Uncovering Structure-Activity Relationships in Pt/CeO2 Catalysts for Hydrogen-Borrowing Amination.

The hydrogen-borrowing amination of alcohols is a promising route to produce amines. In this study, experimental parameters involved in the preparation of Pt/CeO2 catalysts were varied to assess how physicochemical properties influence their performance in such reactions. An amination reaction between cyclopentanol and cyclopentylamine was used as the model reaction for this study. The Pt precursor used in the catalyst synthesis and the properties of the CeO2 support were both found to strongly influence catalytic performance. Aberration corrected scanning transmission electron microscopy revealed that the most active catalyst comprised linearly structured Pt species. The formation of these features, a function result of epitaxial Pt deposition along the CeO2 [100] plane, appeared to be dependent on the properties of the CeO2 support and the Pt precursor used. Density functional theory calculations subsequently confirmed that these sites were more effective for cyclopentanol dehydrogenation-considered to be the rate-determining step of the process-than Pt clusters and nanoparticles. This study provides insights into the desirable catalytic properties required for hydrogen-borrowing amination but has relevance to other related fields. We consider that this study will provide a foundation for further study in this atom-efficient area of chemistry.

Parents' vaccination information seeking, satisfaction with and trust in medical providers in Switzerland: a mixed-methods study.

OBJECTIVES: The aim of this study was to better understand parental trust in and satisfaction with information sources and medical providers regarding decision making about childhood vaccines. SETTING: The study was part of a Swiss national research programme investigating vaccine hesitancy and underimmunisation. PARTICIPANTS: We conducted qualitative interviews with 37 providers and 30 parents, observed 34 vaccination consultations, and then conducted quantitative surveys with 130 providers (both complementary and alternative medicine (CAM) oriented and biomedically oriented) and 1390 parents. MAIN OUTCOME MEASURES: Participants' vaccination information sources used in their decision-making process, parents' trust in and satisfaction with these sources and providers. RESULTS: Based on the Parent Attitudes about Childhood Vaccines scale, we considered 501 parents as vaccine-hesitant (VH) and 889 parents as non-VH. Whereas both groups mentioned providers as the most trusted source of information, VH-parents were less likely to mention paediatricians (N=358 (71%) vs N=755 (85%)) and public health authorities (N=101 (20%) vs N=333 (37%)) than non-VH-parents. VH-parents were more likely to have consulted another provider (N=196 (39%) vs N=173 (19%)) than non-VH-parents, to express less satisfaction with both their primary (N=342 (82%) vs N=586 (91%)) and other providers (N=82 (42%) vs N=142 (82%)) and less trust in their primary (N=368 (88%) vs N=632 (98%)) and other providers (N=108 (55%) vs N=146 (84%)). VH-parents were less likely to be satisfied with their biomedical primary provider than non-VH-parents (100 (69%) vs 467 (91%)). However, when the primary provider was CAM-oriented, there were similar levels of satisfaction among both groups (237 (89%) VH-parents vs 118 (89%) non-VH-parents). All differences were significant (p<0.05). CONCLUSIONS: While the provider remains the main information source, VH parents turn to additional sources and providers, which is likely related to VH parents being rather dissatisfied with and distrusting in obtained information and their provider. ETHICS: The local ethics committee (Ethikkommission Nordwest- und Zentralschweiz, EKNZ; project ID number 2017-00725) approved the study.

Role of the Support in Gold-Containing Nanoparticles as Heterogeneous Catalysts.

In this review, we discuss selected examples from recent literature on the role of the support on directing the nanostructures of Au-based monometallic and bimetallic nanoparticles. The role of support is then discussed in relation to the catalytic properties of Au-based monometallic and bimetallic nanoparticles using different gas phase and liquid phase reactions. The reactions discussed include CO oxidation, aerobic oxidation of monohydric and polyhydric alcohols, selective hydrogenation of alkynes, hydrogenation of nitroaromatics, CO2 hydrogenation, C-C coupling, and methane oxidation. Only studies where the role of support has been explicitly studied in detail have been selected for discussion. However, the role of support is also examined using examples of reactions involving unsupported metal nanoparticles (i.e., colloidal nanoparticles). It is clear that the support functionality can play a crucial role in tuning the catalytic activity that is observed and that advanced theory and characterization add greatly to our understanding of these fascinating catalysts.

Oxidative Carboxylation of 1-Decene to 1,2-Decylene Carbonate.

Cyclic carbonates are valuable chemicals for the chemical industry and thus, their efficient synthesis is essential. Commonly, cyclic carbonates are synthesised in a two-step process involving the epoxidation of an alkene and a subsequent carboxylation to the cyclic carbonate. To couple both steps into a direct oxidative carboxylation reaction would be desired from an economical view point since additional work-up procedures can be avoided. Furthermore, the efficient sequestration of CO2, a major greenhouse gas, would also be highly desirable. In this work, the oxidative carboxylation of 1-decene is investigated using supported gold catalysts for the epoxidation step and tetrabutylammonium bromide in combination with zinc bromide for the cycloaddition of carbon dioxide in the second step. The compatibility of the catalysts for both steps is explored and a detailed study of catalyst deactivation using X-ray photoelectron spectroscopy and scanning electron microscopy is reported. Promising selectivity of the 1,2-decylene carbonate is observed using a one-pot two-step approach.

Pathogen reduction in unpasteurized apple cider: adding cranberry juice to enhance the lethality of warm hold and freeze-thaw steps.

U.S. Food and Drug Administration (FDA) regulations require processors of apple cider sold wholesale to use processing steps that ensure a 5-log reduction in numbers of the pertinent pathogen, generally considered to be Escherichia coli O157:H7. Current widely used validated pathogen-reduction steps are thermal pasteurization and UV light treatment. These techniques may be unaffordable or undesirable for some processors. This study investigated the cran-cider process, which is the addition of cranberry juice at a 15% (vol/vol) level, followed by warm hold (45 degrees C for 2 h) and freeze-thaw steps (-20 degrees C for 24 h, 5 degrees C for 24 h). When enumeration procedures did not include injury repair, the cran-cider process achieved a > or = 5-log reduction in numbers of E. coli O157:H7, Salmonella serovars, and Listeria monocytogenes. However, an injury-repair step was included in the pathogen enumeration procedure in confirmatory trials, and the resulting E. coli O157:H7 reductions of 3.5 to 4.2 log did not meet the FDA requirement. Consumer evaluation of apple cider subjected to the cran-cider process was favorable with a mean (n = 197) score of 5.8 on a seven-point hedonic scale (where 6 equals "like moderately") and 89% of panelists giving the product a positive score of 5, 6, or 7. The cran-cider process provides a novel way to improve microbial safety of unpasteurized apple cider, but it does not meet FDA-mandated pathogen reductions for wholesalers. However, cider makers selling apple cider only at retail could use the process to improve the safety of their product, provided containers were labeled with the FDA-mandated consumer warning.

Fate of Staphylococcus aureus on vacuum-packaged ready-to-eat meat products stored at 21 degrees C.

The U.S. Department of Agriculture has established standards for the composition and shelf stability of various ready-to-eat meat products. These standards may include product pH, moisture:protein ratio, and water activity (aw) values. It is unclear how closely these standards are based on the potential for pathogen growth or toxin production. Because the vacuum packaging used on most ready-to-eat meat products inhibits mold, Staphylococcus aureus is the pathogen most likely to grow on products with reduced aw and increased percentage of water-phase salt. In this study, 34 samples of various ready-to-eat meat products were inoculated with a three-strain mixture of S. aureus, vacuum packaged, and stored at 21 degrees C for 4 weeks. S. aureus numbers decreased by 1.1 to 5.6 log CFU on fermented products (pH < or = 5.1) with a wide range of salt concentrations and moisture content. Similarly, S. aureus numbers decreased by 3.2 to 4.5 log CFU on dried nonacidified jerky (aw < or = 0.82; moisture:protein ratio of < or =0.8). Products that were not fermented or dried clearly supported S. aureus growth and cannot be considered shelf stable. The product pH and moisture:protein ratio were the two compositional factors most highly correlated (R2 = 0.84) with S. aureus survival and growth for the types of products tested, but pH and aw or pH and percentage of water-phase salt also may provide useful predictive guidance (R2 = 0.81 and 0.77, respectively).

Evaluation of fertilization-to-planting and fertilization-to-harvest intervals for safe use of noncomposted bovine manure in Wisconsin vegetable production.

Fresh bovine manure was mechanically incorporated into loamy sand and silty clay loam Wisconsin soils in April 2004. At varying fertilization-to-planting intervals, radish, lettuce, and carrot seeds were planted; crops were harvested 90, 100, 110 or 111, and 120 days after manure application. As an indicator of potential contamination with fecal pathogens, levels of Escherichia coli in the manure-fertilized soil and presence of E. coli on harvested vegetables were monitored. From initial levels of 4.0 to 4.2 log CFU/g, E. coli levels in both manure-fertilized soils decreased by 2.4 to 2.5 log CFU/g during the first 7 weeks. However, E. coli was consistently detected from enriched soil samples through week 17, perhaps as a result of contamination by birds and other wildlife. In the higher clay silty clay loam soil, the fertilization-to-planting interval affected the prevalence of E. coli on lettuce but not on radishes and carrots. Root crop contamination was consistent across different fertilization-to-harvest intervals in silty clay loam, including the National Organic Program minimum fertilization-to-harvest interval of 120 days. However, lettuce contamination in silty clay loam was significantly (P < 0.10) affected by fertilization-to-harvest interval. Increasing the fertilization-to-planting interval in the lower clay loamy sand soil decreased the prevalence of E. coli on root crops. The fertilization-to-harvest interval had no clear effect on vegetable contamination in loamy sand. Overall, these results do not provide grounds for reducing the National Organic Program minimum fertilization-to-harvest interval from the current 120-day standard.