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Air quality observations are performed globally to monitor the status of the atmosphere and its level of pollution and to assess mitigation strategies. Regulations of air quality monitoring programmes in various countries demand high-precision measurements for harmful substances often at low trace concentrations. These requirements can only be achieved by using high-quality calibration gases including high-purity zero gas. For volatile organic compound (VOC) observations, zero gas is defined as being hydrocarbon-free and can be, for example, purified air, nitrogen or helium. It is essential for the characterisation of the measurement devices and procedures, for instrument operation as well as for calibrations. Two commercial and one self-built gas purifiers were tested for their VOC removal efficiency following a standardised procedure. The tested gas purifiers included one adsorption cartridge with an inorganic media and two types of metal catalysts. A large range of VOCs were investigated, including the most abundant species typically measured at air monitoring stations. Both catalysts were able to remove a large range of VOCs whilst the tested adsorption cartridge was not suitable to remove light compounds up to C4. Memory effects occurred for the adsorption cartridge when exposed to higher concentration. This study emphasises the importance of explicitly examining a gas purifier for its intended application before applying it in the field.

In cystic fibrosis (CF), the paranasal sinuses are sites of first and persistent colonization by pathogens such as Pseudomonas aeruginosa. Pathogens subsequently descend to the lower airways, with P. aeruginosa remaining the primary cause of premature death in patients with the inherited disease. Unlike conventional aerosols, vibrating aerosols applied with the PARI Sinus™ nebulizer deposit drugs into the paranasal sinuses. This trial assessed the effects of vibrating sinonasal inhalation of the antibiotic tobramycin in CF patients positive for P. aeruginosa in nasal lavage. To evaluate the effects of sinonasal inhalation of tobramycin on P. aeruginosa quantification in nasal lavage; and on patient quality of life, measured with the Sino-Nasal Outcome Test (SNOT-20), and otologic and renal safety and tolerability. Patients were randomized to inhalation of tobramycin (80 mg/2 mL) or placebo (2 mL isotonic saline) once daily (4 minutes/nostril) with the PARI Sinus™ nebulizer over 28 days, with all patients eligible for a subsequent course of open-label inhalation of tobramycin for 28 days. Nasal lavage was obtained before starting and 2 days after the end of each treatment period by rinsing each nostril with 10 mL of isotonic saline. Nine patients participated, six initially receiving tobramycin and three placebo. Sinonasal inhalation was well tolerated, with serum tobramycin <0.5 mg/L and stable creatinine. P. aeruginosa quantity decreased in four of six (67%) patients given tobramycin, compared with zero of three given placebo (non-significant). SNOT-20 scores were significantly lower in the tobramycin than in the placebo group (P=0.033). Sinonasal inhalation of vibrating antibiotic aerosols appears promising for reducing pathogen colonization of paranasal sinuses and for control of symptoms in patients with CF.

Objectives To assess the agreement in evaluating optical coherence tomography (OCT) variables in the leading macular diseases such as neovascular age-related macular degeneration (nAMD), diabetic macular oedema (DMO) and retinal vein occlusion (RVO) among OCT-certified graders. Methods SD-OCT volume scans of 356 eyes were graded by seven graders. The grading included presence of intra- and subretinal fluid (IRF, SRF), pigment epithelial detachment (PED), epiretinal membrane (ERM), conditions of the vitreomacular interface (VMI), central retinal thickness (CRT) at the foveal centre-point (CP) and central millimetre (CMM), as well as height and location of IRF/SRF/PED. Kappa statistics (κ) and intraclass correlation coefficient (ICC) were used to report categorical grading and measurement agreement. Results The overall agreement on the presence of IRF/SRF/PED was κ = 0.82/0.85/0.81; κ of VMI condition was 0.77, that of ERM presence 0.37. ICC for CRT measurements at CP and CMM was excellent with an ICC of 1.00. Height measurements of IRF/SRF/PED showed robust consistency with ICC = 0.85–0.93. There was substantial to almost perfect agreement in locating IRF/SRF/PED with κ = 0.67–0.86. Between diseases, κ of IRF/SRF presence was 0.69/0.80 for nAMD, 0.64/0.83 for DMO and 0.86/0.89 for RVO. Conclusion Even in the optimized setting, featuring certified graders, standardized image acquisition and the use of a professional reading platform, there is a disease dependent variability in biomarker evaluation that is most pronounced for IRF in nAMD as well as DMO. Our findings highlight the variability in the performance of human expert OCT grading and the need for AI-based automated feature analyses.

Introduction Cortical vein thrombosis (CVT) is a rare disorder, and its diagnosis is challenging. The aim of our study was to evaluate the value of different imaging modalities for the detection of CVT. Methods Thirteen patients with CVT, either isolated ( n  = 3) or in combination with sinus thrombosis ( n  = 10), and 20 control patients without any venous pathologies were included in this study. The analysis was performed independently by three blinded readers who evaluated the following imaging modalities and sequences separately: non-enhanced computed tomography (NCCT); multi-detector row CT angiography (MDCTA); diffusion-weighted (DWI), T1-weighted (T1w), PD-weighted (PDw), T2*-weighted (T2*w), and fluid-attenuated inversion recovery-weighted (FLAIRw) magnetic resonance (MR) sequences; as well as venous MR angiography (vMRA). The sensitivity, specificity, positive (PPV) and negative predictive values, and interobserver agreement of the different modalities were calculated. Results T2*w showed the highest sensitivity for the detection of CVT (97.4%), followed by T1w (70%). FLAIRw and vMRA had a sensitivity of 50% and 41.7%, respectively, whereas the sensitivity of NCCT, MDCTA, DWI, and PDw was below 30%. The specificity and PPV of all modalities was 100%, with good to perfect interobserver agreement. Conclusion T2*w was the superior MR imaging sequence for diagnosing CVT. Besides T2*w, only T1w reached a sensitivity of over 50% for CVT, followed by FLAIRw, and vMRA. On the contrary, our results suggest that NCCT but also MDCTA might not be suitable for diagnosing CVT.