keyword
MENU ▼
Read by QxMD icon Read
search

constant light

keyword
https://www.readbyqxmd.com/read/28805850/dispersible-oxygen-microsensors-map-oxygen-gradients-in-three-dimensional-cell-cultures
#1
Sasha Cai Lesher-Pérez, Ge-Ah Kim, Chuan-Hsien Kuo, Brendan M Leung, Sanda Mong, Taisuke Kojima, Christopher Moraes, M D Thouless, Gary D Luker, Shuichi Takayama
Phase fluorimetry, unlike the more commonly used intensity-based measurement, is not affected by differences in light paths from culture vessels or by optical attenuation through dense 3D cell cultures and hydrogels thereby minimizing dependence on signal intensity for accurate measurements. This work describes the use of phase fluorimetry on oxygen-sensor microbeads to perform oxygen measurements in different microtissue culture environments. In one example, cell spheroids were observed to deplete oxygen from the cell-culture medium filling the bottom of conventional microwells within minutes, whereas oxygen concentrations remained close to ambient levels for several days in hanging-drop cultures...
August 14, 2017: Biomaterials Science
https://www.readbyqxmd.com/read/28805502/the-fundamentals-of-cross-sector-collaboration-for-social-change-to-promote-population-health
#2
Joanne G de Montigny, Sylvie Desjardins, Louise Bouchard
Cross-sector collaboration is increasingly relied upon to tackle society's pressing and intractable problems. Chief among societal problems are unfavorable structural and social determinants of health. The ability to positively change these health determinants rests on the collaborative processes and structures of governance across diverse sectors in society. The purpose of this article is to present a conceptual framework that sheds light on the basic requirements of cross-sector collaboration for social change to promote the health of populations...
August 1, 2017: Global Health Promotion
https://www.readbyqxmd.com/read/28803949/measuring-temporal-summation-in-visual-detection-with-a-single-photon-source
#3
Rebecca Holmes, Michelle Victora, Ranxiao Frances Wang, Paul G Kwiat
Temporal summation is an important feature of the visual system which combines visual signals that arrive at different times. Previous research estimated complete summation to last for 100 ms for stimuli judged "just detectable." We measured the full range of temporal summation for much weaker stimuli using a new paradigm and a novel light source, developed in the field of quantum optics for generating small numbers of photons with precise timing characteristics and reduced variance in photon number. Dark-adapted participants judged whether a light was presented to the left or right of their fixation in each trial...
August 10, 2017: Vision Research
https://www.readbyqxmd.com/read/28800107/sequestration-effect-on-the-open-cyclic-switchable-property-of-warfarin-induced-by-cyclodextrin-time-resolved-fluorescence-study
#4
Naji Al-Dubaili, Na'il Saleh
The excited-state lifetimes of the anticoagulant drug warfarin (W) in water and in the absence and presence of methyl-β-cyclodextrins (Me-β-CD) were recorded using time-resolved fluorescence measurements. Selective excitation of the open and cyclic protonated isomers of W were acquired with laser emitting diodes (LED) producing 320 and 280 nm excitation pulses, respectively. Formation of the inclusion complex was checked by UV-visible absorption spectroscopy, and the values of binding constants (2.9 × 10³ M(-1) and 4...
August 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28799758/ph-sensitive-interactions-between-cellulose-nanocrystals-and-dopc-liposomes
#5
Yotam Navon, Harisoa Radavidson, Jean-Luc Putaux, Bruno Jean, Laurent Heux
The interaction of DOPC vesicles with cellulose nanocrystals (CNCs) have been investigated using several complementary techniques. Dynamic light scattering, zeta-potential, cryo-transmission electron microscopy and isothermal titration calorimetry (ITC) analyses confirmed the formation of pH-dependent CNC-liposome complexes. ITC was used to characterize the thermodynamic properties of this interaction. Positive values of enthalpy were found at pH lower than 5 where the charge sign of the constituents was opposite...
August 11, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28799355/observation-of-propane-cluster-size-distributions-during-nucleation-and-growth-in-a-laval-expansion
#6
Jorge J Ferreiro, Satrajit Chakrabarty, Bernhard Schläppi, Ruth Signorell
We report on molecular-level studies of the condensation of propane gas and propane/ethane gas mixtures in the uniform (constant pressure and temperature) postnozzle flow of Laval expansions using soft single-photon ionization by vacuum ultraviolet light and mass spectrometric detection. The whole process, from the nucleation to the growth to molecular aggregates of sizes of several nanometers (∼5 nm), can be monitored at the molecular level with high time-resolution (∼3 μs) for a broad range of pressures and temperatures...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28797687/the-role-of-nitric-oxide-in-spectral-information-processing-in-the-distal-turtle-retina
#7
Elena Segal, Ido Perlman
Chromaticity type horizontal cells (C-type HCs) are the first retinal neurons exhibiting spectral information processing in cold-blooded vertebrates. The simple input of hyperpolarizing responses of cone photoreceptors is transformed in the C-type HCs into spectral opponent output. Nitric oxide (NO), a known background neuromodulator in the distal retina, was tested here for its effects upon spectral information processing by C-type HCs in the retina of turtle. Photoresponses were intracellularly recorded from C-type HCs, using light stimuli of different wavelength, applied over backgrounds of different wavelengths, and changing retinal NO level...
August 7, 2017: Vision Research
https://www.readbyqxmd.com/read/28797055/an-experimental-study-on-the-thermal-characteristics-and-heating-effect-of-arc-fault-from-cu-core-in-residential-electrical-wiring-fires
#8
Jian-Hua Du, Ran Tu, Yi Zeng, Leng Pan, Ren-Cheng Zhang
The characteristics of a series direct current (DC) arc-fault including both electrical and thermal parameters were investigated based on an arc-fault simulator to provide references for multi-parameter electrical fire detection method. Tests on arc fault behavior with three different initial circuit voltages, resistances and arc gaps were conducted, respectively. The influences of circuit conditions on arc dynamic image, voltage, current or power were interpreted. Also, the temperature rises of electrode surface and ambient air were studied...
2017: PloS One
https://www.readbyqxmd.com/read/28796982/-causes-of-death-in-children-and-adolescents-aged-1-19-in-poland-in-the-light-of-international-statistics-since-2000
#9
Joanna Mazur, Marta Malinowska-Cieślik, Anna Oblacińska
BACKGROUND: Analyses of children and young people mortality continue to be an important component of health monitoring of this population. Such analyses provide the basis to assess the overall trends, the structure of the causes of death over longer periods, and the differences between Poland and other countries. PURPOSE: The purpose of the current study is to present the current status and the direction of changes since 2000 with regard to the level and underlying causes of mortality in children and adolescents aged 1-19 years in Poland on the background of statistics for leading European countries...
2017: Developmental Period Medicine
https://www.readbyqxmd.com/read/28795562/axially-bound-ruthenium-phthalocyanine-monolayers-on-indium-tin-oxide-structure-energetics-and-charge-transfer-properties
#10
Ramanan Ehamparam, Luis E Oquendo, Michael W Liao, Ambjorn Karl Brynnel, Kai-Lin Ou, Neal R Armstrong, Dominic V McGrath, S Scott Saavedra
The efficiency of charge collection at the organic/transparent conducting oxide (TCO) interface in organic photovoltaic (OPV) devices affects overall device efficiency. Modifying the TCO with an electrochemically active molecule may enhance OPV efficiency by providing a charge-transfer pathway between the electrode and the organic active layer, and may also mitigate surface recombination. The synthesis and characterization of phosphonic acid-ruthenium phthalocyanine (RuPcPA) monolayer films on indium tin oxide (ITO), designed to facilitate charge harvesting at ITO electrodes, is presented in this work...
August 10, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28793801/return-to-work-in-the-context-of-everyday-life-7-11-years-after-spinal-cord-injury-a-follow-up-study
#11
Lisa Holmlund, Susanne Guidetti, Gunilla Eriksson, Eric Asaba
PURPOSE: The aim of this follow-up study was to explore experiences of return to work in the context of everyday life among adults 7-11 years after spinal cord injury (SCI). METHODS: This study used in-depth interviews and observations in a qualitative design with eight persons who had previously been interviewed in 2008. A narrative approach was used during data gathering and analysis. RESULTS: Return to work was experienced as something constantly needing to be negotiated in the context of everyday life...
August 9, 2017: Disability and Rehabilitation
https://www.readbyqxmd.com/read/28792767/photon-reabsorption-masks-intrinsic-bimolecular-charge-carrier-recombination-in-ch3nh3pbi3-perovskite
#12
Timothy W Crothers, Rebecca L Milot, Jay B Patel, Elizabeth S Parrott, Johannes Schlipf, Peter Müller-Buschbaum, Michael B Johnston, Laura M Herz
An understanding of charge-carrier recombination processes is essential for the development of hybrid metal halide perovskites for photovoltaic applications. We show that typical measurements of the radiative bimolecular recombination constant in CH3NH3PbI3 are strongly affected by photon reabsorption that masks a much larger intrinsic bimolecular recombination rate constant. By investigating a set of films whose thickness varies between 50 and 533 nm, we find that the bimolecular charge recombination rate appears to slow by an order of magnitude as the film thickness increases...
August 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28791154/co2-induced-ocean-acidification-does-not-affect-individual-or-group-behaviour-in-a-temperate-damselfish
#13
Garfield Tsz Kwan, Trevor James Hamilton, Martin Tresguerres
Open ocean surface CO2 levels are projected to reach approximately 800 µatm, and ocean pH to decrease by approximately 0.3 units by the year 2100 due to anthropogenic CO2 emissions and the subsequent process of ocean acidification (OA). When exposed to these CO2/pH values, several fish species display abnormal behaviour in laboratory tests, an effect proposed to be linked to altered neuronal GABAA- receptor function. Juvenile blacksmith (Chromis punctipinnis) are social fish that regularly experience CO2/pH fluctuations through kelp forest diurnal primary production and upwelling events, so we hypothesized that they might be resilient to OA...
July 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28782728/hetero-interface-and-twin-boundary-mediated-strengthening-in-nano-twinned-cu-ag-multilayered-materials
#14
Yonggang Zheng, Qian Li, Jiayong Zhang, Hongfei Ye, Hong Wu Zhang, Luming Shen
Based on molecular dynamics simulations, tensile mechanical properties and plastic deformation mechanisms of nano-twinned Cu//Ag multilayered materials are investigated in this work. Simulation results show that, due to the stronger strengthening effect of the twin boundary than both the cube-on-cube and hetero-twin interfaces between Cu and Ag layers, the strength increases with the increase of layer thickness for nano-twinned Cu//Ag multilayered materials with a constant twin spacing, while it decreases with the increase of layer thickness for twin-free ones...
August 7, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28780358/formation-reactivity-and-aging-of-amorphous-ferric-oxides-in-the-presence-of-model-and-membrane-bioreactor-derived-organics
#15
Mark W Bligh, Pradeep Maheshwari, T David Waite
Iron salts are routinely dosed in wastewater treatment as a means of achieving effluent phosphorous concentration goals. The iron oxides that result from addition of iron salts partake in various reactions, including reductive dissolution and phosphate adsorption. The reactivity of these oxides is controlled by the conditions of formation and the processes, such as aggregation, that lead to a reduction in accessible surface sites following formation. The presence of organic compounds is expected to significantly impact these processes in a number of ways...
July 31, 2017: Water Research
https://www.readbyqxmd.com/read/28780336/facile-one-pot-synthesis-of-cerium-oxide-sulfur-doped-graphitic-carbon-nitride-g-c3n4-as-efficient-nanophotocatalysts-under-visible-light-irradiation
#16
Milad Jourshabani, Zahra Shariatinia, Alireza Badiei
Porous CeO2/sulfur-doped g-C3N4 (CeO2/CNS) composites were synthesized by one-pot thermal condensation of thiourea and cerium nitrate as starting materials. The obtained CeO2(x)/CNS composites (x=8.4, 9.5 and 10.4wt%) with different CeO2 contents were characterized by the XRD, FT-IR, XPS, TEM, BET, DRS and PL analyses. The TEM images displayed a nonporous and platelet-like morphology for pure CNS but a nanoporous structure with numerous uniform pore sizes of ∼40nm for the CeO2(9.5)/CNS composite. The XRD phase structures and TEM morphologies confirmed that structural evolution trend and stacking degree of CNS were disrupted in precense of the CeO2 nanoparticles...
July 29, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28779843/ssm-based-electrophysiology-for-transporter-research
#17
Andre Bazzone, Maria Barthmes, Klaus Fendler
Functional characterization of transport proteins using conventional electrophysiology can be challenging, especially for low turnover transporters or transporters from bacteria and intracellular compartments. Solid-supported membrane (SSM)-based electrophysiology is a sensitive and cell-free assay technique for the characterization of electrogenic membrane proteins. Purified proteins reconstituted into proteoliposomes or membrane vesicles from cell culture or native tissues are adsorbed to the sensor holding an SSM...
2017: Methods in Enzymology
https://www.readbyqxmd.com/read/28773922/the-structural-photocatalytic-property-characterization-and-enhanced-photocatalytic-activities-of-novel-photocatalysts-bi%C3%A2-gasbo%C3%A2-and-bi%C3%A2-insbo%C3%A2-during-visible-light-irradiation
#18
Jingfei Luan, Yue Shen, Yanyan Li, Yaron Paz
In order to develop original and efficient visible light response photocatalysts for degrading organic pollutants in wastewater, new photocatalysts Bi₂GaSbO₇ and Bi₂InSbO₇ were firstly synthesized by a solid-state reaction method and their chemical, physical and structural properties were characterized. Bi₂GaSbO₇ and Bi₂InSbO₇ were crystallized with a pyrochlore-type structure and the lattice parameter of Bi₂GaSbO₇ or Bi₂InSbO₇ was 10.356497 Å or 10.666031 Å. The band gap of Bi₂GaSbO₇ or Bi₂InSbO₇ was estimated to be 2...
September 27, 2016: Materials
https://www.readbyqxmd.com/read/28773809/template-free-synthesis-of-monoclinic-bivo%C3%A2-with-porous-structure-and-its-high-photocatalytic-activity
#19
Pengyu Dong, Xinguo Xi, Xinjiang Zhang, Guihua Hou, Rongfeng Guan
Monoclinic BiVO₄ photocatalysts with porous structures were synthesized by a two-step approach without assistance of any templates. The as-prepared samples were characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (DRS), photocurrent responses, and electrochemical impedance spectra (EIS). It is found that the as-prepared BiVO₄ samples had a porous structure with aperture diameter of 50-300 nm...
August 11, 2016: Materials
https://www.readbyqxmd.com/read/28772575/kinetic-analysis-of-the-uptake-and-release-of-fluorescein-by-metal-organic-framework-nanoparticles
#20
Tobias Preiß, Andreas Zimpel, Stefan Wuttke, Joachim O Rädler
Metal-organic framework nanoparticles (MOF NPs) are promising guest-host materials with applications in separation, storage, catalysis, and drug delivery. However, on- and off-loading of guest molecules by porous MOF nanostructures are still poorly understood. Here we study uptake and release of fluorescein by two representative MOF NPs, MIL-100(Fe) and MIL-101(Cr). Suspensions of these MOF NPs exhibit well-defined size distributions and crystallinity, as verified by electron microscopy, dynamic light scattering, and X-ray diffraction...
February 22, 2017: Materials
keyword
keyword
88603
1
2
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"