Steady states and kinetic modelling of the acid-catalysed ethanolysis of glucose, cellulose, and corn cob to ethyl levulinate.

Ethyl levulinate is a promising advanced biofuel and platform chemical that can be derived from lignocellulosic biomass by ethanolysis processes. It can be blended with both diesel and gasoline and, thus, used in conventional engines and infrastructure. Previously, it has been shown that alkyl levulinate/alcohol/alkyl ether mixtures exhibit significantly enhanced fuel properties relative to any of the individual fuel components, particularly when blended with conventional hydrocarbon liquid fuels. Consequently, this study specifically quantifies the three primary components of the alcoholysis reaction mixture: ethyl levulinate, diethyl ether, and ethanol. The steady state and kinetic phase fractions of ethyl levulinate and diethyl ether produced from glucose, cellulose, and corn cob with 0.5-2 mass% sulphuric acid in ethanol are determined for 5, 10, and 20 mass% of feedstock at 150 °C. Knowledge of the steady state equilibrium mixture fraction is specifically targeted due to its importance in assessing commercial-scale production and in modelling analysis as: (i) it defines the maximum yield possible at a given condition, and (ii) it is equitable to the minimum free energy state. Maximum steady state yields (mass%) of ethyl levulinate of (46.6 ± 3.7), (50.2 ± 5.4), and (27.0 ± 1.9)% are determined for glucose, cellulose, and corn cob, respectively. The conversion of glucose and cellulose to ethyl levulinate in the presence of ethanol and sulphuric acid is shown to be a catalytic process, where the ethyl levulinate yield is not dependent on the acid concentration. For corn-cob biomass, in a new and contrasting finding, the ethyl levulinate yield is shown to strongly depend on the acid concentration. This effect is also observed in the fractions of diethyl ether formed, providing strong evidence that the hydrogen cation is not being replenished in the ethanolysis process and the overall reaction with corncob is not wholly catalytic. Thus, for the acid catalysed alcoholysis of lignocellulosic biomass, acid concentration must be scaled with feedstock concentration. The critical corn cob-to-acid ratio that maximises ethyl levulinate yields while minimizing the formation of undesired co-products (diethyl ether) is in the range 10-20 : 1 at 150 °C. A detailed, hierarchical, mass-conserved chemical kinetic model capable of accurately predicting the relative abundance of the three primary components of the ethanolysis reaction: ethyl levulinate, diethyl ether, and ethanol, from the biochemical composition of the feedstock, is elucidated and validated.

Investigating the effectiveness of virtual treatment via telephone triage in a New Zealand general practice.

Introduction Telemedicine, including telephone triage, is increasingly being used in New Zealand general practices. Telephone triage involves diverting requests for same-day healthcare to a phone system where presenting complaints are explored only sufficiently to identify the most appropriate management pathway. Aim To assess the rates of repeat triage among general practice patients treated virtually via phone and compare these with outcomes for patients who were dealt with in person. Method 6 weeks of clinical telephone triage data were collected for Gore Medical Centre. Comparisons were made for patients treated virtually or in person, for whether complaints were a respiratory issue or not, and for whether their triage represented incomplete resolution of a previously triaged health complaint. To do this, patient notes for the 7 days prior to the phone triage were reviewed for medical consultations related to the same condition. Results Over 6 weeks, 455 telephone triages took place at the Gore Medical Centre: 133 triage phone calls resulted in 132 (29%) patients being treated virtually. Over the 6 study weeks, 19 virtually treated triage patients phoned again for further care of the same problem within 7 days (14%) while 23 patients (7%) who had been triaged to in person assessment also sought further care within 7 days. This difference was statistically significant (P Discussion Virtual treatment via telephone triage at Gore Medical Centre resulted in a statistically increased likelihood of re-triage within 7 days compared with in person treatment. This raises questions about the efficacy of virtual treatment via telemedicine compared with in person treatment after triage.

Synthesis and characterisation of a mesocyclic tripodal triamine ligand.

Meso- and macrocyclic polydentate amine ligands have been widely explored in oxidation catalysis and for the stabilization of unstable metal-superoxide, -peroxide, and -oxo intermediates. Herein we report on the design and synthesis of a novel mesocyclic, tripodal, triamine ligand that we believe will be an excellent addition to this field. We explored a number of synthetic procedures towards the mesocyclic asymmetric tetraalkylated ligand 1. We expect that 1 will bind metals in a facially capping manner, yielding complexes that display pseudo-tetrahedral geometry, potentially providing access to unprecedented late transition metal-oxo complexes (metal = Co, Ni, Cu). We describe the preparation of a library of mesocyclic polyamine synthons (8, 16, 17, 18, 19) that are precursors in the synthesis of 1. These synthons will be used to tailor the electronic properties of metal complexes of 1 and derivatives thereof. The X-ray crystal structures of 19 and mono- and di-protonated forms of 1b show that the triamine crystalises in a boat­chair conformation which is undesirable for metal coordination. However, solution (1)H NMR studies show that in solution both 19 and the tetraalkylated derivative 1b are remarkably flexible. 1b reacted with [CuI(NCCH3)4](OTf) yielding a 1:1 copper(I) complex [CuI(NCCH3)(1b)](+).

Nucleophilic reactivity of a copper(II)-superoxide complex.

Metal-bound superoxide intermediates are often implicated as electrophilic oxidants in dioxygen-activating metalloenzymes. In the nonheme iron α-ketoglutarate dependent oxygenases and pterin-dependent hydroxylases, however, Fe(III)-superoxide intermediates are postulated to react by nucleophilic attack on electrophilic carbon atoms. By reacting a Cu(II)-superoxide complex (1) with acyl chloride substrates, we have found that a metal-superoxide complex can be a very reactive nucleophile. Furthermore, 1 was found to be an efficient nucleophilic deformylating reagent, capable of Baeyer-Villiger oxidation of a number of aldehyde substrates. The observed nucleophilic chemistry represents a new domain for metal-superoxide reactivity. Our observations provide support for the postulated role of metal-superoxide intermediates in nonheme iron α-ketoglutarate dependent and pterin-dependent enzymes.

Attitudes to immunisation: a survey of health professionals in the Rotorua District.

AIM: To examine the personal attitudes and practice of health professionals regarding childhood vaccinations in order to provide guidance to local professional education strategies. METHODS: A questionnaire was circulated to those involved in the implementation of the childhood immunisation schedule in the Rotorua District. Responses were stratified: a) community vs hospital; b) nurses, midwives, doctors, others. RESULTS: 85% responded, of whom 94% supported vaccinations. 91% considered science the most important basis for recommendations; 91% considered current scientific support adequate. 11% thought immunisations held unacceptable dangers; 17% were unsure. 41% of nurses, 45% of midwives, and 21% of doctors were unsure whether the MMR vaccine was associated with autism or Crohn's disease. Professional training, reading and personal experience were identified most often as having an influence on opinions, while the media and Internet ranked least often. Amongst respondents who had children, 96% reported vaccination (no significant difference between professional groups, but lower rates for children of hospital providers). CONCLUSIONS: Strong national support of vaccinations was demonstrated in this survey of professionals involved with vaccination in one district. Significant underlying uncertainties or concerns were identified regarding risks, the MMR vaccine, and ethical tensions between community protection and perceived individual risk. Continuing education and dialogue through professional training and medical literature are indicated to address these concerns.