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During COP14 in 2022, Ramsar Convention commended 25 cities around the world for their efforts to protect urban wetlands. With the development of cities and the increase in land demand, the trend is to reduce the number of open blue spaces. Yet when preserved and sustainably used, urban nature-based solutions in the form of constructed wetlands could provide water management benefits including water quality regulation and flood mitigation. However, these water management benefits have rarely been evaluated at a catchment scale, and the mechanisms behind them are not fully understood, both of which hinder effective integrated constructed wetlands planning. We aim to explore the impact of wetland changes on water quality and quantity at the catchment scale. This study firstly evaluates the benefits by analysing the monitoring water quantity and quality datasets before and after the wetland construction in Enfield catchment, London. To understand the mechanisms behind the benefits, we build a Water Systems Integration Modelling framework (WSIMOD) to simulate the catchment-scale water cycle. This model is validated against monitoring river flow and water quality data. The constructed wetlands are then conceptualised and integrated into the WSIMOD, and their interactions with the catchment water cycle are simulated. Scenarios are constructed to analyse the impacts of different configurations and sizes of the constructed wetlands on the catchment water cycle. The results show that urban wetlands play a role in flood detention and water quality purification of watershed water resources at the catchment scale. Scattered small wetlands can more effectively reduce the impact of a flood under the same total wetland area. The results provide useful insights into the planning of constructed wetlands for maximising the water management benefits at a catchment scale. Future studies could focus on representing the interaction between the quantity and quality of water in a wetland with biodiversity and leveraging this representation to design interventions to improve biodiversity.

The water cycle is highly interconnected; water fluxes in one part depend on physical and human processes throughout. For example, rivers are a water supply, a receiver of wastewater, and an aggregate of many hydrological, biological, and chemical processes. Thus, simulations of the water cycle that have highly constrained boundaries may miss key interactions that create unanticipated impacts or unexpected opportunities. Integrated environmental models aim to resolve the issue of boundary conditions, however they have some key limitations, and we find a significant need for a parsimonious, self-contained suite that is accessible and easy to setup. With this in mind, we have developed the WSIMOD – a Python package that allows for the representation of the water system’s demands and impacts of multiple sectors and actors’ decisions within a single tool, which is considered beneficial to increasing a shared understanding of system performance and for more collaborative and coherent decisions on integrated water resources, water quality and flood management. The WSIMOD is a self-contained software package that includes modelled representations of key physical and infrastructure elements of the water cycle (urban and rural), with each type of modelled element generically described as a component. Components are written in such a way that any component can interact with any other component. This enables a flexible representation of a water system that is needed to accommodate the wide variety of different built/natural infrastructure configurations and scales. We will showcase how the WSIMOD tool has been developed and successfully tested through a range of applications in the UK, including integrated analysis of urban water systems, catchment water management and urban water neutrality.

Several applications in health diagnostics, food, safety, and environmental monitoring require rapid, simple, selective, and quantitatively accurate viral load monitoring. Here, we introduce the first label-free biosensing method that rapidly detects and quantifies intact virus in human saliva with single-virion resolution. Using pseudotype SARS-CoV-2 as a representative target, we immobilize aptamers with the ability to differentiate active from inactive virions on a photonic crystal, where the virions are captured through affinity with the spike protein displayed on the outer surface. Once captured, the intrinsic scattering of the virions is amplified and detected through interferometric imaging. Our approach analyzes the motion trajectory of each captured virion, enabling highly selective recognition against nontarget virions, while providing a limit of detection of 1 × 10(3) copies/mL at room temperature. The approach offers an alternative to enzymatic amplification assays for point-of-collection diagnostics.

Nature-based solutions (NBS) have co-benefits for water availability, water quality, and flood management. However, searching for optimal integrated urban-rural NBS planning to maximise co-benefits at a catchment scale is still limited by fragmented evaluation. This study develops an integrated urban-rural NBS planning optimisation framework based on the CatchWat-SD model, which is developed to simulate a multi-catchment integrated water cycle in the Norfolk region, UK. Three rural (runoff attenuation features, regenerative farming, floodplain) and two urban (urban green space, constructed wastewater wetlands) NBS interventions are integrated into the model at a range of implementation scales. A many-objective optimization problem with seven water management objectives to account for flow, quality and cost indicators is formulated, and the NSGAII algorithm is adopted to search for optimal NBS portfolios. Results show that rural NBS have more significant impacts across the catchment, which increase with the scale of implementation. Integrated urban-rural NBS planning can improve water availability, water quality, and flood management simultaneously, though trade-offs exist between different objectives. Runoff attenuation features and floodplains provide the greatest benefits for water availability. Regenerative farming is most effective for water quality and flood management, though it decreases water availability by up to 15% because it retains more water in the soil. Phosphorus levels are best reduced by expansion of urban green space to decrease loading on combined sewer systems, though this trades off against water availability, flood, nitrogen and suspended solids. The proposed framework enables spatial prioritisation of NBS, which may ultimately guide multi-stakeholder decision-making, bridging the urban-rural divide in catchment water management.

Ferroelectric nanolaminates have drawn wide attention due to the process convenience of atomic layer deposition (ALD) method and their superior performance. In this work, HfO2/ZrO2 nanolaminates were prepared by alternately depositing HfO2 and ZrO2 single layer with ALD technology. The crystal structures and electrical properties were comprehensively investigated and analyzed. Compared with HfZrO4 solid solution, HfO2/ZrO2 nanolaminates showed much lower leakage current density and similar ferroelectricity, which was beneficial for the improvement of device life. The highest remnant polarization of 17.7 μC cm−2 was achieved in HfO2/ZrO2 nanolaminates with a ratio of 12:12, exhibiting a good endurance of exceeding 5 × 109 cycles. The effects of film thickness and laminated structure on the electrical properties and fatigue performance were also discussed. The differences in ferroelectricity and leakage current were originated from the different grain sizes. The small roughness, fine grains and enough crystallization are essential for the better ferroelectric properties. This work provides a comparison between doped films and laminated films and reveals the thickness dependence on the ferroelectric properties of HfO2/ZrO2 nanolaminates.

Label-free detection and digital counting of nanometer-scaled objects such as nanoparticles, viruses, extracellular vesicles, and protein molecules enable a wide range of applications in cancer diagnostics, pathogen detection, and life science research. The contrast of interferometric scattering microscopy is amplified through a photonic crystal surface, upon which scattered light from an object combines with illumination from a monochromatic plane wave source. The use of a photonic crystal substrate for interference scattering microscopy results in reduced requirements for high-intensity lasers or oil-immersion objectives, thus opening a pathway toward instruments that are more suitable for environments outside the optics laboratory. Here, we report the design, implementation, and characterization of a compact Photonic Resonator Interferometric Scattering Microscope (PRISM) designed for point-of-use environments and applications. The instrument incorporates two innovative elements that facilitate operation on a desktop in ordinary laboratory environments by users that do not have optics expertise. First, because scattering microscopes are extremely sensitive to vibration, we incorporated an inexpensive but effective solution of suspending the instrument’s main components from a rigid metal framework using elastic bands, resulting in an average of 28.7 dBV reduction in vibration amplitude compared to an office desk. Second, an automated focusing module based on the principle of total internal reflection maintains the stability of image contrast over time and spatial position, facilitating automated data collection. In this work, we characterize the system’s performance by measuring the contrast from gold nanoparticles with diameters in the 10-40 nm range and by observing various biological analytes, including HIV virus, SARS-CoV-2 virus, exosomes, and ferritin protein.

Sustainable development is becoming increasingly urgent in the post-COVID recovery and climate crisis era. Despite this need, the water management scientific community is still deciding how to comprehensively represent and assess the role of humans within the hydrological cycle. An explanation may be found in numerous examples where water managers are often challenged when their decisions, policies, and interventions lead to a range of unintended consequences that cause increased pressures on the environment, which have been described by socio-hydrological paradoxes. If the paradoxes are seen as the main obstacles hindering sustainable development in the context of water management, then investigating their mechanisms and understanding logic may help us to reveal unintended system responses and define guiding principles critical for designing robust and sustainable water management plans. We analyse the socio-hydrological paradoxes from a systems perspective and assume that water management decisions and plans developed adopting a linear thinking and goals-focused approach are likely to neglect consequential effects which occur throughout the wider system. This definition enables us to rename the phenomena into water management paradoxes, which might be fundamentally related to systems’ complexity and unexpected behaviour arising from internal feedbacks along with external driving forces that generate nonlinear outcomes which are inconsistent with the expected results or responses from inputs and actions within the system.To find solutions for the water management paradoxes, we hypothesise that they can be described in the context of three feedback mechanisms, which define the purpose of systems water management (SYWM) as coordination of development and water infrastructure with environmental management to improve the quality of life. We argue that the lack of consideration, integration and coordination of the SYWM meta-model loops will result in one of the water management paradoxes. As a solution, we propose three paradox archetypes that form the basis for guiding principles for systems water management. We suggest that environmental capacity indicators should be used in whole-system performance evaluation. The meta-model emphasises the need to better understand the baseline and development scenarios in the context of water neutrality, which is crucial for informing development decisions, including trade-offs in resource and infrastructure planning and operation. We encourage the use of a SYWM meta-model and proposed principles as a guide for analysing, modelling, and assessing human-water systems, thus creating an evidence base of case studies to demonstrate the meta-model’s applicability to solving water management paradoxes. In doing so, we hope to move towards the design of water systems that will support post-COVID recovery and enable long-term sustainable development.

Managing river water quality at critical checkpoints that have significant impacts on water use is important for sustainable catchment development. This requires managing the whole multi-catchment systems upstream of a critical checkpoint. Concepts of systems headroom (deficit below permit) and excess (extra above permit) have been used to distinguish sub-catchments’ roles in pollution contribution. Based on the concepts, we propose a three-phase management approach. In the first phase, we frame the headroom and excess at temporal, spatial, and source domains and evaluate them to investigate the systems mechanisms. The evaluation is by simulating physical processes a semi-distributed integrated model (CatchWat-SD). We apply the model to 12 sub-catchments that make up the Upper Thames river basin and validate it using monitoring data. In the second phase, we incorporate the evaluated headroom and excess in loads allocation to develop a strategy that coordinates systems headroom for more efficient and realistic interventions. In the last phase, we validate the strategies by simulating the scenarios that coordinate headroom at different domains and evaluating them in water quality improvement, efficiency, temporal steadiness, spatial homogeneity, and practical feasibility. Results show that dry seasons, downstream catchments and urban sources generally have more excess. Thus, more target loads reduction is allocated to dry season, downstream catchments and urban sources in the fully coordinated scenario. The higher degree of headroom coordination a strategy achieves, the better performance this strategy generally obtains in all five metrics. This study emphasises the need to incorporate headroom in loads reduction allocation, which helps to more efficiently improve systems water quality performance with a more realistic degree of intervention. The whole procedure can be further expanded to water quality management at multiple checkpoints for sustainable management in large catchments.

In recent years, the biosensor research community has made rapid progress in the development of nanostructured materials capable of amplifying the interaction between light and biological matter. A common objective is to concentrate the electromagnetic energy associated with light into nanometer-scale volumes that, in many cases, can extend below the conventional Abbé diffraction limit. Dating back to the first application of surface plasmon resonance (SPR) for label-free detection of biomolecular interactions, resonant optical structures, including waveguides, ring resonators, and photonic crystals, have proven to be effective conduits for a wide range of optical enhancement effects that include enhanced excitation of photon emitters (such as quantum dots, organic dyes, and fluorescent proteins), enhanced extraction from photon emitters, enhanced optical absorption, and enhanced optical scattering (such as from Raman-scatterers and nanoparticles). The application of photonic metamaterials as a means for enhancing contrast in microscopy is a recent technological development. Through their ability to generate surface-localized and resonantly enhanced electromagnetic fields, photonic metamaterials are an effective surface for magnifying absorption, photon emission, and scattering associated with biological materials while an imaging system records spatial and temporal patterns. By replacing the conventional glass microscope slide with a photonic metamaterial, new forms of contrast and enhanced signal-to-noise are obtained for applications that include cancer diagnostics, infectious disease diagnostics, cell membrane imaging, biomolecular interaction analysis, and drug discovery. This paper will review the current state of the art in which photonic metamaterial surfaces are utilized in the context of microscopy.

Managing river quality is important for sustainable catchment development. In this study, we present how catchment management strategies benefit from a coordinated implementation of measures that are based on understanding key drivers of pollution. We develop a modelling approach that integrates environmental impacts, human activities, and management measures as three hierarchical levels. We present a catchment water management model (CatchWat) that achieves all three hierarchical levels and is applied to the Cherwell Catchment, UK. CatchWat simulations are evaluated against observed river flow and pollutant data including suspended solids, total nitrogen, and total phosphorus. We compare three competing hypotheses, or framings, of the catchment representation (integrated, urban-only, and rural-only framings) to test the impacts of model boundaries on river water quality modelling. Scenarios are formulated to simulate separate, combined and coordinated implementation of fertiliser application reduction and enhanced wastewater treatment. Results show that models must represent both urban and rural pollution emissions to accurately estimate river quality. Agricultural activities are found to drive river quality in wet periods because runoff is the main pathway for rural pollutants. Meanwhile, urban activities are the key source of pollution in dry periods because effluent constitutes a larger percentage of river flow during this time. Based on this understanding, we identify a coordinated management strategy that implements fertiliser reduction measures to improve river quality during wet periods and enhanced wastewater treatment to improve river quality during dry periods. The coordinated strategy performs comparably to the combined strategy but with higher overall efficiency. This study emphasises the importance of systems boundaries in integrated water quality modelling and simulating the mechanisms of seasonal water quality behaviour. Our key recommendation is that incorporating these mechanisms is required to develop coordinated strategies for river water quality management, that can ultimately lead to more efficient and sustainable catchment management.

Estuaries are a special transition zone subject to both riverine and marine processes, where environmental issues, e.g. water pollution, eutrophication and hypoxia, have become an increasing cause of concern in recent decades. The vertical transport of water and material is an intrinsic process in estuarine environments, with the atmosphere and seabed being the upper and lower boundaries. However, vertical water renewal in estuaries is not fully understood despite its significance to the estuarine environment being widely recognized. In the present study, the vertical water renewal process in a large estuary is investigated using the concept of water age. A three-dimensional water age model is built based on a hydrodynamic model, in which the age of a water parcel is defined as the time interval since it last touched the air-water interface, and thus indicates the renewal duration from the free surface. Water renewal durations, especially when relatively long, can provide insight into environmental and water quality issues, e.g. a low dissolved oxygen (DO), that can have a significant impact on ecosystem functioning. Results showed that the water age in the Pearl River Estuary (PRE) was characterized by significant spatial distributions and seasonal variations, which depends heavily on the water density stratification, as indicated by the Richardson number. During the wet season, the bottom water age was large at the lower reach of the estuary, up to 8 days, whereas the maximum bottom age during the dry season was ~1 day at the upper reach. Based on the quantification of vertical renewal, a new approach was proposed, and used to successfully evaluating DO depletion. The data and method would benefit for future environmental management, eco-biological restoration and related policy-making, especially when oxygen-based pollution is considered.

e15588 Background: The clinical trial Keynote 177 is a breakthrough research in colon rectal cancer (CRC), however, the results of subgroups revealed that immunotherapy did not benefit more than chemotherapy in patients with KRAS mutation. Here we assessed characteristics of tumor immune microenvironment in patients with or without KRAS mutation, to find out the underlying mechanisms that prevent KRAS-mutated CRC patients from benefiting from immunotherapy. Methods: Tumor tissue samples of 77 CRC patients were collected from Janary 2019, several kinds of immune cells including CD8+ T cells, M1/M2 tumor associated macrophages (TAM), CD56bright NK cells and CD56dim NK cells in the tumor tissue were evaluated by multiple fluorescence immunohistochemistry (mIHC), and expression of PD-L1 were detected by using Dako PD-L1 IHC 22C3 pharmDx, Tumor Proportion Score (TPS) was used to determine expression of PD-L1. In addition, gene mutation was detected by means of next generation squesing (NGS). All these detections were performed in a College of American Pathologists (CAP)-certified and Clinical Laboratory Improvement Amendments (CLIA)-accredited lab for gene mutation analysis (3D Medicines Inc.,Shanghai, China). Statistical analysis was performed using GraphPad Prism (version 7.01) and SPSS version 21.0 (SPSS,Inc.). Results: According to whether KRAS is mutated, these 77 patients were divided into two groups, KRAS wild type (WT) (n = 49) and KRAS mutation group (n = 28). There was no significant difference in the CD8+T cells infiltrated in tumor tissue of KRAS WT and KRAS mutation samples, however, less CD8+ T cells were found in stroma of tumor tissue of KRAS WT samples than in KRAS mutation. What’s more, both the ratio of M1:M2 and CD56dim NK: CD56bright NK cells in the tumor tissues of KRAS WT were significantly higher than in KRAS mutation samples(p < 0.05). No significant difference was found between two groups, while higher MSI-H proportion was found in KRAS mutation group than in KRAS WT (33.4% and 12.5%, respectively). The proportion of positive PD-L1expression (TPS≥1) in both groups is very low, especially, proportion of strong positive (TPS≥50). Conclusions: The different response to immune checkpoint inhibitors therapy for CRC patient with or without KRAS mutation mainly associated with factors of TIME, not only CD8+T cells, but tumor associated macrophages and different sub-population of NK cells should be put into consideration.

Due to the full compatibility with modern complementary-metal-oxidesemiconductor (CMOS) technology and scalable capability, HfO2-based ferroelectric films have been considered as the most potential materials in micro-nano non-volatile memories. However, despite great achievements, the existence of poor interface still poses a great threat to the improve of ferroelectricity and polarization stability. Here, the excellent ferroelectricity and reliability in the 21.6 nm-thick Hf0.5Zr0.5O2 (HZO) films are reported through interface modification by inserting an ultrathin Al2O3 (AO) layer using atomic layer deposition method. Improved polarization and stability are achieved in HZO/AO bilayers with the AO thickness below 2.4 nm. When the thickness of AO dielectric layer is 1.6 nm, the maximum remnant polarization reaches 30.19 μC/cm2 and the leakage current is decreased by 2 ~ 3 orders of magnitude. The strong interface polarization resulted from the electrostatic coupling between HZO and AO films contributes to the improved ferroelectricity of HZO films. Furthermore, the AO layer, as a dielectric capacitor after switching or during non-switching, can block the electron injection from bottom electrode and therefore improve the cycling reliability. This work demonstrates that an inlaid dielectric layer with much lower dielectric constant can significantly enhance the electrical properties of ferroelectric films.

Ferroelectricity and polarization-switching behavior were investigated in Hf0.5Zr0.5O2 films from 25°C to 150°C. It is found that a large remnant polarization (Pr) of about 30 μC/cm2 is achieved, and Hf0.5Zr0.5O2 films behave a good stability in a wide range of temperature. By analyzing the physical mechanism of leakage current, it indicates that electron conduction mechanism obeys Schottky emission at low voltages, and Fowler-Nordheim (F-N) tunneling mechanism along with space-charge-limited-conduction (SCLC) at high voltages. The temperature dependent polarization switching and related leakage current behaviors reveal a strong thermal activation of the oxygen vacancies, which can explain the varieties of ferroelectricity and leakage current under different temperatures.