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RF pattern

Y Liu, E Subashi, F Yin, J Cai
PURPOSE: Current retrospective 4D-MRI provides superior tumor-to-tissue contrast and accurate respiratory motion information for radiotherapy motion management. The developed 4D-MRI techniques based on 2D-MRI image sorting require a high frame-rate of the MR sequences. However, several MRI sequences provide excellent image quality but have low frame-rate. This study aims at developing a novel retrospective 3D k-space sorting 4D-MRI technique using radial k-space acquisition MRI sequences to improve 4D-MRI image quality and temporal-resolution for imaging irregular organ/tumor respiratory motion...
June 2016: Medical Physics
D Mundy, E Tryggestad, C Beltran, K Furutani, G Gilson, S Ito, J Johnson, J Kruse, N Remmes, A Tasson, T Whitaker, M Herman
PURPOSE: To develop daily and monthly quality assurance (QA) programs in support of a new spot-scanning proton treatment facility using a combination of commercial and custom equipment and software. Emphasis was placed on efficiency and evaluation of key quality parameters. METHODS: The daily QA program was developed to test output, spot size and position, proton beam energy, and image guidance using the Sun Nuclear Corporation rf-DQA™3 device and Atlas QA software...
June 2016: Medical Physics
Nalee Kim, Jeongshim Lee, Kyung Hwan Kim, Jong Won Park, Chang Geol Lee, Ki Chang Keum
PURPOSE: Early hypopharyngeal squamous cell carcinoma (HPSCC) is a rarely diagnosed disease, for which the optimal treatment has not been defined yet. We assessed patterns of failure and outcomes in early HPSCC treated with various therapeutic approaches to identify its optimal treatment. MATERIALS AND METHODS: Thirty-six patients with stage I (n = 10) and II (n = 26) treated between January 1992 and March 2014 were reviewed. Patients received definitive radiotherapy (RT) (R group, n = 10), surgery only (S group, n = 19), or postoperative RT (PORT group, n = 7)...
December 2016: Radiation Oncology Journal
Yun Jiang, Dan Ma, Himanshu Bhat, Huihui Ye, Stephen F Cauley, Lawrence L Wald, Kawin Setsompop, Mark A Griswold
PURPOSE: The purpose of this study is to accelerate an MR fingerprinting (MRF) acquisition by using a simultaneous multislice method. METHODS: A multiband radiofrequency (RF) pulse was designed to excite two slices with different flip angles and phases. The signals of two slices were driven to be as orthogonal as possible. The mixed and undersampled MRF signal was matched to two dictionaries to retrieve T1 and T2 maps of each slice. Quantitative results from the proposed method were validated with the gold-standard spin echo methods in a phantom...
December 26, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Leonardo D De Araujo, Silvia L Roa, Ana C Bueno, Fernanda B Coeli-Lacchini, Clarissa S Martins, Ernane T Uchoa, Jose Antunes-Rodrigues, Lucila L Elias, Paula C Elias, Ayrton C Moreira, Margaret De Castro
Food access restriction is associated to changes in gene expression of the circadian clock system. However, there are only a few studies investigating the effects of non-photic synchronizers, such as food entrainment, on the expression of clock genes in the central oscillators. We hypothesized that different feeding restriction patterns could modulate the expression of clock genes in the suprachiasmatic nucleus (SCN) "master" clock and in extra-SCN oscillators such as the paraventricular (PVN) and arcuate (ARC) hypothalamic nuclei...
2016: Frontiers in Neuroscience
Wujie Zhang, Annegret L Falkner, B Suresh Krishna, Michael E Goldberg, Kenneth D Miller
Little is known about the internal circuitry of the primate lateral intraparietal area (LIP). During two versions of a delayed-saccade task, we found radically different network dynamics beneath similar population average firing patterns. When neurons are not influenced by stimuli outside their receptive fields (RFs), dynamics of the high-dimensional LIP network during slowly varying activity lie predominantly in one multi-neuronal dimension, as described previously. However, when activity is suppressed by stimuli outside the RF, slow LIP dynamics markedly deviate from a single dimension...
January 4, 2017: Neuron
Dai Okushima, David C Poole, Thomas J Barstow, Harry B Rossiter, Narihiko Kondo, T Scott Bowen, Tatsuro Amano, Shunsaku Koga
It is axiomatic that greater aerobic fitness (V˙O2peak) derives from enhanced perfusive and diffusive O2 conductances across active muscles. However, it remains unknown how these conductances might be reflected by regional differences in fractional O2 extraction (i.e., deoxy [Hb+Mb] and tissue O2 saturation [StO2]) and diffusive O2 potential (i.e., total[Hb+Mb]) among muscles spatially heterogeneous in blood flow, fiber type, and recruitment (vastus lateralis, VL; rectus femoris, RF). Using quantitative time-resolved near-infrared spectroscopy during ramp cycling in 24 young participants (V˙O2peak range: ~37...
December 2016: Physiological Reports
M de Ridder, Z A R Gouw, J J Sonke, A Navran, B Jasperse, J Heukelom, M E T Tesselaar, W M C Klop, M W M van den Brekel, Abrahim Al-Mamgani
The objectives is to thoroughly analyze the pattern of failure and oncologic outcome in recurrent oropharyngeal cancer (OPC) after (chemo)radiotherapy and correlate the site of failure to the planned radiation dose. Between January 2010 and April 2014, 57 patients with recurrent OPC after (chemo)radiotherapy were analyzed. Endpoints were pattern of failure and overall survival (OS). Local (LF) and regional failure (RF) were classified as in-field [>50% within gross tumor volume (GTV)], marginal [<50% within GTV but >50% within clinical target volume (CTV)], or out-of-field (>50% outside CTV) recurrences...
December 9, 2016: European Archives of Oto-rhino-laryngology
Ningzhi Li, Shizhe Li, Jun Shen
PURPOSE: Over the past decade, many techniques have been developed to reduce radiofrequency (RF) power deposition associated with proton decoupling in in vivo Carbon-13 ((13)C) magnetic resonance spectroscopy (MRS). In this work we propose a new strategy that uses data under-sampling to achieve reduction in RF power deposition. MATERIALS AND METHODS: Essentially, proton decoupling is required only during randomly selected segments of data acquisition. By taking advantage of the sparse spectral pattern of the carboxylic/amide region of in vivo(13)C spectra of brain, we developed an iterative algorithm to reconstruct spectra from randomly under-sampled data...
December 7, 2016: Magnetic Resonance Imaging
Ahmed Zihni, Tianjia Ge, Shuddhadeb Ray, Robert Wang, Zhe Liang, Jaime A Cavallo, Michael M Awad
BACKGROUND: Robot-assisted laparoscopic surgery (RALS) uses 3-dimensional visualization and wristed instruments that provide more degrees of freedom than rigid traditional laparoscopic (TLS) instrumentation. These features have been touted to improve accuracy and efficiency during surgical task performance. Little is known, however, about the transferability of skills between the two platforms or whether task performance on one platform primes surgeons for task performance on the other...
November 2016: Journal of Surgical Research
Xiang Xiao, Hui Fang, Jiansheng Wu, ChaoYong Xiao, Ting Xiao, Lu Qian, FengJing Liang, Zhou Xiao, Kang Kang Chu, Xiaoyan Ke
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with core symptoms of atypical social interaction, communication, and restricted, repetitive patterns of behavior, interests, and activities. Although the pathophysiologic mechanism of ASD is unclarified yet, the neuroanatomical features are considered as valuable predictors for discriminating ASD from others. But there has been relatively little scientific study about predictive power of different neuroanatomical features of early age ASD...
November 22, 2016: Autism Research: Official Journal of the International Society for Autism Research
Kohei Watanabe, Motoki Kouzaki, Toshio Moritani
Our recent studies showed the rectus femoris (RF) muscle is regionally regulated during the level walking and this unique neuromuscular activation pattern is influenced by aging (Watanabe et al., 2014, 2016 J Biomech). We aimed to investigate and compare regional neuromuscular activation patterns along the RF muscle between the young and elderly during the stair walking. Fourteen young men (age: 20.4±1.0years) and 14 elderly men (age: 73.8±5.9years) performed the stair ascent and descent. Fifteen trials of three steps were performed for both stair ascent and descent...
November 10, 2016: Gait & Posture
He-Hua Zhang, Liuyang Yang, Yuchuan Liu, Pin Wang, Jun Yin, Yongming Li, Mingguo Qiu, Xueru Zhu, Fang Yan
BACKGROUND: The use of speech based data in the classification of Parkinson disease (PD) has been shown to provide an effect, non-invasive mode of classification in recent years. Thus, there has been an increased interest in speech pattern analysis methods applicable to Parkinsonism for building predictive tele-diagnosis and tele-monitoring models. One of the obstacles in optimizing classifications is to reduce noise within the collected speech samples, thus ensuring better classification accuracy and stability...
November 16, 2016: Biomedical Engineering Online
Majidreza Khos Hkholgh, Sajad Nazari
The genetic variation and population structure of narrow-clawed crayfish (Astacus leptodactylus) was examined by means of polymerase chain reaction (PC R) restriction fragment length polymorphism (RF LP) analysis of the cytochrome oxidase subunit I (COI) of mitochondrial DNA. A total of 194 adult specimens were collected from seven sample sites including, two in the south Caspian Sea and one each in Anzali wetland and Aras reservoir and three rivers Chafrood, Masule Rudkhan and S iah Darvishan. The PCR products were digested with 19 restriction enzymes and five enzymes revealed polymorphism patterns (DdeІ, MboІ, TaqI, RsaІ and HinfІ)...
December 2015: Molecular Biology Research Communications
Yuta Goto, Atsushi Okamoto, Yuta Wakayama, Kazuhisa Ogawa, Jin Nozawa, Akihisa Tomita, Takehiro Tsuritani
To obtain a phase distribution without the use of an optical path besides an object beam, a reference-free holographic diversity interferometry (RF-HDI) has been proposed. Although the RF-HDI can generate an internal reference beam from the object beam, the method has a problem of measurement accuracy due to insufficient power of the internal reference beam. To solve the problem, we newly propose a RF-HDI via iterative measurements. Our method improves the measurement accuracy by utilizing iterative measurements and feedback of each obtained phase image to the measurement system...
October 17, 2016: Optics Express
Heijun Jeong, Sungjoon Lim
In this paper, we propose a stretchable radio-frequency (RF) strain sensor fabricated with screen printing technology. The RF sensor is designed using a half-wavelength patch that resonates at 3.7 GHz. The resonant frequency is determined by the length of the patch, and it therefore changes when the patch is stretched. Polydimethylsiloxane (PDMS) is used to create the substrate, because of its stretchable and screen-printable surface. In addition, Dupont PE872 (Dupont, NC, American) silver conductive ink is used to create the stretchable conductive patterns...
November 2, 2016: Sensors
Annachiara Strazza, Alessandro Mengarelli, Sandro Fioretti, Laura Burattini, Valentina Agostini, Marco Knaflitz, Francesco Di Nardo
The research purpose was to quantify the co-contraction patterns of quadriceps femoris (QF) vs. hamstring muscles during free walking, in terms of onset-offset muscular activation, excitation intensity, and occurrence frequency. Statistical gait analysis was performed on surface-EMG signals from vastus lateralis (VL), rectus femoris (RF), and medial hamstrings (MH), in 16315 strides walked by 30 healthy young adults. Results showed full superimpositions of MH with both VL and RF activity from terminal swing, 80 to 100% of gait cycle (GC), to the successive loading response (≈0-15% of GC), in around 90% of the considered strides...
January 2017: Gait & Posture
Blanca Hernández-Cruz, Esther Márquez-Saavedra, Rafael Caliz-Caliz, Federico Navarro-Sarabia
BACKGROUND: Rheumatoid arthritis (RA) patients are treated with a mean of 3-4 conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) with or without glucocorticoids (GCs), before the first biologic prescription. The main reasons for change are inefficacy in 30-40 % of patients, and toxicity ≈ 10 %. Thus, they are treated with the first TNF antagonists in monotherapy. The aim of this study was to analyse the csDMARD and GC prescription patterns before and during treatment with the first TNF antagonist, and compare their effectiveness in three groups of patients...
November 8, 2016: Arthritis Research & Therapy
Wenzhi Yang, Xue Qiao, Kai Li, Jingran Fan, Tao Bo, De-An Guo, Min Ye
To differentiate traditional Chinese medicines (TCM) derived from congeneric species in TCM compound preparations is usually challenging. The roots of Panax ginseng (PG), Panax quinquefolium (PQ) and Panax notoginseng (PN) are used as popular TCM. They contain similar triterpenoid saponins (ginsenosides) as the major bioactive constituents. Thus far, only a few chemical markers have been discovered to differentiate these three species. Herein we present a multiple marker detection approach to effectively differentiate the three Panax species, and to identify them in compound preparations...
November 2016: Acta Pharmaceutica Sinica. B
Marcelo Wu, Nathanael L-Y Wu, Tayyaba Firdous, Fatemeh Fani Sani, Joseph E Losby, Mark R Freeman, Paul E Barclay
Nanophotonic optomechanical devices allow the observation of nanoscale vibrations with a sensitivity that has dramatically advanced the metrology of nanomechanical structures and has the potential to impact studies of nanoscale physical systems in a similar manner. Here we demonstrate this potential with a nanophotonic optomechanical torque magnetometer and radiofrequency (RF) magnetic susceptometer. Exquisite readout sensitivity provided by a nanocavity integrated within a torsional nanomechanical resonator enables observations of the unique net magnetization and RF-driven responses of single mesoscopic magnetic structures in ambient conditions...
October 31, 2016: Nature Nanotechnology
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