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Hideki Kojima, Makoto Takigami, Tomohiro Asano, Yasuhiro Hatanaka, Kazuhiro Aizawa, Masayori Ishikawa
In dynamic multi-leaf collimator (MLC) intensity-modulated radiotherapy (IMRT), the accuracy of delivered dose is influenced by the positional accuracy of the moving MLC. In order to assess the accuracy of the delivered dose during dynamic MLC IMRT, the delivered dose error in dynamic MLC IMRT using the MLC speed control with dose rate change was investigated. Sweeping gap sequence irradiation was performed with constant MLC leaf speed at 0.6 to 5 cm/s or changed MLC speed (4 steps). The positional accuracy of the moving MLC was evaluated from the trajectory log file...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
Nadia Vega, Oscar Marin, Ezequiel Tosi, Gustavo Grinblat, Edgar Mosquera, M Moreno, Mónica Tirado, D Comedi
The room temperature photoluminescence (PL) from ZnO/MgO core/shell nanowires (NWs) grown by a simple two-step vapour transport method was studied for various MgO shell widths (w). Two distinct effects induced by the MgO shell were clearly identified. The first one, related to the ZnO/MgO interface formation, is evidenced by strong enhancements of the zero-phonon and first phonon replica of the excitonic emission, which are accompanied by a total suppression of its second phonon replica. This effect can be explained by the reduction of the band bending within the ZnO NW core that follows the removal of atmospheric adsorbates and associated surface traps during the MgO growth process on one hand, and a reduced exciton-phonon coupling as a result of the mechanical stabilization of the outermost ZnO NW monolayers by the MgO shell on the other hand...
May 19, 2017: Nanotechnology
Kellie Pearce, Francis Schuknecht, Christian Späth, Benjamin Duschner, Florian Richter, Ulf Kleineberg
We use photoemission electron microscopy (PEEM) with single- and two-photon excitation to study the properties of surface plasmon polaritons (SPPs) in tapered silver stripe waveguides. Arrays of waveguides with different widths, grating coupler geometries, and taper angles are fabricated using electron beam lithography (EBL) on Si and indium-tin-oxide (ITO)-covered glass substrates. The presence of propagating SPP modes is indicated by modulations of the non-linear photoemission intensity which run along the length of the waveguide - the result of interfering SPPs reflected from the edges...
May 10, 2017: Ultramicroscopy
Bingchu Li, Xiao Ling, Yixiang Huang, Liang Gong, Chengliang Liu
This paper presents a fixed-switching-frequency model predictive current controller using multiplexed current sensor for switched reluctance machine (SRM) drives. The converter was modified to distinguish currents from simultaneously excited phases during the sampling period. The only current sensor installed in the converter was time division multiplexing for phase current sampling. During the commutation stage, the control steps of adjacent phases were shifted so that sampling time was staggered. The maximum and minimum duty ratio of pulse width modulation (PWM) was limited to keep enough sampling time for analog-to-digital (A/D) conversion...
May 17, 2017: Sensors
Arnaud Delafontaine, Olivier Gagey, Silvia Colnaghi, Manh-Cuong Do, Jean-Louis Honeine
Rigid ankle-foot orthoses (AFO) are commonly used for impeding foot drop during the swing phase of gait. They also reduce pain and improve gait kinematics in patients with weakness or loss of integrity of ankle-foot complex structures due to various pathological conditions. However, this comes at the price of constraining ankle joint mobility, which might affect propulsive force generation and balance control. The present study examined the effects of wearing an AFO on biomechanical variables and electromyographic activity of tibialis anterior (TA) and soleus muscles during gait initiation (GI)...
2017: Frontiers in Human Neuroscience
Wei Wang, Dian Lei, Yuan Dong, Xiao Gong, Eng Soon Tok, Yee-Chia Yeo
We developed a new digital etch process that allows precise etching of Germanium or Germanium-tin (Ge1-x Sn x ) materials. The digital etch approach consists of Ge1-x Sn x oxide formation by plasma oxidation and oxide removal in diluted hydrochloric acid at room temperature. The first step is a self-limiting process, as the thickness of oxide layer grows logarithmically with the oxidation time and saturates fast. Consistent etch rates in each cycle were found on the Ge1-x Sn x samples, with the surfaces remaining smooth after etch...
May 12, 2017: Scientific Reports
Albert Jang, Xiaoping Wu, Edward J Auerbach, Michael Garwood
PURPOSE: To introduce a method of designing single and parallel transmit (pTx) 3D adiabatic π pulses for inverting and refocusing spins that are insensitive to transmit B1 ( B1+) inhomogeneity. THEORY AND METHODS: A 3D adiabatic pulse is created by replacing each piece-wise constant element (or sub-pulse) of an adiabatic full passage (AFP) by a 2D selective pulse. In this study, the parent AFP is an HS1 and each sub-pulse is a 2D pulse derived from a jinc function designed using a spiral k-trajectory...
May 12, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Michiel J van Esdonk, Jacobus Burggraaf, Piet H van der Graaf, Jasper Stevens
Pharmacodynamic modeling of pulsatile endogenous compounds (e.g. growth hormone [GH]) is currently limited to the identification of a low number of pulses. Commonly used pharmacodynamic models are not able to capture the complexity of pulsatile secretion and therefore non-compartmental analyses are performed to extract summary statistics (mean, AUC, Cmax). The aim of this study was to develop a new quantification method that deals with highly variable pulsatile data by using a deconvolution-analysis-informed population pharmacodynamic modeling approach...
May 11, 2017: Journal of Pharmacokinetics and Pharmacodynamics
S M Seleim, Taymour A Hamdalla, Mohamed E Mahmoud
Nanosized (NS) cobalt (II) bis(5-phenyl-azo-8-hydroxyquinolate) (NS Co(II)-(5PA-8HQ)2) thin films have been synthesized using static step-by-step soft surface reaction (SS-b-SSR) technique. Structural and optical characterizations of these thin films have been carried out using thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray diffraction (XRD). The HR-TEM results revealed that the assembled Co(II)-complex exhibited a uniformly NS structure particles in the form of nanorods with width and length up to 16...
April 26, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Jenna M Kim, Michael S Ehrlich
Marking of the eyelid is a crucial presurgical step in blepharoplasty. A number of markers are available for this purpose with variable ink characteristics. In this study, we measured the ink drying time and spread width of 13 markers used for preoperative marking for blepharoplasty. Based on the results, we propose markers that may be best suited for use in this procedure.
April 2017: Cutis; Cutaneous Medicine for the Practitioner
Peihong Xue, Shunsheng Ye, Hongyang Su, Shuli Wang, Jingjie Nan, Xingchi Chen, Weidong Ruan, Junhu Zhang, Zhanchen Cui, Bai Yang
We present an effective approach for fabricating graded plasmonic arrays based on ordered micro-/nanostructures with a geometric gradient. Ag nanowell arrays with graded geometric parameters were fabricated and systematically investigated. The order of the graded plasmonic arrays is generated by colloidal lithography, while the geometric gradient is the result of inclined reactive ion etching. The surface plasmon resonance (SPR) peaks were measured at different positions, which move gradually along the Ag nanowell arrays with a geometric gradient...
May 25, 2017: Nanoscale
Ryu Nagahara, Mirai Mizutani, Akifumi Matsuo, Hiroaki Kanehisa, Tetsuo Fukunaga
This study aimed to describe changes in step width (SW) during accelerated sprinting, and to clarify the relationship of SW with sprinting performance and ground reaction forces. 17 male athletes performed maximal-effort 60 m sprints. The SW and other spatiotemporal variables, as well as ground reaction impulses, over a 52 m distance were calculated. Average values for each 4 steps during acceleration were calculated to examine relationships among variables in different sections. The SW rapidly decreased up to the 13th step and slightly afterward during accelerated sprinting, showing a bilinear phase profile...
May 8, 2017: International Journal of Sports Medicine
Venkatasubbu Thirulogachandar, Ahmad M Alqudah, Ravi Koppolu, Twan Rutten, Andreas Graner, Goetz Hensel, Jochen Kumlehn, Andrea Bräutigam, Nese Sreenivasulu, Thorsten Schnurbusch, Markus Kuhlmann
Exploring genes with impact on yield-related phenotypes is the preceding step to accomplish crop improvements while facing a growing world population. A genome-wide association scan on leaf blade area (LA) in a worldwide spring barley collection (Hordeum vulgare L.), including 125 two- and 93 six-rowed accessions, identified a gene encoding the homeobox transcription factor, Six-rowed spike 1 (VRS1). VRS1 was previously described as a key domestication gene affecting spike development. Its mutation converts two-rowed (wild-type VRS1, only central fertile spikelets) into six-rowed spikes (mutant vrs1, fully developed fertile central and lateral spikelets)...
May 8, 2017: Plant Journal: for Cell and Molecular Biology
Anatole Vilhelm Wiik, Adeel Aqil, Mads Brevadt, Gareth Jones, Justin Cobb
AIM: To analyse ground reaction forces at higher speeds using another method to be more sensitive in assessing significant gait abnormalities. METHODS: A total of 44 subjects, consisting of 24 knee osteoarthritis (OA) patients and 20 healthy controls were analysed. The knee OA patients were recruited from an orthopaedic clinic that were awaiting knee replacement. All subjects had their gait patterns during stance phase at top walking speed assessed on a validated treadmill instrumented with tandem force plates...
April 18, 2017: World Journal of Orthopedics
Karlijn Sporrel, Simone R Caljouw, Rob Withagen
Over the last years, the omnipresent standardization of playgrounds-the distances between, for example, jumping stones tend to be equal-has been criticized by both scientists and architects. First, it has been argued that standardization fails to do justice to the variability in the children's action capabilities. Second, it might simplify play in that children repetitively cross over the same distance and, thus, do not have to worry about their movements anymore. In the present study we examined the gap-crossing behavior of children in both a standardized and a nonstandardized jumping stone configuration...
2017: PloS One
Daniel K Y Chen, Markus Haller, Thor F Besier
Technological developments in the last decade have enabled the integration of sensors and actuators into wearable devices for gait interventions to slow the progression of knee osteoarthritis. Wearable haptic gait retraining is one area which has seen promising results for informing modifications of gait parameters for reducing knee adduction moments (KAM) during walking. Two gait parameters which can be easily adjusted to influence KAM include foot progression angle (FPA) and step width (SW). The purpose of this study was to: (1) determine whether a custom haptic ankle bracelet using binary vibrotactile and tactile apparent movement feedback could retrain ten healthy subjects to walk with a modified FPA and SW within a short training session with 80% accuracy; and (2) whether there was a difference between the number of steps required to complete the retraining task based on the two feedback schemes being tested...
April 24, 2017: Gait & Posture
Gregory E Hicks, J Megan Sions, Peter C Coyle, Ryan T Pohlig
Previous studies in older adults have identified that chronic low back pain (CLBP) is associated with slower gait speed. Given that slower gait speed is a predictor of greater morbidity and mortality among older adults, it is important to understand the underlying spatiotemporal characteristics of gait among older adults with CLBP. The purposes of this study were to determine (1) if there are differences in spatiotemporal parameters of gait between older adults with and without CLBP during self-selected and fast walking and (2) whether any of these gait characteristics are correlated with performance of a challenging walking task, e...
April 23, 2017: Gait & Posture
Selçuk Mülazimoğlu, Emre Ocak, Gülşah Kaygusuz, Mustafa Kürşat Gökcan
BACKGROUND: As the idea of stem cell technology in the treatment of sensorial hearing loss has emerged over the past decades, the need for in vivo models for related experiments becomes explicit. One of the most common experimental models for inner ear stem cell delivery experiments is the Wistar albino rat (WAR). AIMS: To investigate the surgical anatomy of the temporal bone of the WAR with respect to the dissection steps, operative techniques, and potential pitfalls from surgery...
April 6, 2017: Balkan Medical Journal
Sho Kunimune, Shuichi Okada
In order to safely avoid obstacles, humans must rely on visual information regarding the position and shape of the object obtained in advance. The present study aimed to reveal the duration of obstacle visibility necessary for appropriate visuomotor control during obstacle avoidance in healthy older adults. Participants included 13 healthy young women (mean age: 21.5±1.4years) and 15 healthy older women (mean age: 68.5±3.5years) who were instructed to cross over an obstacle along a pressure-sensitive pathway at a self-selected pace while wearing liquid crystal shutter goggles...
April 13, 2017: Gait & Posture
Tobias Kind, Hiroshi Tsugawa, Tomas Cajka, Yan Ma, Zijuan Lai, Sajjan S Mehta, Gert Wohlgemuth, Dinesh Kumar Barupal, Megan R Showalter, Masanori Arita, Oliver Fiehn
Tandem mass spectral library search (MS/MS) is the fastest way to correctly annotate MS/MS spectra from screening small molecules in fields such as environmental analysis, drug screening, lipid analysis, and metabolomics. The confidence in MS/MS-based annotation of chemical structures is impacted by instrumental settings and requirements, data acquisition modes including data-dependent and data-independent methods, library scoring algorithms, as well as post-curation steps. We critically discuss parameters that influence search results, such as mass accuracy, precursor ion isolation width, intensity thresholds, centroiding algorithms, and acquisition speed...
April 24, 2017: Mass Spectrometry Reviews
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