bluuebunny/crossref_metadata_2025 huggingface dataset:
Müde und gereizt ohne ersichtlichen Grund – Differenzialdiagnose und praktisches Vorgehen bei Zeichen von Erschöpfung
Authors: Keel Peter
Published: September 2014

Chronische Müdigkeit ist ein häufiges Symptom, das aber meist erst zum Arzt führt, wenn deren Folgen wie Schlafstörungen und Reduktion der Leistungsfähigkeit den Alltag zu sehr beeinträchtigen. Häufig steht die Befürchtung im Vordergrund, dass ein somatisches Leiden vorliege, doch handelt es sich bei diesen Erschöpfungszeichen meist um die Folgen einer – oft nicht erkannten – anhaltenden psychischen Überlastung, also durch Aktivierung des Stresssystems bedingte somatoforme Beschwerden. Kann eine solche nicht gesehen werden, ist ein Minimum an somatischen Abklärungen angezeigt, denn die Liste der möglichen Differenzialdiagnosen ist lang. Andernfalls gilt es, eine geeignete psychosoziale Beratung in die Wege zu leiten, wozu der Hausarzt u. U. die nötige Motivation durch geeignete Vorarbeit leisten muss.
Anwendung der sport- und bewegungsbezogenen Selbstkonkordanz auf den Leistungssport
Authors: Kröhler Alena , Berti Stefan
Published: September 2014

Basierend auf der Selbstdeterminationstheorie (Deci & Ryan, 2012) und dem Selbstkonkordanz-Modell (Sheldon & Elliot, 1999) haben Seelig und Fuchs (2006) eine Skala zur Messung der sport- und bewegungsbezogenen Selbstkonkordanz (SSK-Skala) konstruiert. Da die SSK-Skala bisher nur im Kontext des Breiten- und Gesundheitssports angewendet und überprüft wurde, ist das Ziel der vorliegenden Studie, das Konzept der Selbstkonkordanz auf den Leistungssport zu übertragen. Aufbauend auf der Arbeit von Seelig und Fuchs (2006) nahmen 100 leistungsorientierte Schwimmer und Schwimmerinnen an einer Online-Befragung teil. Das Ergebnis der explorativen Faktorenanalyse legt nahe, dass es für den Leistungssport eine vereinfachte und auf 9 Items reduzierte Zwei-Faktorenlösung gibt, mit der die Motivation von Leistungssportlern und Leistungssportlerinnen kurz und präzise erfasst werden kann.
Molecular Regulation of Cell Fate in Cerebral Ischemia: Role of the Inflammasome and Connected Pathways
Authors: Trendelenburg George
Published: September 2014

Analogous to Toll-like receptors, NOD-like receptors represent a class of pattern recognition receptors, which are cytosolic and constitute part of different inflammasomes. These large protein complexes are activated not only by different pathogens, but also by sterile inflammation or by specific metabolic conditions. Mutations can cause hereditary autoinflammatory systemic diseases, and inflammasome activation has been linked to many multifactorial diseases, such as diabetes or cardiovascular diseases. Increasing data also support an important role in different central nervous diseases such as stroke. Thus, the current knowledge of the functional role of this intracellular ‘master switch’ of inflammation is discussed with a focus on its role in ischemic stroke, neurodegeneration, and also with regard to the recent data which argues for a relevant role in other organs or biologic systems which influence stroke incidence or prognosis.
Looking beyond endotoxin: a comparative study of pyrogen retention by ultrafilters used for the preparation of sterile dialyis fluid
Authors: Glorieux Griet , Hulko Michael , Speidel Rose , Brodbeck Katrin , Krause Bernd , Vanholder Raymond
Published: September 2014

Sterile single-use ultrafilters are used in dialysis for the preparation of the substitution fluid given to patients undergoing dialysis treatments with high convective fluid removal. The retention of pyrogenic agents by the ultrafilters is crucial to avoiding inflammatory responses. The performance of a new single-use ultrafilter (NUF) with a positively charged flat sheet membrane of relatively small membrane area and large pore size was compared to a reference ultrafilter (RUF) with a hollow fiber membrane. Filter performance was tested with various pyrogen-contaminated dialysis fluids by direct pyrogen quantification and by measuring inflammatory responses in cell-based bioassays. The NUF completely retained oligodeoxynucleotides (ODN), whereas the RUF was fully permeable. Both filters tended to decrease biological activity of DNA in filtered bacterial lysates. The NUF reduced lipopolysaccharides (LPS) and LPS-induced biological activity by 100%, whereas the RUF produced filtrates with low but detectable levels of LPS in most cases. Peptidoglycans (PGN) were fully retained both by the NUF and the RUF. The new ultrafilter retained biologically active ODN, which has not yet been described for any other device used in dialysis and it showed better or equal retention of LPS and PGN even with a smaller membrane surface and larger pore size.
The phosphatase mechanism of bifunctional kinase/phosphatase AceK
Authors: Wang Shu , Shen Qingya , Chen Guangju , Zheng Jimin , Tan Hongwei , Jia Zongchao
Published: September 2014

Through multiple approaches, we identified a novel stepwise mechanism of AceK which is ADP-dependent, enabled by a typical kinase scaffold.
Luminescent europium(iii)–β-diketonate complexes hosted in nanozeolite L as turn-on sensors for detecting basic molecules
Authors: Li Peng , Zhang Yuzhao , Wang Yige , Wang Yanji , Li Huanrong
Published: September 2014

A very simple, effective and robust platform for detecting basic molecule vapors based on the encapsulation of Eu3+–β-diketonate complexes within a nanozeolite L framework using Lundford's ship-in-a-bottle procedure is reported.
Live cell off-target identification of lapatinib using ligand-directed tosyl chemistry
Authors: Yamaura Kei , Kuwata Keiko , Tamura Tomonori , Kioi Yoshiyuki , Takaoka Yousuke , Kiyonaka Shigeki , Hamachi Itaru
Published: September 2014

We demonstrate that ligand-directed tosyl (LDT) chemistry is applicable to off-target identification in live cells.
Novel magnetic nickel telluride nanowires decorated with thorns: synthesis and their intrinsic peroxidase-like activity for detection of glucose
Authors: Wan Lijuan , Liu Jinhuai , Huang Xing-Jiu
Published: September 2014

Highly sensitive and selective colorimetric detection of glucose was performed using the peroxidase-like activity of NiTe TNWs with excellent magnetic performance.
Highly fluorinated naphthalenes and bifurcated C–H⋯F–C hydrogen bonding
Authors: Loader Jason R. , Libri Stefano , Meijer Anthony J. H. M. , Perutz Robin N. , Brammer Lee
Published: September 2014

Bifurcated C–H⋯(F–C)2 hydrogen bonds are most commonly close to being symmetric and are clearly evident in structures of two new fluoronaphthalenes.
Dynamics of a polymer adsorbed to an attractive homogeneous flat surface
Authors: Yang Qing-Hui , Qian Chang-Ji , Li Hong , Luo Meng-Bo
Published: September 2014

Polymer conformation and statistical sizes change with the surface contact number during the adsorption.
Development of a ReaxFF potential for Pt–O systems describing the energetics and dynamics of Pt-oxide formation
Authors: Fantauzzi Donato , Bandlow Jochen , Sabo Lehel , Mueller Jonathan E. , van Duin Adri C. T. , Jacob Timo
Published: September 2014

A ReaxFF force field description of Pt–O systems has been developed, validated and applied to oxygen diffusion on Pt(111).
Organosilane-functionalized graphene quantum dots and their encapsulation into bi-layer hollow silica spheres for bioimaging applications
Authors: Wen Ting , Yang Baocheng , Guo Yanzhen , Sun Jing , Zhao Chunmei , Zhang Shouren , Zhang Miao , Wang Yonggang
Published: September 2014

We demonstrate an affordable method to fabricate organosilane-functionalized graphene quantum dots and their encapsulation into bi-layer hollow silica spheres for bioimaging applications.
A polyoxometalate-based complex with visible-light photochromism as the electrocatalyst for generating hydrogen from water
Authors: Gong Yun , Yang Yong Xi , Zhang Miao Miao , Gao Xiao Lin , Yin Jun Li , Lin Jian Hua
Published: September 2014

A polyoxometalate-based complex can act as the electrocatalyst for the H2 evolution reaction (HER) and the HER current is enhanced with visible-light irradiation.
Photocatalytic reactivity tuning by heterometal and addenda metal variation in Lindqvist polyoxometalates
Authors: Tucher Johannes , Schlicht Stefanie , Kollhoff Fabian , Streb Carsten
Published: September 2014

The photooxidative performance of Lindqvist clusters [VxM6−xO19](2+x)− (M = W, Mo, x = 1, 2) is increased by mono- and di-vanadium functionalization. Divergent reaction mechanisms are observed depending on the type of addenda metal (Mo/W).
Grafting synthetic transmembrane units to the engineered low-toxicity α-hemolysin to restore its hemolytic activity
Authors: Ui Mihoko , Harima Kousuke , Takei Toshiaki , Tsumoto Kouhei , Tabata Kazuhito V. , Noji Hiroyuki , Endo Sumire , Akiyama Kimio , Muraoka Takahiro , Kinbara Kazushi
Published: September 2014

We demonstrated that staphylococcal α-hemolysin restored the hemolytic activity with chemically-synthesized prosthetic stem domains.
Crystal structures and magneto-structural correlation analysis for several cyano-bridged bimetallic complexes based on MnIII–FeIII systems
Authors: Zhou Hongbo , Wang Yingying , Mou Fangyou , Shen Xiaoping , Liu Yashu
Published: September 2014

The rotation of subunits and its influence on the magnetic coupling in MnIII–FeIII systems.
Development of nanocoral-like Cd(SSe) thin films using an arrested precipitation technique and their application
Authors: Khot Kishorkumar V. , Mali Sawanta S. , Pawar Nita B. , Kharade Rohini R. , Mane Rahul M. , Kondalkar Vijay V. , Patil Pallavi B. , Patil Pramod S. , Hong Chang K. , Kim Jin H. , Heo Jaeyeong , Bhosale Popatrao N.
Published: September 2014

First-time synthesis of nanoflakes to nanocoral-like Cd(SSe) thin films using a novel arrested precipitation technique with triethanolamine as complexing agent (η = 0.57%).
Green synthesis of noble metal nanoparticles using cysteine-modified silk fibroin: catalysis and antibacterial activity
Authors: Das Soumen , Dhar Basab Bijayi
Published: September 2014

Noble metal nanoparticles (NPs) have shown remarkable potential for numerous applications.
Use of amine electride chemistry to prepare molybdenum disulfide intercalation compounds
Authors: Liyanage Amila Udayanga , Lerner Michael M.
Published: September 2014

A new intercalation mechanism is identified when electride solutions in ethylenediamine are used to generate MoS2intercalation compounds.
Tunable 3D hierarchical graphene–BiOI nanoarchitectures: their in situ preparation, and highly improved photocatalytic performance and photoelectrochemical properties under visible light irradiation
Authors: Huang Hongwei , Liu Kun , Zhang Yinglei , Chen Kai , Zhang Yihe , Tian Na
Published: September 2014

Tunable 3D hierarchical graphene–BiOI nanoarchitectures result in efficient interfacial charge transfer and improved photochemical performance.
Copper-catalysed cycloaddition reactions of nitrones and alkynes for bioorthogonal labelling of living cells
Authors: Sherratt Allison R. , Chigrinova Mariya , McKay Craig S. , Beaulieu Louis-Philippe B. , Rouleau Yanouchka , Pezacki John Paul
Published: September 2014

An adapted biocompatible version of the Kinugasa reaction, the copper-catalysed alkyne-nitrone cycloaddition followed by rearrangement (CuANCR), was developed for live-cell labelling.
A quinoline-functionalized amphiphilic fluorogenic probe for specific detection of trivalent cations
Authors: Tao Shengyang , Wei Ying , Wang Chan , Wang Zhaoqi , Fan Pan , Shi Da , Ding Baojun , Qiu Jieshan
Published: September 2014

A quinoline-functionalized amphiphilic fluorogenic probe was synthesized which selectively detects trivalent ions viz. Al3+, Fe3+, Cr3+, Ru3+ and Au3+ through a fluorescence turn on signal.
Spherical V-MCM-48: the synthesis, characterization and catalytic performance in styrene oxidation
Authors: Wang Haiqing , Qian Wang , Chen Jin , Wu Yong , Xu Xiaoying , Wang Jun , Kong Yan
Published: September 2014

High-quality spherical V-MCM-48 catalysts were successfully synthesized and showed higher catalytic activity for the selective oxidation of styrene to benzaldehyde.
Metal-free amidation of ether sp3 C–H bonds with sulfonamides using PhI(OAc)2
Authors: Campos Jesús , Goforth Sarah K. , Crabtree Robert H. , Gunnoe T. Brent
Published: September 2014

Ether C–H bonds can be selectively amidated using simple sulfonamides and iodine oxidants in the absence of a metal catalyst.
Functionality-oriented molecular gels: synthesis and properties of nitrobenzoxadiazole (NBD)-containing low-molecular mass gelators
Authors: Yu Hang , Lü Yanchao , Chen Xiangli , Liu Kaiqiang , Fang Yu
Published: September 2014

A fluorescent gel with an ultra-fast and fully reversible response to the presence of ammonia gas is presented, and based upon the gel a conceptual “ammonia leaking” monitor was developed.
Wearable textile biofuel cells for powering electronics
Authors: Jia Wenzhao , Wang Xuan , Imani Somayeh , Bandodkar Amay J. , Ramírez Julian , Mercier Patrick P. , Wang Joseph
Published: September 2014

The article reports on the fabrication of wearable textile biofuel cells integrated with energy storage device for powering electronics with wearer’s perspiration as a fuel source.
Surface plasmon-photosensitizer resonance coupling: an enhanced singlet oxygen production platform for broad-spectrum photodynamic inactivation of bacteria
Authors: Hu Bo , Cao Xian , Nahan Keaton , Caruso Joseph , Tang Hong , Zhang Peng
Published: September 2014

A general platform to improve singlet oxygen productionviaresonance coupling between surface plasmon and photosensitizers, and for broad-spectrum photodynamic inactivation of bacteria.
Targeting metallo-carbapenemases via modulation of electronic properties of cephalosporins
Authors: Yang Hao , Young Heather , Yu Sophia , Sutton Larry , Crowder Michael W.
Published: September 2014

The global proliferation of metallo-carbapenemase-producing Enterobacteriaceae has created an unmet need for inhibitors of these enzymes. The rational design of metallo-carbapenemase inhibitors requires detailed knowledge of their catalytic mechanisms. Nine cephalosporins, structurally identical except for the systematic substitution of electron-donating and withdrawing groups in the para position of the styrylbenzene ring, were synthesized and utilized to probe the catalytic mechanism of New Delhi metallo-β-lactamase (NDM-1). Under steady-state conditions, Km values were all in the micromolar range (1.5–8.1 μM), whereas kcat values varied widely (17–220 s−1). There were large solvent deuterium isotope effects for all substrates under saturating conditions, suggesting a proton transfer is involved in the rate-limiting step. Pre-steady-state UV–visible scans demonstrated the formation of short-lived intermediates for all compounds. Hammett plots yielded reaction constants (ρ) of −0.34±0.02 and −1.15±0.08 for intermediate formation and breakdown, respectively. Temperature-dependence experiments yielded ΔG‡ values that were consistent with the Hammett results. These results establish the commonality of the formation of an azanide intermediate in the NDM-1-catalysed hydrolysis of a range cephalosporins with differing electronic properties. This intermediate is a promising target for judiciously designed β-lactam antibiotics that are poor NDM-1 substrates and inhibitors with enhanced active-site residence times.
Unlocked nucleic acids: implications of increased conformational flexibility for RNA/DNA triplex formation
Authors: Kotkowiak Weronika , Kotkowiak Michał , Kierzek Ryszard , Pasternak Anna
Published: September 2014

Unlocked nucleic acids (UNAs) have been introduced at specific positions in short model DNA hairpins and RNA/DNA triplexes for the first time. UNA residues destabilize the hairpins and decrease triplex thermodynamic stability or suppress triplex formation for most of the evaluated structures. Nevertheless, the incorporation of UNA residues at certain positions of dsDNA was found to be energetically favourable or at least did not affect triplex stability. Notably, the most thermodynamically stable UNA-modified triplexes exhibited improved stability at both acidic and physiological pH. The specificity of the interactions between the triplex-forming oligonucleotide and dsDNA was characterized using EMSA for the most thermodynamically stable structures, and triplex dissociation constants were determined. One of the modified triplexes exhibited an improved Kd in comparison with the unmodified triplex. CD and thermal difference spectra indicated that UNA residues do not alter the overall structure of the most thermodynamically stable triplexes. In addition, incubation of the modified oligonucleotides with human serum indicated that the UNAs demonstrate the potential to improve the biological stability of nucleic acids.
Balanced substrate integrated waveguide bandpass filter with high selectivity and common‐mode suppression
Authors: Chu Hui , Li Peng , Chen Jian‐Xin
Published: September 2014

A new method of designing balanced (differential) bandpass filters (BPFs) with high selectivity and common‐mode suppression is proposed and implemented by taking advantage of the existence of multiple substrate integrated waveguide cavity modes. The major design concept is by properly choosing, feeding and coupling dual‐mode cavities operating at TE102 and TE201 modes so as to not only provide capabilities to realise the desired differential‐mode passband associated with two transmission zeros, but also generate high common‐mode suppression over a wide range. Two X‐band BPFs with different internal coupling mechanisms are then proposed and designed. The two design examples having the same centre frequency of 10 Hz and respective passband width of 300 and 270 Hz are fabricated for demonstration. High selectivity is observed for both filters. Meanwhile, c is ∼37 dB for the first design example, whereas it is improved to 48.5 dB for the second one with multi‐layered structure. Good agreement can be observed between simulated and measured performances in the authors’ study.
Novel compensation method for electromagnetic performance of dielectric radome based on reflector shaping
Authors: Xu Wanye , Duan BaoYan , Li Peng , Zong Yali , Qiu Yuanying
Published: September 2014

From the viewpoint of geometrical optics, dielectric radome degrades the electromagnetic performance of the enclosed antenna by distorting the amplitude distribution and phase distribution of aperture field, of which the latter is mainly responsible for the distortion of far‐field pattern. A novel method based on reflector shaping is proposed to compensate the phase distortion of aperture field caused by radome. The aperture field of the shaped reflector antenna possesses a phase distribution, which has an inverse trend when compared with the phase distortion caused by radome, thus making the aperture field become equiphase after transmitting through the radome. Two different antenna–radome systems are simulated and the results show that the proposed method is effective, particularly for compensating the distortion of far‐field pattern such as the variation of sidelobe and null depth. Further analysis indicates that the shaping method is applicable to multifrequency‐band antenna–radome systems.
Antibiotics and Facial Fractures: Evidence-Based Recommendations Compared with Experience-Based Practice
Authors: Mundinger Gerhard S. , Borsuk Daniel E. , Okhah Zachary , Christy Michael R. , Bojovic Branko , Dorafshar Amir H. , Rodriguez Eduardo D.
Published: September 2014

Efficacy of prophylactic antibiotics in craniofacial fracture management is controversial. The purpose of this study was to compare evidence-based literature recommendations regarding antibiotic prophylaxis in facial fracture management with expert-based practice. A systematic review of the literature was performed to identify published studies evaluating pre-, peri-, and postoperative efficacy of antibiotics in facial fracture management by facial third. Study level of evidence was assessed according to the American Society of Plastic Surgery criteria, and graded practice recommendations were made based on these assessments. Expert opinions were garnered during the Advanced Orbital Surgery Symposium in the form of surveys evaluating senior surgeon clinical antibiotic prescribing practices by time point and facial third. A total of 44 studies addressing antibiotic prophylaxis and facial fracture management were identified. Overall, studies were of poor quality, precluding formal quantitative analysis. Studies supported the use of perioperative antibiotics in all facial thirds, and preoperative antibiotics in comminuted mandible fractures. Postoperative antibiotics were not supported in any facial third. Survey respondents ( n = 17) cumulatively reported their antibiotic prescribing practices over 286 practice years and 24,012 facial fracture cases. Percentages of prescribers administering pre-, intra-, and postoperative antibiotics, respectively, by facial third were as follows: upper face 47.1, 94.1, 70.6; midface 47.1, 100, 70.6%; and mandible 68.8, 94.1, 64.7%. Preoperative but not postoperative antibiotic use is recommended for comminuted mandible fractures. Frequent use of pre- and postoperative antibiotics in upper and midface fractures is not supported by literature recommendations, but with low-level evidence. Higher level studies may better guide clinical antibiotic prescribing practices.
Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates
Authors: Patty Kira , Sadeghi Seyed M. , Campbell Quinn , Hamilton Nathan , West Robert G. , Mao Chuanbin
Published: September 2014

We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.
Asymmetric flexural-gravity lumps in nonuniform media
Authors: Liang Yong , Alam Mohammad-Reza
Published: September 2014

Here we show that asymmetric fully localized flexural-gravity lumps can propagate on the surface of an inviscid and irrotational fluid covered by a variable-thickness elastic material, provided that the thickness varies only in one direction and has a local minimum. We derive and present equations governing the evolution of the envelope of flexural-gravity wave packets allowing the flexing material to have small variations in the transverse (to propagation) direction. We show that the governing equation belongs to the general family of Davey-Stewartson equations, but with an extra term in the surface evolution equation that accounts for the variable thickness of the elastic cover. We then use an iterative Newton-Raphson scheme, with a numerical continuation procedure via Lagrange interpolation, in a search to find fully localized solutions of this system of equations. We show that if the elastic sheet thickness has (at least) a local minimum, flexural-gravity lumps can propagate near the minimum thickness, and in general have an asymmetric bell-shape in the transverse to the propagation direction. In applied physics, flexural-gravity waves describe for instance propagation of waves over the ice-covered bodies of water. Ice is seldom uniform, nor is the seafloor, and in fact near the boundaries (ice-edges, shorelines) they typically vary only in one direction (toward to edge), and are uniform in the transverse direction. This research suggests that fully localized waves are not restricted to constant ice-thickness/water-depth areas and can exist under much broader conditions. Presented results may have implications in experimental generation and observation of flexural-gravity (as well as capillary-gravity) lumps.
Low-temperature Bessel beam trap for single submicrometer aerosol particle studies
Authors: Lu Jessica W. , Isenor Merrill , Chasovskikh Egor , Stapfer David , Signorell Ruth
Published: September 2014

We report on a new instrument for single aerosol particle studies at low temperatures that combines an optical trap consisting of two counter-propagating Bessel beams (CPBBs) and temperature control down to 223 K (−50 °C). The apparatus is capable of capturing and stably trapping individual submicrometer- to micrometer-sized aerosol particles for up to several hours. First results from studies of hexadecane, dodecane, and water aerosols reveal that we can trap and freeze supercooled droplets ranging in size from ∼450 nm to 5500 nm (radius). We have conducted homogeneous and heterogeneous freezing experiments, freezing-melting cycles, and evaporation studies. To our knowledge, this is the first reported observation of the freezing process for levitated single submicrometer-sized droplets in air using optical trapping techniques. These results show that a temperature-controlled CPBB trap is an attractive new method for studying phase transitions of individual submicrometer aerosol particles.
Nanomechanical motion of Escherichia coli adhered to a surface
Authors: Lissandrello C. , Inci F. , Francom M. , Paul M. R. , Demirci U. , Ekinci K. L.
Published: September 2014

Nanomechanical motion of bacteria adhered to a chemically functionalized silicon surface is studied by means of a microcantilever. A non-specific binding agent is used to attach Escherichia coli (E. coli) to the surface of a silicon microcantilever. The microcantilever is kept in a liquid medium, and its nanomechanical fluctuations are monitored using an optical displacement transducer. The motion of the bacteria couples efficiently to the microcantilever well below its resonance frequency, causing a measurable increase in the microcantilever fluctuations. In the time domain, the fluctuations exhibit large-amplitude low-frequency oscillations. In corresponding frequency-domain measurements, it is observed that the mechanical energy is focused at low frequencies with a 1/fα-type power law. A basic physical model is used for explaining the observed spectral distribution of the mechanical energy. These results lay the groundwork for understanding the motion of microorganisms adhered to surfaces and for developing micromechanical sensors for bacteria.
Combined treatment of relaxation and fluctuation dynamics in the calculation of two-dimensional electronic spectra
Authors: Seibt Joachim , Pullerits Tõnu
Published: September 2014

While the theoretical description of population transfer subsequent to electronic excitation in combination with a line shape function description of vibrational dynamics in the context of 2D-spectroscopy is well-developed under the assumption of different timescales of population transfer and fluctuation dynamics, the treatment of the interplay between both kinds of processes lacks a comprehensive description. To bridge this gap, we use the cumulant expansion approach to derive response functions, which account for fluctuation dynamics and population transfer simultaneously. We compare 2D-spectra of a model system under different assumptions about correlations between fluctuations and point out under which conditions a simplified treatment is justified. Our study shows that population transfer and dissipative fluctuation dynamics cannot be described independent of each other in general. Advantages and limitations of the proposed calculation method and its compatibility with the modified Redfield description are discussed.
Mean field limit for bosons with compact kernels interactions by Wigner measures transportation
Authors: Liard Quentin , Pawilowski Boris
Published: September 2014

We consider a class of many-body Hamiltonians composed of a free (kinetic) part and a multi-particle (potential) interaction with a compactness assumption on the latter part. We investigate the mean field limit of such quantum systems following the Wigner measures approach. We prove in particular the propagation of these measures along the flow of a nonlinear (Hartree) field equation. This enhances and complements some previous results of the same type shown in Z. Ammari and F. Nier and Fröhlich et al. [“Mean field limit for bosons and propagation of Wigner measures,” J. Math. Phys. 50(4), 042107 (2009); Z. Ammari and F. Nier and Fröhlich et al., “Mean field propagation of Wigner measures and BBGKY hierarchies for general bosonic states,” J. Math. Pures Appl. 95(6), 585–626 (2011); Z. Ammari and F. Nier and Fröhlich et al., “Mean-field- and classical limit of many-body Schrödinger dynamics for bosons,” Commun. Math. Phys. 271(3), 681–697 (2007)].
Accurate measurements of 13C-13C distances in uniformly 13C-labeled proteins using multi-dimensional four-oscillating field solid-state NMR spectroscopy
Authors: Straasø Lasse Arnt , Nielsen Jakob Toudahl , Bjerring Morten , Khaneja Navin , Nielsen Niels Chr.
Published: September 2014

Application of sets of 13C-13C internuclear distance restraints constitutes a typical key element in determining the structure of peptides and proteins by magic-angle-spinning solid-state NMR spectroscopy. Accurate measurements of the structurally highly important 13C-13C distances in uniformly 13C-labeled peptides and proteins, however, pose a big challenge due to the problem of dipolar truncation. Here, we present novel two-dimensional (2D) solid-state NMR experiments capable of extracting distances between carbonyl (13C′) and aliphatic (13Caliphatic) spins with high accuracy. The method is based on an improved version of the four-oscillating field (FOLD) technique [L. A. Straasø, M. Bjerring, N. Khaneja, and N. C. Nielsen, J. Chem. Phys. 130, 225103 (2009)] which circumvents the problem of dipolar truncation, thereby offering a base for accurate extraction of internuclear distances in many-spin systems. The ability to extract reliable accurate distances is demonstrated using one- and two-dimensional variants of the FOLD experiment on uniformly 13C,15N-labeled-L-isoleucine. In a more challenging biological application, FOLD 2D experiments are used to determine a large number of 13C′-13Caliphatic distances in amyloid fibrils formed by the SNNFGAILSS fibrillating core of the human islet amyloid polypeptide with uniform 13C,15N-labeling on the FGAIL fragment.
CO2 and C2H2 in cold nanodroplets of oxygenated organic molecules and water
Authors: Devlin J. Paul , Balcı F. Mine , Maşlakcı Zafer , Uras-Aytemiz Nevin
Published: September 2014

Recent demonstrations of subsecond and microsecond timescales for formation of clathrate hydrate nanocrystals hint at future methods of control of environmental and industrial gases such as CO2 and methane. Combined results from cold-chamber and supersonic-nozzle [A. S. Bhabhe, “Experimental study of condensation and freezing in a supersonic nozzle,” Ph.D. thesis (Ohio State University, 2012), Chap. 7] experiments indicate extremely rapid encagement of components of all-vapor pre-mixtures. The extreme rates are derived from (a) the all-vapor premixing of the gas-hydrate components and (b) catalytic activity of certain oxygenated organic large-cage guests. Premixing presents no obvious barrier to large-scale conditions of formation. Further, from sequential efforts of the groups of Trout and Buch, a credible defect-based model of the catalysis mechanism exists for guidance. Since the catalyst-generated defects are both mobile and abundant, it is often unnecessary for a high percentage of the cages to be occupied by a molecular catalyst. Droplets represent the liquid phase that bridges the premixed vapor and clathrate hydrate phases but few data exist for the droplets themselves. Here we describe a focused computational and FTIR spectroscopic effort to characterize the aerosol droplets of the all-vapor cold-chamber methodology. Computational data for CO2 and C2H2, hetero-dimerized with each of the organic catalysts and water, closely match spectroscopic redshift patterns in both magnitude and direction. Though vibrational frequency shifts are an order of magnitude greater for the acetylene stretch mode, both CO2 and C2H2 experience redshift values that increase from that for an 80% water–methanol solvent through the solvent series to approximately doubled values for tetrahydrofuran and trimethylene oxide (TMO) droplets. The TMO solvent properties extend to a 50 mol.% solution of CO2, more than an order of magnitude greater than for the water–methanol solvent mixture. The impressive agreement between heterodimer and experimental shift values throughout the two series encourages speculation concerning local droplet structures while the stable shift patterns appear to be useful indicators of the gas solubilities.
Conformational isomers of linear rotaxanes
Authors: Sevick Edith M. , Williams David R. M.
Published: September 2014

We examine a simple model of rotaxane structure, with 3 asymmetric rings interacting via repulsive power-law forces. This interlocked molecule exhibits conformational isomerisation which is different from that of molecules whose connectedness is through covalent bonds. The rings are free to translate along and rotate around the axle, and hence weak interaction forces between the rings can lead to distinct rotamer states. We use energy minimisation to determine these states exactly, and show that there can be transitions from asymmetric to symmetric states by varying the bond lengths. We also use classical statistical mechanics to show the effect of thermal noise.
Relaxation pathway confinement in glassy dynamics
Authors: Rodriguez Fris J. A. , Frechero M. A. , Appignanesi G. A.
Published: September 2014

We compute for an archetypical glass-forming system the excess of particle mobility distributions over the corresponding distribution of dynamic propensity, a quantity that measures the tendency of the particles to be mobile and reflects the local structural constraints. This enables us to demonstrate that, on supercooling, the dynamical trajectory in search for a relaxation event must deal with an increasing confinement of relaxation pathways. This “entropic funnel” of relaxation pathways built upon a restricted set of mobile particles is also made evident from the decay and further collapse of the associated Shannon entropy.
Critical analysis on nanostructured CoFeB synthetic orthogonal ferrimagnet
Authors: Chen Y. S. , Cheng Chih-Wei , Chern G. , Lin J. G.
Published: September 2014

Critical analysis on the magnetic properties of synthetic ferrimagnet (SyF), Ta/MgO/CoFeB/Ru/CoFeB/MgO/Ta, is demonstrated via both static and dynamic techniques. With the Ru thickness being 2.3 nm, the coupling between two CoFeB layers becomes orthogonal, which can be used for spin-transfer-torque nano-oscillator (STNO). The fitting of angular dependent ferromagnetic resonance (FMR) allows the precise determination of magnetic anisotropy of each CoFeB layer, the relative magnetizations and the exchange field near the frequency of STNO applications. In addition, the mechanism of resonance broadening at out-of-plane direction is identified to be magnetic inhomogeneity by fitting the angular dependent linewidth of FMR spectra, which provides indispensable information for the future design of STNO devices.
Evaluation of internal potential distribution and carrier extraction properties of organic solar cells through Kelvin probe and time-of-flight measurements
Authors: Tanaka Yuya , Noguchi Yutaka , Oda Keisuke , Nakayama Yasuo , Takahashi Jun-ichi , Tokairin Hiroshi , Ishii Hisao
Published: September 2014

The carrier extraction property of a prototypical small molecule organic solar cell (OSC) composed of copper phthalocyanine (CuPc), C60, and bathocuproine (BCP) was studied on the basis of the internal potential distribution and carrier dynamics in the device. The internal potential distribution in the OSC structure at the interfaces and in the bulk region was determined by the Kelvin probe method. Significant potential gradients were found in the CuPc film on indium tin oxide and in the C60 film on CuPc, consistent with charge transfer through the contacts. Moreover, surface potential of the BCP layer grew linearly with increasing film thickness with a slope of ca. 35 mV/nm (giant surface potential: GSP), which indicated spontaneous orientation polarization in the film. The potential gradient and GSP significantly changed the built-in potential of the device. Current–voltage and modified time-of-flight measurements revealed that the BCP layer worked as an electron injection and extraction layer despite the wide energy gap. These results were discussed based on the contributions of GSP and the gap states in the BCP layer.
Metalized T graphene: A reversible hydrogen storage material at room temperature
Authors: Ye Xiao-Juan , Liu Chun-Sheng , Zhong Wei , Zeng Zhi , Du You-Wei
Published: September 2014

Lithium (Li)-decorated graphene is a promising hydrogen storage medium due to its high capacity. However, homogeneous mono-layer coating graphene with lithium atoms is metastable and the lithium atoms would cluster on the surface, resulting in the poor reversibility. Using van der Waals-corrected density functional theory, we demonstrated that lithium atoms can be homogeneously dispersed on T graphene due to a nonuniform charge distribution in T graphene and strong hybridizations between the C-2p and Li-2p orbitals. Thus, Li atoms are not likely to form clusters, indicating a good reversible hydrogen storage. Both the polarization mechanism and the orbital hybridizations contribute to the adsorption of hydrogen molecules (storage capacity of 7.7 wt. %) with an optimal adsorption energy of 0.19 eV/H2. The adsorption/desorption of H2 at ambient temperature and pressure is also discussed. Our results can serve as a guide in the design of new hydrogen storage materials based on non-hexagonal graphenes.
Geometrical measurement of cardiac wavelength in reaction-diffusion models
Authors: Dupraz Marie , Jacquemet Vincent
Published: September 2014

The dynamics of reentrant arrhythmias often consists in multiple wavelets propagating throughout an excitable medium. An arrhythmia can be sustained only if these reentrant waves have a sufficiently short wavelength defined as the distance traveled by the excitation wave during its refractory period. In a uniform medium, wavelength may be estimated as the product of propagation velocity and refractory period (electrophysiological wavelength). In order to accurately measure wavelength in more general substrates relevant to atrial arrhythmias (heterogeneous and anisotropic), we developed a mathematical framework to define geometrical wavelength at each time instant based on the length of streamlines following the propagation velocity field within refractory regions. Two computational methods were implemented: a Lagrangian approach in which a set of streamlines were integrated, and an Eulerian approach in which wavelength was the solution of a partial differential equation. These methods were compared in 1D/2D tissues and in a model of the left atrium. An advantage of geometrical definition of wavelength is that the wavelength of a wavelet can be tracked over time with high temporal resolution and smaller temporal variability in an anisotropic and heterogeneous medium. The results showed that the average electrophysiological wavelength was consistent with geometrical measurements of wavelength. Wavelets were however often shorter than the electrophysiological wavelength due to interactions with boundaries and other wavelets. These tools may help to assess more accurately the relation between substrate properties and wavelet dynamics in computer models.
Donor states in inverse opals
Authors: Mahan G. D.
Published: September 2014

We calculate the binding energy of an electron bound to a donor in a semiconductor inverse opal. Inverse opals have two kinds of cavities, which we call octahedral and tetrahedral, according to their group symmetry. We put the donor in the center of each of these two cavities and obtain the binding energy. The binding energies become very large when the inverse opal is made from templates with small spheres. For spheres less than 50 nm in diameter, the donor binding can increase to several times its unconfined value. Then electrons become tightly bound to the donor and are unlikely to be thermally activated to the semiconductor conduction band. This conclusion suggests that inverse opals will be poor conductors.
Three-dimensional whispering gallery modes in InGaAs nanoneedle lasers on silicon
Authors: Tran T.-T. D. , Chen R. , Ng K. W. , Ko W. S. , Lu F. , Chang-Hasnain C. J.
Published: September 2014

As-grown InGaAs nanoneedle lasers, synthesized at complementary metal–oxide–semiconductor compatible temperatures on polycrystalline and crystalline silicon substrates, were studied in photoluminescence experiments. Radiation patterns of three-dimensional whispering gallery modes were observed upon optically pumping the needles above the lasing threshold. Using the radiation patterns as well as finite-difference-time-domain simulations and polarization measurements, all modal numbers of the three-dimensional whispering gallery modes could be identified.
Photoreflectance spectroscopy of GaInSbBi and AlGaSbBi quaternary alloys
Authors: Kopaczek J. , Rajpalke M. K. , Linhart W. M. , Jones T. S. , Ashwin M. J. , Kudrawiec R. , Veal T. D.
Published: September 2014

Molecular beam epitaxy is used to grow Ga1−yInySb1−xBix (y ≤ 5.5% and x ≤ 2.5%) and AlyGa1−ySb1−xBix alloys (y ≤ 6.6% and x ≤ 2.0%). The alloy composition and film thickness are determined by high resolution x-ray diffraction. The band gap of the alloys is determined by photomodulated reflectance (PR) spectroscopy. The band gap energy reduces with increasing In and Bi contents and decreasing Al content. The band gap energy reduction between 15 and 290 K is in the range of 60–75 meV, somewhat lower than the 82 meV for GaSb. The broadening of the band gap-related PR feature is between 16 and 28 meV.
High magnetic field studies of charged exciton localization in GaAs/AlxGa1−xAs quantum wells
Authors: Jadczak J. , Bryja L. , Ryczko K. , Kubisa M. , Wójs A. , Potemski M. , Liu F. , Yakovlev D. R. , Bayer M. , Nicoll C. A. , Farrer I. , Ritchie D. A.
Published: September 2014

We report on low temperature, polarization resolved, high magnetic field (up to 23 T) photoluminescence experiments on high mobility asymmetric GaAs quantum wells. At high magnetic fields, we detect two strong emission lines of the neutral and positively charged excitons (X and X+) and a series of weaker lines of the excitons bound to ionized acceptors (AX−). From polarization energy splittings of these lines, we determine the hole Landé factors (gh) of different complexes. For X and X+, gh initially grows with magnetic field and then saturates at gh = 0.88 and 1.55, respectively; for AX−'s, gh begins from a high value (from 6 to 11 at zero field) and decreases with the field growth. This contrasting behavior is traced to the structure of valence band Landau levels, calculated numerically in the Luttinger model, beyond axial approximation. This points to the coexistence (in the same well) of mobile X and X+ with localized and interface-pressed AX− states.
Uncertain Travel Times and Activity Schedules under Conditions of Space-Time Constraints and Invariant Choice Heuristics
Authors: Rasouli Soora , Timmermans Harry J P
Published: September 2014

The aim of this paper is to assess the impact of uncertain travel times as reflected in travel time variability on the outcomes of individuals' activity-travel scheduling decisions, assuming they are faced with fixed space-time constraints and apply the set of decision rules that they have developed over time by learning how to cope with uncertainty in their environment. Features of resulting activity-travel patterns are compared for different travel times. Results of the analyses indicate that uncertain travel times are reflected primarily in changes in the start and end time of activities and the corresponding duration of activities. There is also evidence that some activities are cancelled, suggesting that increased travel times may have made some activity agendas unfeasible.
Planning Support in Estimating Green Housing Opportunities for Different Socioeconomic Groups in Nanjing, China
Authors: Hu Hong , Geertman Stan , Hooimeijer Pieter
Published: September 2014

The sustainable city concept is often criticized for being unaffordable for the majority. To cater for various socioeconomic groups, it is essential that planners consider both affordability and sustainability. We provide planners with a methodology for estimating green housing potential for various socioeconomic groups in Nanjing, China, with reference to their green housing preferences and budgets. Results indicate that under the current situation the lower-middle class can barely afford a green apartment. If the metro network is extended, the green housing opportunities for the lower-middle class will increase in the central districts if they trade housing size for location. If heavy industries are relocated, green housing opportunities for the upper-middle class will increase in the central districts, but the lower-middle and middle classes will be pushed to the suburbs. Results also show that development of greenfields will provide more options for each socioeconomic group than redevelopment of brownfields.
A Single Solid That Can Generate Two Impossible Motion Illusions
Authors: Sugihara Kokichi
Published: September 2014

We discovered three-dimensional solids that can generate two different impossible motion illusions. When such a solid is seen from two particular viewpoints, two different shapes are perceived. In both cases the perceived physical motion appears to be impossible.
RNA thermometer controls temperature-dependent virulence factor expression in
Vibrio cholerae
Authors: Weber Gregor G. , Kortmann Jens , Narberhaus Franz , Klose Karl E.
Published: September 2014

Significance

Vibrio cholerae
causes the life-threatening diarrheal disease cholera. These bacteria live in aquatic environments and are introduced into humans through contaminated water sources. The bacteria express virulence factors upon entry into the human gastrointestinal tract. The present study shows that virulence factor expression is controlled by the shift in temperature to 37 °C, through an RNA thermometer that controls translation of the major virulence regulator protein ToxT. This simple mechanism allows maximal virulence factor expression within the mammalian host and may be more widespread among human pathogens than currently known.