Many components  in black tea have antioxidant activities. However, it is not clear which components have a greater influence on the antioxidant activity of black tea. In this study, the antioxidant activity and contents of tea polyphenols, catechins, theaflavins, thearubigins, theabrownins, TSA, total flavonoids, amino acids, caffeine, and total soluble sugar were analyzed in 51 black teas. Principal component analysis (PCA), orthogonal partial least-squares discrimination analysis (OPLS-DA), and the correlation analysis method were used for data analysis. The results showed that catechins in tea polyphenols were the most important components that determine the antioxidant activity of black tea. Among them, epicatechin gallate (ECG), epi-gallocatechin gallate (EGCG), epicatechin (EC), and epi-gallocatechin (EGC) were significantly positively correlated with the antioxidant activity of black tea, and theabrownin was negatively correlated with the antioxidant activity of black tea. Furthermore, this study analyzed the correlation between the changes in catechin and its oxidized polymers with antioxidant activity during black tea fermentation; it verified that catechins were significantly positively correlated with the antioxidant activity of black tea, and theabrownin showed a negative correlation. And the antioxidant activity of catechins and their oxidation products in vitro and their correlation in black tea processing were used as validation. This study provides a comparison method for comparing the antioxidant activity of black tea. In the year 2020, the global tea production was 6.27 million tons, and it had been growing for 10 years (data source: China Tea Marketing Association). Black tea is the most produced and consumed tea in the world and accounts for over 70% of the world’s tea production. China, India, Kenya, and Sri Lanka are the world’s largest producers of black tea 24], and Based on the results of the correlation analysis, The oxide products of catechins, such as theasinensins, theaflavins, thearubigins, and theabrownins were also important phenolic compounds with antioxidant activity in black tea , howeverPhenolics were primary antioxidant compounds of black tea. The black tea fermentation process is accompanied by a series of oxidation reactions of catechins. Catechins firstly forms theaflavin and theasinensin through the benzotropolone ring and disproportionation. These catechin dimers are unstable and are prone to forming thearubigin and theabrownin through oxidation reactions . As mentBased on the results of correlation analysis, 4 equivalent ability, catechin dimers took second place, and TSA was stronger than theaflavins, whilst theabrownins were in last place. It showed similar results with the correlation analysis; ECG was also more prominent than other catechins in differences and correlations, and TSA was more prominent than theaflavins and theabrownins.Based on the results of the correlation analysis, the higher the oxidation polymerization degree of catechins, the lower the correlation between the products and antioxidant activity of black tea. The comparison of antioxidant activities among these compounds was shown in Through the partial least squares discriminant analysis (OPLS-DA), the study found that black tea samples from different sources had significant differences in antioxidant activity, and TP, ECG, TSA, EGCG, GA, EC, CAF, and AA were the differential compounds. There were eight compounds with a significant positive correlation with the antioxidant activity. Among them, TP, ECG, EGCG, and EC decreased during the black tea fermentation process. And the study found that the antioxidant activity of black tea also showed a decreasing trend during fermentation. It was speculated that the antioxidant activity of black tea was weakened with the oxidative polymerization of catechins gradually, and the antioxidant activity of catechins and their oxides in vitro supported this view. TSA was the differential component in catechin dimers, and TSA had a higher correlation coefficient with antioxidant activity than theaflavins and theabrownins, and TSA was also stronger than theaflavins in the function of inhibiting melanin synthesis . TSA incThe antioxidant activity of black tea was mainly determined by the content of catechins. The correlation coefficient between the sum of catechins and its dimers with the antioxidant activity could reach more than 0.9, and ECG had the highest correlation coefficient, however the correlation coefficient gradually decreased when thearubigins and theabrownins were increasing. The conclusion could also be proved by exploring the changes of antioxidant activity during the fermentation of black tea and the antioxidant activity of catechins and their oxides in vitro; both the antioxidant activity and catechins contents decreased gradually during black tea fermentation, whereas theabrownin content increased gradually. This study provides a good way for evaluating the antioxidant activity of black tea and could provide new ideas for improving the antioxidant activity of black tea samples and developing new products.


Over the past twenty years, the use of electronic mobile sensors by children and youngsters has played a significant role in environmental education projects in Portugal. This paper describes a research synthesis of a set of case studies  on the use of sensors as epistemic mediators, evidencing the technological, environmental, social, and didactical dimensions of environmental education projects over the last two decades in Portugal. The triggers of the identified changes include: (i) the evolution of sensors, information and communication platforms, and mobile devices; (ii) the increasing relevance of environmental citizenship and participation; (iii) the recognition of the role of multisensory situated information and quantitative information in environmental citizenship; (iv) the cause–effect relation between didactical strategies and environmental education goals; (v) the potential of sensory and epistemic learners’ practices in the environment to produce learning outcomes and new knowledge. To support the use of senses and sensors in environmental education projects, the SEAM model was created based on the developed research synthesis. The final goal of the research presented in this paper is to create a visual model of the use of sensors in environmental education projects. An analysis of a set of environmental education projects implemented in Portugal is developed for that purpose.This introduction outlines the main topics of the present research, connecting environmental education, human senses, and mobile electronic sensors.The environmental education projects discussed in this study align with the overarching objective outlined in the Belgrade Charter: “To develop a world population that is aware of, and concerned about, the environment and its associated problems, and which has the knowledge, skills, attitudes, motivations and commitment to work individually and collectively toward solutions of current problems and prevention of new ones ” (p. 3).The conceptual framework for integrating mobile electronic sensors into environmental education, as outlined in this paper, highlights the potential of these sensors, along with other digital technologies, to cultivate a deeper and more empathetic connection with both the environment and fellow individuals . Human spraxis of the bodies [The joint use of senses and mobile electronic sensors by children and youngsters in the environment involves embodied experiences and facilitates the acquisition of information through perception as well as the quantitative data gathered by the sensors. Abstract knowledge is then synthesized and processed in the mind, rooted in the e bodies . This loe bodies .Collecting and analyzing local environmental data plays a pivotal role in motivating children and youngsters to participate actively within their local communities . To maxiWhen young individuals assume control over sensors and sensory input during environmental exploration, a sense of competence flourishes . FurtherThe tangible information acquired via human senses and the abstract knowledge acquired by sensors are inherently tied to geographic locations. Consequently, the environmental education projects explored in this research study generate Voluntary Geographic Information (VGI), encompassing spatial data. The aim of this study was to encourage children and youngsters to voluntarily produce spatial data and contribute to scientific environmental knowledge .Aligned with the overarching goal of environmental education, the incorporation of mobile electronic sensors into the learning process, in and for the environment, can be mediated to develop awareness, skills, and attitudes to address and prevent environmental problems.The integration of electronic sensors into environmental education has primarily been driven by market forces that have made these tools accessible for everyday educational activities. Electronic sensors have evolved to become smarter, smaller, portable, affordable, and wireless ,10.Over the past two decades, sensor technologies have been moving towards specialization . This trAnother significant trend impacting environmental education is the substantial reduction in sensor costs. This shift is particularly evident in air quality monitoring, where low-cost sensors worn or carried by individuals estimate one’s personal exposure to different types of pollution . An examThe proliferation of low-cost sensors has coincided with a marked increase in the use of Information and Communication Technologies (ICT) devices such as laptops, tablets, and smartphones in educational projects The latter have had a profound impact not only because they are considered an extension of the self by children and youngsters  but alsoThe rise of the Internet of Things has introduced new possibilities, particularly with platforms like Arduino and Raspberry Pi ,18,19. TBeyond this introductory context, the subsequent section examines how the incorporation of sensors into environmental education projects can be framed across multiple dimensions. The third section of this paper synthesizes the research we conducted, and this is followed by the presentation and discussion of our results in With teacher mediation, young learners use mobile sensors in diverse ways and for different objectives within environmental education projects. The multiple dimensions of these projects, including technological, social, didactic, and epistemic aspects, influence how sensors are integrated into the activities of children and youngsters. This influence is described in the present section.Regarding the technological dimension, as elucidated in the Introduction, electronic sensors have evolved to become became simpler, smaller, cheaper, mobile, and wireless ,10. TheyIn 2019, the EU Kids Online network conducted a survey involving children aged 9–17 from 19 European countries, including 1974 children in Portugal . SmartphIn a recent study conducted with younger children aged 3–8 years , researcIn the early years of the second decade of the 21st century, the advent of mobile electronic sensors combined with data loggers ushered in a new era for environmental education. This innovation facilitated data collection, storage, and visualization in multiple representations . These sWithin the social dimension of environmental education projects, the significance of global environmental participation has grown, particularly since the emergence of Agenda 21 and the Rio Declaration on Environment and Development , which pParticipation stands as the highest level among the environmental education objectives, alongside categories like awareness, knowledge, and skills, as originally outlined during the Tbilisi Conference . EmployiFrom a didactic perspective, the development of a specific category of educational goals requires the use of targeted educational strategies. Experiential learning offers an embodied, enactive approach to fostering environmental awareness by facilitating a dialogue between experiential encounters and theoretical learning . AccordiResearch-based learning represents a student-centered model that promotes awareness, knowledge acquisition, and competencies. It integrates research methodologies into the learning process, treating research as a means to uncover, develop, test, and communicate knowledge . While rResearch-based learning combines critical thinking and inquiry, empowering students to take charge of their learning. In this model, inquiry can extend beyond bibliographic research to encompass problem-solving and experimental activities, often converging with problem-based and project-based learning. Within inquiries, sensor use centers around the stages of inquiry. Even bibliographic inquiries can be enriched through sensor integration. For instance, data collected by microphones and cameras can be used for bibliographic searches based on produced sounds and images.Problem-based learning not only facilitates the acquisition of diverse forms of knowledge but also cultivates global competencies such as information searching and organization, the practical application of knowledge in everyday problems, the effective communication of processes and results, the selection of appropriate problem-solving techniques, and collaborative and autonomous work . ProblemIn situated problem-based learning, sensor utilization assumes a central role within environmental education projects, as sensors enable the detection and, often, the measurement of environmental variables. This allows for data collection, which is necessary to address problem statements and arrive at evidence-based conclusions. Sensors also facilitate the creation of multiple data visualizations, aiding in communicating processes and outcomes.Project-based learning can be developed together with problem-based learning. The distinctive factor of project-based learning lies in the requirement for real-world, situated problem statements and the extended timeframe for implementation .Epistemically, the application of diverse didactic strategies engenders the development of distinct epistemic practices among learners—practices that generate knowledge . These pAcross all aforementioned didactic strategies, learners can leverage everyday and laboratory resources, including sensors, as epistemic mediators—external tools utilized to construct knowledge . LearnerThe central goal of this research study was to develop a visual model of the use of sensors within environmental education projects. Our specific research goals included the following: (i) to outline the underlying dimensions of environmental education projects, (ii) to analyze the influence of the projects’ dimensions in the use of sensors, (iii) to create categories of thematic analysis based on the previously defined dimensions, (iv) to classify both common and distinctive features/themes in the use of sensors across environmental education projects using the defined categories of analysis, and (v) to create and organize clusters of fundamental features/themes in a visual model.To achieve these goals, we conducted an in-depth analysis of sensor use in the environmental education initiatives that young learners have been actively engaged with over the past two decades. It is important to note that the projects subjected to analysis herein have already been documented in various publications. This study examines these publications to facilitate the desired analysis, thus enabling the creation of the envisaged visual model.The projects subjected to analysis serve as distinct case studies, in accordance with Yin’s framework , which dA research synthesis encompasses a series of methods that serve to “summarize, integrate, combine, and compare the findings of different studies on a specific topic or research question”  (p. 441)Moreover, this research synthesis bears certain similarities to cross-case studies, as it employs visual aids such as tables and diagrams to analyze and visualize the shared themes and disparities across the various studies .corpus that enables bibliographic data collection. Tables are used in this research study both as analysis and visualization tools, and a bibliographic management tool (Zotero) was also used during our research.The methodology unfolds in several key steps. The outlining and description of the underlying dimensions of environmental education projects, as well as their influence in the use of sensors, is the first step, and this has already been presented in the previous section. In the second step, a preliminary exploratory analysis is undertaken to gain an overarching understanding of the dataset (the diverse projects) and to establish categories of thematic analysis based on the previously defined dimensions. The identification of these categories allows for an initial structured thematic analysis and the presentation of relevant themes within the context of the previously developed theoretical framework. Since the authors of this paper were involved in the projects that constitute the case studies, participant observation is a data collection method with foundational importance in this research study. The analysis of published papers, chapters, and sites where the projects were described constitute the The subsequent step involves scrutinizing the structured presentation to establish interconnections among the identified themes and categories, culminating in the inductive and iterative formulation of a visual model, using diagrams. This model’s development constitutes the final step of the process.This section presents the outcomes of our analysis of sensor use within a series of environmental education case studies. These case studies encompass projects that the authors of this paper have actively engaged with in Portugal over the past two decades.Initially, all eight projects were examined based on the dimensions previously delineated in Context/School grade: This category encompasses age, years of schooling, and their alignment with children’s cognitive development and problem-solving capabilities. The context, whether formal or non-formal, alongside the school grade, shapes the selection of strategies and resources (including sensors) and the techniques employed.Challenges to learners: These challenges are suggested practices aimed toward achieving learning outcomes such as acquired knowledge, attitudes, and competences.Main examples of developed competences: Competences represent a higher-level classification of learning outcomes. They are fostered through sensory and epistemic practices that leverage sensors within various activities, such as inquiries. Competences and practices combine to enable the creation of final products.Main examples of products: Products arise from sensory and epistemic practices and are developed to overcome the initial challenges set forth.Main used resources: This category encompasses a diverse array of resources, including electronic sensors, related apps, experiment plans, registration forms, data platforms, and other everyday and laboratory materials.The selected categories for analysis encompass the following:It is important to identify the close relations between the following dimensions and categories: (i) “technological dimension” and “main used resources”; (ii) “social dimension” and “context/school grade”; (iii) “didactic dimension” and “challenges to learners”; (iv) “epistemic dimension” and “main examples of products”.Through the use of text and tables, as well as the above-mentioned categories, the following subsections present our analysis of the set of environmental education projects in consideration. The analysis is presented following the chronological order of the projects. The title of each of the following subsections epitomize the projects’ main characteristics, primarily with respect to the used hardware and software, the desired learning outcomes, and the didactic strategies of the projects.This section focuses on two pioneering projects, as presented in The Senses@Watch project  stands as a pioneer in harnessing environmental data acquired through human senses for citizen participation processes. This research project introduced novel methods for the concurrent application of human senses and sensors in the evaluation of environmental problems . AdditioDuring the 1990s and the early years of the 21st century, electronic sensors were not yet available for citizen participation and educational settings. Consequently, in the first decade of the Globe Project and within the Senses@Watch project, environmental data were acquired using non-electronic sensors such as colorimetric kits, thermometers, and other laboratory analysis tools .This section highlights two projects that employ smartphones for the multisensory exploration of school environments and georeferenced multimedia communication of these explorations . The firThe SchoolSenses@Internet Project  explored the potential of georeferenced multisensory data to enhance learning within primary schools in the context of schoolyard environmental quality assessment . This prThe advent of virtual globes, including Google Earth, in 2005 significantly impacted projects of this nature. While the proposal for the SchoolSenses@Internet Project preceded the emergence of Google Earth, the advent of virtual globes played a pivotal role in its execution. Its attributes, such as its ease of use, graphical fluidity, and rapid user feedback when creating virtual flights around the world, were instrumental. Additionally, Google Earth affordances to publish geographic, multisensory, multimedia environmental information in multiple representations proved crucial .Prior to the era of virtual globes and ubiquitous mobile technologies, projects of geographic information creation and publication were documented. A notable historical precedent was the creation of the Domesday Book in the 11th century, a registry of English lands and properties initiated by William the Conqueror around 1086 . Nine-hundred years later, in 1986, the BBC introduced the Domesday disk, a laserdisc containing a survey of local geographic data in England carried out by children from thousands of schools, based on the division of the country into parts small enough to be inventoried locally with reduced human resources . While tIn Portugal, the Internet@EB1 project launched in 2003 resulted in the creation and dissemination of nationwide voluntary geographic information provided by over 7000 primary schools . This inThe SchoolSenses@Internet project was didactically centered around experiential learning strategies. Children used their senses and their smartphones’ built-in sensors, such as their phone’s GPS, microphone, and camera systems, to capture georeferenced multisensory environmental data while exploring their familiar schoolyards. Additionally, they crafted and sent multimedia messages that were compiled into KMZ files and subsequently published on Google Earth . This puThe USense2Learn project also centered on experiential learning strategies, inviting children to generate and send georeferenced multisensory multimedia messages to evaluate environmental quality using mobile phones. However, in this project, children were asked to explore and convey information on schoolyard thermal comfort . To suppBoth of the projects outlined in this section served as influential examples for subsequent projects. They illustrated the potential of utilizing smartphones’ built-in sensors to empower children in capturing georeferenced multisensory data. Furthermore, these projects illustrated the smartphone interface’s capability to compose and transmit georeferenced multisensory multimedia messages. The children successfully overcame the challenges presented by these projects, producing messages that represented the environmental quality of their respective schoolyards ,48.This section presents two projects—SOS Abstract and Sensing Urban Places—that used didactic, affordable, and mobile electronic sensors in conjunction with tablet/smartphone apps. These projects challenge children and young individuals to engage with their environment by using their senses. The connection between sensory practices and epistemic processes is explicitly emphasized, with sensory data being linked to the quantitative information acquired by the sensors . Both prThe first project, SOS Abstract (Using Sensors and Senses in the Environment to Develop Abstract Thinking), was tailored for primary school children aged 6 to 12 years old. The primary objective of SOS Abstract was to use both human senses and didactic sensors as epistemic mediators to cultivate abstract thinking . AbstracThe SOS Abstract project employed PASCO PASPORT sensors  due to the fact that their capabilities aligned with the project’s objectives. These plug-and-play sensors are mobile, affordable, and robust. The specific sensors used included a weather anemometer sensor (PS-2174), a conductivity sensor (PS-3210), a PASPORT water temperature sensor (PS-2125), a PASPORT turbidity sensor (PS-2122), a PASPORT conductivity sensor (PS-2116), a pH sensor PASPORT (PS-2147), a digital microscope  with 400× magnification, and the Samsung Galaxy S4’s sound sensor .Didactically, the SOS Abstract Project employed various strategies across different activities, including experiential learning, research-based learning, and problem-based learning. It highlighted the interconnection between sensory and epistemic practices while generating diverse representations of the outcomes derived from such practices. One technique employed to establish this connection and foster abstract thinking is referred to as “concreteness fading”. This approach consists of successively decreasing the concreteness of the representations, to attain an abstract representation that is still connected to the situation represented . Concrethttps://sensesandsensors.wordpress.com/, accessed on 26 July 2023) (i) in-built sensors on the Samsung Galaxy S4 smartphone ; (ii) the multimedia capabilities of the Samsung Galaxy S4, their Google account, and Picasa Web Albums; and (iii) a heart rate sensor  integrated with a smartphone through the Endomondo app to record tracks and heart rate data. The resulting georeferenced multimedia messages, tracks, and heart rate data were converted into kmz/gpx files, allowing for exploration and visualization within Google Earth.The second project—the Sensing Urban Places Project—involved aiming to enhance sensory engagement and convey sensations to architecture students through georeferenced multimedia messages complemented by sensor data. The students were prompted to utilize their senses along with . To promote the integration of project-based learning, the proposed activities started with familiarizing students with prevalent school-related environmental problems, such as sound pollution, air pollution, and thermal discomfort, along with their underlying causes and impacts. Subsequently, children, in collaboration with their teachers, chose a specific problem area (such as sound pollution) and explored the phenomena in a multisensory way [The Eco-Sensors4Health project was established with the goal of assisting educators in guiding students to use their senses and employ sensors to identify, investigate, and address environmental problems within their school environment . This apsory way . The prosory way ,60. Propsory way .The developed Eco-Sensors4Health platform includes a data input section where students and teachers can enter the environmental health data they acquired using sensors. Furthermore, it includes a query area that enables the retrieval of previously submitted data (collected by students). This platform also facilitates the submission and retrieval of inquiry documents such as experiment plans, photographs, and textual descriptions. The design process for this platform was iterative, including characteristics similar to that of design-based research, and led by a multidisciplinary team with expertise in both ICT and education .Within the Eco-Sensors4Health project, the following PASCO PASPORT sensors were used by students: the weather anemometer sensor (PS-2174), the sound level sensor (PS-2109), the carbon dioxide sensor (PS-3208), and the light sensor (PS-2106A). As previously noted, these sensors were intentionally chosen due to their ease of use, mobility, affordability, and robustness. Students were able to independently operate these sensors, while the free SPARKVue app, installed on tablets, functioned as an efficient data logger, allowing students to monitor and visualize data even while on the move.The activities outlined within the Eco-Sensors4Health project were initially designed for primary school students. However, their successful implementation extended beyond this scope and reached high school and higher education levels, including teacher training . This prThe integration of Senses and Sensors: All of the projects involved participants, including children and youngsters, in sensory practices and the use of electronic sensors for epistemic practices.Learning Outcomes: A primary goal across all projects was the attainment of specific learning outcomes, including acquired knowledge, attitudes, and competences aligned with environmental education objectives.Teacher Mediation: All project activities, including sensory and epistemic practices, were conducted under the mediation of teachers, ensuring the proper facilitation of active participant engagement and empowerment.Participants’ agency in the sensory and epistemic practices promoting empowerment.Use of Mobile Devices and Technology: Mobile devices such as sensors, smartphones, and tablets were integral to environmental exploration and communication, aiding both sensory and epistemic practices. Each project involved the creation and use of supportive resources such as registration forms and everyday objects to enhance the exploration of physical environmental phenomena such as sound.Creation of Situated Knowledge: The projects contributed to the generation of context-specific knowledge and geographic information.In addition to the presentation of two pioneering environmental projects that illustrated the potential of senses and sensors, the previous section introduced six projects that were developed with the active involvement of the authors of this paper. These six projects share several common characteristics, including the following:Despite these shared characteristics, it is important to scrutinize the six projects for distinctive features, considering the dimensions of environmental projects as discussed in Similarly, the SOS Abstract project, alongside its knowledge acquisition objectives, placed emphasis on fostering competences that linked concrete practices to abstract environmental information and representations. Additionally, the Eco-Sensors4Health project aimed to address every category of the environmental education goals, from awareness, through competences of environmental problem-solving, to participation in environmental improvement and protection.From a technological perspective, the projects followed the evolution of technology, and this is reflected in their utilization of mobile sensors, apps, mobile phones, tablets, netbooks, and communication platforms. While the SchoolSenses@Internet and USense2Learn projects employed prototype platforms that intertwined various functionalities, the Sensing Urban Places project effectively leveraged existing free apps and services, thereby obviating the need for technical support during task execution.The Dão Kids Academy and SOS Abstract projects used mobile sensors that were linked to an app (functioning as a data logger) installed on a smartphone or tablet, enhancing robustness, affordability, and ease of use for children, youngsters, and teachers. In these projects, the technology used was designed to be transparent, with innovation primarily concentrated on educational and sensor application aspects.The Eco-Sensors4Health project used the same mobile devices as the Dão Kids Academy and SOS Abstract projects but introduced an ad hoc collaborative data-sharing platform. This collaborative platform was iteratively developed by a multidisciplinary research team, enabling children to input, query, and visualize data concerning the environmental problems addressed by different participating schools . This plChronologically, the first two of the six projects in consideration were created to induce innovations in technology to enable the production and processing of georeferenced multisensory multimedia messages. Technological advancements allowed the subsequent projects to focus solely on educational innovation. The creation of the Eco-Sensors4Health platform exemplifies the application of pre-existing technology to achieve educational objectives. Notably, the latter three projects operated without prototypes, enabling autonomous and easily replicable technology use by both children and teachers.From a didactic standpoint, the earlier projects adopted an environmental exploratory approach, while the more recent ones embraced a participatory methodology, mirroring contemporary societal trends that emphasize environmental citizenship and local-global participation. In the SchoolSenses@Internet and in the USense2Learn projects, the focus was on experiential learning. However, children’s actions were not completely autonomous, and they needed more real-time support and guidance. In contrast, the Dão Kids Academy, SOS Abstract, and Sensing Urban Places projects were based on technology robustness and ease of use, enabling increased autonomy among children and affording teachers the opportunity to center their mediation on environmental education objectives. These three projects employed a combination of experiential learning, research-based learning, and problem-based learning strategies. The Eco-Sensors4Health project, epitomizing participatory engagement, granted participants greater autonomy, allowing for teacher’s to adopt a more flexible attitude, with project and problem-based learning emerging as privileged strategies. Consequently, this recent project targeted higher-level environmental education goals, integrating strategies that demanded greater autonomy and complex actions, thereby fostering diverse learning outcomes and greater knowledge creation.Across the spectrum of the six analyzed projects, there is a discernible progression from multisensory observation and communication (the SchoolSenses@Internet and USense2Learn projects) to data collection, representation, and interpretation , culminating in the planning and implementation of experimental inquiries, variable control, and decision-making processes .The analysis and subsequent discussion of the research synthesis findings culminated in the identification of particular themes and subjects which were subsequently structured into a visual model named SEAM—Sensors and Senses in Environmental Education Along with Teacher Mediation . This moIn this model, the use of sensors is part of the learners’ environmental educational practices. Sensors can be used as extended senses in sensory practices and as tools to learn and create knowledge in epistemic practices . Both ofLearning outcomes can include the acquisition of knowledge, as well as the development of attitudes and competences. Moreover, the knowledge generated can exhibit diverse levels of theoretical abstraction, with situated knowledge occupying a more empirical stance. Situated knowledge can be systematically organized and mapped, constituting more abstract information such as Voluntary Geographic Information, and theorized in case studies.To strategically gear learners’ practices towards the attainment of specific learning outcomes and diverse types of knowledge creation, it becomes essential to define the categories of the environmental education goals  that areDidactic strategies combine methods, processes, techniques, and organization approaches, including the use of sensors, to make it possible to achieve the defined goals . The disTeacher mediation transforms sensors and complementary support resources into epistemic mediators, guiding and helping learners through sensory and epistemic practices. This instructional approach serves to bridge learning gaps and surmount challenges such as the continuous integration of tangible experiences with abstract concepts and information. Teacher mediation and learners’ agency unfold in an interactive dynamic before , during, and after learners’ practices .In addition to senses and sensors, the inclusion of other support resources is due to their role in teacher mediation and enhancing the agency of learners in sensory practices and, especially, in the realm of epistemic practices. Notably, everyday household and laboratory items, as well as tools like data platforms and mobile ICT devices, play a vital role. Furthermore, an assortment of documents, ranging from registration and interpretation forms to multimedia presentations and various other multimedia creations, further contribute to the efficacy of teacher mediation and learners’ autonomous engagement in the learning process.The research presented in this paper centers around the use of electronic mobile sensors by children and youngsters in environmental education projects in Portugal. The analysis of the use and of the role of the sensors in a set of environmental education projects included a research synthesis of such projects, which were investigated as case studies.Through examining these environmental education projects in chronological order, we observed that the following overarching trends emerged: (i) The progression towards greater sensor robustness, user-friendliness, complexity, and specificity. (ii) The rise in learners’ autonomy, both in terms of defined goals and executed practices involving senses and sensors. (iii) The increasing grade of complexity in the educational strategies. (iv) The increasing level of abstraction in learning outcomes and in the created knowledge.Our analysis of the goals, strategies, and practices of learners with respect to the environmental education projects discussed in this paper revealed their relation to the environmental education currents defined by Sauvé .All the projects, starting with the SchoolSenses@Internet and the USense2Learn projects, strengthened the importance of practices such as the use of sensors in the environment, thus showing a close relation to the experiential dimension of the naturalist current;The SOS Abstract and the Eco-Sensors4Health projects used sensors in problem-based learning strategies, following the foundational problem-solving current of environmental education;In the Dão Kids Academy project, the use of sensors by children followed the bioregionalist current of environmental education since the project prioritized relationships to the environment and the community, developing a sense of belonging;In the Sensing Urban Places project, architecture students used sensors to enable autonomous, sensory, epistemic, creative, and effective environmental exploration, as preconized by the holistic current;praxic current.In the context of problem- and project-based learning, the use of sensors in the Eco-Sensors4Health project was based upon action and the improvement of action in the school environment, developing the main goals of the Throughout these projects, sensor utilization varied in a set of dimensions, as elaborated in this paper. It is worth noting that cases where sensors were innovatively integrated to create novel functionalities and communication pathways, often through prototypes, required a trade-off between sensor robustness and child autonomy, favoring technological innovation over lower-level educational innovation. Conversely, when the projects utilized commercialized systems, the children’s autonomy enabled more profound and deep-rooted educational innovation.The SEAM model  was developed based on the research presented in this paper (a research synthesis that involved characterizing selected case studies). This model is designed to support environmental educators in the design and implementation of environmental education projects where the use of the human senses and sensors plays a central role. Environmental projects that adhere to the SEAM model may exhibit varying characteristics in terms of their goals, strategies, learners’ practices, resources, learning outcomes, and knowledge creation.


NOTCH3 gene mutation (p.Cys212Gly), the presence of granular osmiophilic material (GOM) in cutaneous vessels in an immunohistochemistry test (IHC) and bilateral focal vasogenic lesions in the white matter of the cerebral hemisphere, with micro-focal infarct in the left external capsule on a magnetic resonance imaging test (MRI). Color Doppler imaging (CDI) confirmed decreased blood flow and increased vascular resistance in the retinal and posterior ciliary arteries, with reduced P50 wave amplitude on a pattern electroretinogram (PERG). An eye fundus examination and fluorescein angiography (FA) revealed the constriction of retinal vessels and a peripheral retinal pigment epithelium (RPE) atrophy with focal drusen. The authors suggest that the cause of TVL may be changes in the hemodynamics of the retinochoroid vessels associated with the narrowing of small vessels and the presence of druses in the retina—which is supported by a decrease in the amplitude of the P50 wave in PERG, changes in OCT correlating simultaneously with changes in MRI imaging and other neurological symptoms.The authors present a new paper examining the disturbances in ocular circulation and electrophysiological changes in the presence of neuro-ophthalmic manifestations in a patient with cerebral autosomal dominant arteriopathy with subcortical infracts and leucoencephalopathy (CADASIL). Symptoms reported by the patient included: transient vision loss (TVL), migraines, diplopia, bilateral peripheral visual field loss and convergence insufficiency. CADASIL was confirmed by the presence of  NOTCH3 gene , which determines the amino acid sequence of NOTCH3 protein, playing a crucial role not only in receptor binding but also in intercellular communication [CADASIL belongs to the group of small vessel diseases (SVD) and is a fairly rare  genetic disorder, caused by mutations in the NOTCH3 mutation causes explicit changes in the basal membrane and the pericytes of the capillaries. Progressive vessel wall thickening and constriction of the vessels lead to disseminated microangiopathy, followed by the formation of pathological changes mainly in the white matter of the brain but also inside the retina. This process is further intensified by the accumulation of elastic and collagen fibrils in the vessel walls. The alternative hypothesis assumes that GOM deposits are caused by smooth muscle cell degeneration. The similarity in the structure of retinal and cerebral cortical vessels results in the formation of histopathological changes simultaneously in both types of vessels. That is why in such cases MRIs reveal characteristic disseminated focal infarcts. These lesions are most often found in the subcortical and periventricular areas of the brain’s white matter, mainly in the temporal lobe, external capsule, the frontal and parietal lobe, subcortical nuclei and in the centrum semiovale. Characteristic lesions are also located in the grey matter of the brain and result in neuronal apoptosis, particularly in the third and the fifth ventricles. A gradual onset of CADASIL symptoms occurs between the ages of 20 and 30, and most often manifests as subcortical infarcts, transient ischemic attack (TIA), transient vision loss (TVL), episodes of migraine (often with aura), apathy, dementia and other psychiatric disorders followed by acute encephalopathy with mood disturbances [The accumulation in the extracellular domain of a receptor protein with smooth muscle cells of small- and medium-sized vessels leads to the formation of 10–15 nm granular osmiophilic material (GOM) deposits and is responsible for the pathophysiology of CADASIL. Furthermore, urbances ,5,6. ThoAccording to the literature, the most common manifestations of CADASIL syndrome include neurological symptoms, such as TIA as well as of ocular origin as TVL, the basis of which may be small vascular changes and blood flow disorders in both the cerebral and retinal vessels. We could not find many studies on ophthalmic manifestations in patients with CADASIL . Only one of them (between PubMed and Google Scholar) focused solely on retinal flow disturbances, assessed by a different method than in our study, scanning laser Doppler flowmetry.Another unreported phenomenon is hemodynamic disturbances in the optic nerve head and retrobulbar vessels, both in the central retinal artery and in the choroidal arteries, in the posterior ciliary arteries measured using CDI (color Doppler imaging). Moreover, only two publications discuss the interpretation of the results of electrophysiological studies (pERG) ,8. ThereNOTCH3 gene on chromosome 19—locus 19p13.1–p13.2; OMIM: 125310).A 43-year-old woman was referred for ophthalmological consultation due to a positive history of transient vision loss, diplopa, near heterophoria, defects in peripheral kinetic perimetry and problems with accommodation with convergence. The patient’s medical history showed CADASIL disease with typical neurological  and cardiological symptoms, including tachycardia and premature supraventricular contractions (PVCs). A neuropsychological examination did not reveal any cognitive function disorders . CADASILThe acuity of vision of both eyes was not disturbed once the episodes of transient vision loss had subsided . Concomitant symptoms included loss of the nasolabial fold as well as increased deep tendon reflexes of the upper-left limb. The orthoptic examination revealed convergence insufficiency  and leftThe abnormalities we confirmed were as follows: bilateral peripheral narrowing of the visual field up to 20° in both eyes, with a defect in the lower part of the left eye’s visual field in kinetic perimetry examination.The intraocular pressure (ICARE-tonometr) was within the normal range (20.6 mmHg in both eyes). No abnormalities appeared on the optical coherent tomography (OCT) of the optic nerve, the ganglion cell complex (GCL + IPL) or the static perimetry. The macular OCT test did, however, show thickening of the central part of the macula , but macThe retinal drusen were observed in the retina of the left eye .Late-phase indocyanine green angiography (ICGA) also confirmed the presence of lesions, demonstrated by the small, linear, focal hyperfluorescence of the lower part of the central fovea exclusively in the left eye. It is not certain whether these changes are the result of focal RPE atrophic lesions.Color Doppler imaging (CDI) confirmed decreased blood flow in both the retinal and choroid arteries , which was clearly marked in the left eye, as well as increased vascular resistance in these arteries .A pattern electrophysiological test (PERG) demonstrated reduced P50 wave amplitude in the patient’s left eye, while a visual evoked potential (VEP) test did not reveal any abnormalities .An MRI of the central nervous system showed multiple focal vasogenic lesions in the white matter of both hemispheres, which were partly merged in the occipital horn region B. A singAn ultrastructural examination of endothelial changes in both muscle and skin biopsies revealed the presence of GOM in small vessels of the skin and the muscle .NOTCH3 gene mutation . The same diagnosis was confirmed in the patient’s mother, who has also manifested CADASIL symptoms, including dementia and muscle and neurological dysfunction with confirmed NOTCH3 gene mutation .The examination also demonstrated discrete degenerative lesions of the pericytes and myocytes of the vessels, along with vacuolation and constriction. Finally, genetic testing confirmed NOTCH3 gene, located on chromosome 19 (p13.1–13.2), is responsible for the onset of symptoms.The first reports of CADASIL were described as familial Binswanger disease by Van Bogaert in 1955 . The firCADASIL steadily worsens the everyday functioning of patients because of its numerous neurological implications, which are caused by vasogenic defects. The source of this condition is thought to be GOM deposits, which are found not only in the brain but also in skeletal muscles, kidneys, pericardium, skin and retinas .The retinal changes in CADASIL include retinal arteriolar constriction, decreased A/V ratio, arteriovenous nicking, artery straightening and enhanced vascular reflex , all of NOTCH3 mutation. Additionally, recent observations by Lin et al. suggest that reduced macular vessel density and inner retinal thickness correlate with the severity of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which may also be of great importance in the future use of the CDI method for diagnosing the advancement of this disease [Our observations of the changes in the ocular circulation in the small vessels of the retina and choroid in color Doppler imaging may be related to the hemodynamic disturbances also suggested but not confirmed by Pretegiani et al.  and with disease .It is possible that in the future a decrease in blood flow velocity and increase in RI in chorioretinal capillaris detected using CDI and confirmed using OCT-A may serve as an additional disease marker in CADASIL and other small vessel diseases.Another interesting observation concerns the early changes in functional retinal ganglion cells and retinal photoreceptors, which were confirmed in the pattern electroretinogram (PERG) and revealed a reduced P50 wave amplitude in the patient’s left eye . A similOther retinal lesions described in the literature include cotton wool spots, which are a result of the obliteration of the arterioles, caused by deposits of axoplasm in retinal nerves. The correlation between retinal effusion and lacunar infarcts in patients with SVD has also been proven, but was not observed in the reported case ,22.The co-occurrence of diplopia and transient vision loss requires excluding vertebral artery insufficiency with the disturbance of blood flow in the optic nerve head , in addiDiplopia is a rare symptom mentioned in CADASIL and, according to Davous et al., may be triggered by vasogenic lesions in the brain stem, which are caused by vertebrobasilar insufficiency, tumor, or stroke of the occipital region ,26,27.In this clinical report, convergence insufficiency might have been the result of impaired extraocular muscle innervation  or exophoria (latent divergent strabismus); other literature mentions the possibility of: ophthalmoplegia, Perinaud syndrome, myasthenia, oculomotor nerve palsy or thyroid-related orbitopathy .In the course of CADASIL, strokes are characterized as focal regions of necrosis (sinus or lacunar infarcts) and are mainly located in the white matter of the brain, particularly around the frontal lobe, temporal lobe and cortical nuclei. They are rarely located in the spinal cord or brain stem region, although such localization was shown in our patient’s history. An infarct in the temporal lobe can often lead to the disturbance of visual spatial orientation, narrowing interests, apathy, behavioral changes and memory and concentration disturbance, all of which were manifested by our patient.Further examples of symptoms include frequent migraines with visual or sensory aura, mostly manifesting between the third and fourth decade of life and usually preceding the identification of morphological vascular lesions , as in tThe clinical presentation of CADASIL may differ, even among family members who are carriers of the same gene mutation, and is characterized by symptoms including migraine with aura, subcortical ischemic events, mood disturbances, apathy and cognitive impairment .NOTCH3 gene mutation  provides final confirmation of the disease [Ultrastructural examination of both muscle and skin biopsies, revealing the presence of GOM in small vessels of the skin and the muscle, is a strong indicator of CADASIL, which can be further confirmed by the presence of degenerative lesions of the pericytes and myocytes of the vessels, along with vacuolation and constriction . The genThe causal treatment includes gene therapy and inhibition of culprit protein translocation. New in vitro and in vivo trials have been carried out and may provide new therapeutic possibilities for patients suffering from genetic diseases. Researchers also hope to succeed in using immunotherapy ,32, growNOTCH3 gene expression variants that will provide successful therapeutic effects with minimal side effects.New treatment options have already been used in patients suffering from other neurological diseases ,37, althIn differential diagnosis, other maculopathies, such as Stargardt macular dystrophy or macular edema, should also be taken into consideration . Among pNOTCH3 gene are particularly important in the CADASIL diagnostic process [Clinical symptoms in the form of transient vision loss, diplopia, convergence disorders, migraine episodes (with aura) together with ischemic stroke and premature dementia in young and middle-aged patients, without the presence of risk factors for vascular disease, can be considered in the diagnosis of CADASIL. Additional ocular symptoms are RPE retinal atrophy, retinal vasoconstriction, focal drusen, and decreased blood flow in the chorio-retinal region with pERG reduction in P50, possibly as a result of a cholinergic deficit or possible dysfunction of macular or ganglion cells. Hyperintensive changes in the white matter of the brain in an MRI, GOM deposits in small vessels of the skin and muscles revealed in ultrastructural examination of muscle and skin biopsies, as well as confirmed mutation of the  process . Circula


Numerous microorganisms and other invertebrates that are able to degrade polyethylene (PE) have been reported. However, studies on PE biodegradation are still limited due to its extreme stability and the lack of explicit insights into the mechanisms and efficient enzymes involved in its metabolism by microorganisms. In this review, current studies of PE biodegradation, including the fundamental stages, important microorganisms and enzymes, and functional microbial consortia, were examined. Considering the bottlenecks in the construction of PE-degrading consortia, a combination of top-down and bottom-up approaches is proposed to identify the mechanisms and metabolites of PE degradation, related enzymes, and efficient synthetic microbial consortia. In addition, the exploration of the plastisphere based on omics tools is proposed as a future principal research direction for the construction of synthetic microbial consortia for PE degradation. Combining chemical and biological upcycling processes for PE waste could be widely applied in various fields to promote a sustainable environment. Plastic pollution remediation is always a global environmental protection issue. As the most commonly used material, plastic products are, however, increasingly in demand and used in all fields globally along with socio-economic development due to their excellent characteristics such as durability, low cost and convenience, and it is predicted that the global production of plastic products will be over 26 billion tons by 2050 . ApproxiAs the primary C–C-chain polymer , PE is cCurrent research indicates that the decomposition of plastic waste, such as PE, in landfills and other ecosystems is predominantly accomplished via physicochemical (abiotic) degradation and biodegradation . PhysicaThis study focused on PE, the most prevalent plastic polymer. We briefly examined its characteristics and biodegradation mechanisms, as well as the current research gaps and recent advances in PE biodegradation. Then, we explored the advantages of using microbial functional consortia and their potential for PE pollution remediation compared to single strains. Lastly, we emphatically investigated the prospect of combining the plastisphere concept and metagenomics to inform the construction of functional microbial consortia.Polyethylene (PE) biodegradation occurs via bacteria, fungi, algae, and other microorganisms that adhere to the plastic’s surface and consume it for growth and reproduction . MicroorThe microbial degradation of plastic polymers, including PE, generally involves five basic stages : microbi(i) The initial phase involves the colonization of microorganisms on the surface of the plastic material. During this period, extracellular polysaccharides or biosurfactants allow microbes to cluster more easily and cling to the hydrophobic surface of the plastic material . The for(ii) Typically, the microorganisms that colonize the surface of a plastic material are the cause of biodeterioration. Through the production of enzymes (such as lipase or dehydrogenase) or other secretions, these colonizing microbes penetrate polymer materials and subsequently generate interstices and cracks . Additio(iii) Biofragmentation is the lytic process by which microorganisms convert macromolecular polymers into oligomers, dimers, or monomers via the action of enzymes or free radicals . Since p2, CH4, and H2O ((iv) When polymers have been degraded into oligomers with low molecular weights (< 600 Da), microbes can easily absorb these oligomers via assimilation . Finally and H2O .2 and H2O. Recent research has shown that Bacillus , PS, PP, and PUR (Pseudomonas aeruginosa to degrade PE under the conditions of an acidic environment (pH = 5) and a temperature of 44°C, and the weight loss rate of PE reached 6.25% after 30 days of culture. Brevibacillus borstelensis 707) from soil and demonstrated that it reduced the weight of LDPE by 11%. Although previous studies have revealed many bacteria with PE-degradation functions, these bacteria have been determined to largely belong to the genera Bacillus and Pseudomonas; however, with the development of isolation and cultivation technologies, additional PE-degrading bacterial resources may still be discovered.Several studies have found that bacteria can inhabit plastic-polluted environments  by forming biofilms on the surfaces of discarded plastic debris, meaning that these microbial communities may be able to colonize plastic surfaces more effectively . The colBacillus , Enterobrobacter , Brevibaacterium , Pseudomudomonas , Arthrobrobacter , Acinetotobacter , and othtobacter . Notably and PUR . In addi and PUR . Mouafo Actinomycetes, as a special subgroup of prokaryotes that can form branching hyphae and conidia, are abundant in soil and other habitats , monohydroxyethyl terephthalate (MHET), terephthalic acid (TPA), and other intermediates, while MHETase (an auxiliary enzyme) further acts on MHET intermediates to convert them into terephthalic acid and ethylene glycol. Both enzymes are found in I. sakaiensis secretions and may work cooperatively to degrade PET , it has been found that PETase (an aromatic polyester enzyme) from rade PET . Magnin Alternaria alternata FB1 with the potential for PE degradation and revealed significant upregulation of the genes that encode 153 enzymes potentially associated with PE degradation, including laccase, peroxidase, and hydroxylase, which further confirmed the ability of some of these enzymes to degrade PE. Laccase is also a potential functional enzyme for PE-degrading bacteria such as Bacillus, Psychrobacter, etc.  degradation activity, while the rubredoxin and rubredoxin reductase were indirectly involved in PE degradation through the transfer of relevant electrons. They also identified two alkane monooxygenases (AlkB1 and AlkB2) in P. aeruginosa and found that AlkB2 displayed higher transcriptional activity in the presence of LMWPE, thus indicating that AlkB2 was more efficient at degrading LMWPE than AlkB1 (Polyethylene (PE) has an extremely stable C–C backbone that is more resistant to hydrolysis than those of PET and PUR, which have chemical bonds in their backbones that can be attacked by hydrolases . For thier, etc. . Jeon anan AlkB1 .Rhodococcus spp. and Bacillus spp. (Alkane hydroxylases (AHs) are key enzymes in the degradation of alkane compounds such as petroleum, and the genes encoding them have recently been identified in the genomes of a variety of PE-degrading species . AHs harlus spp. . The alklus spp. .Microbial consortia, as efficient pollutant-degrading agents, have been applied to various environmental remediation fields, such as the degradation of agricultural and forestry residues [cellulose , hemicelAlthough many strains capable of degrading PE have been isolated and identified, it takes an incredibly long time for single strains/enzymes to degrade PE and the rate of degradation is exceedingly inefficient due to some of the durability characteristics of PE . In addiCompared to single strains, microbial consortia are more efficient, robust, and controllable . (i) FirCurrent research on the development of synthetic microbial consortia has generally followed two traditional approaches: “top-down” and “bottom-up” . Top-dowBacillus sp. and Paenibacillus sp. strains that were isolated from landfill sediments and had PE -degradation capabilities to construct a mixed bacterial consortium that, after 60 days of incubation, degraded up to 14.7% of PE microparticles. Aspergillus and Lysinibacillus strains. The advantage of using fungal–bacterial cross-kingdom consortia is that fungal hyphae may represent media for the bacterial colonization of soil that can facilitate the migration of bacterial strains beyond what can be accomplished individually. These studies have formed the basis for investigations into positive interactions between bacteria and fungi that have high potential for the bioremediation of plastic pollutants , initial weights, pretreatments, measurements, and culture conditions. Therefore, it is crucial to establish standard procedures that can be used to quantify PE degradation in subsequent studies to evaluate the biodegradation ability of microorganisms . CommercMoreover, the low enzyme production capacities and simple enzymatic systems of single strains, as well as the lack of discovery of efficient specific enzymes for PE degradation in studies to date, render single strains incapable of effectively tackling the complex PE -degradation process. Therefore, it is suggested that both the exploration of novel efficient PE-degrading enzymes/genes and the investigation of degradation mechanisms be strengthened in future research. Additionally, the combination of genetic engineering and enzyme engineering technologies could help with the engineering of efficient PE-degrading-enzyme-producing bacteria and the enhancement of related enzyme activities. Various abiotic  and biotic  factors affect the process of microbial PE degradation . Thus, dAs the production and properties of byproducts from PE -biodegradation pathways are not currently fully understood, there is an urgent need for additional studies on the properties of these byproducts and their implications for later-stage fermentation and environmental toxicity.Remarkably, the majority of previous studies have focused on the degradation of large pieces of PE. In contrast, there has been a lack of studies on PE micro/nanoplastics, which are relatively tiny in size and well-hidden in the environment. These micro/nanoplastics are not as easily collected and disposed of as large pieces of plastic and, as they absorb enormous quantities of dangerous compounds during their movements around the environment, they significantly enhance the difficulty of plastic degradation . For thiThe microbial community structures and associated biofilms of the plastispheres in different ecosystems polluted by plastic waste have not been fully explored, particularly those in terrestrial ecosystems; hence, comprehensive multi-omics studies should be conducted to reveal the biodiversity, biofilm-formation mechanisms, and biodegradation capacity of these plastispheres in the future. Additionally, microbial metabolic engineering based on recombinant DNA or gene-editing technology may be effective to some degree in solving the limitations of PE-degrading single strains, such as poor degradation ability and low enzyme production capacity, thereby enhancing the metabolic activities of PE -degrading strains and significantly enhancing their biological degradation efficiency . EngineeEspecially remarkable is the fact that, with the severe damage to the environment caused by conventional plastic disposal methods, more economically and environmentally acceptable plastic valorization is now increasingly being proposing and developed to address the ever-increasing volume of plastic waste. The valorization of waste plastics aims to maximize the value of plastic waste by recycling, upcycling, biodegradation, or energy recovery to dispose of the plastic waste in more sustainable ways and/or to transform them into brand new and functional products ; Table 4The bio-upcycling of plastic waste is more sustainable and reaction conditions are more moderate than chemical processes. Combining biodegradation and upcycling of plastic waste enables to treat the non-recyclable plastic waste in the environment as well as to overcome the issue of product and by-product treatment during degradation of plastics. For one thing, the by-products and products derived from the biodegradation of PE could be taken directly into fuels or platform chemicals such as hydrogen, methane and various alkanes, fatty acids, etc. For the other hand, the oligomers or monomers obtained from the biodepolymerization of plastic can be biotransformed by engineered microbial cell factories to produce various value-added products  by upcycling . SignifiFurthermore, the adoption of gene engineering, metabolic engineering and other technologies allow further enhancement of functional strains and optimization of metabolic pathways for more efficient and targeted biotransformation into different products or specific chemicals derived from waste plastics .The prevalence of plastic waste and micro/nanoplastic pollution has always been a great challenge facing environmental remediation. Traditional plastic disposal methods have not been effective in solving the global plastic waste pollution problem, which is becoming increasingly serious. However, recent studies on plastic biodegradation have led to new perspectives on the sustainable disposal of plastic waste and the discovery of an increasing number of microbes and other invertebrates that are involved in plastic degradation. PE is the most widespread and recalcitrant petroleum-based plastic and the study of its biodegradation has received considerable interest over the years. The microorganisms and other organisms involved in the degradation of PE have been extensively explored in the literature; however, there have been no breakthroughs in the study of PE biodegradation, particularly regarding the mechanisms of PE degradation and the identification of specific PE depolymerases. Recent studies have examined the constraints that single strains encounter when trying to degrade PE, and progressive efforts have been made to combine several strains to develop more effective consortia or co-cultures. Compared to single strains, functional microbial consortia offer many advantages in degrading plastic waste; however, the lack of an understanding of the byproducts and mechanisms of PE degradation has limited the development of artificial functional consortia for PE degradation, which was the focus of this review.Considering the existing bottlenecks in the construction of PE-degrading consortia and the pros and cons of each strategy, we propose combining top-down and bottom-up approaches for the synthesis of efficient PE-degrading consortia. In this way, the selective, top-down enrichment of natural microbial communities can be applied to optimize community functions, and the enriched communities can undergo omics analyses of their functions and community structures to help us better understand the microbial PE -degradation mechanisms and microbial interactions at play within the communities. The insights into microbial communities achieved using top-down strategies could contribute to a more reasonable and appropriate bottom-up synthesis of functional PE -degrading consortia. The plastisphere is a new ecological niche that spontaneously forms on plastic debris and is closely associated with plastic polymers. Investigating the microorganisms or microbial communities that grow in the plastisphere could uncover principal sources of novel PE-degrading microorganisms/microbiota. The combination of genomic, transcriptomic, metagenomic, and other omics/meta-omics analyses could help to unravel the microbial diversity and community composition of the plastispheres in different ecosystems and the metabolic relationships between microbes, which could also enable the discovery of core microbiota and key pathways/genes for PE degradation and provide a foundation for the subsequent construction of functional consortia.We close with a discussion of concerns and bottlenecks in the existing studies on PE biodegradation as well as some insights into the topics that should be considered in future research. Due to insufficient study of the mechanisms of PE biodegradation, the construction of effective microbial consortia currently faces numerous obstacles. In addition, the safety and stability of synthetic microbial consortia and the regulation of coexistence between microorganisms could represent challenges for future research due to the dynamic nature of microbial communities, biological variability, and various other uncertainties.CZ: conceptualization, data curation, and writing-original draft preparation. YM, TL, and F-JJ: data curation and visualization; C-ZJ and H-MO: resources and visualization; H-GL. and LJ: supervision and writing-reviewing and editing. All authors have read and agreed to the published version of the manuscript.


Protein aggregation is the etiopathogenesis of the three most profound vision-threatening eye diseases: age-related cataract, presbyopia, and age-related macular degeneration. This perspective organizes known information on ATP and protein aggregation with a fundamental unrecognized function of ATP. With recognition that maintenance of protein solubility is related to the high intracellular concentration of ATP in cells, tissues, and organs, we hypothesize that (1) ATP serves a critical molecular function for organismal homeostasis of proteins and (2) the hydrotropic feature of ATP prevents pathological protein aggregation while assisting in the maintenance of protein solubility and cellular, tissue, and organismal function. As such, the metabolite ATP plays an extraordinarily important role in the prevention of protein aggregation in the leading causes of vision loss or blindness worldwide. The most wide-spread age-related vision-threatening ocular diseases include age-related cataract, presbyopia, and age-related macular degeneration. A common finding among these three diseases, which ultimately may be experienced by all human beings with advancing age, is protein aggregation. Although protein aggregation can be a healthy advantage in the production of biogenic protein machines and organelles designed for intracellular and organismal gain of function, with aging, protein aggregation may result in loss of function. With aging, the risk of protein-aggregation-causing diseases increases. This is most likely because adenosine triphosphate (ATP) concentrations decline in cells during aging . Age-relDisease development as a result of protein aggregates is not limited to the aforementioned ocular diseases and can be considered a general process of the pathophysiology of disease ,13. The This is a treatise on the three most profound age-related vision-threatening ocular diseases evaluating the interplay between the role of ATP and protein aggregation. The present perspective incorporates context and rationale from our previous works ,21,22. TSince ATP in high concentrations is reportedly functioning as a hydrotrope with dominant functions of preventing intracellular protein aggregation or maintaining protein solubility, the importance of these ATP functions is profound. With a paucity of studies linking ATP with protein aggregation coupled with the great importance of this finding in science and medicine ,19,21, e31P NMR) . Th. Th19]. Additional explanation of the presence of water molecules between adjacent ATP molecules is required. Crystallographic studies show that there are no water molecules within each ATP dimer complex , only beWhen ATP’s adenine moiety is bound to hydrophobic regions of protein surfaces and the hydrophilic triphosphate moiety is oriented into the interstitial water separating proteins, the interstitial water is bound to the ATP phosphates, and these phosphates interact with additional water molecules through hydrogen bonds. Theoretically, this establishes a second ice-like layer of water that is not bound directly to the ATP phosphates but to the water molecules that are bound directly to the ATP phosphates. This process continues outward from the protein-ATP surface forming an aqueous film with each successive water layer being less firmly bound to the ATP phosphate groups. As such, this water film becomes more fluid or water-like with further distancing of water molecules from the phosphate groups of the ATP molecule. In this more fluid-like delocalized region of the interstitial water there are increasingly randomly exchanging water molecules .The crystalline lens contains a higher concentration of protein than any tissue in the body. The proteins are very close together; thus, the concept suggests that the presence of the ATP hydrotropic layer on adjacent proteins acts to stabilize the interstitial water layer as the proteins approach each other. This stabilization of adjacent proteins forms a liquid-crystalline interstitial gel-like layer, where the participating water molecules are more firmly bound into stable locations between the adjacent water layers. This is due to the polarizing effects of the negatively charged ATP phosphate groups . This geHistorically, the principal role or primary function traditionally ascribed to ATP is as the molecular reservoir for energy metabolism and the principal energy carrier and currency of living cells. This ascription appears to have occurred since the main source of ATP production in eukaryotes has been known to be mitochondrial. The mitochondrion is the organelle often cited as the ‘powerhouse’ of the cell. The phenomenon of a millimolar intracellular ATP concentration in eukaryotes appeared consistent, established in our review of various species . This phParadoxically, the concentration of ATP needed for metabolic function is known to require only a small fraction of the millimolar concentration of ATP reported. In fact, it appears that only a small portion of ATP is required for all the known functions of ATP  combined31P NMR, of the relationship between intracellular ATP and water in an intact functioning living organ, the crystalline lens [Although there has been increasing evidence to suggest a critical role for ATP in the maintenance of proteostasis in the cytoplasm , the pauine lens . The hypine lens , unicelline lens ,20, and ine lens .Xenopus laevis oocytes [Hayes and coworkers presented findings on the contribution of ATP to the maintenance of protein solubility using the nucleolar organelles from  oocytes . Employi oocytes .Since ATP is required for the function of chaperones and proteases and ATP is required to fuel its multiple functions in facilitating protein folding and disaggregation, Pu and coworkers demonstrated that as ATP is exhausted and protein aggregation occurs, bacteria are unable to maintain regular metabolism and become dormant . Pu et aAs Takaine and coworkers point out , ATP levUsing multiplexed mass spectrometric data, Sridharan and coworkers interrogated ATP-mediated regulation of protein solubility on a proteome-wide scale . The proATP also may act in a synergistic manner. For example, Cyr observed that the combination of Saa2p, Ydj1p, and ATP almost completely suppressed rhodanese aggregation .The strength of this perspective is the presentation of data and hypotheses organized among multiple scientific disciplines ranging from elemental phosphorus chemistry to physics, biology, and medicine. Our understanding of the mechanisms of protein aggregation and disease, together with our knowledge of the enigmatically high concentration and function of the metabolite ATP ,21, suggLimitations of our hypothesis may include the assumption that lens proteins remain in their nascent state throughout life, where ATP might indeed act as a hydrotropic factor. Additionally, our perspective is limited, since it does not address the implications of ATP as a molecular chaperone for ATP functions , or any Studies designed to expand the understanding of the process of protein aggregation and its prevention increase our opportunity of interfering with the development of protein aggregates. Future directions for the delivery of molecular ATP or ATP-promoting pharmaceuticals to lenticular and retinal tissues should focus on the delivery systems of exogenous ATP or facilitation of intracellular production of ATP. Clinical efficacy using systemic drug delivery to the eye is attained with relatively high concentrations of a medicant when compared to localized topical or intracameral delivery. For example, using a corticosteroid for the treatment of uveitis, systemic delivery of efficacious concentrations of this pharmaceutical requires 60–100 mg. With regard to the delivery of pharmaceuticals, the anatomical site of the eye is privileged because of its accessible location in the body. As such, it permits both topical and intracameral delivery of pharmaceuticals. Other considerations must include molecular size, absorption/diffusion, and possible toxicity of ATP.Topical delivery of a pharmaceutical via eyedrops can reach intraocular tissues including the lens and the retina. This is most evident considering the iatrogenic posterior subcapsular cataract secondary to topically delivered corticosteroids affecting lens cells and tissue . Even inIntracameral delivery of pharmaceuticals has been employed as an efficient route of delivery. Intracameral delivery includes intravitreal injection of fluid or implants or injection into the anterior chamber of implants. In contrast to topical drug delivery, where higher concentrations of ATP or its promoters are required, intravitreal injections can be employed. In this case, an injectable fluid or implant is delivered via the vitreous. Drug delivery is accomplished via syringe by entering the vitreous with a needle through the inferotemporal quadrant of the scleral wall of the eye, 4 mm posterior to the limbus. As such, a pharmaceutical containing ATP might be delivered to the vitreous humor in closer proximity to the retina.As described above, since the eye is in a position of the body that is partially exposed, topical as well as intracameral delivery to attain effective tissue concentrations of a pharmaceutical is possible when attempting to deliver pharmaceuticals to the lens and retinal tissues. The eye offers an ideal opportunity to evaluate and study the effects of multiple drug delivery systems. The selection of appropriate ATP delivery to the lens or retina tissue ,48, as nRegarding effective absorption/diffusion into the lens or retinal tissues, the molecular size and anionic charge of ATP must be considered. Since the uptake of the small-sized molecule must account for possible transport channels, the polyphosphate, magnesium, and calcium ions that line such channels are often associated with the ATP molecule. Also, there exists the possibility that ATP with its small size  may simply be absorbed without the necessity for specific transport channels. Although delivery of the small ATP molecule into the lenticular and retinal tissues may promote maintenance of solubility of crystalline proteins and prevent formation of aggregates, the potential problems/difficulties in intracellular uptake cannot be ignored.ATP delivery requires avoidance of potential toxicities and any adverse side effects of ATP on surrounding tissue structures when considering prescribing topical, intracameral, and systemic system delivery.Considering the high millimolar concentration of ATP ,26, the Worldwide, cataracts reportedly cause more than 40% of cases of blindness ,50,51,52To briefly review, the crystalline lens functions as an organ refracting light to focus objects on the retina . The refConsidering our studies and studies by others supporting the function of ATP as a hydrotrope, ATP should be considered in future goals for the development of anti-cataract drugs. Not only is prevention of protein aggregation important, but novel pharmaceuticals must be also designed that can reverse lens opacification by dissolving the aggregation of crystallin proteins.Recent studies have reported on several compounds that can prevent and dissolve protein aggregates in the lens which may lead to eventually offering a novel anti-cataract drug strategy ,66. ConsFor effective drug delivery strategies, pharmacological future directions might include nanotechnology in combination with ATP that may offer even greater efficiency in drug delivery. This pharmacologic therapy may be an efficient method to reduce the cataract disease burden and its surgical costs . FurtherPresbyopia is the most common eye disease. Presbyopia is a disease as it impairs normal visual function and is manifested by typically distinguishing signs and symptoms. It affects nearly everyone in the fifth decade of life experiencing a noticeable reduction in the rate and amplitude of lenticular accommodation. Uncorrected ability to focus on near objects is a worldwide major vision-related problem because of the absence or unavailability of adequate or affordable vision correction . The onsThe primary etiology of presbyopia with increased lens stiffness (hardness) is due to protein insolubilization and its consequent protein aggregation. In addition to age-related insolubilization and aggregation of lens proteins, there is loss of lens elasticity and an increase in the concentration of water-insoluble protein. With aging, there is an increase in lens organ stiffness , structuAlthough major lens protein modifications have been shown to include acylation , advanceAge-related macular degeneration (AMD) is a major public health issue ,88 and dWith aging, there is a concurrent increase in oxidative stress and consequently increased accumulation of lipid or protein aggregates (lipofuscin) in RPE cell lysosomes  and drusThe use of high concentrations of ATP in maintaining protein solubility, prevention of protein aggregation, and the potential of disaggregation of abnormal proteins in the retina may be important pharmacologically in age-related macular degenerative disease. The possibilities for employment of ATP in maintaining solubilization of proteins and prevention of aggregation in the treatment of macular disease should not be ignored.Since aging is related to increased protein aggregation in both the lenticular and retinal tissues resulting in age-related cataract, presbyopia, and age-related macular degeneration, with increasing life expectancy, the number of people worldwide adversely affected by these diseases will increase. It should be understood that age-related protein aggregation and its potential prevention by ATP as described in our hypothesis may even assist in maintaining general health. The three major vision-threatening eye diseases all related to protein aggregation affect the function of the lenticular and retinal tissues, impairing the ability to perform even ordinary daily tasks.In reviewing the literature regarding protein aggregation in the lens and the retina concerning all three of the above-described diseases, there is a notable paucity of investigations into the ATP metabolite and its relationship with the prevention of protein aggregation. This is especially surprising since ATP has such a high millimolar intracellular concentration that is not yet entirely accountable in the known functions of ATP . FurtherWith recognition that protein aggregation is related to the intracellular concentration of ATP, we hypothesize that (1) ATP serves a critical and foundational molecular function for organismal homeostasis and (2) the hydrotropic feature of ATP prevents pathological protein aggregation while maintaining protein solubility and cellular, tissue, and organismal function. As such, ATP plays a role as a hydrotrope in the prevention of protein aggregation and is involved in the most profound vision-threatening ophthalmic diseases leading to vision loss or blindness worldwide, i.e., age-related cataract, presbyopia, and age-related macular degeneration. This perspective organizes, and links, known information on ATP and protein aggregation with a fundamental unrecognized function of ATP in biology and medicine and its relationship to the three most vision-threatening ocular diseases affecting global eye health. This hydrotropic function of ATP cannot be ignored as a potential foundational change in our understanding of the importance of ATP in cellular, tissue, and organismal metabolism.