Grain Harvesting as a Local Source of Cladosporium 1 spp. in Denmark

Cladosporium spp. are omnipresent moulds that grow on multiple substrates. Their spores possess a high allergenic potential. Currently, little is known about the incidence and the sources of airborne Cladosporium spores in Denmark. Air samples were collected between 31 May and 22 September 2015 in Viborg (Jutland, western Denmark). Eighteen out of 21 days with daily average concentrations exceeding the health relevant threshold of 3,000 Spores m-3, including the day with peak daily (13,553 Spores m-3) and 3-h concentrations (35,662 Spores m-3), occurred in August. The air masses that approached Viborg during the longest episode of elevated spore concentrations originated from northern Poland, the Baltics, passing over southern Sweden and the eastern Danish island of Zealand. The Cladosporium spore concentrations from Viborg were compared with the Cladosporium spore concentrations from the operational monitoring station in Copenhagen (Zealand, eastern Denmark). During the episode concentrations in Viborg were on average 2,268 spores m-3 higher than in Copenhagen. On the peak day between 8:00-15:00 concentrations in Viborg were 4-7 times higher than in Copenhagen, which we associated with grain crop harvesting in eastern Jutland. Elevated day time concentrations in Viborg on the days with daily average concentrations exceeding the threshold also indicate the local character of the sources

Airborne Cladosporium and Alternaria spore concentrations through 26 years in Copenhagen, Denmark

Cladosporium spp. and Alternaria spp. spores are dominating the airspora of Denmark. Currently, little is known about the influence of climate change on the fungal spore abundance in the air. The aim of this study was to examine temporal changes in airborne Alternaria and Cladosporium spores over 26 years. This is the first report of long-term airborne Cladosporium spore occurrence in Denmark. Air spore concentrations were obtained with a Burkard volumetric spore sampler placed in Copenhagen, Denmark, during June–September, 1990–2015. The highest monthly Spore integrals (SIn) for Alternaria were measured in August, whereas for Cladosporium July SIn was nearly as high as August SIn. Average Alternaria seasonal spore integral (SSIn) was 8615 Spores day m−3, while average 3-month (July–September) Cladosporium SIn was 375,533 Spores day m−3. Despite increasing annual temperature and decreasing relative humidity, we found a decreasing trend for Alternaria seasonal SIn (Slope = − 277, R2 = 0.38, p < 0.05), Alternaria (Slope = − 31, R2 = 0.27, p < 0.05) and Cladosporium (Slope = − 440, R2 = 0.23, p < 0.05) annual peak concentrations. We did not find any statistically significant trends for airborne Alternaria seasonal characteristics and duration, and likewise for Cladosporium 3-month SIn and peak concentration dates. Mean temperature was the main meteorological factor affecting daily spore concentrations. However, effect of meteorological parameters on daily spore concentrations was stronger for Cladosporium (R2 = 0.41) than for Alternaria (R2 = 0.21). Both genera had diurnal peaks during the day hours, earlier for Cladosporium (11:30–14:30) and later for Alternaria (15:00–19:00). Although Alternaria and Cladosporium daily concentrations were moderately correlated (Spearman’s correlation coefficient: rs = 0.55, p < 0.05), their overall annual indices were different, which indicates different sources and different factors determining spore release. We explain temporal decreasing trends in Alternaria SSIn by growing urbanisation around Copenhagen and by changes in agricultural practices

Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene

In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included usual methane C0-C2 combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C3-C4 unsaturated hydrocarbons. The main reaction pathways of consumption of 1,3-butadiene and of formation of C6 aromatic species have been derived from flow rate analyses. In this case, the C4 route to benzene formation plays an important role in comparison to the C3 pathway

The influence of reaction conditions on the oxidation of cyclohexane via the in-situ production of H2O2

The oxidation of cyclohexane via the in-situ production of H2O2 from molecular H2 and O2 offers an attractive route to the current industrial means of producing cyclohexanone and cyclohexanol (KA oil), both key materials in the production of Nylon. Herein we demonstrate that through the in-situ production of H2O2 supported AuPd nanoparticles catalyse the formation of KA oil under conditions where activity is limited when using molecular O2, with no loss in catalytic activity observed upon re-use. The effect of key reaction parameters, including reaction temperature, catalyst mass and H2:O2 ratio are evaluated

Study protocol for OptimalTTF-2:enhancing Tumor Treating Fields with skull remodeling surgery for first recurrence glioblastoma: a phase 2, multi-center, randomized, prospective, interventional trial

Abstract Background OptimalTTF-2 is a randomized, comparative, multi-center, investigator-initiated, interventional study aiming to test skull remodeling surgery in combination with Tumor Treating Fields therapy (TTFields) and best physicians choice medical oncological therapy for first recurrence in glioblastoma patients. OptimalTTF-2 is a phase 2 trial initiated in November 2020. Skull remodeling surgery consists of five burrholes, each 15 mm in diameter, directly over the tumor resection cavity. Preclinical research indicates that this procedure enhances the effect of Tumor Treating Fields considerably. We recently concluded a phase 1 safety/feasibility trial that indicated improved overall survival and no additional toxicity. This phase 2 trial aims to validate the efficacy of the proposed intervention. Methods The trial is designed as a comparative, 1:1 randomized, minimax two-stage phase 2 with an expected 70 patients to a maximum sample size of 84 patients. After 12-months follow-up of the first 52 patients, an interim futility analysis will be performed. The two trial arms will consist of either a) TTFields therapy combined with best physicians choice oncological treatment (control arm) or b) skull remodeling surgery, TTFields therapy and best practice oncology (interventional arm). Major eligibility criteria include age ≥ 18 years, 1st recurrence of supratentorial glioblastoma, Karnofsky performance score ≥ 70, focal tumor, and lack of significant co-morbidity. Study design aims to detect a 20% increase in overall survival after 12 months (OS12), assuming OS12 = 40% in the control group and OS12 = 60% in the intervention group. Secondary endpoints include hazard rate ratio of overall survival and progression-free survival, objective tumor response rate, quality of life, KPS, steroid dose, and toxicity. Toxicity, objective tumor response rate, and QoL will be assessed every 3rd month. Endpoint data will be collected at the end of the trial, including the occurrence of suspected unexpected serious adverse reactions (SUSARs), unacceptable serious adverse events (SAEs), withdrawal of consent, or loss-to-follow-up. Discussion New treatment modalities are highly needed for first recurrence glioblastoma. Our proposed treatment modality of skull remodeling surgery, Tumor Treating Fields, and best practice medical oncological therapy may increase overall survival significantly. Trial registration ClinicalTrials.gov Identifier: NCT0422399 , registered 13. January 2020

A comparative study of palladium-gold and palladium-tin catalysts in the direct synthesis of H2O2

Herein we evaluate the promotive effect of Au and Sn incorporation into supported Pd nanoparticles for the direct synthesis of H2O2 from molecular H2 and O2. The introduction of both secondary metal modifiers was found to result in a significant enhancement in catalytic performance, although, in the case of the PdSn system, it was identified that relatively large quantities of the secondary metal were required to rival the activity observed over optimal Au-containing formulations, with the 0.25%Pd-2.25%Sn/TiO2 catalyst offering comparable H2O2 synthesis rates to the optimised 0.25%Pd-0.25%Au/TiO2 formulation. The introduction of Sn was found to considerably improve Pd dispersion, correlating with an improvement in selective H2 utilisation. Notably, the optimal PdSn catalyst identified in this work achieves superior H2O2 selectivities compared to the PdAu analogue and is able to rival the performance of state-of-the-art materials

Alternaria Spores in the Air Across Europe: Abundance, Seasonality and Relationships with Climate, Meteorology and Local Environment

We explored the temporal and spatial variations in airborne Alternaria spore quantitative and phenological features in Europe using 23 sites with annual time series between 3 and 15 years. The study covers seven countries and four of the main biogeographical regions in Europe. The observations were obtained with Hirst-type spore traps providing time series with daily records. Site locations extend from Spain in the south to Denmark in the north and from England in the West to Poland in the East. The study is therefore the largest assessment ever carried out for Europe concerning Alternaria. Aerobiological data were investigated for temporal and spatial patterns in their start and peak season dates and their spore indices. Moreover, the effects of climate were checked using meteorological data for the same period, using a crop growth model. We found that local climate, vegetation patterns and management of landscape are governing parameters for the overall spore concentration, while the annual variations caused by weather are of secondary importance but should not be neglected. The start of the Alternaria spore season varies by several months in Europe, but the peak of the season is more synchronised in central northern Europe in the middle of the summer, while many southern sites have peak dates either earlier or later than northern Europe. The use of a crop growth model to explain the start and peak of season suggests that such methods could be useful to describe Alternaria seasonality in areas with no available observations