Theoretical and experimental study of peroxy and alkoxy radicals in the NO3-initiated oxidation of isoprene.

The initial stages of the nitrate radical (NO3) initiated oxidation of isoprene, in particular the fate of the peroxy (RO2) and alkoxy (RO) radicals, are examined by an extensive set of quantum chemical and theoretical kinetic calculations. It is shown that the oxidation mechanism is highly complex, and bears similarities to its OH-initiated oxidation mechanism as studied intensively over the last decade. The nascent nitrated RO2 radicals can interconvert by successive O2 addition/elimination reactions, and potentially have access to a wide range of unimolecular reactions with rate coefficients as high as 35 s-1; the contribution of this chemistry could not be ascertained experimentally. The chemistry of the alkoxy radicals derived from these peroxy radicals is affected by the nitrate moiety, and can lead to the formation of nitrated epoxy peroxy radicals in competition with isomerisation and decomposition channels that terminate the organic radical chain by NO2 elimination. The theoretical predictions are implemented in the FZJ-NO3-isoprene mechanism for NO3-initiated atmospheric oxidation of isoprene. The model predictions are compared against peroxy radical (RO2) and methyl vinyl ketone (MVK) measurements in a set of experiments on the isoprene + NO3 reaction system performed in the SAPHIR environmental chamber (IsopNO3 campaign). It is shown that the formation of NO2 from the peroxy radicals can prevent a large fraction of the peroxy radicals from being measured by the laser-induced fluorescence (ROxLIF) technique that relies on a quantitative conversion of peroxy radicals to hydroxyl radicals. Accounting for the relative conversion efficiency of RO2 species in the experiments, the agreement between observations and the theory-based FZJ-NO3-isoprene model predictions improves significantly. In addition, MVK formation in the NO3-initiated oxidation was found to be suppressed by the epoxidation of the unsaturated RO radical intermediates, allowing the model-predicted MVK concentrations to be in good agreement with the measurements. The FZJ-NO3-isoprene mechanism is compared against the MCM v3.3.1 and Wennberg et al. (2018) mechanisms.

S2k-Guideline "Prolonged Weaning".

All mechanically ventilated patients must be weaned from the ventilator at some stage. According to an International Consensus Conference the criteria for "prolonged weaning" are fulfilled if patients fail at least 3 weaning attempts (i. e. spontaneous breathing trial, SBT) or require more than 7 days of weaning after the first SBT. This occurs in about 15 - 20 % of patients.Because of the growing number of patients requiring prolonged weaning a German guideline on prolonged weaning has been developed. It is an initiative of the German Respiratory Society (Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V., DGP) in cooperation with other societies (see acknowledgement) engaged in the field chaired by the Association of Scientific and Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF).This guideline deals with the definition, epidemiology, weaning categories, underlying pathophysiology, therapeutic strategies, the weaning unit, transition to out-of-hospital ventilation and therapeutic recommendations for end of life care. This short version summarises recommendations on prolonged weaning from the German guideline.

[Relevance of personal contextual factors of the ICF for use in practical social medicine and rehabilitation]. / Bedeutung der personbezogenen Faktoren der ICF für die Nutzung in der praktischen Sozialmedizin und Rehabilitation.

Personal contextual factors play an essential part in the model of the International Classification of Functioning, Disability and Health (ICF). The WHO has not yet classified personal factors for global use although they impact on the functioning of persons positively or negatively. In 2010, the ICF working group of the German Society of Social Medicine and Prevention (DGSMP) presented a proposal for the classification of personal factors into 72 categories previously arranged in 6 chapters. Now a positioning paper has been added in order to stimulate a discussion about the fourth component of the ICF, to contribute towards a broader and common understanding about the nature of personal factors and to incite a dialogue among all those involved in health care as well as those people with or with-out health problems in order to gain a comprehensive perspective about a person's condition.

[Neoadjuvant chemoradiotherapy or chemotherapy for locally advanced esophageal cancer?] / Neoadjuvante Radiochemotherapie oder Chemotherapie beim lokal fortgeschrittenen Ösophaguskarzinom?

BACKGROUND: According to international guidelines neoadjuvant chemoradiotherapy and chemotherapy are recommended for the treatment of locally advanced esophageal cancer. The treatment approach depends on the tumor entity (adenocarcinoma vs. squamous cell carcinoma). OBJECTIVE: What benefits do patients with locally advanced esophageal cancer have from neoadjuvant treatment? Is there information in the international literature on whether a particular neoadjuvant treatment is preferred? Does the type of neoadjuvant treatment depend on factors other than the tumor entity? Is there a standard in the drug composition of chemotherapy or a clearly defined chemoradiotherapy regimen? MATERIAL AND METHODS: A review, evaluation and critical analysis of the international literature were carried out. RESULTS: Patients with locally advanced esophageal cancer benefit from a neoadjuvant treatment. The current data situation for squamous cell carcinoma of the esophagus demonstrates a better response to neoadjuvant chemoradiotherapy compared to chemotherapy alone. Locally advanced adenocarcinoma of the esophagus can be treated with combined neoadjuvant chemoradiotherapy as well as by chemotherapy alone. Both lead to an improvement in the prognosis. There are often differences particularly among radiation treatment regimens in the different centers. Furthermore, the localization of the tumor can also be important for treatment decisions. CONCLUSION: A neoadjuvant treatment is clearly recommended for locally advanced esophageal cancer. Currently, chemoradiotherapy according to the CROSS protocol is preferred for squamous cell carcinoma. For adenocarcinoma both chemotherapy according to the FLOT protocol as well as chemoradiotherapy in a neoadjuvant treatment concept lead to an improvement in the prognosis.

[Carteolol: general practice-oriented assessment of the effectiveness and tolerance of a new beta-blocker in the treatment of glaucoma]. / Carteolol: Praxisgerechte Prüfung von Wirksamkeit und Verträglichkeit eines neuen Betablockers in der Behandlung des Glaukoms.

During an open multicenter field study the new beta-blocking agent Carteolol, in 1% and 2% solution, proved to be effective and safe in the treatment of 178 patients suffering from glaucoma. On average, IOP was lowered by 5.8 to 18.7 mm Hg in nontreated and by 4.8 to 17.8 mm Hg in pretreated patients. In more than 90% of the cases both the patients and the investigators judged the treatment to be good, or better than the previous therapy. Side affects occurred in less than 3% of the cases.