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Low-intensity pulsed

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https://www.readbyqxmd.com/read/28454170/origin-and-suppression-of-parasitic-signals-in-kagom%C3%A3-lattice-hollow-core-fibers-used-for-srs-microscopy-and-endoscopy
#1
Alberto Lombardini, Esben Ravn Andresen, Alexandre Kudlinski, Ingo Rimke, Hervé Rigneault
Hollow core fibers are considered as promising candidates to deliver intense temporally overlapping picosecond pulses in applications such as stimulated Raman scattering (SRS) microscopy and endoscopy because of their inherent low nonlinearity compared to solid-core silica fibers. Here we demonstrate that, contrary to prior assumptions, parasitic signals are generated in Kagomé lattice hollow core fibers. We identify the origin of the parasitic signals as an interplay between the Kerr nonlinearity of air and frequency-dependent fiber losses...
May 1, 2017: Optics Letters
https://www.readbyqxmd.com/read/28446222/effect-of-quantity-and-intensity-of-pulsed-light-on%C3%A2-human-non-visual-physiological-responses
#2
Qianying Dai, Yuria Uchiyama, Soomin Lee, Yoshihiro Shimomura, Tetsuo Katsuura
BACKGROUND: Exposure to pulsed light results in non-visual physiological responses in humans. The present study aims to investigate whether such non-visual effects are influenced to a greater extent by the intensity of lighting or by the power (quantity) of lighting. METHODS: >Twelve healthy young male participants (23 ± 0.3 years, 21-24 age range) were recruited for the present study. Participants were exposed to light of varying levels of intensity and quantity whose frequency was held constant across the conditions, which consisted of exposure to blue (different intensity, constant quantity) and white (constant intensity, different quantity) LEDs...
April 26, 2017: Journal of Physiological Anthropology
https://www.readbyqxmd.com/read/28439945/enhancement-of-cardiomyogenesis-in-murine-stem-cells-by-low-intensity-ultrasound
#3
Ailing Teo, Amir Morshedi, Jen-Chieh Wang, Yufeng Zhou, Mayasari Lim
OBJECTIVES: Low-intensity ultrasound (LIUS) has been shown to enhance bone and cartilage regeneration from stem cells. The ease of its incorporation makes it an attractive mechanical stimulus for not only osteogenesis and chondrogenesis, but also cardiomyogenesis. However, to date, no study has investigated its effects on cardiomyogenesis from embryonic stem cells. METHODS: In this study, murine embryonic stem cells were differentiated via embryoid body formation and plating, and after 3 days they were subjected to daily 10 minutes of LIUS treatment with various conditions: (1) low-pulsed (21 mW/cm(2) , 20% duty cycle), (2) low-continuous, (3) high-pulsed (147 mW/cm(2) , 20% duty cycle), and (4) high-continuous LIUS...
April 25, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28438002/hot-luminescence-from-gold-nanoflowers-and-its-application-in-high-density-optical-data-storage
#4
Yunbao Zheng, Haiying Liu, Jin Xiang, Qiaofeng Dai, Min Ouyang, Shaolong Tie, Sheng Lan
Gold nanoflowers with feature sizes ranging from several tenths to several hundred nanometers were synthesized by using the one-pot method. They were formed by the self-organization of gold nanoparticles of several nanometers and exhibited broad extinction spectra in the near infrared spectral range. Randomly distributed hot spots originating from the strongly localized modes were generated in gold nanoflowers and their appearances exhibited strong dependences on both the polarization and wavelength of the excitation light...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28433437/optimal-ultrasound-exposure-conditions-for-maximizing-c2c12-muscle-cell-proliferation-and-differentiation
#5
Alice Rita Salgarella, Andrea Cafarelli, Leonardo Ricotti, Lorenzo Capineri, Paolo Dario, Arianna Menciassi
Described here is an in vitro systematic investigation of the effects on C2C12 myoblasts of exposure to finely controlled and repeatable low-intensity pulsed ultrasound of different frequencies (500 kHz, 1 MHz, 3 MHz and 5 MHz) and different intensities (250, 500 and 1000 mW/cm(2)). An in-house stimulation system and an ultrasound-transparent cell culture well minimized reflections and attenuations, allowing precise control of ultrasound delivery. Results indicated that a 3 MHz stimulation at 1 W/cm(2) intensity maximized cell proliferation in comparison with the other exposure conditions and untreated controls...
April 19, 2017: Ultrasound in Medicine & Biology
https://www.readbyqxmd.com/read/28428549/low-noise-time-resolved-optical-sensing-of-electromagnetic-pulses-from-petawatt-laser-matter-interactions
#6
T S Robinson, F Consoli, S Giltrap, S J Eardley, G S Hicks, E J Ditter, O Ettlinger, N H Stuart, M Notley, R De Angelis, Z Najmudin, R A Smith
We report on the development and deployment of an optical diagnostic for single-shot measurement of the electric-field components of electromagnetic pulses from high-intensity laser-matter interactions in a high-noise environment. The electro-optic Pockels effect in KDP crystals was used to measure transient electric fields using a geometry easily modifiable for magnetic field detection via Faraday rotation. Using dielectric sensors and an optical fibre-based readout ensures minimal field perturbations compared to conductive probes and greatly limits unwanted electrical pickup between probe and recording system...
April 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28427634/enhanced-porosity-and-permeability-of-three-dimensional-alginate-scaffolds-via-acoustic-microstreaming-induced-by-low-intensity-pulsed-ultrasound
#7
Gepu Guo, Yong Ma, Yang Guo, Chunbing Zhang, Xiasheng Guo, Juan Tu, Alfred C H Yu, Junru Wu, Dong Zhang
The shear stress resulting from the microstreaming induced by low-intensity pulsed ultrasound (LIPUS) has been often used to improve the permeability of cell membrane or porous engineering scaffolds. In the present study, three-dimensional (3-D) scaffold culture systems were constituted to simulate the in vivo microenvironment, providing benefits for cell growth. In order to investigate the mechanism underlying the enhanced porosity and permeability of the 3-D alginate scaffolds by using LIPUS with varied acoustic intensities, two quantitative imaging techniques (i...
July 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28426102/infection-related-complications-during-treatment-for-childhood-acute-lymphoblastic-leukemia
#8
H Inaba, D Pei, J Wolf, S C Howard, R T Hayden, M Go, O Varechtchouk, T Hahn, J Buaboonnam, M L Metzger, J E Rubnitz, R C Ribeiro, J T Sandlund, S Jeha, C Cheng, W E Evans, M V Relling, C-H Pui
Background: Comprehensive studies on neutropenia and infection-related complications in patients with acute lymphoblastic leukemia (ALL) are lacking. Patients and methods: We evaluated infection-related complications that were grade ≥3 on National Cancer Institute's Common Terminology Criteria for Adverse Events (version 3.0) and their risk factors in 409 children with newly diagnosed ALL throughout the treatment period. Results: Of the 2420 infection episodes, febrile neutropenia and clinically or microbiologically documented infection were seen in 1107 and 1313 episodes, respectively...
February 1, 2017: Annals of Oncology: Official Journal of the European Society for Medical Oncology
https://www.readbyqxmd.com/read/28420958/electrical-stimulation-of-afferent-pathways-for-the-suppression-of-pathological-tremor
#9
Jakob L Dideriksen, Christopher M Laine, Strahinja Dosen, Silvia Muceli, Eduardo Rocon, José L Pons, Julian Benito-Leon, Dario Farina
Pathological tremors are involuntary oscillatory movements which cannot be fully attenuated using conventional treatments. For this reason, several studies have investigated the use of neuromuscular electrical stimulation for tremor suppression. In a recent study, however, we found that electrical stimulation below the motor threshold also suppressed tremor, indicating involvement of afferent pathways. In this study, we further explored this possibility by systematically investigating how tremor suppression by afferent stimulation depends on the stimulation settings...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28414231/organic-phosphorescence-nanowire-lasers
#10
Zhenyi Yu, Yishi Wu, Lu Xiao, Jianwei Chen, Qing Liao, Jiannian Yao, Hongbing Fu
Organic solid-state lasers (OSSLs) based on singlet fluorescence have merited intensive study as an important class of light sources. Although the use of triplet phosphors has led to 100% internal quantum efficiency in organic light-emitting diodes (OLEDs), stumbling blocks in triplet lasing include generally forbidden intersystem crossing (ISC) and a low quantum yield of phosphorescence (ΦP). Here, we reported the first triplet-phosphorescence OSSL from a nanowire microcavity of a sulfide-substituted difluoroboron compound...
April 25, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28412225/enhancing-tissue-permeability-with-mri-guided-preclinical-focused-ultrasound-system-in-rabbit-muscle-from-normal-tissue-to-vx2-tumor
#11
Yao Sun, Xiaobing Xiong, Darpan Pandya, Youngkyoo Jung, Akiva Mintz, Satoru Hayasaka, Thaddeus J Wadas, King C P Li
High Intensity Focused Ultrasound (HIFU) is an emerging noninvasive, nonionizing physical energy based modality to ablate solid tumors with high power, or increase local permeability in tissues/tumors in pulsed mode with relatively low power. Compared with traditional ablative HIFU, nondestructive pulsed HIFU (pHIFU) is present in the majority of novel applications recently developed for enhancing the delivery of drugs and genes. Previous studies have demonstrated the capability of pHIFU to change tissue local permeability for enhanced drug delivery in both mouse tumors and mouse muscle...
April 12, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28393836/transient-birefringence-of-liquids-induced-by-terahertz-electric-field-torque-on-permanent-molecular-dipoles
#12
Mohsen Sajadi, Martin Wolf, Tobias Kampfrath
Collective low-frequency molecular motions have large impact on chemical reactions and structural relaxation in liquids. So far, these modes have mostly been accessed indirectly by off-resonant optical pulses. Here, we provide evidence that intense terahertz (THz) pulses can resonantly excite reorientational-librational modes of aprotic and strongly polar liquids through coupling to the permanent molecular dipole moments. We observe a significantly enhanced response because the transient optical birefringence is up to an order of magnitude higher than obtained with optical excitation...
April 10, 2017: Nature Communications
https://www.readbyqxmd.com/read/28391752/low-intensity-pulsed-ultrasound-for-nonoperative-treatment-of-scaphoid-nonunions-a-meta-analysis
#13
Edward W Seger, Julio J Jauregui, Steven A Horton, Gerardo Davalos, Erika Kuehn, Michael A Stracher
BACKGROUND: Scaphoid fractures progress to nonunion rates of up to 15% when non-displaced, and are even more frequent when the fracture is displaced. Standard treatment in these cases is surgery; however, individuals unable to undergo this operation, or for those who wish to try more conservative measures, there may be benefit from nonoperative options. Of these, low-intensity pulsed ultrasound (LIPUS) has been shown to improve fracture nonunion healing. The purpose of this study was to perform a comprehensive meta-analysis of relevant literature to determine success of the use of LIPUS for treatment of scaphoid nonunion...
April 1, 2017: Hand: Official Journal of the American Association for Hand Surgery
https://www.readbyqxmd.com/read/28391380/low-intensity-pulsed-ultrasound-is-effective-for-progressive-stage-lumbar-spondylolysis-with-mri-high-signal-change
#14
Hideyuki Arima, Yoshiji Suzuki, Daisuke Togawa, Yuki Mihara, Hideyuki Murata, Yukihiro Matsuyama
PURPOSE: This study aimed to investigate the treatment effects of low-intensity pulsed ultrasound (LIPUS) on progressive-stage spondylolysis. Spondylolysis is a stress fracture of the pars interarticularis. Based on the results of computed tomography, spondylolysis was classified into three categories: early, progressive, and terminal. Bone healing was prolonged or not obtained in progressive-stage spondylolysis. The progression of spondylolysis to nonunion has been associated with an increased incidence of spondylolisthesis...
April 8, 2017: European Spine Journal
https://www.readbyqxmd.com/read/28386234/high-intensity-interval-training-in-normobaric-hypoxia-improves-cardiorespiratory-fitness-in-overweight-chinese-young-women
#15
Zhaowei Kong, Qingde Shi, Jinlei Nie, Tomas K Tong, Lili Song, Longyan Yi, Yang Hu
Previous studies have investigated the effects of high-intensity interval training (HIIT) on cardiorespiratory fitness and body composition in overweight populations. However, the additive effect of HIIT and hypoxia on health parameters is not clear. This study compared the effects of HIIT under hypoxic conditions on cardiometabolic function with that under normoxia in overweight Chinese young women. Methods: A double-blind randomized controlled experimental design was applied. Twenty-four sedentary overweight Chinese young women (weight: 68...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28385939/low-intensity-pulsed-ultrasound-does-not-influence-bone-healing-by-distraction-osteogenesis-a-multicentre-double-blind-randomised-control-trial
#16
A H R W Simpson, G Keenan, S Nayagam, R M Atkins, D Marsh, N D Clement
AIMS: The aim of this double-blind prospective randomised controlled trial was to assess whether low intensity pulsed ultrasound (LIPUS) accelerated or enhanced the rate of bone healing in adult patients undergoing distraction osteogenesis. PATIENTS AND METHODS: A total of 62 adult patients undergoing limb lengthening or bone transport by distraction osteogenesis were randomised to treatment with either an active (n = 32) or a placebo (n = 30) ultrasound device...
April 2017: Bone & Joint Journal
https://www.readbyqxmd.com/read/28385161/myocardial-perfusion-cardiovascular-magnetic-resonance-optimized-dual-sequence-and-reconstruction-for-quantification
#17
Peter Kellman, Michael S Hansen, Sonia Nielles-Vallespin, Jannike Nickander, Raquel Themudo, Martin Ugander, Hui Xue
BACKGROUND: Quantification of myocardial blood flow requires knowledge of the amount of contrast agent in the myocardial tissue and the arterial input function (AIF) driving the delivery of this contrast agent. Accurate quantification is challenged by the lack of linearity between the measured signal and contrast agent concentration. This work characterizes sources of non-linearity and presents a systematic approach to accurate measurements of contrast agent concentration in both blood and myocardium...
April 7, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28383017/room-temperature-subnanosecond-waveguide-lasers-in-nd-yvo4-q-switched-by-phase-change-vo2-a-comparison-with-2d-materials
#18
Weijie Nie, Rang Li, Chen Cheng, Yanxue Chen, Qingming Lu, Carolina Romero, Javier R Vázquez de Aldana, Xiaotao Hao, Feng Chen
We report on room-temperature subnanosecond waveguide laser operation at 1064 nm in a Nd:YVO4 crystal waveguide through Q-switching of phase-change nanomaterial vanadium dioxide (VO2). The unique feature of VO2 nanomaterial from the insulating to metallic phases offers low-saturation-intensity nonlinear absorptions of light for subnanosecond pulse generation. The low-loss waveguide is fabricated by using the femtosecond laser writing with depressed cladding geometry. Under optical pump at 808 nm, efficient pulsed laser has been achieved in the Nd:YVO4 waveguide, reaching minimum pulse duration of 690 ps and maximum output average power of 66...
April 6, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28382317/probing-ultra-fast-processes-with-high-dynamic-range-at-4th-generation-light-sources-arrival-time-and-intensity-binning-at-unprecedented-repetition-rates
#19
S Kovalev, B Green, T Golz, S Maehrlein, N Stojanovic, A S Fisher, T Kampfrath, M Gensch
Understanding dynamics on ultrafast timescales enables unique and new insights into important processes in the materials and life sciences. In this respect, the fundamental pump-probe approach based on ultra-short photon pulses aims at the creation of stroboscopic movies. Performing such experiments at one of the many recently established accelerator-based 4th-generation light sources such as free-electron lasers or superradiant THz sources allows an enormous widening of the accessible parameter space for the excitation and/or probing light pulses...
March 2017: Structural Dynamics (Melville, N.Y.)
https://www.readbyqxmd.com/read/28378753/low-intensity-pulsed-ultrasound-lipus-prevents-periprosthetic-inflammatory-loosening-through-fbxl2-traf6-ubiquitination-pathway
#20
Xiang Zhao, Gangsheng Zhao, Zhongli Shi, Chenhe Zhou, Yunlin Chen, Bin Hu, Shigui Yan
Previous studies have shown that Low intensity pulsed ultrasound(LIPUS) prevents polyethylene-debris-induced periprosthetic loosening in vivo, but the details of the mechanism by which it does so remain unclear. In this article, we used polyethylene debris induced RAW 264.7 cells as the in vitro model, and tested the effect of LIPUS on this model. Changes in the level of inflammatory cytokines, cell proliferation, and apoptosis were assessed. Gene overexpression and siRNA technique were applied, and the levels of expression of FBXL2, TRAF6, ERK, and related inflammatory cytokines were also measured...
April 5, 2017: Scientific Reports
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