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https://www.readbyqxmd.com/read/28935528/choroidal-thickness-and-axial-length-changes-in-myopic-children-treated-with-orthokeratology
#1
Zhouyue Li, Dongmei Cui, Yin Hu, Sichun Ao, Junwen Zeng, Xiao Yang
PURPOSE: To analyze the change in subfoveal choroidal thickness (SFChT) and its relationship with changes in axial length (AL) in myopic children treated with Orthokeratology (Ortho-k). METHODS: Fifty myopic children participated in this study: 29 subjects were treated with Ortho-k lenses and 21 with single vision distance spectacles. The SFChT and ocular biometrics, including AL, were measured at baseline, one month, and six months after lens wear in both groups...
September 18, 2017: Contact Lens & Anterior Eye: the Journal of the British Contact Lens Association
https://www.readbyqxmd.com/read/28933842/synthesis-of-benzosiloles-by-intramolecular-anti-hydroarylation-via-ortho-c-h-activation-of-aryloxyethynyl-silanes
#2
Yasunori Minami, Yuta Noguchi, Tamejiro Hiyama
Straightforward synthesis of benzosiloles was achieved by the invention of intramolecular anti-hydroarylation of aryloxyethynyl silanes via ortho-C-H bond activation in the presence of palladium and Brønsted acid catalysis. The aryloxy group bound to the ethynyl carbon is the key factor for this transformation. The proposed hydroarylation mechanism involves the initial formation of a vinylpalladium carboxylate followed by isomerization and ortho-C-H bond activation.
September 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28932464/crystal-structures-of-the-2-2-complex-of-1-1-1-2-phenyl-ene-bis-3-m-tolyl-urea-and-tetra-butyl-ammonium-chloride-or-bromide
#3
Chao Huang, Ruyu Wang, Xi Shu, Yu Fan, Yue Qi, Shoujian Li, Chuanqin Xia
The title compounds, tetra-butyl-ammonium chloride-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C16H36N(+)·Cl(-)·C22H22N4O2 or [(n-Bu4N(+)·Cl(-))(C22H22N4O2)] (I) and tetra-butyl-ammonium bromide-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C16H36N(+)·Br(-)·C22H22N4O2 or [(n-Bu4N(+)·Br(-))(C22H22N4O2)] (II), both comprise a tetra-butyl-ammonium cation, a halide anion and an ortho-phenyl-ene bis-urea mol-ecule. Each halide ion shows four N-H⋯X (X = Cl or Br) inter-actions with two urea receptor sites of different bis-urea moieties...
September 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28932442/steric-repulsion-and-supra-molecular-assemblies-via-a-two-dimensional-plate-by-c-h%C3%A2-o-hydrogen-bonds-in-two-closely-related-2-benzo-furan-2-yl-2-oxoethyl-benzoates
#4
Li Yee Then, C S Chidan Kumar, Huey Chong Kwong, Yip-Foo Win, Siau Hui Mah, Ching Kheng Quah, S Naveen, Ismail Warad
2-(Benzo-furan-2-yl)-2-oxoethyl 2-chloro-benzoate, C17H11ClO4 (I), and 2-(benzo-furan-2-yl)-2-oxoethyl 2-meth-oxy-benzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and mol-ecular structures were analyzed by spectroscopic and single-crystal X-ray diffraction studies, respectively. These compounds possess different ortho-substituted functional groups on their phenyl rings, thus experiencing extra steric repulsion force within their mol-ecules as the substituent changes from 2-chloro (I) to 2-meth-oxy (II)...
July 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28932441/structure-of-equilenin-at-100%C3%A2-k-an-estrone-related-steroid
#5
Christopher S Frampton, David D MacNicol
The structure of the estrone-related steroid, Equilenin, C18H18O2 (systematic name 3-hy-droxy-13-methyl-11,12,13,14,15,16-hexa-hydro-cyclo-penta-[a]phen-anthren-17-one), has been determined at 100 K. The crystals are ortho-rhom-bic, P212121, and the absolute structure of the mol-ecule in the crystal has been determined by resonant scattering [Flack parameter = -0.05 (4)]. The C atoms of the A and B rings are almost coplanar, with an r.m.s. deviation from planarity of 0.0104 Å. The C ring has a sofa conformation, while the D ring has an envelope conformation with the methine C atom as the flap...
July 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28932439/crystallographic-and-spectroscopic-characterization-of-5-chloro-pyridine-2-3-di-amine
#6
Aron Sulovari, Joseph M Tanski
The two ortho-amino groups of the title compound, C5H6ClN3, twist out of the plane of the mol-ecule to minimize intra-molecular inter-action between the amino hydrogen atoms. In the crystal, the amino groups and the pyridine N atom engage in inter-molecular hydrogen bonding. The mol-ecules pack into spiral hydrogen-bonded columns with offset face-to-face π-stacking.
July 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28931283/synthesis-of-3-2-olefinbenzyl-4h-chromen-4-one-through-cyclobenzylation-and-catalytic-c-h-bond-functionalization-using-palladium-ii
#7
Yu-Feng Lin, Chi Fong, Wan-Ling Peng, Kuei-Chien Tang, Yi-En Liang, Wen-Tai Li
An efficient strategy for synthesizing 3-(2-olefinbenzyl)-4H-chromen-4-one in two steps was developed. The first step is a cyclobenzylation reaction between (E)-3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one and benzyl bromide to produce homoisoflavonoid. The second step involves intermolecular Pd-catalyzed π-chelating-assisted C-H bond olefination. Using the C-2/C-3 double bond of chromone, palladium-catalyzed aryl C-H bond activation can be functionalized to generate ortho-olefination derivatives in moderate to high yields...
September 21, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28930445/thermo-responsive-and-active-functional-fiber-mats-for-cultured-cell-recovery
#8
Wilaiporn Graisuwan, Songchan Puthong, Hui Zhao, Suda Kiatkamjornwong, Patrick Theato, Voravee P Hoven
Thermo-responsive and active functional fiber mats were prepared from random copolymer of poly(pentafluorophenyl acrylate-co-N-isopropylacrylamide) (P(PFPA-co-NIPAM)), which was synthesized by a controlled radical polymerization process based on reversible addition-fragmentation chain transfer (RAFT). As reactive sites, pentafluorophenyl ester (PFP) groups were incorporated in the copolymer to allow for a multiple post-polymerization modification. UV-crosslinkable moieties were first introduced by partially reacting PFP groups in the copolymer with ortho-nitrobenzyl (ONB)-protected diamine...
September 20, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28929601/conversion-of-benzoic-acid-into-phenol-in-an-itms-under-ci-ms-n-conditions-recognition-of-ortho-chlorobenzoyl-derivatives
#9
Michela Begala
Isomeric chlorobenzoyl cations (m/z 139), under collision induced experiments, fragment identically. Chlorobenzoyl cations can be efficiently converted into cholorophenol radical cations by the reaction with methanol in the ion trap analyser under CI-MS(n) conditions. The substitution of the carbonyl group with a hydroxyl moiety is able to induce an ortho effect, which is absent in the starting ortho-chlorobenzoyl cation. This transformation could be useful to recognize ortho-chlorinated benzoyl derivatives without the need of MS spectra comparison of the whole set of isomers...
September 19, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28927721/agonistic-effects-of-diverse-xenobiotics-on-the-constitutive-androstane-receptor-as-detected-in-a-recombinant-yeast-cell-assay
#10
Ryo Kamata, Daisuke Nakajima, Fujio Shiraishi
The constitutive androstane receptor (CAR) is a nuclear receptor and transcription factor regulating proteins involved in xenobiotic metabolism. Agonist activation of the CAR can trigger metabolic activation and toxification as well as detoxification and clearance; accordingly, xenobiotic substances acting as CAR ligands may pose a threat to human and animal health. We used yeast cells transduced with the human CAR and the response pathway to measure the CAR-agonistic activities of 549 synthetic or natural compounds: 216 of the tested compounds exhibited CAR-agonistic effects...
September 16, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28922913/regioselective-and-direct-azidation-of-anilines-via-cu-ii-catalyzed-c-h-functionalization-in-water
#11
Hongli Fang, Yandong Dou, Jingyan Ge, Mohit Chhabra, Hongyan Sun, Pengfei Zhang, Yu-Guo Zheng, Qing Zhu
We report herein the first example of Cu(II)-catalyzed site selective azidation of aromatic amines via C-H functionalization in aqueous media. In our strategy, mild reagent was utilized. H2O2 served as the oxidant, and sodium azide was used as the azidation reagent. This method could also be applied to late-stage functionalization of drugs that possess aromatic amine moiety. In addition, we found that bromination or iodination on the ortho-position of aromatic amines could occur efficiently using this catalytic system...
September 19, 2017: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/28920985/enantioselective-synthesis-of-sterically-hindered-%C3%AE-allyl-%C3%AE-aryl-oxindoles-via-palladium-catalysed-decarboxylative-asymmetric-allylic-alkylation
#12
Mark Jackson, Calvin Quince O'Broin, Helge Müller-Bunz, Patrick J Guiry
The highly enantioselective synthesis of sterically hindered α-allyl-α-aryl oxindoles possessing an all-carbon quaternary stereocenter at the oxindole 3-position has been developed. The key step in the synthetic route employed was a novel one-pot, two-step synthesis of α-aryl-β-amido allyl ester substituted oxindoles in good yields of 41-75% (13 examples) by interception of an unstable allyl ester intermediate through reaction with aryllead triacetate reagents. Pd-Catalyzed decarboxylative asymmetric allylic alkylation (DAAA) was optimized with 2,4,6-trimethoxyphenyl as the aryl-containing substrate...
September 18, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28919656/direct-valorisation-of-waste-cocoa-butter-triglycerides-via-catalytic-epoxidation-ring-opening-and-polymerisation
#13
Dorota D Plaza, Vinzent Strobel, Parminder Kaur Ks Heer, Andrew B Sellars, Seng-Soi Hoong, Andrew J Clark, Alexei A Lapkin
BACKGROUND: Development of circular economy requires significant advances in the technologies for valorisation of waste, as waste becomes new feedstock. Food waste is a particularly important feedstock, containing large variation of complex chemical functionality. Although most food waste sources are complex mixtures, waste from food processing, no longer suitable for the human food chain, may also represent relatively clean materials. One such material requiring valorisation is cocoa butter...
September 2017: Journal of Chemical Technology and Biotechnology
https://www.readbyqxmd.com/read/28915049/ruthenium-catalyzed-ortho-meta-selective-dual-c-h-bonds-functionalizations-of-arenes
#14
Gang Li, Biao Zhu, Xingxing Ma, Chunqi Jia, Xulu Lv, Junjie Wang, Feng Zhao, Yunhe Lv, Suling Yang
The first example of transition-metal-catalyzed ortho/meta-selective dual C-H functionalizations of arenes in one reaction is described. In this transformation, ortho-C-H chlorination and meta-C-H sulfonation of 2-phenoxypyri(mi)dines were achieved simultaneously under catalysis by [Ru(p-cymene)Cl2]2. The other reactant, namely, an arylsulfonyl chloride, played the role of both a sulfonation and chlorination reagent. More importantly, the arylsulfonyl chloride was also an oxidant in the process. Mechanistic studies indicated that six-membered ruthenacycles were the key intermediate in the reaction...
September 15, 2017: Organic Letters
https://www.readbyqxmd.com/read/28914669/infection-staging-and-incidence-surveillance-applications-of-high-dynamic-range-diagnostic-immuno-assay-platforms
#15
Eduard Grebe, Alex Welte, Jake Hall, Sheila M Keating, Shelley N Facente, Kara Marson, Jeffrey N Martin, Susan J Little, Matthew A Price, Esper G Kallas, Michael P Busch, Christopher D Pilcher, Gary Murphy
BACKGROUND: Custom HIV staging assays, including the Sedia™ HIV-1 Limiting Antigen Avidity EIA (LAg) and avidity modifications of the Ortho VITROS® anti-HIV-1+2 and Abbott ARCHITECT HIV Ag/Ab Combo assays, are used to identify 'recent' infections in clinical settings and for cross-sectional HIV incidence estimation. However, the high dynamic range of chemiluminescent platforms allows differentiating recent and longstanding infection on signal intensity, and this raises the prospect of using unmodified diagnostic assays for infection timing and surveillance applications...
September 7, 2017: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/28914060/nuclear-spin-symmetry-conservation-in-1-h2-16-o-investigated-by-direct-absorption-ftir-spectroscopy-of-water-vapor-cooled-down-in-supersonic-expansion
#16
Robert Georges, Xavier Michaut, Audrey Moudens, Manuel Goubet, Olivier Pirali, Pascale Soulard, Pierre Asselin, Therese R Huet, Pascale Roy, Martin Fournier, Andrey A Vigasin
We report the results of an experimental study related to the relaxation of the nuclear spin isomers of the water molecule in a supersonic expansion. Rovibrational lines of both ortho- and para- spin isomers were recorded in the spectral range of H2O stretching vibrations around 3700 cm(-1) using FTIR direct absorption. Water vapor seeded either in argon, helium, oxygen or in a mixture of oxygen and argon was expanded into vacuum through a slit nozzle. Partial water vapor pressure in the mixture varied in a wide range from 1...
September 15, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28910589/persistent-organic-pollutants-and-related-biological-responses-measured-in-coastal-fish-using-chemical-and-biological-screening-methods
#17
Zhanna Tairova, Jakob Strand, Rossana Bossi, Martin M Larsen, Lars Förlin, Anders Bignert, Jenny Hedman, Jens Gercken, Thomas Lang, Nicolai F Fricke, Gert Asmund, Manhai Long, Eva C Bonefeld-Jørgensen
The aim of this study was to investigate the spatial distribution, levels of dioxin-like compounds (DLC), and biological responses in two fish species. The viviparous eelpout (Zoarces viviparus) was collected from various locations in the Baltic Sea and in fjords of Kattegat and Skagerrak, while shorthorn sculpin (Myoxocephalus scorpius) was obtained at the polychlorinated biphenyl (PCB) polluted site in North West Greenland. Significant differences were detected both in contaminant levels and relative contributions from either polychlorinated dibenzodioxins (PCDD) or polychlorinated dibenzofurans (PCDF or furans) and mono-ortho- and non-ortho (coplanar) polychlorinated biphenyls (dl-PCB)...
September 14, 2017: Journal of Toxicology and Environmental Health. Part A
https://www.readbyqxmd.com/read/28910536/state-to-state-differential-cross-sections-for-inelastic-collisions-of-no-radicals-with-para-h2-and-ortho-d2
#18
Zhi Gao, Sjoerd N Vogels, Matthieu Besemer, Tijs Karman, Gerrit C Groenenboom, Ad Van der Avoird, Sebastiaan Y T van de Meerakker
We present state-to-state differential cross sections for collisions of NO molecules (X(2)Π1/2, j=1/2f) with para-H2 and ortho-D2 molecules, at a collision energy of 510 and 450 cm(-1), respectively. The angular scattering distributions for various final states of the NO radical are measured with high resolution using a crossed molecular beam apparatus that employs the combination of Stark deceleration and velocity map imaging. Rotational rainbows as well as diffraction oscillations are fully resolved in the scattering images...
September 14, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28910507/intermolecular-c-c-coupling-between-1-methyl-1-2-3-triazole-and-2-2-bipyridine-or-1-10-phenanthroline-at-mo-ii-complexes
#19
Lucia Riera, Julio Pérez, Sergio Fombona, Jesús Díaz
Unsupported 1-methyl-1,2,3-triazole has been coordinated to {Mo(3-methallyl)(CO)2(N-N)} (N-N= 2,2'-bipyridine, bipy; or 1,10-phenanthroline,phen) fragments yielding cationic complexes which can be regarded as metalated triazolium salts. Their reactivity towards a strong base led to the deprotonation of the C5-H group of the triazole moiety, followed by an intermolecular nucleophilic attack to the ortho CH group of a bipy or phen ligand affording cyclic, bimetallic dearomatized C-C coupling products. The reaction of the neutral bipy derivative with an acid led to the formation of dihydropyridyl units by protonation of a CH group of the dearomatized rings, the dimeric nature of complexes being mantained upon protonation...
September 14, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28902505/activation-mechanism-of-the-streptomyces-tyrosinase-assisted-by-the-caddie-protein
#20
Yasuyuki Matoba, Shogo Kihara, Yoshimi Muraki, Naohiko Bando, Hironari Yoshitsu, Teruo Kuroda, Miyuki Sakaguchi, Kure'e Kayama, Hulin Tai, Shun Hirota, Takashi Ogura, Masanori Sugiyama
Tyrosinase (EC 1.14.18.1), which possesses two copper ions at the active center, catalyzes a rate-limiting reaction of melanogenesis: that is, the conversion of a phenol to the corresponding ortho-quinone. The enzyme from the genus Streptomyces is generated as a complex with a "caddie" protein that assists the transport of two copper ions into the active center. In this complex, the Tyr(98) residue in the caddie protein was found to be accommodated in the pocket of the active center of tyrosinase, probably in a manner similar to that of L-tyrosine as a genuine substrate of tyrosinase...
September 13, 2017: Biochemistry
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