bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface effects on the diagnostic of carbon/nitrogen low‐pressure plasmas studied by differentially pumped mass spectrometry
Authors: Alegre Daniel , Ferreira Jose A. , Tabarés Francisco L.
Published: April 2014

In this work, the characterization of the species produced in reactive plasmas by differentially pumped mass spectrometry is addressed. A H2/CH4/N2 mixture (90 : 5 : 5) was fed into a direct current glow discharge and analysed by conventional and cryo‐trap assisted mass spectrometry. The gaseous mixture was chosen because of its particular relevance in the inhibition of tritium‐rich carbon film deposition in fusion plasmas (scavenger technique) and in the deposition of amorphous hydrogenated carbon films by plasma‐assisted chemical vapour deposition. Important changes in the composition of the detected species upon surface modification of the reactor walls (stainless steel or covered by an amorphous hydrogenated carbon layer) or in the way they are sampled (length and spatial configuration of the stainless steel duct) were detected. They are analysed in terms of radical formation and recombination on the reactor walls or into the sampling duct, thus providing some insight into the underlying chemistry. In general, when the reactor walls are covered by an amorphous hydrogenated carbon layer, more hydrocarbons are produced, but the radical production is lower and seem to be less reactive than in stainless steel. Also, two sources of oxygen contamination in the plasma have been identified, from the native oxide layer in stainless steel and from unintended water contamination in the chamber, which modify considerably the detected species. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization of forced degradation products of ketorolac tromethamine using LC/ESI/Q/TOF/MS/MS and in silico toxicity prediction
Authors: Kalariya Pradipbhai D. , Raju B. , Borkar Roshan M. , Namdev Deepak , Gananadhamu S. , Nandekar Prajwal P. , Sangamwar Abhay T. , Srinivas R.
Published: April 2014

Ketorolac, a nonsteroidal anti‐inflammatory drug, was subjected to forced degradation studies as per International Conference on Harmonization guidelines. A simple, rapid, precise, and accurate high‐performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (LC/ESI/Q/TOF/MS/MS) method has been developed for the identification and structural characterization of stressed degradation products of ketorolac. The drug was found to degrade in hydrolytic (acidic, basic, and neutral), photolytic (acidic, basic, and neutral solution), and thermal conditions, whereas the solid form of the drug was found to be stable under photolytic conditions. The method has shown adequate separation of ketorolac tromethamine and its degradation products on a Grace Smart C‐18 (250 mm × 4.6 mm i.d., 5 µm) column using 20 mM ammonium formate (pH = 3.2): acetonitrile as a mobile phase in gradient elution mode at a flow rate of 1.0 ml/min. A total of nine degradation products were identified and characterized by LC/ESI/MS/MS. The most probable mechanisms for the formation of degradation products have been proposed on the basis of a comparison of the fragmentation of the [M + H]+ ions of ketorolac and its degradation products. In silico toxicity of the drug and degradation products was investigated by using topkat and derek softwares. The method was validated in terms of specificity, linearity, accuracy, precision, and robustness as per International Conference on Harmonization guidelines. Copyright © 2014 John Wiley & Sons, Ltd.
Assessment of the various ionization methods in the analysis of metal salen complexes by mass spectrometry
Authors: Słomińska Beata , Chaładaj Wojciech , Danikiewicz Witold
Published: April 2014

Metal salen complexes are one of the most frequently used catalysts in enantioselective organic synthesis. In the present work, we compare a series of ionization methods that can be used for the mass spectral analysis of two types of metalosalens: ionic complexes (abbreviated as Com+X−) and neutral complexes (NCom). These methods include electron ionization and field desorption (FD) which can be applied to pure samples and atmospheric pressure ionization techniques: electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) which are suitable for solutions. We found that FD is a method of choice for recording molecular ions of the complexes containing even loosely bonded ligands. The results obtained using atmospheric pressure ionization methods show that the results depend mainly on the structure of metal salen complex and the ionization method. In ESI spectra, Com+ ions were observed, while in APCI and APPI spectra both Com+ and [Com + H]+ ions are observed in the ratio depending on the structure of the metal salen complex and the solvent used in the analysis. For complexes with tetrafluoroborate counterion, an elimination of BF3 took place, and ions corresponding to complexes with fluoride counterion were observed. Experiments comparing the relative sensitivity of ESI, APCI and APPI (with and without a dopant) methods showed that for the majority of the studied complexes ESI is the most sensitive one; however, the sensitivity of APCI is usually less than two times lower and for some compounds is even higher than the sensitivity of ESI. Both methods show very high linearity of the calibration curve in a range of about 3 orders of magnitude of the sample concentration. Copyright © 2014 John Wiley & Sons, Ltd.
Haploinsufficiency of insulin gene enhancer protein 1 (ISL1) is associated with d‐transposition of the great arteries
Authors: Osoegawa Kazutoyo , Schultz Kathleen , Yun Kenneth , Mohammed Nebil , Shaw Gary M. , Lammer Edward J.
Published: April 2014

Congenital heart defects are the most common malformation, and are the foremost causes of mortality in the first year of life. Among congenital heart defects, conotruncal defects represent about 20% and are severe malformations with significant morbidity. Insulin gene enhancer protein 1 (ISL1) has been considered a candidate gene for conotruncal heart defects based on its embryonic expression pattern and heart defects induced in Isl1 knockout mice. Nevertheless no mutation of ISL1 has been reported from any human subject with a heart defect. From a population base of 974,579 births during 1999–2004, we used multiplex ligation‐dependent probe amplification to screen for microdeletions/duplications of ISL1 among 389 infants with tetralogy of Fallot or d‐transposition of the great arteries (d‐TGA). We also sequenced all exons of ISL1. We identified a novel 20‐kb microdeletion encompassing the entire coding region of ISL1, but not including either flanking gene, from an infant with d‐TGA. We confirmed that the deletion was caused by nonhomologous end joining mechanism. Sequencing of exons of ISL1 did not reveal any subject with a novel nonsynonymous mutation. This is the first report of an ISL1 mutation of a child with a congenital heart defect.
Analysis of 2‒D bimodular materials and wrinkled membranes based on the parametric variational principle and co‒rotational approach
Authors: Zhang L. , Gao Q. , Zhang H. W.
Published: April 2014

In the numerical analysis of 2‒D bimodular materials, strain discontinuity is problematic, and the traditional iterative algorithm is frequently unstable. This paper develops a stable algorithm for the large‒displacement and small‒strain analyses of 2‒D bimodular materials and structures. Geometrically nonlinear formulations are based on the co‒rotational approach. Using the parametric variational principle (PVP), a unified constitutive equation is created to resolve the problem induced by strain discontinuity in the local coordinate system. Because the traditional stress iteration is not required, the local linear stiffness matrix does not need to be updated when computing the global stiffness matrix and the nodal internal force vector. The nonlinear problem is ultimately transformed into a complementarity problem that is simply solved by combing the Newton–Raphson scheme and the mature quadratic programming algorithm. Numerical examples demonstrate that the PVP algorithm presents better convergence behavior than the traditional iterative algorithm. By incorporating the concept of material modification, the new algorithm is also be successfully extended to the wrinkling analysis of thin membranes. Copyright © 2014 John Wiley & Sons, Ltd.
Collaborative Measurement Development as a Tool in CBPR: Measurement Development and Adaptation within the Cultures of Communities
Authors: Gonzalez John , Trickett Edison J.
Published: April 2014

This paper describes the processes we engaged into develop a measurement protocol used to assess the outcomes in a community based suicide and alcohol abuse prevention project with two Alaska Native communities.
While the literature on community‐based participatory research (CBPR) is substantial regarding the importance of collaborations, few studies have reported on this collaboration in the process of developing measures to assess CBPR projects. We first tell a story of the processes around the standard issues of doing cross‐cultural work on measurement development related to areas of equivalence. A second story is provided that highlights how community differences within the same cultural group can affect both the process and content of culturally relevant measurement selection, adaptation, and development.
Trajectories of prosocial behavior from adolescence to early adulthood: Associations with personality change☆
Authors: Luengo Kanacri Bernadette P. , Pastorelli Concetta , Eisenberg Nancy , Zuffianò Antonio , Castellani Valeria , Caprara Gian Vittorio
Published: April 2014

The goal of this study was to identify heterogenic longitudinal patterns of change in prosocial behavior from adolescence to early adulthood and their association with change in Big Five Factor (BFF) personality traits from adolescence until early adulthood. Participants were 573 Italian adolescents aged approximately 13 at the first assessment and 21 at the last assessment. Using growth mixture modeling, low increasing (LI; 18%), medium quadratic (MQ; 26%), and high quadratic (HQ; 54%) trajectories of prosocial behavior were distinguished. Generally, the LI trajectory group predicted an increase in Conscientiousness over time, whereas the HQ trajectory group predicted greater change in Agreeableness and Openness. In addition, positive changes in Conscientiousness, Agreeableness, and Openness between ages 13 and 21 predicted a higher probability of belonging to the HQ prosocial group. Findings support a malleable perspective on personality and identify longterm positive pathways for youths' prosocial development.
Force spectroscopy studies on protein–ligand interactions: A single protein mechanics perspective
Authors: Hu Xiaotang , Li Hongbin
Published: April 2014

Protein–ligand interactions are ubiquitous and play important roles in almost every biological process. The direct elucidation of the thermodynamic, structural and functional consequences of protein–ligand interactions is thus of critical importance to decipher the mechanism underlying these biological processes. A toolbox containing a variety of powerful techniques has been developed to quantitatively study protein–ligand interactions in vitro as well as in living systems. The development of atomic force microscopy‐based single molecule force spectroscopy techniques has expanded this toolbox and made it possible to directly probe the mechanical consequence of ligand binding on proteins. Many recent experiments have revealed how ligand binding affects the mechanical stability and mechanical unfolding dynamics of proteins, and provided mechanistic understanding on these effects. The enhancement effect of mechanical stability by ligand binding has been used to help tune the mechanical stability of proteins in a rational manner and develop novel functional binding assays for protein–ligand interactions. Single molecule force spectroscopy studies have started to shed new lights on the structural and functional consequence of ligand binding on proteins that bear force under their biological settings.
YAP/TAZ as mechanosensors and mechanotransducers in regulating organ size and tumor growth
Authors: Low Boon Chuan , Pan Catherine Qiurong , Shivashankar G.V. , Bershadsky Alexander , Sudol Marius , Sheetz Michael
Published: April 2014

Organ size is controlled by the concerted action of biochemical and physical processes. Although mechanical forces are known to regulate cell and tissue behavior, as well as organogenesis, the precise molecular events that integrate mechanical and biochemical signals to control these processes are not fully known. The recently delineated Hippo‐tumor suppressor network and its two nuclear effectors, YAP and TAZ, shed light on these mechanisms. YAP and TAZ are proto‐oncogene proteins that respond to complex physical milieu represented by the rigidity of the extracellular matrix, cell geometry, cell density, cell polarity and the status of the actin cytoskeleton. Here, we review the current knowledge of how YAP and TAZ function as mechanosensors and mechanotransducers. We also suggest that by deciphering the mechanical and biochemical signals controlling YAP/TAZ function, we will gain insights into new strategies for cancer treatment and organ regeneration.
p53 and ribosome biogenesis stress: The essentials
Authors: Golomb Lior , Volarevic Sinisa , Oren Moshe
Published: April 2014

Cell proliferation and cell growth are two tightly linked processes, as the proliferation program cannot be executed without proper accumulation of cell mass, otherwise endangering the fate of the two daughter cells. It is therefore not surprising that ribosome biogenesis, a key element in cell growth, is regulated by many cell cycle regulators. This regulation is exerted transcriptionally and post‐transcriptionally, in conjunction with numerous intrinsic and extrinsic signals. Those signals eventually converge at the nucleolus, the cellular compartment that is not only responsible for executing the ribosome biogenesis program, but also serves as a regulatory hub, responsible for integrating and transmitting multiple stress signals to the omnipotent cell fate gatekeeper, p53. In this review we discuss when, how and why p53 is activated upon ribosomal biogenesis stress, and how perturbation of this critical regulatory interplay may impact human disease.
Slim by Design or by willpower? Replies to Herman and Polivy and to Roberto, Pomeranz, and Fisher
Authors: Wansink Brian , Chandon Pierre
Published: April 2014

In their commentary of our “Slim by Design” article, Herman and Polivy offer a simple and powerful model of food intake which focuses on the mediating role of hunger, taste, and appropriateness. In their commentary, Roberto, Pomeranz, and Fisher review both new and classic interventions aimed at reducing obesity and raise the issue of whether they can be scalable and sustainable without regulatory oversight. In this rejoinder, we examine the few differences between the Chandon & Wansink and the Herman & Polivy frameworks to highlight critical areas for future research, including focusing on overeating vs. intake, refining the role of normative drivers, and studying lay theories of overeating. We then resolve the questions raised by Roberto, Pomeranz, and Fisher by providing concrete examples of low‐cost design changes that are scalable and sustainable because they benefit both healthy eating and the overall sales and profitability of school and workplace cafeterias.
Association between C‐reactive protein, corrected QT interval and presence of QT prolongation in hypertensive patients
Authors: Chang Kai‐Ting , Shu Hsu‐Shien , Chu Chun‐Yuan , Lee Wen‐Hsien , Hsu Po‐Chao , Su Ho‐Ming , Lin Tsung‐Hsien , Voon Wen‐Chol , Lai Wen‐Ter , Sheu Sheng‐Hsiung
Published: April 2014

C‐reactive protein (CRP) and corrected QT (QTc) interval are predictors of cardiovascular disease. Whether CRP is associated with QTc interval and QT prolongation is unknown in hypertensive patients. We recruited hypertensive patients from a cardiovascular clinic in a tertiary medical center in Taiwan. All received standard 12‐lead electrocardiogram examination. QT prolongation was defined as QTc interval ≥440 ms in men or ≥450 ms in women. High‐sensitive CRP kits were used for the measurement of the CRP levels. A total of 466 consecutive patients were finally enrolled. Mean age was 60.6 ± 12.0 years. CRP level was correlated with QTc interval (p < 0.001) and presence of QT prolongation (p = 0.014). Multivariate regression analysis showed that CRP level (p = 0.001), age (p = 0.004), sex (p < 0.001), height (p = 0.001), low‐density lipoprotein (p = 0.041), and QRS interval (p < 0.001) were associated with QTc interval. Furthermore, CRP level [odds ratio (OR) = 1.203, 95% confidence interval (CI) = 1.027–1.410, p = 0.022], age (OR = 1.040, 95% CI = 1.010–1.071, p = 0.009), waist (OR = 1.033, 95% CI = 1.000–1.066, p = 0.047), triglyceride (OR = 0.993, 95% CI = 0.987–0.999, p = 0.021) and QRS interval (OR = 1.046, 95% CI = 1.028–1.065, p < 0.001) independently predicted the presence of QT prolongation. Because CRP is an independent predictor of QTc interval and presence of QT prolongation, it could be considered in the risk assessment for hypertensive patients.
The preliminary experiences of translocation renal cell carcinoma and literature review
Authors: Su Hsin‐Hao , Sung Ming‐Tse , Chiang Po‐Hui , Cheng Yunan‐Tso , Chen Yen‐Ta
Published: April 2014

Xp11.2 translocation renal cell carcinoma (RCC) is rare and predominantly found in children and young adults. Because of the property of overexpressed transcription factor E3 (TFE3) fusion protein, immunohistochemical (IHC) staining with TFE3 antibody makes an excellent diagnostic tool. This study analyzed preliminary experiences of eight Xp11.2 translocation RCCs in our institution between 2007 and 2012. In four males and four females with a mean age of 28.4 years. Xp11.2 translocation RCCs were diagnosed. TFE3 IHC stain was positive in all tumor specimens. As the initial presentation, four patients suffered from abdominal pain, three cases had gross hematuria, and one case had hemoptysis caused by existing lung metastasis. The tumor was located in the right kidney (75%) with mean diameter of 5.85 ± 2.64 cm. Three cases (38%, 3/8) presented with lymph node metastasis at the time of diagnosis. In five cases (63%, 5/8), the initial diagnosis was Stage III and IV. Treatment included open surgery (one partial nephrectomy and five radical nephrectomies), cryoablation, immunotherapy, and target therapy. The mean follow‐up time was 32 months. One patient died after 23.4 months of follow‐up. The application of TFE3 IHC stain will improve the diagnostic accuracy for detecting XP11.2 translocation renal cell carcinoma. Surgery or cryoablation both had excellent prognosis in early stages. Although the disease is believed to be indolent, an increasingly aggressive clinical course should be kept in mind, especially for children and young adults.
Combined Flexor Carpi Radialis Tear and Flexor Carpi Radialis Brevis Tendinopathy Identified by Ultrasound: A Case Report
Authors: Smith Jay , Kakar Sanjeev
Published: April 2014

A 63‐year‐old right‐handed office worker presented with acute right wrist pain after lifting a heavy file at work. Results of a clinical examination suggested flexor carpi radialis tendinopathy. Diagnostic ultrasound (US) not only detected a complete flexor carpi radialis tear but also revealed the presence of a concomitant flexor carpi radialis brevis (FCRB) tendon with associated tenosynovitis. The ability of US to correctly identify the FCRB has not been previously reported. Furthermore, the US appearance of FCRB tendinopathy and tenosynovitis has not been described. High‐resolution US can identify the FCRB muscle‐tendon in the wrist region. Sonologists and sonographers should be aware of the US appearance of the FCRB as well as the potential for the FCRB to contribute to radial wrist pain syndromes.
Zur Bedeutung von sozialer Unterstützung während der Schwangerschaft
Authors: Ulrich Franziska , Petermann Franz
Published: April 2014

Eine wachsende Zahl an Studien dokumentiert die negativen Auswirkungen von mütterlichen psychosozialen Stressoren (z. B. mütterliche Depression) und gesundheitsrelevanten Verhaltensweisen (z. B. Nikotin- und Alkoholkonsum) während der Schwangerschaft auf den Geburtsausgang. Jedoch werden mütterliche Ressourcen in diesem Kontext noch unzureichend berücksichtigt. Das Ziel ist es daher, die Bedeutung sozialer Unterstützung als frühe Ressource im Schwangerschaftsverlauf und zum Zeitpunkt der Geburt im Hinblick auf das Gesundheitsverhalten der Schwangeren und im Hinblick auf Geburtsmaße zu untersuchen. Die Datenbanken Web of Science und PubMed wurden entsprechend nach deutsch- und englischsprachigen Beiträgen für den Zeitraum 2003 bis 2013 durchsucht. 23 Studien erfüllten die Auswahlkriterien. Die Ergebnisse verdeutlichen, dass die Befundlage sehr inkonsistent ist, was teilweise auf die unterschiedlichen Definitionen sozialer Unterstützung und die Nutzung verschiedener Erhebungsinstrumente zurückzuführen ist. Des Weiteren fehlt es an Studien zur Bedeutung sozialer Unterstützung im Kontext mütterlicher psychosozialer Stressoren und Geburtsmaßen. Es bedarf weiterer Studien an Risiko- und Allgemeinpopulationen, die auf der Basis eines fundierten Rahmenkonzeptes mögliche Effekte der sozialen Unterstützung differenziert analysieren können.
Musik–Energie–Therapie
Authors: Mastnak Wolfgang
Published: April 2014

Der Beitrag setzt sich zunächst kritisch mit dem Begriff der Energie in Therapie und Psychosomatik auseinander und zeigt die Heterogenität der Begriffe im wissenschaftlichen Kontext auf, z. B. im Bereich von Pulsaren. Dem humanwissenschaftlich orientierten Aspekt wird der musikologische gegenübergestellt: Energie in der Musik als perkussiv-motorisches Moment, als Klangdichte und in ihrer dynamischen Spannung. Auf diesen Grundlagen werden musiktherapeutische Ansätze und Praktiken mit energetischem Fokus dargestellt: von musikgeleiteten Energetisierungen und dem Lösen energetischer Blockaden über die Methode des Sound Energizing bis zu Energieprozessen in archaischen Kulttechniken oder in der traditionellen chinesischen Medizin. Dabei kommen auch Fragestellungen zur Kontraindikation von Energiearbeit in der Musiktherapie zur Sprache.
Graphene mechanics: I. Efficient first principles based Morse potential
Authors: Costescu Bogdan I. , Baldus Ilona B. , Gräter Frauke
Published: April 2014

We present a computationally efficient pairwise potential for use in molecular dynamics simulations of large graphene or carbon nanotube systems, in particular those under mechanical deformation, and also for mixed systems including biomolecules.
Graphene mechanics: II. Atomic stress distribution during indentation until rupture
Authors: Costescu Bogdan I. , Gräter Frauke
Published: April 2014

Using the Time-Resolved Force Distribution Analysis, we find a high stress concentration in the graphene sheet under the indenter tip, while the rest of the sheet remains at background stress levels.
TPPi as a flame retardant for rechargeable lithium batteries with sulfur composite cathodes
Authors: Jia Hao , Wang Jiulin , Lin Fengjiao , Monroe Charles W. , Yang Jun , NuLi Yanna
Published: April 2014

In this work, TPPi was adopted as a flame retardant additive into the traditional electrolyte 1 M LiPF6/EC + DMC (1 : 1, v/v) which not only enhanced the carbonates' thermal properties but also improved the electrochemical performances of rechargeable Li-S batteries.
H2 spillover enhanced hydrogenation capability of TiO2 used for photocatalytic splitting of water: a traditional phenomenon for new applications
Authors: Zhu Yingming , Liu Dongsheng , Meng Ming
Published: April 2014

Hydrogen spillover involved hydrogenation of crystal TiO2 greatly increases its photocatalytic activity and stability for water splitting to produce H2.
Insight into the structure and the mechanism of the slow proton transfer in the GFP double mutant T203V/S205A
Authors: Wineman-Fisher Vered , Simkovitch Ron , Shomer Shay , Gepshtein Rinat , Huppert Dan , Saif Mari , Kallio Karen , Remington S. James , Miller Yifat
Published: April 2014

This work proposes an alternative pathway that explains the slow PT in the GFP double mutant T203V/S205A compared to wt-GFP.
Analysis of hydrogen bond energies and hydrogen bonded networks in water clusters (H2O)20 and (H2O)25 using the charge-transfer and dispersion terms
Authors: Iwata Suehiro
Published: April 2014

The relationship of the charge-transfer and dispersion terms with the O–O length for every pair of hydrogen bonded water molecules in the isomers of (H2O)17–(H2O)21.
Microdevice arrays of high aspect ratio poly(dimethylsiloxane) pillars for the investigation of multicellular tumour spheroid mechanical properties
Authors: Aoun Laurène , Weiss Pierre , Laborde Adrian , Ducommun Bernard , Lobjois Valérie , Vieu Christophe
Published: April 2014

A PDMS microdevice made of a circle of high aspect ratio micropillars, acting as flexible force sensors, dedicated to the investigation of mechanical properties on the tissue scale.
Impedance spectroscopic analysis on effects of partial oxidation of TiN bottom electrode and microstructure of amorphous and crystalline HfO2 thin films on their bipolar resistive switching
Authors: Yoon Ji-Wook , Yoon Jung Ho , Lee Jong-Heun , Hwang Cheol Seong
Published: April 2014

Microscopic-level changes such as the dynamic evolutions in conducting filament, interfacial TiON region, and matrix phase during various steps of resistance switching were studied using AC impedance spectroscopy.
N[1,3]-sigmatropic shift in the benzidine rearrangement: experimental and theoretical investigation
Authors: Hou Shili , Li Xinyao , Xu Jiaxi
Published: April 2014

The N[1,3]-sigmatropic shift with an inversion of the configuration in the migrating nitrogen atom exists in the formation of semidines and diphenyline.
Synthesis and characterization of polyfluorene-based photoelectric materials: the effect of coil segment on the spectral stability
Authors: Li Jin-Jin , Wang Jian-Jian , Zhou Yin-Ning , Luo Zheng-Hong
Published: April 2014

The spectral stability of polyfluorene-based copolymers could be improved through incorporating an appropriate coil segment.
Simultaneous immobilization of a matrix containing palladium and phase transfer catalyst on silica nanoparticles: application as a recoverable catalyst for the Heck reaction in neat water
Authors: Hajipour Abdol R. , Azizi Ghobad
Published: April 2014

Simultaneous anchoring of phosphonium salts and palladium catalyst on silica nanoparticles and the application in the Heck reaction in water is described.
Mechanistic insight into the selective crystallization of the metastable polymorph of tolbutamide in ethanol–water solution
Authors: Zhang Jinli , Wu Yujia , Liu Anyuan , Li Wei , Han You
Published: April 2014

A combined experimental and molecular dynamics simulation study discloses the effects of solvents and supersaturation on the tolbutamide polymorphs outcome.
Conducting poly(azomethine)esters: synthesis, characterization and insight into the electronic properties using DFT calculations
Authors: Gul Asghari , Akhter Zareen , Qureshi Rumana , Bhatti Arshad S.
Published: April 2014

Electrostatic potential map, PI; yellow colour around ‘N’ and ‘O’ atoms indicate electron rich area prone to the electrophilic attack.
Copper-catalyzed N-arylation of azoles and diazoles using highly functionalized trivalent organobismuth reagents
Authors: Petiot Pauline , Dansereau Julien , Gagnon Alexandre
Published: April 2014

TheN-arylation of indoles, indazoles, pyrroles, and pyrazoles using highly functionalized trivalent arylbismuth reagents is reported.
Flexible one diode–one resistor resistive switching memory arrays on plastic substrates
Authors: Yoo Hyeon Gyun , Kim Seungjun , Lee Keon Jae
Published: April 2014

Flexible one diode–one resistor resistive random access memory (RRAM) with 8 × 8 arrays composed of high-performance silicon diodes and a resistive change material for fully functional flexible memory operation.
Robust microcapsules with polyurea/silica hybrid shell for one-part self-healing anticorrosion coatings
Authors: Wu Gang , An Jinliang , Sun Dawei , Tang Xiuzhi , Xiang Yong , Yang Jinglei
Published: April 2014

HDI-filled silica/polyurea hybrid microcapsules with superior thermal stability and solvent resistance were prepared and applied to one-part self-healing anticorrosion coatings.
Peptide-based isolation of circulating tumor cells by magnetic nanoparticles
Authors: Bai Linling , Du Yimeng , Peng Jiaxi , Liu Yi , Wang Yanmei , Yang Yanlian , Wang Chen
Published: April 2014

A new CTC isolation method with high efficiency by using EpCAM recognition peptide functionalized magnetic nanoparticles was developed.
Size-controlled growth of germanium nanowires from ternary eutectic alloy catalysts
Authors: O'Regan Colm , Biswas Subhajit , Barth Sven , Morris Michael A. , Petkov Nikolay , Holmes Justin D.
Published: April 2014

We report the simultaneous manipulation of both solute and equilibrium concentration of Ge to synthesise high aspect-ratio Ge nanowires.
Topology and glass structure evolution in (BaO)x((B2O3)32(SiO2)68)100 − x ternary—Evidence of rigid, intermediate, and flexible phases
Authors: Holbrook C. , Chakraborty Shibalik , Ravindren S. , Boolchand P. , Goldstein Jonathan T. , Stutz C. E.
Published: April 2014

We examine variations in the glass transition temperature (Tg(x)), molar volume (Vm(x)), and Raman scattering of titled glasses as a function of modifier (BaO) content in the 25% < x < 48% range. Three distinct regimes of behavior are observed; at low x, 24% < x < 29% range, the modifier largely polymerizes the backbone, Tg(x) increase, features that we identify with the stressed-rigid elastic phase. At high x, 32% < x < 48% range, the modifier depolymerizes the network by creating non-bridging oxygen (NBO) atoms; in this regime Tg(x) decreases, and networks are viewed to be in the flexible elastic phase. In the narrow intermediate x regime, 29% < x < 32% range, Tg(x) shows a broad global maximum almost independent of x, and Raman mode scattering strengths and mode frequencies become relatively x-independent, Vm(x) show a global minimum, features that we associate with the isostatically rigid elastic phase, also called the intermediate phase. In this phase, medium range structures adapt as revealed by the count of Lagrangian bonding constraints and Raman mode scattering strengths.
Synthesis of highly efficient antibacterial agent Ag doped ZnO nanorods: Structural, Raman and optical properties
Authors: Jan Tariq , Iqbal Javed , Ismail Muhammad , Mahmood Arshad
Published: April 2014

Here, synthesis, structural, morphological, Raman, optical properties and antibacterial activity of undoped and Ag doped ZnO nanorods by chemical co-precipitation technique have been reported. Structural analysis has revealed that Ag doping cannot deteriorate the structure of ZnO and wurtzite phase is maintained. Lattice constants are found to be decreased with the Ag doping. Fourier transform infrared and Raman spectroscopy also confirm the X-ray diffraction results. Scanning electron microscopy results have demonstrated the formation of ZnO nanorods with average diameter and length of 96 nm and 700 nm, respectively. Raman spectroscopy results suggest that the Ag doping enhances the number of defects in ZnO crystal. It has been found from optical study that Ag doping results in positional shift of band edge absorption peak. This is attributed to the successful incorporation of Ag dopant into ZnO host matrix. The antibacterial activity of prepared nanorods has been determined by two different methods and compared to that of undoped ZnO nanorods. Ag doped ZnO nanorods exhibit excellent antibacterial activity as compared to that of undoped ZnO nanorods. This excellent antibacterial activity may be attributed to the presence of oxygen vacancies and Zn2+ interstitial defects. Our preliminary findings suggest that Ag doped ZnO nanorods can be used externally to control the spreading of infections related with tested bacterial strains.
Investigation of giant magnetoconductance in organic devices based on hopping mechanism
Authors: Yang F. J. , Qin W. , Xie S. J.
Published: April 2014

We suggest a spin-dependent hopping mechanism which includes the effect of the external magnetic field as well as hyperfine interaction (HFI) to explain the observed giant magnetoconductance (MC) in non-magnetic organic devices. Based on the extended Marcus theory, we calculate the MC by using the master equation. It is found that a MC value as large as 91% is obtained under a low driving voltage. For suitable parameters, the theoretical results are in good agreement with the experimental data. Influences of the carrier density, HFI, and the carrier localization on the MC value are investigated. Especially, it is found that a low-dimensional structure of the organic materials is favorable to get a large MC value.
Magnetoresistance in Mn ion-implanted GaAs:Zn nanowires
Authors: Paschoal W. , Kumar Sandeep , Jacobsson D. , Johannes A. , Jain V. , Canali C. M. , Pertsova A. , Ronning C. , Dick K. A. , Samuelson L. , Pettersson H.
Published: April 2014

We have investigated the magnetoresistance (MR) in a series of Zn doped (p-type) GaAs nanowires implanted with different Mn concentrations. The nanowires with the lowest Mn concentration (∼0.0001%) exhibit a low resistance of a few kΩ at 300 K and a 4% positive MR at 1.6 K, which can be well described by invoking a spin-split subband model. In contrast, nanowires with the highest Mn concentration (4%) display a large resistance of several MΩ at 300 K and a large negative MR of 85% at 1.6 K. The large negative MR is interpreted in terms of spin-dependent hopping in a complex magnetic nanowire landscape of magnetic polarons, separated by intermediate regions of Mn impurity spins. Sweeping the magnetic field back and forth for the 4% sample reveals a hysteresis that indicates the presence of a weak ferromagnetic phase. We propose co-doping with Zn to be a promising way to reach the goal of realizing ferromagnetic Ga1−xMnxAs nanowires for future nanospintronics.
An ultra-high vacuum electrochemical flow cell for in situ/operando soft X-ray spectroscopy study
Authors: Bora Debajeet K. , Glans Per-Anders , Pepper John , Liu Yi-Sheng , Du Chun , Wang Dunwei , Guo J.-H.
Published: April 2014

An in situ flow electrochemical cell has been designed and fabricated to allow better seal under UHV chamber thus to achieve a good signal to noise ratio in fluorescence yield detection of X-ray absorption spectra for spectroelectrochemical study. The cell also stabilizes the thin silicon nitride membrane window in an effective manner so that the liquid cell remains intact during X-ray absorption experiments. With the improved design of the liquid cell, electrochemical experiments such as cyclic voltammetry have been performed for 10 cycles with a good stability of sample window. Also an operando electrochemical experiment during photoelectrochemistry has been performed on n-type hematite electrode deposited on silicon nitride window. The experiment allows us to observe the formation of two extra electronic transitions before pre edge of O K-edge spectra.
High fidelity qubit readout with the superconducting low-inductance undulatory galvanometer microwave amplifier
Authors: Hover D. , Zhu S. , Thorbeck T. , Ribeill G. J. , Sank D. , Kelly J. , Barends R. , Martinis John M. , McDermott R.
Published: April 2014

We describe the high fidelity dispersive measurement of a superconducting qubit using a microwave amplifier based on the Superconducting Low-inductance Undulatory Galvanometer (SLUG). The SLUG preamplifier achieves gain of 19 dB and yields a signal-to-noise ratio improvement of 9 dB over a state-of-the-art HEMT amplifier. We demonstrate a separation fidelity of 99% at 700 ns compared to 59% with the HEMT alone. The SLUG displays a large dynamic range, with an input saturation power corresponding to 700 photons in the readout cavity.
On equivalence of high temperature series expansion and coupling parameter series expansion in thermodynamic perturbation theory of fluids
Authors: Sai Venkata Ramana A.
Published: April 2014

The coupling parameter series expansion and the high temperature series expansion in the thermodynamic perturbation theory of fluids are shown to be equivalent if the interaction potential is pairwise additive. As a consequence, for the class of fluids with the potential having a hardcore repulsion, if the hard-sphere fluid is chosen as reference system, the terms of coupling parameter series expansion for radial distribution function, direct correlation function, and Helmholtz free energy follow a scaling law with temperature. The scaling law is confirmed by application to square-well fluids.
Influence of skin effect on the effective shielding effectiveness of composite materials
Authors: Préault Valentin , Corcolle Romain , Daniel Laurent , Pichon Lionel
Published: April 2014

Composite materials are increasingly used to contribute to structure lightening in electromagnetic shielding applications. The interactions between electromagnetic waves and composite materials are highly dependent on their microstructure. This gives rise to challenging modelling issues. Considering details of the microstructure would involve an excessive number of unknowns with standard numerical tools for structural analysis. Homogenisation methods—such as Maxwell-Garnett model—are a possibility to overcome this problem. The equivalent homogeneous medium obtained with such methods can be introduced into numerical tools to model full shielding enclosures. A homogenisation model has been recently proposed to obtain the equivalent homogeneous properties of composite materials subjected to electromagnetic waves. It relies on the introduction of a length parameter into classical non dimensional semi-analytical homogenisation methods—also known as mean field approaches. The model is applicable at microwave frequencies as long as the induced currents in the fibres (or inclusions) of the composite materials remain weak. This paper proposes an extension of the approach to include skin effect in the homogenisation method. This is done by considering Joule losses within the fibres of the composite. This extension significantly broadens the frequency range covered by the model. The results show that the optimization of composite shielding properties relies on a subtle compromise between internal reflections and Joule losses.
Effects of sodium on electrical properties in Cu2ZnSnS4 single crystal
Authors: Nagaoka Akira , Miyake Hideto , Taniyama Tomoyasu , Kakimoto Koichi , Nose Yoshitaro , Scarpulla Michael A. , Yoshino Kenji
Published: April 2014

We have studied the effect of sodium on the electrical properties of Cu2ZnSnS4 (CZTS) single crystal by using temperature dependence of Hall effect measurement. The sodium substitution on the cation site in CZTS is observed from the increasing of unit-cell size by powder X-ray diffraction. Sodium increases the effective hole concentration and makes the thermal activation energy smaller. The degree of compensation decreases with sodium incorporation, thus the hole mobility is enhanced. We revealed that sodium is important dopant in CZTS to control the electrical properties.
Nano-superconducting quantum interference devices with suspended junctions
Authors: Hazra D. , Kirtley J. R. , Hasselbach K.
Published: April 2014

Nano-Superconducting Quantum Interference Devices (nano-SQUIDs) are usually fabricated from a single layer of either Nb or Al. We describe here a simple method for fabricating suspended nano-bridges in Nb/Al thin-film bilayers. We use these suspended bridges, which act as Josephson weak links, to fabricate nano-SQUIDs which show critical current oscillations at temperatures up to 1.5 K and magnetic flux densities up to over 20 mT. These nano-SQUIDs exhibit flux modulation depths intermediate between all-Al and all-Nb devices, with some of the desirable characteristics of both. The suspended geometry is attractive for magnetic single nanoparticle measurements.
Dielectric Interface Effects on Surface Charge Accumulation and Collection towards High-Efficiency Organic Solar Cells
Authors: Hsiao Yu-Che , Zang Huidong , Ivanov Ilia , Xu Tao , Lu Luyao , Yu Luping , Hu Bin
Published: April 2014

This paper reports the experimental studies on the effects of dielectric thin-film on surface-charge accumulation and collection by using capacitance-voltage (C-V) measurements under photoexcitation. The dielectric thin-films with different surface polarizations are used with inverted device architecture based on the common photovoltaic PTB7:PC71BM film. In the C-V measurements, the peak-voltage shift with light intensity, namely, Vpeak shift, is particularly used to determine the surface-charge accumulation. We find that the Vpeak shows a smaller shift with light intensity when a higher surface polarization of dielectric thin-film is used. This means that a higher surface polarization of dielectric thin-film can decrease the surface-charge accumulation at electrode interface. However, a lower surface polarization of dielectric thin-film leads to a larger shift with light intensity. This implies that a lower surface polarization of dielectric thin-film corresponds to a larger surface-charge accumulation. This experimental finding indicates that dielectric thin-film plays an important role in the surface-charge accumulation and collection in the generation of photocurrent in organic solar cells. We demonstrate that the device performance can reach the power conversion efficiency of 8.7% when a higher dielectric PFN is used to enhance the surface-charge collection based on the inverted design of ITO/PFN/PTB7:PC71BM/MoO3/Ag.
Viability analysis of an offshore wind farm in North Aegean Sea, Greece
Authors: Konstantinidis E. I. , Kompolias D. G. , Botsaris P. N.
Published: April 2014

The scope of the present work is the techno-economic study with concern for the environmental issues and the investigation of the viability of an offshore wind farm in the Greek sea area, northeast of the island of Limnos. In the context of this study, the wind data, the suitable location for the installation of the wind turbines beyond nature protected areas, the type of the wind turbines, the losses due to wind turbines interaction, and the visual impact at the respective study areas are analyzed. Moreover, reliable costing models are used and applied, internationally recognized for techno-economic studies of offshore wind farms. Thereafter, the viability of the project is studied through investment benchmarks. This means that specific economic indices are estimated indicating whether the realization of such an investment is viable or not. In conclusion, based on the analysis performed in this study, it is noted that in the Greek archipelago and especially at the island of Limnos, there is a sufficient offshore wind potential at low depths and at relatively short distances from the shore. These circumstances are necessary conditions for the development of offshore wind farms in these areas. Moreover, economic estimations based on current data of grants, taxation, interest rates, etc., showed that the investment is sustainable, having a cost of energy production equal to 87.92 €/MW h.
Effects of ternary mixed crystal and size on optical phonons in wurtzite nitride core-shell nanowires
Authors: Li J. , Guan J. Y. , Zhang S. F. , Ban S. L. , Qu Y.
Published: April 2014

Within the framework of dielectric continuum and Loudon's uniaxial crystal models, existence conditions dependent on components and frequencies for optical phonons in wurtzite nitride core-shell nanowires (CSNWs) are discussed to obtain dispersion relations and electrostatic potentials of optical phonons in InxGa1−xN/GaN CSNWs. The results show that there may be four types of optical phonons in InxGa1−xN/GaN CSNWs for a given ternary mixed crystal (TMC) component due to the phonon dispersion anisotropy. This property is analogous to wurtzite planar heterojunctions. Among the optical phonons, there are two types of quasi-confined optical (QCO) phonons (named, respectively, as QCO-A and QCO-B), one type of interface (IF) phonons and propagating (PR) phonons existing in certain component and frequency domains while the dispersion relations and electrostatic potentials of same type of optical phonons vary with components. Furthermore, the size effect on optical phonons in CSNWs is also discussed. The dispersion relations of IF and QCO-A are independent of the boundary location of CSNWs. Meanwhile, dispersion relations and electrostatic potentials of QCO-B and PR phonons vary obviously with size, especially, when the ratio of a core radius to a shell radius is small, and dispersion relation curves of PR phonons appear to be close to each other, whereas, this phenomenon disappears when the ratio becomes large. Based on our conclusions, one can further discuss photoelectric properties in nitride CSNWs consisting of TMCs associated with optical phonons.
1/f noise in semiconductor and metal nanocrystal solids
Authors: Liu Heng , Lhuillier Emmanuel , Guyot-Sionnest Philippe
Published: April 2014

Electrical 1/f noise is measured in thin films of CdSe, CdSe/CdS, ZnO, HgTe quantum dots and Au nanocrystals. The 1/f noise, normalized per nanoparticle, shows no systematic dependence on the nanoparticle material and the coupling material. However, over 10 orders of magnitude, it correlates well with the nearest neighbor conductance suggesting some universal magnitude of the 1/f noise in these granular conductors. In the hopping regime, the main mechanism of 1/f noise is determined to be mobility fluctuated. In the metallic regime obtained with gold nanoparticle films, the noise drops to a similar level as bulk gold films and with a similar temperature dependence.
Controllable fully spin-polarized transport in a ferromagnetically doped topological insulator junction
Authors: Zhou Benliang , Zhou Benhu , Tang Dongsheng , Zhou Guanghui
Published: April 2014

We investigate the energy band structure and the spin-dependent transport for a normal/ferromagnetic/normal two-dimension topological insulator (TI) junction. By diagonalizing Hamiltonian for the system, the band structure shows that the edge states on two sides are coupled resulting in a gap opening due to the transverse spatial confinement. Further, the exchange field induced by magnetic impurities can also modulate the band structure with two spin degenerate bands splitting. By using the nonequilibrium Green's function method, the dependence of spin-dependent conductance and spin-polarization on the Fermi energy, the exchange field strength and the ferromagnetic TI (FTI) length are also analyzed, respectively. Interestingly, the degenerate conductance plateaus for spin-up and -down channels are broken, and both the conductances are suppressed by magnetic impurities due to the time-reversal symmetry broken and inelastic scattering. The spin-dependent conductance shows different behaviors when the Fermi energy is tuned into different ranges. Moreover, the conductance can be fully spin polarized by tuning the Fermi energy and the exchange field strength, or by tuning the Fermi energy and the FTI length. Consequently, the junction can transform from a quantum spin Hall state to a quantum anomalous Hall state, which is very important to enable dissipationless charge current for designing perfect spin filter.