The influence of ammonia (NH 3) on the doubly deuterated formic acid (DCOOD, FA) dehydrogenation selectivity for a Pd(111) single crystal model catalyst surface was investigated under ultrahigh vacuum conditions using temperature-programmed desorption and temperatureprogrammed reaction spectroscopy techniques. NH 3 adsorption on Pd(111) revealed reversible, molecular desorption without any significant decomposition products, while DCOOD adsorption on Pd(111) yielded D 2 , D 2 O, CO, and CO 2 as a result of dehydration and dehydrogenation pathways. Functionalizing the Pd(111) surface with ammonia suppressed the FA dehydration and enhanced the dehydrogenation pathway. The boost in the FA dehydrogenation of Pd(111) in the presence of NH 3 can be linked to the ease of FA deprotonation as well as the stabilization of the decomposition intermediate (i.e., formate) due to the presence of ammonium counterions on the surface. In addition, the presence of a Hbonded ammonia network on the Pd(111) surface increased the hydrogen atom mobility and decreased the activation energy for molecular hydrogen desorption. In the presence of NH 3 , catalytic FA decomposition on Pd(111) also yielded amidation reactions, which further suppressed CO liberation and prevented poisoning of the Pd(111) active sites due to strongly bound CO species.
Assessment of the severity of unconsciousness in patients with impaired consciousness, prediction of mortality and prognosis are currently the most studied subjects in intensive care. The aim of this study was to investigate the usefulness of the Full Outline of UnResponsiveness (FOUR) score in intensive care unit patients with stroke and the associations of FOUR score with the clinical outcome and with other coma scales (Glasgow [GCS] and Acute Physiology and Chronic Health Evaluation II). One hundred acute stroke patients (44 male, 56 female), who were followed in a neurology intensive care unit, were included in this prospective study. The mean age of the patients was 70.49±12.42 years. Lesion types were determined as haemorrhagic in 30 and ischaemic in 70 patients. FOUR scores on the day of admission and the first, third and 10th days of patients who died within 15 days were lower when compared to scores of patients who survived (P=0.005, P=0.000, P=0.000 and P=0.000 respectively). Receiver operating characteristic curve analysis showed significant trending with both FOUR score and GCS for prognosis; the area under curve ranged from 0.675 (95% confidence interval 0.565 to 0.786) when measurements had been made on day 3 to 0.922 (95% confidence interval 0.867 to 0.977) and 0.981 (95% confidence interval 0.947 to 1.015) for day 10. We suggest that FOUR score is a useful scale for evaluation of acute stroke patients in the intensive care unit as a homogeneous group, with respect to the outcome estimation.
In this article, we describe the development of a new aerobic C−H oxidation methodology catalyzed by a precious metal-free LaMnO 3 perovskite catalyst. Molecular oxygen is used as the sole oxidant in this approach, obviating the need for other expensive and/or environmentally hazardous stoichiometric oxidants. The electronic and structural properties of the LaMnO 3 catalysts were systematically optimized, and a reductive pretreatment protocol was proved to be essential for acquiring the observed high catalytic activities. It is demonstrated that this newly developed method was extremely effective for the oxidation of alkylarenes to ketones as well as for the oxidative dimerization of 2-naphthol to 1,1-binaphthyl-2,2-diol (BINOL), a particularly important scaffold for asymmetric catalysis. Detailed spectroscopic and mechanistic studies provided valuable insights into the structural aspects of the active catalyst and the reaction mechanism.
Copper nanowires (Cu NWs) hold promise as they possess equivalent intrinsic electrical conductivity and optical transparency to silver nanowires (Ag NWs) and cost substantially less. However, poor resistance to oxidation is the historical challenge that has prevented the large-scale industrial utilization of Cu NWs. Here, we use benzotriazole (BTA), an organic corrosion inhibitor, to passivate Cu NW networks. The stability of BTApassivated networks under various environmental conditions was monitored and compared to that of bare Cu NW control samples. BTA passivation greatly enhanced the stability of networks without deteriorating their optoelectronic performance. Moreover, to demonstrate their potential, BTA-passivated networks were successfully utilized in the fabrication of a flexible capacitive tactile sensor. This passivation strategy has a strong potential to pave the way for large-scale utilization of Cu NW networks in optoelectronic devices.
Several mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) photocatalysts were synthesized by using a hard-templating method comprising thermal polycondensation of guanidine hydrochloride over silica spheres at three different temperatures (450, 500 and 550 ℃). After structural characterization of these mpg-C 3 N 4 photocatalysts, they were tested in NO(g) photo-oxidation under visible (VIS) light. The effects of polycondensation temperature on the structure and photocatalytic performance of mpg-C 3 N 4 in NO photo-oxidation were studied. The results revealed that polycondensation temperature has a dramatic effect on the photocatalytic activity of mpg-C 3 N 4 in NO photo-oxidation, where mpg-C 3 N 4 synthesized at 500 ℃ (mpg-CN500) showed the best performance in NO x abatement as well as a high selectivity towards solid state NO x storage under VIS light illumination. Photocatalytic performance of the mpg-CN500 was further enhanced by the anchoring of 8.0 ± 0.5 wt.% Fe 3 O 4 nanoparticles (NPs) on it. Fe 3 O 4 /mpg-CN500 photocatalyst showed both high activity and high selectivity along with extended reusability without a need for a regeneration step. Enhanced photocatalytic NO x oxidation and storage efficiency of Fe 3 O 4 /mpg-CN500 photocatalyst was attributed to their mesoporous structure, high surface area and slow electron-hole recombination kinetics, efficient electron-hole separation and facile electron transfer from mpg-CN500 to Fe 3 O 4 domains enhancing photocatalytic O 2 reduction, while simultaneously suppressing nitrate photo-reduction and decomposition to NO 2 (g).
Large area 2D WS 2 has been grown successfully by radio frequency magnetron sputtering (RFMS) method. First, in order to investigate the pressure dependence on the grown WS 2 samples, WS 2 were grown at 5 different growth pressures, 5, 10, 15, 20, and 25 mTorr. It has been observed that the surface morphology changes for the samples grown at higher growth pressures, 15, 20, and 25 mTorr. Vertically standing nanowall (NW)-like structures have been formed at these relatively high growth pressures. It has also been observed that the (002) plane is highly dominant, which means layer by layer growth parallel to the substrate, for the sample grown at 20 mTorr. X-ray photoelectron spectroscopy (XPS) measurements revealed an increasing atomic percentage of the S element to W element, S/W, ratio in thin films, as the growth pressure increases. Growth dynamics of WS 2 has been investigated by time-dependent-growth WS 2 samples, 5, 10, 20, 40, and 80 s under 20 mTorr pressure. It has been shown by atomic force microscopy, scanning electron microscopy, and transmission electron microscopy that a highly smooth surface has been achieved in the samples grown for the duration of 5 and 10 s. Raman mapping measurements on the sample grown at 5 s have revealed large area homogeneous growth. As the growth time gets longer, the NWs emerge on the surface at some nucleation points. Only the peak that belongs to the (002) plane has been observed for samples grown at 5 and 10 s by the X-ray diffraction (XRD) measurements. XRD measurements have revealed the appearance of turbostratic peaks of (11l) and (10l) as the thickness increases. Photoluminescence measurements have indicated near-band-edge emission centered at 630 nm for only 5 and 10 s samples.
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