986 resultados para 8-OH-DPAT


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The 1:1 proton-transfer compound of the potent substituted amphetamine hallucinogen (R)-1-(8-bromobenzo[1,2-b; 4,5-b']difuran-4-yl)-2-aminopropane (common trivial name 'bromodragonfly') with 3,5-dinitrosalicylic acid, 1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-mmoniopropane 2-carboxy-4,6-dinitrophenolate, C13H13BrNO2+ C7H3N2O7- forms hydrogen-bonded cation-anion chain substructures comprising undulating head-to-tail anion chains formed through C(8) carboxyl O-H...O(nitro) associations and incorporating the aminium groups of the cations. The intra-chain cation-anion hydrogen-bonding associations feature proximal cyclic R33(8) interactions involving both a N+-H...O(phenolate) and the carboxyl O--H...O(nitro)associations. Also present are aromatic pi-pi ring interactions [minimum ring centroid separation, 3.566(2)A; inter-plane dihedral angle, 5.13(1)deg]. A lateral hydrogen-bonding interaction between the third aminium proton and a carboxyl O acceptor link the chain substructures giving a two-dimensional sheet structure. This determination represents the first of any form of this compound and confirms that it has the (R) absolute configuration. The atypical crystal stability is attributed both to the hydrogen-bonded chain substructures provided by the anions, which accommodate the aminium proton-donor groups of the cations and give cross-linking, and to the presence of cation--anion aromatic ring pi-pi interactions.

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The mineral reevesite and the cobalt substituted reevesite have been synthesised. The d(003) spacings of the minerals ranged from 7.54 to 7.95 Å. The maximum d(003) value occurred at around Ni:Co 0.4:0.6. This maximum in interlayer distance is proposed to be due to a greater number of carbonate anions and water molecules intercalated into the structure. The stability of the reevesite and cobalt doped reevesite was determined by thermogravimetric analysis. The maximum temperature of the reevesite occurs for the unsubstituted reevesite and is around 220°C. The effect of cobalt substitution results in a decrease in thermal stability of the reevesites. Four thermal decomposition steps are observed and are attributed to dehydration, dehydroxylation and decarbonation, decomposition of the formed carbonate and oxygen loss at ~807 °C. A mechanism for the thermal decomposition of the reevesite and the cobalt substituted reevesite is proposed.

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The Raman and infrared spectrum of the antimonate mineral stibiconite Sb3+Sb5+2O6(OH) were used to define aspects of the molecular structure of the mineral. Bands attributable to water, OH stretching and bending and SbO stretching and bending were assigned. The mineral has been shown to contain both calcium and water and the formula is probably best written (Sb3+,Ca)ySb5+2-x(O,OH,H2O)6-7 where y approaches 1 and x varies from 0 to 1. Infrared spectroscopy complimented with thermogravimetric analysis proves the presence of water in the stibiconite structure. The mineral stibiconite is formed through replacement of the sulphur in stibnite. No Raman or infrared bands attributable to stibnite were identified in the spectra.

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Several lines of evidence implicate the p38 mitogen-activated protein kinase (p38 MAPK) in the proinflammatory response to bacterial agents and cytokines. Equally, the transcription factor, nuclear factor (NF)-kappaB, is recognized to be a critical determinant of the inflammatory response in intestinal epithelial cells (IECs). However, the precise inter-relationship between the activation of p38 MAPK and activation of the transcription factor NF-kappaB in the intestinal epithelial cell (IEC) system, remains unknown. Here we show that interleukin (IL)-1beta activates all three MAPKs in Caco-2 cells. The production of IL-8 and monocyte chemotactic protein 1 (MCP-1) was attenuated by 50% when these cells were preincubated with the p38 MAPK inhibitor, SB 203580. Further investigation of the NF-kappaB signalling system revealed that the inhibitory effect was independent of the phosphorylation and degradation of IkappaBalpha, the binding partner of NF-kappaB. This effect was also independent of the DNA binding of the p65 Rel A subunit, as well as transactivation, determined by an NF-kappaB luciferase construct, using both SB 203580 and dominant-negative p38 MAPK. Evaluation of IL-8 and MCP-1 RNA messages by reverse transcription-polymerase chain reaction (RT-PCR) revealed that the inhibitory effect of SB 203580 was associated with a reduction in this parameter. Using an IL-8-luciferase promoter construct, an effect of p38 upon its activation by both pharmacological and dominant-negative p38 construct co-transfection was demonstrated. It is concluded that p38 MAPK influences the expression of chemokines in intestinal epithelial cells, through an effect upon the activation of the chemokine promoter, and does not directly involve the activation of the transcription factor NF-kappaB

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In order to estimate the safety impact of roadway interventions engineers need to collect, analyze, and interpret the results of carefully implemented data collection efforts. The intent of these studies is to develop Accident Modification Factors (AMF's), which are used to predict the safety impact of various road safety features at other locations or in upon future enhancements. Models are typically estimated to estimate AMF's for total crashes, but can and should be estimated for crash outcomes as well. This paper first describes data collected with the intent estimate AMF's for rural intersections in the state of Georgia within the United Sates. Modeling results of crash prediction models for the crash outcomes: angle, head-on, rear-end, sideswipe (same direction and opposite direction) and pedestrian-involved crashes are then presented and discussed. The analysis reveals that factors such as the Annual Average Daily Traffic (AADT), the presence of turning lanes, and the number of driveways have a positive association with each type of crash, while the median width and the presence of lighting are negatively associated with crashes. The model covariates are related to crash outcome in different ways, suggesting that crash outcomes are associated with different pre-crash conditions.

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Raman spectra of bottinoite Ni[Sb(OH)6].6H2O were studied, and related to the molecular structure of the mineral. An intense sharp Raman band at 618 cm-1 is attributed to the SbO symmetric stretching mode. The low intensity band at 735 cm-1 is ascribed to the SbO antisymmetric stretching vibration. Low intensity Raman bands were found at 501, 516 and 578 cm-1. Four Raman bands observed at 1045, 1080, 1111 and 1163 cm-1 are assigned to δ SbOH deformation modes. A complex pattern resulting from the overlapping band of the water and hydroxyl units is observed. Raman bands are observed at 3223, 3228, 3368, 3291, 3458 and 3510 cm-1. The first two Raman bands are assigned to water stretching vibrations. The two higher wavenumber Raman bands observed at 3466 and 3552 cm-1 and two infrared bands at 3434 and 3565 cm-1 are assigned to the stretching vibrations of the hydroxyl units. Observed Raman and infrared bands are connected with O-H…O hydrogen bonds and their lengths 2.72, 2.79, 2.86, 2.88 and 3.0 Å (Raman) and 2.73, 2.83 and 3.07 Å (infrared).

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Raman spectra of the uranyl titanate mineral betafite were obtained and related to the mineral structure. A comparison is made with the spectra of uranyl oxyhydroxide hydrates. Observed bands are attributed to the (UO2)2+ stretching and bending vibrations, U-OH bending vibrations, H2O and (OH)- stretching, bending and libration modes. U-O bond lengths in uranyls and O-H…O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. Raman bands of betafite are comparable with those of the uranyl oxyhydroxides. The mineral betafite is metamict as is evidenced by the intensity of the UO stretching and bending modes being of lower intensity than expected and with bands that are significantly broader.

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Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake. Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7-8 wk in the fall, winter, spring, and summer in Davis, CA [38.5° N, 121.7° W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R^sup 2^ = 0.55; P < 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, ~20 min/d, ~18% body surface area (BSA) exposed] and high (80th percentile, ~90 min/d, ~35% BSA exposed) sun exposure, assuming an intake of 200 IU/d (5 ug/d). Predicted serum 25(OH)D concentrations for AA individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D ≥75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 IU/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 IU/d year-round.

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The α,ω-diyne 4,7,10-trithiatrideca-2,11-diyne reacts with [RuCl2(PPh3)3] and KPF6 to form the phosphonio-substituted metallatricyclic salt [RuCl(PPh3){κ4C,S,S′,S′′-S(C≡CMe)C2H4SC2H4SC(PPh3)CMe}]PF6 arising from the activation of one alkynyl group toward nucleophilic attack by extraneous phosphine.

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Raman spectra of the uranyl titanate mineral davidite-(La) (La,Ce)(Y,U,Fe2+)(Ti,Fe3+)20(O,OH)38 were analysed and related to the mineral structure. Observed bands are attributed to the TiO and (UO2)2+ stretching and bending vibrations, U-OH bending vibrations, H2O and (OH)- stretching, bending and libration modes. U-O bond lengths in uranyls and O-H…O bond lengths are calculated from the wavenumbers assigned to the stretching vibrations. Raman bands of davidite-(La) are in harmony with those of the uranyl oxyhydroxides. The mineral davidite-(La) is metamict as is evidenced by the intensity of the UO stretching and bending modes being of lower intensity than expected and with bands that are significantly broader.

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The mineral dussertite, a hydroxy-arsenate mineral of formula BaFe3+3(AsO4)2(OH)5, has been studied by Raman complimented with infrared spectroscopy. The spectra of three minerals from different origins were investigated and proved quite similar, although some minor differences were observed. In the Raman spectra of Czech dussertite, four bands are observed in the 800 to 950 cm-1 region. The bands are assigned as follows: the band at 902 cm-1 is assigned to the (AsO4)3- ν3 antisymmetric stretching mode, at 870 cm-1 to the (AsO4)3- ν1 symmetric stretching mode, and both at 859 cm-1 and 825 cm-1 to the As-OM2+/3+ stretching modes/and or hydroxyls bending modes. Raman bands at 372 and 409 cm-1 are attributed to the ν2 (AsO4)3- bending mode and the two bands at 429 and 474 cm-1 are assigned to the ν4 (AsO4)3- bending mode. An intense band at 3446 cm-1 in the infrared spectrum and a complex set of bands centred upon 3453 cm-1 in the Raman spectrum are attributed to the stretching vibrations of the hydrogen bonded (OH)- units and/or water units in the mineral structure. The broad infrared band at 3223 cm-1 is assigned to the vibrations of hydrogen bonded water molecules. Raman spectroscopy identified Raman bands attributable to (AsO4)3- and (AsO3OH)2- units.

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The mineral thorikosite Pb3(OH)(SbO3,AsO3)Cl2 is named after the ancient city of Thorikos, in the region of Attica, where the ancient mine sites dating back to the bronze ages are found. Raman spectra of the antimonate bearing mineral thorikosite Pb3(OH)(SbO3,AsO3)Cl2 were studied, and related to the structure of the mineral. Two intense Raman peaks are observed at 596 and 730 cm-1 and are assigned to the Sb3+O3 and As3+O3 stretching vibrations. A peak at 1085 cm-1 is assigned to the Sb3+OH deformation mode. Raman band at 325 cm-1 is assigned to an OAsO bending vibration of the As3+O3 units and the bands at 269 and 275 cm-1 are attributed to the OSbO bending modes of the Sb3+O3 units. The intense Raman bands at 112 and 133 cm-1 are associated with PbCl stretching modes. Minerals such as nealite and thorikosite are minerals of archaeological significance. Yet no spectroscopic studies of these minerals have been undertaken.

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The Raman spectrum of atelestite Bi2O(OH)(AsO4), a hydroxy-arsenate mineral containing bismuth, has been studied in terms of spectra-structure relations. The studied spectrum is compared with the Raman spectrum of atelestite downloaded from the RRUFF database. The sharp intense band at 834 cm-1 is assigned to the 1 AsO43- (A1) symmetric stretching mode and the three bands at 767, 782 and 802 cm-1 to the 3 AsO43- antisymmetric stretching modes. The bands at 310, 324, 353, 370, 395, 450, 480 and 623 cm-1 are assigned to the corresponding ν4 and ν2 bending modes and Bi-O-Bi (vibration of bridging oxygen) and Bi-O (vibration of non-bridging oxygen) stretching vibrations. Lattice modes are observed at 172, 199 and 218 cm-1. A broad low intensity band at 3095 cm-1 is attributed to the hydrogen bonded OH units in the atelestite structure. A weak band at 1082 cm-1 is assigned to  (Bi-OH) vibration.

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In an attempt to make nanofibres based upon cobalt oxides, a novel compound a hydrated cobalt hydroxy carbonate was formed. This compound is related to the minerals of the rosasite mineral group. X-ray diffraction showed that the formed compound was a cobalt hydroxy carbonate and SEM displayed bundles of fibres on the micron scale in length and nanoscale in width. The morphology was compared with that of the rosasite mineral group. XPS proved two bond energies for cobalt and three for oxygen in the compound. The compound was characterised by vibrational spectroscopy and the spectra related to minerals of the rosasite mineral group. The stability of the synthetic mineral was limited to temperatures below 200°C.