Circularity Index Research Articles

Microvascular changes in eyes with non-proliferative diabetic retinopathy with or without macular microaneurysms: an OCT-angiography study.

To evaluate different quantitative non-invasive retinal biomarkers of microvascular impairment and neurodegeneration in patients affected by mild and moderate non proliferative diabetic retinopathy (NPDR) with or without macular microaneurysms (MAs). A cross-sectional case-control study. Ninety-seven eyes with NPDR, 49 with no central MAs and 48 with central MAs, underwent color fundus photography and optical coherence tomography (OCT)/OCT-angiography (OCT-A). Thickness of central macula, retinal nerve fiber layer (NFL), ganglion cell layer (GCL+) and NFL + GCL + was evaluated on OCT. FAZ metrics (ImageJ), perfusion and vessel density (PD/VD), and fractal dimension (FD) (MATLAB) were evaluated on 3 × 3 OCT-A slabs of both superficial and deep capillary plexuses (SCP/DCP). All evaluations were performed on the full image and after subdivision in 4 quadrants. In the MA group, 77 MAs were detected (45.5% in the DCP). The MA group showed: increased FAZ area and perimeter in the SCP (p < 0.01) and DCP (p = 0.02), and reduced circularity index in the SCP (p = 0.03); reduced VD in the SCP (p < 0.01) and reduced PD, VD (p < 0.01) and FD (p = 0.02) in the DCP; decreased VD and FD in the SCP (p = 0.02 and p = 0.05), and in VD and FD in the DCP in the inferior quadrant (p = 0.04 and p = 0.03); a decrease in VD in the SCP in the nasal quadrant (p = 0.05). No differences have been detected in OCT parameters. Our results suggest that the presence of central MAs in patients with NPDR may correlate with more pronounced macular microvascular impairment, particularly during the mild and moderate stages of the disease.

Developing a robust indicator to evaluate circular economy through reuse strategy: A case study of using water treatment sludge as a coagulant for dewatering of iron ore tailings slurry

Due to the lack of tools, which are simple enough to assess the reuse strategy in the concept of circular economy (CE), in the present paper, reuse efficiency index (REI) was introduced as a new indicator, inspired by previously developed indexes, namely circular economy index (CEI) and value-based resource efficiency (VRE). The REI, as a measure of economic efficiency of reuse strategy, is the ratio of the net value obtained from the reuse of end of life (EOL) product instead of using a new product over the value of materials and energy inputs required to reproduce the EOL product. To calculate REI for any specific EOL product, information regarding mass, physicochemical properties and operational data on the consumption of energy, which are mainly available in the financial archives of companies, is crucial and the market price of EOL product must also be predicted. In another part of the study, the reuse of ferric chloride-based water treatment sludge (FCS) as a coagulant, instead of using high cost polymeric coagulant, for iron ore tailings slurry dewatering was evaluated through REI. The results showed that depending on the market prices of energy and materials as well as the iron (FeCl3) content in the FCS, the REI could vary between 0.51 and 1.04, corresponding to 51–104% added value. Overall, REI is based on accessible information and its simplicity and comprehensibility makes it applicable for managers and policymakers to invest and create technologies for reaching closed-loop cycles in the concept of CE through reuse action.

Modular steel panel for walls: life cycle environmental impact, life cycle cost, and potential for material circulation

The impacts of civil construction are widely recognized and justify the transition from a linear to a circular economy. Furthermore, with building users increasingly demanding greater adaptability, strategies such as modularity and flexibility to adapt to changing uses are being discussed. Modular wall panels allow quick installation and have the potential for disassembly, refurbishment, reuse, and recycling. We evaluate a modular steel panel system in two Brazilian case studies through life cycle assessment (LCA), life cycle cost (LCC), and building circularity index (BCI). The study applies the circular reuse and remanufacture, recycling, and life extension strategies for internal and external walls. For the external panel, the life extension strategy (SE02) stands out positively in all impact categories, with the lowest environmental impact and costs. However, the SE02′s BCI does not have the best result. The second best option is reuse (SE03), with the highest percentage of circularity. Furthermore, the differences between SE02 and SE03 are reduced in several impact categories, and the sensitivity analysis (transport, damage, and the number of reuses) shows that the differences could be even smaller. For the internal panel, life extension (SI02) and reuse (SI03) scenarios are the best options. Recycling (SI04) has the highest environmental impact and the best potential for circularity. BCI communication must be aligned with LCA and LCC, such that an increase in circularity is accompanied by a decrease in environmental impacts or with infeasible costs, especially for developing countries.

Macular Changes in Adults with History of Premature Birth.

To characterize changes in macular structure and vascularity seen in premature-birth adults. Retrospective review of adult patients seen in our clinic from July 2018 to November 2020 with history of premature birth not requiring treatment for retinopathy of prematurity (ROP), as well as healthy controls. Swept-source OCT-angiography (OCT-A) scans were analyzed for various parameters related to macular structure and vascularity. Statistical analysis was performed using univariate linear regression. Thirty-four eyes were included (17 eyes from 10 premature-birth adults, 17 eyes from 11 control patients). Prematurity was associated with vascular changes on OCT-A: decreased foveal avascular zone (FAZ) area (p=0.001), decreased FAZ circularity index (p<0.001), decreased superficial capillary plexus vessel (CPV) density (p=0.02), and decreased deep CPV density (p<0.001). Prematurity was also associated with structural changes: shallower foveal pit depth (p<0.001), decreased cube average thickness (CAT) (p=0.005), and increased central subfield thickness-to-CAT ratio (p=0.002). This is the largest published series of OCT-A data for premature-birth adults. Even without a history of ROP treatment, premature birth is associated with multiple changes to macular structure and vascularity that persist into adulthood. These include a smaller, more irregularly shaped FAZ, decreased juxtafoveal vascular density, and a shallower foveal pit.

Echocardiography-guided percutaneous closure of oval-shaped secundum atrial septal defects

BackgroundAn atrial septal defect (ASD) is considered oval-shaped when its shortest diameter is less than 75% of the longest diameter. Research on percutaneous closure of oval-shaped ASDs is limited, with no known reports of non-fluoroscopic closure for this population.ObjectiveTo assess the effectiveness of non-fluoroscopic percutaneous closure for oval-shaped ASDs.MethodsThis single-center retrospective study evaluates patients undergoing non-fluoroscopic percutaneous closure of oval-shaped ASDs, defined by the shortest to longest diameter ratio < 0.75, a circular index of 1.33, or ultrasound visualization of an oval shape. Device size was chosen to be 0–4 mm larger than the defect’s longest diameter, based on transthoracic and transesophageal ultrasound measurements.ResultsWe identified 78 patients (33.3% children, 20.5% males) with a mean age of 27.4 ± 16.3 years and a mean weight of 46.8 ± 19.8 kg. The mean longest diameter and mean shortest diameter of ASDs were 23.3 ± 6.8 mm and 15.8 ± 5 mm, respectively. The mean ratio of the shortest to longest diameter was 0.7 ± 0.1. Percutaneous closure was not attempted in 7/78 (9%) patients. Three out of 71 (4.2%) procedures were fluoroscopy-guided upfront due to technical difficulties, and 5/71 (7%) were converted to fluoroscopy-guided closure. Overall procedural success rate was 98.6% (70/71) including 63/71 (88.7%) performed with zero fluoroscopy. Mean device size was 26.5 ± 7.1 mm. Mean procedural time was 45.3 ± 22.6 min. Eleven intraprocedural complications occurred including 6 arrhythmias, 3 pericardial effusions, and 2 device dislodgements.ConclusionTranscatheter closure of oval-shaped ASD is safe and feasible. Echocardiography is adequate for adequate operative guidance.

Detecting active sinkholes through combination of morphometric-cluster assessment and deformation precursors

Sinkhole hazards pose considerable challenges in the west-central region of Texas. This study integrates multisource datasets and innovative techniques to detect early sinkhole development and identify the processes governing their formation. The techniques employed encompass feature extraction, cluster analysis, and deformation process monitoring. Potential sinkholes were initially mapped using high-resolution elevation data, and a circularity index (CI) threshold value of 0.85 was applied to filter out depressions with noncircular shapes. Subsequently, Persistent Scatterer Interferometry (PSInSAR) followed by the Getis-Ord Gi* statistic methods were used to identify statistically significant subsidence clusters with rates of <−2 mm/yr, indicating active sinkhole formation. The findings reveal the following: (1) surface deformation analysis revealed significant subsidence hotspots, particularly in areas underlain by units containing significant sequences of evaporites, which nominally belong to the Clear Fork Group and the Blaine Formation, compared with those dominated by carbonates; (2) potential sinkholes are undergoing displacement up to a rate of −11.31 mm/yr, and (3) extreme groundwater pumping of karst aquifers and the subsequent decline in groundwater levels are found to be the leading causes of the susceptibility of the region to sinkhole hazards. In such cases, the decline of the water table deprives the overlying bedrock of buoyant support provided by the groundwater in the cavity. The bedrock will undergo sagging subsidence under the influence of gravity and eventually form a sinkhole. Extensive oil and gas activity in the study area, including extreme withdrawal rates and the injection of fluids associated with the activity, are other potential causes of the observed sinkhole susceptibility in several parts of the study area. This study underscores the importance of understanding the geologic, hydrologic, and anthropogenic factors driving sinkhole hazards for effective mitigation strategies to protect public safety, infrastructure, and the environment.

Environmental Impact Assessment of a Plant Cell-Based Bio-Manufacturing Process for Producing Plant Natural Product Ingredients

Purpose: This study employed a Life Cycle Assessment (LCA) methodology to evaluate the environmental impacts of a novel plant cell-based biomanufacturing process for producing plant natural product ingredients. The primary purpose was to assess the relative sustainability of the process and to provide insights into potential areas of improvement in the biomanufacturing process. Method: The LCA method used an MS Excel (Ver. 2407) -based approach with a cradle-to-gate system boundary covering raw material sourcing (A1), raw material transportation (A2), and product extract manufacturing (A3) stages. Energy use and material inventory data are presented for different unit operations, and environmental impact factors were obtained from the Ecoinvent database. The study included a Material Circularity Index (MCI) calculation to assess the circularity of the biomanufacturing process for the production of saponin emulsifiers that are normally extracted from the woody tissue of the Chilean soapbark tree (Quillaja saponaria). Comparative analyses were performed against a wild-harvest approach for plant tannin extraction from spruce (Picea abies) tree bark. Key Results: The environmental impact assessment focused on determining relative Global Warming Potential (GWP), Acidification Potential (AP), Freshwater Eutrophication (FE), Particulate Matter Formation (PMF), and Ozone Depletion Potential (ODP). Results indicated that the extract manufacturing stage (A3) contributed significantly to adverse environmental impacts, with varying levels of effects based on the energy source used. Comparative analysis with the wild harvest approach highlights the lower environmental impact of the alternative biomanufacturing process. The biomanufacturing process showed a 23% reduction in GWP, AP, and FE and a 25% reduction in PMF and ODP relative to the wild harvest approach. However, the MCI for the biomanufacturing process was estimated to be 0.186, indicating a low material circularity. Conclusions: The results revealed that the extract manufacturing stage, particularly energy consumption, significantly influences the relative environmental impacts of the alternative production processes. Different energy sources exhibit varying effects, with renewable energy sources showing lower environmental impacts. The Material Circularity Index indicated a low circularity for the biomanufacturing process, suggesting opportunities for improvement, such as incorporating recycled or reused materials. Compared with the tannin extraction process, the plant cell-based biomanufacturing process demonstrated lower environmental impacts, emphasising the importance of sustainable practices and the use of renewable energy sources in future plant natural product sourcing. Recommendations include implementing more sustainable practices, optimising raw material choices, and extending product life spans to enhance circularity and overall environmental benefits.

Theory of Stimulated Brillouin Scattering in Fibers for Highly Multimode Excitations

Stimulated Brillouin scattering (SBS) is often an unwanted loss mechanism in both active and passive fibers. Highly multimode excitation of fibers has been proposed as a novel route toward efficient SBS suppression. Here, we develop a detailed, quantitative theory which confirms this proposal and elucidates the physical mechanisms involved. Starting from the vector optical and scalar acoustic equations, we derive appropriate nonlinear coupled mode equations for the signal and Stokes modal amplitudes and an analytical formula for the SBS (Stokes) gain with applicable approximations, such as the neglect of shear effects. This allows us to calculate the exponential growth rate of the Stokes power as a function of the distribution of power in a highly multimode signal. The peak value of the gain spectrum across the excited modes determines the SBS threshold—the maximum SBS-limited power that can be sent through the fiber. The theory shows that the peak SBS gain is greatly reduced by highly multimode excitation due to gain broadening and relatively weaker intermodal SBS gain. The inclusion of exact vector optical modes in the calculation is crucial in order to capture the incomplete intermodal coupling due to mismatch of polarization patterns of higher-order modes. We demonstrate that equal excitation of the 160 modes of a commercially available, highly multimode circular step index fiber raises the SBS threshold by a factor of 6.5 and find comparable suppression of SBS in similar fibers with a D-shaped cross section. Published by the American Physical Society 2024

In Vivo Visualization of Intravascular Patrolling Immune Cells in the Primate Eye.

Insight into the immune status of the living eye is essential as we seek to understand ocular disease and develop new treatments. The nonhuman primate (NHP) is the gold standard preclinical model for therapeutic development in ophthalmology, owing to the similar visual system and immune landscape in the NHP relative to the human. Here, we demonstrate the utility of phase-contrast adaptive optics scanning light ophthalmoscope (AOSLO) to visualize immune cell dynamics on the cellular scale, label-free in the NHP. Phase-contrast AOSLO was used to image preselected areas of retinal vasculature in five NHP eyes. Images were registered to correct for eye motion, temporally averaged, and analyzed for immune cell activity. Cell counts, dimensions, velocities, and frequency per vessel were determined manually and compared between retinal arterioles and venules. Based on cell appearance and circularity index, cells were divided into three morphologies: ovoid, semicircular, and flattened. Immune cells were observed migrating along vascular endothelium with and against blood flow. Cell velocity did not significantly differ between morphology or vessel type and was independent of blow flood. Venules had a significantly higher cell frequency than arterioles. A higher proportion of cells resembled "flattened" morphology in arterioles. Based on cell speeds, morphologies, and behaviors, we identified these cells as nonclassical patrolling monocytes (NCPMs). Phase-contrast AOSLO has the potential to reveal the once hidden behaviors of single immune cells in retinal circulation and can do so without the requirement of added contrast agents that may disrupt immune cell behavior.

Evaluation of Foveal Vasculature by Optical Coherence Tomography Angiography after Pan-Retinal Photocoagulation versus Intravitreal Anti-VEGF Injections.

This study aimed to compare macular vascular changes one and three months after treatment with either panretinal photocoagulation (PRP) or intravitreal bevacizumab (IVB). A total of 62 eyes with very severe non-proliferative diabetic retinopathy or early proliferative diabetic retinopathy without center-involved diabetic macular edema, were included in this retrospective study. Thirty-nine eyes were allocated to the PRP group, while 23 eyes were treated with IVB. Optical coherence tomography angiography (OCTA) was performed to measure foveal avascular zone (FAZ) characteristics as well as the densities of superficial and deep capillary plexuses (SCP and DCP). In the IVB group, the FAZ area and perimeter expanded at month one but returned to baseline level after three months. In the PRP group, however, the FAZ area and perimeter were rather steady. Changes in the FAZ area were significantly different between the treatment groups at month one (P = 0.02), but not at month three (P = 0.31). There was no significant difference in the change in FAZ circularity index between the two groups at each time point (P = 0.55 and P = 0.31). Similarly, changes in SCP density were not statistically significant between the two groups at both time points (all Ps 0.05). A comparison of the two treatment arms based on the mean change in DCP density revealed a significant difference at month one, but not at month three (P = 0.01 and P = 0.49, respectively). Although bevacizumab and PRP have different short-term macular vascular responses, both therapies have the ability to normalize or stabilize vascular measures over time.

Circular economy, economic growth, and e-waste generation in EU27 countries: Further evidence from the novel circular economy index and threshold effect.

The circular economy has been identified as a critical keyword for achieving the Sustainable Development Goals. Nevertheless, there is a lack of in-depth empirical literature on the impact mechanisms of the circular economy (CE) and economic growth (GDP) in mitigating e-waste generation (waste electrical and electronic equipment -WEEE). Given Europe's leading position in e-waste generation per capita, the study aims to scrutinize the interplay between CE, GDP, and WEEE for 2010-2020. The research applies advanced econometric methods, primarily centered around the system generalized method of moment and dynamic panel threshold. It was noteworthy that different CE indicators exhibited varying effects on WEEE through the econometric analysis. Therefore, the research uniquely utilized the entropy weight method to compute a holistic composite index for the circular economy (CEI) and gained some interesting findings. Firstly, CEI significantly reduced WEEE, while GDP drove its increase. However, an overly developed CEI of 0.7616 counteracted its beneficial effect. Secondly, the synergy of CEI*GDP engendered the circular economy rebound effect, diminishing environmental benefits. Thirdly, in the circular context, the environmental Kuznets curve was validated, showcasing an inverted U-shaped pattern. Finally, the study found CEI to have different threshold effects, with thresholds of 0.2161 to inhibit WEEE, 0.2114 to avert the circular economy rebound effect, and 0.2360 to leverage GDP in reducing WEEE. These outcomes give insights to policymakers in designing sound policies targeting circular economy development and decoupling e-waste generation from economic growth towards the United Nations' SDGs.

AI-DRIVEN CIRCULARITY INDEX: A COMPREHENSIVE METRIC FOR EVALUATING PRODUCT LIFECYCLE SUSTAINABILITY

Sophisticated instruments are required for the analysis of sustainability in a product in all its complexity during a transition towards a circular economy. In this respect, the new metric presented in this article is the AI-driven Circularity Index, which assesses product circularity according to four dimensions: material selection, modular design, recyclability, and resource efficiency. This index-powered by machine learning - provides predictive insights and actionable recommendations toward product lifecycle sustainability, hence adding a more solid solution to the more pressing issues of traditional linear economic models.

A gender-based analysis of retinal microvascular alterations in patients with diabetes mellitus using OCT angiography

PurposeTo assess the difference in microvascular changes between males and females with diabetes mellitus (DM) without diabetic retinopathy (NoDR) and with mild-to-moderate non-proliferative diabetic retinopathy (NPDR) using Optical Coherence Tomography Angiography (OCT-A). DesignRetrospective cross-sectional study. Methods267 DM patients, 133 females (49.81 %), 111 with NoDR (41.57 %) and 156 NPDR (58.43 %) were included. Foveal-centered 3 × 3 mm OCT-A images corresponding to the superficial (SCP), intermediate (ICP) and deep capillary plexus (DCP), and full retinal (RET) slab were used for analysis. For each slab, FAZ area, perimeter, and circularity index (CI) were determined, following manual delineation of the FAZ; perfusion (PD) and vessel density (VD), fractal dimension (FD), vessel length density (VLD), geometric perfusion deficits (GPD) were also computed. Flow voids (FV) were determined in the choriocapillaris plexus; and perfused capillary density (PCD) in the RET slab. ResultsFemales showed larger FAZ CI in SCP and greater FAZ area and perimeter than males in NPDR group. Males had higher central macular thickness than females in NPDR group. All density metrics at the level of ICP and DCP were affected in the NPDR group with no gender differences. Of note, the same significant findings were found in type 1 DM patients, and not in type 2 DM patients. ConclusionsOur OCT-A findings suggest significant microvascular changes in females with NPDR compared to males, but no such differences in patients without DR. Therefore, gender-related vascular alterations might be present in early stages of DR with potential role.

Investigating the effect of circularity index on a closed loop supply chain with multi-shipment policy

Environmental sustainability has emerged as a crucial aspect for every business, as the wastage of used products greatly contributes to greenhouse gas emissions and environmental hazards. Adopting the circular economy concept is essential to address this problem. This approach prioritizes reliability and re-manufacturability, aiming to simultaneously reduce waste and enhance sustainability and profitability. In this context, the proposed model introduces a sustainable closed-loop supply chain model wherein the manufacturer oversees the production process and delivers requested batches to the retailer under the single order and multi-shipment policy. The model incorporates the notion of circularity, quantified by a circularity index representing the degree to which the product's circularity level. The level of product circularity can be enhanced by material choice, supplier selection, and innovative design while manufacturing. The model being presented aims to maximize the total integrated profit of the closed-loop supply chain system by optimizing the number of shipments as well as the circularity index. It is evident from the analysis that the circularity index significantly influences profits and environmental sustainability by increasing product demand and extending product life cycles. Notably, the numerical example provided in the model illustrates that accounting for the effects of the circularity index results in an optimal profit up to 5% higher compared to scenarios where such effects are not considered.

An EOQ Model for Circularity Index with Waste Minimization and Reduced Emission in Electrical and Electronic Equipment

A circular economy uses limited natural resources and is efficient and environmentally productive. It aims to transform from a "take-make-waste" approach to a more restorative and regenerative one. A closed-loop system reduces waste, pollution, and carbon emissions by reusing, sharing, repairing, refurbishing, remanufacturing, and recycling. We developed a new model on reverse logistics economic order quantity with the circular economy. This paper proposes a profit-maximizing economic lot size system in which all products are at variable circularity levels. The product's degree of circularity directly influences customers' demand and gross profit per unit, and we study these effects using both linear and nonlinear forms of analysis as consumers become more socially responsible about their consumption practices. This paper aims to maximize profits from the waste of electrical and electronic equipment (WEEE) by reducing carbon emissions. Some examples are discussed to find the profit of a business with variations of parameters. The goal of this study is to help reverse the flow of products to re-manufacturers of electrical equipment, especially computer equipment manufacturers, to acquire the ideal circular index for the products they manufacture to maximize profit and preserve the environment simultaneously.

Effects of High-Intensity Swimming Interval Training on Area, Perimeter, Circularity Index and Phenotype of Cardiac Mitochondrial Ultrastructure in Sprague Dawley Rats.

Physical inactivity impairs health by increasing morbidity. In childhood, modifiable risk factors associated with cardiovascular pathologies and related to mitochondrial function and structure are initiated by physical inactivity. The objective of this study was to analyze the effect of high-intensity swimming interval training (HIIT-swim) on cardiac mitochondrial ultrastructure in young Sprague Dawley rats compared with a sedentary group. Five-week-old Sprague Dawley rats (n = 18) were divided into a control group (C) (n = 6), a sedentary group (S) (n = 6) and an HIIT-swim group (H-s) (n = 6), the last of which performed HIIT-swim for 4 weeks. A mitochondrial ultrastructural evaluation was performed using transmission electron microscopy. In the H-s rats, mitochondrial areas and perimeters were found to be statistically significantly different from those of the C and S rats. In addition, no predominant intramitochondrial multifragmentation was observed in the mitochondria of H-s rats, but multifragmentation was evident in the mitochondria of S rats.

Fluid flow zones along fracture corridors inferred from collapse dolines in carbonates of the Irecê Basin, Brazil

AbstractDolines are a widespread karst landform, and understanding their genesis can provide critical information about the evolution of subsurface karstification and groundwater flow zones. Swarms of collapse dolines characterise the karst in the southern portion of the Irecê Basin, northeastern Brazil. The basin comprises Neoproterozoic carbonate rocks approximately 100 m thick, bounded by less soluble older quartzites. The distribution of dolines is not uniform, as they cluster along NW‐SE axes and are aligned with cave systems and permeability (fracture) corridors mostly associated with the Almas and Água de Rega ephemeral rivers. Detailed analysis of sectors with a higher density of dolines was performed using LiDAR and unmanned aerial vehicle (UAV) imagery at two different scales to obtain morphometric and orientation patterns. As expected, scale dependency is observed, with an increase in density and circularity index at a higher resolution scale, but a decrease in mean area and perimeter. However, Voronoi polygon indices are similar at both scales (6.86 ± 1); the departure from the more stable number of six due to the clustering of dolines associated with NW‐SE oriented structural trends. Doline density trends closely follow the orientation of caves, but they are not always spatially connected, since doline evolution may either occlude the caves or be related to a non‐identified void. The Irecê Basin karst system displays a continuum of landforms evolving initially from high‐density fracture zones (fracture corridors), which work as favourable dissolution zones, grading into more integrated flow routes, cave systems and eventually clusters of collapse dolines. Collapse dolines are widespread karst landforms worldwide, and their genesis requires the presence of dissolution voids at depth, which may pass undetected from the surface. In some sectors of Irecê Basin, the existence of doline alignments but the absence of known caves indicates the potential of collapse dolines to be used as proxies for subsurface karstification. Such an approach may allow the prediction of the location and orientation of subsurface zones of enhanced dissolution that can potentially represent productive aquifers or favourable zones for geofluids.

A scalable index for quantifying circularity of bioeconomy systems

Increasing resource demands and efforts to mitigate anthropogenic impacts have thrust circular bioeconomy into the spotlight. However, there currently lacks a metric to provide singular quantification of circularity. This study showed development of a Circularity Index (CI) with value between 0 (completely linear) and 1 (completely circular) to quantify circularity of resource flows at different system scales, identify weak links in value-chains, and determine tradeoffs in the system. This study describes 1) CI for systems containing consumable, renewable, and recovered resources; 2) CI application for two examples: nitrogen in a corn-soybean farm and energy in the U.S. food and agricultural system. CI showed that nitrogen circularity increased from 0.687 to 0.860 through implementation of renewable fertilizer from manure compared to synthetic fertilizer. CI also demonstrated improved energy circularity in the U.S. food and agricultural system, increasing from 0.179 to 0.843 when integrating food-energy-water systems via hydrothermal liquefaction and nutrient recycling.

Spectral-domain OCT characteristics of intraretinal hyper-reflective foci associated with age-related macular degeneration and diabetic retinopathy

ObjectiveThe purpose of this study was to quantitatively analyze and compare OCT characteristics of intraretinal hyper-reflective foci (IHRF) in eyes with diabetic retinopathy (DR) versus age-related macular degeneration (AMD). Designa retrospective observational study. Participants54 treatment-naïve eyes (27 DR and 27 AMD). MethodsThe IHRF lesions in OCT B-scan were semi-automatically segmented. Mean reflectivity (MR), maximum diameter, circularity index (Cir), area, and the angle between the greatest linear dimension (GLD) and the horizontal were computed for each IHRF lesion. The presence and absence of a posterior shadow and the axial location were assessed. The MR was normalized using the vitreous and nerve fiber layer reflectance as dark and bright reference standards, respectively. ResultsA total of 1149 IHRF (1051 in DR and 98 in the AMD group) were identified, with a mean of 39 ± 36 lesions in DR eyes compared to only 4 ± 4 in AMD eyes (p < 0.001). The mean area of individual IHRF lesions was greater in DR eyes (1305 ± 1647 μm² vs 1031 ± 750 μm²; p = 0.016), but IHRF in AMD eyes had higher reflectivity (1.17 ± 0.14 vs 1.03 ± 0.17; p < 0.001). The angle of the GLD relative to the horizontal was greater in AMD eyes, indicating that IHRF in AMD eyes were more horizontally oriented. In AMD eyes, 88.8% of IHRF were located beneath the inner border of the outer nuclear layer (ONL), while in DR eyes, 56.9% were located there (p < 0.001). ConclusionsIHRF lesions in eyes with DR and AMD demonstrate significant differences, with IHRF in DR eyes tending to be larger and less hyper-reflective compared to AMD eyes.

Comparing the circularity and life cycle environmental performance of batteries for electric vehicles

Batteries account for a significant share of the life cycle impact of electric vehicles (EV). Nonetheless, the circularity and environmental performance of EV batteries remains underexplored in the literature. This paper compares the circularity (Circularity Index and Product Circularity Indicator) and environmental performance (Global Warming Potential (GWP) and Abiotic Depletion Potential of minerals (ADPm)) of lithium nickel manganese cobalt (NMC) and lithium iron phosphate (LFP) batteries subjected to pyrometallurgy and hydrometallurgy recycling. Lifetime extension, improved energy efficiency, and material recovery ratios were also calculated to identify the optimal battery design. The findings show that NMC batteries are 6–25% more circular and environmentally sustainable (<4–6% GWP and <13–16% ADPm) than LFP batteries, primarily due to better material recovery ratios. Moreover, the longer lifetime of LFP does not sufficiently offset resource and environmental impacts. Finally, the study discusses the results to support circular and environmental innovation in EV battery design.