Every breath you take: High concentration of breathable microplastics in indoor environments.

The widespread presence of microplastics (MPs) in the air and their potential impact on human health underscore the pressing need to develop robust methods for quantifying their presence, particularly in the breathable fraction (<5 µm). In this study, Raman micro-spectroscopy (µRaman) was employed to assess the concentration of indoor airborne MPs >1 µm in four indoor environments (a meeting room, a workshop, and two apartments) under different levels of human activity. The indoor airborne MP concentration spanned between 58 and 684 MPs per cubic meter (MP m-3) (median 212 MP m-3, MPs/non-plastic ratio 0-1.6%), depending not only on the type and level of human activity, but also on the surface area and air circulation of the investigated locations. Additionally, we assessed in the same environments the filtration performance of a type IIR surgical facemask, which could overall retain 85.4 ± 3.9% of the MPs. We furthermore estimated a human MP intake from indoor air of 3415 ± 2881 MPs day-1 (mostly poly-amide MPs), which could be decreased to 283 ± 317 MPs day-1 using the surgical facemask. However, for the breathable fraction of MPs (1-5 µm), the efficiency of the surgical mask was reduced to 57.6%.

"What matters to you" on the day of surgery: Protocol for a mixed methods study.

BACKGROUND: The anticipation of anesthesia and surgery is the source of fear and anxiety in millions of patients worldwide. Although patients' fear and anxiety are recognized, more knowledge is needed to address patient responses and needs. Understanding the needs of the patients are important, and asking patients directly is the first step towards addressing these needs. This again might help reducing medications such as anesthetics and postoperative pain relief. The aim of this study protocol is to describe how we will investigate what matters to patients on the day of surgery, as well as their degree-of-worry and surgical fear. METHODS: Using a convergent mixed methods design with equal weighting of the qualitative and quantitative data strand we take advantage of the international "What Matters To You" Day on June 6, 2024 to conduct a flash mob study. We will approach perioperative departments around Denmark to participate and eligible patients arriving to the perioperative department for surgery will be invited to participate. Consenting patients are asked to complete a survey in three parts regarding (1) what matters to you, (2) degree-of-worry, and (3) surgical fear. We will use qualitative analysis for the first part and descriptive statistics for second and third parts. The data strands will be analyzed separately followed by integrated analysis and joint displays.

Cascades of Parametric Instabilities in the Tokamak Plasma Edge during Electron Cyclotron Resonance Heating.

We report observations of nonlinear two-plasmon decay instabilities (TPDIs) of a high-power microwave beam, a process similar to half-harmonic generation in optics, during electron cyclotron resonance heating in a tokamak. TPDIs are found to occur regularly in the plasma edge due to wave trapping in density fluctuations for various confinement modes, and the frequencies of both observed daughter waves agree with modeling. Emissions from a cascade of subsequent decays, which indicate a generation of ion Bernstein waves, are correlated with fast-ion generation. This emphasizes the limitations of standard linear microwave propagation models and possibly paves the way for novel microwave applications in plasmas.

It matters how we measure - Quantification of microplastics in drinking water by µFTIR and µRaman.

The water treatment for microplastics (MP) at a Danish groundwater-based waterworks was assessed by Fourier-Transform IR micro-spectroscopy (µFTIR) (nominal size limit 6.6 µm) and compared to results from Raman micro-spectroscopy (µRaman) (nominal size limit 1.0 µm) on the same sample set. The MP abundance at the waterworks' inlet and outlet was quantified as MP counts per cubic metre (N/m3) and estimated MP mass per cubic metre (µg/m3). The waterworks' MP removal efficiency was found to be higher when analysing by µFTIR (counts: 78.14 ± 49.70%, mass: 98.73 ± 11.10%) and less fluctuating than when using µRaman (counts: 43.2%, mass: 75.1%). However, both techniques pointed to a value of ∼80% for the counts' removal efficiency of MPs >6.6 µm. Contrarily to what was shown by µRaman, no systematic leaking of MPs from the plastic elements of the facility could be identified for the µFTIR dataset, either from the counts (inlet 31.86 ± 17.17 N/m3, outlet 4.98 ± 2.09 N/m3) or mass estimate (inlet 76.30 ± 106.30 µg/m3, outlet 2.81 ± 2.78 µg/m3). The estimation of human MP intake from drinking water calculated from the µFTIR data (5 N/(year·capita)) proved to be approximately 332 times lower than that calculated from the µRaman dataset, although in line with previous studies employing µFTIR. By merging the MP length datasets from the two techniques, it could be shown that false negatives became prevalent in the µFTIR dataset already below 50 µm. Further, by fitting the overall frequency of the MP length ranges with a power function, it could be shown that µFTIR missed approximately 95.7% of the extrapolated MP population (1-1865.9 µm). Consequently, relying on only µFTIR may have led to underestimating the MP content of the investigated drinking water, as most of the 1-50 µm MP would have been missed.

Effect of initiating biologics compared to intensifying conventional DMARDs on clinical and MRI outcomes in established rheumatoid arthritis patients in clinical remission: Secondary analyses of the IMAGINE-RA trial.

OBJECTIVES: To compare the effect of treat-to-target-based escalations in conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and biologics on clinical disease activity and magnetic resonance imaging (MRI) inflammation in a rheumatoid arthritis (RA) cohort in clinical remission. METHOD: One-hundred patients with established RA, Disease Activity Score based on 28-joint count-C-reactive protein (DAS28-CRP) < 3.2, and no swollen joints (hereafter referred to as 'in clinical remission') who received csDMARDs underwent clinical evaluation and MRI of the wrist and second to fifth metacarpophalangeal joints every 4 months. They followed a 2 year MRI treatment strategy targeting DAS28-CRP ≤ 3.2, no swollen joints, and absence of MRI osteitis, with predefined algorithmic treatment escalation: first: increase in csDMARDs; second: adding a biologic; third: switch biologic. MRI osteitis and Health Assessment Questionnaire (HAQ) (co-primary outcomes) and MRI combined inflammation and Simplified Disease Activity Index (SDAI) (key secondary outcomes) were assessed 4 months after treatment change and expressed as estimates of group differences. Statistical analyses were based on the intention-to-treat population analysed using repeated-measures mixed models. RESULTS: Escalation to first biologic compared to csDMARD escalation more effectively reduced MRI osteitis (difference between least squares means 1.8, 95% confidence interval 1.0-2.6), HAQ score (0.08, 0.03-0.1), MRI combined inflammation (2.5, 0.9-4.1), and SDAI scores (2.7, 1.9-3.5). CONCLUSIONS: Treat-to-target-based treatment escalations to biologics compared to escalation in csDMARDs more effectively improved MRI inflammation, physical function, and clinical disease activity in patients with established RA in clinical remission. Treatment escalation in RA patients in clinical remission reduces clinical and MRI-assessed disease activity. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01656278.

Low-to-High Confinement Transition Mediated by Turbulence Radial Wave Number Spectral Shift in a Fusion Plasma.

A new model for the low-to-high (L-H) confinement transition has been developed based on a new paradigm for turbulence suppression by velocity shear [G. M. Staebler et al., Phys. Rev. Lett. 110, 055003 (2013)]. The model indicates that the L-H transition can be mediated by a shift in the radial wave number spectrum of turbulence, as evidenced here, for the first time, by the direct observation of a turbulence radial wave number spectral shift and turbulence structure tilting prior to the L-H transition at tokamak edge by direct probing. This new mechanism does not require a pretransition overshoot in the turbulent Reynolds stress, shunting turbulence energy to zonal flows for turbulence suppression as demonstrated in the experiment.

New edge coherent mode providing continuous transport in long-pulse H-mode plasmas.

An electrostatic coherent mode near the electron diamagnetic frequency (20-90 kHz) is observed in the steep-gradient pedestal region of long pulse H-mode plasmas in the Experimental Advanced Superconducting Tokamak, using a newly developed dual gas-puff-imaging system and diamond-coated reciprocating probes. The mode propagates in the electron diamagnetic direction in the plasma frame with poloidal wavelength of ∼8 cm. The mode drives a significant outflow of particles and heat as measured directly with the probes, thus greatly facilitating long pulse H-mode sustainment. This mode shows the nature of dissipative trapped electron mode, as evidenced by gyrokinetic turbulence simulations.

Kinetics of aerobic oxidation of volatile sulfur compounds in wastewater and biofilm from sewers.

Laboratory experiments were conducted to investigate the kinetics of aerobic chemical and biological oxidation of selected odorous volatile sulfur compounds (VSCs) by wastewater and biofilm from sewers. The VSCs included methyl mercaptan (MeSH), ethyl mercaptan (EtSH), dimethyl sulfide (DMS) and total inorganic sulfide, which have all been reported as the main constituents of foul sewer gas. Samples of wastewater and biofilm for the experiments were obtained from two locations that differed significantly with respect to the occurrence of VSCs. One location represented an odor hot-spot downstream of a force main and the other was a gravity sewer transporting young aerobic wastewater. The kinetics of VSC oxidation for both wastewater and suspended biofilm samples followed a first-order rate equation. The average values of the reaction rate constants demonstrated the following order of reactivity: total inorganic sulfide > EtSH ≥ MeSH >> DMS. Except for total inorganic sulfide oxidation in wastewater, kinetic parameters for each VSC were of similar magnitude for the two locations. In the wastewater from the odor hot-spot, sulfide inorganic oxidation rates were approximately 12 times faster than in the aerobic wastewater.

A method for on-line measurement of wastewater organic substrate oxidation level during aerobic heterotrophic respiration.

A method for on-line measurement of the organic carbon oxidation level (OXC) during aerobic heterotrophic respiration in domestic wastewater was developed and tested. The method is based on batch incubation of sewer wastewater in an intermittently aerated respirometric reactor. Between aeration cycles, measured pH, dissolved oxygen (DO) and dissolved carbon dioxide (CO2) were used to calculate electron flow accepted by DO and the resulting production of dissolved inorganic carbon (DIC). The CO2 production was measured using a novel fiber-optic sensor based on luminescence quenching. The method was tested on domestic wastewater with a relatively high pH and alkalinity. From the DO and DIC measurements, it was possible to evaluate substrate oxidation levels with a temporal resolution of less than an hour. Addition of organic substrates during the experiments confirmed the method's applicability. The substrates tested included ethanol (OXC = -2), glucose (OXC = 0) and oxalic acid (OXC = 3).

A sewer process model as planning and management tool--hydrogen sulfide simulation at catchment scale.

The collection system of a major city at the Persian Gulf was simulated for bulk water hydrogen sulfide and the release of sewer gas to the urban atmosphere. Geometry data on 870 km of sanitary sewer and data on dry weather flow entering all nodes in the catchment was exported from a Mike Urban database and imported to the sewer process model WATS. The process model then routed sewage and sewer gas through the system and simulated relevant physical, chemical and biological processes. In its non-calibrated state, the model was used as a planning tool to identify problem areas and to identify locations to install monitoring equipment and make preliminary choices for control strategies in terms of dosing of nitrate and iron salts. The monitoring equipment consisted of flow meters, level gauges, UV-Vis spectroscopes, and H2S gas sensors. Data from the first set of installed monitoring equipment were applied to calibrate and validate the model. It was illustrated how the calibrated model can be applied to assess compliance with quantitative formulated service levels and to design control strategies in terms of dosing of iron and nitrate salts.

Heavy metals, PAHs and toxicity in stormwater wet detention ponds.

Concentrations of 6 different heavy metals and total polycyclic aromatic hydrocarbons (PAHs) were determined in stormwater runoff and in the pond water of two Danish wet detention ponds. The pond water samples were analyzed for toxic effects, using the algae Selenastrum capricornutum as a test organism. Stormwater and pond water from a catchment with light industry showed high levels of heavy metals, especially zinc and copper. The pond water showed high toxic effects and copper were found to be the main toxicant. Additionally, a large part of the copper was suspected to be complex bound, reducing the potential toxicity of the metal. Another catchment (residential) produced stormwater and pond water with moderate concentration of heavy metals. The pond water occasionally showed toxic effects but no correlation between heavy metals and toxicity was identified. PAHs concentrations were for both catchments low and no correlations between PAH concentrations in the pond and toxicity were found.

Hydrogen sulphide removal from corroding concrete: comparison between surface removal rates and biomass activity.

Corrosion of concrete sewer pipes caused by hydrogen sulphide is a problem in many sewer networks. The mechanisms of production and fate of hydrogen sulphide in the sewer biofilms and wastewater as well as its release to the sewer atmosphere are largely understood. In contrast, the mechanisms of the uptake of hydrogen sulphide on the concrete surfaces and subsequent concrete corrosion are basically unknown. To shed light on these mechanisms, the uptake of hydrogen sulphide from a sewer gas phase was compared to the biological hydrogen sulphide removal potential of the concrete corrosion products. The results showed that both microbial degradation at and sorption to the concrete surfaces were important for the uptake of hydrogen sulphide on the concrete surfaces.

Monitoring the startup of a wet detention pond equipped with sand filters and sorption filters.

The startup of a wet retention pond designed for extended stormwater treatment was monitored by more than one year of continual measurement of hydraulic parameters, nutrients and quality parameters in the pond itself (pH, temperature, dissolved oxygen, turbidity). The data revealed that photosynthesis played an important role for dissolved oxygen and pH for most of the year. Another important observation was that the pond behaved more like a completely mixed reactor than like a plug flow reactor--even though the length to width ratio was as high as 4.5:1. The pond was equipped with sand filters and sorption filters whereby very good nutrient removal efficiencies were achieved.

Survival of hydrogen sulfide oxidizing bacteria on corroded concrete surfaces of sewer systems.

The activity of hydrogen sulfide oxidizing bacteria within corroded concrete from a sewer manhole was investigated. The bacteria were exposed to hydrogen sulfide starvation for up till 18 months, upon which their hydrogen sulfide oxidizing activity was measured. It was tested whether the observed reduction in biological activity was caused by a biological lag phase or by decay of the bacteria. The results showed that the bacterial activity declined with approximately 40% pr. month during the first two months of hydrogen sulfide starvation. After 2-3 months of starvation, the activity stabilized. Even after 6 months of starvation, exposure to hydrogen sulfide for 6 hours a day on three successive days could restore the bacteriological activity to about 80% of the initial activity. After 12 months of starvation, the activity could, however, not be restored, and after 18 months the biological activity approached zero. The long-term survival aspect of concrete corroding bacteria has implications for predicting hydrogen sulfide corrosion in sewer systems subject to irregular hydrogen sulfide loadings, e.g. as they occur in temperate climates where hydrogen sulfide often is a summer-problem only.

Recent findings on sinks for sulfide in gravity sewer networks.

Sulfide buildup in sewer networks is associated with several problems, including health impacts, corrosion of sewer structures and odor nuisance. In recent years, significant advances in the knowledge of the major processes governing sulfide buildup in sewer networks have been made. This paper summarizes this newly obtained knowledge and emphasizes important implications of the findings. Model simulations of the in-sewer processes important for the sulfur cycle showed that sulfide oxidation in the wetted biofilm is typically the most important sink for dissolved sulfide in gravity sewers. However, sulfide emission and thereby potential hydrogen sulfide buildup in the sewer atmosphere is of particular importance in sewers constructed with large diameter pipes, in sewers constructed with steep slopes and in sewers conveying low pH wastewater. Precipitation of metal sulfides is only important when the sulfide concentration in the wastewater is low; i.e. less than 1 g Sm(-3).

Pulse-wave morphology and pulse-wave velocity in healthy human volunteers: examination conditions.

OBJECTIVE: Applanation tonometry for pulse-wave analysis (PWA) and determination of pulse-wave velocity (PWV) is a non-invasive method for assessment of the central aortic pressure waveform and indices of arterial stiffness. The objective of this study was to examine the influence of eating and smoking on PWA and PWV measurements in order to establish standard examination conditions. Furthermore, intra- and interobserver reproducibility and the effects of varying the site of measurements were observed. MATERIAL AND METHODS: Duplicate measurements of the radial pressure waveform and of the brachial and aortic PWV on the right and left side of the body were recorded in 23 healthy subjects by two trained observers. Measurements were performed in the fasting state and 3 h after a high-calorie meal, and before and 1 h after smoking a cigarette. RESULTS: Intake of a high-calorie meal as well as smoking caused significant changes in both PWA and PWV parameters and an inter-arm difference was observed. Intra- and interobserver reproducibility was good. CONCLUSIONS: Pulse-wave measurements by applanation tonometry should be undertaken in the same arm during fasting and smoking abstinence.

The uremic environment and muscle dysfunction in man and rat.

BACKGROUND: Patients reaching end-stage renal disease experience debilitating fatigue, with progression of this disease, rendering patients dysfunctional in their everyday lives. METHODS: In vivo measurements of muscle function, assessed using surface electromyography (EMG), were made on 25 patients prior to and after a session of hemodialysis (HD) treatment, along side in vitro measurements of muscle function in isolated rat muscles incubated in normal or uremic conditions approximating to those found in uremic rats (rat uremic: RU) or uremic humans (human uremic: HU). RESULTS: HD significantly affected plasma values, e.g. reducing urea (69%), creatinine (62%), potassium (23%) and phosphate (48%) concentrations in patients (all p < 0.01). Treatment also improved the EMG frequency of 2nd dorsal interosseous (fast-twitch) (p < 0.01), although no change was noted for vastus lateralis (slow-twitch). In isolated rat muscles, a uremic environment had no significant effect on slow-twitch soleus during field stimulation, however, in fast-twitch extensor digitorum longus, a significant 23% (RU) and 22% (HU) faster rate of decline in force was measured, compared to controls (p < 0.001 and p < 0.01, respectively). CONCLUSION: It is concluded that (1) muscle weakness and its electrophysiological correlates may be rapidly induced by uremic solutes and rapidly reversed when the solutes are removed by dialysis, and (2) fast-twitch muscles are more readily affected by uremic conditions than slow-twitch muscles.

Effects of in-sewer processes: a stochastic model approach.

Transformations of organic matter, nitrogen and sulfur in sewers can be simulated taking into account the relevant transformation and transport processes. One objective of such simulation is the assessment and management of hydrogen sulfide formation and corrosion. Sulfide is formed in the biofilms and sediments of the water phase, but corrosion occurs on the moist surfaces of the sewer gas phase. Consequently, both phases and the transport of volatile substances between these phases must be included. Furthermore, wastewater composition and transformations in sewers are complex and subject to high, natural variability. This paper presents the latest developments of the WATS model concept, allowing integrated aerobic, anoxic and anaerobic simulation of the water phase and of gas phase processes. The resulting model is complex and with high parameter variability. An example applying stochastic modeling shows how this complexity and variability can be taken into account.

Simulation of sulfide buildup in wastewater and atmosphere of sewer networks.

A model concept for prediction of sulfide buildup in sewer networks is presented. The model concept is an extension to--and a further development of--the WATS model (Wastewater Aerobic-anaerobic Transformations in Sewers), which has been developed by Hvitved-Jacobsen and co-workers at Aalborg University. In addition to the sulfur cycle, the WATS model simulates changes in dissolved oxygen and carbon fractions of different biodegradability. The sulfur cycle was introduced via six processes: 1. sulfide production taking place in the biofilm covering the permanently wetted sewer walls; 2. biological sulfide oxidation in the permanently wetted biofilm; 3. chemical and biological sulfide oxidation in the water phase; 4. sulfide precipitation with metals present in the wastewater; 5. emission of hydrogen sulfide to the sewer atmosphere and 6. adsorption and oxidation of hydrogen sulfide on the moist sewer walls where concrete corrosion may take place.

Computations of intermittent transport in scrape-off layer plasmas.

Two-dimensional fluid simulations of interchange turbulence for geometry and parameters relevant for the scrape-off layer of magnetized plasmas are presented. The computations, which have distinct plasma production and loss regions, reveal bursty ejection of particles and heat from the bulk plasma in the form of blobs. These structures propagate far into the scrape-off layer where they are dissipated due to transport along open magnetic field lines. From single-point recordings it is shown that the blobs have asymmetric conditional wave forms and lead to positively skewed and flattened probability distribution functions. The radial propagation velocity may reach one-tenth of the sound speed. These results are in excellent agreement with recent experimental measurements.