bluuebunny/crossref_metadata_2025_split huggingface dataset:
Features of Double‐Spiral “Valley‐Hills” Surface Topography Formation in Photochromic Cholesteric Oligomer‐Based Films and Their Changes Under Polarized Light Action
Authors: Bobrovsky Alexey , Mochalov Konstantin , Chistyakov Anton , Oleinikov Vladimir , Shibaev Valery 
Published: November 2012

AbstractUsing a novel experimental method combining of polarizing optical microscopy (POM) and atomic force microscopy (AFM), the surface topography and optical properties of chiral‐ photochromic LC systems were studied. For this purpose, a mixture of cholesteric cyclosiloxanes with azobenzene‐containing dopant was prepared. Correlations between the features of surface topography of mixture films and POM images of planarly oriented texture were found. Polarized light action (532 nm) leads to the formation of partially aligned surface structure features. The observed photooptical effects are associated with E‐Z, Z‐E isomerization cycles of azobenzene groups, anisotropic cooperative photoinduced rotational diffusion and directional mass‐transport of chromophores and mesogens in the films.
Irregularity and the period determinant for irregular singular connections on surfaces
Authors: Hien M. 
Published: November 2012

AbstractIn [6], we constructed a period pairing for flat irregular singular conncetions on surfaces. We now extend these constructions to a perfect period pairing between the irregularity complex of the connection and the complex of relative rapid decay chains. As a consequence, the period determinant of the connection decomposes as a product of a topological period determinant on the open surface and a determinant coming from the irregularity of the connection. Additionally, we deduce a method to compute the irregularity sheaf up to local isomorphism in topological terms (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Association of Tef polymorphism with depression in Parkinson disease
Authors: Hua Ping , Liu Weiguo , Kuo Sheng‐Han , Zhao Yanyan , Chen Ling , Zhang Ning , Wang Chun , Guo Suwan , Wang Li , Xiao Hong , Kwan Justin Y. , Wu Tianxia 
Published: November 2012

AbstractBackground:Circadian rhythm disturbance has been implicated in depression, and polymorphisms of circadian genes Cry1, Cry2, and Tef are associated with depression. However, the relationship between these genes and depression symptoms in Parkinson's disease (PD) has not been established.Methods:Four hundred eight subjects with PD participated in this study. Demographics, UPDRS, Mini–Mental Status Examination (MMSE), and Hamilton Rating Scale for Depression (HAMD) were obtained in all subjects. Frequency of polymorphisms of Cry1 rs2287161, Cry2 rs10838524, and Tef rs738499 was determined, and the association between genetic polymorphisms of circadian genes and HAMD scores in patients with PD was examined.Results:Tef, but not Cry1 or Cry2, is associated with HAMD scores in patients with PD in a linear regression model after adjusting for clinical variables (P = 0.004).Conclusions:The polymorphism of Tef rs738499 is associated with depression symptoms in PD. © 2012 Movement Disorder Society
Physikalische Chemie 2007
Authors: Meijer Gerard , Küpper Jochen 
Published: November 2012

AbstractKalte Moleküle erlauben faszinierende Experimente: von der hochaufgelösten Spektroskopie bis zur Chemie, bei der Tunnelprozesse die Reaktionen dominieren. Kohlenstoffnanostrukturen bieten großes Anwendungspotenzial für die molekulare Elektronik. Mit Freie‐Elektronen‐Lasern verbindet sich die Hoffnung, chemische Reaktionen in Raum und Zeit mit atomarer Auflösung zu verfolgen.
Glucocorticoidhaltige Magistralrezepturen. Rationaler Einsatz in der Dermatologie
Authors: Högger Petra 
Published: November 2012

AbstractTopisch angewandte Glucocorticoide spielen in der Therapie entzündlicher Hauterkrankungen eine zentrale Rolle. Eine hohe Konzentration am Wirkort und eine geringe Rate unerwünschter Wirkungen führen zu einer hohen Effektivität und Sicherheit der Behandlung. Kenntnisse der Wirkstoffkinetik und ‐dynamik, aber auch der Vehikeleinflüsse, sind die Grundlage für das Verständnis der erwünschten und unerwünschten Effekte und für eine erfolgreiche Therapie.
Spins unter Kontrolle
Authors: Kronast Florian 
Published: November 2012

AbstractDie Spintronik verspricht kleinere, schnellere und energiesparendere Bauteile im Vergleich zu herkömmlicher Elektronik. Sie ist keine Zukunftsvision mehr; spintronische Bauteile halten mittlerweile Einzug in technische Dinge wie Festplatten und Sensoren (Phys. unserer Zeit 2008, 39 (6), 274). Vincent Garcia und seinen Kollegen von der Unité Mixte de Physique CNRS/Thales ist jüngst in einer internationalen Zusammenarbeit, an der auch unsere Gruppe vom Helmholtz‐Zentrum‐Berlin für Materialien und Energie beteiligt war, ein großer Fortschritt mit der ferroelektrischen Kontrolle der Spin‐Polarisation gelungen.
Ring‐opening polymerization of lactides catalyzed by magnesium complexes coordinated with NNO‐tridentate pyrazolonate ligands
Authors: Chuang Hui‐Ju , Chen Hsiao‐Li , Ye Jian‐Li , Chen Zn‐Yun , Huang Pei‐Ling , Liao Tzu‐Ting , Tsai Tsung‐En , Lin Chu‐Chieh 
Published: November 2012

AbstractA series of magnesium benzylalkoxide complexes, [LnMg(μ‐OBn)]2 (1–14) supported by NNO‐tridentate pyrazolonate ligands with various electron withdrawing‐donating subsituents have been synthesized and characterized. X‐ray crystal structural studies revealed that Complexes 1–3, 5, 7, 9, and 10 are dinuclear bridging through benzylalkoxy oxygen atoms with penta‐coordinated metal centers. All of these complexes acted as efficient initiators for the ring‐opening polymerization of L‐lactide and rac‐lactide. Based on kinetic studies, the activity of these metal complexes is significantly influenced by the electronic effect of the ancillary ligands with the electron‐donating substituents at the phenyl rings enhancing the polymerization rate. In addition, the “living” and “immortal” character of 6 has paved a way to synthesize as much as 40‐fold polymer chains of polylactides with a very narrow polydispersity index in the presence of a small amount of initiator. Among all of magnesium complexes, Complex 6 exhibits the highest stereoselectivity toward ring‐opening polymerization of rac‐lactide with Pr up to 88% in THF at 0 °C. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Synthesis and characterization of Y‐type polymers for second‐order nonlinear optical applications
Authors: Kolli Balakrishna , Mishra Sarada P. , Palai Akshaya K. , Kanai Tapan , Joshi M. P. , Mohan S. Raj , Dhami T. S. , Kukreja L. M. , Samui A. B. 
Published: November 2012

AbstractA series of dicyanomethylene‐substituted polymers having Y‐type molecular architecture were synthesized by Knoevenagel condensation reaction. The polymers were found to be soluble in organic solvents like tetrahydrofuran and chloroform. From gel permeation chromatography, the molecular weights of the polymers were found to be in the range of 15,300–33,800 g/mol. Thermal analysis showed that the polymers were stable up to 350 °C with glass transition temperature (Tg) in the range of 129–212 °C. These polymers were found to form good optical quality films. The order parameter was calculated to be in the range of 0.01–0.48. Atomic force microscopy indicated prominent morphology changes due to alignment of dipoles after poling. By using Nd:YAG laser of 1064 nm, angular dependence and temperature dependence of second‐harmonic generation intensity were investigated. The geometry optimization, shape of polymers, and restricted torsion angle between acceptor and donor substituents (push–pull system) were calculated. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Multiple binding modes for palmitate to barley lipid transfer protein facilitated by the presence of proline 12
Authors: Smith Lorna J. , Gunsteren Wilfred F. Van , Allison Jane R. 
Published: November 2012

AbstractMolecular dynamics simulations have been used to characterise the binding of the fatty acid ligand palmitate in the barley lipid transfer protein 1 (LTP) internal cavity. Two different palmitate binding modes (1 and 2), with similar protein–ligand interaction energies, have been identified using a variety of simulation strategies. These strategies include applying experimental protein–ligand atom–atom distance restraints during the simulation, or protonating the palmitate ligand, or using the vacuum GROMOS 54B7 force‐field parameter set for the ligand during the initial stages of the simulations. In both the binding modes identified the palmitate carboxylate head group hydrogen bonds with main chain amide groups in helix A, residues 4 to 19, of the protein. In binding mode 1 the hydrogen bonds are to Lys 11, Cys 13, and Leu 14 and in binding mode 2 to Thr 15, Tyr 16, Val 17, Ser 24 and also to the OH of Thr 15. In both cases palmitate binding exploits irregularity of the intrahelical hydrogen‐bonding pattern in helix A of barley LTP due to the presence of Pro 12. Simulations of two variants of barley LTP, namely the single mutant Pro12Val and the double mutant Pro12Val Pro70Val, show that Pro 12 is required for persistent palmitate binding in the LTP cavity. Overall, the work identifies key MD simulation approaches for characterizing the details of protein–ligand interactions in complexes where NMR data provide insufficient restraints.
A comparison of successful and failed protein interface designs highlights the challenges of designing buried hydrogen bonds
Authors: Stranges P. Benjamin , Kuhlman Brian 
Published: November 2012

AbstractThe accurate design of new protein–protein interactions is a longstanding goal of computational protein design. However, most computationally designed interfaces fail to form experimentally. This investigation compares five previously described successful de novo interface designs with 158 failures. Both sets of proteins were designed with the molecular modeling program Rosetta. Designs were considered a success if a high‐resolution crystal structure of the complex closely matched the design model and the equilibrium dissociation constant for binding was less than 10 μM. The successes and failures represent a wide variety of interface types and design goals including heterodimers, homodimers, peptide‐protein interactions, one‐sided designs (i.e., where only one of the proteins was mutated) and two‐sided designs. The most striking feature of the successful designs is that they have fewer polar atoms at their interfaces than many of the failed designs. Designs that attempted to create extensive sets of interface‐spanning hydrogen bonds resulted in no detectable binding. In contrast, polar atoms make up more than 40% of the interface area of many natural dimers, and native interfaces often contain extensive hydrogen bonding networks. These results suggest that Rosetta may not be accurately balancing hydrogen bonding and electrostatic energies against desolvation penalties and that design processes may not include sufficient sampling to identify side chains in preordered conformations that can fully satisfy the hydrogen bonding potential of the interface.
Probing the dynamic reversibility and generation of dynamic combinatorial libraries in the presence of bacterial model oligopeptides as templating guests of tetra‐carbohydrazide macrocycles using electrospray mass spectrometry
Authors: Nour Hany F. , Islam Tuhidul , Fernández‐Lahore Marcelo , Kuhnert Nikolai 
Published: November 2012

RATIONALEOver the past few decades, bacterial resistance to antibiotics has emerged as a real threat to human health. Accordingly, there is an urgent demand for the development of innovative strategies for discovering new antibiotics. We present the first use of tetra‐carbohydrazide cyclophane macrocycles in dynamic combinatorial chemistry (DCC) and molecular recognition as chiral hosts binding oligopeptides, which mimic bacterial cell wall. This study introduces an innovative application of electrospray ionisation time‐of‐flight mass spectrometry (ESI‐TOF MS) to oligopeptides recognition using DCC.METHODSA small dynamic library composed of eight functionalised macrocycles has been generated in solution and all members were characterised by ESI‐TOF MS. We also probed the dynamic reversibility and mechanism of formation of tetra‐carbohydrazide cyclophanes in real‐time using ESI‐TOF MS.RESULTSDynamic reversibility of tetra‐carbohydrazide cyclophanes is favored under thermodynamic control. The mechanism of formation of tetra‐carbohydrazide cyclophanes involves key dialdehyde intermediates, which have been detected and assigned according to their high‐resolution m/z values. Three members of the dynamic library bind efficiently in the gas phase to a selection of oligopeptides, unique to bacteria, allowing observation of host/guest complex ions in the gas phase.CONCLUSIONSWe probed the mechanism of the [2+2]‐cyclocondensation reaction forming library members, proved dynamic reversibility of tetra‐carbohydrazide cyclophanes and showed that complex ions formed between library members and hosts can be observed in the gas phase, allowing the solution of an important problem of biological interest. Copyright © 2012 John Wiley & Sons, Ltd.
Confident identification of isomeric N‐glycan structures by combined ion mobility mass spectrometry and hydrophilic interaction liquid chromatography
Authors: Yamaguchi Yoshiki , Nishima Wataru , Re Suyong , Sugita Yuji 
Published: November 2012

RATIONALEA central issue in glycan mass analysis is the ambiguity of structural assignments due to the heterogeneity and complexity of glycan structures. Ion mobility mass spectrometry (IM‐MS) has the potential to separate isomeric glycans depending on their unique collisional cross section especially when coupled with hydrophilic interaction liquid chromatography (HILIC).METHODSTen pyridylaminated biantennary N‐glycans including isomeric structures were measured by electrospray ionization quadrupole‐time‐of‐flight mass spectrometry with an ion mobility phase. We investigated which adduct ions would be suitable for good separation in the ion mobility phase. The differences in observed drift time of isomeric glycans were assessed by molecular dynamics (MD) simulations in vacuum. Connecting an HILIC system with IM‐MS provided another, augmented separation mode.RESULTSBy selecting doubly protonated precursor ion species, we succeeded in separating a pair of isomeric glycans in the ion mobility phase with reasonable resolution. MD simulations of monogalactosylated glycan isomers indicate that the galactosylated Man α1‐3 branch preferentially folds back to the core chitobiose portion to form a compact structure. IM‐MS combined with HILIC resulted in even clearer separation of isomeric glycans within 15 min.CONCLUSIONSA combination of IM‐MS with an HILIC system is eminently suitable for the confident and rapid distinction of glycan structures within a defined mixture. Copyright © 2012 John Wiley & Sons, Ltd.
Metal cation detection in positive ion mode electrospray ionization mass spectrometry using a tetracationic salt as a gas‐phase ion‐pairing agent: Evaluation of the effect of chelating agents on detection sensitivity
Authors: Xu Chengdong , Dodbiba Edra , Padivitage Nilusha L. T. , Breitbach Zachary S. , Armstrong Daniel W. 
Published: November 2012

RATIONALEThe detection of metal cations continues to be essential in many scientific and industrial areas of interest. The most common electrospray ionization mass spectrometry (ESI‐MS) approach involves chelating the metal ions and detecting the organometallic complex in the negative ion mode. However, it is well known that negative ion mode ESI‐MS is generally less sensitive than the positive ion mode. To achieve greater sensitivity, it is necessary to examine the feasibility of detecting the chelated metal cations in positive ion mode ESI‐MS.METHODSSince highly solvated native metal cations have relatively low ionization efficiency in ESI‐MS, and can be difficult to detect in the positive ion mode, a tetracationic ion‐pairing agent was added to form a complex with the negatively charged metal chelate. The use of the ion‐pairing agent leads to the generation of an overall positively charged complex, which can be detected at higher m/z values in the positive ion mode by electrospray ionization linear quadrupole ion trap mass spectrometry.RESULTSThirteen chelating agents with diverse structures were evaluated in this study. The nature of the chelating agent played as important a role as was previously determined for cationic pairing agents. The detection limits of six metal cations reached sub‐picogram levels and significant improvements were observed when compared to negative ion mode detection where the metal‐chelates were monitored without adding the ion‐pairing reagent (IPR). Also, selective reaction monitoring (SRM) analyses were performed on the ternary complexes, which improved detection limits by one to three orders of magnitude.CONCLUSIONSWith this method it was possible to analyze the metal cations in the positive ion mode ESI‐MS with the advantage of speed, sensitivity and selectivity. The optimum solution pH for this type of analysis is 5–7. Tandem mass spectrometry (MS/MS) further increases the sensitivity. Speciation is straightforward making this a broadly useful approach for the analysis of metal ions. Copyright © 2012 John Wiley & Sons, Ltd.
Component‐based security system (COMSEC) with QoS for wireless sensor networks
Authors: Kifayat Kashif , Merabti Madjid , Shi Qi , Abbas Sohail 
Published: November 2012

ABSTRACTIn the last decade, many security solutions have been proposed to fulfil the security requirements of wireless sensor networks (WSNs). However, these solutions are specifically designed for particular security issues, based on different assumptions, and limited to certain WSNs applications. Can these security solutions work together to handle multiple problems at the same time? It is an interesting and difficult question. We believe good solutions in various security areas do not mean they can work together and deliver similar results, i.e. occurrence of any security weakness or attack in a particular security solution could expose the vulnerabilities of other solutions. Using these solutions together might also degrade WSN quality of service. To deal with the aforementioned issues, we therefore propose a novel component‐based security system (COMSEC) based on proactive and reactive components. Each component looks after a particular security issue and is integrated with others. The proposed system provides better secure communication, Sybil attack detection, secure data aggregation and resilience against node capture attacks and replication attacks. COMSEC has been evaluated and compared against existing schemes. Evaluation results show a significant improvement in resilience against node capture attacks, Sybil attack detection data confidentiality, privacy, memory overhead and connectivity. Copyright © 2012 John Wiley & Sons, Ltd.
Nitric Oxide Donors for Cardiovascular Implant Applications
Authors: Naghavi Noora , de Mel Achala , Alavijeh Omid Sadeghi , Cousins Brian G. , Seifalian Alexander M. 
Published: November 2012

AbstractIn an era of increased cardiovascular disease burden in the ageing population, there is great demand for devices that come in to contact with the blood such as heart valves, stents, and bypass grafts that offer life saving treatments. Nitric oxide (NO) elution from healthy endothelial tissue that lines the vessels maintains haemostasis throughout the vasculature. Surgical devices that release NO are desirable treatment options andN‐diazeniumdiolates andS‐nitrosothiols are recognized as preferred donor molecules. There is a keen interest to investigate newer methods by which NO donors can be retained within biomaterials so that their release and kinetic profiles can be optimized. A range of polymeric scaffolds incorporating microparticles and nanomaterials are presenting solutions to current challenges, and have been investigated in a range of clinical applications. This review outlines the application of NO donors for cardiovascular therapy using biomaterials that release NO locally to prevent thrombosis and intimal hyperplasia (IH) and enhance endothelialization in the fabrication of next generation cardiovascular device technology.
Development of a Continuous Desiliconization Process in the Hot Metal Runner of a Blast Furnace
Authors: Nakasuga Takamitsu , Kimura Sei , Mimura Tsuyoshi , Tadai Rikizo , Ito Kenji , Ono Reiji 
Published: November 2012

Abstract An efficient continuous desiliconization process equipped with a mechanical stirrer in a hot metal runner was newly developed. The facility was installed during the revamping of No.3 blast furnace at Kobe Works, and the commercial operation started up successfully in January 2008. Before the installation of the commercial facility, the reaction behaviour was investigated under various experimental conditions for the application of a mechanical stirring method to continuous desiliconization treatment in the hot metal runner. Hot metal experiments at laboratory scale showed that the stirring intensity was an important factor for the process performance, and the mechanical stirring method was available for the improvement of reaction efficiency. As a result of plant tests, it was confirmed that a higher oxygen efficiency of desiliconization was achieved by the combination of runner arrangement and mechanical stirrer compared with the conventional injection of the desiliconizing agent. According to the reaction analysis of continuous desiliconization in the hot metal runner using the semi‐batch reaction model, it was estimated that the average slag‐metal residence time in the reaction region is improved due to an increased entrainment of foamed slag into the stirred metal bath in the mechanical stirring method, and therefore, it leads to a high desiliconization efficiency. Based on the experimental results, the equipment specifications and the runner design for this process were determined.
MicroRNA-302 Increases Reprogramming Efficiency via Repression of NR2F2
Authors: Hu Shijun , Wilson Kitchener D. , Ghosh Zhumur , Han Leng , Wang Yongming , Lan Feng , Ransohoff Katherine J. , Burridge Paul , Wu Joseph C. 
Published: November 2012

Abstract
MicroRNAs (miRNAs) have emerged as critical regulators of gene expression through translational inhibition and RNA decay and have been implicated in the regulation of cellular differentiation, proliferation, angiogenesis, and apoptosis. In this study, we analyzed global miRNA and mRNA microarrays to predict novel miRNA-mRNA interactions in human embryonic stem cells and induced pluripotent stem cells (iPSCs). In particular, we demonstrate a regulatory feedback loop between the miR-302 cluster and two transcription factors, NR2F2 and OCT4. Our data show high expression of miR-302 and OCT4 in pluripotent cells, while NR2F2 is expressed exclusively in differentiated cells. Target analysis predicts that NR2F2 is a direct target of miR-302, which we experimentally confirm by reporter luciferase assays and real-time polymerase chain reaction. We also demonstrate that NR2F2 directly inhibits the activity of the OCT4 promoter and thus diminishes the positive feedback loop between OCT4 and miR-302. Importantly, higher reprogramming efficiencies were obtained when we reprogrammed human adipose-derived stem cells into iPSCs using four factors (KLF4, C-MYC, OCT4, and SOX2) plus miR-302 (this reprogramming cocktail is hereafter referred to as “KMOS3”) when compared to using four factors (“KMOS”). Furthermore, shRNA knockdown of NR2F2 mimics the over-expression of miR-302 by also enhancing reprogramming efficiency. Interestingly, we were unable to generate iPSCs from miR-302a/b/c/d alone, which is in contrast to previous publications that have reported that miR-302 by itself can reprogram human skin cancer cells and human hair follicle cells. Taken together, these findings demonstrate that miR-302 inhibits NR2F2 and promotes pluripotency through indirect positive regulation of OCT4. This feedback loop represents an important new mechanism for understanding and inducing pluripotency in somatic cells.