FA-SIFT study of the reactions of H₃O⁺∙(H₂O)n (n=0, 1, 2), NO⁺ and O₂˙⁺ with the terpenoid aldehydes citral, citronellal and myrtenal and their alcohol analogues

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MS/MS studies on the selective on-line detection of sesquiterpenes using a Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS)

A Flowing Afterglow-Tandem Mass Spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of a series of seven sesquiterpenes (SQTs). These SQTs were chemically ionized by either H3O+ or NO+ reagent ions in the FA, resulting among others in protonated SQT and SQT molecular ions, respectively. These and other Chemical Ionization (CI) product ions were subsequently subjected to dissociation by collisions with Ar atoms in the collision cell of the tandem mass spectrometer. The fragmentation spectra show similarities with mass spectra obtained for these compounds with other instruments such as a Proton Transfer Reaction-Linear Ion Trap (PTR-LIT), a Proton Transfer Reaction-Mass Spectrometer (PTR-MS), a Triple Quadrupole-Mass Spectrometer (QqQ-MS) and a Selected Ion Flow Tube-Mass Spectrometer (SIFT-MS). Fragmentation of protonated SQT is characterized by fragment ions at the same masses but with different intensities for the individual SQT. Distinction of SQTs is based on well-chosen intensity ratios and collision energies. The fragmentation patterns of SQT molecular ions show specific fragment ion tracers at m/z 119, m/z 162, m/z 137 and m/z 131 for alpha-cedrene, delta-neoclovene, isolongifolene and alpha-humulene, respectively. Consequently, chemical ionization of SQT by NO+, followed by MS/MS of SQT(+) seems to open a way for selective quantification of SQTs in mixtures

Response of BVOC emissions from Fraxinus excelsior to biotic stress

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Politics and the resilience of ecosystem services

© Cambridge University Press 2015Decisions around which ecosystem services are the focus for resilience-building initiatives, and ensuring that these choices do not lead to undesirable lock-in effects that compromise the possibility for future adaptation and change, are far from ..

The confidential enquiry into maternal deaths in South Africa : a case study

The Confidential Enquiry into Maternal Deaths (CEMD) in South Africa has been operational for 15 years. This case study describes the process of notification and independent assessment of maternal deaths, predominantly in facilities. In the earlier years of the Enquiry, institutional maternal mortality ratio increased and was 176.2 per 100 000 live births in the 2008–10 triennium; thereafter it decreased to 146.7 in the 2011/12 period. The slow progress was due to the significant contribution of HIV/AIDs to maternal mortality and challenges in implementing the recommendations that were devised from the findings of the Enquiry. Nevertheless, the CEMD process has been maintained and strengthened so it is currently able to perform routine maternal death surveillance at both national and district levels, identify deficiencies within the health system, generate reports and also provide early warning about alarming trends such as the increasing numbers of deaths due to caesarean-section-associated haemorrhage.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1471-05282015-09-30hj201

Novel cryoballoon 180° ablation system for treatment of Barrett's esophagus-related neoplasia:a first-in-human study

Background The novel 180 degrees cryoballoon (CbAS (180) ) enables semicircumferential treatment over a length of 3cm per application. This first-in-human study evaluates its feasibility, efficacy, and safety for the treatment of Barrett's esophagus (BE) neoplasia. Methods This multicenter study consisted of dose-finding and extension phases. Dose-finding started with the lowest dose possible (1.0mm/s). For each dose, six patients were treated circumferentially over a 3-cm length. The dose was increased until the median BE regression was >= 60% without serious adverse events (SAEs). In the extension phase, the dose was confirmed in 19 new patients. The outcomes were technical success, BE regression after one treatment, and SAEs. Results 25 patients (median Prague C0M3) were included (6 dose-finding/19 extension). In two patients, the CbAS (180) could not be applied because of unstable balloon positioning. The technical success rate was 96% (22/23). In the six dose-finding patients, the starting dose resulted in median BE regression of 94% (95% confidence interval [CI] 60%-97%) without SAEs and was thus considered effective. Overall median BE regression was 80% (95%CI 60%-90%). Conclusion Single-session CbAS (180) seems feasible, safe, and effective, and is a promising technique for the treatment of patients with BE neoplasia