bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic active space selection for the similarity transformed equations of motion coupled cluster method
Authors: Dutta Achintya Kumar , Nooijen Marcel , Neese Frank , Izsák Róbert
Published: February 2017

An efficient scheme for the automatic selection of an active space for similarity transformed equations of motion (STEOM) coupled cluster method is proposed. It relies on state averaged configuration interaction singles (CIS) natural orbitals and makes it possible to use STEOM as a black box method. The performance of the new scheme is tested for singlet and triplet valence, charge transfer, and Rydberg excited states.
Ultrafast observation of lattice dynamics in laser-irradiated gold foils
Authors: Hartley N. J. , Ozaki N. , Matsuoka T. , Albertazzi B. , Faenov A. , Fujimoto Y. , Habara H. , Harmand M. , Inubushi Y. , Katayama T. , Koenig M. , Krygier A. , Mabey P. , Matsumura Y. , Matsuyama S. , McBride E. E. , Miyanishi K. , Morard G. , Okuchi T. , Pikuz T. , Sakata O. , Sano Y. , Sato T. , Sekine T. , Seto Y. , Takahashi K. , Tanaka K. A. , Tange Y. , Togashi T. , Umeda Y. , Vinci T. , Yabashi M. , Yabuuchi T. , Yamauchi K. , Kodama R.
Published: February 2017

We have observed the lattice expansion before the onset of compression in an optical-laser-driven target, using diffraction of femtosecond X-ray beams generated by the SPring-8 Angstrom Compact Free-electron Laser. The change in diffraction angle provides a direct measure of the lattice spacing, allowing the density to be calculated with a precision of ±1%. From the known equation of state relations, this allows an estimation of the temperature responsible for the expansion as <1000 K. The subsequent ablation-driven compression was observed with a clear rise in density at later times. This demonstrates the feasibility of studying the dynamics of preheating and shock formation with unprecedented detail.
Simultaneous achievement of high perpendicular exchange bias and low coercivity by controlling ferromagnetic/antiferromagnetic interfacial magnetic anisotropy
Authors: Shiratsuchi Yu , Kuroda Wataru , Nguyen Thi Van Anh , Kotani Yoshinori , Toyoki Kentaro , Nakamura Tetsuya , Suzuki Motohiro , Nakamura Kohji , Nakatani Ryoichi
Published: February 2017

This study investigates the influence of Pt and Au spacer layers on the perpendicular exchange bias field and coercivity of Pt/Co/(Pt or Au)/Cr2O3/Pt films. When using a Pt-spacer, the perpendicular exchange bias was highly degraded to less than 0.1 erg/cm2, which was about half that of the Au-spacer system. The Au spacer also suppressed the enhancement in coercivity that usually occurs at around room temperature when using Pt. It is suggested that this difference in exchange bias field is due to in-plane interfacial magnetic anisotropy at the Pt/Cr2O3 interface, which cants the interfacial Cr spin from the surface normal and results in degradation in the perpendicular exchange bias.
Brownian ratchets: How stronger thermal noise can reduce diffusion
Authors: Spiechowicz Jakub , Kostur Marcin , Łuczka Jerzy
Published: February 2017

We study diffusion properties of an inertial Brownian motor moving on a ratchet substrate, i.e., a periodic structure with broken reflection symmetry. The motor is driven by an unbiased time-periodic symmetric force that takes the system out of thermal equilibrium. For selected parameter sets, the system is in a non-chaotic regime in which we can identify a non-monotonic dependence of the diffusion coefficient on temperature: for low temperature, it initially increases as the temperature grows, passes through its local maximum, next starts to diminish reaching its local minimum, and finally it monotonically increases in accordance with the Einstein linear relation. Particularly interesting is the temperature interval in which diffusion is suppressed by the thermal noise, and we explain this effect in terms of transition rates of a three-state stochastic model.
An L-band transit-time oscillator with mechanical frequency tunability
Authors: Song Lili , He Juntao , Ling Junpu , Cao Yibing
Published: February 2017

An L-band coaxial Transit-time Oscillator (TTO) with mechanical frequency tunability is introduced in this paper. Particle-in-cell simulations have been done. The output power efficiency has been improved at least 20% under a 10.2 GW input power and with a tunable range from 1.57 GHz to 1.90 GHz by modulating the outer conductor. It is worth to note that the efficiency can reach as high as 41% at 1.75 GHz. The mechanical engineering method is also detailed in this work. The frequency tuning range of the coaxial TTO is 22.6% of the central frequency. On the other hand, the frequency can be tuned from 1.6 GHz to 1.85 GHz by modulating the inner conductor. The author highlights a hollow structure of the L-band coaxial TTO which can work from 1.03 GHz to 1.31 GHz via modulating the outer conductor in the rest of the article. The frequency tuning range of the hollow TTO is 21.4% of the central frequency. More importantly, the hollow TTO can be easily achieved after the inner conductor is removed from the coaxial TTO. The electric field distributions of the coaxial and hollow TTOs are analyzed, resulting in that the longitudinal and transverse working modes are TM01 and π mode, respectively. The same working mode from these two structures implies the stability of the TTOs mentioned above.
Microfluidic devices fabricated using fast wafer-scale LED-lithography patterning
Authors: Challa Pavan K. , Kartanas Tadas , Charmet Jérôme , Knowles Tuomas P. J.
Published: February 2017

Current lithography approaches underpinning the fabrication of microfluidic devices rely on UV exposure of photoresists to define microstructures in these materials. Conventionally, this objective is achieved with gas discharge mercury lamps, which are capable of producing high intensity UV radiation. However, these sources are costly, have a comparatively short lifetime, necessitate regular calibration, and require significant time to warm up prior to exposure taking place. To address these limitations we exploit advances in solid state sources in the UV range and describe a fast and robust wafer-scale laboratory exposure system relying entirely on UV-Light emitting diode (UV-LED) illumination. As an illustration of the potential of this system for fast and low-cost microfluidic device production, we demonstrate the microfabrication of a 3D spray-drying microfluidic device and a 3D double junction microdroplet maker device.
Transverse eV ion heating by random electric field fluctuations in the plasmasphere
Authors: Artemyev A. V. , Mourenas D. , Agapitov O. V. , Blum L.
Published: February 2017

Charged particle acceleration in the Earth inner magnetosphere is believed to be mainly due to the local resonant wave-particle interaction or particle transport processes. However, the Van Allen Probes have recently provided interesting evidence of a relatively slow transverse heating of eV ions at distances about 2–3 Earth radii during quiet times. Waves that are able to resonantly interact with such very cold ions are generally rare in this region of space, called the plasmasphere. Thus, non-resonant wave-particle interactions are expected to play an important role in the observed ion heating. We demonstrate that stochastic heating by random transverse electric field fluctuations of whistler (and possibly electromagnetic ion cyclotron) waves could explain this weak and slow transverse heating of H+ and O+ ions in the inner magnetosphere. The essential element of the proposed model of ion heating is the presence of trains of random whistler (hiss) wave packets, with significant amplitude modulations produced by strong wave damping, rapid wave growth, or a superposition of wave packets of different frequencies, phases, and amplitudes. Such characteristics correspond to measured characteristics of hiss waves in this region. Using test particle simulations with typical wave and plasma parameters, we demonstrate that the corresponding stochastic transverse ion heating reaches 0.07–0.2 eV/h for protons and 0.007–0.015 eV/h for O+ ions. This global temperature increase of the Maxwellian ion population from an initial Ti∼0.3 eV could potentially explain the observations.
An ultra-sensitive and wideband magnetometer based on a superconducting quantum interference device
Authors: Storm Jan-Hendrik , Hömmen Peter , Drung Dietmar , Körber Rainer
Published: February 2017

The magnetic field noise in superconducting quantum interference devices (SQUIDs) used for biomagnetic research such as magnetoencephalography or ultra-low-field nuclear magnetic resonance is usually limited by instrumental dewar noise. We constructed a wideband, ultra-low noise system with a 45 mm diameter superconducting pick-up coil inductively coupled to a current sensor SQUID. Thermal noise in the liquid helium dewar is minimized by using aluminized polyester fabric as superinsulation and aluminum oxide strips as heat shields. With a magnetometer pick-up coil in the center of the Berlin magnetically shielded room 2 (BMSR2), a noise level of around 150 aT Hz−1∕2 is achieved in the white noise regime between about 20 kHz and the system bandwidth of about 2.5 MHz. At lower frequencies, the resolution is limited by magnetic field noise arising from the walls of the shielded room. Modeling the BMSR2 as a closed cube with continuous μ-metal walls, we can quantitatively reproduce its measured field noise.
Exchange bias in Ba0.4Sr0.6TiO3/La0.7Sr0.3MnO3 heterostructures
Authors: Singamaneni Srinivasa Rao , Prater John T. , Narayan Jagdish
Published: February 2017

This work relates to the integration of the two-layer stack of the proposed multiferroic structure onto silicon substrates. Ba1-xSrxTiO3 is an excellent material for room-temperature voltage-tunable dielectric applications due to its high (ε=6000) dielectric constant. In this study we choose a composition of Ba0.4Sr0.6TiO3 (BST), which is cubic and paraelectric at 300K, and transforms to a ferroelectric tetragonal phase upon cooling through the Curie temperature (TC) at 200K. The main focus of the present work is to study what happens when BST is placed in contact with a room temperature ferromagnetic layer such as La0.7Sr0.3MnO3 (LSMO). In this study, the magnetic properties of a BST (200nm)/LSMO (63nm) heterostructure was compared to that of a single LSMO layer (63nm). Both films were deposited onto MgO/TiN buffered Si (100) using pulsed laser deposition (PLD) and a domain matching epitaxy (DME) paradigm. X-ray diffraction (XRD) measurements showed that these films were of single phase and epitaxial in nature, with an unrelaxed lattice strain of ∼0.2% that was predominately composed of thermal and defect-induced strain. The magnetic measurements showed that the Curie temperature (TC) of LSMO remained unchanged at 350K when the BST was in contact with the LSMO layer. Interestingly, at 4K both the coercive field (Hc) and the exchange bias (HEB) of the BST/LSMO heterostructure as compared to the lone LSMO film increased significantly from 400 to 800 Oe and from 155 to 305 Oe, respectively. These differences were found to disappear above 200 K, the ferroelectric TC of the BST over-layer. This strongly suggests that the observed changes in the magnetic behavior of the heterostructure was the result of stress and/or charge redistributions that resulted when the BST layer transformed from the cubic (paraelectric) to tetragonal (ferroelectric) phase at low temperature.
Reconciling transition path time and rate measurements in reactions with large entropic barriers
Authors: Makarov Dmitrii E.
Published: February 2017

Recent experiments and simulation studies showed that protein/DNA folding barriers inferred from folding rates or from potentials of mean force are often much higher than the barriers estimated from the distributions of transition path times. Here a toy model is used to explain a possible origin of this effect: It is shown that when the transition in question involves an entropic barrier, the one-dimensional Langevin model commonly used to interpret experimental data, while adequately predicting the transition rate, fails to describe the properties of the subset of the trajectories that form the transition path ensemble; the latter may still be describable in terms of a one-dimensional model, but with a different potential, just as observed experimentally.
Role for dithiolopyrrolones in disrupting bacterial metal homeostasis
Authors: Chan Andrew N. , Shiver Anthony L. , Wever Walter J. , Razvi Sayyeda Zeenat A. , Traxler Matthew F. , Li Bo
Published: February 2017

Significance

Antibiotic resistance is a rising health threat worldwide, against which novel strategies are urgently needed. We have taken a systems approach to examine a potent and underexplored class of broad-spectrum antibiotics, the dithiolopyrrolones (DTPs). Our results indicate that DTPs disrupt cellular processes by high-affinity chelation of essential metal ions and inhibition of a subset of metalloenzymes. This mode of action is unique amongst antibiotics and may be further explored for treatment of multidrug-resistant infections. Our study also highlights chemical genomics as a powerful approach for the identification of antimicrobial mechanisms of action.
CD6 as a potential target for treating multiple sclerosis
Authors: Li Yan , Singer Nora G. , Whitbred Joy , Bowen Michael A. , Fox David A. , Lin Feng
Published: February 2017

Significance

Multiple sclerosis (MS), an autoimmune disease that affects the central nervous system, is driven by activated T lymphocytes that invade the brain and spinal cord, leading to damage to the myelin sheaths that surround nerve axons. Current treatments are only partly successful, especially for the later stages of chronic forms of MS. Experimental autoimmune encephalomyelitis (EAE) is a useful animal model of MS, suitable for testing new approaches to treatment. By genetically altering mice to eliminate a T lymphocyte surface protein known as CD6, we show that the CD6 molecule is essential for the development of EAE. Furthermore, an anti-CD6 monoclonal antibody is effective in treating EAE in mice that express human CD6 but not mouse CD6 on their T lymphocytes.
General noun-modifying clause constructions in Japanese
Authors: Matsumoto Yoshiko
Published: February 2017

Instances of Japanese clausal modification of a noun illustrate that Japanese exhibits a single construction, the general noun-modifying clause construction (GNMCC), in which a clause in the finite form precedes the head noun. The GNMCC expresses extensive grammatical and semantic relations between the head noun and the modifying clause with apparently fewer restrictions than in most other languages. This extensiveness is a likely reflection of such properties as the low referential density and the lack of explicit marking in Japanese of the relation between the main constituents, which, in turn, make the construal of the construction rely upon an aggregate of structural, semantic and pragmatic factors. The ubiquity of GNMCC instances may reflect the lack of available alternative constructions.
General noun-modifying clause constructions in Hinuq and Bezhta, with a note on other Daghestanian languages
Authors: Comrie Bernard , Forker Diana , Khalilova Zaira
Published: February 2017

Hinuq and Bezhta, two languages of the Tsezic sub-group of the Nakh-Daghestanian (East Caucasian) language family, have General noun modifying clause constructions (GNMCCs), which have also been noted in some other Nakh-Daghestanian languages. While readily acceptable and interpretable, GNMCCs that do not receive an interpretation with a coreferential element in the modifying clause are rare in natural discourse, certainly in comparison with Japanese, and the range of types also seems more restricted. We speculate that this is because Japanese by and large lacks sentential complement structures independent of GNMCCs, and moreover because Hinuq and Bezhta do not have highly frequent GNMCCs with light nouns, whose presence in Japanese serves to make GNMCCs a much more salient feature of discourse.
Noun-modifying clause constructions in Ainu
Authors: Bugaeva Anna
Published: February 2017

The Ainu (Southern Hokkaido) relative clause construction is built on the model of the nominal attributive construction, while the noun-complement construction is based on that of the nominal possessive construction in which the head is marked with a possessive suffix. Also, relative and noun-complement clauses behave differently with regard to island violation constraints: only the latter allow such violations. However, there is a small number of noun-complement clauses without possessive marking on the perception/relational head noun, which makes them look like relative clauses; these are the so-called emergent GNMCCs. I suggest that these head nouns appear in non-possessive form in order to dissociate themselves from the few homonymous possessive heads which are grammaticalized as modal/evidential markers in the relevant constructions.
Engineering crystal orientation of p-Cu2O on heterojunction solar cells
Authors: Wu Xiaoping , Liu Jinyang , Huang Pingping , Huang Zhigao , Lai Fachun , Chen Guilin , Lin Limei , Lv Peiwei , Zheng Weifeng , Qu Yan
Published: February 2017

The Cu2O/AZO heterojunction solar cells were successfully constructed by synthesising p-Cu2O layer upon AZO using the electrochemical deposition method. The p-Cu2O nanostructures with different grain shape and preferred crystal orientation, including (100), (110) and (111) indicated by SEM and XRD, were obtained by controlling electrodeposition bath pH. The J– V characteristic shows that the performance of the Cu2O/AZO heterojunction solar cells is found to be dependent on the crystal orientation of p-Cu2O. Only the solar cell with Cu2O (111) exhibits well-defined rectifying behaviour and good photoelectric conversion efficiency, which may due to the optimised energy band structure of Cu2O (111)/AZO heterojunction solar cells . Furthermore, VOC and JSC were sharply increased by further optimising energy band structure through inserting the intrinsic ZnO layer between the Cu2O (111) and AZO. Therefore, the results illustrated above may offer a helpful guidance to design and construct the high performance solar cell.
eIF2α links mitochondrial dysfunction to dendritic degeneration
Authors: Qi Xin
Published: February 2017

Although mitochondrial dysfunction has been associated with dendritic pathology in many neuronal types, how mitochondrial impairment causes the vulnerability of neuronal subtypes remains unknown. In this issue, Tsuyama et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201604065) identify eIF2α phosphorylation as a critical regulator of mitochondrial dysfunction-mediated selective dendritic loss in Drosophila neurons.
Adsorption of Pb(II) ion from aqueous solution onto Chitosan/silica/polyethylene glycol (Ch/Si/P) composites membrane
Authors: Mahatmanti F W , Rengga W D P , Kusumastuti E , Nuryono
Published: February 2017

In this research, chitosan/silica/polyethylene glycol (Ch/Si/P) composites membrane was studied for selective adsorbent of Pb(II) from aqueous solution. This study started by preparation of Ch/Si/P composites membrane. The structure and surface morphology of Ch/Si/P composites membrane was characterized by X-ray diffraction (XRD), Fourier Transform Infra Red (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM). Batch adsorption experiments were conducted with various contact time and Pb(II) concentrations to evaluate the adsorption kinetics and thermodynamics. Results show that adsorption fitted to Langmuir model and followed a kinetic model of pseudo-second-order. The adsorption capacity of Pb(II) onto the Ch/Si/P composites membrane is 0.16 mmol/g. The relative selective factor (αf) value of Pb(II)/Rhodamine B is 2.38. This means that Pb(II) can be determined even in the presence of Rhodamine B interference.
Synthetic Studies of Bioactive Substances of 4-Hydroxybenzalhydantoin Derivatives
Authors: Hidayat IW , Sumiarsa D , Permatasari M , AKania  , Riska  , Priani L
Published: February 2017

4-hydroxybenzalhydantoin derivatives were synthesized by the condensation reaction between benzaldehydes 12-13 and substituted hydantoins 14-16 under standard conditions of reflux in glacial acetic acid, in the present of sodium acetate and a little amount of acetic anhydride as a catalyst. All compounds were identified by spectral analysis to give 4-hydroxybenzalhydantoins 17-21.
Simple Colorimetric Sensor for Trinitrotoluene Testing
Authors: Samanman S , Masoh N , Salah Y , Srisawat S , Wattanayon R , Wangsirikul P , Phumivanichakit K
Published: February 2017

A simple operating colorimetric sensor for trinitrotoluene (TNT) determination using a commercial scanner as a captured image was designed. The sensor is based on the chemical reaction between TNT and sodium hydroxide reagent to produce the color change within 96 well plates, which observed finally, recorded using a commercial scanner. The intensity of the color change increased with increase in TNT concentration and could easily quantify the concentration of TNT by digital image analysis using the Image J free software. Under optimum conditions, the sensor provided a linear dynamic range between 0.20 and 1.00 mg mL-1(r = 0.9921) with a limit of detection of 0.10± 0.01 mg mL-1. The relative standard deviation for eight experiments for the sensitivity was 3.8%. When applied for the analysis of TNT in two soil extract samples, the concentrations were found to be non-detectable to 0.26±0.04 mg mL-1. The obtained recovery values (93-95%) were acceptable for soil samples tested.
Direct measurement of cortical force generation and polarization in a living parasite
Authors: Stadler Rachel V. , White Lauren A. , Hu Ke , Helmke Brian P. , Guilford William H.
Published: February 2017

Apicomplexa is a large phylum of intracellular parasites that are notable for the diseases they cause, including toxoplasmosis, malaria, and cryptosporidiosis. A conserved motile system is critical to their life cycles and drives directional gliding motility between cells, as well as invasion of and egress from host cells. However, our understanding of this system is limited by a lack of measurements of the forces driving parasite motion. We used a laser trap to measure the function of the motility apparatus of living Toxoplasma gondii by adhering a microsphere to the surface of an immobilized parasite. Motion of the microsphere reflected underlying forces exerted by the motile apparatus. We found that force generated at the parasite surface begins with no preferential directionality but becomes directed toward the rear of the cell after a period of time. The transition from nondirectional to directional force generation occurs on spatial intervals consistent with the lateral periodicity of structures associated with the membrane pellicle and is influenced by the kinetics of actin filament polymerization and cytoplasmic calcium. A lysine methyltransferase regulates both the magnitude and polarization of the force. Our work provides a novel means to dissect the motile mechanisms of these pathogens.
Transport of fungal RAB11 secretory vesicles involves myosin-5, dynein/dynactin/p25, and kinesin-1 and is independent of kinesin-3
Authors: Peñalva Miguel A. , Zhang Jun , Xiang Xin , Pantazopoulou Areti
Published: February 2017

Hyphal tip cells of the fungus Aspergillus nidulans are useful for studying long-range intracellular traffic. Post-Golgi secretory vesicles (SVs) containing the RAB11 orthologue RabE engage myosin-5 as well as plus end– and minus end–directed microtubule motors, providing an experimental system with which to investigate the interplay between microtubule and actin motors acting on the same cargo. By exploiting the fact that depolymerization of F-actin unleashes SVs focused at the apex by myosin-5 to microtubule-dependent motors, we establish that the minus end–directed transport of SVs requires the dynein/dynactin supercomplex. This minus end–directed transport is largely unaffected by genetic ablation of the Hook complex adapting early endosomes (EEs) to dynein but absolutely requires p25 in dynactin. Thus dynein recruitment to two different membranous cargoes, namely EEs and SVs, requires p25, highlighting the importance of the dynactin pointed-end complex to scaffold cargoes. Finally, by studying the behavior of SVs and EEs in null and rigor mutants of kinesin-3 and kinesin-1 (UncA and KinA, respectively), we demonstrate that KinA is the major kinesin mediating the anterograde transport of SVs. Therefore SVs arrive at the apex of A. nidulans by anterograde transport involving cooperation of kinesin-1 with myosin-5 and can move away from the apex powered by dynein.
Historical connections between early marine science research and dissemination: the case study of aquarium Vasco Da Gama (Portugal) from late 19th century to mid-20th century
Authors: Pinto Bruno
Published: February 2017

In the late 19th century, there was a bloom of public aquariums throughout Europe. Some of them were built for entertainment purposes, whereas others were connected to marine science stations. This article explores the origins and development of the aquarium/marine research station Vasco da Gama (Portugal) as an example of this duality. Initially, the aquarium was created in 1898 by the Portuguese Society of Geography, in a political context of national affirmation. In the first years, a deficient establishment, lack of financial resources, and scarce technical knowledge contributed for its degradation. Therefore, the Navy took over the aquarium in the early 1900s, delivering its management some years later to the Portuguese Society of Natural Sciences. After improvements and modifications, it became one of the first marine biological stations in 1919. This was important for the development of national marine science research at a time of scarce resources. Despite many years of a symbiotic relation between science research and dissemination, the demolition of part of the aquarium/marine station due to a road construction in 1940 brought issues of disequilibrium between both functions. This eventually led to the separation of aquarium and marine station in 1950. Other themes such as connections to national and international institutions are also discussed.
Study of the progenitor of the magnetar 1E 2259+586 through Suzaku observations of the associated supernova remnant CTB 109
Authors: Nakano Toshio , Murakami Hiroaki , Furuta Yoshihiro , Enoto Teruaki , Masuyama Miyu , Shigeyama Toshikazu , Makishima Kazuo
Published: February 2017

We present a study of the progenitor of the magnetar 1E 2259+586, from Suzaku observations of the associated supernova remnant CTB 109. The Suzaku spectra, either spatially integrated or spatially resolved, were successfully described by a two-component plasma model, which reconfirms a previous Chandra result on the northwestern part of this remnant (Sasaki et al. 2013, A&A, 552, A45). The hotter component, with a temperature of ∼0.7 keV, can be identified as the stellar ejecta heated by reverse shock, because its contribution increases towards the remnant center. The cooler one, with a temperature of ∼0.25 keV, can be identified as the shocked interstellar matter. The abundances of Ne, Mg, Si, and S of the hotter component support these identifications. The total masses of the cooler and hotter components are estimated to be 220 ± 40 M⊙ and 42 ± 11 M⊙, respectively. The remnant is considered to be adiabatically expanding as in the Sedov–Taylor phase. The explosion energy, estimated to be 1.0 × 1051 erg by a canonical Sedov model, is typical of a core-collapse supernova explosion. Assuming that the hotter component includes the ejecta as well as the matter lost by the progenitor star via stellar winds, 1E 2259+586 is inferred to have originated from a very massive star.
Spontaneous Breathing during Extracorporeal Membrane Oxygenation in Acute Respiratory Failure
Authors: Crotti Stefania , Bottino Nicola , Ruggeri Giulia Maria , Spinelli Elena , Tubiolo Daniela , Lissoni Alfredo , Protti Alessandro , Gattinoni Luciano
Published: February 2017

Background

We evaluate the clinical feasibility of spontaneous breathing on extracorporeal membrane oxygenation and the interactions between artificial and native lungs in patients bridged to lung transplant or with acute exacerbation of chronic obstructive pulmonary disease (COPD) or acute respiratory distress syndrome.

Methods

The clinical course of a total of 48 patients was analyzed. Twenty-three of 48 patients were enrolled in the prospective study (nine bridged to lung transplant, six COPD, and eight acute respiratory distress syndrome). The response to the carbon dioxide removal was evaluated in terms of respiratory rate and esophageal pressure swings by increasing (“relief” threshold) and decreasing (“distress” threshold) the extracorporeal membrane oxygenation gas flow, starting from baseline condition.

Results

Considering all 48 patients, spontaneous breathing extracorporeal membrane oxygenation was performed in 100% bridge to lung transplant (9 of 9 extubated), 86% COPD (5 of 6 extubated), but 27% acute respiratory distress syndrome patients (6 of 8 extubated; P < 0.001) and was maintained for 92, 69, and 38% of the extracorporeal membrane oxygenation days (P = 0.021), respectively. In all the 23 patients enrolled in the study, gas flow increase (from 2.3 ± 2.2 to 9.2 ± 3.2 l/min) determined a decrease of both respiratory rate (from 29 ± 6 to 8 ± 9 breaths/min) and esophageal pressure swings (from 20 ± 9 to 4 ± 4 cm H2O; P < 0.001 for all). All COPD and bridge to lung transplant patients were responders (reached the relief threshold), while 50% of acute respiratory distress syndrome patients were nonresponders.

Conclusions

Carbon dioxide removal through extracorporeal membrane oxygenation relieves work of breathing and permits extubation in many patients, mainly bridge to lung transplant and COPD. Only few patients with acute respiratory distress syndrome were able to perform the spontaneous breathing trial, and in about 50% of these, removal of large amount of patient’s carbon dioxide production was not sufficient to prevent potentially harmful spontaneous respiratory effort.
Expansion of Prosodic Abilities at the Transition From Babble to Words: A Comparison Between Children With Cochlear Implants and Normally Hearing Children
Authors: Pettinato Michèle , Clerck Ilke De , Verhoeven Jo , Gillis Steven
Published: February 2017

Objectives:

This longitudinal study examined the effect of emerging vocabulary production on the ability to produce the phonetic cues to prosodic prominence in babbled and lexical disyllables of infants with cochlear implants (CI) and normally hearing (NH) infants. Current research on typical language acquisition emphasizes the importance of vocabulary development for phonological and phonetic acquisition. Children with CI experience significant difficulties with the perception and production of prosody, and the role of possible top-down effects is, therefore, particularly relevant for this population.

Design:

Isolated disyllabic babble and first words were identified and segmented in longitudinal audio–video recordings and transcriptions for nine NH infants and nine infants with CI interacting with their parents. Monthly recordings were included from the onset of babbling until children had reached a cumulative vocabulary of 200 words. Three cues to prosodic prominence, fundamental frequency (f0), intensity, and duration, were measured in the vocalic portions of stand-alone disyllables. To represent the degree of prosodic differentiation between two syllables in an utterance, the raw values for intensity and duration were transformed to ratios, and for f0, a measure of the perceptual distance in semitones was derived. The degree of prosodic differentiation for disyllabic babble and words for each cue was compared between groups. In addition, group and individual tendencies on the types of stress patterns for babble and words were also examined.

Results:

The CI group had overall smaller pitch and intensity distances than the NH group. For the NH group, words had greater pitch and intensity distances than babbled disyllables. Especially for pitch distance, this was accompanied by a shift toward a more clearly expressed stress pattern that reflected the influence of the ambient language. For the CI group, the same expansion in words did not take place for pitch. For intensity, the CI group gave evidence of some increase of prosodic differentiation. The results for the duration measure showed evidence of utterance final lengthening in both groups. In words, the CI group significantly reduced durational differences between syllables so that a more even-timed, less differentiated pattern emerged.

Conclusions:

The onset of vocabulary production did not have the same facilitatory effect for the CI infants on the production of phonetic cues for prosody, especially for pitch. It was argued that the results for duration may reflect greater articulatory difficulties in words for the CI group than the NH group. It was suggested that the lack of clear top-down effects of the vocabulary in the CI group may be because of a lag in development caused by an initial lack of auditory stimulation, possibly compounded by the absence of auditory feedback during the babble phase.
The Impact of a Cochlear Implant Electrode Array on the Middle Ear Transfer Function
Authors: Pazen David , Anagiotos Andreas , Nünning Maike , Gostian Antoniu-Oreste , Ortmann Magdalene , Beutner Dirk
Published: February 2017

Objectives:

As a treatment for partial deafness with residual hearing in the lower frequency range, the combined acoustic and electric stimulation of the cochlea has become widespread. Acoustic stimulation is provided by a hearing aid’s airborne sound and the electric stimulation by a cochlear implant electrode array, which may be inserted through the round window or a cochleostomy. To take advantage of that concept, it is essential to preserve residual hearing after surgery. Therefore, the intracochlear electrode array should not compromise the middle ear vibration transmission. This study investigates the influence of different electrode types and insertion paths on the middle ear transfer function and the inner ear fluid dynamics.

Design:

Sound-induced oval and round window net volume velocities were calculated from vibration measurements with laser vibrometers on six nonfixated human temporal bones. After baseline measurements in the “natural” condition, a cochleostomy was drilled and closed with connective tissue. Then, four different electrode arrays were inserted through the cochleostomy. Afterwards, they were inserted through the round window while the cochleostomy was patched again with connective tissue.

Results:

After having drilled a cochleostomy and electrode insertion, no systematic trends in the changes of oval and round window volume velocities were observed. Nearly all changes of middle ear transfer functions, as well as oval and round window volume velocity ratios, were statistically insignificant.

Conclusions:

Intracochlear electrode arrays do not significantly increase cochlear input impedance immediately after insertion. Any changes that may occur seem to be independent of electrode array type and insertion path.
Speech Intelligibility as a Cue for Acceptable Noise Levels
Authors: Recker Karrie L. , Micheyl Christophe
Published: February 2017

Objectives:

The goal of this study was to examine whether individuals are using speech intelligibility to determine how much noise they are willing to accept while listening to running speech. Previous research has shown that the amount of background noise that an individual is willing to accept while listening to speech is predictive of his or her likelihood of success with hearing aids. If it were possible to determine the criterion by which individuals make this judgment, then it may be possible to alter this cue, especially for those who are unlikely to be successful with hearing aids, and thereby improve their chances of success with hearing aids.

Design:

Twenty-one individuals with normal hearing and 21 with sensorineural hearing loss participated in this study. In each group, there were 7 with a low, moderate, and high acceptance of background noise, as determined by the Acceptable Noise Level (ANL) test. (During the ANL test, listeners adjusted speech to their most comfortable listening level, then background noise was added, and they adjusted it to the maximum level that they were “willing to put up with” while listening to the speech.) Participants also performed a modified version of the ANL test in which the speech was fixed at four different levels (50, 63, 75, and 88 dBA), and they adjusted only the level of the background noise. The authors calculated speech intelligibility index (SII) scores for each participant and test level. SII scores ranged from 0 (no speech information is present) to 1 (100% of the speech information is present). The authors considered a participant’s results to be consistent with a speech intelligibility-based listening criterion if his or her SIIs remained constant across all of the test conditions.

Results:

For all but one of the participants with normal hearing, their SIIs remained constant across the entire 38-dB range of speech levels. For all participants with hearing loss, the SII increased with speech level.

Conclusions:

For most listeners with normal hearing, their ANLs were consistent with the use of speech intelligibility as a listening cue; for listeners with hearing impairment, they were not. Future studies should determine what cues these individuals are using when selecting an ANL. Having a better understanding of these cues may help audiologists design and optimize treatment options for their patients.
Multidirectional Instability of the Ankle: Surgical Reconstruction
Authors: Dodd Andrew , Daniels Timothy R.
Published: February 2017

Lateral ligamentous instability of the ankle is common, and numerous surgical techniques have been described to repair or reconstruct the lateral ligaments. Medial-sided ankle instability has become increasingly appreciated in recent years. Many patients present with multidirectional ankle instability and need both medial and lateral ligament reconstructions. We describe a surgical technique for managing patients with multidirectional instability of the ankle using hamstring autograft and readily available surgical instruments.

Level of Evidence: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.
Blood Loss in Orthopedic Surgery: A Historical Review
Authors: Fafalak Marc , Cushner Fred D.
Published: February 2017

Joint arthroplasty since its inception has been associated with substantial blood loss and this blood loss has led to high allogenic transfusion rates as well as the development of hemarthrosis. Once hemarthrosis occurs, joint infection, wound complications, and increased recovery time also occur. The administration of allogenic blood products is not without risk and has been associated with incorrect blood crossmatching, transmission of both bacterial and viral pathogens, anaphylactic reactions, immunosuppression, and fluid overload. Postoperative anemia coupled with the resulting increase in transfusion requirements increases morbidity, mortality, length of hospital stay as well as overall health care costs. These factors have driven orthopedic surgeons to modify existing technology as well as propose new devices and protocols in an effort to maximize positive outcomes for their patients. The result is a robust, multimodal approach to blood conservation which is constantly changing and improving. This article chronicles the history of blood conservation techniques, analyzes their advantages and disadvantages and brings to light the cutting edge technology which modern medicine has produced to combat this problem.
Safety of Tranexamic Acid: Are Precautions Needed?
Authors: Kane Ian W. , Naseer Zan A. , Jones Lynne C. , Khanuja Harpal S. , Sterling Robert S.
Published: February 2017

There are a numerous approaches to limit blood loss in orthopedic surgery, including meticulous surgical technique and hemostasis, use of tourniquets, hypotensive anesthesia, and pharmacologic methods such as tranexamic acid (TXA). TXA is an antifibrinolytic drug that has been found to effectively treat several bleeding-related conditions. It has also been used widely among surgical subspecialties because of its effects on hemostasis and ability to reduce transfusion rates. TXA is positively transforming blood management practices with respect to orthopedic surgery. The use of TXA in orthopedic surgery remains off-label use despite the numerous studies demonstrating the benefits of TXA in orthopedic patients. However, there are concerns over potential risks associated with the use of an antifibrinolytic agent during orthopedic surgery because of the inherent risk of thromboembolic events in the perioperative period. In this article, we review the use and safety of TXA in orthopedic surgery to guide clinical practice and blood product management. Complications and evidence for the contraindications of TXA administration are also examined to provide a clear picture of the risks and benefits of using TXA in orthopedic surgery patients.
Systemic Versus Topical Tranexamic Acid: How Best to Dose and Administer
Authors: Amin Nirav H. , Scudday Travis S. , Cushner Fred D.
Published: February 2017

Tranexamic acid, a potent antifibrinolytic is widely accepted as an effective medication for blood conservation during hip and knee arthroplasty. There remain many dosing regimens and schedules presented in the literature without a consensus on dosing route or concentration. We review the current literature and discuss the differences between the various dosing regimens.
Validation of the INCEPT: A Multisource Feedback Tool for Capturing Different Perspectives on Physicians' Professional Performance
Authors: van der Meulen Mirja W. , Boerebach Benjamin C. M. , Smirnova Alina , Heeneman Sylvia , oude Egbrink Mirjam G. A. , van der Vleuten Cees P. M. , Arah Onyebuchi A. , Lombarts Kiki M. J. M. H.
Published: February 2017

Introduction:

Multisource feedback (MSF) instruments are used to and must feasibly provide reliable and valid data on physicians' performance from multiple perspectives. The “INviting Co-workers to Evaluate Physicians Tool” (INCEPT) is a multisource feedback instrument used to evaluate physicians' professional performance as perceived by peers, residents, and coworkers. In this study, we report on the validity, reliability, and feasibility of the INCEPT.

Methods:

The performance of 218 physicians was assessed by 597 peers, 344 residents, and 822 coworkers. Using explorative and confirmatory factor analyses, multilevel regression analyses between narrative and numerical feedback, item-total correlations, interscale correlations, Cronbach's α and generalizability analyses, the psychometric qualities, and feasibility of the INCEPT were investigated.

Results:

For all respondent groups, three factors were identified, although constructed slightly different: “professional attitude,” “patient-centeredness,” and “organization and (self)-management.” Internal consistency was high for all constructs (Cronbach's α ≥ 0.84 and item-total correlations ≥ 0.52). Confirmatory factor analyses indicated acceptable to good fit. Further validity evidence was given by the associations between narrative and numerical feedback. For reliable total INCEPT scores, three peer, two resident and three coworker evaluations were needed; for subscale scores, evaluations of three peers, three residents and three to four coworkers were sufficient.

Discussion:

The INCEPT instrument provides physicians performance feedback in a valid and reliable way. The number of evaluations to establish reliable scores is achievable in a regular clinical department. When interpreting feedback, physicians should consider that respondent groups' perceptions differ as indicated by the different item clustering per performance factor.
Basement Membrane Matrix Promotes the Efficiency of Hair Follicle Reconstruction In Vivo and Is a Cell Delivery Vehicle for Follicle Regeneration
Authors: Xiao Shune , Miao Yong , Wang Jin , Lin Bojie , Hu Zhiqi
Published: February 2017

BACKGROUND

The efficiency of hair follicle (HF) reconstruction is decreased by extensive apoptotic remodeling that occurs soon after grafting.

OBJECTIVE

To evaluate a basement membrane matrix (matrix) to improve the efficiency of HF reconstruction and serve as a cell delivery vehicle.

MATERIALS AND METHODS

Newborn mouse skin cells were suspended in a matrix and transplanted in a chamber assay. The viability and proliferation of mouse dermal papilla cells seeded in the matrix were tested. Dermal papilla cells and epidermal cells seeded in matrix sheets were grafted into nude mice to observe hair formation.

RESULTS

The matrix significantly shortened the time to hair formation. The first hair shafts appeared within the matrix at 17.67 ± 1.21 days versus 23.00 ± 1.41 days for Dulbecco's modified Eagle medium controls. There was a significant difference (p < .05) in the number of newly formed hairs in areas of reconstructed skin with the matrix (100 μL) grafts (323 ± 12) versus controls (276 ± 11). Dermal papilla cells were successfully cultured in the matrix, and hair formation was dense when the matrix was used as a cell delivery vehicle for follicle reconstruction.

CONCLUSION

The matrix improved the efficiency of HF reconstruction and was a suitable delivery vehicle of cells for HF engineering.
Changes in the Lipidomic Profile of Aqueous Humor in Open-Angle Glaucoma
Authors: Cabrerizo Javier , Urcola Javier A. , Vecino Elena
Published: February 2017

Purpose:

To identify and determine differences in lipid profiles of aqueous humor (AH) in patients with open-angle glaucoma (OAG).

Materials and Methods:

The lipidomic profile of 10 samples of AH of patients with OAG and 10 controls was analyzed. Patients with a history of anterior segment surgery, anterior segment pathology, or intraocular injections were excluded. Topical ocular medications within the last 6 months were reported. AH was obtained during the first step of nonperforating deep sclerotomy in OAG patients and during refractive lensectomy in controls. Lipidomic ultra-performance liquid chromatography mass spectrometry was used to perform an optimal profiling of glycerolipids, sterol lipids, sphingolipids, and glycerophospholipids. Metabolite extraction was accomplished by fractionating the samples into pools of species with similar physicochemical properties.

Results:

The levels of 37 of 110 lipids changed in OAG when compared with controls samples. The concentration of most diacylglycerophosphocholines and 1-ether, 2-acylglycerophosphocholines increases in OAG when compared with healthy controls. In addition, 14 sphingomyelins increased significantly, up to 2.75-fold, in OAG. 5 cholesteryl esters are also present at higher levels in OAG when compared with controls.

Conclusions:

The lipid composition of AH in OAG patients shows differences when compared with healthy individuals. Changes in lipid synthesis may relate to oxidative stress metabolic response in OAG and may play an important role in the pathophysiology of the disease.