Read by QxMD icon Read

constant light

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
Sergey V Bondarchuk, Boris F Minaev
A new ambient-pressure metastable single-bonded 3D nitrogen allotrope (TrigN) of trigonal symmetry (space group R3[combining macron]) was calculated using density functional theory (DFT). A comprehensive characterization of this material, comprising thermodynamic, elastic, and spectral (vibrational, UV-vis absorption, and nuclear magnetic resonance) properties, was performed. Using high-throughput band structure calculation, the TrigN phase was characterized as an insulator with an indirect band gap of 2.977 eV...
February 17, 2017: Physical Chemistry Chemical Physics: PCCP
Marco A Gutiérrez, Luis J Manso, Harit Pandya, Pedro Núñez
Object detection and classification have countless applications in human-robot interacting systems. It is a necessary skill for autonomous robots that perform tasks in household scenarios. Despite the great advances in deep learning and computer vision, social robots performing non-trivial tasks usually spend most of their time finding and modeling objects. Working in real scenarios means dealing with constant environment changes and relatively low-quality sensor data due to the distance at which objects are often found...
February 11, 2017: Sensors
Liyi Huang, Grzegorz Szewczyk, Tadeusz Sarna, Michael R Hamblin
It is known that non-cationic porphyrins such as Photofrin (PF) are effective in mediating antimicrobial photodynamic inactivation (aPDI) of Gram-positive bacteria or fungi. However the aPDI activity of PF against Gram-negative bacteria is accepted to be extremely low. Here we report that the non-toxic inorganic salt, potassium iodide (KI) at a concentration of 100mM when added to microbial cells (10(8)/mL) + PF (10µM hematoporphyrin equivalent) + 415nm light (10J/cm2) can eradicate (>6 logs killing) five different Gram-negative species (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Acinetobacter baumannii), while no killing was obtained without KI...
February 16, 2017: ACS Infectious Diseases
Juliette Boiffin, Vincent Badeau, Nathalie Bréda
Species distribution models (SDMs), which statistically relate species occurrence to climatic variables, are widely used to identify areas suitable for species growth under future climates and to plan for assisted migration. When SDMs are projected across times or spaces, it is assumed that species climatic requirements remain constant. However, empirical evidence supporting this assumption is rare, and SDM predictions could be biased. Historical human-aided movements of tree species can shed light on the reliability of SDM predictions in planning for assisted migration...
October 4, 2016: Ecological Applications: a Publication of the Ecological Society of America
Zofia Kautzka, Sandhya Clement, Ewa M Goldys, Wei Deng
We developed light-triggered liposomes incorporating 3-5 nm hydrophobic gold nanoparticles and Rose Bengal (RB), a well-known photosensitizer used for photodynamic therapy. Singlet oxygen generated by these liposomes with 532 nm light illumination was characterized for varying the molar ratio of lipids and gold nanoparticles while keeping the amount of RB constant. Gold nanoparticles were found to enhance the singlet oxygen generation rate, with a maximum enhancement factor of 1.75 obtained for the molar ratio of hydrogenated soy l-α-phosphatidylcholine:1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(hexanoylamine):gold of 57:5:17 compared with liposomes loaded with RB alone...
2017: International Journal of Nanomedicine
Sophie Pantalacci, Laurent Guéguen, Coraline Petit, Anne Lambert, Renata Peterkovà, Marie Sémon
BACKGROUND: Comparative transcriptomics can answer many questions in developmental and evolutionary developmental biology. Most transcriptomic studies start by showing global patterns of variation in transcriptomes that differ between species or organs through developmental time. However, little is known about the kinds of expression differences that shape these patterns. RESULTS: We compared transcriptomes during the development of two morphologically distinct serial organs, the upper and lower first molars of the mouse...
February 15, 2017: Genome Biology
Jason Webster, Carmelo Rosales-Guzmán, Andrew Forbes
While photons travel in a straight line at constant velocity in free space, the intensity profile of structured light may be tailored for acceleration in any degree of freedom. Here we propose a simple approach to control the angular acceleration of light. Using Laguerre-Gaussian modes as our twisted beams carrying orbital angular momentum, we show that superpositions of opposite handedness result in a radially dependent angular acceleration as they pass through a focus (waist plane). Due to conservation of orbital angular momentum, we find that propagation dynamics are complex despite the free-space medium: the outer part of the beam (rings) rotates in an opposite direction to the inner part (petals), and while the outer part accelerates, the inner part decelerates...
February 15, 2017: Optics Letters
Bin Yang, Xuhui Mao, Liu Pi, Yixiao Wu, Huijun Ding, Weihao Zhang
In this study, g-C3N4 was synthesized by thermal polycondensation of melamine and was characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV-visible diffuse reflection spectroscopy, and scanning electron microscopy. Results showed that g-C3N4 degraded sulfadimidine (SMD) under visible light, in which the adsorption and photocatalytic degradation was influenced by pH. The maximum adsorption capacity was achieved at approximately pH 5. The highest degradation rate constant was obtained at strong acid and alkali...
February 15, 2017: Environmental Science and Pollution Research International
Feiqiao Brian Yu, Lisa Willis, Rosanna Man Wah Chau, Alessandro Zambon, Mark Horowitz, Devaki Bhaya, Kerwyn Casey Huang, Stephen R Quake
BACKGROUND: Cyanobacteria are important agents in global carbon and nitrogen cycling and hold great promise for biotechnological applications. Model organisms such as Synechocystis sp. and Synechococcus sp. have advanced our understanding of photosynthetic capacity and circadian behavior, mostly using population-level measurements in which the behavior of individuals cannot be monitored. Synechocystis sp. cells are small and divide slowly, requiring long-term experiments to track single cells...
February 14, 2017: BMC Biology
Alle A Y Lie, Zhenfeng Liu, Ramon Terrado, Avery O Tatters, Karla B Heidelberg, David A Caron
BACKGROUND: Ochromonas is a genus of mixotrophic chrysophytes that is found ubiquitously in many aquatic environments. Species in this genus can be important consumers of bacteria but vary in their ability to perform photosynthesis. We studied the effect of light and bacteria on growth and gene expression of a predominantly phagotrophic Ochromonas species. Axenic cultures of Ochromonas sp. were fed with heat-killed bacteria (HKB) and grown in constant light or darkness. RNA was extracted from cultures in the light or in the dark with HKB present (Light + HKB; Dark + HKB), and in the light after HKB were depleted (Light + depleted HKB)...
February 14, 2017: BMC Genomics
Ioannis Tsivintzelis, Georgios M Kontogeorgis, Costas Panayiotou
The association term of the Non-Random Hydrogen-Bonding theory, which is an equation of state model, is extended to describe the dimerization of carboxylic acids in binary mixtures with inert solvents and in systems of two different acids. Subsequently, the model is applied to describe the excess enthalpies and the vapor-liquid equilibrium of relevant binary mixtures containing low molecular weight organic acids. The model sheds light on the interplay of intermolecular interactions through the calculation of the various contributions to the mixing enthalpies, namely from hydrogen bonding and non-hydrogen bonding (dipolar, induced polar or dispersive) interactions...
February 14, 2017: Journal of Physical Chemistry. B
Gonzalo Angulo, Jadwiga Milkiewicz, Daniel Kattnig, Michał Nejbauer, Yuriy Stepanenko, Jan Szczepanek, Czesław Radzewicz, Paweł Wnuk, Günter Grampp
The effect of multiple light excitation events on bimolecular photo-induced electron transfer reactions in liquid solution is studied experimentally. It is found that the decay of fluorescence can be up to 25% faster if a second photon is absorbed after a first cycle of quenching and recombination. A theoretical model is presented which ascribes this effect to the enrichment of the concentration of quenchers in the immediate vicinity of fluorophores that have been previously excited. Despite its simplicity, the model delivers a qualitative agreement with the observed experimental trends...
February 14, 2017: Physical Chemistry Chemical Physics: PCCP
M Callea, F Pedica, C Doglioni
The interest in better understanding the immune-microenvironment and tumor cells crosstalk, recently leads to focus on immune checkpoints role, notably on PD-1/PD-L1 axis. The current backdrop concerning cancer immunotherapy is constantly evolving and new biomarkers still need to be granted in this dynamic context. This review tries to get lights on PD-L1 complex scenario mainly focusing on troubling issues in assessing this marker in daily practice. It's still necessary to look deeper into this matter in order to make easier the pathologists-oncologist interaction...
June 2016: Pathologica
Takashi Tsukamoto, Susumu Yoshizawa, Takashi Kikukawa, Makoto Demura, Yuki Sudo
Several new retinal-based photoreceptor proteins that act as light-driven electrogenic halide ion pumps have recently been discovered. Some of them, called "NTQ" rhodopsins, contain a conserved Asn-Thr-Gln motif in the 3(rd) or C-helix. In this study, we investigated the photochemical characteristics of a NTQ rhodopsin, Nonlabens marinus rhodopsin 3 (NM-R3), which was discovered in the N. marinus S1-08(T) strain, using static and time-resolved spectroscopic techniques. We demonstrate that NM-R3 binds a Cl(-) in the vicinity of the retinal chromophore accompanied by a spectral blue shift from 568 nm in the absence of Cl(-) to 534 nm in the presence of Cl(-)...
February 14, 2017: Journal of Physical Chemistry. B
Steven M Scherr, David S Freedman, Krystle N Agans, Alexandru Rosca, Erik Carter, Melody Kuroda, Helen E Fawcett, Chad E Mire, Thomas W Geisbert, M Selim Ünlü, John H Connor
Light microscopy is a straightforward and highly portable imaging approach that is used for the detection of parasites, fungi, and bacteria. The detection of individual virus particles has historically not been possible through this approach. Thus, characterization of virus particles is typically performed using high-energy approaches such as electron microscopy. These approaches require purification of virions away from its normal milieu, significant levels of expertise, and only count a small number of particles at a time...
February 14, 2017: Lab on a Chip
Peifang Wang, Liya Xu, Yanhui Ao, Chao Wang
In this work, flower-like Au/Bi2O2CO3/Bi2O3 multi-heterojunction photocatalysts were prepared by a in-situ growth method. The as-prepared samples were characterized by different techniques including Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectrometry (DRS), X-ray photoelectron spectroscopy (XPS), Photoluminescence (PL) and photo-induced current. The photocatalytic performance of the as prepared samples was evaluated by degradation of rhodamine B (RhB) under visible light (λ>400nm)...
February 7, 2017: Journal of Colloid and Interface Science
Courtney Eichorn, Michael Hrabar, Emma C Van Ryn, Bekka S Brodie, Adam J Blake, Gerhard Gries
BACKGROUND: Flies have some of the most elaborate visual systems in the Insecta, often featuring large, sexually dimorphic eyes with specialized "bright zones" that may have a functional role during mate-seeking behavior. The fast visual system of flies is considered to be an adaptation in support of their advanced flight abilities. Here, we show that the immense processing speed of the flies' photoreceptors plays a crucial role in mate recognition. RESULTS: Video-recording wing movements of abdomen-mounted common green bottle flies, Lucilia sericata, under direct light at 15,000 frames per second revealed that wing movements produce a single, reflected light flash per wing beat...
February 14, 2017: BMC Biology
Ross Koppel, Craig Kuziemsky
Usability of health information technology (HIT), if considered at all, is usually focused on individual providers, settings and vendors. However, in light of transformative models of healthcare delivery such as collaborative care delivery that crosses providers and settings, we need to think of usability as a collective and constantly emerging process. To address this new reality we develop a matrix of usability that spans several dimensions and contexts, incorporating differing vendors, user, settings, disciplines, and display configurations...
2017: Studies in Health Technology and Informatics
Nasibeh Haghighi, Rahman Hallaj, Abdollah Salimi
In this work a new organic-inorganic nanocomposite has been introduced for enzyme immobilization. The composite consisting of graphene oxide (GO) and titanium oxide nanoparticles (TiO2) modified with 2, 2'-dithioxo-3, 3'-bis (3-(triethoxysilyl) propyl)-2H, 2'H-[5, 5'-bithiazolylidene]-4, 4'(3H, 3'H)-dione as Organic-Inorganic Supporting Ligand (OISL). The OISL was covalently attached to TiO2 nanoparticles and employed for obtaining a suitable solid surface to enzyme attachment. The glucose oxidase (GOD) was irreversibly loaded on the GC/GO/TiO2-OISL using consecutive cyclic voltammetry...
April 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"