bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Tool Selection in Left Brain-Damaged Patients With Apraxia of Tool Use: A Study of Three Cases
Authors: Osiurak François , Granjon Marine , Bonnevie Isabelle , Brogniart Joël , Mechtouff Laura , Benoit Amandine , Nighoghossian Norbert , Lesourd Mathieu
Published: December 2017

Objectives: Recent evidence indicates that some left brain-damaged (LBD) patients have difficulties to use familiar tools because of the inability to reason about physical object properties. A fundamental issue is to understand the residual capacity of those LBD patients in tool selection. Methods: Three LBD patients with tool use disorders, three right brain-damaged (RBD) patients, and six matched healthy controls performed a novel tool selection task, consisting in extracting a target out from a box by selecting the relevant tool among eight, four, or two tools. Three criteria were manipulated to make relevant and irrelevant tools (size, rigidity, shape). Results: LBD patients selected a greater number of irrelevant tools and had more difficulties to solve the task compared to RBD patients and controls. All participants committed more errors for selecting relevant tools based on rigidity and shape than size. In some LBD patients, the difficulties persisted even in the 2-Choice condition. Conclusions: Our findings confirm that tool use disorders result from impaired technical reasoning, leading patients to meet difficulties in selecting tools based on their physical properties. We also go further by showing that these difficulties can decrease as the choice is reduced, at least for some properties, opening new avenues for rehabilitation programs. (JINS, 2018, 24, 524–529)
As the World Leaks into the Work: Composition and architecture
Authors: Alvim Diogo
Published: December 2017

This article proposes a framework as a contribution to the expansion of compositional practice. It analyses and problematises different dimensions of architectural thinking and practice, and transposes them to the field of music. This way it suggests and develops compositional strategies that are more deeply engaged with the several spatialities of music creation, performance and listening.Material,site,drawing,programmeanduseoperate as conceptual tools to articulate music and architecture in a discussion towards a more comprehensive understanding of music composition. This was the theoretical ground of a practice-based PhD research in which I developed a portfolio of works. I will describe some of these to contextualise and demonstrate the contemporary relevance of this framework.
Value chains in renewable and sustainable food systems
Authors: Swisher Marilyn E. , Ruiz-Menjivar Jorge , Koenig Rosalie
Published: December 2017

Globalization of food trade in agricultural commodities is in some senses the antithesis of key concepts of sustainable agriculture. Global trade in food products distances the depletion of resources and environmental impacts of food production from the economic and social processes that drive consumption and increases the global risks from introduction of species that become pests. However, both supply and market value chains have emerged as major sub-systems in the larger global agro-food trade system that exert enormous importance over the potential for change in agricultural production at the farm level. This special issue presents studies of seven value chains that exhibit the breadth of research about value chains and their potential contributions to sustainable agriculture. They address value chains at different scales and dealing in various products. These studies contribute to the body of knowledge with a focus on lesser researched regions and products. Most important, they demonstrate the potential for value chains to enhance agricultural sustainability for rural populations and reduce food insecurity and inequities.
‘Fair innings’ in the face of ageing and demographic change
Authors: Hazra Nisha C. , Gulliford Martin C. , Rudisill Caroline
Published: December 2017

There are now 125 million people aged 80 years and over worldwide, projected by the United Nations to grow threefold by 2050. While increases in life expectancy and rapid increases in the older-age population are considered positive developments, the consequential future health care burden represents a leading concern for health services. We revisit Williams’ ‘fair innings’ argument from 1997, in light of technological and demographic changes, and challenge the notion that greater longevity may impose an unfair burden on younger generations. We discuss perspectives on the equity-efficiency trade-off in terms of their implications for the growing over-80 population, as well as society in general. This includes questioning the comparison of treatment cost-effectiveness in younger vs. older populations when using quality-adjusted life years and the transience of life expectancies over generations. While recognising that there will never be a clear consensus regarding societal value judgements, we present empirical evidence on the very elderly that lends support to a stronger anti-ageist stance given current increases in longevity.
Frame diffusion and institutional choice in regional economic cooperation
Authors: Lenz Tobias
Published: December 2017

Why have many regional organizations adopted common markets and customs unions? This article proposes a cognitive diffusion mechanism – termed frame diffusion – to explain convergent institutional choices across structurally diverse settings. Using Strang and Meyer’s (1993) notion of ‘theorization’ to combine foundational work on framing with the literature on diffusion, I argue that processes of theorization transform the experience of successful institutional innovators into abstract cognitive schemas, which link a particular understanding of a cooperation problem to specific institutional solutions. As policymakers in other contexts encounter similar cooperation problems, they adopt framed institutional solutions, which results in institutional convergence at the macro level. I further suggest that this process of frame diffusion is conditional on ideational affinities in social purpose between the innovating organization and other regional organizations. Where other organizations pursue a distinct social purpose, policymakers rely on alternative frames and thereby cement institutional variation. After developing this argument theoretically, I illustrate it in an exploratory comparison of institutional choice in three most different regional organizations: Association of Southeast Asian Nations, Common Market of the South, and the Southern African Development Community. The argument points to significant ‘blind spots’ and conceptual complementarity between prominent mechanisms of diffusion.
Mossy Oaks Are Dripping with Organic Matter
Authors: Underwood Emily
Published: December 2017

Epiphyte-bearing trees leach carbon when it rains.
The protease GtgE from Salmonella exclusively targets inactive Rab GTPases
Authors: Wachtel Rudolf , Bräuning Bastian , Mader Sophie L. , Ecker Felix , Kaila Ville R. I. , Groll Michael , Itzen Aymelt
Published: December 2017

Salmonella infections require the delivery of bacterial effectors into the host cell that alter the regulation of host defense mechanisms. The secreted cysteine protease GtgE from S. Typhimurium manipulates vesicular trafficking by modifying the Rab32 subfamily via cleaving the regulatory switch I region. Here we present a comprehensive biochemical, structural, and computational characterization of GtgE in complex with Rab32. Interestingly, GtgE solely processes the inactive GDP-bound GTPase. The crystal structure of the Rab32:GDP substrate in complex with the inactive mutant GtgEC45A reveals the molecular basis of substrate recognition. In combination with atomistic molecular dynamics simulations, the structural determinants for protein and activity-state specificity are identified. Mutations in a central interaction hub lead to loss of the strict GDP specificity. Our findings shed light on the sequence of host cell manipulation events during Salmonella infection and provide an explanation for the dependence on the co-secreted GTPase activating protein SopD2.
Antiferromagnetic correlations in the metallic strongly correlated transition metal oxide LaNiO3
Authors: Guo H. , Li Z. W. , Zhao L. , Hu Z. , Chang C. F. , Kuo C.-Y. , Schmidt W. , Piovano A. , Pi T. W. , Sobolev O. , Khomskii D. I. , Tjeng L. H. , Komarek A. C.
Published: December 2017

The material class of rare earth nickelates with high Ni3+ oxidation state is generating continued interest due to the occurrence of a metal-insulator transition with charge order and the appearance of non-collinear magnetic phases within this insulating regime. The recent theoretical prediction for superconductivity in LaNiO3 thin films has also triggered intensive research efforts. LaNiO3 seems to be the only rare earth nickelate that stays metallic and paramagnetic down to lowest temperatures. So far, centimeter-sized impurity-free single crystal growth has not been reported for the rare earth nickelates material class since elevated oxygen pressures are required for their synthesis. Here, we report on the successful growth of centimeter-sized LaNiO3 single crystals by the floating zone technique at oxygen pressures of up to 150 bar. Our crystals are essentially free from Ni2+ impurities and exhibit metallic properties together with an unexpected but clear antiferromagnetic transition.
Structural and computational understanding of weak interactions in “bridge-flipped” isomeric tetrafluoro-bis-benzylideneanilines
Authors: Dhingra Shallu , Barman Dibya Jyoti , Yadav Hare Ram , Eyyathiyil Jusaina , Bhowmik Prasanta , Kaur Parmeet , Adhikari Debashis , Roy Choudhury Angshuman
Published: December 2017

Structural and computational insights into inter-molecular interactions in isomeric bridge-flipped tetrafluoro-bis-benzylideneanilines.
Tuning the nucleophilicity of electron-rich diborane(4) compounds with bridging guanidinate substituents by substitution
Authors: Horn Julian , Widera Anna , Litters Sebastian , Kaifer Elisabeth , Himmel Hans-Jörg
Published: December 2017

The proton affinity, HOMO energy and ionization energy of electron-rich sp3–sp3-hybridized diborane(4) compounds with bridging guanidinate substituents can be varied by substitution.
Bipyridine-triggered modulation of structure and properties of zinc-diphosphonates: coordination role vs. template rule
Authors: Ma Yu-Juan , Han Song-De , Mu Ying , Pan Jie , Li Jin-Hua , Wang Guo-Ming
Published: December 2017

Two layered zinc-diphosphonates driven by 4,4′-bipy are prepared and their structural diversities are caused by the distinct roles of 4,4′-bipy in the process of assembly. The luminescence and proton conduction are studied.
Proton triggered emission and selective sensing of 2,4,6-trinitrophenol using a fluorescent hydrosol of 2-phenylquinoline
Authors: Maity Samir , Shyamal Milan , Das Debasish , Maity Ashim , Dey Sudipto , Misra Ajay
Published: December 2017

Compound 2-phenylquinoline (PhQ) displayed novel aggregation induced emission enhancement (AIEE) characteristics in its aggregate/solid state. It allows reversible fluorescence switching in acidic and basic media and ‘turn off’ fluorescence sensor for TNP.
Semimetallic carbon honeycombs: new three-dimensional graphene allotropes with Dirac cones
Authors: Wang Shuaiwei , Wu Donghai , Yang Baocheng , Ruckenstein Eli , Chen Houyang
Published: December 2017

Strain-induced and original Dirac cones and their origins in the newly proposed 3D carbon honeycomb structures.
Triangular AgAu@Pt core–shell nanoframes with a dendritic Pt shell and enhanced electrocatalytic performance toward the methanol oxidation reaction
Authors: Yan Xiaoxiao , Yu Sijia , Tang Yawen , Sun Dongmei , Xu Lin , Xue Can
Published: December 2017

Triangular AgAu@Pt core–shell nanoframes with a dendritic Pt shell were synthesized by employing triangular Ag nanoprisms as sacrificial templates.
Synthesis and structure of new binuclear ruthenium(ii) arene benzil bis(benzoylhydrazone) complexes: investigation on antiproliferative activity and apoptosis induction
Authors: Mohamed Kasim Mohamed Subarkhan , Sundar Saranya , Rengan Ramesh
Published: December 2017

New binuclear Ru(ii) arene benzil bis(benzoylhydrazone) complexes show excellent cytotoxicity against human cancer cell lines. The results of biochemical assays demonstrated that complexes are able to induce apoptosis.
Band-gap engineering of BiOCl with oxygen vacancies for efficient photooxidation properties under visible-light irradiation
Authors: Cui Dandan , Wang Liang , Xu Kang , Ren Long , Wang Li , Yu Youxing , Du Yi , Hao Weichang
Published: December 2017

Engineering the electronic structure of BiOCl through the creation of oxygen vacancies can be a good strategy to enhance the photooxidation activity of BiOCl.
Regenerative Medicine/Cardiac Cell Therapy: Adult/Somatic Progenitor Cells
Authors: Nazari-Shafti Timo , Kempfert Jörg , Falk Volkmar , Röll Wilhelm , Stamm Christof
Published: December 2017

Preclinical data suggested that somatic stem or progenitor cells derived induce and/or support endogenous repair mechanisms of the myocardium. Such cell populations were clearly shown to promote neovascularization in postischemic tissue, and some evidence also indicated transdifferentiation into cardiomyocytes. In the clinical setting, however, many attempts to regenerate damaged myocardium with a variety of autologous and allogeneic somatic progenitors have failed to generate the expected therapeutic efficacy. Currently, efforts are being made to select specific cellular subpopulations, modify somatic cells to augment their regenerative capacity, improve delivery methods, and develop markers selection of potentially responding patients. Cardiac surgical groups have pioneered and continue to advance the field of cellular therapies. While the initial excitement has subsided, the field has evolved into one of the pillars of surgical research and benefits from novel methods such as cellular reprogramming, genetic modification, and pluripotent stem cell technology. This review highlights developments and controversies in somatic cardiac cell therapy and provides a comprehensive overview of completed and ongoing clinical trials.
Otoplasty Online Information: A Comprehensive Analysis of the Websites and Videos that Patients View Regarding Cosmetic Ear Surgery
Authors: Gupta Amar , Rayess Hani , Black Kevin , Carron Michael , Nissan Michael
Published: December 2017

Physicians should be aware of both websites and videos available online regarding the otoplasty procedure to provide quality care. This study systematically analyzes the authorships, reliability, quality, and readability of the websites, as well as the authorships and primary objectives of the videos regarding otoplasty. Validated instruments were used to analyze the reliability, quality, and readability of websites, and videos were systematically categorized and analyzed. A Google search was conducted, and the first five pages of results were included in this study. After excluding unrelated websites, the remaining 44 websites were categorized by authorship (physician, patient, academic, or unaffiliated) and were analyzed using the validated DISCERN instrument for reliability and quality, as well as various other validated instruments to measure readability. A YouTube search was also conducted, and the first 50 relevant videos were included in the study. These videos were categorized by authorship and their primary objective. Website authorships were physician-dominated. Reliability, quality, and overall DISCERN score differ between the four authorship groups by a statistically significant margin (Kruskall–Wallis test, p < 0.05). Unaffiliated websites were the most reliable, and physician websites were the least reliable. Academic websites were of the highest quality, and patient websites were of the lowest quality. Readability did not differ significantly between the groups, though the readability measurements made showed a general lack of material easily readable by the general public. YouTube was likewise dominated by physician-authored videos. While the physician-authored videos sought mainly to inform and to advertise, patient-authored videos sought mainly to provide the patient's perspective. Academic organizations showed very little representation on YouTube, and the YouTube views on otoplasty videos were dominated by the top 20 videos, which represented over 93% of the total views of videos included in this study.
Frontal Fibrosing Alopecia: A Retrospective Analysis of 72 Patients from a German Academic Center
Authors: Letulé Valerie , Laniauskaite Ieva , Reinholz Markus , Tietze Julia , Wolff Hans , Ruzicka Thomas , Sattler Elke , Heppt Markus
Published: December 2017

Frontal fibrosing alopecia (FFA) describes the scarring, band-like recession of the frontotemporal hairline. Treatment is difficult, and currently, no evidence-based therapy exists. The purpose of this study is to report clinical features and treatment responses in a large cohort of patients with FFA. The authors analyzed a series of 72 patients with a clinical or histologic diagnosis of FFA. A total of 70 patients were female (97.2%), and 2 were male (2.8%). In females, the first onset of FFA was postmenopausal in 81.4% (n = 57). Documented eyebrow loss was present in 61.1% (n = 44), whereas involvement of eyelashes and body hair was reported in only 4.2% (n = 3) and 5.6% (n = 4), respectively. Clinical symptoms were itching (40.3%, n = 29) and trichodynia (4.2%, n = 3) in the alopecic area. Virtually all patients were treated with topical high-potency steroids. Additional treatments were topical tacrolimus, systemic retinoids, and hydroxychloroquine. A total of 48 patients (66.7%) received a combination of high-potency steroids with topical pimecrolimus. In this subgroup, subjective improvement or disease stabilization was reported by 64.6% (n = 31), and the hairline was stabilized on average after 9 to 12 months of therapy. The combination therapy of topical high-potency steroids with pimecrolimus may be an effective and steroid-saving treatment for FFA.
Comparison of Male and Female Prolactinoma Patients Requiring Surgical Intervention
Authors: Yoo Frederick , Chan Carmen , Kuan Edward , Bergsneider Marvin , Wang Marilene
Published: December 2017

Objectives Prolactinomas are the most common functional pituitary adenoma. Symptoms of a prolactinoma stem from hormonal causes (menstrual irregularities, galactorrhea, and reduced libido) or from tumor mass effect (visual changes and headache). Gender differences have been noted in prolactinomas, with males presenting with larger tumors and sequelae of mass effect, while females present commonly with hormonal symptoms. The purpose of this study is to evaluate differences in patient and disease characteristics, and outcomes between male and female prolactinoma patients undergoing surgery.

Design This was a retrospective chart review.

Setting This was done at the tertiary medical center.

Participants The medical records of prolactinomas patients who underwent endoscopic endonasal surgery between March 2008 and August 2016 were reviewed.

Main Outcome Measures Demographic information, tumor characteristics, and treatment characteristics and outcomes were collected. Statistical analysis was performed using chi-squared test or Student's t-test as applicable.

Results Seventy-nine patients were identified, 22 males and 57 females. The average age for males was 38 years and for females was 35 years. Males were more likely to present with decreased libido (p < 0.0001), whereas females more often presented with galactorrhea (p < 0.0001) and menstrual irregularities. Tumor size was larger in males (p = 0.0044) with higher likelihood of suprasellar extension (p = 0.0409) and cavernous sinus invasion (p = 0.0026). Males were more likely to have a subtotal resection rather than gross total resection (p = 0.0086) and less likely to have normalization of prolactin levels following surgery (p = 0.0019)

Conclusion Male prolactinoma patients tend to have larger tumors with more aggressive features. This may have a role in the differences in outcomes noted in this study.
Rapidly Growing Pulmonary Metastasis from Anaplastic Meningioma with Lethal Outcome: A Case Report
Authors: Corniola Marco , Landis Basile , Migliorini Denis , Lobrinus Johannes , Ares Carmen , Schaller Karl , Jägersberg Max
Published: December 2017

Anaplastic meningioma is seldom encountered. Moreover, distant metastasis is extremely rare, with only a handful cases reported. Here, we report the case of a 74-year-old female patient who underwent a combined cranial and endonasal approach for an extensive spheno-orbital anaplastic meningioma (WHO grade III), followed by adjuvant radiotherapy. Although local tumor control was achieved, she presented with lung metastasis 2 years later. The patient then died from pulmonary complications related to chest metastasis.

On the basis of this case, we discuss the available literature on metastatic meningiomas and radiologic follow-up strategies.
Lactate Threshold as a Measure of Aerobic Metabolism in Resistance Exercise
Authors: Domínguez Raúl , Maté-Muñoz José , Serra-Paya Noemí , Garnacho-Castaño Manuel
Published: December 2017

In resistance training, load intensity is usually calculated as the percentage of a maximum repetition (1RM) or maximum number of possible repetitions (% of 1RM). Some studies have proposed a lactate threshold (LT) intensity as an optimal approach for concurrent training of cardiorespiratory endurance and muscle strength, as well as an alternative in resistance training. The objective of the present study was to analyze the results obtained in research evaluating the use of LT in resistance training. A keyword and search tree strategy identified 14 relevant articles in the Dialnet, Elsevier, Medline, Pubmed, Scopus and Web of Science databases. Based on the studies analyzed, the conclusion was that the LT in resistance exercises can be determined either by mathematical methods or by visual inspection of graphical plots. Another possibility is to measure the intensity at which LT might coincide with the first ventilatory threshold (VT1). Since performing an exercise session at one’s LT intensity has been shown to accelerate the cardiorespiratory response and induce neuromuscular fatigue, this intensity could be used to set the training load in a resistance training program.
The chimera state in colloidal phase oscillators with hydrodynamic interaction
Authors: Hamilton Evelyn , Bruot Nicolas , Cicuta Pietro
Published: December 2017

The chimera state is the incongruous situation where coherent and incoherent populations coexist in sets of identical oscillators. Using driven non-linear oscillators interacting purely through hydrodynamic forces at low Reynolds number, previously studied as a simple model of motile cilia supporting waves, we find concurrent incoherent and synchronised subsets in small arrays. The chimeras seen in simulation display a “breathing” aspect, reminiscent of uniformly interacting phase oscillators. In contrast to other systems where chimera has been observed, this system has a well-defined interaction metric, and we know that the emergent dynamics inherit the symmetry of the underlying Oseen tensor eigenmodes. The chimera state can thus be connected to a superposition of eigenstates, whilst considering the mean interaction strength within and across subsystems allows us to make a connection to more generic (and abstract) chimeras in populations of Kuramoto phase oscillators. From this work, we expect the chimera state to emerge in experimental observations of oscillators coupled through hydrodynamic forces.
The Landau-de Gennes approach revisited: A minimal self-consistent microscopic theory for spatially inhomogeneous nematic liquid crystals
Authors: Gârlea Ioana C. , Mulder Bela M.
Published: December 2017

We design a novel microscopic mean-field theory of inhomogeneous nematic liquid crystals formulated entirely in terms of the tensor order parameter field. It combines the virtues of the Landau-de Gennes approach in allowing both the direction and magnitude of the local order to vary, with a self-consistent treatment of the local free-energy valid beyond the small order parameter limit. As a proof of principle, we apply this theory to the well-studied problem of a colloid dispersed in a nematic liquid crystal by including a tunable wall coupling term. For the two-dimensional case, we investigate the organization of the liquid crystal and the position of the point defects as a function of the strength of the coupling constant.
A fermionic de Finetti theorem
Authors: Krumnow Christian , Zimborás Zoltán , Eisert Jens
Published: December 2017

Quantum versions of de Finetti’s theorem are powerful tools, yielding conceptually important insights into the security of key distribution protocols or tomography schemes and allowing one to bound the error made by mean-field approaches. Such theorems link the symmetry of a quantum state under the exchange of subsystems to negligible quantum correlations and are well understood and established in the context of distinguishable particles. In this work, we derive a de Finetti theorem for finite sized Majorana fermionic systems. It is shown, much reflecting the spirit of other quantum de Finetti theorems, that a state which is invariant under certain permutations of modes loses most of its anti-symmetric character and is locally well described by a mode separable state. We discuss the structure of the resulting mode separable states and establish in specific instances a quantitative link to the quality of the Hartree-Fock approximation of quantum systems. We hint at a link to generalized Pauli principles for one-body reduced density operators. Finally, building upon the obtained de Finetti theorem, we generalize and extend the applicability of Hudson’s fermionic central limit theorem.
Second harmonic generation property of monolayer TMDCs and its potential application in producing terahertz radiation
Authors: Hu Lei , Wei Dongshan , Huang Xuri
Published: December 2017

Second harmonic generation (SHG) properties in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have aroused great interest. However, until now SHG for TMDC monolayer alloys is seldom investigated. Meanwhile, there is considerable controversy over the static SHG coefficients of monolayer MoS2. The feasibility to produce terahertz (THz) radiation via SHG in pure and alloyed TMDCs has never been reported. We first calculate the SHG coefficients of monolayer MoS2, MoSe2, and MoS2(1-x)Se2x using the independent particle approximation plus scissors correction. We then simulate their THz absorption by applying density function perturbation theory plus the Lorentzian line and try to calculate their zero-frequency THz refractive index and birefringence. The physical property of MoS2(1-x)Se2x alloys is simulated by considering various combinations. Results indicate that monolayer MoS2, MoSe2, and MoS2(1-x)Se2x possess large static SHG coefficients and THz birefringence and display low absorption over broadband THz frequencies. Therefore, they have applications in producing THz radiation via SHG. This study demonstrates that THz radiation can be attained in a large number of monolayers and few-layers and will extend applications of 2D materials. Moreover, it is possible to identify the magnitude of static coefficients of single-layer MoS2 by measuring THz intensities.
Quantum tunneling in real space: Tautomerization of single porphycene molecules on the (111) surface of Cu, Ag, and Au
Authors: Kumagai Takashi , Ladenthin Janina N. , Litman Yair , Rossi Mariana , Grill Leonhard , Gawinkowski Sylwester , Waluk Jacek , Persson Mats
Published: December 2017

Tautomerization in single porphycene molecules is investigated on Cu(111), Ag(111), and Au(111) surfaces by a combination of low-temperature scanning tunneling microscopy (STM) experiments and density functional theory (DFT) calculations. It is revealed that the trans configuration is the thermodynamically stable form of porphycene on Cu(111) and Ag(111), whereas the cis configuration occurs as a meta-stable form. The trans → cis or cis → trans conversion on Cu(111) can be induced in an unidirectional fashion by injecting tunneling electrons from the STM tip or heating the surface, respectively. We find that the cis ↔ cis tautomerization on Cu(111) occurs spontaneously via tunneling, verified by the negligible temperature dependence of the tautomerization rate below ∼23 K. Van der Waals corrected DFT calculations are used to characterize the adsorption structures of porphycene and to map the potential energy surface of the tautomerization on Cu(111). The calculated barriers are too high to be thermally overcome at cryogenic temperatures used in the experiment and zero-point energy corrections do not change this picture, leaving tunneling as the most likely mechanism. On Ag(111), the reversible trans ↔ cis conversion occurs spontaneously at 5 K and the cis ↔ cis tautomerization rate is much higher than on Cu(111), indicating a significantly smaller tautomerization barrier on Ag(111) due to the weaker interaction between porphycene and the surface compared to Cu(111). Additionally, the STM experiments and DFT calculations reveal that tautomerization on Cu(111) and Ag(111) occurs with migration of porphycene along the surface; thus, the translational motion couples with the tautomerization coordinate. On the other hand, the trans and cis configurations are not discernible in the STM image and no tautomerization is observed for porphycene on Au(111). The weak interaction of porphycene with Au(111) is closest to the gas-phase limit and therefore the absence of trans and cis configurations in the STM images is explained either by the rapid tautomerization rate or the similar character of the molecular frontier orbitals of the trans and cis configurations.
Optimal stretching in the reacting wake of a bluff body
Authors: Wang Jinge , Tithof Jeffrey , Nevins Thomas D. , Colón Rony O. , Kelley Douglas H.
Published: December 2017

We experimentally study spreading of the Belousov-Zhabotinsky reaction behind a bluff body in a laminar flow. Locations of reacted regions (i.e., regions with high product concentration) correlate with a moderate range of Lagrangian stretching and that range is close to the range of optimal stretching previously observed in topologically different flows [T. D. Nevins and D. H. Kelley, Phys. Rev. Lett. 117, 164502 (2016)]. The previous work found optimal stretching in a closed, vortex dominated flow, but this article uses an open flow and only a small area of appreciable vorticity. We hypothesize that optimal stretching is common in advection-reaction-diffusion systems with an excitation threshold, including excitable and bistable systems, and that the optimal range depends on reaction chemistry and not on flow shape or characteristic speed. Our results may also give insight into plankton blooms behind islands in ocean currents.
Compact quantum random number generator based on superluminescent light-emitting diodes
Authors: Wei Shihai , Yang Jie , Fan Fan , Huang Wei , Li Dashuang , Xu Bingjie
Published: December 2017

By measuring the amplified spontaneous emission (ASE) noise of the superluminescent light emitting diodes, we propose and realize a quantum random number generator (QRNG) featured with practicability. In the QRNG, after the detection and amplification of the ASE noise, the data acquisition and randomness extraction which is integrated in a field programmable gate array (FPGA) are both implemented in real-time, and the final random bit sequences are delivered to a host computer with a real-time generation rate of 1.2 Gbps. Further, to achieve compactness, all the components of the QRNG are integrated on three independent printed circuit boards with a compact design, and the QRNG is packed in a small enclosure sized 140 mm × 120 mm × 25 mm. The final random bit sequences can pass all the NIST-STS and DIEHARD tests.
Potential energy and dipole moment surfaces for HF@C60: Prediction of spectral and electric response properties
Authors: Kalugina Yulia N. , Roy Pierre-Nicholas
Published: December 2017

We present a five-dimensional potential energy surface (PES) for the HF@C60 system computed at the DF-LMP2/cc-pVTZ level of theory. We also calculated a five-dimensional dipole moment surface (DMS) based on DFT(PBE0)/cc-pVTZ calculations. The HF and C60 molecules are considered rigid with bond length rHF = 0.9255 Å (gas phase ground rovibrational state geometry). The C60 geometry is of Ih symmetry. The ab initio points were fitted to obtain a PES in terms of bipolar spherical harmonics. The minimum of the PES corresponds to a geometry where the center of mass of HF is located 0.11 Å away from the center of the cage with an interaction energy of −6.929 kcal/mol. The DMS was also represented in terms of bipolar spherical harmonics. The PES was used to calculate the rotation-translation bound states of HF@C60, and good agreement was found relative to the available experimental data [A. Krachmalnicoff et al., Nat. Chem. 8, 953 (2016)] except for the splitting of the first rotational excitation levels. We propose an empirical adjustment to the PES in order to account for the experimentally observed symmetry breaking. The form of that effective PES is additive. We also propose an effective Hamiltonian with an adjusted rotational constant in order to quantitatively reproduce the experimental results including the splitting of the first rotational state. We use our models to compute the molecular volume polarizability of HF confined by C60 and obtain good agreement with experiment.
Efficient use of single molecule time traces to resolve kinetic rates, models and uncertainties
Authors: Schmid Sonja , Hugel Thorsten
Published: December 2017

Single molecule time traces reveal the time evolution of unsynchronized kinetic systems. Especially single molecule Förster resonance energy transfer (smFRET) provides access to enzymatically important time scales, combined with molecular distance resolution and minimal interference with the sample. Yet the kinetic analysis of smFRET time traces is complicated by experimental shortcomings—such as photo-bleaching and noise. Here we recapitulate the fundamental limits of single molecule fluorescence that render the classic, dwell-time based kinetic analysis unsuitable. In contrast, our Single Molecule Analysis of Complex Kinetic Sequences (SMACKS) considers every data point and combines the information of many short traces in one global kinetic rate model. We demonstrate the potential of SMACKS by resolving the small kinetic effects caused by different ionic strengths in the chaperone protein Hsp90. These results show an unexpected interrelation between conformational dynamics and ATPase activity in Hsp90.
Evolution of a liquid-like fluid phase on Ge/Au(111) at room temperature: A direct observation by STM
Authors: Wakabayashi Yousuke , Hashiguchi Kouhei , Inase Yousuke , Kamiko Masao , Kyuno Kentaro
Published: December 2017

The evolution of a Au(111) surface after deposition of a submonolayer amount of Ge atoms has been investigated by STM. Diffusion and incorporation of Ge atoms into Au are active at room temperature where only negligible solubility is expected at equilibrium. It turned out that this surface phase is fluid, where the migration of step edges and successive appearance and disappearance of monolayer islands on the surface are confirmed. These phenomena seem to imply the weakening of the bonding strength between Au atoms by Ge incorporation and could be playing an important role in the low temperature crystallization process of Ge nanowires and thin films using Au as a catalyst.
An integrated tunable isolator based on NiZn film fabricated by spin-spray plating
Authors: Guo Rongdi , Lin Hwaider , Shi Wei , Gao Yuan , Wang Zhiguang , Sun Nian Xiang , Yu Zhong , Lan Zhongwen
Published: December 2017

An innovative type of tunable isolator with a planar comb-like microstrip transmission line, which generate circular polarization magnetic field, has been realized with polycrystalline NiZn ferrite thick films fabricated by spin-spray plating (SSP) process with thickness of 10μm. The phase compositions, microstructure, magnetic hysteresis loop, and ferromagnetic resonance (FMR) linewidth of NiZn ferrite thick films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and electron spin resonance (ESR) spectrometer, respectively. The NiZn ferrite thick films possess 4800Gauss saturation magnetization and 190Oe FMR linewidth measured at X-band. With an in-plane dc magnetic bias perpendicular to the comb-like microstrip transmission line, the transmission direction of left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) were proved to be opposite. The non-reciprocal ferromagnetic resonance absorption leads to 11.6dB isolation and 5.78dB insertion loss at 17.57GHz with magnetic bias field of 3.5kOe. Furthermore, with external in-plane magnetic fields range from 0.5kOe to 3.5kOe, the central frequency was tuned from 5.63GHz to 17.57GHz. The state-of-the-art tunable isolator with a planar comb-like microstrip transmission line exhibit a great potential to be applied in different microwave components and radar system.
Brillouin-Mandelstam spectroscopy of standing spin waves in a ferrite waveguide
Authors: Balinskiy Michael , Kargar Fariborz , Chiang Howard , Balandin Alexander A. , Khitun Alexander G.
Published: December 2017

This article reports results of experimental investigation of the spin wave interference over large distances in the Y3Fe2(FeO4)3 waveguide using Brillouin-Mandelstam spectroscopy. Two coherent spin waves are excited by the micro-antennas fabricated at the edges of the waveguide. The amplitudes of the input spin waves are adjusted to provide approximately the same intensity in the central region of the waveguide. The relative phase between the excited spin waves is controlled by the phase shifter. The change of the local intensity distribution in the standing spin wave is monitored using Brillouin-Mandelstam light scattering spectroscopy. Experimental data demonstrate the oscillation of the scattered light intensity depending on the relative phase of the interfering spin waves. The oscillations of the intensity, tunable via the relative phase shift, are observed as far as 7.5 mm away from the spin-wave generating antennas at room temperature. The obtained results are important for developing techniques for remote control of spin currents, with potential applications in spin-based memory and logic devices.
Magnetocrystalline anisotropy of ε-Fe2O3
Authors: Ahamed Imran , Pathak Rohit , Skomski Ralph , Kashyap Arti
Published: December 2017

The epsilon Fe2O3 phase of iron oxide has been studied to understand the spin structure and the magnetocrystalline anisotropy in the bulk and in thin films of ε-Fe2O3 and Co-doped ε-Fe2O3. The preferential magnetization direction in the nanoparticles of ε-Fe2O3 is along the a-axis [M. Gich et al., Chem. Mater. 18, 3889 (2006)]. Compared to the bulk band gap of 1.9 eV, the thin-film band gap is reduced to 1.3 eV in the Co-free films and to 0.7 eV in the film with partial Co substitution. The easy magnetization direction of the bulk and Co-free ε-Fe2O3 is along the c-axis, but it switches to the a-axis on Co substitution. All three systems exhibit in-plane anisotropies associated with the orthorhombic crystal structure of the oxide.
TMR tape drive for a 15 TB cartridge
Authors: Biskeborn Robert G. , Fontana Robert E. , Lo Calvin S. , Czarnecki W. Stanley , Liang Jason , Iben Icko E. T. , Decad Gary M. , Hipolito Venus A.
Published: December 2017

This paper highlights the development of tunnel magnetoresistive (TMR) sensors for magnetic tape recording applications. This has led to the introduction of a tape drives supporting a 15 TB native tape cartridge, currently the highest capacity available. Underscoring this development is the fact that the TMR sensors must run in continual contact with the tape media. This is contrasted with modern hard disk drive (hdd) sensors, which fly above the disk platters. Various challenges encountered in developing and deploying TMR are presented. In addition, advances to the write transducer are also discussed. Lastly, the authors show that future density scaling for tape recording, unlike that for hdd, is not facing limits imposed by photolithography or superparamagnetic physics, suggesting that cartridge capacity improvements of 4 to 6x will be achieved in the next 4 to 8 years.
ENDOR investigations of the Ce3+ ions in YAG: Transferred hyperfine interaction with nearest aluminum ions
Authors: Azamat D. V. , Badalyan A. G. , Feng D. H. , Lančok J. , Jastrabik L. , Dejneka A. , Baranov P. G. , Yakovlev D. R. , Bayer M.
Published: December 2017

The transferred hyperfine interactions of Ce3+ centers with 27Al neighbor nuclei in heavily cerium doped yttrium aluminum garnet (YAG) are resolved using Pulsed-Electron Nuclear Double Resonance (Pulsed-ENDOR). It is demonstrated that substitution of Ce3+ for Y3+ in YAG crystals leads to the strong reduction of the nuclear quadrupole coupling at the tetrahedral aluminum d-sites (e2qQ/h ≈ 4.67 MHz).
Enhanced visible light generation in an active microcavity via third-harmonic conversion beyond the non-depletion approximation
Authors: Yu Rong , Ding Chunling , Wang Jiangpeng , Zhang Duo
Published: December 2017

We explore the possibility of using an active doubly resonant microtoroid resonator to produce high-efficiency third-harmonic generation (THG) by exploiting optical third-order nonlinearity. In a microresonator, the active fundamental mode is coherently driven with a continuous-wave input laser at the telecommunication wavelength (1550 nm), and then, the visible THG signal (517 nm) is monitored via an individual bus waveguide. We thoroughly compare our results with those obtained from the conventional passive (i.e., loss) microtoroid resonator by a systematic analysis and detailed numerical simulations based on the Heisenberg-Langevin equations of motion. It is shown that the achievable THG spectrum features an ultralow critical input power. The THG power transmission can be significantly enhanced by about three orders of magnitude at a low input power of 0.1 μW as compared with the obtained results in the passive microtoroid resonator THG system. Moreover, the THG efficiency can reach up to 100% with optical critical input power as low as a few microwatts. In turn, the analytical expressions of the critical intracavity intensity of the light in the microcavity, the critical input pump power, and the maximum THG efficiency are obtained. The enhanced THG power transmission and high conversion efficiency are attributed to a gain-induced loss compensation in the microtoroid resonator, reducing the effective loss felt by the resonator photons. With state-of-the art technologies in the field of solid-state resonators, including but not limited to microtoroids, the proposed THG scheme is experimentally realizable.
Elastic scattering and vibrational excitation for electron impact on para-benzoquinone
Authors: Jones D. B. , Blanco F. , García G. , da Costa R. F. , Kossoski F. , Varella M. T. do N. , Bettega M. H. F. , Lima M. A. P. , White R. D. , Brunger M. J.
Published: December 2017

We report on theoretical elastic and experimental vibrational-excitation differential cross sections (DCSs) for electron scattering from para-benzoquinone (C6H4O2), in the intermediate energy range 15–50 eV. The calculations were conducted with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that also now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (Nopen) at the static-exchange-plus-polarisation (Nopench-SEP) level was used to calculate the scattering amplitudes using a channel coupling scheme that ranges from 1ch-SE up to the 89ch-SEP level of approximation. We found that in going from the 38ch-SEP to the 89ch-SEP, at all energies considered here, the elastic DCSs did not change significantly in terms of both their shapes and magnitudes. This is a good indication that our SMCPP 89ch-SEP elastic DCSs are converged with respect to the multichannel coupling effect for the investigated intermediate energies. While agreement between our IAM-SCAR+I and SMCPP 89ch-SEP computations improves as the incident electron energy increases from 15 eV, overall the level of accord is only marginal. This is particularly true at middle scattering angles, suggesting that our SCAR and interference corrections are failing somewhat for this molecule below 50 eV. We also report experimental DCS results, using a crossed-beam apparatus, for excitation of some of the unresolved (“hybrid”) vibrational quanta (bands I–III) of para-benzoquinone. Those data were derived from electron energy loss spectra that were measured over a scattered electron angular range of 10°–90° and put on an absolute scale using our elastic SMCPP 89ch-SEP DCS results. The energy resolution of our measurements was ∼80 meV, which is why, at least in part, the observed vibrational features were only partially resolved. To the best of our knowledge, there are no other experimental or theoretical vibrational excitation results against which we might compare the present measurements.
Anisotropic upper critical field in pressure-induced CrAs superconductor
Authors: Kim Sung-Il , Jung Soon-Gil , Shin Soohyeon , Kang Won Nam , Park Tuson
Published: December 2017

We report the upper critical field (Hc2) and its anisotropy in the pressure-induced superconductor CrAs. At ambient pressure, CrAs shows an antiferromagnetic phase transition at TN ∼ 264 K, where magnetostriction occurs simultaneously. TN is rapidly suppressed with increasing pressure and bulk superconductivity is induced near 7 kbar, above which the signature associated with TN is not visible in electrical resistivity measurements. With further increasing pressure, the superconducting phase shows a broad dome shape centered at the optimal pressure of 12.2 kbar. The Hc2 anisotropy of CrAs at 12.2 kbar, γHc2 = H//a/H⊥a, increases with decreasing temperature and becomes saturated at lower temperatures. Taken together with the positive curvature in Hc2 near Tc, these results suggest that the pressure-induced superconductor CrAs possesses multiple superconducting gaps.
Communication: On the calculation of time-dependent electron flux within the Born-Oppenheimer approximation: A flux-flux reflection principle
Authors: Albert Julian , Hader Kilian , Engel Volker
Published: December 2017

It is commonly assumed that the time-dependent electron flux calculated within the Born-Oppenheimer (BO) approximation vanishes. This is not necessarily true if the flux is directly determined from the continuity equation obeyed by the electron density. This finding is illustrated for a one-dimensional model of coupled electronic-nuclear dynamics. There, the BO flux is in perfect agreement with the one calculated from a solution of the time-dependent Schrödinger equation for the coupled motion. A reflection principle is derived where the nuclear BO flux is mapped onto the electronic flux.
Derivation of the magnetized Balescu-Lenard-Guernsey collision term based on the Fokker-Planck approach
Authors: Dong Chao , Zhang Wenlu , Cao Jintao , Li Ding
Published: December 2017

The Fokker-Planck approach is employed to derive the kinetic equation for spatially uniform magnetized plasmas. By using the fluctuating electrostatic field for quiescent plasmas, the magnetized Fokker-Planck coefficients are calculated explicitly based on the wave theory which takes into account the collective effects in a proper manner. Manipulating the magnetized Fokker-Planck collision term into the Landau form, the magnetized Balescu-Lenard-Guernsey collision term is obtained, which is identical to the results derived by using the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy of equations and the quasilinear method. The H theorem is proved in the end.