keyword
MENU ▼
Read by QxMD icon Read
search

Quantum yield

keyword
https://www.readbyqxmd.com/read/28213950/benchmark-performance-of-global-switching-versus-local-switching-for-trajectory-surface-hopping-molecular-dynamic-simulation-cis-trans-azobenzene-photoisomerization
#1
Ling Yue, Le Yu, Chao Xu, Yibo Lei, Yajun Liu, Chaoyuan Zhu
Newly developed global switching algorithm that does not require calculation of nonadiabatic coupling vector reduces computational cost significantly. However, there is a lack of extensive checking its accuracy for this simplest nonadiabatic molecular dynamic method in comparison with conventional Tully's fewest switches. It is very necessary to demonstrate how accurate global switching algorithm is. Extensive comparison between local and global switching on-the-fly trajectory surface hopping molecular dynamics is performed for cis-to-trans (800 sampling trajectories) and trans-to-cis (600 sampling trajectories) azobenzene photoisomerization at the OM2/MRCI level...
February 18, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28213325/carbon-dots-based-fret-for-the-detection-of-dna-damage
#2
Jiri Kudr, Lukas Richtera, Kledi Xhaxhiu, David Hynek, Zbynek Heger, Ondrej Zitka, Vojtech Adam
Here, we aimed our attention at the synthesis of carbon dots (C-dots) with the ability to interact with DNA to suggest an approach for the detection of DNA damage. Primarily, C-dots modified with amine moieties were synthesized using the one-step microwave pyrolysis of citric acid in the presence of diethylenetriamine. The C-dots showed strong photoluminescence with a quantum yield of 4%. In addition, the C-dots (2.8±0.8nm) possessed a good colloidal stability and exhibited a positive surface charge (ζ=36mV) at a neutral pH...
February 9, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28213258/p-aminothiophenol-coated-cdse-zns-quantum-dots-as-a-turn-on-fluorescent-probe-for-ph-detection-in-aqueous-media
#3
Dong Li, Hu Xu, Dan Li, Yuhong Wang
Since controlling hydrogen ion concentration (i.e. pH) is fairly important in various fields, developing a facile pH detection method is highly desired. Owing to the superior optical properties, semiconductor quantum dots (QDs) have been developed as a promising alternative for organic fluorophores in fluorescence analysis. In this study, a hydrophilic p-aminothiophenol (pATP) capped CdSe/ZnS QDs (denoted as pATP-QDs) as a selective "turn-on" fluorescence probe for pH in aqueous media is reported. The pATP-QDs probe easily obtained via ligand exchange are characterized by various analytic techniques including ultraviolet-visible, fourier transform infrared, fluorescence, time-resolved fluorescence spectroscopies, and transmission electron microscope etc...
May 1, 2017: Talanta
https://www.readbyqxmd.com/read/28212121/identification-and-evaluation-of-clinically-significant-prostate-cancer-a-step-towards-personalized-diagnosis
#4
Adnan Ali, Alexander Hoyle, Esther Baena, Noel W Clarke
PURPOSE OF REVIEW: Prostate cancer (PCa) diagnostics are evolving rapidly. The quest to differentiate 'clinically significant' from 'clinically insignificant' disease has gathered momentum, leading to substantial change in traditional diagnostic approaches. Herein, we review the relevant information on currently available biomarkers and assess their ability to help physicians and patients in making a shared and personalized decision based on their individual risk of harbouring clinically significant disease...
February 16, 2017: Current Opinion in Urology
https://www.readbyqxmd.com/read/28210728/self-initiation-of-uv-photopolymerization-reactions-using-tetrahalogenated-bisphenol-a-meth-acrylates
#5
Théophile Pelras, Wolfgang Knolle, Sergej Naumov, Katja Heymann, Olesya Daikos, Tom Scherzer
The potential of tetrachlorinated and tetrabrominated bisphenol A diacrylates and dimethacrylates for self-initiation of a radical photopolymerization was investigated. The kinetics of the photopolymerization of an acrylic model varnish containing halogenated monomers was studied by real-time FTIR spectroscopy, whereas the formation of reactive species and secondary products was elucidated by laser flash photolysis and product analysis by GC-MS after steady-state photolysis. The interpretation of the experimental data and the analysis of possible reaction pathways were assisted by quantum chemical calculations...
February 17, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28209541/luminescent-properties-and-energy-transfer-of-luminescent-carbon-dots-assembled-mesoporous-al2o3-eu-3-co-doped-materials-for-temperature-sensing
#6
Youling He, Jiangling He, Haoran Zhang, Yingliang Liu, Bingfu Lei
Owning to the hydrogen-band interactions, blue-light-emitting luminescent carbon dots (CDs) synthesized by one-pot hydrothermal treatment were successfully assembled into Eu(3+) doped mesoporous aluminas (MAs). Interesting, dual-emissive CDs/MAs co-doped materials with higher quantum yield (QY), long-term stability, mesoporous structure, high thermal stability, and large surface areas were obtained. Furthermore, the obtained CDs/MAs co-doped materials possessed tunable color, and excellent temperature sensitivity due to the existing of energy transfer between CDs and Eu(3+) ion...
February 9, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28208588/depicting-binding-mediated-translocation-of-hiv-1-tat-peptides-in-living-cells-with-nanoscale-pens-of-tat-conjugated-quantum-dots
#7
Chien Y Lin, Jung Y Huang, Leu-Wei Lo
Cell-penetrating peptides (CPPs) can translocate across cell membranes, and thus have great potential for the cellular delivery of macromolecular cargoes. However, the mechanism of this cellular uptake process is not yet fully understood. In this study, a time-lapse single-particle light-sheet microscopy technique was implemented to obtain a parallel visualization of the translocating process of individual human immunodeficiency virus 1 (HIV-1) transactivator of transcription (Tat) peptide conjugated quantum dots (TatP-QDs) in complex cellular terrains...
February 10, 2017: Sensors
https://www.readbyqxmd.com/read/28208094/a-simple-strategy-to-refine-cu2o-photocatalytic-capacity-for-refractory-pollutants-removal-roles-of-oxygen-reduction-and-fe-ii-chemistry
#8
Ai-Yong Zhang, Yuan-Yi He, Tan Lin, Nai-Hui Huang, Qiao Xu, Jing-Wei Feng
Visible-light-driven photocatalysis is a promising technology for advanced water treatment, but it usually exhibits a low efficiency. Cu2O is a low-cost semiconductor with narrow band gap, high absorption coefficient and suitable conduction band, but suffers from low charge mobility, poor quantum yield and weak catalytic performance. Herein, the Cu2O catalytic capacity for refractory pollutants degradation is drastically improved by a simple and effective strategy. By virtue of the synergistic effects between photocatalysis and Fenton, a novel and efficient photocatalysis-driven Fenton system, PFC, is originally proposed and experimentally validated using Cu2O/Nano-C hybrids...
January 29, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28205400/design-features-for-optimization-of-tetrapyrrole-macrocycles-as-antimicrobial-and-anticancer-photosensitizers
#9
EDITORIAL
Alejandra Martinez De Pinillos Bayona, Pawel Mroz, Connor Thunshelle, Michael R Hamblin
Photodynamic therapy (PDT) uses non-toxic dyes called photosensitizers (PS) and harmless visible light that combine to form highly toxic reactive oxygen species that kill cells. Originally, a cancer therapy, PDT, now includes applications for infections. The most widely studied PS are tetrapyrrole macrocycles including porphyrins, chlorins, bacteriochlorins, and phthalocyanines. The present review covers the design features in PS that can work together to maximize the PDT activity for various disease targets...
February 2017: Chemical Biology & Drug Design
https://www.readbyqxmd.com/read/28202243/potential-toxicity-of-ionic-liquid-c12mim-bf4-on-the-growth-and-biochemical-characteristics-of-a-marine-diatom-phaeodactylum-tricornutum
#10
Xiang-Yuan Deng, Da Li, Ling Wang, Xiao-Li Hu, Jie Cheng, Kun Gao
Recently, some researchers have pointed out that the threats of ionic liquids (ILs) to aquatic environment cannot be ignored. Thus, this study investigated the potential toxicity of 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12mim]BF4) on a marine diatom Phaeodactylum tricornutum at population, biochemical and physiological levels using 96h growth tests with a batch-culture system. Results showed that [C12mim]BF4 was very stable in aquatic environment during 96h of exposure. The growth of P. tricornutum was significantly inhibited by [C12mim]BF4 with 24, 48, 72 and 96h EC50 values of 0...
February 12, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28201910/mode-specific-excited-state-dynamics-study-of-bis-phenylethynyl-benzene-from-ultrafast-raman-loss-spectroscopy
#11
Khokan Roy, Surajit Kayal, Freek Ariese, Andrew Beeby, Siva Umapathy
Femtosecond transient absorption (fs-TA) and Ultrafast Raman Loss Spectroscopy (URLS) have been applied to reveal the excited state dynamics of bis(phenylethynyl)benzene (BPEB), a model system for one-dimensional molecular wires that have numerous applications in opto-electronics. It is known from the literature that in the ground state BPEB has a low torsional barrier, resulting in a mixed population of rotamers in solution at room temperature. For the excited state this torsional barrier had been calculated to be much higher...
February 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28201896/plasmon-coupled-resonance-energy-transfer-a-real-time-electrodynamics-approach
#12
Wendu Ding, Liang-Yan Hsu, George C Schatz
This paper presents a new real-time electrodynamics approach for determining the rate of resonance energy transfer (RET) between two molecules in the presence of plasmonic or other nanostructures (inhomogeneous absorbing and dispersive media). In this approach to plasmon-coupled resonance energy transfer (PC-RET), we develop a classical electrodynamics expression for the energy transfer matrix element which is evaluated using the finite-difference time-domain (FDTD) method to solve Maxwell's equations for the electric field generated by the molecular donor and evaluated at the position of the molecular acceptor...
February 14, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28197610/novel-and-easy-access-to-highly-luminescent-eu-and-tb-doped-ultra-small-caf2-srf2-and-baf2-nanoparticles-structure-and-luminescence
#13
Benjamin Ritter, Philipp Haida, Friedrich Fink, Thoralf Krahl, Kornelia Gawlitza, Knut Rurack, Gudrun Scholz, Erhard Kemnitz
A universal fast and easy access at room temperature to transparent sols of nanoscopic Eu(3+) and Tb(3+) doped CaF2, SrF2 and BaF2 particles via the fluorolytic sol-gel synthesis route is presented. Monodisperse quasi-spherical nanoparticles with sizes of 3-20 nm are obtained with up to 40% rare earth doping showing red or green luminescence. In the beginning luminescence quenching effects are only observed for the highest content, which demonstrates the unique and outstanding properties of these materials...
February 15, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28196917/validation-of-milliflex%C3%A2-quantum-for-bioburden-testing-of-pharmaceutical-products
#14
Oliver Gordon, Marcel Goverde, Alexandra Staerk, David Roesti
This article reports the validation strategy used to demonstrate that the Milliflex® Quantum yielded non-inferior results to the traditional bioburden method. It was validated according to USP <1223>, Ph. Eur. 5.1.6 and PDA Technical Report No. 33 and comprised the validation parameters Robustness, Ruggedness, Repeatability, Specificity, Limit of Detection and Quantification, Accuracy, Precision, Linearity, Range and Equivalence in Routine Operation. For the validation, a combination of pharmacopeial ATCC strains as well as a broad selection of in-house isolates was used...
February 14, 2017: PDA Journal of Pharmaceutical Science and Technology
https://www.readbyqxmd.com/read/28196324/delivery-of-liposomal-quantum-dots-via-monocytes-for-imaging-of-inflamed-tissue
#15
Gil Aizik, Nir Waiskopf, Majd Agbaria, Yael Levi-Kalisman, Uri Banin, Gershon Golomb
Quantum Dots (QDs), semiconductor nanocrystals, are fluorescent nanoparticles of growing interest as an imaging tool of a diseased tissue. However, a major concern is their biocompatibility, cytotoxicity and fluorescence instability in biological milieu, impeding their use in biomedical applications, in general, and for inflammation imaging, in particular. In addition, for an efficient fluorescent signal at the desired tissue, and avoiding systemic biodistribution and possible toxicity, targeting is desired...
February 14, 2017: ACS Nano
https://www.readbyqxmd.com/read/28195690/scalable-ligand-mediated-transport-synthesis-of-organic-inorganic-hybrid-perovskite-nanocrystals-with-resolved-electronic-structure-and-ultrafast-dynamics
#16
Lili Wang, Nicholas E Williams, Edward W Malachosky, John P Otto, Dugan Hayes, Ryan E Wood, Philippe Guyot-Sionnest, Gregory S Engel
Colloidal perovskite nanocrystals support bright, narrow PL tunable over the visible spectrum. However, bandgap tuning of these materials remains limited to laboratory-scale syntheses. In this work, we present a polar-solvent-free ligand-mediated transport synthesis of high-quality organic-inorganic perovskite nanocrystals under ambient conditions with photoluminescence quantum yields up to 97%. Our synthesis employs a ligand-mediated transport mechanism that circumvents the need for exquisite external control (e...
February 20, 2017: ACS Nano
https://www.readbyqxmd.com/read/28195668/towards-monodisperse-star-shaped-ladder-type-conjugated-systems-design-synthesis-stabilized-blue-electroluminescence-and-amplified-spontaneous-emission
#17
Wen-Yong Lai, Yi Jiang, Mei Fang, Si-Ju Chang, Jin-Jin Huang, Shuang-Quan Chu, Shan-Ming Hu, Cheng-Fang Liu, Wei Huang
A novel series of monodisperse star-shaped ladder-type oligo(p-phenylene)s, named as TrL-n (n = 1-3), have been explored. Their thermal and electrochemical properties, fluorescence transients, photoluminescence quantum yields, density functional theory calculations, electroluminescence (EL) and amplified spontaneous emission (ASE) properties have been systematically investigated to unravel the molecular design on optoelectronic properties. The resulting materials showed excellent structural perfection free of chemical defects, exhibiting great thermal stability (Td: 404-418°C and Tg:147-184°C) and amorphous glassy morphologies...
February 14, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28195285/magic-size-inp-and-inas-clusters-synthesis-characterization-and-shell-growth
#18
Jiajia Ning, Uri Banin
Magic size III-V semiconductor nanoclusters were synthesized. Non-continuous transition of the absorption spectra upon mild heating of the reaction solution is observed, indicating transformation between differently sized clusters. Further manipulation of the clusters is demonstrated for an InP MSC by growing a ZnS and ZnSe shell aiming at blue fluorescence. The quantum yield is limited due to formation of interfacial defects for thick ZnS shells.
February 14, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28194972/fragment-based-approach-for-the-evaluation-of-nmr-chemical-shifts-for-large-biomolecules-incorporating-the-effects-of-the-solvent-environment
#19
K V Jovan Jose, Krishnan Raghavachari
We present an efficient implementation of the molecules-in-molecules (MIM) fragment-based quantum chemical method for the evaluation of NMR chemical shifts of large biomolecules. Density functional techniques have been employed in conjunction with large basis sets and including the effects of the solvent environment in these calculations. The MIM-NMR method is initially benchmarked on a set of (alanine)10 conformers containing strong intramolecular interactions. The incorporation of a second low level of theory to recover the missing long-range interactions in the primary fragmentation scheme is critical to yield reliable chemical shifts, with a mean absolute deviation (MAD) from direct unfragmented calculations of 0...
February 14, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28192302/tuning-luminescent-properties-of-cdse-nanoclusters-by-phosphine-surface-passivation
#20
Iryna Lysova, Halina Anton, Igor Dmitruk, Yves Mely
Appropriate surface ligands are required for tuning the physicochemical and photophysical properties of nanoclusters (NCs). These surface ligands are especially critical for passivating the small (CdSe)33,34 NCs where the majority of atoms are at the NC surface. In this study, triphenylphosphine (TPP), trioctylphosphine (TOP) and tris(pentafluorophenyl)phosphine (TPFP) have been tested as capping agents for alkylamine-coated CdSe NCs. TPP and TOP compounds are found to increase the quantum yield of photoluminescence (PL) from 0...
November 25, 2016: Methods and Applications in Fluorescence
keyword
keyword
46935
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"