bluuebunny/crossref_metadata_2025 huggingface dataset:
Optogenetic approaches to retinal prosthesis
Authors: BARRETT JOHN MARTIN , BERLINGUER-PALMINI ROLANDO , DEGENAAR PATRICK
Published: August 2014

The concept of visual restoration via retinal prosthesis arguably started in 1992 with the discovery that some of the retinal cells were still intact in those with the retinitis pigmentosa disease. Two decades later, the first commercially available devices have the capability to allow users to identify basic shapes. Such devices are still very far from returning vision beyond the legal blindness. Thus, there is considerable continued development of electrode materials, and structures and electronic control mechanisms to increase both resolution and contrast. In parallel, the field of optogenetics—the genetic photosensitization of neural tissue holds particular promise for new approaches. Given that the eye is transparent, photosensitizing remaining neural layers of the eye and illuminating from the outside could prove to be less invasive, cheaper, and more effective than present approaches. As we move toward human trials in the coming years, this review explores the core technological and biological challenges related to the gene therapy and the high radiance optical stimulation requirement.
Sportkardiologie – ein praxisorientiertes Update
Authors: Schmied Christian
Published: August 2014

Die Sportkardiologie beschäftigt sich als Subspezialität der Kardiologie im speziellen Kontext mit der Sportmedizin bzw. den Sport- und Bewegungswissenschaften im Allgemeinen. Im Zentrum steht dabei das sogenannte «Sport-Paradox», das den Umstand bezeichnet, das einerseits der gesundheitsfördernde, primär- und sekundärpräventive Nutzen eines regelmässigen Trainings heutzutage unbestritten und wissenschaftlich sehr gut belegt ist und andererseits Sport, insbesondere im Falle einer zugrundeliegenden Herzerkrankung, als Trigger für den plötzlichen Herztod identifiziert werden konnte. Dennoch überwiegen die gesundheitsfördernden Effekte bei Weitem, wenn jeder Sporttreibende durch eine kardiale Vorsorgeuntersuchung und individuelle Sportempfehlungen adäquat vorbereitet wurde. Dieser Review beleuchtet verschiedenste Aspekte der Sportkardiologie, wie etwa Präventionsstrategien zur Verhinderung des plötzlichen Herztods im Sport, Trainingsempfehlungen bei vorliegender kardialer Erkrankung oder gesundheitsfördernden Sport.
Ein ungewöhnliches Leitsymptom
Authors: von Felten Claudia , Eberhard Stephan
Published: August 2014

Wir berichten über einen 81-jährigen Patienten mit einer langsam zunehmenden invalidisierenden Dyspnoe und depressiver Verstimmung. Trotz umfangreicher detaillierter kardiologischer, pneumologischer sowie neurologischer Abklärungen blieb die Ursache der Beschwerden lange Zeit unbekannt. Bei bekanntem parasellärem Meningeom und weiterhin persistierender unklarer klinischer wie auch diagnostischer Konstellation wurde trotz unverändertem Schädel-MRI-Befund im Vergleich zur Voruntersuchung eine endokrinologische Untersuchung veranlasst, was die Diagnosestellung eines Panhypopituitarismus ermöglichte.
The Validity of Specific Cognitive Abilities for the Prediction of Training Success in Germany
Authors: Goertz Wiebke , Hülsheger Ute R. , Maier Günter W.
Published: August 2014

General mental ability (GMA) has long been considered one of the best predictors of training success and considerably better than specific cognitive abilities (SCAs). Recently, however, researchers have provided evidence that SCAs may be of similar importance for training success, a finding supporting personnel selection based on job-related requirements. The present meta-analysis therefore seeks to assess validities of SCAs for training success in various occupations in a sample of German primary studies. Our meta-analysis (k = 72) revealed operational validities between ρ = .18 and ρ = .26 for different SCAs. Furthermore, results varied by occupational category, supporting a job-specific benefit of SCAs.
Do High Working Memory Groups Perform Better?
Authors: Mojzisch Andreas , Krumm Stefan , Schultze Thomas
Published: August 2014

A growing body of research shows that individual differences in working memory capacity play a pivotal role for a large number of higher order cognitive tasks. Surprisingly, however, the impact of individual differences in working memory capacity on group performance has received little attention. In this conceptual article, we focus on three typical group tasks (group idea generation, group decision making, group judgment) and, for each task, provide an analysis of how individual differences in working memory capacity might affect group performance. Our key idea is that group interaction is a cognitively demanding task as group members have to continuously monitor the ongoing conversation, hold their ideas in memory, integrate the information put forth by others, and update their mental representations accordingly. Therefore, individual differences in working memory capacity are presumed to have a profound impact on how people process information during group interaction.
Functional MRI in Mice Lacking IP3-Dependent Calcium Signaling in Astrocytes
Authors: Jego Pierrick , Pacheco-Torres Jesús , Araque Alfonso , Canals Santiago
Published: August 2014

Functional magnetic resonance imaging (fMRI) is a fundamental tool to investigate human brain networks. However, the cellular mechanisms underlying fMRI signals are not fully understood. One hypothetical mechanism is the putative vascular control exerted by cytosolic calcium in perivascular astrocytes. We have performed combined fMRI-electrophysiology experiments in mice lacking the inositol 1,4,5-triphosphate-type-2 receptor, with the primary pathway of cytosolic calcium increase eliminated into astrocytes. Our results show that evoked electrophysiologic activity and fMRI signals acquired during either transient or sustained neuronal activations occur independently of these large calcium signals. This result challenges the suggested intermediary role of astrocytic calcium surges in fMRI-signal generation.
Highly sensitive and portable mercury(ii) ion sensor using personal glucose meter
Authors: Xue-tao Xu , Kai-yi Liang , Jia-ying Zeng
Published: August 2014

A highly sensitive and portable mercury(ii) ion sensor based on personal glucose meter (PGM) recording is reported.
A bifunctional curcumin analogue for two-photon imaging and inhibiting crosslinking of amyloid beta in Alzheimer's disease
Authors: Zhang Xueli , Tian Yanli , Yuan Peng , Li Yuyan , Yaseen Mohammad A. , Grutzendler Jaime , Moore Anna , Ran Chongzhao
Published: August 2014

A highly bright bifunctional curcumin analogue CRANAD-28 was designed as a potential theranostic agent for Alzheimer's disease.
A self-assembled ultrathin crystalline polymer film for high performance phototransistors
Authors: Li Hui , Wu Yishi , Wang Xuedong , Kong Qinghua , Fu Hongbing
Published: August 2014

An ultrathin crystalline polymer film was prepared using a novel solution-phase self-assembled method and exhibited high performance in phototransistor devices.
Water adsorption in UiO-66: the importance of defects
Authors: Ghosh Pritha , Colón Yamil J. , Snurr Randall Q.
Published: August 2014

Density distributions of water in an ideal UiO-66 unit cell (left) and a unit cell missing linkers (right).
Anion–π interactions and positive electrostatic potentials of N-heterocycles arise from the positions of the nuclei, not changes in the π-electron distribution
Authors: Wheeler Steven E. , Bloom Jacob W. G.
Published: August 2014

The positive ESPs that underlie anion-binding by N-heterocycles do not stem from a depletion of π-electron density, as widely assumed.
Enzyme immobilised novel core–shell superparamagnetic nanocomposites for enantioselective formation of 4-(R)-hydroxycyclopent-2-en-1-(S)-acetate
Authors: Sharifabad Maneea Eizadi , Hodgson Ben , Jellite Mourad , Mercer Tim , Sen Tapas
Published: August 2014

One step conversion of meso-cyclopent-2-en-1,4-diacetate to pharmaceutically important chiral isomers using enzymes immobilised novel high surface area core–shell superparamagnetic nanoparticles.
A highly selective sulfinate ester probe for thiol bioimaging
Authors: Malwal Satish R. , Labade Ajay , Andhalkar Abhijeet S. , Sengupta Kundan , Chakrapani Harinath
Published: August 2014

The sulfinate ester functional group is found to be highly selective to cleavage by a thiol.
The effect of the oxidation environment on the activity and selectivity to aromatics and octenes over cobalt molybdate in the oxidative dehydrogenation of n-octane
Authors: Fadlalla Mohamed I. , Friedrich Holger B.
Published: August 2014

Varying the oxidative environment can cause phase changes in the catalyst which influence the product selectivity of octane activation.
Silver nanoparticles supported on passivated silica: preparation and catalytic performance in alkyne semi-hydrogenation
Authors: Oakton Emma , Vilé Gianvito , S. Levine Daniel , Zocher Eva , Baudouin David , Pérez-Ramírez Javier , Copéret Christophe
Published: August 2014

When X = SiMe3, small (2.1 ± 0.5 nm) densely packed silica-supported Ag particles can be prepared, which show an improved catalytic activity (per gram) whilst maintaining high alkene selectivity.
Switching and redox isomerism in first-row transition metal complexes containing redox active Schiff base ligands
Authors: Sasmal Ashok , Garribba Eugenio , Gómez-García Carlos J. , Desplanches Cédric , Mitra Samiran
Published: August 2014

Switching and redox isomerism in first row transition metal complexes through the metal-to-ligand or ligand-to-ligand electron transfer stabilize redox isomeric forms in transition metal complexes with redox-active ligands.
Thermal structural characterization of the acentric layered perovskite LiHSrTa2O7: X-ray and neutron diffraction, SHG and Raman experiments
Authors: Galven Cyrille , Mounier Denis , Pagnier Thierry , Suard Emmanuelle , Le Berre Françoise , Crosnier-Lopez Marie-Pierre
Published: August 2014

LiHSrTa2O7 undergoes a reversible structural transition from an orthorhombic to a tetragonal symmetry around 200 °C. This transition, from acentric to centric space group, is revealed especially by the vanishing of the SHG signal.
DNA fragment conformations in adducts with Kiteplatin
Authors: Margiotta Nicola , Petruzzella Emanuele , Platts James A. , Mutter Shaun T. , Deeth Robert J. , Ranaldo Rosa , Papadia Paride , Marzilli Patricia A. , Marzilli Luigi G. , Hoeschele James D. , Natile Giovanni
Published: August 2014

The anticancer-active platinum complex with cis-1,4-diaminocyclohexane has proved to be very valuable in detecting multiple conformers in adducts with oligonucleotides.
Single molecule DNA intercalation in continuous homogenous elongational flow
Authors: Griffis Joshua W. , Safranovitch Mikhail M. , Vyas Shilpi P. , Gerrin Sean , Protozanova Ekaterina , Malkin Gene , Meltzer Robert H.
Published: August 2014

Single molecule DNA intercalation in continuous elongational flow.
Crosslinked polyelectrolyte complex fiber membrane based on chitosan–sodium alginate by freeze-drying
Authors: Jiang Chengling , Wang Zhiliang , Zhang Xueqin , Zhu Xiaoqun , Nie Jun , Ma Guiping
Published: August 2014

The formation mechanism polyelectrolyte complex nanofibers during the process of freeze drying.
Indium-assisted aluminium-based stereoselective allylation of prostereogenic α,α-disubstituted cycloalkanones and imines
Authors: Reddy Chennakesava , Babu Srinivasarao Arulananda , Aslam Nayyar Ahmad
Published: August 2014

Stereoselective allylation of prostereogenic cycloalkanone and imine systems using allylic halides, aluminium powder and a catalytic amount of InCl3is reported.
The role of F-dopants in adsorption of gases on anatase TiO2 (001) surface: a first-principles study
Authors: Liu Huazhong , Liew K. M. , Pan Chunxu
Published: August 2014

Ti3+ induced by F-dopants plays an important role in enhancing interaction between gas molecules and TiO2 surfaces.
Facile synthesis of nitrogen-doped carbon derived from polydopamine-coated Li3V2(PO4)3as cathode material for lithium-ion batteries
Authors: Zhang Cunliang , Li Hongshen , Ping Nie , Pang Gang , Xu Guiyin , Zhang Xiaogang
Published: August 2014

Nitrogen-doped, carbon-coated Li3V2(PO4)3cathode materials were prepared by the oxidative self-polymerization of dopamine on the Li3V2(PO4)3surface and subsequent carbonization of polydopamine.
Electroanalytical study of the viability of conversion reactions as energy storage mechanisms
Authors: Ponrouch Alexandre , Cabana Jordi , Dugas Romain , Slack Jonathan L. , Palacín M. Rosa
Published: August 2014

Electroanalytical techniques indicate that voltage hysteresis in electrochemical conversion reactions has thermodynamic origins, which highlights the significant challenge to their prospects of application.
Enforced conformational changes in the structural units of glycosaminoglycan (non-sulfated heparin-based oligosaccharides)
Authors: Brzyska A. , Woliński K.
Published: August 2014

The conformational transitions in the structural units of glycosaminoglycans (GAGs) were the subject of many theoretical and experimental studies.
Demonstration of efficient electrochemical biogas reforming in a solid oxide electrolyser with titanate cathode
Authors: Qin Qingqing , Xie Kui , Wei Haoshan , Qi Wentao , Cui Jiewu , Wu Yucheng
Published: August 2014

Direct electrochemical biogas reforming is successfully demonstrated in a solid oxide electrolyser with titanate cathode under external voltages.
Polymethacrylic acid–facilitated nanofiber matrix loading Ag nanoparticles for SERS measurements
Authors: Yang Hui , Huang Cheng Zhi
Published: August 2014

By introducing polymethacrylic acid (PMAA), fairly uniform PMAA/poly(N-vinylpyrrolidone) (PVP) ultrafine fibers containing silver nanoparticles (AgNPs) for SERS substrates were successfully preparedviaelectrospinning by means ofin situphotoreduction of silver ions. This makes the detection results reproducible with RSD values below 0.2% through the SERS signals to detect malachite green (MG), a significant environmental organic pollutant, for its genotoxicity.
Label and indicator free electrochemical nanobiosensing of DNA hybridization based on MnO2 nanomaterial modified GCPE
Authors: Sultan Sinan Cemgil , Kara Pinar , Anik Ülkü , Ozsoz Mehmet
Published: August 2014

A label and indicator free electrochemical DNA hybridization detection method based on MnO2-Nps/GCPE was developed. Compared to plain GCPE, a very robust and sensitive genosensor was obtained.
Determination of particle size distribution of water-soluble CdTe quantum dots by optical spectroscopy
Authors: Sousa J. C. L. , Vivas M. G. , Ferrari J. L. , Mendonca C. R. , Schiavon M. A.
Published: August 2014

In the present study, we report the synthesis of glutathione (GSH) capped CdTe quantum dots (QDs) using the one-pot approach as well as their optical properties.
Design and synthesis of optically pure 3-aryl-6-methyl-2-thioxotetrahydropyrimidin-4(1H)-ones as anti-prostate cancer agents
Authors: Kumar Varun , Rachamalla Mahesh , Nandekar Prajwal , Khatik Gopal L. , Sangamwar Abhay T. , Tikoo Kulbhushan , Nair Vipin A.
Published: August 2014

3-Aryl-6-methyl-2-thioxotetrahydropyrimidin-4(1H)-ones were designed and synthesized as a new class of anti-prostate cancer agents.
A novel approach to prepare Si/C nanocomposites with yolk–shell structures for lithium ion batteries
Authors: Li Huan-Huan , Wang Jia-Wei , Wu Xing-Long , Sun Hai-Zhu , Yang Feng-Mei , Wang Kang , Zhang Lin-Lin , Fan Chao-Ying , Zhang Jing-Ping
Published: August 2014

A novel method was developed to prepare mesoporous Si/C nanocomposites with yolk–shell structure (MSi@C), which showed good retention of specific capacity (1264.7 mA h g−1 after 150 cycles with coulombic efficiency above 99%). This work provides an alternative method to fabricate yolk–shell structured materials.
A simple and catalyst free one pot access to the pyrazolone fused 2,8-dioxabicyclo[3.3.1]nonanes
Authors: Bingi Chiranjeevi , Emmadi Narender Reddy , Chennapuram Madhu , Nanubolu Jagadeesh Babu , Atmakur Krishnaiah
Published: August 2014

Synthesis of a series of novel aryl and heteroaryl fused 2,8-dioxabicyclo[3.3.1]nonanes (3) was accomplished by one pot, catalyst free reaction of 2-hydroxy chalcones (1) with 3-trifluoromethyl substituted pyrazolones (2) in xylene at reflux temperature. The role of –CF3 in formation of 3 was confirmed by comparing with 3-methyl pyrazolones.
Transition metal-catalyzed redox isomerization of codeine and morphine in water
Authors: Gómez Antonio Bermejo , Holmberg Pär , Bäckvall Jan-E. , Martín-Matute Belén
Published: August 2014

A water-soluble rhodium complex formed from commercially available [Rh(COD)(CH3CN)2]BF4and 1,3,5-triaza-7-phosphaadamantane (PTA) catalyzes the isomerization of both codeine and morphine into hydrocodone and hydromorphone in water with very high efficiency.
Preparation and adsorption performance of cross-linked porous polycarbazoles
Authors: Zhu Jian-Hua , Chen Qi , Sui Zhu-Yin , Pan Long , Yu Jiaguo , Han Bao-Hang
Published: August 2014

Hypercrosslinked carbazole-based porous organic polymers were prepared via FeCl3-promoted one-step oxidative coupling reaction and Friedel–Crafts alkylation in one pot.
A universal method to form the equivalent ohmic contact for efficient solution-processed organic tandem solar cells
Authors: Li Ning , Stubhan Tobias , Krantz Johannes , Machui Florian , Turbiez Mathieu , Ameri Tayebeh , Brabec Christoph J.
Published: August 2014

A solution-processed Ag nanostructure based thin layer is introduced to lift the recombination restrictions at the interface of the intermediate layer.
Loop antenna producing uniform horizontal magnetic fields over plane for HF RFID applications
Authors: Son H.‐W. , Park C.‐H.
Published: August 2014

A planar loop antenna producing uniform magnetic fields horizontal to its plane is presented. The antenna consists of a pair of two‐turn spiral coils that are sequentially excited. To prevent undesirable magnetic coupling between the coils, a novel coil‐switching circuit is proposed, which is automatically operated using the interrogating signal from the reader. The antenna is suitable for a high‐frequency radio frequency identification reader antenna installed under a chip tray to monitor gaming chips in a casino.
Message propagation decoder with error correction code based on rateless code under partial information
Authors: Fanglin Niu , Hongyu Wang , Chen Lei
Published: August 2014

The receiver with message propagation (MP) decoder algorithm realises the decoding of traditional Luby transform (LT) encoded packages when there is only one unknown packet adjacent to the encoded package. Error packets can be recovered by decoding with jointing product code composed of shifted Luby transform (SLT)‐encoded package and error packets. In this study, error correction scheme based on single feedback of SLT‐encoded package was adopted for the recovery of received partial error packets over the erasure channel. The scheme of an MP decoder with an error correction code was proposed, and expand shifted robust soliton distribution (ESRSD) appropriate for the scheme feature was designed. Experimental results indicate that the scheme effectively improves the efficiency of the decoder. Compared with the traditional shifted robust soliton distribution, the ESRSD has better decoding performance for the LT code.
Akzeptanz bei Tinnitus: Validierung des „Akzeptanzfragebogen bei chronischem Tinnitus“ (AFCT)
Authors: Riedl D. , Rumpold G. , Schmidt A. , Bliem H. , Moschen R.
Published: August 2014

Hintergrund: Tinnitus ist ein weit verbreitetes Symptom, welches von etwa 10% der Bevölkerung chronisch wahrgenommen wird. Während sich die große Mehrheit durch die Ohrgeräusche langfristig nicht beeinträchtigt fühlt, erleben zwischen 5 und 30% der TinnituspatientInnen einen starken bis extremen psychischen Leidensdruck. Die Schwere der Belastung kann nicht durch die Beschaffenheit des Ohrgeräusches (Lautstärke oder Dauer) erklärt werden, weshalb die Unterschiede der Belastung durch Tinnitus in neueren Forschungen z. T. durch das Konstrukt der Akzeptanz erklärt werden. Ziel der vorliegenden Studie ist es, die psychometrische Qualität einer deutschen Version des „Chronic Pain Acceptance Questionnaire“ (CPAQ), dem „Akzeptanzfragebogen bei chronischem Tinnitus“ (AFCT) zu überprüfen, welcher für Tinnitus adaptiert wurde.

Material und Methoden: 97 PatientInnen mit chronischem Tinnitus wurden zu Beginn einer ambulanten Tinnitusbewältigungsgruppe untersucht. Es wurden der „Akzeptanzfragebogen bei chronischem Tinnitus“ (AFCT) und der „Tinnitusfragebogen“ (TF) eingesetzt. Die Struktur des AFCT wurde anhand einer Faktorenanalyse ermittelt, zur Ermittlung der Reliabilität des Fragebogens wurde die innere Konsistenz (Cronbach Alpha) überprüft.

Ergebnisse: Aufgrund psychometrischer Schwächen sowie unklarer faktorieller Zuordenbarkeit wurden 8 Items des AFCT eliminiert und aus den verbleibenden Items der AFCT-12 gebildet. Der AFCT-12 verfügt über eine gute 2-Faktoren-Lösung, die 54,9% der Varianz aufklären. Sowohl der AFCT als auch der AFCT-12 verfügen über eine gute Reliabilität und gute Validität.

Schlussfolgerungen: Der AFCT-12 hat sich als re­liables und valides Instrument zur Erfassung der Akzeptanz bei Menschen mit chronischem Tinnitus erwiesen.
Versatility of Subscapular Chimeric Free Flaps in the Secondary Reconstruction of Composite Posttraumatic Defects of the Upper Face
Authors: Stalder MarkWinston , Wise MatthewWhitten , Dupin Charles L. , St Hilaire Hugo
Published: August 2014

High energy injuries to the upper face present challenging reconstructive problems. In some cases, initial reconstructive efforts result in unfavorable outcomes that require secondary intervention. Chimeric free flaps based on the subscapular system offer the tissue components and volume needed for these complex reconstructions. This is a series of five patients who underwent secondary reconstruction of the middle and upper face following traumatic injury. Mechanism of injury, prior attempts at reconstruction, and characteristics of the tissue defects and the flaps used in their reconstruction are described. Two patients were female and three were male. Three injuries resulted from gunshot wounds, and two from motor vehicle accidents. All patients had multiple prior failed attempts at reconstruction using local/regional tissue. Defects included symptomatic oronasal or oro-orbital fistulas, enophthalmos, and forehead contour deformities. Two of the flaps used included scapular bone and latissimus muscular components, and three included scapular bone and thoracodorsal artery perforator-based skin paddle components. All free tissue transfers were successful, and no patients suffered significant complications. Chimeric free flaps based on the subscapular system offer a valuable secondary strategy for reconstruction of composite defects of the upper face when other options have been exhausted through previous efforts.
Diskectomy during Pregnancy: Case Report and Review of the Literature
Authors: Kanas Michel , Kunzle Hugo , Martins Delio E. , Kirsch Luiz A. , Puertas Eduardo B. , Wajchenberg Marcelo
Published: August 2014

Study Design

Case report.

Objective

The purpose of this report is to discuss the management of a disk herniation during pregnancy and the indication and particularities of surgery in this situation.

Methods

We describe a case of diskectomy performed in a 35-year-old woman at 18 weeks of gestation. After 4 weeks of trying to manage the disk herniation with rest and medications without success, the muscle strength of the L5 right root decreased to grade 4, and the patient was not responding to intravenous analgesia. After discussion with the patient and family, a decision was made to perform the diskectomy.

Results

After surgery, the patient's pain lessened, and the Lasegue test became negative. Two weeks after the procedure, the patient's muscle strength was normal. In the 40th week of pregnancy, the patient gave birth without any complications.

Conclusion

When necessary, diskectomy can be indicated and performed during pregnancy. However, appropriate precautions must be taken. Awareness of these precautions is important for the success of the procedure and for the well-being of the mother and the newborn.
Rotational piezoelectric wind energy harvesting using impact-induced resonance
Authors: Yang Ying , Shen Qinlong , Jin Jiamei , Wang Yiping , Qian Wangjie , Yuan Dewang
Published: August 2014

To improve the output power of a rotational piezoelectric wind energy harvester, impact-induced resonance is proposed to enable effective excitation of the piezoelectric cantilevers' vibration modes and obtain optimum deformation, which enhances the mechanical/electrical energy transformation. The impact force is introduced by forming a piezoelectric bimorph cantilever polygon that is fixed at the circumference of the rotating fan's internal surface. Elastic balls are placed inside the polygon. When wind rotates the device, the balls strike the piezoelectric cantilevers, and thus electricity is generated by the piezoelectric effect. The impact point is carefully chosen to use the first bending mode as much as possible, and thus maximize the harvesting efficiency. The design enables each bimorph to be struck in a similar area and every bimorph is struck in that area at different moments. As a result, a relatively stable output frequency can be obtained. The output frequency can also be changed by choosing different bimorph dimensions, which will also make the device simpler and the costs lower. A prototype piezoelectric energy harvester consisting of twelve piezoelectric cantilevers was constructed. The piezoelectric cantilevers were made from phosphor bronze, the lead zirconium titanate (PZT)-based bimorph cantilever had dimensions of 47 mm × 20 mm × 0.5 mm, and the elastic balls were made from steel with a diameter of 10 mm. The optimal DC output power was 613 μW across the 20 kΩ resistor at a rotation speed of 200 r/min with an inscribed circle diameter of 31 mm.
Geminal-spanning orbitals make explicitly correlated reduced-scaling coupled-cluster methods robust, yet simple
Authors: Pavošević Fabijan , Neese Frank , Valeev Edward F.
Published: August 2014

We present a production implementation of reduced-scaling explicitly correlated (F12) coupled-cluster singles and doubles (CCSD) method based on pair-natural orbitals (PNOs). A key feature is the reformulation of the explicitly correlated terms using geminal-spanning orbitals that greatly reduce the truncation errors of the F12 contribution. For the standard S66 benchmark of weak intermolecular interactions, the cc-pVDZ-F12 PNO CCSD F12 interaction energies reproduce the complete basis set CCSD limit with mean absolute error <0.1 kcal/mol, and at a greatly reduced cost compared to the conventional CCSD F12.
Mass-ablation-rate measurements in direct-drive cryogenic implosions using x-ray self-emission images
Authors: Davis A. K. , Michel D. T. , Hu S. X. , Craxton R. S. , Epstein R. , Goncharov V. N. , Igumenshchev I. V. , Sangster T. C. , Froula D. H.
Published: August 2014

A technique to measure the mass ablation rate in direct-drive inertial confinement fusion implosions using a pinhole x-ray framing camera is presented. In target designs consisting of two layers of different materials, two x-ray self-emission peaks from the coronal plasma were measured once the laser burned through the higher-Z outer layer. The location of the inner peak is related to the position of the ablation front and the location of the outer peak corresponds to the position of the interface of the two layers in the plasma. The emergence of the second peak was used to measure the burnthrough time of the outer layer, giving the average mass ablation rate of the material and instantaneous mass remaining. By varying the thickness of the outer layer, the mass ablation rate can be obtained as a function of time. Simulations were used to validate the methods and verify that the measurement techniques are not sensitive to perturbation growth at the ablation surface.
Atomic scale trap state characterization by dynamic tunneling force microscopy
Authors: Wang R. , King S. W. , Williams C. C.
Published: August 2014

Dynamic tunneling force microscopy (DTFM) is applied to the study of point defects in an inter-layer dielectric film. A recent development enables simultaneous acquisition of DTFM, surface potential, and topographic images while under active height feedback control. The images show no clear correlation between trap state location and surface potential or topography of the surface. The energy and depth of individual trap states are determined by DTFM images obtained at different probe tip heights and applied voltages and quantitative tunneling and electrostatic models. The measured density of states in these films is found to be approximately 1 × 1019 cm−3 eV−1 near the dielectric film surface.
Quasilinear carbon transport in an impurity hole plasma in LHD
Authors: Mikkelsen D. R. , Tanaka K. , Nunami M. , Watanabe T.-H. , Sugama H. , Yoshinuma M. , Ida K. , Suzuki Y. , Goto M. , Morita S. , Wieland B. , Yamada I. , Yasuhara R. , Tokuzawa T. , Akiyama T. , Pablant N. A.
Published: August 2014

Comprehensive electrostatic gyrokinetic linear stability calculations for ion-scale microinstabilities in an LHD plasma with an ion-internal transport barrier (ITB) and carbon “impurity hole” are used to make quasilinear estimates of particle flux to explore whether microturbulence can explain the observed outward carbon fluxes that flow “up” the impurity density gradient. The ion temperature is not stationary in the ion-ITB phase of the simulated discharge, during which the core carbon density decreases continuously. To fully sample these varying conditions, the calculations are carried out at three radial locations and four times. The plasma parameter inputs are based on experimentally measured profiles of electron and ion temperature, as well as electron and carbon density. The spectroscopic line-average ratio of hydrogen and helium densities is used to set the density of these species. Three ion species (H,He,C) and the electrons are treated kinetically, including collisions. Electron instability drive does enhance the growth rate significantly, but the most unstable modes have characteristics of ion temperature gradient modes in all cases. As the carbon density gradient is scanned between the measured value and zero, the quasilinear carbon flux is invariably inward when the carbon density profile is hollow, so turbulent transport due to the instabilities considered here does not explain the observed outward flux of impurities in impurity hole plasmas. The stiffness of the quasilinear ion heat flux is found to be 1.7–2.3, which is lower than several estimates in tokamaks.
Response function stability of single crystal diamond detectors to 14 MeV neutrons
Authors: Zbořil Miroslav , Zimbal Andreas
Published: August 2014

Detectors based on single crystal synthetic diamond show promise as neutron spectrometers for the ITER project. In this work, the stability of the response function of two diamond detectors was tested at the Physikalisch-Technische Bundesanstalt (PTB) accelerator using a 14 MeV neutron field and a method of time-resolved fluence monitoring. In addition, measurements at the PTB ion-microbeam were made to investigate the charge collection properties of the detectors in more detail. The 12C(n,α)9Be peak response of one of the detectors was found to be stable within 1% after irradiation with a neutron fluence of 8 × 109 cm−2. The absolute value of the peak response of this detector was determined as 8.65(26) × 10−5 cm2.
Two-dimensional percolation at the free water surface and its relation with the surface tension anomaly of water
Authors: Sega Marcello , Horvai George , Jedlovszky Pál
Published: August 2014

The percolation temperature of the lateral hydrogen bonding network of the molecules at the free water surface is determined by means of molecular dynamics computer simulation and identification of the truly interfacial molecules analysis for six different water models, including three, four, and five site ones. The results reveal that the lateral percolation temperature coincides with the point where the temperature derivative of the surface tension has a minimum. Hence, the anomalous temperature dependence of the water surface tension is explained by this percolation transition. It is also found that the hydrogen bonding structure of the water surface is largely model-independent at the percolation threshold; the molecules have, on average, 1.90 ± 0.07 hydrogen bonded surface neighbors. The distribution of the molecules according to the number of their hydrogen bonded neighbors at the percolation threshold also agrees very well for all the water models considered. Hydrogen bonding at the water surface can be well described in terms of the random bond percolation model, namely, by the assumptions that (i) every surface water molecule can form up to 3 hydrogen bonds with its lateral neighbors and (ii) the formation of these hydrogen bonds occurs independently from each other.
Multi-channel Doppler backscattering measurements in the C-2 field reversed configuration
Authors: Schmitz L. , Ruskov E. , Deng B. H. , Gota H. , Gupta D. , Tuszewski M. , Douglass J. , Peebles W. A. , Binderbauer M. , Tajima T.
Published: August 2014

A versatile heterodyne Doppler Backscattering (DBS) system is used to measure density fluctuation levels (in the wavenumber range kρs ≤ 50), and the toroidal E × B flow velocity in the C-2 Field-Reversed Configuration (FRC). Six tunable frequencies in three waveguide bands (26 GHz ≤ f ≤ 90 GHz) are launched using monostatic beam optics, via a quasi-optical beam combiner/polarizer and an adjustable parabolic focusing mirror (inside the vacuum enclosure) achieving Gaussian beam spot sizes of 3–5.5 cm at the X/O-mode cutoff. The DBS system covers plasma densities of 0.8 × 1013 ≤ ne ≤ 1 × 1014 cm−3, and provides access to the FRC core (up to the field null) and across the FRC separatrix into the scrape-off layer plasma.
A low temperature nonlinear optical rotational anisotropy spectrometer for the determination of crystallographic and electronic symmetries
Authors: Torchinsky Darius H. , Chu Hao , Qi Tongfei , Cao Gang , Hsieh David
Published: August 2014

Nonlinear optical generation from a crystalline material can reveal the symmetries of both its lattice structure and underlying ordered electronic phases and can therefore be exploited as a complementary technique to diffraction based scattering probes. Although this technique has been successfully used to study the lattice and magnetic structures of systems such as semiconductor surfaces, multiferroic crystals, magnetic thin films, and multilayers, challenging technical requirements have prevented its application to the plethora of complex electronic phases found in strongly correlated electron systems. These requirements include an ability to probe small bulk single crystals at the μm length scale, a need for sensitivity to the entire nonlinear optical susceptibility tensor, oblique light incidence reflection geometry, and incident light frequency tunability among others. These measurements are further complicated by the need for extreme sample environments such as ultra low temperatures, high magnetic fields, or high pressures. In this review we present a novel experimental construction using a rotating light scattering plane that meets all the aforementioned requirements. We demonstrate the efficacy of our scheme by making symmetry measurements on a μm scale facet of a small bulk single crystal of Sr2IrO4 using optical second and third harmonic generation.
Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector
Authors: Pace D. C. , Pipes R. , Fisher R. K. , Van Zeeland M. A.
Published: August 2014

New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.
High resolution polarimeter-interferometer system for fast equilibrium dynamics and MHD instability studies on Joint-TEXT tokamak (invited)
Authors: Chen J. , Zhuang G. , Li Q. , Liu Y. , Gao L. , Zhou Y. N. , Jian X. , Xiong C. Y. , Wang Z. J. , Brower D. L. , Ding W. X.
Published: August 2014

A high-performance Faraday-effect polarimeter-interferometer system has been developed for the J-TEXT tokamak. This system has time response up to 1 μs, phase resolution < 0.1° and minimum spatial resolution ∼15 mm. High resolution permits investigation of fast equilibrium dynamics as well as magnetic and density perturbations associated with intrinsic Magneto-Hydro-Dynamic (MHD) instabilities and external coil-induced Resonant Magnetic Perturbations (RMP). The 3-wave technique, in which the line-integrated Faraday angle and electron density are measured simultaneously by three laser beams with specific polarizations and frequency offsets, is used. In order to achieve optimum resolution, three frequency-stabilized HCOOH lasers (694 GHz, >35 mW per cavity) and sensitive Planar Schottky Diode mixers are used, providing stable intermediate-frequency signals (0.5–3 MHz) with S/N > 50. The collinear R- and L-wave probe beams, which propagate through the plasma poloidal cross section (a = 0.25–0.27 m) vertically, are expanded using parabolic mirrors to cover the entire plasma column. Sources of systematic errors, e.g., stemming from mechanical vibration, beam non-collinearity, and beam polarization distortion are individually examined and minimized to ensure measurement accuracy. Simultaneous density and Faraday measurements have been successfully achieved for 14 chords. Based on measurements, temporal evolution of safety factor profile, current density profile, and electron density profile are resolved. Core magnetic and density perturbations associated with MHD tearing instabilities are clearly detected. Effects of non-axisymmetric 3D RMP in ohmically heated plasmas are directly observed by polarimetry for the first time.
Alfvén modes in the Madison Symmetric Torus
Authors: Li M. , Breizman B. N. , Zheng L. J. , Lin L. , Ding W. X. , Brower D. L.
Published: August 2014

This work presents a theoretical and computational analysis of core-localized energetic particle driven modes observed near the magnetic axis in the Madison Symmetric Torus [L. Lin, W. X. Ding, D. L. Brower et al., Phys. Plasmas 20, 030701 (2013)]. Using measured safety factor and plasma pressure profiles as input, the linear ideal MHD code Adaptive EiGenfunction Independent Solution (AEGIS) [L. J. Zheng and M. Kotschenreuther, J. Comput. Phys. 211, 748 (2006)] reveals Alfvénic modes close to the measured frequencies. The AEGIS results together with a reduced analytical model demonstrate that the modes are essentially “cylindrical” and dominated by a single poloidal component (m = 1). The modes are localized at the plasma core where the magnetic shear is weak and continuum damping is minimal. Detailed analysis establishes constraints on the safety factor and plasma pressure, under which two modes can exist simultaneously.
Theoretical/experimental comparison of deep tunneling decay of quasi-bound H(D)OCO to H(D) + CO2
Authors: Wagner Albert F. , Dawes Richard , Continetti Robert E. , Guo Hua
Published: August 2014

The measured H(D)OCO survival fractions of the photoelectron-photofragment coincidence experiments by the Continetti group are qualitatively reproduced by tunneling calculations to H(D) + CO2 on several recent ab initio potential energy surfaces for the HOCO system. The tunneling calculations involve effective one-dimensional barriers based on steepest descent paths computed on each potential energy surface. The resulting tunneling probabilities are converted into H(D)OCO survival fractions using a model developed by the Continetti group in which every oscillation of the H(D)-OCO stretch provides an opportunity to tunnel. Four different potential energy surfaces are examined with the best qualitative agreement with experiment occurring for the PIP-NN surface based on UCCSD(T)-F12a/AVTZ electronic structure calculations and also a partial surface constructed for this study based on CASPT2/AVDZ electronic structure calculations. These two surfaces differ in barrier height by 1.6 kcal/mol but when matched at the saddle point have an almost identical shape along their reaction paths. The PIP surface is a less accurate fit to a smaller ab initio data set than that used for PIP-NN and its computed survival fractions are somewhat inferior to PIP-NN. The LTSH potential energy surface is the oldest surface examined and is qualitatively incompatible with experiment. This surface also has a small discontinuity that is easily repaired. On each surface, four different approximate tunneling methods are compared but only the small curvature tunneling method and the improved semiclassical transition state method produce useful results on all four surfaces. The results of these two methods are generally comparable and in qualitative agreement with experiment on the PIP-NN and CASPT2 surfaces. The original semiclassical transition state theory method produces qualitatively incorrect tunneling probabilities on all surfaces except the PIP. The Eckart tunneling method uses the least amount of information about the reaction path and produces too high a tunneling probability on PIP-NN surface, leading to survival fractions that peak at half their measured values.
Exciton Seebeck effect in molecular systems
Authors: Yan Yun-An , Cai Shaohong
Published: August 2014

We investigate the exciton dynamics under temperature difference with the hierarchical equations of motion. Through a nonperturbative simulation of the transient absorption of a heterogeneous trimer model, we show that the temperature difference causes exciton population redistribution and affects the exciton transfer time. It is found that one can reproduce not only the exciton population redistribution but also the change of the exciton transfer time induced by the temperature difference with a proper tuning of the site energies of the aggregate. In this sense, there exists a site energy shift equivalence for any temperature difference in a broad range. This phenomenon is similar to the Seebeck effect as well as spin Seebeck effect and can be named as exciton Seebeck effect.
Supersymmetric analysis of the Dirac-Weyl operator within $\mathcal{PT}$PT symmetry
Authors: Yeşiltaş Özlem
Published: August 2014

Two-dimensional effective Hamiltonian for a massless Dirac electron interacting with a hyperbolic magnetic field is discussed within \documentclass[12pt]{minimal}\begin{document}$\mathcal{PT}$\end{document}PT symmetry. Factorization method and polynomial procedures are used to solve Dirac equation for the constant Fermi velocity and the effective potential which is complex Scarf II potential. The more general effective Scarf II potential models are also obtained within pseudo-supersymmetry. Finally, an extension of Panella and Roy's work [Phys. Lett. A 376, 2580–2583 (2012)] to the both \documentclass[12pt]{minimal}\begin{document}$\mathcal{PT}$\end{document}PT symmetric and real Scarf II partner potentials is given using the position dependent Fermi velocity.
Communication: Transient anion states of phenol…(H2O)n (n = 1, 2) complexes: Search for microsolvation signatures
Authors: de Oliveira Eliane M. , Freitas Thiago C. , Coutinho Kaline , do N. Varella Márcio T. , Canuto Sylvio , Lima Marco A. P. , Bettega Márcio H. F.
Published: August 2014

We report on the shape resonance spectra of phenol-water clusters, as obtained from elastic electron scattering calculations. Our results, along with virtual orbital analysis, indicate that the well-known indirect mechanism for hydrogen elimination in the gas phase is significantly impacted on by microsolvation, due to the competition between vibronic couplings on the solute and solvent molecules. This fact suggests how relevant the solvation effects could be for the electron-driven damage of biomolecules and the biomass delignification [E. M. de Oliveira et al., Phys. Rev. A 86, 020701(R) (2012)]. We also discuss microsolvation signatures in the differential cross sections that could help to identify the solvated complexes and access the composition of gaseous admixtures of these species.
Low-temperature plasma-deposited silicon epitaxial films: Growth and properties
Authors: Demaurex Bénédicte , Bartlome Richard , Seif Johannes P. , Geissbühler Jonas , Alexander Duncan T. L. , Jeangros Quentin , Ballif Christophe , De Wolf Stefaan
Published: August 2014

Low-temperature (≤200 °C) epitaxial growth yields precise thickness, doping, and thermal-budget control, which enables advanced-design semiconductor devices. In this paper, we use plasma-enhanced chemical vapor deposition to grow homo-epitaxial layers and study the different growth modes on crystalline silicon substrates. In particular, we determine the conditions leading to epitaxial growth in light of a model that depends only on the silane concentration in the plasma and the mean free path length of surface adatoms. For such growth, we show that the presence of a persistent defective interface layer between the crystalline silicon substrate and the epitaxial layer stems not only from the growth conditions but also from unintentional contamination of the reactor. Based on our findings, we determine the plasma conditions to grow high-quality bulk epitaxial films and propose a two-step growth process to obtain device-grade material.