bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modification of Electrode Surfaces by Self‐Assembled Monolayers of Thiol‐Terminated Oligo(Phenyleneethynylene)s
Authors: Kaur Inderpreet , Zhao Xiaotao , Bryce Martin R. , Schauer Phil A. , Low Paul J. , Kataky Ritu 
Published: January 2013

AbstractThe wire‐like properties of four S‐(4‐{2‐[4‐(2‐phenylethynyl)phenyl]ethynyl}phenyl) thioacetate derivatives, PhC≡CC6H4C≡CC6H4SAc (1), H2NC6H4C≡CC6H4C≡CC6H4SAc (2), PhC≡CC6H2(OMe)2C≡CC6H4SAc (3) and AcSC6H4C≡CC6H4C≡CC6H4SAc (4) (Figure 1), all of which possess a high degree of conjugation along the oligo(phenyleneethynylene) (OPE) backbone, were investigated as self‐assembled monolayers (SAMs) on gold and platinum electrodes by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The redox probe [Fe(CN)6]4− was used in both the CV and impedance experiments. The results indicate that the thiolates derived from thioacetate‐protected precursor molecules 1 and 2 form well‐ordered monolayers on a gold electrode, whereas SAMs derived from 3 and 4 exhibit randomly distributed pinholes. The electron tunnelling resistance and fractional coverage of SAMs of all four compounds were examined using electron tunnelling theory. The analysis of the results reveal that the well‐ordered SAMs of 1 and 2 exhibit higher charge‐transfer resistance in comparison to the defect‐ridden SAMs of 3 and 4. The additional steric bulk offered by the methoxy groups in 3 is likely to prevent efficient packing within the SAM, leading to a microelectrode behaviour, when assembled on a gold electrode surface. The protected dithiol derivative 4 probably binds to the surface through both terminal groups which prevents dense packing and leads to the formation of a monolayer with randomly distributed pinholes. Atomic force microscopy (AFM) was used to examine the morphology of the monolayers, and height images gave root‐mean‐square (RMS) roughness′s which are in agreement with the proposed SAM structures.
The Charging of Micellar Nanoparticles in Electrospray Ionization
Authors: Doussineau Tristan , Santacreu Marion , Antoine Rodolphe , Dugourd Philippe , Zhang Wenjing , Chaduc Isabelle , Lansalot Muriel , D'Agosto Franck , Charleux Bernadette 
Published: January 2013

AbstractCharging of nanoparticles through electrospray has scarcely been explored. Spherical nanometer‐sized amphiphilic block copolymer nanoparticles with diameters ranging from ∼65 to ∼150 nm were electrosprayed and analysed by charge detection spectrometry. Herein, we explore the charging of these micellar nano‐objects by conducting a thorough study in different solvents, including pure water, and upon the addition of “supercharging” agents. The charge (z) of micellar nanoparticles electrosprayed from water solution is compared to the Rayleigh’s limiting charge (zR) of a charged water droplet of the same dimensions. An average ratio (z/zR) of 0.6–0.65 is observed for the micellar macro‐ions, supporting the charge residue mechanism, where the number of charges available to the micellar macro‐ion is limited by the number of charges on the nanodroplet, which is a function of the surface tension of the solvent. Also we show the possibility of increasing the charging of micellar nanoparticles in the negative mode by adding organic bases (in particular piperidine) to water/methanol solutions.
MP2.5 and MP2.X: Approaching CCSD(T) Quality Description of Noncovalent Interaction at the Cost of a Single CCSD Iteration
Authors: Sedlak Robert , Riley Kevin E. , Řezáč Jan , Pitoňák Michal , Hobza Pavel 
Published: January 2013

AbstractThe performance of the second‐order Møller–Plesset perturbation theory MP2.5 and MP2.X methods, tested on the S22, S66, X40, and other benchmark datasets is briefly reviewed. It is found that both methods produce highly accurate binding energies for the complexes contained in these data sets. Both methods also provide reliable potential energy curves for the complexes in the S66 set. Among the routinely used wavefunction methods, the only other technique that consistently produces lower errors, both for stabilization energies and geometry scans, is the spin‐component‐scaled coupled‐clusters method covering iterative single‐ and double‐electron excitations, which is, however, substantially more computationally intensive. The structures originated from full geometrical gradient optimizations at the MP2.5 and MP2.X level of theory were confirmed to be the closest to the CCSD(T)/CBS (coupled clusters covering iterative single‐ and double‐electron excitations and perturbative triple‐electron excitations performed at the complete basis set limit) geometries among all the tested methods (e.g. MP3, SCS(MI)‐MP2, MP2, M06‐2X, and DFT‐D method evaluated with the TPSS functional). The MP2.5 geometries for the tested complexes deviate from the references almost negligibly. Inclusion of the scaled third‐order correlation energy results in a substantial improvement of the ability to accurately describe noncovalent interactions. The results shown here serve to support the notion that MP2.5 and MP2.X are reasonable alternative methods for benchmark calculations in cases where system size or (lack of) computational resources preclude the use of CCSD(T)/CBS computations. MP2.X allows for the use of smaller basis sets (i.e. 6‐31G*) with results that are nearly identical to those of MP2.5 with larger basis sets, which dramatically decreases computation times and makes calculations on much larger systems possible.
Nonlinear dynamics of divide‐by‐two injection‐locked frequency dividers in locked operation mode
Authors: Buonomo Antonio , Lo Schiavo Alessandro 
Published: January 2013

SUMMARYA method for analyzing the nonlinear dynamics of the injection‐locked frequency dividers in synchronized operation mode is presented, including the stability analysis of locked states. We use a specific divide‐by‐two circuit, namely a differential LC CMOS divider with a complementary topology, as a guideline for presentation, showing that the sizing of the devices significantly affects the synchronization mechanism of the divider, which exhibits a very rich dynamical behavior. We provide closed‐form expressions to determine the amplitude and the phase in the locked state, as well as the locking range, leading to accurate results, which are validated by numerical simulations. The presented analysis of the frequency divider dynamics enables us to establish that stable locked oscillations occur on the whole locking range predicted by the well‐known Adler's equation and that these are possible also beyond that range. Copyright © 2013 John Wiley & Sons, Ltd.
On some optimal control problems for electrical circuits
Authors: Altmann Kristof , Stingelin Simon , Tröltzsch Fredi 
Published: January 2013

AbstractSome optimal control problems for linear and nonlinear ordinary differential equations related to the optimal switching between different magnetic fields are considered. The main aim is to move an electrical initial current by a controllable voltage in shortest time to a desired terminal current and to hold it afterwards. Necessary optimality conditions are derived by Pontryagin's principle and a formal Lagrange technique. In the case of a linear system, the principal structure of time‐optimal controls is discussed. The associated optimality systems are solved by a one‐shot strategy using a multigrid software package. Various numerical examples are discussed. Copyright © 2013 John Wiley & Sons, Ltd.
Design of a novel adder‐less Barker matched filter for RFID
Authors: Amin Md. Syedul , Reaz Mamun Bin Ibne , Jalil Jubayer 
Published: January 2013

ABSTRACTRadio frequency identification (RFID) is the utilization of the radio frequency for the purpose of identification. RFID is lagging behind due to vendor specific solutions and excessive implementation cost. A Wireless Fidelity (WiFi) compatible IEEE 802.11 RFID tag can overcome these limitations. IEEE 802.11 utilizes Direct Sequence Spread Spectrum (DSSS) technique and a matched filter is a vital block in a DSSS system. A low‐power and low‐area novel adder‐less Barker matched filter is proposed in this paper by eliminating the conventional multiple multiplications. The matched filter designed in 0.18 µm CMOS technology achieves average and maximum power consumption of 33.747 μW and 8.08 mW, respectively and chip area of 0.41184 mm2 only. The simulation result shows the correct matching of data against the threshold value. Compared with the conventional matched filter, the design achieves 25% power reduction (maximum power) and 51% chip area reduction. Therefore, the design will help to implement a low‐power matched filter for IEEE 801.11 compatible RFID tag. Copyright © 2013 John Wiley & Sons, Ltd.
Optimized quantification of lymphocyte subsets by use of CD7 and CD33
Authors: Hauser Andrea , Schrattbauer Karl , Najdanovic Djurdjica , Schlossnickel Regina , Koch Astrid , Hejtman Milos , Krugluger Walter 
Published: January 2013

AbstractIdentification and quantification of lymphocyte subsets is based on the expression of specific cell surface antigens. As only a minority of these structures is lineage‐restricted gating strategies were established, which should permit to include a maximum of lymphocytes, to reach a high purity within the gate and to avoid specific loss of subsets. Two problems remain: First, the incomplete removal of nonlymphoid cells when CD14 is used to exclude them from the lymphocyte gate. Second, the lack of a restricted marker to identify NK cells that are usually defined as CD3‐/CD16/56+ lymphocytes, though contaminating monocyte subsets share the expression of CD16, respectively, CD56. This study demonstrates the advantage of CD33 over CD14 at the creation of a pure lymphocyte gate, because CD33 enables the exclusion of all monocyte subpopulations as well as basophils and granulocytes. Independent of the applied NK cell marker mean purity was significantly higher, when CD33 was used (P < 0.001). For the identification of NK cells, CD7 was compared with CD16/56 and with single stained CD56. CD7 and CD16/56 exhibited as equivalent in various CD33 settings (P ≥ 0.173), whereas the mean proportion of CD56+ NK cells was significantly lower (P ≤ 0.008). Use of CD14 entailed a significantly higher amount of CD3‐/CD16/56+ cells than of CD3‐/CD7+ cells (P = 0.008) because of the remaining CD14‐/CD16+ monocytes. As CD7 is restricted to T cells and NK cells in peripheral blood, misclassification of contaminating monocytes is avoided and CD7+ NK cells can be identified by lack of CD3. Applying this new selection of mAbs, we reached a mean purity of ≥99.50% within the revised lymphocyte gate. As gates can be set very broadly, high inclusivity and high purity are not mutually exclusive. We propose the adoption of CD7 and CD33 for the quantification of lymphocyte subsets. © 2013 International Society for Advancement of Cytometry
Ovarian hormones and emotional eating associations across the menstrual cycle: An examination of the potential moderating effects of body mass index and dietary restraint
Authors: Klump Kelly L. , Keel Pamela K. , Burt S. Alexandra , Racine Sarah E. , Neale Michael C. , Sisk Cheryl L. , Boker Steven 
Published: January 2013

AbstractObjective:Associations between within‐person changes in ovarian hormones and dysregulated eating (binge eating, emotional eating) have been observed across the menstrual cycle. However, studies have not examined moderators that may contribute to differential associations between individuals. We investigated body‐weight regulation variables [body mass index (BMI), dietary restraint] that have theoretical relevance by virtue of their associations with both phenotypes.Method:Women (N = 196) provided emotional eating ratings and saliva samples for 45 days. BMI and restraint were assessed at three time points and averaged.Results:Results showed significant estradiol × progesterone interactions in the prediction of within‐subject changes in emotional eating. Neither BMI nor restraint moderated these relationships, although a trend‐level dietary restraint × estradiol interaction was observed where estradiol's effects were enhanced in high restraint scorers.Discussion:Findings confirm a role for hormones in changes in emotional eating and suggest that restraint might enhance hormone effects in severegroups. © 2013 by Wiley Periodicals, Inc. (Int J Eat Disord 2013)
Synthesis, Characterizations, and Morphological Studies of Polyoxometalate‐Containing Rod–Coil Diblock Copolymers
Authors: Chakraborty Sanjiban , Jin Lu , Li Yong , Liu Yucong , Dutta Tanmoy , Zhu Da‐Ming , Yan Xingzhong , Keightley Andrew , Peng Zhonghua 
Published: January 2013

AbstractA set of hybrid rod–coil diblock copolymers containing different sizes of poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) as the rod block and a polystyryl‐type (PS) coil block with covalently linked polyoxometalates (POMs) as side chains have been synthesized. The P3HT rod blocks, synthesized using Grignard metathesis polymerization, and the PS coil block, prepared by atom transfer radical polymerization were successfully coupled using “click” chemistry to form the rod–coil diblock copolymers (PS‐PTn). POM cluster attachment was performed on the diblock copolymers through a post‐polymerization functionalization approach. The thin film morphology of the diblock copolymers prior to cluster attachment shows a strong dependence on the solvent and the size of the P3HT block. Following cluster attachment, the hybrid diblock copolymers show much less solvent and size dependence in phase‐separated morphologies of their pristine films. The sporadic and isolated conducting domains seen in the pristine films change to widespread worm‐like conducting networks after thermal annealing; such morphologies are conducive to photovoltaic properties.
Coordination Versatility and Amide Shift in Mononuclear FeII Complexes with the Asymmetrical Tripod [(6‐Bromo‐2‐pyridyl)methyl][(6‐pivaloylamido‐2‐pyridyl)methyl](2‐pyridylmethyl)amine (BrMPPA)
Authors: Thibon Aurore , Karmazin‐Brelot Lydia , Mandon Dominique 
Published: January 2013

AbstractWe report in this communication the preparation of the BrMPPA ligand, a new tris(2‐pyridylmethyl)amine‐type tripod in which di‐α‐substitution by an amido group and a bromine atom, respectively, provide functionality and sterically induced ligand flexibility. The coordination versatility of this tripod is evidenced by the complete characterization of two dichlorido and di‐triflato FeII complexes in the solid state and in solution. The new tripod can potentially act as a κ5 ligand with coordination of the carbonyl group of the amide function. This is true when there is little steric hindrance at the coordination site. With bulky chlorido ligands, however, decoordination occurs, and the tripod becomes a κ4 chelate. In this case, a state‐dependent coordination mode is reported: A dangling pyridyl group is observed in solution, whereas the carbonyl group is noncoordinated in the solid state, the three pyridine groups remaining bound.
Repeatability of odour preferences across time
Authors: Craig Roberts S. , Havlíček Jan , Petrie Marion 
Published: January 2013

ABSTRACTHuman body odour is often associated with negative attributions, hence the term ‘malodour’. Another perspective is that odours contain biologically meaningful information involved in communication of social cues, notably in perception of suitable mates. This evolutionarily informed perspective indicates that we retain capacity to infer mate quality through olfaction (e.g. preferring odours of high‐quality or genetically compatible individuals). From either perspective, knowing the extent to which body odour is stable over time is important: either in order to fully understand how perfumes might interact with body odour or whether the biological cues gained from odour are reliable. In addition, from the second perspective, odour‐based mate preferences should also be relatively stable over time, especially if both traits and preferences are genetically influenced. Here we measured repeatability in young women of body odour preferences for male odours, over a 3‐month period. We also compare stability of body odour preferences with that of preferences for faces and fragrances. We find that preferences for all stimuli were highly repeatable over time. Since the odour stimuli used were repeated samples from the same set of men, repeatability of preferences also indicates odour constancy of individuals over time. Our results on both odour constancy and repeatability of preference have implications for the perfume industry and also lend weight to the assumption that body odour constitutes a meaningful cue of quality that can be used in individual assessment during human interactions. Copyright © 2013 John Wiley & Sons, Ltd.
Der Charme der Transparenz
Authors: Roye Andreas 
Published: January 2013

AbstractNeue 3‐D‐Textilien und Fertigungsverfahren bilden die Grundlagen für Lichtbetonelemente, die Festigkeit und Dauerhaftigkeit mit Leichtigkeit verbinden. Der „Lichtbeton 2.0”︁ eröffnet ungeahnte Möglichkeiten für den Erkenntnistransfer in die Praxis.
Das Ende des Waldes auf dem Dach der Welt
Authors: Miehe Georg , Opgenoorth Lars 
Published: January 2013

AbstractIm Tibetischen Hochland und im Himalaya untersuchen Biogeografen die höchstgelegenen Baum‐ und Waldinseln der Nordhemisphäre. Ihre interdisziplinären Studien zeigen im Detail, wie tief der Mensch und das Klima in die Natur eingegriffen haben.
Fetal exposure to 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin transactivates aryl hydrocarbon receptor‐responsive element III in the tyrosine hydroxylase immunoreactive neurons of the mouse midbrain
Authors: Tanida Takashi , Tasaka Ken , Akahoshi Eiichi , Ishihara‐Sugano Mitsuko , Saito Michiko , Kawata Shigehisa , Danjo Megumi , Tokumoto Junko , Mantani Youhei , Nagahara Daichi , Tabuchi Yoshiaki , Yokoyama Toshifumi , Kitagawa Hiroshi , Kawata Mitsuhiro , Hoshi Nobuhiko 
Published: January 2013

ABSTRACTFetal exposure to dioxins and related compounds is known to disrupt normal development of the midbrain dopaminergic system, which regulates behavior, cognition and emotion. The toxicity of these chemicals is mediated mainly by aryl hydrocarbon receptor (AhR) signaling. Previously, we identified a novel binding motif of AhR, the AhR‐responsive element III (AHRE‐III), in vitro. This motif is located upstream from the gene encoding tyrosine hydroxylase (TH), the rate‐limiting enzyme of dopamine biosynthesis. To provide in vivo evidence, we investigated whether 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) could regulate AHRE‐III transcriptional activity in midbrain dopaminergic neurons. We produced transgenic mice with inserted constructs of the AHRE‐III enhancers, TH gene promoter and the c‐myc‐tagged luciferase gene. Single oral administrations of TCDD (0–2000 ng kg–1 body weight) to the transgenic dams markedly enhanced TH‐immunoreactive (ir) intensity in the A9, A10 and A8 areas of their offspring at 3 days and 8 weeks of age. The offspring of dams treated with 200 ng kg–1 TCDD exhibited significant increases in the numbers of TH‐ and double (TH and c‐myc)‐ir neurons in area A9 compared with controls at 8 weeks. These results show that fetal exposure to TCDD upregulates TH expression and increases TH‐ir neurons in the midbrain. Moreover, the results suggest that TCDD directly transactivates the TH promoter via the AhR‐AHRE‐III‐mediated pathway in area A9. Fetal exposure to TCDD caused stable upregulation of TH via the AhR‐AHRE‐III signaling pathway and overgrowth of TH‐ir neurons in the midbrain, implying possible involvement in the etiology of neurodevelopmental disorders such as attention‐deficit/hyperactivity disorder (ADHD). Copyright © 2013 John Wiley & Sons, Ltd.
Effects of the mold temperature on the mechanical properties and crystallinity of hydroxyapatite whisker‐reinforced polyetheretherketone scaffolds
Authors: Conrad Timothy L. , Jaekel David J. , Kurtz Steven M. , Roeder Ryan K. 
Published: January 2013

AbstractPorous and bioactive polyetheretherketone (PEEK) scaffolds have potential to replace metallic scaffolds for biologic fixation of permanent implants adjacent to trabecular bone, such as interbody spinal fusion devices. The objective of this study was to investigate the effects of the mold temperature and PEEK powder on the mechanical properties and crystallinity of hydroxyapatite (HA) whisker‐reinforced PEEK scaffolds prepared using compression molding and porogen leaching. Scaffolds were prepared at mold temperatures ranging 340–390°C with a 50 or 10 μm PEEK powder, 75 vol% porosity, and 20 vol% HA whiskers. Scaffold mechanical properties were evaluated in unconfined, uniaxial compression and the PEEK matrix crystallinity was measured using specular reflectance Fourier transform infrared spectroscopy. Increased mold temperature resulted in increased compressive modulus, yield strength, and yield strain, reaching a plateau at ∼370°C. HA reinforcements were observed to be segregated between PEEK particles, which inhibited PEEK particle coalescence during compression molding at temperatures less than 365°C but also ensured that bioactive HA reinforcements were exposed on scaffold strut surfaces. Increased mold temperature also resulted in decreased PEEK crystallinity, particularly for scaffolds molded at greater than 375°C. The PEEK powder size exhibited relatively minor effects on the scaffold mechanical properties and PEEK crystallinity. Therefore, the results of this study suggested that HA‐reinforced PEEK scaffolds should be compression molded at 370–375°C. The apparent compressive modulus, yield strength, and yield strain for scaffolds molded at 370–375°C was 75–92 MPa, 2.0–2.2 MPa, and 2.5–3.6%, respectively, which was within the range exhibited by human vertebral trabecular bone. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Arsenic and the Epigenome: Interindividual Differences in Arsenic Metabolism Related to Distinct Patterns of DNA Methylation
Authors: Bailey Kathryn A. , Wu Michael C. , Ward William O. , Smeester Lisa , Rager Julia E. , García‐Vargas Gonzalo , Del Razo Luz‐Maria , Drobná Zuzana , Stýblo Miroslav , Fry Rebecca C. 
Published: January 2013

ABSTRACTBiotransformation of inorganic arsenic (iAs) is one of the factors that determines the character and magnitude of the diverse detrimental health effects associated with chronic iAs exposure, but it is unknown how iAs biotransformation may impact the epigenome. Here, we integrated analyses of genome‐wide, gene‐specific promoter DNA methylation levels of peripheral blood leukocytes with urinary arsenical concentrations of subjects from a region of Mexico with high levels of iAs in drinking water. These analyses revealed dramatic differences in DNA methylation profiles associated with concentrations of specific urinary metabolites of arsenic (As). The majority of individuals in this study had positive indicators of As‐related disease, namely pre‐diabetes mellitus or diabetes mellitus (DM). Methylation patterns of genes with known associations with DM were associated with urinary concentrations of specific iAs metabolites. Future studies will determine whether these DNA methylation profiles provide mechanistic insight into the development of iAs‐associated disease, predict disease risk, and/or serve as biomarkers of iAs exposure in humans. © 2012 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:106‐115, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21462