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https://www.readbyqxmd.com/read/27910829/optimization-of-photon-beam-energies-in-gold-nanoparticle-enhanced-arc-radiation-therapy-using-monte-carlo-methods
#1
B Koger, C Kirkby
As a recent area of development in radiation therapy, gold nanoparticle (GNP) enhanced radiation therapy has shown potential to increase tumour dose while maintaining acceptable levels of healthy tissue toxicity. In this study, the effect of varying photon beam energy in GNP enhanced arc radiation therapy (GEART) is quantified through the introduction of a dose scoring metric, and GEART is compared to a conventional radiotherapy treatment. The PENELOPE Monte Carlo code was used to model several simple phantoms consisting of a spherical tumour containing GNPs (concentration: 15 mg Au g(-1) tumour, 0...
December 2, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27910614/upgraded-millimeter-wave-interferometer-for-measuring-the-electron-density-during-the-beam-extraction-in-the-negative-ion-source
#2
T Tokuzawa, M Kisaki, K Nagaoka, K Tsumori, Y Ito, K Ikeda, H Nakano, M Osakabe, Y Takeiri, O Kaneko
The upgraded millimeter-wave interferometer with the frequency of 70 GHz is installed on a large-scaled negative ion source. Measurable line-averaged electron density is from 2 × 10(15) to 3 × 10(18) m(-3) in front of the plasma grid. Several improvements such as the change to shorter wavelength probing with low noise, the installation of special ordered horn antenna, the signal modulation for a high accuracy digital phase detection, the insertion of insulator, and so on, are carried out for the measurement during the beam extraction by applying high voltage...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910452/spectroscopic-determination-of-the-composition-of-a-50-kv-hydrogen-diagnostic-neutral-beam
#3
X Feng, M D Nornberg, D Craig, D J Den Hartog, S P Oliva
A grating spectrometer with an electron multiplying charge-coupled device camera is used to diagnose a 50 kV, 5 A, 20 ms hydrogen diagnostic neutral beam. The ion source density is determined from Stark broadened Hβ emission and the spectrum of Doppler-shifted Hα emission is used to quantify the fraction of ions at full, half, and one-third beam energy under a variety of operating conditions including fueling gas pressure and arc discharge current. Beam current is optimized at low-density conditions in the ion source while the energy fractions are found to be steady over most operating conditions...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910441/ultra-high-vacuum-compatible-preparation-chain-for-intermetallic-compounds
#4
A Bauer, G Benka, A Regnat, C Franz, C Pfleiderer
We report the development of a versatile material preparation chain for intermetallic compounds, which focuses on the realization of a high-purity growth environment. The preparation chain comprises an argon glovebox, an inductively heated horizontal cold boat furnace, an arc melting furnace, an inductively heated rod casting furnace, an optically heated floating-zone furnace, a resistively heated annealing furnace, and an inductively heated annealing furnace. The cold boat furnace and the arc melting furnace may be loaded from the glovebox by means of a load-lock permitting to synthesize compounds starting with air-sensitive elements while handling the constituents exclusively in an inert gas atmosphere...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910309/spatial-resolution-measurements-of-the-advanced-radiographic-capability-x-ray-imaging-system-at-energies-relevant-to-compton-radiography
#5
G N Hall, N Izumi, O L Landen, R Tommasini, J P Holder, D Hargrove, D K Bradley, A Lumbard, J G Cruz, K Piston, J J Lee, E Romano, P M Bell, A C Carpenter, N E Palmer, B Felker, V Rekow, F V Allen
Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro-channel plate) to provide gating and high DQE at the 40-200 keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27908453/volumetric-modulated-arc-therapy-with-dynamic-collimator-rotation-for-improved-multileaf-collimator-tracking-of-the-prostate
#6
Ghulam Murtaza, Jakob Toftegaard, Ehsan Ullah Khan, Per Rugaard Poulsen
PURPOSE: To improve MLC tracking of prostate VMAT plans by dynamic rotation of the collimator to align the MLC leaves with the dominant prostate motion direction. METHODS: For 22 prostate cancer patients, two dual arc VMAT plans were made with (1) fixed collimators (45° and 315°) and (2) a rotating collimator that aligned the MLC leaves with the dominant prostate motion direction (population-based first principal component). The fixed and rotating collimator plan quality was compared using selected dose-volume indices...
November 28, 2016: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/27908160/correspondence-optimization-in-2d-standardized-carotid-wall-thickness-map-by-description-length-minimization-a-tool-for-increasing-reproducibility-of-3d-ultrasound-based-measurements
#7
Yimin Chen, Bernard Chiu
PURPOSE: The previously described 2D standardized vessel-wall-plus-plaque thickness (VWT) maps constructed from 3D ultrasound vessel wall measurements using an arc-length (AL) scaling approach adjusted the geometric variability of carotid arteries and has allowed for the comparisons of VWT distributions in longitudinal and cross-sectional studies. However, this mapping technique did not optimize point correspondence of the carotid arteries investigated. The potential misalignment may lead to errors in point-wise VWT comparisons...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27907244/analyzing-the-dynamics-and-morphology-of-cast-off-pattern-at-different-speed-levels-using-high-speed-digital-video-imaging
#8
Sebastian Niko Kunz, Jiri Adamec, Christina Grove
During a bloodstain pattern analysis, one of the essential tasks is to distinguish between different kinds of applied forces as well as to estimate their level of intensity. In this study, high-speed digital imaging has been used to analyze the formation of cast-off patterns generated by a simulated backswing with a blood-bearing object. For this purpose, 0.5 mL blood was applied evenly over the last 5 cm of a blade simulant. Bloodstains were created through the controlled acceleration of a backswing at different speed levels between 1...
December 1, 2016: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/27906259/spatiotemporal-blue-noise-coded-aperture-design-for-multi-shot-compressive-spectral-imaging
#9
Claudia V Correa, Henry Arguello, Gonzalo R Arce
Multi-shot coded aperture snapshot spectral imaging (CASSI) systems capture the spectral information of a scene using a small set of coded focal plane array (FPA) compressive measurements. Compressed sensing (CS) reconstruction algorithms are then used to reconstruct the underlying spectral 3D data cube from an underdetermined system of linear equations. Multiple snapshots result in a less ill-posed inverse problem and improved reconstructions. The only varying components in CASSI are the coded apertures, whose structure is crucial inasmuch as they determine the minimum number of FPA measurements needed for correct image reconstruction and the corresponding attainable quality...
December 1, 2016: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/27905609/pursuing-reliable-thermal-analysis-techniques-for-energetic-materials-decomposition-kinetics-and-thermal-stability-of-dihydroxylammonium-5-5-bistetrazole-1-1-diolate-tkx-50
#10
Nikita V Muravyev, Konstantin A Monogarov, Andrey F Asachenko, Mikhail S Nechaev, Ivan V Ananyev, Igor V Fomenkov, Vitaly G Kiselev, Alla N Pivkina
Thermal decomposition of a novel promising high-performance explosive dihydroxylammonium 5,5'-bistetrazole-1,1'-diolate (TKX-50) was studied using a number of thermal analysis techniques (thermogravimetry, differential scanning calorimetry, and accelerating rate calorimetry, ARC). To obtain more comprehensive insight into the kinetics and mechanism of TKX-50 decomposition, a variety of complementary thermoanalytical experiments were performed under various conditions. Non-isothermal and isothermal kinetics were obtained at both atmospheric and low (up to 0...
December 1, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27905536/post-translational-incorporation-of-l-phenylalanine-into-the-c-terminus-of-%C3%AE-tubulin-as-a-possible-cause-of-neuronal-dysfunction
#11
Yanina Ditamo, Yanela M Dentesano, Silvia A Purro, Carlos A Arce, C Gastón Bisig
α-Tubulin C-terminus undergoes post-translational, cyclic tyrosination/detyrosination, and L-Phenylalanine (Phe) can be incorporated in place of tyrosine. Using cultured mouse brain-derived cells and an antibody specific to Phe-tubulin, we showed that: (i) Phe incorporation into tubulin is reversible; (ii) such incorporation is not due to de novo synthesis; (iii) the proportion of modified tubulin is significant; (iv) Phe incorporation reduces cell proliferation without affecting cell viability; (v) the rate of neurite retraction declines as level of C-terminal Phe incorporation increases; (vi) this inhibitory effect of Phe on neurite retraction is blocked by the co-presence of tyrosine; (vii) microtubule dynamics is reduced when Phe-tubulin level in cells is high as a result of exogenous Phe addition and returns to normal values when Phe is removed; moreover, microtubule dynamics is also reduced when Phe-tubulin is expressed (plasmid transfection)...
December 1, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27904213/functional-outcome-of-intraarticular-distal-humerus-fracture-fixation-using-triceps-sparing-paratricipital-approach
#12
Vishal Yadav, Pulak Sharma, Ashish Gohiya
BACKGROUND: Displaced intraarticular distal humerus fracture has been conventionally treated operatively with various triceps disrupting approaches. These approaches are associated with several complications, such as triceps weakness, nonunion or delayed union of osteotomy, implant prominence, and delayed mobilization of the elbow. We present the functional outcome of intraarticular distal humerus fracture fixation using a triceps-sparing paratricipital approach which allows early elbow mobilization and preserving triceps strength...
November 2016: Indian Journal of Orthopaedics
https://www.readbyqxmd.com/read/27903745/inhibiting-microglia-expansion-prevents-diet-induced-hypothalamic-and-peripheral-inflammation
#13
Caroline André, Omar Guzman-Quevedo, Charlotte Rey, Julie Rémus-Borel, Samantha Clark, Ashley Castellanos-Jankiewicz, Elodie Ladeveze, Thierry Leste-Lasserre, Agnes Nadjar, Djoher Nora Abrous, Sophie Laye, Daniela Cota
Cell proliferation and neuroinflammation in the adult hypothalamus may contribute to the pathogenesis of obesity. Here we tested whether the intertwining of these two processes has a role in the metabolic changes caused by three weeks of saturated high-fat diet (HFD) consumption.As compared to chow, HFD-fed mice rapidly increased body weight and fat mass, and specifically showed increased microglia number in the arcuate nucleus (ARC) of the hypothalamus. Microglia expansion required the adequate presence of fats and carbohydrates in the diet, since feeding mice a very high-fat, very low-carbohydrate diet did not affect cell proliferation...
November 30, 2016: Diabetes
https://www.readbyqxmd.com/read/27903198/dosimetric-characterization-of-hypofractionated-gamma-knife-radiosurgery-of-large-or-complex-brain-tumors-versus-linear-accelerator-based-treatments
#14
Peng Dong, Angélica Pérez-Andújar, Dilini Pinnaduwage, Steve Braunstein, Philip Theodosopoulos, Michael McDermott, Penny Sneed, Lijun Ma
OBJECTIVE Noninvasive Gamma Knife (GK) platforms, such as the relocatable frame and on-board imaging, have enabled hypofractionated GK radiosurgery of large or complex brain lesions. This study aimed to characterize the dosimetric quality of such treatments against linear accelerator-based delivery systems that include the CyberKnife (CK) and volumetric modulated arc therapy (VMAT). METHODS Ten patients treated with VMAT at the authors' institution for large brain tumors (> 3 cm in maximum diameter) were selected for the study...
December 2016: Journal of Neurosurgery
https://www.readbyqxmd.com/read/27902923/kisspeptin-expression-is-decreased-in-the-arcuate-nucleus-of-hypothyroid-female-rats-with-irregular-estrus-cycles
#15
Yuji Tomori, Ken Takumi, Norio Iijima, Shinro Takai, Hitoshi Ozawa
Insufficiency of thyroid hormones inhibits gonadotropin release and results in dysregulation of reproductive function, although the precise mechanism of this disrupted gonadotropin secretion remains unclear. Kisspeptin is a neuropeptide that strongly stimulates gonadotropin secretion and plays an important role in reproductive function. To examine the involvement of kisspeptin in the dysregulation of gonadotropin secretion in hypothyroidism, we investigated Kiss1 mRNA expression and kisspeptin immunoreactivity in the hypothalamus of female rats treated with propylthiouracil (PTU)...
November 27, 2016: Neuroscience Research
https://www.readbyqxmd.com/read/27902677/perception-of-fechner-illusory-colors-in-alzheimer-disease-patients
#16
Gintaras Kaubrys, Vera Bukina, Ieva Bingelytė, Vladas Taluntis
BACKGROUND Alzheimer disease (AD) primarily affects cognition. A variety of visual disorders was established in AD. Fechner illusory colors are produced by a rotating disk with a black and white pattern. The purpose of our research was to explore the perception of illusory colors in AD. MATERIAL AND METHODS W recruited 40 AD patients (MMSE ≥14) and 40 normal controls (CG group) matched by age, education, gender in this prospective, cross-sectional, case-control study. An achromatic Benham's disk attached to a device to control the speed and direction of rotation was used to produce illusory colors...
November 30, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/27898749/-dosimetric-comparison-of-different-techniques-for-external-beam-accelerated-partial-breast-irradiation
#17
Gábor Stelczer, Tibor Major, Norbert Mészáros, Csaba Polgár, Csilla Pesznyák
The aim of this article is to evaluate and compare four different radiotherapy techniques of accelerated partial breast irradiation (APBI) considering planning quality, dosimetric and practical aspects. The investigated techniques are three dimensional conformal radiotherapy (3D-CRT), "step and shoot" (SS) and "sliding window" (SW) intensity-modulated radiotherapy, intensity-modulated arc therapy (RA). CT scans of 10 patients previously treated with APBI were selected for the study. Surgical clips were placed on the borders of the tumour bed during breast conserving surgery...
November 29, 2016: Magyar Onkologia
https://www.readbyqxmd.com/read/27898748/-investigating-the-clinical-applicability-of-ebt2-self-developing-films
#18
Zsuzsánna Zongor, Dalma Béla, Réka Király, Gábor Stelczer, Tibor Major, Csilla Pesznyák
The purpose of the study was to investigate the physical properties of the EBT2 radiochromic films and define the conditions of its clinical applicability. We irradiated the films with different treatment techniques 3D conformal (3DCRT), intensity-modulated (IMRT) and stereotactic body radiotherapy with arc therapy (SBRT), and then compared the data with the dose distribution exported from the treatment planning system (Eclipse). Two film analysis softwares were investigated for the comparison: PTW Mephysto and FilmQA Pro...
November 29, 2016: Magyar Onkologia
https://www.readbyqxmd.com/read/27898058/ccl5-rantes-contributes-to-hypothalamic-insulin-signaling-for-systemic-insulin-responsiveness-through-ccr5
#19
Szu-Yi Chou, Reni Ajoy, Chun Austin Changou, Ya-Ting Hsieh, Yang-Kao Wang, Barry Hoffer
Many neurodegenerative diseases are accompanied by metabolic disorders. CCL5/RANTES, and its receptor CCR5 are known to contribute to neuronal function as well as to metabolic disorders such as type 2 diabetes mellitus, obesity, atherosclerosis and metabolic changes after HIV infection. Herein, we found that the lack of CCR5 or CCL5 in mice impaired regulation of energy metabolism in hypothalamus. Immunostaining and co-immunoprecipitation revealed the specific expression of CCR5, associated with insulin receptors, in the hypothalamic arcuate nucleus (ARC)...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27895566/allostatic-self-efficacy-a-metacognitive-theory-of-dyshomeostasis-induced-fatigue-and-depression
#20
Klaas E Stephan, Zina M Manjaly, Christoph D Mathys, Lilian A E Weber, Saee Paliwal, Tim Gard, Marc Tittgemeyer, Stephen M Fleming, Helene Haker, Anil K Seth, Frederike H Petzschner
This paper outlines a hierarchical Bayesian framework for interoception, homeostatic/allostatic control, and meta-cognition that connects fatigue and depression to the experience of chronic dyshomeostasis. Specifically, viewing interoception as the inversion of a generative model of viscerosensory inputs allows for a formal definition of dyshomeostasis (as chronically enhanced surprise about bodily signals, or, equivalently, low evidence for the brain's model of bodily states) and allostasis (as a change in prior beliefs or predictions which define setpoints for homeostatic reflex arcs)...
2016: Frontiers in Human Neuroscience
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