keyword
MENU ▼
Read by QxMD icon Read
search

Cation

keyword
https://www.readbyqxmd.com/read/28241701/-application-of-means-of-surfaces-with-nonhomogeneity-in-estimating-the-incidence-of-pneumoconiosis
#1
C X Zhao, J Zhang, S B Hao, J Zhang, P Xu, Y W Can, J Q Zhao, J G Li
Objective: To investigate the value of means of surfaces with nonhomogeneity (MSN) in esti-mating the incidence of pneumoconiosis. Methods: Based on the principal component analysis, all counties (districts) of Hebei Province, China, were divided into three categories according to the degree of pneumoconiosis hazards and the MSN model was used to estimate the incidence rate of pneumoconiosis and the number of pneu-moconiosis cases using the data of the incidence of pneumoconiosis in 2010. Results: With reference to the appli-cation requirements of the MSN model, results of the principal component analysis, and expert experience, the 172 counties (districts) in Hebei Province were divided into three categories with mild, moderate, and severe pneumoconiosis hazards...
January 20, 2017: Chinese Journal of Industrial Hygiene and Occupational Diseases
https://www.readbyqxmd.com/read/28241583/improving-cavity-enhanced-spectroscopy-of-molecular-ions-in-the-mid-infrared-with-up-conversion-detection-and-brewster-plate-spoilers
#2
Charles R Markus, Adam J Perry, James N Hodges, Benjamin J McCall
The performance of sensitive spectroscopic methods in the mid-IR is often limited by fringing due to parasitic etalons and the background noise in mid-infrared detectors. In particular, the technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS), which is capable of determining the frequencies of strong rovibrational transitions of molecular ions with sub-MHz uncertainty, needs improved sensitivity in order to probe weaker transitions. In this work, we have implemented up-conversion detection with NICE-OHVMS in the 3...
February 20, 2017: Optics Express
https://www.readbyqxmd.com/read/28241416/determination-of-inorganic-cations-and-anions-in-chitooligosaccharides-by-ion-chromatography-with-conductivity-detection
#3
Lidong Cao, Xiuhuan Li, Li Fan, Li Zheng, Miaomiao Wu, Shanxue Zhang, Qiliang Huang
Chitooligosaccharides (COSs) are a promising drug candidate and food ingredient because they are innately biocompatible, non-toxic, and non-allergenic to living tissues. Therefore, the impurities in COSs must be clearly elucidated and precisely determined. As for COSs, most analytical methods focus on the determination of the average degrees of polymerization (DPs) and deacetylation (DD), as well as separation and analysis of the single COSs with different DPs. However, little is known about the concentrations of inorganic cations and anions in COSs...
February 22, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28240902/organic-cation-rotation-and-immobilisation-in-pure-and-mixed-methylammonium-lead-halide-perovskites
#4
Oleg Selig, Aditya Sadhanala, Christian Müller, Robert Lovrincic, Zhuoying Chen, Yves L A Rezus, Jarvist M Frost, Thomas L C Jansen, Artem A Bakulin
Three-dimensional lead-halide perovskites have attracted a lot of attention due to their ability to combine solution processing with outstanding optoelectronic properties. Despite their soft ionic nature these materials demonstrate a surprisingly low level of electronic disorder resulting in sharp band edges and narrow distributions of the electronic energies. Understanding how structural and dynamic disorder impacts the optoelectronic properties of these perovskites is important for many applications. Here we combine ultrafast two-dimensional vibrational spectroscopy and molecular dynamics simulations to study the dynamics of the organic methylammonium (MA) cation orientation in a range of pure and mixed tri-halide perovskite materials...
February 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28240899/synthesis-structure-and-reactivity-of-the-sterically-crowded-th-3-complex-c5me5-3th-including-formation-of-the-thorium-carbonyl-c5me5-3th-co-bph4
#5
Ryan R Langeslay, Guo P Chen, Cory J Windorff, Alan K Chan, Joseph W Ziller, Filipp Furche, William J Evans
The Th(3+) complex, (C5Me5)3Th, has been isolated despite the fact that tris(pentamethylcyclopentadienyl) complexes are highly reactive due to steric crowding and few crystallographically characterizable Th(3+) complexes are known due to their highly reducing nature. Reaction of (C5Me5)2ThMe2 with [Et3NH][BPh4] produces the cationic thorium complex [(C5Me5)2ThMe][BPh4] that can be treated with KC5Me5 to generate (C5Me5)3ThMe, 1. The methyl group on (C5Me5)3ThMe can be removed with [Et3NH][BPh4] to form [(C5Me5)3Th][BPh4], 2, the first cationic tris(pentamethylcyclopentadienyl) metal complex, which can be reduced with KC8 to yield (C5Me5)3Th, 3...
February 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28240887/hierarchy-of-supramolecular-arrangements-and-building-blocks-inverted-paradigm-of-crystal-engineering-in-the-unprecedented-metal-coordination-of-methylene-blue
#6
Stefano Canossa, Alessia Bacchi, Claudia Graiff, Paolo Pelagatti, Giovanni Predieri, Andrea Ienco, Gabriele Manca, Carlo Mealli
The aromatic methylene blue cation (MB(+)) shows unprecedented ligand behavior in the X-ray structures of the trigonal-planar (TP) complexes MBMCl2 (M = Cu(I), Ag(I)). The two isostructural compounds were exclusively synthesized by grinding together methylene blue chloride and MCl solids. Only in the case of AuCl did the technique lead to a different, yet isoformular, Au(I) derivative with separated MB(+) and AuCl2(-) counterions and no direct N-Au linkage. While the density functional theory (DFT) molecular modeling failed in reproducing the isolated Cu and Ag complexes, the solid-state program CRYSTAL satisfactorily provided for Cu the correct TP building block associated with a highly compact π stacking of the MB(+) ligands...
February 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28240885/redox-potential-and-electronic-structure-effects-of-proximal-nonredox-active-cations-in-cobalt-schiff-base-complexes
#7
Alexander H Reath, Joseph W Ziller, Charlene Tsay, Austin J Ryan, Jenny Y Yang
Redox inactive Lewis acidic cations are thought to facilitate the reactivity of metalloenzymes and their synthetic analogues by tuning the redox potential and electronic structure of the redox active site. To explore and quantify this effect, we report the synthesis and characterization of a series of tetradentate Schiff base ligands appended with a crown-like cavity incorporating a series of alkali and alkaline earth Lewis acidic cations (1M, where M = Na(+), K(+), Ca(2+), Sr(2+), and Ba(2+)) and their corresponding Co(II) complexes (2M)...
February 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28240873/photochemical-processes-in-a-rhenium-i-tricarbonyl-n-heterocyclic-carbene-complex-studied-by-time-resolved-measurements
#8
Tatsuhiko Mukuta, Peter V Simpson, Jamila G Vaughan, Brian W Skelton, Stefano Stagni, Massimiliano Massi, Kazuhide Koike, Osamu Ishitani, Ken Onda
We carried out time-resolved infrared (TR-IR) and emission lifetime measurements on a Re(I) carbonyl complex having an N-heterocyclic carbene ligand, namely, fac-[Re(CO)3(PyImPh)Br], under photochemically reactive (in solution in acetonitrile) and nonreactive (in solution in dichloromethane) conditions to investigate the mechanism of photochemical ligand substitution reactions. The TR-IR measurements revealed that no reaction occurs on a picosecond time scale and the cationic product, namely, fac-[Re(CO)3(PyImPh)(MeCN)](+), is produced on a nanosecond time scale only in solution in acetonitrile, which indicates that the reaction proceeds thermally from the excited state...
February 27, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28240871/photoinduced-stark-effects-and-mechanism-of-ion-displacement-in-perovskite-solar-cell-materials
#9
Meysam Pazoki, T Jesper Jacobsson, Jolla Kullgren, Erik M J Johansson, Anders Hagfeldt, Gerrit Boschloo, Tomas Edvinsson
Organometallic halide perovskites (OMHPs) have recently emerged as a promising class of materials in photovoltaic technology. Here we present an in-depth investigation of the physics in these systems by measuring the photo-induced absorption (PIA) in OMHPs as a function of materials composition, excitation wavelength and modulation frequency. We report a photoinduced Stark effect that depends on the excitation wavelength and on the dipole strength of the monovalent cations in the A position of the ABX3 perovskite...
February 27, 2017: ACS Nano
https://www.readbyqxmd.com/read/28240850/ascorbate-promoted-surface-iron-cycle-for-efficient-heterogeneous-fenton-alachlor-degradation-with-hematite-nanocrystals
#10
Xiaopeng Huang, Xiaojing Hou, Falong Jia, Fahui Song, Jincai Zhao, Lizhi Zhang
This study reports the H2O2 activation with different hematite nanocrystals and ascorbate ions for the herbicide alachlor degradation at pH 5. We found that hematite nanoplates (HNPs) exposed with {001} facets exhibited better catalytic performance than hematite nanocubes (HNCs) exposed with {012} facets, which was attributed to the formation of inner-sphere iron-ascorbate complexes on the hematite facets. The 3-fold undercoordination Fe cations of {001} facet favors the formation of inner-sphere iron-ascorbate complexes, while the 5-fold undercoordination Fe cations of {012} facet has stereo-hindrance effect, disfavoring the complex formation...
February 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28240750/radical-anion-and-dianion-salts-of-titanyl-macrocycles-with-acceptor-substituents-or-an-extended-%C3%AF-system
#11
Maxim A Faraonov, Dmitri V Konarev, Alexey M Fatalov, Salavat S Khasanov, Sergey I Troyanov, Rimma N Lyubovskaya
Crystalline anionic salts of titanyl macrocycles with acceptor substituents or an extended π-system have been obtained for the first time: (PPN(+))2{O[double bond, length as m-dash]Ti(IV)(PcCl8(4-))}(2-) (1), (PPN(+)){O[double bond, length as m-dash]Ti(IV)(Nc˙(3-))}˙(-)·2C6H4Cl2 (2) and (PPN(+))2{O[double bond, length as m-dash]Ti(IV)(AceTPrzPz(4-))}(2-)·1.3C6H4Cl2·0.8C6H5CN (3) where PPN(+) is the bis(triphenylphosphoranylidene)ammonium cation, PcCl8 - 2,3,9,10,16,17,23,24-octachlorophthalocyanine; Nc - 2,3-naphthalocyanine, AceTPrzPz - tetra(acenaphthenopyrazino)porphyrazine...
February 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28240556/unbalanced-hole-and-electron-diffusion-in-lead-bromide-perovskites
#12
Giselle A Elbaz, Daniel B Straus, Octavi E Semonin, Trevor D Hull, Daniel W Paley, Philip Kim, Jonathan S Owen, Cherie R Kagan, Xavier Roy
We use scanning photocurrent microscopy and time-resolved microwave conductivity to measure the diffusion of holes and electrons in a series of lead bromide perovskite single crystals, APbBr3, with A = methylammonium (MA), formamidinium (FA), and Cs. We find that the diffusion length of holes (LD(h+) ∼ 10-50 μm) is on average an order of magnitude longer than that of electrons (LD(e-) ∼ 1-5 μm), regardless of the A-type cation or applied bias. Furthermore, we observe a weak dependence of LD across the A-cation series MA > FA > Cs...
February 27, 2017: Nano Letters
https://www.readbyqxmd.com/read/28240539/intrinsic-ultrahigh-drug-mirna-loading-capacity-of-biodegradable-bioactive-glass-nanoparticles-towards-highly-efficient-pharmaceutical-delivery
#13
Meng Yu, Yumeng Xue, Peter X Ma, Cong Mao, Bo Lei
The lack of safe and efficient drug/gene delivery vectors has become a major obstacle for the clinical applications of drug/non-viral gene therapy. To date, for non-viral gene vectors, most of studies are focused on cationic polymers, liposomes and modified inorganic nanoparticles which have shown high cellular toxicity or low transfection efficiency or non-degradation. Additionally, few biodegradable biomaterials demonstrate intrinsic high binding abilities to both drug and gene. Bioactive glasses (BGs) have achieved successful applications in bone regeneration due to their high biocompatibility and biodegradation...
February 27, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28240255/hierarchical-self-assembly-of-squaraine-and-silica-nanoparticle-functionalized-with-cationic-coordination-sites-for-near-infrared-detection-of-atp
#14
Ruizhi Feng, Weining Shi, Dejia Wang, Jia Wen, Hongjuan Li, Shiguo Sun, Yongqian Xu
Optical activity of hierarchical supramolecular assemblies based on organic dyes would create multiple functional architectures. In this work, three kinds of silica nanoparticles with or without functional groups were synthesized. For the first time, silica nanoparticles can induce positively charged squaraine (SQ) to aggregate to form supramolecular assemblies. Adenosine-5'-triphosphate (ATP) as building blocks was absorbed on the surface of silica nanoparticles through metal-anion coordination and electrostatic interactions, in which the aggregates of SQ was transferred to monomer...
February 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28240241/calcium-pre-conditioning-substitution-enhances-viability-and-glucose-sensitivity-of-pancreatic-beta-cells-encapsulated-using-polyelectrolyte-multilayer-coating-method
#15
Niusha Nikravesh, Sophie C Cox, Gurpreet Birdi, Richard L Williams, Liam M Grover
Type I diabetics are dependent on daily insulin injections. A therapy capable of immunoisolating pancreatic beta-cells and providing normoglycaemia is an alternative since it would avoid the late complications associated with insulin use. Here, 3D-concave agarose micro-wells were used to culture robust pancreatic MIN-6 cell spheroids within 24 hours that were shown to exhibit cell-cell contact and uniform size (201 ± 2 μm). A polyelectrolyte multilayer (PEM) approach using alginate and poly-l-lysine was employed to coat cell spheroids...
February 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28239789/impairment-of-energy-dependent-processes-in-the-muscle-tissue-as-a-pathogenetic-mechanism-of-statin-induced-myopathy
#16
Z I Mikashinovich, E S Belousova, O G Sarkisyan
Administration of simvastatin was followed by a decrease in activities of superoxide dismutase and cytochrome oxidase in rat mitochondria, which attested to dysfunction of the respiratory chain. The decrease in total ATPase and Ca(2+)-ATPase activities in muscle tissue homogenates reflected impaired transport of active cations essential for muscle contraction. We conclude that abnormal relationships in the system of energy synthetic and energy-dependent processes in myocytes serve as the molecular basis for the formation of statin-induced degenerative changes...
February 27, 2017: Bulletin of Experimental Biology and Medicine
https://www.readbyqxmd.com/read/28239731/formation-of-hybrid-abx3-perovskite-compounds-for-solar-cell-application-first-principles-calculations-of-effective-ionic-radii-and-determination-of-tolerance-factors
#17
Markus Becker, Thorsten Klüner, Michael Wark
The development of hybrid organic-inorganic perovskite solar cells is one of the most rapidly growing fields in the photovoltaic community and is on its way to challenge polycrystalline silicon and thin film technologies. High power conversion efficiencies can be achieved by simple processing with low cost. However, due to the limited long-term stability and environmental toxicity of lead in the prototypic CH3NH3PbI3, there is a need to find alternative ABX3 constitutional combinations in order to promote commercialization...
February 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28239728/chemistry-of-cs2-and-scnph-adducts-of-the-pyramidal-phosphinidene-bridged-complex-mo2cp-%C3%AE-%C3%AE%C2%BA-1-%C3%AE%C2%BA-1-%C3%AE-5-pc5h4-co-2-%C3%AE-6-hmes-pme3
#18
Isabel G Albuerne, M Angeles Alvarez, M Esther García, Daniel García-Vivó, Miguel A Ruiz
The title complex reacted readily with CS2 and SCNPh to give the phosphinidene-cumulene adducts [Mo2Cp{μ-κ(1)P:κ(1)S,η(5)-P(CS2)C5H4}(CO)2(η(6)-HMes*)(PMe3)] and [Mo2Cp{μ-κ(1)P:κ(1)S,η(5)-P(C(NPh)S)C5H4}(CO)2(η(6)-HMes*)(PMe3)] respectively (Mes* = 2,4,6-C6H2(t)Bu3), as a result of the formal insertion of the C[double bond, length as m-dash]S bond of the heterocumulene into the metallocene Mo-P bond of the phosphinidene complex. The newly formed species bear a pyramidal P atom with a lone electron pair involved in fast inversion, and displayed strong nucleophilicity which enabled easy addition at the P site of carbon-based electrophiles and chalcogen atoms, while the uncoordinated S and N atoms were also competitive nucleophilic sites in these complexes...
February 27, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28239699/stabilization-of-carbocations-ch3-c2h5-i-c3h7-tert-bu-and-cyclo-pentyl-in-solid-phases-experimental-data-versus-calculations
#19
Evgenii S Stoyanov, Anton S Nizovtsev
Comparison of experimental infrared (IR) spectra of the simplest carbocations (with the weakest carborane counterions in terms of basicity, CHB11Hal11(-), Hal = F, Cl) with their calculated IR spectra revealed that they are completely inconsistent, as previously reported for the t-Bu(+) cation [Stoyanov E. S., et al. J. Phys. Chem. A, 2015, 119, 8619]. This means that the generally accepted explanation of hyperconjugative stabilization of the carbocations should be revised. According to the theory, one CH bond (denoted as ) from each CH3/CH2 group transfers its σ-electron density to the empty 2pz orbital of the sp(2) C atom, whereas the σ-electron density on the other CH bonds of the CH3/CH2 group slightly increases...
February 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28239563/synthesis-of-some-mg-co-al-type-nano-hydrotalcites-and-characterization
#20
Khadijeh Shekoohi, Fatemeh Sadat Hosseini, Amir Hossein Haghighi, Atefe Sahrayian
Hydrotalcites are quite prevalent in nature and their importance is growing more and more because of their very wide range of potential applications and uses. Because hydrotalcite does not exist in significant quantities in nature, coprecipitation methods are the most used for prepartion of hydrotalcite. In this study: Two types of Nano hydrotalcite compounds containing one divalent (Mg-Al) and two divalent cation(Co-Mg-Al) were synthesized based on aqueous solutions of corresponding nitrates by co-precipitation method...
2017: MethodsX
keyword
keyword
120149
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"