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Ortho k

Kevin M Hickson, Yury V Suleimanov
In a previous joint experimental and theoretical study of the barrierless chemical reaction C((1)D) + H2 at low temperatures (300-50 K) [K. M. Hickson, J.-C. Loison, H. Guo and Y. V. Suleimanov, J. Phys. Chem. Lett., 2015, 6, 4194], excellent agreement was found between experimental thermal rate constants and theoretical estimates based on ring polymer molecular dynamics (RPMD) over the two lowest singlet potential energy surfaces (PESs). Here, we extend this work to one of its isotopologues, C((1)D) + D2, over the same temperature range...
December 1, 2016: Physical Chemistry Chemical Physics: PCCP
Aimee K Clarke, John T R Liddon, James D Cuthbertson, Richard J K Taylor, William P Unsworth
Two complementary dearomatising spirocyclisation protocols to generate spirocyclic dienones from anisole and phenol-tethered ynones are described, each proceeding via electrophilic alkyne activation. The first approach focuses on the spirocyclisation of para-substituted anisoles using either SnCl2·2H2O or Cu(OTf)2. The second approach, which enables the spirocyclisation of both ortho- and para-substituted phenols, uses silica-supported AgNO3 to generate similar scaffolds with much greater efficiency. Initial asymmetric studies are also outlined...
November 30, 2016: Organic & Biomolecular Chemistry
Xiao Yang, Zhouyue Li, Junwen Zeng
Myopia has become a worldwide public health issue. Recent studies have consistently reported that orthokeratology (Ortho-K) significantly inhibits the progression of myopia by slowing the elongation of axial length. It has been hypothesized that this effect results from the induction of peripheral myopic defocus, which is a result of the effects of the Ortho-K lenses on the midperipheral corneal topography. Previous studies have investigated the relationship between predicting factors and the inhibitory effect of Ortho-K for slowing childhood myopic progression and found some meaningful results; however, some of the findings are controversial...
November 2016: Asia-Pacific Journal of Ophthalmology
Katsuyuki Hirai, Kana Bessho, Kosaku Tsujita, Toshikazu Kitagawa
Diphenyldiazomethane with four iodine groups at the ortho positions and two tert-butyl groups at the para positions, i.e., bis(4-tert-butyl-2,6-diiodophenyl)diazomethane (1a-N₂), was synthesized as a sterically hindered triplet carbene precursor. Irradiation of 1a-N₂ in solution effectively generated the corresponding triplet diphenylcarbene ³1a, which was characterized by UV-vis spectroscopy at low temperature, along with laser flash photolysis techniques at room temperature. The UV-vis spectrum of ³1a was obtained by irradiating 1a-N₂ in a 2-methyltetrahydrofuran matrix at 77 K...
November 15, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
D Nagarajan, Balashanmugam Baskaranarayanan, K Usha, M S Jayanthi, M Vijjaykanth
INTRODUCTION: The application of light and continuous forces for optimum physiological response and the least damage to the tooth supporting structures should be the primary aim of an orthodontist. Nickel-titanium (NiTi) alloys with their desirable properties are one of the natural choices of the clinicians. AIM: This study was aimed to compare and rank them based on its tensile strength and electrical resistivity. MATERIALS AND METHODS: The sample consisted of eight groups of 0...
October 2016: Journal of Pharmacy & Bioallied Sciences
Vipin Tyagi, M D Mustafa, Tusha Sharma, B D Banerjee, Rafat S Ahmed, A K Tripathi, Kiran Guleria
BACKGROUND & OBJECTIVES: Preterm birth (PTB) is an important cause of prenatal death, neonatal morbidity and mortality and adult illness. Increased inflammation occurs in normal parturition, and inflammatory cytokines and oxidative stress are found to be higher in PTB cases. The present study was planned to investigate the association of organochlorine pesticides (OCPs) with mRNA expression of inflammatory pathway genes such as tumour necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2) in preterm delivery (PTD) cases...
June 2016: Indian Journal of Medical Research
Orsolya K Gondor, Tibor Janda, Vilmos Soós, Magda Pál, Imre Majláth, Malay K Adak, Ervin Balázs, Gabriella Szalai
Salicylic acid is a promising compound for the reduction of stress sensitivity in plants. Although several biochemical and physiological changes have been described in plants treated with salicylic acid, the mode of action of the various treatments has not yet been clarified. The present work reports a detailed comparative study on the effects of different modes of salicylic acid application at the physiological, metabolomic, and transcriptomic levels. Seed soaking and hydroponic treatments were found to induce various changes in the protective mechanisms of wheat plants...
2016: Frontiers in Plant Science
Y A Kharkov, O P Sushkov
We find unknown s- and d-wave amplitudes of the recently discovered charge density wave (CDW) in underdoped cuprates. To do so we perform a combined analysis of experimental data for ortho-II YBa2Cu3Oy. The analysis includes data on nuclear magnetic resonance, resonant inelastic X-ray scattering, and hard X-ray diffraction. The amplitude of doping modulation found in our analysis is 3.5 · 10(-3) in a low magnetic field and T = 60 K, the amplitude is 6.5 · 10(-3) in a magnetic field of 30T and T = 1...
October 10, 2016: Scientific Reports
Rosa Padilla, Verónica Salazar-Pereda, Daniel Mendoza-Espinosa, José M Vásquez-Pérez, Noemí Andrade-López, Joaquín Tamariz, José G Alvarado-Rodríguez, Julián Cruz-Borbolla
The Ir(i) complexes [Tp(Me2)Ir(η(4)-1,4-diene)] 2b and 2c react thermally with a variety of aromatic aldehydes, 3a-e, to generate the metallabicyclic compounds 4e-k and the Fischer-type carbenes 5a-b in moderate yields. These reactions are proposed to take place with the initial formation of η(1)-aldehyde adducts as key intermediates. The formation of the metallabicyclic compounds 4e-k involves a formal decarboxylation process at the exo-2-oxazolidinone diene and an ortho metallation of the aromatic ring...
September 29, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
S K Sharma, K Sudarshan, P K Pujari
A microscopic model of the interfacial region is required to improve understanding of the role of local structure in bulk physical properties in metal organic framework-based polymer nanocomposites. A zeolitic imidazolate framework (ZIF-8)-based (loading 2-30 wt%) composite of poly vinyl alcohol (PVA) is studied as a model system to investigate the role of interfacial interaction in molecular packing, glass transition process and tensile properties. Attractive interfacial interaction between the surface of ZIF particles and PVA chains is established by Fourier transform infra red (FTIR) measurements...
September 14, 2016: Physical Chemistry Chemical Physics: PCCP
A Fuente, J Cernicharo, E Roueff, M Gerin, J Pety, N Marcelino, R Bachiller, B Lefloch, O Roncero, A Aguado
CONTEXT: Barnard B1b has revealed as one of the most interesting globules from the chemical and dynamical point of view. It presents a rich molecular chemistry characterized by large abundances of deuterated and complex molecules. Furthermore, it hosts an extremely young Class 0 object and one candidate to First Hydrostatic Core (FHSC) proving the youth of this star forming region. AIMS: Our aim is to determine the cosmic ray ionization rate, [Formula: see text], and the depletion factors in this extremely young star forming region...
September 2016: Astronomy and Astrophysics
Gin S Malhi, Yulisha Byrow, Frederick Cassidy, Andrea Cipriani, Koen Demyttenaere, Mark A Frye, Michael Gitlin, Sidney H Kennedy, Terence A Ketter, Raymond W Lam, Rupert McShane, Alex J Mitchell, Michael J Ostacher, Sakina J Rizvi, Michael E Thase, Mauricio Tohen
SUMMARY: The appeal of ketamine - in promptly ameliorating depressive symptoms even in those with non-response - has led to a dramatic increase in its off-label use. Initial promising results await robust corroboration and key questions remain, particularly concerning its long-term administration. It is, therefore, timely to review the opinions of mood disorder experts worldwide pertaining to ketamine's potential as an option for treating depression and provide a synthesis of perspectives - derived from evidence and clinical experience - and to consider strategies for future investigations...
May 2016: BJPsych Open
Michael Bodnar, Ashok K Malla, Carolina Makowski, M Mallar Chakravarty, Ridha Joober, Martin Lepage
BACKGROUND: Current neuroscience literature has related treatment with aripiprazole to improved memory performance and subcellular changes in the hippocampus. AIMS: To explore the volumetric changes in hippocampal grey matter in people with a first episode of psychosis (FEP) treated with second-generation antipsychotics. METHOD: Baseline and 1-year follow-up magnetic resonance images were obtained. Hippocampal volumes were estimated by using FreeSurfer and MAGeT-Brain...
March 2016: BJPsych Open
Nery García-Porta, Laura Rico-Del-Viejo, Alba Martin-Gil, Gonzalo Carracedo, Jesus Pintor, José Manuel González-Méijome
Purpose. To compare the ocular surface symptoms and signs in an adult population of silicone-hydrogel (Si-Hy) contact lens (CL) wearers with another modality of CL wear, overnight orthokeratology (OK). Materials and Methods. This was a prospective and comparative study in which 31 myopic subjects were fitted with the same Si-Hy CL and 23 underwent OK treatment for 3 months. Dry eye questionnaire (DEQ) was filled in at the beginning of the study and then after 15 days, 1 month, and 3 months using each CL modality...
2016: BioMed Research International
Miguel Faria-Ribeiro, Rafael Navarro, José Manuel González-Méijome
PURPOSE: It has been hypothesized that central and peripheral refraction, in eyes treated with myopic overnight orthokeratology, might vary with changes in pupil diameter. The aim of this work was to evaluate the axial and peripheral refraction and optical quality after orthokeratology, using ray tracing software for different pupil sizes. METHODS: Zemax-EE was used to generate a series of 29 semi-customized model eyes based on the corneal topography changes from 29 patients who had undergone myopic orthokeratology...
November 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
S Iida, K Wada, I Mochizuki, T Tachibana, T Yamashita, T Hyodo, Y Nagashima
We have measured the time-of-flight of ortho-positronium emitted from Cs-, Na- and Li-coated single-crystal tungsten surfaces. The data obtained after the coating show a new positronium energy component with a specific energy loss in addition to the component whose emission energy is simply determined by the positron and the electron work functions. We suggest that this new component is attributed to the formation of positronium accompanied by inter-band transition and/or surface plasmon excitation at the surfaces...
November 30, 2016: Journal of Physics. Condensed Matter: An Institute of Physics Journal
K Jung, R J C Everson, B Joshi, P A Bulsara, R Upasani, M J Clarke
OBJECTIVES: The present work analyzed the antioxidative activity of phenol-based antioxidants by using an Electron Spin Resonance method to predict the activity and stability of these antioxidants in cosmetic products. METHODS: The Antioxidative Power (AP) method was chosen to measure both the capacity and kinetics of an antioxidative reaction by detecting the DPPH (diphenylpicrylhydrazyl) radical. The antioxidative capacity (wc ) relates to the amount of free radicals that can be reduced, whereas the antioxidative reactivity (tr ) relates to the reaction speed and offers a fingerprinting of the redox state of the antioxidant molecules...
September 19, 2016: International Journal of Cosmetic Science
Shilpi Pal, Deepak Choudhary, Mohit Jainth, Sonu Kumar, Rakesh K Tiwari, Akhilesh K Verma
An environmentally benign Au(III)-catalyzed regio- and stereoselective domino synthesis of oxazolo fused pyridoindoles 7a-v and benzofurooxazolo pyridines 8a-n by the reaction of o-alkynylaldehydes 4a-t and 5a-k with (S)-phenylglycinol 6a and (R)-phenylglycinol 6b under mild reaction conditions using water as reaction medium is reported. The reaction proceeded via selective C-N bond formation on the more electrophilic alkynyl carbon through 6-endo-dig cyclization. The reaction tolerates a wide variety of functional groups...
October 7, 2016: Journal of Organic Chemistry
N Zhang, Y S Ma, H K Xu, Y X Bai
OBJECTIVE: To develop a novel protein-repellent orthodontic adhesive by incorporating 2-methacryloyloxyethyl phosphorylcholine(MPC). METHODS: MPC was incorporated into a commercially available orthodontic adhesive(Fuji ORTHO) at 0% (control), 1.5%, 3.0%, and 5.0% by mass. Enamel shear bond strength(SBS) was determined. Protein adsorption onto specimens was determined by a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate biofilm viability...
September 2016: Zhonghua Kou Qiang Yi Xue za Zhi, Zhonghua Kouqiang Yixue Zazhi, Chinese Journal of Stomatology
F Calvo, E Yurtsever
The coating of various fullerenes by para-hydrogen and ortho-deuterium molecules has been computationally studied as a function of the solvent amount. Rotationally averaged interaction potentials for structureless hydrogen molecules are employed to model their interaction with neutral or charged carbonaceous dopants containing between 20 and 240 atoms, occasionally comparing different fullerenes having the same size but different shapes. The solvation energy and the size of the first solvation shell obtained from path-integral molecular dynamics simulations at 2 K show only minor influence on the dopant charge and on the possible deuteration of the solvent, although the shell size is largest for ortho-D2 coating cationic fullerenes...
August 28, 2016: Journal of Chemical Physics
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