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https://www.readbyqxmd.com/read/28181804/rhodium-iii-catalyzed-ortho-alkylation-of-phenoxy-substrates-with-diazo-compounds-via-c-h-activation-a-case-of-decarboxylative-pyrimidine-pyridine-migratory-cyclization-rather-than-removal-of-pyrimidine-pyridine-directing-group
#1
Manjula Ravi, Srinivasarao Allu, K C Kumara Swamy
An efficient Rh(III)-catalyzed ortho-alkylation of phenoxy substrates with diazo compounds has been achieved for the first time using pyrimidine or pyridine as the directing group. Furthermore, bis-alkylation has also been achieved using para-substituted phenoxypyrimidine using 3 mole equiv of the diazo ester. The ortho-alkylated derivatives of phenoxy products possessing the ester functionality undergo decarboxylative pyrimidine/pyridine migratory cyclization (rather than deprotection of pyrimidine/pyridine group) using 20% NaOEt in EtOH affording a novel class of 3-(pyrimidin-2(1H)-ylidene)benzofuran-2(3H)-ones and 6-methyl-3-(pyridin-2(1H)-ylidene)benzofuran-2(3H)-one...
February 9, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28148667/the-effect-of-two-different-orthoses-on-pain-hand-function-patient-satisfaction-and-preference-in-patients-with-thumb-carpometacarpal-osteoarthritis-a-multicentre-crossover-randomised-controlled-trial
#2
RANDOMIZED CONTROLLED TRIAL
A E van der Vegt, R Grond, J S Grüschke, M F Boomsma, C H Emmelot, P U Dijkstra, C K van der Sluis
AIMS: The aim of this study was to compare the Push Ortho Thumb Brace CMC and a custom-made orthosis in the treatment of patients with primary osteoarthritis of the carpometacarpal joint of the thumb. Our outcome measures were pain scores, tests of hand function, patient satisfaction and patient preference. PATIENTS AND METHODS: A multicentre crossover randomised controlled trial was conducted which included 63 patients (44 women) with primary osteoarthritis of the carpometacarpal joint of the thumb...
February 2017: Bone & Joint Journal
https://www.readbyqxmd.com/read/28088023/a-novel-model-to-predict-gas-phase-hydroxyl-radical-oxidation-kinetics-of-polychlorinated-compounds
#3
Shuang Luo, Zongsu Wei, Richard Spinney, Zhihui Yang, Liyuan Chai, Ruiyang Xiao
In this study, a novel model based on aromatic meta-substituent grouping was presented to predict the second-order rate constants (k) for OH oxidation of PCBs in gas-phase. Since the oxidation kinetics are dependent on the chlorination degree and position, we hypothesized that it may be more accurate for k value prediction if we group PCB congeners based on substitution positions (i.e., ortho (o), meta (m), and para (p)). To test this hypothesis, we examined the correlation of polarizability (α), a quantum chemical based descriptor for k values, with an empirical Hammett constant (σ(+)) on each substitution position...
April 2017: Chemosphere
https://www.readbyqxmd.com/read/28065983/herschel-hifi-observations-of-the-circumstellar-ammonia-lines-in-irc-10216
#4
M R Schmidt, J H He, R Szczerba, V Bujarrabal, J Alcolea, J Cernicharo, L Decin, K Justtanont, D Teyssier, K M Menten, D A Neufeld, H Olofsson, P Planesas, A P Marston, A M Sobolev, A de Koter, F L Schöier
CONTEXT: A discrepancy exists between the abundance of ammonia (NH3) derived previously for the circumstellar envelope (CSE) of IRC+10216 from far-IR submillimeter rotational lines and that inferred from radio inversion or mid-infrared (MIR) absorption transitions. AIMS: To address the discrepancy described above, new high-resolution far-infrared (FIR) observations of both ortho- and para-NH3 transitions toward IRC+10216 were obtained with Herschel, with the goal of determining the ammonia abundance and constraining the distribution of NH3 in the envelope of IRC+10216...
August 2016: Astronomy and Astrophysics
https://www.readbyqxmd.com/read/28062628/specificity-of-b-type-natriuretic-peptide-assays-cross-reactivity-with-different-bnp-nt-probnp-and-probnp-peptides
#5
Amy K Saenger, Olaia Rodriguez-Fraga, Ranka Ler, Jordi Ordonez-Llanos, Allan S Jaffe, Jens Peter Goetze, Fred S Apple
BACKGROUND: B-type natriuretic peptides (BNPs) are used clinically to diagnose and monitor heart failure and are present in the circulation as multiple proBNP-derived fragments. We investigated the specificity of BNP immunoassays with glycosylated and nonglycosylated BNP, N-terminal proBNP (NT-proBNP), and proBNP peptides to probe the cross-reactivity of each assay. METHODS: Nine B-type natriuretic peptides were studied,including synthetic and recombinant BNP (Shionogi, Scios, Mayo), human and synthetic glycosylated and nonglycosylated NT-proBNP (HyTest, Roche Diagnostics), and human glycosylated and nonglycosylated proBNP (HyTest, Scios)...
January 2017: Clinical Chemistry
https://www.readbyqxmd.com/read/28038841/discontinuation-of-orthokeratology-on-eyeball-elongation-doee
#6
P Cho, S W Cheung
PURPOSE: To evaluate and compare changes in axial elongation, over a 14-month period, in subjects who discontinued and then resumed ortho-k lens wear with those who continued to wear their lenses or spectacles following a 2-year myopia control study. METHOD: This single masked, prospective study recruited subjects who had just completed a 2-year myopia control study. Ortho-k subjects were classified as Group OKc, in which subjects continued ortho-k lens wear for the duration of the study; or Group OKd in which subjects discontinued lens wear for seven months and wore single-vision spectacles (Phase I) and then resumed ortho-k lens wear for another seven months (Phase II)...
December 27, 2016: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
https://www.readbyqxmd.com/read/28001071/tensile-fracture-of-molecular-glasses-studied-by-differential-scanning-calorimetry-reduction-of-heat-capacity-by-lateral-constraint
#7
Yinshan Chen, C Travis Powell, Lian Yu
Molecular glasses indomethacin and ortho-terphenyl were formed and fractured by cooling a liquid on a less thermally expansive substrate. In-plane tension was created by the mismatch of thermal expansion coefficients and accumulated to cause catastrophic network fracture. Differential scanning calorimetry was used to characterize the process. The heat of fracture exceeds by 10 times the strain energy released, and matches the excess enthalpy stored by an elastic film that is cooled under lateral constraint...
January 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/27982082/the-involvement-of-dityrosine-crosslinking-in-%C3%AE-synuclein-assembly-and-deposition-in-lewy-bodies-in-parkinson-s-disease
#8
Youssra K Al-Hilaly, Luca Biasetti, Ben J F Blakeman, Saskia J Pollack, Shahin Zibaee, Alaa Abdul-Sada, Julian R Thorpe, Wei-Feng Xue, Louise C Serpell
Parkinson's disease (PD) is characterized by intracellular, insoluble Lewy bodies composed of highly stable α-synuclein (α-syn) amyloid fibrils. α-synuclein is an intrinsically disordered protein that has the capacity to assemble to form β-sheet rich fibrils. Oxidiative stress and metal rich environments have been implicated in triggering assembly. Here, we have explored the composition of Lewy bodies in post-mortem tissue using electron microscopy and immunogold labeling and revealed dityrosine crosslinks in Lewy bodies in brain tissue from PD patients...
December 16, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27981750/isomeric-detergent-comparison-for-membrane-protein-stability-importance-of-inter-alkyl-chain-distance-and-alkyl-chain-length
#9
Kyung Ho Cho, Parameswaran Hariharan, Jonas S Mortensen, Yang Du, Anne K Nielsen, Bernadette Byrne, Brian K Kobilka, Claus J Loland, Lan Guan, Pil Seok Chae
Membrane proteins encapsulated by detergent micelles are widely used for structural study. Because of their amphipathic property, detergents have the ability to maintain protein solubility and stability in an aqueous medium. However, conventional detergents have serious limitations in their scope and utility, particularly for eukaryotic membrane proteins and membrane protein complexes. Thus, a number of new agents have been devised; some have made significant contributions to membrane protein structural studies...
December 14, 2016: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/27978731/ruthenium-ii-catalyzed-regioselective-ortho-amidation-of-imidazo-heterocycles-with-isocyanates
#10
S M Abdul Shakoor, Santosh Kumari, Sadhika Khullar, Sanjay K Mandal, Anil Kumar, Rajeev Sakhuja
Direct ortho amidation at the phenyl ring of 2-phenylimidazo heterocycles with aryl isocyanates has been achieved via a chelation-assisted cationic ruthenium(II) complex catalyzed mechanism. The methodology provides a straightforward, high-yielding regioselective approach toward the synthesis of an array of ortho-amidated phenylimidazo heterocycles without prior activation of C(sp(2))-H. This also reports the first method for coupling of aryl isocyanates with the imidazo[1,2-a]pyridine system via a pentacyclometalated intermediate...
December 16, 2016: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/27934013/blue-phosphorescent-zwitterionic-iridium-iii-complexes-featuring-weakly-coordinating-nido-carborane-based-ligands
#11
Jonathan C Axtell, Kent O Kirlikovali, Peter I Djurovich, Dahee Jung, Vinh T Nguyen, Brian Munekiyo, A Timothy Royappa, Arnold L Rheingold, Alexander M Spokoyny
We report the development of a new class of phosphorescent zwitterionic bis(heteroleptic) Ir(III) compounds containing pyridyl ligands with weakly coordinating nido-carboranyl substituents. Treatment of phenylpyridine-based Ir(III) precursors with C-substituted ortho-carboranylpyridines in 2-ethoxyethanol results in a facile carborane deboronation and the formation of robust and highly luminescent metal complexes. The resulting nido-carboranyl fragments associate with the cationic Ir(III) center through primarily electrostatic interactions...
December 7, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27920924/crystal-structure-of-6-p-tol-yl-benzo-b-naphtho-2-3-d-thio-phene-and-of-an-ortho-rhom-bic-polymorph-of-7-phenyl-anthra-2-3-b-benzo-d-thio-phene
#12
S Gopinath, K Sethusankar, Helen Stoeckli-Evans, Muhamad Rafiq, Arasambattu K Mohanakrishnan
The title compounds, C23H16S, (I), and C26H16S, (II), are benzo-thio-phene derivatives in which the benzo-thio-phene moiety is fused with a naphthalene ring system in (I), and with an anthracene ring system in (II). In (I), the mean plane of the benzo-thio-phene ring system makes a dihedral angle of 2.28 (6)° with the naphthalene ring system, and a dihedral angle of 1.28 (6)° with the anthracene ring system in (II), showing that the fused units are essentially planar. In (I), the 4-methyl-benzene ring substituent makes a dihedral angle of 71...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920919/crystal-structure-of-di-methyl-formamidium-bis-tri-fluoro-methane-sulfon-yl-amide-an-ionic-liquid
#13
Allan Jay P Cardenas, Molly O'Hagan
At 100 K, the title mol-ecular salt, C3H8NO(+)·C2F6NO4S2(-), has ortho-rhom-bic (P212121) symmetry; the amino H atom of bis-(tri-fluoro-methane-sulfon-yl)amine (HNTf2) was transferred to the basic O atom of di-methyl-formamide (DMF) when the ionic liquid components were mixed. The structure displays an O-H⋯N hydrogen bond, which links the cation to the anion, which is reinforced by a non-conventional C-H⋯O inter-action, generating an R2(2)(7) loop. A further very weak C-H⋯O inter-action generates an [001] chain...
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27920910/crystal-structure-of-tibi2
#14
Kei Watanabe, Hisanori Yamane
Black granular single crystals of monotitanium dibismuth, TiBi2, were synthesized by slow cooling of a mixture of Bi and Ti from 693 K. The title compound is isostructural with CuMg2 (ortho-rhom-bic Fddd symmetry). Ti atoms are located in square anti-prisms of Bi atoms. The network of one type of Bi atom spirals along the a-axis direction while honeycomb layers of the other type of Bi atom spreading in the ab plane inter-lace one another.
September 1, 2016: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/27905604/an-experimental-and-theoretical-investigation-of-the-c-1-d-d2-reaction
#15
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 21, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27901167/dearomatisation-approaches-to-spirocyclic-dienones-via-the-electrophilic-activation-of-alkynes
#16
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...
December 20, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27898447/a-review-of-the-potential-factors-influencing-myopia-progression-in-children-using-orthokeratology
#17
REVIEW
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
https://www.readbyqxmd.com/read/27854298/diphenylcarbene-protected-by-four-ortho-iodine-groups-an-unusually-persistent-triplet-carbene
#18
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
https://www.readbyqxmd.com/read/27829751/comparison-and-ranking-of-superelasticity-of-different-austenite-active-nickel-titanium-orthodontic-archwires-using-mechanical-tensile-testing-and-correlating-with-its-electrical-resistivity
#19
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
https://www.readbyqxmd.com/read/27748297/association-of-organochlorine-pesticides-with-the-mrna-expression-of-tumour-necrosis-factor-alpha-tnf-%C3%AE-cyclooxygenase-2-cox-2-genes-in-idiopathic-preterm-birth
#20
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
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