858 research outputs found

    COOP Charts in French: translation and preliminary data on instrument properties

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    This paper describes the procedure used to translate the COOP Charts into French and provides preliminary information on the instrument's acceptability, reliability and validity. The charts were translated in several steps: seven initial translations were combined into a first pilot version, which was then tested for acceptability, clarity and alternate wordings in two convenience samples taken from the general population (n=53). The modified version was then reviewed by a lay panel and another translator and submitted by mail to 209 congress participants to test several construct validity hypotheses through known-groups comparisons. A panel of public health professionals discussed the content validity of the charts. Finally, test-retest reliability and concurrent validity with SF-36 Health Survey scores were examined among 65 patients with end-stage renal disease. The translation process identified a wide variability in translation options for several items. The acceptability of the charts was excellent. The test-retest correlations ranged from 0.60 to 0.87. Content validity appeared to be appropriate, except for the chart on ‘social support', which combines the questions of need and availability of social support. The utility of illustrations was questioned by some respondents: many claimed not to have used the illustrations in selecting their response, while others found them to be not expressive enough. Most preliminary tests of construct validity were consistent with theory. This French translation of the COOP Charts appears to be ready for more extensive testing in the intended target population of ambulatory patient

    Saliva Cotinine Levels in Smokers and Nonsmokers

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    7-(5-Methyl­sulfanyl-β-d-erythrofuran­osyl)-7H-pyrrolo­[2,3-d]pyrimidin-4-amine monohydrate (MT-tubercidin·H2O)

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    The title compound, C12H16N4O3S·H2O, which has potential as a possible anti­malarial drug, was studied when small deviations in melting points, for two differently aged preparations, were observed. The unexpected existence of a water mol­ecule of crystallization is considered to be the cause of this variation. The 7H-pyrrolo­[2,3-d]pyrimidine unit is very slightly puckered with a total puckering amplitude of 0.035 (2) Å; its mean plane makes an angle of 88.40 (12)° with the mean plane through the ribofuranosyl unit. In the crystal, the mol­ecules are bound by strong O—H⋯N and N—H⋯O hydrogen bonds, utilizing all available protons and linking mainly through the water of crystallization

    Correlated electron metal properties of the honeycomb ruthenate Na2_2RuO3_3

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    We report the synthesis and characterisation of polycrystalline Na2_2RuO3_3, a layered material in which the Ru4+^{4+} (4d44d^4 configuration) form a honeycomb lattice. The optimal synthesis condition was found to produce a nearly ordered Na2_2RuO3_3 (C2/cC2/c phase), as assessed from the refinement of the time-of-flight neutron powder diffraction. Magnetic susceptibility measurements reveal a large temperature-independent Pauli paramagnetism (χ01.42(2)×103\chi_0 \sim 1.42(2)\times10^{-3} emu/mol Oe) with no evidence of magnetic ordering down to 1.5 K, and with an absence of dynamic magnetic correlations, as evidenced by neutron scattering spectroscopy. The intrinsic susceptibility (χ0\chi_0) together with the Sommerfeld coeficient of γ=11.7(2)\gamma=11.7(2) mJ/Ru mol K2^2 estimated from heat capacity measurements, gives an enhanced Wilson ratio of RW8.9(1)R_W\approx8.9(1), suggesting that magnetic correlations may be present in this material. While transport measurements on pressed pellets show nonmetallic behaviour, photoemission spectrocopy indicate a small but finite density of states at the Fermi energy, suggesting that the bulk material is metallic. Except for resistivity measurements, which may have been compromised by near surface and interface effects, all other probes indicate that Na2_2RuO3_3 is a moderately correlated electron metal. Our results thus stand in contrast to earlier reports that Na2_2RuO3_3 is an antiferromagnetic insulator at low temperatures.Comment: 9 pages, 6 figure

    Nicotinamide–2,2,2-trifluoro­ethanol (2/1)

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    The nicotinamide (NA) mol­ecules of the title compound, 2C6H6N2O·C2H3F3O, form centrosymmetric R 2 2(8) hydrogen-bonded dimers via N—H⋯O contacts. The asymmetric unit contains two mol­ecules of NA and one trifluoroethanol molecule disordered over two sites of equal occupancy. The packing consists of alternating layers of nicotinamide dimers and disordered 2,2,2-trifluoro­ethanol mol­ecules stacking in the c-axis direction. Intra­molecular C—H⋯O and inter­molecular N—H⋯N, O—H⋯N, C—H⋯N, C—H⋯O and C—H⋯F inter­actions are present

    Kinetic alteration of the 6Mg(NH2)2-9LiH-LiBH4 system by co-adding YCl3 and Li3N

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    The 6Mg(NH2)2-9LiH-LiBH4 composite system has a maximum reversible hydrogen content of 4.2 wt% and a predicted dehydrogenation temperature of about 64 °C at 1 bar of H2. However, the existence of severe kinetic barriers precludes the occurrence of de/re-hydrogenation processes at such a low temperature (H. Cao, G. Wu, Y. Zhang, Z. Xiong, J. Qiu and P. Chen, J. Mater. Chem. A, 2014, 2, 15816-15822). In this work, Li3N and YCl3 have been chosen as co-additives for this system. These additives increase the hydrogen storage capacity and hasten the de/re-hydrogenation kinetics: a hydrogen uptake of 4.2 wt% of H2 was achieved in only 8 min under isothermal conditions at 180 °C and 85 bar of H2 pressure. The re-hydrogenation temperature, necessary for a complete absorption process, can be lowered below 90 °C by increasing the H2 pressure above 185 bar. Moreover, the results indicate that the hydrogenation capacity and absorption kinetics can be maintained roughly constant over several cycles. Low operating temperatures, together with fast absorption kinetics and good reversibility, make this system a promising on-board hydrogen storage material. The reasons for the improved de/re-hydrogenation properties are thoroughly investigated and discussed

    Optimizing Sales Using Mobile Sales Ticketing Application

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    A pressure-induced collapse of magnetic ordering in βLi2IrO3β−Li_{2}IrO_3 at Pm1.52P_m ∼ 1.5–2 GPa has previously been interpreted as evidence for possible emergence of spin liquid states in this hyperhoneycomb iridate, raising prospects for experimental realizations of the Kitaev model. Based on structural data obtained at room temperature, this magnetic transition is believed to originate in small lattice perturbations that preserve crystal symmetry, and related changes in bond-directional anisotropic exchange interactions. Here we report on the evolution of the crystal structure of βLi2IrO3β−Li_{2}IrO_3 under pressure at low temperatures (T50K)(T≤50 K) and show that the suppression of magnetism coincides with a change in lattice symmetry involving Ir-Ir dimerization. The critical pressure for dimerization shifts from 4.4(2) GPa at room temperature to 1.52∼1.5–2 GPa below 50 K. While a direct FdddC2/cFddd→C2/c transition is observed at room temperature, the low temperature transitions involve new as well as coexisting dimerized phases. Further investigation of the Ir (L3/L2L3/L_2) isotropic branching ratio in x-ray absorption spectra indicates that the previously reported departure of the electronic ground state from a Jeff=1/2J_{eff} = 1/2 state is closely related to the onset of dimerized phases. In essence, our results suggest that the predominant mechanism driving the collapse of magnetism in βLi2IrO3β−Li_{2}IrO_3 is the pressure-induced formation of Ir2Ir_2 dimers in the hyperhoneycomb network. The results further confirm the instability of the Jeff=1/2J_{eff} = 1/2 moments and related noncollinear spiral magnetic ordering against formation of dimers in the low-temperature phase of compressed βLi2IrO3β−Li_{2}IrO_3

    Predicting the exposure of diving grey seals to shipping noise.

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    There is high spatial overlap between grey seals and shipping traffic, and the functional hearing range of grey seals indicates sensitivity to underwater noise emitted by ships. However, there is still very little data regarding the exposure of grey seals to shipping noise, constraining effective policy decisions. Particularly, there are few predictions that consider the at-sea movement of seals. Consequently, this study aimed to predict the exposure of adult grey seals and pups to shipping noise along a three-dimensional movement track, and assess the influence of shipping characteristics on sound exposure levels. Using ship location data, a ship source model, and the acoustic propagation model, RAMSurf, this study estimated weighted 24-h sound exposure levels (10-1000 Hz) (SELw). Median predicted 24-h SELw was 128 and 142 dB re 1 μPa2s for the pups and adults, respectively. The predicted exposure of seals to shipping noise did not exceed best evidence thresholds for temporary threshold shift. Exposure was mediated by the number of ships, ship source level, the distance between seals and ships, and the at-sea behaviour of the seals. The results can inform regulatory planning related to anthropogenic pressures on seal populations

    Reported patterns of vaping to support long-term abstinence from smoking: a cross-sectional survey of a convenience sample of vapers

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    Background: E-cigarettes are the most popular aid to smoking cessation attempts in England and the USA. This research examined associations between e-cigarette device characteristics and patterns of use, tobacco-smoking relapse, and smoking abstinence. Methods: A convenience sample of 371 participants with experience of vaping, and tobacco-smoking abstinence and/or relapse completed an online cross-sectional survey about e-cigarettes. Factors associated with smoking relapse were examined using multiple linear and logistic regression models. Results: Most participants were self-reported long-term abstinent smokers (86.3%) intending to continue vaping. Most initiated e-cigarette use with a vape pen (45.8%) or cig-a-like (38.7%) before moving onto a tank device (89%). Due to missing data, managed through pairwise deletion, only around 70 participants were included in some of the main analyses. Those using a tank or vape pen appeared less likely to relapse than those using a cig-a-like (tank vs. cig-a-like OR = 0.06, 95% CI 0.01-0.64, p = 0.019). There was an inverse association between starting self-reported e-cigarette liquid nicotine concentration and relapse, interacting with device type (OR = 0.79, 95% CI 0.63-0.99, p = 0.047), suggesting that risk of relapse may have been greater if starting with a low e-cigarette liquid nicotine concentration and/or cig-a-like device. Participants reported moving from tobacco-flavored cig-a-likes to fruit/sweet/food flavors with tank devices. Conclusions: Knowledge of how people have successfully maintained tobacco-smoking abstinence using vaping could help other tobacco smokers wishing to quit tobacco smoking through vaping

    Processing of aluminum-graphite particulate metal matrix composites by advanced shear technology

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    Copyright @ 2009 ASM International. This paper was published in Journal of Materials Engineering and Performance 18(9) and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.To extend the possibilities of using aluminum/graphite composites as structural materials, a novel process is developed. The conventional methods often produce agglomerated structures exhibiting lower strength and ductility. To overcome the cohesive force of the agglomerates, a melt conditioned high-pressure die casting (MC-HPDC) process innovatively adapts the well-established, high-shear dispersive mixing action of a twin screw mechanism. The distribution of particles and properties of composites are quantitatively evaluated. The adopted rheo process significantly improved the distribution of the reinforcement in the matrix with a strong interfacial bond between the two. A good combination of improved ultimate tensile strength (UTS) and tensile elongation (e) is obtained compared with composites produced by conventional processes.EPSR
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