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https://www.readbyqxmd.com/read/28526480/human-seasonal-and-circadian-studies-in-antarctica-halley-75-0-s
#1
Josephine Arendt, Benita Middleton
Living for extended periods in Antarctica exposes base personnel to extremes of daylength (photoperiod) and temperature. At the British Antarctic Survey base of Halley, 75(0)S, the sun does not rise for 110 d in the winter and does not set for 100 d in summer. Photoperiod is the major time cue governing the timing of seasonal events such as reproduction in many species. The neuroendocrine signal providing photoperiodic information to body physiology is the duration of melatonin secretion which reflects the length of the night: longer in the short days of winter and shorter in summer...
May 16, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28522838/fabrication-of-full-color-gan-based-light-emitting-diodes-on-nearly-lattice-matched-flexible-metal-foils
#2
Hyeryun Kim, Jitsuo Ohta, Kohei Ueno, Atsushi Kobayashi, Mari Morita, Yuki Tokumoto, Hiroshi Fujioka
GaN-based light-emitting diodes (LEDs) have been widely accepted as highly efficient solid-state light sources capable of replacing conventional incandescent and fluorescent lamps. However, their applications are limited to small devices because their fabrication process is expensive as it involves epitaxial growth of GaN by metal-organic chemical vapor deposition (MOCVD) on single crystalline sapphire wafers. If a low-cost epitaxial growth process such as sputtering on a metal foil can be used, it will be possible to fabricate large-area and flexible GaN-based light-emitting displays...
May 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28521103/organic-inorganic-hybrid-perovskite-nanowire-laser-arrays
#3
Peng Liu, Xianxiong He, Jiahuan Ren, Qing Liao, Jiannian Yao, Hongbing Fu
Fabrication of semiconductor nanowire laser arrays with multi-color outputs are very challenging, owing to difficulties in direct monolithic growth and patterning of III-V semiconductors on silicon substrates. Recently, methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) have emerged as an important class of high-performance solution-processed optoelectronic materials. Here, we combined the 'top-down' fabricated polydimethylsiloxane (PDMS) rectangular groove-template (RGT) with the 'bottom-up' solution self-assembly together to prepare large-scale perovskite nanowire (PNW) arrays...
May 18, 2017: ACS Nano
https://www.readbyqxmd.com/read/28511811/autoimmune-voltage-gated-potassium-channelopathy-presenting-with-catecholamine-excess
#4
K Amy Stepp, Christin Folker, Marie Tanzer, Jennifer Hayman, Thomas Reynolds, Leah Mallory
BACKGROUND: Autoimmune voltage-gated potassium channelopathies have been associated with a range of neurological presenting symptoms, including central, peripheral, and autonomic dysfunction. PATIENT DESCRIPTION: We describe a 12-year-old boy who presented with nine months of pain, anxiety, and 30-pound weight loss. He was admitted for failure to thrive, then noted to be persistently hypertensive and tachycardic. Plasma metanephrines and urine metanephrines and catecholamines were elevated...
April 8, 2017: Pediatric Neurology
https://www.readbyqxmd.com/read/28505777/impact-of-the-dipole-contribution-on-the-terahertz-emission-of-air-based-plasma-induced-by-tightly-focused-femtosecond-laser-pulses
#5
Alexander P Shkurinov, Anton S Sinko, Peter M Solyankin, Alexander V Borodin, Mikhail N Esaulkov, Vladimir V Annenkov, Igor A Kotelnikov, Igor V Timofeev, Xi-Cheng Zhang
The present paper studies the generation mechanism of terahertz (THz) radiation from tightly focused femtosecond laser pulses in a gas medium. We measured the angular radiation pattern under different focusing conditions and observed that, with the deepening of focus, the angular radiation pattern changes and optical-to-THz conversion efficiency increases. The analysis of the observed phenomena led to the assumption that the dipole radiation prevails in most cases despite the existing conception regarding the dominating role of the quadrupole mechanism of radiation...
April 2017: Physical Review. E
https://www.readbyqxmd.com/read/28502048/the-effects-of-cadmium-pulse-dosing-on-physiological-traits-and-growth-of-the-submerged-macrophyte-vallisneria-spinulosa-and-phytoplankton-biomass-a-mesocosm-study
#6
Hui Liu, Yu Cao, Wei Li, Zhao Zhang, Erik Jeppesen, Wei Wang
Pulse inputs of heavy metals are expected to increase with a higher frequency of extreme climate events (heavy rain), leading to stronger erosion of contaminated and fertilized farmland soils to freshwaters, with potentially adverse effects on lake ecosystems. We conducted a 5-month mesocosm study to elucidate the responses of the submerged macrophyte Vallisneria spinulosa and phytoplankton to four different doses of cadmium (Cd): 0 (control), 0.05, 0.5, and 5 g m(-2) (CK, I, II, and III, respectively) under mesotrophic conditions...
May 13, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28492684/oxidative-remediation-of-4-methylcyclohexanemethanol-mchm-and-propylene-glycol-phenyl-ether-pph-evidence-of-contaminant-repair-reaction-pathways
#7
Cen Zhao, Julie R Peller, Stephen P Mezyk, Prashant V Kamat, Kevin E O'Shea
A large spill of 4-methylcyclohexanemethanol (MCHM) and propylene glycol phenyl ether (PPh) into the Elk River near Charleston, West Virginia on January 9, 2014 led to serious water contamination and public concerns about appropriate remediation. To assess the feasibility of advanced oxidation processes (AOPs) for remediation of waters contaminated with these compounds, we induced hydroxyl radical (HO˙) reactions using time-resolved and steady-state radiolysis methods. Detailed product analyses showed initial HO˙ attack was at the benzene ring of PPh, and occurred through H-atom abstraction reactions for MCHM...
May 11, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28488433/attosecond-electron-dynamics-in-molecules
#8
Mauro Nisoli, Piero Decleva, Francesca Calegari, Alicia Palacios, Fernando Martín
Advances in attosecond science have led to a wealth of important discoveries in atomic, molecular, and solid-state physics and are progressively directing their footsteps toward problems of chemical interest. Relevant technical achievements in the generation and application of extreme-ultraviolet subfemtosecond pulses, the introduction of experimental techniques able to follow in time the electron dynamics in quantum systems, and the development of sophisticated theoretical methods for the interpretation of the outcomes of such experiments have raised a continuous growing interest in attosecond phenomena, as demonstrated by the vast literature on the subject...
May 10, 2017: Chemical Reviews
https://www.readbyqxmd.com/read/28485872/new-lasers-and-light-sources-old-and-new-risks
#9
REVIEW
Uwe Paasch, Antje Schwandt, Nikolaus Seeber, Gerd Kautz, Sonja Grunewald, Merete Haedersdal
Recent developments (new wavelengths, treatment concepts, and combinations) in the field of lasers, intense pulsed light (IPL), LED, as well as new energy and light sources have opened up new therapeutic options that extend beyond mere aesthetic indications. Thus, while fractional lasers used to be employed to merely treat wrinkles, the same devices - in the context of laser-assisted drug delivery - have now become important tools in the treatment of scars, field cancerization, and epithelial tumors. The requirements posed to physicians, both with respect to establishing the indication and conducting treatment, have been growing along with the increase in technological complexity as well as the rising number of comorbidities and comedications in a patient population that continues to age...
May 2017: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
https://www.readbyqxmd.com/read/28482596/surface-roughness-in-action-cells-in-opposition
#10
P Slepička, I Michaljaničová, S Rimpelová, V Švorčík
Aim of this work is to study the interaction of krypton fluoride (KrF) excimer laser beam with a biopolymer and creation of new nanostructures with great potential for cell growth guidance. As a substrate we used biocompatible and biodegradable polymer polyhydroxybutyrate, which is frequently used in medicine and drug delivery system. Modification was carried out by KrF laser and method was also supplemented by treatment with Ar(+) plasma. The changes in physico-chemical properties of surface layer were determined by goniometry, gravimetry and X-ray photoelectron spectroscopy (XPS)...
July 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28466954/-downregulation-of-lh-in-the-bitch-after-application-of-the-gnrh-agonist-buserelin-as-a-slow-release-implant
#11
Andrea Piepenbrink, Klaus Failing, Anja Riesenbeck, Peter Schmid, Bernd Hoffmann
OBJECTIVES: Demonstration of downregulation of luteinizing hormone (LH) using the gonadotropin-releasing hormone (GnRH)-agonist buserelin as the active ingredient in the form of a slow-release implant. MATERIAL AND METHODS: To eliminate any negative feedback mechanisms of endogenous sex steroids, nine bitches were ovariohysterectomized prior to treatment. The applied drug was the slow-release implant Profact Depot(®) with the active ingredient buserelin; dosages were 3...
May 3, 2017: Tierärztliche Praxis. Ausgabe K, Kleintiere/Heimtiere
https://www.readbyqxmd.com/read/28463045/mitigation-of-epidermal-growth-factor-receptor-inhibitor-induced-side-effects-utilizing-melanin-and-vascular-specific-lasers-a-case-report-series
#12
Karen Y Kuo, Bernice Kwong, Zakia Rahman
The advent of targeted chemotherapy has led to the emergence of new dermatologic toxicities. We sought to use lasers and light devices to treat recalcitrant cutaneous adverse effects related to cancer treatment. Three stage III or IV cancer patients with cutaneous complications due to epidermal growth factor receptor (EGFR) inhibitors were treated with melanin and vascular-specific laser and light technologies. Two patients reported reduction in papulopustular eruption following pulse dye laser (PDL) treatment...
March 2, 2017: Journal of Cosmetic and Laser Therapy: Official Publication of the European Society for Laser Dermatology
https://www.readbyqxmd.com/read/28459967/survival-and-electrotransformation-of-pseudomonas-syringae-strains-under-simulated-cloud-like-conditions
#13
Laurine S Blanchard, Anaïs Monin, Hounaïda Ouertani, Lamia Touaibia, Elisa Michel, François Buret, Pascal Simonet, Cindy E Morris, Sandrine Demanèche
To diversify their genetic material, and thereby allow adaptation to environmental disturbances and colonization of new ecological niches, bacteria use various evolutionary processes, including the acquisition of new genetic material by horizontal transfer mechanisms such as conjugation, transduction and transformation. Electrotransformation mediated by lightning-related electrical phenomena may constitute an additional gene transfer mechanism occurring in nature. The presence in clouds of bacteria such as Pseudomonas syringae capable of forming ice nuclei that lead to precipitation and that are likely to be involved in triggering lightning, led us to postulate that natural electrotransformation in clouds may contribute to the adaptive potential of these bacteria...
April 28, 2017: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/28446222/effect-of-quantity-and-intensity-of-pulsed-light-on%C3%A2-human-non-visual-physiological-responses
#14
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/28438710/a-purpose-built-neck-coil-for-black-blood-dante-prepared-carotid-artery-imaging-at-7t
#15
Konstantinos Papoutsis, Linqing Li, Jamie Near, Stephen Payne, Peter Jezzard
Atherosclerotic plaques in the bifurcation of the carotid arteries can pose a significant health risk due to possible plaque rupture and subsequent stroke. The assessment of plaques, and evaluation of the risk they pose, can be performed with Black-Blood (BB) vessel wall magnetic resonance imaging. However, resolution at standard clinical field strengths (up to 3T) is limited, hampering reliable assessment and diagnosis. The aim of this study was to investigate the benefits of 7T MRI using a BB application that has been successful at clinical field strengths...
April 22, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28437920/cmos-integrated-gan-led-array-for-discrete-power-level-stepping-in-visible-light-communications
#16
Alexander D Griffiths, Mohamed Sufyan Islim, Johannes Herrnsdorf, Jonathan J D McKendry, Robert Henderson, Harald Haas, Erdan Gu, Martin D Dawson
We report a CMOS integrated micro-LED array capable of generating discrete optical output power levels. A 16 × 16 array of individually addressable pixels are on-off controlled through parallel logic signals. With carefully selected groups of LEDs driven together, signals suitable for discrete transmission schemes are produced. The linearity of the device is assessed, and data transmission using pulse amplitude modulation (PAM) and orthogonal frequency division multiplexing (OFDM) is performed. Error-free transmission at a symbol rate of 100 MSamples/s is demonstrated with 4-PAM, yielding a data rate of 200 Mb/s...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28428213/clinically-feasible-microstructural-mri-to-quantify-cervical-spinal-cord-tissue-injury-using-dti-mt-and-t2-weighted-imaging-assessment-of-normative-data-and-reliability
#17
A R Martin, B De Leener, J Cohen-Adad, D W Cadotte, S Kalsi-Ryan, S F Lange, L Tetreault, A Nouri, A Crawley, D J Mikulis, H Ginsberg, M G Fehlings
BACKGROUND AND PURPOSE: DTI, magnetization transfer, T2*-weighted imaging, and cross-sectional area can quantify aspects of spinal cord microstructure. However, clinical adoption remains elusive due to complex acquisitions, cumbersome analysis, limited reliability, and wide ranges of normal values. We propose a simple multiparametric protocol with automated analysis and report normative data, analysis of confounding variables, and reliability. MATERIALS AND METHODS: Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences...
April 20, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28423235/hepatic-sinusoidal-obstruction-syndrome-during-maintenance-therapy-of-childhood-acute-lymphoblastic-leukemia-is-associated-with-continuous-asparaginase-therapy-and-mercaptopurine-metabolites
#18
Linea Natalie Toksvang, Silvia De Pietri, Stine N Nielsen, Jacob Nersting, Birgitte K Albertsen, Peder S Wehner, Steen Rosthøj, Päivi M Lähteenmäki, Daniel Nilsson, Tove A Nystad, Kathrine Grell, Thomas L Frandsen, Kjeld Schmiegelow
BACKGROUND: Hepatic sinusoidal obstruction syndrome (SOS) during treatment of childhood acute lymphoblastic leukemia (ALL) has mainly been associated with 6-thioguanine. The occurrence of several SOS cases after the introduction of extended pegylated asparaginase (PEG-asparaginase) therapy in the Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol led us to hypothesize that PEG-asparaginase, combined with other drugs, may trigger SOS during 6-thioguanine-free maintenance therapy...
April 19, 2017: Pediatric Blood & Cancer
https://www.readbyqxmd.com/read/28414231/organic-phosphorescence-nanowire-lasers
#19
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/28412455/effects-of-rf-pulse-profile-and-intra-voxel-phase-dispersion-on-mr-fingerprinting-with-balanced-ssfp-readout
#20
Su-Chin Chiu, Te-Ming Lin, Jyh-Miin Lin, Hsiao-Wen Chung, Cheng-Wen Ko, Martin Büchert, Michael Bock
PURPOSE: To investigate possible errors in T1 and T2 quantification via MR fingerprinting with balanced steady-state free precession readout in the presence of intra-voxel phase dispersion and RF pulse profile imperfections, using computer simulations based on Bloch equations. MATERIALS AND METHODS: A pulse sequence with TR changing in a Perlin noise pattern and a nearly sinusoidal pattern of flip angle following an initial 180-degree inversion pulse was employed...
April 13, 2017: Magnetic Resonance Imaging
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