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Five alumina-supported palladium catalysts have been prepared from a range of precursor compounds [palladium(II) nitrate, palladium(II) chloride, palladium(II) acetylacetonate, and tetraamminepalladium(II) tetraazidopalladate(II)] and at different metal loadings (1-7.3 wt %). Collectively, this series of catalysts provides a range of metal particle sizes (1.2-8.5 nm) that emphasize different morphological aspects of the palladium crystallites. The infrared spectra of chemisorbed CO applied under pulse-flow conditions reveal distinct groupings between metal crystallites dominated by low index planes and those that feature predominantly corner/edge atoms. Temperature-programmed infrared spectroscopy establishes that the linear CO band can be resolved into contributions from corner atoms and a combination of (111)(111) and (111)(100) particle edges. Propene hydrogenation has been used as a preliminary assessment of catalytic performance for the 1 wt % loaded catalysts, with the relative inactivity of the catalyst prepared from palladium(II) chloride attributed to a diminished hydrogen supply due to decoration of edge sites by chlorine originating from the preparative process. It is anticipated that refinements linking the vibrational spectrum of a probe molecule with surface structure and accessible adsorption sites for such a versatile catalytic substrate provide a platform against which structure/reactivity relationships can be usefully developed.

Alumina-supported vanadium particles were prepared under ultrahigh vacuum (UHV) conditions and characterized with respect to their structural and CO adsorption properties. As supporting oxide, we used a thin, well-ordered alumina film grown on NiAl(110). This allows the application of scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRAS), and X-ray photoelectron spectroscopy (XPS) without charging effects. Vanadium evaporation under UHV conditions leads to the growth of nanometer-sized particles which strongly interact with the alumina support. At very low vanadium coverages, these particles are partially incorporated into the alumina film and get oxidized through the contact to alumina. Low-temperature CO adsorption in this coverage regime permits the preparation of isolated vanadium carbonyls, of which we have identified mono-, di-, and tricarbonyls of the V(CO)(y)() type. A charge-frequency relationship was set up which allows one to quantify the extent of charge transfer from vanadium to alumina. It turns out that this charge transfer depends on the V nucleation site.

Palladium was vapor deposited on a thin FeO(111) film grown on a Pt(111) substrate. Scanning tunneling microscopy study has revealed that Pd wets the FeO substrate and at elevated temperatures forms extended Pd(111) monolayer islands in contrast to other oxide supports previously studied. For the first time, we have imaged the metal-oxide interface structure with atomic resolution and explained the results on the basis of ab initio calculations.

Purpose: Analysis of medical decisions in the differential allocation of traumatic brain injury (TBI) rehabilitation programmes., Method: Medical specialists routinely involved in the treatment and rehabilitation of TBI patients from acute hospitals, rehabilitation centres, and the Medical Services of the Workers' Pension Insurance of Sachsen-Anhalt and Mecklenburg-Vorpommern were included in a systematic survey, in which they had to give their opinions on the individually optimal rehabilitation setting and therapies and probable outcome on the basis of case vignettes. These specialists are crucial for decision-making in rehabilitation resource allocation., Results: Both allocation and prognosis depended mainly on patient characteristics. In a mixed logistic regression model, which takes into account that: (a) patient and physician characteristics may influence each other; and (b) that expert assessments might be correlated, setting preferences were related to chronicity and degree of motor and cognitive impairment, but also to the institutional background of the reviewer. Neuropsychological therapy dominated intervention recommendations, followed by physio- and occupational therapy. A comparatively great demand of psychotherapy and medicosocial assessment was recognized. Preferred rehabilitation setting did not influence the physicians' subjective prognosis. Older, chronic and motorically impaired patients were considered to profit less from rehabilitation. Physician characteristics and recommendations of either rehabilitation setting or therapies did not influence prognostic expectations., Conclusions: Physician characteristics influenced setting preferences. Preferences for type of treatment and ADL-prognosis depended on patients' variables only. Expected effects of rehabilitation were independent on rehabilitation setting and kinds of treatment.

More than activity, selectivity of catalytic reactions is the focus of research in the 21(st) century. We review studies on model systems that address the issue of directing a catalytic reaction on disperse metal catalysts by controlling the specific surface site. Three examples are explored: methanol dehydrogenation over Pd/alumina, NO dissociation on Pd/alumina, and reaction studies for molecules relevant in a Fischer-Tropsch scenario on a bimetallic Pd/Co/alumina model catalyst. We show how surface science can be used by combining a variety of experimental techniques to study the chemistry of model catalysts at the atomic level., (Copyright 2003 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.)

Purpose: The provision of rehabilitation services is organized differently in Germany than most other countries, with large indication-specific in-patient centres. This study is aimed at the rehabilitative knowledge of physicians who initiate and conduct rehabilitation in Germany., Methods: Medical specialists routinely involved in the treatment and rehabilitation of patients with stroke and traumatic brain injury (TBI) from acute hospitals, rehabilitation centres, and the Medical Services of the Workers' Pension Funds of Sachsen-Anhalt and Mecklenburg-Vorpommern were included in a systematic questionnaire survey aiming at the rehabilitation requirements of patients under their care or evaluation. These specialists are crucial for decision-making in rehabilitation ressource allocation., Results: According to these experts, rehabilitation requirements for stroke and TBI patients are dominated by deficits in motor functions and daily-living. They are aware that TBI rehabilitation includes a greater focus on memory functions, problem-solving and attention, and in stroke on language functions. According to the surveyed specialists, the present system of medical rehabilitation in Germany covers the requirements of stroke and TBI patients only partially. Deficits are identified in out-patient and day clinic rehabilitation., Conclusions: Although the knowledge of rehabilitation requirements is adequate in general, its large ranges reflect the necessity for further analysis. The opinions of the surveyed specialists reflect their respective professional setting. Advantages and disadvantages of the German system require further investigation.

In budding yeast, the Ras/cAMP pathway is involved in the coordination of cell growth and cell division. Glucose-rich medium stimulates Ras/cAMP signaling, which causes an increase in the critical cell size for cell cycle entry. Here we show that glucose and activated Ras proteins also influence the function of the anaphase-promoting complex (APC/C), a ubiquitin-protein ligase required for sister chromatid separation and mitotic exit. We found that apc10-22 and other mutants defective in the APC/C are suppressed by reduced Ras signaling activity, by a deletion of the RAS2 gene, by a cdc25 mutation, by elevated levels of PDE2, or by growth without glucose. Viability of these mutants is also enhanced by decreased Cdk1 activity. In contrast, a constitutively activated RAS2(Val19) allele or shifts to glucose medium are deleterious to apc10-22 mutants. Remarkably, cdc34-2 mutants, which are impaired in SCF function, are differently affected with respect to Ras activity. Viability of cdc34-2 mutants at elevated temperatures is dependent on glucose and the RAS2 gene. We conclude that glucose and Ras proteins influence the APC/C and the SCF complex in an opposite manner. These ubiquitin ligases might represent novel targets for modulating cell division in response to growth conditions.

Sister chromatid separation and mitotic exit are triggered by the anaphase-promoting complex (APC/C) which is a multi-subunit ubiquitin ligase required for proteolytic degradation of various target proteins. Cdc20 and Cdh1 are substrate-specific activators of the APC/C. It was previously proposed that Cdh1 is essential for proteolysis of the yeast mitotic cyclin Clb2. We show that Clb2 proteolysis is triggered by two different modes during mitosis. A fraction of Clb2 is degraded during anaphase in the absence of Cdh1. However, a second fraction of Clb2 remains stable during anaphase and is degraded in a Cdh1-dependent manner as cells exit from mitosis. Most of cyclin Clb3 is degraded independently of Cdh1. Our data imply that degradation of mitotic cyclins is initiated by a Cdh1-independent mechanism.