bluuebunny/crossref_metadata_2025 huggingface dataset:
Gold nanoparticle density-multiplication by tuning block copolymer self-assembly processes toward increased charge storage
Authors: Suresh Vignesh , Ling Yap Fung , Thu Ye Lin , Ru Tan Hui , Kiong Choi Wee , Srinivasan M. P.
Published: September 2015

Enhanced charge storage in flash memories using AuNPs as charge storage centers enabled through block copolymer self - assembly processes.
Genetic variants affecting human TRPA1 or TRPM8 structure can be classified in vitro as ‘well expressed’, ‘poorly expressed’ or ‘salvageable’
Authors: Morgan Kevin , Sadofsky Laura Rachel , Morice Alyn Hugh
Published: September 2015

Multiple mis-sense variants of TRPA1 (transient receptor potential A1) and TRPM8 (transient receptor potential M8) are recorded in the human genome single nt polymorphism (SNP) database, but their potential impact on channel signalling in patho-physiology is not fully explored. Variants, mostly quite rare in the general human population, alter sites in different structural domains of these homo-tetrameric ion channel proteins. The effects of individual SNPs affecting the large cytoplasmic N-terminal domain have not been completely documented for TRPM8 or TRPA1. We examined the Ca2+ signalling properties of a short-list of eight variants affecting the N-terminal domain by individual expression in human embryonic kidney HEK293 or neuroblastoma (SH-SY5Y) cell lines (four SNP variants for TRPM8: G150R, K423N, R475C, R485W and four for TRPA1: Y69C, A366D, E477K, D573A). These were compared with TRPA1 SNP variants affecting intracellular loops located beyond the N-terminal domain and associated with gain of function (such as increased sensitivity to agonists: TRPA1 R797T and N855S). A substitution in TRPA1 (Y69C) exhibited high expression/sensitivity to agonists (high iCa2+max (maximum level of intracellular calcium ion), similar to R797T, but less sensitive than N855S), whereas each of the other non-conservative substitutions exhibited poor signalling response (low iCa2+max). Responses from these poorly expressed variants could be salvaged, to different extents, by pre-treating cells with the Src (Src protein) family inhibitor protein kinase inhibitor PP2 (PP2: 4-Amino-3-(4-chlorophenyl)-1-(t-butyl)-1H-pyrazolo[3,4-d]pyrimidine, 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), or with micromolar Zn2+. The TRPA1 variants and several experimental mutants (TRPA1 Y97F, Y226F and YY654–655FF) expressed poorly in SH-SY5Y compared with HEK293 cells. More in-depth studies are needed to identify SNP variants eliciting gain of function in these TRP (transient receptor potential) channels and to assess their roles in medical conditions.
Cellular and molecular effects of the mTOR inhibitor everolimus
Authors: Saran Uttara , Foti Michelangelo , Dufour Jean-François
Published: September 2015

mTOR (mechanistic target of rapamycin) functions as the central regulator for cell proliferation, growth and survival. Up-regulation of proteins regulating mTOR, as well as its downstream targets, has been reported in various cancers. This has promoted the development of anti-cancer therapies targeting mTOR, namely fungal macrolide rapamycin, a naturally occurring mTOR inhibitor, and its analogues (rapalogues). One such rapalogue, everolimus, has been approved in the clinical treatment of renal and breast cancers. Although results have demonstrated that these mTOR inhibitors are effective in attenuating cell growth of cancer cells under in vitro and in vivo conditions, subsequent sporadic response to rapalogues therapy in clinical trials has promoted researchers to look further into the complex understanding of the dynamics of mTOR regulation in the tumour environment. Limitations of these rapalogues include the sensitivity of tumour subsets to mTOR inhibition. Additionally, it is well known that rapamycin and its rapalogues mediate their effects by inhibiting mTORC (mTOR complex) 1, with limited or no effect on mTORC2 activity. The present review summarizes the pre-clinical, clinical and recent discoveries, with emphasis on the cellular and molecular effects of everolimus in cancer therapy.
Phonological Awareness at 5 years of age in Children Who Use Hearing Aids or Cochlear Implants
Authors: Ching Teresa Y. C. , Cupples Linda
Published: September 2015

Children with hearing loss typically underachieve in reading, possibly as a result of their underdeveloped phonological skills. This study addressed the questions of (1)whether or not the development of phonological awareness (PA) is influenced by the degree of hearing loss and (2) whether or not performance of children with severe-profound hearing loss differed according to the hearing devices used. Drawing on data collected as part of the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI,www.outcomes.nal.gov.au) study, the authors found that sound-matching scores of children with hearing loss ranging from mild to profound degrees were, on average, within the normal range. The degree of hearing loss did not have a significant impact on scores, but there was a non-significant tendency for the proportion of children who achieved zero scores to increase with increase in hearing loss. For children with severe hearing loss, there was no significant group difference in scores among children who used bilateral hearing aids, bimodal fitting (a cochlear implant and a hearing aid in contralateral ears), and bilateral cochlear implants. Although there is a need for further prospective research, professionals have an important role in targeting PA skills for rehabilitation of young children with hearing loss.
Suppression of ambipolar leakage current in Schottky barrier MOSFET using gate engineering
Authors: Kale S. , Kondekar P.N.
Published: September 2015

A novel asymmetric isolated gates dopant segregated Schottky barrier MOSFET (AIG DS‐SBMOS) for the suppression of ambipolar leakage current (IAMB) using gate engineering is reported. The AIG DS‐SBMOS consists of a dopant segregated source/drain with two asymmetric isolated gates (control gate, fixed gate) having different metal work functions. The control gate is used to control current conduction by modifying the Schottky barrier height and width at the source/channel junction; while, the fixed gate modulates the drain side Schottky barrier to the suppress IAMB caused by hole injection in the off‐state condition. In contrast to the conventional SBMOS and DS‐SBMOS that suffer from ambipolarity, the proposed device is free from severe IAMB. Moreover, the proposed AIG DS‐SBMOS has a high ION/IOFF ratio of 107 with nearly the same ION and subthreshold swing as that of the DS‐SBMOS. The proposed device structure is especially beneficial for nanowire‐based transistors.
Tunable microstrip lowpass filter with compact size and ultra‐wide stopband
Authors: Cai Chuantao , Wang Jianpeng , Zhang Gang
Published: September 2015

A compact varactor‐tuned microstrip lowpass filter (LPF) with a large cutoff frequency tuning range and an ultra‐wide stopband is presented. By employing a pair of parallel coupled‐lines and a low‐impedance stub loaded with a varactor diode, the introduced filter can successfully realise the tunable cutoff frequency function. Besides, both radial patch resonators and stepped‐impedance resonators are introduced to achieve an ultra‐wide stopband in all the states in this design. A varactor‐tuned microstrip LPF is designed, fabricated and measured. The measured results show that the proposed LPF provides not only a large cutoff frequency tuning range of 91.3% from 0.85 to 2.28 GHz, but also an ultra‐wide stopband which extends to 20 GHz.
Spectrum sensing scheme for overlay cognitive radio networks
Authors: Chin Wen‐Long , Lee Jia‐Ming
Published: September 2015

Considering the effects of primary user traffic, timing misalignment and multiple arrival and departure issues in a sensing period should be addressed for spectrum sensing in future overlay cognitive radio (CR) networks, such as femtocell networks. To achieve this goal, division of the whole sensing duration into multiple windows is proposed. For each window, a two‐step detection scheme, i.e. coarse and fine detection, is proposed to improve the performance of the conventional energy detector (ED) in the overlay CR scenario.
Absolute added correlative coding: an enhanced M‐PAM modulation format
Authors: Dong‐Nhat N. , Malekmohammadi A.
Published: September 2015

The performance assessment of a novel multilevel modulation format based on partial‐response signalling called absolute added correlative coding (AACC) by numerical simulations is delineated, targeting short‐range and interconnect high‐speed optical networks. The spectral efficiency, chromatic dispersion tolerance and receiver sensitivity of 4‐instensity level AACC are discussed and compared against other well‐known existing modulation formats, namely, non‐return‐to‐zero on–off keying and 4‐ary pulse‐amplitude modulation (4‐PAM). The robustness of the higher order of AACC over 8‐PAM and 16‐PAM is also discussed.
Random telegraph signals originating from unrelaxed neutral oxygen vacancy centres in SiO2
Authors: Nour M. , Çelik‐Butler Z. , Sonnet A. , Hou F.C. , Tang S.
Published: September 2015

Unrelaxed neutral oxygen deficiency centres (ODCs) (V0 ODC II) in SiO2 have been identified as the cause of random telegraph signals (RTSs) in highly scaled n‐type metal–oxide–semiconductor field‐effect transistors. Variable temperature RTS measurements were performed to extract trap capture cross‐sections, capture activation energy, relaxation energy associated with the gate oxide defects, and the trap energy in the SiO2 bandgap to determine the trap species and type. The results indicate that the electron is captured by a neutral ODC that is transformed into a negatively charged vacancy (V−). This is the first time V0 ODC II centre is confirmed to be the source of electron switching through RTS measurements defining four different trap characteristics.
Method to suppress transient interference in skywave OTHR
Authors: Liu Ziwei , Su Hongtao , Hu Qinzhen
Published: September 2015

In skywave over‐the‐horizon radar (OTHR), transient interference is always suppressed with steps of interference localisation, corruption segment blanking and data restoration. The gapped data amplitude and phase estimation (GAPES) method has been proved to achieve good restoration performance. However, the large computational cost limits its application. A computationally efficient method for transient interference suppression is proposed. Quadratic smoothing is used to suppress transient interference instead of blanking the contaminated data. After that, the GAPES method only needs to restore the smoothed target echoes. Since quadratic smoothing can preserve most clutter echoes, the GAPES method will converge much faster. Experimental results demonstrated the effectiveness of the proposed method.
4.3 μW 10 fA‐sensitivity dual‐mode current converter for implantable glucose monitoring
Authors: Tan Xi , Chen Xianliang , Zhang Yiwu , Wang Junyu , Min Hao , Huang Yue , Mason Andrew J.
Published: September 2015

A low‐power, high‐sensitive current converter for implantable electrochemical glucose sensor tags based on radio frequency identification is presented. The current converter can work in the incremental sigma delta (ΣΔ) converter mode or the dual‐slope converter mode. The two modes can be switched automatically according to the input current value for the target measuring range from 10 fA to 1 nA. The dual‐mode converter offers a 10 fA‐input current sensitivity, 100 dB dynamic range and consumes 4.26 μW of power from a 1.5 V supply.
Exploiting multi‐lead electrocardiogram correlations using robust third‐order tensor decomposition
Authors: Padhy Sibasankar , Dandapat Samarendra
Published: September 2015

In this Letter, a robust third‐order tensor decomposition of multi‐lead electrocardiogram (MECG) comprising of 12‐leads is proposed to reduce the dimension of the storage data. An order‐3 tensor structure is employed to represent the MECG data by rearranging the MECG information in three dimensions. The three‐dimensions of the formed tensor represent the number of leads, beats and samples of some fixed ECG duration. Dimension reduction of such an arrangement exploits correlations present among the successive beats (intra‐beat and inter‐beat) and across the leads (inter‐lead). The higher‐order singular value decomposition is used to decompose the tensor data. In addition, multiscale analysis has been added for effective care of ECG information. It grossly segments the ECG characteristic waves (P‐wave, QRS‐complex, ST‐segment and T‐wave etc.) into different sub‐bands. In the meantime, it separates high‐frequency noise components into lower‐order sub‐bands which helps in removing noise from the original data. For evaluation purposes, we have used the publicly available PTB diagnostic database. The proposed method outperforms the existing algorithms where compression ratio is under 10 for MECG data. Results show that the original MECG data volume can be reduced by more than 45 times with acceptable diagnostic distortion level.
Estimation of transmission line parameters using multiple methods
Authors: Costa Eduardo Coelho M. , Kurokawa Sérgio
Published: September 2015

An estimation procedure for transmission line parameters is developed that combines a new method of determining line parameters with others available in the technical literature. Each estimation method has certain advantages and restrictions that depend on the operating conditions of the transmission system (e.g. the load profile), the physical characteristics of the line (e.g. the length and the geometry) and electromagnetic phenomena (e.g. single‐ or multiphase faults). The proposed estimation procedure exploits the major attributes of both the new determination method developed in this study and other well‐established methods previously presented in the technical literature. Based on current and voltage measurements obtained from synchronised fault records from both line terminals, a combination of multiple methods can be used to accurately estimate most line parameters, a task that is typically impossible using a single method.
Applying high‐voltage direct current emergency control to suppress the peak value of ultra‐high‐voltage tie‐line power oscillation
Authors: Zhou Xin , Sun Haishun , Zhao Bing , Wen Jinyu , Waqar Asad
Published: September 2015

The Central China Power Grid (CCPG) and North China Power Grid (NCPG) are connected together by a single AC ultra‐high‐voltage (UHV) transmission link. When suffering power disturbances, power oscillation with high magnitude and long period would happen on the UHV tie‐line, which may affect the synchronous and stable operation of the interconnected two power grids. This study proposes a novel emergency control scheme for high‐voltage direct current (HVDC) in CCPG to suppress the high peak value of the power oscillation. Based on a two‐machine equivalent model, the maximum rising slope of power oscillat`ion is used to predict the peak value of power oscillation and power disturbance which is used as the reference of emergency power modulation. Simulation verification is carried out based on the full model of the CCPG and NCPG, using Power System Analysis Software Package. Moreover, field test has also been carried out in CCPG. Both simulation results and recorded wave curve show that the proposed HVDC emergency control scheme can effectively suppress the peak value under different power disturbances. This significantly improves the transient performance of the interconnected power system and the power transfer capacity of the UHV tie‐line.
Super resolution reconstruction based on block matching and three‐dimensional filtering with sharpening
Authors: Kim Yookyung , Oh Han , Bilgin Ali
Published: September 2015

Super resolution (SR) reconstruction is often considered to be an inverse problem in the sense that unknown high resolution images are sought for giving low resolution images. Recent studies have shown that the sparsity regularisation used in compressed sensing (CS) reconstruction improves the performance of SR reconstruction. Furthermore, under the assumption that mutually similar regions exist within a natural image, non‐local (NL) estimation produces accurate estimates for given degraded images. The incorporation of this NL estimation in SR reconstruction has been shown to yield better reconstructions. In this study, the authors propose the use of block matching and three‐dimensional filtering with sharpening estimation as the regularisation constraint under the CS‐based SR framework. This estimation collects similar blocks and adaptively filters them by the shrinkage of the transform coefficients. It recovers detailed structures while attenuating ringing artefacts. In addition, a sharpening technique used in the estimation also emphasises edges. As a result, the proposed SR algorithm searches for the solution that is similar to this enhanced estimate from among all feasible solutions. The experimental results demonstrate that the proposed method provides high‐quality SR images, both numerically and subjectively.
Experimental investigation of the incremental conductance maximum power point tracking algorithm at high perturbation rates
Authors: Elgendy Mohammed Ali , Atkinson David John , Zahawi Bashar
Published: September 2015

One of the most commonly utilised maximum power point tracking (MPPT) algorithms for photovoltaic (PV) generators is the incremental conductance (INC) algorithm. Yet, the operating characteristics of this algorithm at high perturbation frequencies, when the system response to MPPT perturbations is never allowed to settle, have not been addressed in the literature. This study characterises system behaviour in this operating mode experimentally for a standalone PV system with a dc motor–pump load. Results show that the INC algorithm operating at a high perturbation rate offers higher energy utilisation efficiency and better system performance despite the resulting non‐periodic waveforms of the system.
Efficient imaging algorithm for spaceborne synthetic aperture radar/ground moving target indication systems
Authors: Li Yongkang , Wang Tong
Published: September 2015

The use of spaceborne synthetic aperture radar (SAR) for ground moving target indication (GMTI) has recently attracted a great deal of interest. In this study, an efficient imaging algorithm for spaceborne SAR/GMTI systems is proposed. The proposed imaging algorithm first implements the secondary range compression and the range cell migration correction in the two‐dimensional frequency domain and then the azimuth compression in the range Doppler domain. The proposed algorithm can finely focus the stationary scene and coarsely focus multiple slow‐moving targets simultaneously without a priori knowledge of targets’ motion parameters and position parameters. Moreover, the proposed algorithm is interpolation free and can be efficiently implemented by using only complex multiplications and fast Fourier transforms. These advantages make the proposed algorithm useful in practice. Experimental results from both simulated data and real data validate the proposed algorithm.
Human gait recognition with cane assistive device using quadratic time–frequency distributions
Authors: Amin Moeness G. , Ahmad Fauzia , Zhang Yimin D. , Boashash Boualem
Published: September 2015

In this study, the authors consider the problem of human gait recognition in the presence of a walking cane using radars. Quadratic time–frequency distributions are used to provide the local signal behaviour over frequency and to detail the changes in the Doppler and micro‐Doppler signatures over time. New features that capture the intrinsic differences in the time–frequency signatures of the gait observed with and without the use of a cane are proposed. The results based on real data experiments conducted in a laboratory environment are provided that validate the effectiveness of the proposed features in discriminating gait with cane from normal human gait.
Short-Time Impact of Laser Ablation of Placental Anastomoses on Myocardial Function in Monochorionic Twins with Twin-to-Twin Transfusion Syndrome
Authors: Degenhardt Jan , Reinold Meike , Enzensberger Christian , Wolter Aline , Kawecki Andrea , Kohl Thomas , Graupner Oliver , Willruth Arne , Gembruch Ulrich , Bahlmann Franz , Steinhard Johannes , Axt-Fliedner Roland
Published: September 2015

Purpose To evaluate pre- and post-procedure myocardial function in monochorionic twins with TTTS who underwent laser ablation of placental anastomoses using pulsed wave tissue Doppler imaging (pw TDI).

Materials and Methods 20 monochorionic twin gestations with TTTS were included and underwent laser ablation at our center between 2011 and 2014. Prior to and after the intervention, cardiac function was assessed by measuring the mitral annular plane systolic excursion (MAPSE), the tricuspid annular plane systolic excursion (TAPSE), Tei index, isovolumetric contraction time (ICT), ejection time (ET), isovolumetric relaxation time (IRT) for the left ventricle in pulsed wave Doppler (pw D) ultrasound as well as ICT, ET, IRT and Tei index in pw TDI for the left and right ventricle. E-, A-, E´- and A´-wave peak velocity and the systolic downward motion (S´) were measured for both ventricles and the E/A, E/E´ and E´/A´ ratios were calculated. In a mean of 1.3 (SD 0.6) days after laser ablation, this measurement protocol was repeated.

Results Pre-intervention recipients had longer ICT, ET and IRT in pw D and pw TDI compared to donors not reaching statistical significance for most parameters. Statistically significant were prolonged ICT in pw D (p 0.01) and ET (p 0.01) in pw TDI in recipients. In donor fetuses preoperative myocardial function did not differ significantly from postoperative myocardial function except in increased left ventricular ejection time of the left ventricle in pw TDI (p 0.04) and an increased E´/A´ratio (p 0.01). After laser coagulation, myocardial function was slightly altered in recipients as ICT and IRT shortened and Tei indices decreased but only reaching statistical significance in shortened IRTs in pw TDI for both ventricles.

Conclusion Laser ablation of placental anastomoses in TTTS might influence myocardial function in the postoperative period. Shortened IRT intervals may reflect an improvement of diastolic function in recipients.
Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note
Authors: Mommaerts Maurice Y. , Büttner Michael , Vercruysse Herman , Wauters Lauri , Beerens Maikel
Published: September 2015

The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis.
High temperature phase stability in Li0.12Na0.88NbO3: A combined powder X-ray and neutron diffraction study
Authors: Mishra S. K. , Krishna P. S. R. , Shinde A. B. , Jayakrishnan V. B. , Mittal R. , Sastry P. U. , Chaplot S. L.
Published: September 2015

The phase stabilities of ecofriendly piezoelectric material of lithium doped sodium niobate for composition Li0.12Na0.88NbO3 (LNN12) have been investigated by a combination of powder X-ray and neutron diffraction techniques in the temperature range of 300–1100 K. We observed interesting changes with appearance or disappearance of the super-lattice reflections in the powder diffraction patterns. Unambiguous experimental evidence is shown for coexistence of paraelectric and ferroelectric orthorhombic phases in the temperature range of 525 K to 675 K. We identified the correct crystal structure of LNN12 with temperature and correlated it with observed anomaly in the physical properties. Identification of crystal structure also helps in the mode assignments in Raman and infrared spectroscopies. We argued that application of chemical pressure as a result of Li substitution in NaNbO3 matrix favors the freezing of zone centre phonons in contrast to the freezing of zone boundary phonons in pure NaNbO3 with the variation of temperature.
Fluctuations and local ice structure in model supercooled water
Authors: Overduin S. D. , Patey G. N.
Published: September 2015

Large-scale simulations (up to 32 000 molecules) are used to analyze local structures and fluctuations for the TIP4P/2005 and TIP5P water models, under deeply supercooled conditions, near previously proposed liquid-liquid critical points. Bulk freezing does not occur in our simulations, but correlations between molecules with local ice-like structure (ice-like molecules) are strong and long ranged (∼4 nm), exceeding the shortest dimension of smaller simulation cells at the lowest temperatures considered. Correlations between ice-like molecules decay slowly at low temperature, on the order of a hundred nanoseconds. Local ice-like structure is strongly correlated with highly tetrahedral liquid structure at all times, both structures contribute to density fluctuations, and to the associated anomalous scattering. For the TIP4P/2005 and TIP5P models, we show that the apparent spontaneous liquid-liquid phase separations, recently reported [T. Yagasaki, M. Matsumoto, and H. Tanaka, Phys. Rev. E 89, 020301 (2014)] for small rectangular simulation cells below the proposed critical points, exhibit strong system size dependence and do not occur at all in the largest systems we consider. Furthermore, in the smaller rectangular systems where layers of different densities do occur, we find that the appearance of a region of low density is always accompanied simultaneously by an excess of local ice density, with no separation in time. Our results suggest that the density differences observed in direct simulations for the two models considered here are likely due to long-range correlations between ice-like molecules and do not provide strong evidence of liquid-liquid phase separation.
The impact of resolution upon entropy and information in coarse-grained models
Authors: Foley Thomas T. , Shell M. Scott , Noid W. G.
Published: September 2015

By eliminating unnecessary degrees of freedom, coarse-grained (CG) models tremendously facilitate numerical calculations and theoretical analyses of complex phenomena. However, their success critically depends upon the representation of the system and the effective potential that governs the CG degrees of freedom. This work investigates the relationship between the CG representation and the many-body potential of mean force (PMF), W, which is the appropriate effective potential for a CG model that exactly preserves the structural and thermodynamic properties of a given high resolution model. In particular, we investigate the entropic component of the PMF and its dependence upon the CG resolution. This entropic component, SW, is a configuration-dependent relative entropy that determines the temperature dependence of W. As a direct consequence of eliminating high resolution details from the CG model, the coarsening process transfers configurational entropy and information from the configuration space into SW. In order to further investigate these general results, we consider the popular Gaussian Network Model (GNM) for protein conformational fluctuations. We analytically derive the exact PMF for the GNM as a function of the CG representation. In the case of the GNM, −TSW is a positive, configuration-independent term that depends upon the temperature, the complexity of the protein interaction network, and the details of the CG representation. This entropic term demonstrates similar behavior for seven model proteins and also suggests, in each case, that certain resolutions provide a more efficient description of protein fluctuations. These results may provide general insight into the role of resolution for determining the information content, thermodynamic properties, and transferability of CG models. Ultimately, they may lead to a rigorous and systematic framework for optimizing the representation of CG models.
A pump-free membrane-controlled perfusion microfluidic platform
Authors: Goral Vasiliy N. , Tran Elizabeth , Yuen Po Ki
Published: September 2015

In this article, we present a microfluidic platform for passive fluid pumping for pump-free perfusion cell culture, cell-based assay, and chemical applications. By adapting the passive membrane-controlled pumping principle from the previously developed perfusion microplate, which utilizes a combination of hydrostatic pressure generated by different liquid levels in the wells and fluid wicking through narrow strips of a porous membrane connecting the wells to generate fluid flow, a series of pump-free membrane-controlled perfusion microfluidic devices was developed and their use for pump-free perfusion cell culture and cell-based assays was demonstrated. Each pump-free membrane-controlled perfusion microfluidic device comprises at least three basic components: an open well for generating fluid flow, a micron-sized deep chamber/channel for cell culture or for fluid connection, and a wettable porous membrane for controlling the fluid flow. Each component is fluidically connected either by the porous membrane or by the micron-sized deep chamber/channel. By adapting and incorporating the passive membrane-controlled pumping principle into microfluidic devices, all the benefits of microfluidic technologies, such as small sample volumes, fast and efficient fluid exchanges, and fluid properties at the micro-scale, can be fully taken advantage of with this pump-free membrane-controlled perfusion microfluidic platform.
Acoustic wave characterization of silicon phononic crystal plate
Authors: Feng Duan , Jiang Wanli , Xu Dehui , Xiong Bin , Wang Yuelin
Published: September 2015

In this paper, characterization of megahertz Lamb waves in a silicon phononic crystal based asymmetry filter by laser Doppler vibrometer is demonstrated. The acoustic power from a piezoelectric substrate was transmitted into the silicon superstrate by fluid coupling method, and measured results show that the displacement amplitude of the acoustic wave in the superstrate was approximately one fifth of that in the piezoelectric substrate. Effect of the phononic bandgap on the propagation of Lamb wave in the silicon superstrate is also measured, and the result shows that the phononic crystal structure could reflect part of the acoustic waves back.
Effect of residual feed intake phenotype–nutritional treatment interaction on the growth performance, plasma metabolic variables and somatotropic axis gene expression of growing ewes
Authors: Nie H. T. , Wang Z. Y. , Lan S. , Zhang H. , Wan Y. J. , Fan Y. X. , Zhang Y. L. , Wang F.
Published: September 2015

This study aimed to evaluate the effect of residual feed intake (RFI) phenotype and nutritional treatment interaction on the growth performance, plasma variables and gene expression levels within the somatotropic axis. Growing ewes [n = 52, initial bodyweight (BW) = 17.5 ± 0.5 kg, 2 months of age] were offered ad libitum access to diets for 63 days and ranked based on RFI phenotype. Thirty ewes with the highest and lowest RFI values were selected and randomly assigned to three nutritional treatments based on dry matter intake (DMI), which are ad libitum (AL), low restriction (LR) and high restriction (HR) groups, respectively. Each nutritional treatment group included ewes with high (n = 5) and low RFI (n = 5) values. During nutritional treatment (from Day 64 to Day 138), plasma samples were obtained to measure metabolite and hormone concentrations. Tissues of the hypothalamus, pituitary, liver, and Longissimus dorsi muscle (LM) were harvested at the end of the experiment (Day 138) to measure the gene expression level within the somatotropic axis. Muscle growth hormone receptor mRNA abundance of low RFI ewes tended to be greater (P = 0.09) under AL feeding, but this difference was abolished by underfeeding (P > 0.10). Low RFI ewes under HR treatment showed slightly greater growth performance, which was accompanied with lower pituitary somatostain receptor 2 mRNA abundance (P < 0.05), plasma non-esterified fatty acid concentration (P < 0.05), and greater concentration of triglyceride (P < 0.05), compared with ewes classified as high RFI group. Our results suggested that ewes categorised as low RFI showed higher resistance to the condition of high feed restriction, which might be attributed to less intensity of fat mobilisation under negative energy balance. The mechanism underlying resistance to such feed restriction was presumably through action of somatostain receptor 2 and was potentially mediated by inhibitory effects of somatostatin on growth hormone release but not basal growth hormone secretion.
Usability of patient experience surveys in Australian primary health care: a scoping review
Authors: Gardner Karen , Parkinson Anne , Banfield Michelle , Sargent Ginny M. , Desborough Jane , Hehir Kanupriya Kalia
Published: September 2015

Monitoring patient experience is essential for stimulating innovation in health care and improving quality and accountability. Internationally, standardised approaches are used to collect patient experience information, but in Australian primary health care (PHC), little is known about which patient experience surveys are used and which aspects of experience they measure. This prevents routine inclusion of patient experience data in quality improvement or system performance measurement. A scoping review was undertaken to identify relevant surveys. Data on survey availability, psychometric properties, target population, method and frequency of administration were extracted. Survey items were mapped against six dimensions of patient experience described internationally. Ninety-five surveys were identified; 34 were developed for use in Australia. Surveys vary in content, size, aspects of experience measured and methods of administration. The quality of data collected and the extent to which it is used in quality improvement is unclear. Collection of patient experience data in Australian PHC is not well developed or standardised and there are few publicly available instruments. There is a need to clearly identify the purposes for which data are to be used and to develop an integrated approach that articulates these collections with other quality and performance data. Some options are discussed.
Non-prescribed antibiotic use and general practitioner service utilisation among Chinese migrants in Australia
Authors: Hu Jie , Wang Zhiqiang
Published: September 2015

Non-prescribed antibiotic use occurs worldwide and is an important contributor to antibiotic resistance. Social and health system factors were related to the practice of self-medication with antibiotics. This study aims to investigate the practice of non-prescribed antibiotic use, and to assess the impact of primary health service access and use on this practice among Australian Chinese migrants. Four-hundred and twenty-six participants, who self-identified as Chinese and who had been residing in Australia for at least 12 months, were recruited through several Australian Chinese social websites to participate in an online health survey about antibiotic use and health services use from July to October 2013. Logistic regression analyses were conducted to assess the associations between health services utilisation factors and the use of non-prescribed antibiotics. In total, 20.2% (86/426) participants reported having used antibiotics without medical consultation in the last 12 months. Of 170 antibiotic users, 50.6% (86/170) used antibiotics without medical consultation. Chinese migrants who self-evaluated as ‘satisfied’ with the experiences of GP services were less likely to self-medicate with antibiotics. In addition, Chinese migrants without any perceived barriers to using primary health services in Australia were less likely to use non-prescribed antibiotics. Among Australian Chinese migrants, over half of antibiotic users admitted that they had used antibiotics without medical consultation. Participants with positive experience and perception of primary health services, primarily GP services, had a lower risk of using non-prescribed antibiotics.
Redox-induced activation of the proton pump in the respiratory complex I
Authors: Sharma Vivek , Belevich Galina , Gamiz-Hernandez Ana P. , Róg Tomasz , Vattulainen Ilpo , Verkhovskaya Marina L. , Wikström Mårten , Hummer Gerhard , Kaila Ville R. I.
Published: September 2015

Significance

Complex I is a redox-driven proton pump, central for aerobic energy transduction. We show here by large-scale quantum and classical molecular simulations how reduction of quinone (Q) in the hydrophilic domain of complex I activates the proton pump in the membrane domain. Our simulations indicate that reduction of Q leads to local charge redistributions that trigger conformational changes via an array of alternating charged residues in the membrane domain, nearly 40 Å away. These mechanistic observations are supported by site-directed mutagenesis of a key residue triggering the activation process. The combined data provide molecular insight into how the long-range energy transduction is accomplished by complex I.
Resilient 3D hierarchical architected metamaterials
Authors: Meza Lucas R. , Zelhofer Alex J. , Clarke Nigel , Mateos Arturo J. , Kochmann Dennis M. , Greer Julia R.
Published: September 2015

Significance

Fractal-like architectures exist in natural materials, like shells and bone, and have drawn considerable interest because of their mechanical robustness and damage tolerance. Developing hierarchically designed metamaterials remains a highly sought after task impaired mainly by limitations in fabrication techniques. We created 3D hierarchical nanolattices with individual beams comprised of multiple self-similar unit cells spanning length scales over four orders of magnitude in fractal-like geometries. We show, through a combination of experiments and computations, that introducing hierarchy into the architecture of 3D structural metamaterials enables the attainment of a unique combination of properties: ultralightweight, recoverability, and a near-linear scaling of stiffness and strength with density.
Convergence of the PML method for elastic wave scattering problems
Authors: Chen Zhiming , Xiang Xueshuang , Zhang Xiaohui
Published: September 2015

In this paper we study the convergence of the perfectly matched layer (PML) method for solving the time harmonic elastic wave scattering problems. We introduce a simple condition on the PML complex coordinate stretching function to guarantee the ellipticity of the PML operator. We also introduce a new boundary condition at the outer boundary of the PML layer which allows us to extend the reflection argument of Bramble and Pasciak to prove the stability of the PML problem in the truncated domain. The exponential convergence of the PML method in terms of the thickness of the PML layer and the strength of PML medium property is proved. Numerical results are included.
Linear chaos and frequent hypercyclicity
Authors: Menet Quentin
Published: September 2015

We answer one of the main current questions in Linear Dynamics by constructing a chaotic operator which is not

U

\mathcal {U}

-frequently hypercyclic and thus not frequently hypercyclic. This operator also gives us an example of a chaotic operator which is not distributionally chaotic and an example of a chaotic operator with only countably many unimodular eigenvalues. We complement this result by showing that every chaotic operator is reiteratively hypercyclic.
Vector bundles on proper toric 3-folds and certain other schemes
Authors: Perling Markus , Schröer Stefan
Published: September 2015

We show that a proper algebraic

n
n

-dimensional scheme

Y
Y

admits non-trivial vector bundles of rank

n
n

, even if

Y
Y

is non-projective, provided that there is a modification containing a projective Cartier divisor that intersects the exceptional locus in only finitely many points. Moreover, there are such vector bundles with arbitrarily large top Chern number. Applying this to toric varieties, we infer that every proper toric threefold admits such vector bundles of rank three. Furthermore, we describe a class of higher-dimensional toric varieties for which the result applies, in terms of convexity properties around rays.
Homological dimensions for co-rank one idempotent subalgebras
Authors: Ingalls Colin , Paquette Charles
Published: September 2015

Let

k
k

be an algebraically closed field and

A
A

a (left and right) Noetherian associative

k
k

-algebra. Assume further that

A
A

is either positively graded or semiperfect (this includes the class of finite dimensional

k
k

-algebras and

k
k

-algebras that are finitely generated modules over a Noetherian central Henselian ring). Let

e
e

be a primitive idempotent of

A
A

, which we assume is of degree

0
0

if

A
A

is positively graded. We consider the idempotent subalgebra

Γ
=
(
1
−
e
)
A
(
1
−
e
)

\Gamma = (1-e)A(1-e)

and

S
e

S_e

the simple right

A
A

-module

S
e

=
e
A

/

e

rad

A

S_e = eA/e\textrm {rad}A

, where

rad

A

\textrm {rad}A

is the Jacobson radical of

A
A

or the graded Jacobson radical of

A
A

if

A
A

is positively graded. In this paper, we relate the homological dimensions of

A
A

and

Γ
\Gamma

, using the homological properties of

S
e

S_e

. First, if

S
e

S_e

has no self-extensions of any degree, then the global dimension of

A
A

is finite if and only if that of

Γ
\Gamma

is. On the other hand, if the global dimensions of both

A
A

and

Γ
\Gamma

are finite, then

S
e

S_e

cannot have self-extensions of degree greater than one, provided

A

/

rad

A

A/\textrm {rad}A

is finite dimensional.
The algebra of slice functions
Authors: Ghiloni Riccardo , Perotti Alessandro , Stoppato Caterina
Published: September 2015

In this paper we study some fundamental algebraic properties of slice functions and slice regular functions over an alternative

∗

^*

-algebra

A
A

over

R

\mathbb {R}

. These recently introduced function theories generalize to higher dimensions the classical theory of functions of a complex variable. Slice functions over

A
A

, which comprise all polynomials over

A
A

, form an alternative

∗

^*

-algebra themselves when endowed with appropriate operations. We presently study this algebraic structure in detail and we confront questions about the existence of multiplicative inverses. This study leads us to a detailed investigation of the zero sets of slice functions and of slice regular functions, which are of course of independent interest.
Changes in Clinical Presentation and Epidemiology of Respiratory Pathogens Associated With Acute Respiratory Illness in Military Trainees After Reintroduction of Adenovirus Vaccine
Authors: Yun Heather C. , Young Adam N. , Caballero Manuel Y. , Lott Lisa , Cropper Thomas L. , Murray Clinton K.
Published: September 2015

Background.  Adenovirus (Ad) has long been the predominant cause of acute respiratory illness (ARI) in military trainees. In 2011, live oral Ad vaccines for serotypes 4 and 7 were reintroduced into US basic military training populations. This study evaluated the impact on clinical presentations and other respiratory pathogens.

Methods.  The Center for Advanced Molecular Detection at Joint Base San Antonio-Lackland prospectively collects demographic, clinical, and polymerase chain reaction data from respiratory specimens (throat swab and nasal wash) among Air Force trainees presenting for care of ARI.

Results.  From June 2008 to August 2013, 2660 trainees enrolled and were tested for selected respiratory pathogens. Post-vaccine introduction (VI), reported systemic symptoms were less frequent, including fever (38% vs 94%) and myalgia (37% vs 67%; P < .01). Median temperature and heart rate decreased (98.4 vs 101.3°F, 81 vs 96 beats per minute; P < .01). Ad detection decreased for all Ad (3% vs 68%), Ad4 (1% vs 70%), 7 (0% vs 8%), 14 (0% vs 5%), and 3 (0.1% vs 2%); P < .01). Rhinovirus and cases with no pathogen identified increased in frequency (35% vs 18%, 51% vs 14%; P < .01).

Conclusions.  Acute respiratory illness in military trainees post-VI is associated with decreased severity of systemic symptoms and reduced fever and heart rate. Marked reductions in frequency of Ad serotypes are seen, including those in the vaccine, with no serotype shift. However, detection of several other respiratory pathogens, most notably rhinovirus, is observed in increasing proportions, and a majority are now undiagnosed clinical syndromes.
A Survey Study of Pregnant Women and Healthcare Practitioners Assessing the Knowledge of Attitudes and Practices of Hepatitis B Management at a Teaching Hospital in Kumasi, Ghana, West Africa
Authors: Cheng Anita , Jose JoAnn , Larsen-Reindorf Roderick , Small Christina , Nde Helen , Dugas Lara , Ehrhardt Stephan , Nelson Kenrad , Ezeanolue Eche , Layden Jennifer
Published: September 2015

Hepatitis B virus (HBV) infection is a major global health problem, with sub-Saharan Africa (SSA), including West Africa, bearing a large proportion of cases. Mother-to-child and early childhood horizontal transmission, the most common mechanisms of disease spread in West Africa, lead to a high rate of chronic infection. Although these transmission mechanisms are preventable through vaccine and hepatitis B immunoglobulin, they are not routinely used due to limited resources. Antiviral therapy in pregnant women who are HBV positive is another option to reduce transmission. We conducted a survey study of pregnant women and clinicians at a teaching hospital in West Africa to determine the knowledge base about HBV and willingness to implement measures to reduce HBV transmission. Pregnant women had limited knowledge about HBV and the common transmission mechanisms. Clinicians identified cost and time as the major barriers to implementation of HBV prevention measures. Both pregnant women and clinicians were largely willing to implement and use measures, including antivirals, to help reduce HBV transmission.