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Artificial lighting

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https://www.readbyqxmd.com/read/28222021/intense-blue-light-therapy-during-the-night-time-does-not-suppress-the-rhythmic-melatonin-biosynthesis-in-a-young-boy
#1
K Stebelova, J Kosnacova, M Zeman
OBJECTIVE: Melatonin is a hormone predominantly synthesized and secreted during the night by the pineal gland. Artificial light at night, especially its blue part, acutely suppresses the melatonin production. Th e aim of the present study was to find out, whether an intense blue light phototherapy of severe hyperbilirubinemia, may suppress the melatonin production during the night when the eyes will be properly protected by a sleep mask. METHODS: The main melatonin metabolite, 6-sulphatoxymelatonin was measured in urine in a nine-year old boy suffering from the Crigler-Najjar syndrome type I...
January 1, 2017: Endocrine Regulations
https://www.readbyqxmd.com/read/28221361/dynamic-control-of-chirality-and-self-assembly-of-double-stranded-helicates-with-light
#2
Depeng Zhao, Thomas van Leeuwen, Jinling Cheng, Ben L Feringa
Helicity switching in biological and artificial systems is a fundamental process that allows for the dynamic control of structures and their functions. In contrast to chemical approaches to responsive behaviour in helicates, the use of light as an external stimulus offers unique opportunities to invert the chirality of helical structures in a non-invasive manner with high spatiotemporal precision. Here, we report that unidirectional rotary motors with connecting oligobipyridyl ligands, which can dynamically change their chirality upon irradiation, assemble into metal helicates that are responsive to light...
March 2017: Nature Chemistry
https://www.readbyqxmd.com/read/28218314/implicating-the-contributions-of-surface-and-bulk-states-on-carrier-trapping-and-photocurrent-performance-of-bivo4-photoanodes
#3
B Pattengale, J Huang
Monoclinic-scheelite BiVO4 has been widely studied as a promising oxygen evolution reaction (OER) catalyst in artificial photosynthesis. Though significant progress to improve or augment its catalysis performance has been made, fundamental understanding of its relatively poor performance as a bare material is lacking. In this paper, we report the correlation of the surface structure and trap states with charge separation efficiency and OER performance of bare BiVO4 photoanodes via varying the sample thickness...
February 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28215049/laparoscopic-implantation-of-artificial-urinary-sphincter-in-women-with-intrinsic-sphincter-deficiency-mid-term-outcomes
#4
Carlos Ferreira, Pierre-Emannuel Brychaert, Johann Menard, Eric Mandron
OBJECTIVES: To analyze the safety and the mid-term continence rates of laparoscopic implantation of artificial urinary sphincter in women. METHODS: A total of 52 women with intrinsic sphincter deficiency underwent a laparoscopic artificial urinary sphincter implantation from 2005 to 2015 at Surgical Clinic Du Pré, Le Mans, France. The artificial urinary sphincter was implanted around the bladder neck by a transperitoneal laparoscopic approach to the Retzius space...
February 19, 2017: International Journal of Urology: Official Journal of the Japanese Urological Association
https://www.readbyqxmd.com/read/28214594/association-between-light-at-night-melatonin-secretion-sleep-deprivation-and-the-internal-clock-health-impacts-and-mechanisms-of-circadian-disruption
#5
REVIEW
Yvan Touitou, Alain Reinberg, David Touitou
Exposure to Artificial Light At Night (ALAN) results in a disruption of the circadian system, which is deleterious to health. In industrialized countries, 75% of the total workforce is estimated to have been involved in shift work and night work. Epidemiologic studies, mainly of nurses, have revealed an association between sustained night work and a 50-100% higher incidence of breast cancer.The potential and multifactorial mechanisms of the effects include the suppression of melatonin secretion by ALAN, sleep deprivation, and circadian disruption...
February 15, 2017: Life Sciences
https://www.readbyqxmd.com/read/28213210/comparison-of-sensitivity-to-artificial-spectral-errors-and-multivariate-lod-in-nir-spectroscopy-determining-the-performance-of-miniaturizations-on-melamine-in-milk-powder
#6
Raphael Henn, Christian G Kirchler, Maria-Elisabeth Grossgut, Christian W Huck
This study compared three commercially available spectrometers - whereas two of them were miniaturized - in terms of prediction ability of melamine in milk powder (infant formula). Therefore all spectra were split into calibration- and validation-set using Kennard Stone and Duplex algorithm in comparison. For each instrument the three best performing PLSR models were constructed using SNV and Savitzky Golay derivatives. The best RMSEP values were 0.28g/100g, 0.33g/100g and 0.27g/100g for the NIRFlex N-500, the microPHAZIR and the microNIR2200 respectively...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28212399/instrument-design-and-protocol-for-the-study-of-light-controlled-processes-in-aquatic-organisms-and-its-application-to-examine-the-effect-of-infrared-light-on-zebrafish
#7
Marcus P S Dekens, Nicholas S Foulkes, Kristin Tessmar-Raible
The acquisition of reliable data strongly depends on experimental design. When studying the effects of light on processes such as behaviour and physiology it is crucial to maintain all environmental conditions constant apart from the one under study. Furthermore, the precise values of the environmental factors applied during the experiment should be known. Although seemingly obvious, these conditions are often not met when the effects of light are being studied. Here, we document and discuss the wavelengths and light intensities of natural and artificial light sources...
2017: PloS One
https://www.readbyqxmd.com/read/28212113/age-and-gender-dependency-of-physiological-networks-in-sleep
#8
Dagmar Krefting, Christoph Jansen, Thomas Penzel, Fang Han, Jan Kantelhardt
Recently, time delay stability analysis of biosignals has been successfully applied as a multivariate time series analysis method to assess the human physiological network in young adults. The degree of connectivity between different network nodes is described by the so-called link strength. Based on polysomnographic recordings (PSGs), it could be shown that the network changes with the sleep stage. Here, we apply the method to a large set of healthy controls spanning six decades of age. As it is well known, that the overall sleep architecture is dependent both on age and on gender, we particularly address the question, if these changes are also found in the network dynamics...
February 17, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28209805/effects-of-photophase-illuminance-on-locomotor-activity-urine-production-and-urinary-6-sulfatoxymelatonin-in-nocturnal-and-diurnal-south-african-rodents
#9
Ingrid van der Merwe, Maria K Oosthuizen, Andre Ganswindt, Abraham Haim, Nigel C Bennett
Effects of photophase illuminance (1, 10, 100 and 330 lux of white incandescent lighting) on daily rhythms of locomotor activity, urine production and 6-sulfatoxymelatonin (6-SMT; 10 lux vs. 330 lux) were studied in nocturnal Namaqua rock mice (Micaelamys namaquensis) and diurnal four striped field mice (Rhabdomys pumilio). Micaelamys namaquensis was consistently nocturnal (∼90-94% nocturnal activity), whereas considerable individual variation marked activity profiles in R. pumilio, but with activity mostly pronounced around twilight (∼55-66% diurnal activity)...
February 16, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28208286/derivatization-technique-to-identify-specifically-carbonyl-groups-by-infrared-spectroscopy-characterization-of-photooxidative-aging-products-in-terpenes-and-terpeneous-resins
#10
Stefan Zumbühl, Andreas Brändle, Andreas Hochuli, Nadim C Scherrer, Walter Caseri
Analysis of bioorganic materials by infrared spectroscopy (FT-IR) is frequently limited due to overlapping of diagnostic bands from the various components, which poses a fundamental problem to this analytical technique. The distinction of oxidized di- and triterpenes, for example, is hindered by the superposition of similar absorption bands of carbonyl functional groups summing up to a broad, nondistinctive signal. This study presents a technique for selective fluorination of various carboxylic acids by exposure to gaseous sulfur tetrafluoride...
February 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28208235/warmer-night-time-temperature-promotes-microbial-heterotrophic-activity-and-modifies-stream-sediment-community
#11
Anna Freixa, Vicenç Acuña, Maria Casellas, Stoyana Pecheva, Anna M Romaní
Diel temperature patterns are changing because of global warming, with higher temperatures being predicted to be more pronounced at night. Biological reactions are temperature dependent, with some occurring only during the daylight hours (e.g., light photosynthesis) and other during the entire day (e.g., respiration). Consequently, we expect the modification of daily temperature cycles to alter microbial biological reactions in stream sediments. Here, we aimed to study the effect of warming and changes of the diel temperature patterns on stream sediment biofilm functions tied to organic carbon decomposition, as well as on biofilm meiofaunal community structure...
February 16, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28206765/ultrafast-electronic-energy-transfer-in-an-orthogonal-molecular-dyad
#12
Christian Wiebeler, Felix Plasser, Gordon J Hedley, Arvydas Ruseckas, Ifor D W Samuel, Stefan Schumacher
Understanding electronic energy transfer (EET) is an important ingredient in the development of artificial photosynthetic systems and photovoltaic technologies. Although EET is at the heart of these applications and crucially influences their light-harvesting efficiency, the nature of EET over short distances for covalently bound donor and acceptor units is often not well understood. Here we investigate EET in an orthogonal molecular dyad (BODT4), in which simple models fail to explain the very origin of EET...
February 21, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28206752/columnar-self-assemblies-of-triarylamines-as-scaffolds-for-artificial-biomimetic-channels-for-ion-and-for-water-transport
#13
Susanne Schneider, Erol-Dan Licsandru, Istvan Kocsis, Arnaud Gilles, Florina Dumitru, Emilie Moulin, Junjun Tan, Jean-Marie Lehn, Nicolas Giuseppone, Mihail Barboiu
Triarylamine molecules appended with crown-ethers or carboxylic moieties form self-assembled supramolecular channels within lipid bilayers. Fluorescence assays and voltage clamp studies reveal that the self-assemblies incorporating the crown ethers work as single channels for the selective transport of K+ or Rb+. The X-ray crystallographic structures confirm the mutual columnar self-assembly of triarylamines and crown-ethers. The dimensional fit of K+ cations within the 18-crown-6, leads to a partial dehydration and to the formation of alternating K+ cation-water wires within the channel...
February 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28199775/a-photoregulated-dna-based-rotary-system-and-direct-observation-of-its-rotational-movement
#14
Yangyang Yang, Ryu Tashiro, Yuki Suzuki, Tomoko Emura, Kumi Hidaka, Hiroshi Sugiyama, Masayuki Endo
Various DNA-based nanodevices have been developed on the nanometer scale using light as regulation input. However, the programmed controllability is still a major challenge for these artificial nanodevices. Herein, we demonstrate a rotary DNA nanostructure in which the rotations are controlled by light. A bar-shaped DNA rotor, fabricated as a stiff double-crossover molecule, was placed on the top of a rectangular DNA tile. The photoresponsive oligonucleotides modified with azobenzenes were employed as switching motifs to release/trap the rotor at specific angular position on DNA tile by switching photoirradiations between ultraviolet and visible light...
February 15, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28199209/photosystem-ii-and-terminal-respiratory-oxidases-molecular-machines-operating-in-opposite-directions
#15
Sergey A Siletsky, Vitaliy B Borisov, Mahir D Mamedov
In the thylakoid membrane of green plants, cyanobacteria and algae, photosystem II (PSII) uses light energy to split water and generate molecular oxygen. In the opposite process of the biochemical transformation of dioxygen, in heterotrophs, the terminal respiratory oxidases (TRO) are at the end of the respiratory chain in mitochondria and in plasma membrane of many aerobic bacteria reducing dioxygen back to water. Despite the different sources of free energy (light or oxidation of the substrates), energy conversion by these enzymes is based on the spatial organization of enzymatic reactions in which the conversion of water to dioxygen (and vice versa) involves the transfer of protons and electrons in opposite directions across the membrane, which is accompanied by generation of proton-motive force...
March 1, 2017: Frontiers in Bioscience (Landmark Edition)
https://www.readbyqxmd.com/read/28198893/elucidating-light-induced-charge-accumulation-in-an-artificial-analogue-of-methane-monooxygenase-enzymes-using-time-resolved-x-ray-absorption-spectroscopy
#16
Dooshaye Moonshiram, Antonio Picón, Alvaro Vazquez-Mayagoitia, Xiaoyi Zhang, Ming-Feng Tu, Pablo Garrido-Barros, Jean-Pierre Mahy, Frédéric Avenier, Ally Aukauloo
We report the use of time-resolved X-ray absorption spectroscopy in the ns-μs time scale to track the light induced two electron transfer processes in a multi-component photocatalytic system, consisting of [Ru(bpy)3](2+)/ a diiron(iii,iii) model/triethylamine. EXAFS analysis with DFT calculations confirms the structural configurations of the diiron(iii,iii) and reduced diiron(ii,ii) states.
February 15, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28193823/stellar-performance-mechanisms-underlying-milky-way-orientation-in-dung-beetles
#17
James J Foster, Basil El Jundi, Jochen Smolka, Lana Khaldy, Dan-Eric Nilsson, Marcus J Byrne, Marie Dacke
Nocturnal dung beetles (Scarabaeus satyrus) are currently the only animals that have been demonstrated to use the Milky Way for reliable orientation. In this study, we tested the capacity of S. satyrus to orient under a range of artificial celestial cues, and compared the properties of these cues with images of the Milky Way simulated for a beetle's visual system. We find that the mechanism that permits accurate stellar orientation under the Milky Way is based on an intensity comparison between different regions of the Milky Way...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28193813/subtle-changes-in-the-landmark-panorama-disrupt-visual-navigation-in-a-nocturnal-bull-ant
#18
Ajay Narendra, Fiorella Ramirez-Esquivel
The ability of ants to navigate when the visual landmark information is altered has often been tested by creating large and artificial discrepancies in their visual environment. Here, we had an opportunity to slightly modify the natural visual environment around the nest of the nocturnal bull ant Myrmecia pyriformis We achieved this by felling three dead trees, two located along the typical route followed by the foragers of that particular nest and one in a direction perpendicular to their foraging direction...
April 5, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28186789/meissner-like-effect-for-a-synthetic-gauge-field-in-multimode-cavity-qed
#19
Kyle E Ballantine, Benjamin L Lev, Jonathan Keeling
Previous realizations of synthetic gauge fields for ultracold atoms do not allow the spatial profile of the field to evolve freely. We propose a scheme which overcomes this restriction by using the light in a multimode cavity with many nearly degenerate transverse modes, in conjunction with Raman coupling, to realize an artificial magnetic field which acts on a Bose-Einstein condensate of neutral atoms. We describe the evolution of such a system and present the results of numerical simulations which show dynamical coupling between the effective field and the matter on which it acts...
January 27, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28186138/the-spectral-and-spatial-distribution-of-light-pollution-in-the-waters-of-the-northern-gulf-of-aqaba-eilat
#20
Raz Tamir, Amit Lerner, Carynelisa Haspel, Zvy Dubinsky, David Iluz
The urbanization of the shores of the Gulf of Aqaba has exposed the marine environment there, including unique fringing coral reefs, to strong anthropogenic light sources. Here we present the first in situ measurements of artificial nighttime light under water in such an ecosystem, with irradiance measured in 12 wavelength bands, at 19 measurement stations spread over 44 square km, and at 30 depths down to 30-m depth. At 1-m depth, we find downwelling irradiance values that vary from 4.6 × 10(-4) μW cm(-2) nm(-1) 500 m from the city to 1 × 10(-6) μW cm(-2) nm(-1) in the center of the gulf (9...
February 10, 2017: Scientific Reports
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