coatings)
Authors: Vetter Jörg , Ackerman Cyndi , Meunier Frederic , Jarry Olivier , Schumacher Dan , Erkens Georg 
Published: April 2012

AbstractDifferent dLc coating types are applied at an industrial scale by sulzer Metco thin Film. The coatings are generated with different coating architecture. Deposition methods are: magnetron sputtering, electron beam evaporation and PA‐cVd. Reactive magnetron sputtering is used to deposit metal containing a‐c:h coatings (a‐c:h:Me), e.g. MAXit W‐ch. Pure a‐c:h coatings as functional top coatings are used for cavidur®, MAXit® AhdLc and special versions of dylyn® coatings. In addition to the pure a‐c:h coatings, doped a‐c:h coatings are also used. The dylyn® family of coatings is comprised of at least one layer a‐c:h:si:O. The dylyn® coatings may be doped with metal (a‐c:h:ti:si:O) to adapt selected properties like electrical conductivity.
Kohlenstoffbasierte Beschichtungen für automotive‐Komponenten
Authors: Huben Theresa , Becker Jürgen 
Published: April 2012

AbstractDie herausragenden Eigenschaften von kohlenstoffbasierten Beschichtungen sind die geringe Reibung gegen Stahl und die mit der erreichbaren hohen Härte verbundene Verschleißbeständigkeit. In geschmierten Systemen wirken Beschichtungen nur im Bereich der Misch‐ und Grenzreibung, d. h. solange Körper und Gegenkörper noch in Kontakt sind.Die Eigenschaften von Beschichtungen lassen sich in weiten Bereichen anpassen. Ein zielgerechtes Anpassen setzt voraus, dass das tribologische System hinreichend genau verstanden ist.Es hat sich gezeigt, dass Beschichtungslösungen nur sub‐optimal sind, wenn die Beschichtung erst „zum Schluss”︁ in das System‐Design eingebracht wird. Ein größerer Nutzen ergibt sich, wenn die konstruktiven Freiräume, die eine Beschichtung eröffnet, schon zu Beginn der Design‐Phase ausgeschöpft werden. Die Beschichtung wird als Konstruktionselement verstanden.Um die Eignung der gewählten Beschichtung schnell und kostengünstig vorab testen zu können, sind die üblichen Standard ‐ Labortests nicht immer geeignet. Ein Prüfaufbau muss hinreichend anwendungsnah sein, um verwertbare Ergebnisse zu generieren.Diese Überlegungen werden am Beispiel einer Kolbenbolzenbeschichtung dargelegt. Die Rauheit von Körper und Gegenkörper ist vor allem bei Anwendungen unter hohen Lasten von besonderer Bedeutung für die Anpassung des Schichtsystems. Das hier vorgestellte Beispiel zeigt auch, dass die üblicherweise verwendeten Kenngrößen für Oberflächenrauheit wie Ra und Rz nicht immer ausreichend sind.
Models of spoken‐word recognition
Authors: Weber Andrea , Scharenborg Odette 
Published: April 2012

AbstractAll words of the languages we know are stored in the mental lexicon. Psycholinguistic models describe in which format lexical knowledge is stored and how it is accessed when needed for language use. The present article summarizes key findings in spoken‐word recognition by humans and describes how models of spoken‐word recognition account for them. Although current models of spoken‐word recognition differ considerably in the details of implementation, there is general consensus among them on at least three aspects: multiple word candidates are activated in parallel as a word is being heard, activation of word candidates varies with the degree of match between the speech signal and stored lexical representations, and activated candidate words compete for recognition. No consensus has been reached on other aspects such as the flow of information between different processing levels, and the format of stored prelexical and lexical representations. WIREs Cogn Sci 2012, 3:387–401. doi: 10.1002/wcs.1178This article is categorized under:

Linguistics > Computational Models of Language
Molecular structure and function of Hv1 channels
Authors: Rebolledo Santiago , Qiu Feng , Peter Larsson H. 
Published: April 2012

AbstractVoltage‐gated proton (Hv) channels have long been found with electrophysiological tools in many different cell types. However, the molecular identity of Hv channels was not discovered until 2006, when two labs independently demonstrated that the gene HVCN1 that codes for a protein called Hv1 or VSOP generates voltage‐gated proton currents when expressed in heterologous cells. Surprisingly, the sequence of Hv1/VSOP was found to be homologous to the sequence of the voltage‐sensing domain of voltage‐gated K+ channels. Recent studies have led to our present understanding of the structure of Hv1/VSOP channels and the structural underpinnings of some of the functional properties of Hv1/VSOP channels, including voltage sensing, subunit cooperativity, permeation and selectivity, pH dependence, zinc inhibition and modulation by PKC of Hv1/VSOP channels. The cloned Hv1/VSOP channels display most of the properties of native voltage‐gated proton channels. However, the molecular mechanisms underlying some of these properties are still unknown. WIREs Membr Transp Signal 2012, 1:763–777. doi: 10.1002/wmts.49For further resources related to this article, please visit the WIREs website.Conflict of interest: The authors declare no conflict of interest.