bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel experimental setup for simultaneous adsorption and induced deformation measurements in microporous materials
Authors: Perrier L. , Plantier F. , Grégoire D.
Published: March 2017

A new experimental setup is presented allowing the simultaneous measurement of adsorption isotherms and adsorption-induced deformations. It is composed of a manometric technique coupled with a digital image correlation setup for full-field displacement measurements. The manometric part is validated by comparing adsorption isotherms with those obtained by a gravimetric method. The principles and methods of both adsorption isotherm and induced deformation measurements are presented in detail. As a first application of this new apparatus, the coupling between adsorption and induced deformation is characterised for a microporous media (activated carbon) saturated by pure CO2 (318.15 K, [0–60] bars) and pure CH4 (303.15 K, [0–130] bars). For this very homogeneous porous material, the induced deformation is characteristic of a pure volumetric swelling but the full-field setup may allow the characterisation of the localised pattern of deformation for heterogenous or cracked microporous media.
Lithium ion conductivity and dielectric relaxation in dendritic nanostructured LiTaO3 glass–nanocrystal composites
Authors: Jaschin P. W. , Varma K. B. R.
Published: March 2017

Lithium tantalate in single-crystalline and coarse-grained configurations is a poor ionic conductor and does not qualify as a solid electrolyte for lithium-based batteries. In this work, ionic conductivity was sought to be enhanced by the use of nanocrystals of LiTaO3 embedded in a borate-based glass matrix. Glasses of composition 3Li2O–4B2O3–Ta2O5 were formed by melt-quenching. The crystallization process was described by using isothermal crystallization kinetics, invoking the Johnson–Mehl–Avrami–Kolmogorov equation, which indicated a three-dimensional growth with an Avrami exponent of 3.5 and an effective activation energy for crystallization of 735 ± 65 kJ mol–1. Heat treatment of the as-quenched glasses was performed between 530 and 560 °C, and the evolution of LiTaO3 phase was studied by X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The heat treatment yielded coalesced LiTaO3 nanocrystals of 18–32 nm size, forming dendritic structures in the glass matrix. Impedance analyses of the as-quenched and heat-treated glasses showed a dramatic improvement in dc conductivity (σdc), with a maximum around 3 × 10–3 S m−1 at 200 °C (σdcT = 1.5 S m−1 K) and activation energy of 0.54 eV for 530 °C/3 h heat-treated glasses. The values of σdc of the as-quenched glasses and of the 530 °C/3 h and 540 °C/3 h heat-treated glasses were about seven orders of magnitude higher than those of the single crystalline LiTaO3. Furthermore, the effect of heat treatment on lithium ion dynamics in the 40–200 °C temperature range was investigated by modulus formalism invoking the stretched exponential Kohlrausch–Williams–Watts function. The 7Li magic angle spinning NMR was used to investigate lithium self-diffusion in the nanostructured glass nanocrystal composites as a function of temperature between −10 °C and 60 °C.
Low-temperature growth of dense and hard Ti0.41Al0.51Ta0.08N films via hybrid HIPIMS/DC magnetron co-sputtering with synchronized metal-ion irradiation
Authors: Fager H. , Tengstrand O. , Lu J. , Bolz S. , Mesic B. , Kölker W. , Schiffers Ch. , Lemmer O. , Greene J. E. , Hultman L. , Petrov I. , Greczynski G.
Published: March 2017

Hard Ti1−xAlxN thin films are of importance for metal-cutting applications. The hardness, thermal stability, and oxidation resistance of these coatings can be further enhanced by alloying with TaN. We use a hybrid high-power pulsed and dc magnetron co-sputtering (HIPIMS/DCMS) technique to grow dense and hard Ti0.41Al0.51Ta0.08N alloys without external heating (Ts < 150 °C). Separate Ti and Al targets operating in the DCMS mode maintain a deposition rate of ∼50 nm/min, while irradiation of the growing film by heavy Ta+/Ta2+ ions from the HIPIMS-powered Ta target, using dc bias synchronized to the metal-ion-rich part of each HIPIMS pulse, provides effective near-surface atomic mixing resulting in densification. The substrate is maintained at floating potential between the short bias pulses to minimize Ar+ bombardment, which typically leads to high compressive stress. Transmission and scanning electron microscopy analyses reveal dramatic differences in the microstructure of the co-sputtered HIPIMS/DCMS films (Ta-HIPIMS) compared to films with the same composition grown at floating potential with all targets in the DCMS mode (Ta-DCMS). The Ta-DCMS alloy films are only ∼70% dense due to both inter- and intra-columnar porosity. In contrast, the Ta-HIPIMS layers exhibit no inter-columnar porosity and are essentially fully dense. The mechanical properties of Ta-HIPIMS films are significantly improved with hardness and elastic modulus values of 28.0 and 328 GPa compared to 15.3 and 289 GPa for reference Ta-DCMS films.
Gate-tunable, normally-on to normally-off memristance transition in patterned LaAlO3/SrTiO3 interfaces
Authors: Maier P. , Hartmann F. , Gabel J. , Frank M. , Kuhn S. , Scheiderer P. , Leikert B. , Sing M. , Worschech L. , Claessen R. , Höfling S.
Published: March 2017

We report gate-tunable memristive switching in patterned LaAlO3/SrTiO3 interfaces at cryogenic temperatures. The application of voltages in the order of a few volts to the back gate of the device allows controlling and switching on and off the inherent memory functionality (memristance). For large and small gate voltages, a simple non-linear resistance characteristic is observed, while a pinched hysteresis loop and memristive switching occur in an intermediate voltage range. The memristance is further controlled by the density of oxygen vacancies, which is tuned by annealing the sample at 300 °C in a nitrogen atmosphere. Depending on the annealing time, the memristance at zero gate voltage can be switched on and off, leading to normally-on and normally-off memristors. The presented device offers reversible and irreversible control of memristive characteristics by gate voltages and annealing, respectively, which may allow compensating fabrication variabilities of memristors that complicate the realization of large memristor-based neural networks.
Single-electron quantization at room temperature in a-few-donor quantum dot in silicon nano-transistors
Authors: Samanta Arup , Muruganathan Manoharan , Hori Masahiro , Ono Yukinori , Mizuta Hiroshi , Tabe Michiharu , Moraru Daniel
Published: March 2017

Quantum dots formed by donor-atoms in Si nanodevices can provide a breakthrough for functionality at the atomic level with one-by-one control of electrons. However, single-electron effects in donor-atom devices have only been observed at low temperatures mainly due to the low tunnel barriers. If a few donor-atoms are closely coupled as a molecule to form a quantum dot, the ground-state energy level is significantly deepened, leading to higher tunnel barriers. Here, we demonstrate that such an a-few-donor quantum dot, formed by selective conventional doping of phosphorus (P) donors in a Si nano-channel, sustains Coulomb blockade behavior even at room temperature. In this work, such a quantum dot is formed by 3 P-donors located near the center of the selectively-doped area, which is consistent with a statistical analysis. This finding demonstrates practical conditions for atomic- and molecular-level electronics based on donor-atoms in silicon nanodevices.
Formation of highly preferred orientation of β-Sn grains in solidified Cu/SnAgCu/Cu micro interconnects under temperature gradient effect
Authors: Zhao N. , Zhong Y. , Dong W. , Huang M. L. , Ma H. T. , Wong C. P.
Published: March 2017

β-Sn grain orientation and configuration are becoming crucial factors to dominate the lifetime of solder interconnects in three-dimensional integrated circuit packaging. In this paper, we found that a temperature gradient during solidification significantly dominated the orientation and configuration of the final β-Sn grains in Cu/SnAgCu/Cu micro interconnects. Being different from the random orientations and growth fronts meeting or cyclic twin boundary forming near the center after homogeneous temperature bonding, the β-Sn grains solidified under a certain temperature gradient were observed to follow a highly preferred orientation with their c-axis departing from the direction of temperature gradient by about 45°–88°. Meanwhile, these preferred oriented β-Sn grains consisted of low angle grain boundary structures with misorientation in the range of 0°–15°. The mechanism was explained in terms of the anisotropy and directional growth of β-Sn grains. The results pave the way for grain orientation control in 3D packaging technology.
Broadband optical absorption based on single-sized metal-dielectric-metal plasmonic nanostructures with high-ε″ metals
Authors: Wang Wei , Qu Yurui , Du Kaikai , Bai Songang , Tian Jingyi , Pan Meiyan , Ye Hui , Qiu Min , Li Qiang
Published: March 2017

We propose a broadband, efficient, ultra-thin metal-insulator-metal (MIM) absorber with a simple single-sized disk configuration by utilizing metals with high imaginary part of permittivity (ε″). The physics behind this is that field dissipation is remarkably enhanced in MIM absorbers with high-ε″ metals, significantly extending the absorption bandwidths, which are conventionally limited by magnetic resonances of MIM absorbers with low-ε″ metals. The experimentally demonstrated MIM absorber based on tungsten with high-ε″ yields broadband absorption from visible to near-infrared range (400–1700 nm) with an average measured absorption of 84%. The ultra-thin and single-sized nanostructure with broadband efficient absorption facilitates the scalability to large-area photonic applications.
Anharmonicity of monolayer MoS2, MoSe2, and WSe2: A Raman study under high pressure and elevated temperature
Authors: Yang Mei , Cheng Xuerui , Li Yuanyuan , Ren Yufen , Liu Miao , Qi Zeming
Published: March 2017

In this paper, the thermodynamic parameters such as Grüneisen parameters and anharmonicity are investigated utilizing pressure- and temperature-dependent Raman spectroscopy of monolayer transition-metal dichalcogenides MX2 (M = Mo, W; X = S, Se). The result indicates a good stability of these compounds in the pressure range of 0–9.0 GPa and the temperature range of 175–575 K. It is a general trend that Raman mode varies with temperature and pressure linearly for monolayer MX2, and the thermodynamic Grüneisen parameters can be determined from the temperature- and pressure-dependencies of Raman spectra. Based on these measurable parameters, anharmonic parameters are extracted for each active Raman mode. The result shows that the temperature dependencies of the phonon frequencies are well described by considering the contributions from thermal expansion and lattice anharmonicity.
Realization of electron vortices with large orbital angular momentum using miniature holograms fabricated by electron beam lithography
Authors: Mafakheri E. , Tavabi A. H. , Lu P.-H. , Balboni R. , Venturi F. , Menozzi C. , Gazzadi G. C. , Frabboni S. , Sit A. , Dunin-Borkowski R. E. , Karimi E. , Grillo V.
Published: March 2017

Free electron beams that carry high values of orbital angular momentum (OAM) possess large magnetic moments along the propagation direction. This makes them an ideal probe for measuring the electronic and magnetic properties of materials, as well as for fundamental experiments in magnetism. However, their generation requires the use of complex diffractive elements, which usually take the form of nano-fabricated holograms. Here, we show how the limitations of the current fabrication of such holograms can be overcome by using electron beam lithography. We demonstrate experimentally the realization of an electron vortex beam with the largest OAM value that has yet been reported to the first diffraction order (L = 1000 ℏ), paving the way for even more demanding demonstrations and applications of electron beam shaping.
Fast sodium ionic conduction in Na2B10H10-Na2B12H12 pseudo-binary complex hydride and application to a bulk-type all-solid-state battery
Authors: Yoshida Koji , Sato Toyoto , Unemoto Atsushi , Matsuo Motoaki , Ikeshoji Tamio , Udovic Terrence J. , Orimo Shin-ichi
Published: March 2017

In the present work, we developed highly sodium-ion conductive Na2B10H10-Na2B12H12 pseudo-binary complex hydride via mechanically ball-milling admixtures of the pure Na2B10H10 and Na2B12H12 components. Both of these components show a monoclinic phase at room temperature, but ball-milled mixtures partially stabilized highly ion-conductive, disordered cubic phases, whose fraction and favored structural symmetry (body-centered cubic or face-centered cubic) depended on the conditions of mechanical ball-milling and molar ratio of the component compounds. First-principles molecular-dynamics simulations demonstrated that the total energy of the closo-borane mixtures and pure materials is quite close, helping to explain the observed stabilization of the mixed compounds. The ionic conductivity of the closo-borane mixtures appeared to be correlated with the fraction of the body-centered-cubic phase, exhibiting a maximum at a molar ratio of Na2B10H10:Na2B12H12 = 1:3. A conductivity as high as log(σ/S cm−1) = –3.5 was observed for the above ratio at 303 K, being approximately 2–3 orders of magnitude higher than that of either pure material. A bulk-type all-solid-state sodium-ion battery with a closo-borane-mixture electrolyte, sodium-metal negative-electrode, and TiS2 positive-electrode demonstrated a high specific capacity, close to the theoretical value of NaTiS2 formation and a stable discharge/charge cycling for at least eleven cycles, with a high discharge capacity retention ratio above 91% from the second cycle.
Stable nonpolar resistive switching characteristics in Cu/Cu-dispersed ZrO2/Pt memory devices
Authors: Du Gang , Chen Zhian , Mao Qinan , Ji Zhenguo
Published: March 2017

In this study, stable nonpolar resistive switching characteristics in Cu/Cu-dispersed ZrO2/Pt electrochemical metallization (ECM) memory devices were reported by dispersing metallic Cu into the ZrO2 matrix. Reversible transition among different switching modes can be realized simply by modulating the polarities and magnitudes of the voltages. Moreover, improved uniformity with lower switching voltages and forming-free behaviors were also demonstrated in this device. The experiment results confirmed that metallic Cu clusters were penetrated into the ZrO2 matrix during the annealing process, which would function as an effective cation source responsible for the nonpolar RS switches. These results suggest that controlling the distribution state of active metal atoms in ECM stacks is a feasible approach for reliable memory applications.
Strain-induced improvement of photoluminescence from the groups of laterally ordered SiGe quantum dots
Authors: Zinovyev V. A. , Zinovieva A. F. , Kuchinskaya P. A. , Smagina Zh. V. , Armbrister V. A. , Dvurechenskii A. V. , Borodavchenko O. M. , Zhivulko V. D. , Mudryi A. V.
Published: March 2017

Photoluminescence properties of highly strained Ge/Si multi-layer heterostructures with incorporated groups of laterally ordered SiGe quantum dots are studied in the wide range of temperatures from 4.2 to 300 K. The phononless radiative recombination mechanism in the groups is found to be dominating. A photoluminescence signal from SiGe quantum dots is observed up to 300 K. The activation energy (≈211 meV) of photoluminescence thermal quenching can be associated with transition of holes from the laterally ordered quantum dots to the valence band states in the Ge wetting layer.
The Zeeman splitting of bulk 2H-MoTe2 single crystal in high magnetic field
Authors: Sun Yan , Zhang Junpei , Ma Zongwei , Chen Cheng , Han Junbo , Chen Fangchu , Luo Xuan , Sun Yuping , Sheng Zhigao
Published: March 2017

A high magnetic field magneto-optical spectrum is utilized to study the A exciton of bulk 2H-MoTe2 single crystal. A clear Zeeman splitting of the A exciton is observed under high magnetic fields up to 41.68 T, and the g-factor (−2.09 ± 0.08) is deduced. Moreover, a high magnetic field enables us to obtain the quadratic diamagnetic shifts of the A exciton (0.486 μeV T−2). Accordingly, the binding energy, reduced mass, and radius of the A exciton were obtained by using both two and three dimensional models. Compared with other transition metal dichalcogenides (TMDs), the A exciton of bulk 2H-MoTe2 has a relatively small binding energy and larger exciton radius, which provide fundamental parameters for comprehensive understanding of excitons in TMDs as well as their future applications.
Magnetic anisotropy of epitaxial Co2Fe-Ge Heusler alloy films on MgO (100) substrates
Authors: Pogorily A. N. , Kravets A. F. , Nevdacha V. V. , Podyalovskiy D. Y. , Ryabchenko S. M. , Kalita V. M. , Kulik M. M. , Lozenko A. F. , Vovk A. Ya. , Godinho M. , Maurel L. , Pardo J. A. , Magen C. , Korenivski V.
Published: March 2017

Films of Co2Fe-Ge Heusler alloy with variable Ge concentration deposited on monocrystalline MgO (100) substrates by magnetron co-sputtering are investigated using microstructural, morphological, magnetometric, and magnetic resonance methods. The films were found to grow epitaxially, with island-like or continuous-layer morphology depending the Ge-content. The ferromagnetic resonance data versus out-of-plane and in-plane angle indicate the presence of easy plane and 4-fold in-plane anisotropy. The magnetometry data indicate additional weak 2-fold in-plane anisotropy and pronounced at low fields rotatable anisotropy. The observed magnetic anisotropy properties discussed in correlation with the microstructure and morphology of the films.
Calibration of 4π NaI(Tl) detectors with coincidence summing correction using new numerical procedure and ANGLE4 software
Authors: Badawi Mohamed S. , Jovanovic Slobodan I. , Thabet Abouzeid A. , El-Khatib Ahmed M. , Dlabac Aleksandar D. , Salem Bohaysa A. , Gouda Mona M. , Mihaljevic Nikola N. , Almugren Kholud S. , Abbas Mahmoud I.
Published: March 2017

The 4π NaI(Tl) γ-ray detectors are consisted of the well cavity with cylindrical cross section, and the enclosing geometry of measurements with large detection angle. This leads to exceptionally high efficiency level and a significant coincidence summing effect, much more than a single cylindrical or coaxial detector especially in very low activity measurements. In the present work, the detection effective solid angle in addition to both full-energy peak and total efficiencies of well-type detectors, were mainly calculated by the new numerical simulation method (NSM) and ANGLE4 software. To obtain the coincidence summing correction factors through the previously mentioned methods, the simulation of the coincident emission of photons was modeled mathematically, based on the analytical equations and complex integrations over the radioactive volumetric sources including the self-attenuation factor. The measured full-energy peak efficiencies and correction factors were done by using 152Eu, where an exact adjustment is required for the detector efficiency curve, because neglecting the coincidence summing effect can make the results inconsistent with the whole. These phenomena, in general due to the efficiency calibration process and the coincidence summing corrections, appear jointly. The full-energy peak and the total efficiencies from the two methods typically agree with discrepancy 10%. The discrepancy between the simulation, ANGLE4 and measured full-energy peak after corrections for the coincidence summing effect was on the average, while not exceeding 14%. Therefore, this technique can be easily applied in establishing the efficiency calibration curves of well-type detectors.
Two-beam laser fabrication technique and the application for fabricating conductive silver nanowire on flexible substrate
Authors: He Gui-Cang , Zheng Mei-Ling , Dong Xian-Zi , Liu Jie , Duan Xuan-Ming , Zhao Zhen-Sheng
Published: March 2017

In this study, a two-beam laser fabrication technique is proposed to fabricate silver nanowire (AgNW) on the polyethylene terephthalate (PET) substrate. The femtosecond pulse laser in the technique plays a role in generating Ag nanoparticles from the silver aqueous solution by multiphoton photoreduction. The continuous wave (CW) laser of the technique works as optical tweezers, and make the Ag nanoparticles gather to a continuous AgNW by the optical trapping force. The optical trapping force of the CW laser was calculated under our experimental condition. The flexibility and the resistance stability of the AgNW that fabricated by this technique are very excellent. Compared to the resistance of the AgNW without bending, the decreasing rate of the AgNW resistance is about 16% under compressed bending condition at the radius of 1 mm, and the increasing rate of the AgNW resistance is only 1.3% after the AgNW bended about 3500 times at the bending radius of 1 mm. The study indicates that the AgNW is promising for achieving flexible device and would promote the development of the flexible electronics.
LDPC product coding scheme with extrinsic information for bit patterned media recoding
Authors: Jeong Seongkwon , Lee Jaejin
Published: March 2017

Since the density limit of the current perpendicular magnetic storage system will soon be reached, bit patterned media recording (BPMR) is a promising candidate for the next generation storage system to achieve an areal density beyond 1 Tb/in2. Each recording bit is stored in a fabricated magnetic island and the space between the magnetic islands is nonmagnetic in BPMR. To approach recording densities of 1 Tb/in2, the spacing of the magnetic islands must be less than 25 nm. Consequently, severe inter-symbol interference (ISI) and inter-track interference (ITI) occur. ITI and ISI degrade the performance of BPMR. In this paper, we propose a low-density parity check (LDPC) product coding scheme that exploits extrinsic information for BPMR. This scheme shows an improved bit error rate performance compared to that in which one LDPC code is used.
Kinetics of the permanent deactivation of the boron-oxygen complex in crystalline silicon as a function of illumination intensity
Authors: Steckenreiter Verena , Walter Dominic C. , Schmidt Jan
Published: March 2017

Based on contactless carrier lifetime measurements performed on p-type boron-doped Czochralski-grown silicon (Cz-Si) wafers, we examine the rate constant Rde of the permanent deactivation process of the boron-oxygen-related defect center as a function of the illumination intensity I at 170°C. While at low illumination intensities, a linear increase of Rde on I is measured, at high illumination intensities, Rde seems to saturate. We are able to explain the saturation by assuming that Rde increases proportionally with the excess carrier concentration Δn and take the fact into account that at sufficiently high illumination intensities, the carrier lifetime decreases with increasing Δn and hence the slope of Δn(I) decreases, leading to an apparent saturation. Importantly, on low-lifetime Cz-Si samples no saturation of the deactivation rate constant is observed for the same illumination intensities, proving that the deactivation is stimulated by the presence of excess electrons and not directly by the photons.
Searching for imperatives in European sign languages
Authors: Donati Caterina , Barberà Gemma , Branchini Chiara , Cecchetto Carlo , Geraci Carlo , Quer Josep
Published: March 2017

This article presents the first results of a pilot project aiming at analyzing how European sign languages realize a syntactic domain that is very solid, likely to be grammaticalized in any language but very poorly described or not described at all for sign languages: the imperative. Our innovative approach covers the characterization of the manual and non-manual components that identify imperatives in Italian, French and Catalan Sign Language, together with a number of other properties typically associated with imperative clauses in spoken languages.
Crossing the categorial divide
Authors: Swearingen Andrew
Published: March 2017

Imperatives and interjections are distinct categories differing in both form and function. As the prototypical directive verb form, an imperative exhibits both typical as well as unique morphosyntactic properties of its class. Interjections are discourse markers anchored in pragmatics and peripheral to phrasal grammar. However, imperatives and interjections also exhibit a number of similar properties which underlie instances of transcategorization between the two. With examples from a variety of Romance languages, I explore the shared features and processes leading to transcategorization, touch upon the language origins of imperatives and interjections and refer to Heine’s (1993) overlap model to argue that a combination of shared features and frequency constitute the principle triggers for these processes.
Live Transport of Yellow Perch and Nile Tilapia in AQUI-S 20E (10% Eugenol) at High Loading Densities
Authors: Cupp Aaron R , Schreier Theresa M , Schleis Susan M
Published: March 2017

Fish transport costs are a substantial portion of the operational expenses for aquaculture facilities in the USA. Safely transporting higher loading densities of fish would benefit haulers by increasing efficiency and reducing costs, but research evaluating transport for individual species is generally lacking. In this study, Yellow Perch Perca flavescens and Nile Tilapia Oreochromis niloticus were transported for 6 h immersed in water containing AQUI-S 20E (10% eugenol) at fish loading densities of 240 g/L (2 lb/gal) for perch and 480 g/L (4 lb/gal) for tilapia. Survival was quantified for fish transported in AQUI-S 20E concentrations of (1) control or 0 mg/L of water, (2) 100 mg/L, or (3) 200 mg/L. Yellow Perch had 98–100% survival, and Nile Tilapia had 100% survival up to through 14 d after transport across all AQUI-S 20E levels, including the control. Eugenol concentrations decreased rapidly in transport tank water, and fish showed no signs of sedation by the end of transport. We conclude that live transport of Yellow Perch and Nile Tilapia at higher loading densities resulted in high survival regardless of the AQUI-S 20E concentrations we tested.
Longtime existence of the Kähler-Ricci flow on ℂⁿ
Authors: Chau Albert , Li Ka-Fai , Tam Luen-Fai
Published: March 2017

We produce longtime solutions to the Kähler-Ricci flow for complete Kähler metrics on

C

n

\mathbb {C}^n

without assuming the initial metric has bounded curvature, thus extending results in an earlier work of the authors. We prove the existence of a longtime bounded curvature solution emerging from any complete

U
(
n
)

U(n)

-invariant Kähler metric with non-negative holomorphic bisectional curvature, and that the solution converges as

t
→
∞

t\to \infty

to the standard Euclidean metric after rescaling. We also prove longtime existence results for more general Kähler metrics on

C

n

\mathbb {C}^n

which are not necessarily

U
(
n
)

U(n)

-invariant.
Metastatic Liposarcoma of the Skull Base: A Case Report and Review of Literature
Authors: Zagzoog Nirmeen , Ra Greta , Koziarz Alex , Provias John , Sommer Doron , Almenawer Saleh A. , Reddy Kesava
Published: March 2017

BACKGROUND AND IMPORTANCE: Myxoid liposarcoma is not an uncommon form of sarcoma. However, it usually affects the lower extremity long bones. Scapular involvement is extremely rare, as is a metastasis to the parasellar region. We present a case of liposarcoma of the skull base originating in the scapular region and metastasizing to the sellar and parasellar regions and provide a review of the pertinent literature.

CLINICAL PRESENTATION: A 43-year-old female patient diagnosed with left scapular myxoid liposarcoma was treated with surgical resection. She had clear resection margins and was treated pre- and postoperatively with radiotherapy to the region. She remained asymptomatic for 2 years following surgery, after which she abruptly developed diplopia with right lateral gaze. There were no symptoms of raised intracranial pressure or impaired vision. Her examination was normal apart from complete right sixth nerve palsy. Imaging studies of the brain showed a large mass in the clivus eroding into the floor of the sella, encircling the right internal carotid artery in the cavernous sinus. The mass also displaced the sellar contents superiorly. An endonasal, endoscopic skull base approach was undertaken, and a subtotal resection was performed in an effort to avoid multiple cranial nerve pareses.

CONCLUSION: Our literature search revealed that this case report is the first to document liposarcoma metastasis to the skull base originating from the scapular region. Subtotal surgical resection resulted in minimal improvement of the patient's sixth nerve palsy. Postoperative radiation was undertaken. A multidisciplinary approach on an individual patient basis is recommended.
C. elegansexhibits coordinated oscillation in gene activation in single-cell developmental data
Authors: Hutchison Luke A.D. , Berger Bonnie , Kohane Isaac
Published: March 2017

Background

The advent ofin vivoautomated single-cell lineaging and sequencing will dramatically increase our understanding of development. New integrative analysis techniques are needed to generate insights from single-cell developmental data.

Results

We applied novel meta-analysis techniques to the EPIC single-cell-resolution developmental gene expression dataset forC. elegansto show that a simple linear combination of the expression levels of the developmental genes is strongly correlated with the developmental age of the organism, irrespective of the cell division rate of different cell lineages. We uncovered a pattern of collective sinusoidal oscillation in gene activation, in multiple dominant frequencies and in multiple orthogonal axes of gene expression, pointing to the existence of a coordinated, multi-frequency global timing mechanism. We developed a novel method based on Fisher’s Discriminant Analysis (FDA) to identify linear gene expression weightings that are able to produce sinusoidal oscillations of any frequency and phase, adding to the evidence that oscillatory mechanisms likely play an important role in the timing of development. We cross-linked EPIC with gene ontology and anatomy ontology terms, employing FDA methods to identify previously unknown positive and negative genetic contributions to developmental processes and cell phenotypes.

Conclusions

This meta-analysis demonstrates new evidence for direct linear and/or sinusoidal mechanisms regulating the timing of development. We uncovered a number of previously unknown positive and negative correlations between developmental genes and developmental processes or cell phenotypes. The presented novel analysis techniques are broadly applicable within developmental biology.
Two new isostructural mercury(II) complexes involving the N-heterocyclic 1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole ligand: syntheses, structures and properties
Authors: Wei Xu , Li Jian-Hua , Huang Qiu-Ying , Meng Xiang-Ru
Published: March 2017

The unsymmetrical N-heterocyclic ligand 1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole (bmi) has three potential N-atom donors and can act in monodentate or bridging coordination modes in the construction of complexes. In addition, the bmi ligand can adopt different coordination conformations, resulting in complexes with different structures due to the presence of the flexible methylene spacer. Two new complexes, namely bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}dibromidomercury(II), [HgBr2(C10H9N5)2], and bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}diiodidomercury(II), [HgI2(C10H9N5)2], have been synthesized through the self-assembly of bmi with HgBr2or HgI2. Single-crystal X-ray diffraction shows that both complexes are mononuclear structures, in which the bmi ligands coordinate to the HgIIions in monodentate modes. In the solid state, both complexes display three-dimensional networks formed by a combination of hydrogen bonds and π–π interactions. The IR spectra and PXRD patterns of both complexes have also been recorded.
Tools for ligand validation inCoot
Authors: Emsley Paul
Published: March 2017

Cootis a molecular-graphics program primarily aimed at model building using X-ray data. Recently, tools for the manipulation and representation of ligands have been introduced. Here, these new tools for ligand validation and comparison are described. Ligands in the wwPDB have been scored by density-fit, distortion and atom-clash metrics. The distributions of these scores can be used to assess the relative merits of the particular ligand in the protein–ligand complex of interest by means of `sliders' akin to those now available for each accession code on the wwPDB websites.
Proper modelling of ligand binding requires an ensemble of bound and unbound states
Authors: Pearce Nicholas M. , Krojer Tobias , von Delft Frank
Published: March 2017

Although noncovalent binding by small molecules cannot be assumeda priorito be stoichiometric in the crystal lattice, occupancy refinement of ligands is often avoided by convention. Occupancies tend to be set to unity, requiring the occupancy error to be modelled by theBfactors, and residual weak density around the ligand is necessarily attributed to `disorder'. Where occupancy refinementisperformed, the complementary, superposed unbound state is rarely modelled. Here, it is shown that superior accuracy is achieved by modelling the ligand as partially occupied and superposed on a ligand-free `ground-state' model. Explicit incorporation of this model of the crystal, obtained from a reference data set, allows constrained occupancy refinement with minimal fear of overfitting. Better representation of the crystal also leads to more meaningful refined atomic parameters such as theBfactor, allowing more insight into dynamics in the crystal. An outline of an approach for algorithmically generating ensemble models of crystals is presented, assuming that data sets representing the ground state are available. The applicability of various electron-density metrics to the validation of the resulting models is assessed, and it is concluded that ensemble models consistently score better than the corresponding single-state models. Furthermore, it appears that ignoring the superposed ground state becomes the dominant source of model error, locally, once the overall model is accurate enough; modelling the local ground state properly is then more meaningful than correcting all remaining model errors globally, especially for low-occupancy ligands. Implications for the simultaneous refinement ofBfactors and occupancies, and for future evaluation of the limits of the approach, in particular its behaviour at lower data resolution, are discussed.
Older consumers’ TV shopping: emotions and satisfaction
Authors: Lim Chae Mi , Kim Youn-Kyung
Published: March 2017

Purpose

The purpose of this paper is to identify the emotional factors that affect older consumers’ satisfaction with TV shopping and examined the relationships among these factors.

Design/methodology/approach

A sample of 285 consumers aged 60 years and older who had watched a TV home shopping channel was used. Structural equation modeling (SEM) examined the relationships among emotional factors that affect satisfaction.

Findings

This study found that loneliness was an antecedent of both gratification shopping motivation and telepresence and that telepresence positively affected consumer satisfaction with TV shopping.

Research limitations/implications

The findings of this study validate social-compensation motive of media consumption and deficiency paradigm in the context of TV shopping. The relationship between telepresence and satisfaction also supported transportation theory. However, the findings of the current study should be interpreted with caution due to the non-random sampling method. Constructs other than those employed in this study could be examined regarding outcomes of loneliness.

Practical implications

This study suggested that telepresence and shopping for self-gratification are effective ways to alleviate older consumers’ loneliness. In addition, the findings from relationships among emotional variables suggested potential marketing strategies for shaping positive consumer attitudes toward and satisfaction with TV shopping networks.

Originality/value

This study extended knowledge on loneliness by demonstrating how it related to attitudinal outcomes such as satisfaction and knowledge on telepresence by examining it in the context of TV shopping.
The state of social media engagement in Saudi universities
Authors: Alsufyan Norah Khalid , Aloud Monira
Published: March 2017

Purpose

The purpose of this paper is to investigate the way that Saudi universities are engaging their audience via social media platforms by means of the five meaningful themes: visibility, branding, authenticity, commitment, and engagement. The study will answer the questions: how do Saudi universities exploit social media platforms to engage their target audience? What are the recommendations for Saudi universities toward maximizing the value of social media engagement?

Design/methodology/approach

A content analysis approach was used to study all Saudi universities (26 public, 11 private). Facebook, YouTube, LinkedIn and Twitter were the anticipated social media platforms in this study.

Findings

The results showed that Twitter is the most frequently used platform to communicate with audiences. While visibility in the anticipated social media platforms was high, the engagement was lacking. On the other hand, authenticity and branding in the anticipated social media platforms were medium, while commitment was low except on Twitter. In general, the private universities exceed the public universities in terms of visibility, branding, authenticity, commitment and engagement in the anticipated social media platforms, which indicates their attention on gaining their audience’s satisfaction, a dynamic of trust which will lead to maintaining current relationships or building new ones.

Originality/value

Since there are few studies in the field regarding social media platforms usage by Saudi universities, this study aims to understand how Saudi universities are utilizing social media platforms to engage their audiences and propose recommendations for how Saudi universities can build value from social media platforms.
Supervisor/peer involvement in evaluation Transfer of Training process and results reliability
Authors: Capaldo Guido , Depolo Marco , Rippa Pierluigi , Schiattone Domenico
Published: March 2017

Purpose

The aim of this paper is to present a study performed in conjunction with a branch of the Italian Public Italian Administration, the ISSP (Istituto Superiore di Studi Penitenziari – the Higher Institute of Penitentiary Studies). The study aimed to develop a Transfer of Training (ToT) evaluation methodology that would be both scientifically robust and practitioner-friendly, in an attempt to build a bridge between researchers and practitioners on the topic of ToT process evaluation.

Design/methodology/approach

The ToT evaluation system was built using an action research approach, taking into account workplace specifics and stakeholder needs. An “action research” (with the researchers involved throughout the ToT system building phases) and a “Focus Group” (to identify factors influencing ToT and to define items and grids for behavioural assessment) were used.

Findings

This study showed that the active engagement of stakeholders (trainees and their supervisors and colleagues) is useful in designing context-adapted tools for ToT evaluation and can help organizations improve the fit between their training activities and organizational goals.

Research limitations/implications

The generalizability of the proposed ToT evaluation methodology is not guaranteed, and the procedure needs to be replicated and monitored in different organizational settings and cultures.

Practical implications

The organization decided to implement the ToT evaluation methodology developed during the course of the study for all future training programmes.

Originality/value

In this study, a ToT evaluation methodology was built that will be both scientifically robust and practitioner-friendly.
OligoG CF‐5/20 normalizes cystic fibrosis mucus by chelating calcium
Authors: Ermund Anna , Recktenwald Christian V , Skjåk‐Bræk Gudmund , Meiss Lauren N , Onsøyen Edvar , Rye Philip D , Dessen Arne , Myrset Astrid Hilde , Hansson Gunnar C
Published: March 2017

The goal of this study was to determine whether the guluronate (G) rich alginate OligoG CF‐5/20 (OligoG) could detach cystic fibrosis (CF) mucus by calcium chelation, which is also required for normal mucin unfolding. Since bicarbonate secretion is impaired in CF, leading to insufficient mucin unfolding and thereby attached mucus, and since bicarbonate has the ability to bind calcium, we hypothesized that the calcium chelating property of OligoG would lead to detachment of CF mucus. Indeed, OligoG could compete with the N‐terminus of the MUC2 mucin for calcium binding as shown by microscale thermophoresis. Further, effects on mucus thickness and attachment induced by OligoG and other alginate fractions of different length and composition were evaluated in explants of CF mouse ileum mounted in horizontal Ussing‐type chambers. OligoG at 1.5% caused effective detachment of CF mucus and the most potent alginate fraction tested, the poly‐G fraction of about 12 residues, had similar potency compared to OligoG whereas mannuronate‐rich (M) polymers had minimal effect. In conclusion, OligoG binds calcium with appropriate affinity without any overt harmful effect on the tissue and can be exploited for treating mucus stagnation.
Ageing in remote and cyclone‐prone communities: geography, policy, and disaster relief
Authors: Astill Sandra
Published: March 2017

Focusing on the experience of independent‐living older adults, this study explored how those in regional Australian coastal communities have coped with repeated natural disasters. Using an exploratory, mixed‐method, and phenomenological approach, an array of non‐probability snowballing techniques was used to seek participation from residents aged 65 years or more, and from emergency services officers, disaster managers, and community health care providers located in regional communities affected by Cyclone Larry (2006) and Cyclone Yasi (2011). The research found that post‐disaster political decisions have had a negative long‐term impact on local economies, causing outmigration by those seeking employment, and resulting in many elderly residents facing a future without family support. As government policies encourage ageing‐in‐place by providing subsidised in situ care, increasingly older adults are remaining in exposed vulnerable locations, reliant on authorities for their survival both day‐to‐day and during an emergency. Findings also uncovered inconsistent disaster management policies between neighbouring local government councils and an unrealistic reliance on in situ care organisations by disaster managers during preparation and recovery stages of a natural hazard. These results highlight the need for those charged with emergency management to reassess both the future natural hazard adaptive capacities of ageing regional communities and policy responses to such challenges.
Functional responses of cougars (Puma concolor) in a multiple prey‐species system
Authors: SORIA‐DÍAZ Leroy , FOWLER Mike S. , MONROY‐VILCHIS Octavio , ORO Daniel
Published: March 2017

The study of predator–prey interactions is commonly analyzed using functional responses to gain an understanding of predation patterns and the impact they have on prey populations. Despite this, little is known about predator–prey systems with multiple prey species in sites near the equator. Here we studied the functional response of cougars (Puma concolor) in relation to their main prey, armadillo (Dasypus novemcinctus), coati (Nasua narica) and white‐tailed deer (Odocoileus virginianus). Between 2004 and 2010, cougar scats were collected along 5 transects to estimate the consumption of different prey species. A relative abundance index (RAI) was calculated for each prey species and cougar using 18 camera traps. We compared Holling type I, II and III functional response models to determine patterns in prey consumption based on the relative abundance and biomass of each prey species consumed. The 3 main prey species comprised 55% (armadillo), 17% (coati) and 8% (white‐tailed deer) of the diet. Type I and II functional responses described consumption of the 2 most common prey species armadillos and coati similarly well, while a type I response best characterized consumption of white‐tailed deer. A negative correlation between the proportions of armadillo versus coati and white‐tailed deer biomass in cougar scats suggests switching to consume alternative prey, confirming high foraging plasticity of this carnivore. This work represents one of the few studies to compare functional responses across multiple prey species, combined with evidence for prey‐switching at low densities of preferred prey.
Remote physiological ischemic training promotes coronary angiogenesis via molecular and cellular mobilization after myocardial ischemia
Authors: Zheng Yu , Xiao Mingyue , Li Ling , Li Jianan , Reinhardt Jan D. , Lu Xiao
Published: March 2017

Aim

This study was designed to explore the mechanism of physiological ischemic training (PIT) on remote limbs, with a special focus on the potential role of endothelial progenitor cells (EPCs), vascular endothelial growth factor (VEGF), and nitric oxide (NO) in local ischemic myocardium.

Method

Myocardial ischemia (MI) rabbit models were randomly assigned to sham‐operated group (SO), training‐only group (TO), MI group, PIT group, VEGF inhibitor group (VEGF‐), NO inhibitor group (NO‐), VEGF and NO inhibitor group (VEGF‐/NO‐), and EPC inhibitor group (EPC‐). A constrictor was implanted around the left ventricular branch to induce controlled MI. The PIT procedure consisted of three cycles of a 3‐minutes cuff inflation on the hindlimbs with a reperfusion of 5 minutes. Plasma and myocardial EPC numbers, VEGF level, and NO concentration, as well as capillary density (CD), coronary blood flow (CBF), and coronary collateral blood flow (CCBF) in myocardium, were measured.

Results

Nonparametric statistical techniques were applied to identify the differences between groups, and regression models were used to detect correlations between agents. VEGF levels, NO concentrations, and also EPC counts in both plasma and myocardium were highest in the PIT group. Capillary density, CCBF, and CCBF/CBF were also statistically elevated in the PIT group. VEGF explained 74% of variance in NO. NO explained 65% of variance in EPCs. EPCs explained 68% of variance in capillary density. Capillary density explained 78% of variance in CCBF and CCBF/CBF.

Conclusion

PIT mobilized EPCs and promoted revascularization through upregulating VEGF and NO level.