Environmental pollution by pharmaceuticals is increasingly recognized as a major threat to aquatic ecosystems worldwide. A variety of pharmaceuticals enter waterways by way of treated wastewater ...effluents and remain biochemically active in aquatic systems. Several ecotoxicological studies have been done, but generally, little is known about the ecological effects of pharmaceuticals. Here we show that a benzodiazepine anxiolytic drug (oxazepam) alters behavior and feeding rate of wild European perch (Perca fluviatilis) at concentrations encountered in effluent-influenced surface waters. Individuals exposed to water with dilute drug concentrations (1.8 micrograms liter -1 ) exhibited increased activity, reduced sociality, and higher feeding rate. As such, our results show that anxiolytic drugs in surface waters alter animal behaviors that are known to have ecological and evolutionary consequences.
Long-distance migratory species can reduce mortality risks by synchronizing the migration event and create confusion by swamping predators with high densities. To reduce confusion, predators are ...known to primarily select aberrant prey. We hypothesized that at the start of their sea sojourn, particularly small and large Atlantic salmon (Salmo salar L., 1758) would spread the risk by also migrating at other times of the year. Based on data from the Norwegian river Imsa between 1976 and 2015, we found that juveniles, 14–19 cm in total length, started their sea sojourn during a short period between late April and early June. However, more than 20% of fish 13 cm or shorter migrated downstream between October and March, whereas 55% of fish 20 cm or longer migrated downstream between July and September. The regular-sized, spring-migrating juveniles had 2–3 times higher survival at sea than similar-sized conspecifics migrating to sea at other times of the year. The survival at sea for smaller juveniles was not improved by migration in spring relative to winter, and the survival of the largest juveniles was similar in spring and summer. Thus, the migration phenology appears adapted to survival in a high-risk environment by changing the timing according to their sizes.
Ionic thermoelectric supercapacitors Zhao, D; Wang, H; Khan, Z U ...
Energy & environmental science,
01/2016, Letnik:
9, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Temperature gradients are generated by the sun and a vast array of technologies and can induce molecular concentration gradients in solutions via thermodiffusion (Soret effect). For ions, this leads ...to a thermovoltage that is determined by the thermal gradient Delta T across the electrolyte, together with the ionic Seebeck coefficient alpha i. So far, redox-free electrolytes have been poorly explored in thermoelectric applications due to a lack of strategies to harvest the energy from the Soret effect. Here, we report the conversion of heat into stored charge via a remarkably strong ionic Soret effect in a polymeric electrolyte (Seebeck coefficients as high as alpha i = 10 mV K-1). The ionic thermoelectric supercapacitor (ITESC) is charged under a temperature gradient. After the temperature gradient is removed, the stored electrical energy can be delivered to an external circuit. This new means to harvest energy is particularly suitable for intermittent heat sources like the sun. We show that the stored electrical energy of the ITESC is proportional to ( Delta T alpha i)2. The resulting ITESC can convert and store several thousand times more energy compared with a traditional thermoelectric generator connected in series with a supercapacitor.
Summary
Healthcare workers involved in aerosol‐generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID‐19. However, the magnitude of this risk is unknown. We ...conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID‐19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self‐reporting. The primary endpoint was the incidence of laboratory‐confirmed COVID‐19 diagnosis or new symptoms requiring self‐isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure‐related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR range) follow‐up of 32 (18–48 0–116) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID‐19 subsequently reported a COVID‐19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID‐19 transmission.
Summary
Transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE) can prolong apnoea time in adults. Therefore, THRIVE used for pre‐oxygenation in rapid sequence induction of anaesthesia ...could extend safe apnoea time during prolonged laryngoscopy and intubation. In this randomised controlled trial, we compared the lowest peripheral oxygen saturation (SpO2) during intubation when pre‐oxygenating with either traditional facemask or THRIVE. Eighty adult patients, undergoing rapid sequence induction of anaesthesia for emergency surgery, were randomly allocated to pre‐oxygenation with 100% oxygen with facemask or with THRIVE. Median (IQR range) lowest SpO2 until 1 min after intubation was 99% (97–100 70–100%) for the facemask group vs. 99% (99–100 96–100%) for the THRIVE group (p = 0.097). Five patients (12.5%) desaturated below 93% when pre‐oxygenated with the facemask vs. none in the THRIVE group (p = 0.019). There were no differences in intubation time or apnoea time between the groups. Median intubation time was 51 (34–66 22–261) s in the facemask group vs. 48 (38–63 10–146) s in the THRIVE group (p = 0.99). Median apnoea time was 109 (86–142 37–291) s and 116 (92–146 63–249) s when using facemask and THRIVE, respectively (p = 0.49). No signs of regurgitation of gastric content were detected. The data on desaturation indicate potential benefits of oxygenation with THRIVE for rapid sequence induction compared with facemask pre‐oxygenation.
Photoelectrochemical (PEC) water splitting is a promising technology that uses light absorbing semiconductors to convert solar energy directly into a chemical fuel (
i.e.
, hydrogen). PEC water ...splitting has the potential to become a key technology in achieving a sustainable society, if high solar to fuel energy conversion efficiencies are obtained with earth abundant materials. This review article discusses recent developments and discoveries in the mechanisms by which the localized surface plasmon resonance (LSPR) in metallic nanoparticles can increase or complement a neighbouring semiconductor in light absorption for catalytic water splitting applications. These mechanisms can mitigate the intrinsic optical limitations of semiconductors (
e.g.
, metal oxides) for efficient solar water splitting. We identify four types of enhancement mechanisms in the recent literature: (i) light scattering, (ii) light concentration, (iii) hot electron injection (HEI), and (iv) plasmon-induced resonance energy transfer (PIRET). (i) Light scattering and (ii) light concentration are light trapping mechanisms that can increase the absorption of light with energies above the semiconductor optical band-edge. These two mechanisms are ideal to enhance the absorption of promising semiconductors with narrow bandgap energies that suffer from limited absorption coefficients and bulk charge recombination. On the other hand, (iii) HEI and the recently discovered (iv) PIRET are mechanisms that can enhance the absorption also below the semiconductor optical band-edge. Therefore, HEI and PIRET have the potential to extend the light utilization to visible and near-infrared wavelengths of semiconductors with excellent electrochemical properties, but with large bandgap energies. New techniques and theories that have been developed to elucidate the above mentioned plasmonic mechanisms are presented and discussed for their application in metal oxide photoelectrodes. Finally, other plasmonic and non-plasmonic effects that do not increase the device absorption, but affect the electrochemical properties of the semiconductor (
e.g.
, charge carrier transport) are also discussed, since a complete understanding of these phenomena is fundamental for the design of an efficient plasmonic NP-semiconductor water splitting device.
Review of plasmonic nanoparticle effects on the semiconductors' light absorption, charge transfer and energetics for efficient solar water splitting.
Apnoeic oxygenation during anaesthesia has traditionally been limited by the rapid increase in carbon dioxide and subsequent decrease in pH. Using a Transnasal Humidified Rapid-Insufflation ...Ventilatory Exchange (THRIVE) technique a slower increase in carbon dioxide than earlier studies was seen. Notably, apnoeic oxygenation using THRIVE has not been systematically evaluated with arterial blood gases or in patients undergoing laryngeal surgery. The primary aim of this study was to characterize changes in arterial PO2, PCO2 and pH during apnoeic oxygenation using THRIVE under general anaesthesia.
Adult patients, (ASA I-II), undergoing shorter laryngeal surgery under general anaesthesia, were oxygenated during apnoea using THRIVE, 100% oxygen, 40–70 litres min−1. A cohort was randomized to hyperventilate during pre-oxygenation. Vital parameters and blood gases were monitored.
Thirty-one patients, age 51 (34–76) yr, BMI 25 (4) were included. Mean apnoea time was 22.5 (4.5) min. Patients were well oxygenated, SpO2 was never below 91%. The increase in PaCO2 and end-tidal CO2 during apnoea was 0.24 (0.05) and 0.12 (0.04) kPa min−1, respectively. Hyperventilation during pre-oxygenation generated no difference in PaCO2 at the end of apnoea compared with normoventilation.
This physiological study of apnoeic oxygenation using THRIVE during laryngeal surgery shows that this technique is able to keep patients with mild systemic disease and a BMI <30 well oxygenated for a period of up to 30 min. The THRIVE concept makes it possible to extend the apnoeic window but monitoring of CO2 and/or pH is recommended.
NCT02706431.
In this study, the probabilistic reaction norm was calculated for length at different ages of smolting before seaward migration of Atlantic salmon Salmo salar spawning in the Norwegian River Imsa. ...The reaction norm was compared with the optimal length at smolting estimated as the product of survival and female fecundity on the return, given their length at smolting. Logistic regression analysis on pre-migratory and migratory fish was used to estimate the probabilistic reaction norm. Length at 50% probability of smolting varied between 11.5 cm and 13.4 cm for age groups 1 to 3 yr with a minimum at Age-2. The estimated optimal length at smolting exhibited a maximum at 13.5 cm. Fecundity of adult females was not significantly affected by their length at smolting, making survival the chief variable influencing the optimal smolt size. The results lend support to the hypotheses that body length at 50% probability of seaward migration was similar for all smolt-age-groups independent of growth, and that mean length at each age of the young fish in fresh water reflected the probability of seaward migration. The slight difference between estimated optimal length at smolting and size at 50% probability of smolting may be chiefly caused by size dependent mortality at sea because of the tagging and larger pre-migratory mortality of young than older juveniles in the river. Thus, size appears crucially important for when to migrate.
Summary
Pre‐oxygenation using high‐flow nasal oxygen can decrease the risk of desaturation during rapid sequence induction in patients undergoing emergency surgery. Previous studies were ...single‐centre and often in limited settings. This randomised, international, multicentre trial compared high‐flow nasal oxygen with standard facemask pre‐oxygenation for rapid sequence induction in emergency surgery at all hours of the day and night. A total of 350 adult patients from six centres in Sweden and one in Switzerland undergoing emergency surgery where rapid sequence induction was required were included and randomly allocated to pre‐oxygenation with 100% oxygen using high‐flow nasal oxygen or a standard tight‐fitting facemask. The primary outcome was the number of patients developing oxygen saturations <93% from the start of pre‐oxygenation until 1 min after tracheal intubation. Data from 349 of 350 patients who entered the study were analysed (174 in the high‐flow nasal oxygen group and 175 in the facemask group). No difference was detected in the number of patients desaturating <93%, five (2.9%) vs. six (3.4%) patients in the high‐flow nasal oxygen and facemask group, respectively (p = 0.77). The risk of desaturation was not increased during on‐call hours. No difference was seen in end‐tidal carbon dioxide levels in the first breath after tracheal intubation or in the number of patients with signs of regurgitation between groups. These results confirm that high‐flow nasal oxygen maintains adequate oxygen levels during pre‐oxygenation for rapid sequence induction.
Pharmaceuticals derived from manufacturing and human consumption contaminate surface waters worldwide. To what extent such pharmaceutical contamination accumulates and disperses over time in ...different compartments of aquatic food webs is not well known. In this study we assess to what extent five pharmaceuticals (diphenhydramine, oxazepam, trimethoprim, diclofenac, and hydroxyzine) are taken up by fish (European perch) and four aquatic invertebrate taxa (damselfly larvae, mayfly larvae, waterlouse, and ramshorn snail), by tracing their bioconcentrations over several months in a semi-natural large-scale (pond) system. The results suggest both significant differences among drugs in their capacity to bioaccumulate and differences among species in uptake. While no support for in situ uptake of diclofenac and trimethoprim was found, oxazepam, diphenhydramine, and hydroxyzine were detected in all analyzed species. Here, the highest bioaccumulation factor (tissue:water ratio) was found for hydroxyzine. In the food web, the highest concentrations were found in the benthic species ramshorn snail and waterlouse, indicating that bottom-living organism at lower trophic positions are the prime receivers of the pharmaceuticals. In general, concentrations in the biota decreased over time in response to decreasing water concentrations. However, two interesting exceptions to this trend were noted. First, mayfly larvae (primarily grazers) showed peak concentrations (a fourfold increase) of oxazepam, diphenhydramine, and hydroxyzine about 30days after initial addition of pharmaceuticals. Second, perch (top-predator) showed an increase in concentrations of oxazepam throughout the study period. Our results show that drugs can remain bioavailable for aquatic organism for long time periods (weeks to months) and even re-enter the food web at a later time. As such, for an understanding of accumulation and dispersion of pharmaceuticals in aquatic food webs, detailed ecological knowledge is required.
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•A study of uptake of five pharmaceuticals by fish and four aquatic invertebrates•There are inter-specific differences in uptake of pharmaceuticals.•Highest concentrations were found for the benthic species.•Important to not only consider waterborne exposure in risk assessments•Important to include organisms from different trophic levels in risk assessments
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