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21.
Alcohol expectancy-challenge programs are effective in changing expectancies and reducing drinking in college men (J. Darker & M. S. Goldman. 1993. 1998); however, recent evidence suggests this protocol might not be effective for women (M. E. Dunn, C. Lau, & I. Y. Cruz, 2000). This study was designed to reevaluate the effectiveness of a social/sexual expectancy-challenge intervention in college women reporting moderate to heavy alcohol use. Forty-six undergraduate women were randomly assigned to the prevention or control condition. Participants reported alcohol expectancies at pre- and posttest and monitored their drinking patterns daily for 6 weeks. The program was effective in changing some expectancies but did not reduce drinking. This further confirms differences in the mechanisms by which expectancy-challenge programs function for men and women. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
22.
Oxygen was determined accurately in eight U.S. Bureau of Mines coal ash samples A, B, D, F, G, I, and J, NBS coal fly ash 1633 reference material, and two low-temperature ashes (LTA) from lllinois State Geological Survey. The method uses fast-neutron activation (FNA) analysis employing a dual counting and irradiation system which is essentially free from interferences. The stoichiometric balance based on analyses of the ashes performed by the USBM is calculated and summations given in oxide and element percent. Excellent agreement is found with the chemical data obtained by classical silicate analysis methods. Accurate oxygen determination for coal ash and LT-ash (or mineral matter) is important for calculation of data in the ultimate analysis of coal as such. Knowledge is required for recalculation of the data on a dry and dry-ash-free basis. The routinely used ‘oxygen by difference’ values are inadequate for accurate work. In order to determine the organic oxygen in coal one also has to correct for oxygen in mineral matter and oxygen in the water removed as moisture. The Parr formula and other methods of empirical estimation are inadequate and may be replaced in some cases by the oxygen determination. The complete data provide a quantitative basis for stoichiometric interpretation of coal analyses. It was found that the eight coal-ash samples analysed contained 45.5 ± 3% oxygen. Since these ashes represent a large variety of U.S. coals, this figure can be used as an estimate for recalculation and evaluation of the proximate and ultimate coal analyses. It is better, however, to use values actually determined in ash by the rapid fast-neutron activation method. This permits a better estimation of the sum of cations plus sulphates in the ash. 相似文献
23.
Potié A Baron T Dhalluin F Rosaz G Salem B Latu-Romain L Kogelschatz M Gentile P Oehler F Montès L Kreisel J Roussel H 《Nanoscale research letters》2011,6(1):187-9
The growth of semiconductor (SC) nanowires (NW) by CVD using Au-catalyzed VLS process has been widely studied over the past few years. Among others SC, it is possible to grow pure Si or SiGe NW thanks to these techniques. Nevertheless, Au could deteriorate the electric properties of SC and the use of other metal catalysts will be mandatory if NW are to be designed for innovating electronic. First, this article's focus will be on SiGe NW's growth using Au catalyst. The authors managed to grow SiGe NW between 350 and 400°C. Ge concentration (x) in Si1-xGex NW has been successfully varied by modifying the gas flow ratio: R = GeH4/(SiH4 + GeH4). Characterization (by Raman spectroscopy and XRD) revealed concentrations varying from 0.2 to 0.46 on NW grown at 375°C, with R varying from 0.05 to 0.15. Second, the results of Si NW growths by CVD using alternatives catalysts such as platinum-, palladium- and nickel-silicides are presented. This study, carried out on a LPCVD furnace, aimed at defining Si NW growth conditions when using such catalysts. Since the growth temperatures investigated are lower than the eutectic temperatures of these Si-metal alloys, VSS growth is expected and observed. Different temperatures and HCl flow rates have been tested with the aim of minimizing 2D growth which induces an important tapering of the NW. Finally, mechanical characterization of single NW has been carried out using an AFM method developed at the LTM. It consists in measuring the deflection of an AFM tip while performing approach-retract curves at various positions along the length of a cantilevered NW. This approach allows the measurement of as-grown single NW's Young modulus and spring constant, and alleviates uncertainties inherent in single point measurement. 相似文献
24.
Weissman KJ Hong H Oliynyk M Siskos AP Leadlay PF 《Chembiochem : a European journal of chemical biology》2004,5(1):116-125
Phosphopantetheinyl transferases (PPTases) catalyze the essential post-translational activation of carrier proteins (CPs) from fatty acid synthases (FASs) (primary metabolism), polyketide synthases (PKSs), and non-ribosomal polypeptide synthetases (NRPSs) (secondary metabolism). Bacteria typically harbor one PPTase specific for CPs of primary metabolism ("ACPS-type" PPTases) and at least one capable of modifying carrier proteins involved in secondary metabolism ("Sfp-type" PPTases). In order to identify the PPTase(s) associated with erythromycin biosynthesis in Saccharopolyspora erythraea, we have used the genome sequence of this organism to identify, clone, and express (in Escherichia coli) three candidate PPTases: an ACPS-type PPTase (S. erythraea ACPS) and two Sfp-type PPTases (a discrete enzyme (SePptII) and another that is integrated into a modular PKS subunit (SePptI)). In vitro analysis of these recombinant PPTases, with an acyl carrier protein-thioesterase (ACP-TE) didomain from the erythromycin PKS as substrate, revealed that only SePptII is active in phosphopantetheinyl transfer with this substrate. SePptII was also shown to provide complete modification of ACP-TE and of an entire multienzyme subunit from the erythromycin PKS in E. coli. The efficiency of the SePptII in phosphopantetheinyl transfer in E. coli makes it an attractive alternative to other Sfp-type PPTases for co-expression experiments with PKS proteins. 相似文献
25.
Julie K. Furmick Dr. Ichiro Kaneko Angela N. Walsh Joanna Yang Jaskaran S. Bhogal Geoffrey M. Gray Juan C. Baso Drew O. Browder Jessica L. S. Prentice Luis A. Montano Chanh C. Huynh Lisa M. Marcus Dorian G. Tsosie Jungeun S. Kwon Alexis Quezada Nicole M. Reyes Brittney Lemming Puneet Saini Dr. Arjan van der Vaart Dr. Thomas L. Groy Dr. Pamela A. Marshall Dr. Peter W. Jurutka Dr. Carl E. Wagner 《ChemMedChem》2012,7(9):1551-1566
26.
The effect of ceria on the partial oxidation of methanol to formaldehyde over VOx/CeO2/SiO2 catalysts was investigated. A two-dimensional layer of ceria on silica was prepared by grafting cerium (IV) t-butoxide (Ce(OC4H9)4) onto high surface area, mesoporous silica, SBA-15, and then calcining the resulting product in air at 773 K. Ce surface concentrations obtained this way ranged from 0.2 to 0.9 Ce nm?2. Next, V was introduced by grafting VO(OiPr)3 onto CeO2/SiO2 in order to achieve a surface concentration of 0.6 V nm?2. XANES spectra indicate that all of the V is in the 5+ oxidation state and Raman spectra show that vanadia exist as pseudo-tetrahedra bonded to either silica or ceria. Data from Raman spectroscopy and temperature-programmed desorption of adsorbed methanol indicate that with increasing Ce surface density, most of the V becomes associated with the deposited ceria. The turnover frequency for methanol oxidation is nearly two orders of magnitude higher for VOx/CeO2/SiO2 than for VOx/SiO2, whereas the apparent activation energy and apparent first-order pre-exponential factor are 17 kcal/mol and 1.4 × 106 mol CH2O (mol V atm s)?1, respectively, for VOx/CeO2/SiO2 and 23 kcal/mol and 2.3 × 107 mol CH2O (mol V atm s)?1, respectively, for VOx/SiO2. 相似文献
27.
Rémi Nguyen Mathilde Amouroux Alexis Duda Zéphirin Mouloungui 《Journal of the American Oil Chemists' Society》2020,97(7):679-689
The aim of this study was to develop an improved general method for detecting and quantifying mixtures of hydroxy acids and other products of glycerol oxidation in aqueous media, to prevent the confusions that can occur due to similarities and interactions between these compounds depending on media conditions. Standard potential products of glycerol oxidation—glycerol, glyceraldehyde, dihydroxyacetone, glyceric acid, lactic acid, glycolic acid, glyoxylic acid, oxalic acid, tartronic acid, and mesoxalic acid—were analyzed by high-performance liquid chromatography (HPLC) and quantitative 13C nuclear magnetic resonance (NMR), in mixtures of known composition. The results obtained were concordant with the known compositions tested. HPLC was more accurate than quantitative 13C NMR for simple mixtures, but 13C NMR was required for complex mixtures containing dihydroxyacetone and glycerol, oxalic acid and mesoxalic acid, or glyoxylic acid and tartronic acid, pairs of compounds not well separated or detected by HPLC. As proof-of-concept, an unknown mixture generated by glycerol oxidation was analyzed by HPLC and quantitative 13C NMR. The results obtained were concordant and allowed accurate determination of the composition of the sample, which contained mesoxalic acid as the major product, with oxalic acid, tartronic acid, and glyceric acid as by-products. 相似文献
28.
Wai Ling Cheung-Lee Madison E. Parry Dr. Chuhan Zong Alexis Jaramillo Cartagena Prof. Seth A. Darst Prof. Nancy D. Connell Dr. Riccardo Russo Prof. A. James Link 《Chembiochem : a European journal of chemical biology》2020,21(9):1335-1340
We report the heterologous expression, structure, and antimicrobial activity of a lasso peptide, ubonodin, encoded in the genome of Burkholderia ubonensis. The topology of ubonodin is unprecedented amongst lasso peptides, with 18 of its 28 amino acids found in the mechanically bonded loop segment. Ubonodin inhibits RNA polymerase in vitro and has potent antimicrobial activity against several pathogenic members of the Burkholderia genus, most notably B. cepacia and B. multivorans, causative agents of lung infections in cystic fibrosis patients. 相似文献
29.
Tikole S Jaravine V Rogov VV Rozenknop A Schmöe K Löhr F Dötsch V Güntert P 《Chembiochem : a European journal of chemical biology》2012,13(7):964-967
Faster than death: NMR techniques that make use of nonlinear sampling and hyperdimensional processing enable the recording of complete NMR data sets for the automated assignment of the backbone and side-chain resonances of short-lived protein samples of cell lysates. 相似文献
30.
Cecilia Arriagada Viviana A. Cavieres Charlotte Luchsinger Alexis E. Gonzlez Vanessa C. Muoz Jorge Cancino Patricia V. Burgos Gonzalo A. Mardones 《International journal of molecular sciences》2020,21(22)
Protein trafficking is altered when normal cells acquire a tumor phenotype. A key subcellular compartment in regulating protein trafficking is the Golgi apparatus, but its role in carcinogenesis is still not well defined. Golgi phosphoprotein 3 (GOLPH3), a peripheral membrane protein mostly localized at the trans-Golgi network, is overexpressed in several tumor types including glioblastoma multiforme (GBM), the most lethal primary brain tumor. Moreover, GOLPH3 is currently considered an oncoprotein, however its precise function in GBM is not fully understood. Here, we analyzed in T98G cells of GBM, which express high levels of epidermal growth factor receptor (EGFR), the effect of stable RNAi-mediated knockdown of GOLPH3. We found that silencing GOLPH3 caused a significant reduction in the proliferation of T98G cells and an unexpected increase in total EGFR levels, even at the cell surface, which was however less prone to ligand-induced autophosphorylation. Furthermore, silencing GOLPH3 decreased EGFR sialylation and fucosylation, which correlated with delayed ligand-induced EGFR downregulation and its accumulation at endo-lysosomal compartments. Finally, we found that EGF failed at promoting EGFR ubiquitylation when the levels of GOLPH3 were reduced. Altogether, our results show that GOLPH3 in T98G cells regulates the endocytic trafficking and activation of EGFR likely by affecting its extent of glycosylation and ubiquitylation. 相似文献