CO adsorption and CO and O coadsorption on Rh(111) studied by reflection absorption infrared spectroscopy and density functional theory.

The adsorption of carbon monoxide on Rh(111) and on oxygen modified Rh(111) was investigated using thermal desorption spectroscopy, reflection absorption infrared spectroscopy (RAIRS), and density functional theory. The results show that CO adsorbs on Rh(111) in on top sites at low coverages. With increasing coverage hollow sites and bridge sites get occupied according to the RAIRS results. A new vibrational feature at high wave numbers was found in the on top region of the CO stretching frequency. This feature can be explained by a local high density CO structure where two CO molecules are adsorbed in the ( radical3x radical3)R30 degrees structure. The coadsorption of oxygen and carbon monoxide leads to a shift of the CO stretching frequency to higher wave numbers with increasing O to CO ratio. CO adsorption on a (2x1) oxygen layer is possible and RAIRS shows that the CO adsorbs in on top and most likely in bridge sites in this case.

A reflection absorption infrared spectroscopy and density-functional theory investigation of methanol dehydrogenation on Rh(111)V alloy surfaces.

The dehydrogenation reaction of methanol on a Rh(111) surface, a Rh(111)V subsurface alloy, and on a Rh(111)V islands surface has been studied by thermal-desorption spectroscopy, reflection absorption infrared spectroscopy, and density-functional theory calculations. The full monolayer of methanol forms a structure with a special geometry with methanol rows, where two neighboring molecules have different oxygen-rhodium distances. They are close enough to form a H-bonded bilayer structure, with such a configuration, where every second methanol C-O bond is perpendicular to the surface on both Rh(111) and on the Rh(111)V subsurface alloy. The Rh(111)V subsurface alloy is slightly more reactive than the Rh(111) surface which is due to the changes in the electronic structure of the surface leading to slightly different methanol species on the surface. The Rh(111)V islands surface is the most reactive surface which is due to a new reaction mechanism that involves a methanol species stabilized up to about 245 K, partial opening of the methanol C-O bond, and dissociation of the product carbon monoxide. The latter two reactions also lead to a deactivation of the Rh(111)V islands surface.

Adsorption and reaction of methanol on clean and oxygen modified rhodium/vanadium surface alloys.

The dehydrogenation of methanol on Rh(111), on a Rh(111)/V subsurface alloy and on Rh(111) with V islands has been studied with and without preadsorbed oxygen using a supersonic molecular beam and temperature programmed desorption. The reactivity is highest for the V islands surface without oxygen. But this surface is deactivated due to CO dissociation. The subsurface alloy is less reactive than the islands, but still more active than the Rh(111) surface. The reaction products are carbon monoxide and hydrogen only. With preadsorbed oxygen Rh(111) is the most active surface, but a strong dependence of the activity on the amount of preadsorbed oxygen is found for all three surfaces. The reaction products with preadsorbed oxygen are water, hydrogen, carbon dioxide and carbon monoxide. The reactions follow the same mechanism on all surfaces, but the activation energy of the individual reaction steps is different leading to significant changes in the thermal desorption spectra and in King and Wells-type experiments.

Changes in psychological distress of women in long-term remission from breast cancer in two different geographical settings: a randomized study.

GOALS OF WORK: Psychological distress and coping styles in women diagnosed with stages I and II breast cancer have attracted substantial clinical and research attention over the last several decades. The contradictory and, at times, controversial findings stimulated the present randomized research whose purpose was to explore the possibility and probability of predicting which variables affect the psychological distress level of women with breast cancer 1 to 5 years after diagnosis (time period 1) and 6 to 8 months after period 1 (time period 2). PATIENTS AND METHODS: The study was conducted in two large oncology centers in Graz, Austria, and Jerusalem, Israel, with a sample population comprising 424 patients. MAIN RESULTS: The only variables that significantly predicted change in the psychological distress levels (Grand Severity Index, GSI; except for the GSI level during period 1) were Fighting Spirit (Mental Adjustment to Cancer, MAC) in the Graz sample and Perceived Family Support (PFS) in the Jerusalem sample. These results are discussed in relation to other findings. CONCLUSIONS: In light of these findings, it is highly important to preliminarily identify women with less adaptive psychological coping mechanisms and to provide them with efficacy tools for behavioral and cognitive changes within their own network of social and health resources.

Effects of age on coping and psychological distress in women diagnosed with breast cancer: review of literature and analysis of two different geographical settings.

Age-related differences in emotional distress were examined by studying two random samples (N=424) of women diagnosed with early stages of breast cancer in Graz, Austria and Jerusalem, Israel. We found that psychological distress, coping abilities, and different perceptions of illness are attributable to socialization differences of age experience according to young (49 or younger), intermediate (50-64) and old (65 and older) age groups. Patients were interviewed at home to obtain sociodemographic and medical background data. They also completed five standardized instruments (Brief Symptom Inventory, Psychological Adjustment to Illness Scale, Impact of Events Scale, Mental Adjustment to Cancer, and Perceived Family Support). A two-way MANOVA for all the demographic variables yielded significant main group (Graz vs. Jerusalem) effect (P<0.0001), significant main age effect (P<0.0001) and significant interaction (group by age) effect (P<0.001). Examination of the contribution of the age category to the level of the coping variables showed a different pattern in each group. The psychological distress variables revealed that, in the Jerusalem sample, there is a tendency toward decreasing distress levels with age and, in the Graz sample, elevated scores for the intermediate-age group. Age was found to be related to the level of Global Severity Index (GSI) and to the variables correlated to the GSI level. Psychological intervention should be guided to the different age groups.