An in situ FTIR study of the plasma- and thermally-driven reaction of isopropyl alcohol at CeO2: evidence for a loose transition state involving Ce3+?

This paper reports on the thermally-driven and non-thermal plasma-driven reaction of IsoPropyl Alcohol (IPA) on ceria (CeO2) with the aim to investigate the differences between plasma catalytic interactions and the analogous thermal reactions. Both were studied by in situ infrared spectroscopy: using diffuse reflectance for the thermal reaction and reflectance infrared for the plasma. For the thermal reaction, the activity towards the formation of acetone and acetaldehyde and, at higher temperatures, CO2 was dependent upon the coverage of surface carbonates and bicarbonates, suggesting at least some of these species blocked the relevant active sites. However, for the first time, methane and cold CO was observed and this was interpreted in terms of a roaming mechanism taking place at the surface via a loose transition state. By contrast, the plasma-driven process was not inhibited by adsorbed carbonaceous species producing acetone followed by isophorone and a polymethylacetylene-like polymer. Comparisons are made between the equivalent thermal and plasma reactions of isopropyl alcohol on Macor and tin oxide surfaces. On Macor the plasma produced similar products whereas on tin oxide there was no reaction. This suggests that the selection of catalysts for plasma processing cannot necessarily be determined from the equivalent thermal process.

In situ FTIR studies on the oxidation of isopropyl alcohol over SnO2 as a function of temperature up to 600 °C and a comparison to the analogous plasma-driven process.

This paper reports the application of in situ reflectance Fourier Transform InfraRed spectroscopy to the study of the thermal and plasma driven reaction of IsoPropyl Alcohol (IPA) at SnO2-coated Macor, the latter a ceramic material comprised of the oxides of Al, Mg and Si. The data so obtained were compared to those obtained using uncoated Macor. When uncoated Macor was employed, no reaction of the IPA was observed up to 600 °C in the thermal experiments, whereas a number of products were observed in the plasma-driven experiments. The results obtained using coated Macor were somewhat different, with no reaction taking place in the plasma-driven experiments, whilst significant reaction took place in the thermally-driven process. In the latter experiments, the chemistry was observed to show four distinct temperature regions, with electron injection into the conduction band of the SnO2 playing a significant role, culminating in the production of CO2. The data were interpreted in terms of a model in which physisorbed IPA was converted to two forms of isopropoxide: this was converted to acetone and acetaldehyde via adsorbed enolate. The data clearly support the catalytic activity of Macor in the plasma-driven conversion of IPA.

An in situ FTIR spectroscopic and thermogravimetric analysis study of the dehydration and dihydroxylation of SnO2: the contribution of the (100), (110) and (111) facets.

Nanoparticulate SnO2 produced by a hydrothermal method was characterised by BET, XRD, TGA-MS and in situ variable temperature diffuse reflectance infra red spectroscopy (DRIFTS) to determine the surface behaviour of water. For the (100) facets, hydrogen bonding does not occur, and water adsorption is less strong than for the (111) and (110) facets where hydrogen bonding does occur. Reversible uptake of oxygen was observed. These findings have implications for other surface-gas reactions in which Ni and Sb co-doped SnO2 (NATO) anodes are used for ozone generation. BET showed the relatively high surface area and nanometer scale of the SnO2 particles, whilst XRD confirmed the nano dimension of the crystallites and showed only the cassiterite phase. TGA analysis indicated four temperature regions over which mass loss was observed. These and the in situ DRIFTS studies revealed the existence of various forms of water associated with specific crystal facets of the SnO2, as well as the existence of isolated O-H groups and adsorbed oxygen species. Electronic absorptions were also observed and the data rationalised in terms of the existence of both free electron absorptions, and absorptions from oxygen vacancy states. The role of adsorbed molecular oxygen in electrochemical ozone generation at Ni and Sb co-doped SnO2 (NATO) anodes was strongly suggested by this work.

Alterations in molecular muscle mass regulators after 8 days immobilizing Special Forces mission.

In military operations, declined physical capacity can endanger the life of soldiers. During special support and reconnaissance (SSR) missions, Special Forces soldiers sustain 1-2 weeks full-body horizontal immobilization, which impairs muscle strength and performance. Adequate muscle mass and strength are necessary in combat or evacuation situations, which prompt for improved understanding of muscle mass modulation during SSR missions. To explore the molecular regulation of myofiber size during a simulated SSR operation, nine male Special Forces soldiers were biopsied in m. vastus lateralis pre and post 8 days immobilizing restricted prone position. After immobilization, total mammalian target of rapamycin protein was reduced by 42% (P < 0.05), whereas total and phosphorylated protein levels of Akt, ribosomal protein S6k, 4E-BP1, and glycogen synthase kinase3ß were unchanged. Messenger RNA (mRNA) levels of the atrogenes forkhead box O3 (FoxO3), atrogin1, and muscle ring finger protein1 (MuRF1) increased by 36%, 53%, and 71% (P < 0.01), MuRF1 protein by 51% (P = 0.05), whereas FoxO1 and peroxisome proliferator-activated receptor γ coactivator-1 ß mRNAs decreased by 29% and 40% (P < 0.01). In conclusion, occupational immobilization in Special Forces soldiers led to modulations in molecular muscle mass regulators during 8 days prone SSR mission, which likely contribute to muscle loss observed in such operations. The present data expand our knowledge of human muscle mass regulation during short-term immobilization.

An in situ FTIR spectroscopic study of the electrochemical oxidation of ethanol at a Pb-modified polycrystalline Pt electrode immersed in aqueous KOH.

A study of the mechanism of ethanol oxidation in alkaline solution on a platinum electrode modified with an irreversibly-deposited layer of lead has been carried out using in situ FTIR spectroscopy. This study provides support for the suggestion that the adsorption mechanism of ethanol is substantially modified in the presence of Pb, with a carbon-bonded intermediate being favoured leading to facile scission of the C-C bond in ethanol. We have found that the formation of carbonate takes place at potentials close to the thermodynamic value. At higher potentials, when Pb is lost to solution, the mechanism of oxidation of ethanol reverts to that found on a normal polycrystalline Pt surface, with the primary product being acetate.

Post-operative pain treatment in Denmark from 2000 to 2009: a nationwide sequential survey on organizational aspects.

BACKGROUND: In Denmark, the first acute pain service (APS) was introduced in 1993. An important objective became to facilitate implementation of accelerated post-operative rehabilitation programmes (ACC) in selected procedures in abdominal, gynaecological and orthopaedic surgery. Therefore, it is of considerable interest to study the association between the developments of post-operative pain management and the ACC by sequential analyses from 2000 to 2009. METHODS: In 2000, 2003, 2006 and 2009, a questionnaire was mailed to all Danish anaesthesiology departments. The headings of the questionnaire were demographics of responder departments, resources allocated to pain management methods, quality assessment methods, research activities and implementation of ACC. RESULTS: The responder rates varied between 80% and 94% (mean 88%) representing a mean number of anaesthetics of 340.000 per year. The number of APSs in the study period varied in university hospitals between 52% and 71% (P = 0.01), regional hospitals between 8% and 40% (P < 0.01), and local hospitals between 0% and 47% (P < 0.01). The prevalences of departments actively engaged in ACC were 40% in 2000, 54% in 2003, 73% in 2006 and 80% in 2009 (P < 0.01). CONCLUSIONS: The study, spanning nearly a decade, illustrates that following an increase in number of APSs from 2000 to 2006, followed by a significant decline, a steadily increasing number of departments implemented ACC.

Oxygen reduction and fuel oxidation in alkaline solution.

This paper reviews work carried out over a number of years to try to elucidate the mechanism of oxygen reduction and methanol oxidation in alkaline solution. We have sought to achieve this by combining electrochemical, spectroscopic and solid-state chemical approaches, bringing together as wide a variety of techniques as possible both to shed light on the mechanisms and to point the way to more effective and efficient fuel cells. This work has become considerably more topical in recent years with the development of anion-exchange electrolyte membranes that can operate in alkaline environments, an important advance since it permits both the use of non-noble-metal catalysts and organic fuels at the anode, the latter precluded in aqueous alkaline electrolyte due to precipitation of inorganic carbonates at the electrode surface.

The electro-oxidation of formate ions at a polycrystalline Pt electrode in alkaline solution: an in situ FTIR study.

This paper reports in situ FTIR studies on the oxidation of formate at polycrystalline Pt in aqueous KOH. Data are presented which show that hydroxyl species play a major role in the electro-oxidation of small organic molecules under alkaline conditions at polycrystalline Pt, and that a number of possible mechanistic pathways are possible. Small changes in experimental conditions appear to be able to cause the reaction to flick between these pathways; for example, the presence of oxygen has a marked effect upon the observed electrochemistry. In contrast to acid solution, our postulated model includes the formation of intermediates bonded through O atoms, rather than C, as being an important option in alkaline solution. Finally, the pH distribution across the reflective electrode in external reflectance IR is modelled and significant variations in pH across the electrode surface in FTIR cells predicted and confirmed experimentally.

Changes in muscle strength and morphology after muscle unloading in Special Forces missions.

The purpose of the present study was to determine the changes in maximal muscle strength, rapid force capacity, jumping performance and muscle morphology following a Special Forces military operation involving 8 days of muscle unloading. Nine male Special Forces soldiers were tested before (pre) and immediately after (post1) an 8-day simulated special support and reconnaissance (SSR) mission and after 3 h of active recovery (post2). Maximal muscle strength (MVC) and rate of force development (RFD) were measured along with maximal counter movement jump height (JH). Muscle biopsies were obtained from the vastus lateralis at pre and post1. Acute reductions were found in MVC (11%), JH (10%) and RFD (17-22%) after 8 days of muscle unloading (post1) (P≤0.05). Type IIX fiber type area% increased (P≤0.05) at post1 together with a tendency toward increased type IIX fiber type % (P=0.09) and decreased type I fiber type % (P=0.06), suggesting a transition toward a less fatigue-resistant fiber-type profile. In conclusion, short-term unloading during SSR missions led to marked reductions in mechanical muscle function and functional performance, which may be partly explained by the changes in muscle morphology. Future studies should identify intervention strategies to counter-act the observed impairments.

Modifying antibody specificity by chain shuffling of V / V between antibodies with related specificities.

Histo-blood group antigens are important markers of developmental stages and as such also often of tumours. Generation of antibodies towards these carbohydrate structures is still a challenging task as they may lack specificity, affinity or are only of the IgM class. We have examined four own antibodies to Lewis Y/H type 2 for their fine specificities using a large panel of mono- and oligosaccharides. Sequence alignment to other antibodies with similar specificity revealed an overall limited variation, and that our antibodies constitute a novel set. Based on produced and analysed chimeric mouse-human antibodies, extensive chain shuffling experiments were performed in order to analyse influences of the respective H and L chains on the specificity of the antibodies, and to generate modified antibodies with improved properties. One chIgG1 out of the shuffled antibodies revealed improved specificity and markedly enhanced functional affinity to Lewis Y compared to the parental chIgG1 antibodies. Therefore, the combinatorial approach of chain shuffling provides a platform to improve specificity and/or affinity of anti-carbohydrate antibodies.

A novel electrochemical device for the disinfection of fluids by OH radicals.

This paper describes a novel, composite device, based not on optical excitation but on the transfer of holes from Si to the TiO(2)/air or TiO(2)/water interface, for the disinfection and detoxification of fluid streams.

Crystallization and preliminary diffraction analysis of caudoxin and notexin; two monomeric phospholipase A2 neurotoxins.

Two monomeric neurotoxic phospholipases A2 have been crystallized and their diffraction properties characterized. Crystals of caudoxin (from the venom of Bitis caudalis) and notexin (from the venom of Notechis scutatus scutatus) were grown at neutral pH, in the absence of calcium ion, and diffract to a resolution of 2.3 and 1.6 A, respectively.

Fate of Cryptosporidium oocysts in an immobilised titanium dioxide reactor with electric field enhancement.

We have undertaken simple proof of principle experiments to find out if electric field enhanced photo-oxidation using immobilised titanium dioxide will damage Cryptosporidium oocysts. Using a simple Petri dish reactor and two forms of immobilised titanium catalyst (sol-gel and thermal-film) we have tested the ability of this technology to affect Cryptosporidium oocysts permeability assessed by propidium iodide exclusion. Test and control reactor runs were significantly different (P = 0.007). The thermal-film reactor had the greatest effect (approximately 27% of the seed) and was statistically distinguishable from the sol-gel reactor and the controls. The sol-gel reactor showed an increase in oocyst permeability, but was not statistically distinguishable from one of the controls. The enhanced performance of the thermal film reactor is attributed to the superior conversion of photochemical holes to hydroxyl radicals at the surface of this catalyst.

The effects of the specific adsorption of anion on the reactivity of the Ru(0001) surface towards CO adsorption and oxidation: in situ FTIRS studies.

The dynamics of adsorption and oxidation of CO on Ru(0001) electrode in sulfuric acid solution have been studied using in situ FTIR spectroscopy under potential control and at open circuit, the latter at 20 and 55 degrees C. The in situ IR data show clearly that the bisulfate anion adsorbs on the Ru(0001) surface over the potential range from -200 mV to 350 mV (vs. Ag/AgCl) at 20 degrees C in the absence and presence of adsorbed CO; however, increasing the temperature to 55 degrees C and/or increasing the concentration of dissolved O(2) reduces the bisulfate adsorption. The formation of surface (hydro-) oxide at higher potentials replaces the bisulfate adsorbates. Both linear (CO(L)) and three-fold hollow bonded CO (CO(H)) adsorbates were produced following CO adsorption at Ru(0001) in H(2)SO(4), as was observed in our previous studies in HClO(4). However, the amount of adsorbed CO observed in H(2)SO(4) was ca. 10% less than that in HClO(4); in addition, the CO(L) and CO(H) frequencies were higher in H(2)SO(4), and the onset potential for CO(ads) oxidation 25 mV lower. These new results are interpreted in terms of a model in which the adsorbed bisulfate weakens the CO adlayer, allowing the active Ru oxide layer to form at lower potentials. Significantly different results were observed at open circuit in H(2)SO(4) compared both to the data under potential control and to our earlier data in HClO(4), and these observations were rationalized in terms of the adsorbed HSO(4)(-) anions (pre-adsorbed at -200 mV) inhibiting the oxidation of the surface at open circuit (after stepping from the initial potential of -200 mV), as the latter was no longer driven by the imposed electrochemical potential but via chemical oxidation by trace dissolved O(2). Results from experiments at open circuit at 55 degrees C and using oxygen-saturated H(2)SO(4) supported this model. The difference in Ru surface chemistry between imposed electrochemical control and chemical control has potential implications with respect to fuel cell electrocatalysis.

A monoclonal antibody to Lewis Y/Lewis b revealing mimicry of the histone H1 to carbohydrate structures.

Antibodies to either peptide or carbohydrate tumour antigens are established tools for diagnostics and therapy. We here describe an antibody (A70-A/A9) recognizing a carbohydrate epitope common to the tumour-associated Lewis Y and Lewis b antigens (Fucalpha1-2Galbeta1-4/3[Fucalpha1-3/4]GlcNAcbeta-). Its specificity was established without doubt with a panel of 86 synthetic mono- and oligosaccharidic structures. This antibody was found to cross-react with the nuclear protein histone H1. Binding to H1 was specific, periodate-insensitive (non-carbohydrate) and saturable. Histone H1 was able to inhibit Lewis Y binding very effectively in a concentration-dependent manner. We conclude that it represents an example of natural peptide mimicry of a carbohydrate epitope. It may explain the observed occurrence of 'anti-histone autoantibodies' in cancer patients.

In situ FTIR studies on the effect of temperature on the electro-oxidation of small organic molecules at the Ru(0001) electrode.

The adsorption and electro-oxidation of formaldehyde, formic acid and methanol at the Ru(0001) electrode in perchloric acid solution have been studied as a function of temperature, potential and time using in situ FTIR spectroscopy, and the results interpreted in terms of the surface chemistry of the Ru(000 1) electrode and compared to those obtained during our previous studies on the adsorption of CO under the same conditions. It was found that no dissociative adsorption or electro-oxidation of methanol takes place at Ru(0001) at potentials < 900 mV vs. Ag/AgCl, and at all three temperatures employed, 10, 25 and 50 degrees C. However, both formaldehyde and formic acid did undergo dissociative adsorption, even at -200 mV, to form linear (CO(L)) and 3-fold-hollow (COH) binding CO adsorbates. In contrast to the adsorption of CO, it was found that increasing the temperature to 50 degrees C markedly increased the amount of CO adsorbates formed on the Ru(0001) surface from the adsorption of both formaldehyde and formic acid. On increasing the potential, the electro-oxidation of the CO adsorbates to CO2 took place via reaction with the active (1 x 1)-O oxide. Formic acid was detected as a partial oxidation product during formaldehyde electro-oxidation. At all three temperatures employed, it was found that adsorbed CO species were formed from the adsorption of both formic acid and formaldehyde, and were oxidised to CO2 faster than was observed in the experiments involving CO adsorbed from CO(g), suggesting a higher mobility of the CO adsorbates formed from the adsorption of the HCOOH and HCHO. At potentials > 1000 mV, both the oxidation of formic acid to CO2 and the oxidation of formaldehyde to both CO2 and formic acid were significantly increased, and the oxidation of methanol to CO2 and methyl formate was observed, all of which were attributed to the formation of an active RuO2 phase on the Ru(0001) surface.