bluuebunny/crossref_metadata_2025 huggingface dataset:
XPS analysis of a heat‐treated NiTi surface for elucidating Ni segregation phenomena
Authors: Ohtsu Naofumi , Sakamoto Kouta , Hirano Yuma , Yamane Misao
Published: March 2016

Heat treatment of nickel–titanium (NiTi) alloy was employed to form a chemically stable titanium dioxide (TiO2) layer on its surface to reduce Ni release. However, heating caused Ni to concentrate just beneath the topmost surface. To elucidate the mechanism of this segregation, the formation of this surface layer was analyzed with X‐ray photoelectron spectroscopy under various thermal conditions. The Ni on the surface consisted of NiO and NiTiO3, and their concentrations hardly changed when treated in a reduced oxygen atmosphere. The surface formed in reduced oxygen pressure would mimic the pathway of the layer forming process. Thus, Ni segregation is considered to be completed at a very early stage. On the other hand, increasing the temperature facilitated the inward diffusion of Ni from the surface decreasing its surface content. Segregation of Ni in a heat‐treated NiTi surface was hardly detected in the case of a chemical pretreatment of immersion into 1 M HNO3 for 24 h. It was concluded that the Ni segregation phenomenon is dominated by the surface condition before heating, which can be controlled by preliminary surface treatment. Copyright © 2016 John Wiley & Sons, Ltd.
Medium energy, heavy and inert ion irradiation of metallic thin films: studies of surface nano‐structuring and metal burrowing
Authors: Kumar Pravin , Mal Kedar , Kumar Sunil , Sulania Indra
Published: March 2016

In context to the ion induced surface nanostructuring of metals and their burrowing in the substrates, we report the influence of Xe and Kr ion‐irradiation on Pt:Si and Ag:Si thin films of ~5‐nm thickness. For the irradiation of thin films, several ion energies (275 and 350 keV of Kr; 450 and 700 keV of Xe) were chosen to maintain a constant ratio of the nuclear energy loss to the electronic energy loss (Sn/Se) in Pt and Ag films (five in present studies). The ion‐fluence was varied from 1.0 × 1015 to 1.0 × 1017 ions/cm2. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The AFM and SEM images show ion beam induced systematic surface nano‐structuring of thin films. The surface nano‐structures evolve with the ion fluence. The RBS spectra show fluence dependent burrowing of Pt and Ag in Si upon the irradiation of both ion beams. At highest fluence, the depth of metal burrowing in Si for all irradiation conditions remains almost constant confirming the synergistic effect of energy losses by the ion beams. The RBS analysis also shows quite large sputtering of thin films bombarded with ion beams. The sputtering yield varied from 54% to 62% by irradiating the thin films with Xe and Kr ions of chosen energies at highest ion fluence. In the paper, we present the experimental results and discuss the ion induced surface nano‐structuring of Pt and Ag and their burrowing in Si. Copyright © 2016 John Wiley & Sons, Ltd.
In Vivo Interleukin-13-Primed Macrophages Contribute to Reduced Alloantigen-Specific T Cell Activation and Prolong Immunological Survival of Allogeneic Mesenchymal Stem Cell Implants
Authors: Hoornaert Chloé J. , Luyckx Evi , Reekmans Kristien , Dhainaut Maxime , Guglielmetti Caroline , Le Blon Debbie , Dooley Dearbhaile , Fransen Erik , Daans Jasmijn , Verbeeck Louca , Quarta Alessandra , De Vocht Nathalie , Lemmens Evi , Goossens Herman , Van der Linden Annemie , Roobrouck Valerie D. , Verfaillie Catherine , Hendrix Sven , Moser Muriel , Berneman Zwi N. , Ponsaerts Peter
Published: March 2016

Transplantation of mesenchymal stem cells (MSCs) into injured or diseased tissue—for the in situ delivery of a wide variety of MSC-secreted therapeutic proteins—is an emerging approach for the modulation of the clinical course of several diseases and traumata. From an emergency point-of-view, allogeneic MSCs have numerous advantages over patient-specific autologous MSCs since “off-the-shelf” cell preparations could be readily available for instant therapeutic intervention following acute injury. Although we confirmed the in vitro immunomodulatory capacity of allogeneic MSCs on antigen-presenting cells with standard coculture experiments, allogeneic MSC grafts were irrevocably rejected by the host's immune system upon either intramuscular or intracerebral transplantation. In an attempt to modulate MSC allograft rejection in vivo, we transduced MSCs with an interleukin-13 (IL13)-expressing lentiviral vector. Our data clearly indicate that prolonged survival of IL13-expressing allogeneic MSC grafts in muscle tissue coincided with the induction of an alternatively activated macrophage phenotype in vivo and a reduced number of alloantigen-reactive IFNγ- and/or IL2-producing CD8+ T cells compared to nonmodified allografts. Similarly, intracerebral IL13-expressing MSC allografts also exhibited prolonged survival and induction of an alternatively activated macrophage phenotype, although a peripheral T cell component was absent. In summary, this study demonstrates that both innate and adaptive immune responses are effectively modulated in vivo by locally secreted IL13, ultimately resulting in prolonged MSC allograft survival in both muscle and brain tissue.
Foxi3 Deficiency Compromises Hair Follicle Stem Cell Specification and Activation
Authors: Shirokova Vera , Biggs Leah C. , Jussila Maria , Ohyama Takahiro , Groves Andrew K. , Mikkola Marja L.
Published: March 2016

The hair follicle is an ideal system to study stem cell specification and homeostasis due to its well characterized morphogenesis and stereotypic cycles of stem cell activation upon each hair cycle to produce a new hair shaft. The adult hair follicle stem cell niche consists of two distinct populations, the bulge and the more activation-prone secondary hair germ (HG). Hair follicle stem cells are set aside during early stages of morphogenesis. This process is known to depend on the Sox9 transcription factor, but otherwise the establishment of the hair follicle stem cell niche is poorly understood. Here, we show that that mutation of Foxi3, a Forkhead family transcription factor mutated in several hairless dog breeds, compromises stem cell specification. Further, loss of Foxi3 impedes hair follicle downgrowth and progression of the hair cycle. Genome-wide profiling revealed a number of downstream effectors of Foxi3 including transcription factors with a recognized function in hair follicle stem cells such as Lhx2, Runx1, and Nfatc1, suggesting that the Foxi3 mutant phenotype results from simultaneous downregulation of several stem cell signature genes. We show that Foxi3 displays a highly dynamic expression pattern during hair morphogenesis and cycling, and identify Foxi3 as a novel secondary HG marker. Absence of Foxi3 results in poor hair regeneration upon hair plucking, and a sparse fur phenotype in unperturbed mice that exacerbates with age, caused by impaired secondary HG activation leading to progressive depletion of stem cells. Thus, Foxi3 regulates multiple aspects of hair follicle development and homeostasis.
Variation in fibre volume and orientation in walls: experimental and numerical investigations
Authors: Žirgulis Giedrius , Švec Oldřich , Geiker Mette Rica , Cwirzen Andrzej , Kanstad Terje
Published: March 2016

Previous research with fibre‐reinforced slab elements has shown that the surface roughness of formwork and the presence of rebars affect fibre orientation and fibre volume distribution. This paper discusses the orientation and volume distribution of steel fibres in wall elements cast from a single point. Aparticular focus of the work was the effect of formwork tie ba rs on fibre orientation and distribution. Numerical simulations and X‐ray computed tomography were appliedto quantify the fibre orientation and distribution, and the mechanical performance was determined using three‐point bending tests on sawn beams. The Thorenfeldt model (applied in the Norwegian proposal for the new fibre‐reinforced concrete guideline) was used to estimate the residual flexural tensile strength based on fibre orientation and distribution.

The simulation results show that the fibre orientation can be related to the flow pattern. The results indicate a large variation in fibre orientation, which was confirmedexperimentally. The fibre volume distribution was mostly uniform, except for an area with fewer fibres at the casting point. The large variation in fibre orientation was reflected in a large variation in residual flexural tensile strengths. Weak zones due to anisotropic fibre orientation, caused by formwork tie bars, were observed.
Effect of diesel exhaust particles on renal vascular responses in rats with chronic kidney disease
Authors: Al Suleimani Y. M. , Al Mahruqi A. S. , Al Za'abi M. , Shalaby A. , Ashique M. , Nemmar A. , Ali B. H.
Published: March 2016

Several recent studies have indicated the possible association between exposure to particulate air pollution and the increased rate of morbidity and mortality in patients with kidney diseases. The link of this observation to vascular damage has not been adequately addressed. Therefore, this study aims to investigate possible vascular damage that might be associated with exposure to diesel exhaust particles (DP) in adenine (AD)‐induced chronic kidney disease (CKD) in rats, and the possible ameliorative effect of gum acacia (GA). CKD was induced by feeding AD (0.75%, w/w), and DP (0.5 mg/kg) was instilled intratracheally every second day and GA was given concomitantly in the drinking water at a dose of 15% w/v. All treatments were given concomitantly for 28 days. Changes in renal blood flow (RBF) and systolic and diastolic blood pressure were monitored in these animals after anesthesia, together with several other endpoints. Exposure to DP significantly reduced RBF and this was significantly potentiated in AD‐treated rats. Phenylephrine‐induced decreases in RBF and increases in systolic and diastolic blood pressure were severely potentiated in rats exposed to DP, and these actions were significantly augmented in AD‐treated rats. GA did not significantly affect the vascular impairment induced by AD and DP given together. This study provides experimental evidence that exposure to particulate air pollution can exacerbate the vascular damage seen in patients with CKD. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 541–549, 2017.
How large is a river? Conceptualizing river landscape signatures and envelopes in four dimensions
Authors: Gurnell Angela M. , Bertoldi Walter , Tockner Klement , Wharton Geraldene , Zolezzi Guido
Published: March 2016

River research often addresses the influence of anthropogenic and natural processes on the ecological, hydrological, and geomorphological dynamics of river systems. However, here we take a river‐centered approach and consider how rivers influence their landscapes by developing concepts of river landscape ‘signatures’ and ‘envelopes.’ The influence of a river penetrates well beyond its channel into the atmosphere, across the land surface, and into the subsurface. We define a signature as an emergent property of a set of processes acting on a river landscape, and its envelope as the dynamic penetration of the signature across the landscape. The potential to recognize river signatures and envelopes is driven by unprecedented expansion in data acquisition, processing, and modeling technologies. The spatial envelope of any particular signature will have fuzzy and temporally dynamic edges, may rapidly expand and contract, may differ in its extent from other signatures, and may be highly permeable to many organisms using the river (and broader) landscape. However, an understanding of the approximate dynamic envelope of a signature is crucial to understanding the contribution of rivers at a landscape scale and to informing the sustainable management of these landscapes and their ecosystem services. WIREs Water 2016, 3:313–325. doi: 10.1002/wat2.1143

This article is categorized under:

Water and Life > Conservation, Management, and Awareness

Water and Life > Nature of Freshwater Ecosystems

Engineering Water > Planning Water
Age‐specific survival of reintroduced swift fox in Badlands National Park and surrounding lands
Authors: Sasmal Indrani , Klaver Robert W. , Jenks Jonathan A. , Schroeder Greg M.
Published: March 2016

In 2003, a reintroduction program was initiated at Badlands National Park (BNP), South Dakota, USA, with swift foxes (Vulpes velox) translocated from Colorado and Wyoming, USA, as part of a restoration effort to recover declining swift fox populations throughout its historical range. Estimates of age‐specific survival are necessary to evaluate the potential for population growth of reintroduced populations. We used 7 years (2003–2009) of capture–recapture data of 243 pups, 29 yearlings, and 69 adult swift foxes at BNP and the surrounding area to construct Cormack–Jolly–Seber model estimates of apparent survival within a capture–mark–recapture framework using Program MARK. The best model for estimating recapture probabilities included no differences among age classes, greater recapture probabilities during early years of the monitoring effort than later years, and variation among spring, winter, and summer. Our top ranked survival model indicated pup survival differed from that of yearlings and adults and varied by month and year. The apparent annual survival probability of pups (0.47, SE = 0.10) in our study area was greater than the apparent annual survival probability of yearlings and adults (0.27, SE = 0.08). Our results indicate low survival probabilities for a reintroduced population of swift foxes in the BNP and surrounding areas. Management of reintroduced populations and future reintroductions of swift foxes should consider the effects of relative low annual survival on population demography. © 2016 The Wildlife Society.
Signaling via the NFκB system
Authors: Mitchell Simon , Vargas Jesse , Hoffmann Alexander
Published: March 2016

The nuclear factor kappa B (NFκB) family of transcription factors is a key regulator of immune development, immune responses, inflammation, and cancer. The NFκB signaling system (defined by the interactions between NFκB dimers, IκB regulators, and IKK complexes) is responsive to a number of stimuli, and upon ligand–receptor engagement, distinct cellular outcomes, appropriate to the specific signal received, are set into motion. After almost three decades of study, many signaling mechanisms are well understood, rendering them amenable to mathematical modeling, which can reveal deeper insights about the regulatory design principles. While other reviews have focused on upstream, receptor proximal signaling (Hayden MS, Ghosh S. Signaling to NF‐κB. Genes Dev 2004, 18:2195–2224; Verstrepen L, Bekaert T, Chau TL, Tavernier J, Chariot A, Beyaert R. TLR‐4, IL‐1R and TNF‐R signaling to NF‐κB: variations on a common theme. Cell Mol Life Sci 2008, 65:2964–2978), and advances through computational modeling (Basak S, Behar M, Hoffmann A. Lessons from mathematically modeling the NF‐κB pathway. Immunol Rev 2012, 246:221–238; Williams R, Timmis J, Qwarnstrom E. Computational models of the NF‐KB signalling pathway. Computation 2014, 2:131), in this review we aim to summarize the current understanding of the NFκB signaling system itself, the molecular mechanisms, and systems properties that are key to its diverse biological functions, and we discuss remaining questions in the field. WIREs Syst Biol Med 2016, 8:227–241. doi: 10.1002/wsbm.1331

This article is categorized under:

Biological Mechanisms > Cell Signaling

Models of Systems Properties and Processes > Mechanistic Models

Physiology > Organismal Responses to Environment
Overexpression of the truncated version of ILV2 enhances glycerol production in Saccharomyces cerevisiae
Authors: Murashchenko Lidiia , Abbas Charles , Dmytruk Kostyantyn , Sibirny Andriy
Published: March 2016

Acetolactate synthase is a mitochondrial enzyme that catalyses the conversion of two pyruvate molecules to an acetolactate molecule with release of carbon dioxide. The overexpression of the truncated version of the corresponding gene, ILV2, that codes for presumably cytosolic acetolactate synthase in the yeast Saccharomyces cerevisiae, led to a decrease in intracellular pyruvate concentration. This recombinant strain was also characterized by a four‐fold increase in glycerol production, with a concomitant 1.8‐fold reduction in ethanol production, when compared to that of the wild‐type strain under anaerobic conditions in a glucose alcoholic fermentation. Copyright © 2016 John Wiley & Sons, Ltd.
A Team Approach to Improving Tissue Management
Authors: Sions Jacqueline A. , Cheuvront Kimberly A. , Grove Georgiana L. , Beach Myra J. , Bowers Jay W. , Cendaña Cinthia R. , Hixson Jesse R. , Wilson Mary C.
Published: March 2016

Tissue implant management can be labor intensive because of multiple storage locations and cumbersome tracking systems. The purpose of this quality improvement (QI) project was to enhance patient safety and nursing satisfaction by upgrading our tissue‐management facility and processes. We created a centralized storage room for tissue implants and staffed this room during all shifts. Tissue management was executed using tracking software and transportation devices that supported tissue receipt, storage, disposition, documentation, and reporting. Our project resulted in our full compliance with tissue implant requirements from the US Food and Drug Administration (FDA) and The Joint Commission. We also reduced our documentation error rate from 3% to less than 1%, and decreased the tissue‐expiration rate by 1.1%. Tissues are now delivered to ORs, which allows RNs to focus on patient care rather than retrieval of implants. Monitoring of the tissue inventory has improved, resulting in the reduction of tissue wastage.
Absence seizure associated with coloprep consumption in colonoscopy
Authors: Chandrakumar Abin , Tharakan Pretty Geevarghese , Thomas Bittu , Albert Anu , Jacob Teena
Published: March 2016

Coloprep is a bowel preparatory solution given before endoscopic procedures to get a unobscured internal vision. It has among its constituents’ sodium sulphate, potassium sulphate and magnesium sulphate which produce an osmotic effect in the bowel. However, the use of such agents in hyponatremic and patients predisposed to seizures can have adverse ramifications. The current case outlines manifestation of absence seizure in a 52-year-old male patient who was administered Coloprep for colonoscopy. There was absence of other predisposing factors and the symptoms were ameliorated using timely identification and rectification of the underlying derangements.
Homophobia: An Impulsive Attraction to the Same Sex? Evidence From Eye-Tracking Data in a Picture-Viewing Task
Authors: Cheval Boris , Radel Remi , Grob Emmanuelle , Ghisletta Paolo , Bianchi-Demicheli Francesco , Chanal Julien
Published: March 2016

Introduction

Some models suggest that homophobia can be explained as a denied attraction toward same-sex individuals. While it has been found that homophobic men have same-sex attraction, these results are not consistent.

Aim

This study drew on the dual-process models to test the assumption that sexual interest in homosexual cues among men high in homophobia will depend on their specific impulses toward homosexual-related stimuli.

Methods

Heterosexual men (N = 38) first completed a scale measuring their level of homonegativity. Then, they performed a manikin task to evaluate their impulsive approach tendencies toward homosexual stimuli (IAHS).

Main outcomes measures

A picture-viewing task was performed with simultaneous eye-tracking recording to assess participants' viewing time of the visual area of interest (i.e., face and body).

Results

IAHS positively predicted the viewing time of homosexual photographs among men with a high score of homonegativity. Men with a high homonegativity score looked significantly longer at homosexual than at heterosexual photographs but only when they had a high IAHS.

Conclusion

These findings confirm the importance of considering the variability in impulsive processes to understand why some (but not all) men high in homophobia have homosexual interest. These findings reinforce the theoretical basis for elaborating a dual-process model for behaviors in the sexual context.
Extended explanation of transformation optics for metamaterial-modified wireless power transfer systems
Authors: Zhu Lin , Luo Xudong , Ma Hongru
Published: March 2016

We analytically extend the scope of transformation optics (TO) to metamaterial-modified wireless power transfer (WPT) systems and demonstrate that the extended TO can help design the highly efficient WPT. The methodology is based on rigorous scattering theory, enabling an equivalent model under certain circumstances to be established, that can significantly simplify investigating metamaterial-enhanced WPT. More important, from the analytical study on the equivalent model, we prove that TO is still applicable, even when the conditions of complementary media are not satisfied. Our findings are verified numerically using our methodology as well as COMSOL simulations. Moreover, a further study also indicates the extended TO explanation as well as the analysis of the equivalent model could help improve the transfer efficiency of WPT significantly. The demonstrations are not restricted to any specific frequency, and the conclusions could be extended to a broad range of wavelengths, including applications to active cloaks and other related devices.
Tuning the band gap of silicene by functionalisation with naphthyl and anthracyl groups
Authors: Brennan Mathew D. , Morishita Tetsuya , Spencer Michelle J. S.
Published: March 2016

Silicene is a relatively new material consisting of a two-dimensional sheet of silicon atoms. Functionalisation of silicene with different chemical groups has been suggested as a way to tune its electronic properties. In this work, density functional theory calculations and ab initio molecular dynamics simulations are used to examine the effects of functionalisation with naphthyl or anthracyl groups, which are two examples of small polycyclic aromatic hydrocarbons (PAHs). Different attachment positions on the naphthyl and anthracyl groups were compared, as well as different thicknesses of the silicene nanosheet. It was found that the carbon attachment position farthest from the bond fusing the aromatic rings gave the more stable structures for both functional groups. All structures showed direct band gaps, with tuning of the band gap being achievable by increasing the length of the PAH or the thickness of the silicene. Hence, modifying the functional group or thickness of the silicene can both be used to alter the electronic properties of silicene making it a highly promising material for use in future electronic devices and sensors.
Observation of extreme ultraviolet transitions in highly charged Ba16+ to Ba23+ ions with electron beam ion trap
Authors: Ali S. , Shimizu E. , Nakamura N.
Published: March 2016

We have investigated extreme ultraviolet emission from highly charged barium using a compact electron beam ion trap at the Tokyo EBIT laboratory. The spectra were recorded for several beam energies ranging from 440 to 740 eV, while keeping the electron beam current constant at 10 mA. Radiation from charge states Zr-like Ba16+ to As-like Ba23+ were recorded and identified by varying the electron beam energy across the ionization thresholds and comparing with calculated results. The calculations were performed with a detailed relativistic configuration interaction approach using the Flexible Atomic Code. Several new lines belonging to electric dipole transitions were observed and identified.
VUV and soft x-ray ionization of a plant volatile: Vanillin (C8H8O3)
Authors: Betancourt A. Moreno , Coutinho L. H. , Bernini R. B. , de Moura C. E. V. , Rocha A. B. , de Souza G. G. B.
Published: March 2016

Plant volatiles are emitted by plants in response to several forms of stress, including interaction with energetic photons. In the present work, we discuss the interaction of extreme UV and soft X-ray photons with a plant volatile, vanillin. The single and double (multiple) ionization of the vanillin molecule have been studied for the first time using time-of-flight mass spectrometry and VUV and soft X-ray photons (synchrotron radiation, at 12.0 eV, 21.2 eV, 130 eV, 310 eV, 531 eV, and 550 eV). At 12.0 and 21.2 eV, only singly charged species are observed and the parent ion, C8H8O3+, is the dominant species. Energy differences for some selected fragments were calculated theoretically in this energy region. At 130 eV, direct double and triple ionization of the valence electrons may occur. The fragmentation increases and CHO+ becomes one of the main cations in the mass spectrum. The molecular ion is still the dominant species, but other fragments, such as C6H5O+, begin to present similar intensities. At 310 eV, C 1s electrons may be ionized and Auger processes give rise to dissociative doubly ionized cations. Ionization around the O 1s edge has been studied both at the 531 eV resonance and above the ionization edge. Resonant and normal Auger processes play a significant role in each case and a large fragmentation of the molecule is observed at both photon energies, with intense fragments such as CHO+ and CH3+ being clearly observed. A near edge X-ray absorption fine structure spectrum of the vanillin molecule was obtained around the O 1s ionization threshold. In addition, the fragmentation of vanillin has also been studied using a fast beam of electrons (800 eV), for the sake of comparison.
Colligative thermoelectric transport properties in n-type filled CoSb3 determined by guest electrons in a host lattice
Authors: Lim Young Soo , Park Kwan-Ho , Tak Jang Yeul , Lee Soonil , Seo Won-Seon , Park Cheol-Hee , Kim Tae Hoon , Park PumSuk , Kim Il-Ho , Yang Jihui
Published: March 2016

Among many kinds of thermoelectric materials, CoSb3 has received exceptional attention for automotive waste heat recovery. Its cage structure provides an ideal framework for the realization of phonon-glass electron-crystal strategy, and there have been numerous reports on the enhanced thermoelectric performance through the independent control of the thermal and electrical conductivity by introducing fillers into its cage sites. Herein, we report colligative thermoelectric transport properties in n-type CoSb3 from the viewpoint of “guest electrons in a host lattice.” Both the Seebeck coefficient and the charge transport properties are fundamentally determined by the concentration of the guest electrons, which are mostly donated by the fillers, in the conduction band of the host CoSb3. Comparing this observation to our previous results, colligative relations for both the Seebeck coefficient and the mobility were deduced as functions of the carrier concentration, and thermoelectric transport constants were defined to predict the power factor in filled CoSb3. This discovery not only increases the degree of freedom for choosing a filler but also provides the predictability of power factor in designing and engineering the n-type filled CoSb3 materials.
Photoreflectance study of the near-band-edge transitions of chemical vapor deposition-grown mono- and few-layer MoS2 films
Authors: Lin Kuang-I , Chen Yen-Jen , Wang Bo-Yan , Cheng Yung-Chen , Chen Chang-Hsiao
Published: March 2016

Room-temperature photoreflectance (PR) and reflectance (R) spectroscopy are utilized to investigate the near-band-edge transitions of molybdenum disulfide (MoS2) thin films grown on sapphire substrates by a hot-wall chemical vapor deposition system. The layer thickness and optical properties of the MoS2 thin films are confirmed by Raman spectroscopy, atomic force microscope, and photoluminescence (PL) analysis. The B exciton shows relatively weak PL intensity in comparing with the A exciton even for monolayer MoS2 films. In the R spectrum of few-layer MoS2, it is not possible to clearly observe exciton related features. The PR spectra have two sharp, derivative-like features on a featureless background. Throughout the PR lineshape fitting, the transition energies are designated as the A and B excitons at the K-point of the Brillouin zone, but at room temperature there seems to be no distinguishable feature corresponding to an H-point transition for the mono- and few-layer MoS2 films unlike in bulk. These transition energies are slightly larger than those obtained by PL, which is attributed to the Stokes shifts related to doping level. The obtained values of valence-band spin-orbit splitting are in good agreement with those from other experimental methods. By comparing the PR lineshapes, the dominant modulation mechanism is attributed to variations of the exciton transition energies due to change in the built-in electric field. On the strength of this study, PR spectroscopy is demonstrated as a powerful technique for characterizing the near-band-edge transitions of MoS2 from monolayer to bulk.
Research on supporting mounts of spheres in measurement of gravitational constant G
Authors: Li Qing , Liu Jian-Ping , Xue Chao , Wu Jun-Fei , Yang Shan-Qing , Luo Jun
Published: March 2016

The ongoing precision measurement of the gravitational constant G at our group is performed by using two different kinds of methods: time-of-swing method (ToS) and angular acceleration feedback method. In the two methods, the stainless steel spheres are employed as source masses, and the position stability of the spheres is an important parameter, which make suitable mounts for supporting the spheres needed extremely. In this paper, an upgraded three-point mount is introduced and tested in detail. Experimental results show that, for the sphere supported by the three-point mount used in the ToS method, the repeatability, the temperature influence, and the vibration influence are all less than 0.1 μm (about 2 ppm for the value of G). For the sphere supported by the three-point mount used in the AAF method, similar results are obtained, the largest change of the sphere’s position is about 0.6 μm, introduced by a temperature change of 1 °C, which also results in an uncertainty of 2 ppm for the value of G.
Crossed beam energy transfer: Assessment of the paraxial complex geometrical optics approach versus a time-dependent paraxial method to describe experimental results
Authors: Colaïtis A. , Hüller S. , Pesme D. , Duchateau G. , Tikhonchuk V. T.
Published: March 2016

The Crossed Beam Energy Transfer (CBET) of two large laser beams is modeled using two approaches: (i) the time-independent Paraxial Complex Geometrical Optics (PCGO) for stochastically distributed Gaussian-shaped beamlets and (ii) the time-dependent conventional paraxial propagation of smoothed laser beams. Each description of the laser propagation is coupled to a hydrodynamics code. Both approaches are compared in a well-defined plasma configuration with density- and velocity- profiles corresponding to an inhomogeneous plasma, including a resonance zone in which the matching conditions for a resonant coupling between the two laser beams are fulfilled. The comparison is made for laser beams smoothed by random phase plates and for “regular beams” without speckles. The role of the laser speckles is also investigated for each approach. In general, a good agreement is found between the PCGO simulations and the fully time-dependent paraxial-type simulations, carried out with the code Harmony, past a transient period on the picosecond time scale. The PCGO-based CBET model is applied to the hydrodynamics simulations of a CBET experiment, the results of which reproduce essential features of the experimental data. Based on these comparisons, performed for interaction parameters up to 2×1014W cm−2μm2, the PCGO approach proves to be a reliable method to be implemented in the hydrodynamics codes to describe the CBET in mm-scale plasmas.
Observability of localized magnetoplasmons in quantum dots: Scrutinizing the eligibility of far-infrared, Raman, and electron-energy-loss spectroscopies
Authors: Kushwaha Manvir S.
Published: March 2016

We investigate a one-component, quasi-zero dimensional, quantum plasma exposed to a parabolic potential and an applied magnetic field in the symmetric gauge. If the size of such a system as can be realized in the semiconducting quantum dots is on the order of the de-Broglie wavelength, the electronic and optical properties become highly tunable. Then the quantum size effects challenge the observation of many-particle phenomena such as the magneto-optical absorption, Raman intensity, and electron energy-loss spectrum. An exact analytical solution of the problem leads us to infer that these many-particle phenomena are, in fact, dictated by the generalized Kohn’s theorem (GKT) in the long-wavelength limit. Maneuvering the confinement and/or the magnetic field furnishes the resonance energies capable of being explored with the FIR, Raman, and/or electron-energy-loss spectroscopy. This implies that either of these probes is competent in observing the localized magnetoplasmons in the system. As an application of the rigorous analytical diagnosis of the system, we have presented various pertinent single-particle, such as Fock-Darwin spectrum, Fermi energy, zigzag excitation spectrum, and magneto-optical transitions, and the many-particle phenomena, such as magneto-optical absorption, Raman intensity, and electron energy-loss probability. In the latter, the energy position of the resonance peaks is observed to be independent of the electron-electron interactions and hence of the number of electrons in the quantum dot in compliance with the GKT. It is found that both confinement potential and magnetic field play a decisive role in influencing the aforementioned many-particle phenomena. Specifically, increasing (decreasing) the strength of the confining potential is found to be analogous to shrinking (expanding) the size of the quantum dots and results into a blue (red) shift in the respective spectra. Intensifying the magnetic field has two-fold effects in the resonance spectra associated with all three spectroscopies considered here: the lower resonance peak observes a red shift, whereas the higher one experiences a blue shift. This is a unique and intriguing behavior observed in the quantum dots with complete confinement. A deeper insight into the physics of the quantum dots is paving the way for their implementation in such diverse fields as quantum computing and medical imaging.
Effects of Prone Position and Positive End-Expiratory Pressure on Noninvasive Estimators of ICP: A Pilot Study
Authors: Robba Chiara , Bragazzi Nicola Luigi , Bertuccio Alessandro , Cardim Danilo , Donnelly Joseph , Sekhon Mypinder , Lavinio Andrea , Duane Derek , Burnstein Rowan , Matta Basil , Bacigaluppi Susanna , Lattuada Marco , Czosnyka Marek
Published: March 2016

Background:

Prone positioning and positive end-expiratory pressure can improve pulmonary gas exchange and respiratory mechanics. However, they may be associated with the development of intracranial hypertension. Intracranial pressure (ICP) can be noninvasively estimated from the sonographic measurement of the optic nerve sheath diameter (ONSD) and from the transcranial Doppler analysis of the pulsatility (ICPPI) and the diastolic component (ICPFVd) of the velocity waveform.

Methods:

The effect of the prone positioning and positive end-expiratory pressure on ONSD, ICPFVd, and ICPPI was assessed in a prospective study of 30 patients undergoing spine surgery. One-way repeated measures analysis of variance, fixed-effect multivariate regression models, and receiver operating characteristic analyses were used to analyze numerical data.

Results:

The mean values of ONSD, ICPFVd, and ICPPI significantly increased after change from supine to prone position. Receiver operating characteristic analyses demonstrated that, among the noninvasive methods, the mean ONSD measure had the greatest area under the curve signifying it is the most effective in distinguishing a hypothetical change in ICP between supine and prone positioning (0.86±0.034 [0.79 to 0.92]). A cutoff of 0.43 cm was found to be a best separator of ONSD value between supine and prone with a specificity of 75.0 and a sensitivity of 86.7.

Conclusions:

Noninvasive ICP estimation may be useful in patients at risk of developing intracranial hypertension who require prone positioning.
The Pathophysiology of Early Hypotension Following Epinephrine-containing Local Anesthetic Infiltration of the Nasal Mucosa in Patients Undergoing Endoscopic Transsphenoidal Hypophysectomy: A Prospective, Observational Study
Authors: Wiles Matthew D , Sanders Matthew I , Sinha Saurabh , Mirza Showkat , Andrzejowski John C
Published: March 2016

In patients undergoing endoscopic transsphenoidal hypophysectomy, the nasal mucosa is often infiltrated with local anesthetic solutions that contain epinephrine to aid hemostasis. This may, however, result in hemodynamic changes, especially hypotension. We characterized the cardiovascular changes using a LiDCOrapid monitor in 13 patients after the infiltration of 4% articaine containing 1:200,000 epinephrine. Nine (69%) had a >20% decrease in mean arterial pressure at a median time of 116 seconds after the infiltration of articaine with epinephrine. Analysis of the cardiac output data revealed that this was caused by a sustained reduction in systemic vascular resistance. The arterial blood pressure normalized over a period of 60 to 90 seconds secondary to increases in stroke volume and heart rate producing an elevation in cardiac output. Transient hypotension following the infiltration of epinephrine-containing local anesthetics may be caused by epinephrine stimulation of β2-adrenoceptors producing vasodilation.
The 6-Hour Rule for Surgical Debridement of Open Tibial Fractures: A Systematic Review and Meta-Analysis of Infection and Nonunion Rates
Authors: Prodromidis Apostolos D. , Charalambous Charalambos P.
Published: March 2016

Objectives:

The aim of this study was a systematic review and meta-analysis of studies comparing early (<6 hours) versus late (>6 hours) surgical debridement of open tibial fractures, with regards to infection and nonunion rates.

Methods:

A systematic literature search of MEDLINE, Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature (1961 to present), Allied and Complementary Medicine, and COCHRANE databases was conducted using any combination of the key words: “open,” “tibial,” and “fractures.” After appropriate screening, 7 studies were included for analysis. Inclusion criteria were studies assessing the relation between time to debridement from injury and infection and/or nonunion rates.

Results:

Three studies (n = 365) evaluated overall infection rates that varied from 7.7% to 8.9% in the early group versus 1%–18.5% in the late group. Three studies (n = 197) evaluated deep infection rates that varied from 13% to 18.5% in the early group versus 7.1%–18.6% in the late group. Four studies (n = 245) evaluated nonunion rates that varied from 13.2% to 26.1% in the early group versus 0%–32.6% in the late group. Meta-analysis showed no statistical difference between groups with regards to overall infection rates (risk ratio = 1.32; 95% CI, 0.54–3.23; P = 0.55), deep infection rates (risk ratio = 0.99; 95% CI, 0.48–2.07; P = 0.98), and nonunion rates (risk ratio = 1.49; 95% CI, 0.64–3.49; P = 0.36).

Conclusions:

The available literature suggests that there is no obvious difference in the overall/deep infection and nonunion rates between open tibial fractures debrided within 6 hours and those debrided at more than 6 hours. The findings presented here would appear to indicate that judicious delays of greater than 6 hours may not result in a significantly increased risk of adverse events or peri-operative morbidity.

Level of Evidence:

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Efficacy of Local Administration of Tranexamic Acid for Blood Salvage in Patients Undergoing Intertrochanteric Fracture Surgery
Authors: Drakos Athanasios , Raoulis Vasilios , Karatzios Konstantinos , Doxariotis Nikolaos , Kontogeorgakos Vasilios , Malizos Konstantinos , Varitimidis Sokratis E.
Published: March 2016

Objectives:

The primary aim of this study was to assess whether local administration of tranexamic acid (TXA) reduced the need for a blood transfusion in elderly patients treated with an intramedullary (IM) nail for an intertrochanteric fracture.

Design:

Randomized prospective trial.

Setting:

Academic level 1 trauma center.

Patients:

Two hundred patients (200 fractures) over 65 years with an intertrochanteric fracture treated by IM nail between April 1, 2012, and March 31, 2014.

Intervention:

Subfascial administration of 3 g of TXA around the fracture site at the end of the surgical procedure, versus a control group without TXA. Follow-up ranged from 12 to 24 months.

Main Outcome Measures:

Group differences in number of transfused packed red blood cell (PRBC) units, and hematocrit, hemoglobin, and platelet count.

Results:

There was a 43% reduction in transfusion requirements in the TXA group (P < 0.01). Twenty-seven units of PRBC were transfused in 22/100 patients in the TXA group, whereas 48 PRBC units were transfused in 29/100 patients in control group. There was no difference between the 2 groups in terms of late complications and overall mortality rate.

Conclusions:

Subfascial administration of TXA around the fracture site in elderly patients undergoing IM nailing for intertrochanteric fractures is safe and cost-effective. A significant reduction in blood loss and transfused blood units, and health care cost can be achieved.

Level of Evidence:

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
Tardy ulnar nerve palsy caused by chronic radial head dislocation after Monteggia fracture: a report of two cases
Authors: Nishimura Masahiro , Itsubo Toshiro , Horii Emiko , Hayashi Masanori , Uchiyama Shigeharu , Kato Hiroyuki
Published: March 2016

Dislocation of the radial head is often encountered as a result of a pediatric Monteggia fracture. We report two rare cases of tardy ulnar nerve palsy associated with anterior radial head dislocation combined with anterior bowing of the ulna. They had cubitus valgus deformity, valgus instability, and osteoarthritis of the elbow, and had elbow injury more than 40 years back. They were diagnosed with chronic radial head dislocation long after a Bado type 1 Monteggia fracture. Anterior subcutaneous ulnar nerve transposition yielded favorable results. It is important to recognize the possibility of tardy ulnar nerve palsy caused by an improperly treated Monteggia fracture.
Clinical Features and Prognostic Factors of Pediatric Spine Tumors
Authors: Song Dianwen , Meng Tong , Lin Zaijun , Fan Tianqi , Yin Huabin , Li Bo , Li Zhenxi , Xu Wei , Huang Quan , Zhou Lei , Li Song , Yang Xinghai , Wei Haifeng , Liu Tielong , Yan Wangjun , Zhou Wang , Xiao Jianru
Published: March 2016

Study Design.

A retrospective study was performed.

Objective.

The aim of the study was to illustrate the characteristics of pediatric spine tumors (PSTs) and obtain better insight into therapeutic strategies of such kinds of tumors.

Summary of Background Data.

PSTs, a heterogeneous group of tumors occurred among pediatric group, are relatively uncommon and rarely reported in the literature.

Methods.

A retrospective study was performed to analyze clinical features and prognostic factors of patients with PSTs who were treated in our center between 2000 and 2013. Local relapse-free survival (LRFS) and overall survival (OS) rate were estimated using the Kaplan-Meier method to identify potential prognostic factors. Factors with P values of 0.1 or lower were subjected to multivariate analysis by Cox regression analysis. P values of 0.05 or lower were considered statistically significant.

Results.

A total of 190 patients with PSTs were included in the study. The mean follow-up period was 53.5 months. Of the 190 patients, 127 cases (66.8%) were diagnosed as benign lesions or tumor-like lesions, with 19 cases as aggressive lesions and 44 cases as malignant lesions. Recurrence was detected in 30 patients after initial surgery in our center, whereas death occurred in 24 cases. Implant failure and spinal deformity occurred in 3 and 5 patients, respectively. The statistical analysis suggested that multiple segments involvement (n ≥ 3), aggressive and malignant lesion were independent prognostic factors for LRFS, whereas malignant lesion was the only unfavorable factors for OS. In the subgroup analysis, multiple segments involvement (n ≥ 3) and Enneking stages III were independent factors for LRFS of patients with benign or aggressive lesions.

Conclusion.

Malignant lesion was significantly associated with decreased OS and LRFS of PSTs, whereas multiple segments involvement (n ≥ 3) and aggressive lesions were significantly associated with LRFS.

Level of Evidence: 4
Structural Equation Model of Disability in Low Back Pain
Authors: Melton Brittany L. , Moqbel Murad , Kanaan Saddam , Sharma Neena K.
Published: March 2016

Study Design.

The effects of participant characteristics along with descriptions of pain and psychological involvement, such as fear avoidance, were assessed using structural equation modeling (SEM) to identify relationships between these factors and disability as a result of low back pain (LBP).

Objective.

The aim of this study was to evaluate the relationship between factors related to pain description, participants’ characteristics, psychological involvement, and disability through SEM.

Summary of Background Data.

LBP is a complex multifactorial condition that can lead to disability. Understanding which factors contribute to disability and how those factors interact is important for predicting and minimizing disability in patients with LBP.

Methods.

We analyzed data from 156 participants (63% female) with LBP. A stepwise SEM was built with patient characteristics, pain intensity, depression, anxiety, and fear avoidance to predict disability in LBP.

Results.

Participants were 23–84 years (49.7 ± 15.1 yrs) of age and experienced 0.03 to 300 months duration (25.5 ± 36.4 months) of current LBP. The final model explained 62% of the variance in disability and included female gender, full-time employment, depression, and fear avoidance beliefs as significant predictors. Full-time employment was the only significant predictor that reduced disability; all other significant predictors increased disability in the model.

Conclusion.

Understanding the relationship between these predictors and disability provides a foundation for predicting and managing disability for individual patients who suffer from LBP.

Level of Evidence: 3