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Pulsed light OR IPL

Fausto Caruana, Marzio Gerbella, Pietro Avanzini, Francesca Gozzo, Veronica Pelliccia, Roberto Mai, Rouhollah O Abdollahi, Francesco Cardinale, Ivana Sartori, Giorgio Lo Russo, Giacomo Rizzolatti
The cingulate cortex is a mosaic of different anatomical fields, whose functional characterization is still a matter of debate. In humans, one method that may provide useful insights on the role of the different cingulate regions, and to tackle the issue of the functional differences between its anterior, middle and posterior subsectors, is intracortical electrical stimulation. While previous reports showed that a variety of integrated behaviours could be elicited by stimulating the midcingulate cortex, little is known about the effects of the electrical stimulation of anterior and posterior cingulate regions...
August 13, 2018: Brain: a Journal of Neurology
Kun Huang, Jing Zeng, Jiwei Gan, Qiang Hao, Heping Zeng
We report on a new class of mode-locked fiber lasers that allow direct creation of ultrafast vector vortex beams at arbitrary positions on the higher-order Poincaré sphere. The on-demand generation of space-variant polarization patterns was realized by controlling geometric phases inside the laser resonator to map polarization to orbital angular momentum. Thanks to the special cavity design, the required intracavity manipulation of the geometric phase imposed no disturbance on the passively mode-locked operation, thus demonstrating robust and flexible switching of vectorial modes with an 8...
August 15, 2018: Optics Letters
Ju-Hung Chao, Wenbin Zhu, Chang-Jiang Chen, Yun-Goo Lee, Annan Shang, Shizhuo Yin, Robert C Hoffman
We report a new type of photoconductive semiconductor switch (PCSS), consisting of a semi-insulating gallium arsenic (GaAs) substrate and a front-bonded ruby crystal. The 532 nm laser pulses from an Nd-YAG laser incident on the front surface of the ruby crystal. A portion of the laser pulse passes through the crystal and reaches the GaAs substrate, and the remaining portion of the laser pulse is absorbed by the ruby crystal. This results in the emission of 694 nm fluorescent light. Furthermore, a portion of emitted fluorescent light also reaches the GaAs substrate...
August 15, 2018: Optics Letters
H Esat Kondakci, Ayman F Abouraddy
Space-time (ST) wave packets are diffraction-free, dispersion-free pulsed beams whose propagation invariance stems from correlations introduced into their spatio-temporal spectra. We demonstrate here experimentally and computationally that ST light sheets exhibit self-healing properties upon traversing obstacles in the form of opaque obstructions. The unscattered fraction of the wave packet retains the spatio-temporal correlations and, thus, propagation invariance is maintained. The scattered component does not satisfy the requisite correlation and thus, undergoes diffractive spreading...
August 15, 2018: Optics Letters
Christina L Ruby, Gerneleh Paye, Jason L Fabi, Jiawen Zhang, Megan O Risinger, Kaitlyn N Palmer, Natalie M Verbanes, Ariana D'Angelo, Tia M Watts, Lauren Mabe, H Scott Swartzwelder
BACKGROUND: Evidence supports a role for the circadian system in alcohol use disorders, but the impact of adolescent alcohol exposure on circadian timing later in life is unknown. Acute ethanol attenuates circadian photic phase-resetting in adult, but not adolescent, rodents. However, nearly all studies have focused on males and it is unknown whether this adolescent-typical insensitivity to ethanol persists into adulthood after adolescent drinking. METHODS: Circadian activity was monitored in C57BL6/J mice receiving adolescent intermittent ethanol (AIE) exposure (15% ethanol and water every other day throughout adolescence) or water alone followed by 24 days wherein ethanol was not available (washout)...
August 13, 2018: Alcoholism, Clinical and Experimental Research
Junhyun Lim, Ji-Hwan Park, Sukjoon Jung, Daehee Hwang, Hong Gil Nam, Sunghyun Hong
Leaf senescence is regulated by diverse developmental and environmental factors to maximize plant fitness. The red to far-red light ratio (R:FR) detected by plant phytochromes is reduced under vegetation shade, thus initiating leaf senescence. However, the role of phytochromes in promoting leaf senescence under FR-enriched conditions is not fully understood. In this study, we investigated the role of phyA and phyB in regulating leaf senescence under FR in Arabidopsis thaliana (Arabidopsis). FR enrichment and intermittent FR pulses promoted the senescence of Arabidopsis leaves...
August 7, 2018: Plant & Cell Physiology
José Carlos Tatmatsu-Rocha, Carla Roberta Tim, Lucimar Avo, Rubens Bernardes-Filho, Patricia Brassolatti, Hueliton Wilian Kido, Michael R Hamblin, Nivaldo Antonio Parizotto
OBJECTIVE: Mitochondrial dysfunction has been associated with the development of diabetes mellitus which is characterized by disorders of collagen production and impaired wound healing. This study analyzed the effects of photobiomodulation (PBM) mediated by laser and light-emitting diode (LED) on the production and organization of collagen fibers in an excisional wound in an animal model of diabetes, and the correlation with inflammation and mitochondrial dynamics. METHODS: Twenty Wistar rats were randomized into 4 groups of 5 animals...
August 3, 2018: Journal of Photochemistry and Photobiology. B, Biology
Luca F Ticini, Thomas Dolk, Florian Waszak, Simone Schütz-Bosbach
The conscious experience of being the author of our own actions is thought to be grounded in pre-reflective and low-level sensorimotor representations of the self as different from the other. It has been suggested that the inferior parietal lobe (IPL) is generally involved in self-other differentiation processes and in providing an explicit sense of action authorship. However, direct evidence for its causal and functional role in distinguishing self-related and other-related sensorimotor representations is lacking...
August 10, 2018: Scientific Reports
Do-Kyun Kim, Dong-Hyun Kang
UVC light, a strong surface disinfection technology, is used world-wide to ensure not only environmental safety, but also food safety. Several drawbacks associated with usage of mercury-containing UV lamps, especially, human and environmental health risks, led to the Minamata convention which prohibits manufacturing and import/export of products containing mercury. Therefore, LED-based UVC irradiation, a new technology which is eco-friendly and an effective UV emitting source, has been researched recently. However, to date, there has been no report describing pulsed UVC-LED for improving inactivation of foodborne pathogens, although much research regarding conventional pulsed xenon lamps has been published...
August 10, 2018: Applied and Environmental Microbiology
Alisson Alves da Silva, Gustavo Graciano Fonseca
Growth studies are important to increase the knowledge about the physiology of microalgae. The development of suitable culture media allows optimum growth to each species. The genus Chlorella has the ability to adapt to various environmental and nutritional conditions. Thus, the aim of this work was to evaluate the physiology of Chlorella sorokiniana CTT 7727 at different growth conditions with Basal Bold (BB) medium. For that, heterotrophic, autotrophic and mixotrophic cultures were carried out. The maximum specific growth rates (µmax ), the maximum biomass concentrations (Xmax ) and cell productivities (PX ) were calculated for each experiment...
August 9, 2018: Environmental Technology
J Matthew Knight, Gerd Kautz
BACKGROUND: While skin aging is triggered by multiple factors and typically presents with multiple manifestations, conventional treatment regimens deploy a single treatment modality. Typical approaches exploit ablative techniques, which involve considerable patient discomfort and downtime and can induce adverse events. Non-ablative fractionated laser (NAFL) resurfacing promotes neocollagenesis, with significantly fewer complications and discomfort. At the same time, intense pulsed light (IPL) therapies have a marked impact on skin tone, with an effect on collagen deposition...
August 8, 2018: Lasers in Surgery and Medicine
Xueming Liu, Xiankun Yao, Yudong Cui
Real-time spectroscopy access to ultrafast fiber lasers opens new opportunities for exploring complex soliton interaction dynamics. Here, we have reported the first observation, to the best of our knowledge, of the entire buildup process of soliton molecules (SMs) in a mode-locked laser. We have observed that the birth dynamics of a stable SM experiences five different stages, i.e., the raised relaxation oscillation (RO) stage, beating dynamics stage, transient single pulse stage, transient bound state, and finally the stable bound state...
July 13, 2018: Physical Review Letters
Sarojini Jeeva Panchu, Shanel Dhani, Anil Chuturgoon, Mathew K Moodley
Here in, we report the investigation of the immunotoxicity of gold nanoparticles decorated on inorganic fullerene like MoS2 nanostructure (IFMoS2 - AuNPs) on the THP-1 immune cell line. The MoS2 nanoparticle with fullerene like nanostructure (IFMoS2 ) was synthesized by double pulsed laser-assisted chemical vapour deposition (LCVD) method from bulk MoS2 at the temperature of 700 °C. The MoS2 inorganic fullerene-like nanoparticles grown by vapour-solid process (VS). The surface of the IFMoS2 was decorated with gold nanoparticles (AuNPs) to develop the semiconductor biocompatibility interface...
August 1, 2018: Journal of Photochemistry and Photobiology. B, Biology
Tanawan Soimala, Antina Lübke-Becker, Stefan Schwarz, Andrea T Feßler, Charlotte Huber, Torsten Semmler, Roswitha Merle, Heidrun Gehlen, Johanna C Eule, Birgit Walther
Severe infections due to methicillin-resistant Staphylococcus aureus (MRSA) have been increasingly recognized in virtually all fields of veterinary medicine. Our objective was to study the occurrence, phylogenetic relationships and antimicrobial resistance properties of MRSA isolated from ocular surfaces of horses prior to invasive procedures. Within a 49-week sampling period, ocular swabs obtained from 46 eyes of 44 horses, including eyes with clinical signs of conjunctivitis/blepharitis, keratitis or uveitis were screened for the presence of S...
August 2018: Veterinary Microbiology
Farid Atry, Rex Chin-Hao Chen, Jane Pisaniello, Sarah Brodnick, Aaron Suminski, Joseph Novello, Jared Ness, Justin Williams, Ramin Pashaie
We introduce an engineering approach to study spatiotemporal correlations between vasodynamics and the nearby neural activity in open-loop and closed-loop paradigms. 
 Approach: We integrated optogenetic technology with optical coherence tomography to apply spatiotemporal patterns of optical neurostimulation to the cortex of transgenic optogenetic mice and measure blood flow-rate, velocity, and diameter changes of selected middle cerebral artery branches.
 Main results: The spatiotemporal characteristics of blood flow-rate, velocity, and vessel diameter responses to localized neurostimulation light pulses were measured...
August 6, 2018: Journal of Neural Engineering
A Cantaluppi, M Buzzi, G Jotzu, D Nicoletti, M Mitrano, D Pontiroli, M Riccò, A Perucchi, P Di Pietro, A Cavalleri
Optical excitation at terahertz frequencies has emerged as an effective means to dynamically manipulate complex materials. In the molecular solid K3 C60 , short mid-infrared pulses transform the high-temperature metal into a non-equilibrium state with the optical properties of a superconductor. Here we tune this effect with hydrostatic pressure and find that the superconducting-like features gradually disappear at around 0.3 GPa. Reduction with pressure underscores the similarity with the equilibrium superconducting phase of K3 C60 , in which a larger electronic bandwidth induced by pressure is also detrimental for pairing...
August 2018: Nature Physics
Mary Matthews, Felipe Morales, Alexander Patas, Albrecht Lindinger, Julien Gateau, Nicolas Berti, Sylvain Hermelin, Jerome Kasparian, Maria Richter, Timm Bredtmann, Olga Smirnova, Jean-Pierre Wolf, Misha Ivanov
Light can be used to modify and control properties of media, as in the case of electromagnetically induced transparency or, more recently, for the generation of slow light or bright coherent XUV and X-ray radiation. Particularly unusual states of matter can be created by light fields with strengths comparable to the Coulomb field that binds valence electrons in atoms, leading to nearly-free electrons oscillating in the laser field and yet still loosely bound to the core [1,2]. These are known as Kramers-Henneberger states [3], a specific example of laser-dressed states [2]...
July 2018: Nature Physics
Xin Mu, Li Wang, Lijuan Wang, Rui Ge, Haiqiang Dang, Kuanhou Mou
BACKGROUND/PURPOSE: Basal cell carcinoma (BCC) often occurs in the face of middle and old aged people. Given its particular location, aminolevulinic acid-photodynamic therapy (ALA-PDT) is often applied in cosmetology and inappropriate surgical treatment. Specific measures in PDT treatment should be performed to increase the ALA penetration capability because of the limited depth of ALA penetration. This research aims to explore the method that facilitates ALA penetration. METHODS: Three patients with BCC were subjected to four regular sessions of ALA-PDT every other week...
August 2, 2018: Photodiagnosis and Photodynamic Therapy
Diao Li, Hui Xue, Yadong Wang, Mei Qi, Wonjae Kim, Changfeng Li, Juha Riikonen, Zhaoyu Ren, Jintao Bai, Harri Lipsanen, Zhipei Sun
We report the synchronization of two actively Q -switched fiber lasers operating at 1.5 μm and 2 μm with a shared broadband graphene electro-optic modulator. Two graphene monolayer sheets separated with a high- k HfO 2 dielectric layer are configured to enable broadband light modulation. The graphene electro-optic modulator is shared by two optical fiber laser cavities (i.e., an erbium-doped fiber laser cavity and a thulium/holmium-codoped fiber laser cavity) to actively Q -switch the two lasers, resulting in stable synchronized pulses at 1...
August 1, 2018: Optics Letters
Bingjie Zhou, Jingui Ma, Jing Wang, Peng Yuan, Guoqiang Xie, Liejia Qian
Slow and fast light are ubiquitous in optical amplifiers. In this Letter, we show for the first time, to the best of our knowledge, that optical parametric amplification (OPA) in chirped quasi-phase-matching structures can act as a platform for group-velocity control in the femtosecond regime. The resonant cascaded nonlinear phase underlies the group-velocity control, which manifests an unusual effect that both slow and fast light can be achieved under the normal condition of signal amplification. As numerically demonstrated in the OPA based on the lithium niobate crystal, the signal and idler pulse can be significantly delayed in time comparable to the signal duration and can also keep high fidelity for durations down to 100 fs until the crystal dispersion becomes effective...
August 1, 2018: Optics Letters
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