Partial oxidation of methane to methanol on boron nitride at near critical acetonitrile.

Direct catalytic conversion of methane to methanol with O2 has been a fundamental challenge in unlocking abundant natural gas supplies. Metal-free methane conversion with 17% methanol yield based on the limiting reagent O2 at 275 °C was achieved with near supercritical acetonitrile in the presence of boron nitride. Reaction temperature, catalyst loading, dwell time, methane-oxygen molar ratio, and solvent-oxygen molar ratios were identified as critical factors controlling methane activation and the methanol yield. Extension of the study to ethane (C2) showed moderate yields of methanol (3.6%) and ethanol (4.5%).

Excitation wavelength dependent photon anti-bunching/bunching from single quantum dots near gold nanostructures.

In this study, we aim to investigate the change in photon emission statistics of single CdSe/CdS core/shell quantum dots (QDs) on dielectric modified gold nanoparticle (NP) substrates as a function of the excitation wavelength. Photons emitted from single QDs are typically "anti-bunched" and are independent of the excitation wavelength. However, when QDs are coupled to plasmonic substrates, even at the low excitation power regime, we observed a significant change in photoluminescence emission behavior of single QDs; i.e. the emission transformed from incomplete photon anti-bunched to bunched when the excitation was changed from "off" to "on" plasmon resonance. Theoretical studies based on electrodynamics modeling suggested that for the QD-Au NP system, the quantum yield of single excitons decreases while that of biexcitons increases. In addition, when excited at the "on" resonance condition, the absorption is highly enhanced, resulting in an increased population of higher order excitons of the QDs. The higher order exciton emission was directly observed as an additional peak appeared at the blue side of the exciton peak of single QDs. The combined effect of the change in quantum yield and the increase in the absorption cross-section switches the photons emitted by single QDs from anti-bunched to bunched. These results provided direct evidence that not only the plasmonic nanostructures but also the excitation wavelength can effectively control the photon emission statistics of single QDs in the hybrid metal-semiconductor system. Manipulating the multiexciton-plasmon interaction in a hybrid complex like this could possibly open up new doors for applications such as entangled photon pair generation and plasmon-enhanced optoelectronic devices.

[Testing the Psychometric Properties of the Helping Alliance Questionnaire (HAQ) in Different Health Care Settings]. / Psychometrische Überprüfung des Helping Alliance Questionnaire (HAQ) in unterschiedlichen Versorgungssettings.

Introduction The Helping Alliance Questionnaire developed by Luborsky was psychometricly examined for the first time and translated into German by Bassler et al. in the mid-1990s. It consists of 11 Items, which are summarized to the scales "relation to the therapist" and "satisfaction with therapeutic outcome". HAQ is now one of the most used instruments to measure therapeutic alliance. The goal of this study was to test the psychometric properties based on three large patient samples in different treatment settings. Material and methods Analyses were conducted based on 2 samples of patients in inpatient psychosomatic/psychotherapeutic rehabilitation (n=655, n=2494) and one sample in outpatient psychotherapy (n=1477). Exploratory factor analyses and for verification confirmatory factor analyses were applied. Furthermore reliability and validity analysis were conducted. Results The 2-factorial structure found in literature was replicated with an increasing stability at the end of treatment. Item 2 and 3 had inconsistent factor loadings at different points of measurement and study. Reliability and validity indices were satisfying to good. The fit of the model, on the other hand, was less satisfying and suggests a solution without Item 2 and 3. For reasons of content as well as for reasons of dissemination, it is pleaded for the maintenance of the existing item assignments in the HAQ for the present.

Cu supported on mesoporous ceria: water gas shift activity at low Cu loadings through metal-support interactions.

We have synthesized and tested a highly active Cu doped mesoporous CeO2 catalyst system for the low temperature water-gas shift (WGS) reaction. While typical oxide-supported copper WGS catalysts are characterized by high copper loadings (30-40%), the morphological properties of the mesoporous CeO2 material enable high catalytic activity at copper loadings as low as 1%. Operando X-ray diffraction, in situ X-ray absorption near-edge structure spectroscopy (XANES), and operando diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) methods were used to probe the interactions between the metal and mesoporous oxide components under reaction conditions. Copper was observed to undergo reduction from oxide to metal under WGS conditions at 150 °C, while the CeO2 lattice was observed to expand upon heating, indicating Ce3+ formation correlated with CO2 production. The active state of the catalysts was confirmed by in situ XANES to contain Cu0 and partially reduced CeO2. DRIFTS analysis revealed carboxyl species bound to copper during reduction, as well as formate and carbonate surface species on ceria. Lower concentrations of copper were observed to foster enhanced metal-support interactions.

Understanding the role of gold nanoparticles in enhancing the catalytic activity of manganese oxides in water oxidation reactions.

The Earth-abundant and inexpensive manganese oxides (MnOx) have emerged as an intriguing type of catalysts for the water oxidation reaction. However, the overall turnover frequencies of MnOx catalysts are still much lower than that of nanostructured IrO2 and RuO2 catalysts. Herein, we demonstrate that doping MnOx polymorphs with gold nanoparticles (AuNPs) can result in a strong enhancement of catalytic activity for the water oxidation reaction. It is observed that, for the first time, the catalytic activity of MnOx/AuNPs catalysts correlates strongly with the initial valence of the Mn centers. By promoting the formation of Mn(3+) species, a small amount of AuNPs (<5%) in α-MnO2/AuNP catalysts significantly improved the catalytic activity up to 8.2 times in the photochemical and 6 times in the electrochemical system, compared with the activity of pure α-MnO2.

Synthesis of highly monodisperse porous manganese oxide spheres using a butyric acid microemulsion.

Porous manganese oxide spheres form readily from a reaction between KMnO4 and n-butanol in aqueous butyric acid under ambient conditions. Spheres have uniform size, tuneable diameters and high surface areas. The material is an active catalyst for the oxidation of isopropanol to acetone.

Crystalline mesoporous K(2-x)Mn8O16 and ε-MnO2 by mild transformations of amorphous mesoporous manganese oxides and their enhanced redox properties.

Synthesis of crystalline mesoporous K(2-x)Mn8O16 (Meso-OMS-2), and ε-MnO2 (Meso-ε-MnO2) is reported. The synthesis is based on the transformation of amorphous mesoporous manganese oxide (Meso-Mn-A) under mild conditions: aqueous acidic solutions (0.5 M H(+) and 0.5 M K(+)), at low temperatures (70 °C), and short times (2 h). Meso-OMS-2 and Meso-ε-MnO2 maintain regular mesoporosity (4.8-5.6 nm) and high surface areas (as high as 277 m(2)/g). The synthesized mesoporous manganese oxides demonstrated enhanced redox (H2-TPR) and catalytic performances (CO oxidation) compared to nonporous analogues. The order of reducibility and enhanced catalytic performance of the samples is Commercial-Mn2O3 < nonporous-OMS-2 < Meso-Mn2O3 < Meso-OMS-2 < Meso-ε-MnO2 < Meso-Mn-A.

Self-assembly of manganese oxide nanoparticles and hollow spheres. Catalytic activity in carbon monoxide oxidation.

Reactions between MnSO(4) and KMnO(4) in the presence of carboxylic acids provide a facile, one-pot route to nanostructured manganese oxides with high surface areas. Acetic and propionic acid induce formation of hierarchical nanosphere morphologies whereas butyric acid promotes assembly of hollow spheres. The materials are active catalysts for CO oxidation.

Acute altitude-induced hypoxia suppresses plasma glucose and leptin in healthy humans.

To examine the effects of acute altitude-induced hypoxia on the hormonal and metabolic response to ingested glucose, 8 young, healthy subjects (5 men and 3 women; age, 26 +/- 2 years; body mass index, 23.1 +/- 1.0 kg/m(2)) performed 2 randomized trials in a hypobaric chamber where a 75-g glucose solution was ingested under simulated altitude (ALT, 4300 m) or ambient (AMB, 362 m) conditions. Plasma glucose, insulin, C-peptide, epinephrine, leptin, and lactate concentrations were measured at baseline and 30, 60, 90, and 120 minutes after glucose ingestion during both trials. Compared with AMB, the plasma glucose response to glucose ingestion was reduced during the ALT trial (P = .04). There were no differences in the insulin and C-peptide responses between trials or in insulin sensitivity based on the homeostasis model assessment of insulin resistance. Epinephrine and lactate were both elevated during the ALT trial (P < .05), whereas the plasma leptin response was reduced compared with AMB (P < .05). The data suggest that the plasma glucose response is suppressed at ALT, but this is not due to insulin per se because insulin and C-peptide levels were similar for both trials. Elevated plasma epinephrine and lactate during ALT are indicative of increased glycogenolysis, which may have masked the magnitude of the reduced glucose response. We conclude that, during acute altitude exposure, there is a rapid metabolic response that is accompanied by a shift in the hormonal milieu that appears to favor increased glucose utilization.

[The satisfaction of relatives with service delivery of nursing homes for the elderly. Development of the screening-questionnaire ZUF-A-7]. / Zufriedenheit von Angehörigen mit der Versorgung in stationären Altenpflegeeinrichtungen. Entwicklung des Screening-Fragebogens ZUF-A-7.

PURPOSE: To enable the measurement of satisfaction with the service delivery of residential homes, a practicable and statistical proven screening-test was supposed to educe. In order to identify critical quality-related situations a specific cut-off should be allocated. METHODS: Based on literature research a questionnaire was developed and responded by 3581 relatives of residents of 45 nursing homes for the elderly. The questionnaire was analysed and compressed based on scale, item and factor analysis. For validation, demographic variables and separate quality-ratings were available. Finally a ROC analysis was performed to recognize specificity and sensitivity of possible cut-offs. RESULTS: The Angehörigen-Screening-Fragebogen (relatives-screening-questionnaire) ZUF-A-7 was generated consisting of seven items. The scale is reliable (Cronbach's Alpha). Like other satisfaction measurements it displays a skew distribution. Middle size up to large correlations with the quality-ratings exists but there were no relevant coherences to the demographic variables. The ROC analysis suggested a critical cut-off of 21 (range = 7-28).

[The social situation of patients with late-life depression]. / Die soziale Situation von Patienten mit Altersdepressionen.

The social situation of patients with late-onset late-life depression admitted to a gerontopsychiatric day-clinic was assessed with respect to activities, social contacts, living conditions and finances. The patients were compared with an age- and sex-matched control group. Relationships of the social situation to life satisfaction and severity of depression were investigated. In the patients, there were significant deficits in activities and contacts, especially with respect to those features which directly depend on the patients' level of activity (e. g. frequency of activities outside the household). Social infrastructure (e. g. frequency of attendance) and living conditions were positively correlated with life satisfaction, but were not significantly impaired in the depressed patients, neither were there differences in the financial situation between patients and controls. Thus, the social situation of elderly depressed patients is mainly characterised by a decreased level of activities, to which special therapeutic attention should be given.