Journal of Clinical Monitoring and Computing 2015 end of year summary:tissue oxygenation and microcirculation

Last year we started this series of end of year summaries of papers published in the 2014 issues of the Journal Of Clinical Monitoring And Computing with a review on near infrared spectroscopy (Scheeren et al. in J Clin Monit Comput 29(2):217-220, 2015). This year we will broaden the scope and include papers published in the field of tissue oxygenation and microcirculation, or a combination of both entities. We present some promising new technologies that might enable a deeper insight into the (patho)physiology of certain diseases such as sepsis, but also in healthy volunteers. These may help researchers and clinicians to evaluate both tissue oxygenation and microcirculation beyond macro-hemodynamic measurements usually available at the bedside

Continuing emissions of methyl chloroform from Europe

The consumption of methyl chloroform (1,1,1-trichloroethane), an industrial solvent, has been banned by the 1987 Montreal Protocol because of its ozone-depleting potential. During the 1990s, global emissions have decreased substantially and, since 1999, near-zero emissions have been estimated for Europe and the United States. Here we present measurements of methyl chloroform that are inconsistent with the assumption of small emissions. Using a tracer transport model, we estimate that European emissions were greater than 20 Gg in 2000. Although these emissions are not significant for stratospheric ozone depletion, they have important implications for estimates of global tropospheric hydroxyl radical (OH) concentrations, deduced from measurements of methyl chloroform. Ongoing emissions therefore cast doubt upon recent reports of a strong and unexpected negative trend in OH during the 1990s and a previously calculated higher OH abundance in the Southern Hemisphere compared to the Northern Hemisphere

AIRFORCE: Effecten van vliegtuigen en stralingsforcering van emissies

Het mondiale vliegverkeer is de laatste decennia sterk gestegen en groeit naar verwachting in de komende 20 jaar met 5-6% per jaar. De emissies van sporengassen door het vliegverkeer, zoals kooldioxide, stikstofoxiden, koolwaterstoffen, zwaveldioxide, waterdamp en roet kunnen effecten hebben op het milieu en direct en indirect bijdragen aan klimaatveranderingen. Het AIRFORCE project (Aircraft Influences and Radiative Forcing from Emissions) is een project van de drie onderzoeksinstituten (IMAU, KNMI en RIVM) die samen het Nederlands Centrum voor Klimaatonderzoek (CKO) vormen. De doelstellingen van AIRFORCE zijn: onderzoek naar het effect van vliegtuigemissies op de samenstelling van de atmosfeer en naar de directe en indirecte effecten van vliegtuigemissies via de stralings-forcering op het klimaat. De modelresultaten laten zien dat NOx emissies van het huidige vliegverkeer een toename veroorzaken van de NOx- en ozonconcentraties in de hoge troposfeer en lage stratosfeer, hetgeen leidt tot een positieve stralingsforcering. In het project is de dynamica en het chemisch mechanisme van enkele drie dimensionale chemie-transportmodellen (CTMK/TM3 en MOGUNTIA) sterk verbeterd. De resultaten van modelberekeningen zijn vergeleken met beschikbare metingen van de STREAM/AIRFORCE en POLINAT campagnes. In het kader van AIRFORCE is een pluimmodel ontwikkeld dat de chemische omzettingen in de pluim direct achter verkeersvliegtuigen beschrijft.Global air traffic has increased extensively during the last few decades and is expected to increase further over the next 20 years by about 5-6% per year. Emissions of trace gases such as carbon dioxide, nitrogen oxides, hydrocarbons, sulphur oxides, water vapour and soot from aircraft can have environmental effects and contribute directly or indirectly to global warming. The three institutes (IMAU, KNMI en RIVM) that form the Netherlands Centre for Climate Research (CKO) participated in the AIRFORCE project (Aircraft Influences and Radiative Forcing from Emissions). The goals of AIRFORCE are: Research on the effect of aircraft emissions on the composition of the atmosphere and on the direct and indirect effects of aircraft emissions on radiative forcing and climate. The model results indicate that NOx emissions from aircraft cause an increase in the NOx and ozone concentrations in the upper troposphere and lower stratosphere, and a positive radiative forcing. The dynamical and chemical mechanisms of several 3-dimensional chemical-transport models (CTMK/TM3 and MOGUNTIA) have been improved considerable in the project. The results have been compared with available measurements from the STREAM/AIRFORCE and POLINAT campaigns. To account for the chemical conversion and dispersion directly behind an aircraft, an aircraft plume model has been developed in the AIRFORCE project, to translate the aircraft NOx emissions into effective emissions that are used as input in the chemical transport models.DGM/GVV&W/RL

Isoprene and its oxidation products methyl vinyl ketone, methacrolein, and isoprene related peroxides measured online over the tropical rain forest of Surinam in March 1998

Airborne measurements of volatile organic compounds (VOC) were performed over the tropical rainforest in Surinam (0-12 km altitude, 2 degrees -7 degrees N, 54 degrees -58 degrees W) using the proton transfer reaction mass spectrometry (PTR-MS) technique, which allows online monitoring of compounds like isoprene, its oxidation products methyl vinyl ketone, methacrolein, tentatively identified hydroxy-isoprene-hydroperoxides, and several other organic compounds. Isoprene volume mixing ratios (VMR) varied from below the detection limit at the highest altitudes to about 7 nmol/mol in the planetary boundary layer shortly before sunset. Correlations between isoprene and its product compounds were made for different times of day and altitudes, with the isoprene-hydroperoxides showing the highest correlation. Model calculated mixing ratios of the isoprene oxidation products using a detailed hydrocarbon oxidation mechanism, as well as the intercomparison measurement with air samples collected during the flights in canisters and later analysed with a GC-FID, showed good agreement with the PTR-MS measurements, in particular at the higher mixing ratios. Low OH concentrations in the range of 1-3 x 10(5) molecules cm(-3) averaged over 24 hours were calculated due to loss of OH and HO(2) in the isoprene oxidation chain, thereby strongly enhancing the lifetime of gases in the forest boundary layer

High acetone concentrations throughout the 0-12 km altitude range over the tropical rainforest in Surinam

Airborne measurements of acetone were performed over the tropical rainforest in Surinam (2 degrees -7 degrees N, 54 degrees -58 degrees W, 0-12 km altitude) during the LBA-CLAIRE campaign in March 1998, using a novel proton transfer reaction mass spectrometer (PTR-MS) that enables the on-line monitoring of volatile organic compounds (VOC) with a higher proton affinity than water. The measured acetone volume mixing ratios ranged from similar to0.1 nmol/mol up to similar to8 nmol/mol with an overall average of 2.6 nmol/mol and a standard deviation of 1.0 nmol/mol. The observed altitude profile and correlations with CO, acetonitrile, propane and wind direction are discussed with respect to potential acetone sources. No linear correlation between acetone and CO mixing ratios was observed, at variance with results of previous measurement campaigns. The mean acetone/CO ratio (0.022) was substantially higher than typical values found before. The abundance of acetone appears to be influenced, but not dominated, by biomass burning, thus suggesting large emissions of acetone and/or acetone precursors, such as possibly 2-propanol, from living plants or decaying litter in the rainforest