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Sample records for randomly positioned dots

  1. Lead-position dependent regular oscillations and random fluctuations of conductance in graphene quantum dots.

    Science.gov (United States)

    Huang, Liang; Yang, Rui; Lai, Ying-Cheng; Ferry, David K

    2013-02-27

    Quantum interference causes a wavefunction to have sensitive spatial dependence, and this has a significant effect on quantum transport. For example, in a quantum-dot system, the conductance can depend on the lead positions. We investigate, for graphene quantum dots, the conductance variations with the lead positions. Since for graphene the types of boundaries, e.g., zigzag and armchair, can fundamentally affect the quantum transport characteristics, we focus on rectangular graphene quantum dots, for which the effects of boundaries can be systematically studied. For both zigzag and armchair horizontal boundaries, we find that changing the positions of the leads can induce significant conductance variations. Depending on the Fermi energy, the variations can be either regular oscillations or random conductance fluctuations. We develop a physical theory to elucidate the origin of the conductance oscillation/fluctuation patterns. In particular, quantum interference leads to standing-wave-like-patterns in the quantum dot which, in the absence of leads, are regulated by the energy-band structure of the corresponding vertical graphene ribbon. The observed 'coexistence' of regular oscillations and random fluctuations in the conductance can be exploited for the development of graphene-based nanodevices.

  2. Random matrix theory of a chaotic Andreev quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Altland, A.; Zirnbauer, M.R. [Institut fuer Theoretische Physik, Universitaet zu Koeln, Zuelpicher Str.77, 50937 Koeln (Germany)

    1996-04-01

    A new universality class distinct from the standard Wigner-Dyson class is identified. This class is realized by putting a metallic quantum dot in contact with a superconductor, while applying a magnetic field so as to make the pairing field effectively vanish on average. A random-matrix description of the spectral and transport properties of such a quantum dot is proposed. The weak-localization correction to the tunnel conductance is nonzero and results from the depletion of the density of states due to the coupling with the superconductor. Semiclassically, the depletion is caused by a singular mode of phase-coherent long-range propagation of particles and holes. {copyright} {ital 1996 The American Physical Society.}

  3. Performance characterization of Watson Ahumada motion detector using random dot rotary motion stimuli.

    Directory of Open Access Journals (Sweden)

    Siddharth Jain

    Full Text Available The performance of Watson & Ahumada's model of human visual motion sensing is compared against human psychophysical performance. The stimulus consists of random dots undergoing rotary motion, displayed in a circular annulus. The model matches psychophysical observer performance with respect to most parameters. It is able to replicate some key psychophysical findings such as invariance of observer performance to dot density in the display, and decrease of observer performance with frame duration of the display.Associated with the concept of rotary motion is the notion of a center about which rotation occurs. One might think that for accurate estimation of rotary motion in the display, this center must be accurately known. A simple vector analysis reveals that this need not be the case. Numerical simulations confirm this result, and may explain the position invariance of MST(d cells. Position invariance is the experimental finding that rotary motion sensitive cells are insensitive to where in their receptive field rotation occurs.When all the dots in the display are randomly drawn from a uniform distribution, illusory rotary motion is perceived. This case was investigated by Rose & Blake previously, who termed the illusory rotary motion the omega effect. Two important experimental findings are reported concerning this effect. First, although the display of random dots evokes perception of rotary motion, the direction of motion perceived does not depend on what dot pattern is shown. Second, the time interval between spontaneous flips in perceived direction is lognormally distributed (mode approximately 2 s. These findings suggest the omega effect fits in the category of a typical bistable illusion, and therefore the processes that give rise to this illusion may be the same processes that underlie much of other bistable phenomenon.

  4. A Random Dot Product Model for Weighted Networks

    CERN Document Server

    DeFord, Daryl R

    2016-01-01

    This paper presents a generalization of the random dot product model for networks whose edge weights are drawn from a parametrized probability distribution. We focus on the case of integer weight edges and show that many previously studied models can be recovered as special cases of this generalization. Our model also determines a dimension--reducing embedding process that gives geometric interpretations of community structure and centrality. The dimension of the embedding has consequences for the derived community structure and we exhibit a stress function for determining appropriate dimensions. We use this approach to analyze a coauthorship network and voting data from the U.S. Senate.

  5. Psychophysiology of 3D vision: short (hi)story of random dot autostereograms

    Science.gov (United States)

    Jaroszewicz, Zbigniew

    2001-07-01

    The short outline of random dot autostereograms is presented. First a concise historical sketch of basic notions and concepts used in theory of stereoscopy is reminded. Then two principal techniques of the random dot autostereograms perception are explained. At last the design of autostereograms is shortly discussed, as well as the mechanisms which enable perception of these stimuli.

  6. Controlled positioning of self-assembled InAs quantum dots on (1 1 0) GaAs

    Science.gov (United States)

    Schuh, D.; Bauer, J.; Uccelli, E.; Schulz, R.; Kress, A.; Hofbauer, F.; Finley, J. J.; Abstreiter, G.

    2005-02-01

    We report on a new approach for positioning of self-assembled InAs quantum dots on (1 1 0) GaAs with nanometer precision. By combining self-assembly of quantum dots with molecular beam epitaxy on in situ cleaved surfaces (cleaved-edge overgrowth) we have successfully fabricated arrays of long-range ordered InAs quantum dots. Both atomic force microscopy and micro-photoluminescence measurements demonstrate the ability to control position and ordering of the quantum dots with epitaxial precision as well as size and size homogeneity. Furthermore, photoluminescence investigations on dot ensembles and on single dots confirm the high homogeneity and the excellent optical quality of the quantum dots fabricated.

  7. Tuberculosis recurrence in smear-positive patients cured under DOTS in southern Ethiopia: retrospective cohort study.

    Science.gov (United States)

    Datiko, Daniel G; Lindtjørn, Bernt

    2009-09-18

    Decentralization of DOTS has increased the number of cured smear-positive tuberculosis (TB) patients. However, the rate of recurrence has increased mainly due to HIV infection. Recurrence rate could be taken as an important measure of long-term success of TB treatment. We aimed to find out the rate of recurrence in smear-positive patients cured under DOTS in southern Ethiopia. We did a retrospective cohort study on cured smear-positive TB patients who were treated from 1998 to 2006. Recurrence of smear-positive TB was used as an outcome measure. Person-years of observation (PYO) were calculated per 100 PYO from the date of cure to date of interview. Kaplan-Meier and Cox-regression methods were used to determine the survival and the hazard ratio (HR). 368 cured smear-positive TB patients which were followed for 1463 person-years. Of these, 187 patients (50.8%) were men, 277 patients (75.5%) were married, 157 (44.2%) were illiterate, and 152 patients (41.3%) were farmers. 15 of 368 smear-positive patients had recurrence. The rate of recurrence was 1 per 100 PYO (0.01 per annum). Recurrence was not associated with age, sex, occupation, marital status and level of education. High recurrence rate occurred among smear-positive patients cured under DOTS. Further studies are required to identify factors contributing to high recurrence rates to improve disease free survival of TB patients after treatment.

  8. Enhanced Telecom Emission from Single Group-IV Quantum Dots by Precise CMOS-Compatible Positioning in Photonic Crystal Cavities.

    Science.gov (United States)

    Schatzl, Magdalena; Hackl, Florian; Glaser, Martin; Rauter, Patrick; Brehm, Moritz; Spindlberger, Lukas; Simbula, Angelica; Galli, Matteo; Fromherz, Thomas; Schäffler, Friedrich

    2017-03-15

    Efficient coupling to integrated high-quality-factor cavities is crucial for the employment of germanium quantum dot (QD) emitters in future monolithic silicon-based optoelectronic platforms. We report on strongly enhanced emission from single Ge QDs into L3 photonic crystal resonator (PCR) modes based on precise positioning of these dots at the maximum of the respective mode field energy density. Perfect site control of Ge QDs grown on prepatterned silicon-on-insulator substrates was exploited to fabricate in one processing run almost 300 PCRs containing single QDs in systematically varying positions within the cavities. Extensive photoluminescence studies on this cavity chip enable a direct evaluation of the position-dependent coupling efficiency between single dots and selected cavity modes. The experimental results demonstrate the great potential of the approach allowing CMOS-compatible parallel fabrication of arrays of spatially matched dot/cavity systems for group-IV-based data transfer or quantum optical systems in the telecom regime.

  9. From positive to negative magnetoresistance behavior at low applied magnetic fields for polyaniline:titania quantum dot nanocomposites

    Science.gov (United States)

    Mombrú, Dominique; Romero, Mariano; Faccio, Ricardo; Mombrú, Alvaro W.

    2017-06-01

    Here, we report the tuning from the positive to negative magnetoresistance response at room temperature and low applied magnetic fields (H ˜ 200 mT) for polyaniline nancomposites prepared via in situ growth of titanium oxide quantum dots. In addition, we showed experimental Raman evidence revealing that the positive magnetoresistance response in these polyaniline nanocomposites is mediated by the bipolaron mechanism. Confocal Raman spectroscopy under applied magnetic field analysis showed the decrease of the polaron population to form bipolarons of polyaniline when exposed to an applied magnetic field for the TiO2 quantum dot diluted regime. Negative magnetoresistance, observed for the TiO2 quantum dot higher concentration regime, was attributed to the suppression of polyaniline polarons probably associated with its partial chemical functionalization at the interface due to the increasing concentration of TiO2 quantum dots.

  10. Sub-diffraction positioning of a two-photon excited and optically trapped quantum dot

    DEFF Research Database (Denmark)

    Pedersen, Liselotte Jauffred; Kyrsting, Anders Højbo; Christensen, Eva Arnspang

    2014-01-01

    Colloidal quantum dots are luminescent long-lived probes that can be two-photon excited and manipulated by a single laser beam. Therefore, quantum dots can be used for simultaneous single molecule visualization and force manipulation using an infra-red laser. Here, we show that even a single...... two-photon absorption likely. This is in accordance with the observation that a trapped quantum dot is only fluorescing 5-10 percent of the time. The results are important for realizing nano-scale quantum dot control and visualization and for correct interpretation of experiments using two...

  11. Tuning colloidal quantum dot band edge positions through solution-phase surface chemistry modification

    Science.gov (United States)

    Kroupa, Daniel M.; Vörös, Márton; Brawand, Nicholas P.; McNichols, Brett W.; Miller, Elisa M.; Gu, Jing; Nozik, Arthur J.; Sellinger, Alan; Galli, Giulia; Beard, Matthew C.

    2017-05-01

    Band edge positions of semiconductors determine their functionality in many optoelectronic applications such as photovoltaics, photoelectrochemical cells and light emitting diodes. Here we show that band edge positions of lead sulfide (PbS) colloidal semiconductor nanocrystals, specifically quantum dots (QDs), can be tuned over 2.0 eV through surface chemistry modification. We achieved this remarkable control through the development of simple, robust and scalable solution-phase ligand exchange methods, which completely replace native ligands with functionalized cinnamate ligands, allowing for well-defined, highly tunable chemical systems. By combining experiments and ab initio simulations, we establish clear relationships between QD surface chemistry and the band edge positions of ligand/QD hybrid systems. We find that in addition to ligand dipole, inter-QD ligand shell inter-digitization contributes to the band edge shifts. We expect that our established relationships and principles can help guide future optimization of functional organic/inorganic hybrid nanostructures for diverse optoelectronic applications.

  12. Position dependent optical coupling between single quantum dots and photonic crystal nanocavities

    Energy Technology Data Exchange (ETDEWEB)

    Kuruma, K.; Takamiya, D. [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Ota, Y.; Kakuda, M. [Institute of Nano Quantum Information Electronics, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Iwamoto, S.; Arakawa, Y. [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Institute of Nano Quantum Information Electronics, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2016-08-15

    We demonstrate precise and quick detection of the positions of quantum dots (QDs) embedded in two-dimensional photonic crystal nanocavities. We apply this technique to investigate the QD position dependence of the optical coupling between the QD and the nanocavity. We use a scanning electron microscope (SEM) operating at a low acceleration voltage to detect surface bumps induced by the QDs buried underneath. This enables QD detection with a sub-10 nm precision. We then experimentally measure the vacuum Rabi spectra to extract the optical coupling strengths (gs) between single QDs and cavities, and compare them to the values estimated by a combination of the SEM-measured QD positions and electromagnetic cavity field simulations. We found a highly linear relationship between the local cavity field intensities and the QD-cavity gs, suggesting the validity of the point dipole approximation used in the estimation of the gs. The estimation using SEM has a small standard deviation of ±6.2%, which potentially enables the high accuracy prediction of g prior to optical measurements. Our technique will play a key role for deeply understanding the interaction between QDs and photonic nanostructures and for advancing QD-based cavity quantum electrodynamics.

  13. Effect of hotspot position fluctuation to writing capability in heated-dot magnetic recording

    Science.gov (United States)

    Tipcharoen, Warunee; Warisarn, Chanon; Kaewrawang, Arkom; Kovintavewat, Piya

    2016-07-01

    This work presents the effect of hotspot position fluctuation to writing capability in heated-dot magnetic recording systems at an areal density (AD) beyond 2 Tbpsi via a micromagnetic modeling. At high ADs, the hotspot and the write field gradient may not be correctly focused on the target island because the bit islands are closely positioned to one another. This may lead to the overwriting/erasing of the previously written islands, which can severely affect the recording performance. Therefore, this work studies the 3-by-3 data patterns that easily cause an error when the hotspot and write head positions are fluctuated by various island pitches. Simulation results indicate that the data pattern that leads to the highest/lowest error occurrence frequency is the one with the first, second and fourth islands having the opposite/same magnetization direction to/as the write field, regardless of the magnetization direction of the third island. This result can, for example, be utilized to design a two-dimensional modulation code to prevent such destructive data patterns, thus helping enhance the overall system performance.

  14. Reward devaluation: Dot-probe meta-analytic evidence of avoidance of positive information in depressed persons.

    Science.gov (United States)

    Winer, E Samuel; Salem, Taban

    2016-01-01

    Cognitive theories of depression and anxiety have traditionally emphasized the role of attentional biases in the processing of negative information. The dot-probe task has been widely used to study this phenomenon. Recent findings suggest that biased processing of positive information might also be an important aspect of developing psychopathological symptoms. However, despite some evidence suggesting persons with symptoms of depression and anxiety may avoid positive information, many dot-probe studies have produced null findings. The present review used conventional and novel meta-analytic methods to evaluate dot-probe attentional biases away from positive information and, for comparison, toward negative information, in depressed and anxious individuals. Results indicated that avoidance of positive information is a real effect exhibiting substantial evidential value among persons experiencing psychopathology, with individuals evidencing primary symptoms of depression clearly demonstrating this effect. Different theoretical explanations for these findings are evaluated, including those positing threat-processing structures, even-handedness, self-regulation, and reward devaluation, with the novel theory of reward devaluation emphasized and expanded. These novel findings and theory suggest that avoidance of prospective reward helps to explain the cause and sustainability of depressed states. Suggestions for future research and methodological advances are discussed. (c) 2015 APA, all rights reserved).

  15. Positive random fields for modeling material stiffness and compliance

    DEFF Research Database (Denmark)

    Hasofer, Abraham Michael; Ditlevsen, Ove Dalager; Tarp-Johansen, Niels Jacob

    1998-01-01

    with material properties modeled in terms of the considered random fields.The paper addsthe gamma field, the Fisher field, the beta field, and their reciprocal fields to the catalogue. These fields are all defined on the basis of sums of squares of independent standard Gaussian random variables.All the existing......Positive random fields with known marginal properties and known correlation function are not numerous in the literature. The most prominent example is the log\\-normal field for which the complete distribution is known and for which the reciprocal field is also lognormal. It is of interest...... to supplement the catalogue of positive fields beyond the class of those obtained by simple marginal transformation of a Gaussian field, this class containing the lognormal field.As a minimum for a random field to be included in the catalogue itis required that an algorithm for simulation of realizations can...

  16. Exponential Inequalities for Positively Associated Random Variables and Applications

    Directory of Open Access Journals (Sweden)

    Yang Shanchao

    2008-01-01

    Full Text Available Abstract We establish some exponential inequalities for positively associated random variables without the boundedness assumption. These inequalities improve the corresponding results obtained by Oliveira (2005. By one of the inequalities, we obtain the convergence rate for the case of geometrically decreasing covariances, which closes to the optimal achievable convergence rate for independent random variables under the Hartman-Wintner law of the iterated logarithm and improves the convergence rate derived by Oliveira (2005 for the above case.

  17. Comparative analysis of computerized random-dot stereogram in stereopsis and TNO test on postcataract patients

    Directory of Open Access Journals (Sweden)

    Qiang Wang

    2015-06-01

    Full Text Available AIM:To compare the inspection result of computerized random-dot stereotest(CRDSwith TNO test and to study the clinical value of CRDS.METHODS: Seventy-eight patients who received bilateral phacoemulsification from Januray, 2011 to June, 2011 were involved. The operations were performed by the same surgeon. Three months after the operation, CRDS and TNO test were used to evaluate the patients' stereopsis respectively. The inspection results of the two methods were compared.RESULTS:All patients presented stereoscopic vision. There were 26 patients with foveal stereoacuity, 14 with macular stereoscopic vision and 38 with peripheral stereovision measured with CRDS, while it was 24, 11, 43 measured with TNO test. There were 32 patients with normal stereopsis, 46 patients with abnormal stereopsis and 35 patients with normal stereopsis, 43 patients with abnormal stereopsis respectively measured with CRDS and TNO test. No significant differences were found between the two methods.CONCLUSION: The inspection result of CRDS has a high coherence with that of TNO test. It suggests that the CRDS is a reliable method for stereoaeuity evaluation in post-operative patients.

  18. Noise-driven diamagnetic susceptibility of impurity doped quantum dots: Role of anisotropy, position-dependent effective mass and position-dependent dielectric screening function

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Aindrila [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India); Saha, Surajit [Department of Chemistry, Bishnupur Ramananda College, Bishnupur, Bankura 722122, West Bengal (India); Ganguly, Jayanta [Department of Chemistry, Brahmankhanda Basapara High School, Basapara, Birbhum 731215, West Bengal (India); Ghosh, Manas, E-mail: pcmg77@rediffmail.com [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India)

    2016-08-02

    Highlights: • Diamagnetic susceptibility (DMS) of doped quantum dot is studied. • The dot is subjected to Gaussian white noise. • Role of anisotropy, PDEM and PDDSF have been analyzed. • Noise amplifies and suppresses DMS depending on particular condition. • Findings bear significant technological importance. - Abstract: We explore Diamagnetic susceptibility (DMS) of impurity doped quantum dot (QD) in presence of Gaussian white noise introduced to the system additively and multiplicatively. In view of this profiles of DMS have been pursued with variations of geometrical anisotropy and dopant location. We have invoked position-dependent effective mass (PDEM) and position-dependent dielectric screening function (PDDSF) of the system. Presence of noise sometimes suppresses and sometimes amplifies DMS from that of noise-free condition and the extent of suppression/amplification depends on mode of application of noise. It is important to mention that the said suppression/amplification exhibits subtle dependence on use of PDEM, PDDSF and geometrical anisotropy. The study reveals that DMS, or more fundamentally, the effective confinement of LDSS, can be tuned by appropriate mingling of geometrical anisotropy/effective mass/dielectric constant of the system with noise and also on the pathway of application of latter.

  19. From Random Telegraph to Gaussian Stochastic Noises: Decoherence and Spectral Diffusion in a Semiconductor Quantum Dot

    Directory of Open Access Journals (Sweden)

    A. Berthelot

    2010-01-01

    We emphasize the generality and the versatility of our model where the inclusion of asymmetric jump processes appears as an essential extension for the understanding of semiconductor quantum dot physics.

  20. Structure-Related Optical Fingerprints in the Absorption Spectra of Colloidal Quantum Dots: Random Alloy vs. Core/Shell Systems

    CERN Document Server

    Mourad, Daniel

    2016-01-01

    We argue that the experimentally easily accessible optical absorption spectrum can often be used to distinguish between a random alloy phase and a stoichiometrically equivalent core/shell realization of ensembles of monodisperse colloidal semiconductor quantum dots without the need for more advanced structural characterization tools. Our proof-of-concept is performed by conceptually straightforward exact-disorder tight-binding calculations. The underlying stochastical tight-binding scheme only parametrizes bulk band structure properties and does not employ additional free parameters to calculate the optical absorption spectrum, which is an easily accessible experimental property. The method is applied to selected realizations of type-I Cd(Se,S) and type-II (Zn,Cd)(Se,S) alloyed quantum dots with an underlying zincblende crystal structure and the corresponding core/shell counterparts.

  1. Depth perception not found in human observers for static or dynamic anti-correlated random dot stereograms.

    Directory of Open Access Journals (Sweden)

    Paul B Hibbard

    Full Text Available One of the greatest challenges in visual neuroscience is that of linking neural activity with perceptual experience. In the case of binocular depth perception, important insights have been achieved through comparing neural responses and the perception of depth, for carefully selected stimuli. One of the most important types of stimulus that has been used here is the anti-correlated random dot stereogram (ACRDS. In these stimuli, the contrast polarity of one half of a stereoscopic image is reversed. While neurons in cortical area V1 respond reliably to the binocular disparities in ACRDS, they do not create a sensation of depth. This discrepancy has been used to argue that depth perception must rely on neural activity elsewhere in the brain. Currently, the psychophysical results on which this argument rests are not clear-cut. While it is generally assumed that ACRDS do not support the perception of depth, some studies have reported that some people, some of the time, perceive depth in some types of these stimuli. Given the importance of these results for understanding the neural correlates of stereopsis, we studied depth perception in ACRDS using a large number of observers, in order to provide an unambiguous conclusion about the extent to which these stimuli support the perception of depth. We presented observers with random dot stereograms in which correlated dots were presented in a surrounding annulus and correlated or anti-correlated dots were presented in a central circular region. While observers could reliably report the depth of the central region for correlated stimuli, we found no evidence for depth perception in static or dynamic anti-correlated stimuli. Confidence ratings for stereoscopic perception were uniformly low for anti-correlated stimuli, but showed normal variation with disparity for correlated stimuli. These results establish that the inability of observers to perceive depth in ACRDS is a robust phenomenon.

  2. Realization of position-dependent absorption based on biexciton coherence in a Quantum Dot Nanostructure

    Science.gov (United States)

    Hamedi, H. R.; Afshari, Hadi

    2016-01-01

    In this letter, the two-dimensional (2D) spatial-dependent of probe absorption based on biexciton coherence is investigated by monitoring the probe absorption spectra in a Quantum Dot (QD) Nanostructure. We find that due to the quantum interference which is set up by two control pulses that couples to a resonance of the biexciton, the 2D spatial distribution of probe absorption spectrum can be controlled via adjusting the system parameters. We study the effect of controlling parameters of the QD system on spatial distribution of the probe field absorption for two different cases in which the QD interacts with the standing-wave laser fields; first, when two laser fields which couple to a biexciton state, correspond to the two orthogonal standing-wave fields and couple the different transitions. Second, when only one of laser fields correspond to the combination of two orthogonal standing-wave fields, while the other one corresponds to a traveling-wave field. Results exhibit different interesting 2D absorption patterns.

  3. The signature of positive selection at randomly chosen loci.

    Science.gov (United States)

    Przeworski, Molly

    2002-03-01

    In Drosophila and humans, there are accumulating examples of loci with a significant excess of high-frequency-derived alleles or high levels of linkage disequilibrium, relative to a neutral model of a random-mating population of constant size. These are features expected after a recent selective sweep. Their prevalence suggests that positive directional selection may be widespread in both species. However, as I show here, these features do not persist long after the sweep ends: The high-frequency alleles drift to fixation and no longer contribute to polymorphism, while linkage disequilibrium is broken down by recombination. As a result, loci chosen without independent evidence of recent selection are not expected to exhibit either of these features, even if they have been affected by numerous sweeps in their genealogical history. How then can we explain the patterns in the data? One possibility is population structure, with unequal sampling from different subpopulations. Alternatively, positive selection may not operate as is commonly modeled. In particular, the rate of fixation of advantageous mutations may have increased in the recent past.

  4. Positive polynomials, convex integral polytopes, and a random walk problem

    CERN Document Server

    Handelman, David E

    1987-01-01

    Emanating from the theory of C*-algebras and actions of tori theoren, the problems discussed here are outgrowths of random walk problems on lattices. An AGL (d,Z)-invariant (which is a partially ordered commutative algebra) is obtained for lattice polytopes (compact convex polytopes in Euclidean space whose vertices lie in Zd), and certain algebraic properties of the algebra are related to geometric properties of the polytope. There are also strong connections with convex analysis, Choquet theory, and reflection groups. This book serves as both an introduction to and a research monograph on the many interconnections between these topics, that arise out of questions of the following type: Let f be a (Laurent) polynomial in several real variables, and let P be a (Laurent) polynomial with only positive coefficients; decide under what circumstances there exists an integer n such that Pnf itself also has only positive coefficients. It is intended to reach and be of interest to a general mathematical audience as we...

  5. Quantum Electrodynamics with Semiconductor Quantum Dots Coupled to Anderson‐localized Random Cavities

    DEFF Research Database (Denmark)

    Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren

    2011-01-01

    of the spontaneous emission decay rate by up to a factor 15 and an efficiency of channeling single photons into Anderson-localized modes reaching values as high as 94%. These results prove that disordered photonic media provide an efficient platform for quantum electrodynamics, offering a novel route to quantum......We demonstrate that the spontaneous emission decay rate of semiconductor quantum dots can be strongly modified by the coupling to disorder-induced Anderson-localized photonic modes. We experimentally measure, by means of time-resolved photoluminescence spectroscopy, the enhancement...

  6. A novel multiplexer-based structure for random access memory cell in quantum-dot cellular automata

    Science.gov (United States)

    Naji Asfestani, Mazaher; Rasouli Heikalabad, Saeed

    2017-09-01

    Quantum-dot cellular automata (QCA) is a new technology in scale of nano and perfect replacement for CMOS circuits in the future. Memory is one of the basic components in any digital system, so designing the random access memory (RAM) with high speed and optimal in QCA is important. In this paper, by employing the structure of multiplexer, a novel RAM cell architecture is proposed. The proposed architecture is implemented without the coplanar crossover approach. The proposed architecture is simulated using the QCADesigner version 2.0.3 and QCAPro. The simulation results demonstrate that the proposed QCA RAM architecture has the best performance in terms of delay, circuit complexity, area, cell count and energy consumption in comparison with other QCA RAM architectures.

  7. Continuous Positive Airway Pressure in Bronchiolitis: A Randomized Controlled Trial.

    Science.gov (United States)

    Lal, Sandeep Narayan; Kaur, Jaspreet; Anthwal, Pooja; Bahl, Pinky; Puliyel, Jacob M

    2017-09-26

    To evaluate the efficacy of nasal continuous positive airway pressure (nCPAP) in decreasing respiratory distress in bronchiolitis. Randomized controlled trial. Tertiary-care hospital in New Delhi, India. 72 infants (age Silverman-Anderson score and a Modified Pediatric Society of New Zealand Severity Score were compared between the 2 groups after 1 hour of treatment. 14 out of 32 in nCPAP group had change in respiratory rate ≥10, while 5 out of 35 had change in respiratory rate ≥10 with standard care (P=0.008). The mean (SD) change in respiratory rate following nCPAP was 8.03 (5.8), while with standard care it was 5.11 (3.98) (P=0.018). Mean (SD) change in Silverman-Anderson score following nCPAP was 0.78 (0.87), while with standard care it was 0.39 (0.73) (P=0.029). Mean (SD) change in Modified Pediatric Society of New Zealand Severity Score following nCPAP was 2.5 (3.01) compared to 1.08 (1.3) (P=0.012) with standard care. nCPAP helped reduce respiratory distress significantly compared to standard care.

  8. A prospective randomized trial on preventative methods for positional head deformity: physiotherapy versus a positioning pillow.

    Science.gov (United States)

    Wilbrand, Jan-Falco; Seidl, Maximilian; Wilbrand, Martina; Streckbein, Philipp; Böttger, Sebastian; Pons-Kuehnemann, Joern; Hahn, Andreas; Howaldt, Hans-Peter

    2013-06-01

    To evaluate the impact of stretching exercises versus available bedding pillows on positional head deformities. Fifty children aged 5 months or younger with positional head deformity were included in this prospective clinical trial (n=20 plagiocephaly, n=10 brachycephaly, n=20 combination). A random distribution was performed for treatment with the bedding pillow alone (n=25) or with stretching exercises (n=25) for 6 weeks. Anthropometric caliper measurements were done before and after that interval. Cranial vault asymmetry index (CVAI) and cranial index (CI) were calculated and analyzed using a descriptive statistical general linear model. ΔCVAI in the stretching group was 2.09% for plagiocephaly and 2.34% for combined head deformities. Using the bedding pillow, ΔCVAI was 3.01% in plagiocephal children and 2.86% for combined head deformity. The ΔCI in the stretching group was 0.94% for isolated brachycephal children and 2.24% for combined head deformity. ΔCI in the pillow group was 3.63% for brachycephaly and 3.23% in children with combined head deformities, respectively. Bedding pillows and stretching exercises both resulted in improvements in positional cranial deformation. For children with combined plagiocephaly and brachycephaly, improvement in cranial asymmetry was slightly greater when using bedding pillows versus stretching. Copyright © 2013 Mosby, Inc. All rights reserved.

  9. Influence of correspondence noise and spatial scaling on the upper limit for spatial displacement in fully-coherent random-dot kinematogram stimuli.

    Directory of Open Access Journals (Sweden)

    Srimant P Tripathy

    Full Text Available Correspondence noise is a major factor limiting direction discrimination performance in random-dot kinematograms. In the current study we investigated the influence of correspondence noise on Dmax, which is the upper limit for the spatial displacement of the dots for which coherent motion is still perceived. Human direction discrimination performance was measured, using 2-frame kinematograms having leftward/rightward motion, over a 200-fold range of dot-densities and a four-fold range of dot displacements. From this data Dmax was estimated for the different dot densities tested. A model was proposed to evaluate the correspondence noise in the stimulus. This model summed the outputs of a set of elementary Reichardt-type local detectors that had receptive fields tiling the stimulus and were tuned to the two directions of motion in the stimulus. A key assumption of the model was that the local detectors would have the radius of their catchment areas scaled with the displacement that they were tuned to detect; the scaling factor k linking the radius to the displacement was the only free parameter in the model and a single value of k was used to fit all of the psychophysical data collected. This minimal, correspondence-noise based model was able to account for 91% of the variability in the human performance across all of the conditions tested. The results highlight the importance of correspondence noise in constraining the largest displacement that can be detected.

  10. Fluid Dynamics Appearing during Simulated Microgravity Using Random Positioning Machines.

    Science.gov (United States)

    Wuest, Simon L; Stern, Philip; Casartelli, Ernesto; Egli, Marcel

    2017-01-01

    Random Positioning Machines (RPMs) are widely used as tools to simulate microgravity on ground. They consist of two gimbal mounted frames, which constantly rotate biological samples around two perpendicular axes and thus distribute the Earth's gravity vector in all directions over time. In recent years, the RPM is increasingly becoming appreciated as a laboratory instrument also in non-space-related research. For instance, it can be applied for the formation of scaffold-free spheroid cell clusters. The kinematic rotation of the RPM, however, does not only distribute the gravity vector in such a way that it averages to zero, but it also introduces local forces to the cell culture. These forces can be described by rigid body analysis. Although RPMs are commonly used in laboratories, the fluid motion in the cell culture flasks on the RPM and the possible effects of such on cells have not been examined until today; thus, such aspects have been widely neglected. In this study, we used a numerical approach to describe the fluid dynamic characteristic occurring inside a cell culture flask turning on an operating RPM. The simulations showed that the fluid motion within the cell culture flask never reached a steady state or neared a steady state condition. The fluid velocity depends on the rotational velocity of the RPM and is in the order of a few centimeters per second. The highest shear stresses are found along the flask walls; depending of the rotational velocity, they can reach up to a few 100 mPa. The shear stresses in the "bulk volume," however, are always smaller, and their magnitude is in the order of 10 mPa. In conclusion, RPMs are highly appreciated as reliable tools in microgravity research. They have even started to become useful instruments in new research fields of mechanobiology. Depending on the experiment, the fluid dynamic on the RPM cannot be neglected and needs to be taken into consideration. The results presented in this study elucidate the fluid

  11. Is the randomized controlled drug trial in Europe lagging behind the USA?

    NARCIS (Netherlands)

    Lambers Heerspink, Hiddo J.; Knol, Mirjam J.; Tijssen, Robert J. W.; van Leeuwen, Thed N.; Grobbee, Diederick E.; de Zeeuw, Dick

    2008-01-01

    WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT? center dot The USA, UK and Germany have a strong position in performance of drug and nondrug randomized controlled trials. center dot Europe's position in the quantitative and qualitative performance in drug randomized controlled trials in particular, and

  12. Multi-bit quantum random number generation by measuring positions of arrival photons.

    Science.gov (United States)

    Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

    2014-10-01

    We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator.

  13. The role of the random dot Stereo Butterfly test as an adjunct test for the detection of constant strabismus in vision screening.

    Science.gov (United States)

    Moll, Angela M; Rao, Rajesh C; Rotberg, Leemor B; Roarty, John D; Bohra, Lisa I; Baker, John D

    2009-08-01

    A goal of vision screening is the detection of amblyopia risk factors, including strabismus. The random dot Stereo Butterfly test requires no instruction, has a simple pass/fail response with no monocular clues, and is easily administered. The purpose of this study was to determine whether this test could be used as a cost-effective and reliable component of preschool vision screening. The Stereo Butterfly was presented to children with no previous history of ocular problems or treatment. The test was presented with the use of polarized glasses at a 16-inch testing distance. A "pass" was recorded if the patient reported seeing a butterfly; a "refer" was denoted otherwise. Vision and motility measurements were recorded, and the patient underwent a complete eye examination with cycloplegic refraction. A total of 281 children 3 to 6 years of age were tested: 221 children passed the test. Of those who passed, 7 (3.2%) had intermittent strabismus, 1 had a small-angle constant strabismus, 60 failed screening for constant strabismus (of whom 24 [40%] had constant strabismus), and 6 were false-negative results. The sensitivity of the Stereo Butterfly for detecting constant strabismus was 96%; the specificity, 86%. The Stereo Butterfly test may be a valuable adjunctive tool in vision screening programs for the detection of manifest strabismus because it is easy to administer and effectively detects constant strabismus. It has a high specificity for detection of constant strabismus but, if used alone, the low positive predictive value would allow for many false-positive results.

  14. Cost-effectiveness of online positive psychology: Randomized controlled trial

    NARCIS (Netherlands)

    Bolier, Linda; Majo, Cristina; Smit, Filip; Westerhof, Gerben Johan; Haverman, Merel; Walburg, J.A.; Riper, Heleen; Bohlmeijer, Ernst Thomas

    2014-01-01

    As yet, no evidence is available about the cost-effectiveness of positive psychological interventions. When offered via the Internet, these interventions may be particularly cost-effective, because they are highly scalable and do not rely on scant resources such as therapists’ time. Alongside a

  15. Templated self-assembly of SiGe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Dais, Christian

    2009-08-19

    This PhD thesis reports on the fabrication and characterization of exact aligned SiGe quantum dot structures. In general, SiGe quantum dots which nucleate via the Stranski-Krastanov growth mode exhibit broad size dispersion and nucleate randomly on the surface. However, to tap the full potential of SiGe quantum dots it is necessary to control the positioning and size of the dots on a nanometer length, e.g. for electronically addressing of individual dots. This can be realized by so-called templated self-assembly, which combines top-down lithography with bottom-up selfassembly. In this process the lithographically defined pits serve as pre-defined nucleation points for the epitaxially grown quantum dots. In this thesis, extreme ultraviolet interference lithography at a wavelength of e=13.4 nm is employed for prepatterning of the Si substrates. This technique allows the precise and fast fabrication of high-resolution templates with a high degree of reproducibility. The subsequent epitaxial deposition is either performed by molecular beam epitaxy or low-pressure chemical vapour deposition. It is shown that the dot nucleation on pre-patterned substrates depends strongly on the lithography parameters, e.g. size and periodicity of the pits, as well as on the epitaxy parameters, e.g. growth temperature or material coverage. The interrelations are carefully analyzed by means of scanning force microscopy, transmission electron microscopy and X-ray diffraction measurements. Provided that correct template and overgrowth parameters are chosen, perfectly aligned and uniform SiGe quantum dot arrays of different period, size as well as symmetry are created. In particular, the quantum dot arrays with the so far smallest period (35 nm) and smallest size dispersion are fabricated in this thesis. Furthermore, the strain fields of the underlying quantum dots allow the fabrication of vertically aligned quantum dot stacks. Combining lateral and vertical dot alignment results in three

  16. Imaging and magnetotransport in superconductor/magnetic dot arrays

    Science.gov (United States)

    Silevitch, D. M.; Reich, D. H.; Chien, C. L.; Field, S. B.; Shtrikman, H.

    2001-06-01

    Magnetoresistance and scanning Hall probe microscopy studies of Nb-film/Ni-dot structures are reported. The dots act as pinning sites for superconducting vortices. The transport measurements focus on the effects of introducing disorder into the positions of the pinning lattice near the superconducting critical temperature Tc in structures with 250 nm diameter Ni dots randomized about an ideal square lattice with lattice constant a=560 nm. Features observable in the ordered arrays at higher multiples of the matching field H0=Φ0/a2 are washed out in the disordered arrays, but those at H0 remain. Scanning Hall probe microscope images were taken of the vortex configurations at fields up to 1.2H0 in ordered arrays of 1-μm-diameter dots on a 5.2 μm×4 μm rectangular lattice. These show that despite the relatively weak pinning of the magnetic dots, ordering commensurate with the dot lattice occurs even for fields below H0. Both transport and imaging studies point to the importance of interstitial vortices in determining the properties of superconductor/magnetic dot arrays.

  17. Reporting of positive results in randomized controlled trials of mindfulness-based mental health interventions

    NARCIS (Netherlands)

    Coronado-Montoya, S.; Levis, A.W.; Kwakkenbos, C.M.C.; Steele, R.J.; Turner, E.H.; Thombs, B.D.

    2016-01-01

    Background A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of

  18. Upregulating Positive Affectivity in the Transdiagnostic Treatment of Emotional Disorders: A Randomized Pilot Study.

    Science.gov (United States)

    González-Robles, Alberto; García-Palacios, Azucena; Baños, Rosa; Quero, Soledad; Botella, Cristina

    2017-10-01

    Transdiagnostic cognitive-behavioral therapy for emotional disorders (ED) has proven to be effective. However, current transdiagnostic treatment protocols address only the regulation of negative affectivity, and they do not include treatment components to more directly target the regulation of positive affectivity. In this study, we propose to evaluate the preliminary efficacy and acceptability of a transdiagnostic treatment protocol for ED that includes, as an innovative feature, a specific treatment component to directly upregulate positive affectivity based on positive psychology interventions. A total of 24 participants were randomized to either a transdiagnostic treatment protocol ( n = 12) or a transdiagnostic treatment protocol with an additional component designed to regulate positive affectivity ( n = 12). Participants completed measures of anxiety, depression, positive and negative affectivity, and quality of life, as well as treatment acceptability at pre- and posttreatment and at the 3-month follow-up. Both interventions led to improvements in all measures at posttreatment, and these outcomes were maintained at the 3-month follow-up, with large effect sizes for all measures. The effect sizes for positive affect were larger in the condition that included the component to upregulate positive affectivity. Attrition rate was low, and both treatment protocols were well accepted by participants. The results obtained in this study indicate the feasibility of testing the treatment protocol in a larger, randomized, controlled trial, and they suggest the potential of including treatment components for directly upregulating positive affectivity in future research on transdiagnostic treatment protocols for ED.

  19. Quantum tunneling recombination in a system of randomly distributed trapped electrons and positive ions.

    Science.gov (United States)

    Pagonis, Vasilis; Kulp, Christopher; Chaney, Charity-Grace; Tachiya, M

    2017-09-13

    During the past 10 years, quantum tunneling has been established as one of the dominant mechanisms for recombination in random distributions of electrons and positive ions, and in many dosimetric materials. Specifically quantum tunneling has been shown to be closely associated with two important effects in luminescence materials, namely long term afterglow luminescence and anomalous fading. Two of the common assumptions of quantum tunneling models based on random distributions of electrons and positive ions are: (a) An electron tunnels from a donor to the nearest acceptor, and (b) the concentration of electrons is much lower than that of positive ions at all times during the tunneling process. This paper presents theoretical studies for arbitrary relative concentrations of electrons and positive ions in the solid. Two new differential equations are derived which describe the loss of charge in the solid by tunneling, and they are solved analytically. The analytical solution compares well with the results of Monte Carlo simulations carried out in a random distribution of electrons and positive ions. Possible experimental implications of the model are discussed for tunneling phenomena in long term afterglow signals, and also for anomalous fading studies in feldspars and apatite samples.

  20. A randomized trial of suprasternal palpation to determine endotracheal tube position in neonates.

    Science.gov (United States)

    Jain, Alok; Finer, Neil N; Hilton, Saskia; Rich, Wade

    2004-03-01

    To compare suprasternal palpation, a previously described bedside technique, with standard chest radiography for correct positioning of the endotracheal tube (ETT) in newborn infants. A randomized single-blinded study in an academic medical center. Preterm and term newborn infants requiring intubation were eligible, provided that they had not had their initial chest roentgenogram (CXR). Infants were randomized to ETT palpation and non-adjustment (Controls), or to ETT palpation and adjustment (Treatment), following digital palpation of the ETT tip in the suprasternal notch. ETT position was considered correct when only the tip of the ETT was palpable in the suprasternal notch. ETT position by CXR was blindly assessed by an experienced pediatric radiologist. Fifty-five infants were enrolled in the delivery room or neonatal intensive care unit. Correct tube placements improved from 48% pre-study to 85 and 93% in the Control and Treatment arms, respectively. The majority of incorrect estimations were that the ETT position using palpation was judged to be too low when it was, in fact, in correct position, as noted in 11 infants. ETT palpation had a 70% concordance with the position determined by CXR. No difficulties or complications were associated with the use of suprasternal palpation. Suprasternal palpation is a simple, safe, teachable, method of confirming ETT position in neonates when CXR is unavailable, and may especially helpful during neonatal resuscitation prior to surfactant administration.

  1. Random Lasing with Systematic Threshold Behavior in Films of CdSe/CdS Core/Thick-Shell Colloidal Quantum Dots.

    Science.gov (United States)

    Gollner, Claudia; Ziegler, Johannes; Protesescu, Loredana; Dirin, Dmitry N; Lechner, Rainer T; Fritz-Popovski, Gerhard; Sytnyk, Mykhailo; Yakunin, Sergii; Rotter, Stefan; Yousefi Amin, Amir Abbas; Vidal, Cynthia; Hrelescu, Calin; Klar, Thomas A; Kovalenko, Maksym V; Heiss, Wolfgang

    2015-10-27

    While over the past years the syntheses of colloidal quantum dots (CQDs) with core/shell structures were continuously improved to obtain highly efficient emission, it has remained a challenge to use them as active materials in laser devices. Here, we report random lasing at room temperature in films of CdSe/CdS CQDs with different core/shell band alignments and extra thick shells. Even though the lasing process is based on random scattering, we find systematic dependencies of the laser thresholds on morphology and laser spot size. To minimize laser thresholds, optimizing the film-forming properties of the CQDs, proven by small-angle X-ray scattering, was found to be more important than the optical parameters of the CQDs, such as biexciton lifetime and binding energy or fluorescence decay time. Furthermore, the observed systematic behavior turned out to be highly reproducible after storing the samples in air for more than 1 year. These highly reproducible systematic dependencies suggest that random lasing experiments are a valuable tool for testing nanocrystal materials, providing a direct and simple feedback for further development of colloidal gain materials toward lasing in continuous wave operation.

  2. The effect of cervical stabilization exercise on active joint position sense: A randomized controlled trial.

    Science.gov (United States)

    Lee, Mi-Young; Kim, Seong-Gil; Lee, Hae-Yong

    2016-01-01

    We attempted to investigate the effect of cervical stabilization exercise for a period of 5 weeks on active joint position sense in healthy young adults. Twenty-four subjects were randomly assigned to either the exercise group or the control group. The exercise group performed cervical stabilization exercise during the 5-week period. Cervical active joint position sense was measured using the head repositioning accuracy test. The result showed a positive interaction between time and group in the left and right rotation, flexion, and extension. Cervical stabilization exercise significantly improved the sense for four position senses in the exercise group (p 0.05). In conclusion, we suggested that cervical stabilization exercise leads to improvement in accuracy of the joint position sense.

  3. DOT or SAT for Rifampicin-resistant tuberculosis? A non-randomized comparison in a high HIV-prevalence setting.

    Science.gov (United States)

    Mohr, Erika; Daniels, Johnny; Beko, Busisiwe; Isaakidis, Petros; Cox, Vivian; Steele, Sarah Jane; Muller, Odelia; Snyman, Leigh; De Azevedo, Virginia; Shroufi, Amir; Trivino Duran, Laura; Hughes, Jennifer

    2017-01-01

    Daily directly-observed therapy (DOT) is recommended for rifampicin-resistant tuberculosis (RR-TB) patients throughout treatment. We assessed the impact of self-administered treatment (SAT) in a South African township with high rates of RR-TB and HIV. Community-supported SAT for patients who completed the intensive phase was piloted in five primary care clinics in Khayelitsha. We compared final treatment outcomes among RR-TB patients initiating treatment before (standard-of-care (SOC)-cohort, January 2010-July 2013) and after the implementation of the pilot (SAT-cohort, January 2012-December 2014). All patients with outcomes before January 1, 2017 were considered in the analysis of outcomes. One-hundred-eighteen patients in the SOC-cohort and 174 patients in the SAT-cohort had final RR-TB treatment outcomes; 70% and 73% were HIV-co-infected, respectively. The proportion of patients with a final outcome of loss to follow-up (LTFU) did not differ whether treated in the SOC (25/118, 21.2%) or SAT-cohort (31/174, 17.8%) (P = 0.47). There were no significant differences in the time to 24-month LTFU among HIV-infected and uninfected patients (HR 0.90, 95% CI: 0.51-1.6, P = 0.71), or among patients enrolled in the SOC-cohort versus the SAT-cohort (HR 0.83, 95% CI: 0.49-1.4, P = 0.50) who received at least 6-months of RR-TB treatment. The introduction of SAT during the continuation phase of RR-TB treatment does not adversely affect final RR-TB treatment outcomes in a high TB and HIV-burden setting. This differentiated, patient-centred model of care could be considered in RR-TB programmes to decrease the burden of DOT on patients and health facilities.

  4. Stochastic clustered-dot dithering

    Science.gov (United States)

    Ostromoukhov, Victor; Hersch, Roger D.

    1999-10-01

    A new technique for building stochastic clustered-dot screens is being proposed. A large dither matrix comprising thousands of stochastically laid out screen dots is constructed by first laying out the screen dot centers. Screen dot centers are obtained by placing discrete disks of a chosen radius at free cell locations when traversing the dither array cells according to either a discretely rotated Hilbert space-filling curve or a random space-filling curve. After Delauney triangulation of the screen dot centers, the maximal surface of each screen dot is computed and isointensity regions are created. This isointensity map is converted into an antialiased gray scale image, i.e., into an array of preliminary threshold values. These threshold values are renumbered to obtain the threshold values of the final dither threshold array. By changing the disk radius, the screen dot size can be adapted to the characteristics of particular printing devices. Larger screen dots may improve the one reproduction of printers having important dot gain.

  5. Occupational position and its relation to mental distress in a random sample of Danish residents

    DEFF Research Database (Denmark)

    Rugulies, Reiner Ernst; Madsen, Ida E H; Nielsen, Maj Britt D

    2010-01-01

    somatization symptoms (OR = 6.28, 95% CI = 1.39-28.46). CONCLUSIONS: Unskilled manual workers, the unemployed, and, to a lesser extent, the low-grade self-employed showed an increased level of mental distress. Activities to promote mental health in the Danish population should be directed toward these groups.......PURPOSE: To analyze the distribution of depressive, anxiety, and somatization symptoms across different occupational positions in a random sample of Danish residents. METHODS: The study sample consisted of 591 Danish residents (50% women), aged 20-65, drawn from an age- and gender-stratified random...... sample of the Danish population. Participants filled out a survey that included the 92 item version of the Hopkins Symptom Checklist (SCL-92). We categorized occupational position into seven groups: high- and low-grade non-manual workers, skilled and unskilled manual workers, high- and low-grade self...

  6. Microgravity simulations with human lymphocytes in the free fall machine and in the random positioning machine

    Science.gov (United States)

    Schwarzenberg, M.; Pippia, P.; Meloni, M. A.; Cossu, G.; Cogoli-Greuter, M.; Cogoli, A.

    1998-01-01

    The purpose of this paper is to present the results obtained in our laboratory with both instruments, the FFM [free fall machine] and the RPM [random positioning machine], to compare them with the data from earlier experiments with human lymphocytes conducted in the FRC [fast rotating clinostat] and in space. Furthermore, the suitability of the FFM and RPM for research in gravitational cell biology is discussed.

  7. Sniff to see. Comparing sniffing position versus simple head extension position for glottic exposure - A prospective, randomized cross over study

    Directory of Open Access Journals (Sweden)

    Nishant Sahay

    2016-01-01

    Conclusion: Sniffing position provides better glottis exposure and it is easier to intubate a patient in the sniffing position as compared to simple head extension position. Sniffing position should therefore be used as initial position when attempting intubation.

  8. Positive Psychology Interventions for Patients With Heart Disease: A Preliminary Randomized Trial.

    Science.gov (United States)

    Nikrahan, Gholam Reza; Suarez, Laura; Asgari, Karim; Beach, Scott R; Celano, Christopher M; Kalantari, Mehrdad; Abedi, Mohammad Reza; Etesampour, Ali; Abbas, Rezaei; Huffman, Jeff C

    2016-01-01

    Positive psychologic characteristics have been linked to superior cardiac outcomes. Accordingly, in this exploratory study, we assessed positive psychology interventions in patients who had recently undergone a procedure to treat cardiovascular disease. Participants were randomly assigned to receive 1 of 3 different 6-week face-to-face interventions or a wait-list control condition. We assessed intervention feasibility and compared changes in psychologic outcome measures postintervention (7wk) and at follow-up (15wk) between intervention and control participants. Across the interventions, 74% of assigned sessions were completed. When comparing outcomes between interventions and control participants (N = 55 total), there were no between-group differences post-intervention, but at follow-up intervention participants had greater improvements in happiness (β = 14.43, 95% CI: 8.66-20.2, p positive psychology intervention for cardiac patients. Copyright © 2016 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.

  9. Countable Alphabet Random Subhifts of Finite Type with Weakly Positive Transfer Operator

    Science.gov (United States)

    Mayer, Volker; Urbański, Mariusz

    2015-09-01

    We deal with countable alphabet locally compact random subshifts of finite type (the latter merely meaning that the symbol space is generated by an incidence matrix) under the absence of big images property and under the absence of uniform positivity of the transfer operator. We first establish the existence of random conformal measures along with good bounds for the iterates of the Perron-Frobenius operator. Then, using the technique of positive cones and proving a version of Bowen's type contraction (see Equilibrium states and the ergodic theory of Anosov diffeomorphisms, 1975), we also establish a fairly complete thermodynamical formalism. This means that we prove the existence and uniqueness of fiberwise invariant measures (giving rise to a global invariant measure) equivalent to the fiberwise conformal measures. Furthermore, we establish the existence of a spectral gap for the transfer operators, which in the random context precisely means the exponential rate of convergence of the normalized iterated transfer operator. This latter property in a relatively straightforward way entails the exponential decay of correlations and the Central Limit Theorem.

  10. Social and emotional wellbeing, natural helpers, critical health literacy and translational research: connecting the dots for positive health outcomes.

    Science.gov (United States)

    Drew, Neil

    2015-12-01

    The tripartite framework for principled practice was developed as part of the Wundargoodie Aboriginal Youth and Community Wellbeing Programme. The programme engages natural helpers to enhance critical health literacy. This paper examines the importance of translational research to enhancing critical health literacy for this group of de facto health workers using the work of the Australian Indigenous HealthInfoNet as an example. Translational research provides workforce support for those who are time poor and overburdened. Connecting these concepts and natural helpers will make a positive difference to Aboriginal health outcomes. There is a need for the development of translational research products that enhance the critical health literacy of natural helpers. The tripartite framework for principled practice supports reflective and accountable practice in the intercultural space to build trust and confidence between Aboriginal and non-Aboriginal people to enhance the opportunity for authentic knowledge production and transfer. © The Royal Australian and New Zealand College of Psychiatrists 2015.

  11. RedDots Replayed

    DEFF Research Database (Denmark)

    Kinnunen, Tomi; Sahidullah, Md; Falcone, Mauro

    2017-01-01

    the protection of text-dependent ASV systems from replay attacks in the face of variable recording and playback conditions. Derived from the re-recording of the original RedDots database, the effort is aligned with that in text-dependent ASV and thus well positioned for future assessments of replay spoofing...

  12. Postpartum positioning and attachment education for increasing breastfeeding: a randomized trial.

    Science.gov (United States)

    Henderson, A; Stamp, G; Pincombe, J

    2001-12-01

    Although lactation experts suggest that a correct positioning and attachment technique reduces breastfeeding problems and enhances long-term breastfeeding, evidence from randomized trials is lacking. The objective of this study was to evaluate the effect of postpartum positioning and attachment education on breastfeeding outcomes in first-time mothers. A randomized trial was performed in a public hospital in Adelaide, South Australia, where 160 first-time mothers were randomly allocated to receive either structured one-to-one education (experimental group) or usual postpartum care (control group) within 24 hours of birth. The primary outcome was breastfeeding at 6 weeks and 3 and 6 months postpartum; other outcomes were nipple pain and trauma in hospital and at 6 weeks and 3 and 6 months, and satisfaction with breastfeeding. No significant differences occurred in breastfeeding rates between the groups at each endpoint, although a trend in the direction of lower rates was seen at each endpoint in the experimental group. This group reported less nipple pain on days 2 (p = 0.004) and 3 (p = 0.04), but this was not sustained on follow-up. No differences were observed in nipple trauma in hospital or in self-reported nipple pain and/or trauma at the three endpoints. Experimental group women were less satisfied with breastfeeding at 3 and 6 months postpartum when using a one-item measure; however, a multiple-item measure showed no significant differences at the three endpoints. The intervention did not increase breastfeeding duration at any assessment time or demonstrate any differences between the groups on secondary outcomes. The trend toward lower breastfeeding rates in the experimental group suggests a need for a larger trial to evaluate whether or nor postpartum positioning and attachment education may negatively affect breastfeeding.

  13. Local random quantum circuits: Ensemble completely positive maps and swap algebras

    Energy Technology Data Exchange (ETDEWEB)

    Zanardi, Paolo [Department of Physics and Astronomy, and Center for Quantum Information Science and Technology, University of Southern California, Los Angeles, California 90089-0484, USA and Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore)

    2014-08-15

    We define different classes of local random quantum circuits (L-RQC) and show that (a) statistical properties of L-RQC are encoded into an associated family of completely positive maps and (b) average purity dynamics can be described by the action of these maps on operator algebras of permutations (swap algebras). An exactly solvable one-dimensional case is analyzed to illustrate the power of the swap algebra formalism. More in general, we prove short time area-law bounds on average purity for uncorrelated L-RQC and infinite time results for both the uncorrelated and correlated cases.

  14. Local random quantum circuits: Ensemble completely positive maps and swap algebras

    Science.gov (United States)

    Zanardi, Paolo

    2014-08-01

    We define different classes of local random quantum circuits (L-RQC) and show that (a) statistical properties of L-RQC are encoded into an associated family of completely positive maps and (b) average purity dynamics can be described by the action of these maps on operator algebras of permutations (swap algebras). An exactly solvable one-dimensional case is analyzed to illustrate the power of the swap algebra formalism. More in general, we prove short time area-law bounds on average purity for uncorrelated L-RQC and infinite time results for both the uncorrelated and correlated cases.

  15. Informed Cytology for Triaging HPV-Positive Women: Substudy Nested in the NTCC Randomized Controlled Trial

    Science.gov (United States)

    Bergeron, Christine; Giorgi-Rossi, Paolo; Cas, Frederic; Schiboni, Maria Luisa; Ghiringhello, Bruno; Dalla Palma, Paolo; Minucci, Daria; Rosso, Stefano; Zorzi, Manuel; Naldoni, Carlo; Segnan, Nereo; Confortini, Massimo

    2015-01-01

    Background: Human papillomavirus (HPV)–based screening needs triage. In most randomized controlled trials (RCTs) on HPV testing with cytological triage, cytology interpretation has been blind to HPV status. Methods: Women age 25 to 60 years enrolled in the New Technology in Cervical Cancer (NTCC) RCT comparing HPV testing with cytology were referred to colposcopy if HPV positive and, if no cervical intraepithelial neoplasia (CIN) was detected, followed up until HPV negativity. Cytological slides taken at the first colposcopy were retrieved and independently interpreted by an external laboratory, which was only aware of patients’ HPV positivity. Sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values were computed for histologically proven CIN2+ with HPV status–informed cytology for women with a determination of atypical squamous cells of undetermined significance (ASCUS) or more severe. All statistical tests were two-sided. Results: Among HPV-positive women, informed cytology had cross-sectional sensitivity, specificity, PPV and 1-NPV for CIN2+ of 85.6% (95% confidence interval [CI] = 76.6 to 92.1), 65.9% (95% CI = 63.1 to 68.6), 16.2% (95% CI = 13.0 to 19.8), and 1.7 (95% CI = 0.9 to 2.8), respectively. Cytology was also associated with subsequent risk of newly diagnosed CIN2+ and CIN3+. The cross-sectional relative sensitivity for CIN2+ vs blind cytology obtained by referring to colposcopy and following up only HPV positive women who had HPV status–informed cytology greater than or equal to ASCUS was 1.58 (95% CI = 1.22 to 2.01), while the corresponding relative referral to colposcopy was 0.95 (95% CI = 0.86 to 1.04). Conclusions: Cytology informed of HPV positivity is more sensitive than blind cytology and could allow longer intervals before retesting HPV-positive, cytology-negative women. PMID:25568167

  16. Automatic control of tracheal tube cuff pressure in ventilated patients in semirecumbent position: a randomized trial.

    Science.gov (United States)

    Valencia, Mauricio; Ferrer, Miquel; Farre, Ramon; Navajas, Daniel; Badia, Joan Ramon; Nicolas, Josep Maria; Torres, Antoni

    2007-06-01

    The aspiration of subglottic secretions colonized by bacteria pooled around the tracheal tube cuff due to inadvertent deflation (automatic, validated device for the continuous regulation of tracheal tube cuff pressure in preventing ventilator-associated pneumonia. Prospective randomized controlled trial. Respiratory intensive care unit and general medical intensive care unit. One hundred and forty-two mechanically ventilated patients (age, 64 +/- 17 yrs; Acute Physiology and Chronic Health Evaluation II score, 18 +/- 6) without pneumonia or aspiration at admission. Within 24 hrs of intubation, patients were randomly allocated to undergo continuous regulation of the cuff pressure with the automatic device (n = 73) or routine care of the cuff pressure (control group, n = 69). Patients remained in a semirecumbent position in bed. The primary end point variable was the incidence of ventilator-associated pneumonia. Main causes for intubation were decreased consciousness (43, 30%) and exacerbation of chronic respiratory diseases (38, 27%). Cuff pressure control than the automatic group (45.3 vs. 0.7% determinations, p automatic and control groups, respectively. Cuff pressure is better controlled with the automatic device. However, it did not result in additional benefits to the semirecumbent position in preventing ventilator-associated pneumonia.

  17. Continuous Positive Airway Pressure Versus Oxygen Therapy in the Cardiac Surgical Ward: A Randomized Trial.

    Science.gov (United States)

    Olper, Luigi; Bignami, Elena; Di Prima, Ambra L; Albini, Santina; Nascimbene, Simona; Cabrini, Luca; Landoni, Giovanni; Alfieri, Ottavio

    2017-02-01

    Noninvasive ventilation (NIV) is a common technique to manage patients with acute respiratory failure in the intensive care unit. However, use of NIV in general wards is less well described. The authors' aim was to demonstrate efficacy of NIV, applied in a cardiac surgery ward, in improving oxygenation in patients who developed hypoxemic acute respiratory failure after being discharged from the intensive care unit. Randomized, open-label trial. University hospital. Sixty-four patients with hypoxemia (PaO2/FIO2 ratio between 100 and 250) admitted to the main ward after cardiac surgery. Patients were randomized to receive standard treatment (oxygen, early mobilization, a program of breathing exercises and diuretics) or continuous positive airway pressure in addition to standard treatment. Continuous positive airway pressure was administered 3 times a day for 2 consecutive days. Every cycle lasted 1 to 3 hours. All patients completed their 1-year follow-up. Data were analyzed according to the intention-to-treat principle. The primary endpoint was the number of patients with PaO2/FIO2pressure use was associated with a statistically significant reduction in the number of patients with PaO2/FIO2pressure in the main ward was associated with improved respiratory outcome. This was the first study that was performed in the main ward of post-surgical patients with acute respiratory failure. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Random Forest Based Coarse Locating and KPCA Feature Extraction for Indoor Positioning System

    Directory of Open Access Journals (Sweden)

    Yun Mo

    2014-01-01

    Full Text Available With the fast developing of mobile terminals, positioning techniques based on fingerprinting method draw attention from many researchers even world famous companies. To conquer some shortcomings of the existing fingerprinting systems and further improve the system performance, on the one hand, in the paper, we propose a coarse positioning method based on random forest, which is able to customize several subregions, and classify test point to the region with an outstanding accuracy compared with some typical clustering algorithms. On the other hand, through the mathematical analysis in engineering, the proposed kernel principal component analysis algorithm is applied for radio map processing, which may provide better robustness and adaptability compared with linear feature extraction methods and manifold learning technique. We build both theoretical model and real environment for verifying the feasibility and reliability. The experimental results show that the proposed indoor positioning system could achieve 99% coarse locating accuracy and enhance 15% fine positioning accuracy on average in a strong noisy environment compared with some typical fingerprinting based methods.

  19. Scanning gate microscopy of ultra clean carbon nanotube quantum dots

    OpenAIRE

    Xue, Jiamin; Dhall, Rohan; Cronin, Stephen B.; LeRoy, Brian J.

    2015-01-01

    We perform scanning gate microscopy on individual suspended carbon nanotube quantum dots. The size and position of the quantum dots can be visually identified from the concentric high conductance rings. For the ultra clean devices used in this study, two new effects are clearly identified. Electrostatic screening creates non-overlapping multiple sets of Coulomb rings from a single quantum dot. In double quantum dots, by changing the tip voltage, the interactions between the quantum dots can b...

  20. One Small Randomly Blinking Dot in an Otherwise Dark Environment: Effects on Visual Cortical Neurons of Kittens.

    Science.gov (United States)

    1982-06-23

    curvature, which provided a slight positive correction. The retinas were inspected with an ophthalmascope. Retinal landmarks were either back...stimulus had no moving features and flashed so briefly (10 msec) that not significant retinal slip would occur. In our five kittens who viewed the...a prothesis for the blind. J. Physiol 243: 553-76 Gordon B, Presson J, Packwood J, Scheer R (1979) Alteration of cortical orientation selectivity

  1. Expressive writing and positive writing for participants with mood disorders: an online randomized controlled trial.

    Science.gov (United States)

    Baikie, Karen A; Geerligs, Liesbeth; Wilhelm, Kay

    2012-02-01

    Expressive writing--writing about traumatic, stressful or emotional events--often leads to improvements in physical and psychological health in non-clinical and clinical populations. Recent studies have shown that positive writing may also be beneficial. Research has not yet investigated whether either expressive writing or positive writing offers benefits for people with mood disorders. Participants were recruited online and were randomly allocated to expressive writing, positive writing or control writing. The following questionnaires were completed online: Centre for Epidemiological Studies-Depression Scale (CES-D), Depression Anxiety Stress Scales (DASS), Pennebaker Inventory of Limbic Languidness (PILL), overall health questions, Temperament and Personality Questionnaire (TPQ) and COPE Inventory (COPE). Participants then wrote for 20 min on 4 occasions, and then completed follow-up questionnaires. Linear mixed models with custom contrasts were conducted to assess differences between groups and over time. All 3 groups showed significant improvements over time on mental health and some physical health outcomes. There were no significant differences between groups and no significant group by time interactions. These results were not moderated by demographic factors, personality subtypes or coping styles. The expressive writing, positive writing and time management control writing groups all reported significantly fewer mental and physical symptoms for at least 4 months post-writing. When expressive and positive writing groups were combined, the resulting `emotional writing group' showed significantly lower scores on the DASS stress subscale than the control writing group at all time-points. Potential reasons are discussed and areas of further study identified. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Rationale and design of mDOT-HuA study: a randomized trial to assess the effect of mobile-directly observed therapy on adherence to hydroxyurea in adults with sickle cell anemia in Tanzania

    Directory of Open Access Journals (Sweden)

    Abel Makubi

    2016-10-01

    Full Text Available Abstract Background Hydroxyurea (HU has been demonstrated to be efficacious in reducing complications in individuals with sickle cell anemia (SCA but poor adherence is a barrier. Directly Observed Therapy (DOT has been shown to improve adherence in various chronic diseases but there is limited data in adults with SCA. Methods and design To examine the effect of mobile-directly observed therapy (mDOT on adherence to HU (mDOT-HuA in adults with SCA at Muhimbili National Hospital in Tanzania. The mDOT-HuA study is a single centre, prospective, randomized, open label clinical trial. One-hundred individuals with SCA with haemoglobin SS genotype, aged ≥18 years, living in Dar es Salaam, able and willing to record and submit videos electronically will be included. Participants will be divided into two treatment arms; 50 in the standard monitoring (SM arm will receive mobile phones and fixed dose HU therapy with standard monitoring; 50 in the mDOT arm will receive mobile phones, fixed dose HU therapy with standard monitoring and a mobile directly observed web based medication adherence monitoring system. The primary outcome is the proportion of participants achieving ≥80 % HU adherence compared between the two arms as assessed through medication possession ratio at the end of 3 months of treatment. REDCap, an open source software application will be used to collect data using clinical research forms. The proportions of adherence in the two arms will be compared by Fisher’s exact test. Analysis of outcomes will have performed by both the intention-to treat and per-protocol methods. Discussion Should this study become sucessful, it will have the potential for the development of novel strategies for improving HU adherence in SCA. Trial registration ClinicalTrials.gov Identifier: NCT02844673 , registered on 25tht July 2016 (retrospectively registered.

  3. A novel single-order diffraction grating: Random position rectangle grating

    Science.gov (United States)

    Zuhua, Yang; Qiangqiang, Zhang; Jing, Wang; Quanping, Fan; Yuwei, Liu; Lai, Wei; Leifeng, Cao

    2016-05-01

    Spectral diagnosis of radiation from laser plasma interaction and monochromation of radiation source are hot and important topics recently. Grating is one of the primary optical elements to do this job. Although easy to fabricate, traditional diffraction grating suffers from multi-order diffraction contamination. On the other hand, sinusoidal amplitude grating has the nonharmonic diffraction property, but it is too difficult to fabricate, especially for x-ray application. A novel nonharmonic diffraction grating named random position rectangle grating (RPRG) is proposed in this paper. Theoretical analysis and experiment results show that the RPRG is both higher order diffraction suppressing and not difficult to fabricate. Additionally, it is highly efficient; its first order absolute theoretical diffraction efficiency reaches 4.1%. Our result shows that RPRG is a novel tool for radiation diagnosis and monochromation. Project supported by the National Natural Science Foundation of China (Grant No. 11375160) and the National Science Instruments Major Project of China (Grant No. 2012YQ130125).

  4. Promoting a positive transition to parenthood: a randomized clinical trial of couple relationship education.

    Science.gov (United States)

    Halford, W Kim; Petch, Jemima; Creedy, Debra K

    2010-03-01

    The transition to parenthood is often associated with a decline in couple relationship adjustment. Couples (n = 71) expecting their first child were randomly assigned to either: (a) Becoming a Parent (BAP), a maternal parenting education program; or (b) Couple CARE for Parents (CCP), a couple relationship and parenting education program. Couples were assessed pre-intervention (last trimester of pregnancy), post-intervention (5 months postpartum), and follow-up (12 months postpartum). Relative to BAP, CCP reduced negative couple communication from pre- to post-intervention, and prevented erosion of relationship adjustment and self-regulation in women but not men from pre-intervention to follow-up. Mean parenting stress reflected positive adjustment to parenthood with no differences between BAP and CCP. CCP shows promise as a brief program that can enhance couple communication and women's adjustment to parenthood.

  5. Positioning of aquatic animals based on time-of-arrival and random walk models using YAPS (Yet Another Positioning Solver)

    DEFF Research Database (Denmark)

    Baktoft, Henrik; Gjelland, Karl Øystein; Økland, Finn

    2017-01-01

    and error control. Feasibility and performance of YAPS was rigorously tested in a simulation study and by applying YAPS to data from an acoustic transmitter towed in a receiver array. Performance was compared to an alternative positioning model and proprietary software. The simulation study and field test......Aquatic positional telemetry offers vast opportunities to study in vivo behaviour of wild animals, but there is room for improvement in the data quality provided by current procedures for estimating positions. Here we present a novel positioning method called YAPS (Yet Another Positioning Solver......), involving Maximum Likelihood analysis of a state-space model applied directly to time of arrival (TOA) data in combination with a movement model. YAPS avoids the sequential positioning-filtering-approach applied in alternative tools by using all available data in a single model, and offers better accuracy...

  6. Effects of Positive Action on the emotional health of urban youth: a cluster-randomized trial.

    Science.gov (United States)

    Lewis, Kendra M; DuBois, David L; Bavarian, Niloofar; Acock, Alan; Silverthorn, Naida; Day, Joseph; Ji, Peter; Vuchinich, Samuel; Flay, Brian R

    2013-12-01

    We examined the effects of Positive Action (PA), a school-based social-emotional learning and health promotion program, on the emotional health of predominately low-income and ethnic minority urban youth. The study was a matched-pair, cluster-randomized controlled trial involving 14 Chicago public schools. Outcomes were assessed over a 6-year period of program implementation for a cohort of youth in each school, followed from grades 3 to 8. Youth reported on their emotional health (positive affect, life satisfaction, depression, anxiety) and social-emotional and character development. Growth-curve and structural-equation modeling analyses assessed overall program effects on the emotional health outcomes as well as mediation of these effects via the program's impact on youths' social-emotional and character development. Students in PA schools, compared with those in control schools, had more favorable change over the course of the study in positive affect (standardized mean difference effect size [ES] = .17) and life satisfaction (ES = .13) as well as significantly lower depression (ES = -.14) and anxiety (ES = -.26) at study end point. Program effects for positive affect, depression, and anxiety were mediated by more favorable change over time in social-emotional and character development for students in PA schools. Results suggest that universal, school-based programs can benefit the emotional health of youth in low-income, urban settings. The modest magnitude of effects over an extended period of program implementation, however, reflects the challenges of both mounting interventions and offsetting formidable risks for mental health problems in such environments. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  7. Visible Persistence of Single-Transient Random Dot Patterns: Spatial Parameters Affect the Duration of Fading Percepts.

    Directory of Open Access Journals (Sweden)

    Maximilian Bruchmann

    Full Text Available Visible persistence refers to the continuation of visual perception after the physical termination of a stimulus. We studied an extreme case of visible persistence by presenting two matrices of randomly distributed black and white pixels in succession. On the transition from one matrix to the second, the luminance polarity of all pixels within a disk- or annulus-shaped area reversed, physically creating a single second-order transient signal. This transient signal produces the percept of a disk or an annulus with an abrupt onset and a gradual offset. To study the nature of this fading percept we varied spatial parameters, such as the inner and the outer diameter of annuli (Experiment I and the radius and eccentricity of disks (Experiment III, and measured the duration of visible persistence by having subjects adjust the synchrony of the onset of a reference stimulus with the onset or the offset of the fading percept. We validated this method by comparing two modalities of the reference stimuli (Experiment I and by comparing the judgments of fading percepts with the judgments of stimuli that actually fade in luminance contrast (Experiment II. The results show that (i irrespective of the reference modality, participants are able to precisely judge the on- and the offsets of the fading percepts, (ii auditory reference stimuli lead to higher visible persistence durations than visual ones, (iii visible persistence duration increases with the thickness of annuli and the diameter of disks, but decreases with the diameter of annuli, irrespective of stimulus eccentricity. These effects cannot be explained by stimulus energy, which suggests that more complex processing mechanisms are involved. Seemingly contradictory effects of disk and annulus diameter can be unified by assuming an abstract filling-in mechanism that speeds up with the strength of the edge signal and takes more time the larger the stimulus area is.

  8. A Web-Based Adolescent Positive Psychology Program in Schools: Randomized Controlled Trial.

    Science.gov (United States)

    Burckhardt, Rowan; Manicavasagar, Vijaya; Batterham, Philip J; Miller, Leonie M; Talbot, Elizabeth; Lum, Alistair

    2015-07-28

    Adolescent mental health is characterized by relatively high rates of psychiatric disorders and low levels of help-seeking behaviors. Existing mental health programs aimed at addressing these issues in adolescents have repeated inconsistent results. Such programs have generally been based on techniques derived from cognitive behavioral therapy, which may not be ideally suited to early intervention among adolescent samples. Positive psychology, which seeks to improve well-being rather than alleviate psychological symptoms, offers an alternative approach. A previous community study of adolescents found that informal engagement in an online positive psychology program for up to 6 weeks yielded significant improvements in both well-being and depression symptoms. However, this approach had not been trialed among adolescents in a structured format and within a school setting. This study examines the feasibility of an online school-based positive psychology program delivered in a structured format over a 6-week period utilizing a workbook to guide students through website content and interactive exercises. Students from four high schools were randomly allocated by classroom to either the positive psychology condition, "Bite Back", or the control condition. The Bite Back condition consisted of positive psychology exercises and information, while the control condition used a series of non-psychology entertainment websites. Both interventions were delivered online for 6 hours over a period of 4-6 weeks during class time. Symptom measures and measures of well-being/flourishing and life satisfaction were administered at baseline and post intervention. Data were analyzed using multilevel linear modeling. Both conditions demonstrated reductions in depression, stress, and total symptom scores without any significant differences between the two conditions. Both the Bite Back and control conditions also demonstrated significant improvements in life satisfaction scores post

  9. A Web-Based Adolescent Positive Psychology Program in Schools: Randomized Controlled Trial

    Science.gov (United States)

    Manicavasagar, Vijaya; Batterham, Philip J; Miller, Leonie M; Talbot, Elizabeth; Lum, Alistair

    2015-01-01

    Background Adolescent mental health is characterized by relatively high rates of psychiatric disorders and low levels of help-seeking behaviors. Existing mental health programs aimed at addressing these issues in adolescents have repeated inconsistent results. Such programs have generally been based on techniques derived from cognitive behavioral therapy, which may not be ideally suited to early intervention among adolescent samples. Positive psychology, which seeks to improve well-being rather than alleviate psychological symptoms, offers an alternative approach. A previous community study of adolescents found that informal engagement in an online positive psychology program for up to 6 weeks yielded significant improvements in both well-being and depression symptoms. However, this approach had not been trialed among adolescents in a structured format and within a school setting. Objective This study examines the feasibility of an online school-based positive psychology program delivered in a structured format over a 6-week period utilizing a workbook to guide students through website content and interactive exercises. Methods Students from four high schools were randomly allocated by classroom to either the positive psychology condition, "Bite Back", or the control condition. The Bite Back condition consisted of positive psychology exercises and information, while the control condition used a series of non-psychology entertainment websites. Both interventions were delivered online for 6 hours over a period of 4-6 weeks during class time. Symptom measures and measures of well-being/flourishing and life satisfaction were administered at baseline and post intervention. Results Data were analyzed using multilevel linear modeling. Both conditions demonstrated reductions in depression, stress, and total symptom scores without any significant differences between the two conditions. Both the Bite Back and control conditions also demonstrated significant improvements in

  10. Existence Results for a Michaud Fractional, Nonlocal, and Randomly Position Structured Fragmentation Model

    Directory of Open Access Journals (Sweden)

    Emile Franc Doungmo Goufo

    2014-01-01

    Full Text Available Until now, classical models of clusters’ fission remain unable to fully explain strange phenomena like the phenomenon of shattering (Ziff and McGrady, 1987 and the sudden appearance of infinitely many particles in some systems having initial finite number of particles. That is why there is a need to extend classical models to models with fractional derivative order and use new and various techniques to analyze them. In this paper, we prove the existence of strongly continuous solution operators for nonlocal fragmentation models with Michaud time derivative of fractional order (Samko et al., 1993. We focus on the case where the splitting rate is dependent on size and position and where new particles generating from fragmentation are distributed in space randomly according to some probability density. In the analysis, we make use of the substochastic semigroup theory, the subordination principle for differential equations of fractional order (Prüss, 1993, Bazhlekova, 2000, the analogy of Hille-Yosida theorem for fractional model (Prüss, 1993, and useful properties of Mittag-Leffler relaxation function (Berberan-Santos, 2005. We are then able to show that the solution operator to the full model is positive and contractive.

  11. Promoting Afterschool Quality and Positive Youth Development: Cluster Randomized Trial of the Pax Good Behavior Game.

    Science.gov (United States)

    Smith, Emilie Phillips; Osgood, D Wayne; Oh, Yoonkyung; Caldwell, Linda C

    2018-02-01

    This randomized trial tested a strategy originally developed for school settings, the Pax Good Behavior Game (PAX GBG), in the new context of afterschool programs. We examined this approach in afterschool since 70% of all juvenile crime occurs between the hours of 3-6 pm, making afterschool an important setting for prevention and promotion. Dual-career and working families need monitoring and supervision for their children in quality settings that are safe and appropriately structured. While substantial work has identified important features of afterschool programs, increasing attention is being given to how to foster quality. PAX GBG, with its focus on shared norms, cooperative teams, contingent activity rewards, and liberal praise, could potentially enhance not only appropriate structure and supportive relationships, but also youth self-regulation, co-regulation, and socio-emotional development. This study examined the PAX GBG among 76 afterschool programs, serving 811 youth ages 5-12, who were diverse in race-ethnicity, socio-economic status, and geographic locale. Demographically matched pairs of afterschool programs were randomized to PAX GBG or treatment-as-usual. Independent observers conducted ratings of implementation fidelity and program quality across time; along with surveys of children's problem and prosocial behavior. Interaction effects were found using hierarchical linear models such that experimental programs evidencing higher implementation fidelity demonstrated better program quality than controls, (i.e., less harshness, increased appropriate structure, support, and engagement), as well as reduced child-reported hyperactivity and intent-to-treat effects on prosocial behavior. This study demonstrates that best practices fostered by PAX GBG and implemented with fidelity in afterschool result in higher quality contexts for positive youth development.

  12. Enhanced single photon emission from positioned InP/GaInP quantum dots coupled to a confined Tamm-plasmon mode

    Energy Technology Data Exchange (ETDEWEB)

    Braun, T.; Baumann, V.; Iff, O.; Schneider, C.; Kamp, M. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); Höfling, S. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg (Germany); SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS (United Kingdom)

    2015-01-26

    We report on the enhancement of the spontaneous emission in the visible red spectral range from site-controlled InP/GaInP quantum dots by resonant coupling to Tamm-plasmon modes confined beneath gold disks in a hybrid metal/semiconductor structure. The enhancement of the emission intensity is confirmed by spatially resolved micro-photoluminescence area scans and temperature dependent measurements. Single photon emission from our coupled system is verified via second order autocorrelation measurements. We observe bright single quantum dot emission of up to ∼173 000 detected photons per second at a repetition rate of the excitation source of 82 MHz, and calculate an extraction efficiency of our device as high as 7%.

  13. Positive psychotherapy for depression and self-efficacy in undergraduate nursing students: A randomized, controlled trial.

    Science.gov (United States)

    Guo, Yu-Fang; Zhang, Xia; Plummer, Virginia; Lam, Louisa; Cross, Wendy; Zhang, Jing-Ping

    2017-08-01

    Nursing students across the globe experience depressive symptoms, and many interventions have been used to alleviate their depression. However, few interventions focus on students' personal strengths and advantages. The aim of the present study was to explore the effects of an 8-week group positive psychotherapy (PPT) programme on depression and self-efficacy in full-time undergraduate nursing students. A randomized, controlled trial was conducted for 76 nursing students (34 in the experimental group, 42 in the control group). The Beck Depression Inventory-II and the General Self-Efficacy Scale were used to collect data prior to, immediately after PPT, 3 months', and 6 months' post-PPT. Repeated-measures analysis of variance indicated that the intervention significantly alleviated depression and improved self-efficacy (each P self-efficacy. We recommend that PPT is effective in alleviating depression and improving self-efficacy in undergraduate nursing students. Academic mental health nurses should appreciate the value of PPT and consider incorporating it in psychological support methods in order to facilitate nursing students' mental health. © 2016 Australian College of Mental Health Nurses Inc.

  14. Proteome Analysis of Thyroid Cancer Cells After Long-Term Exposure to a Random Positioning Machine

    Science.gov (United States)

    Pietsch, Jessica; Bauer, Johann; Weber, Gerhard; Nissum, Mikkel; Westphal, Kriss; Egli, Marcel; Grosse, Jirka; Schönberger, Johann; Eilles, Christoph; Infanger, Manfred; Grimm, Daniela

    2011-11-01

    Annulling gravity during cell culturing triggers various types of cells to change their protein expression in a time dependent manner. We therefore decided to determine gravity sensitive proteins and their period of sensitivity to the effects of gravity. In this study, thyroid cancer cells of the ML-1 cell line were cultured under normal gravity (1 g) or in a random positioning machine (RPM), which simulated near weightlessness for 7 and 11 days. Cells were then sonicated and proteins released into the supernatant were separated from those that remained attached to the cell fragments. Subsequently, both types of proteins were fractionated by free-flow isoelectric focussing (FF-IEF). The fractions obtained were further separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to which comparable FF-IEF fractions derived from cells cultured either under 1 g or on the RPM had been applied side by side. The separation resulted in pairs of lanes, on which a number of identical bands were observed. Selected gel pieces were excised and their proteins determined by mass spectrometry. Equal proteins from cells cultured under normal gravity and the RPM, respectively, were detected in comparable gel pieces. However, many of these proteins had received different Mascot scores. Quantifying heat shock cognate 71 kDa protein, glutathione S-transferase P, nucleoside diphosphate kinase A and annexin-2 by Western blotting using whole cell lysates indicated usefulness of Mascot scores for selecting the most efficient antibodies.

  15. DOT's CAFE rulemaking analysis.

    Science.gov (United States)

    2013-02-13

    Presentation discusses what DOT needs to consider in setting CAFE standards. How DOT's use of the CAFE Compliance and Effects Modeling System helps to analyze potential CAFE Standards. How DOT might approach the next round of CAFE standards for model...

  16. Climbing Has a Positive Impact on Low Back Pain: A Prospective Randomized Controlled Trial.

    Science.gov (United States)

    Schinhan, Martina; Neubauer, Benedikt; Pieber, Karin; Gruber, Michael; Kainberger, Franz; Castellucci, Clara; Olischar, Boris; Maruna, Andrea; Windhager, Reinhard; Sabeti-Aschraf, Manuel

    2016-05-01

    Comparison of climbing versus no treatment to treat chronic low back pain. Prospective randomized controlled trial. Tertiary. A total of 30 patients with chronic low back pain were recruited and randomly assigned to 2 different groups: climbing and control. The inclusion criteria were defined as chronic low back pain, age between 18 and 45 years, body mass index lower than 25, and no climbing experience. Patients in the climbing group were instructed to climb 5 different climbing routes. A climbing activity of 10 sessions in 8 weeks, at least once a week with a minimum duration of 1 hour, was mandatory. The participants were examined before (T0) and after therapy (8 weeks, T8) and after another 6 weeks (T14). The outcome was evaluated using Oswestry Disability Index, Visual Analog Scale (VAS), Likert scale, and magnetic resonance imaging (MRI). Radiologists evaluating MRI were blinded. The study was performed as a single-center study. Evaluating the Oswestry Disability Index, a significant difference in the time course between the 2 groups was detected (P = 0.022). Significant improvements comparing climbing and control group were also found when assessing VAS in a minimal finger-floor-distance position (P = 0.048). Patients in the climbing group showed a reduction in size of disc protrusion. Climbing may be an effective and low-cost therapy option for people with chronic low back pain. Low back pain is a very common disease but still a challenge to treat. Therapy strategies vary from conservative ones, pharmacological treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and weak opioids, to invasive treatment with acupuncture, injections, and operative reconstruction. Some can be costly and not without risks. For instance, many people who use NSAIDs are at risk of common side effects such as gastrointestinal complications (irritation, ulcers, and bleeding) that may lead to hospitalization. Climbing could offer reduction of pain and better performance in

  17. Noninvasive positive pressure ventilation in subjects with stable COPD: a randomized trial

    Directory of Open Access Journals (Sweden)

    Bhatt SP

    2013-11-01

    Full Text Available Surya P Bhatt,1 Michael W Peterson,2 Jeffrey S Wilson,1 Lakshmi Durairaj1 1Division of Pulmonary, Critical Care, and Occupational Medicine, Department of Internal Medicine, Roy J and Lucille A, Carver College of Medicine, University of Iowa Hospital, Iowa City, IA, USA; 2Department of Medicine, UCSF Fresno Medical Education Program, Fresno, CA, USA Background: The use of domiciliary noninvasive positive pressure ventilation (NPPV in stable chronic obstructive pulmonary disease (COPD with chronic hypercapnic respiratory failure has yielded variable effects on survival, quality of life, and dyspnea. We hypothesized that use of NPPV in stable COPD and partial pressure of carbon dioxide (PaCO2 <52 mmHg might result in improvement in quality of life and dyspnea. Methods: Thirty patients with stable COPD (forced expiratory volume in the first second <50% predicted and PaCO2 <52 mmHg were prospectively randomized to receive domiciliary NPPV (bilevel positive airway pressure, 15/5 cm H2O or usual therapy for 6 months. Measurements were made at baseline, 6 weeks, 3 months, and 6 months. Primary outcomes were quality of life as assessed by the Chronic Respiratory Disease Questionnaire (CRQ, and dyspnea as measured by the Transitional Dyspnea Index (TDI. Results: Fifteen subjects in the NPPV arm and 12 controls completed all the study visits. At 6 weeks and 3 months, the NPPV arm showed significant improvement in TDI total score. However, this effect persisted only in the TDI-Task at 6 months (P=0.03. NPPV use was associated with a small improvement in the CRQ-Mastery domain (0.6 versus –0.1, P=0.04. The arterial partial pressure of oxygen (PaO2 in the control arm worsened over the period of the study, whereas it remained stable in the NPPV arm (change –7.2 mmHg versus +2.1 mmHg, respectively, P=0.02. Conclusion: NPPV resulted in a small improvement in quality of life indices in stable COPD patients with PaCO2 <52 mmHg. Future larger studies will

  18. An analysis of noise reduction in variable reluctance motors using pulse position randomization

    Science.gov (United States)

    Smoot, Melissa C.

    1994-05-01

    The design and implementation of a control system to introduce randomization into the control of a variable reluctance motor (VRM) is presented. The goal is to reduce noise generated by radial vibrations of the stator. Motor phase commutation angles are dithered by 1 or 2 mechanical degrees to investigate the effect of randomization on acoustic noise. VRM commutation points are varied using a uniform probability density function and a 4 state Markov chain among other methods. The theory of VRM and inverter operation and a derivation of the major source of acoustic noise are developed. The experimental results show the effects of randomization. Uniform dithering and Markov chain dithering both tend to spread the noise spectrum, reducing peak noise components. No clear evidence is found to determine which is the optimum randomization scheme. The benefit of commutation angle randomization in reducing VRM loudness as perceived by humans is found to be questionable.

  19. Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation

    Directory of Open Access Journals (Sweden)

    Daniela Franco Rizzo Komatsu

    Full Text Available Summary Objective: To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV and continuous positive airway pressure (nCPAP. Method: Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA ≤ 36 weeks and birth weight (BW > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Results: Among the 36 premature infants randomized to nIPPV, six (16.6% presented extubation failure in comparison to 11 (30.5% of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. Conclusion: We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

  20. Oral appliance therapy versus nasal continuous positive airway pressure in obstructive sleep apnea: a randomized, placebo-controlled trial

    NARCIS (Netherlands)

    Aarab, G.; Lobbezoo, F.; Hamburger, H.L.; Naeije, M.

    2011-01-01

    Background: Previous randomized controlled trials have addressed the efficacy of mandibular advancement devices (MADs) in the treatment of obstructive sleep apnea (OSA). Their common control condition, nasal continuous positive airway pressure (nCPAP), was frequently found to be superior to MAD

  1. Video-Feedback Intervention to Promote Positive Parenting Adapted to Autism (VIPP-AUTI): A Randomized Controlled Trial

    Science.gov (United States)

    Poslawsky, Irina E; Naber, Fabiënne BA; Bakermans-Kranenburg, Marian J; van Daalen, Emma; van Engeland, Herman; van IJzendoorn, Marinus H

    2015-01-01

    In a randomized controlled trial, we evaluated the early intervention program Video-feedback Intervention to promote Positive Parenting adapted to Autism (VIPP-AUTI) with 78 primary caregivers and their child (16-61 months) with Autism Spectrum Disorder. VIPP-AUTI is a brief attachment-based intervention program, focusing on improving parent-child…

  2. [Wuling Capsule for climacteric patients with depression and anxiety state: a randomized, positive parallel controlled trial].

    Science.gov (United States)

    Wang, Xing-juan; Li, Ji; Zou, Qin-di; Jin, Ling

    2009-11-01

    The incidence of menopausal anxiety and depression is increasing. It can induce and aggravate a variety of somatic symptoms. Despite of the good effects of psychotropic drugs on the disease, patients' compliance is poor. Therefore, it is necessary to find a drug which is practical, effective, and easy for patients to take. To evaluate the efficacy of Wuling Capsule (WC), a Chinese herbal medicine, in treatment of female climacteric syndrome with depression and anxiety state. A total of 96 outpatients of female climacteric syndrome from Department of Gynecology of Integrated Traditional Chinese and Western Medicine, Huashan Hospital, Fudan University, Department of Gynecology of Traditional Chinese Medicine, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, and Department of Traditional Chinese Medicine, Obstetrics and Gynecology Hospital, Fudan University were included. The study was designed as a randomized, positive drug parallel controlled trial. The patients were divided into WC group (64 cases) and control group (32 cases) and were orally administered Wuling Capsule and Gengnianan Tablet, respectively. The efficacy was evaluated with Kupperman menopausal index (KMI), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS) before treatment, and after 3-week and 6-week treatment. The total response rate was 89.66% (52/58) in the WC group, which was superior to that in the control group [76.67% (23/30)]. Ridit test showed that there was a significant difference between the two groups (P<0.05). Kupperman score of the two groups decreased markedly after the treatment (P<0.01), but there was no statistical difference between the two groups. The scales of SAS and SDS in both groups were improved obviously after the treatment (P<0.01). Covariance analysis showed that the decrease of SAS score in the WC group was more significant than that in the control group after 3- and 6-week treatment (P<0.05, P<0.01), but the SDS score was

  3. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra.Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dots states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  4. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra. Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dot states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  5. Rationale and design of the Staying Positive with Arthritis (SPA) Study: A randomized controlled trial testing the impact of a positive psychology intervention on racial disparities in pain.

    Science.gov (United States)

    Hausmann, Leslie R M; Ibrahim, Said A; Kwoh, C Kent; Youk, Ada; Obrosky, D Scott; Weiner, Debra K; Vina, Ernest; Gallagher, Rollin M; Mauro, Genna T; Parks, Acacia

    2018-01-01

    Knee osteoarthritis is a painful, disabling condition that disproportionately affects African Americans. Existing arthritis treatments yield small to moderate improvements in pain and have not been effective at reducing racial disparities in the management of pain. The biopsychosocial model of pain and evidence from the positive psychology literature suggest that increasing positive psychological skills (e.g., gratitude, kindness) could improve pain and functioning and reduce disparities in osteoarthritis pain management. Activities to cultivate positive psychological skills have been developed and validated; however, they have not been tested in patients with osteoarthritis, their effects on racial differences in health outcomes have not been examined, and evidence of their effects on health outcomes in patients with other chronic illnesses is of limited quality. In this article we describe the rationale and design of Staying Positive with Arthritis (SPA) study, a randomized controlled trial in which 180 African American and 180 White primary care patients with chronic pain from knee osteoarthritis will be randomized to a 6-week program of either positive skill-building activities or neutral control activities. The primary outcomes will be self-reported pain and functioning as measured by the WOMAC Osteoarthritis Index. We will assess these primary outcomes and potential, exploratory psychosocial mediating variables at an in-person baseline visit and by telephone at 1, 3, and 6months following completion of the assigned program. If effective, the SPA program would be a novel, theoretically-informed psychosocial intervention to improve quality and equity of care in the management of chronic pain from osteoarthritis. Published by Elsevier Inc.

  6. Connecting dots

    DEFF Research Database (Denmark)

    Murakami, Kyoko; Jacobs, Rachel L.

    2017-01-01

    and Middleton, 1995). A reminiscence conversation is a dynamic talk-in-interaction, which can produce valuable learning experience for the participants involved. Reminiscence talk contains rich, personal, historic data that can reveal and inform family members of an unknown past. In this seminar/chapter, we......Reminiscence is a self-reflecting process on past events and experiences. Not only does it enable past experiences to be brought to light through talk, but it also creates an affective environment, which allows participants to explore and construct a representation of the self (Buchanan...... of connecting the dots of recalled moments of individual family members lives and is geared towards building a family’s shared future for posterity. Lastly, we consider a wider implication of family reminiscence in terms of human development. http://www.infoagepub.com/products/Memory-Practices-and-Learning...

  7. Positive psychology interventions: a meta-analysis of randomized controlled studies

    National Research Council Canada - National Science Library

    Bolier, L; Haverman, M; Westerhof, G.J; Riper, H; Smit, H.F.E; Bohlmeijer, E

    2013-01-01

    .... The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for individuals with specific psychosocial problems...

  8. Occupation Time of a Randomly Accelerated Particle on the Positive Half Axis: Results for the First Five Moments

    Science.gov (United States)

    Burkhardt, Theodore W.

    2017-11-01

    In the random acceleration process a point particle is accelerated by Gaussian white noise with zero mean. Although several fundamental statistical properties of the motion have been analyzed in detail, the statistics of occupation times is still not well understood. We consider the occupation or residence time T_+ on the positive x axis of a particle which is randomly accelerated on the unbounded x axis for a time t. The first two moments of T_+ were recently derived by Ouandji Boutcheng et al. (J Stat Mech 053213:1-10, 2016). With an alternate approach utilizing basis functions which have proved useful in other studies of randomly accelerated motion, results for the first five moments are obtained in this paper.

  9. Occupation Time of a Randomly Accelerated Particle on the Positive Half Axis: Results for the First Five Moments

    Science.gov (United States)

    Burkhardt, Theodore W.

    2017-10-01

    In the random acceleration process a point particle is accelerated by Gaussian white noise with zero mean. Although several fundamental statistical properties of the motion have been analyzed in detail, the statistics of occupation times is still not well understood. We consider the occupation or residence time T_+ on the positive x axis of a particle which is randomly accelerated on the unbounded x axis for a time t. The first two moments of T_+ were recently derived by Ouandji Boutcheng et al. (J Stat Mech 053213:1-10, 2016). With an alternate approach utilizing basis functions which have proved useful in other studies of randomly accelerated motion, results for the first five moments are obtained in this paper.

  10. Positive psychology interventions: A meta-analysis of randomized controlled studies

    NARCIS (Netherlands)

    Bolier, Linda; Haverman, M.; Westerhof, Gerben Johan; Riper, H.; Smit, F.; Bohlmeijer, Ernst Thomas

    2013-01-01

    Background The use of positive psychological interventions may be considered as a complementary strategy in mental health promotion and treatment. The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for

  11. Positive Psychology Interventions Addressing Pleasure, Engagement, Meaning, Positive Relationships, and Accomplishment Increase Well-Being and Ameliorate Depressive Symptoms: A Randomized, Placebo-Controlled Online Study

    Science.gov (United States)

    Gander, Fabian; Proyer, René T.; Ruch, Willibald

    2016-01-01

    Seligman (2002) suggested three paths to well-being, the pursuit of pleasure, the pursuit of meaning, and the pursuit of engagement, later adding two more, positive relationships and accomplishment, in his 2011 version. The contribution of these new components to well-being has yet to be addressed. In an online positive psychology intervention study, we randomly assigned 1624 adults aged 18–78 (M = 46.13; 79.2% women) to seven conditions. Participants wrote down three things they related to either one of the five components of Seligman's Well-Being theory (Conditions 1–5), all of the five components (Condition 6) or early childhood memories (placebo control condition). We assessed happiness (AHI) and depression (CES-D) before and after the intervention, and 1-, 3-, and 6 months afterwards. Additionally, we considered moderation effects of well-being levels at baseline. Results confirmed that all interventions were effective in increasing happiness and most ameliorated depressive symptoms. The interventions worked best for those in the middle-range of the well-being continuum. We conclude that interventions based on pleasure, engagement, meaning, positive relationships, and accomplishment are effective strategies for increasing well-being and ameliorating depressive symptoms and that positive psychology interventions are most effective for those people in the middle range of the well-being continuum. PMID:27242600

  12. Positive Psychology Interventions Addressing Pleasure, Engagement, Meaning, Positive Relationships, and Accomplishment Increase Well-Being and Ameliorate Depressive Symptoms: A Randomized, Placebo-Controlled Online Study.

    Science.gov (United States)

    Gander, Fabian; Proyer, René T; Ruch, Willibald

    2016-01-01

    Seligman (2002) suggested three paths to well-being, the pursuit of pleasure, the pursuit of meaning, and the pursuit of engagement, later adding two more, positive relationships and accomplishment, in his 2011 version. The contribution of these new components to well-being has yet to be addressed. In an online positive psychology intervention study, we randomly assigned 1624 adults aged 18-78 (M = 46.13; 79.2% women) to seven conditions. Participants wrote down three things they related to either one of the five components of Seligman's Well-Being theory (Conditions 1-5), all of the five components (Condition 6) or early childhood memories (placebo control condition). We assessed happiness (AHI) and depression (CES-D) before and after the intervention, and 1-, 3-, and 6 months afterwards. Additionally, we considered moderation effects of well-being levels at baseline. Results confirmed that all interventions were effective in increasing happiness and most ameliorated depressive symptoms. The interventions worked best for those in the middle-range of the well-being continuum. We conclude that interventions based on pleasure, engagement, meaning, positive relationships, and accomplishment are effective strategies for increasing well-being and ameliorating depressive symptoms and that positive psychology interventions are most effective for those people in the middle range of the well-being continuum.

  13. Randomized trial of prongs or mask for nasal continuous positive airway pressure in preterm infants.

    LENUS (Irish Health Repository)

    Kieran, Emily A

    2012-11-01

    To determine whether nasal continuous positive airway pressure (NCPAP) given with nasal prongs compared with nasal mask reduces the rate of intubation and mechanical ventilation in preterm infants within 72 hours of starting therapy.

  14. Optimal positions and parameters of translational and rotational mass dampers in beams subjected to random excitation

    Science.gov (United States)

    Łatas, Waldemar

    2018-01-01

    The problem of vibrations of the beam with the attached system of translational and rotational dynamic mass dampers subjected to random excitations with peaked power spectral densities, is presented in the hereby paper. The Euler-Bernoulli beam model is applied, while for solving the equation of motion the Galerkin method and the Laplace time transform are used. The obtained transfer functions allow to determine power spectral densities of the beam deflection and other dependent variables. Numerical examples present simple optimization problems of mass dampers parameters for local and global objective functions.

  15. Positive psychology interventions: a meta-analysis of randomized controlled studies.

    Science.gov (United States)

    Bolier, Linda; Haverman, Merel; Westerhof, Gerben J; Riper, Heleen; Smit, Filip; Bohlmeijer, Ernst

    2013-02-08

    The use of positive psychological interventions may be considered as a complementary strategy in mental health promotion and treatment. The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for individuals with specific psychosocial problems. We conducted a systematic literature search using PubMed, PsychInfo, the Cochrane register, and manual searches. Forty articles, describing 39 studies, totaling 6,139 participants, met the criteria for inclusion. The outcome measures used were subjective well-being, psychological well-being and depression. Positive psychology interventions included self-help interventions, group training and individual therapy. The standardized mean difference was 0.34 for subjective well-being, 0.20 for psychological well-being and 0.23 for depression indicating small effects for positive psychology interventions. At follow-up from three to six months, effect sizes are small, but still significant for subjective well-being and psychological well-being, indicating that effects are fairly sustainable. Heterogeneity was rather high, due to the wide diversity of the studies included. Several variables moderated the impact on depression: Interventions were more effective if they were of longer duration, if recruitment was conducted via referral or hospital, if interventions were delivered to people with certain psychosocial problems and on an individual basis, and if the study design was of low quality. Moreover, indications for publication bias were found, and the quality of the studies varied considerably. The results of this meta-analysis show that positive psychology interventions can be effective in the enhancement of subjective well-being and psychological well-being, as well as in helping to reduce depressive symptoms. Additional high-quality peer-reviewed studies in diverse (clinical) populations are needed to strengthen the evidence-base for positive

  16. Enhancing positive parent-child interactions and family functioning in a poverty sample: a randomized control trial.

    Science.gov (United States)

    Negrão, Mariana; Pereira, Mariana; Soares, Isabel; Mesman, Judi

    2014-01-01

    This study tested the attachment-based intervention program Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD) in a randomized controlled trial with poor families of toddlers screened for professional's concerns about the child's caregiving environment. The VIPP-SD is an evidence-based intervention, but has not yet been tested in the context of poverty. The sample included 43 families with 1- to 4-year-old children: mean age at the pretest was 29 months and 51% were boys. At the pretest and posttest, mother-child interactions were observed at home, and mothers reported on family functioning. The VIPP-SD proved to be effective in enhancing positive parent-child interactions and positive family relations in a severely deprived context. Results are discussed in terms of implications for support services provided to such poor families in order to reduce intergenerational risk transmission.

  17. Motivational Interviewing (MINT) Improves Continuous Positive Airway Pressure (CPAP) Acceptance and Adherence: A Randomized Controlled Trial

    Science.gov (United States)

    Olsen, Sara; Smith, Simon S.; Oei, Tian P. S.; Douglas, James

    2012-01-01

    Objective: Adherence to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA) is poor. We assessed the effectiveness of a motivational interviewing intervention (motivational interview nurse therapy [MINT]) in addition to best practice standard care to improve acceptance and adherence to CPAP therapy in people with…

  18. Positive Psychology Intervention to Alleviate Child Depression and Increase Life Satisfaction: A Randomized Clinical Trial

    Science.gov (United States)

    Kwok, Sylvia Y. C. L.; Gu, Minmin; Kit, Katrina Tong Kai

    2016-01-01

    Purpose: The study aims to examine the effectiveness of a positive psychology group-based intervention program, incorporating elements of hope and gratitude, in decreasing depression and increasing life satisfaction among primary school students in Hong Kong. Method: A total of 68 children, with the Depression score of Chinese Hospital Anxiety and…

  19. Exploring daily affective changes in university students with a mindful positive reappraisal intervention: A daily diary randomized controlled trial.

    Science.gov (United States)

    Pogrebtsova, Ekaterina; Craig, Jacqueline; Chris, Alexandra; O'Shea, Deirdre; González-Morales, M Gloria

    2017-05-17

    Brief and cost-effective interventions focused on emotion regulation techniques can buffer against stress and foster positive functioning. Mindfulness and positive reappraisal are two techniques that can mutually enhance one another to promote well-being. However, research testing the effectiveness of interventions combining mindfulness and reappraisal is lacking. The current pilot examined the effect of a combined mindful-reappraisal intervention on daily affect in a 5-day diary study with 106 university students. Participants were randomized to a mindful-reappraisal intervention (n = 36), a reappraisal-only intervention (n = 34), or an active control activity (n = 36). All participants described a negative event each day but only reappraised the event in the intervention conditions. Using multilevel growth modelling, results indicated that negative affect in both interventions declined over 5 days compared to the control; however, there were no differences in the growth of positive affect. Compared to reappraisal-only, the mindful-reappraisal group reported overall lower daily negative affect and marginally higher daily positive affect over the 5-day intervention. These findings suggest that brief daily practice combining mindfulness and positive reappraisal can be trained as a self-regulatory resource to promote positive affect and buffer negative affect above and beyond reappraisal practice alone. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Check it! A randomized pilot of a positive psychology intervention to improve adherence in adolescents with type 1 diabetes.

    Science.gov (United States)

    Jaser, Sarah S; Patel, Niral; Rothman, Russell L; Choi, Leena; Whittemore, Robin

    2014-01-01

    The purpose of the current study was to pilot-test a positive psychology intervention to improve adherence to diabetes management in adolescents with type 1 diabetes. A total of 39 adolescents (ages, 13-17 years) with type 1 diabetes and their caregivers were randomized to a positive psychology intervention (n = 20) or an attention control (education) intervention (n = 19). The intervention condition used positive psychology exercises (eg, gratitude, self-affirmation), small gifts, and parent affirmations to boost positive affect. Outcomes included frequency of blood glucose monitoring, quality of life, and glycemic control. No main effects for treatment were observed at the 6-month follow-up. However, there was a significant association between adolescents' levels of positive affect and measures of adherence, including self-report and meter downloads of glucose monitoring. The results from the current study support the assertion that positive affect in the context of diabetes education is an important factor to consider in adolescents with type 1 diabetes. © 2014 The Author(s).

  1. A randomized in-place algorith for positioning the k\\'th element in a multiset

    DEFF Research Database (Denmark)

    Katajainen, Jyrki; Pasanen, Tomi A.

    2002-01-01

    for all j, 1 = j space even if the input contains equal elements and if only pairwise element comparisons are permitted....... To be more precise, the algorithm solves the positioning problem in-place in linear time using at most n + k + o(n) element comparisons, k + o(n) element exchanges, and the probability for succeeding within stated time bounds is at least 1-e-nO(1)....

  2. Continuous non-invasive monitoring improves blood pressure stability in upright position: randomized controlled trial.

    Science.gov (United States)

    Benes, Jan; Simanova, Alena; Tovarnicka, Tereza; Sevcikova, Silvie; Kletecka, Jakub; Zatloukal, Jan; Pradl, Richard; Chytra, Ivan; Kasal, Eduard

    2015-02-01

    Intermittent blood pressure (BP) monitoring is the standard-of-care during low and intermediate risk anaesthesia, yet it could lead to delayed recognition of BP fluctuations. Perioperative hypotension is known to be associated with postoperative complications. Continuous, non-invasive methods for BP monitoring have been developed recently. We have tested a novel non-invasive, continuous monitor (using the volume clamp method) to assist with maintaining BP in safe ranges for patients undergoing surgery in a beach chair position. Forty adult patients undergoing thyroid gland surgery in an upright position were included in this prospective randomised controlled trial. Patients were equally allocated to the group with continuous monitoring of BP using the CNAP® Monitor and to the control group managed using an intermittent oscillometric BP cuff. The absolute and proportional time spent outside the range of ±20% of the target BP along with other hemodynamic and clinical parameters were evaluated. The continuous monitoring decreased the anaesthesia time spent below -20% pressure range [absolute: 12 min (4-20) vs. 27 min (16-34); p=0.001; relative to procedure length: 14% (7-20) vs. 33.5% (17.5-53); p=0.003]. No significant differences were observed in postoperative morbidity or in hospital length of stay. Continuous non-invasive BP monitoring via the CNAP® Monitor allows for better BP management in patients undergoing surgery in a beach chair position. In our randomised trial the time spent in hypotension was significantly shorter using continuous monitoring.

  3. Number of traps and trap depth position on statistical distribution of random telegraph noise in scaled NAND flash memory

    Science.gov (United States)

    Tomita, Toshihiro; Miyaji, Kousuke

    2016-04-01

    The dependence of random telegraph noise (RTN) amplitude distribution on the number of traps and trap depth position is investigated using three-dimensional Monte Carlo device simulation including random dopant fluctuation (RDF) in a 30 nm NAND multi level flash memory. The ΔV th tail distribution becomes broad at fixed double traps, indicating that the number of traps greatly affects the worst RTN characteristics. It is also found that for both fixed single and fixed double traps, the ΔV th distribution in the lowest cell threshold voltage (V th) state shows the broadest distribution among all cell V th states. This is because the drain current flows at the channel surface in the lowest cell V th state, while at a high cell V th, it flows at the deeper position owing to the fringing coupling between the control gate (CG) and the channel. In this work, the ΔV th distribution with the number of traps following the Poisson distribution is also considered to cope with the variations in trap number. As a result, it is found that the number of traps is an important factor for understanding RTN characteristics. In addition, considering trap position in the tunnel oxide thickness direction is also an important factor.

  4. The Effects of Positive or Neutral Communication during Acupuncture for Relaxing Effects: A Sham-Controlled Randomized Trial

    Science.gov (United States)

    Rosén, Annelie; Lekander, Mats; Jensen, Karin; Sachs, Lisbeth; Petrovic, Predrag; Ingvar, Martin; Enblom, Anna

    2016-01-01

    Introduction. The link between patient-clinician communication and its effect on clinical outcomes is an important clinical issue that is yet to be elucidated. Objective. Investigating if communication type (positive or neutral) about the expected treatment outcome affected (i) participants' expectations and (ii) short-term relaxation effects in response to genuine or sham acupuncture and investigating if expectations were related to outcome. Methods. Healthy volunteers (n = 243, mean age of 42) were randomized to one treatment with genuine or sham acupuncture. Within groups, participants were randomized to positive or neutral communication, regarding expected treatment effects. Visual Analogue Scales (0–100 millimeters) were used to measure treatment expectations and relaxation, directly before and after treatment. Results. Participants in the positive communication group reported higher treatment expectancy, compared to the neutral communication group (md 12 versus 6 mm, p = 0.002). There was no difference in relaxation effects between acupuncture groups or between communication groups. Participants with high baseline expectancy perceived greater improvement in relaxation, compared to participants with low baseline levels (md 27 versus 15 mm, p = 0.022). Conclusion. Our data highlights the importance of expectations for treatment outcome and demonstrates that expectations can be effectively manipulated using a standardized protocol that in future research may be implemented in clinical trials. PMID:26981138

  5. The Effects of Positive or Neutral Communication during Acupuncture for Relaxing Effects: A Sham-Controlled Randomized Trial

    Directory of Open Access Journals (Sweden)

    Annelie Rosén

    2016-01-01

    Full Text Available Introduction. The link between patient-clinician communication and its effect on clinical outcomes is an important clinical issue that is yet to be elucidated. Objective. Investigating if communication type (positive or neutral about the expected treatment outcome affected (i participants’ expectations and (ii short-term relaxation effects in response to genuine or sham acupuncture and investigating if expectations were related to outcome. Methods. Healthy volunteers (n=243, mean age of 42 were randomized to one treatment with genuine or sham acupuncture. Within groups, participants were randomized to positive or neutral communication, regarding expected treatment effects. Visual Analogue Scales (0–100 millimeters were used to measure treatment expectations and relaxation, directly before and after treatment. Results. Participants in the positive communication group reported higher treatment expectancy, compared to the neutral communication group (md 12 versus 6 mm, p=0.002. There was no difference in relaxation effects between acupuncture groups or between communication groups. Participants with high baseline expectancy perceived greater improvement in relaxation, compared to participants with low baseline levels (md 27 versus 15 mm, p=0.022. Conclusion. Our data highlights the importance of expectations for treatment outcome and demonstrates that expectations can be effectively manipulated using a standardized protocol that in future research may be implemented in clinical trials.

  6. Cervical Joint Position Sense in Hypobaric Conditions: A Randomized Double-Blind Controlled Trial.

    Science.gov (United States)

    Bagaianu, Diana; Van Tiggelen, Damien; Duvigneaud, N; Stevens, Veerle; Schroyen, Danny; Vissenaeken, Dirk; D'Hondt, Gino; Pitance, Laurent

    2017-09-01

    Well-adapted motor actions require intact and well-integrated information from all of the sensory systems, specifically the visual, vestibular, and somatosensory systems, including proprioception. Proprioception is involved in the sensorimotor control by providing the central nervous system with an updated body schema of the biomechanical and spatial properties of the body parts. With regard to the cervical spine, proprioceptive information from joint and muscle mechanoreceptors is integrated with vestibular and visual feedback to control head position, head orientation, and whole body posture. Postural control is highly complex and proprioception from joints is an important contributor to the system. Altitude has been used as a paradigm to study the mechanisms of postural control. Determining the mechanisms of postural control that are affected by moderate altitude is important as unpressurized aircrafts routinely operate at altitudes where hypoxia may be a concern. Deficits in motor performance arise when the reliance on proprioceptive feedback is abolished either experimentally or because of a disorder. As pilots require good neck motor control to counteract the weight of their head gear and proprioceptive information plays an important role in this process, the aim of this study was to determine if hypoxia at moderate altitudes would impair proprioception measured by joint position sense of the cervical spine in healthy subjects. Thirty-six healthy subjects (Neck Disability Index sense was evaluated using a three-dimensional motion analyzer. To create the environment, a hypobaric chamber was used to simulate artificial moderate altitude. Head repositioning error was measured by asking the subject to perform a head-to-neutral task after submaximal flexion-extension and right/left rotation movements, and a head-to-target task, in which the subjects had to return to a 30° right and left rotation position. Exposure to artificial acute moderate altitude of 7

  7. Morphological and mechanical analyses of laminates manufactured from randomly positioned carbon fibre/epoxy resin prepreg scraps

    Science.gov (United States)

    Souza, Christiane S. R.; Cândido, Geraldo M.; Alves, Wellington; Marlet, José Maria F.; Rezende, Mirabel C.

    2017-10-01

    This study aims to contribute to sustainability by proposing the reuse of composite prepreg scrap as an added value from discards. The research evaluates the microstructure and mechanical properties of laminates processed by the reuse of uncured carbon fibre/F155-epoxy resin prepreg scraps, waste from the ply cutting area of an aeronautical industry. The composite scraps were used as collected and were randomly positioned to produce laminates to be cured at an autoclave. The mechanical characterization shows a decrease of 39% for the compression property due to the discontinuous fibres in the laminate and an increase of 34% for the interlaminar shear strength, when compared to continuous fibre laminates. This increase is attributed to the higher crosslink density of the epoxy resin, as a result of the cure temperature used in autoclave (60 °C higher than suggested by supplier) and also to the randomly positioned scraps. Microscopic analyses confirm the consolidation of laminates, although show resin rich areas with different sizes and shapes attributed to the overlapping of the scraps with different sizes and shapes. These resin rich areas may contribute to decrease the mechanical properties of laminates. The correlation between mechanical and morphological results shows potential to be used on non-critical structural application, as composite jigs, contributing to sustainability.

  8. The incidence of positive peritoneal cytology in colon cancer: a prospective randomized blinded trial.

    Science.gov (United States)

    Lucha, Paul A; Ignacio, Romeo; Rowley, Dennis; Francis, Michael

    2002-11-01

    Many investigators have attempted to explain the suspected increased incidence of port site metastasis in patients undergoing laparoscopic colorectal resections for cancer with animal models in which cancer is simulated by injection of a tumor slurry into the peritoneal cavity. This approach makes the basic assumption that all patients with colorectal malignancies have viable cancer cells freely circulating within the peritoneal cavity. Recent reports in open colorectal resections have conflicting results. Some suggest that the true incidence is negligible and related to advanced-stage cancers whereas others implicate a much higher incidence. We initiated a prospective blinded trial to establish the true incidence of malignant peritoneal cytology in colorectal cancer. One hundred eight consecutive colon resections underwent conventional peritoneal cytologic evaluation. The patients included those with inflammatory conditions of the colon as well as malignant disease. The cytopathologist was blinded as to the indications for surgery as well as the final pathology result. In only one case--stage IV rectal cancer with peritoneal carcinomatosis--was the cytologic specimen positive. Malignant cytology appears to be an infrequent occurrence and is restricted to advanced-stage cancer.

  9. The effectiveness of group positive psychotherapy on depression and happiness in breast cancer patients: A randomized controlled trial

    Science.gov (United States)

    Dowlatabadi, Mohammad Mehdi; Ahmadi, Seyed Mojtaba; Sorbi, Mohammad Hossein; Beiki, Omid; Razavi, Tayebeh Khademeh; Bidaki, Reza

    2016-01-01

    Background Breast cancer is one of the most prevalent cancers in women in the world. It causes fear, despair, and takes a tremendous toll on psychological status. Objective To determine the effectiveness of group positive psychotherapy on the depression and happiness of breast cancer patients. Methods This randomized controlled trial was conducted with 42 breast cancer patients in The Oncology Center at Kermanshah, Iran in 2015. The Data were gathered before intervention and ten weeks afterwards. The data were collected using Beck’s Depression Inventory (BDI-II) and Oxford’s happiness Inventory (OHI). The data were analyzed by SPSS-16, Kolmogorov-Smirnov (K-S), chi-squared, and multivariate analysis of covariance (MANCOVA). Results The results showed a significant reduction in the depression of the group on positive psychotherapy compared with the control group. Also the positive psychotherapy group experienced a significant increase in the patients’ happiness, while there was no significant increase in the control group. Conclusion The results of this research showed the effectiveness of positive psychotherapy on the reduction of mental pressure and the improvement of the mental status of breast cancer patients. This economical therapy can be used to increase patients’ psychological health. Clinical Trial Registration The trial was registered at the Iranian Registry of Clinical Trials (IRST) with the identification number IRCT2013101410063N4. Funding The authors received financial support for the research from Kermanshah University of Medical Sciences. PMID:27123227

  10. Effects of Positive Psychology Interventions on Risk Biomarkers in Coronary Patients: A Randomized, Wait-List Controlled Pilot Trial.

    Science.gov (United States)

    Nikrahan, Gholam Reza; Laferton, Johannes A C; Asgari, Karim; Kalantari, Mehrdad; Abedi, Mohammad Reza; Etesampour, Ali; Rezaei, Abbas; Suarez, Laura; Huffman, Jeff C

    2016-01-01

    Among cardiac patients, positive psychologic factors are consistently linked with superior clinical outcomes and improvement in key markers of inflammation and hypothalamic-pituitary-adrenal axis functioning. Further, positive psychology interventions (PPI) have effectively increased psychologic well-being in a wide variety of populations. However, there has been minimal study of PPIs in cardiac patients, and no prior study has evaluated their effect on key prognostic biomarkers of cardiac outcome. Accordingly, we investigated the effect of 3 distinct PPIs on risk biomarkers in cardiac patients. In an exploratory trial, 69 patients with recent coronary artery bypass graft surgery or percutaneous intervention were randomized to (1) one of three 6-week in-person PPIs (based on the work of Seligman, Lyubomirsky, or Fordyce) or (2) a wait-list control group. Risk biomarkers were assessed at baseline, postintervention (7 weeks), and at 15-week follow-up. Between-group differences in change from baseline biomarker levels were examined via random effects models. Compared with the control group, participants randomized to the Seligman (B = -2.06; p = 0.02) and Fordyce PPI (B = -1.54; p = 0.04) had significantly lower high-sensitivity C-reactive protein levels at 7 weeks. Further, the Lyubomirsky PPI (B = -245.86; p = 0.04) was associated with a significantly lower cortisol awakening response at 7 weeks when compared with control participants. There were no other significant between-group differences. Despite being an exploratory pilot study with multiple between-group comparisons, this initial trial offers the first suggestion that PPIs might be effective in reducing risk biomarkers in high-risk cardiac patients. Copyright © 2016 The Academy of Psychosomatic Medicine. All rights reserved.

  11. Quantum dots with single-atom precision.

    Science.gov (United States)

    Fölsch, Stefan; Martínez-Blanco, Jesús; Yang, Jianshu; Kanisawa, Kiyoshi; Erwin, Steven C

    2014-07-01

    Quantum dots are often called artificial atoms because, like real atoms, they confine electrons to quantized states with discrete energies. However, although real atoms are identical, most quantum dots comprise hundreds or thousands of atoms, with inevitable variations in size and shape and, consequently, unavoidable variability in their wavefunctions and energies. Electrostatic gates can be used to mitigate these variations by adjusting the electron energy levels, but the more ambitious goal of creating quantum dots with intrinsically digital fidelity by eliminating statistical variations in their size, shape and arrangement remains elusive. We used a scanning tunnelling microscope to create quantum dots with identical, deterministic sizes. By using the lattice of a reconstructed semiconductor surface to fix the position of each atom, we controlled the shape and location of the dots with effectively zero error. This allowed us to construct quantum dot molecules whose coupling has no intrinsic variation but could nonetheless be tuned with arbitrary precision over a wide range. Digital fidelity opens the door to quantum dot architectures free of intrinsic broadening-an important goal for technologies from nanophotonics to quantum information processing as well as for fundamental studies of confined electrons.

  12. Collective Rabi dynamics of electromagnetically coupled quantum-dot ensembles

    Science.gov (United States)

    Glosser, Connor; Shanker, B.; Piermarocchi, Carlo

    2017-09-01

    Rabi oscillations typify the inherent nonlinearity of optical excitations in quantum dots. Using an integral kernel formulation to solve the three-dimensional Maxwell-Bloch equations in ensembles of up to 104 quantum dots, we observe features in Rabi oscillations due to the interplay of nonlinearity, nonequilibrium excitation, and electromagnetic coupling between the dots. This approach allows us to observe the dynamics of each dot in the ensemble without resorting to spatial averages. Our simulations predict synchronized multiplets of dots that exchange energy, dots that dynamically couple to screen the effect of incident external radiation, localization of the polarization due to randomness and interactions, as well as wavelength-scale regions of enhanced and suppressed polarization.

  13. Spin-Orbit Coupling, Antilocalization, and Parallel Magnetic Fields in Quantum Dots

    DEFF Research Database (Denmark)

    Zumbuhl, D.; Miller, Jessica; M. Marcus, C.

    2002-01-01

    We investigate antilocalization due to spin-orbit coupling in ballistic GaAs quantum dots. Antilocalization that is prominent in large dots is suppressed in small dots, as anticipated theoretically. Parallel magnetic fields suppress both antilocalization and also, at larger fields, weak...... localization, consistent with random matrix theory results once orbital coupling of the parallel field is included. In situ control of spin-orbit coupling in dots is demonstrated as a gate-controlled crossover from weak localization to antilocalization....

  14. Enhancing legacy in palliative care: study protocol for a randomized controlled trial of Dignity Therapy focused on positive outcomes.

    Science.gov (United States)

    Montross-Thomas, Lori P; Irwin, Scott A; Meier, Emily A; Gallegos, Jarred V; Golshan, Shahrokh; Roeland, Eric; McNeal, Helen; Munson, Diane; Rodseth, Laura

    2015-09-21

    Dignity Therapy is a brief psychotherapy that can enhance a sense of legacy while addressing the emotional and existential needs of patients receiving hospice or palliative care. In Dignity Therapy, patients create a formalized "legacy" document that records their most cherished memories, their lessons learned in life, as well as their hopes and dreams for loved ones in the future. To date, this treatment has been studied for its impact on mitigating distress within hospice and palliative care populations and has provided mixed results. This study will instead focus on whether Dignity Therapy enhances positive outcomes in this population. In this study, 90 patients with cancer receiving hospice or palliative care will complete a mixed-methods randomized controlled trial of Dignity Therapy (n = 45) versus Supportive Attention (n = 45). The patients will be enrolled in the study for 3 weeks, receiving a total of six study visits. The primary outcomes examine whether the treatment will quantitatively increase levels of positive affect and a sense of life closure. Secondary outcomes focus on gratitude, hope, life satisfaction, meaning in life, resilience, and self-efficacy. Using a fixed, embedded dataset design, this study will additionally use qualitative interviews to explore patients' perceptions regarding the use of positive outcome measures and whether these outcomes are appropriately matched to their experiences in therapy. Dignity Therapy has shown mixed results when evaluating its impact on distress, although no other study to date has solely focused on the potential positive aspects of this treatment. This study is novel in its use of mixed methods assessments to focus on positive outcomes, and will provide valuable information about patients' direct experiences in this area. ISRCTN91389194.

  15. Efficacy of a Multicomponent Positive Psychology Self-Help Intervention: Study Protocol of a Randomized Controlled Trial.

    Science.gov (United States)

    Schotanus-Dijkstra, Marijke; Drossaert, Constance Hc; Pieterse, Marcel E; Walburg, Jan A; Bohlmeijer, Ernst T

    2015-08-20

    Positive psychology interventions have been found to enhance well-being and decrease clinical symptomatology. However, it is still unknown how flourishing can also be increased. Although multicomponent interventions seem to be necessary for this purpose, different formats can be used. A cost-effective approach could be a positive psychology-based self-help book with tailored email support to reach large target groups and to prevent dropout. This study will evaluate the efficacy of a comprehensive multicomponent self-help intervention with or without email support on well-being and flourishing, and will seek to determine the working mechanisms underlying the intervention. In this 3-armed, parallel, randomized controlled trial, 396 participants with low or moderate levels of well-being and without clinical symptomatology will be randomly assigned to (1) a self-help book condition with weekly email support, (2) a self-help book condition without email support but with a weekly information email, or (3) a waiting list control condition. Online measurements will be assessed at baseline, at post-test (3 months after baseline), and at 6 and 12 months after baseline. The primary outcomes are well-being and flourishing (ie, high levels of well-being). Secondary outcomes are the well-being components included in the intervention: positive emotion, use of strengths, optimism, self-compassion, resilience, and positive relations. Other measures include depressive and anxiety symptoms, personality traits, direct medical and non-medical costs, life-events, and client satisfaction. This study will add knowledge to the efficacy and cost-effectiveness of a multicomponent positive psychology intervention. We will also explore who can benefit most from this intervention. If the intervention is found to be effective, our results will be especially relevant for public mental health services, governments, and primary care. The Netherlands Trial Register NTR4297; http

  16. Financial Incentives for Linkage to Care and Viral Suppression Among HIV-Positive Patients: A Randomized Clinical Trial (HPTN 065).

    Science.gov (United States)

    El-Sadr, Wafaa M; Donnell, Deborah; Beauchamp, Geetha; Hall, H Irene; Torian, Lucia V; Zingman, Barry; Lum, Garret; Kharfen, Michael; Elion, Richard; Leider, Jason; Gordin, Fred M; Elharrar, Vanessa; Burns, David; Zerbe, Allison; Gamble, Theresa; Branson, Bernard

    2017-08-01

    Achieving linkage to care and viral suppression in human immunodeficiency virus (HIV)-positive patients improves their well-being and prevents new infections. Current gaps in the HIV care continuum substantially limit such benefits. To evaluate the effectiveness of financial incentives on linkage to care and viral suppression in HIV-positive patients. A large community-based clinical trial that randomized 37 HIV test and 39 HIV care sites in the Bronx, New York, and Washington, DC, to financial incentives or standard of care. Participants at financial incentive test sites who had positive test results for HIV received coupons redeemable for $125 cash-equivalent gift cards upon linkage to care. HIV-positive patients receiving antiretroviral therapy at financial incentive care sites received $70 gift cards quarterly, if virally suppressed. Linkage to care: proportion of HIV-positive persons at the test site who linked to care within 3 months, as indicated by CD4+ and/or viral load test results done at a care site. Viral suppression: proportion of established patients at HIV care sites with suppressed viral load (incentive test sites and 39 359 gift cards were dispensed to 9641 HIV-positive patients eligible for gift cards at 17 financial incentive care sites. Financial incentives did not increase linkage to care (adjusted odds ratio, 1.10; 95% CI, 0.73-1.67; P = .65). However, financial incentives significantly increased viral suppression. The overall proportion of patients with viral suppression was 3.8% higher (95% CI, 0.7%-6.8%; P = .01) at financial incentive sites compared with standard of care sites. Among patients not previously consistently virally suppressed, the proportion virally suppressed was 4.9% higher (95% CI, 1.4%-8.5%; P = .007) at financial incentive sites. In addition, continuity in care was 8.7% higher (95% CI, 4.2%-13.2%; P incentive sites. Financial incentives, as used in this study (HPTN 065), significantly increased viral

  17. [Effect of acupuncture on early cerebral palsy infants with parafunctional sitting position: a multi-centre, randomized, control research].

    Science.gov (United States)

    Zhang, Hong-yun; Sun, Qun-ying; Yang, Kun-peng; Chen, Yu-xia; Wang, Qi; Wang, Xi; Liu, Yuan

    2015-02-01

    To study the clinical effect of development theory based acupuncture on early cerebral palsy (CP) infants with parafunctional sitting position. Totally 120 early CP infants were randomly assigned to two groups equally, the treatment group and the control group. All received acupuncture combined with training rehabilitation. Patients in the treatment group adopted acupuncture based on infants development theory, while those in the control group were treated by head acupuncture. Sitting functional points in Gross motor function measure (GMFM) 88 were observed in different groups and infant patients of various types before and after treatment. Root mean square (RMS) signals of sitting correlated muscles (latissimus dorsi, erector spinae, rectus abdominis) were recorded by surface electromyography (sEMG). The effective rate was evaluated by Nimodipine method. Compared with before treatment, sitting functional points were significantly improved in the two groups (Pvs. 77.78%, Pacupuncture could effectively elevate dorsi-extensor muscles force, improve sitting position of 8 months to 1 year old CP infants with parafunctional sitting position.

  18. Experimental Evaluation of Novel Master-Slave Configurations for Position Control under Random Network Delay and Variable Load for Teleoperation

    Directory of Open Access Journals (Sweden)

    Ahmet Kuzu

    2014-01-01

    Full Text Available This paper proposes two novel master-slave configurations that provide improvements in both control and communication aspects of teleoperation systems to achieve an overall improved performance in position control. The proposed novel master-slave configurations integrate modular control and communication approaches, consisting of a delay regulator to address problems related to variable network delay common to such systems, and a model tracking control that runs on the slave side for the compensation of uncertainties and model mismatch on the slave side. One of the configurations uses a sliding mode observer and the other one uses a modified Smith predictor scheme on the master side to ensure position transparency between the master and slave, while reference tracking of the slave is ensured by a proportional-differentiator type controller in both configurations. Experiments conducted for the networked position control of a single-link arm under system uncertainties and randomly varying network delays demonstrate significant performance improvements with both configurations over the past literature.

  19. Examining Contextual Influences on Classroom-Based Implementation of Positive Behavior Support Strategies: Findings from a Randomized Controlled Effectiveness Trial.

    Science.gov (United States)

    Pas, Elise T; Waasdorp, Tracy E; Bradshaw, Catherine P

    2015-11-01

    Although it is widely recognized that variation in implementation fidelity influences the impact of preventive interventions, little is known about how specific contextual factors may affect the implementation of social and behavioral interventions in classrooms. Theoretical research highlights the importance of multiple contextual influences on implementation, including factors at the classroom and school level (Domitrovich et al., Advances in School Mental Health Promotion, 1, 6-28, 2008). The current study used multi-level modeling to empirically examine the influence of teacher, classroom, and school characteristics on the implementation of classroom-based positive behavior support strategies over the course of 4 years. Data were collected in the context of a 37-school randomized controlled trial examining the effectiveness of school-wide Positive Behavioral Interventions and Supports. Multi-level results identified several school-level contextual factors (e.g., school size, behavioral disruptions) and teacher-level factors (perceptions of school organizational health and grade level taught) associated with variability in the implementation of classroom-based positive behavior supports. Implications for prevention research and practice are discussed.

  20. Three-dimensional Si/Ge quantum dot crystals.

    Science.gov (United States)

    Grützmacher, Detlev; Fromherz, Thomas; Dais, Christian; Stangl, Julian; Müller, Elisabeth; Ekinci, Yasin; Solak, Harun H; Sigg, Hans; Lechner, Rainer T; Wintersberger, Eugen; Birner, Stefan; Holý, Vaclav; Bauer, Günther

    2007-10-01

    Modern nanotechnology offers routes to create new artificial materials, widening the functionality of devices in physics, chemistry, and biology. Templated self-organization has been recognized as a possible route to achieve exact positioning of quantum dots to create quantum dot arrays, molecules, and crystals. Here we employ extreme ultraviolet interference lithography (EUV-IL) at a wavelength of lambda = 13.5 nm for fast, large-area exposure of templates with perfect periodicity. Si(001) substrates have been patterned with two-dimensional hole arrays using EUV-IL and reactive ion etching. On these substrates, three-dimensionally ordered SiGe quantum dot crystals with the so far smallest quantum dot sizes and periods both in lateral and vertical directions have been grown by molecular beam epitaxy. X-ray diffractometry from a sample volume corresponding to about 3.6 x 10(7) dots and atomic force microscopy (AFM) reveal an up to now unmatched structural perfection of the quantum dot crystal and a narrow quantum dot size distribution. Intense interband photoluminescence has been observed up to room temperature, indicating a low defect density in the three-dimensional (3D) SiGe quantum dot crystals. Using the Ge concentration and dot shapes determined by X-ray and AFM measurements as input parameters for 3D band structure calculations, an excellent quantitative agreement between measured and calculated PL energies is obtained. The calculations show that the band structure of the 3D ordered quantum dot crystal is significantly modified by the artificial periodicity. A calculation of the variation of the eigenenergies based on the statistical variation in the dot dimensions as determined experimentally (+/-10% in linear dimensions) shows that the calculated electronic coupling between neighboring dots is not destroyed due to the quantum dot size variations. Thus, not only from a structural point of view but also with respect to the band structure, the 3D ordered

  1. The complex sleep apnea resolution study: a prospective randomized controlled trial of continuous positive airway pressure versus adaptive servoventilation therapy.

    Science.gov (United States)

    Morgenthaler, Timothy I; Kuzniar, Tomasz J; Wolfe, Lisa F; Willes, Leslee; McLain, William C; Goldberg, Rochelle

    2014-05-01

    Prior studies show that adaptive servoventilation (ASV) is initially more effective than continuous positive airway pressure (CPAP) for patients with complex sleep apnea syndrome (CompSAS), but choosing therapies has been controversial because residual central breathing events may resolve over time in many patients receiving chronic CPAP therapy. We conducted a multicenter, randomized, prospective trial comparing clinical and polysomnographic outcomes over prolonged treatment of patients with CompSAS, with CPAP versus ASV. Qualifying participants meeting criteria for CompSAS were randomized to optimized CPAP or ASV treatment. Clinical and polysomnographic data were obtained at baseline and after 90 days of therapy. We randomized 66 participants (33 to each treatment). At baseline, the diagnostic apnea-hypopnea index (AHI) was 37.7 ± 27.8 (central apnea index [CAI] = 3.2 ± 5.8) and best CPAP AHI was 37.0 ± 24.9 (CAI 29.7 ± 25.0). After second-night treatment titration, the AHI was 4.7 ± 8.1 (CAI = 1.1 ± 3.7) on ASV and 14.1 ± 20.7 (CAI = 8.8 ± 16.3) on CPAP (P ≤ 0.0003). At 90 days, the ASV versus CPAP AHI was 4.4 ± 9.6 versus 9.9 ± 11.1 (P = 0.0024) and CAI was 0.7 ± 3.4 versus 4.8 ± 6.4 (P Scale and Sleep Apnea Quality of Life Index were not significantly different between treatment groups. Adaptive servoventilation (ASV) was more reliably effective than CPAP in relieving complex sleep apnea syndrome. While two thirds of participants experienced success with CPAP, approximately 90% experienced success with ASV. Because both methods produced similar symptomatic changes, it is unclear if this polysomnographic effectiveness may translate into other desired outcomes. Clinicaltrials.Gov NCT00915499.

  2. A Randomized Trial of Low-Flow Oxygen versus Nasal Continuous Positive Airway Pressure in Preterm Infants

    DEFF Research Database (Denmark)

    Heiring, Christian; Steensberg, Jesper; Bjerager, Mia

    2015-01-01

    BACKGROUND: Nasal continuous positive airway pressure (nCPAP) stabilizes the residual volume and may decrease the risk of 'atelectotrauma', potentially promoting lung development in neonates. OBJECTIVES: To assess whether replacing nCPAP by low-flow O2 by nasal cannula affects lung function...... expressed as the arterial/alveolar oxygen tension ratio (a/A pO2 ratio) on postnatal day 28. METHODS: Preterm infants (birth weight 26 + 0 weeks) stable on nCPAP between postnatal days 4 and 7 were randomized to nCPAP or low-flow O2 by nasal cannula (....001. There was no difference between groups in the fraction needing any respiratory support at 36 weeks' corrected age, length of stay, weight at discharge, and relative weight gain. CONCLUSIONS: Replacing nCPAP by low-flow O2 in preterm infants with GA >26 weeks at the end of the first week of life did not seem to affect...

  3. From DOT to Dotty

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    - Module types are interfaces, which can be abstracted. In this talk Martin will present DOT, a particularly simple calculus that can express systems following these principles. DOT has been developed as the foundation of the next version of Scala. He will also report on dotty, a new Scala compiler that implements the constructs of DOT in its core data structures and that uses the lessons learned to drive Scala’s evolution.

  4. Health outcomes of continuous positive airway pressure versus oral appliance treatment for obstructive sleep apnea: a randomized controlled trial.

    Science.gov (United States)

    Phillips, Craig L; Grunstein, Ronald R; Darendeliler, M Ali; Mihailidou, Anastasia S; Srinivasan, Vasantha K; Yee, Brendon J; Marks, Guy B; Cistulli, Peter A

    2013-04-15

    Continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) therapy are commonly used to treat obstructive sleep apnea (OSA). Differences in efficacy and compliance of these treatments are likely to influence improvements in health outcomes. To compare health effects after 1 month of optimal CPAP and MAD therapy in OSA. In this randomized crossover trial, we compared the effects of 1 month each of CPAP and MAD treatment on cardiovascular and neurobehavioral outcomes. Cardiovascular (24-h blood pressure, arterial stiffness), neurobehavioral (subjective sleepiness, driving simulator performance), and quality of life (Functional Outcomes of Sleep Questionnaire, Short Form-36) were compared between treatments. Our primary outcome was 24-hour mean arterial pressure. A total of 126 patients with moderate-severe OSA (apnea hypopnea index [AHI], 25.6 [SD 12.3]) were randomly assigned to a treatment order and 108 completed the trial with both devices. CPAP was more efficacious than MAD in reducing AHI (CPAP AHI, 4.5 ± 6.6/h; MAD AHI, 11.1 ± 12.1/h; P health outcomes were similar after 1 month of optimal MAD and CPAP treatment in patients with moderate-severe OSA. The results may be explained by greater efficacy of CPAP being offset by inferior compliance relative to MAD, resulting in similar effectiveness. Clinical trial registered with https://www.anzctr.org.au (ACTRN 12607000289415).

  5. A positioning pillow to improve lumbar puncture success rate in paediatric haematology-oncology patients: a randomized controlled trial.

    Science.gov (United States)

    Marec-Bérard, Perrine; Bissery, Alvine; Kebaïli, Kamila; Schell, Matthias; Aubert, Françoise; Gaillard, Ségolène; Rabilloud, Muriel; Kassaï, Behrouz; Cornu, Catherine

    2009-01-15

    Lumbar punctures (LPs) are common in children with cancer. Although pain management during the lumbar puncture has been well standardized, dealing with stress and anxiety is not well addressed yet. Our objective was to evaluate the potential improvement of the LP success rate using a positioning pillow, to ensure maximum lumbar flexion, and allow paravertebral muscles to relax, in children who are awake, with either conscious sedation or no sedation. Children aged 2-18 years undergoing LP were randomly assigned to a positioning pillow or no intervention. The primary outcome was the rate of success, i.e. achieving the LP (sampling or injection) at the first attempt, without bleeding (RBC pillow tended to increase the success rate of LPs (67% vs. 57%, p = 0.23), and decreased the post-LP syndromes (15% vs. 24%, p = 0.17) but the differences were not statistically significant. In children over 6-year of age (n = 72), the rate of success was significantly higher in the pillow group (58.5% vs. 41.5%, p = 0.031), with a tendency to feel less pain (median VAS 25 vs. 15 mm, p = 0.39) and being more satisfied (84.4% vs. 75.0%, p = 0.34). Overall results do not demonstrate a benefit in using this pillow for lumbar punctures. This study results also suggest a benefit in the sub group of children over 6-year of age; this result needs confirmation.

  6. Randomized Controlled Trial of Clozapine and CBT for First-Episode Psychosis with Enduring Positive Symptoms: A Pilot Study

    Directory of Open Access Journals (Sweden)

    J. Edwards

    2011-01-01

    Full Text Available Here we report the results of a pilot study investigating the relative and combined effects of a 12 week course of clozapine and CBT in first-episode psychosis patients with prominent ongoing positive symptoms following their initial treatment. Patients from our early psychosis service who met the inclusion criteria (=48 were randomized to one of four treatment groups: clozapine, clozapine plus CBT, thioridazine, or thioridazine plus CBT. The degree of psychopathology and functionality of all participants was measured at baseline then again at 6, 12 and 24 weeks, and the treatment outcomes for each group determined by statistical analysis. A substantial proportion (52% of those treated with clozapine achieved symptomatic remission, as compared to 35% of those who were treated with thioridazine. Overall, those who received clozapine responded more rapidly to treatment than those receiving the alternative treatments. Interestingly, during the early treatment phase CBT appeared to reduce the intensity of both positive and negative symptoms and thus the time taken to respond to treatment, as well having as a stabilizing effect over time.

  7. Polarized quantum dot emission in electrohydrodynamic jet printed photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    See, Gloria G. [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 208 North Wright Street, Urbana, Illinois 61801 (United States); Xu, Lu; Nuzzo, Ralph G. [Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801 (United States); Sutanto, Erick; Alleyne, Andrew G. [Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, 154 Mechanical Engineering Building, Urbana, Illinois 61801 (United States); Cunningham, Brian T. [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 208 North Wright Street, Urbana, Illinois 61801 (United States); Department of Bioengineering, University of Illinois at Urbana-Champaign, 1270 Digital Computer Laboratory, MC-278, Urbana, Illinois 61801 (United States)

    2015-08-03

    Tailored optical output, such as color purity and efficient optical intensity, are critical considerations for displays, particularly in mobile applications. To this end, we demonstrate a replica molded photonic crystal structure with embedded quantum dots. Electrohydrodynamic jet printing is used to control the position of the quantum dots within the device structure. This results in significantly less waste of the quantum dot material than application through drop-casting or spin coating. In addition, the targeted placement of the quantum dots minimizes any emission outside of the resonant enhancement field, which enables an 8× output enhancement and highly polarized emission from the photonic crystal structure.

  8. Quantum Dots: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  9. Hybrid Double Quantum Dots

    DEFF Research Database (Denmark)

    Sherman, D.; Yodh, J. S.; Albrecht, S. M.

    2016-01-01

    Epitaxial semiconductor-superconductor hybrid materials are an excellent basis for studying mesoscopic and topological superconductivity, as the semiconductor inherits a hard superconducting gap while retaining tunable carrier density. Here, we investigate double-quantum-dot devices made from InA...... that the individual dots host weakly hybridized Majorana modes....

  10. Feasibility and effectiveness of a web-based positive psychology program for youth mental health: randomized controlled trial.

    Science.gov (United States)

    Manicavasagar, Vijaya; Horswood, Deserae; Burckhardt, Rowan; Lum, Alistair; Hadzi-Pavlovic, Dusan; Parker, Gordon

    2014-06-04

    Youth mental health is a significant public health concern due to the high prevalence of mental health problems in this population and the low rate of those affected seeking help. While it is increasingly recognized that prevention is better than cure, most youth prevention programs have utilized interventions based on clinical treatments (eg, cognitive behavioral therapy) with inconsistent results. This study explores the feasibility of the online delivery of a youth positive psychology program, Bite Back, to improve the well-being and mental health outcomes of Australian youth. Further aims were to examine rates of adherence and attrition, and to investigate the program's acceptability. Participants (N=235) aged 12-18 years were randomly assigned to either of two conditions: Bite Back (n=120) or control websites (n=115). The Bite Back website comprised interactive exercises and information across a variety of positive psychology domains; the control condition was assigned to neutral entertainment-based websites that contained no psychology information. Participants in both groups were instructed to use their allocated website for 6 consecutive weeks. Participants were assessed pre- and postintervention on the Depression Anxiety Stress Scale-Short form (DASS-21) and the Short Warwick-Edinburgh Mental Well-Being Scale (SWEMWBS). Of the 235 randomized participants, 154 (65.5%) completed baseline and post measures after 6 weeks. Completers and dropouts were equivalent in demographics, the SWEMWBS, and the depression and anxiety subscales of the DASS-21, but dropouts reported significantly higher levels of stress than completers. There were no differences between the Bite Back and control conditions at baseline on demographic variables, DASS-21, or SWEMWBS scores. Qualitative data indicated that 49 of 61 Bite Back users (79%) reported positive experiences using the website and 55 (89%) agreed they would continue to use it after study completion. Compared to the

  11. A prospective, randomized, controlled study of a suspension positioning system used with elderly bedridden patients with neurogenic fecal incontinence.

    Science.gov (United States)

    Su, Mei-Yin; Lin, Shi-Quan; zhou, Ye-Wen; Zhou, Ye-Wen; Liu, Si-Ya; Lin, Ai; Lin, Xi-Rong

    2015-01-01

    Elderly patients with acute neurological impairment are prone to severe disability, fecal incontinence (FI), and resultant complications. A suspension positioning system (SPS), based on the orthopedic suspension traction system commonly used for conservative treatment of pediatric femoral fracture and uncomplicated adult pelvic fracture, was developed to facilitate FI management in patients immobilized secondary to an acute neurological condition. To evaluate the effectiveness and safety of the system, a prospective, randomized, controlled study was conducted between October 2009 and July 2012. Two hundred (200) elderly, bedridden, hospitalized patients with acute, nonchronic neurological impairment were randomly assigned to receive routine FI nursing care (ie, individualized dietary modification, psychological support, health education, and social support for caregivers and family members [control group]) or routine incontinence care plus the SPS (experimental group) during the day. Rates of perianal fecal contamination, skin breakdown, incontinence associated dermatitis, pressure ulcer development, and lower urinary tract infection (LUTI) were significantly lower in the SPS than in the control group (P care were also lower in the SPS group (P <0.05). Patient quality-of-life (QoL) and FI QoL scores were similar at baseline but significantly higher (better) at the 6-month follow-up interview in the SPS than in the control group (P <0.05). In this study, the rate of FI-associated morbidities was lower and 6-month patient QoL scores were higher in the SPS than in the control group. No adverse events were observed, and all patients completed the study. Further clinical studies are needed to examine the long-term effects of SPS use among neurologically impaired FI patients.

  12. Noradrenergic α₁ receptor antagonist treatment attenuates positive subjective effects of cocaine in humans: a randomized trial.

    Directory of Open Access Journals (Sweden)

    Thomas F Newton

    Full Text Available Preclinical research implicates dopaminergic and noradrenergic mechanisms in mediating the reinforcing effects of drugs of abuse, including cocaine. The objective of this study was to evaluate the impact of treatment with the noradrenergic α(1 receptor antagonist doxazosin on the positive subjective effects of cocaine.Thirteen non-treatment seeking, cocaine-dependent volunteers completed this single-site, randomized, placebo-controlled, within-subjects study. In one study phase volunteers received placebo and in the other they received doxazosin, with the order counterbalanced across participants. Study medication was masked by over-encapsulating doxazosin tablets and matched placebo lactose served as the control. Study medication treatment was initiated at 1 mg doxazosin or equivalent number of placebo capsules PO/day and increased every three days by 1 mg. After receiving 4 mg doxazosin or equivalent number of placebo capsules participants received masked doses of 20 and 40 mg cocaine IV in that order with placebo saline randomly interspersed to maintain the blind.Doxazosin treatment was well tolerated and doxazosin alone produced minimal changes in heart rate and blood pressure. During treatment with placebo, cocaine produced dose-dependent increases in subjective effect ratings of "high", "stimulated", "like cocaine", "desire cocaine", "any drug effect", and "likely to use cocaine if had access" (p<.001. Doxazosin treatment significantly attenuated the effects of 20 mg cocaine on ratings of "stimulated", "like cocaine", and "likely to use cocaine if had access" (p<.05. There were trends for doxazosin to reduce ratings of "stimulated", "desire cocaine", and "likely to use cocaine if had access" (p<.10.Medications that block noradrenergic α₁ receptors, such as doxazosin, may be useful as treatments for cocaine dependence, and should be evaluated further.Clinicaltrials.gov NCT01062945.

  13. Synthesis of quantum dots

    Science.gov (United States)

    McDaniel, Hunter

    2017-10-17

    Common approaches to synthesizing alloyed quantum dots employ high-cost, air-sensitive phosphine complexes as the selenium precursor. Disclosed quantum dot synthesis embodiments avoid these hazardous and air-sensitive selenium precursors. Certain embodiments utilize a combination comprising a thiol and an amine that together reduce and complex the elemental selenium to form a highly reactive selenium precursor at room temperature. The same combination of thiol and amine acts as the reaction solvent, stabilizing ligand, and sulfur source in the synthesis of quantum dot cores. A non-injection approach may also be used. The optical properties of the quantum dots synthesized by this new approach can be finely tuned for a variety of applications by controlling size and/or composition of size and composition. Further, using the same approach, a shell can be grown around a quantum dot core that improves stability, luminescence efficiency, and may reduce toxicity.

  14. A Randomized Controlled Trial of Continuous Positive Airway Pressure on Glucose Tolerance in Obese Patients with Obstructive Sleep Apnea.

    Science.gov (United States)

    Salord, Neus; Fortuna, Ana Maria; Monasterio, Carmen; Gasa, Mercè; Pérez, Antonio; Bonsignore, Maria R; Vilarrasa, Núria; Montserrat, Josep Maria; Mayos, Mercedes

    2016-01-01

    Obstructive sleep apnea (OSA) is associated with an increased prevalence of metabolic syndrome (MetS), even in patients with morbid obesity. Our goal was to address whether continuous positive airway pressure (CPAP) treatment improved glucose metabolism in this population. A prospective randomized controlled trial was performed in severe OSA patients with morbid obesity without diabetes in two university referral hospitals. Patients received conservative (CT) versus CPAP treatment for 12 weeks. MetS components, homeostasis model assessment of insulin resistance (HOMA-IR) and oral glucose tolerance were assessed at baseline and after treatment. A total of 80 patients completed the study (42 CPAP and 38 CT patients). After 12 w of CPAP treatment, weight loss was similar in both groups and physical activity, prevalence of MetS, and HOMA-IR did not change in either group. In the CPAP group impaired glucose tolerance (IGT) reversed in nine patients and IGT developed in none, whereas IGT reversed in five patients and IGT developed in five patients in the CT group (P = 0.039 in the Fisher test). Changes in 2-h plasma glucose after glucose load were greater in the CPAP group than in the CT group (CPAP: -0.5 ± 1.5 versus CT: 0.33 ± 1.9, P = 0.007). The improvement of glucose tolerance in morbidly obese patients with severe obstructive sleep apnea, without changes in homeostasis model assessment of insulin resistance, supports an improvement in peripheral insulin resistance after continuous positive airway pressure treatment. NCT 01029561. © 2016 Associated Professional Sleep Societies, LLC.

  15. [A positioning pillow to improve lumbar puncture in paediatric haematology-oncology patients: a randomized controlled trial.].

    Science.gov (United States)

    Marec-Bérard, P; Bissery, A; Kebaïli, K; Schell, M; Aubert, F; Gaillard, S; Rabilloud, M; Kassaï, B; Cornu, C

    2009-09-01

    ObjectivesLumbar punctures (LPs) are common in children with cancer. Although pain management during the LP has been well standardised, dealing with stress and anxiety is not well addressed yet. Our objective was to evaluate the potential improvement of the LPs success rate using a positioning pillow, to ensure maximum lumbar flexion, and allow paravertebral muscles to relax, in children who are awake, with either conscious sedation or no sedation.Patients and methodsChildren aged 2-18 years undergoing LPs were randomly assigned to a positioning pillow or no intervention. The primary outcome was the rate of success, i.e. achieving the LPs (sampling or injection) at the first attempt, without bleeding (RBC pillow tended to increase the success rate of LPs (67 vs 57%; P = 0.23), and decreased the post-LP syndromes (15 vs 24%; P = 0.17) but the differences were not statistically significant. In children over 6-year of age (N = 72), the rate of success was significantly higher in the pillow group (58.5 vs 41.5%; P = 0.031), with a tendency to feel less pain (for less pain and better satisfaction) [median VAS: 25 vs 15 mm; P = 0.39] and being more satisfied (84.4 vs 75.0%; P = 0.34).ConclusionEven if the results presented here are not as optimistic as we might have wished, we can confirm that there is a benefit in using this pillow for LPs. It is especially promising in children over 6-year of age.

  16. Effects of a modified technique for TVT-O positioning on postoperative pain: single-blind randomized study.

    Science.gov (United States)

    Tommaselli, Giovanni A; Formisano, Carmen; Di Carlo, Costantino; Fabozzi, Annamaria; Nappi, Carmine

    2012-09-01

    One of the most frequent and distressing complications of the tension-free vaginal tape obturator (TVT-O) procedure for stress urinary incontinence (SUI) is groin pain, which may be related to the surgical technique or to the tape. The aim of this study was to evaluate the impact of a more limited dissection and a more medial trocar trajectory in TVT-O positioning on postoperative pain. Seventy-two SUI patients were randomized to undergo TVT-O either with the traditional technique (group A) or a modified procedure (reduced paraurethral dissection and a more medial trocar trajectory) (group B). Visual analog scale pain scores 12 h, 24 h, and 1 month after the procedure, number of analgesic vials, objective cure rate, and patient functional and quality of life scores 6 months after the procedure were evaluated. Data were analyzed by the Student's t test for parametric variables, the Mann-Whitney U and Wilcoxon tests for nonparametric variables, and Fisher's exact test for categorical variables. Pain scores were significantly lower in group B compared with group A 24 h after surgery (P = 0.01). Pain scores significantly decreased from 12-24 h postoperatively to 1 month follow-up in both groups (P TVT-O seem to reduce postoperative groin pain at 24 h after the procedure, but not the analgesic requirement.

  17. Microcurrent stimulation at shenmen acupoint facilitates EEG associated with sleepiness and positive mood: a randomized controlled electrophysiological study.

    Science.gov (United States)

    Cheung, Mei-Chun; Chan, Agnes S; Yip, Joanne

    2015-01-01

    To examine the electrophysiological effects of microcurrent stimulation at the Shenmen acupoint, 40 healthy normal subjects were randomly assigned to a placebo group (sham stimulation) and an experimental group (bilateral electrocutaneous stimulation at the Shenmen). The following two electroencephalographic indicators were used to measure brain activity. (1) Arousal level was measured with reference to log-transformed absolute alpha power and power source and analyzed using low-resolution electromagnetic tomography and (2) frontal alpha asymmetry was used as an indicator of mood. After real stimulation for 10 minutes, absolute alpha power was globally reduced in the experimental group, particularly in the anterior and centrotemporal regions of the brain. This indicates a decline in the brain activity associated with arousal. Moreover, the reduction was more prominent in the left frontal region, as compared to the right frontal region, resulting in significant increase from negative to positive frontal alpha asymmetry scores and reflecting an increase in the brain activity associated with enhanced mood. However, the placebo group exhibited no significant changes in two indicators after sham stimulation. This study provides initial electrophysiological evidence of changes in brain activity associated with reduced arousal (and thus greater sleepiness) and enhanced mood after microcurrent stimulation at the Shenmen acupoint.

  18. Microcurrent Stimulation at Shenmen Acupoint Facilitates EEG Associated with Sleepiness and Positive Mood: A Randomized Controlled Electrophysiological Study

    Directory of Open Access Journals (Sweden)

    Mei-chun Cheung

    2015-01-01

    Full Text Available To examine the electrophysiological effects of microcurrent stimulation at the Shenmen acupoint, 40 healthy normal subjects were randomly assigned to a placebo group (sham stimulation and an experimental group (bilateral electrocutaneous stimulation at the Shenmen. The following two electroencephalographic indicators were used to measure brain activity. (1 Arousal level was measured with reference to log-transformed absolute alpha power and power source and analyzed using low-resolution electromagnetic tomography and (2 frontal alpha asymmetry was used as an indicator of mood. After real stimulation for 10 minutes, absolute alpha power was globally reduced in the experimental group, particularly in the anterior and centrotemporal regions of the brain. This indicates a decline in the brain activity associated with arousal. Moreover, the reduction was more prominent in the left frontal region, as compared to the right frontal region, resulting in significant increase from negative to positive frontal alpha asymmetry scores and reflecting an increase in the brain activity associated with enhanced mood. However, the placebo group exhibited no significant changes in two indicators after sham stimulation. This study provides initial electrophysiological evidence of changes in brain activity associated with reduced arousal (and thus greater sleepiness and enhanced mood after microcurrent stimulation at the Shenmen acupoint.

  19. The impact of schoolwide positive behavioral interventions and supports on bullying and peer rejection: a randomized controlled effectiveness trial.

    Science.gov (United States)

    Waasdorp, Tracy E; Bradshaw, Catherine P; Leaf, Philip J

    2012-02-01

    To build on prior research documenting the impact of School-wide Positive Behavioral Interventions and Supports (SWPBIS) on school climate and discipline problems to examine the extent to which it affects bullying and peer rejection during the transition into early adolescence. Three-level models were fit using hierarchical linear modeling to determine the effect of SWPBIS on children's involvement in bullying. Thirty-seven Maryland public elementary schools. Data involved 12 344 children (52.9% male, 45.1% African American, 46.1% white) followed up longitudinally across 4 school years. A randomized controlled effectiveness trial of SWPBIS. Reports from teachers on bully-related behaviors were assessed through the Teacher Observation of Classroom Adaptation-Checklist. Analyses indicated that children in schools that implemented SWPBIS displayed lower rates of teacher-reported bullying and peer rejection than those in schools without SWPBIS. A significant interaction also emerged between grade level of first exposure to SWPBIS and intervention status, suggesting that the effects of SWPBIS on rejection were strongest among children who were first exposed to SWPBIS at a younger age. The results indicated that SWPBIS has a significant effect on teachers' reports of children's involvement in bullying as victims and perpetrators. The findings were considered in light of other outcomes for students, staff, and the school environment, and they suggest that SWPBIS may help address the increasing national concerns related to school bullying by improving school climate.

  20. Coherent transport through interacting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Hiltscher, Bastian

    2012-10-05

    the linear-conductance regime. The second work deals with the ratio of coherent processes in transport through quantum dots. To this end, a quantum dot is embedded in one of the arms of an Aharonov-Bohm interferometer. In former theoretical as well as experimental works it has been observed that an important source of decoherence are cotunneling processes that flip the dot's spin. In order to elucidate the role of spin in more detail, we assume one of the leads to be ferromagnetic and the other one to be normal. The main motivations of our work are the two questions: (1) What fraction of the total current through a single-level quantum dot weakly coupled to the electrodes is coherent? (2) How and under which circumstances can this fraction be extracted from a current measurement in an Aharonov-Bohm setup? The measurable quantity in such an experiment is the magnetic-flux dependent ratio of the total current. It turns out that the answers of the two questions strongly depend on the dot level position, the polarization of the ferromagnet, and the transport direction. Especially the flux-dependent and the coherent ratios are not necessarily the same. The main motivation of the third work is to identify crossed Andreev reflection in quantum dots, that is, a Cooper pair splits into two single electrons, which are transferred into different quantum dots in one coherent process. We consider a setup, where two quantum dots are tunnel coupled to the same superconductor and each dot is additionally coupled to a normal conductor. In previous works a bias voltage has been applied between the superconductor and the normal conductors. Then, three processes sustain transport. Beside crossed Andreev reflection also local Andreev reflection, where both electrons of the Cooper pair tunnel into the same dot, and single-particle tunneling occur. This complicates the identification of crossed Andreev reflection. Therefore, we propose the transport mechanism of adiabatic pumping in

  1. Long-range ordered self-assembled InAs quantum dots epitaxially grown on (110) GaAs

    Science.gov (United States)

    Bauer, J.; Schuh, D.; Uccelli, E.; Schulz, R.; Kress, A.; Hofbauer, F.; Finley, J. J.; Abstreiter, G.

    2004-11-01

    We report on a promising approach for positioning of self-assembled InAs quantum dots on (110) GaAs with nanometer precision. By combining self-assembly of quantum dots with molecular beam epitaxy on previously grown and in situ cleaved substrates (cleaved-edge overgrowth), arrays of long-range ordered InAs quantum dots have been fabricated. Both atomic force microscopy and micro-photoluminescence measurements demonstrate the ability to control size, position, and ordering of the quantum dots. Furthermore, single dot photoluminescence investigations confirm the high optical quality of the quantum dots fabricated.

  2. Connecting the dots: Semi-analytical and random walk numerical solutions of the diffusion-reaction equation with stochastic initial conditions

    Science.gov (United States)

    Paster, Amir; Bolster, Diogo; Benson, David A.

    2014-04-01

    We study a system with bimolecular irreversible kinetic reaction A+B→∅ where the underlying transport of reactants is governed by diffusion, and the local reaction term is given by the law of mass action. We consider the case where the initial concentrations are given in terms of an average and a white noise perturbation. Our goal is to solve the diffusion-reaction equation which governs the system, and we tackle it with both analytical and numerical approaches. To obtain an analytical solution, we develop the equations of moments and solve them approximately. To obtain a numerical solution, we develop a grid-less Monte Carlo particle tracking approach, where diffusion is modeled by a random walk of the particles, and reaction is modeled by annihilation of particles. The probability of annihilation is derived analytically from the particles' co-location probability. We rigorously derive the relationship between the initial number of particles in the system and the amplitude of white noise represented by that number. This enables us to compare the particle simulations and the approximate analytical solution and offer an explanation of the late time discrepancies.

  3. Effects of balance Vestibular Rehabilitation Therapy in elderly with Benign Paroxysmal Positional Vertigo: a randomized controlled trial.

    Science.gov (United States)

    Ribeiro, Karyna Myrelly Oliveira Bezerra de Figueiredo; Freitas, Raysa Vanessa de Medeiros; Ferreira, Lidiane Maria de Brito Macedo; Deshpande, Nandini; Guerra, Ricardo Oliveira

    2017-06-01

    To evaluate short-term effects of balance Vestibular Rehabilitation Therapy (VRT) on balance, dizziness symptoms and quality of life of the elderly with chronic Benign Paroxysmal Positional Vertigo (BPPV). In this randomized, single-blind and controlled trial, older adults with chronic BPPV were randomized into two groups, the experimental group (n = 7, age: 69 (65-78) years) and the control group (n = 7, age: 73 (65-76) years). Patients in the experimental group underwent balance VRT (50 min per session, two times a week) and Canalith Repositioning Maneuver (CRM) as required, for 13 weeks. The control group was treated using only CRM as required. Standing and dynamic balance, dizziness symptoms and quality of life were measured at the baseline, and at one, five, nine and thirteen weeks. There were no between-group differences in dizziness, quality of life and standing balance over the 13 weeks. Significant differences were observed in dynamic balance measures between groups (p <  0.05 for most tests) through assessments. In intragroup analysis, both groups showed improvements in all measurements except no improvement was found in majority of the dynamic balance tests in the control group. The patients who received additional balance VRT demonstrated better results in dynamic balance than those who received only CRM. Implications for Rehabilitation The findings that balance VRT in addition to CRM improves dynamic balance in elderly people with BPPV should be useful in guiding rehabilitation professionals' clinical decision making to design interventions for seniors suffering from BPPV; Improvements in tests of dynamic balance suggest that the risk of adverse consequences of BPPV in the elderly such as falls and fractures can be potentially reduced through implementation of CRM in conjunction with balance VRT; Lack of additional improvement in Visual Analogue Scale of dizziness and Dizziness Handicap Index suggests that addition of balance VRT does

  4. Positive impact of child feeding training program for primary care health professionals: a cluster randomized field trial

    Directory of Open Access Journals (Sweden)

    Márcia Regina Vitolo

    2014-12-01

    Full Text Available OBJECTIVE: To assess the impact of a child feeding training program for primary care health professionals about breastfeeding and complementary feeding practices. METHODS: Cluster-randomized field trial conducted in the city of Porto Alegre, (RS, Brazil. Twenty primary health care centers (HCC were randomized into intervention (n = 9 and control (n = 11 groups. The health professionals (n = 200 at the intervention group centers received training about healthy feeding practices. Pregnant women were enrolled at the study. Up to six months of child's age, home visits were made to obtain variables related to breastfeeding and introduction of foods. RESULTS: 619 children were evaluated: 318 from the intervention group and 301 from the control group. Exclusive breastfeeding prevalence in the first (72.3 versus 59.4%; RR = 1.21; 95%CI 1.08 - 1.38, second (62.6 versus 48.2%; RR = 1.29; 95%CI 1.10 - 1.53, and third months of life (44.0% versus 34.6%; RR = 1.27; 95%CI 1.04 - 1.56 was higher in the intervention group compared to the control group. The prevalence of children who consumed meat four or five times per week was higher in the intervention group than in the control group (36.8 versus 22.6%; RR = 1.62; 95%CI 1.32 - 2.03. The prevalence of children who had consumed soft drinks (34.9 versus 52.5%; RR = 0.66; 95%CI 0.54 - 0.80, chocolate (24.5 versus 36.7% RR = 0.66 95%CI 0.53 - 0.83, petit suisse (68.9 versus 79.7; 95%CI 0.75 - 0.98 and coffee (10.4 versus 20.1%; RR = 0.51; 95%CI 0.31 - 0.85 in their six first months of life was lower in the intervention group. CONCLUSION: The training of health professionals had a positive impact on infant feeding practices, contributing to the promotion of child health.

  5. Positive impact of child feeding training program for primary care health professionals: a cluster randomized field trial.

    Science.gov (United States)

    Vitolo, Márcia Regina; Louzada, Maria Laura da Costa; Rauber, Fernanda

    2014-12-01

    To assess the impact of a child feeding training program for primary care health professionals about breastfeeding and complementary feeding practices. Cluster-randomized field trial conducted in the city of Porto Alegre, (RS), Brazil. Twenty primary health care centers (HCC) were randomized into intervention (n = 9) and control (n = 11) groups. The health professionals (n = 200) at the intervention group centers received training about healthy feeding practices. Pregnant women were enrolled at the study. Up to six months of child's age, home visits were made to obtain variables related to breastfeeding and introduction of foods. 619 children were evaluated: 318 from the intervention group and 301 from the control group. Exclusive breastfeeding prevalence in the first (72.3 versus 59.4%; RR = 1.21; 95%CI 1.08 - 1.38), second (62.6 versus 48.2%; RR = 1.29; 95%CI 1.10 - 1.53), and third months of life (44.0% versus 34.6%; RR = 1.27; 95%CI 1.04 - 1.56) was higher in the intervention group compared to the control group. The prevalence of children who consumed meat four or five times per week was higher in the intervention group than in the control group (36.8 versus 22.6%; RR = 1.62; 95%CI 1.32 - 2.03). The prevalence of children who had consumed soft drinks (34.9 versus 52.5%; RR = 0.66; 95%CI 0.54 - 0.80), chocolate (24.5 versus 36.7% RR = 0.66 95%CI 0.53 - 0.83), petit suisse (68.9 versus 79.7; 95%CI 0.75 - 0.98) and coffee (10.4 versus 20.1%; RR = 0.51; 95%CI 0.31 - 0.85) in their six first months of life was lower in the intervention group. The training of health professionals had a positive impact on infant feeding practices, contributing to the promotion of child health.

  6. Effect of Telemedicine Education and Telemonitoring on Continuous Positive Airway Pressure Adherence. The Tele-OSA Randomized Trial.

    Science.gov (United States)

    Hwang, Dennis; Chang, Jeremiah W; Benjafield, Adam V; Crocker, Maureen E; Kelly, Colleen; Becker, Kendra A; Kim, Joseph B; Woodrum, Rosa R; Liang, Joanne; Derose, Stephen F

    2018-01-01

    Automated telemedicine interventions could potentially improve adherence to continuous positive airway pressure (CPAP) therapy. Examining the effects of telemedicine-delivered obstructive sleep apnea (OSA) education and CPAP telemonitoring with automated patient feedback messaging on CPAP adherence. This four-arm, randomized, factorial design clinical trial enrolled 1,455 patients (51.0% women; age, 49.1 ± 12.5 yr [mean ± SD]) referred for suspected OSA. Nine hundred and fifty-six underwent home sleep apnea testing, and 556 were prescribed CPAP. Two telemedicine interventions were implemented: 1) web-based OSA education (Tel-Ed) and 2) CPAP telemonitoring with automated patient feedback (Tel-TM). Patients were randomized to 1) usual care, 2) Tel-Ed added, 3) Tel-TM added, or 4) Tel-Ed and Tel-TM added (Tel-both). The primary endpoint was 90-day CPAP usage. Secondary endpoints included attendance to OSA evaluation, and change in Epworth Sleepiness Scale score. CPAP average daily use at 90 days was 3.8 ± 2.5, 4.0 ± 2.4, 4.4 ± 2.2, and 4.8 ± 2.3 hours in usual care, Tel-Ed, Tel-TM, and Tel-both groups. Usage was significantly higher in the Tel-TM and Tel-both groups versus usual care (P = 0.0002 for both) but not for Tel-Ed (P = 0.10). Medicare adherence rates were 53.5, 61.0, 65.6, and 73.2% in usual care, Tel-Ed, Tel-TM, and Tel-both groups (Tel-both vs. usual care, P = 0.001; Tel-TM vs. usual care, P = 0.003; Tel-Ed vs. usual care, P = 0.07), respectively. Telemedicine education improved clinic attendance compared with no telemedicine education (show rate, 68.5 vs. 62.7%; P = 0.02). The use of CPAP telemonitoring with automated feedback messaging improved 90-day adherence in patients with OSA. Telemedicine-based education did not significantly improve CPAP adherence but did increase clinic attendance for OSA evaluation. Clinical trial registered with www.clinicaltrials.gov (NCT02279901).

  7. A positioning pillow to improve lumbar puncture success rate in paediatric haematology-oncology patients: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Kassaï Behrouz

    2009-01-01

    Full Text Available Abstract Background Lumbar punctures (LPs are common in children with cancer. Although pain management during the lumbar puncture has been well standardized, dealing with stress and anxiety is not well addressed yet. Our objective was to evaluate the potential improvement of the LP success rate using a positioning pillow, to ensure maximum lumbar flexion, and allow paravertebral muscles to relax, in children who are awake, with either conscious sedation or no sedation. Methods Children aged 2–18 years undergoing LP were randomly assigned to a positioning pillow or no intervention. The primary outcome was the rate of success, i.e. achieving the LP (sampling or injection at the first attempt, without bleeding (RBC 3. The secondary outcomes included: the child's pain, assessed by a self-administered visual analogical scales (VAS for children over 6 years of age; the parents' and caregivers' perception of the child's pain; the satisfaction of the children, the parents, the caregivers and the physician. The child's cooperation and the occurrence of post-LP syndrome were also evaluated. Results 124 children (62 in each group were included. The LP pillow tended to increase the success rate of LPs (67% vs. 57%, p = 0.23, and decreased the post-LP syndromes (15% vs. 24%, p = 0.17 but the differences were not statistically significant. In children over 6-year of age (n = 72, the rate of success was significantly higher in the pillow group (58.5% vs. 41.5%, p = 0.031, with a tendency to feel less pain (median VAS 25 vs. 15 mm, p = 0.39 and being more satisfied (84.4% vs. 75.0%, p = 0.34. Conclusion Overall results do not demonstrate a benefit in using this pillow for lumbar punctures. This study results also suggest a benefit in the sub group of children over 6-year of age; this result needs confirmation. Trial Registration The trial was registered with Clinical Trials.gov (number NCT00775112.

  8. Elastic Tape Improved Shoulder Joint Position Sense in Chronic Hemiparetic Subjects: A Randomized Sham-Controlled Crossover Study

    Science.gov (United States)

    Souza, Matheus Bragança; Desloovere, Kaat; Russo, Thiago Luiz

    2017-01-01

    Background Elastic tape has been widely used in clinical practice in order to improve upper limb (UL) sensibility. However, there is little evidence that supports this type of intervention in stroke patients. Objective To verify the effect of elastic tape, applied to the paretic shoulder, on joint position sense (JPS) during abduction and flexion in subjects with chronic hemiparesis compared to sham tape (non-elastic tape). Furthermore, to verify if this potential effect is correlated to shoulder subluxation measurements and sensorimotor impairment. Methods A crossover and sham-controlled study was conducted with post-stroke patients who were randomly allocated into two groups: 1) those who received Sham Tape (ST) first and after one month they received Elastic Tape (ET); 2) those who received Elastic Tape (ET) first and after one month they received Sham Tape (ST). The JPS was evaluated using a dynamometer. The absolute error for shoulder abduction and flexion at 30° and 60° was calculated. Sensorimotor impairment was determined by Fugl-Meyer, and shoulder subluxation was measured using a caliper. Results Thirteen hemiparetic subjects (average time since stroke 75.23 months) participated in the study. At baseline (before interventions), the groups were not different for abduction at 30° (p = 0.805; p = 0.951), and 60° (p = 0.509; p = 0.799), or flexion at 30° (p = 0.872; p = 0.897) and 60° (p = 0.853; p = 0.970). For the ET group, differences between pre and post-elastic tape for abduction at 30° (ptape for abduction at 30° (ptape improved shoulder JPS of subjects with chronic hemiparesis regardless of the level of UL sensorimotor impairment. However, this improvement was influenced by the subluxation degree at abduction. PMID:28099472

  9. Nebulization during spontaneous breathing, CPAP, and bi-level positive-pressure ventilation: a randomized analysis of pulmonary radioaerosol deposition.

    Science.gov (United States)

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Savi, Augusto; de Oliveira, Roselaine Pinheiro; Machado, André Sant'ana; Tonietto, Tulio Frederico; Ludwig, Eduardo; Teixeira, Paulo José Zimermann; Knorst, Marli Maria

    2014-04-01

    There have been few reports of factors affecting aerosol delivery during noninvasive ventilation (NIV). Nebulization is a standard practice, and our objective was to determine the effect of spontaneous breathing (SB) and NIV mode on lung technetium-99m ((99m)Tc) deposition in subjects with normal lungs. Thirteen health care volunteers were submitted to a randomized radioaerosol nebulization with (99m)Tc during SB, CPAP (10 cm H2O), and bi-level positive-pressure ventilation (bi-level; inspiratory-expiratory pressures of 15/5 cm H2O). NIV was performed via a ventilator (VPAP II ST-A, ResMed, Sydney, Australia). The radioaerosol deposition was evaluated by pulmonary scintigraphy after 10 min of inhalation. Regions of interest (ROIs) were outlined on the left lung (LL), right lung (RL), and trachea (TRQ). The average number of counts/pixel in each ROI was determined, and the ratio of lung and trachea was calculated. The three techniques showed comparable lung deposition. Analysis of radioaerosol deposition in the lungs showed a mean count at RL of 108.7 ± 40 with CPAP, 111.5 ± 15 with bi-level, and 196.6 ± 167 with SB. At LL, the values were 92.7 ± 15 with CPAP, 98.4 ± 14 with bi-level, and 225.0 ± 293 with SB. There was no difference between the means of radioaerosol deposition in RL, LL, or TRQ, as well as the lung calculated ratio (LCR = [RL + LL]/TRQ), which was similar in comparing ventilatory strategies. Based on our data, there is an equivalent deposition of inhaled substances in individuals with healthy lungs when SB, CPAP, and bi-level are compared.

  10. Quantum dot molecules

    CERN Document Server

    Wu, Jiang

    2014-01-01

    This book reviews recent advances in the exciting and rapidly growing field of quantum dot molecules (QDMs). It offers state-of-the-art coverage of novel techniques and connects fundamental physical properties with device design.

  11. Graphene quantum dots

    CERN Document Server

    Güçlü, Alev Devrim; Korkusinski, Marek; Hawrylak, Pawel

    2014-01-01

    This book reflects the current status of theoretical and experimental research of graphene based nanostructures, in particular quantum dots, at a level accessible to young researchers, graduate students, experimentalists and theorists. It presents the current state of research of graphene quantum dots, a single or few monolayer thick islands of graphene. It introduces the reader to the electronic and optical properties of graphite, intercalated graphite and graphene, including Dirac fermions, Berry's phase associated with sublattices and valley degeneracy, covers single particle properties of

  12. Dot probe performance in two specific phobias.

    Science.gov (United States)

    Wenzel, A; Holt, C S

    1999-11-01

    The present study applied MacLeod, Mathews & Tata's (1986) dot probe attentional deployment methodology to individuals with specific phobias. Attentional deployment towards spider-related, blood-related, positive, negative, and neutral words was examined. Individuals with either spider phobia (N = 13) or blood/injury phobia (N = 14) and non-anxious controls (N = 14) completed the dot probe attentional deployment task. Individuals with specific phobias did not demonstrate an attentional bias towards phobia-related stimuli relevant to their particular fears. Semantic-based information processing paradigms may not be sufficiently potent to demonstrate biased performance towards threatening stimuli in individuals with mild specific phobias who are otherwise healthy.

  13. Recalling Positive Events at Work Makes Employees Feel Happier, Move More, but Interact Less: A 6-Week Randomized Controlled Intervention at a Japanese Workplace

    OpenAIRE

    Chancellor, J; Layous, K; Lyubomirsky, S

    2015-01-01

    © 2014, Springer Science+Business Media Dordrecht. Simple self-administered activities, such as practicing gratitude or kindness, have been shown to increase happiness, yet only self-report measures have been used so far. Our study, conducted with a Japanese workplace sample, incorporated a novel technology to gather precise behavioral data reflecting participant movement and social interactions. Employees were randomly assigned to either recount three positive events at work (a positive acti...

  14. Free Carrier Distribution Criterion in Quantum Dot Lasers

    Directory of Open Access Journals (Sweden)

    HIFSA SHAHID

    2016-07-01

    Full Text Available The spontaneous emission spectra of a 1.28?m InAs/GaAs QD (Quantum Dot Fabry-Perot laser device has been measured under continuous wave operation at a fixed junction temperature of 300K. At low carrier densities, empirically observed static peak wavelength position and a fixed spectral shape of the spontaneous emission spectra are indicative of the random-like population distribution rather than a global Fermi level in the system. A theoretical model based on the Monte-Carlo method has been shown to have good agreement with the empirical results. In addition the evolutions of spontaneous emission spectral shapes are also explained in terms of many body effects.

  15. Electrostatically confined trilayer graphene quantum dots

    Science.gov (United States)

    Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Peeters, F. M.

    2017-04-01

    Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry EKe(m ) =-EK'h(m ) for the electron (e ) and hole (h ) states, where m is the angular momentum quantum number and K and K ' label the two valleys. The electron and hole spectra for B =0 are twofold degenerate due to the intervalley symmetry EK(m ) =EK'[-(m +1 ) ] . For both ABC [α =1.5 (1.2) for large (small) R ] and ABA (α =1 ) stackings, the lowest-energy levels show approximately a R-α dependence on the dot radius R in contrast with the 1 /R3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B , the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings.

  16. Reducing Sexual Risk Behaviors and Alcohol Use among HIV-Positive Men Who Have Sex with Men: A Randomized Clinical Trial

    Science.gov (United States)

    Velasquez, Mary M.; von Sternberg, Kirk; Johnson, David H.; Green, Charles; Carbonari, Joseph P.; Parsons, Jeffrey T.

    2009-01-01

    This randomized clinical trial (N = 253) evaluated the efficacy of a theory-based intervention designed to reduce both alcohol use and incidence of unprotected sexual behaviors among HIV-positive men who have sex with men with alcohol use disorders. An integrated, manualized intervention, using both individual counseling and peer group…

  17. Self-consistent Maxwell-Bloch model of quantum-dot photonic-crystal-cavity lasers

    DEFF Research Database (Denmark)

    Cartar, William; Mørk, Jesper; Hughes, Stephen

    2017-01-01

    We present a powerful computational approach to simulate the threshold behavior of photonic-crystal quantum-dot (QD) lasers. Using a finite-difference time-domain (FDTD) technique, Maxwell-Bloch equations representing a system of thousands of statistically independent and randomly positioned two...... by matching the cavity quality factors and resonance properties. We also demonstrate how to obtain the correct point-dipole radiative decay rate from Fermi's golden rule, which is captured naturally by the FDTD method. Our numerical simulations predict that the pump threshold plateaus around cavity lengths...

  18. Germanium based electrostatic quantum dots: design and characterization.

    Science.gov (United States)

    Mazzeo, Giovanni; Yablonovitch, Eli; Jiang, Hong-Wen

    2010-03-01

    While the less mature Germanium technology requires an extra effort for the realization of single electron quantum dots, unique properties of Germanium rich heterostructures together with spin coherence times comparable to Silicon, can justify the development of such new technology. We report our progresses on the formation of electrostatic quantum dots in Germanium. We employ an MOS-like structure with no modulation doping already successfully proven in Silicon devices. A two level gate stack is used: the top gate is positively biased to attract electrons while the lowers gates are negatively biased to form the quantum dot and attract holes in a transistor channel, used to detect the electrons in the adjacent quantum dot. Finite Element Method simulations are used to prove the concept of this hybrid holes-transistor/electron-QD device and estimate the sensitivity of the charge detection. Preliminary characterizations of quantum dot devices built with this structure are reported.

  19. Effects of stereospecific positioning of fatty acids in triacylglycerol structures in native and randomized fats: a review of their nutritional implications

    Directory of Open Access Journals (Sweden)

    Sundram Kalyana

    2007-07-01

    Full Text Available Abstract Most studies on lipid lowering diets have focused on the total content of saturated, polyunsaturated and monounsaturated fatty acids. However, the distribution of these fatty acids on the triacylglycerol (TAG molecule and the molecular TAG species generated by this stereospecificity are characteristic for various native dietary TAGs. Fat randomization or interesterification is a process involving the positional redistribution of fatty acids, which leads to the generation of new TAG molecular species. A comparison between native and randomized TAGs is the subject of this review with regards to the role of stereospecificity of fatty acids in metabolic processing and effects on fasting lipids and postprandial lipemia. The positioning of unsaturated versus saturated fatty acids in the sn-2 position of TAGs indicate differences in early metabolic processing and postprandial clearance, which may explain modulatory effects on atherogenecity and thrombogenecity. Both human and animal studies are discussed with implications for human health.

  20. Needle Tip Position and Bevel Direction Have No Effect in the Fluoroscopic Epidural Spreading Pattern in Caudal Epidural Injections: A Randomized Trial

    Directory of Open Access Journals (Sweden)

    Won Kyoung Kwon

    2016-01-01

    Full Text Available Background. Caudal epidural steroid injections (CESIs are an effective treatment for pain. If the injection spreads in a specific pattern depending on the needle position or bevel direction, it would be possible to inject the agent into a specific and desired area. Objectives. We conducted a prospective randomized trial to determine if the needle position and bevel direction have any effect on the epidural spreading pattern in CESI. Methods. Demographic data of the patient were collected. During CESI, the needle position (middle or lateral and direction (ventral or dorsal were randomly allocated. Following fluoroscope-guided injection of 4 mL contrast media and 10 mL of injectates, the epidural spreading patterns (ventral or dorsal, bilateral or lateral were imaged. Results. In the 210 CESIs performed, the needle tip position and bevel direction did not influence the epidural spreading patterns at L4-5 and L5-S1 disc levels. A history of Lumbar spine surgery was associated with a significantly limited spread to each disc level. A midline needle tip position was more effective than the lateral position in spreading to the distant disc levels. Conclusions. Neither the needle tip position nor the bevel direction affected the epidural drug spreading pattern during CESI.

  1. Atomistic theory of excitonic fine structure in InAs/InP nanowire quantum dot molecules

    Science.gov (United States)

    Świderski, M.; Zieliński, M.

    2017-03-01

    Nanowire quantum dots have peculiar electronic and optical properties. In this work we use atomistic tight binding to study excitonic spectra of artificial molecules formed by a double nanowire quantum dot. We demonstrate a key role of atomistic symmetry and nanowire substrate orientation rather than cylindrical shape symmetry of a nanowire and a molecule. In particular for [001 ] nanowire orientation we observe a nonvanishing bright exciton splitting for a quasimolecule formed by two cylindrical quantum dots of different heights. This effect is due to interdot coupling that effectively reduces the overall symmetry, whereas single uncoupled [001 ] quantum dots have zero fine structure splitting. We found that the same double quantum dot system grown on [111 ] nanowire reveals no excitonic fine structure for all considered quantum dot distances and individual quantum dot heights. Further we demonstrate a pronounced, by several orders of magnitude, increase of the dark exciton optical activity in a quantum dot molecule as compared to a single quantum dot. For [111 ] systems we also show spontaneous localization of single particle states in one of nominally identical quantum dots forming a molecule, which is mediated by strain and origins from the lack of the vertical inversion symmetry in [111 ] nanostructures of overall C3 v symmetry. Finally, we study lowering of symmetry due to alloy randomness that triggers nonzero excitonic fine structure and the dark exciton optical activity in realistic nanowire quantum dot molecules of intermixed composition.

  2. Using ArcMap, Google Earth, and Global Positioning Systems to select and locate random households in rural Haiti

    Directory of Open Access Journals (Sweden)

    Wampler Peter J

    2013-01-01

    Full Text Available Abstract Background A remote sensing technique was developed which combines a Geographic Information System (GIS; Google Earth, and Microsoft Excel to identify home locations for a random sample of households in rural Haiti. The method was used to select homes for ethnographic and water quality research in a region of rural Haiti located within 9 km of a local hospital and source of health education in Deschapelles, Haiti. The technique does not require access to governmental records or ground based surveys to collect household location data and can be performed in a rapid, cost-effective manner. Methods The random selection of households and the location of these households during field surveys were accomplished using GIS, Google Earth, Microsoft Excel, and handheld Garmin GPSmap 76CSx GPS units. Homes were identified and mapped in Google Earth, exported to ArcMap 10.0, and a random list of homes was generated using Microsoft Excel which was then loaded onto handheld GPS units for field location. The development and use of a remote sensing method was essential to the selection and location of random households. Results A total of 537 homes initially were mapped and a randomized subset of 96 was identified as potential survey locations. Over 96% of the homes mapped using Google Earth imagery were correctly identified as occupied dwellings. Only 3.6% of the occupants of mapped homes visited declined to be interviewed. 16.4% of the homes visited were not occupied at the time of the visit due to work away from the home or market days. A total of 55 households were located using this method during the 10 days of fieldwork in May and June of 2012. Conclusions The method used to generate and field locate random homes for surveys and water sampling was an effective means of selecting random households in a rural environment lacking geolocation infrastructure. The success rate for locating households using a handheld GPS was excellent and only

  3. Using ArcMap, Google Earth, and Global Positioning Systems to select and locate random households in rural Haiti.

    Science.gov (United States)

    Wampler, Peter J; Rediske, Richard R; Molla, Azizur R

    2013-01-18

    A remote sensing technique was developed which combines a Geographic Information System (GIS); Google Earth, and Microsoft Excel to identify home locations for a random sample of households in rural Haiti. The method was used to select homes for ethnographic and water quality research in a region of rural Haiti located within 9 km of a local hospital and source of health education in Deschapelles, Haiti. The technique does not require access to governmental records or ground based surveys to collect household location data and can be performed in a rapid, cost-effective manner. The random selection of households and the location of these households during field surveys were accomplished using GIS, Google Earth, Microsoft Excel, and handheld Garmin GPSmap 76CSx GPS units. Homes were identified and mapped in Google Earth, exported to ArcMap 10.0, and a random list of homes was generated using Microsoft Excel which was then loaded onto handheld GPS units for field location. The development and use of a remote sensing method was essential to the selection and location of random households. A total of 537 homes initially were mapped and a randomized subset of 96 was identified as potential survey locations. Over 96% of the homes mapped using Google Earth imagery were correctly identified as occupied dwellings. Only 3.6% of the occupants of mapped homes visited declined to be interviewed. 16.4% of the homes visited were not occupied at the time of the visit due to work away from the home or market days. A total of 55 households were located using this method during the 10 days of fieldwork in May and June of 2012. The method used to generate and field locate random homes for surveys and water sampling was an effective means of selecting random households in a rural environment lacking geolocation infrastructure. The success rate for locating households using a handheld GPS was excellent and only rarely was local knowledge required to identify and locate households. This

  4. Double quantum dot memristor

    Science.gov (United States)

    Li, Ying; Holloway, Gregory W.; Benjamin, Simon C.; Briggs, G. Andrew D.; Baugh, Jonathan; Mol, Jan A.

    2017-08-01

    Memristive systems are generalizations of memristors, which are resistors with memory. In this paper, we present a quantum description of quantum dot memristive systems. Using this model we propose and experimentally demonstrate a simple and practical scheme for realizing memristive systems with quantum dots. The approach harnesses a phenomenon that is commonly seen as a bane of nanoelectronics, i.e., switching of a trapped charge in the vicinity of the device. We show that quantum dot memristive systems have hysteresis current-voltage characteristics and quantum jump-induced stochastic behavior. While our experiment requires low temperatures, the same setup could, in principle, be realized with a suitable single-molecule transistor and operated at or near room temperature.

  5. A randomized controlled trial for an individualized positive psychosocial intervention for the affective and behavioral symptoms of dementia in nursing home residents.

    Science.gov (United States)

    Van Haitsma, Kimberly S; Curyto, Kimberly; Abbott, Katherine M; Towsley, Gail L; Spector, Abby; Kleban, Morton

    2015-01-01

    This randomized controlled study tested the effectiveness of individualized activities, led by certified nursing assistants (CNAs), to increase positive and reduce negative affect and behavior among nursing home residents with dementia. Nursing home residents with mild to advanced dementia (N = 180) were randomly assigned to usual care (UC, n = 93) or 1 of 2 experimental conditions. Residents in the attention control group (AC, N = 43) participated in standardized one-to-one activities with their CNAs. Individualized Positive Psychosocial Intervention (IPPI) participants (n = 44) received a CNA-led activity matched to their interests and ability. Outcomes were residents' positive and negative affect and verbal and nonverbal behavior. The IPPI and AC groups experienced similar benefits-more pleasure, alertness, engagement, positive touch, and positive verbal behavior-compared with UC. The AC group displayed more anger, uncooperativeness, and very negative verbal behavior than UC or IPPI. This study demonstrates the value of individualized activities for nursing home residents with dementia. In a stringent test, residents were happier and less angry during a customized intervention compared with a standardized intervention. Even brief individualized CNA-led activities bring pleasure to nursing home residents and constitute an effective strategy to enhance positive affect and engagement in persons with dementia. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Hexagonal graphene quantum dots

    KAUST Repository

    Ghosh, Sumit

    2016-12-05

    We study hexagonal graphene quantum dots, using density functional theory, to obtain a quantitative description of the electronic properties and their size dependence, considering disk and ring geometries with both armchair and zigzag edges. We show that the electronic properties of quantum dots with armchair edges are more sensitive to structural details than those with zigzag edges. As functions of the inner and outer radii, we find in the case of armchair edges that the size of the band gap follows distinct branches, while in the case of zigzag edges it changes monotonically. This behaviour is further analyzed by studying the ground state wave function and explained in terms of its localisation.

  7. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  8. Wafer scale integration of catalyst dots into nonplanar microsystems

    DEFF Research Database (Denmark)

    Gjerde, Kjetil; Kjelstrup-Hansen, Jakob; Gammelgaard, Lauge

    2007-01-01

    In order to successfully integrate bottom-up fabricated nanostructures such as carbon nanotubes or silicon, germanium, or III-V nanowires into microelectromechanical systems on a wafer scale, reliable ways of integrating catalyst dots are needed. Here, four methods for integrating sub-100-nm...... diameter nickel catalyst dots on a wafer scale are presented and compared. Three of the methods are based on a p-Si layer utilized as an in situ mask, an encapsulating layer, and a sacrificial window mask, respectively. All methods enable precise positioning of nickel catalyst dots at the end...

  9. Carbon dots based FRET for the detection of DNA damage.

    Science.gov (United States)

    Kudr, Jiri; Richtera, Lukas; Xhaxhiu, Kledi; Hynek, David; Heger, Zbynek; Zitka, Ondrej; Adam, Vojtech

    2017-06-15

    Here, we aimed our attention at the synthesis of carbon dots (C-dots) with the ability to interact with DNA to suggest an approach for the detection of DNA damage. Primarily, C-dots modified with amine moieties were synthesized using the one-step microwave pyrolysis of citric acid in the presence of diethylenetriamine. The C-dots showed strong photoluminescence with a quantum yield of 4%. In addition, the C-dots (2.8±0.8nm) possessed a good colloidal stability and exhibited a positive surface charge (ζ=36mV) at a neutral pH. An interaction study of the C-dots and the DNA fragment of λ bacteriophage was performed, and the DNA binding resulted in changes to the photoluminescent and absorption properties of the C-dots. A binding of the C-dots to DNA was also observed as a change to DNA electrophoretic mobility and a decreased ability to intercalate ethidium bromide (EtBr). Moreover, the Förster (or fluorescence) resonance energy transfer (FRET) between the C-dots and EtBr was studied, in which the C-dots serve as an excitation energy donor and the EtBr serves as an acceptor. When DNA was damaged using ultraviolet (UV) radiation (λ=254nm) and hydroxyl radicals, the intensity of the emitted photoluminescence at 612nm significantly decreased. The concept was proved on analysis of the genomic DNA from PC-3 cells and DNA isolated from melanoma tissues. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. From Dot to Line to Plane: Constellating Unconscious Imagery in Art Therapy

    Science.gov (United States)

    Steinhardt, Lenore

    2017-01-01

    In this article I describe an art-based procedure with a gradual sequence of drawing tasks that guides an art therapy client through graphic stages from point, to line, to plane. The client begins by making random dots, connecting them one to another with an unbroken line that reaches all the dots, perceiving abstract or figurative imagery in the…

  11. Effects of a health education and telephone counseling program on patients with a positive fecal occult blood test result for colorectal cancer screening: A randomized controlled trial.

    Science.gov (United States)

    Chiu, Hui-Chuan; Hung, Hsin-Yuan; Lin, Hsiu-Chen; Chen, Shu-Ching

    2017-10-01

    Our purpose was to evaluate the effects of a health education and telephone counseling program on knowledge and attitudes about colorectal cancer and screening and the psychological impact of positive screening results. A randomized controlled trial was conducted with 2 groups using a pretest and posttest measures design. Patients with positive colorectal cancer screening results were selected and randomly assigned to an experimental (n = 51) or control (n = 51) group. Subjects in the experimental group received a health education and telephone counseling program, while the control group received routine care only. Patients were assessed pretest before intervention (first visit to the outpatient) and posttest at 4 weeks after intervention (4 weeks after first visit to the outpatient). Patients in the experimental group had a significantly better level of knowledge about colorectal cancer and the psychological impact of a positive screening result than did the control group. Analysis of covariance revealed that the health education and telephone counseling program had a significant main effect on colorectal cancer knowledge. A health education and telephone counseling program can improve knowledge about colorectal cancer and about the psychological impact in patients with positive colorectal cancer screening results. The health education and telephone counseling program is an easy, simple, and convenient method of improving knowledge, improving attitudes, and alleviating psychological distress in patients with positive colorectal cancer screening results, and this program can be expanded to other types of cancer screening. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

    Low temperature electron transport measurements on individual single wall carbon nanotubes are described in this thesis. Carbon nanotubes are small hollow cylinders made entirely out of carbon atoms. At low temperatures (below ~10 K) finite length nanotubes form quantum dots. Because of its small

  13. White dots do matter

    DEFF Research Database (Denmark)

    Soeken, Mathias; Thomsen, Michael Kirkedal

    2013-01-01

    Toffoli circuits. We also show how to use these rules to derive more complex formulas. The major difference compared to existing approaches is the use of negative controls (white dots), which significantly increases the algebraic strength. We show how existing optimisation approaches can be adapted...

  14. Reducing inhomogeneity in the dynamic properties of quantum dots via self-aligned plasmonic cavities.

    Science.gov (United States)

    Demory, Brandon; Hill, Tyler A; Teng, Chu-Hsiang; Deng, Hui; Ku, P C

    2018-01-05

    A plasmonic cavity is shown to greatly reduce the inhomogeneity of dynamic optical properties such as quantum efficiency and radiative lifetime of InGaN quantum dots. By using an open-top plasmonic cavity structure, which exhibits a large Purcell factor and antenna quantum efficiency, the resulting quantum efficiency distribution for the quantum dots narrows and is no longer limited by the quantum dot inhomogeneity. The standard deviation of the quantum efficiency can be reduced to 2% while maintaining the overall quantum efficiency at 70%, making InGaN quantum dots a viable candidate for high-speed quantum cryptography and random number generation applications.

  15. Quantum-dot infrared photodetectors: a review

    Science.gov (United States)

    Stiff-Roberts, Adrienne D.

    2009-04-01

    Quantum-dot infrared photodetectors (QDIPs) are positioned to become an important technology in the field of infrared (IR) detection, particularly for high-temperature, low-cost, high-yield detector arrays required for military applications. High-operating temperature (>=150 K) photodetectors reduce the cost of IR imaging systems by enabling cryogenic dewars and Stirling cooling systems to be replaced by thermo-electric coolers. QDIPs are well-suited for detecting mid-IR light at elevated temperatures, an application that could prove to be the next commercial market for quantum dots. While quantum dot epitaxial growth and intraband absorption of IR radiation are well established, quantum dot non-uniformity remains as a significant challenge. Nonetheless, state-of-the-art mid-IR detection at 150 K has been demonstrated using 70-layer InAs/GaAs QDIPs, and QDIP focal plane arrays are approaching performance comparable to HgCdTe at 77 K. By addressing critical challenges inherent to epitaxial QD material systems (e.g., controlling dopant incorporation), exploring alternative QD systems (e.g., colloidal QDs), and using bandgap engineering to reduce dark current and enhance multi-spectral detection (e.g. resonant tunneling QDIPs), the performance and applicability of QDIPs will continue to improve.

  16. Atomically precise, coupled quantum dots fabricated by cleaved edge overgrowth

    Science.gov (United States)

    Wegscheider, W.; Schedelbeck, G.; Bichler, M.; Abstreiter, G.

    Recent progress in the fabrication of quantum dots by molecular beam epitaxy along three directions in space is reviewed. The optical properties of different sample structures consisting of individual quantum dots, pairs of coupled dots as well as of linear arrays of dots are studied by microscopic photoluminescence spectroscopy. The high degree of control over shape, composition and position of the 7×7×7 nm3 size GaAs quantum dots, which form at the intesection of three orthogonal quantum wells, allows a detailed investigation of the influence of coupling between almost identical zero-dimensional objects. In contrast to the inhomogeneously broadened quantum well and quantum wire signals originating from the complex twofold cleaved edge overgrowth structure, the photoluminescence spetrum of an individual quantum dot exhibits a single sharp line (full width at half maximum denomination "artificial atoms" for the quantum dots. It is further demonstrated that an "artifical molecule", characterized by the existence of bonding and antibonding states can be assembled from two of such "artificial atoms". The coupling strength between the "artificial atoms" is adjusted by the "interatomic" distance and is reflected in the energetic separation of the bonding and antibonding levels and the linewidths of the corresponding interband transitions.

  17. Design and Synthesis of Antiblinking and Antibleaching Quantum Dots in Multiple Colors via Wave Function Confinement.

    Science.gov (United States)

    Cao, Hujia; Ma, Junliang; Huang, Lin; Qin, Haiyan; Meng, Renyang; Li, Yang; Peng, Xiaogang

    2016-12-07

    Single-molecular spectroscopy reveals that photoluminescence (PL) of a single quantum dot blinks, randomly switching between bright and dim/dark states under constant photoexcitation, and quantum dots photobleach readily. These facts cast great doubts on potential applications of these promising emitters. After ∼20 years of efforts, synthesis of nonblinking quantum dots is still challenging, with nonblinking quantum dots only available in red-emitting window. Here we report synthesis of nonblinking quantum dots covering most part of the visible window using a new synthetic strategy, i.e., confining the excited-state wave functions of the core/shell quantum dots within the core quantum dot and its inner shells (≤ ∼5 monolayers). For the red-emitting ones, the new synthetic strategy yields nonblinking quantum dots with small sizes (∼8 nm in diameter) and improved nonblinking properties. These new nonblinking quantum dots are found to be antibleaching. Results further imply that the PL blinking and photobleaching of quantum dots are likely related to each other.

  18. Promoting a Positive Middle School Transition: A Randomized-Controlled Treatment Study Examining Self-Concept and Self-Esteem.

    Science.gov (United States)

    Coelho, Vitor Alexandre; Marchante, Marta; Jimerson, Shane R

    2017-03-01

    The middle school transition is a salient developmental experience impacting adolescents around the world. This study employed a randomized-controlled treatment design, with randomization at the school level, to investigate the impact of a school adjustment program for middle school transition and potential gender differences. Participants included 1147 students (M age = 9.62; SD = 0.30, 45.7 % girls), who were assessed at four time points during the transition, regarding five dimensions of self-concept (academic, social, emotional, physical and family) and self-esteem. Parallel growth curves were employed to analyze the evolution of self-concept. Following the transition to middle school, students reported lower levels of self-concept (academic, emotional and physical) and self-esteem, while participation in the intervention led to increases in self-esteem and gains in social self-concept. No gender differences were found. These results provide preliminary evidence supporting such interventions in early middle school transitions.

  19. Up-Down Hand Position Switch May Delay the Fatigue of Non-Dominant Hand Position Rescuers and Improve Chest Compression Quality during Cardiopulmonary Resuscitation: A Randomized Crossover Manikin Study

    Science.gov (United States)

    Xu, Bing; Wang, Huang-Lei; Xiong, Dan; Sheng, Li-Pin; Yang, Qi-Sheng; Jiang, Shan; Xu, Peng; Chen, Zhi-Qiao; Zhao, Yan

    2015-01-01

    Previous studies have shown improved external chest compression (ECC) quality and delayed rescuer fatigue when the dominant hand (DH) was in contact with the sternum. However, many rescuers prefer placing the non-dominant hand (NH) in contact with the sternum during ECC. We aimed to investigate the effects of up-down hand position switch on the quality of ECC and the fatigue of rescuers during cardiopulmonary resuscitation (CPR). After completion of a review of the standard adult basic life support (BLS) course, every candidate performed 10 cycles of single adult CPR twice on an adult manikin with either a constant hand position (CH) or a switched hand position (SH) in random order at 7-day intervals. The rescuers’ general characteristics, hand positions, physiological signs, fatigue appearance and ECC qualities were recorded. Our results showed no significant differences in chest compression quality for the DH position rescuers between the CH and SH sessions (p>0.05, resp.). And also no significant differences were found for Borg score (p = 0.437) or cycle number (p = 0.127) of fatigue appearance after chest compressions between the two sessions. However, for NH position rescuers, the appearance of fatigue was delayed (p = 0.046), with a lower Borg score in the SH session (12.67 ± 2.03) compared to the CH session (13.33 ± 1.95) (p = 0.011). Moreover, the compression depth was significantly greater in the SH session (39.3 ± 7.2 mm) compared to the CH session (36.3 ± 8.1 mm) (p = 0.015). Our data suggest that the up-down hand position switch during CPR may delay the fatigue of non-dominant hand position rescuers and improve the quality of chest compressions. PMID:26267353

  20. Influence of Head and Neck Position on Oropharyngeal Leak Pressure and Cuff Position with the ProSeal Laryngeal Mask Airway and the I-Gel: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar Mishra

    2015-01-01

    Full Text Available Background. This study was designed to assess and compare the effect of head and neck position on the oropharyngeal leak pressures and cuff position (employing fibreoptic view of the glottis and ventilation scores between ProSeal LMA and the I-gel. Material and Methods. After induction of anesthesia, the supraglottic device was inserted and ventilation confirmed. The position of the head was randomly changed from neutral to flexion, extension, and lateral rotation (left. The oropharyngeal leak pressures, fibreoptic view of glottis, ventilation scores, and delivered tidal volumes and end tidal CO2 were noted in all positions. Results. In both groups compared with neutral position, oropharyngeal leak pressures were significantly higher with flexion and lower with extension but similar with rotation of head and neck. However the oropharyngeal leak pressure was significantly higher for ProSeal LMA compared with the I-gel in all positions. Peak airway pressures were significantly higher with flexion in both groups (however this did not affect ventilation, lower with extension in ProSeal group, and comparable in I-gel group but did not change significantly with rotation of head and neck in both groups. Conclusion. Effective ventilation can be done with both ProSeal LMA and I-gel with head in all the above positions. ProSeal LMA has a better margin of safety than I-gel due to better sealing pressures except in flexion where the increase in airway pressure is more with the former. Extreme precaution should be taken in flexion position in ProSeal LMA.

  1. Dot1 binding induces chromatin rearrangements by histone methylation-dependent and -independent mechanisms

    Directory of Open Access Journals (Sweden)

    Stulemeijer Iris JE

    2011-02-01

    Full Text Available Abstract Background Methylation of histone H3 lysine 79 (H3K79 by Dot1 is highly conserved among species and has been associated with both gene repression and activation. To eliminate indirect effects and examine the direct consequences of Dot1 binding and H3K79 methylation, we investigated the effects of targeting Dot1 to different positions in the yeast genome. Results Targeting Dot1 did not activate transcription at a euchromatic locus. However, chromatin-bound Dot1 derepressed heterochromatin-mediated gene silencing over a considerable distance. Unexpectedly, Dot1-mediated derepression was established by both a H3K79 methylation-dependent and a methylation-independent mechanism; the latter required the histone acetyltransferase Gcn5. By monitoring the localization of a fluorescently tagged telomere in living cells, we found that the targeting of Dot1, but not its methylation activity, led to the release of a telomere from the repressive environment at the nuclear periphery. This probably contributes to the activity-independent derepression effect of Dot1. Conclusions Targeting of Dot1 promoted gene expression by antagonizing gene repression through both histone methylation and chromatin relocalization. Our findings show that binding of Dot1 to chromatin can positively affect local gene expression by chromatin rearrangements over a considerable distance.

  2. A community-engaged randomized controlled trial of an integrative intervention with HIV-positive, methamphetamine-using men who have sex with men.

    Science.gov (United States)

    Carrico, Adam W; Jain, Jennifer; Discepola, Michael V; Olem, David; Andrews, Rick; Woods, William J; Neilands, Torsten B; Shoptaw, Steven; Gómez, Walter; Dilworth, Samantha E; Moskowitz, Judith T

    2016-07-30

    Contingency management (CM) is an evidence-based intervention providing tangible rewards as positive reinforcement for abstinence from stimulants such as methamphetamine. Integrative approaches targeting affect regulation could boost the effectiveness of CM in community-based settings and optimize HIV/AIDS prevention efforts. This randomized controlled trial with HIV-positive, methamphetamine-using men who have sex with men (MSM) is examining the efficacy of a 5-session, individually delivered positive affect regulation intervention - Affect Regulation Treatment to Enhance Methamphetamine Intervention Success (ARTEMIS). ARTEMIS is designed to sensitize individuals to non-drug-related sources of reward as well as assist with managing depression and other symptoms of stimulant withdrawal during CM. HIV-positive, methamphetamine-using MSM who are enrolled in a community-based, 12-week CM program are randomized to receive ARTEMIS or an attention-matched control condition. Follow-up assessments are conducted at 3, 6, 12, and 15 months after enrollment in CM. Four peripheral venous blood samples are collected over the 15-month follow-up with specimen banking for planned biomarker sub-studies. The primary outcome is mean HIV viral load. Secondary outcomes include: sustained HIV viral suppression, T-helper cell count, psychological adjustment, stimulant use, and potentially amplified transmission risk behavior. Implementation of this randomized controlled trial highlights the importance of delineating boundaries between research activities and community-based service provision. It also provides insights into best practices for integrating the distinct agendas of academic and community partners in clinical research. This trial is currently enrolling and data collection is anticipated to be completed in September of 2018. This trial was registered on clinicaltrials.gov ( NCT01926184 ) on August 16, 2013.

  3. A community-engaged randomized controlled trial of an integrative intervention with HIV-positive, methamphetamine-using men who have sex with men

    Directory of Open Access Journals (Sweden)

    Adam W. Carrico

    2016-07-01

    Full Text Available Abstract Background Contingency management (CM is an evidence-based intervention providing tangible rewards as positive reinforcement for abstinence from stimulants such as methamphetamine. Integrative approaches targeting affect regulation could boost the effectiveness of CM in community-based settings and optimize HIV/AIDS prevention efforts. Methods/Design This randomized controlled trial with HIV-positive, methamphetamine-using men who have sex with men (MSM is examining the efficacy of a 5-session, individually delivered positive affect regulation intervention – Affect Regulation Treatment to Enhance Methamphetamine Intervention Success (ARTEMIS. ARTEMIS is designed to sensitize individuals to non-drug-related sources of reward as well as assist with managing depression and other symptoms of stimulant withdrawal during CM. HIV-positive, methamphetamine-using MSM who are enrolled in a community-based, 12-week CM program are randomized to receive ARTEMIS or an attention-matched control condition. Follow-up assessments are conducted at 3, 6, 12, and 15 months after enrollment in CM. Four peripheral venous blood samples are collected over the 15-month follow-up with specimen banking for planned biomarker sub-studies. The primary outcome is mean HIV viral load. Secondary outcomes include: sustained HIV viral suppression, T-helper cell count, psychological adjustment, stimulant use, and potentially amplified transmission risk behavior. Discussion Implementation of this randomized controlled trial highlights the importance of delineating boundaries between research activities and community-based service provision. It also provides insights into best practices for integrating the distinct agendas of academic and community partners in clinical research. This trial is currently enrolling and data collection is anticipated to be completed in September of 2018. Trial registration This trial was registered on clinicaltrials.gov ( NCT01926184 on

  4. Positive imagery cognitive bias modification (CBM) and internet-based cognitive behavioral therapy (iCBT) : a randomized controlled trial

    NARCIS (Netherlands)

    Williams, Alishia D; O'Moore, Kathleen; Blackwell, Simon E; Smith, Jessica; Holmes, Emily A; Andrews, Gavin

    2015-01-01

    BACKGROUND: Accruing evidence suggests that positive imagery-based cognitive bias modification (CBM) could have potential as a standalone targeted intervention for depressive symptoms or as an adjunct to existing treatments. We sought to establish the benefit of this form of CBM when delivered prior

  5. Effect of Continuous Positive Airway Pressure on Airway Reactivity in Asthma. A Randomized, Sham-controlled Clinical Trial

    OpenAIRE

    Holbrook, Janet T.; Sugar, Elizabeth A.; Brown, Robert H., Jr.; Drye, Lea T.; Irvin, Charles G.; Schwartz, Alan R.; Tepper, Robert S.; Wise, Robert A; Yasin, Razan Z.; Busk, Michael F.

    2016-01-01

    Rationale: Studies have demonstrated that application of stress suppresses airway smooth muscle contractility. In animal models of asthma, continuous positive airway pressure (CPAP) reduced airway reactivity. Short-term studies of CPAP in patients with asthma showed reductions in airway reactivity.

  6. Challenging medical students with an interim assessment: a positive effect on formal examination score in a randomized controlled study.

    NARCIS (Netherlands)

    Olde Bekkink, M.; Donders, R.; Muijen, G.N.P. van; Ruiter, D.J.

    2012-01-01

    Until now, positive effects of assessment at a medical curriculum level have not been demonstrated. This study was performed to determine whether an interim assessment, taken during a small group work session of an ongoing biomedical course, results in students' increased performance at the formal

  7. Efficacy of a Multicomponent Positive Psychology Self-Help Intervention: Study Protocol of a Randomized Controlled Trial

    NARCIS (Netherlands)

    Schotanus-Dijkstra, Marijke; Drossaert, Constance H.C.; Pieterse, Marcel E.; Walburg, J.A.; Bohlmeijer, Ernst Thomas

    2015-01-01

    Background: Positive psychology interventions have been found to enhance well-being and decrease clinical symptomatology. However, it is still unknown how flourishing can also be increased. Although multicomponent interventions seem to be necessary for this purpose, different formats can be used. A

  8. "Familias: Preparando La Nueva Generación": A Randomized Control Trial Testing the Effects on Positive Parenting Practices

    Science.gov (United States)

    Marsiglia, Flavio F.; Williams, Lela Rankin; Ayers, Stephanie L.; Booth, Jaime M.

    2014-01-01

    Objectives: This article reports the effects of a culturally grounded parenting intervention to strengthen positive parenting practices. Method: The intervention was designed and tested with primarily Mexican origin parents in a large urban setting of the southwestern United States using an ecodevelopmental approach. Parents (N = 393) were…

  9. iRPIS-PseNNC: identifying RNA-protein interaction sites by incorporating the position-specific dinucleotide propensity into ensemble random forest approach

    Science.gov (United States)

    Li, Long; Chen, Guojin; Jin, Tingdu

    2017-06-01

    As the pile of RNA-Protein complexes sequences mounted, in order to overcome time-consuming problem of the traditional identify RNA-Protein interaction sites (RPIS) method, it is urgent need develop intelligent recognition approach for quickly and reliable recognition of the RNA-Protein interaction sites (RPIS). To settle the question, we developed a new method named iRPIS-PseNNC, in which each sample is a nineteen nucleotides segment that for positive the centre of the segments is RPIS and for negative the segments centre is non-RPIS, and the sample was obtained by sliding window. The RNA sample was formulated by combining the dipeptide position-specific propensity into random forest approach, and by using the random sampling to balance the training dataset. According the voting system, we combine eleven random forest together to construct an ensemble classifier. It is shown that via the rigorous cross validations that the new predictor “iRPIS-PseNNC” achieved very high percentage of accuracy than any other existing algorithms in this field, indicating that the iRPIS-PseNNC predictor will be an effective tool for prediction RNA-Protein interaction sites.

  10. Problem behavior and urban, low-income youth: a randomized controlled trial of positive action in Chicago.

    Science.gov (United States)

    Lewis, Kendra M; Schure, Marc B; Bavarian, Niloofar; DuBois, David L; Day, Joseph; Ji, Peter; Silverthorn, Naida; Acock, Alan; Vuchinich, Samuel; Flay, Brian R

    2013-06-01

    Youth problem behaviors remain a public health issue. Youth in low-income, urban areas are particularly at risk for engaging in aggressive, violent, and disruptive behaviors. To evaluate the effects of a school-based social-emotional learning and health promotion program on problem behaviors and related attitudes among low-income, urban youth. A matched-pair, cluster RCT. Participants were drawn from 14 Chicago Public Schools over a 6-year period of program delivery with outcomes assessed for a cohort of youth followed from Grades 3 to 8. Data were collected from Fall 2004 to Spring 2010, and analyzed in Spring 2012. The Positive Action program includes a scoped and sequenced K-12 classroom curriculum with six components: self-concept, social and emotional positive actions for managing oneself responsibly, and positive actions directed toward physical and mental health, honesty, getting along with others, and continually improving oneself. The program also includes teacher, counselor, family, and community training as well as activities directed toward schoolwide climate development. Youth reported on their normative beliefs in support of aggression and on their bullying, disruptive, and violent behaviors; parents rated youths' bullying behaviors and conduct problems; schoolwide data on disciplinary referrals and suspensions were obtained from school records. Multilevel growth-curve modeling analyses conducted on completion of the trial indicated that Positive Action mitigated increases over time in (1) youth reports of normative beliefs supporting aggressive behaviors and of engaging in disruptive behavior and bullying (girls only) and (2) parent reports of youth bullying behaviors (boys only). At study end-point, students in Positive Action schools also reported a lower rate of violence-related behavior than students in control schools. Schoolwide findings indicated positive program effects on both disciplinary referrals and suspensions. Program effect sizes

  11. Positive Effect of Probiotics on Constipation in Children: A Systematic Review and Meta-Analysis of Six Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Jianan Hu

    2017-04-01

    Full Text Available Context: Constipation in children is a prevalent, burdensome, and psychologically important pediatric issue, the treatment of which remains a global challenge. The use of probiotics has been reported for management of the gastrointestinal microbiota.Objective: This study reviewed the existing literatures of 6 Randomized Control Trials (RCTs to ascertain some baseline understanding and available information for the effects of probiotics on stool frequency and consistency in children with constipation.Data Sources: PubMed, Springer, Elsevier Science, Cochrane Library, Scopus, Ovid (Medline, EMBASE, PsycINFO, Orbis, and Web of Science from the earliest record in each database to 15 September, 2016.Study selection: Eligible studies were randomized controlled trials that compared the effect of probiotics interventions to any control intervention on stool frequency and consistency.Data Extraction: Studies were identified by searching electronic databases. The meta-analysis was performed by Review Manager 5.3 software using a randomized model.Results: Six studies were identified. The use of probiotics significantly increased the stool frequency [mean difference (MD, 0.73; 95% confidence interval (CI, 0.14–1.31; P = 0.02]. Subgroup assessment showed a significantly increased stool frequency in Asian patients (MD, 1.18; 95% CI, 0.33–2.02; P = 0.006, but no significant difference in stool consistency (MD, −0.07; 95% CI, −0.21–0.06; P = 0.27.Limitations: Only six RCTs met the criteria and were included. Each RCT in this study was performed in a different country, and some of the included studies had a small sample size, which might have influenced the reliability and validity of the conclusions.Conclusion: The present study shows that probiotics increase stool frequency and have beneficial effects in Asian children. However, caution is needed when interpreting these outcomes because of the existence of heterogeneity. Evidence from larger samples

  12. Free choice access to multipoint wellness education and related services positively impacts employee wellness: a randomized and controlled trial.

    Science.gov (United States)

    Sforzo, Gary A; Kaye, Miranda P; Calleri, David; Ngai, Nancy

    2012-04-01

    Examine effects of voluntary participation in employer-sponsored, multipoint wellness education programming on employee wellness. A randomized and controlled design was used to organize 96 participants into an education + access group; an access-only group, and control group. Outcome measures were made at start and end of a 12-week intervention period. Education + access improved wellness knowledge, which, in turn, enhanced life satisfaction, employee morale, and energy, and nearly improved stress level. Those who received facility access without educational programming did not reap health benefits. Employees voluntarily used the fitness facility and healthy meal cards only 1.3 and 1.5 times per week, respectively. Participants made limited and likely inadequate use of wellness opportunities. As a result, physical health benefits (eg, blood pressure, fitness parameters) were not seen in the present study. However, multipoint wellness education resulted in psychosocial health benefits in 12 weeks.

  13. A Randomized-Controlled Trial of the Triple P-Positive Parenting Program Seminar Series with Indonesian Parents.

    Science.gov (United States)

    Sumargi, Agnes; Sofronoff, Kate; Morawska, Alina

    2015-10-01

    There are limited evaluations of an evidence-based parenting program for parents from large developing countries, such as Indonesia. This study aimed to test the efficacy and acceptability of an evidence-based parenting program, the Triple P seminar series, among Indonesian parents. The level of child emotional and behavioral problems was the primary outcome of this study. Participants were 143 parents of children aged 2-12 years in Indonesia that were randomly allocated into the intervention (n = 72) or waitlist control group (n = 71). Participants, investigators, and data collectors were not blinded to the group assignment. A randomized-controlled trial was conducted with 143 parents of children aged 2-12 years in Indonesia. Results showed that parents in the intervention group reported a greater decrease in child behavioral problems (d = 0.45), dysfunctional parenting practices (d = 0.69), parental stress (d = 0.44), and a greater increase in parenting confidence (d = 0.45) in comparison to parents in the waitlist control group at post intervention. The intervention effects were maintained at 6-month follow up for parents in the intervention group. The program was deemed to be culturally appropriate as parents indicated high levels of acceptability and satisfaction with the program content. It is suggested that future studies include families with lower income and employ a more stringent design (e.g., using validated measures, multiple facilitators, and blinding).

  14. Sexual risk reduction for HIV-infected persons: a meta-analytic review of "positive prevention" randomized clinical trials.

    Directory of Open Access Journals (Sweden)

    Lu Yin

    Full Text Available BACKGROUND: Prevention intervention trials have been conducted to reduce risk of sexual transmission among people living with HIV/AIDS (PLWHA, but the findings were inconsistent. We performed a systematic review and meta-analysis to evaluate overall efficacy of prevention interventions on unprotected vaginal or anal intercourse (UVAI among PLWHA from randomized clinical trials (RCTs. METHODS: RCTs of prevention interventions among PLWHA published as of February 2012 were identified by systematically searching thirteen electronic databases. The primary outcome was UVAI. The difference of standardized mean difference (SMD of UVAI between study arms, defined as effect size (ES, was calculated for each study and then pooled across studies using standard meta-analysis with a random effects model. RESULTS: Lower likelihood of UVAI was observed in the intervention arms compared with the control arms either with any sexual partners (mean ES: -0.22; 95% confidence interval [CI]: -0.32, -0.11 or with HIV-negative or unknown-status sexual partners (mean ES and 95% CI: -0.13 [-0.22, -0.04]. Short-term efficacy of interventions with ≤ 10 months of follow up was significant in reducing UVAI (1-5 months: -0.27 [-0.45, -0.10]; 6-10 months: -0.18 [-0.30, -0.07], while long-term efficacy of interventions was weaker and might have been due to chance (11-15 months: -0.13 [-0.34, 0.08]; >15 months: -0.05 [-0.43, 0.32]. CONCLUSIONS: Our meta-analyses confirmed the short-term impact of prevention interventions on reducing self-reported UVAI among PLWHA irrespective of the type of sexual partner, but did not support a definite conclusion on long-term effect. It is suggested that booster intervention sessions are needed to maintain a sustainable reduction of unprotected sex among PLWHA in future risk reduction programs.

  15. Photolithographic process for the patterning of quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Na, Young Joo; Park, Sang Joon; Lee, Sang Wha [Department of Chemical and Bioengineering, Kyungwon University, Seongnam-si, Gyeonggi-Do 461-701 (Korea, Republic of); Kim, Jong Sung [Department of Chemical and Bioengineering, Kyungwon University, Seongnam-si, Gyeonggi-Do 461-701 (Korea, Republic of)], E-mail: jskim@kyungwon.ac.kr

    2008-09-15

    Recently, quantum dots have been used as molecular probes substituting for conventional organic fluorophores. Quantum dots are stable against photobleaching and have more controllable emission bands, broader absorption spectra, and higher quantum yields. In this study, an array of ZnS-coated CdSe quantum dots on a slide glass has been prepared by photolithographic method. The array pattern was prepared using a positive photoresist (AZ1518) and developer (AZ351). The patterned glass was silanized with 3-aminopropyltriethoxysilane (APTES), and carboxyl-coated quantum dots were selectively attached onto the array pattern. The silanization was examined by measuring contact angle and the surface of the array pattern was analyzed using AFM and fluorescent microscope.

  16. A triple quantum dot based nano-electromechanical memory device

    Energy Technology Data Exchange (ETDEWEB)

    Pozner, R.; Lifshitz, E. [Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Peskin, U., E-mail: uri@tx.technion.ac.il [Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Lise Meitner Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

    2015-09-14

    Colloidal quantum dots (CQDs) are free-standing nano-structures with chemically tunable electronic properties. This tunability offers intriguing possibilities for nano-electromechanical devices. In this work, we consider a nano-electromechanical nonvolatile memory (NVM) device incorporating a triple quantum dot (TQD) cluster. The device operation is based on a bias induced motion of a floating quantum dot (FQD) located between two bound quantum dots (BQDs). The mechanical motion is used for switching between two stable states, “ON” and “OFF” states, where ligand-mediated effective interdot forces between the BQDs and the FQD serve to hold the FQD in each stable position under zero bias. Considering realistic microscopic parameters, our quantum-classical theoretical treatment of the TQD reveals the characteristics of the NVM.

  17. Nanocrystal quantum dots

    CERN Document Server

    Klimov, Victor I

    2010-01-01

    ""Soft"" Chemical Synthesis and Manipulation of Semiconductor Nanocrystals, J.A. Hollingsworth and V.I. Klimov Electronic Structure in Semiconductor Nanocrystals: Optical Experiment, D.J. NorrisFine Structure and Polarization Properties of Band-Edge Excitons in Semiconductor Nanocrystals, A.L. EfrosIntraband Spectroscopy and Dynamics of Colloidal Semiconductor Quantum Dots, P. Guyot-Sionnest, M. Shim, and C. WangMultiexciton Phenomena in Semiconductor Nanocrystals, V.I. KlimovOptical Dynamics in Single Semiconductor Quantum Do

  18. Effect of using HIV and infant feeding counselling cards on the quality of counselling provided to HIV positive mothers: a cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Babaniyi Olusegun

    2011-09-01

    Full Text Available Abstract Background Counselling human immunodeficiency virus (HIV positive mothers on safer infant and young child feeding (IYCF options is an important component of programmes to prevent mother to child transmission of HIV, but the quality of counselling is often inadequate. The aim of this study was to determine the effect the World Health Organization HIV and infant feeding cards on the quality of counselling provided to HIV positive mothers by health workers about safer infant feeding options. Method This was a un-blinded cluster-randomized controlled field trial in which 36 primary health facilities in Kafue and Lusaka districts in Zambia were randomized to intervention (IYCF counselling with counselling cards or non- intervention arm (IYCF counselling without counselling cards. Counselling sessions with 10 HIV positive women attending each facility were observed and exit interviews were conducted by research assistants. Results Totals of 180 women in the intervention group and 180 women in the control group were attended to by health care providers and interviewed upon exiting the health facility. The health care providers in the intervention facilities more often discussed the advantages of disclosing their HIV status to a household member (RR = 1.46, 95% CI [1.11, 1.92]; used visual aids in explaining the risk of HIV transmission through breast milk (RR = 4.65, 95% CI [2.28, 9.46]; and discussed the advantages and disadvantages of infant feeding options for HIV positive mothers (all p values Conclusion The addition of counselling cards to the IYCF counselling session for HIV positive mothers were a valuable aid to counselling and significantly improved the quality of the counselling session.

  19. Happy Despite Pain: A Randomized Controlled Trial of an 8-Week Internet-delivered Positive Psychology Intervention for Enhancing Well-being in Patients With Chronic Pain.

    Science.gov (United States)

    Peters, Madelon L; Smeets, Elke; Feijge, Marion; van Breukelen, Gerard; Andersson, Gerhard; Buhrman, Monica; Linton, Steven J

    2017-11-01

    There is preliminary evidence for the efficacy of positive psychology interventions for pain management. The current study examined the effects of an internet-based positive psychology self-help program for patients with chronic musculoskeletal pain and compared it with an internet-based cognitive-behavioral program. A randomized controlled trial was carried out with 3 conditions: an internet-delivered positive psychology program, an internet-delivered cognitive-behavioral program and waitlist control. A total of 276 patients were randomized to 1 of the 3 conditions and posttreatment data were obtained from 206 patients. Primary outcomes were happiness, depression, and physical impairments at posttreatment and at 6-month follow-up. Intention-to-treat analyses were carried out using mixed regression analyses. Both treatments led to significant increases in happiness and decreases in depression. Physical impairments did not significantly decrease compared with waitlist. Improvements in happiness and depression were maintained until 6-month follow-up. There were no overall differences in the efficacy of the 2 active interventions but effects seemed to be moderated by education. Patients with a higher level of education profited slightly more from the positive psychology intervention than from the cognitive-behavioral program. The results suggest that an internet-based positive psychology and cognitive-behavioral self-help interventions for the management of chronic pain are clinically useful. Because the self-help exercises as used in the current program do not require therapist involvement, dissemination potential is large. Further studies should examine whether it can best be used as stand-alone or add-on treatment combined with established pain treatment programs.

  20. Spontaneous emission of quantum dots in disordered photonic crystal waveguides

    DEFF Research Database (Denmark)

    Sapienza, Luca; Nielsen, Henri Thyrrestrup; Stobbe, Søren

    2010-01-01

    We report on the enhancement of the spontaneous emission rate of single semiconductor quantum dots embedded in a photonic crystal waveguide with engineered disorder. Random high-Q cavities, that are signature of Anderson localization, are measured in photoluminescence experiments and appear...

  1. A prospective, randomized, controlled trial of autologous haematopoietic stem cell transplantation for aggressive multiple sclerosis: a position paper.

    Science.gov (United States)

    Saccardi, R; Freedman, M S; Sormani, M P; Atkins, H; Farge, D; Griffith, L M; Kraft, G; Mancardi, G L; Nash, R; Pasquini, M; Martin, R; Muraro, P A

    2012-06-01

    Haematopoietic stem cell transplantation (HSCT) has been tried in the last 15 years as a therapeutic option in patients with poor-prognosis autoimmune disease who do not respond to conventional treatments. Worldwide, more than 600 patients with multiple sclerosis (MS) have been treated with HSCT, most of them having been recruited in small, single-centre, phase 1-2 uncontrolled trials. Clinical and magnetic resonance imaging outcomes from case series reports or Registry-based analyses suggest that a major response is achieved in most patients; quality and duration of response are better in patients transplanted during the relapsing-remitting phase than in those in the secondary progressive stage. An interdisciplinary group of neurologists and haematologists has been formed, following two international meetings supported by the European and American Blood and Marrow Transplantation Societies, for the purpose of discussing a controlled clinical trial, to be designed within the new scenarios of evolving MS treatments. Objectives of the trial, patient selection, transplant technology and outcome assessment were extensively discussed. The outcome of this process is summarized in the present paper, with the goal of establishing the background and advancing the development of a prospective, randomized, controlled multicentre trial to assess the clinical efficacy of HSCT for the treatment of highly active MS.

  2. Image enhancement for increased dot-counting efficiency in FISH.

    Science.gov (United States)

    Shah, Shishir

    2007-11-01

    The most commonly used molecular cytogenetic technique is fluorescence in situ hybridization (FISH). It has been widely applied in many areas of diagnosis and research, including pre-natal and post-natal screening of chromosomal aberrations, pre-implantation genetic diagnosis, cancer cytogenetics, gene mapping, molecular pathology and developmental molecular biology. The analysis of FISH images consists of detecting fluorescent dots, after which the number of dots per cell can be counted or their relative positions can be measured. A major impediment in the analysis of FISH specimens is signal (dot) quality, which is influenced by the hybridization efficiency and/or the sensitivity of the camera that records the images. In this paper, we present an approach to improve the efficiency of detecting fluorescent signals in FISH images by recovering the radiance map of the camera. This allows us to generate a high-dynamic-range image wherein an extended range of the sample radiance captured by the camera can be visualized at distinct intensity values. The resulting higher-order numeric complexity of the transformed image is adjusted (or simplified) by examining the intensity distribution in each of the three colour channels (red, green and blue), and remapping the intensity values to generate a high-contrast image with a lower-order (compressed) dynamic range. The remapping is based on a criterion that optimizes the detection of the hybridized signals, allowing attenuation of saturated intensity values while amplifying low-intensity signals. A simple dot-counting algorithm is used to automatically process 2000 FISH images. The images are taken for lymphocytes from cultured blood specimens for cytogenetic testing. Images are manually analyzed by an expert to obtain ground truth for dot counts. A quantitative analysis is performed by comparing results of automated dot detection on images before and after enhancement with the developed algorithms. In addition, common errors

  3. A randomized trial of noninvasive positive end expiratory pressure in patients with acquired immune deficiency syndrome and hypoxemic respiratory failure.

    Science.gov (United States)

    Anjos, Carlos Frederico Dantas; Schettino, Guilherme Paula Pinto; Park, Marcelo; Souza, Vladimir Silva; Scalabrini Neto, Augusto

    2012-02-01

    Acquired immunodeficiency syndrome (AIDS) is a pandemic disease commonly associated with respiratory infections, hypoxemia, and death. Noninvasive PEEP has been shown to improve hypoxemia. In this study, we evaluated the physiologic effects of different levels of noninvasive PEEP in hypoxemic AIDS patients. Thirty AIDS patients with acute hypoxemic respiratory failure received a randomized sequence of noninvasive PEEP (5, 10, or 15 cm H(2)O) for 20 min. PEEP was provided through a facial mask with pressure-support ventilation (PSV) of 5 cm H(2)O and an F(IO(2)) of 1. Patients were allowed to breathe spontaneously for a 20-min washout period in between each PEEP trial. Arterial blood gases and clinical variables were recorded after each PEEP treatment. The results indicate that oxygenation improves linearly with increasing levels of PEEP. However, oxygenation levels were similar regardless of the first PEEP level administered (5, 10, or 15 cm H(2)O), and only the subgroup that received an initial treatment of the lowest level of PEEP (ie, 5 cm H(2)O) showed further improvements in oxygenation when higher PEEP levels were subsequently applied. The P(aCO(2)) also increased in response to PEEP elevation, especially with the highest level of PEEP (ie, 15 cm H(2)O). PSV of 5 cm H(2)O use was associated with significant and consistent improvements in the subjective sensations of dyspnea and respiratory rate reported by patients treated with any level of PEEP (from 0 to 15 cm H(2)O). AIDS patients with hypoxemic respiratory failure improve oxygenation in response to a progressive sequential elevation of PEEP (up to 15 cm H(2)O). However, corresponding elevations in P(aCO(2)) limit the recommended level of PEEP to 10 cm H(2)O. At a level of 5 cm H(2)O, PSV promotes an improvement in the subjective sensation of dyspnea regardless of the PEEP level employed.

  4. Fabrication and optical properties of type-II InP/InAs nanowire/quantum-dot heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xin; Zhang, Xia; Li, Junshuai; Wu, Yao; Li, Bang; Ren, Xiaomin [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 (China)

    2016-02-15

    The growth and optical properties of InAs quantum dots on a pure zinc blende InP nanowire are investigated. The quantum dots are formed in Stranski-Krastanov mode and exhibit pure zinc blende crystal structure. A substantial blueshift of the dots peak with a cube-root dependence on the excitation power is observed, suggesting a type-II band alignment. The peak position of dots initially red-shifts and then blue-shifts with increasing temperature, which is attributed to the carrier redistribution among the quantum dots. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Digital palpation of endotracheal tube tip as a method of confirming endotracheal tube position in neonates: an open-label, three-armed randomized controlled trial.

    Science.gov (United States)

    Saboo, Ashwin R; Dutta, Sourabh; Sodhi, Kushaljit Singh

    2013-10-01

    To compare the malposition rates of endotracheal tubes (ETTs) when the insertional length (IL) is determined by a weight-based nomogram versus when IL is determined by palpation of the ETT tip. Open-label, randomized controlled trial (RCT). Level III neonatal intensive care unit (NICU). All newborn babies admitted in NICU requiring intubation. Subjects were randomly allocated to one of three groups, wherein IL was determined by (i) weight-based nomogram alone, (ii) weight-based nomogram combined with suprasternal palpation of ETT tip performed by specially trained neonatology fellows, or (iii) combination of weight-based and suprasternal methods by personnel not specially trained. Rate of malposition of ETT as judged on chest X-ray (CXR). Fifty seven babies were randomized into group 1(n = 15), group 2 (n = 20), and group 3 (n = 22). The proportion of correct ETT placement was highest in group 2, being 66.7%, 83.3%, and 66.7% in groups 1 through 3, respectively (P value = 0.58). No complication was attributable to palpation technique. Suprasternal palpation shows promise as a simple, safe, and teachable method of confirming ETT position in neonates. © 2013 John Wiley & Sons Ltd.

  6. Magneto-optical absorption in semiconducting spherical quantum dots: Influence of the dot-size, confining potential, and magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kushwaha, Manvir S. [Department of Physics and Astronomy, Rice University, P.O. Box 1892, Houston, TX 77251 (United States)

    2014-12-15

    Semiconducting quantum dots – more fancifully dubbed artificial atoms – are quasi-zero dimensional, tiny, man-made systems with charge carriers completely confined in all three dimensions. The scientific quest behind the synthesis of quantum dots is to create and control future electronic and optical nanostructures engineered through tailoring size, shape, and composition. The complete confinement – or the lack of any degree of freedom for the electrons (and/or holes) – in quantum dots limits the exploration of spatially localized elementary excitations such as plasmons to direct rather than reciprocal space. Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting spherical quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done within the framework of Bohm-Pines’ random-phase approximation that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. As an application of our theoretical strategy, we compute various single-particle and many-particle phenomena such as the Fock-Darwin spectrum; Fermi energy; magneto-optical transitions; probability distribution; and the magneto-optical absorption in the quantum dots. It is observed that the role of an applied magnetic field on the absorption spectrum is comparable to that of a confining potential. Increasing (decreasing) the strength of the magnetic field or the confining potential is found to be analogous to shrinking (expanding) the size of the quantum dots: resulting into a blue (red) shift in the absorption spectrum. The Fermi energy diminishes with both increasing magnetic-field and dot-size; and exhibits saw-tooth-like oscillations at large values of field or dot-size. Unlike laterally confined quantum dots, both (upper and lower) magneto-optical transitions survive even in the extreme instances. However, the intra-Landau level

  7. Magneto-optical absorption in semiconducting spherical quantum dots: Influence of the dot-size, confining potential, and magnetic field

    Directory of Open Access Journals (Sweden)

    Manvir S. Kushwaha

    2014-12-01

    Full Text Available Semiconducting quantum dots – more fancifully dubbed artificial atoms – are quasi-zero dimensional, tiny, man-made systems with charge carriers completely confined in all three dimensions. The scientific quest behind the synthesis of quantum dots is to create and control future electronic and optical nanostructures engineered through tailoring size, shape, and composition. The complete confinement – or the lack of any degree of freedom for the electrons (and/or holes – in quantum dots limits the exploration of spatially localized elementary excitations such as plasmons to direct rather than reciprocal space. Here we embark on a thorough investigation of the magneto-optical absorption in semiconducting spherical quantum dots characterized by a confining harmonic potential and an applied magnetic field in the symmetric gauge. This is done within the framework of Bohm-Pines’ random-phase approximation that enables us to derive and discuss the full Dyson equation that takes proper account of the Coulomb interactions. As an application of our theoretical strategy, we compute various single-particle and many-particle phenomena such as the Fock-Darwin spectrum; Fermi energy; magneto-optical transitions; probability distribution; and the magneto-optical absorption in the quantum dots. It is observed that the role of an applied magnetic field on the absorption spectrum is comparable to that of a confining potential. Increasing (decreasing the strength of the magnetic field or the confining potential is found to be analogous to shrinking (expanding the size of the quantum dots: resulting into a blue (red shift in the absorption spectrum. The Fermi energy diminishes with both increasing magnetic-field and dot-size; and exhibits saw-tooth-like oscillations at large values of field or dot-size. Unlike laterally confined quantum dots, both (upper and lower magneto-optical transitions survive even in the extreme instances. However, the intra

  8. Passive continuous positive airway pressure ventilation during cardiopulmonary resuscitation: a randomized cross-over manikin simulation study.

    Science.gov (United States)

    Winkler, Bernd E; Muellenbach, Ralf M; Wurmb, Thomas; Struck, Manuel F; Roewer, Norbert; Kranke, Peter

    2017-02-01

    While controlled ventilation is most frequently used during cardiopulmonary resuscitation (CPR), the application of continuous positive airway pressure (CPAP) and passive ventilation of the lung synchronously with chest compressions and decompressions might represent a promising alternative approach. One benefit of CPAP during CPR is the reduction of peak airway pressures and therefore a potential enhancement in haemodynamics. We therefore evaluated the tidal volumes and airway pressures achieved during CPAP-CPR. During CPR with the LUCAS™ 2 compression device, a manikin model was passively ventilated at CPAP levels of 5, 10, 20 and 30 hPa with the Boussignac tracheal tube and the ventilators Evita® V500, Medumat® Transport, Oxylator® EMX, Oxylog® 2000, Oxylog® 3000, Primus® and Servo®-i as well as the Wenoll® diver rescue system. Tidal volumes and airway pressures during CPAP-CPR were recorded and analyzed. Tidal volumes during CPAP-CPR were higher than during compression-only CPR without positive airway pressure. The passively generated tidal volumes increased with increasing CPAP levels and were significantly influenced by the ventilators used. During ventilation at 20 hPa CPAP via a tracheal tube, the mean tidal volumes ranged from 125 ml (Medumat®) to 309 ml (Wenoll®) and the peak airway pressures from 23 hPa (Primus®) to 49 hPa (Oxylog® 3000). Transport ventilators generated lower tidal volumes than intensive care ventilators or closed-circuit systems. Peak airway pressures during CPAP-CPR were lower than those during controlled ventilation CPR reported in literature. High peak airway pressures are known to limit the applicability of ventilation via facemask or via supraglottic airway devices and may adversely affect haemodynamics. Hence, the application of ventilators generating high tidal volumes with low peak airway pressures appears desirable during CPAP-CPR. The limited CPAP-CPR capabilities of transport ventilators in our study might

  9. Effect of intravenous ondansetron on reducing the incidence of hypotension and bradycardia events during shoulder arthroscopy in sitting position under interscalene brachial plexus block: A prospective randomized trial

    Directory of Open Access Journals (Sweden)

    Srinivasa Rao Nallam

    2015-01-01

    Full Text Available Background and Aims: Sudden, profound hypotension and bradycardia events (HBEs have been reported in more than 20% of patients undergoing shoulder arthroscopy in the sitting position. The present study was designed to know whether intravenous (IV ondansetron (selective 5-hydroxy tryptamine 3-antagonist can help in reducing the HBEs associated with shoulder arthroscopy performed in sitting position under interscalene brachial plexus block (ISBPB. Methods: A total of 100 patients (age 20-50 years undergoing shoulder arthroscopy performed in the sitting position under ISBPB were assigned randomly to one of the two groups: Group C received 10 ml of normal saline and Group T received 4 mg of ondansetron diluted in 10 ml of normal saline` IV. All patients received ISBPB using levobupivacaine 0.5%. Assessment of motor and sensory blockade, pulse rate, systolic blood pressure, respiration, and side effects were noted every 5 min for first 30 min and every 10 min till the end of surgery. HBEs were recorded in both groups. Results: IV injection of ondansetron significantly reduces the incidence of HBEs from 11 (22.44% in Group C to 3 (6.1% in Group T. The duration of analgesia was significantly longer in Group C (8.1 ± 3.3 in comparison with Group T (6.3 ± 4.2 h. Conclusion: We conclude that 4 ml of IV ondansetron can significantly reduce the HBEs during shoulder arthroscopy done in the sitting position under ISBPB.

  10. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial.

    Science.gov (United States)

    Komasawa, Nobuyasu; Mihara, Ryosuke; Imagawa, Kentaro; Hattori, Kazuo; Minami, Toshiaki

    2015-01-01

    The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP) and taper-shaped (taper) cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n = 20; HVLP group) or taper-shaped (n = 20; Taper group) cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  11. Comparison of Pressure Changes by Head and Neck Position between High-Volume Low-Pressure and Taper-Shaped Cuffs: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Nobuyasu Komasawa

    2015-01-01

    Full Text Available The present study compared changes in cuff pressure by head and neck position between high-volume low-pressure (HVLP and taper-shaped (taper cuffs in a prospective randomized clinical trial. Methods. Forty patients were intubated using tracheal tubes with either HVLP (n=20; HVLP group or taper-shaped (n=20; Taper group cuffs. Initial cuff pressure was adjusted to 15, 20, or 25 cmH2O in the neutral position. Cuff pressure was evaluated after changing the head and neck positions to flexion, extension, and rotation. Results. Cuff pressure significantly increased with flexion in both HVLP and Taper groups at all initial cuff pressures. It significantly increased with extension in the HVLP group, but not in the Taper group. Cuff pressure did not significantly differ with rotation in either group and was significantly smaller in the Taper group during flexion and extension than in the HVLP group, regardless of initial cuff pressure. Conclusion. Cuff pressure changes with head and neck flexion and extension were smaller in the Taper group than in the HVLP group. Our results highlight the potential for taper cuffs to prevent excessive cuff pressure increases with positional changes in the head and neck. This trial is registered with UMIN000016119.

  12. Effect of position of infant during phototherapy in management of hyperbilirubinemia in late preterm and term neonates: a randomized controlled trial.

    Science.gov (United States)

    Bhethanabhotla, S; Thukral, A; Sankar, M J; Agarwal, R; Paul, V K; Deorari, A K

    2013-10-01

    To evaluate the effect of supine position when compared with periodic change of position during phototherapy in late preterm and term neonates (35 to 42 weeks) with hyperbilirubinemia on the duration of phototherapy. We randomly allocated enrolled neonates with hyperbilirubinemia to either no change in position (supine group (SG); n=54) or two-hourly change of position from supine to prone and vice versa (turning group (TG); n=46). All the infants received single surface phototherapy by two dedicated compact fluorescent light units. Total serum bilirubin (TSB) was measured at the start of phototherapy and then every 12 ± 2 h until the end of phototherapy. Phototherapy was stopped when two values were below the cut-off for age and gestational age as per the American Academy of Pediatrics Subcommittee on Hyperbilirubinemia guidelines nomogram for the management of hyperbilirubinemia in infants >35 weeks of gestation. The primary outcome was duration of phototherapy and secondary outcome was rate of fall of bilirubin within the first 24 ± 2 h after the initiation of phototherapy. Baseline characteristics including birth weight (g, 2752 ± 478 vs 2748 ± 416 P=0.96), gestation (week, 37.1 ± 1.2 vs 37.4 ± 1.3, P=0.26) were similar in the two groups. There was no difference in the duration of phototherapy between the SG (mean ± s.d., hour, 25.5 ± 8) and TG (mean ± s.d., hour, 24.8 ± 5), mean difference (95% confidence interval), hour, 0.7 (-2.03, 3.44, P=0.6). Rate of fall of bilirubin was also similar in both supine and turning groups with mean difference of -0.020 (95% confidence interval: -0.061, 0.021, P=0.34). Nursing babies in supine position when compared with periodic position change during phototherapy does not decrease the duration of phototherapy.

  13. Red Dot Basal Cell Carcinoma

    Science.gov (United States)

    2017-01-01

    Red dot basal cell carcinoma, a distinctive morphologic variant of basal cell carcinoma that presents as a small red macule (dot) or papule, is described on a woman’s thigh. A high index of suspicion is necessary to consider the diagnosis since the tumor mimics a telangiectasia or an angioma. PMID:28670359

  14. An Internet-Based Intervention (Condom-Him) to Increase Condom Use Among HIV-Positive Men Who Have Sex With Men: Protocol for a Randomized Controlled Trial.

    Science.gov (United States)

    Miranda, Joyal; Côté, José; Godin, Gaston; Blais, Martin; Otis, Joanne; Guéhéneuc, Yann-Gaël; Fadel, Ghayas; Barton, Luisa; Fowler, Shawn

    2013-10-16

    In the recent years, the Internet has been used as a medium to find sexual partners and engage in risky sexual behavior. This has changed the way in which men having have sex with men (MSM) seek sexual partners and has increased the number of high-risk sexual encounters. Therefore, developers of human immunodeficiency virus (HIV)-prevention interventions have also started using the Internet as a viable medium to promote safe sexual behaviors. However, much of the efforts thus far have been aimed at HIV-negative rather than HIV-positive MSM. HIV-positive individuals continue to engage in risky sexual behaviors and thus constitute an important group in which HIV prevention strategies need to be addressed. Therefore, HIV prevention in HIV-positive MSM is a critical issue. Condom-Him, an Internet-based intervention tailored to increase condom use among HIV-positive MSM, was developed with the aim of improving condom use, self-efficacy, and intentions to use condoms among these individuals. The acceptability and feasibility of this Internet-based intervention will be examined in a pilot study. We will perform a randomized controlled parallel-group superiority trial. HIV-positive MSM who currently engage in unprotected anal sex will be recruited for the study. Participants will be randomly assigned using a one-to-one allocation ratio generated by the computer program. The researchers will be blinded to participant's group assignment. Participants will be assigned either to use the Condom-Him intervention (experimental arm) or to view a list of websites containing HIV/AIDS related information (control arm). Self-administered questionnaires will be provided online before randomization (baseline) and two weeks after intervention (post-test). The study will include a total of 60 participants with 30 in each group. The results from this pilot study will provide further evidence for a larger study to examine the effectiveness of this intervention and will provide a cost

  15. Trastuzumab in the adjuvant treatment of HER2-positive early breast cancer patients: a meta-analysis of published randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Wenjin Yin

    Full Text Available BACKGROUND: Adjuvant trastuzumab therapy has yielded conflicting results for overall survival, concerns about central nervous system (CNS metastasis, and questions about optimal schedule. Therefore, we carried out a meta-analysis to assess the benefits of concurrent or sequential trastuzumab with adjuvant chemotherapy for early breast cancer patients with HER2-positive tumors. METHODS: Computerized and manual searches were performed to identify randomized clinical trials comparing adjuvant chemotherapy with or without trastuzumab in HER2-positive early breast cancer patients. Odds ratios were used to estimate the association between the addition of trastuzumab to adjuvant chemotherapy and various survival outcomes. The fixed-effects or random-effects model was used to combine data. FINDINGS: With six eligible studies identified, this analysis demonstrated that patients with HER2-positive breast cancer derived benefit in disease-free survival, overall survival, locoregional recurrence and distant recurrence (all P<0.001 from the addition of trastuzumab to adjuvant chemotherapy, whereas trastuzumab did worse in CNS recurrence as compared to the control group (P = 0.018. Furthermore, concomitant use of trastuzumab significantly lowered the hazard of death (P<0.001 but bore a higher incidence of CNS recurrence (P = 0.010, while statistical significance failed to be discerned for either overall survival (P = 0.069 or CNS metastasis (P = 0.374 between the sequential and observation arms. CONCLUSION: This analysis verifies the efficacy of trastuzumab in the adjuvant setting. Additionally, our findings indirectly corroborate the superiority of concurrent trastuzumab to sequential use and also illuminate that prolonged survival is the possible reason for the higher incidence of CNS with trastuzumab versus observation.

  16. Self-generation and positivity effects following transcranial random noise stimulation in medial prefrontal cortex: A reality monitoring task in older adults.

    Science.gov (United States)

    Mammarella, Nicola; Di Domenico, Alberto; Palumbo, Rocco; Fairfield, Beth

    2017-06-01

    Activation of medial Prefrontal Cortex (mPFC) has been typically found during reality monitoring tasks (i.e., distinguishing between internal self-generated vs external information). No study, however, has yet investigated whether transcranial Random Noise Stimulation (tRNS) over the mPFC leads to a reduction in reality-monitoring misattributions in aging. In particular, stimulating mPFC should increase the number of cognitive operations engaged while encoding and this distinctive information may help older adults to discriminate between internal and external sources better. In addition, given that older adults are more sensitive to positively-charged information compared to younger adults and that mPFC is typically recruited during encoding of positive stimuli with reference to themselves, activation of mPFC should further sustain source retrieval in older adults. In this double-blind, sham-controlled study, we examined whether tRNS over the mPFC of healthy younger and older adults during encoding enhances subsequent reality monitoring for seen versus imagined emotionally-charged words. Our findings show that tRNS enhances reality monitoring for positively-charged imagined words in the older adult group alone, highlighting the role that mPFC plays in their memory for positive information. In line with the control-based account of positivity effects, our results add evidence about the neurocognitive processes involved in reality monitoring when older adults face emotionally-charged events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of glutamate positive modulators on cognitive deficits in schizophrenia: a systematic review and meta-analysis of double-blind randomized controlled trials.

    Science.gov (United States)

    Iwata, Y; Nakajima, S; Suzuki, T; Keefe, R S E; Plitman, E; Chung, J K; Caravaggio, F; Mimura, M; Graff-Guerrero, A; Uchida, H

    2015-10-01

    Hypofunction of N-methyl-d-aspartate (NMDA) receptors has been proposed to have an important role in the cognitive impairments observed in schizophrenia. Although glutamate modulators may be effective in reversing such difficult-to-treat conditions, the results of individual studies thus far have been inconsistent. We conducted a systematic review and meta-analysis to examine whether glutamate positive modulators have beneficial effects on cognitive functions in patients with schizophrenia. A literature search was conducted to identify double-blind randomized placebo-controlled trials in schizophrenia or related disorders, using Embase, Medline, and PsycINFO (last search: February 2015). The effects of glutamate positive modulators on cognitive deficits were evaluated for overall cognitive function and eight cognitive domains by calculating standardized mean differences (SMDs) between active drugs and placebo added to antipsychotics. Seventeen studies (N=1391) were included. Glutamate positive modulators were not superior to placebo in terms of overall cognitive function (SMD=0.08, 95% confidence interval=-0.06 to 0.23) (11 studies, n=858) nor each of eight cognitive domains (SMDs=-0.03 to 0.11) (n=367-940) in this population. Subgroup analyses by diagnosis (schizophrenia only studies), concomitant antipsychotics, or pathway of drugs to enhance the glutamatergic neurotransmission (glycine allosteric site of NMDA receptors or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors) suggested no procognitive effect of glutamate positive modulators. Further, no effect was found in individual compounds on cognition. In conclusion, glutamate positive modulators may not be effective in reversing overall cognitive impairments in patients with schizophrenia as adjunctive therapies.

  18. Postoperative leg position following total knee arthroplasty influences blood loss and range of motion: a meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Fu, Xin; Tian, Peng; Li, Zhi-jun; Sun, Xiao-lei; Ma, Xin-long

    2016-01-01

    Postoperative leg position has been reported as an efficient and convenient technique to minimize blood loss and improve early recovery following total knee arthroplasty (TKA); however, no single study was large enough to definitively determine optimal leg position. Therefore, we performed a meta-analysis pooling the results from randomized controlled trials (RCTs) to evaluate the effect of postoperative leg position on blood loss and range of motion (ROM) in TKA. Potential academic articles were identified from the Cochrane Library, Medline (1966-October 2015), PubMed (1966-October 2015), Embase (1980-October 2015), ScienceDirect (1985-October 2015) and other databases. Gray studies were identified from the references of included literature reports. The pooling of data was analyzed by RevMan 5.1. Ten RCTs were included in the meta-analysis. There were significant differences in the total blood loss (mean difference [MD] = -130.66, 95% CI: -198.74 to -62.57, P = 0.0002), hidden blood loss (MD = -73.27, 95% CI: -117.57 to -28.96, P = 0.001), blood transfusion requirement (risk difference [RD] = -0.10, 95% CI: -0.19 to -0.22, P = 0.02), postoperative hemoglobin level (MD = 0.73, 95% CI: 0.42 to 1.04, P extension group. No significant differences were found regarding length of hospital stay, deep vein thrombosis (DVT) and wound infection between the two groups. This meta-analysis indicated that the postoperative flexion position of the leg in TKA was effective and safe, significantly decreasing total blood loss, hidden blood loss and blood transfusion requirement. In addition, the postoperative range of motion is significantly improved by the flexion position of the leg.

  19. Efficacy of a Transdiagnostic internet-based treatment for emotional disorders with a specific component to address positive affect: Study protocol for a randomized controlled trial.

    Science.gov (United States)

    Díaz-García, Amanda; González-Robles, Alberto; Fernández-Álvarez, Javier; García-Palacios, Azucena; Baños, Rosa María; Botella, Cristina

    2017-04-20

    Emotional disorders (ED) are among the most prevalent mental disorders. However, less than 50% of people suffering from ED receive the appropriate treatment. This situation has led to the development of new intervention proposals based on the transdiagnostic perspective, which tries to address the underlying processes common to ED. Most of these programs focus primarily on down-regulating negative affectivity, rather than increasing strengths and up-regulating positive affectivity. The data suggest the existence of disturbances in positive affectivity in these disorders, and so new interventions focusing on these problems are greatly needed. It is also essential to provide assistance to all the people in need. Information and Communication Technologies can be very useful. This study aims to evaluate the efficacy of a transdiagnostic Internet-based treatment for ED in a community sample. The protocol includes traditional CBT components, as well as a specific component to address positive affect. We intend to test this protocol, including this specific component or not, versus a waiting list control group. Moreover, we aim to test the differential effect of this specific component, and study the effectiveness (in terms of patients' acceptance) of using a self-applied Internet-based program. This paper presents the study protocol. The study is a randomized controlled trial. 207 participants will be randomly assigned to: a)Transdiagnostic Internet-based protocol (TIBP), b)Transdiagnostic Internet-based protocol + positive affect component (TIBP + PA), or c)a Waiting List control group (WL). Primary outcomes measures will be the BDI-II, the BAI, and the PANAS. Secondary outcomes will include diagnosis-specific measures of the principal disorder. Participants' treatment acceptance will also be measured. Participants will be assessed at pre-, post-treatment, and 3- and 12- month follow-ups. The data will be analyzed based on the Intention-to-treat principle. Per

  20. Effectiveness of a night positioning programme on ankle range of motion in patients after hemiparesis: a prospective randomized controlled pilot study.

    Science.gov (United States)

    DeMeyer, Lauren; Brown, Marcie; Adams, Ashley

    2015-10-05

    To investigate the effect of night positioning on ankle motion in patients after stroke or brain injury. Prospective randomized controlled pilot study with 3 groups: bivalve cast; pressure-relieving ankle-foot orthosis; and control. Adults (n = 46) in inpatient rehabilitation with lower extremity paresis following stroke or brain injury. Intervention group participants wore a custom bivalve cast or pre-fabricated orthosis 8-12 h/night. The primary outcome variable was passive ankle dorsiflexion. Muscle spasticity (Modified Ashworth Scale) and functional mobility (Functional Independence Measure) were also assessed. No significant differences were found between groups for all outcome measures at the pilot sample size (p > 0.05). Control and pressure-relieving ankle-foot orthosis groups showed improvement in ankle dorsiflexion, and the bivalve cast group demonstrated a trend toward decreased spasticity. Positioning interventions were tolerated for approximately 11 h/night. Baseline range of motion was measured and a retrospective power analysis determined that a sample size of 234 is needed for 80% power to establish significance. Future research with a larger sample size is re-commended to determine significance and whether a more specific subset of patients would benefit from night positioning to maximize treatment time during daytime therapy sessions.

  1. A non-randomized, open-label, single-arm, Phase 2 study of emibetuzumab in Asian patients with MET diagnostic positive, advanced gastric cancer.

    Science.gov (United States)

    Sakai, Daisuke; Chung, Hyun Cheol; Oh, Do-Youn; Park, Se Hoon; Kadowaki, Shigenori; Kim, Yeul Hong; Tsuji, Akihito; Komatsu, Yoshito; Kang, Yoon-Koo; Uenaka, Kazunori; Wijayawardana, Sameera R; Wacheck, Volker; Wang, Xuejing; Yamamura, Ayuko; Doi, Toshihiko

    2017-12-01

    Mesenchymal-epithelial transition factor (MET) is expressed in gastric cancer and associated with poor clinical outcomes. We assessed activity, safety, and pharmacokinetics of emibetuzumab, a bivalent monoclonal anti-MET antibody that blocks ligand-dependent and ligand-independent MET signaling. This non-randomized, single-arm, Phase 2 study enrolled Asian patients with MET diagnostic positive advanced gastric adenocarcinoma. Emibetuzumab (2000 mg, intravenous) was given on days 1 and 15 (28-day cycle). The primary endpoint was 8-week progression-free survival rate. Secondary objectives included safety, pharmacokinetics, overall survival, and change in tumor size. Tumors from 65 patients were immunohistochemically screened to enroll 15 MET diagnostic positive patients (23% positivity; 8 Japanese, 7 Korean; 10 male). Eight-week progression-free survival rate was 0.47 (70% CI, 0.33-0.59). Disease control rate was 40% (target lesion decreases, three patients; no complete/partial responses according to RECIST). Median overall survival was 17.1 weeks (95% CI, 6.3-not achievable). No serious emibetuzumab-related adverse events or new safety signals emerged. Grade ≥ 3 possibly drug-related adverse events were hyperkalemia, hyponatremia, and hyperuricemia (one each). Emibetuzumab's pharmacokinetics profile was similar to that observed previously. MET expression and clinical outcomes were not obviously associated. Emibetuzumab was well tolerated with limited single-agent activity in advanced gastric adenocarcinoma.

  2. Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Bluth, T; Teichmann, R; Kiss, T; Bobek, I; Canet, J; Cinnella, G; De Baerdemaeker, L; Gregoretti, C; Hedenstierna, G; Hemmes, S N; Hiesmayr, M; Hollmann, M W; Jaber, S; Laffey, J G; Licker, M J; Markstaller, K; Matot, I; Müller, G; Mills, G H; Mulier, J P; Putensen, C; Rossaint, R; Schmitt, J; Senturk, M; Serpa Neto, A; Severgnini, P; Sprung, J; Vidal Melo, M F; Wrigge, H; Schultz, M J; Pelosi, P; Gama de Abreu, M

    2017-04-28

    Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016.

  3. Reducing and preventing internalizing and externalizing behavior problems in children with type 1 diabetes: a randomized controlled trial of the Triple P-Positive Parenting Program.

    Science.gov (United States)

    Westrupp, E M; Northam, E; Lee, K J; Scratch, S E; Cameron, F

    2015-11-01

    Children with type 1 diabetes are at increased risk of mental health problems, which in turn are associated with poor glycemic control, diabetes-related complications, and long-term psychiatric morbidity. We tested the efficacy of the Triple P-Positive Parenting Program in reducing or preventing mental health problems and improving glycemic control in children with type 1 diabetes in a randomized controlled trial. Participants were recruited from the Diabetes Clinic, Royal Children's Hospital, Melbourne, Australia, and randomized to Triple P or standard diabetes care. The primary outcome was child internalizing and externalizing behavior problems 3 and 12 months postrandomization. Secondary outcomes were glycemic control, parent mental health, parenting skills, and family functioning at 3 and 12 months, and glycemic control at 24 months. A total of 76 participants were randomized (38 to intervention and 38 to control), 60 completed 3-month, and 57 completed 12-month assessments. Benefits of Triple P were evident at 3 months for parent mental health, parenting skills, and family functioning (p parent mental health, parenting skills, and diabetes family conflict (p parenting self-efficacy at 3 months. Improvements in parent mental health and parenting competency associated with Triple P were sustained to 12 months for children with pre-existing mental health problems. This study provides some support for the efficacy of Triple P in improving parent and family outcomes, and reducing child internalizing and externalizing behavior problems primarily in children who have pre-existing mental health problems. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Clinical and Radiographic Evaluation of Marginal Bone Changes around Platform-Switching Implants Placed in Crestal or Subcrestal Positions: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Kütan, Esma; Bolukbasi, Nilufer; Yildirim-Ondur, Esra; Ozdemir, Tayfun

    2015-10-01

    It has been reported in many articles that marginal bone resorptions are prevented by platform-switching design. However, what occurs when these implants are placed in the apical position is not completely known. This report describes a randomized controlled clinical trial study that aims to test the hypothesis that less resorption will occur when platform-switching implants are placed 1 mm below bone level. A total of 56 randomly selected implants were inserted bilaterally, either 1 mm below bone level (test group, 28 implants) or at bone level (control group, 28 implants) of the patients' posterior regions. Marginal bone resorptions were examined through periapical radiographies taken with the parallel technique at the time of crown cementation and the third, sixth, 12th, and 36th months after prosthetic loading. The modified plaque index, gingival index, bleeding on probing, and probing depths were used for follow-up periodontal care of the implants. After 3 years, the mean radiographic vertical bone loss in the control group was significantly lower than in the test group (0.56 ± 0.35 mm and 1.21 ± 1.05 mm, respectively) (p  .05). No peri-implantitis or peri-implant mucositis was observed around the test or control implants. More marginal bone resorptions occurred after the third year of loading in implants placed 1 mm below bone level. However, the resorptions did not reach the implants thread. In the control group, the first bone implant contact was placed under the level of the first threads. Therefore, the present randomized clinical trial confirmed the hypothesis that placing platform-switching implants 1 mm below bone level reduced marginal bone loss. It can be noted that to reduce resorption, platform-switching implants should be placed below bone level. © 2014 Wiley Periodicals, Inc.

  5. GPS Position Time Series @ JPL

    Science.gov (United States)

    Owen, Susan; Moore, Angelyn; Kedar, Sharon; Liu, Zhen; Webb, Frank; Heflin, Mike; Desai, Shailen

    2013-01-01

    Different flavors of GPS time series analysis at JPL - Use same GPS Precise Point Positioning Analysis raw time series - Variations in time series analysis/post-processing driven by different users. center dot JPL Global Time Series/Velocities - researchers studying reference frame, combining with VLBI/SLR/DORIS center dot JPL/SOPAC Combined Time Series/Velocities - crustal deformation for tectonic, volcanic, ground water studies center dot ARIA Time Series/Coseismic Data Products - Hazard monitoring and response focused center dot ARIA data system designed to integrate GPS and InSAR - GPS tropospheric delay used for correcting InSAR - Caltech's GIANT time series analysis uses GPS to correct orbital errors in InSAR - Zhen Liu's talking tomorrow on InSAR Time Series analysis

  6. Randomized prospective crossover study of biphasic intermittent positive airway pressure ventilation (BIPAP) versus pressure support ventilation (PSV) in surgical intensive care patients.

    Science.gov (United States)

    Elrazek, E Abd

    2004-10-01

    The aim of this prospective, randomized and crossover study was to assess the role of a relatively new mode of mechanical ventilation, biphasic intermittent positive airway pressure (BIPAP) in comparison to another well established one, pressure-support ventilation (PSV) in surgical intensive care patients. 24 generally stable patients, breathing on their own after short-term (PSV or BIPAP, and indirect calorimetry measurements were performed after 1 hour adaptation period at two time intervals; immediately after the investigated ventilatory mode was started and 1 hour later. Statistics included a two-tailed paired t-test to compare the two sets of different data, p PSV and BIPAP can be used for weaning patients comfortably in surgical intensive care after short-term postoperative ventilation. BIPAP may have the credit of being smoother than PSV where no patient effort is required.

  7. High-Flow Nasal Cannula versus Nasal Continuous Positive Airway Pressure for Primary Respiratory Support in Preterm Infants with Respiratory Distress: A Randomized Controlled Trial.

    Science.gov (United States)

    Murki, Srinivas; Singh, Jayesh; Khant, Chiragkumar; Kumar Dash, Swarup; Oleti, Tejo Pratap; Joy, Percy; Kabra, Nandkishor S

    2018-01-23

    Nasal continuous positive airway pressure (nCPAP) is the standard noninvasive respiratory support for newborns with respiratory distress. Evidence for high-flow nasal cannula (HFNC) as an alternative mode of respiratory support is inconclusive. The aim of this work was to evaluate whether HFNC is not inferior to nCPAP in reducing the need for higher respiratory support in the first 72 h of life when applied as a noninvasive respiratory support mode for preterm neonates with respiratory distress. Preterm infants (gestation ≥28 weeks and birth weight ≥1,000 g) with respiratory distress were randomized to either HFNC or nCPAP in a non-inferiority trial. Failure of the support mode in the first 72 h after birth was the primary outcome. Infants failing HFNC were rescued either with nCPAP or mechanical ventilation, and those failing nCPAP received mechanical ventilation. During the study period, 139 and 133 infants were randomized to the nCPAP and HFNC groups, respectively. The study was stopped after an interim analysis showed a significant difference (p respiratory distress (SAS score >5). When comparing HFNC to nCPAP as a primary noninvasive respiratory support in preterm infants with respiratory distress, HFNC is inferior to nCPAP in avoiding the need for a higher mode of respiratory support in the first 72 h of life. © 2018 S. Karger AG, Basel.

  8. [A multi-center, randomized, double-blind, positive controlled clinical trial of salbutamol sulfate MDI without CFC in the treatment of asthma].

    Science.gov (United States)

    2014-03-01

    To evaluate the efficacy and safety of domestically produced Salbutamol Sulfate metered dose inhaler (MDI) without chloro-fluro-carbon (CFC) in the treatment of asthmatic patients. A muticenter, randomized, double-blind, positive controlled clinical trial was conducted in asthmatic patients. The participants were randomized divided into trial group treated with domestically produced Salbutamol Sulfate Aerosol MDI (200 microg single-dose) and control group treated with imported Salbutamol Sulfate Aerosol MDI (200 microg single-dose). The lung function was measured by spirometry and a scoring questionaire before medications and 15, 30, 120 and 240 min post medications. A total of 238 patients were enrolled in the trial. Compared with baselines, the forced expiratory volume in 1 s (FEV1) of the participants in both groups increased significantly 15, 30, 120 and 240 min after medications (P 0.05). Similarly, the forced vital capacity (FVC) and asthma symptomatic scores of the participants in both groups improved significantly after administration of medications (P 0.05). In both groups, drugs were well tolerated. The domestically produced Salbutamol Sulfate Aerosol MDI without CFC is effective and safe for treating asthma.

  9. Experimental blunt chest trauma--cardiorespiratory effects of different mechanical ventilation strategies with high positive end-expiratory pressure: a randomized controlled study.

    Science.gov (United States)

    Schreiter, Dierk; Carvalho, Nadja C; Katscher, Sebastian; Mende, Ludger; Reske, Alexander P; Spieth, Peter M; Carvalho, Alysson R; Beda, Alessandro; Lachmann, Burkhard; Amato, Marcelo B P; Wrigge, Hermann; Reske, Andreas W

    2016-01-12

    Uncertainty persists regarding the optimal ventilatory strategy in trauma patients developing acute respiratory distress syndrome (ARDS). This work aims to assess the effects of two mechanical ventilation strategies with high positive end-expiratory pressure (PEEP) in experimental ARDS following blunt chest trauma. Twenty-six juvenile pigs were anesthetized, tracheotomized and mechanically ventilated. A contusion was applied to the right chest using a bolt-shot device. Ninety minutes after contusion, animals were randomized to two different ventilation modes, applied for 24 h: Twelve pigs received conventional pressure-controlled ventilation with moderately low tidal volumes (VT, 8 ml/kg) and empirically chosen high external PEEP (16 cmH2O) and are referred to as the HP-CMV-group. The other group (n = 14) underwent high-frequency inverse-ratio pressure-controlled ventilation (HFPPV) involving respiratory rate of 65 breaths · min(-1), inspiratory-to-expiratory-ratio 2:1, development of intrinsic PEEP and recruitment maneuvers, compatible with the rationale of the Open Lung Concept. Hemodynamics, gas exchange and respiratory mechanics were monitored during 24 h. Computed tomography and histology were analyzed in subgroups. Comparing changes which occurred from randomization (90 min after chest trauma) over the 24-h treatment period, groups differed statistically significantly (all P values for group effect ventilation improved respiratory function and fulfilled relevant ventilation endpoints for trauma patients, i.e. restoration of oxygenation and lung aeration while avoiding hypercapnia and respiratory acidosis.

  10. Randomized controlled trial of a positive affect intervention to reduce stress in people newly diagnosed with HIV; protocol and design for the IRISS study

    Directory of Open Access Journals (Sweden)

    Moskowitz JT

    2014-09-01

    currently few established interventions for people who are newly diagnosed with HIV. We present the design and methods for a randomized trial in which we test the efficacy of one such skills-based intervention that targets positive affect as a novel mechanism of change. The proposed research builds on observational findings of the important unique functions of positive affect. We aim to determine whether a five-session theory- and evidence-based intervention designed to teach skills for increasing the frequency and intensity of daily positive affect does so, and whether this intervention has beneficial effects on subsequent psychological well-being, health behaviors, and physical health up to 15 months after diagnosis with HIV. This is a randomized controlled trial in a sample of adults recruited within 12 weeks of testing positive for HIV. The control group is attention-matched, and follow up assessments will be conducted immediately post intervention (approximately 5 months post diagnosis and at 10 and 15 months post diagnosis. This study is an important next step in research concerning the adaptive functions of positive affect for people coping with HIV or other health-related life stress. Keywords: positive affect, HIV diagnosis, stress, coping, RCT, intervention, physical health

  11. Do false positive alerts in naïve clinical decision support system lead to false adoption by physicians? A randomized controlled trial.

    Science.gov (United States)

    Tsai, Chung-You; Wang, Shi-Heng; Hsu, Min-Huei; Li, Yu-Chuan Jack

    2016-08-01

    False positive alerts in patient-safety-related clinical decision support systems (CDSS) are defined as alerts which incorrectly prompt when no-risk patients are encountered. It is an unfavorable condition which may potentially mislead physicians. The aim is to investigate physician responses toward false positive (FP) and true positive (TP) alerts in CDSS for the prevention of contrast-induced nephropathy (CIN). A two-arm cluster randomized controlled trial was conducted in university hospitals. Eligible physicians were randomized to receive alert intervention or no intervention (groups 1 and 2, respectively). The alert system was embedded with a deliberately non-specific risk detection tool in order to generate TP and FP alerts. The naïve alert system would alert the physician to cancel the order regardless of the patient being at-risk or not at-risk. CIN risk was stratified as at-risk and no-risk according to a patient's pre-existing renal function. Contrast imaging order-cancellation rate was measured as primary outcome. 3802 contrast-enhanced examination orders from 66 physicians were analyzed. Demographic data and risk distributions of patients were similar and well-balanced between two groups. In the intervention group, a total of 1892 alerts were generated (332 TP alerts and 1560 FP alerts). Order-cancellation rates were 5.1% versus 1.4% in groups 1 and 2 for at-risk patients (relative risk [RR] = 3.69) from TP alerts, and 1.0% versus 1.4% for no-risk patients (RR = 0.71) from FP alerts. Using generalized linear model with generalized estimating equation, the FP alerts had no order-cancellation effect when compared to the control arm (adjusted RR = 0.69; 95%CI, 0.36-1.32). The TP alerts had a larger order-cancellation effect than that of the control arm (adjusted RR = 2.95; 95%CI, 0.94-9.27), which revealed a marginal trend toward significance. However, the effect was not statistically significant (adjusted RR = 1.24; 95%CI, 0

  12. What are the reasons for low use of graphene quantum dots in immunosensing of cancer biomarkers?

    Science.gov (United States)

    Hasanzadeh, Mohammad; Shadjou, Nasrin

    2017-02-01

    Graphene quantum dots-based immunosensors have recently gained importance for detecting antigens and biomarkers responsible for cancer diagnosis. This paper reports a literature survey of the applications of graphene quantum dots for sensing cancer biomarkers. The survey sought to explore three questions: (1) Do graphene quantum dots improve immunosensing technology? (2) If so, can graphene quantum dots have a critical, positive impact on construction of immuno-devices? And (3) What is the reason for some troubles in the application of this technology? The number of published papers in the field seems positively answer the first two questions. However additional efforts must be made to move from the bench to the real diagnosis. Some approaches to improve the analytical performance of graphene quantum dots-based immunosensors through their figures of merit have been also discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. A randomized, double-blind, crossover comparison of novel continuous bed motion versus traditional bed position whole-body PET/CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schatka, Imke [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Charite, Department of Nuclear Medicine, Berlin (Germany); Weiberg, Desiree; Reichelt, Stephanie; Owsianski-Hille, Nicole; Derlin, Thorsten; Berding, Georg; Bengel, Frank M. [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany)

    2016-04-15

    Continuous bed motion has recently been introduced for whole-body PET/CT, and represents a paradigm shift towards individualized and flexible acquisition without the limitations of bed position-based planning. Increased patient comfort due to lack of abrupt table position changes may be another albeit still unproven advantage. For robust clinical implementation, image quality and quantitative accuracy should at least be equal to the prior standard of bed position-based step-and-shoot imaging. The study included 68 consecutive patients referred for whole-body PET/CT for various malignancies. The patients underwent traditional step-and-shoot and novel continuous bed motion acquisition in the same session in a randomized crossover design. The patients and two independent observers were blinded to the sequence of scan techniques. Patient comfort/satisfaction was examined using a standardized questionnaire. SUVs were compared for reference tissue (liver, muscle) and tumour lesions. PET image quality and misalignment with CT images were evaluated on a scale of 1 - 4. Patients preferred continuous bed motion over step-and-shoot (P = 0.0001). It was considered to be more relaxing (38 % vs. 8 %), quieter (34 % vs. 8 %), and more fluid (64 % vs. 8 %). Image quality, SUV and CT misalignment did not differ between the techniques. Continuous bed motion resulted in better end-plane image quality (P < 0.0001). Regardless of the technique, second examinations had significantly higher tumour lesion SUVmax values (P = 0.0002), and a higher CT misalignment score (P = 0.0017). Oncological PET/CT with continuous bed motion enhances patient comfort and is associated with image quality at least comparable to that with traditional bed position-based step-and-shoot acquisition. (orig.)

  14. Templating growth of gold nanostructures with a CdSe quantum dot array

    Science.gov (United States)

    Paul, Neelima; Metwalli, Ezzeldin; Yao, Yuan; Schwartzkopf, Matthias; Yu, Shun; Roth, Stephan V.; Müller-Buschbaum, Peter; Paul, Amitesh

    2015-05-01

    In optoelectronic devices based on quantum dot arrays, thin nanolayers of gold are preferred as stable metal contacts and for connecting recombination centers. The optimal morphology requirements are uniform arrays with precisely controlled positions and sizes over a large area with long range ordering since this strongly affects device performance. To understand the development of gold layer nanomorphology, the detailed mechanism of structure formation are probed with time-resolved grazing incidence small-angle X-ray scattering (GISAXS) during gold sputter deposition. Gold is sputtered on a CdSe quantum dot array with a characteristic quantum dot spacing of ~7 nm. In the initial stages of gold nanostructure growth, a preferential deposition of gold on top of quantum dots occurs. Thus, the quantum dots act as nucleation sites for gold growth. In later stages, the gold nanoparticles surrounding the quantum dots undergo a coarsening to form a complete layer comprised of gold-dot clusters. Next, growth proceeds dominantly via vertical growth of gold on these gold-dot clusters to form an gold capping layer. In this capping layer, a shift of the cluster boundaries due to ripening is found. Thus, a templating of gold on a CdSe quantum dot array is feasible at low gold coverage.

  15. Multi-million atom electronic structure calculations for quantum dots

    Science.gov (United States)

    Usman, Muhammad

    Quantum dots grown by self-assembly process are typically constructed by 50,000 to 5,000,000 structural atoms which confine a small, countable number of extra electrons or holes in a space that is comparable in size to the electron wavelength. Under such conditions quantum dots can be interpreted as artificial atoms with the potential to be custom tailored to new functionality. In the past decade or so, these nanostructures have attracted significant experimental and theoretical attention in the field of nanoscience. The new and tunable optical and electrical properties of these artificial atoms have been proposed in a variety of different fields, for example in communication and computing systems, medical and quantum computing applications. Predictive and quantitative modeling and simulation of these structures can help to narrow down the vast design space to a range that is experimentally affordable and move this part of nanoscience to nano-Technology. Modeling of such quantum dots pose a formidable challenge to theoretical physicists because: (1) Strain originating from the lattice mismatch of the materials penetrates deep inside the buffer surrounding the quantum dots and require large scale (multi-million atom) simulations to correctly capture its effect on the electronic structure, (2) The interface roughness, the alloy randomness, and the atomistic granularity require the calculation of electronic structure at the atomistic scale. Most of the current or past theoretical calculations are based on continuum approach such as effective mass approximation or k.p modeling capturing either no or one of the above mentioned effects, thus missing some of the essential physics. The Objectives of this thesis are: (1) to model and simulate the experimental quantum dot topologies at the atomistic scale; (2) to theoretically explore the essential physics i.e. long range strain, linear and quadratic piezoelectricity, interband optical transition strengths, quantum confined

  16. Neratinib Plus Paclitaxel vs Trastuzumab Plus Paclitaxel in Previously Untreated Metastatic ERBB2-Positive Breast Cancer: The NEfERT-T Randomized Clinical Trial.

    Science.gov (United States)

    Awada, Ahmad; Colomer, Ramon; Inoue, Kenichi; Bondarenko, Igor; Badwe, Rajendra A; Demetriou, Georgia; Lee, Soo-Chin; Mehta, Ajay O; Kim, Sung-Bae; Bachelot, Thomas; Goswami, Chanchal; Deo, Suryanarayan; Bose, Ron; Wong, Alvin; Xu, Feng; Yao, Bin; Bryce, Richard; Carey, Lisa A

    2016-12-01

    Efficacious ERBB2 (formerly HER2 or HER2/neu)-directed treatments, in addition to trastuzumab and lapatinib, are needed. To determine whether neratinib, an irreversible pan-ERBB tyrosine kinase inhibitor, plus paclitaxel improves progression-free survival compared with trastuzumab plus paclitaxel in the first-line treatment of recurrent and/or metastatic ERBB2-positive breast cancer. In the randomized, controlled, open-label NEfERT-T trial conducted from August 2009 to December 2014 at 188 centers in 34 countries in Europe, Asia, Africa, and North America, 479 women with previously untreated recurrent and/or metastatic ERBB2-positive breast cancer were randomized to 1 of 2 treatment arms (neratinib-paclitaxel [n = 242] or trastuzumab-paclitaxel [n = 237]). Women with asymptomatic central nervous system metastases were eligible, and randomization was stratified by prior trastuzumab and lapatinib exposure, hormone-receptor status, and region. Women received neratinib (240 mg/d orally) or trastuzumab (4 mg/kg then 2 mg/kg weekly), each combined with paclitaxel (80 mg/m2 on days 1, 8, and 15 every 28 days). Primary prophylaxis for diarrhea was not mandatory. The primary outcome was progression-free survival. Secondary end points were response rate, clinical benefit rate, duration of response, frequency, and time to symptomatic and/or progressive central nervous system lesions, and safety. The intent-to-treat population comprised 479 women 18 years or older (neratinib-paclitaxel, n = 242; trastuzumab-paclitaxel, n = 237) randomized and stratified in their respective treatment arms by prior trastuzumab and lapatinib exposure, hormone-receptor status, and region. Median progression-free survival was 12.9 months (95% CI, 11.1-14.9) with neratinib-paclitaxel and 12.9 months (95% CI, 11.1-14.8) with trastuzumab-paclitaxel (hazard ratio [HR], 1.02; 95% CI, 0.81-1.27; P =.89). With neratinib-paclitaxel, the incidence of central nervous system recurrences was

  17. Submonolayer Quantum Dot Infrared Photodetector

    Science.gov (United States)

    Ting, David Z.; Bandara, Sumith V.; Gunapala, Sarath D.; Chang, Yia-Chang

    2010-01-01

    A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency.

  18. Long-term outcome of a randomized controlled universal prevention trial through a positive parenting program: is it worth the effort?

    Directory of Open Access Journals (Sweden)

    Bertram Heike

    2010-05-01

    Full Text Available Abstract Background Approximately 20% of children experience internalizing or externalizing DSM-IV-TR disorders. This prevalence rate cannot be reduced through treatment only. Effective preventive interventions are therefore urgently needed. The aim of the current investigation is to evaluate the two-year efficacy of the group Triple P parenting program administered universally for the prevention of child behavior problems. Methods Based on their respective preschool, N = 280 families were randomly assigned either to the parent training or to the control group. The efficacy was analyzed using multi-source assessments, including questionnaires by mother and father, behavioral observation of mother-child interaction, and teacher evaluations. Results At the 2-year follow-up, both parents in the Triple P intervention reported significant reductions in dysfunctional parenting behavior, and mothers also an increase in positive parenting behavior. In addition, mothers reported significant reductions in internalizing and externalizing child behavior. Single-parent mothers in the Triple P intervention did not report significant changes in parenting or child problem behavior which is primarily due to inexplicable high positive effects in single parent mothers of the control group. Neither mother-child interactions nor teacher ratings yielded significant results. Conclusions The results support the long-term efficacy of the Triple P - group program as a universal prevention intervention for changing parenting behavior in two-parent households, but not necessarily in single-parent mothers.

  19. Long-term outcome of a randomized controlled universal prevention trial through a positive parenting program: is it worth the effort?

    Science.gov (United States)

    Hahlweg, Kurt; Heinrichs, Nina; Kuschel, Annett; Bertram, Heike; Naumann, Sebastian

    2010-05-16

    Approximately 20% of children experience internalizing or externalizing DSM-IV-TR disorders. This prevalence rate cannot be reduced through treatment only. Effective preventive interventions are therefore urgently needed. The aim of the current investigation is to evaluate the two-year efficacy of the group Triple P parenting program administered universally for the prevention of child behavior problems. Based on their respective preschool, N = 280 families were randomly assigned either to the parent training or to the control group. The efficacy was analyzed using multi-source assessments, including questionnaires by mother and father, behavioral observation of mother-child interaction, and teacher evaluations. At the 2-year follow-up, both parents in the Triple P intervention reported significant reductions in dysfunctional parenting behavior, and mothers also an increase in positive parenting behavior. In addition, mothers reported significant reductions in internalizing and externalizing child behavior. Single-parent mothers in the Triple P intervention did not report significant changes in parenting or child problem behavior which is primarily due to inexplicable high positive effects in single parent mothers of the control group. Neither mother-child interactions nor teacher ratings yielded significant results. The results support the long-term efficacy of the Triple P - group program as a universal prevention intervention for changing parenting behavior in two-parent households, but not necessarily in single-parent mothers.

  20. Randomized crossover study assessing oropharyngeal leak pressure and fiber optic positioning : Laryngeal Mask Airway Supreme™ versus Laryngeal Tube LTS II™ size 2 in non-paralyzed anesthetized children.

    Science.gov (United States)

    Gasteiger, L; Ofner, S; Stögermüller, B; Ziegler, B; Brimacombe, J; Keller, C

    2016-08-01

    As there are currently no data available comparing the practicability of the laryngeal mask airway (LMA) Supreme™ size 2 versus the laryngeal tube LTS II™ size 2 in children, this trial was conducted to quantify the differences between these two airway devices concerning leak pressure and fiber optic-controlled positioning in non-paralyzed, anesthetized pediatric patients. A total of 56 children aged 1-6 years and weighing between 11 and 23 kg were enrolled in the study. Anesthesia was intravenously induced according to local standards using fentanyl and propofol. After induction of anesthesia both airway devices were inserted consecutively in accordance with the randomization protocol. The mean oropharyngeal leak pressure was significantly higher for the LTS II™ (33±8 cmH2O) than for the LMA Supreme™ (21±7 cmH2O, p insertion (55Supreme LMA vs. 43LTSII, p insertion time (25 s Supreme LMA vs. 34 s LTSII, p laryngeal tube LTS II™. We conclude that oropharyngeal leak pressure, fiber optic position, first attempt insertion success rate and bloodstaining differed between the LMA Supreme™ and the LTS II™ in children.

  1. Biexciton in nanoheterostructures of germanium quantum dots

    Science.gov (United States)

    Pokutnyi, Sergey I.

    2017-06-01

    The theory of biexciton (formed from spatially separated electrons and holes) in a nanosystem consisting of double quantum dots (QDs) of germanium synthesized in a silicon matrix is presented. It is shown that the major contribution to the biexciton binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes. The position of the biexciton state energy band depends both on the mean radius of the QDs and the distance between their surfaces, which enables one to purposefully control it by varying these parameters of the nanostructure.

  2. Magnetic resonance imaging zygapophyseal joint space changes (gapping) in low back pain patients following spinal manipulation and side-posture positioning: a randomized controlled mechanisms trial with blinding.

    Science.gov (United States)

    Cramer, Gregory D; Cambron, Jerrilyn; Cantu, Joe A; Dexheimer, Jennifer M; Pocius, Judith D; Gregerson, Douglas; Fergus, Michael; McKinnis, Ray; Grieve, Thomas J

    2013-05-01

    The purpose of this study was to quantify lumbar zygapophyseal (Z) joint space separation (gapping) in low back pain (LBP) subjects after spinal manipulative therapy (SMT) or side-posture positioning (SPP). This was a controlled mechanisms trial with randomization and blinding. Acute LBP subjects (N = 112; four n = 28 magnetic resonance imaging [MRI] protocol groups) had 2 MRI appointments (initial enrollment and after 2 weeks of chiropractic treatment, receiving 2 MRI scans of the L4/L5 and L5/S1 Z joints at each MRI appointment. After the first MRI scan of each appointment, subjects were randomized (initial enrollment appointment) or assigned (after 2 weeks of chiropractic treatment appointment) into SPP (nonmanipulation), SMT (manipulation), or control MRI protocol groups. After SPP or SMT, a second MRI was taken. The central anterior-posterior joint space was measured. Difference between most painful side anterior-posterior measurements taken postintervention and preintervention was the Z joint "gapping difference." Gapping differences were compared (analysis of variance) among protocol groups. Secondary measures of pain (visual analog scale, verbal numeric pain rating scale) and function (Bournemouth questionnaire) were assessed. Gapping differences were significant at the first (adjusted, P = .009; SPP, 0.66 ± 0.48 mm; SMT, 0.23 ± 0.86; control, 0.18 ± 0.71) and second (adjusted, P = .0005; SPP, 0.65 ± 0.92 mm; SMT, 0.89 ± 0.71; control, 0.35 ± 0.32) MRI appointments. Verbal numeric pain rating scale differences were significant at first MRI appointment (P = .04) with SMT showing the greatest improvement. Visual analog scale and Bournemouth questionnaire improved after 2 weeks of care in all groups (both P < .0001). Side-posture positioning showed greatest gapping at baseline. After 2 weeks, SMT resulted in greatest gapping. Side-posture positioning appeared to have additive therapeutic benefit to SMT. Copyright © 2013 National University of Health

  3. The efficiency and safety of trastuzumab and lapatinib added to neoadjuvant chemotherapy in Her2-positive breast cancer patients: a randomized meta-analysis

    Directory of Open Access Journals (Sweden)

    Chen ZL

    2016-05-01

    Full Text Available Zhe-Ling Chen, Yan-Wei Shen, Shu-Ting Li, Chun-Li Li, Ling-Xiao Zhang, Jiao Yang, Meng Lv, Ya-Yun Lin, Xin Wang, Jin Yang Department of Medical Oncology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China Background: The addition of human epidermal growth factor receptor 2 (Her2 therapies to neoadjuvant chemotherapy (NAC during treatment of Her2-positive breast cancer has been proposed as an effective way to improve the prognosis. However, the treatment outcomes of adding trastuzumab, lapatinib, or both to NAC were not unequivocal in randomized clinical trials. Based on these data, a meta-analysis was performed. Objective: The main objective was to evaluate the efficiency and safety of trastuzumab and lapatinib added to NAC for treatment of Her2-positive breast cancer. Methods: ClinicalTrials.gov and PubMed were searched for randomized clinical trials that compared trastuzumab, lapatinib, or both, added to NAC. The main endpoint was a pathologically complete response (pCR rate, in breast only or in breast and lymph nodes. The drug safety and the influence of hormone-receptor status, comparing the clinical response and the rate of breast conservation, were evaluated. Results: A total of eight publications were included in the primary analysis, designed as two or three subgroups. The cumulative cases were 2,349 and the analyses of all the clinical trials showed that the pCR rate was significantly higher in the group receiving trastuzumab than that in the group with lapatinib, either in breast only (P=0.001 or in breast and lymph nodes (P=0.0001. Similar results could be seen in comparisons of the combination versus trastuzumab group. Further studies of subgroups divided into hormone receptor-positive or-negative patients showed that the addition of trastuzumab or dual Her2-targeted therapy significantly improved the pCR rate in patients who were hormone-insensitive. Regarding the toxic

  4. DOT Official County Highway Map

    Data.gov (United States)

    Minnesota Department of Natural Resources — The County Highway Map theme is a scanned and rectified version of the original MnDOT County Highway Map Series. The cultural features on some of these maps may be...

  5. Marvelous applications of quantum dots.

    Science.gov (United States)

    Cheki, M; Moslehi, M; Assadi, M

    2013-05-01

    Nanotechnology is developed to convert research, prevention, and treatment of cancer through the novel diagnostic imaging techniques and therapies. In particular, the imaging nanotechnology has gained substantial momentum in recent years. The main progress in nanotechnology has led to the production of novel fluorescent probes named quantum dots (QDs). Quantum dots develop a revolution in the molecular tagging processes within research, in vivo and in vitro studies. Due to unique physical and chemical features of QD probes, new possible techniques of early cancer detection and therapeutic management are being surveyed. Quantum dots have also dissolved many of the restrictions of organic fluorophores and are a talented option as a research tool. This review addresses on the present status of research, preclinical applications and also future visions of quantum dots.  

  6. PennDOT : fact book

    Science.gov (United States)

    2008-06-01

    PennDOT was created in 1970 when the former : Department of Highways was merged with transportation related : functions from the Departments of Revenue, : Commerce, Community Affairs and Military Affairs. With : an annual budget of about $5.4 billion...

  7. Safety and effectiveness of alveolar recruitment maneuvers and positive end-expiratory pressure during general anesthesia for cesarean section: a prospective, randomized trial.

    Science.gov (United States)

    Aretha, D; Fligou, F; Kiekkas, P; Messini, C; Panteli, E; Zintzaras, E; Karanikolas, M

    2017-05-01

    During cesarean section, the supine position reduces functional residual capacity and worsens lung compliance. We tested the hypothesis that alveolar recruitment maneuvers and positive end-expiratory pressure improve lung compliance in women undergoing general anesthesia for cesarean section. Ninety women undergoing cesarean section were randomly assigned to one of two groups in a prospective, double-blind trial. In the alveolar recruitment maneuver group, pressure-control ventilation was used and inspiratory time was increased to 50% after delivery; positive end-expiratory pressure was increased to 20cmH 2 O and peak airway inspiratory pressure gradually increased to 45-50cmH 2 O. Volume-control ventilation was then used with low tidal volumes (6mL/kg) and positive end-expiratory pressure was reduced stepwise to 8cmH 2 O. In the control group, alveolar recruitment maneuvers were not used. Data were collected before and 3, 10 and 20min after the alveolar recruitment maneuver, before extubation and postoperatively at 10 and 20min. Dynamic compliance, peak airway inspiratory pressure, PaO 2 and PaO 2 /FiO 2 were significantly different in the alveolar recruitment maneuver group compared to controls at all time points during surgery except at baseline. Oxygen saturation was significantly greater in the alveolar recruitment maneuver group at 10 and 20min and before extubation. Dynamic compliance was 29.7-42.5% higher and peak airway inspiratory pressure 3.6-10.2% lower in the alveolar recruitment maneuver group compared to controls. The PaO 2 , PaO 2 /FiO 2 and oxygen saturation were higher (9.4-12%, 10.3-11.9% and 0.4-1.3%, respectively) in the alveolar recruitment maneuver group. Postoperatively, PaO 2 and oxygen saturation were significantly higher in the alveolar recruitment maneuver group compared to controls (PaO 2 9.2% at 10min and 8.4% at 20min, oxygen saturation 0.8% at 10min and 1.1% at 20min). There were no significant differences in hemodynamic stability or

  8. Filtering algorithm for dotted interferences

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K., E-mail: kurt.osterloh@bam.de [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Buecherl, T.; Lierse von Gostomski, Ch. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany); Zscherpel, U.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Bock, S. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany)

    2011-09-21

    An algorithm has been developed to remove reliably dotted interferences impairing the perceptibility of objects within a radiographic image. This particularly is a major challenge encountered with neutron radiographs collected at the NECTAR facility, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II): the resulting images are dominated by features resembling a snow flurry. These artefacts are caused by scattered neutrons, gamma radiation, cosmic radiation, etc. all hitting the detector CCD directly in spite of a sophisticated shielding. This makes such images rather useless for further direct evaluations. One approach to resolve this problem of these random effects would be to collect a vast number of single images, to combine them appropriately and to process them with common image filtering procedures. However, it has been shown that, e.g. median filtering, depending on the kernel size in the plane and/or the number of single shots to be combined, is either insufficient or tends to blur sharp lined structures. This inevitably makes a visually controlled processing image by image unavoidable. Particularly in tomographic studies, it would be by far too tedious to treat each single projection by this way. Alternatively, it would be not only more comfortable but also in many cases the only reasonable approach to filter a stack of images in a batch procedure to get rid of the disturbing interferences. The algorithm presented here meets all these requirements. It reliably frees the images from the snowy pattern described above without the loss of fine structures and without a general blurring of the image. It consists of an iterative, within a batch procedure parameter free filtering algorithm aiming to eliminate the often complex interfering artefacts while leaving the original information untouched as far as possible.

  9. Intracellular distribution of nontargeted quantum dots after natural uptake and microinjection

    Science.gov (United States)

    Damalakiene, Leona; Karabanovas, Vitalijus; Bagdonas, Saulius; Valius, Mindaugas; Rotomskis, Ricardas

    2013-01-01

    Background: The purpose of this study was to elucidate the mechanism of natural uptake of nonfunctionalized quantum dots in comparison with microinjected quantum dots by focusing on their time-dependent accumulation and intracellular localization in different cell lines. Methods: The accumulation dynamics of nontargeted CdSe/ZnS carboxyl-coated quantum dots (emission peak 625 nm) was analyzed in NIH3T3, MCF-7, and HepG2 cells by applying the methods of confocal and steady-state fluorescence spectroscopy. Intracellular colocalization of the quantum dots was investigated by staining with Lysotracker®. Results: The uptake of quantum dots into cells was dramatically reduced at a low temperature (4°C), indicating that the process is energy-dependent. The uptake kinetics and imaging of intracellular localization of quantum dots revealed three accumulation stages of carboxyl-coated quantum dots at 37°C, ie, a plateau stage, growth stage, and a saturation stage, which comprised four morphological phases: adherence to the cell membrane; formation of granulated clusters spread throughout the cytoplasm; localization of granulated clusters in the perinuclear region; and formation of multivesicular body-like structures and their redistribution in the cytoplasm. Diverse quantum dots containing intracellular vesicles in the range of approximately 0.5–8 μm in diameter were observed in the cytoplasm, but none were found in the nucleus. Vesicles containing quantum dots formed multivesicular body-like structures in NIH3T3 cells after 24 hours of incubation, which were Lysotracker-negative in serum-free medium and Lysotracker-positive in complete medium. The microinjected quantum dots remained uniformly distributed in the cytosol for at least 24 hours. Conclusion: Natural uptake of quantum dots in cells occurs through three accumulation stages via a mechanism requiring energy. The sharp contrast of the intracellular distribution after microinjection of quantum dots in comparison

  10. Implementace hry Dots and Boxes

    OpenAIRE

    Balko, Martin

    2010-01-01

    Title: Dots and Boxes implementation Author: Martin Balko Department: Department of Applied Mathematics Supervisor: RNDr. Ondřej Pangrác, Ph.D. Supervisor's email address: Abstract: The presented thesis deals with the analysis of a popular logical game Dots and Boxes and its generalized versions. It focuses on the different methods and algorithms of opponent's artificial intelligence. The result of the work is implementation of the generalized version of this game in w...

  11. Quantum dots in cell biology.

    Science.gov (United States)

    Barroso, Margarida M

    2011-03-01

    Quantum dots are semiconductor nanocrystals that have broad excitation spectra, narrow emission spectra, tunable emission peaks, long fluorescence lifetimes, negligible photobleaching, and ability to be conjugated to proteins, making them excellent probes for bioimaging applications. Here the author reviews the advantages and disadvantages of using quantum dots in bioimaging applications, such as single-particle tracking and fluorescence resonance energy transfer, to study receptor-mediated transport.

  12. Efficiency of a phone coaching program on adherence to continuous positive airway pressure in sleep apnea hypopnea syndrome: a randomized trial.

    Science.gov (United States)

    Sedkaoui, Kamila; Leseux, Ludivine; Pontier, Sandrine; Rossin, Nicole; Leophonte, Paul; Fraysse, Jean-Louis; Didier, Alain

    2015-09-14

    Continuous Positive Airway Pressure (CPAP) remains the reference treatment for moderate to severe forms of the Sleep Apnea/Hypopnea Syndrome (SAHS). Compliance to the treatment appears to be a key factor to improving health status of these patients. We conducted a multicenter, prospective, randomized, controlled, parallel group trial of standard support completed or not within 3 months of coaching sessions for newly diagnosed SAHS patients starting CPAP therapy. This study has been recorded by AFSSAPS with the RCB number: 2009-A01127-50 and received favourably by the Human Studies Committee in France. The coaching session consisted of 5 sessions of telephone-based counselling by competent staff. The primary outcome was the proportion of patients using CPAP more than 3 h per night for 4 months; the secondary outcome was mean hours of CPAP usage in the 2 groups. Three hundred and seventy-nine patients fulfilled the inclusion criteria and were randomized. The percentage of patients using CPAP more than 3 h per night for 4 months was 65 % for the standard support group and 75 % for the coached group. This difference reached a statistical significance (χ2 = 3.97). The mean CPAP usage was increased in the coached group versus standard group. A difference of 26 min was observed (4 h34+/-2 h17 and 4 h08+/-2 h25 respectively, p = 0.04). This study shows that SAHS patients who benefit from phone coaching are statistically more compliant to CPAP than a standard support group is. A simple phone coaching procedure based on knowledge of the disease and reinforcement messages about treatment benefits helps to improve CPAP adherence in SAHS patients. NCT02435355.

  13. Menatetrenone versus alfacalcidol in the treatment of Chinese postmenopausal women with osteoporosis: a multicenter, randomized, double-blinded, double-dummy, positive drug-controlled clinical trial

    Science.gov (United States)

    Jiang, Yan; Zhang, Zhen-Lin; Zhang, Zhong-Lan; Zhu, Han-Min; Wu, Yi-Yong; Cheng, Qun; Wu, Feng-Li; Xing, Xiao-Ping; Liu, Jian-Li; Yu, Wei; Meng, Xun-Wu

    2014-01-01

    Objective To evaluate whether the efficacy and safety of menatetrenone for the treatment of osteoporosis is noninferior to alfacalcidol in Chinese postmenopausal women. Method This multicenter, randomized, double-blinded, double-dummy, noninferiority, positive drug-controlled clinical trial was conducted in five Chinese sites. Eligible Chinese women with postmenopausal osteoporosis (N=236) were randomized to Group M or Group A and received menatetrenone 45 mg/day or alfacalcidol 0.5 μg/day, respectively, for 1 year. Additionally, all patients received calcium 500 mg/day. Posttreatment bone mineral density (BMD), new fracture onsets, and serum osteocalcin (OC) and undercarboxylated OC (ucOC) levels were compared with the baseline value in patients of both groups. Results A total of 213 patients (90.3%) completed the study. After 1 year of treatment, BMD among patients in Group M significantly increased from baseline by 1.2% and 2.7% at the lumbar spine and trochanter, respectively (P0.05). In Group M, OC and ucOC decreased from baseline by 38.7% and 82.3%, respectively (P<0.001). In Group A, OC and ucOC decreased by 25.8% and 34.8%, respectively (P<0.001). Decreases in serum OC and ucOC were more obvious in Group M than in Group A (P<0.001). The safety profile of menatetrenone was similar to alfacalcidol. Conclusion Menatetrenone is an effective and safe choice in the treatment of postmenopausal osteoporosis in Chinese women. PMID:24426779

  14. Efficacy of continuous positive airway pressure and incentive spirometry on respiratory functions during the postoperative period following supratentorial craniotomy: A prospective randomized controlled study.

    Science.gov (United States)

    Sah, Hulya Kahraman; Akcil, Eren Fatma; Tunali, Yusuf; Vehid, Hayriye; Dilmen, Ozlem Korkmaz

    2017-11-01

    Volume controlled ventilation with low PEEP is used in neuro-anesthesia to provide constant PaCO2 levels and prevent raised intracranial pressure. Therefore, neurosurgery patients prone to atelectasis formation, however, we could not find any study that evaluates prevention of postoperative pulmonary complications in neurosurgery. A prospective, randomized controlled study. Intensive care unit in a university hospital in Istanbul. Seventy-nine ASAI-II patients aged between 18 and 70years scheduled for elective supratentorial craniotomy were included in the study. Patients randomized into 3 groups after surgery. The Group IS (n=20) was treated with incentive spirometry 5 times in 1min and 5min per hour, the Group CPAP (n=20) with continuous positive airway pressure 10 cmH2O pressure and 0.4 FiO2 via an oronasal mask 5min per hour, and the Group Control (n=20) 4L·min-1O2 via mask; all during the first 6h postoperatively. Respiratory functions tests and arterial blood gases analysis were performed before the induction of anesthesia (Baseline), 30min, 6h, 24h postoperatively. The IS and CPAP applications have similar effects with respect to FVC values. The postoperative 30min FEV1 values were statistically significantly reduced compared to the Baseline in all groups (ppostoperative 24h compared to the postoperative 30min in the Groups IS and CPAP (ppostoperative 24h FEV1 values were statistically significantly lower in the Group Control compared to the Group IS (p=0.015). Although this study is underpowered to detect differences in FEV1 values, the postoperative 24h FEV1 values were significantly higher in the IS group than the Control group and this difference was not observed between the CPAP and Control groups. It might be evaluate a favorable effect of IS in neurosurgery patients. But larger studies are needed to make a certain conclusion. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Strengths-based positive psychology interventions: A randomized placebo-controlled online trial on long-term effects for a signature strengths- vs. a lesser strengths-intervention

    Directory of Open Access Journals (Sweden)

    René T. Proyer

    2015-04-01

    Full Text Available Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using signature strengths with one on using individual low scoring (or lesser strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions (i.e., using five signature vs. five lesser strengths in a new way or a placebo control condition (i.e., early memories. We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups and character strengths at pre-test. The main findings are that (1 there were increases in happiness for up to three months and decreased depressive symptoms in the short term in both intervention conditions; (2 participants found working with strengths equally rewarding (enjoyment and benefit in both conditions; (3 those participants that reported generally higher levels of strengths benefitted more from working on lesser strengths rather than signature strengths and those with comparatively lower levels of strengths tended to benefit more from working on signature strengths; and (4 deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths (VIA-IS were associated with greater benefit from the interventions in the signature strengths intervention. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness.

  16. Effects of continuous positive airway pressure treatment on clinic and ambulatory blood pressures in patients with obstructive sleep apnea and resistant hypertension: a randomized controlled trial.

    Science.gov (United States)

    Muxfeldt, Elizabeth S; Margallo, Victor; Costa, Leonardo M S; Guimarães, Gleison; Cavalcante, Aline H; Azevedo, João C M; de Souza, Fabio; Cardoso, Claudia R L; Salles, Gil F

    2015-04-01

    The effect of continuous positive airway pressure (CPAP) on blood pressures (BPs) in patients with resistant hypertension and obstructive sleep apnea is not established. We aimed to evaluate it in a randomized controlled clinical trial, with blinded assessment of outcomes. Four hundred thirty-four resistant hypertensive patients were screened and 117 patients with moderate/severe obstructive sleep apnea, defined by an apnea-hypopnea index ≥15 per hour, were randomized to 6-month CPAP treatment (57 patients) or no therapy (60 patients), while maintaining antihypertensive treatment. Clinic and 24-hour ambulatory BPs were obtained before and after 6-month treatment. Primary outcomes were changes in clinic and ambulatory BPs and in nocturnal BP fall patterns. Intention-to-treat and per-protocol (limited to those with uncontrolled ambulatory BPs) analyses were performed. Patients had mean (SD) 24-hour BP of 129(16)/75(12) mm Hg, and 59% had uncontrolled ambulatory BPs. Mean apnea-hypopnea index was 41 per hour and 58.5% had severe obstructive sleep apnea. On intention-to-treat analysis, there was no significant difference in any BP change, neither in nocturnal BP fall, between CPAP and control groups. The best effect of CPAP was on night-time systolic blood pressure in per-protocol analysis, with greater reduction of 4.7 mm Hg (95% confidence interval, -11.3 to +3.1 mm Hg; P=0.24) and an increase in nocturnal BP fall of 2.2% (95% confidence interval, -1.6% to +5.8%; P=0.25), in comparison with control group. In conclusion, CPAP treatment had no significant effect on clinic and ambulatory BPs in patients with resistant hypertension and moderate/severe obstructive sleep apnea, although a beneficial effect on night-time systolic blood pressure and on nocturnal BP fall might exist in patients with uncontrolled ambulatory BP levels. © 2015 American Heart Association, Inc.

  17. A randomized, double-blind, parallel-group, dose-response study of micafungin compared with fluconazole for the treatment of esophageal candidiasis in HIV-positive patients.

    Science.gov (United States)

    de Wet, N; Llanos-Cuentas, A; Suleiman, J; Baraldi, E; Krantz, E F; Della Negra, M; Diekmann-Berndt, H

    2004-09-15

    Severely immunocompromised individuals are highly susceptible to Candida infection of the esophagus. This randomized, double-blind study assessed the dose-response relationship of the new echinocandin antifungal, micafungin, compared with that of standard fluconazole treatment. A total of 245 patients (age, > or =18 years) with a prior diagnosis of acquired immunodeficiency syndrome/human immunodeficiency virus (HIV) infection and esophageal candidiasis, confirmed by endoscopy and culture, were randomized to receive micafungin (50, 100, or 150 mg per day) or fluconazole (200 mg per day). Both agents were administered once per day by a 1-h intravenous infusion for 14-21 days. The primary efficacy end point was endoscopic cure rate, defined as endoscopy grade of 0 at the end of therapy. The endoscopic cure rate (grade 0) was dose-dependent with 50, 100, and 150 mg of micafungin per day at 68.8%, 77.4%, and 89.8%, respectively. Symptoms improved or resolved rapidly (3-7 days of treatment in the majority of patients). The endoscopic cure rate for 100 and 150 mg of micafungin per day (83.5%) was comparable to that for 200 mg of fluconazole per day (86.7%; 95% confidence interval for the difference in endoscopic cure rate, -14.0% to 7.7%). The overall safety and tolerability was acceptable, with no important differences between micafungin (all doses) and fluconazole. The dose-response findings demonstrate a greater efficacy with micafungin at 100 and 150 mg per day than at 50 mg per day. This study also indicates that the efficacy of micafungin (at dosages of 100 and 150 mg per day) was comparable to that of fluconazole, suggesting that micafungin represents a valuable new treatment option for esophageal candidiasis in HIV-positive patients.

  18. Magnetic Resonance Imaging Zygapophyseal Joint Space Changes (Gapping) in Low Back Pain Patients following Spinal Manipulation and Side Posture Positioning: A Randomized Controlled Mechanisms Trial with Blinding

    Science.gov (United States)

    Cramer, Gregory D.; Cambron, Jerrilyn; Cantu, Joe A; Dexheimer, Jennifer M.; Pocius, Judith D; Gregerson, Douglas; Fergus, Michael; McKinnis, Ray; Grieve, Thomas J

    2013-01-01

    Objective The purpose of this study was to quantify lumbar zygapophyseal (Z) joint space separation (gapping) in low back pain (LBP) subjects after spinal manipulative therapy (SMT) or side-posture positioning (SPP). Methods This was a controlled mechanisms trial with randomization and blinding. Acute LBP subjects (N=112, four n=28 MRI protocol groups) had 2 magnetic resonance imaging (MRI) appointments (initial enrollment [M1] and following 2 weeks of chiropractic treatment [M2]; receiving 2 MRI scans of the L4/L5 and L5/S1 Z joints at each MRI appointment. After the first MRI scan of each appointment, subjects were randomized (M1 appointment) or assigned (M2 appointment) into SPP (non-manipulation), SMT (manipulation), or control MRI protocol groups. After SPP or SMT, a second MRI was taken. The central anterior-posterior (A-P) joint space was measured. Difference between most painful side A-P measurements taken post- and pre-intervention was the Z joint “gapping difference.” Gapping differences were compared (ANOVA) among protocol groups. Secondary measures of pain visual analog scale (VAS), verbal numeric pain rating scale (VNPRS), and function Bournemouth questionnaire (BQ) were assessed. Results Gapping differences were significant at the first (adjusted, p=0.01; SPP=0.66 +0.48mm; SMT=0.23 +0.86; control=0.18 +0.71) and second (adjusted, p=0.0005; SPP=0.65 +0.92mm, SMT=0.89 +0.71; control=0.35 +0.32) MRI appointments. VNPRS differences were significant at first MRI appointment (p=0.04) with SMT showing the greatest improvement. VAS and BQ improved after two weeks of care in all groups (both p<0.0001). Conclusions SPP showed greatest gapping at baseline. After two weeks, SMT resulted in greatest gapping. SPP appeared to have additive therapeutic benefit to SMT. PMID:23648055

  19. Early routine versus late selective surfactant in preterm neonates with respiratory distress syndrome on nasal continuous positive airway pressure: a randomized controlled trial.

    Science.gov (United States)

    Kandraju, Hemasree; Murki, Srinivas; Subramanian, Sreeram; Gaddam, Pramod; Deorari, Ashok; Kumar, Praveen

    2013-01-01

    Preterm neonates with respiratory distress syndrome (RDS) benefit from early application of nasal continuous positive airway pressure (nCPAP). However, it is not clear whether surfactant should be administered early as a routine to all such infants or later in a selective manner. It was the aim of this study to compare the efficacy of early routine versus late selective surfactant treatment in reducing the need for mechanical ventilation (MV) during the first week of life among moderate-sized preterm infants with RDS being supported by nCPAP. Infants born at 28(0/7) to 33(6/7) weeks of gestation with RDS and on nCPAP were randomly assigned within the first 2 h of life to early routine surfactant administration by the InSurE technique (early surfactant group) or to late selective administration of surfactant (late surfactant group). The primary outcome was need for MV in the first 7 days of life. Among 153 infants randomized to early (n = 74) or late surfactant (n = 79) groups, the need for MV was significantly lower in the early surfactant group (16.2 vs. 31.6%; relative risk 0.41, 95% confidence interval 0.19-0.91). The incidence of pneumothorax (1.9 vs. 2.3%) and the need for supplemental O2 at 28 days (2.7 vs. 8.9%) were similar in the two groups. Early routine surfactant administration within 2 h of life as compared to late selective administration significantly reduced the need for MV in the first week of life among preterm infants with RDS on nCPAP. Copyright © 2012 S. Karger AG, Basel.

  20. Strengths-based positive psychology interventions: a randomized placebo-controlled online trial on long-term effects for a signature strengths- vs. a lesser strengths-intervention.

    Science.gov (United States)

    Proyer, René T; Gander, Fabian; Wellenzohn, Sara; Ruch, Willibald

    2015-01-01

    Recent years have seen an increasing interest in research in positive psychology interventions. There is broad evidence for their effectiveness in increasing well-being and ameliorating depression. Intentional activities that focus on those character strengths, which are most typical for a person (i.e., signature strengths, SS) and encourage their usage in a new way have been identified as highly effective. The current study aims at comparing an intervention aimed at using SS with one on using individual low scoring (or lesser) strengths in a randomized placebo-controlled trial. A total of 375 adults were randomly assigned to one of the two intervention conditions [i.e., using five signature vs. five lesser strengths (LS) in a new way] or a placebo control condition (i.e., early memories). We measured happiness and depressive symptoms at five time points (i.e., pre- and post-test, 1-, 3-, and 6-months follow-ups) and character strengths at pre-test. The main findings are that (1) there were increases in happiness for up to 3 months and decreases in depressive symptoms in the short term in both intervention conditions; (2) participants found working with strengths equally rewarding (enjoyment and benefit) in both conditions; (3) those participants that reported generally higher levels of strengths benefitted more from working on LS rather than SS and those with comparatively lower levels of strengths tended to benefit more from working on SS; and (4) deviations from an average profile derived from a large sample of German-speakers completing the Values-in-Action Inventory of Strengths were associated with greater benefit from the interventions in the SS-condition. We conclude that working on character strengths is effective for increasing happiness and discuss how these interventions could be tailored to the individual for promoting their effectiveness.

  1. Intrinsic subtypes and benefit from postmastectomy radiotherapy in node-positive premenopausal breast cancer patients who received adjuvant chemotherapy - results from two independent randomized trials.

    Science.gov (United States)

    Laurberg, Tinne; Tramm, Trine; Nielsen, Torsten; Alsner, Jan; Nord, Silje; Myhre, Simen; Sørlie, Therese; Leung, Samuel; Fan, Cheng; Perou, Charles; Gelmon, Karen; Overgaard, Jens; Voduc, David; Prat, Aleix; Cheang, Maggie Chon U

    2017-11-25

    The study of the intrinsic molecular subtypes of breast cancer has revealed differences among them in terms of prognosis and response to chemotherapy and endocrine therapy. However, the ability of intrinsic subtypes to predict benefit from adjuvant radiotherapy has only been examined in few studies. Gene expression-based intrinsic subtyping was performed in 228 breast tumors collected from two independent post-mastectomy clinical trials (British Columbia and the Danish Breast Cancer Cooperative Group 82b trials), where pre-menopausal patients with node-positive disease were randomized to adjuvant radiotherapy or not. All patients received adjuvant chemotherapy and a subgroup of patients underwent ovarian ablation. Tumors were classified into intrinsic subtypes: Luminal A, Luminal B, HER2-enriched, Basal-like and Normal-like using the research-based PAM50 classifier. In the British Columbia study, patients treated with radiation had an overall significant lower incidence of locoregional recurrence compared to the controls. For Luminal A tumors the risk of loco-regional recurrence was low and was further lowered by adjuvant radiation. These findings were validated in the DBCG 82b study. The individual data from the two cohorts were merged, the hazard ratio (HR) for loco-regional recurrence associated with giving radiation was 0.34 (0.19 to 0.61) overall and 0.12 (0.03 to 0.52) for Luminal A tumors. In both postmastectomy trials, patients with Luminal A tumors turned out to have a significant lower incidence of loco-regional recurrence when randomized to adjuvant radiotherapy, leaving no indication to omit postmastectomy adjuvant radiation in pre-menopausal high-risk patients with Luminal A tumors. It was not possible to evaluate the effect of radiotherapy among the other subtypes because of limited sample sizes.

  2. Role of Cytotoxic Tumor-Infiltrating Lymphocytes in Predicting Outcomes in Metastatic HER2-Positive Breast Cancer: A Secondary Analysis of a Randomized Clinical Trial.

    Science.gov (United States)

    Liu, Shuzhen; Chen, Bingshu; Burugu, Samantha; Leung, Samuel; Gao, Dongxia; Virk, Shakeel; Kos, Zuzana; Parulekar, Wendy R; Shepherd, Lois; Gelmon, Karen A; Nielsen, Torsten O

    2017-11-09

    Accumulating evidence indicates that tumor-infiltrating lymphocytes (TILs) are associated with clinical outcomes and may predict the efficacy of chemotherapy and human epidermal growth factor receptor 2 (HER2, encoded by the gene ERBB2)-targeted therapy in patients with HER2-positive breast cancer. To investigate the role of TILs, particularly cytotoxic CD8+ T cells, in the prediction of outcomes in patients with HER2-positive metastatic breast cancer randomized to an antibody-based (trastuzumab) vs a small molecule-based (lapatinib) anti-HER2 therapy. The Canadian Cancer Trials Group MA.31 phase 3 clinical trial accrued patients from 21 countries and randomized 652 with HER2-positive metastatic breast cancer to receive trastuzumab or lapatinib, in combination with a taxane, from January 17, 2008, through December 1, 2011. Patients had received no prior chemotherapy or HER2-targeted therapy in the metastatic setting. The median follow-up was 21.5 months (interquartile range, 14.3-31.0). The tumor tissue collected for primary diagnosis was used in this ad hoc substudy. Sections were scored for TILs on hematoxylin-eosin (H&E)-stained sections, and immunohistochemical analysis was performed to assess CD8, FOXP3, CD56, and programmed cell death protein 1 (PD-1) expression on stromal (sTILs) and intratumoral TILs. Data were analyzed from July 15, 2015, through July 27, 2016. Treatment with trastuzumab or lapatinib in combination with taxane chemotherapy (paclitaxel or docetaxel) for 24 weeks. Prognostic effects of biomarkers were evaluated for progression-free survival by stratified univariate log-rank test with Kaplan-Meier curves and by multivariate Cox proportional hazards regression; predictive effects were examined with a test of interaction between treatment allocation and biomarker classification. Of the 647 treated women (mean [SD] age, 55.0 [10.8] years), 614 had tumor tissue samples scored for H&E sTILs and 427 for CD8 biomarker assessments. Overall H&E s

  3. Effect of a Proposed Trastuzumab Biosimilar Compared With Trastuzumab on Overall Response Rate in Patients With ERBB2 (HER2)-Positive Metastatic Breast Cancer: A Randomized Clinical Trial.

    Science.gov (United States)

    Rugo, Hope S; Barve, Abhijit; Waller, Cornelius F; Hernandez-Bronchud, Miguel; Herson, Jay; Yuan, Jinyu; Sharma, Rajiv; Baczkowski, Mark; Kothekar, Mudgal; Loganathan, Subramanian; Manikhas, Alexey; Bondarenko, Igor; Mukhametshina, Guzel; Nemsadze, Gia; Parra, Joseph D; Abesamis-Tiambeng, Maria Luisa T; Baramidze, Kakhaber; Akewanlop, Charuwan; Vynnychenko, Ihor; Sriuranpong, Virote; Mamillapalli, Gopichand; Ray, Sirshendu; Yanez Ruiz, Eduardo P; Pennella, Eduardo

    2017-01-03

    Treatment with the anti-ERBB2 humanized monoclonal antibody trastuzumab and chemotherapy significantly improves outcome in patients with ERBB2 (HER2)-positive metastatic breast cancer; a clinically effective biosimilar may help increase access to this therapy. To compare the overall response rate and assess the safety of a proposed trastuzumab biosimilar plus a taxane or trastuzumab plus a taxane in patients without prior treatment for ERBB2-positive metastatic breast cancer. Multicenter, double-blind, randomized, parallel-group, phase 3 equivalence study in patients with metastatic breast cancer. From December 2012 to August 2015, 500 patients were randomized 1:1 to receive a proposed biosimilar or trastuzumab plus a taxane. Chemotherapy was administered for at least 24 weeks followed by antibody alone until unacceptable toxic effects or disease progression occurred. Proposed biosimilar (n = 230) or trastuzumab (n = 228) with a taxane. The primary outcome was week 24 overall response rate (ORR) defined as complete or partial response. Equivalence boundaries were 0.81 to 1.24 with a 90% CI for ORR ratio (proposed biosimilar/trastuzumab) and -15% to 15% with a 95% CI for ORR difference. Secondary outcome measures included time to tumor progression, progression-free and overall survival at week 48, and adverse events. Among 500 women randomized, the intention-to-treat population included 458 women (mean [SD] age, 53.6 [11.11] years) and the safety population included 493 women. The ORR was 69.6% (95% CI, 63.62%-75.51%) for the proposed biosimilar vs 64.0% (95% CI, 57.81%-70.26%) for trastuzumab. The ORR ratio (1.09; 90% CI, 0.974-1.211) and ORR difference (5.53; 95% CI, -3.08 to 14.04) were within the equivalence boundaries. At week 48, there was no statistically significant difference with the proposed biosimilar vs trastuzumab for time to tumor progression (41.3% vs 43.0%; -1.7%; 95% CI, -11.1% to 6.9%), progression-free survival (44.3% vs 44.7%; -0.4%; 95

  4. Excitonic complexes in natural InAs/GaAs quantum dots

    Science.gov (United States)

    Zieliński, M.; Gołasa, K.; Molas, M. R.; Goryca, M.; Kazimierczuk, T.; Smoleński, T.; Golnik, A.; Kossacki, P.; Nicolet, A. A. L.; Potemski, M.; Wasilewski, Z. R.; Babiński, A.

    2015-02-01

    The quantum confinement in a typical quantum dot (QD) is determined primarily by the nanosystem's dimensions and average composition. We demonstrate, however, that excitonic properties of natural QDs formed in the InAs/GaAs wetting layer are governed predominantly by effects of random fluctuations of the lattice composition. It is shown that the biexciton binding energy is a very sensitive function of the lattice randomness with a nearly flat dependence on the exciton energy. The large variation in different random realizations of a QD structure is shown to lead in some cases to the reversal of the order of excitonic lines. Results of theoretical calculations correspond to statistical properties of neutral excitons and biexcitons as well as trions confined to single natural QDs studied in our microspectroscopic measurements. We observe substantial variation of the biexciton and trion binding energies as well as a correlation of the trion and the biexciton energies. The transition from the negative to the positive binding energy of the trion is also observed, which strongly supports the attribution of the observed trion to the positively charged exciton.

  5. SELF-ORGANIZATION OF LEAD SULFIDE QUANTUM DOTS INTO SUPERSTRUCTURES

    Directory of Open Access Journals (Sweden)

    Elena V. Ushakova

    2014-11-01

    Full Text Available The method of X-ray structural analysis (X-ray scattering at small angles is used to show that the structures obtained by self-organization on a substrate of lead sulfide (PbS quantum dots are ordered arrays. Self-organization of quantum dots occurs at slow evaporation of solvent from a cuvette. The cuvette is a thin layer of mica with teflon ring on it. The positions of peaks in SAXS pattern are used to calculate crystal lattice of obtained ordered structures. Such structures have a primitive orthorhombic crystal lattice. Calculated lattice parameters are: a = 21,1 (nm; b = 36,2 (nm; c = 62,5 (nm. Dimensions of structures are tens of micrometers. The spectral properties of PbS QDs superstructures and kinetic parameters of their luminescence are investigated. Absorption band of superstructures is broadened as compared to the absorption band of the quantum dots in solution; the luminescence band is slightly shifted to the red region of the spectrum, while its bandwidth is not changed much. Luminescence lifetime of obtained structures has been significantly decreased in comparison with the isolated quantum dots in solution, but remained the same for the lead sulfide quantum dots close-packed ensembles. Such superstructures can be used to produce solar cells with improved characteristics.

  6. Valley blockade in a silicon double quantum dot

    Science.gov (United States)

    Perron, Justin K.; Gullans, Michael J.; Taylor, Jacob M.; Stewart, M. D.; Zimmerman, Neil M.

    2017-11-01

    Electrical transport in double quantum dots (DQDs) illuminates many interesting features of the dots' carrier states. Recent advances in silicon quantum information technologies have renewed interest in the valley states of electrons confined in silicon. Here we show measurements of dc transport through a mesa-etched silicon double quantum dot. Comparing bias triangles (i.e., regions of allowed current in DQDs) at positive and negative bias voltages we find a systematic asymmetry in the size of the bias triangles at the two bias polarities. Asymmetries of this nature are associated with blocked tunneling events due to the occupation of a metastable state. Several features of our data lead us to conclude that the states involved are not simple spin states. Rather, we develop a model based on selective filling of valley states in the DQD that is consistent with all of the qualitative features of our data.

  7. Randomized clinical trial of thrice-weekly 4-month moxifloxacin or gatifloxacin containing regimens in the treatment of new sputum positive pulmonary tuberculosis patients.

    Directory of Open Access Journals (Sweden)

    Mohideen S Jawahar

    Full Text Available Shortening tuberculosis (TB treatment duration is a research priority. This paper presents data from a prematurely terminated randomized clinical trial, of 4-month moxifloxacin or gatifloxacin regimens, in South India.Newly diagnosed, sputum-positive HIV-negative pulmonary TB patients were randomly allocated to receive gatifloxacin or moxifloxacin, along with isoniazid and rifampicin for 4 months with pyrazinamide for first 2 months (G or M or isoniazid and rifampicin for 6 months with ethambutol and pyrazinamide for first 2 months (C. All regimens were administered thrice-weekly. Clinical and bacteriological assessments were done monthly during treatment and for 24 months post-treatment. The Data and Safety Monitoring Board recommended termination of the trial due to high TB recurrence rates in the G and M regimens.Of 416 patients in intent-to-treat analysis, 6 (5% of 124, 2 (2% of 110 and 2 (2% of 137 patients with drug-susceptible TB in the G, M and C arms respectively had unfavorable response at the end of treatment; during the next 24 months, 17 (15% of 115, 11 (11% of 104 and 8 (6% of 132 patients respectively, had TB recurrence. Of 38 drug-resistant patients 1 of 8 and 3 of 26 in the G and C arms respectively had unfavourable response at the end of treatment; and TB recurrence occurred in 2 of 7 and 2 of 23 patients, respectively. The differences in TB recurrence rates between the G and C arms was statistically significant (p = 0.02. Gastro-intestinal symptoms occurred in 23%, 22% and 9% of patients in the G, M and C arms respectively, but most reactions were mild and manageable with symptomatic measures; 1% required regimen modification.4-month thrice-weekly regimens of gatifloxacin or moxifloxacin with isoniazid, rifampicin and pyrazinamide, were inferior to standard 6-month treatment, in patients with newly diagnosed sputum positive pulmonary TB.Clinical Trials Registry of India CTRI/2012/10/003060.

  8. Duration of adjuvant trastuzumab in HER2 positive breast cancer: Overall and disease free survival results from meta-analyses of randomized controlled trials.

    Science.gov (United States)

    Gyawali, Bishal; Niraula, Saroj

    2017-11-01

    One year of trastuzumab, chosen empirically, improves survival of women with early-stage, HER2-positive breast cancer but also adds substantially to cost, toxicity, and inconvenience. Longer treatment does not improve outcomes, but potentiates toxicities. Medline, Embase, and major conference proceedings were searched systematically in June 2017 to identify Randomized Controlled Trials (RCTs) comparing one year versus shorter durations of trastuzumab in adjuvant treatment of breast cancer. Reported Hazard-Ratios (HR) for Overall Survival (OS) and Disease-Free Survival (DFS), and Odds-Ratio for cardiac events, with respective 95% Confidence Intervals (CI) from each study was weighted using generic inverse-variance, and pooled in a meta-analysis. Inter-study heterogeneity and sub-group difference (based on hormone-receptors and node-positivity) were assessed using I 2 , and chi 2 statistics, respectively. Four studies (n=7614) satisfied inclusion criteria. Individual RCTs had diverse pre-specified upper-limits of 95% CI for declaring non-inferiority (range: <1.15 to <1.53). Pooled results demonstrated significant improvements in OS (HR 1.28, p=0.04), and DFS (HR 1.24, p=0.005) with 1year of trastuzumab compared to shorter durations. Absence of multiplicity argument allowed for declaring superiority of 1year of trastuzumab based on our results despite non-inferiority designs of individual trials. No influence on overall effect by duration of trastuzumab in experimental arm (9weeks versus 6months) was noted. No statistical interaction by hormone-receptor status and node-positivity on overall results was noticed [p(sub-group difference) 0.73, and 0.52, respectively]. Odds-Ratio for cardiac events was 2.65 (p<0.001) favoring shorter duration. One year of trastuzumab prolongs overall, and disease-free survivals in women with early-stage HER2 positive breast cancer compared to shorter durations and this should remain as the standard of care. Cardiotoxicity increased

  9. Stability of quantum dots in live cells

    Science.gov (United States)

    Zhu, Zheng-Jiang; Yeh, Yi-Cheun; Tang, Rui; Yan, Bo; Tamayo, Joshua; Vachet, Richard W.; Rotello, Vincent M.

    2011-12-01

    Quantum dots are highly fluorescent and photostable, making them excellent tools for imaging. When using these quantum dots in cells and animals, however, intracellular biothiols (such as glutathione and cysteine) can degrade the quantum dot monolayer, compromising function. Here, we describe a label-free method to quantify the intracellular stability of monolayers on quantum dot surfaces that couples laser desorption/ionization mass spectrometry with inductively coupled plasma mass spectrometry. Using this new approach we have demonstrated that quantum dot monolayer stability is correlated with both quantum dot particle size and monolayer structure, with appropriate choice of both particle size and ligand structure required for intracellular stability.

  10. Imaging and Manipulating Energy Transfer Among Quantum Dots at Individual Dot Resolution.

    Science.gov (United States)

    Nguyen, Duc; Nguyen, Huy A; Lyding, Joseph W; Gruebele, Martin

    2017-06-27

    Many processes of interest in quantum dots involve charge or energy transfer from one dot to another. Energy transfer in films of quantum dots as well as between linked quantum dots has been demonstrated by luminescence shift, and the ultrafast time-dependence of energy transfer processes has been resolved. Bandgap variation among dots (energy disorder) and dot separation are known to play an important role in how energy diffuses. Thus, it would be very useful if energy transfer could be visualized directly on a dot-by-dot basis among small clusters or within films of quantum dots. To that effect, we report single molecule optical absorption detected by scanning tunneling microscopy (SMA-STM) to image energy pooling from donor into acceptor dots on a dot-by-dot basis. We show that we can manipulate groups of quantum dots by pruning away the dominant acceptor dot, and switching the energy transfer path to a different acceptor dot. Our experimental data agrees well with a simple Monte Carlo lattice model of energy transfer, similar to models in the literature, in which excitation energy is transferred preferentially from dots with a larger bandgap to dots with a smaller bandgap.

  11. Brain networks involved in tactile speed classification of moving dot patterns: the effects of speed and dot periodicity.

    Science.gov (United States)

    Yang, Jiajia; Kitada, Ryo; Kochiyama, Takanori; Yu, Yinghua; Makita, Kai; Araki, Yuta; Wu, Jinglong; Sadato, Norihiro

    2017-02-01

    Humans are able to judge the speed of an object's motion by touch. Research has suggested that tactile judgment of speed is influenced by physical properties of the moving object, though the neural mechanisms underlying this process remain poorly understood. In the present study, functional magnetic resonance imaging was used to investigate brain networks that may be involved in tactile speed classification and how such networks may be affected by an object's texture. Participants were asked to classify the speed of 2-D raised dot patterns passing under their right middle finger. Activity in the parietal operculum, insula, and inferior and superior frontal gyri was positively related to the motion speed of dot patterns. Activity in the postcentral gyrus and superior parietal lobule was sensitive to dot periodicity. Psycho-physiological interaction (PPI) analysis revealed that dot periodicity modulated functional connectivity between the parietal operculum (related to speed) and postcentral gyrus (related to dot periodicity). These results suggest that texture-sensitive activity in the primary somatosensory cortex and superior parietal lobule influences brain networks associated with tactually-extracted motion speed. Such effects may be related to the influence of surface texture on tactile speed judgment.

  12. Selective biosensing of Staphylococcus aureus using chitosan quantum dots

    Science.gov (United States)

    Abdelhamid, Hani Nasser; Wu, Hui-Fen

    2018-01-01

    Selective biosensing of Staphylococcus aureus (S. aureus) using chitosan modified quantum dots (CTS@CdS QDs) in the presence of hydrogen peroxide is reported. The method is based on the intrinsic positive catalase activity of S. aureus. CTS@CdS quantum dots provide high dispersion in aqueous media with high fluorescence emission. Staphylococcus aureus causes a selective quenching of the fluorescence emission of CTS@CdS QDs in the presence of H2O2 compared to other pathogens such as Escherichia coli and Pseudomonas aeruginosa. The intrinsic enzymatic character of S. aureus (catalase positive) offers selective and fast biosensing. The present method is highly selective for positive catalase species and requires no expensive reagents such as antibodies, aptamers or microbeads. It could be extended for other species that are positive catalase.

  13. Changes in gene expression, protein content and morphology of chondrocytes cultured on a 3D Random Positioning Machine and 2D rotating clinostat

    Science.gov (United States)

    Aleshcheva, Ganna; Hauslage, Jens; Hemmersbach, Ruth; Infanger, Manfred; Bauer, Johann; Grimm, Daniela; Sahana, Jayashree

    Chondrocytes are the only cell type found in human cartilage consisting of proteoglycans and type II collagen. Several studies on chondrocytes cultured either in Space or on a ground-based facility for simulation of microgravity revealed that these cells are very resistant to adverse effects and stress induced by altered gravity. Tissue engineering of chondrocytes is a new strategy for cartilage regeneration. Using a three-dimensional Random Positioning Machine and a 2D rotating clinostat, devices designed to simulate microgravity on Earth, we investigated the early effects of microgravity exposure on human chondrocytes of six different donors after 30 min, 2 h, 4 h, 16 h, and 24 h and compared the results with the corresponding static controls cultured under normal gravity conditions. As little as 30 min of exposure resulted in increased expression of several genes responsible for cell motility, structure and integrity (beta-actin); control of cell growth, cell proliferation, cell differentiation and apoptosis; and cytoskeletal components such as microtubules (beta-tubulin) and intermediate filaments (vimentin). After 4 hours disruptions in the vimentin network were detected. These changes were less dramatic after 16 hours, when human chondrocytes appeared to reorganize their cytoskeleton. However, the gene expression and protein content of TGF-β1 was enhanced for 24 h. Based on the results achieved, we suggest that chondrocytes exposed to simulated microgravity seem to change their extracellular matrix production behavior while they rearrange their cytoskeletal proteins prior to forming three-dimensional aggregates.

  14. Assessing water filtration and safe storage in households with young children of HIV-positive mothers: a randomized, controlled trial in Zambia.

    Science.gov (United States)

    Peletz, Rachel; Simunyama, Martin; Sarenje, Kelvin; Baisley, Kathy; Filteau, Suzanne; Kelly, Paul; Clasen, Thomas

    2012-01-01

    Unsafe drinking water presents a particular threat to people living with HIV/AIDS (PLHIV) due to the increased risk of opportunistic infections, diarrhea-associated malabsorption of essential nutrients, and increased exposure to untreated water for children of HIV-positive mothers who use replacement feeding to reduce the risk of HIV transmission. This population may particularly benefit from an intervention to improve water quality in the home. We conducted a 12-month randomized, controlled field trial in Zambia among 120 households with children water filter and jerry cans for safe storage. Households were followed up monthly to assess use, drinking water quality (thermotolerant coliforms (TTC), an indicator of fecal contamination) and reported diarrhea (7-day recall) among children filter have been unsuccessful, we also assessed weight-for-age Z-scores (WAZ) as an objective measure of diarrhea impact. Filter use was high, with 96% (596/620) of household visits meeting the criteria for users. The quality of water stored in intervention households was significantly better than in control households (3 vs. 181 TTC/100 mL, respectively, pwater filter combined with safe storage was used correctly and consistently, was highly effective in improving drinking water quality, and was protective against diarrhea. Clinicaltrials.gov NCT01116908.

  15. Positive effects of transcranial direct current stimulation in adult patients with attention-deficit/hyperactivity disorder - A pilot randomized controlled study.

    Science.gov (United States)

    Cachoeira, Carolina Tosetto; Leffa, Douglas Teixeira; Mittelstadt, Suzana Doneda; Mendes, Lorenna Sena Teixeira; Brunoni, Andre R; Pinto, Jairo Vinicius; Blazius, Vtor; Machado, Vitoria; Bau, Claiton Henrique Dotto; Rohde, Luis Augusto; Grevet, Eugenio Horacio; Schestatsky, Pedro

    2017-01-01

    Almost 30% of adult patients with attention-deficit/hyperactivity disorder (ADHD) do not respond or tolerate standard pharmacological interventions. Few clinical investigations addressed the efficacy and tolerability of transcranial direct current stimulation (tDCS), a non-invasive neuromodulatory technique, in the disorder. We performed a double-blind, sham-controlled randomized clinical trial in 17 patients with ADHD. The set up for tDCS was the following: 2mA/20min/day for 5 days with the anode over the right dorsolateral prefrontal cortex and cathode over the left dorsolateral prefrontal cortex. ADHD symptoms were measured by the Adult ADHD Self-Report Scale (ASRS) and impairment with the Sheehan Disability Scale (SDS) in four different time points after stimulation. Participants achieved significant lower ASRS inattention and SDS scores after active tDCS in comparison with sham stimulation group. In addition, we detected a trend for a lower ASRS total score in the active tDCS group. Follow up data analysis revealed a positive interaction between time and treatment in both ASRS inattention, SDS and ASRS total scores. Short-term application of tDCS in adult patients with ADHD improved their symptoms, and this improvement persisted after the end of the stimulation. Future studies with larger sample sizes are needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Antibiotic Conjugated Fluorescent Carbon Dots as a Theranostic Agent for Controlled Drug Release, Bioimaging, and Enhanced Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Mukeshchand Thakur

    2014-01-01

    Full Text Available A novel report on microwave assisted synthesis of bright carbon dots (C-dots using gum arabic (GA and its use as molecular vehicle to ferry ciprofloxacin hydrochloride, a broad spectrum antibiotic, is reported in the present work. Density gradient centrifugation (DGC was used to separate different types of C-dots. After careful analysis of the fractions obtained after centrifugation, ciprofloxacin was attached to synthesize ciprofloxacin conjugated with C-dots (Cipro@C-dots conjugate. Release of ciprofloxacin was found to be extremely regulated under physiological conditions. Cipro@C-dots were found to be biocompatible on Vero cells as compared to free ciprofloxacin (1.2 mM even at very high concentrations. Bare C-dots (∼13 mg mL−1 were used for microbial imaging of the simplest eukaryotic model—Saccharomyces cerevisiae (yeast. Bright green fluorescent was obtained when live imaging was performed to view yeast cells under fluorescent microscope suggesting C-dots incorporation inside the cells. Cipro@C-dots conjugate also showed enhanced antimicrobial activity against both model gram positive and gram negative microorganisms. Thus, the Cipro@C-dots conjugate paves not only a way for bioimaging but also an efficient new nanocarrier for controlled drug release with high antimicrobial activity, thereby serving potential tool for theranostics.

  17. Early ART initiation among HIV-positive pregnant women in central Mozambique: a stepped wedge randomized controlled trial of an optimized Option B+ approach.

    Science.gov (United States)

    Cowan, James F; Micek, Mark; Cowan, Jessica F Greenberg; Napúa, Manuel; Hoek, Roxanne; Gimbel, Sarah; Gloyd, Stephen; Sherr, Kenneth; Pfeiffer, James T; Chapman, Rachel R

    2015-04-30

    Despite effective prevention strategies and increasing investments in global health, maternal to child transmission (MTCT) of HIV remains a significant problem globally, especially in sub-Saharan Africa. In 2012, there were 94,000 HIV-positive pregnant women in Mozambique. Approximately 15% of these women transmitted HIV to their newborn infants, resulting in nearly 14,000 new pediatric HIV infections that year. To address this issue, in 2013, the Mozambican Ministry of Health implemented the World Health Organization-recommended "Option B+" strategy in which all newly diagnosed HIV-positive pregnant women are counseled to initiate combination anti-retroviral therapy (ART) immediately upon diagnosis regardless of CD4 count and to continue treatment for life. Given the limited experience with Option B+ in sub-Saharan Africa, few rigorous pragmatic trials have studied this new treatment strategy. This study utilizes an initial formative research process involving patient and health care provider interviews and focus groups, workforce assessments, value stream mapping, and commodity utilization assessments to understand the strengths and weaknesses in the current Option B+ care cascade. The formative research is intended to guide identification and prioritization of key workflow modifications and the development of an enhanced adherence and retention package. These two components are bundled into a defined intervention implemented and evaluated across six health facilities utilizing a stepped wedge randomized controlled trial study design. The overall objective of this trial is to develop and test a pilot intervention in central Mozambique to implement the new Option B+ guidelines with high fidelity and increase the proportion of HIV-positive pregnant women in target antenatal clinics (ANC) who start ART prior to delivery and are retained in care. This pragmatic study utilizes research strategies that have the potential to meaningfully improve the Option B+ care

  18. Inter-dot coupling effects on transport through correlated parallel ...

    Indian Academy of Sciences (India)

    The effect of inter-dot tunnelling on transport properties has been explored. Results, in intermediate inter-dot coupling regime show signatures of merger of two dots to form a single composite dot and in strong coupling regime the behaviour of the system resembles the two decoupled dots. Keywords. Coupled quantum dots ...

  19. Transport through graphene quantum dots

    Science.gov (United States)

    Güttinger, J.; Molitor, F.; Stampfer, C.; Schnez, S.; Jacobsen, A.; Dröscher, S.; Ihn, T.; Ensslin, K.

    2012-12-01

    We review transport experiments on graphene quantum dots and narrow graphene constrictions. In a quantum dot, electrons are confined in all lateral dimensions, offering the possibility for detailed investigation and controlled manipulation of individual quantum systems. The recently isolated two-dimensional carbon allotrope graphene is an interesting host to study quantum phenomena, due to its novel electronic properties and the expected weak interaction of the electron spin with the material. Graphene quantum dots are fabricated by etching mono-layer flakes into small islands (diameter 60-350 nm) with narrow connections to contacts (width 20-75 nm), serving as tunneling barriers for transport spectroscopy. Electron confinement in graphene quantum dots is observed by measuring Coulomb blockade and transport through excited states, a manifestation of quantum confinement. Measurements in a magnetic field perpendicular to the sample plane allowed to identify the regime with only a few charge carriers in the dot (electron-hole transition), and the crossover to the formation of the graphene specific zero-energy Landau level at high fields. After rotation of the sample into parallel magnetic field orientation, Zeeman spin splitting with a g-factor of g ≈ 2 is measured. The filling sequence of subsequent spin states is similar to what was found in GaAs and related to the non-negligible influence of exchange interactions among the electrons.

  20. Intranasal oxytocin reduces provoked symptoms in female patients with posttraumatic stress disorder despite exerting sympathomimetic and positive chronotropic effects in a randomized controlled trial.

    Science.gov (United States)

    Sack, M; Spieler, D; Wizelman, L; Epple, G; Stich, J; Zaba, M; Schmidt, U

    2017-02-17

    Posttraumatic stress disorder (PTSD) is a severe psychiatric disease accompanied by neuroendocrine changes such as adrenergic overdrive and hence an elevated cardiovascular morbidity. Current pharmacotherapeutic options for PTSD are less than suboptimal, necessitating the development of PTSD-specific drugs. Although the neuropeptide oxytocin has been repeatedly suggested to be effective in PTSD treatment, there are, to our knowledge, only three studies that have assessed its efficacy on the intensity of PTSD symptoms in PTSD patients - among them one symptom provocation study in male veterans. To evaluate for the first time how oxytocin influences the intensity of provoked PTSD symptoms and, furthermore, cardiac control in female PTSD patients, we assessed their psychic and cardiac response to trauma-script exposure with and without oxytocin pretreatment in a double-blind randomized placebo-controlled study. We used a within-subject design to study 35 female PTSD patients who received oxytocin and placebo in a 2-week interval. Furthermore, we performed a small pilot study to get an idea of the relation of the stress-modulated endogenous oxytocin levels and heart rate - we correlated oxytocin serum levels with the heart rate of 10 healthy individuals before and after exposure to the Trier Social Stress Test (TSST). Intranasal oxytocin treatment was followed by a reduction of provoked total PTSD symptoms, in particular of avoidance, and by an elevation in baseline and maximum heart rate together with a drop in the pre-ejection period, a marker for sympathetic cardiac control. Furthermore, we found a positive correlation between endogenous oxytocin levels and heart rate both before and after TSST challenge in healthy control subjects. This study provides the first evidence that oxytocin treatment reduces the intensity of provoked PTSD symptoms in female PTSD patients. The small size of both samples and the heterogeneity of the patient sample restrict the

  1. Initial treatment of respiratory distress syndrome with nasal intermittent mandatory ventilation versus nasal continuous positive airway pressure: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2014-01-01

    Full Text Available Background: Neonatal respiratory distress syndrome (RDS in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV compared with early nasal continuous positive airway pressure (early NCPAP obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO 2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group. The Preventive power of MV of NIMV usage (95.5% was not lower than the NCPAP (98.1% strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66; P: 0.23. The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range was 24 (18.00-48.00 h versus 48.00 (22.00-120.00 h in NIMV versus NCPAP groups; P < 0.001. Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range was 96.00 (41.00-504.00 h versus144.00 (70.00-1130.00 h in NIMV versus NCPAP groups; P: 0.009. Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  2. Ultrafast spectroscopy of quantum dots

    CERN Document Server

    Foo, E

    2001-01-01

    exchange-correlation interactions among the confined carriers inside the dots are suggested to be responsible. A density functional calculation for BGR of the ground state transition shows good agreement with our experimental results, especially in the high dot occupancy regime. Many-particle state scattering gives rise to large homogeneous spectral broadening of the PL peaks, from which an intradot relaxation time approx 300 fs is estimated. This observation supports the results obtained by direct excitation of carriers within the QDs. Femtosecond time-resolved photoluminescence measured by frequency up-conversion has been used to investigate carrier dynamics in InAs/GaAs self-assembled quantum dots (QDs). Our results reveal ultrafast carrier relaxation and sequential state filling. Carrier relaxation is proposed to occur by Auger-type processes, and the sequential state filling suggests that intradot relaxation is much faster than carrier capture from the InAs wetting layer. Measurements obtained by direct ...

  3. Quantum-dot emitters in photonic nanostructures

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Stobbe, Søren; Lodahl, Peter

    2010-01-01

    The spontaneous emission from self-assembled semiconductor quantum dots is strongly influenced by the environment in which they are placed. This can be used to determine fundamental optical properties of the quantum dots as well as to manipulate and control the quantum-dot emission itself....

  4. Simulations of axial B-dot monitors inside a groove in the beam pipe

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiaozhong, E-mail: hexiaozhong@tsinghua.org.cn [Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan (China); Pang, Jian; Li, Qin [Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan (China); Du, Yingchao [Department of Engineering Physics, Tsinghua University, Beijing (China)

    2013-11-21

    Beam tilt measurement is important for understanding the beam dynamics. Our previous theoretical studies and simulations have shown that the axial B-dot in smooth beam pipe can be used to measure the beam tilt directly. Practical azimuthal B-dot loops typically are placed inside a groove in the beam pipe to avoid direct beam interception. For the same purpose, practical axial B-dot loops should also be placed inside such a groove. In this paper, responses of axial magnetic field to the beam tilt and to the beam offset, in the presence of the groove, are investigated by simulations. The simulation results show that the axial magnetic field in the central plane of the groove is proportional to the beam tilt and independent on the centroid position. The ratio between the axial magnetic field and the beam tilt depends on the position of the axial B-dot loop and the dimensions of the groove. -- Highlights: •MAFIA simulations were carried out to analyze the influence of recessed groove to axial B dots. •It is found that axial B dots still works in the central plane of the recessed groove. •The dimensions of the groove greatly influence the signal strength of axial B dots. •Results can be used for future optimizations.

  5. Do clinical decision-support reminders for medical providers improve isoniazid preventative therapy prescription rates among HIV-positive adults? Study protocol for a randomized controlled trial.

    Science.gov (United States)

    Green, Eric P; Catalani, Caricia; Diero, Lameck; Carter, E Jane; Gardner, Adrian; Ndwiga, Charity; Keny, Aggrey; Owiti, Philip; Israelski, Dennis; Biondich, Paul

    2015-04-09

    This document describes a research protocol for a study designed to estimate the impact of implementing a reminder system for medical providers on the use of isoniazid preventative therapy (IPT) for adults living with HIV in western Kenya. People living with HIV have a 5% to 10% annual risk of developing active tuberculosis (TB) once infected with TB bacilli, compared to a 5% lifetime risk in HIV-negative people with latent TB infection. Moreover, people living with HIV have a 20-fold higher risk of dying from TB. A growing body of literature suggests that IPT reduces overall TB incidence and is therefore of considerable benefit to patients and the larger community. However, in 2009, of the estimated 33 million people living with HIV, only 1.7 million (5%) were screened for TB, and about 85,000 (0.2%) were offered IPT. This study will examine the use of clinical decision-support reminders to improve rates of initiation of preventative treatment in a TB/HIV co-morbid population living in a TB endemic area. This will be a pragmatic, parallel-group, cluster-randomized superiority trial with a 1:1 allocation to treatment ratio. For the trial, 20 public medical facilities that use clinical summary sheets generated from an electronic medical records system will participate as clusters. All HIV-positive adult patients who complete an initial encounter at a study cluster and at least one return encounter during the study period will be included in the study cohort. The primary endpoint will be IPT prescription at 3 months post the initial encounter. We will conduct both individual-level and cluster-level analyses. Due to the nature of the intervention, the trial will not be blinded. This study will contribute to the growing evidence base for the use of electronic health interventions in low-resource settings to promote high-quality clinical care, health system optimization and positive patient outcomes. Trial registration ClinicalTrials.gov NCT01934309, registered 29

  6. Secondary prevention of cardiogenic arterial thromboembolism in the cat: The double-blind, randomized, positive-controlled feline arterial thromboembolism; clopidogrel vs. aspirin trial (FAT CAT).

    Science.gov (United States)

    Hogan, Daniel F; Fox, Philip R; Jacob, Kristin; Keene, Bruce; Laste, Nancy J; Rosenthal, Steven; Sederquist, Kimberly; Weng, Hsin-Yi

    2015-12-01

    To determine if clopidogrel administration is associated with a reduced likelihood of recurrent cardiogenic arterial thromboembolism (CATE) in cats compared to aspirin administration. Secondary aims were to determine if clopidogrel administration had an effect on the composite endpoint of recurrent CATE and cardiac death and to identify adverse effects of chronic clopidogrel or aspirin therapy. Seventy-five cats that survived a CATE event. Multicenter, double-blind, randomized, positive-controlled study. Cats were assigned to clopidogrel (18.75 mg/cat PO q 24 h) or aspirin (81 mg/cat PO q 72 h). Kaplan-Meier survival curves were created for each endpoint and the log rank test performed to compare treatment groups with respect to time to event and the likelihood of the event occurring. The mean age of all cats was 8.0 ± 3.5 yr and 57/75 (76%) were male (p history of heart disease recorded prior to the CATE event. Clopidogrel administration was associated with significantly reduced likelihood of recurrent CATE compared to aspirin (p = 0.024) and had a longer median time to recurrence [443 (95% CI 185-990) days vs. 192 (95% CI 62-364) days, respectively]. Clopidogrel was also associated with a significantly reduced likelihood of the composite endpoint of recurrent CATE or cardiac death (p = 0.033) with a longer median time to event [346 (95% CI 146-495) days vs. 128 (95% CI 58-243) days]. Clopidogrel administration significantly reduces the likelihood of recurrent CATE compared with aspirin in cats; both drugs were well tolerated. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. A randomized trial of written emotional disclosure interventions in school teachers: controlling for positive expectancies and effects on health and job satisfaction.

    Science.gov (United States)

    Ashley, Laura; O'Connor, Daryl B; Jones, Fiona

    2013-01-01

    Writing expressively about distressing experiences has been found to have beneficial health effects. This study examined the effects of written emotional disclosure (WED) interventions on the self-reported health and job satisfaction of school teachers, and compared standard WED instructions with two commonly used more prescriptive variants. The study also controlled and measured the between-condition comparability of participants' post-writing benefit expectations. Teachers (final N = 77) were randomized to a control writing condition or one of three WED conditions that varied the number and/or type of experiences participants wrote about. All teachers wrote for 20 min on three consecutive days at home. Psychological health, physical health, and job satisfaction were assessed at baseline, two weeks, two months, and six months post-intervention. Participants' expectations of benefit following writing were equivalent across conditions. There was no significant effect of any of the three WED interventions, compared to control writing, on psychological or physical health or job satisfaction. There was, however, a significant and sizeable improvement in physical health across writing conditions from baseline to two-month follow-up, and this was maintained at six months. The findings show that control writing can produce comparable expectations of benefit to WED, and are consistent with the possibility that benefit expectancies can effect health improvements following disclosure or control writing. Most previous studies have examined WED with students or patient groups, and the findings also raise an important question about the feasibility of multi-session writing interventions for mid-life working samples. Further studies with occupational groups are warranted, as is further investigation into the role of positive expectancies in WED effects.

  8. Impact of continuous positive airway pressure treatment on left ventricular ejection fraction in patients with obstructive sleep apnea: a meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Hao Sun

    Full Text Available BACKGROUND: It has been known for a long time that obstructive sleep apnea (OSA is associated with a decreased left ventricular ejection fraction (LVEF. Continuous positive airway pressure (CPAP is the gold standard treatment for OSA; however, it is unknown whether or not CPAP treatment will improve the LVEF. The aim of the current study was to assess whether or not CPAP treatment improves the LVEF. A meta-analysis was conducted to determine the effect of CPAP treatment on the LVEF among patients with OSA. METHODS: A literature search of PubMed, the Web of Science, and Cochrane Collaboration's database were utilized to identify eligible reports for this trial. Ten randomized controlled trails were examined and the meta-analysis was performed using STATA 11. RESULTS: A significant improvement in the LVEF was observed after CPAP treatment (weighted mean difference(WMD = 3.59, 95% CI = 1.74-5.44; P<0.001. Subgroup analysis revealed that patients with OSA and heart failure had a significant improvement in the LVEF after CPAP treatment (WMD = 5.18, 95% CI = 3.27-7.08; P<0.001; however, the LVEF of patients with OSA only increased 1.11% and there was no statistical significance (WMD = 1.11, 95% CI = -1.13-3.35; P = 0.331. Furthermore, based on univariate meta-regression analysis, only the baseline AHI had a statistically significant correlation with the LVEF. CONCLUSIONS: Our meta-analysis supports the notion that CPAP may improve the LVEF among patients with OSA.

  9. Effects of short-term continuous positive airway pressure on myocardial sympathetic nerve function and energetics in patients with heart failure and obstructive sleep apnea: a randomized study.

    Science.gov (United States)

    Hall, Allison B; Ziadi, Maria C; Leech, Judith A; Chen, Shin-Yee; Burwash, Ian G; Renaud, Jennifer; deKemp, Robert A; Haddad, Haissam; Mielniczuk, Lisa M; Yoshinaga, Keiichiro; Guo, Ann; Chen, Li; Walter, Olga; Garrard, Linda; DaSilva, Jean N; Floras, John S; Beanlands, Rob S B

    2014-09-09

    Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics. Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and 11C-acetate and 11C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷Kmono), where Kmono is the monoexponential function fit to the myocardial 11C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the 11C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus -0.006 [-0.013, 0.005] min(-1); P=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index>20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (Penergetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted. http://www.clinicaltrials.gov. Unique identifier: NCT00756366. © 2014 American Heart Association, Inc.

  10. A Randomized Multicenter Study Comparing a Tacrolimus-Based Protocol with and without Steroids in HCV-Positive Liver Allograft Recipients

    Directory of Open Access Journals (Sweden)

    Ulf Neumann

    2012-01-01

    This randomized study evaluated HCV recurrence in HCV-positive liver allograft recipients using steroid-free immunosuppression. All patients received tacrolimus (TAC at an initial dose of 0.10–0.15 mg/kg. The steroid-free arm (TAC/daclizumab (TAC/DAC, n=67 received daclizumab induction, and the steroid arm (TAC/steroid (TAC/STR, n=68 received a steroid bolus (≤ 500mg followed by 15–20 mg/day with discontinuation after month 3. Median HCV viral load at month 12, the primary endpoint, was similar at 5.46 (0.95–6.54 IU/mL with TAC/DAC and 5.91 (0.95–6.89 IU/mL with TAC/STR. Small numerical differences in the estimated rate of freedom from HCV recurrence (19.1 versus 13.8% and freedom from biopsy proven rejection (78.4 versus 66.1% were observed between TAC/DAC and TAC/STR. Patient survival estimates were significantly lower with TAC/DAC than with TAC/STR (83.1 versus 95.5%; 95% CI, −0.227 to −0.019%, and graft survival was numerically lower (80.1 versus 91.1%, P=NS. Completion rates (45 versus 82% indicated poorer tolerability with TAC/DAC than with TAC/STR. Steroid-free immunosuppression had no real impact on HCV viral load. HCV recurrence was higher with TAC/STR. Results are inconclusive due to the unexpected lower completion rates in the TAC/DAC arm.

  11. Do manual therapy techniques have a positive effect on quality of life in people with tension-type headache? A randomized controlled trial.

    Science.gov (United States)

    Espí-López, Gemma V; Rodríguez-Blanco, Cleofás; Oliva-Pascual-Vaca, Angel; Molina-Martínez, Francisco; Falla, Deborah

    2016-08-01

    Controversy exists regarding the effectiveness of manual therapy for the relief of tension-type headache (TTH). However most studies have addressed the impact of therapy on the frequency and intensity of pain. No studies have evaluated the potentially significant effect on the patient's quality of life. To assess the quality of life of patients suffering from TTH treated for 4 weeks with different manual therapy techniques. Factorial, randomized, single-blinded, controlled clinical trial. Specialized center for the treatment of headache. Seventy-six (62 women) patients aged between 18 and 65 years (age: 39.9±10.9) with either episodic or chronic TTH. Patients were divided into four groups: suboccipital inhibitory pressure; suboccipital spinal manipulation; a combination of the two treatments; control. Quality of life was assessed using the SF-12 questionnaire (considering both the overall score and the different dimensions) at the beginning and end of treatment, and after a one month follow-up. Compared to baseline, the suboccipital inhibition treatment group showed a significant improvement in their overall quality of life at the one month follow-up and also showed specific improvement in the dimensions related to moderate physical activities, and in their emotional role. All the treatment groups, but not the control group, showed improvements in their physical role, bodily pain, and social functioning at the one month follow-up. Post treatment and at the one month follow-up, the combined treatment group showed improved vitality and the two treatment groups that involved manipulation showed improved mental health. All three treatments were effective at changing different dimensions of quality of life, but the combined treatment showed the most change. The results support the effectiveness of treatments applied to the suboccipital region for patients with TTH. Manual therapy techniques applied to the suboccipital region, for as little as four weeks, offered a

  12. Simulated Microgravity Regulates Gene Transcript Profiles of 2T3 Preosteoblasts: Comparison of the Random Positioning Machine and the Rotating Wall Vessel Bioreactor

    Science.gov (United States)

    Patel, Mamta J.; Liu, Wenbin; Sykes, Michelle C.; Ward, Nancy E.; Risin, Semyon A.; Risin, Diana; Hanjoong, Jo

    2007-01-01

    Microgravity of spaceflight induces bone loss due in part to decreased bone formation by osteoblasts. We have previously examined the microgravity-induced changes in gene expression profiles in 2T3 preosteoblasts using the Random Positioning Machine (RPM) to simulate microgravity conditions. Here, we hypothesized that exposure of preosteoblasts to an independent microgravity simulator, the Rotating Wall Vessel (RWV), induces similar changes in differentiation and gene transcript profiles, resulting in a more confined list of gravi-sensitive genes that may play a role in bone formation. In comparison to static 1g controls, exposure of 2T3 cells to RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 genes and upregulated 45 genes by more than two-fold as shown by microarray analysis. The microarray results were confirmed with real time PCR for downregulated genes osteomodulin, bone morphogenic protein 4 (BMP4), runx2, and parathyroid hormone receptor 1. Western blot analysis validated the expression of three downregulated genes, BMP4, peroxiredoxin IV, and osteoglycin, and one upregulated gene peroxiredoxin I. Comparison of the microarrays from the RPM and the RWV studies identified 14 gravi-sensitive genes that changed in the same direction in both systems. Further comparison of our results to a published database showing gene transcript profiles of mechanically loaded mouse tibiae revealed 16 genes upregulated by the loading that were shown to be downregulated by RWV and RPM. These mechanosensitive genes identified by the comparative studies may provide novel insights into understanding the mechanisms regulating bone formation and potential targets of countermeasure against decreased bone formation both in astronauts and in general patients with musculoskeletal disorders.

  13. A randomized controlled trial of strong minds: A school-based mental health program combining acceptance and commitment therapy and positive psychology.

    Science.gov (United States)

    Burckhardt, Rowan; Manicavasagar, Vijaya; Batterham, Philip J; Hadzi-Pavlovic, Dusan

    2016-08-01

    To date, most early intervention programs have been based on emotion regulation strategies that address dysfunctional cognitive appraisals, problem-solving skills, and rumination. Another emotion regulation strategy, 'acceptance' training, has largely been overlooked. To examine the efficacy of this strategy, a school-based mental health program combining positive psychology with acceptance and commitment therapy (Strong Minds) was evaluated in a randomized controlled trial with a sample of 267 Year 10 and 11 high-school students in Sydney, Australia. Mixed models for repeated measures examined whether the program led to reductions in symptoms amongst students who commenced the program with high depression, anxiety, and stress scores, and increased wellbeing scores amongst all students. Results demonstrated that compared to controls, participants in the Strong Minds condition with elevated symptom scores (n=63) reported significant reductions in depression (p=.047), stress (p=.01), and composite depression/anxiety symptoms (p=.02) with medium to strong effect sizes (Cohen's d=0.53, 0.74, and 0.57, respectively). Increased wellbeing (p=.03) in the total sample and decreased anxiety scores (p=.048) for students with elevated symptoms were significant for Year 10 students with medium effect sizes (Cohen's d=0.43 and 0.54, respectively). This study tentatively suggests that including the emotion regulation strategy of acceptance in early intervention programs may be effective in reducing symptoms and improving wellbeing in high school students. Further research to investigate the generalizability of these findings is warranted. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  14. The fabrication and characterization of quantum dots-conjugated opal photonic crystals structure.

    Science.gov (United States)

    Isnaeni; Cho, Yong-Hoon

    2010-06-04

    We have fabricated opal photonic crystal structure, which is assembled from quantum dots-conjugated polystyrene spheres. We found that the quantum dots (QD) emission from QD-conjugated photonic crystal (PC) structure experienced not only shifting to shorter wavelength, but also an asymmetrical broadening. This photonic crystal structure uses less quantum dots and may lead to great application such as single photon source and QD laser, since we may sharpen and broaden the QD emission by selecting the proper position of stop band.

  15. Trion formation in GaAs-AlGaAs quantum dots by tunneling

    Science.gov (United States)

    Zhang, Botao; Snoke, David W.; Heberle, Albert P.

    2012-02-01

    Based on time-resolved microscopic photoluminescence ( μPL) from single self-assembled GaAs/Al xGa 1- xAs quantum dots, we identify one of the emission lines as arising from positive trions (two holes and one electron) in these nominally undoped quantum dots. The trion is formed via tunneling of one electron out of the dot after optical excitation of a biexciton. The rise time of trion emission line matches the decay of the biexciton due to electron tunneling.

  16. Using quantum dot photoluminescence for load detection

    Directory of Open Access Journals (Sweden)

    M. Moebius

    2016-08-01

    Full Text Available We propose a novel concept for an integrable and flexible sensor capable to visualize mechanical impacts on lightweight structures by quenching the photoluminescence (PL of CdSe quantum dots. Considering the requirements such as visibility, storage time and high optical contrast of PL quenching with low power consumption, we have investigated a symmetrical and an asymmetrical layer stack consisting of semiconductor organic N,N,N′,N′-Tetrakis(3-methylphenyl-3,3′-dimethylbenzidine (HMTPD and CdSe quantum dots with elongated CdS shell. Time-resolved series of PL spectra from layer stacks with applied voltages of different polarity and simultaneous observation of power consumption have shown that a variety of mechanisms such as photo-induced charge separation and charge injection, cause PL quenching. However, mechanisms such as screening of external field as well as Auger-assisted charge ejection is working contrary to that. Investigations regarding the influence of illumination revealed that the positive biased asymmetrical layer stack is the preferred sensor configuration, due to a charge carrier injection at voltages of 10 V without the need of coincident illumination.

  17. Nano-laser on silicon quantum dots

    Science.gov (United States)

    Huang, Wei-Qi; Liu, Shi-Rong; Qin, Chao-Jian; Lü, Quan; Xu, Li

    2011-04-01

    A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the population inversion can be formed between the valence band and the localized states in gap produced from the surface bonds of nano-clusters. Here we report the experimental demonstration of nano-laser on silicon quantum dots fabricated by nanosecond pulse laser. The peaks of stimulated emission are observed at 605 nm and 693 nm. Through the micro-cavity of nano-laser, a full width at half maximum of the peak at 693 nm can reach to 0.5 nm. The theoretical model and the experimental results indicate that it is a necessary condition for setting up nano-laser that the smaller size of QD (d nano-laser will be limited in the range of 1.7-2.3 eV generally due to the position of the localized states in gap, which is in good agreement between the experiments and the theory.

  18. Spin storage in quantum dot ensembles and single quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, Dominik

    2009-10-15

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T{sub 1}=20 ms at B=4 T and T=1 K. A strong magnetic field dependence T{sub 1}{proportional_to}B{sup -5} has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T{sub 1}{proportional_to}T{sup -1}. The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T{sub 1}{sup h

  19. Effect of Sb and As spray on emission characteristics of InAs quantum dots with AlAs capping layer

    Science.gov (United States)

    Zhang, Z.; Tan, S.; Kim, Y.; Liu, Z.; Reece, P. J.; Bremner, S. P.

    2017-10-01

    We report on the influence of an Sb/As combined spray on the physical and optical characteristics of AlAs-capped InAs/GaAs quantum dots grown by Molecular Beam Epitaxy. Photoluminescence emission from the quantum dots shows a significant peak position shift under different Sb/As spray sequences. A blue-shifted quantum dot emission peak with an initial Sb rest indicates a large-to-small quantum dots transition process, with a bi-modal quantum dot size distribution inferred. High-resolution Transmission Electron Microscopy results reveal a large density of small quantum dots when the Sb spray is treated first. Furthermore, defect passivation in the vicinity of the quantum dots by use of Sb spray was detected.

  20. One-step synthesis of photoluminescent carbon dots with excitation-independent emission for selective bioimaging and gene delivery.

    Science.gov (United States)

    Yang, Xudong; Wang, Yang; Shen, Xiran; Su, Chunyan; Yang, Jinghua; Piao, Mingjun; Jia, Fei; Gao, Guanghui; Zhang, Long; Lin, Quan

    2017-04-15

    Photoluminescent carbon dots (C-dots), as new members of the quantum sized carbon analogues have attracted significant attention due to their unique size, less toxicity, good compatibility and relatively easy surface modification. In this work, we report a simple, low-cost and one-step hydrothermal carbonization approach to synthesize the positively charged C-dots using PEI and FA. From the photoluminescence (PL) measurements, the as-prepared C-dots exhibit good stability and intense PL with the high quantum yield (QY) at Ca. 42%. Significantly, The as-prepared C-dots integrate the advantages of C-dots and PEI: the presence of C-dots can effectively decrease the cytotoxicity of PEI, the C-dots can be applied in biological system for selective imaging of folate receptor (FR)-positive cancerous cells from normal cells, while the cationic PEI with positive charges can make them link to plasmid DNA and efficiently transfect the therapeutic plasmid into cells. Therefore, the as-prepared with the facile synthesis method can be a promising photoluminescent probe for cancer diagnosis and gene therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Seeing the world through target-tinted glasses: Positive mood broadens perceptual tuning.

    Science.gov (United States)

    Uddenberg, Stefan; Shim, Won Mok

    2015-06-01

    Research shows that positive mood can serve to broaden the scope of attention at both the perceptual and conceptual level (e.g., increasing the size of spatial attentional focus and semantic access to remote associates). We investigated whether this relaxation of attentional filters by positive affect reduces their selectivity for basic visual features. We induced positive, neutral, or negative affect and asked observers to identify a target motion direction in a series of rapid random moving dot displays. Using a reverse correlation method, we examined the differential effects of emotion on observers' perceptual tuning curves for motion direction. Here we find that positive affect reduces selectivity for motion direction by broadening observers' perceptual tuning relative to both neutral and negative affect conditions. These findings provide the first behavioral evidence that positive emotion influences selectivity for basic visual features through modulation of tuning properties. (c) 2015 APA, all rights reserved).

  2. Menatetrenone versus alfacalcidol in the treatment of Chinese postmenopausal women with osteoporosis: a multicenter, randomized, double-blinded, double-dummy, positive drug-controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Jiang Y

    2014-01-01

    Full Text Available Yan Jiang,1,* Zhen-Lin Zhang,2,* Zhong-Lan Zhang,3 Han-Min Zhu,4 Yi-Yong Wu,5 Qun Cheng,4 Feng-Li Wu,5 Xiao-Ping Xing,1 Jian-Li Liu,3 Wei Yu,6 Xun-Wu Meng11Department of Endocrinology, Key Laboratory of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, 2Metabolic Bone Disease and Genetic Research Unit, Department of Osteoporosis and Bone Disease, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 3Department of Gynecology and Obstetrics, General Hospital of the People's Liberation Army, Beijing, 4Department of Geriatrics, Shanghai Huadong Hospital, Shanghai, 5Department of Gynecology and Obstetrics, Beijing Hospital, Ministry of Public Health, Beijing, 6Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, People's Republic of China*These authors contributed equally to this workObjective: To evaluate whether the efficacy and safety of menatetrenone for the treatment of osteoporosis is noninferior to alfacalcidol in Chinese postmenopausal women.Method: This multicenter, randomized, double-blinded, double-dummy, noninferiority, positive drug-controlled clinical trial was conducted in five Chinese sites. Eligible Chinese women with postmenopausal osteoporosis (N=236 were randomized to Group M or Group A and received menatetrenone 45 mg/day or alfacalcidol 0.5 µg/day, respectively, for 1 year. Additionally, all patients received calcium 500 mg/day. Posttreatment bone mineral density (BMD, new fracture onsets, and serum osteocalcin (OC and undercarboxylated OC (ucOC levels were compared with the baseline value in patients of both groups.Results: A total of 213 patients (90.3% completed the study. After 1 year of treatment, BMD among patients in Group M significantly increased from baseline by 1.2% and 2.7% at the lumbar spine and trochanter, respectively (P<0.001; and the percentage increase of BMD in Group A was 2

  3. Hyperdense dots mimicking microcalcifications : Mammographic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nam Hyeon; Park, Jeong Mi; Goo, Hyun Woo; Bang, Sun Woo [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    1996-12-01

    To differentiate fine hyperdense dots mimicking microcalcifications from true microcalcifications on mammography. Mammograms showing hyperdense dots in ten patients (mean age, 59 years) were evaluated. Two radiologists were asked to differentiate with the naked eye the hyperdense dots seen on ten mammograms and proven microcalcifications seen on ten mammograms. Densitometry was also performed for all lesions and the contrast index was calculated. The shape and distribution of the hyperdense dots were evaluated and enquires were made regarding any history of breast disease and corresponding treatment. Biopsies were performed for two patients with hyperdense dots. Two radiologists made correct diagnoses in 19/20 cases(95%). The contrast index was 0.10-0.88 (mean 0.58) for hyperdense dots and 0.02-0.45 (mean 0.17) for true microcalcifications. The hyperdense dots were finer and homogeneously rounder than the microcalcifications. Distribution of the hyperdense dots was more superficial in subcutaneous fat (seven cases) and subareolar area (six cases). All ten patients with hyperdense dots had history of mastitis and abscesses and had been treated by open drainage (six cases) and/or folk remedy (four cases). In eight patients, herb patches had been attached. Biopsies of hyperdense dots did not show any microcalcification or evidence of malignancy. These hyperdense dots were seen mainly in older patients. Their characteristic density, shape, distribution and clinical history makes differential diagnosis from true microcalcifications easy and could reduce unnecessary diagnostic procedures such as surgical biopsy.

  4. Optophononics with Coupled Quantum Dots

    Science.gov (United States)

    2014-02-18

    single InAs/GaAs quantum dots. Phys. Rev. B 68, 233301 (2003). 9. Bennemann, K.-H. & Ketterson, J. B. (eds), Superconductivity : Conventional and...superlattices. Science 338, 935–939 (2012). 17. Kim, J.-H. et al. Coherent phonons in carbon nanotubes and graphene . Chem. Phys. 413, 55–80 (2013). 18

  5. DOT strategies versus orbiter strategies

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    The Dutch Open Telescope is a high-resolution solar imager coming on-line at La Palma. The definition of the DOT science niche, strategies, and requirements resemble Solar Orbiter considerations and deliberations. I discuss the latter in the light of the former, and claim that multi-line observation

  6. Luminescent Surface Quaternized Carbon Dots

    KAUST Repository

    Bourlinos, Athanasios B.

    2012-01-10

    Thermal oxidation of a salt precursor made from the acid base combination of tris(hydroxymethyl)aminomethane and betaine hydrochloride results in light-emitting surface quaternized carbon dots that are water-dispersible, display anion exchange properties, and exhibit uniform size/surface charge. © 2011 American Chemical Society.

  7. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, N.; Liu, Rongrong; Vancso, Gyula J.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of

  8. Nuclear Spins in Quantum Dots

    NARCIS (Netherlands)

    Erlingsson, S.I.

    2003-01-01

    The main theme of this thesis is the hyperfine interaction between the many lattice nuclear spins and electron spins localized in GaAs quantum dots. This interaction is an intrinsic property of the material. Despite the fact that this interaction is rather weak, it can, as shown in this thesis,

  9. Silicon quantum dots: surface matters

    NARCIS (Netherlands)

    Dohnalová, K.; Gregorkiewicz, T.; Kůsová, K.

    2014-01-01

    Silicon quantum dots (SiQDs) hold great promise for many future technologies. Silicon is already at the core of photovoltaics and microelectronics, and SiQDs are capable of efficient light emission and amplification. This is crucial for the development of the next technological frontiers—silicon

  10. The 2-dot technique: minimalist donor lenticule marking in endothelial keratoplasty.

    Science.gov (United States)

    Bhogal, Maninder; Angunawela, Romesh I; Allan, Bruce

    2011-04-01

    Correct orientation of the donor lenticule within the anterior chamber is essential for the success of Descemet stripping automated endothelial keratoplasty. We describe a 2-dot pattern for gentian violet marking of the donor lenticule that confirms correct graft positioning while minimizing associated endothelial toxicity. The 2-dot pattern is the smallest pattern possible with no axis of rotational symmetry about any diameter across the lenticule.

  11. [Dot enzyme-linked immunosorbent assay for detection of serum antibody to Blastocystis hominis in humans].

    Science.gov (United States)

    Su, Shui-lian; Yan, Yi-ming; Liao, Hua; Chen, Gui-feng; Zhang, Rui-qi; Xie, Qiong-jun; Le, Xiao; Hu, Ya-qiong; Zeng, Xue-ying; Lan, Hai-ying; Xie, Rui-lian; Huang, Zhen

    2007-06-01

    Serum and stool samples were collected from 322 undergraduate students in medical school. Using stool in vitro cultivation as golden standard, 178 cases were found Blastocystis hominis positive and 144 were negative. Dot-ELISA was used to examine the serum samples with a sensitivity of 92.1% (164/178) and specificity of 97.1% (141/144). This revealed that dot-ELISA can be used for antibody detection against Blastocystis hominis.

  12. Color Charts, Esthetics, and Subjective Randomness

    Science.gov (United States)

    Sanderson, Yasmine B.

    2012-01-01

    Color charts, or grids of evenly spaced multicolored dots or squares, appear in the work of modern artists and designers. Often the artist/designer distributes the many colors in a way that could be described as "random," that is, without an obvious pattern. We conduct a statistical analysis of 125 "random-looking" art and design color charts and…

  13. Early intervention influences positively quality of life as reported by prematurely born children at age nine and their parents; a randomized clinical trial.

    Science.gov (United States)

    Landsem, Inger Pauline; Handegård, Bjørn Helge; Ulvund, Stein Erik; Kaaresen, Per Ivar; Rønning, John A

    2015-02-22

    The Tromsø Intervention Study on Preterms evaluates an early, sensitizing intervention given to parents of prematurely born children (birth-weight intervention on children's self-reported and parental proxy-reported quality of life (QoL) at children's age of nine. Participants were randomized to either intervention (PI, n = 72) or preterm control (PC, n = 74) in the neonatal care unit, while healthy term-born infants were recruited to a term reference group (TR, n = 75). The intervention was a modified version of the Mother-Infant Transaction Program, and comprised eight one-hour sessions during the last week before discharge and four home visits at 1, 2, 4 and 12 weeks post-discharge. The two control groups received care in accordance with written guidelines drawn up at the hospital. Participants and parents reported QoL independently on the Kinder Lebensqualität Fragebogen (KINDL) questionnaire. Differences between groups were analyzed by SPSS; Linear Mixed Models and parent-child agreement were analyzed and compared by intra-class correlations within each group. On average, children in all groups reported high levels of well-being. The PI children reported better physical well-being than the PC children (p = 0.002). In all other aspects of QoL both the PI and the PC children reported at similar levels as the term reference group. PI parents reported better emotional wellbeing (p = 0.05) and a higher level of contentment in school (p = 0.003) compared with PC parents. Parent-child agreement was significantly weaker in the PI group than in the PC group on dimensions such as emotional well-being and relationships with friends (p parents reported QoL similar to parents of terms on all aspects except the subscale self-esteem, while PC parents generally reported moderately lower QoL than TR parents. This early intervention appears to have generated long-lasting positive effects, improving perceived physical well-being among prematurely

  14. Interpersonal psychotherapy for depression and posttraumatic stress disorder among HIV-positive women in Kisumu, Kenya: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Onu, Chinwe; Ongeri, Linnet; Bukusi, Elizabeth; Cohen, Craig R; Neylan, Thomas C; Oyaro, Patrick; Rota, Grace; Otewa, Faith; Delucchi, Kevin L; Meffert, Susan M

    2016-02-03

    Mental disorders are the leading global cause of years lived with disability; the majority of this burden exists in low and middle income countries (LMICs). Over half of mental illness is attributable to depression and anxiety disorders, both of which have known treatments. While the scarcity of mental health care providers is recognized as a major contributor to the magnitude of untreated disorders in LMICs, studies in LMICs find that evidence-based treatments for depression and anxiety disorders, such as brief, structured psychotherapies, are feasible, acceptable and have strong efficacy when delivered by local non-specialist personnel. However, most mental health treatment studies using non-specialist providers in LMICs deploy traditional efficacy designs (T1) without the benefit of integrated mental health treatment models shown to succeed over vertical interventions or methods derived from new implementation science to speed policy change. Here, we describe an effectiveness-implementation hybrid study that evaluates non-specialist delivery of mental health treatment within an HIV clinic for HIV-positive (HIV+) women affected by gender- based violence (GBV) (HIV+ GBV+) in the Nyanza region of Kenya. In this effectiveness-implementation hybrid type I design, 200 HIV+ women with major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) who are receiving care at a Family AIDS Care Education and Services (FACES)-supported clinic in Kisumu, Kenya will be randomized to: (1) interpersonal psychotherapy (IPT) + treatment as usual (TAU) or (2) TAU, both delivered within the HIV clinic. IPT will consist of 12 weekly 60-minute individual IPT sessions, delivered by non-specialists trained to provide IPT. Primary effectiveness outcomes will include MDD and PTSD diagnosis on the Mini International Diagnostic Interview (MINI). Primary implementation outcomes will include treatment cost-benefit, acceptability, appropriateness, feasibility and fidelity of the

  15. Effects of Continuous Positive Airway Pressure on Cognitive Deficits in Middle-aged Patients with Obstructive Sleep Apnea Syndrome: A Meta-analysis of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Yue-Ying Pan

    2015-01-01

    Conclusions: Cognition partially improved in patients with OSAS after CPAP treatment. The only domain with significant improvement was vigilance. Rigorous randomized controlled trials need to be performed to obtain clear results.

  16. Scanning gate imaging of two coupled quantum dots in single-walled carbon nanotubes.

    Science.gov (United States)

    Zhou, Xin; Hedberg, James; Miyahara, Yoichi; Grutter, Peter; Ishibashi, Koji

    2014-12-12

    Two coupled single wall carbon nanotube quantum dots in a multiple quantum dot system were characterized by using a low temperature scanning gate microscopy (SGM) technique, at a temperature of 170 mK. The locations of single wall carbon nanotube quantum dots were identified by taking the conductance images of a single wall carbon nanotube contacted by two metallic electrodes. The single electron transport through single wall carbon nanotube multiple quantum dots has been observed by varying either the position or voltage bias of a conductive atomic force microscopy tip. Clear hexagonal patterns were observed in the region of the conductance images where only two sets of overlapping conductance rings are visible. The values of coupling capacitance over the total capacitance of the two dots, C(m)/C(1(2)) have been extracted to be 0.21 ∼ 0.27 and 0.23 ∼ 0.28, respectively. In addition, the interdot coupling (conductance peak splitting) has also been confirmed in both conductance image measurement and current-voltage curves. The results show that a SGM technique enables spectroscopic investigation of coupled quantum dots even in the presence of unexpected multiple quantum dots.

  17. Probing silicon quantum dots by single-dot techniques

    Science.gov (United States)

    Sychugov, Ilya; Valenta, Jan; Linnros, Jan

    2017-02-01

    Silicon nanocrystals represent an important class of non-toxic, heavy-metal free quantum dots, where the high natural abundance of silicon is an additional advantage. Successful development in mass-fabrication, starting from porous silicon to recent advances in chemical and plasma synthesis, opens up new possibilities for applications in optoelectronics, bio-imaging, photovoltaics, and sensitizing areas. In this review basic physical properties of silicon nanocrystals revealed by photoluminescence spectroscopy, lifetime, intensity trace and electrical measurements on individual nanoparticles are summarized. The fabrication methods developed for accessing single Si nanocrystals are also reviewed. It is concluded that silicon nanocrystals share many of the properties of direct bandgap nanocrystals exhibiting sharp emission lines at low temperatures, on/off blinking, spectral diffusion etc. An analysis of reported results is provided in comparison with theory and with direct bandgap material quantum dots. In addition, the role of passivation and inherent interface/matrix defects is discussed.

  18. A Transfer Hamiltonian Model for Devices Based on Quantum Dot Arrays

    Directory of Open Access Journals (Sweden)

    S. Illera

    2015-01-01

    Full Text Available We present a model of electron transport through a random distribution of interacting quantum dots embedded in a dielectric matrix to simulate realistic devices. The method underlying the model depends only on fundamental parameters of the system and it is based on the Transfer Hamiltonian approach. A set of noncoherent rate equations can be written and the interaction between the quantum dots and between the quantum dots and the electrodes is introduced by transition rates and capacitive couplings. A realistic modelization of the capacitive couplings, the transmission coefficients, the electron/hole tunneling currents, and the density of states of each quantum dot have been taken into account. The effects of the local potential are computed within the self-consistent field regime. While the description of the theoretical framework is kept as general as possible, two specific prototypical devices, an arbitrary array of quantum dots embedded in a matrix insulator and a transistor device based on quantum dots, are used to illustrate the kind of unique insight that numerical simulations based on the theory are able to provide.

  19. Dot-in-Well Quantum-Dot Infrared Photodetectors

    Science.gov (United States)

    Gunapala, Sarath; Bandara, Sumith; Ting, David; Hill, cory; Liu, John; Mumolo, Jason; Chang, Yia Chung

    2008-01-01

    Dot-in-well (DWELL) quantum-dot infrared photodetectors (QDIPs) [DWELL-QDIPs] are subjects of research as potentially superior alternatives to prior QDIPs. Heretofore, there has not existed a reliable method for fabricating quantum dots (QDs) having precise, repeatable dimensions. This lack has constituted an obstacle to the development of uniform, high-performance, wavelength-tailorable QDIPs and of focal-plane arrays (FPAs) of such QDIPs. However, techniques for fabricating quantum-well infrared photodetectors (QWIPs) having multiple-quantum- well (MQW) structures are now well established. In the present research on DWELL-QDIPs, the arts of fabrication of QDs and QWIPs are combined with a view toward overcoming the deficiencies of prior QDIPs. The longer-term goal is to develop focal-plane arrays of radiationhard, highly uniform arrays of QDIPs that would exhibit high performance at wavelengths from 8 to 15 m when operated at temperatures between 150 and 200 K. Increasing quantum efficiency is the key to the development of competitive QDIP-based FPAs. Quantum efficiency can be increased by increasing the density of QDs and by enhancing infrared absorption in QD-containing material. QDIPs demonstrated thus far have consisted, variously, of InAs islands on GaAs or InAs islands in InGaAs/GaAs wells. These QDIPs have exhibited low quantum efficiencies because the numbers of QD layers (and, hence, the areal densities of QDs) have been small typically five layers in each QDIP. The number of QD layers in such a device must be thus limited to prevent the aggregation of strain in the InAs/InGaAs/GaAs non-lattice- matched material system. The approach being followed in the DWELL-QDIP research is to embed In- GaAs QDs in GaAs/AlGaAs multi-quantum- well (MQW) structures (see figure). This material system can accommodate a large number of QD layers without excessive lattice-mismatch strain and the associated degradation of photodetection properties. Hence, this material

  20. Quantum Dot Light Emitting Diode

    Energy Technology Data Exchange (ETDEWEB)

    Keith Kahen

    2008-07-31

    The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m2, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

  1. Quantum Dot Light Emitting Diode

    Energy Technology Data Exchange (ETDEWEB)

    Kahen, Keith

    2008-07-31

    The project objective is to create low cost coatable inorganic light emitting diodes, composed of quantum dot emitters and inorganic nanoparticles, which have the potential for efficiencies equivalent to that of LEDs and OLEDs and lifetime, brightness, and environmental stability between that of LEDs and OLEDs. At the end of the project the Recipient shall gain an understanding of the device physics and properties of Quantum-Dot LEDs (QD-LEDs), have reliable and accurate nanocrystal synthesis routines, and have formed green-yellow emitting QD-LEDs with a device efficiency greater than 3 lumens/W, a brightness greater than 400 cd/m{sup 2}, and a device operational lifetime of more than 1000 hours. Thus the aim of the project is to break the current cost-efficiency paradigm by creating novel low cost inorganic LEDs composed of inorganic nanoparticles.

  2. Electronic triple-dot transport through a bilayer graphene island with ultrasmall constrictions

    Science.gov (United States)

    Bischoff, D.; Varlet, A.; Simonet, P.; Ihn, T.; Ensslin, K.

    2013-08-01

    A quantum dot has been etched in bilayer graphene connected by two small constrictions to the leads. We show that this structure does not behave like a single quantum dot but consists of at least three sites of localized charge in series. The high symmetry and electrical stability of the device allowed us to triangulate the positions of the different sites of localized charge and find that one site is located in the island and one in each of the constrictions. Nevertheless we measure many consecutive non-overlapping Coulomb-diamonds in series. In order to describe these findings, we treat the system as a strongly coupled serial triple quantum dot. We find that the non-overlapping Coulomb diamonds arise due to higher order cotunneling through the outer dots located in the constrictions. We extract all relevant capacitances, simulate the measured data with a capacitance model and discuss its implications on electrical transport.

  3. Folic acid-CdTe quantum dot conjugates and their applications for cancer cell targeting

    Energy Technology Data Exchange (ETDEWEB)

    Suriamoorthy, Preethi; Zhang, Xing; Hao, Guiyang; Joly, Alan G.; Singh, S.; Hossu, Marius; Sun, Xiankai; Chen, Wei

    2010-12-01

    In this study, we report the preparation,luminescence, and targeting properties of folic acid- CdTe quantum dot conjugates. Water-soluble CdTe quantum dots were synthesized and conjugated with folic acid using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide chemistry. The in-fluence of folic acid on the luminescence properties of CdTe quantum dots was investigated, and no energy transfer between them was observed. To investigate the efficiency of folic acid-CdTe nanoconjugates for tumor targeting, pure CdTe quantum dots and folic acid-coated CdTe quantum dots were incubated with human naso- pharyngeal epidermal carcinoma cell line with positive expressing folic acid receptors (KB cells) and lung cancer cells without expression of folic acid receptors (A549 cells). For the cancer cells with positive folate receptors (KB cells), the uptake for CdTe quantum dots is very low, but for folic acid-CdTe nanoconjugates, the uptake is very high. For the lung cancer cells without folate receptors (A549 cells), the uptake for folic acid- CdTe nanoconjugates is also very low. The results indicate that folic acid is an effective targeting molecule for tumor cells with overexpressed folate receptors.

  4. Orientation and position-controlled block copolymer nanolithography for bit-patterned media

    Science.gov (United States)

    Yamamoto, R.; Kanamaru, M.; Sugawara, K.; Sasao, N.; Ootera, Y.; Okino, T.; Hieda, H.; Kihara, N.; Kamata, Y.; Kikitsu, A.

    2013-03-01

    Bit-patterned media (BPM) is a candidate for high-density magnetic recording media. Directed self-assembly (DSA) is expected to be a solution for the fabrication process of high-density BPM. A BPM with 20 nm-pitch dot pattern is fabricated. A 100 nm-pitch triangle lattice dot pattern, which is fabricated by EB lithography, is used as a guide post to order PS-PDMS self-assembled diblock co-polymer with 20 nm pitch. Dot-pitch fluctuation and linearity of pseudo dot tracks are estimated. The standard deviation of the dot-pitch variation including the post guide is 8% of the self-assembled dot pitch. The dot-position deviation is estimated to be about 8% of the pseudo dot track pitch. In both cases, variation of the size and pitch of the post guides is found to increase the dot-pitch fluctuation and dot-position deviation from pseudo dot-track.

  5. Alleviating Parenting Stress in Parents with Intellectual Disabilities: A Randomized Controlled Trial of a Video-Feedback Intervention to Promote Positive Parenting

    Science.gov (United States)

    Hodes, Marja W.; Meppelder, Marieke; Moor, Marleen; Kef, Sabina; Schuengel, Carlo

    2017-01-01

    Background: Adapted parenting support may alleviate the high levels of parenting stress experienced by many parents with intellectual disabilities. Methods: Parents with mild intellectual disabilities or borderline intellectual functioning were randomized to experimental (n = 43) and control (n = 42) conditions. Parents in both groups received…

  6. Quantum dots: lasers and amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Bimberg, Dieter; Ledentsov, Nikolai [Institut fuer Festkoerperphysik, PN5-2, Technische Universitaet Berlin, Hardenbergstrasse 36, 10623 (Germany)

    2003-06-25

    Continuous wave room-temperature output power of {approx} 3 W for edge emitters and of 1.2 mW for vertical-cavity surface-emitting lasers is realized for GaAs-based devices using InAs quantum dots (QDs) operating at 1.3 {mu}m. Characteristic temperatures up to 170 K below 330 K are realized. Simultaneously, differential efficiency exceeds 80% for these devices. Lasers emitting up to 12 W at 1140-1160 nm are useful as pump sources for Tm{sup 3+}-doped fibres for frequency up-conversion to 470 nm. Both types of lasers show transparency current densities of 6 A cm{sup -2} per dot layer, {eta}{sub int} = 98% and {alpha}{sub i} around 1.5 cm{sup -1}. Long operation lifetimes (above 3000 h at 50 deg C heatsink temperature at 1.5 W CW) and improved radiation hardness as compared to quantum well (QW) devices are manifested. Cut-off frequencies of about 10 GHz at 1100 nm and 6 GHz at 1300 nm and low {alpha} factors resulting in reduced filamentation and improved M{sup 2} values in single-mode operation are realized. Quantum dot semiconductor optical amplifiers (QD SOAs) demonstrate gain recovery times of 120-140 fs, 4-7 times faster than bulk/QW SOAs. The breakthrough became possible due to the development of self-organized growth in QD technology. (topical review)

  7. Spin Echo of a Single Electron Spin in a Quantum Dot

    NARCIS (Netherlands)

    Koppens, F.H.L.; Nowack, K.C.; Vandersypen, L.M.K.

    2008-01-01

    We report a measurement of the spin-echo decay of a single electron spin confined in a semiconductor quantum dot. When we tip the spin in the transverse plane via a magnetic field burst, it dephases in 37 ns due to the Larmor precession around a random effective field from the nuclear spins in the

  8. Barrier Engineered Quantum Dot Infrared Photodetectors

    Science.gov (United States)

    2015-06-01

    AFRL-RV-PS- AFRL-RV-PS- TR-2015-0111 TR-2015-0111 BARRIER ENGINEERED QUANTUM DOT INFRARED PHOTODETECTORS Sanjay Krishna Center for High Technology...2011 – 22 May 2012 4. TITLE AND SUBTITLE Barrier Engineered Quantum Dot Infrared Photodetectors 5a. CONTRACT NUMBER FA9453-12-1-0336 5b. GRANT...is Unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT To investigate barrier engineered designs to reduce the dark current in quantum dot infrared

  9. Adjustment of issue positions based on network strategies in a nelection campaign: A two-mode network autoregression model with cross-nested random effects

    NARCIS (Netherlands)

    Kleinnijenhuis, J.; de Nooy, W.

    2013-01-01

    During election campaigns, political parties deliver statements on salient issues in the news media, which are called issue positions. This article conceptualizes issue positions as a valued and longitudinal two-mode network of parties by issues. The network is valued because parties pronounce pro

  10. Adjustment of issue positions based on network strategies in an election campaign: a two-mode network autoregression model with cross-nested random effects

    NARCIS (Netherlands)

    Kleinnijenhuis, J.; de Nooy, W.

    2013-01-01

    During election campaigns, political parties deliver statements on salient issues in the news media, which are called issue positions. This article conceptualizes issue positions as a valued and longitudinal two-mode network of parties by issues. The network is valued because parties pronounce pro

  11. Today's DOT and the quest for more accountable organizational structures.

    Science.gov (United States)

    2005-12-01

    This study investigates the impact of DOT organizational structures on effective transportation planning and performance. A review of the 50 state DOT authorizing statutes and DOT organizational charts found minimal differences in organizational stru...

  12. Spin Switching via Quantum Dot Spin Valves

    Science.gov (United States)

    Gergs, N. M.; Bender, S. A.; Duine, R. A.; Schuricht, D.

    2018-01-01

    We develop a theory for spin transport and magnetization dynamics in a quantum dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate that, as a result of these strong correlations, the dot gate voltage enables control over the current-induced torques on the magnets and, in particular, enables voltage-controlled magnetic switching. The electrical resistance of the structure can be used to read out the magnetic state. Our model may be realized by a number of experimental systems, including magnetic scanning-tunneling microscope tips and artificial quantum dot systems.

  13. Quantum dots for quantum information technologies

    CERN Document Server

    2017-01-01

    This book highlights the most recent developments in quantum dot spin physics and the generation of deterministic superior non-classical light states with quantum dots. In particular, it addresses single quantum dot spin manipulation, spin-photon entanglement and the generation of single-photon and entangled photon pair states with nearly ideal properties. The role of semiconductor microcavities, nanophotonic interfaces as well as quantum photonic integrated circuits is emphasized. The latest theoretical and experimental studies of phonon-dressed light matter interaction, single-dot lasing and resonance fluorescence in QD cavity systems are also provided. The book is written by the leading experts in the field.

  14. Preparation of tin oxide quantum dots

    Science.gov (United States)

    Fauzi, N. F. S. M.; Kamarulzaman, N.; Kasim, M. F.; Chayed, N. F.; Aziz, N. D. A.

    2017-09-01

    Quantum dots are interesting nanostructures with have novel physical and chemical characteristics. It is not an easy task to obtain quantum dots because materials tend to agglomerate. In this work, SnO2 quantum dots have been successfully synthesized via a simple and low cost method which is the sol-gel method. Thermal analysis of the precursors were carried out using a Simultaneous Thermogravimetric Analyzer (STA). The annealed samples were characterized using X-Ray Diffraction (XRD) for phase studies. Finally, the crystallite size and morphology of tin oxide quantum dots were determined using Field Emission Scanning Electron Microscopy (FESEM).

  15. POLARON IN CYLINDRICAL AND SPHERICAL QUANTUM DOTS

    Directory of Open Access Journals (Sweden)

    L.C.Fai

    2004-01-01

    Full Text Available Polaron states in cylindrical and spherical quantum dots with parabolic confinement potentials are investigated applying the Feynman variational principle. It is observed that for both kinds of quantum dots the polaron energy and mass increase with the increase of Frohlich electron-phonon coupling constant and confinement frequency. In the case of a spherical quantum dot, the polaron energy for the strong coupling is found to be greater than that of a cylindrical quantum dot. The energy and mass are found to be monotonically increasing functions of the coupling constant and the confinement frequency.

  16. Transmission and scarring in graphene quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Huang Liang; Lai Yingcheng; Ferry, David K; Akis, Richard; Goodnick, Stephen M [Department of Electrical Engineering, Arizona State University, Tempe, AZ 85287 (United States)

    2009-08-26

    We study electronic transport in quantum-dot structures made of graphene. Focusing on the rectangular dot geometry and utilizing the non-equilibrium Green's function to calculate the transmission in the tight-binding framework, we find significant fluctuations in the transmission as a function of the electron energy. The fluctuations are correlated with the formation of quantum scarring states, or pointer states in the dot. Both enhancement and suppression of transmission have been observed. As the size of the quantum dot is increased, more scarring states can be formed, leading to stronger transmission or conductance fluctuations.

  17. Mixed-quantum-dot solar cells.

    Science.gov (United States)

    Yang, Zhenyu; Fan, James Z; Proppe, Andrew H; Arquer, F Pelayo García de; Rossouw, David; Voznyy, Oleksandr; Lan, Xinzheng; Liu, Min; Walters, Grant; Quintero-Bermudez, Rafael; Sun, Bin; Hoogland, Sjoerd; Botton, Gianluigi A; Kelley, Shana O; Sargent, Edward H

    2017-11-06

    Colloidal quantum dots are emerging solution-processed materials for large-scale and low-cost photovoltaics. The recent advent of quantum dot inks has overcome the prior need for solid-state exchanges that previously added cost, complexity, and morphological disruption to the quantum dot solid. Unfortunately, these inks remain limited by the photocarrier diffusion length. Here we devise a strategy based on n- and p-type ligands that judiciously shifts the quantum dot band alignment. It leads to ink-based materials that retain the independent surface functionalization of quantum dots, and it creates distinguishable donor and acceptor domains for bulk heterojunctions. Interdot carrier transfer and exciton dissociation studies confirm efficient charge separation at the nanoscale interfaces between the two classes of quantum dots. We fabricate the first mixed-quantum-dot solar cells and achieve a power conversion of 10.4%, which surpasses the performance of previously reported bulk heterojunction quantum dot devices fully two-fold, indicating the potential of the mixed-quantum-dot approach.

  18. Is the benefit of postmastectomy irradiation limited to patients with four or more positive nodes, as recommended in international consensus reports? A subgroup analysis of the DBCG 82 b & c randomized trials

    DEFF Research Database (Denmark)

    Overgaard, Marie; Nielsen, Hanne Melgaard; Overgaard, Jens

    2007-01-01

    to evaluate the loco-regional recurrence rate and survival in relation to number of positive nodes. MATERIALS AND METHODS: In the DBCG 82 b&c trials 3083 pre- and postmenopausal high-risk women were randomized to postoperative RT in addition to adjuvant systemic therapy. Since many patients had relatively few...... lymph nodes removed (median 7), the present analysis was limited to 1152 node positive patients with 8 or more nodes removed. RESULTS: The overall 15-year survival rate in the subgroup was 39% and 29% (p=0.015) after RT and no RT, respectively. RT reduced the 15-year loco-regional failure rate from 51......=0.03). CONCLUSION: The survival benefit after postmastectomy RT was substantial and similar in patients with 1-3 and 4+ positive lymph nodes. Furthermore, it was not strictly associated with the risk of loco-regional recurrence, which was most pronounced in patients with 4+ positive nodes...

  19. Long-term outcome of a randomized controlled universal prevention trial through a positive parenting program: is it worth the effort?

    OpenAIRE

    Hahlweg, Kurt; Heinrichs, Nina; Kuschel, Annett; Bertram, Heike; Naumann, Sebastian

    2010-01-01

    Background Approximately 20% of children experience internalizing or externalizing DSM-IV-TR disorders. This prevalence rate cannot be reduced through treatment only. Effective preventive interventions are therefore urgently needed. The aim of the current investigation is to evaluate the two-year efficacy of the group Triple P parenting program administered universally for the prevention of child behavior problems. Methods Based on their respective preschool, N = 280 families were randomly a...

  20. Positive parenting program (triple P) for families of adolescents with type 1 diabetes: a randomized controlled trial of self-directed teen triple P.

    Science.gov (United States)

    Doherty, Francesca M; Calam, Rachel; Sanders, Matthew R

    2013-09-01

    Adolescents with type 1 diabetes (T1D) have shown improvements in glycemic control and family relations, via clinic-based family interventions. However, reach and clinician availability may be limited. We evaluated a self-directed intervention for this purpose. Recruitment for a randomized controlled trial (RCT) occurred through national advertising with diabetes charities and conducted with online data collection. Parents of 11-17-year-olds with diabetes were randomized to usual care (n = 37) or intervention (n = 42) using computerized block randomization. The 10-week intervention comprised the Self-directed Teen Triple P workbook (10 × 1 hr modules) plus chronic illness tip sheet. Primary outcomes of diabetes-related family conflict and parenting stress were assessed pre and post-intervention. Intention-to-treat analyses (n = 79) identified significantly improved diabetes-related conflict, but not parental stress, compared with usual care. The preliminary findings suggest that this could be a useful way to expand intervention reach for this population.

  1. Confinement sensitivity in quantum dot singlet-triplet relaxation

    Science.gov (United States)

    Wesslén, C. J.; Lindroth, E.

    2017-11-01

    Spin-orbit mediated phonon relaxation in a two-dimensional quantum dot is investigated using different confining potentials. Elliptical harmonic oscillator and cylindrical well results are compared to each other in the case of a two-electron GaAs quantum dot subjected to a tilted magnetic field. The lowest energy set of two-body singlet and triplet states are calculated including spin-orbit and magnetic effects. These are used to calculate the phonon induced transition rate from the excited triplet to the ground state singlet for magnetic fields up to where the states cross. The roll of the cubic Dresselhaus effect, which is found to be much more important than previously assumed, and the positioning of ‘spin hot-spots’ are discussed and relaxation rates for a few different systems are exhibited.

  2. Quantum Dot Spectrum Converters for Enhanced High Efficiency Photovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research proposes to enhance solar cell efficiency, radiation resistance and affordability. The Quantum Dot Spectrum Converter (QDSC) disperses quantum dots...

  3. Nitrogen-Doped Carbon Dots for "green" Quantum Dot Solar Cells.

    Science.gov (United States)

    Wang, Hao; Sun, Pengfei; Cong, Shan; Wu, Jiang; Gao, Lijun; Wang, Yun; Dai, Xiao; Yi, Qinghua; Zou, Guifu

    2016-12-01

    Considering the environment protection, "green" materials are increasingly explored for photovoltaics. Here, we developed a kind of quantum dots solar cell based on nitrogen-doped carbon dots. The nitrogen-doped carbon dots were prepared by direct pyrolysis of citric acid and ammonia. The nitrogen-doped carbon dots' excitonic absorption depends on the N-doping content in the carbon dots. The N-doping can be readily modified by the mass ratio of reactants. The constructed "green" nitrogen-doped carbon dots solar cell achieves the best power conversion efficiency of 0.79 % under AM 1.5 G one full sun illumination, which is the highest efficiency for carbon dot-based solar cells.

  4. Mid-Infrared Quantum-Dot Quantum Cascade Laser: A Theoretical Feasibility Study

    Directory of Open Access Journals (Sweden)

    Stephan Michael

    2016-05-01

    Full Text Available In the framework of a microscopic model for intersubband gain from electrically pumped quantum-dot structures we investigate electrically pumped quantum-dots as active material for a mid-infrared quantum cascade laser. Our previous calculations have indicated that these structures could operate with reduced threshold current densities while also achieving a modal gain comparable to that of quantum well active materials. Here, we study the influence of two important quantum-dot material parameters, namely inhomogeneous broadening and quantum-dot sheet density, on the performance of a proposed quantum cascade laser design. In terms of achieving a positive modal net gain, a high quantum-dot density can compensate for moderately high inhomogeneous broadening, but at a cost of increased threshold current density. However, by minimizing quantum-dot density with presently achievable inhomogeneous broadening and total losses, significantly lower threshold densities than those reported in quantum-well quantum-cascade lasers are predicted by our theory.

  5. Comprehensive identification of protein substrates of the Dot/Icm type IV transporter of Legionella pneumophila.

    Directory of Open Access Journals (Sweden)

    Wenhan Zhu

    2011-03-01

    Full Text Available A large number of proteins transferred by the Legionella pneumophila Dot/Icm system have been identified by various strategies. With no exceptions, these strategies are based on one or more characteristics associated with the tested proteins. Given the high level of diversity exhibited by the identified proteins, it is possible that some substrates have been missed in these screenings. In this study, we took a systematic method to survey the L. pneumophila genome by testing hypothetical orfs larger than 300 base pairs for Dot/Icm-dependent translocation. 798 of the 832 analyzed orfs were successfully fused to the carboxyl end of β-lactamase. The transfer of the fusions into mammalian cells was determined using the β-lactamase reporter substrate CCF4-AM. These efforts led to the identification of 164 proteins positive in translocation. Among these, 70 proteins are novel substrates of the Dot/Icm system. These results brought the total number of experimentally confirmed Dot/Icm substrates to 275. Sequence analysis of the C-termini of these identified proteins revealed that Lpg2844, which contains few features known to be important for Dot/Icm-dependent protein transfer can be translocated at a high efficiency. Thus, our efforts have identified a large number of novel substrates of the Dot/Icm system and have revealed the diverse features recognizable by this protein transporter.

  6. Adiabatic pumping through interacting quantum dots

    OpenAIRE

    Splettstoesser, Janine; Governale, Michele; König, Jürgen; Fazio, Rosario

    2005-01-01

    We present a general formalism to study adiabatic pumping through interacting quantum dots. We derive a formula that relates the pumped charge to the local, instantaneous Green function of the dot. This formula is then applied to the infinite-U Anderson model both for weak and strong tunnel-coupling strengths.

  7. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    We have produced GaAs-based quantum-dot edge-emitting lasers operating at 1.16 mu m with record-low transparency current, high output power, and high internal quantum efficiencies. We have also realized GaAs-based quantum-dot lasers emitting at 1.3 mu m, both high-power edge emitters and low...

  8. Thick-shell nanocrystal quantum dots

    Science.gov (United States)

    Hollingsworth, Jennifer A [Los Alamos, NM; Chen, Yongfen [Eugene, OR; Klimov, Victor I [Los Alamos, NM; Htoon, Han [Los Alamos, NM; Vela, Javier [Los Alamos, NM

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  9. Optical Properties of Semiconductor Quantum Dots

    NARCIS (Netherlands)

    Perinetti, U.

    2011-01-01

    This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots

  10. Quantum Dots Coupled to a Superconductor

    DEFF Research Database (Denmark)

    Jellinggaard, Anders Robert

    are tuned electrostatically. This includes tuning the odd occupation of the dot through a quantum phase transition, where it forms a singlet with excitations in the superconductor. We detail the fabrication of these bottom gated devices, which additionally feature ancillary sensor dots connected...

  11. Effect of temperature on quantum dots

    Indian Academy of Sciences (India)

    MAHDI AHMADI BORJI

    2017-07-12

    Jul 12, 2017 ... applications. Quantum dot semiconductor lasers, due to the discrete density of states, low threshold current and temperature dependence, high optical gain and quan- tum efficiency and high modulation speed, ... elastic properties of neighbour materials, lattice mis- match, and geometry of the quantum dot ...

  12. Surround-gated vertical nanowire quantum dots

    NARCIS (Netherlands)

    Van Weert, M.H.M.; Den Heijer, M.; Van Kouwen, M.P.; Algra, R.E.; Bakkers, E.P.A.M.; Kouwenhoven, L.P.; Zwiller, V.

    2010-01-01

    We report voltage dependent photoluminescence experiments on single indium arsenide phosphide (InAsP) quantum dots embedded in vertical surround-gated indium phosphide (InP) nanowires. We show that by tuning the gate voltage, we can access different quantum dot charge states. We study the

  13. Optical studies of capped quantum dots

    NARCIS (Netherlands)

    Wuister, S.F.

    2005-01-01

    This thesis describes the synthesis and spectroscopy of CdSe and CdTe semiconductor quantum dots (QDs). The first chapter gives an introduction into the unique size dependent properties of semiconductor quantum dots. Highly luminescent QDs of CdSe and CdTe were prepared via a high temperature method

  14. Many electron effects in semiconductor quantum dots

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 26; Issue 1. Many electron effects in ... Semiconductor quantum dots (QDs) exhibit shell structures, very similar to atoms. Termed as 'artificial atoms' by some, ... Our calculations have been performed in a three-dimensional quantum dot. We have carried out a study of ...

  15. Positive effects of resistant starch supplementation on bowel function in healthy adults: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Shen, Deqiang; Bai, Hao; Li, Zhaoping; Yu, Yue; Zhang, Huanhuan; Chen, Liyong

    2017-03-01

    Animal experimental studies have found that resistant starch can significantly improve bowel function, but the outcomes are mixed while conducting human studies. Thus, we conducted a systematic review and meta-analysis of randomized controlled trials to evaluate the relationship between resistant starch supplementation and large intestinal function. Three electronic databases (PubMed, Embase, Scopus) were searched to identify eligible studies. The standardized mean difference (SMD) or weighted mean difference (WMD) was calculated using a fixed-effects model or a random-effects model. The pooled findings revealed that resistant starch significantly increased fecal wet weight (WMD 35.51 g/d, 95% CI 1.21, 69.82) and butyrate concentration (SMD 0.61, 95% CI 0.32, 0.89). Also, it significantly reduced fecal PH (WMD -0.19, 95% CI -0.35, -0.03), but the increment of defecation frequency were not statistically significant (WMD 0.04stools/g, 95% CI -0.08, 0.16). To conclude, our study found that resistant starch elicited a beneficial effect on the function of large bowel in healthy adults.[Formula: see text].

  16. Coherent control of quantum dots

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Lodahl, Peter; Hvam, Jørn Märcher

    In recent years much effort has been devoted to the use of semiconductor quantum dotsystems as building blocks for solid-state-based quantum logic devices. One importantparameter for such devices is the coherence time, which determines the number ofpossible quantum operations. From earlier...... measurements the coherence time of the selfassembledquantum dots (QDs) has been reported to be limited by the spontaneousemission rate at cryogenic temperatures1.In this project we propose to alter the coherence time of QDs by taking advantage of arecent technique on modifying spontaneous emission rates...

  17. Controlling Goos-Hänchen shift in a negative-refractive-index quantum-dot nanostructure

    Science.gov (United States)

    Jamshidnejad, M.; Jabbari, M.; Ahmadi Sangachin, Elnaz; Solookinejad, Gh

    2017-08-01

    The Goos-Hänchen (GH) shifts due to a negative refractive index in double quantum-dot nanostructures are discussed in reflected and transmitted light beams. It is realized that positive and negative GH shifts can be attained in the negative-refraction medium due to the presence of the indirect incoherent pumping field and electron tunneling. We found that the lateral shift at the fixed incident angle can be enhanced (positive or negative) under suitable conditions on the control field, without changing the structure of the cavity. We hope that our proposed configuration may be helpful for future all-optical sensor devices based on quantum-dot nanostructures.

  18. Exciton in closed and opened quantum dot

    Directory of Open Access Journals (Sweden)

    M.V.Tkach

    2007-01-01

    Full Text Available The theory of exciton spectrum in spherically symmetric states for the three- shell closed spherical quantum dot is proposed. The evolution of the exciton spectrum while varying the outer well thickness from zero (stationary spectrum of single closed spherical quantum dot to infinity (quasistationary spectrum of a single open spherical quantum dot is investigated. The mechanism of damping (semiwidth of quasistationary states due to the redistribution over the energy levels of probability of exciton location in the space of two inner shells of nanosystem is studied. It is shown that the three shell closed spherical quantum dot of a rather big thickness of the outer well quite sufficiently and exactly reflects the basic properties of the quasistationary exciton spectrum in a single open spherical quantum dot.

  19. Biocompatible Quantum Dots for Biological Applications

    Science.gov (United States)

    Rosenthal, Sandra J.; Chang, Jerry C.; Kovtun, Oleg; McBride, James R.; Tomlinson, Ian D.

    2011-01-01

    Semiconductor quantum dots are quickly becoming a critical diagnostic tool for discerning cellular function at the molecular level. Their high brightness, long-lasting, sizetunable, and narrow luminescence set them apart from conventional fluorescence dyes. Quantum dots are being developed for a variety of biologically oriented applications, including fluorescent assays for drug discovery, disease detection, single protein tracking, and intracellular reporting. This review introduces the science behind quantum dots and describes how they are made biologically compatible. Several applications are also included, illustrating strategies toward target specificity, and are followed by a discussion on the limitations of quantum dot approaches. The article is concluded with a look at the future direction of quantum dots. PMID:21276935

  20. Biocompatible quantum dots for biological applications.

    Science.gov (United States)

    Rosenthal, Sandra J; Chang, Jerry C; Kovtun, Oleg; McBride, James R; Tomlinson, Ian D

    2011-01-28

    Semiconductor quantum dots are quickly becoming a critical diagnostic tool for discerning cellular function at the molecular level. Their high brightness, long-lasting, size-tunable, and narrow luminescence set them apart from conventional fluorescence dyes. Quantum dots are being developed for a variety of biologically oriented applications, including fluorescent assays for drug discovery, disease detection, single protein tracking, and intracellular reporting. This review introduces the science behind quantum dots and describes how they are made biologically compatible. Several applications are also included, illustrating strategies toward target specificity, and are followed by a discussion on the limitations of quantum dot approaches. The article is concluded with a look at the future direction of quantum dots. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Hole spin relaxation in quantum dots

    Science.gov (United States)

    Woods, L. M.; Reinecke, T. L.; Kotlyar, R.

    2004-03-01

    We present results for relaxation of the spin of a hole in a cylindrical quantum dot due to acoustic phonon assisted spin flips at low temperatures with an applied magnetic field. The hole dispersion is calculated by numerical diagonalization of the Luttinger Hamiltonian and applying perturbation theory with respect to the magnetic field, and the hole-phonon coupling is described by the Bir-Pikus Hamiltonian. We find that the decoherence time for hole spins for dots ≲20 nm is on the order of 10-8 s. This is several orders smaller than the decoherence time due to phonon assisted processes for electron spins in similar dots and is comparable to the total decoherence time of an electron spin in a quantum dot, which is controlled by the hyperfine interaction with nuclei. We obtain the dependence of the relaxation rate of the hole spin on dot size and hole mass.

  2. Effect of Omega-3 Fatty Acids on Depressive Symptoms in HIV-Positive Individuals: A Randomized, Placebo-Controlled Clinical Trial.

    Science.gov (United States)

    Ravi, Saeedeh; Khalili, Hossein; Abbasian, Ladan; Arbabi, Mohammad; Ghaeli, Padideh

    2016-10-01

    The antidepressant effect of omega-3 fatty acids has been described in the non-HIV population. The effect of omega-3 fatty acid supplementation on the mood status of HIV-positive patients has not been evaluated yet. In this study, the effect of omega-3 fatty acids on depressive symptoms was evaluated in HIV-positive individuals. A total of 100 HIV-positive patients with Beck Depression Score ≥16, were assigned to receive either omega-3 fatty acids or placebo twice daily for 8 weeks. Depressive symptoms of each participant were evaluated at baseline (month 0) and at the end of months 1 and 2 of the study. Beck Depression Inventory Second Edition, depression subscale of the Hospital Anxiety and Depression Scale, and Patient Health Questionnaire were used for assessment of depressive symptoms. Reduction in mean ± SD of all depression scores during the study period was statistically significant within the omega-3 group and when compared with the placebo group (for both comparisons, P omega-3 and the placebo group, respectively, experienced mild gastrointestinal problems, but the incidence of adverse drug reactions related to the interventions was not statistically different between the groups (P = 0.09). Omega-3 fatty acids improved depressive symptoms in HIV-positive individuals without any significant adverse reaction. © The Author(s) 2016.

  3. Sexual function and obstructive sleep apnea-hypopnea : A randomized clinical trial evaluating the effects of oral-appliance and continuous positive airway pressure therapy

    NARCIS (Netherlands)

    Hoekema, Aarnoud; Stel, Anna-Lucia; Stegenga, Boudewijn; van der Hoeven, Johannes H.; Wijkstra, Peter J.; van Driel, Mels F.; de Bont, Lambert G. M.

    Introduction. The obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with sexual dysfunction. Although successful treatment with continuous positive airway pressure (CPAP) has been demonstrated to improve sexual function, the effects of oral-appliance therapy are unknown. Aim. The aims

  4. Effect of Positive Airway Pressure on Cardiovascular Outcomes in Coronary Artery Disease Patients with Non-Sleepy Obstructive Sleep Apnea : The RICCADSA Randomized Controlled Trial

    NARCIS (Netherlands)

    Peker, Yüksel; Glantz, Helena; Eulenburg, Christine; Wegscheider, Karl; Herlitz, Johan; Thunström, Erik

    2016-01-01

    RATIONALE: Obstructive sleep apnea is common in patients with coronary artery disease, many of whom do not report daytime sleepiness. First-line treatment for symptomatic obstructive sleep apnea is continuous positive airway pressure, but its value in patients without daytime sleepiness is

  5. Acupuncture versus venlafaxine for the management of vasomotor symptoms in patients with hormone receptor-positive breast cancer: a randomized controlled trial.

    Science.gov (United States)

    Walker, Eleanor M; Rodriguez, Alba I; Kohn, Beth; Ball, Ronald M; Pegg, Jan; Pocock, Jeffrey R; Nunez, Ramon; Peterson, Ed; Jakary, Susan; Levine, Robert A

    2010-02-01

    Vasomotor symptoms are common adverse effects of antiestrogen hormone treatment in conventional breast cancer care. Hormone replacement therapy is contraindicated in patients with breast cancer. Venlafaxine (Effexor), the therapy of choice for these symptoms, has numerous adverse effects. Recent studies suggest acupuncture may be effective in reducing vasomotor symptoms in menopausal women. This randomized controlled trial tested whether acupuncture reduces vasomotor symptoms and produces fewer adverse effects than venlafaxine. Fifty patients were randomly assigned to receive 12 weeks of acupuncture (n = 25) or venlafaxine (n = 25) treatment. Health outcomes were measured for up to 1 year post-treatment. Both groups exhibited significant decreases in hot flashes, depressive symptoms, and other quality-of-life symptoms, including significant improvements in mental health from pre- to post-treatment. These changes were similar in both groups, indicating that acupuncture was as effective as venlafaxine. By 2 weeks post-treatment, the venlafaxine group experienced significant increases in hot flashes, whereas hot flashes in the acupuncture group remained at low levels. The venlafaxine group experienced 18 incidences of adverse effects (eg, nausea, dry mouth, dizziness, anxiety), whereas the acupuncture group experienced no negative adverse effects. Acupuncture had the additional benefit of increased sex drive in some women, and most reported an improvement in their energy, clarity of thought, and sense of well-being. Acupuncture appears to be equivalent to drug therapy in these patients. It is a safe, effective and durable treatment for vasomotor symptoms secondary to long-term antiestrogen hormone use in patients with breast cancer.

  6. Electron transport in quantum dots

    CERN Document Server

    2003-01-01

    When I was contacted by Kluwer Academic Publishers in the Fall of 200 I, inviting me to edit a volume of papers on the issue of electron transport in quantum dots, I was excited by what I saw as an ideal opportunity to provide an overview of a field of research that has made significant contributions in recent years, both to our understanding of fundamental physics, and to the development of novel nanoelectronic technologies. The need for such a volume seemed to be made more pressing by the fact that few comprehensive reviews of this topic have appeared in the literature, in spite of the vast activity in this area over the course of the last decade or so. With this motivation, I set out to try to compile a volume that would fairly reflect the wide range of opinions that has emerged in the study of electron transport in quantum dots. Indeed, there has been no effort on my part to ensure any consistency between the different chapters, since I would prefer that this volume instead serve as a useful forum for the...

  7. Chiral quantum dot based materials

    Science.gov (United States)

    Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii

    2014-05-01

    Recently, the use of stereospecific chiral stabilising molecules has also opened another avenue of interest in the area of quantum dot (QD) research. The main goal of our research is to develop new types of technologically important quantum dot materials containing chiral defects, study their properties and explore their applications. The utilisation of chiral penicillamine stabilisers allowed the preparation of new water soluble white emitting CdS quantum nanostructures which demonstrated circular dichroism in the band-edge region of the spectrum. It was also demonstrated that all three types of QDs (D-, L-, and Rac penicillamine stabilised) show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. In this work the chiral CdS based quantum nanostructures have also been doped by copper metal ions and new chiral penicilamine stabilized CuS nanoparticles have been prepared and investigated. It was found that copper doping had a strong effect at low levels in the synthesis of chiral CdS nanostructures. We expect that this research will open new horizons in the chemistry of chiral nanomaterials and their application in biotechnology, sensing and asymmetric synthesis.

  8. Quantum dots: lasers and amplifiers

    CERN Document Server

    Bimberg, D

    2003-01-01

    Continuous wave room-temperature output power of approx 3 W for edge emitters and of 1.2 mW for vertical-cavity surface-emitting lasers is realized for GaAs-based devices using InAs quantum dots (QDs) operating at 1.3 mu m. Characteristic temperatures up to 170 K below 330 K are realized. Simultaneously, differential efficiency exceeds 80% for these devices. Lasers emitting up to 12 W at 1140-1160 nm are useful as pump sources for Tm sup 3 sup + -doped fibres for frequency up-conversion to 470 nm. Both types of lasers show transparency current densities of 6 A cm sup - sup 2 per dot layer, eta sub i sub n sub t = 98% and alpha sub i around 1.5 cm sup - sup 1. Long operation lifetimes (above 3000 h at 50 deg C heatsink temperature at 1.5 W CW) and improved radiation hardness as compared to quantum well (QW) devices are manifested. Cut-off frequencies of about 10 GHz at 1100 nm and 6 GHz at 1300 nm and low alpha factors resulting in reduced filamentation and improved M sup 2 values in single-mode operation are ...

  9. Enhancing the Emotional and Social Skills of the Youth to Promote their Wellbeing and Positive Development: A Systematic Review of Universal School-based Randomized Controlled Trials.

    Science.gov (United States)

    Sancassiani, Federica; Pintus, Elisa; Holte, Arne; Paulus, Peter; Moro, Maria Francesca; Cossu, Giulia; Angermeyer, Matthias C; Carta, Mauro Giovanni; Lindert, Jutta

    2015-01-01

    The acquisition of social and emotional skills is associated with positive youth development, character education, healthy lifestyle behaviours, reduction in depression and anxiety, conduct disorders, violence, bullying, conflict, and anger. School-based interventions aimed to enhance these skills go beyond a problem-focused approach to embrace a more positive view of health; they could also improve the youth's wellbeing. To describe the main features and to establish the effectiveness of universal school-based RCTs for children and the youth, aimed to promote their psychosocial wellbeing, positive development, healthy lifestyle behaviours and/or academic performance by improving their emotional and social skills. Systematic review by searching for relevant papers in PubMed/Medline with the following key words: "mental health" OR "wellbeing" OR "health promotion" OR "emotional learning" OR "social learning" OR "emotional and social learning" OR "positive youth development" OR "life skills" OR "life skills training" AND "school". Interval was set from January 2000 to April 2014. 1,984 papers were identified through the search. Out of them 22 RCTs were included. While most interventions were characterized by a whole-school approach and SAFE practices, few studies only used standardized measures to assess outcomes, or had collected follow-up data after ≥ 6 months. The results of all these trials were examined and discussed. Universal school-based RCTs to enhance emotional and social skills showed controversial findings, due to some methodological issues mainly. Nevertheless they show promising outcomes that are relatively far-reaching for children and youth wellbeing and therefore are important in the real world.

  10. Randomized clinical trial comparing ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows.

    Science.gov (United States)

    Cortinhas, Cristina Simões; Tomazi, Tiago; Zoni, Mário Sérgio Ferreira; Moro, Elio; Veiga Dos Santos, Marcos

    2016-07-01

    The objective of this study was to compare ceftiofur hydrochloride with a positive control protocol for intramammary treatment of nonsevere clinical mastitis in dairy cows. A total of 264 clinical mastitis cases on 11 commercial dairy farms were treated with intramammary infusions, once a day for 4 d using 1 of 2 treatments: (1) ceftiofur hydrochloride 125mg; or (2) control: tetracycline 200mg + neomycin 250mg + bacitracin 28mg + prednisolone 10mg. Streptococcus agalactiae was the most frequently isolated gram-positive pathogen from clinical mastitis, followed by Staphylococcus aureus. Klebsiella spp. and Escherichia coli were the most isolated gram-negative bacteria from clinical mastitis. No significant differences were observed between treatments regarding the overall clinical cure, bacteriological cure, and new infection. No effect of treatment regimen was observed when the bacterial group (gram-positive vs. gram-negative) was evaluated. The overall clinical cure was 0.79 for ceftiofur-treated cows and 0.74 for control-treated cows, whereas the overall bacteriological cure was 0.79 for ceftiofur-treated cows and 0.76 for control-treated cows. Furthermore, the new intramammary infection was 0.10 for cows treated with ceftiofur and 0.11 for cows treated with control. In conclusion, the use of intramammary ceftiofur hydrochloride for treatment of nonsevere clinical mastitis has similar efficacy as a treatment regimen with a combination of antimicrobial agents (tetracycline + neomycin + bacitracin). Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Peptide dot immunoassay and immunoblotting: electroblotting from aluminum thin-layer chromatography plates and isoelectric focusing gels to activated nitrocellulose

    DEFF Research Database (Denmark)

    Bjerrum, O.J.; Holm, A.; Lauritzen, Edgar

    1993-01-01

    Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins......Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins...

  12. Online attention modification for social anxiety disorder: replication of a randomized controlled trial.

    Science.gov (United States)

    Carleton, R Nicholas; Teale Sapach, Michelle J N; Oriet, Chris; LeBouthillier, Daniel M

    2017-01-01

    Social anxiety disorder (SAD) models posit vigilance for external social threat cues and exacerbated self-focused attention as key in disorder development and maintenance. Evidence indicates a modified dot-probe protocol may reduce symptoms of SAD; however, the efficacy when compared to a standard protocol and long-term maintenance of treatment gains remains unclear. Furthermore, the efficacy of such protocols on SAD-related constructs remains relatively unknown. The current investigation clarified these associations using a randomized control trial replicating and extending previous research. Participants with SAD (n = 113; 71% women) were randomized to complete a standard (i.e. control) or modified (i.e. active) dot-probe protocol consisting of 15-min sessions twice weekly for four weeks. Self-reported symptoms were measured at baseline, post-treatment, and 4-month and 8-month follow-ups. Hierarchical linear modeling indicated significant self-reported reductions in symptoms of social anxiety, fear of negative evaluation, trait anxiety, and depression, but no such reductions in fear of positive evaluation. Symptom changes did not differ based on condition and were maintained at 8-month follow-up. Attentional biases during the dot-probe task were not related to symptom change. Overall, our results replicate support for the efficacy of both protocols in reducing symptoms of SAD and specific related constructs, and suggest a role of exposure, expectancy, or practice effects, rather than attention modification, in effecting such reductions. The current results also support distinct relationships between fears of negative and positive evaluation and social anxiety. Further research focused on identifying the mechanisms of change in attention modification protocols appears warranted.

  13. Direct measurement of the beam deflection angle using the axial B-dot field

    Directory of Open Access Journals (Sweden)

    Xiaozhong He

    2011-05-01

    Full Text Available Beam position monitors are an important diagnostics tool for particle accelerator operation and related beam dynamics research. The measurement of the beam deflection angle, or moving direction of a charged particle beam with respect to the beam pipe axis, can provide useful additional information. Beam monitors sensitive to the beam’s azimuthal B-dot field (sometimes referred as B dots are used to measure the displacement (position of the beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. Similarly, a dipole term of the axial magnetic field will be generated by the beam moving in a direction not parallel to the axis of the beam pipe. In this paper, a new method using the axial B-dot field is presented to measure the beam deflection angle directly, including the theoretical background. Simulations using the MAFIA numerical code have been performed, demonstrating a good agreement to the new established analytical model.

  14. Self-assembly of vertically aligned quantum ring-dot structure by Multiple Droplet Epitaxy

    Science.gov (United States)

    Elborg, Martin; Noda, Takeshi; Mano, Takaaki; Kuroda, Takashi; Yao, Yuanzhao; Sakuma, Yoshiki; Sakoda, Kazuaki

    2017-11-01

    We successfully grow vertically aligned quantum ring-dot structures by Multiple Droplet Epitaxy technique. The growth is achieved by depositing GaAs quantum rings in a first droplet epitaxy process which are subsequently covered by a thin AlGaAs barrier. In a second droplet epitaxy process, Ga droplets preferentially position in the center indentation of the ring as well as attached to the edge of the ring in [ 1 1 bar 0 ] direction. By designing the ring geometry, full selectivity for the center position of the ring is achieved where we crystallize the droplets into quantum dots. The geometry of the ring and dot as well as barrier layer can be controlled in separate growth steps. This technique offers great potential for creating complex quantum molecules for novel quantum information technologies.

  15. Inter-dot coupling effects on transport through correlated parallel ...

    Indian Academy of Sciences (India)

    Transport through symmetric parallel coupled quantum dot system has been studied, using non-equilibrium Green function formalism. The inter-dot tunnelling with on-dot and inter-dot Coulomb repulsion is included. The transmission coefficient and Landaur–Buttiker like current formula are shown in terms of internal states ...

  16. Innovative interventions to promote positive dental health behaviors and prevent dental caries in preschool children: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Gao, Xiaoli; Lo, Edward Chin Man; McGrath, Colman; Ho, Samuel Mun Yin

    2013-04-30

    Dental caries (tooth decay) is highly prevalent and is largely attributable to unhealthy self-care behaviors (diet and oral hygiene). The conventional (health) education (CE), focusing on disseminating information and giving normative advice, often fails to achieve sustained behavioral changes. This study incorporates two innovative elements into CE: (i) motivational interviewing (MI), a client-centered counseling for changing behaviors, and (ii) an interactive caries risk assessment (RA) tool, which is devised to facilitate dental counseling and may enhance MI in several ways. Through a randomized, controlled, evaluator-blinded trial, three intervention schemes (CE, CE+MI, and CE+MI+RA) will be compared for their effectiveness in eliciting dentally healthy behaviors and preventing caries in preschool children. This study targets 3-year-old children who are at a critical stage for embedding health habits. Children with unfavorable dental behaviors (insufficient toothbrushing and/or frequent snacking) and their parents will be recruited from 12 participating kindergartens. Parent-child dyads (n=690) will be randomly assigned into three groups. In the first group (CE), oral health information and advice will be delivered to parents through pamphlets. In the second group (CE+MI), in addition to the pamphlets, individual MI counseling with each parent will be performed by one of two trained dental hygienists. In the third group (CE+MI+RA), besides pamphlets and MI, interactive RA will be integrated into MI to motivate parents and facilitate their informed decision making and goal planning. At baseline and after 12 and 24 months, parents will complete a questionnaire and children will undergo a dental examination. The effectiveness of the intervention schemes will be compared over 12 and 24 months. The primary outcome will be caries increment in children and proportion of caries-free children. Secondary outcomes will be changes in parental efficacy for protecting

  17. Positive effect of mushrooms substituted for meat on body weight, body composition, and health parameters. A 1-year randomized clinical trial.

    Science.gov (United States)

    Poddar, Kavita H; Ames, Meghan; Hsin-Jen, Chen; Feeney, Mary Jo; Wang, Youfa; Cheskin, Lawrence J

    2013-12-01

    Reducing energy density (ED) of the diet is an important strategy for controlling obesity. This 1-year, randomized clinical trial examined the effect of substituting mushrooms for red meat ('mushroom diet'), compared to a standard diet ('meat diet'), on weight loss and maintenance among 73 obese adults (64 women, 9 men). The subjects completed anthropometric measurements and 7-day food records four times during a standardized weight loss and maintenance regimen. At the end of the 1-year trial, compared to participants on the standard diet, participants on the mushroom diet (n=36) reported lower intakes of energy (mean ± [SE]=-123 ± 113 kcals) and fat (-4.25 ± 6.88 g), lost more pounds and percentage body weight (-7.03 ± 3.34 lbs, 3.6%), achieved lower body mass index (-1.53 ± 0.36), waist circumference (-2.6 ± 3.5 in.) and percent total body fat (-0.85 ± 0.53), and had lower systolic and diastolic pressure (-7.9 and -2.5 mmHg); their lipid profile and inflammatory markers also improved. After initial weight loss, subjects following the mushroom diet maintained that loss well. Those who completed the full 12-month trial still weighed a mean of 7 lbs less than baseline. Thus, encouraging adults to substitute mushrooms for red meat was a useful strategy for enhancing weight loss, weight maintenance, and health parameters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The position of a written document in preoperative information for pediatric surgery: A randomized controlled trial on parental anxiety, knowledge and satisfaction.

    Science.gov (United States)

    Landier, M; Villemagne, T; Le Touze, A; Braïk, K; Meignan, P; Cook, A R; Morel, B; Lardy, H; Binet, A

    2017-04-21

    Preoperative information is a legal and ethical obligation. Very little studies have evaluated the preoperative information method in pediatrics. Having a child operated on is stressful for the parents. Improving information is a way to lower their anxiety. Our study aims to measure the impact of a leaflet, which supports spoken information on parental anxiety, the comprehension-memorization of the information and their satisfaction. Prospective study including 178 patients of outpatient surgery, randomized in two groups: spoken information versus spoken information supported by a leaflet, which is then handed out to the parents. The messages were identical: physiopathology, risks without treatment, surgical technique and its possible complications, description of the hospitalization day, and postoperative care. Parental evaluation was made with self-questionnaires after the preoperative consultation, then on the day of surgery. At each moment we evaluated the level of anxiety, satisfaction of information quality and the comprehension-memorization of the data. Written information significantly improves the scores of comprehension-memorization, parental satisfaction and significantly decreases the level of anxiety. Significant impact of the written document as communication support in pediatric surgery, validating the method and encouraging it to be generalized to other pediatric surgery acts. Level I. Prognosis study. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Ribociclib with letrozole vs letrozole alone in elderly patients with hormone receptor-positive, HER2-negative breast cancer in the randomized MONALEESA-2 trial.

    Science.gov (United States)

    Sonke, Gabe S; Hart, Lowell L; Campone, Mario; Erdkamp, Frans; Janni, Wolfgang; Verma, Sunil; Villanueva, Cristian; Jakobsen, Erik; Alba, Emilio; Wist, Erik; Favret, Anne M; Bachelot, Thomas; Hegg, Roberto; Wheatley-Price, Paul; Souami, Farida; Sutradhar, Santosh; Miller, Michelle; Germa, Caroline; Burris, Howard A

    2017-10-22

    Determine the efficacy and safety of first-line ribociclib plus letrozole in elderly patients with HR+, HER2- advanced breast cancer. 668 postmenopausal women with HR+, HER2- advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021); 295 patients were aged ≥ 65 years. Patients were randomized to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was PFS, which was evaluated in elderly (≥ 65 years) and younger ( 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm in both subgroups; most events were grade 1/2. In elderly patients, grade 1/2 anemia and fatigue were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm and discontinuation rates were similar in both arms. Addition of ribociclib to letrozole is a valid therapeutic option for elderly patients with HR+, HER2- advanced breast cancer in the first-line setting.

  20. Self-declared stock ownership and association with positive trial outcome in randomized controlled trials with binary outcomes published in general medical journals: a cross-sectional study.

    Science.gov (United States)

    Falk Delgado, Alberto; Falk Delgado, Anna

    2017-07-26

    Describe the prevalence and types of conflicts of interest (COI) in published randomized controlled trials (RCTs) in general medical journals with a binary primary outcome and assess the association between conflicts of interest and favorable outcome. Parallel-group RCTs with a binary primary outcome published in three general medical journals during 2013-2015 were identified. COI type, funding source, and outcome were extracted. Binomial logistic regression model was performed to assess association between COI and funding source with outcome. A total of 509 consecutive parallel-group RCTs were included in the study. COI was reported in 74% in mixed funded RCTs and in 99% in for-profit funded RCTs. Stock ownership was reported in none of the non-profit RCTs, in 7% of mixed funded RCTs, and in 50% of for-profit funded RCTs. Mixed-funded RCTs had employees from the funding company in 11% and for-profit RCTs in 76%. Multivariable logistic regression revealed that stock ownership in the funding company among any of the authors was associated with a favorable outcome (odds ratio = 3.53; 95% confidence interval = 1.59-7.86; p company among authors is associated with a favorable outcome.

  1. Efficacy and safety of trastuzumab emtansine (T-DM1) in the treatment of HER2-positive metastatic breast cancer (MBC): a meta-analysis of randomized controlled trial.

    Science.gov (United States)

    Yan, Hongjing; Yu, Kewei; Zhang, Kaile; Liu, Linxia; Li, Yue

    2017-11-24

    Trastuzumab emtansine (T-DM1), an antibody-drug conjugate against human epidermal growth factor receptor 2 (HER2), has been used in the treatment of patients with HER2-positive metastatic breast cancer (MBC). We conducted a meta-analysis to evaluate the efficacy and toxicity of T-DM1 for the treatment of patients with HER2-positive MBC. Randomized controlled trials (RCTs), published in Pubmed, Embase, and Web of Science were systematically reviewed to assess the survival benefits and toxicity profile of HER2-positive patients with MBC who were treated with T-DM1. Outcomes included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and toxicities. Results were expressed as the hazard ratio (HR) with 95% confidence intervals (CIs). A total of 5 RCTs involving 3,720 patients met the inclusion criteria and were included in this meta-analysis. T-DM1 significantly prolonged PFS (HR = 0.73, 95% CI: 0.61, 0.86; P HER2 therapies. Based on the current evidence, T-DM1 significantly prolonged PFS and OS with a tolerated toxicity than other anti-HER2 therapies in patients with HER2-positive MBC. These findings confirm the use of T-DM1 for the treatment of patients with HER2-positive MBC. Further well-designed, multi-center RCTs needed to identify these findings.

  2. Curcumin Quantum Dots Mediated Degradation of Bacterial Biofilms.

    Science.gov (United States)

    Singh, Ashish K; Prakash, Pradyot; Singh, Ranjana; Nandy, Nabarun; Firdaus, Zeba; Bansal, Monika; Singh, Ranjan K; Srivastava, Anchal; Roy, Jagat K; Mishra, Brahmeshwar; Singh, Rakesh K

    2017-01-01

    Bacterial biofilm has been reported to be associated with more than 80% of bacterial infections. Curcumin, a hydrophobic polyphenol compound, has anti-quorum sensing activity apart from having antimicrobial action. However, its use is limited by its poor aqueous solubility and rapid degradation. In this study, we attempted to prepare quantum dots of the drug curcumin in order to achieve enhanced solubility and stability and investigated for its antimicrobial and antibiofilm activity. We utilized a newer two-step bottom up wet milling approach to prepare Curcumin Quantum Dots (CurQDs) using acetone as a primary solvent. Minimum inhibitory concentration against select Gram-positive and Gram-negative bacteria was performed. The antibiofilm assay was performed at first using 96-well tissue culture plate and subsequently validated by Confocal Laser Scanning Microscopy. Further, biofilm matrix protein was isolated using formaldehyde sludge and TCA/Acetone precipitation method. Protein extracted was incubated with varying concentration of CurQDs for 4 h and was subjected to SDS-PAGE. Molecular docking study was performed to observe interaction between curcumin and phenol soluble modulins as well as curli proteins. The biophysical evidences obtained from TEM, SEM, UV-VIS, fluorescence, Raman spectroscopy, and zeta potential analysis confirmed the formation of curcumin quantum dots with increased stability and solubility. The MICs of curcumin quantum dots, as observed against both select gram positive and negative bacterial isolates, was observed to be significantly lower than native curcumin particles. On TCP assay, Curcumin observed to be having antibiofilm as well as biofilm degrading activity. Results of SDS-PAGE and molecular docking have shown interaction between biofilm matrix proteins and curcumin. The results indicate that aqueous solubility and stability of Curcumin can be achieved by preparing its quantum dots. The study also demonstrates that by sizing down the

  3. Investigation on DOT guided FMT: Whether the FMT image quality is robust to the priori DOT information?

    Science.gov (United States)

    Wang, Daifa; Bai, Jing

    2009-01-01

    The fluorescence molecular tomography (FMT) image quality could be improved significantly with reconstructed optical properties using diffuse optical tomography (DOT). However, different DOT algorithms and different constraint parameters usually lead to DOT images of obvious different image quality. In this paper, simulation experiment results demonstrate that the FMT image quality is robust to the great variation in DOT image quality.

  4. X-H{center_dot}{center_dot}{center_dot}{pi} and X-H{center_dot}{center_dot}{center_dot}N hydrogen bonds - Acetylene and hydrogen cyanide as proton acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Domagala, Malgorzata, E-mail: mdomagala@uni.lodz.pl [Department of Chemistry, University of Lodz, ul.Pomorska 149/153, 90-236 Lodz (Poland); Grabowski, Slawomir J., E-mail: slagra@uni.lodz.pl [Department of Chemistry, University of Lodz, ul.Pomorska 149/153, 90-236 Lodz (Poland)

    2009-09-18

    The hydrogen-bonded systems were considered where acetylene or hydrogen cyanide acts as a proton acceptor and different proton donating molecules are taken into account. The B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) calculations were performed for the systems considered; for HCN{center_dot}{center_dot}{center_dot}HF and C{sub 2}H{sub 2}{center_dot}{center_dot}{center_dot}HF complexes various levels of approximation were applied up to CCSD(T)/6-311++G(3df,3pd)//CCSD/6-311++G(3df,3pd). The Quantum Theory of 'Atoms in Molecules' (QTAIM) was also applied. It was found that {pi}-electrons of acetylene might act as the proton accepting centers and the found complex conformations are T-shaped ones. For hydrogen cyanide molecule the nitrogen atom acts as the proton acceptor center but not {pi}-electrons. The characteristics of the bond critical points were also considered for the analyzed interactions and numerous correlations were found between geometrical, energetic and QTAIM parameters. The decomposition of the interaction energy for the systems analyzed was also applied.

  5. Moment of inertia in elliptical quantum dots

    Science.gov (United States)

    Serra, Llorenç; Puente, Antonio; Lipparini, Enrico

    The moment of inertia of deformed quantum dots and its experimental relevance in relation to the dot spectroscopic features is theoretically investigated. A strong link to the low-energy orbital current mode that manifests in the magnetic dipole (M1) spectrum is stressed. The moment of inertia is obtained by solving the cranked Kohn-Sham equations within the local-spin-density approximation and the results discussed in comparison with the predictions of an analytical non-interacting model. The results as a function of deformation and size indicate that the existence of spin transitions in the dot ground state has an important effect on the moment of inertia.

  6. Odd triplet superconductivity in ultrasmall quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Stephan; Koenig, Juergen [Theoretische Physik, Universitaet Duisburg-Essen and CENIDE (Germany); Sothmann, Bjoern [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany)

    2016-07-01

    We report on the possibility to create odd frequency Cooper pairs in proximized interacting quantum dots attached to ferromagnetic leads. Spin blockade effects together with induced superconductivity allow electron pairs with same spin at different times to carry superconducting correlations. Besides the conventional finite singlet pairing amplitude on the dot, only odd frequency triplet pairing is possible here. This is in contrast to the double dot case. We demonstrate how the order parameter for odd-frequency triplet pairing as well as the differential Andreev conductance are influenced when tuning gate and/or bias voltages, the angle of magnetizations of the leads and the coupling to the nearby superconductor.

  7. Excitonic quasimolecules in nanosystems of quantum dots

    Science.gov (United States)

    Pokutnyi, Sergey I.

    2017-09-01

    The theory of excitonic quasimolecules (biexcitons) (formed of spatially separated electrons and holes) in a nanosystem that consists of semiconductor quantum dots synthesized in a borosilicate glass matrix is presented. It is shown that exciton quasimolecule formation is of a threshold character and is possible in nanosystem, if the spacing between the quantum dots surfaces is larger than a certain critical spacing. It was found that the binding energy of the singlet ground state of an exciton quasimolecule, consisting of two semiconductor quantum dots is a significant large values, larger than the binding energy of the biexciton in a semiconductor single crystal by almost two orders of magnitude.

  8. Fluorescent Quantum Dots for Biological Labeling

    Science.gov (United States)

    McDonald, Gene; Nadeau, Jay; Nealson, Kenneth; Storrie-Lomardi, Michael; Bhartia, Rohit

    2003-01-01

    Fluorescent semiconductor quantum dots that can serve as "on/off" labels for bacteria and other living cells are undergoing development. The "on/off" characterization of these quantum dots refers to the fact that, when properly designed and manufactured, they do not fluoresce until and unless they come into contact with viable cells of biological species that one seeks to detect. In comparison with prior fluorescence-based means of detecting biological species, fluorescent quantum dots show promise for greater speed, less complexity, greater sensitivity, and greater selectivity for species of interest. There are numerous potential applications in medicine, environmental monitoring, and detection of bioterrorism.

  9. Analysis list: DOT1L [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available DOT1L Pluripotent stem cell + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/DOT1...L.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/DOT1L.5.tsv http://dbarchive.biosc...iencedbc.jp/kyushu-u/hg19/target/DOT1L.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/DOT1L.Plu

  10. Parallel carbon nanotube quantum dots and their interactions

    OpenAIRE

    Goss K.; Leijnse M.; Smerat S.; Wegewijs M.R.; Schneider C.M.; Meyer C

    2012-01-01

    We present quantum transport measurements of interacting parallel quantum dots formed in the strands of a carbon nanotube rope. In this molecular quantum dot system, transport is dominated by one quantum dot, while additional resonances from parallel side dots appear, which exhibit a weak gate coupling. This differential gating effect provides a tunability of the quantum dot system with only one gate electrode and provides control over the carbon nanotube strand that carries the current. By t...

  11. Randomized controlled trial of a pictorial aid intervention for medication adherence among HIV-positive patients with comorbid diabetes or hypertension.

    Science.gov (United States)

    Monroe, A K; Pena, J S; Moore, R D; Riekert, K A; Eakin, M N; Kripalani, S; Chander, G

    2018-02-01

    As the HIV-infected population ages and the burden of chronic comorbidities increases, adherence to medications for HIV and diabetes and hypertension is crucial to improve outcomes. We pilot-tested a pictorial aid intervention to improve medication adherence for both HIV and common chronic conditions. Adult patients with HIV and diabetes (DM) and/or hypertension (HTN) attending a clinic for underserved patients and at risk for poor health outcomes were enrolled. Patients were randomized to receive either a pictorial aid intervention (a photographic representation of their medications, the indications, and the dosing schedule) or a standard clinic visit discharge medication list. Adherence to antiretroviral therapy (ART) for HIV and therapy for DM or HTN was compared. Predictors of ART adherence at baseline were determined using logistic regression. Medication adherence was assessed using medication possession ratio (MPR) for the 6-month interval before and after the intervention. Change in adherence by treatment group was compared by ANOVA. Among the 46 participants, there was a trend towards higher adherence to medications for HIV compared with medications for hypertension/diabetes (baseline median MPR for ART 0.92; baseline median MPR for the medication for the comorbid condition 0.79, p = 0.07). The intervention was feasible to implement and satisfaction with the intervention was high. With a small sample size, the intervention did not demonstrate significant improvement in adherence to medications for HIV or comorbid conditions. Patients with HIV are often medically complex and may have multiple barriers to medication adherence. Medication adherence is a multifaceted process and adherence promotion interventions require an approach that targets patient-specific barriers.

  12. High Flow Nasal Cannulae versus Nasal Continuous Positive Airway Pressure in Neonates with Respiratory Distress Syndrome Managed with INSURE Method: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Maliheh Kadivar

    2016-11-01

    Full Text Available Background: In recent years, various noninvasive respiratory support (NRS of ventilation has been provided more in neonates. The aim of this study was to compare the effect of HFNC with NCPAP in post-extubation of preterm infants with RDS after INSURE method (intubation, surfactant, extubation. Methods: A total of 54 preterm infants with RDS (respiratory distress syndrome were enrolled in this study. Using a randomized sequence, they were assigned into two groups after INSURE method. The first group received HFNC while the second group received NCPAP for respiratory support after extubation. A comparison was made between these two groups by the rate of reintubation, air leak syndrome, duration of oxygen therapy, hospitalization, the rate of bronchopulmonary dysplasia (BPD, intraventricular hemorrhage (IVH, retinopathy of prematurity (ROP, and mortality. Data were analyzed by using the SPSS version 18 software. The statistical analyses included Student’s t-test for continuous data and compared proportions using Chi-squared test and Fisher‘s exact test for categorical data. Result: The rate of reintubation was higher in the HFNC compared with the NCPAP group. The rate of either IVH or ROP had no significant differences between the two groups. In addition, duration of oxygen requirement and hospitalization were not statistically different. There was no case of BPD or mortality among these patients. Conclusion: This study showed that preterm infants with RDS could manage post-extubation after INSURE method with either NCPAP or HFNC. However, in this single-center study, the rate of reintubation was higher in the HFNC group while further multicenter study might be assigned. Trial Registration Number: IRCT201201228800N1

  13. Formations of magnetic vortices in a chain array of triangle Py dots and an isosceles triangle Py dot

    Science.gov (United States)

    Miyata, M.; Kiseki, K.; Yakata, S.; Wada, H.; Kimura, T.

    2012-04-01

    We have studied the magnetic domain structures in a magneto-statically-coupled chain array of the triangle dots and an isosceles triangle dot by means of magnetic force microscopy (MFM). Despite the strong magneto-static interaction in the chain array of the dots, each triangle dot takes a single vortex structure. The chirality of each dot is found to behave similarly to that for the isolated triangle dot. We also demonstrated that single-vortex and double-vortex structures with the desired chiralities can be stabilized in an isosceles triangle dot.

  14. Intrinsic subtypes and benefit from postmastectomy radiotherapy in node-positive premenopausal breast cancer patients who received adjuvant chemotherapy - results from two independent randomized trials

    DEFF Research Database (Denmark)

    Laurberg, Tinne; Tramm, Trine; Nielsen, Torsten

    2018-01-01

    BACKGROUND: The study of the intrinsic molecular subtypes of breast cancer has revealed differences among them in terms of prognosis and response to chemotherapy and endocrine therapy. However, the ability of intrinsic subtypes to predict benefit from adjuvant radiotherapy has only been examined...... in few studies. METHODS: Gene expression-based intrinsic subtyping was performed in 228 breast tumors collected from two independent post-mastectomy clinical trials (British Columbia and the Danish Breast Cancer Cooperative Group 82b trials), where pre-menopausal patients with node-positive disease were......: In the British Columbia study, patients treated with radiation had an overall significant lower incidence of locoregional recurrence compared to the controls. For Luminal A tumors the risk of loco-regional recurrence was low and was further lowered by adjuvant radiation. These findings were validated in the DBCG...

  15. Detection of M2 antimitochondrial antibodies by dot blot assay is more specific than by enzyme linked immunosorbent assay.

    Science.gov (United States)

    Bargou, I; Mankaï, A; Jamaa, A; Ben Jazia, I; Skandrani, K; Sfar, H; Baccouche, A; Ajmi, S; Letaief, A; Fabien, N; Jeddi, M; Ghedira, I

    2008-02-01

    The objective of our study was, in one hand, to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ELISA and dot blot assay to investigate IgG M2 antimitochondrial antibodies (M2 AMA) and, on the other hand, to compare these results with those of indirect immunofluorescence technique (IIF). Sera from patients suffering from primary biliary cirrhosis (PBC) (n=55), systemic lupus erythematosus (n=21), celiac disease (n=30) and blood donors (n=75) were analyzed. M2 AMA were detected by ELISA and dot blot using pyruvate dehydrogenase purified from porcine heart and by IIF on cryostat sections of rat liver-kidney-stomach. IIF was more sensitive (98%) than ELISA (93%) and dot blot (91%). The specificity of AMA for PBC using IIF, ELISA and dot blot reached 100%, 92% and 100%, respectively. The PPV of IIF, ELISA and dot blot was 100%, 93% and 100%, respectively. The NPV was 98% for IIF, 92% for ELISA and 91% for dot blot. Dot blot, using purified pyruvate dehydrogenase, had a higher specificity than ELISA and may be useful in confirming the specificity of AMA in cases of doubt with IIF.

  16. Thermoelectric transport through quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Merker, Lukas Heinrich

    2016-06-30

    In this thesis the thermoelectric properties (electrical conductance, Seebeck coefficient and thermal conductance)of quantum dots described by the Anderson impurity model have been investigated by using the numerical renormalization group (NRG) method. In order to make accurate calculations for thermoelectric properties of quantum impurity systems, a number of recent developments and refinements of the NRG have been implemented. These include the z-averaging and Campo discretization scheme, which enable the evaluation of physical quantities on an arbitrary temperature grid and at large discretization parameter Λ and the full density matrix (FDM) approach, which allows a more accurate calculation of spectral functions and transport coefficients. The implementation of the z-averaging and Campo discretization scheme has been tested within a new method for specific heats of quantum impurities. The accuracy of this new method was established by comparison with the numerical solution of the Bethe-ansatz equations for the Anderson model. The FDM approach was implemented and tested within a new approach to the calculation of impurity contributions to the uniform susceptibilities. Within this method a non-negligible contribution from the ''environmental'' degrees of freedom needs to be taken into account to recover the correct susceptibility, as shown by comparison with the Bethe-ansatz approach. An accurate method to calculate the conductance of a quantum dot is implemented, enabling the extraction of the Fermi liquid scaling coefficients c{sub T} and c{sub B} to high accuracy, being able to verify the results of the renormalized super perturbation theory approach (within its regime of validity). The method was generalized to higher order moments of the local level spectral function. This, as well as reduction of the SU(2) code to the U(1) symmetry, enabled the investigation of the effect of a magnetic field on the thermoelectric properties of quantum

  17. Phonon impact on optical control schemes of quantum dots: Role of quantum dot geometry and symmetry

    Science.gov (United States)

    Lüker, S.; Kuhn, T.; Reiter, D. E.

    2017-12-01

    Phonons strongly influence the optical control of semiconductor quantum dots. When modeling the electron-phonon interaction in several theoretical approaches, the quantum dot geometry is approximated by a spherical structure, though typical self-assembled quantum dots are strongly lens-shaped. By explicitly comparing simulations of a spherical and a lens-shaped dot using a well-established correlation expansion approach, we show that, indeed, lens-shaped dots can be exactly mapped to a spherical geometry when studying the phonon influence on the electronic system. We also give a recipe to reproduce spectral densities from more involved dots by rather simple spherical models. On the other hand, breaking the spherical symmetry has a pronounced impact on the spatiotemporal properties of the phonon dynamics. As an example we show that for a lens-shaped quantum dot, the phonon emission is strongly concentrated along the direction of the smallest axis of the dot, which is important for the use of phonons for the communication between different dots.

  18. Efficacy of long-term noninvasive positive pressure ventilation in stable hypercapnic COPD patients with respiratory failure: a meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Liao H

    2017-10-01

    Full Text Available Hao Liao,* Wendi Pei,* Hongfu Li,* Yuwen Luo, Kai Wang, Rui Li, Limei Xu, Xin Chen Department of Respiratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Introduction: The efficacy of long-term noninvasive positive pressure ventilation (NPPV in stable hypercapnic COPD patients with respiratory failure remains unclear. The aim of this meta-analysis was to critically assess the efficacy of long-term NPPV on mortality, acute exacerbation, exercise capacity, symptoms and significant physiological parameters (lung function, respiratory muscle function and gas exchange.Patients and methods: We performed an electronic literature search using the PubMed, Cochrane Library, Embase, OVID and Chinese Biomedical Literature Database in May 2017. Studies comparing treatment effects of NPPV with oxygen therapy in stable hypercapnic COPD patients with respiratory failure were conducted, and at least one of the following parameters were reviewed: frequency of acute exacerbation, mortality, lung function, respiratory muscle function, gas exchange, exercise capacity.Results: Seven studies with 810 subjects were identified. The partial pressure of arterial carbon dioxide (PaCO2 significantly decreased in patients who received long-term NPPV (weighted mean difference [WMD] −3.73, 95% CI: −5.83 to −1.64, P=0.0005. No significant difference was found in mortality, partial pressure of arterial oxygen (PaO2, frequency of acute exacerbation, lung function, respiratory muscle function and exercise capacity. The subgroup analysis showed that NPPV significantly improved the survival of patients when it was targeted at greatly reducing hypercapnia (WMD 0.35, 95% CI: 0.19 to 0.64, P=0.0006.Conclusion: The results indicate that long-term NPPV decreases the PaCO2 of stable hypercapnic COPD patients with respiratory failure and improves mortality with the aim of reducing Pa

  19. Quantum Phase Transitions in Quantum Dots

    OpenAIRE

    Rau, I. G.; Amasha, S.; Oreg, Y.; Goldhaber-Gordon, D.

    2013-01-01

    This review article describes theoretical and experimental advances in using quantum dots as a system for studying impurity quantum phase transitions and the non-Fermi liquid behavior at the quantum critical point.

  20. Double quantum dots defined in bilayer graphene

    Science.gov (United States)

    Żebrowski, D. P.; Peeters, F. M.; Szafran, B.

    2017-07-01

    Artificial molecular states of double quantum dots defined in bilayer graphene are studied with the atomistic tight-binding method and its low-energy continuum approximation. We indicate that the extended electron wave functions have opposite parities on sublattices of the layers and that the ground-state wave-function components change from bonding to antibonding with the interdot distance. In the weak-coupling limit, the one most relevant for quantum dots defined electrostatically, the signatures of the interdot coupling include, for the two-electron ground state, formation of states with symmetric or antisymmetric spatial wave functions split by the exchange energy. In the high-energy part of the spectrum the states with both electrons in the same dot are found with the splitting of energy levels corresponding to simultaneous tunneling of the electron pair from one dot to the other.

  1. Large quantum dots with small oscillator strength

    DEFF Research Database (Denmark)

    Stobbe, Søren; Schlereth, T.W.; Höfling, S.

    2010-01-01

    We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... oscillator strength due to Coulomb effects. This is in stark contrast to the measured oscillator strength, which turns out to be so small that it can be described by excitons in the strong confinement regime. We attribute these findings to exciton localization in local potential minima arising from alloy...

  2. Ge Quantum Dot Infrared Imaging Camera Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations Incorporated proposes to develop a high performance Ge quantum dots-based infrared (IR) imaging camera on Si substrate. The high sensitivity, large...

  3. Carbon Quantum Dots for Zebrafish Fluorescence Imaging

    National Research Council Canada - National Science Library

    Kang, Yan-Fei; Li, Yu-Hao; Fang, Yang-Wu; Xu, Yang; Wei, Xiao-Mi; Yin, Xue-Bo

    2015-01-01

    Carbon quantum dots (C-QDs) are becoming a desirable alternative to metal-based QDs and dye probes owing to their high biocompatibility, low toxicity, ease of preparation, and unique photophysical properties...

  4. Preparation and Application of Fluorescent Carbon Dots

    National Research Council Canada - National Science Library

    Zuo, Jun; Jiang, Tao; Zhao, Xiaojing; Xiong, Xiaohong; Xiao, Saijin; Zhu, Zhiqiang

    2015-01-01

      Fluorescent carbon dots (CDs) are a novel type of fluorescent nanomaterials, which not only possess the specific quantum confinement effects of nanomaterials due to the small size of nanomaterials, but also have good...

  5. Nanomaterials: Earthworms lit with quantum dots

    Science.gov (United States)

    Tilley, Richard D.; Cheong, Soshan

    2013-01-01

    Yeast, bacteria and fungi have been used to synthesize a variety of nanocrystals. Now, the metal detoxification process in the gut of an earthworm is exploited to produce biocompatible cadmium telluride quantum dots.

  6. Effective mass theory of a two-dimensional quantum dot in the ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 73; Issue 3. Effective mass theory of a two-dimensional quantum dot in the presence of magnetic field. Himanshu ... The standard kinetic energy operator of quantum mechanics for this position-dependent mass is non-Hermitian and needs to be modified. This is ...

  7. Location memory for dots in polygons versus cities in regions: evaluating the category adjustment model.

    Science.gov (United States)

    Friedman, Alinda; Montello, Daniel R; Burte, Heather

    2012-09-01

    We conducted 3 experiments to examine the category adjustment model (Huttenlocher, Hedges, & Duncan, 1991) in circumstances in which the category boundaries were irregular schematized polygons made from outlines of maps. For the first time, accuracy was tested when only perceptual and/or existing long-term memory information about identical locations was cued. Participants from Alberta, Canada and California received 1 of 3 conditions: dots-only, in which a dot appeared within the polygon, and after a 4-s dynamic mask the empty polygon appeared and the participant indicated where the dot had been; dots-and-names, in which participants were told that the first polygon represented Alberta/California and that each dot was in the correct location for the city whose name appeared outside the polygon; and names-only, in which there was no first polygon, and participants clicked on the city locations from extant memory alone. Location recall in the dots-only and dots-and-names conditions did not differ from each other and had small but significant directional errors that pointed away from the centroids of the polygons. In contrast, the names-only condition had large and significant directional errors that pointed toward the centroids. Experiments 2 and 3 eliminated the distribution of stimuli and overall screen position as causal factors. The data suggest that in the "classic" category adjustment paradigm, it is difficult to determine a priori when Bayesian cue combination is applicable, making Bayesian analysis less useful as a theoretical approach to location estimation. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  8. Preoperative carbohydrate load and intraoperatively infused omega-3 polyunsaturated fatty acids positively impact nosocomial morbidity after coronary artery bypass grafting: a double-blind controlled randomized trial.

    Science.gov (United States)

    Feguri, Gibran Roder; de Lima, Paulo Ruiz Lúcio; de Cerqueira Borges, Danilo; Toledo, Laura Ramos; Batista, Larissa Nadaf; E Silva, Thaís Carvalho; Segri, Neuber José; de Aguilar-Nascimento, José Eduardo

    2017-04-20

    A strategy of limited preoperative fasting, with carbohydrate (CHO) loading and intraoperative infusion of omega-3 polyunsaturated fatty acids (ω-3 PUFA), has seldom been tried in cardiovascular surgery. Brief fasting, followed by CHO intake 2 h before anesthesia, may improve recovery from CABG procedures and lower perioperative vasoactive drug requirements. Infusion of ω-3 PUFA may reduce occurrences of postoperative atrial fibrillation (POAF) and shorten hospital stays. The aim of this study was to assess morbidity (especially POAF) in ICU patients after coronary artery bypass grafting (CABG)/cardiopulmonary bypass (CPB) in combination, if preoperative fasts are curtailed in favor of CHO loading, and ω-3 PUFA are infused intraoperatively. Fifty-seven patients undergoing CABG were randomly assigned to receive 12.5% maltodextrin (200 ml, 2 h before anesthesia), without infusing ω-3 PUFA (CHO, n = 14); water (200 ml, 2 h before anesthesia), without infusing ω-3 PUFA (controls, n = 14); 12.5% maltodextrin (200 ml, 2 h before anesthesia) plus intraoperative ω-3 PUFA (0.2 mcg/kg) (CHO + W3, n = 15); or water (200 ml, 2 h before anesthesia) plus intraoperative ω-3 PUFA (0.2 mcg/kg) (W3, n = 14). Perioperative clinical variables and mortality were analyzed, examining the incidence of POAF, as well as the need for inotropic vasoactive drugs during surgery and in ICU. Two deaths occurred (3.5%), but there were no instances of bronchoaspiration and mediastinitis. Neither ICU stays nor total postoperative stays differed by group (P > 0.05). Patients given preoperative CHO loads (CHO and CHO + W3 groups) experienced fewer instances of hospital infection (RR = 0.29, 95%CI 0.09-0.94; P = 0.023) and were less reliant on vasoactive amines during surgery (RR = 0.60, 95% CI 0.38-0.94; P = 0.020). Similarly, the number of patients requiring vasoactive drugs while recovering in ICU differed significantly by group (P = 0

  9. Piscivory and trophic position of Anguilla anguilla in two lakes: importance of macrozoobenthos density

    DEFF Research Database (Denmark)

    Dorner, H.; Skov, Christian; Berg, Søren

    2009-01-01

    and no submerged macrophytes). The density of macrozoobenthos was higher in LV (3500 individuals m(-2)) than in LGV (1500 individuals m(-2)). The abundance of small prey fishes (40-99 mm L-T) was highest in LV. In LV, A. anguilla fed on macrozoobenthos, in particular, chironomid larvae. In LGV, A. anguilla used...... fishes as the main food component. Stable isotope analyses confirmed the stomach contents dietary results. The estimated mean +/- s.d. trophic positions of A. anguilla in LGV (3 center dot 7 +/- 0 center dot 2) was one level higher than those of fish in LV (2 center dot 7 +/- 0 center dot 2). Based...

  10. Micromagnetic Simulations of Submicron Cobalt Dots

    Energy Technology Data Exchange (ETDEWEB)

    Parker, G.J.; Cerjan, C.

    1999-08-30

    Numerical simulations of submicron Co extruded elliptical dots were performed to illustrate the relative importance of different physical parameters on the switching behavior in the easy direction. Shape, size, magnetic moment magnitude and crystalline anisotropy, both magnitude and distribution, were varied. The simulation includes calculation of the magnetostatic, exchange and crystalline anisotropy fields on a structured mesh using finite difference techniques. The smooth boundary of the dots are accurately represented by use of the Embedded Curve Boundary method.

  11. Same day ART initiation versus clinic-based pre-ART assessment and counselling for individuals newly tested HIV-positive during community-based HIV testing in rural Lesotho - a randomized controlled trial (CASCADE trial).

    Science.gov (United States)

    Labhardt, Niklaus Daniel; Ringera, Isaac; Lejone, Thabo Ishmael; Masethothi, Phofu; Thaanyane, T'sepang; Kamele, Mashaete; Gupta, Ravi Shankar; Thin, Kyaw; Cerutti, Bernard; Klimkait, Thomas; Fritz, Christiane; Glass, Tracy Renée

    2016-04-14

    Achievement of the UNAIDS 90-90-90 targets in Sub-Sahara Africa is challenged by a weak care-cascade with poor linkage to care and retention in care. Community-based HIV testing and counselling (HTC) is widely used in African countries. However, rates of linkage to care and initiation of antiretroviral therapy (ART) in individuals who tested HIV-positive are often very low. A frequently cited reason for non-linkage to care is the time-consuming pre-ART assessment often requiring several clinic visits before ART-initiation. This two-armed open-label randomized controlled trial compares in individuals tested HIV-positive during community-based HTC the proposition of same-day community-based ART-initiation to the standard of care pre-ART assessment at the clinic. Home-based HTC campaigns will be conducted in catchment areas of six clinics in rural Lesotho. Households where at least one individual tested HIV positive will be randomized. In the standard of care group individuals receive post-test counselling and referral to the nearest clinic for pre-ART assessment and counselling. Once they have started ART the follow-up schedule foresees monthly clinic visits. Individuals randomized to the intervention group receive on the spot point-of-care pre-ART assessment and adherence counselling with the proposition to start ART that same day. Once they have started ART, follow-up clinic visits will be less frequent. First primary outcome is linkage to care (individual presents at the clinic at least once within 3 months after the HIV test). The second primary outcome is viral suppression 12 months after enrolment in the study. We plan to enrol a minimum of 260 households with 1:1 allocation and parallel assignment into both arms. This trial will show if in individuals tested HIV-positive during community-based HTC campaigns the proposition of same-day ART initiation in the community, combined with less frequent follow-up visits at the clinic could be a pragmatic approach to

  12. Same day ART initiation versus clinic-based pre-ART assessment and counselling for individuals newly tested HIV-positive during community-based HIV testing in rural Lesotho – a randomized controlled trial (CASCADE trial

    Directory of Open Access Journals (Sweden)

    Niklaus Daniel Labhardt

    2016-04-01

    Full Text Available Abstract Background Achievement of the UNAIDS 90-90-90 targets in Sub-Sahara Africa is challenged by a weak care-cascade with poor linkage to care and retention in care. Community-based HIV testing and counselling (HTC is widely used in African countries. However, rates of linkage to care and initiation of antiretroviral therapy (ART in individuals who tested HIV-positive are often very low. A frequently cited reason for non-linkage to care is the time-consuming pre-ART assessment often requiring several clinic visits before ART-initiation. Methods This two-armed open-label randomized controlled trial compares in individuals tested HIV-positive during community-based HTC the proposition of same-day community-based ART-initiation to the standard of care pre-ART assessment at the clinic. Home-based HTC campaigns will be conducted in catchment areas of six clinics in rural Lesotho. Households where at least one individual tested HIV positive will be randomized. In the standard of care group individuals receive post-test counselling and referral to the nearest clinic for pre-ART assessment and counselling. Once they have started ART the follow-up schedule foresees monthly clinic visits. Individuals randomized to the intervention group receive on the spot point-of-care pre-ART assessment and adherence counselling with the proposition to start ART that same day. Once they have started ART, follow-up clinic visits will be less frequent. First primary outcome is linkage to care (individual presents at the clinic at least once within 3 months after the HIV test. The second primary outcome is viral suppression 12 months after enrolment in the study. We plan to enrol a minimum of 260 households with 1:1 allocation and parallel assignment into both arms. Discussion This trial will show if in individuals tested HIV-positive during community-based HTC campaigns the proposition of same-day ART initiation in the community, combined with less frequent follow

  13. [Efficacy of the Boussignac continuous positive airway pressure device in patients with acute respiratory failure attended by an emergency medical service: a randomized clinical trial].

    Science.gov (United States)

    Pérez Regueiro, Irene; Mosteiro Díaz, María Pilar; Herrero Puente, Pablo; Argüelles Luis, Juan; Campa García, Ana María; García Fernández, José Antonio

    2016-02-01

    To assess the efficacy of the Boussignac continuous positive airway pressure (CPAP) device for treating patients with acute respiratory failure transported by an emergency medical service. Retrospective, descriptive study of a series of patients treated with the Boussignac CPAP system by emergency medical service responders in Asturias between February 1, 2006, and March 19, 2012. We recorded demographic data, diagnosis, techniques and drugs used, technique failure and reasons, vital constants, (heart rate [HR], respiratory frequency [RF], systolic and diastolic blood pressures, and arterial oxygen saturation by pulse oximetry [SpO2]) at 5 times during the event (on contact without oxygen therapy in place, with conventional oxygen therapy, 5 and 15 minutes after starting CPAP, and on hospital transfer), and the duration of prehospital care. A total of 203 patients with a mean (SD) age of 74.5 (10.6) years were enrolled; 133 (65.5%) were men. One hundred five (81.3%) had acute heart failure. The device failed in 28 patients (13.8%), 13 (6.4%) of whom required intubation. One (0.5%) died while still in prehospital care. All vital constants improved with CPAP. SpO2 values increased at all 5 recording times (P<.001); HR and RF improved significantly at 5 and 15 minutes of CPAP and on transfer (P<.001). Systolic and diastolic pressures were significantly lower than baseline after 15 minutes of CPAP and on transfer. Duration of care was significantly longer in patients who did not tolerate CPAP and in patients who were intubated (P<.001). Most patients tolerated treatment with the Boussignac CPAP device and improved clinically. Few required intubation and mortality was very low.

  14. Ten years’ experience of Directly Observed Treatment Short-course (DOTS) in Gambella Regional State, Ethiopia: An evaluation of tuberculosis control program

    National Research Council Canada - National Science Library

    Sisay, Solomon; Mengistu, Belete; Erku, Woldargay; Woldeyohannes, Desalegne

    2016-01-01

    .... The objective of the study was, therefore, to evaluate the impact of DOTS strategy on smear-positive pulmonary tuberculosis case finding and their treatment outcomes in Gambella Regional State, Ethiopia. Methods...

  15. A comparative analysis of electronic and molecular quantum dot cellular automata

    Energy Technology Data Exchange (ETDEWEB)

    Umamahesvari, H., E-mail: umamaheswarihema@gmail.com, E-mail: ajithavijay1@gmail.com [Sreenivasa Institute of Technology and Management Studies, (SITAMS) Autonomous, Chittoor (India); Ajitha, D., E-mail: umamaheswarihema@gmail.com, E-mail: ajithavijay1@gmail.com [JNTUCEA, Anatapuramu Andrapradesh (India)

    2015-06-24

    This paper presents a comparative analysis of electronic quantum-dot cellular automata (EQCA) and Magnetic quantum dot Cellular Automata (MQCA). QCA is a computing paradigm that encodes and processes information by the position of individual electrons. To enhance the high dense and ultra-low power devices, various researches have been actively carried out to find an alternative way to continue and follow Moore’s law, so called “beyond CMOS technology”. There have been several proposals for physically implementing QCA, EQCA and MQCA are the two important QCAs reported so far. This paper provides a comparative study on these two QCAs.

  16. Statistical study of stacked/coupled site-controlled pyramidal quantum dots and their excitonic properties

    Science.gov (United States)

    Moroni, S. T.; Chung, T. H.; Juska, G.; Gocalinska, A.; Pelucchi, E.

    2017-08-01

    We report on stacked multiple quantum dots (QDs) formed inside inverted pyramidal recesses, which allow for the precise positioning of the QDs themselves. Specifically, we fabricated double QDs with varying inter-dot distances and ensembles with more than two nominally highly symmetric QDs. For each, the effect of the interaction between QDs is studied by characterizing a large number of QDs through photoluminescence spectroscopy. A clear red-shift of the emission energy is observed together with a change in the orientation of its polarization, suggesting an increasing interaction between the QDs. Finally, we show how stacked QDs can help influencing the charging of the excitonic complexes.

  17. Vibrational effects in charge transport through a molecular double quantum dot

    Science.gov (United States)

    Sowa, Jakub K.; Mol, Jan A.; Briggs, G. Andrew D.; Gauger, Erik M.

    2017-02-01

    Recent progress in the field of molecular electronics has revealed the fundamental importance of the coupling between the electronic degrees of freedom and specific vibrational modes. Considering the examples of a molecular dimer and a carbon nanotube double quantum dot, we here theoretically investigate transport through a two-site system that is strongly coupled to a single vibrational mode. Using a quantum master equation approach, we demonstrate that, depending on the relative positions of the two dots, electron-phonon interactions can lead to negative differential conductance and suppression of the current through the system. We also discuss the experimental relevance of the presented results and possible implementations of the studied system.

  18. Quantum-dot-in-perovskite solids

    KAUST Repository

    Ning, Zhijun

    2015-07-15

    © 2015 Macmillan Publishers Limited. All rights reserved. Heteroepitaxy - atomically aligned growth of a crystalline film atop a different crystalline substrate - is the basis of electrically driven lasers, multijunction solar cells, and blue-light-emitting diodes. Crystalline coherence is preserved even when atomic identity is modulated, a fact that is the critical enabler of quantum wells, wires, and dots. The interfacial quality achieved as a result of heteroepitaxial growth allows new combinations of materials with complementary properties, which enables the design and realization of functionalities that are not available in the single-phase constituents. Here we show that organohalide perovskites and preformed colloidal quantum dots, combined in the solution phase, produce epitaxially aligned \\'dots-in-a-matrix\\' crystals. Using transmission electron microscopy and electron diffraction, we reveal heterocrystals as large as about 60 nanometres and containing at least 20 mutually aligned dots that inherit the crystalline orientation of the perovskite matrix. The heterocrystals exhibit remarkable optoelectronic properties that are traceable to their atom-scale crystalline coherence: photoelectrons and holes generated in the larger-bandgap perovskites are transferred with 80% efficiency to become excitons in the quantum dot nanocrystals, which exploit the excellent photocarrier diffusion of perovskites to produce bright-light emission from infrared-bandgap quantum-tuned materials. By combining the electrical transport properties of the perovskite matrix with the high radiative efficiency of the quantum dots, we engineer a new platform to advance solution-processed infrared optoelectronics.

  19. Quantum dots and spin qubits in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Recher, Patrik; Trauzettel, Bjoern, E-mail: precher@physik.uni-wuerzburg.de, E-mail: trauzettel@physik.uni-wuerzburg.de [Institut fuer Theoretische Physik und Astrophysik, University of Wuerzburg, 97074 Wuerzburg (Germany)

    2010-07-30

    This is a review on graphene quantum dots and their use as a host for spin qubits. We discuss the advantages but also the challenges to use graphene quantum dots for spin qubits as compared to the more standard materials like GaAs. We start with an overview of this young and fascinating field and then discuss gate-tunable quantum dots in detail. We calculate the bound states for three different quantum dot architectures where a bulk gap allows for confinement via electrostatic fields: (i) graphene nanoribbons with armchair boundaries, (ii) a disc in single-layer graphene, and (iii) a disc in bilayer graphene. In order for graphene quantum dots to be useful in the context of spin qubits, one needs to find reliable ways to break the valley degeneracy. This is achieved here, either by a specific termination of graphene in (i) or in (ii) and (iii) by a magnetic field, without the need of a specific boundary. We further discuss how to manipulate spin in these quantum dots and explain the mechanism of spin decoherence and relaxation caused by spin-orbit interaction in combination with electron-phonon coupling, and by hyperfine interaction with the nuclear-spin system. (topical review)

  20. Semiconductor Quantum Dots with Photoresponsive Ligands.

    Science.gov (United States)

    Sansalone, Lorenzo; Tang, Sicheng; Zhang, Yang; Thapaliya, Ek Raj; Raymo, Françisco M; Garcia-Amorós, Jaume

    2016-10-01

    Photochromic or photocaged ligands can be anchored to the outer shell of semiconductor quantum dots in order to control the photophysical properties of these inorganic nanocrystals with optical stimulations. One of the two interconvertible states of the photoresponsive ligands can be designed to accept either an electron or energy from the excited quantum dots and quench their luminescence. Under these conditions, the reversible transformations of photochromic ligands or the irreversible cleavage of photocaged counterparts translates into the possibility to switch luminescence with external control. As an alternative to regulating the photophysics of a quantum dot via the photochemistry of its ligands, the photochemistry of the latter can be controlled by relying on the photophysics of the former. The transfer of excitation energy from a quantum dot to a photocaged ligand populates the excited state of the species adsorbed on the nanocrystal to induce a photochemical reaction. This mechanism, in conjunction with the large two-photon absorption cross section of quantum dots, can be exploited to release nitric oxide or to generate singlet oxygen under near-infrared irradiation. Thus, the combination of semiconductor quantum dots and photoresponsive ligands offers the opportunity to assemble nanostructured constructs with specific functions on the basis of electron or energy transfer processes. The photoswitchable luminescence and ability to photoinduce the release of reactive chemicals, associated with the resulting systems, can be particularly valuable in biomedical research and can, ultimately, lead to the realization of imaging probes for diagnostic applications as well as to therapeutic agents for the treatment of cancer.

  1. A compact T-shaped nanodevice for charge sensing of a tunable double quantum dot in scalable silicon technology

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferri, M.L.V., E-mail: marco.tagliaferri@mdm.imm.cnr.it [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); Crippa, A. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); De Michielis, M. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Mazzeo, G.; Fanciulli, M. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Via Cozzi 53, 20125 Milano (Italy); Prati, E. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2016-03-11

    We report on the fabrication and the characterization of a tunable complementary-metal oxide semiconductor (CMOS) system consisting of two quantum dots and a MOS single electron transistor (MOSSET) charge sensor. By exploiting a compact T-shaped design and few gates fabricated by electron beam lithography, the MOSSET senses the charge state of either a single or double quantum dot at 4.2 K. The CMOS compatible fabrication process, the simplified control over the number of quantum dots and the scalable geometry make such architecture exploitable for large scale fabrication of multiple spin-based qubits in circuital quantum information processing. - Highlights: • Charge sensing of tunable, by position and number, quantum dots is demonstrated. • A compact T-shaped design with five gates at a single metalization level is proposed. • The electrometer is a silicon-etched nanowire acting as a disorder tolerant MOSSET.

  2. Yellowish dots in the retina: a finding of ocular syphilis?

    Directory of Open Access Journals (Sweden)

    Renan Albert Mendonça Rodrigues

    2014-10-01

    Full Text Available Here we report the occurrence of pale yellowish perivascular preretinal dots in 12 patients with ocular syphilis. A case series of these patients was examined between March and October 2012 at the Uveitis Sector of Universidade Federal de São Paulo. After diagnostic confirmation of syphilis, fundus photographs and optical coherence tomography (OCT were performed to verify the localization of the dots, and patients were treated with IV crystalline penicillin for 14 days. The study comprised 11 men (91.6%, 19 eyes, median presentation age of 38.1 years, and panuveitis as the main clinical manifestation (seven patients, 58.3%, being bilateral in four. Ten patients were taking oral prednisone (83.3%. Serum panels performed by the Venereal Disease Research Laboratory (VDRL showed positive results in eight patients (66.7%, whereas VDRL cerebrospinal fluid (CSF tests were negative in seven of nine collected (77.8%. However, serum FTA-Abs was positive in 100% of patients, and eight patients (66.7% had HIV infection. The best corrected visual acuity (BCVA presented after treatment improved in 10 eyes (55.6%, did not change in seven eyes (38.9%, and worsened in one eye (5.6%. Although not yet acknowledged in the literature as a typical manifestation of ocular syphilis, these are very common findings in clinical practice. We believe that preretinal dots are due to perivasculitis secondary to treponema infection. It is important recognize them and remember that syphilis can present in several forms, including the one presented in this study.

  3. Influence of a tilted cavity on quantum-dot optoelectronic active devices

    Energy Technology Data Exchange (ETDEWEB)

    Liu Wanglai; Xu Bo; Liang Ping; Hu Ymg; Sun Hong; Lu Xueqin; Wang Zhanguo, E-mail: liuwanglai@semi.ac.c [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2009-09-15

    Quantum-dot laser diodes (QD-LDs) with a Fabry-Perot cavity and quantum-dot semiconductor optical amplifiers (QD-SOAs) with 7{sup 0} tilted cavity were fabricated. The influence of a tilted cavity on optoelectronic active devices was also investigated. For the QD-LD, high performance was observed at room temperature. The threshold current was below 30 mA and the slope efficiency was 0.36 W/A. In contrast, the threshold current of the QD-SOA approached 1000 mA, which indicated that low facet reflectivity was obtained due to the tilted cavity design. A much more inverted carrier population was found in the QD-SOA active region at high operating current, thus offering a large optical gain and preserving the advantages of quantum dots in optical amplification and processing applications. Due to the inhomogeneity and excited state transition of quantum dots, the full width at half maximum of the electroluminescence spectrum of the QD-SOA was 81.6 nm at the injection current of 120 mA, which was ideal for broad bandwidth application in a wavelength division multiplexing system. In addition, there was more than one lasing peak in the lasing spectra of both devices and the separation of these peak positions was 6-8 nm, which is approximately equal to the homogeneous broadening of quantum dots.

  4. Sensing flexural motion of a photonic crystal membrane with InGaAs quantum dots

    Science.gov (United States)

    Carter, S. G.; Bracker, A. S.; Yakes, M. K.; Zalalutdinov, M. K.; Kim, M.; Kim, C. S.; Czarnocki, C.; Scheibner, M.; Gammon, D.

    2017-10-01

    Optical coupling between quantum dots and photonic crystal cavities and waveguides has been studied for many years in order to explore interesting physics and to advance quantum technologies. Here, we demonstrate strain-based coupling between mechanical motion of a photonic crystal membrane and embedded single InGaAs quantum dots. The response to high frequency mechanical vibration is measured for a series of quantum dots along the length of a photonic crystal waveguide for several flexural modes by optically driving the membrane while measuring high resolution time-resolved photoluminescence. The position-dependent response is similar to the measured and calculated displacement profile of the membrane but falls off less rapidly at higher frequencies. These results indicate potential for nanoscale strain sensing with high bandwidth and sensitivity.

  5. Using the minimum spanning tree to recognize dotted and dashed curves

    CERN Document Server

    Zahn, C T

    1974-01-01

    An important problem in pattern recognition is the organization into two and three-dimensional space curves of data given as points ('dots') or short line segments ('dashes'). This paper describes a general method for recognizing such dotted or dashed space curves employing the Minimum Spanning Tree (MST). The use of the MST is motivated by its successful use in grouping two-dimensional point sets in a fashion closely resembling human visual perception. The extension of the method to handle 'dashed' curves requires only the definition of a closeness measure between dashes which reflects the directional information as well as positional. It is possible to use the method in a layered hierarchy where the MST of dots is used to detect dashes, the MST of dashes to detect short curves without inflexions, and an MST constructed from these curves is used to detect larger curves with possible inflexions. (8 refs).

  6. Linear and nonlinear absorption coefficients of spherical quantum dot inside external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Çakır, Bekir, E-mail: bcakir@selcuk.edu.tr [Physics Department, Faculty of Science, Selcuk University, Campus, 42075 Konya (Turkey); Yakar, Yusuf, E-mail: yuyakar@yahoo.com [Physics Department, Faculty of Arts and Science, Aksaray University, Campus, 68100 Aksaray (Turkey); Özmen, Ayhan [Physics Department, Faculty of Science, Selcuk University, Campus, 42075 Konya (Turkey)

    2017-04-01

    We have calculated the wavefunctions and energy eigenvalues of spherical quantum dot with infinite potential barrier inside uniform magnetic field. In addition, we have investigated the magnetic field effect on optical transitions between Zeeman energy states. The results are expressed as a function of dot radius, incident photon energy and magnetic field strength. The results present that, in large dot radii, the external magnetic field affects strongly the optical transitions between Zeeman states. In the strong spatial confinement case, energy level is relatively insensitive to the magnetic field, and electron spatial confinement prevails over magnetic confinement. Also, while m varies from −1 to +1, the peak positions of the optical transitions shift toward higher energy (blueshift).

  7. Micromagnetic calculations of Co dots: domain configuration, stability, and inter-dot coupling

    Science.gov (United States)

    Yu, Chengtao; Pearson, John; Li, Dongqi

    2002-03-01

    We have carried out micromagnetic simulations with a public code [1] to investigate the stability of single domain vs. vortex states in hexagonal Co dots of 10-900 nm in diameter and 1-40 nm in thickness, as well as the magnetostatic interactions among dots. The ground state of an isolated dot is determined to be single-domain for small dots, i.e., magneto-static coupling within a dot-pair introduces a uniaxial anisotropy with easy axis along the pair direction, which corresponds to 5 Oe at a pair distance of 640 nm, and increases to 270 Oe when two dots connect to each other. The results are compared to the experimental results of our self-assembled Co dots and dot chains [2]. * Work supported by DOE BES-MS under #W-31-109-ENG-38. 1. M.J. Donahue and D.G. Porter, http://math.nist.gov/oommf. 2. Chengtao Yu, Dongqi Li, J. Pearson, and S. Bader, Appl. Phys. Lett. 78, 1228 (2001); ibid. 79 (in press).

  8. Happy Family Kitchen II: a cluster randomized controlled trial of a community-based positive psychology family intervention for subjective happiness and health-related quality of life in Hong Kong.

    Science.gov (United States)

    Ho, Henry C Y; Mui, Moses; Wan, Alice; Ng, Yin-Lam; Stewart, Sunita M; Yew, Carol; Lam, Tai Hing; Chan, Sophia S

    2016-07-29

    Most positive psychology interventions conducted in the West have been focused on the individual. Family relationships are highly valued in the Chinese collectivist culture, and it is of interest to know whether family-focused interventions can improve the well-being of Chinese people. We have previously reported the effectiveness of a positive psychology family intervention in terms of family well-being. Based on the data derived from the Happy Family Kitchen II project, this paper examines the effectiveness of a community-based positive psychology family intervention on subjective happiness and health-related quality of life. Thirty-one social service units and schools organized intervention programs for 2070 participants in Hong Kong. In a cluster randomized controlled trial, participants were randomly assigned on the basis of computer-generated numbers into the intervention group or the control group. The intervention programs emphasized one of five positive psychology themes: joy, gratitude, flow, savoring, and listening. The control group engaged in activities unrelated to the intervention, such as arts and crafts workshops. Subjective happiness and mental and physical quality of life were assessed at baseline and at 4 weeks and 12 weeks postintervention. Data of 1261 participants were analyzed. The results showed that the intervention was more effective than the control condition in improving subjective happiness, with a small effect size, at 12 weeks postintervention (β = .15, p = .020, Cohen's d = .16). However, there were no improvements in mental and physical quality of life in the intervention group compared with the control group at 4 weeks (β = .39, p = .494, d = .05; β = -.10, p = 1.000, d = -.01, respectively) and 12 weeks postintervention (β = .71, p = .233, d = .08; β = -.05, p = 1.000, d = -.01, respectively). Furthermore, the booster session was no more effective than the tea

  9. Computational intelligence applied to the growth of quantum dots

    Science.gov (United States)

    Singulani, Anderson P.; Vilela Neto, Omar P.; Aurélio Pacheco, Marco C.; Vellasco, Marley B. R.; Pires, Maurício P.; Souza, Patrícia L.

    2008-11-01

    We apply two computational intelligence techniques, namely, artificial neural network and genetic algorithm to the growth of self-assembled quantum dots. The method relies on an existing database of growth parameters with a resulting quantum dot characteristic to be able to later obtain the growth parameters needed to reach a specific value for such a quantum dot characteristic. The computational techniques were used to associate the growth input parameters with the mean height of the deposited quantum dots. Trends of the quantum dot mean height behavior as a function of growth parameters were correctly predicted and the growth parameters required to minimize the quantum dot mean height were provided.

  10. Dot gain compensation in the blue noise mask

    Science.gov (United States)

    Yao, Meng; Parker, Kevin J.

    1995-04-01

    Frequency modulated (FM) halftoning or 'stochastic screening,' has attracted a great deal of attention in the printing industry in recent years. It has several advantages over conventional halftoning. But one serious problem that arises in FM halftoning is dot gain. One approach to stochastic screening uses a specially constructed halftone screen, the blue noise mask (BNM), to produce an unstructured and visually appealing pattern of halftone dots at any gray level. In this paper, we will present methods to correct dot gain with the BNM. Dot gain is related to the area-to-perimeter ration of printed spots. We can exploit this feature in different ways. At a medium level, a B>NM pattern will have 'connected' as well as 'isolated' dots. Normally, as we build down BNM patterns to lower levels, a specific number of white dots will be replace by black dots. Since connected white dots are more likely to be picked than isolated white dots, this will results in substantial dot gain because of the increasing number of isolated white dots. We show that it is possible to constrain the process of constructing a BNM such that isolated dots are preferentially removes, thus significantly reducing dot gain in a BNM.

  11. Quantum dot DNA bioconjugates: attachment chemistry strongly influences the resulting composite architecture.

    Science.gov (United States)

    Boeneman, Kelly; Deschamps, Jeffrey R; Buckhout-White, Susan; Prasuhn, Duane E; Blanco-Canosa, Juan B; Dawson, Philip E; Stewart, Michael H; Susumu, Kimihiro; Goldman, Ellen R; Ancona, Mario; Medintz, Igor L

    2010-12-28

    The unique properties provided by hybrid semiconductor quantum dot (QD) bioconjugates continue to stimulate interest for many applications ranging from biosensing to energy harvesting. Understanding both the structure and function of these composite materials is an important component in their development. Here, we compare the architecture that results from using two common self-assembly chemistries to attach DNA to QDs. DNA modified to display either a terminal biotin or an oligohistidine peptidyl sequence was assembled to streptavidin/amphiphilic polymer- or PEG-functionalized QDs, respectively. A series of complementary acceptor dye-labeled DNA were hybridized to different positions on the DNA in each QD configuration and the separation distances between the QD donor and each dye-acceptor probed with Förster resonance energy transfer (FRET). The polyhistidine self-assembly yielded QD-DNA bioconjugates where predicted and experimental separation distances matched reasonably well. Although displaying efficient FRET, data from QD-DNA bioconjugates assembled using biotin-streptavidin chemistry did not match any predicted separation distances. Modeling based upon known QD and DNA structures along with the linkage chemistry and FRET-derived distances was used to simulate each QD-DNA structure and provide insight into the underlying architecture. Although displaying some rotational freedom, the DNA modified with the polyhistidine assembles to the QD with its structure extended out from the QD-PEG surface as predicted. In contrast, the random orientation of streptavidin on the QD surface resulted in DNA with a wide variety of possible orientations relative to the QD which cannot be controlled during assembly. These results suggest that if a particular QD biocomposite structure is desired, for example, random versus oriented, the type of bioconjugation chemistry utilized will be a key influencing factor.

  12. Photoresponse of polyaniline-functionalized graphene quantum dots

    Science.gov (United States)

    Lai, Sin Ki; Luk, Chi Man; Tang, Libin; Teng, Kar Seng; Lau, Shu Ping

    2015-03-01

    Polyaniline-functionalized graphene quantum dots (PANI-GQD) and pristine graphene quantum dots (GQDs) were utilized for optoelectronic devices. The PANI-GQD based photodetector exhibited higher responsivity which is about an order of magnitude at 405 nm and 7 folds at 532 nm as compared to GQD-based photodetectors. The improved photoresponse is attributed to the enhanced interconnection of GQD by island-like polymer matrices, which facilitate carrier transport within the polymer matrices. The optically tunable current-voltage (I-V) hysteresis of PANI-GQD was also demonstrated. The hysteresis magnifies progressively with light intensity at a scan range of +/-1 V. Both GQD and PANI-GQD devices change from positive to negative photocurrent when the bias reaches 4 V. Photogenerated carriers are excited to the trapping states in GQDs with increased bias. The trapped charges interact with charges injected from the electrodes which results in a net decrease of free charge carriers and a negative photocurrent. The photocurrent switching phenomenon in GQD and PANI-GQD devices may open up novel applications in optoelectronics.Polyaniline-functionalized graphene quantum dots (PANI-GQD) and pristine graphene quantum dots (GQDs) were utilized for optoelectronic devices. The PANI-GQD based photodetector exhibited higher responsivity which is about an order of magnitude at 405 nm and 7 folds at 532 nm as compared to GQD-based photodetectors. The improved photoresponse is attributed to the enhanced interconnection of GQD by island-like polymer matrices, which facilitate carrier transport within the polymer matrices. The optically tunable current-voltage (I-V) hysteresis of PANI-GQD was also demonstrated. The hysteresis magnifies progressively with light intensity at a scan range of +/-1 V. Both GQD and PANI-GQD devices change from positive to negative photocurrent when the bias reaches 4 V. Photogenerated carriers are excited to the trapping states in GQDs with increased bias. The

  13. Randomized phase II trial of the efficacy and safety of trastuzumab combined with docetaxel in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer administered as first-line treatment: the M77001 study group.

    Science.gov (United States)

    Marty, Michel; Cognetti, Francesco; Maraninchi, Dominique; Snyder, Ray; Mauriac, Louis; Tubiana-Hulin, Michèle; Chan, Stephen; Grimes, David; Antón, Antonio; Lluch, Ana; Kennedy, John; O'Byrne, Kenneth; Conte, PierFranco; Green, Michael; Ward, Carol; Mayne, Karen; Extra, Jean-Marc

    2005-07-01

    This randomized, multicenter trial compared first-line trastuzumab plus docetaxel versus docetaxel alone in patients with human epidermal growth factor receptor 2 (HER2) -positive metastatic breast cancer (MBC). Patients were randomly assigned to six cycles of docetaxel 100 mg/m2 every 3 weeks, with or without trastuzumab 4 mg/kg loading dose followed by 2 mg/kg weekly until disease progression. A total of 186 patients received at least one dose of the study drug. Trastuzumab plus docetaxel was significantly superior to docetaxel alone in terms of overall response rate (61% v 34%; P = .0002), overall survival (median, 31.2 v 22.7 months; P = .0325), time to disease progression (median, 11.7 v 6.1 months; P = .0001), time to treatment failure (median, 9.8 v 5.3 months; P = .0001), and duration of response (median, 11.7 v 5.7 months; P = .009). There was little difference in the number and severity of adverse events between the arms. Grade 3 to 4 neutropenia was seen more commonly with the combination (32%) than with docetaxel alone (22%), and there was a slightly higher incidence of febrile neutropenia in the combination arm (23% v 17%). One patient in the combination arm experienced symptomatic heart failure (1%). Another patient experienced symptomatic heart failure 5 months after discontinuation of trastuzumab because of disease progression, while being treated with an investigational anthracycline for 4 months. Trastuzumab combined with docetaxel is superior to docetaxel alone as first-line treatment of patients with HER2-positive MBC in terms of overall survival, response rate, response duration, time to progression, and time to treatment failure, with little additional toxicity.

  14. The effect of a trunk release maneuver on Peak Pressure Index, trunk displacement and perceived discomfort in older adults seated in a High Fowler's position: a randomized controlled trial.

    Science.gov (United States)

    Best, Krista L; Desharnais, Guylaine; Boily, Jeanette; Miller, William C; Camp, Pat G

    2012-11-16

    Pressure ulcers pose significant negative individual consequences and financial burden on the healthcare system. Prolonged sitting in High Fowler's position (HF) is common clinical practice for older adults who spend extended periods of time in bed. While HF aids in digestion and respiration, being placed in a HF may increase perceived discomfort and risk of pressure ulcers due to increased pressure magnitude at the sacral and gluteal regions. It is likely that shearing forces could also contribute to risk of pressure ulcers in HF. The purpose of this study was to evaluate the effect of a low-tech and time-efficient Trunk Release Manuever (TRM) on sacral and gluteal pressure, trunk displacement and perceived discomfort in ambulatory older adults. A randomized controlled trial was used. We recruited community-living adults who were 60 years of age and older using posters, newspaper advertisements and word-of-mouth. Participants were randomly allocated to either the intervention or control group. The intervention group (n = 59) received the TRM, while the control group (n = 58) maintained the standard HF position. The TRM group had significantly lower mean (SD) PPI values post-intervention compared to the control group, 59.6 (30.7) mmHg and 79.9 (36.5) mmHg respectively (p = 0.002). There was also a significant difference in trunk displacement between the TRM and control groups, +3.2 mm and -5.8 mm respectively (p = 0.005). There were no significant differences in perceived discomfort between the groups. The TRM was effective for reducing pressure in the sacral and gluteal regions and for releasing the trunk at the point of contact between the skin and the support surface, but did not have an effect on perceived discomfort. The TRM is a simple method of repositioning which may have important clinical application for the prevention of pressure ulcers that may occur as a result of HF.

  15. Ultra-slow propagation of light located in ultra-narrow transparency windows through four quantum dot molecules

    Science.gov (United States)

    Hamedi, Hamid Reza

    2014-08-01

    This letter investigates the dispersion and absorption properties of a weak probe field in a multiple quantum dot molecule composed of four quantum dots. It is found that, by manipulating the electric field, the inter-dot tunneling coupling and the laser detunings, the transparency window as well as the positive derivative in the refractive index can be efficiently qualified. It is shown that switching from positive to negative dispersion or vice versa can be achieved by changing the tunneling couplings. Moreover, we realize that the width and the number of transparency windows can be properly controlled by adjusting the system’s parameters. We show that this multiple QD medium can experience very narrow transparency windows accompanied by very steep positive dispersions. The effect of an incoherent pumping field on the absorption-dispersion properties of the QD molecule is then discussed. We note that tunneling is used in this QD system instead of coupling lasers.

  16. AlInAs quantum dots

    Science.gov (United States)

    Gaisler, A. V.; Derebezov, I. A.; Gaisler, V. A.; Dmitriev, D. V.; Toropov, A. I.; Kozhukhov, A. S.; Shcheglov, D. V.; Latyshev, A. V.; Aseev, A. L.

    2017-01-01

    A system of quantum dots on the basis of AlxIn1-xAs/AlyGa1-y As solid solutions has been studied. The usage of broadband AlxIn1-x solid solutions as the basis of quantum dots makes it possible to expand considerably the spectral emission range into the short-wave region, including the wavelength region near 770 nm being of interest for the design of aerospace systems of quantum cryptography. The optical characteristics of single AlxIn1-xAs quantum dots grown according to the Stranski-Krastanov mechanism are studied by the cryogenic microphotoluminescence method. The fine structure of exciton states of quantum dots is studied in the wavelength region near 770 nm. It is shown that the splitting of exciton states is comparable with the natural width of exciton lines, which is of great interest for the design of emitters of pairs of entangled photons on the basis of AlxAs1-x quantum dots.

  17. Thermoelectric properties of hexagonal graphene quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yonghong, E-mail: yhyan@fudan.edu.cn [Department of Physics, Shaoxing University, Shaoxing 312000 (China); Liang, Qi-Feng [Department of Physics, Shaoxing University, Shaoxing 312000 (China); Zhao, Hui [Department of Physics, Tongji University, Shanghai 200092 (China); Wu, Chang-Qin [Department of Physics, Fudan University, Shanghai 200433 (China)

    2012-02-27

    By using the atomistic nonequilibrium Green's function method, we investigate the thermoelectric properties of graphene nanoribbons in the presence of two constrictions (or hexagonal graphene quantum dots). With decreasing widths of the constrictions, the thermal conductance of the nanoribbon can be reduced largely while S{sup 2}G{sub e} (S is the Seebeck coefficient and G{sub e} is the electronic conductance) remains still high as compared with the results of the pristine nanoribbon. Thus, the thermoelectric figure of merit ZT can be enhanced largely. In fact, in the presence of narrowest constrictions the ZT values of the zigzag quantum dots can exceed one at room temperature, while the ZT values of the armchair quantum dots may be close to one, depending on the size of the dot. -- Highlights: ► We study thermoelectric properties of hexagonal graphene quantum dots. ► By point contacts to two leads, the thermal conductance can be reduced greatly while keeping the power factor still high. ► Thermoelectric figure of merit (ZT) can exceed unity.

  18. Analysis of MoDOT communication and outreach effectiveness

    Science.gov (United States)

    2008-07-01

    Personal interviews were held with MoDOT personnel to assess MoDOTs current communication practices and existing customer segmentation practices. Focus groups were then held to help gauge the effectiveness of existing communication practices and t...

  19. Inorganic passivation and doping control in colloidal quantum dot photovoltaics

    KAUST Repository

    Hoogland, Sjoerd H.

    2012-01-01

    We discuss strategies to reduce midgap trap state densities in colloidal quantum dot films and requirements to control doping type and magnitude. We demonstrate that these improvements result in colloidal quantum dot solar cells with certified 7.0% efficiency.

  20. TxDOT administration research : tasks completed in FY2009.

    Science.gov (United States)

    2010-01-01

    Texas Department of Transportation (TxDOT) Project 0-6581-TI, TxDOT Administration : Research, encompasses multiple tasks that explore and support administrative aspects of : transportation research. : The project term began in October 2008 and has b...

  1. Surface treatment of nanocrystal quantum dots after film deposition

    Science.gov (United States)

    Sykora, Milan; Koposov, Alexey; Fuke, Nobuhiro

    2015-02-03

    Provided are methods of surface treatment of nanocrystal quantum dots after film deposition so as to exchange the native ligands of the quantum dots for exchange ligands that result in improvement in charge extraction from the nanocrystals.

  2. Few-quantum-dot lasing in photonic crystal nanocavities

    DEFF Research Database (Denmark)

    Liu, Jin; Ates, Serkan; Stobbe, Søren

    2012-01-01

    A very smooth lasing transition in photonic crystal nanocavities with embedded quantum dots is observed and compared to the theory. Decay rate measurements reveal that only a few quantum dots are feeding the cavity....

  3. Ferritin-Templated Quantum-Dots for Quantum Logic Gates

    Science.gov (United States)

    Choi, Sang H.; Kim, Jae-Woo; Chu, Sang-Hyon; Park, Yeonjoon; King, Glen C.; Lillehei, Peter T.; Kim, Seon-Jeong; Elliott, James R.

    2005-01-01

    Quantum logic gates (QLGs) or other logic systems are based on quantum-dots (QD) with a stringent requirement of size uniformity. The QD are widely known building units for QLGs. The size control of QD is a critical issue in quantum-dot fabrication. The work presented here offers a new method to develop quantum-dots using a bio-template, called ferritin, that ensures QD production in uniform size of nano-scale proportion. The bio-template for uniform yield of QD is based on a ferritin protein that allows reconstitution of core material through the reduction and chelation processes. One of the biggest challenges for developing QLG is the requirement of ordered and uniform size of QD for arrays on a substrate with nanometer precision. The QD development by bio-template includes the electrochemical/chemical reconsitution of ferritins with different core materials, such as iron, cobalt, manganese, platinum, and nickel. The other bio-template method used in our laboratory is dendrimers, precisely defined chemical structures. With ferritin-templated QD, we fabricated the heptagonshaped patterned array via direct nano manipulation of the ferritin molecules with a tip of atomic force microscope (AFM). We also designed various nanofabrication methods of QD arrays using a wide range manipulation techniques. The precise control of the ferritin-templated QD for a patterned arrangement are offered by various methods, such as a site-specific immobilization of thiolated ferritins through local oxidation using the AFM tip, ferritin arrays induced by gold nanoparticle manipulation, thiolated ferritin positioning by shaving method, etc. In the signal measurements, the current-voltage curve is obtained by measuring the current through the ferritin, between the tip and the substrate for potential sweeping or at constant potential. The measured resistance near zero bias was 1.8 teraohm for single holoferritin and 5.7 teraohm for single apoferritin, respectively.

  4. Stark shift of impurity doped quantum dots: Role of noise

    Science.gov (United States)

    Arif, Sk. Md.; Bera, Aindrila; Ghosh, Anuja; Ghosh, Manas

    2018-02-01

    Present study makes a punctilious investigation of the profiles of Stark shift (SS) of doped GaAs quantum dot (QD) under the supervision of Gaussian white noise. A few physical parameters have been varied and the consequent variations in the SS profiles have been monitored. The said physical parameters comprise of magnetic field, confinement potential, dopant location, dopant potential, noise strength, aluminium concentration (only for AlxGa1-x As alloy QD), position-dependent effective mass (PDEM), position-dependent dielectric screening function (PDDSF), anisotropy, hydrostatic pressure (HP) and temperature. The SS profiles unfurl interesting features that heavily depend upon the particular physical quantity concerned, presence/absence of noise and the manner (additive/multiplicative) noise enters the system. The study highlights feasible means of maximizing SS of doped QD in presence of noise by suitable adjustment of several control parameters. The study deems importance in view of technological applications of QD devices where noise plays some prominent role.

  5. Coherence and dephasing in self-assembled quantum dots

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Leosson, K.; Birkedal, Dan

    2003-01-01

    We measured dephasing times in InGaAl/As self-assembled quantum dots at low temperature using degenerate four-wave mixing. At 0K, the coherence time of the quantum dots is lifetime limited, whereas at finite temperatures pure dephasing by exciton-phonon interactions governs the quantum dot...... coherence. The inferred homogeneous line widths are significantly smaller than the line widths usually observed in the photoluminescence from single quantum dots indicating an additional inhomogeneours broadening mechanism in the latter....

  6. Modulation Response of Semiconductor Quantum Dot Nanocavity Lasers

    DEFF Research Database (Denmark)

    Lorke, Michael; Nielsen, Torben Roland; Mørk, Jesper

    2011-01-01

    The modulation response of quantum-dot based nanocavity devices is investigated using a semiconductor theory. We show that high modulation bandwidth is achieved even in the presence of inhomogeneous broadening of the quantum dot ensemble.......The modulation response of quantum-dot based nanocavity devices is investigated using a semiconductor theory. We show that high modulation bandwidth is achieved even in the presence of inhomogeneous broadening of the quantum dot ensemble....

  7. Carbon quantum dots and a method of making the same

    Science.gov (United States)

    Zidan, Ragaiy; Teprovich, Joseph A.; Washington, Aaron L.

    2017-08-22

    The present invention is directed to a method of preparing a carbon quantum dot. The carbon quantum dot can be prepared from a carbon precursor, such as a fullerene, and a complex metal hydride. The present invention also discloses a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride and a polymer containing a carbon quantum dot made by reacting a carbon precursor with a complex metal hydride.

  8. A roadmap towards habitable exoplanets by the Blue Dots Initiative

    Science.gov (United States)

    Coudé du Foresto, V.

    2011-11-01

    This paper is an abridged version of the report produced by the Blue Dots initiative, whose activities include the elaboration of a roadmap towards the spectroscopic characterization of habitable exoplanets. The full version of the Blue Dots report can be downloaded at http://www.blue-dots.net/spip.php?article105. While the roadmap will need to be updated regularly, it is expected that the methodology developed within Blue Dots will provide a durable framework for the elaboration of future revisions.

  9. Pegylated Interferon Alfa-2b Add-on Treatment in Hepatitis B Virus Envelope Antigen-Positive Chronic Hepatitis B Patients Treated with Nucleos(t)ide Analogue: A Randomized, Controlled Trial (PEGON).

    Science.gov (United States)

    Chi, Heng; Hansen, Bettina E; Guo, Simin; Zhang, Ning Ping; Qi, Xun; Chen, Liang; Guo, Qing; Arends, Pauline; Wang, Ji-Yao; Verhey, Elke; de Knegt, Robert J; Xie, Qing; Janssen, Harry L A

    2017-04-01

    We studied whether 48 weeks of pegylated interferon alfa-2b (peginterferon) add-on therapy increases serological response in hepatitis B virus (HBV) envelope antigen (HBeAg)-positive patients receiving nucleos(t)ide analogue (NA) therapy, compared with continued NA monotherapy. This randomized trial included HBeAg-positive patients with compensated liver disease who were treated with entecavir/tenofovir for >12 months and had an HBV DNA load of interferon-naive patients, add-on therapy led to a greater frequency of HBeAg seroconversion (30% vs 7%; P = .034) and response (26% vs 7%; P = .068) at week 96, compared with monotherapy. Among 8 responders at week 48 who discontinued NA therapy at week 72, 6 patients (75%) maintained a response until week 96 (4 of 6 [67%] in the add-on therapy group vs 2 of 2 [100%] in the monotherapy group; P = 1.00). Adverse events were mainly related to peginterferon. The primary end point was negative, but peginterferon add-on therapy appeared to result in a greater frequency of HBeAg seroconversion, compared with NA monotherapy, in interferon-naive patients receiving NA therapy. NCT01532843.

  10. Anomalous thermoelectric properties in double quantum dots coupled with Majorana bound states

    Directory of Open Access Journals (Sweden)

    Yi-Jie Zheng

    2016-12-01

    Full Text Available We discuss the transport properties of thermal electrons in double quantum dots that are coupled with Majorana bound states (MBSs corresponding to two model systems with T-type structure and series connection structure. It has been found that the thermoelectric figure of merit ZT in these model systems is suppressed when we consider the effects of the Majorana bound states. Here, ZT=GS2Tκ, where G is the electric conductance, S is the thermopower, T is the temperature and κ is the thermal conductance. The sign of the thermopower S changes from negative to positive when the energy levels of the quantum dots are less than μ while the sign of the thermopower S changes from positive to negative when the energy levels of the quantum dots are above μ in the model system of T-type structure, where μ is the chemical potential. As a result, the figure of merit ZT first decreases and then increases as the temperature kBT increases. This behavior is different from what is seen in the general quantum dot structure without MBSs. It is interesting to show that in the series connection structure, the thermopower S and ZT are robustness and do not vary with changes in εM when |εd|<λ, even if κ changes with εM.

  11. Fluorescent carbon nanomaterials: "quantum dots" or nanoclusters?

    Science.gov (United States)

    Dekaliuk, Mariia O; Viagin, Oleg; Malyukin, Yuriy V; Demchenko, Alexander P

    2014-08-14

    Despite many efforts, the mechanisms of light absorption and emission of small fluorescent carbon nanoparticles (C-dots) are still unresolved and are a subject of active discussion. In this work we address the question as to whether the fluorescence is a collective property of these nanoparticles or they are composed of assembled individual emitters. Selecting three types of C-dots with "violet", "blue" and "green" emissions and performing a detailed study of fluorescence intensity, lifetime and time-resolved anisotropy as a function of excitation and emission wavelengths together with the effect of viscogen and dynamic fluorescence quencher, we demonstrate that the C-dots represent assemblies of surface-exposed fluorophores. They behave as individual emitters, display electronic anisotropy, do not exchange their excited-state energies via homo-FRET and possibly display sub-nanosecond intra-particle mobility.

  12. Magnon cotunneling through a quantum dot

    Science.gov (United States)

    Karwacki, Łukasz

    2017-11-01

    I consider a single-level quantum dot coupled to two reservoirs of spin waves (magnons). Such systems have been studied recently from the point of view of possible coupling between electronic and magnonic spin currents. However, usually weakly coupled systems were investigated. When coupling between the dot and reservoirs is not weak, then higher order processes play a role and have to be included. Here I consider cotunneling of magnons through a spin-occupied quantum dot, which can be understood as a magnon (spin) leakage current in analogy to leakage currents in charge-based electronics. Particular emphasis has been put on investigating the effect of magnetic field and temperature difference between the magnonic reservoirs.

  13. Angiogenic Profiling of Synthesized Carbon Quantum Dots.

    Science.gov (United States)

    Shereema, R M; Sruthi, T V; Kumar, V B Sameer; Rao, T P; Shankar, S Sharath

    2015-10-20

    A simple method was employed for the synthesis of green luminescent carbon quantum dots (CQDs) from styrene soot. The CQDs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, and Raman spectroscopy. The prepared carbon quantum dots did not show cellular toxicity and could successfully be used for labeling cells. We also evaluated the effects of carbon quantum dots on the process of angiogenesis. Results of a chorioallantoic membrane (CAM) assay revealed the significant decrease in the density of branched vessels after their treatment with CQDs. Further application of CQDs significantly downregulated the expression levels of pro-angiogenic growth factors like VEGF and FGF. Expression of VEGFR2 and levels of hemoglobin were also significantly lower in CAMs treated with CQDs, indicating that the CQDs inhibit angiogenesis. Data presented here also show that CQDs can selectively target cancer cells and therefore hold potential in the field of cancer therapy.

  14. Analysis of some parameters for random nodes in priority trees

    Directory of Open Access Journals (Sweden)

    Alois Panholzer

    2008-04-01

    Full Text Available Priority trees are a certain data structure used for priority queue administration. Under the model that all permutations of the numbers $1, dots, n$ are equally likely to construct a priority tree of size $n$ we study the following parameters in size-$n$ trees: depth of a random node, number of right edges to a random node, and number of descendants of a random node. For all parameters studied we give limiting distribution results.

  15. Positioning consumption

    DEFF Research Database (Denmark)

    Halkier, Bente; Keller, Margit

    2014-01-01

    positionings emerges based on empirical examples of research in parent–children consumption. Positionings are flexible discursive fixations of the relationship between the performances of the practitioner, other practitioners, media discourse and consumption activities. The basic positioning types...

  16. An orientation analysis method for protein immobilized on quantum dot particles

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Satoka, E-mail: aoyagi@life.shimane-u.ac.jp [Faculty of Life and Environmental Science, Shimane University, 1060 Matsue-shi, Shimane 690-8504 (Japan); Inoue, Masae [Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan)

    2009-11-30

    The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga{sup +}) and a cluster ion source (Au{sub 3}{sup +}) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga{sup +} and Au{sub 3}{sup +}, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

  17. Bright infrared LEDs based on colloidal quantum-dots

    KAUST Repository

    Sun, Liangfeng

    2013-01-01

    Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm. © 2013 Materials Research Society.

  18. Electron-hole confinement symmetry in silicon quantum dots

    NARCIS (Netherlands)

    Müller, F.; Mueller, Filipp; Konstantaras, Georgios; Spruijtenburg, P.C.; van der Wiel, Wilfred Gerard; Zwanenburg, Floris Arnoud

    2015-01-01

    We report electrical transport measurements on a gate-defined ambipolar quantum dot in intrinsic silicon. The ambipolarity allows its operation as either an electron or a hole quantum dot of which we change the dot occupancy by 20 charge carriers in each regime. Electron−hole confinement symmetry is

  19. Imaging vasculature and lymphatic flow in mice using quantum dots

    DEFF Research Database (Denmark)

    Ballou, Byron; Ernst, Lauren A.; Andreko, Susan

    2009-01-01

    Quantum dots are ideal probes for fluorescent imaging of vascular and lymphatic tissues. On injection into appropriate sites, red- and near-infrared-emitting quantum dots provide excellent definition of vasculature, lymphoid organs, and lymph nodes draining both normal tissues and tumors. We detail...... methods for use with commercially available quantum dots and discuss common difficulties....

  20. Glowing graphene quantum dots and carbon dots: properties, syntheses, and biological applications.

    Science.gov (United States)

    Zheng, Xin Ting; Ananthanarayanan, Arundithi; Luo, Kathy Qian; Chen, Peng

    2015-04-08

    The emerging graphene quantum dots (GQDs) and carbon dots (C-dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Random-matrix theory of Majorana fermions and topological superconductors

    Science.gov (United States)

    Beenakker, C. W. J.

    2015-07-01

    The theory of random matrices originated half a century ago as a universal description of the spectral statistics of atoms and nuclei, dependent only on the presence or absence of fundamental symmetries. Applications to quantum dots (artificial atoms) followed, stimulated by developments in the field of quantum chaos, as well as applications to Andreev billiards—quantum dots with induced superconductivity. Superconductors with topologically protected subgap states, Majorana zero modes, and Majorana edge modes, provide a new arena for applications of random-matrix theory. These recent developments are reviewed, with an emphasis on electrical and thermal transport properties that can probe the Majorana fermions.

  2. Atomistic theory of electronic and optical properties of InAs/InP self-assembled quantum dots on patterned substrates

    Science.gov (United States)

    Sheng, Weidong; Hawrylak, Pawel

    2005-07-01

    We report on an atomistic theory of electronic structure and optical properties of a single InAs quantum dot grown on InP patterned substrate. The spatial positioning of individual dots using InP nanotemplates results in a quantum dot embedded in InP pyramid. The strain distribution of a quantum dot in the InP pyramid is calculated using the continuum elasticity theory. The electron and valence hole single-particle states are calculated using an atomistic effective-bond-orbital model with second nearest-neighbor interactions, coupled to strain via the Bir-Pikus Hamiltonian. The optical properties are determined by solving the many-exciton Hamiltonian for interacting electron and hole complexes using the configuration-interaction method. The effect of positioning of quantum dots using a nanotemplate on their optical spectra is determined by a comparison with dots on unpatterned substrates, and with experimental results. The possibility of tuning the quantum dot properties with varying the nanotemplate is explored.

  3. Magnetoconductivity of quantum dots with Rashba interaction

    Science.gov (United States)

    Lipparini, E.; Barranco, M.; Malet, F.; Pi, M.

    2009-03-01

    We address the magnetoconductivity of a quantum dot with Rashba spin-orbit interaction within linear-response theory. As a consequence of the generalized Kohn’s theorem, the magnetoconductivity of the dot is zero when the spin-orbit coupling is neglected. The inclusion of the spin-orbit interaction violates the mentioned theorem and gives rise to a nonzero magnetoconductivity. We derive a simple expression for this quantity valid up to the second order in the Rashba parameter. In the limit of vanishing lateral confinement, i.e., for a quantum well, a similar calculation yields the quantum Hall-effect result.

  4. Covalent functionalized black phosphorus quantum dots

    Science.gov (United States)

    Scotognella, Francesco; Kriegel, Ilka; Sassolini, Simone

    2018-01-01

    Black phosphorus (BP) nanostructures enable a new strategy to tune the electronic and optical properties of this atomically thin material. In this paper we show, via density functional theory calculations, the possibility to modify the optical properties of BP quantum dots via covalent functionalization. The quantum dot selected in this study has chemical formula P24H12 and has been covalent functionalized with one or more benzene rings or anthracene. The effect of functionalization is highlighted in the absorption spectra, where a red shift of the absorption is noticeable. The shift can be ascribed to an electron delocalization in the black phosphorus/organic molecule nanostructure.

  5. Cadmium telluride quantum dots advances and applications

    CERN Document Server

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  6. Mitigation of quantum dot cytotoxicity by microencapsulation.

    Science.gov (United States)

    Romoser, Amelia; Ritter, Dustin; Majitha, Ravish; Meissner, Kenith E; McShane, Michael; Sayes, Christie M

    2011-01-01

    When CdSe/ZnS-polyethyleneimine (PEI) quantum dots (QDs) are microencapsulated in polymeric microcapsules, human fibroblasts are protected from acute cytotoxic effects. Differences in cellular morphology, uptake, and viability were assessed after treatment with either microencapsulated or unencapsulated dots. Specifically, QDs contained in microcapsules terminated with polyethylene glycol (PEG) mitigate contact with and uptake by cells, thus providing a tool to retain particle luminescence for applications such as extracellular sensing and imaging. The microcapsule serves as the "first line of defense" for containing the QDs. This enables the individual QD coating to be designed primarily to enhance the function of the biosensor.

  7. Mitigation of quantum dot cytotoxicity by microencapsulation.

    Directory of Open Access Journals (Sweden)

    Amelia Romoser

    Full Text Available When CdSe/ZnS-polyethyleneimine (PEI quantum dots (QDs are microencapsulated in polymeric microcapsules, human fibroblasts are protected from acute cytotoxic effects. Differences in cellular morphology, uptake, and viability were assessed after treatment with either microencapsulated or unencapsulated dots. Specifically, QDs contained in microcapsules terminated with polyethylene glycol (PEG mitigate contact with and uptake by cells, thus providing a tool to retain particle luminescence for applications such as extracellular sensing and imaging. The microcapsule serves as the "first line of defense" for containing the QDs. This enables the individual QD coating to be designed primarily to enhance the function of the biosensor.

  8. Potential clinical applications of quantum dots

    Science.gov (United States)

    Medintz, Igor L; Mattoussi, Hedi; Clapp, Aaron R

    2008-01-01

    The use of luminescent colloidal quantum dots in biological investigations has increased dramatically over the past several years due to their unique size-dependent optical properties and recent advances in biofunctionalization. In this review, we describe the methods for generating high-quality nanocrystals and report on current and potential uses of these versatile materials. Numerous examples are provided in several key areas including cell labeling, biosensing, in vivo imaging, bimodal magnetic-luminescent imaging, and diagnostics. We also explore toxicity issues surrounding these materials and speculate about the future uses of quantum dots in a clinical setting. PMID:18686776

  9. Spin qubits in graphene quantum dots

    OpenAIRE

    Trauzettel, Björn; Bulaev, Denis V.; Loss, Daniel; Burkard, Guido

    2006-01-01

    We propose how to form spin qubits in graphene. A crucial requirement to achieve this goal is to find quantum dot states where the usual valley degeneracy in bulk graphene is lifted. We show that this problem can be avoided in quantum dots based on ribbons of graphene with semiconducting armchair boundaries. For such a setup, we find the energies and the exact wave functions of bound states, which are required for localized qubits. Additionally, we show that spin qubits in graphene can not on...

  10. Polymers in Carbon Dots: A Review

    Directory of Open Access Journals (Sweden)

    Yiqun Zhou

    2017-02-01

    Full Text Available Carbon dots (CDs have been widely studied since their discovery in 2004 as a green substitute of the traditional quantum dots due to their excellent photoluminescence (PL and high biocompatibility. Meanwhile, polymers have increasingly become an important component for both synthesis and modification of CDs to provide polymeric matrix and enhance their PL property. Furthermore, critical analysis of composites of CDs and polymers has not been available. Herein, in this review, we summarized the use of polymers in the synthesis and functionalization of CDs, and the applications of these CDs in various fields.

  11. Improved dot size uniformity and luminescense of InAs quantum dots on InP substrate

    Science.gov (United States)

    Qiu, Y.; Uhl, D.

    2002-01-01

    InAs self-organized quantum dots have been grown in InGaAs quantum well on InP substrates by metalorganic vapor phase epitaxy. Atomic Force Microscopy confirmed of quantum dot formation with dot density of 3X10(sup 10) cm(sup -2). Improved dot size uniformity and strong room temperature photoluminescence up to 2 micron were observed after modifying the InGaAs well.

  12. Manipulating single electron spins and coherence in quantum dots

    Science.gov (United States)

    Awschalom, David

    2008-05-01

    The non-destructive detection of a single electron spin in a quantum dot (QD) is demonstrated using a time- averaged magneto-optical Kerr rotation measurementootnotetextJ. Berezovsky, M. H. Mikkelsen, O. Gywat, N. G. Stoltz, L. A. Coldren, and D. D. Awschalom, Science 314, 1916 (2006).. This technique provides a means to directly probe the spin off- resonance, thus minimally disturbing the system. Furthermore, the ability to sequentially initialize, manipulate, and read out the state of a qubit, such as an electron spin in a quantum dot, is necessary for virtually any scheme for quantum information processing. In addition to the time-averaged measurements, we have extended the single dot KR technique into the time domain with pulsed pump and probe lasers, allowing the observation of the coherent evolution of an electron spin stateootnotetextM. H. Mikkelsen, J. Berezovsky, N. G. Stoltz, L. A. Coldren, and D. D. Awschalom, Nature Physics 3, 770 (2007).. The dot is formed by interface fluctuations of a GaAs quantum well and embedded in a diode structure to allow controllable gating/charging of the QD. To enhance the small single spin signal, the QD is positioned within a vertical optical cavity. Observations of coherent single spin precession in an applied magnetic field allow a direct measurement of the electron g-factor and transverse spin lifetime. These measurements reveal information about the relevant spin decoherence mechanisms, while also providing a sensitive probe of the local nuclear spin environment. Finally, we have recently eveloped a scheme for high speed all-optical manipulation of the spin state that enables multiple operations within the coherence timeootnotetextJ. Berezovsky, M. H. Mikkelsen, N. G. Stoltz, L. A. Coldren, and D. D. Awschalom, accepted for publication (2008).. The results represent progress toward the control and coupling of single spins and photons for quantum information processingootnotetextS. Ghosh, W.H. Wang, F. M. Mendoza, R. C

  13. The beneficial effects of a positive attention bias amongst children with a history of psychosocial deprivation.

    Science.gov (United States)

    Troller-Renfree, Sonya; McLaughlin, Katie A; Sheridan, Margaret A; Nelson, Charles A; Zeanah, Charles H; Fox, Nathan A

    2017-01-01

    Children raised in institutions experience psychosocial deprivation that has detrimental influences on attention and mental health. The current study examined patterns of attention biases in children from institutions who were randomized at approximately 21.6 months to receive either a high-quality foster care intervention or care-as-usual. At age 12, children performed a dot-probe task and indices of attention bias were calculated. Additionally, children completed a social stress paradigm and cortisol reactivity was computed. Children randomized into foster care (N=40) exhibited an attention bias toward positive stimuli but not threat, whereas children who received care-as-usual (N=40) and a never-institutionalized comparison group (N=47) showed no bias. Stability of foster care placement was related to positive bias, while instability of foster care placement was related to threat bias. The magnitude of the positive bias was associated with fewer internalizing problems and better coping mechanisms. Within the foster care group, positive attention bias was related to less blunted cortisol reactivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  15. Effects of long-range disorder and electronic interactions on the optical properties of graphene quantum dots

    Science.gov (United States)

    Altıntaş, A.; ćakmak, K. E.; Güçlü, A. D.

    2017-01-01

    We theoretically investigate the effects of long-range disorder and electron-electron interactions on the optical properties of hexagonal armchair graphene quantum dots consisting of up to 10 806 atoms. The numerical calculations are performed using a combination of tight-binding, mean-field Hubbard, and configuration interaction methods. Imperfections in the graphene quantum dots are modeled as a long-range random potential landscape, giving rise to electron-hole puddles. We show that, when the electron-hole puddles are present, the tight-binding method gives a poor description of the low-energy absorption spectra compared to mean-field and configuration interaction calculation results. As the size of the graphene quantum dot is increased, the universal optical conductivity limit can be observed in the absorption spectrum. When disorder is present, the calculated absorption spectrum approaches the experimental results for isolated monolayers of graphene sheets.

  16. 49 CFR 40.13 - How do DOT drug and alcohol tests relate to non-DOT tests?

    Science.gov (United States)

    2010-10-01

    ... respects. (b) DOT tests must take priority and must be conducted and completed before a non-DOT test is... a blood or urine specimen collected by the employee's physician or a DNA test result purporting to... 49 Transportation 1 2010-10-01 2010-10-01 false How do DOT drug and alcohol tests relate to non...

  17. Investigation of confinement effects in ZnO quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Haranath, D; Sahai, Sonal; Joshi, Amish G; Gupta, Bipin K; Shanker, V, E-mail: haranath@nplindia.or [National Physical Laboratory, Council of Scientific and Industrial Research, Dr K S Krishnan Road, New Delhi-110 012 (India)

    2009-10-21

    We report a simple method for the synthesis of Na{sup +} doped and stable zinc oxide quantum dots, using the quantum confinement atom method. An intense broad green photoluminescence (PL) was observed with a maximum located at {approx}535 nm when excited by UV radiation of 332 nm. The PL peak intensity is found to be highly dependent on the size of the quantum dots (QDs). Electron microscopy observation revealed that the radius of the QD was {approx}1 nm, which clearly indicated that the QDs are in the strong quantum confinement region (exciton Bohr radius, r{sub B}, for bulk ZnO is 1.8 nm). Phase purity of ZnO and the presence of Na{sup +} was confirmed by x-ray diffraction (XRD) and atomic absorption spectroscopy (AAS), respectively. The results are well incremented by x-ray photoelectron spectroscopy (XPS) studies. Intentional ageing of QDs for several days under controlled experimental conditions such as temperature, relative humidity and pH etc, facilitated the formation of various nanostructures with a slight red shift in the PL peak position. Time resolved emission spectroscopy measurements indicated that PL decay time changes from 35 ns for QDs to 1660 {mu}s for nanocrystals. The observed high-intensity and stable green PL emissions have been analyzed and thoroughly discussed.

  18. Double-blind, randomized placebo controlled trial of fulvestrant compared with exemestane after prior nonsteroidal aromatase inhibitor therapy in postmenopausal women with hormone receptor-positive, advanced breast cancer: results from EFECT.

    Science.gov (United States)

    Chia, Stephen; Gradishar, William; Mauriac, Louis; Bines, Jose; Amant, Frederic; Federico, Miriam; Fein, Luis; Romieu, Gilles; Buzdar, Aman; Robertson, John F R; Brufsky, Adam; Possinger, Kurt; Rennie, Pamela; Sapunar, Francisco; Lowe, Elizabeth; Piccart, Martine

    2008-04-01

    The third-generation nonsteroidal aromatase inhibitors (AIs) are increasingly used as adjuvant and first-line advanced therapy for postmenopausal, hormone receptor-positive (HR+) breast cancer. Because many patients subsequently experience progression or relapse, it is important to identify agents with efficacy after AI failure. Evaluation of Faslodex versus Exemestane Clinical Trial (EFECT) is a randomized, double-blind, placebo controlled, multicenter phase III trial of fulvestrant versus exemestane in postmenopausal women with HR+ advanced breast cancer (ABC) progressing or recurring after nonsteroidal AI. The primary end point was time to progression (TTP). A fulvestrant loading-dose (LD) regimen was used: 500 mg intramuscularly on day 0, 250 mg on days 14, 28, and 250 mg every 28 days thereafter. Exemestane 25 mg orally was administered once daily. A total of 693 women were randomly assigned to fulvestrant (n = 351) or exemestane (n = 342). Approximately 60% of patients had received at least two prior endocrine therapies. Median TTP was 3.7 months in both groups (hazard ratio = 0.963; 95% CI, 0.819 to 1.133; P = .6531). The overall response rate (7.4% v 6.7%; P = .736) and clinical benefit rate (32.2% v 31.5%; P = .853) were similar between fulvestrant and exemestane respectively. Median duration of clinical benefit was 9.3 and 8.3 months, respectively. Both treatments were well tolerated, with no significant differences in the incidence of adverse events or quality of life. Pharmacokinetic data confirm that steady-state was reached within 1 month with the LD schedule of fulvestrant. Fulvestrant LD and exemestane are equally active and well-tolerated in a meaningful proportion of postmenopausal women with ABC who have experienced progression or recurrence during treatment with a nonsteroidal AI.

  19. A study of the lunisolar secular resonance $2dot{omega}+dot{Omega}=0$

    Directory of Open Access Journals (Sweden)

    Alessandra eCelletti

    2016-03-01

    Full Text Available The dynamics of small bodies around the Earth has gained a renewed interest,since the awareness of the problems that space debris can cause in thenearby future. A relevant role in space debris is played by lunisolarsecular resonances, which might contribute to an increase of the orbitalelements, typically of the eccentricity. We concentrate our attention onthe lunisolar secular resonance described by the relation$2dot{omega}+dot{Omega}=0$, where $omega$ and $Omega$ denotethe argument of perigee and the longitude of the ascending node of the space debris.We introduce three different models with increasing complexity. We show that the growth in eccentricity, as observed in space debris located in the MEO region at the inclination about equal to $56^circ$, can be explained as a natural effect of the secular resonance $2dot{omega}+dot{Omega}=0$, while the chaotic variations of the orbital parameters are the result of interaction and overlapping of nearby resonances.

  20. Generation of singlet oxygen and other radical species by quantum dot and carbon dot nanosensitizers

    Science.gov (United States)

    Generalov, Roman; Christensen, Ingeborg L.; Chen, Wei; Sun, Ya-Ping; Kristensen, Solveig; Juzenas, Petras

    2009-06-01

    Medicinal applications of luminescent semiconductor quantum dots are of growing interest. In spite of the fact that their fabrication and imaging applications have been extensively investigated for the last decade, very little is documented on photodynamic action of quantum dots. In this study we demonstrate generation of singlet oxygen and other radical species upon exposure of quantum dots to blue light and therapeutic red light. Extent of radical production can be readily modified by antioxidants. Lay and scientific communities are two sites concerning potential hazards and enthusiastic applications of nanotechnology. Synthesis of quantum dots composed of less toxic materials is of great interest. A new candidate is a ubiquitous element carbon, which on nanoscale exhibits strong photoluminescence.

  1. Binding energy and photoionization cross-section of hydrogen-like donor impurity in strongly oblate ellipsoidal quantum dot

    Science.gov (United States)

    Hayrapetyan, D. B.; Ohanyan, G. L.; Baghdasaryan, D. A.; Sarkisyan, H. A.; Baskoutas, S.; Kazaryan, E. M.

    2018-01-01

    Hydrogen-like donor impurity states in strongly oblate ellipsoidal quantum dot have been studied. The hydrogen-like donor impurity states are investigated within the framework of variational method. The trial wave function constructed on the base of wave functions of the system without impurity. The dependence of the energy and binding energy for the ground and first excited states on the geometrical parameters of the ellipsoidal quantum dot and on the impurity position have been calculated. The behavior of the oscillator strength for different angles of incident light and geometrical parameters have been revealed. Photoionization cross-section of the electron transitions from the impurity ground state to the size-quantized ground and first excited states have been studied. The effects of impurity position and the geometrical parameters of the ellipsoidal quantum dot on the photoionization cross section dependence on the photon energy have been considered.

  2. Lateral excitonic switching in vertically stacked quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Jarzynka, Jarosław R.; McDonald, Peter G.; Galbraith, Ian [Institute of Photonics and Quantum Sciences, SUPA, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Shumway, John [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)

    2016-06-14

    We show that the application of a vertical electric field to the Coulomb interacting system in stacked quantum dots leads to a 90° in-plane switching of charge probability distribution in contrast to a single dot, where no such switching exists. Results are obtained using path integral quantum Monte Carlo with realistic dot geometry, alloy composition, and piezo-electric potential profiles. The origin of the switching lies in the strain interactions between the stacked dots hence the need for more than one layer of dots. The lateral polarization and electric field dependence of the radiative lifetimes of the excitonic switch are also discussed.

  3. Photoluminescent carbon dots from 1,4-addition polymers.

    Science.gov (United States)

    Jiang, Zhiqiang; Nolan, Andrew; Walton, Jeffrey G A; Lilienkampf, Annamaria; Zhang, Rong; Bradley, Mark

    2014-08-25

    Photoluminescent carbon dots were synthesised directly by thermopyrolysis of 1,4-addition polymers, allowing precise control of their properties. The effect of polymer composition on the properties of the carbon dots was investigated by TEM, IR, XPS, elemental analysis and fluorescence analysis, with carbon dots synthesised from nitrogen-containing polymers showing the highest fluorescence. The carbon dots with high nitrogen content were observed to have strong fluorescence in the visible region, and culture with cells showed that the carbon dots were non-cytotoxic and readily taken up by three different cell lines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The Influence of Formulating a Damping Solution on Dot Gain

    Directory of Open Access Journals (Sweden)

    Povilas Mikalainis

    2011-02-01

    Full Text Available Difference in dot gain using various additives to the damping solution was investigated on two offset web presses. Dot gain was measured using a densitometer and calculated considering CIE L*a*b* coordinates. It was found that while using a non alcohol additive instead of the alcohol one, dot gain became smaller and printing stability was lower. Changes in dot gain depend on the ink that may vary in colours. The influence of changes in dot gain on the colour was determined. Besides, it was found that differences in colour were unacceptable in many cases.Article in Lithuanian

  5. Phase II Randomized Preoperative Window-of-Opportunity Study of the PI3K Inhibitor Pictilisib Plus Anastrozole Compared With Anastrozole Alone in Patients With Estrogen Receptor-Positive Breast Cancer.

    Science.gov (United States)

    Schmid, Peter; Pinder, Sarah E; Wheatley, Duncan; Macaskill, Jane; Zammit, Charles; Hu, Jennifer; Price, Robert; Bundred, Nigel; Hadad, Sirwan; Shia, Alice; Sarker, Shah-Jalal; Lim, Louise; Gazinska, Patrycja; Woodman, Natalie; Korbie, Darren; Trau, Matt; Mainwaring, Paul; Gendreau, Steven; Lackner, Mark R; Derynck, Mika; Wilson, Timothy R; Butler, Hannah; Earl, Gemma; Parker, Peter; Purushotham, Arnie; Thompson, Alastair

    2016-06-10

    Preclinical data support a key role for the PI3K pathway in estrogen receptor-positive breast cancer and suggest that combining PI3K inhibitors with endocrine therapy may overcome resistance. This preoperative window study assessed whether adding the PI3K inhibitor pictilisib (GDC-0941) can increase the antitumor effects of anastrozole in primary breast cancer and aimed to identify the most appropriate patient population for combination therapy. In this randomized, open-label phase II trial, postmenopausal women with newly diagnosed operable estrogen receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers were recruited. Participants were randomly allocated (2:1, favoring the combination) to 2 weeks of preoperative treatment with anastrozole 1 mg once per day (n = 26) or the combination of anastrozole 1 mg with pictilisib 260 mg once per day (n = 49). The primary end point was inhibition of tumor cell proliferation as measured by change in Ki-67 protein expression between tumor samples taken before and at the end of treatment. There was significantly greater geometric mean Ki-67 suppression of 83.8% (one-sided 95% CI, ≥ 79.0%) for the combination and 66.0% (95% CI, ≤ 75.4%) for anastrozole (geometric mean ratio [combination:anastrozole], 0.48; 95% CI, ≤ 0.72; P = .004). PIK3CA mutations were not predictive of response to pictilisib, but there was significant interaction between response to treatment and molecular subtype (P = .03); for patients with luminal B tumors, the combination:anastrozole geometric mean ratio of Ki-67 suppression was 0.37 (95% CI, ≤ 0.67; P = .008), whereas no significant Ki-67 response was observed for pictilisib in luminal A tumors (1.01; P = .98). Multivariable analysis confirmed Ki-67 response to the combination treatment of patients with luminal B tumors irrespective of progesterone receptor status or baseline Ki-67 expression. Adding pictilisib to anastrozole significantly increases suppression

  6. The effect of a trunk release maneuver on Peak Pressure Index, trunk displacement and perceived discomfort in older adults seated in a high Fowler’s position: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Best Krista L

    2012-11-01

    Full Text Available Abstract Background Pressure ulcers pose significant negative individual consequences and financial burden on the healthcare system. Prolonged sitting in High Fowler’s position (HF is common clinical practice for older adults who spend extended periods of time in bed. While HF aids in digestion and respiration, being placed in a HF may increase perceived discomfort and risk of pressure ulcers due to increased pressure magnitude at the sacral and gluteal regions. It is likely that shearing forces could also contribute to risk of pressure ulcers in HF. The purpose of this study was to evaluate the effect of a low-tech and time-efficient Trunk Release Manuever (TRM on sacral and gluteal pressure, trunk displacement and perceived discomfort in ambulatory older adults. Method A randomized controlled trial was used. We recruited community-living adults who were 60 years of age and older using posters, newspaper advertisements and word-of-mouth. Participants were randomly allocated to either the intervention or control group. The intervention group (n = 59 received the TRM, while the control group (n = 58 maintained the standard HF position. Results The TRM group had significantly lower mean (SD PPI values post-intervention compared to the control group, 59.6 (30.7 mmHg and 79.9 (36.5 mmHg respectively (p = 0.002. There was also a significant difference in trunk displacement between the TRM and control groups, +3.2 mm and −5.8 mm respectively (p = 0.005. There were no significant differences in perceived discomfort between the groups. Conclusion The TRM was effective for reducing pressure in the sacral and gluteal regions and for releasing the trunk at the point of contact between the skin and the support surface, but did not have an effect on perceived discomfort. The TRM is a simple method of repositioning which may have important clinical application for the prevention of pressure ulcers that may occur as a result of HF.

  7. Prospective Biomarker Analysis of the Randomized CHER-LOB Study Evaluating the Dual Anti-HER2 Treatment With Trastuzumab and Lapatinib Plus Chemotherapy as Neoadjuvant Therapy for HER2-Positive Breast Cancer.

    Science.gov (United States)

    Guarneri, Valentina; Dieci, Maria Vittoria; Frassoldati, Antonio; Maiorana, Antonino; Ficarra, Guido; Bettelli, Stefania; Tagliafico, Enrico; Bicciato, Silvio; Generali, Daniele Giulio; Cagossi, Katia; Bisagni, Giancarlo; Sarti, Samanta; Musolino, Antonino; Ellis, Catherine; Crescenzo, Rocco; Conte, PierFranco

    2015-09-01

    The CHER-LOB randomized phase II study showed that the combination of lapatinib and trastuzumab plus chemotherapy increases the pathologic complete remission (pCR) rate compared with chemotherapy plus either trastuzumab or lapatinib. A biomarker program was prospectively planned to identify potential predictors of sensitivity to different treatments and to evaluate treatment effect on tumor biomarkers. Overall, 121 breast cancer patients positive for human epidermal growth factor 2 (HER2) were randomly assigned to neoadjuvant chemotherapy plus trastuzumab, lapatinib, or both trastuzumab and lapatinib. Pre- and post-treatment samples were centrally evaluated for HER2, p95-HER2, phosphorylated AKT (pAKT), phosphatase and tensin homolog, Ki67, apoptosis, and PIK3CA mutations. Fresh-frozen tissue samples were collected for genomic analyses. A mutation in PIK3CA exon 20 or 9 was documented in 20% of cases. Overall, the pCR rates were similar in PIK3CA wild-type and PIK3CA-mutated patients (33.3% vs. 22.7%; p = .323). For patients receiving trastuzumab plus lapatinib, the probability of pCR was higher in PIK3CA wild-type tumors (48.4% vs. 12.5%; p = .06). Ki67, pAKT, and apoptosis measured on the residual disease were significantly reduced from baseline. The degree of Ki67 inhibition was significantly higher in patients receiving the dual anti-HER2 blockade. The integrated analysis of gene expression and copy number data demonstrated that a 50-gene signature specifically predicted the lapatinib-induced pCR. PIK3CA mutations seem to identify patients who are less likely to benefit from dual anti-HER2 inhibition. p95-HER2 and markers of phosphoinositide 3-kinase pathway deregulation are not confirmed as markers of different sensitivity to trastuzumab or lapatinib. HER2 is currently the only validated marker to select breast cancer patients for anti-HER2 treatment; however, it is becoming evident that HER2-positive breast cancer is a heterogeneous disease. In addition, more

  8. Tumor-infiltrating lymphocytes in patients with HER2-positive breast cancer treated with neoadjuvant chemotherapy plus trastuzumab, lapatinib or their combination: A meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Solinas, C; Ceppi, M; Lambertini, M; Scartozzi, M; Buisseret, L; Garaud, S; Fumagalli, D; de Azambuja, E; Salgado, R; Sotiriou, C; Willard-Gallo, K; Ignatiadis, M

    2017-06-01

    A relationship between baseline tumor-infiltrating lymphocytes (TIL) and outcomes has been described in HER2-positive breast cancer. Nevertheless, the magnitude of this association and whether this effect differs based on the type of anti-HER2 agent remain controversial. This meta-analysis investigated the association between baseline TIL and pathologic complete response (pCR) rates in HER2-positive breast cancer patients treated with neoadjuvant chemotherapy plus trastuzumab and lapatinib either alone or in combination. A literature search covering PubMed, Embase and the Cochrane library up to October 31, 2016 identified randomized, controlled trials investigating neoadjuvant chemotherapy plus trastuzumab and lapatinib either alone or in combination where published data for pCR based on pre-treatment TIL scores were available. Two subgroups were considered: high baseline TIL vs. non-high TIL, according to each study definition. Summary risk estimates (odds ratio) and 95% confidence intervals (CI) were calculated for pCR using pre-treatment TIL levels for each trial. Pooled analyses were conducted using random and fixed effects models. Interaction P-values were computed using a Monte Carlo permutation test. A total of 5 studies (N=1256 patients) were included. Overall, high TIL subgroup was associated with a significantly increased pCR rate (OR 2.46; 95% CI 1.36-4.43; P=0.003). No interaction was observed between TIL subgroup (high vs. non-high TIL) and response to anti-HER2 agent(s) (trastuzumab vs. lapatinib vs. their combination; P=0.747) and chemotherapy (anthracycline and taxanes vs. taxanes only; P=0.201). A stronger association between high TIL subgroup and pCR rates was observed when examining only the 4 studies using anthracycline- and taxane- based neoadjuvant chemotherapy and the 60% cut-off for high TIL (N=869, NeoALTTO excluded) with an OR of 2.88 (95% CI 2.03-4.08; Pchemotherapy regimens used. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. An energy and cost efficient majority-based RAM cell in quantum-dot cellular automata

    Directory of Open Access Journals (Sweden)

    Milad Bagherian Khosroshahy

    Full Text Available Nanotechnologies, notably quantum-dot cellular automata, have achieved major attentions for their prominent features as compared to the conventional CMOS circuitry. Quantum-dot cellular automata, particularly owning to its considerable reduction in size, high switching speed and ultra-low energy consumption, is considered as a potential alternative for the CMOS technology. As the memory unit is one of the most essential components in a digital system, designing a well-optimized QCA random access memory (RAM cell is an important area of research. In this paper, a new five-input majority gate is presented which is suitable for implementing efficient single-layer QCA circuits. In addition, a new RAM cell with set and reset capabilities is designed based on the proposed majority gate, which has an efficient and low-energy structure. The functionality, performance and energy consumption of the proposed designs are evaluated based on the QCADesigner and QCAPro tools. According to the simulation results, the proposed RAM design leads to on average 38% lower total energy dissipation, 25% smaller area, 20% lower cell count, 28% lower delay and 60% lower QCA cost as compared to its previous counterparts. Keywords: Quantum-dot cellular automata (QCA, Majority gate, Random access memory (RAM, Energy efficiency

  10. Palbociclib in Combination With Fulvestrant in Women With Hormone Receptor-Positive/HER2-Negative Advanced Metastatic Breast Cancer: Detailed Safety Analysis From a Multicenter, Randomized, Placebo-Controlled, Phase III Study (PALOMA-3).

    Science.gov (United States)

    Verma, Sunil; Bartlett, Cynthia Huang; Schnell, Patrick; DeMichele, Angela M; Loi, Sherene; Ro, Jungsil; Colleoni, Marco; Iwata, Hiroji; Harbeck, Nadia; Cristofanilli, Massimo; Zhang, Ke; Thiele, Alexandra; Turner, Nicholas C; Rugo, Hope S

    2016-10-01

    Palbociclib enhances endocrine therapy and improves clinical outcomes in hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). Because this is a new target, it is clinically important to understand palbociclib's safety profile to effectively manage toxicity and optimize clinical benefit. Patients with endocrine-resistant, HR-positive/HER2-negative MBC (n = 521) were randomly assigned 2:1 to receive fulvestrant (500 mg intramuscular injection) with or without goserelin with oral palbociclib (125 mg daily; 3 weeks on/1 week off) or placebo. Safety assessments at baseline and day 1 of each cycle included blood counts on day 15 for the first 2 cycles. Hematologic toxicity was assessed by using laboratory data. A total of 517 patients were treated (palbociclib, n = 345; placebo, n = 172); median follow-up was 8.9 months. With palbociclib, neutropenia was the most common grade 3 (55%) and 4 (10%) adverse event; median times to onset and duration of grade ≥3 episodes were 16 and 7 days, respectively. Asian ethnicity and below-median neutrophil counts at baseline were significantly associated with an increased chance of developing grade 3-4 neutropenia with palbociclib. Dose modifications for grade 3-4 neutropenia had no adverse effect on progression-free survival. In the palbociclib arm, febrile neutropenia occurred in 3 (Palbociclib plus fulvestrant treatment was well-tolerated, and the primary toxicity of asymptomatic neutropenia was effectively managed by dose modification without apparent loss of efficacy. This study appears at ClinicalTrials.gov, NCT01942135. Treatment with palbociclib in combination with fulvestrant was generally safe and well-tolerated in patients with hormone receptor (HR)-positive metastatic breast cancer. Consistent with the drug's proposed mechanism of action, palbociclib-related neutropenia differs in its clinical time course, patterns, and consequences from those seen with

  11. Inter-dot strain field effect on the optoelectronic properties of realistic InP lateral quantum-dot molecules

    Energy Technology Data Exchange (ETDEWEB)

    Barettin, Daniele, E-mail: Daniele.Barettin@uniroma2.it; Auf der Maur, Matthias [Department of Electronic Engineering, University of Rome “Tor Vergata,” Via del Politecnico 1, 00133, Rome (Italy); De Angelis, Roberta; Prosposito, Paolo; Casalboni, Mauro [Department of Industrial Engineering, University of Rome Tor Vergata, Via del Politecnico 1 00133 Rome, Italy and INSTM, Unitá di ricerca dell' Universitá di Roma “Tor Vergata,” Via della Ricerca Scientifica 1, 00133, Rome (Italy); Pecchia, Alessandro [CNR-ISMN, via Salaria Km. 29.300, 00017 Monterotondo, Rome (Italy)

    2015-03-07

    We report on numerical simulations of InP surface lateral quantum-dot molecules on In{sub 0.48}Ga{sub 0.52 }P buffer, using a model strictly derived by experimental results by extrapolation of the molecules shape from atomic force microscopy images. Our study has been inspired by the comparison of a photoluminescence spectrum of a high-density InP surface quantum dot sample with a numerical ensemble average given by a weighted sum of simulated single quantum-dot spectra. A lack of experimental optical response from the smaller dots of the sample is found to be due to strong inter-dot strain fields, which influence the optoelectronic properties of lateral quantum-dot molecules. Continuum electromechanical, k{sup →}·p{sup →} bandstructure, and optical calculations are presented for two different molecules, the first composed of two dots of nearly identical dimensions (homonuclear), the second of two dots with rather different sizes (heteronuclear). We show that in the homonuclear molecule the hydrostatic strain raises a potential barrier for the electrons in the connection zone between the dots, while conversely the holes do not experience any barrier, which considerably increases the coupling. Results for the heteronuclear molecule show instead that its dots do not appear as two separate and distinguishable structures, but as a single large dot, and no optical emission is observed in the range of higher energies where the smaller dot is supposed to emit. We believe that in samples of such a high density the smaller dots result as practically incorporated into bigger molecular structures, an effect strongly enforced by the inter-dot strain fields, and consequently it is not possible to experimentally obtain a separate optical emission from the smaller dots.

  12. Annealing-induced change in quantum dot chain formation mechanism

    Directory of Open Access Journals (Sweden)

    Tyler D. Park

    2014-12-01

    Full Text Available Self-assembled InGaAs quantum dot chains were grown using a modified Stranski-Krastanov method in which the InGaAs layer is deposited under a low growth temperature and high arsenic overpressure, which suppresses the formation of dots until a later annealing process. The dots are capped with a 100 nm GaAs layer. Three samples, having three different annealing temperatures of 460°C, 480°C, and 500°C, were studied by transmission electron microscopy. Results indicate two distinct types of dot formation processes: dots in the 460°C and 480°C samples form from platelet precursors in a one-to-one ratio whereas the dots in the sample annealed at 500°C form through the strain-driven self-assembly process, and then grow larger via an additional Ostwald ripening process whereby dots grow into larger dots at the expense of smaller seed islands. There are consequently significant morphological differences between the two types of dots, which explain many of the previously-reported differences in optical properties. Moreover, we also report evidence of indium segregation within the dots, with little or no indium intermixing between the dots and the surrounding GaAs barrier.

  13. Annealing-induced change in quantum dot chain formation mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Park, Tyler D.; Colton, John S.; Farrer, Jeffrey K. [Department of Physics and Astronomy, Brigham Young University, Provo UT 84602 (United States); Yang, Haeyeon [Department of Nanoscience and Nanoengineering, South Dakota School of Mines and Technology, Rapid City, SD 57701 (United States); Kim, Dong Jun [IPG Photonics Corporation, Oxford, MA 01540 (United States)

    2014-12-15

    Self-assembled InGaAs quantum dot chains were grown using a modified Stranski-Krastanov method in which the InGaAs layer is deposited under a low growth temperature and high arsenic overpressure, which suppresses the formation of dots until a later annealing process. The dots are capped with a 100 nm GaAs layer. Three samples, having three different annealing temperatures of 460°C, 480°C, and 500°C, were studied by transmission electron microscopy. Results indicate two distinct types of dot formation processes: dots in the 460°C and 480°C samples form from platelet precursors in a one-to-one ratio whereas the dots in the sample annealed at 500°C form through the strain-driven self-assembly process, and then grow larger via an additional Ostwald ripening process whereby dots grow into larger dots at the expense of smaller seed islands. There are consequently significant morphological differences between the two types of dots, which explain many of the previously-reported differences in optical properties. Moreover, we also report evidence of indium segregation within the dots, with little or no indium intermixing between the dots and the surrounding GaAs barrier.

  14. Spin-wave excitations in quantum dots

    Science.gov (United States)

    Lipparini, Enrico; Serra, Llorenç

    1998-03-01

    The transverse response function for a quantum dot in a uniform magnetic field B is calculated using current-density-functional theory. The poles corresponding to the ΔLz=+/-1 and ΔSz=+/-1 spin waves are investigated as a function of B.

  15. Orbital current mode in elliptical quantum dots

    Science.gov (United States)

    Serra, Llorenç; Puente, Antonio; Lipparini, Enrico

    1999-11-01

    An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that makes it possible to analytically interpret its main characteristics, and second, by numerically solving the microscopic equations of time evolution after an initial perturbation within the time-dependent local-spin-density approximation. Results for different deformations and sizes are shown.

  16. Competing interactions in semiconductor quantum dots

    NARCIS (Netherlands)

    van den Berg, R.; Brandino, G.P.; El Araby, O.; Konik, R.M.; Gritsev, V.; Caux, J.S.

    2014-01-01

    We introduce an integrability-based method enabling the study of semiconductor quantum dot models incorporating both the full hyperfine interaction as well as a mean-field treatment of dipole-dipole interactions in the nuclear spin bath. By performing free-induction decay and spin-echo simulations

  17. Decoherence in Nearly-Isolated Quantum Dots

    DEFF Research Database (Denmark)

    Folk, J.; M. Marcus, C.; Harris jr, J.

    2000-01-01

    Decoherence in nearly-isolated GaAs quantum dots is investigated using the change in average Coulomb blockade peak height upon breaking time-reversal symmetry. The normalized change in average peak height approaches the predicted universal value of 1/4 at temperatures well below the single...

  18. System and method for making quantum dots

    KAUST Repository

    Bakr, Osman M.

    2015-05-28

    Embodiments of the present disclosure provide for methods of making quantum dots (QDs) (passivated or unpassivated) using a continuous flow process, systems for making QDs using a continuous flow process, and the like. In one or more embodiments, the QDs produced using embodiments of the present disclosure can be used in solar photovoltaic cells, bio-imaging, IR emitters, or LEDs.

  19. Quantum dot devices for optical communications

    DEFF Research Database (Denmark)

    Mørk, Jesper

    2005-01-01

    Semiconductor quantum dots are often described as "artificial atoms": They are small nanometre-sized structures in which electrons only are allowed to exist at certain discrete levels due to size quantization, thus allowing the engineering of fundamental properties such as the coupling to light. ...

  20. Assembling quantum dots via critical Casimir forces

    NARCIS (Netherlands)

    Marino, E.; Kodger, T.E.; Hove, J.B. ten; Velders, A.H.; Schall, P.

    2016-01-01

    Programmed assembly of colloidal inorganic nanocrystal superstructures is crucial for the realization of future artificial solids as well as present optoelectronic applications. Here, we present a new way to assemble quantum dots reversibly using binary solvents. By tuning the temperature and