Hypercrosslinked materials

This chapter describes the chemistry of hypercrosslinked materials, and presents a description of their synthesis, defining physico-chemical features and their most important applications. The synthesis section will examine the different monomers, precursor polymers, reagents and synthetic strategies used to prepare hypercrosslinked materials. Each synthesis section also details the chemical and morphological properties of the hypercrosslinked materials and the main field of application

Hypercrosslinked materials : preparation, characterisation and applications

This review article provides an overview of hypercrosslinking technology. In particular, it covers the preparation and characterisation of hypercrosslinked materials and their applications. The synthesis section examines the different monomers, precursor polymers and reagents used to prepare hypercrosslinked materials, but also the different synthetic approaches disclosed in the literature. The various chemical modification reactions relevant to this area are also reviewed. Several examples of applications for hypercrosslinked materials are described; these applications are grouped into thematic areas such as chromatography, gas storage and the trapping of organic contaminants

Core-shell polymer microspheres with strong cation-exchange character for the extraction of basic pharmaceuticals from aqueous samples

The application of core-shell materials as packing materials for liquid chromatography columns is common in analytical chemistry, however their use as sorbents in solid-phase extraction (SPE) is surprisingly underexplored. In the present study, core-shell polymer microspheres with strong cation-exchange character were designed and synthesized. These new materials benefit from having hypercrosslinked and relatively thin functional shells, which raises the specific surface areas and sorption capacities of the sorbents and allows for relatively shorter diffusion path lengths for analytes. The core-shell polymer microspheres were evaluated as SPE sorbents for the extraction of basic pharmaceuticals from environmental water samples. Following optimization of the pH and volume of the loading solution, as well as optimization of the loading step, the SPE method was validated in terms of apparent and relative recoveries, matrix effect, limits of detection and quantification and precision. The method yielded very promising results in terms of apparent recoveries (>39%) and matrix effect (<±29%) and was applied successfully to the determination of basic pharmaceuticals in environmental water samples (river water, effluent wastewater and influent wastewater)

Sources of skill in lake temperature, discharge and ice-off seasonal forecasting tools

Despite high potential benefits, the development of seasonal forecasting tools in the water sector has been slower than in other sectors. Here we assess the skill of seasonal forecasting tools for lakes and reservoirs set up at four sites in Australia and Europe. These tools consist of coupled hydrological catchment and lake models forced with seasonal meteorological forecast ensembles to provide probabilistic predictions of seasonal anomalies in water discharge, temperature and ice-off. Successful implementation requires a rigorous assessment of the tools' predictive skill and an apportionment of the predictability between legacy effects and input forcing data. To this end, models were forced with two meteorological datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF), the seasonal forecasting system, SEAS5, with 3-month lead times and the ERA5 reanalysis. Historical skill was assessed by comparing both model outputs, i.e. seasonal lake hindcasts (forced with SEAS5), and pseudo-observations (forced with ERA5). The skill of the seasonal lake hindcasts was generally low although higher than the reference hindcasts, i.e. pseudo-observations, at some sites for certain combinations of season and variable. The SEAS5 meteorological predictions showed less skill than the lake hindcasts. In fact, skilful lake hindcasts identified for selected seasons and variables were not always synchronous with skilful SEAS5 meteorological hindcasts, raising questions on the source of the predictability. A set of sensitivity analyses showed that most of the forecasting skill originates from legacy effects, although during winter and spring in Norway some skill was coming from SEAS5 over the 3-month target season. When SEAS5 hindcasts were skilful, additional predictive skill originates from the interaction between legacy and SEAS5 skill. We conclude that lake forecasts forced with an ensemble of boundary conditions resampled from historical meteorology are currently likely to yield higher-quality forecasts in most cases.</p

ESAR-Net: a collaborative effort to expand the application of wastewater epidemiology in Spain

Resumen del trabajo presentado en el SETAC Europe 30th Annual Meeting, celebrado en modalidad virtual del 3 al 7 de mayo de 2020.Data obtained from wastewater analysis can provide rapid and complementary insights in illict drug consumption at community level. Drug use has been assessed through wastewater analysis at national level in, for example, Australia, Belgium, Finland and South Korea and has also provided annually a one week snapshot of illicit drug volumes consumed in European cities (http://www.emcdda.europa.eu/topics/ pods/waste-water-analysis). However, a wastewater monitoring program did not exist in Spain, but leading experts have formed a network (https://www.esarnet.es/) to promote wastewater-based epidemiology at national level and communicate their findings to authorities and policymakers. Within Europe, Spain is an important country of transit of both cocaine and cannabis, due to its cultural, linguistic and colonial ties to Latin America and its proximity to Morocco. The quantity of seized cocaine and cannabis and prevalence of use, locates Spain at the top of Europe. In this work, a national wastewater campaign has been performed to get more insight on the consumption of illicit drugs and NPS within Spain for the first time. Wastewater results from 14 Spanish cities were compared with previously reported data and other national indicators. The cities, located in 7 of the 17 autonomous communities, cover approximately 6 million inhabitants (12.8 of the Spanish population). Untreated wastewater samples were analyzed for urinary biomarkers of amphetamine, methamphetamine, MDMA, cocaine and cannabis. In addition to these conventional drugs, weekend samples were monitored for several new psychoactive substances (NPS) (i.e. phenethylamines and cathinones). The selected NPS are known as possible replacement of these conventional drugs or among those previously reported. Finally, enantiomeric profiling of amphetamine was performed for one city in order to assure the results were due to consumption and not illegal dumping of production residues. This demonstrates another application of wastewater-based epidemiology, which allows to identify the originof drugs in wastewater.This work has been supported by the Spanish State Research Agency (Agencia Estatal de Investigación, AEI) through the “Redes de Excelencia” programme, ESAR-Net, ref. CTM2016-81935-RED

Cranial biomechanics in basal urodeles: the Siberian salamander (Salamandrella keyserlingii) and its evolutionary and developmental implications

Developmental changes in salamander skulls, before and after metamorphosis, afect the feeding capabilities of these animals. How changes in cranial morphology and tissue properties afect the function of the skull are key to decipher the early evolutionary history of the crown-group of salamanders. Here, 3D cranial biomechanics of the adult Salamandrella keyserlingii were analyzed under diferent tissue properties and ossifcation sequences of the cranial skeleton. This helped unravel that: (a) Mechanical properties of tissues (as bone, cartilage or connective tissue) imply a consensus between the stifness required to perform a function versus the fxation (and displacement) required with the surrounding skeletal elements. (b) Changes on the ossifcation pattern, producing fontanelles as a result of bone loss or failure to ossify, represent a trend toward simplifcation potentially helping to distribute stress through the skull, but may also imply a major destabilization of the skull. (c) Bone loss may be originated due to biomechanical optimization and potential reduction of developmental costs. (d) Hynobiids are excellent models for biomechanical reconstruction of extinct early urodeles

Attribution of global lake systems change to anthropogenic forcing

Lake ecosystems are jeopardized by the impacts of climate change on ice seasonality and water temperatures. Yet historical simulations have not been used to formally attribute changes in lake ice and temperature to anthropogenic drivers. In addition, future projections of these properties are limited to individual lakes or global simulations from single lake models. Here we uncover the human imprint on lakes worldwide using hindcasts and projections from five lake models. Reanalysed trends in lake temperature and ice cover in recent decades are extremely unlikely to be explained by pre-industrial climate variability alone. Ice-cover trends in reanalysis are consistent with lake model simulations under historical conditions, providing attribution of lake changes to anthropogenic climate change. Moreover, lake temperature, ice thickness and duration scale robustly with global mean air temperature across future climate scenarios (+0.9 °C °Cair–1, –0.033 m °Cair–1 and –9.7 d °Cair–1, respectively). These impacts would profoundly alter the functioning of lake ecosystems and the services they provide

Experimental Evidence for Reduced Rodent Diversity Causing Increased Hantavirus Prevalence

Emerging and re-emerging infectious diseases have become a major global environmental problem with important public health, economic, and political consequences. The etiologic agents of most emerging infectious diseases are zoonotic, and anthropogenic environmental changes that affect wildlife communities are increasingly implicated in disease emergence and spread. Although increased disease incidence has been correlated with biodiversity loss for several zoonoses, experimental tests in these systems are lacking. We manipulated small-mammal biodiversity by removing non-reservoir species in replicated field plots in Panama, where zoonotic hantaviruses are endemic. Both infection prevalence of hantaviruses in wild reservoir (rodent) populations and reservoir population density increased where small-mammal species diversity was reduced. Regardless of other variables that affect the prevalence of directly transmitted infections in natural communities, high biodiversity is important in reducing transmission of zoonotic pathogens among wildlife hosts. Our results have wide applications in both conservation biology and infectious disease management

Global heat uptake by inland waters

Heat uptake is a key variable for understanding the Earth system response to greenhouse gas forcing. Despite the importance of this heat budget, heat uptake by inland waters has so far not been quantified. Here we use a unique combination of global-scale lake models, global hydrological models and Earth system models to quantify global heat uptake by natural lakes, reservoirs, and rivers. The total net heat uptake by inland waters amounts to 2.6 ± 3.2 ×1020 J over the period 1900–2020, corresponding to 3.6% of the energy stored on land. The overall uptake is dominated by natural lakes (111.7%), followed by reservoir warming (2.3%). Rivers contribute negatively (-14%) due to a decreasing water volume. The thermal energy of water stored in artificial reservoirs exceeds inland water heat uptake by a factor ∼10.4. This first quantification underlines that the heat uptake by inland waters is relatively small, but non-negligible