Regeneration Scenarios Research Articles

Co-designing with community for net zero: Case study of a housing estate

To meet the UK’s 2050 net zero carbon targets, Whole Life Carbon Assessment (WLCA) is used to calculate the lifetime carbon emissions of building projects. This paper aims to compare different estate regeneration scenarios for meeting the interim 2030 benchmarks for the 2050 target. The research consists of a case study employing co-design and WLCA experiments, and impact evaluation surveys. The results of the WLCA demonstrate the lower operational impacts of fossil-fuel-free scenarios, and lower embodied and overall carbon emissions of retrofitting scenarios. To make an informed decision towards the future of the estates, different regeneration scenarios need to be studied, and the stakeholders should understand the carbon emissions of different materials and systems. The findings of this study can be used to compare regeneration schemes of other building types.

Separating the impact of climate change and human activities on the connection between meteorological and hydrological drought

AbstractUnderstanding the transition from meteorological to hydrological drought is essential for accurately predicting hydrological droughts. However, the factors driving this transition are intricate, and a comprehensive understanding of how direct human activities influence this shift in drought is lacking. In this study, we initially explored the spatiotemporal correlation between the occurrence of meteorological and hydrological droughts. Subsequently, we formulated multiple hydrological replenishment scenarios using the soil and water assessment tool (SWAT) model to assess the environmental impact of the transition from meteorological to hydrological droughts. The Xijiang River Basin (XRB), the primary tributary of the Pearl River basin, was selected as the study area. Our results identified 91 meteorological droughts in the XRB, and only 66 hydrological droughts from 1978 to 2018. The transition rate from meteorological to hydrological drought demonstrated large spatial variability, with a basin‐average rate of 56% and the lowest transition rate of 45% in the headstream The transition from meteorological to hydrological drought was mostly rapid between November and December (~2 months), but can be prolonged during spring (about 3–5 months) and winter (around 7–9 months). Additionally, analysis of regeneration scenarios indicated that human activity has mitigated drought severity over recent decades. The primary driver affecting drought duration and frequency during the transition from meteorological to hydrological droughts shows conspicuous spatial disparities in densely populated areas. Although human activity significantly contributes to drought duration and severity compared to climate change during the transition in the headstream, its effects are more pronounced downstream in terms of drought duration and frequency. One plausible explanation is that increased water consumption downstream has considerably prolonged drought progression, whereas water management has counteractive effects on drought progression due to climate change in the headstream. Our findings offer valuable insights into the transition process from meteorological to hydrological droughts in the presence of extensive human activities.

Regeneration of post‐mining and post‐fire soil function by assessment of tree nutrient status: Evidence from pioneer and N‐fixing species

AbstractNutrient concentrations in the foliage of particular tree species can identify growth‐limiting factors. Therefore, the adaptability and usefulness of certain trees in the afforestation of barren soils after disturbances could be based on nutrient supply and stoichiometry. In this study, we investigated the macronutrient supply to (i.e., nitrogen [N], phosphorus [P], potassium, sulfur, calcium [Ca], and magnesium [Mg]) and C:N:P (carbon:nitrogen:phosphorus) stoichiometry of the foliage of black alder (Alnus glutinosa), common birch (Betula pendula), and Scots pine (Pinus sylvestris) in two different regeneration scenarios—a reclaimed mine site with primary succession and an afforested post‐fire (PF) site with secondary succession. The control plot was on an undisturbed forest site hosting stands of the studied tree species. The lower concentrations of elements in the post‐mining soils developed from “point zero” were enough to supply the trees with a similar level of nutrition to those in the PF and undisturbed soils. The studied tree species differed in their foliage chemistry and had different effects on the soil properties. The alder and birch foliage contained more nutrients than the pine foliage. In particular, the birch foliage contained the highest concentrations of Ca, Mg, and P, thus enhancing the biogeochemical cycling of these elements. The alder foliage had the highest N concentration, albeit the soil total N contents under this species were not higher than those under birch. Thus, its phytomeliorative effect may have been overestimated. The pine foliage contained the lowest concentrations of nutrients, indicating the high nutrient use efficiency of this species. On the sites degraded after disturbance, pine and birch grew under N‐limitation stress, while the alder—a N‐fixing species—grew under P‐limitation stress, especially at the PF site. The PF soils under alder were also characterized by higher acidity, P depletion, and higher C:P and N:P ratios compared to the PF soils under the other studied species. We found that birch should be the most common tree species in the first phase of area regeneration after disturbances. Introducing alder into afforestation should take place in admixtures, especially at the PF site.

Simultaneous effect of oxygen impurity and flow rate of purge gas on adsorption capacity of and heel buildup on activated carbon during cyclic adsorption-desorption of VOC

Irreversible adsorption, or heel buildup, negatively impacts activated carbon performance and shortens its lifetime. This study elucidates the interconnections between flow rate and the oxygen impurity of desorption purge gas with heel buildup on beaded activated carbon (BAC). Nine thermal desorption scenarios were explored, varying nitrogen purge gas oxygen impurity levels (<5 ppmv, 10,000 ppmv, 210,000 ppm (21 %)) and flow rates (0.1, 1, 10 SLPM or 1 %, 10 %, 100 % of adsorption flow rate) during thermal desorption. Results reveal that increasing purge gas flow rate improves adsorption capacity recovery and mitigates adverse effects of purge gas oxygen impurity. Cumulative heel increased with higher purge gas oxygen impurity and lower flow rates. In the least effective regeneration scenario (0.1 SLPM N2, 21 % O2), a 32.8 wt% cumulative heel formed on BAC after five cycles, while the best-case scenario (10 SLPM N2, <5 ppmv O2) resulted in only 0.3 wt%. Comparing the pore size distributions of virgin and used BAC shows that heel initially forms in narrow micropores (<8.5Å) and later engages mesopores. Thermogravimetric analysis (TGA) showed that oxygen impurity creates high boiling point and/or strongly bound heel species. TGA confirmed that higher purge gas flow rates reduce heel amounts but encourage chemisorbed heel formation in oxygen's presence. These findings can guide optimization of regeneration conditions, enhancing activated carbon's long-term performance in cyclic adsorption processes.

Identifying the criteria for community-centred Life Cycle Sustainability Assessment of estate regeneration schemes

Identifying the overall environmental, and socioeconomic impacts of different estate regeneration scenarios can contribute to the overall sustainability of such schemes. Life Cycle Sustainability Assessment (LCSA) is an appropriate tool for assessing holistic sustainability. To achieve resilient societies, the interests of communities should be considered in decision making. This paper proposes a method for incorporating community needs in identifying sustainability metrics for the sustainability assessment of estate regeneration schemes. A literature review in the field of sustainability assessment of buildings is conducted followed by a mixed methods empirical research. Collection of data has been through surveys, an interview, and an evaluation questionnaire. Data has been analysed through statistical and thematic analysis and triangulation of the results. The findings have consistently yielded the limitations of the scope of the current sustainability assessment methodologies, especially for lack of attention to societal impacts of regeneration. The results have justified the need for this research to employ participatory approaches for identifying a relevant set of sustainability indicators and criteria for assessing the lifetime impacts of estate regeneration schemes. Issues related to community involvement in decision making, maintenance and management, community facilities, refurbishment, and disruption have been identified as the stakeholders’ top priorities. Mental Health and Socioeconomic Values have been introduced as new criteria. The findings confirm the need for an in-depth approach towards identifying the regeneration priorities of the communities for the scope of LCSA studies. The identified list of criteria can apply to other studies of this context for an equitable approach for selecting the indicators across different criteria and for communicating the LCSA results with different stakeholders.

Induction vacuum swing adsorption over magnetic sorbent monoliths and extrudates for ethylene/ethane separation

AbstractElectrification of adsorption processes is emerging as an adaptable solution for future gas separations. This study develops magnetic sorbent structures for use in induction vacuum swing adsorption (IVSA) process specifically designed for olefin/paraffin separation. Two sorbents, namely Fe3O4/ZIF‐7 (ethane‐selective) and Fe3O4/13X (ethylene‐selective) were developed and formulated into extrudates (Fe20/ZIF‐7‐P) and monoliths (Fe20/13X‐M), and tested under different regeneration scenarios, including simultaneous and subsequent induction‐evacuation, induction only, and evacuation only. The dynamic adsorption results demonstrated that regeneration under subsequent induction‐evacuation improves desorption rate and capability. Under this regeneration scenario, Fe20/ZIF‐7‐P achieved an ethane desorption rate of 0.24 mmol/g.min, representing a remarkable 37.5% enhancement over the induction‐only scenario. Similarly, Fe20/13X‐M exhibited an ethylene desorption rate of 0.35 mmol/g.min, indicative of a 34.2% enhancement. Moreover, the IVSA cyclic runs highlighted the excellent regeneration capability and stability of both Fe20/ZIF‐7‐P and Fe20/13X‐M with Fe20/13X‐M exhibiting ethylene purity, recovery, and productivity of 99.4%, 99.6%, and 39.9 mol/kg.h, respectively. Overall, these findings underscore the potential of the hybrid induction/vacuum process as an effective technique for achieving efficient regeneration of sorbents in olefin/paraffin separation.

A spatial decision support system for multi-dimensional sustainability assessment of river basin districts: the case study of Sarno river, Italy

Effective management of the complex Socio-ecological systems (SES) of the river basin, influenced by a range of social, economic, and environmental variables, requires multi-purpose Spatial Decision Support Systems (SDSSs) to identify and select balanced and sustainable regeneration scenarios. In many cases, the lack of cooperation between administrative institutions and the low level of participation of the stakeholders involved are the main obstacles to effective planning and regeneration practices and call for new forms of governance. However, to address these critical issues, few studies use quantitative approaches to assess the multidimensional resources of river basins in an integrated perspective in terms of their capacity to activate cooperation networks between river-crossed cities. This study aims to suggest a methodological approach combining Multi-Criteria Decision Analysis and Geographic Information Systems to achieve integration in pursuing sustainable regeneration pathways for a river basin district, analysing the case study of the Sarno River, composed of 20 administrative units, in Southern Italy. The specific purpose is to provide decision-makers with an SDSS to evaluate sustainability scenarios based on the multi-dimensional performances of River Basin District Units (RBDU). The results delivered four partial rankings of RBDU related to social, cultural, ecological, and economic scenarios and one overall ranking for an integrated sustainability scenario. Each ranking includes a clustering of municipalities according to three classes: Leader, Link and Follower. The outcome is twofold: to provide decision-makers with recommendations for supporting governance models based on sustainability pathways and to suggest valuable methods and tools for dealing with the spatial misfits, considered as the mismatch between the physical boundaries of a natural system and the management area of an organization.

The greenhouse gas emissions reduction co-benefit of end-of-life electric vehicle battery treatment strategies

Vehicle electrification stands as a pivotal catalyst for effecting a low-carbon transition within the transportation sector. End-of-life (EoL) battery treatment, which is mainly aimed at facilitating material recycling, provides considerable co-benefit in reducing greenhouse gas (GHG) emissions. This study assesses the life-cycle GHG emissions from battery production, and examines the impact of three EoL battery treatment strategies: second use, regeneration, and recycling. Prospective scenarios of GHG emissions from electric vehicle battery production in China are further provided. The results show that under the Business as Usual (BAU) scenario, GHG emissions peak at 36 million tons in 2030, with 18 million tons for LFP and 18 million tons for NCM, and decrease to 11 million tons in 2060, with 4 million tons for LFP and 7 million tons for NCM. GHG emissions have more reduction potential as the collection rate increases and the proportion of different strategies applied changes. In a scenario with improved collection rates, GHG emissions would be reduced by 21% in 2060 compared to BAU. In a prioritized regeneration scenario, GHG emissions can be reduced by 32% in 2060, with 64% of lithium resources being supplied by regenerated batteries. In a prioritized second use scenario, GHG emissions can be reduced by 104% in 2060, which involves replacing 27 kilotons of lithium input and mitigating 13 million tons of GHG emissions related to the energy storage system. In light of these findings, we advocate for policy recommendations aimed at fostering the advancement of EoL battery treatment technologies and expediting the transformation of battery manufacturing processes towards carbon neutrality.

A Community-based Whole Life Carbon Assessment: Case study of a London estate community plan

In the attempt to adhere to the UK’s 2050 Net-Zero Strategy, more attention has been given to energy-centric decision-making over the regeneration of housing estates. Whole Life Carbon Assessment (WLCA) is the methodology used for the evaluation of the overall carbon dioxide equivalent (CO2e) emissions of building projects over their lifecycle. The WLCA studies are mostly not understood by different stakeholders and are less effective in reducing the Global Warming Potential (GWP) impacts in the development of regeneration scenarios. This paper is part of a larger study on a multistakeholder lifecycle-based sustainability assessment framework and aims to further explore whether retrofitting can outperform the existing and new build scenarios for lower GWP impacts, and intends to examine the use of WLCA for the development of a regeneration scenario. The research consists of a single-case case study employing co-design workshops, surveys, and WLCA experiments. The community’s preferred regeneration scenario has been developed through knowledge mobility and co-design workshops with the members of the community and a UCL team of designers and researchers. The WLCA of different regeneration scenarios (existing building, different refurbishment scenarios, and a previously approved redevelopment scheme) has been conducted using the data from desk-based research, site surveys, building regulations, retrofit case studies and guidelines, and the planning documents of the council’s previously approved new build scheme. The results of the WLCA support the current studies in favour of the refurbishment scenarios over the demolition and rebuilding of the estate, and make a case for the necessity of understanding the GWP in design development to reduce the GWP of regeneration scenarios.

Fine root and soil nutrients pool in the ecosystem following two scenarios of reconstruction—post‐fire and post‐mining large‐scale disturbance

AbstractThis study compares the concentration and quantitative ratios of macronutrients (nitrogen, phosphorus, magnesium, and potassium) in the litter and fine roots of various species stands, comprising Scots pine, Common birch, and European larch, in the context of nutrient pool formation and nutrient uptake efficiency in various regeneration scenarios and the reconstruction of forest ecosystems. The control plots were located on podzols in the natural habitats. The performed experiments showed that in all species scenarios, the nitrogen pool supplied to the soil with fine roots was equivalent to the pool supplied with the leaves; furthermore, in the case of phosphorus, the pool was even higher than the one reaching the soil through under‐canopy litterfall. However, the total amount of nutrients supplied to the soil by the birch, larch, and pine in different afforestation scenarios varied. Scots pine was the species that supplied the largest amounts of nitrogen and phosphorus in the reconstructed forest ecosystems, while birch was the species that provided the largest amounts of total nitrogen and phosphorus in the regenerated and control forest ecosystems.

ψ(2S) production and nuclear modification factor in nucleus–nucleus collisions with ALICE

Charmonium production is sensitive to deconfinement in nucleusnucleus collisions. The production via regeneration within the QGP or at the phase boundary has been identified as an important ingredient for the description of the centrality and transverse momentum dependence (pT) of the J/ψ nuclear modification factor (RAA) at the LHC. ψ(2S) production relative to J/ψ is one possible discriminator between the two different regeneration scenarios. At the LHC. there is so far no significant observation of the ψ(2S) in central nucleus-nucleus collisions at low-pT, where regeneration is expected to play an important role. The combined Run 2 data set of ALICE allows one to extract a significant ψ(2S) signal in this kinematic region at forward rapidity, in the dimuon decay channel. In this contribution, we present for the first time results on the ψ(2S)-to-J/ψ single ratio and double ratio (to pp collisions) as well as the ψ(2S) nuclear modification factor, in Pb-Pb collisions at √SNN = 5.02 TeV. The ψ(2S)-to-J/ψ double ratio and ψ(2S) RAA are calculated using a new proton-proton reference with improved precision. Results are compared with model calculations.

Systemic control of plant regeneration and wound repair.

Plants have a broad capacity to regenerate damaged organs. The study of wounding in multiple developmental systems has uncovered many of the molecular properties underlying plants' competence for regeneration at the local cellular level. However, in nature, wounding is rarely localized to one place, and plants need to coordinate regeneration responses at multiple tissues with environmental conditions and their physiological state. Here, we review the evidence for systemic signals that regulate regeneration on a plant-wide level. We focus on the role of auxin and sugars as short- and long-range signals in natural wounding contexts and discuss the varied origin of these signals in different regeneration scenarios. Together, this evidence calls for a broader, system-wide view of plant regeneration competence.

Natural forest regeneration on anthropized landscapes could overcome climate change effects on the endangered maned sloth (Bradypus torquatus, Illiger 1811)

Abstract Climate change and habitat loss have been identified as the main causes of species extinction. Forest regeneration and protected areas are essential to buffer climate change impacts and to ensure quality habitats for threatened species. We assessed the current and future environmental suitability for the maned sloth, Bradypus torquatus, under both future climate and forest restoration scenarios, using ecological niche modeling. We compared environmental suitability for two Evolutionarily Significant Units (ESUnorth and ESUsouth) using two climate change scenarios for 2070, and three potential forest regeneration scenarios. Likewise, we evaluated the protection degree of the suitable areas resulting from the models, according to Brazilian law: PA—Protected Areas; PPA—Permanent Protection Areas (environmentally sensitive areas in private properties); and LR—Legal Reserves (natural vegetation areas in private properties). Finally, we calculated the deficit of PPA and LR in each ESU, considering the current forest cover. Forest regeneration might mitigate the deleterious effects of climate change by maintaining and increasing environmental suitability in future scenarios. The ESUnorth contains more suitable areas (21,570 km²) than the ESUsouth (12,386 km²), with an increase in all future scenarios (up to 45,648 km² of new suitable areas), while ESUsouth might have a significant decrease (up to 7,546 km² less). Suitable areas are mostly unprotected (ESUnorth—65.5% and ESUsouth—58.3%). Therefore, PPA and PA can maintain only a small portion of current and future suitable areas. Both ESUs present a high deficit of PPA and LR, highlighting the necessity to act in the recovery of these areas to accomplish a large-scale restoration, mitigate climate change effects, and achieve, at least, a minimum forested area to safeguard the species. Notwithstanding, a long-term conservation of B. torquatus will benefit from forest regeneration besides those minimum requirements, allied to the protection of forest areas.

Seed Dispersal Models for Natural Regeneration: A Review and Prospects

Natural regeneration in forest management, which relies on artificial planting, is considered a desirable alternative to reforestation. However, there are large uncertainties regarding the natural regeneration processes, such as seed production, seed dispersal, and seedling establishment. Among these processes, seed dispersal by wind must be modeled accurately to minimize the risks of natural regeneration. This study aimed to (1) review the main mechanisms of seed dispersal models, their characteristics, and their applications and (2) suggest prospects for seed dispersal models to increase the predictability of natural regeneration. With improving computing and observation systems, the modeling technique for seed dispersal by wind has continued to progress steadily from a simple empirical model to the Eulerian-Lagrangian model. Mechanistic modeling approaches with a dispersal kernel have been widely used and have attempted to be directly incorporated into spatial models. Despite the rapid development of various wind-dispersal models, only a few studies have considered their application in natural regeneration. We identified the potential attributes of seed dispersal modeling that cause high uncertainties and poor simulation results in natural regeneration scenarios: topography, pre-processing of wind data, and various inherent complexities in seed dispersal processes. We suggest that seed dispersal models can be further improved by incorporating (1) seed abscission mechanisms by wind, (2) spatiotemporally complex wind environments, (3) collisions with the canopy or ground during seed flight, and (4) secondary dispersal, long-distance dispersal, and seed predation. Interdisciplinary research linking climatology, biophysics, and forestry would help improve the prediction of seed dispersal and its impact on natural regeneration.

Forest regeneration may reduce the negative impacts of climate change on the biodiversity of a tropical hotspot

AbstractAimEvaluate how large‐scale forest regeneration based on a low‐cost restoration method may mitigate the effects of habitat loss and fragmentation associated to future climate changes on the distribution of birds and arboreal mammals in a tropical biodiversity hotspot; find areas with different current and future potential species richness and assess how passive restoration can reduce the risk of species extinction.LocationBrazilian Atlantic Forest (BAF).MethodsWe built a forest regeneration scenario via a model of seed dispersal based on the potential movement of frugivorous fauna and projected the potential distribution of 356 bird species and 21 arboreal mammals based on Species Distribution Models (SDM) which employed 79,462 occurrence records and four algorithms for different climate and landscape scenarios. SDM were based on climate and landscape predictors separately and the results were combined into maps of species richness. Finally, we assessed the species’ risk of extinction based on the species–area relationship.ResultsWithout considering the effects of climate change, the potential distribution area for each species increases on average by 72.5% (SD = 8%) in the scenario of potential regeneration. Climate change decreases the area of potential occurrence of 252 species, which may suffer a mean reduction of 74.4% (SD = 9.3%) in their current potential distribution areas. BAF regions with the largest amounts of forest had the greatest potential richness of species. In future climate scenario, 3.4% of species may become extinct, but we show that large‐scale regeneration may prevent these extinctions.Main conclusionsDespite the possible negative impacts of climate change on the distribution of 67% of the studied species, which would increase the risk of species extinction, our analysis indicated that promoting large‐scale BAF restoration based on natural regeneration may prevent biodiversity loss.

Influence of tree species on carbon, nitrogen, and phosphorus stocks and stoichiometry under different soil regeneration scenarios on reclaimed and afforested mine and post-fire forest sites

In this work, we present the effects of Scots pine (Pinus sylvestris L.), common birch (Betula pendula Roth), and black alder (Alnus glutinosa Gaertn.) on the carbon (Cstock), nitrogen (Nstock), and phosphorus (Pstock) stocks and stoichiometry in the uppermost soil horizons (Oi + Oe, 0–5 cm) on afforested post-mining sand-pit and post-fire forest sites. These results were compared to those for undisturbed forest sites under the same tree species. The Cstock and Nstock of the post-fire soils were similar to those of the undisturbed soils, but lower for the reclaimed mine site. Notably, tree species affected the distribution of Cstock between the organic and mineral horizons. Compared to the other tree species, pine was characterized by a higher Cstock in the Oi + Oe horizons of the post-mining and undisturbed soils. In the 0–5-cm soil horizons, the highest Cstock values were detected under alder at the post-mining site and under birch and alder at the undisturbed site. For all of the studied sites, the C:N ratios in the litter horizons occurred in the following order: alder < birch < pine. This trend was only reflected in the mineral horizons of the undisturbed sites, which indicates the very temporary impact of organic matter on the disturbed sites. The C:P and N:P ratios in the mineral soil horizons were higher for the post-fire site than the post-mining and undisturbed sites, which may indicate a P limitation for the given content of C and N. Black alder, as a N-fixer, can increase the C:P and N:P ratios in nutrient-poor, sandy soils after disturbance in comparison with the other studied tree species, especially in post-fire soils. The uppermost mineral soil horizons under alder were characterized by higher C:P and N:P ratios than the soils under pine on the post-mining site and under the other tree species on the post-fire site. The N:P ratios in the litter horizons under alder on the disturbed sites were higher than for the other tree species, while this was not true for the undisturbed soils where alder grew under nutrient-optimal conditions. This suggests that the phytomelioration influence of N-fixers on degraded and nutrient-poor soils, may be inhibited by P limitation.

Dynamic health risk assessment model for construction dust hazards in the reuse of industrial buildings

The reuse of industrial buildings produces large amounts of construction dust, which poses significant health risks to construction workers. A dynamic health risk assessment (DHRA) framework is proposed to comprehensively estimate and reduce the hazards caused by dust produced during the renovation construction of polluted industrial buildings. The proposed framework primarily considers the changes in the construction process due to the changes in the temporal and spatial dimensions and is used to perform highly specialised risk assessments of dust hazards. The DHRA framework identified four time-varying factors: construction procedures, construction behaviours, site characteristics, and regeneration scenarios. In addition, the spatial distribution characteristics of dust and industrial pollutants produced through various construction processes were considered, and a spatio-temporal risk assessment model was developed to predict the degree of construction dust risk caused by construction behaviour. The DHRA framework expands the connotation of the United States Environmental Protection Agency (USEPA) model from a dynamic perspective and provides new ideas and methods for the occupational health and safety management of related construction projects. This framework can effectively promote the development of a sustainable theory. It can be used as a tool for predicting and assessing hazards, which can provide certain theoretical and technical references for dust control in various construction projects, especially in the reconstruction of old industrial buildings.

Life cycle environmental impacts of regeneration options for anion exchange resin remediation of PFAS impacted water

Although anion exchange resin (AER) treatment is considered an effective technology for removing per- and polyfluoroalkyl substances (PFASs) from impacted water, the environmental impacts associated with AER regeneration have not been systematically explored. In particular, the trade-offs of altering the composition of the regeneration solution and disposing of or recycling the waste regeneration solution are not known. To fill these important gaps in the literature, this research conducted a comparative life cycle assessment (LCA) of an AER-based PFAS remediation system with different regeneration scenarios including disposing of waste regeneration solution via incineration, reusing the organic cosolvent and brine fractions of the waste regeneration solution, and altering the composition of the regeneration solution to avoid organic cosolvent or NaCl. The results show that disposing of waste regeneration solution via incineration, without recycling organic cosolvent or brine, had the greatest environmental impact, and that incineration accounted for the greatest impact among contributing processes. Recycling of the cosolvent (or cosolvent and brine) fraction of the waste regeneration solution resulted in lower environmental impacts due to reduced mass of waste disposed of via incineration. Replacing NaCl in the brine with an alternative salt resulted in higher environmental impacts, with salts derived from chemical production, such as ammonium chloride and potassium carbonate, showing the largest increases in impacts. The results of this research highlight the importance of understanding the fate of PFASs during incineration, and the need for PFAS destruction technologies that can be coupled to AER regeneration to avoid incineration.

In Vitro Models for the Development of Peripheral Nerve Conduits, Part I: Design of a Fibrin Gel-Based Non-Contact Test.

Current clinical strategies to repair peripheral nerve injuries draw on different approaches depending on the extent of lost tissue. Nerve guidance conduits (NGCs) are considered to be a promising, off-the-shelf alternative to autografts when modest gaps need to be repaired. Unfortunately, to date, the implantation of an NGC prevents the sacrifice of a healthy nerve at the price of suboptimal clinical performance. Despite the significant number of materials and fabrication strategies proposed, an ideal combination has not been yet identified. Validation and comparison of NGCs ultimately requires in vivo animal testing due to the lack of alternative models, but in the spirit of the 3R principles, a reliable in vitro model for preliminary screening is highly desirable. Nevertheless, more traditional in vitro tests, and direct cell seeding on the material in particular, are not representative of the actual regeneration scenario. Thus, we have designed a very simple set-up in the attempt to appreciate the relevant features of NGCs through in vitro testing, and we have verified its applicability using electrospun NGCs. To this aim, neural cells were encapsulated in a loose fibrin gel and enclosed within the NGC membrane. Different thicknesses and porosity values of two popular polymers (namely gelatin and polycaprolactone) were compared. Results indicate that, with specific implementation, the system might represent a useful tool to characterize crucial NGC design aspects.

Sensibility, Sensation, and Nerve Regeneration after Reconstructive Genital Surgery: Evolving Concepts in Neurobiology.

Sensory recovery following phalloplasty and vaginoplasty for gender dysphoria is essential to the overall success of gender-confirming surgery. Anecdotal evidence suggests that superior reinnervation results are seen in genitoplasty compared to other peripheral nerve repair scenarios. Despite these observed differences, the quality of available literature is poor. The authors reviewed the body of English language literature regarding sensory outcomes following genitoplasty for gender confirmation. The available body of literature discussing the basic science and clinical science aspects of sensory recovery following gender-confirming genitoplasty is small. Available data show that sensory recovery following vaginoplasty produces high rates of reported orgasmic ability, largely through the neoclitoris, and a neovagina with vibratory and pressure sensation similar to that of the native vagina. Phalloplasty sensory outcomes are variable, with the largest series reporting return of sensation in the neophallus that is slightly less than what is measured in control men. Erogenous sensation, including the ability to orgasm, is present in nearly all patients after several months. Existing series indicate that genitoplasty patients experience faster and more complete recovery than any other peripheral nerve regeneration scenarios. However, there are many potential confounding factors in assessment and reporting, and more consistent and reproducible measure endpoints measures are needed. Further research is needed to better understand both the basic science and clinical science of peripheral nerve regeneration in genitoplasty, which may change fundamental aspects of current paradigms of peripheral nerve regeneration.