This paper offers a short overview of epoxy resins, encompassing their diverse characteristics, variants, chemical modifications, curing processes, and intriguing electrical properties. Epoxies, valued for their multifunctional attributes, serve as fundamental materials across industries. In the realm of dielectric strength, epoxy resins play a crucial role in electrical insulation. This paper discusses the mechanisms governing dielectric breakdown, strategies to enhance dielectric strength, and the impact of various fillers and additives on insulation performance. Through an exploration of recent research and advancements, this paper delves into the spectrum of epoxy properties, the array of subspecies and variants, their chemical adaptability, and the intricacies of curing. The examination of electrical resistance and conductivity, with a focus on their frequency-dependent behavior, forms a pivotal aspect of the discussion. By shedding light on these dimensions, this review provides a concise yet holistic understanding of epoxies and their role in shaping modern materials science. The evolving landscape of electronics and microprocessor technology, characterized by increasingly potent components within devices, necessitates the advancement of highly efficient composite materials. This also calls for the innovation of robust resins  that are capable of performing reliably under extreme conditions, including elevated temperatures, exposure to solar radiation, and high humidity levels. These materials are essential for effectively sealing electronic devices that are made from diverse substrates such as plastic, brass, aluminum, copper, and carbon steels. Additionally, they play a vital role in providing protective coatings for structural materials, safeguarding them against various forms of impact and shock ,2.The range of use is determined by the parameters of epoxy resins (ERs): thermal conductivity and electrical conductivity. Ensuring reliable adhesion on boards formed from fiberglass with plastic and metal, as well as a combination of dielectric properties with light transmission, are in demand in microelectronics and electrical engineering .Excellent dielectric/electrical insulating properties;Ultra-high water resistance;Chemical resistance ;High mechanical properties ;The highest adhesion ;Low shrinkage during curing (minor deformations);High stability;Increased heat resistance ;The absence of volatile products and the release of side substances during curing;A low coefficient of shrinkage in the course of hardening;Minimum creep under load;Low odor;Ease of production and versatility of processing processes;Small weight of the finished product;Durability and shelf life;Environmental friendliness;Safety.The widespread use of epoxy resins in the production of electronic components is due to their high manufacturability and the unique set of performance characteristics of their curing products ,5,6,7:ExThe complex of unique physicomechanical  and physicochemical properties  of epoxy resin allows products based on them to cover a wide range of applications in various fields of electrical and radio engineering. Scientific and technical research that focuses on the development of the most specialized coatings (epoxy fills) that are resistant to highly aggressive environments, improving the properties of epoxy resin as a dielectric , and satisfying certain operating conditions is steadily growing . At the present stage of the development of space technology, it has been established that the most dangerous factor for existing spacecraft is the functional damage to on-board radio-electronic equipment from ionizing and secondary electromagnetic radiation. The impact of such radiation leads to structural changes in materials, the occurrence of ionization, heating, the appearance of induced radioactivity, and other phenomena that disrupt physical and chemical processes in technical devices .After curing, epoxy resins act as a high-quality insulator that provides the sealing  of conductive circuits from the effects of electrostatic discharge, high temperatures, vibrations, moisture, chemicals, and shocks in electrical and radio engineering products.Epoxy resin hold significant importance within the electronics industry and find applications in a range of equipment including motors, generators, transformers, switchgear, bushings, and insulators. These epoxy resins offer outstanding electrical insulation properties, effectively shielding electrical components from potential issues like short circuits, dust ingress, and moisture exposure .In addition, metal-filled polymers are widely adopted for electromagnetic interference shielding . Epoxy mAs sealants, epoxy resins (compounds) remain popular among polymeric materials in terms of application. To date, due to the thermodynamic and reactive compatibility of epoxy oligomers, a huge number of compounds have been synthesized, and various hardeners have been successfully used to turn thermoplastic resins into infusible ones .Radio, electrical industry, electronics, and microelectronics ;The rocket and space industry;The energy industry;The engineering industry (production of components);Construction ; sealants; adhesives; the waterproofing of floors, walls of basements, and swimming pools; the impregnation of concrete, brick, wood, and mortar; the successful replacement of bitumen—bitumen–epoxy composition);The textile and leather industries;The furniture industry (designer furniture);Arts and crafts ;The domestic sphere and household .ERs are one of the most important class of thermoplastics and the following broad areas of their application are listed below ,15,16,17Printed circuit boards (PCBs): epoxy resin is used as a substrate material for printed circuit boards, providing insulation between board layers and protecting components from environmental influences;Sealing: epoxy resin is used to seal electronic components, protecting them from environmental influences such as moisture and dust;Adhesives: epoxy resin is used as an adhesive in the production of electronic components, and is a sensitive strong bond between components and substrates;Coatings: epoxy resin is used as a coating material for electronic components, providing protection against moisture, chemical compounds, and abrasion.Their implementations, specifically in the production of electronic components, are the following ,19,20:PrThe use of epoxy resin in the manufacturing of electronic components typically involves a curing process, in which the resin is mixed with hardener and then subjected to heating or ultraviolet radiation to initiate a curing reaction. Amines were among the first epoxy resin hardeners, and they have retained a leading position among all reagents of this type ,22.Vacuum impregnation: this involves placing the electronic component within a vacuum chamber, where epoxy resin is drawn into the component under vacuum pressure;Pouring: in this method, an electronic component is situated in a mold and epoxy resin is poured over it, effectively sealing the component;Dispensing: epoxy is administered onto an electronic component using a dispensing machine;Spray coating: here, epoxy resin is applied onto an electronic component via a spray gun.The curing process can be carried out using various technologies, including the following :Vacuum iThe cross-linking or curing process is usually slow, especially when small volumes of resin are involved. Fast curing hardeners can be used, but they generate a lot of heat during the process, resulting in a strong exothermic reaction that can damage electronic components and cause high mechanical stress not only on them, but also on the circuit .The process of curing epoxy polymers involves the utilization of a hardening agent, typically a primary or secondary amine or an acid anhydride. This agent serves as a binding element among the distinct macromolecules. In order to facilitate the creation of a three-dimensional network, which is crucial for conferring the ultimate product with the characteristics of an impenetrable and non-soluble material , novolac (phenolic and cresol), aliphatic , glycidyl, and acrylic epoxy. Dozens of their subspecies are known, including light-cured and water-borne ones (their widespread introduction is hindered by high cost) .An integral component of epoxy resin, as a two-component thermosetting polymer, is a hardener, of either the cold or hot type, which determines the further technical characteristics of the epoxy . Their percentage ratio is extremely important for the quality performance of the composition. The main part of the additives are the plasticizers: dibutyl phthalate, diethylene glycol (DEG-1), diphenyl phthalate, polyesters, styrene oxide, and thiokol, and the inclusion of silicon components in the mixture determines the resistance to heat.The chemical modification of polymers is carried out by introducing small fragments of a different nature into the composition of macromolecules. Changing the chemical nature of oligomers and hardeners makes it possible to increase the length of the molecular chain of the oligomer and hardener to vary the structure of the internodal sections of the cured system, to modify the end groups of oligomer macromolecules, thereby changing the macroscopic properties of the epoxy polymer. The introduction of reactive additives that are capable of entering into a chemical reaction with the polymer makes it possible to regulate the physical and mechanical properties of epoxides, such as heat resistance, aging resistance, etc., in a wide range .It is known from the literature that dispersed fillers cause a change in almost all properties of liquid and cured epoxy compositions: they increase the viscosity of the binder, and reduce its mobility and viability ,31,32, aIn the study and regulation of the dielectric properties of epoxy oligomers, using various thinners, fillers, curing accelerators, and plasticizers, special attention is paid to the molecular structure of the resulting composites.The composition (epoxy–bakelite or epoxy–phenolic) has very high dielectric, and especially mechanical, properties, water resistance, and heat resistance. These epoxy compositions are widely used for the production of electrical insulating varnishes and adhesives. Polysulfide resins (thiokols) are also used to cure epoxy resins. The resulting compositions have high elasticity and impact strength, and good dielectric properties are applied to the production of elastic filling compounds. Epoxy–polyester compositions with the introduction of fillers are widely used for the manufacture of casting compounds for the cast insulation of windings of electrical machines, apparatus, and transformers . PlasticDue to their low viscosity, they are called active ES thinners, since they are able to replace solvents in the composition of epoxy compositions and copolymerize with ES without releasing by-products. There is a “chemical” modification of the epoxy composition due to the incorporation of flexible fragments into a rigid polymer network and an increase in the molecular weight of the segment ,43,44. EThe development of new composite materials has expanded the production and use of epoxy resins by several orders of magnitude. Depending on the use, the composition and the amount of filler  are taken into account; thus, the dielectric and physicomechanical properties of cured epoxy resins can vary widely. Depending on the number of epoxy groups, uncured epoxy resins are in a liquid or solid state. They are popular and cover a wide range of applications (from 70 to 90%), such as epoxy–diane resins (diphenylol propane) based on bisphenol A.The curing agent polyaminoamide is utilized for curing liquid, low-molecular-weight epoxy resins and their compounds. The weight ratio of epoxy resin to curing agent can be adjusted to achieve specific properties in the final cured material. A higher content of the curing agent (above 70% by weight) results in a more elastic and impact-resistant cured resin. However, this comes at the expense of reduced hardness and resistance to high temperatures (attributed to a lower glass transition temperature). This curing agent is suitable for applications requiring cold-cure epoxy resin, where the curing process occurs at room temperature. It is important to note that, according to the product’s safety data sheet, this substance is caustic, may cause skin irritation, and has the potential for sensitization .When epoxy resins are exposed to compounds containing a mobile hydrogen atom, they are able to cure with the formation of three-dimensional infusible and insoluble products with high physical and technical properties. Thus, it is not the epoxy resins themselves that are thermosetting, but their mixtures with hardeners and catalysts. Various substances are used as hardeners for epoxy resins: diamines , carboxylic acids, or their anhydrides .High adhesion to the surface of the material on which they harden;High dielectric properties;High mechanical strength;Good chemical resistance and water resistance;Hardening does not emit volatile products and are characterized by low shrinkage (2–2.5%) .Epoxy resins mixed with the above hardeners form thermoset compositions with valuable properties:Recently, the traditionally used non-reactive modifiers , which, along with an increase in the elasticity of epoxy materials, lead to a decrease in network density and are able to migrate from the material during operation and increase shrinkage, are being replaced by modifiers that can be embedded in the epoxy matrix. In this case, preference is given to those modifiers that do not lead to the formation of by-products of the reaction and do not increase the number of volatiles released. Such modifiers include, in particular, mono- and polyfunctional low-molecular-weight and oligomeric epoxy compounds, as well as mono- and polyfunctional cyclocarbonates .The study of the phenomenon of heat transfer is very important in the manufacturing of composite materials for protective screens. We consider multilayer plates as radiation shields, which compete with single-layer plates made from the same complex composite materials. Samples in the form of thin plates of epoxy resin grade ED-20 with a filler of soot, graphite, and aluminum powder were studied. Analyzing the results, we can conclude that the introduction of graphite and aluminum powder can significantly increase the effective thermal conductivity of the tested samples. The values of thermal conductivity with carbon black are ambiguous, and to determine the reason for this behavior, an X-ray diffraction study of both the carbon black and graphite that were used is necessary .Dielectric analysis (DEA) is a method used to monitor the curing process of polymer materials. It involves the measurement of electrical properties, such as dielectric permittivity (or capacitance) and dielectric loss (or conductivity), as a function of time, temperature, or frequency during the curing process. DEA is particularly useful for materials like thermosetting resins, which undergo a chemical transformation during the curing process. It provides a non-destructive and real-time method to monitor and control the curing process, ensuring that the final material possesses the desired properties ,52,53,54In the context of the dielectric analysis (DEA) method, the ionic viscosity parameter and the actual viscosity of a system are related through the dielectric properties of the material being analyzed. Specifically, the ionic viscosity parameter is related to the ion mobility of the material, which in turn can affect its dielectric properties. The actual viscosity of a material refers to its resistance to flow or deformation. It is a measure of the material’s mechanical behavior. The ionic viscosity parameter is, on the other hand, related to ion mobility and electrical behavior; the actual viscosity is related to the material’s mechanical response. In some cases, there may be a correlation between the ionic viscosity parameter and the actual viscosity, especially if the movement of ions significantly impacts the flow behavior of the material ,54,55.There are several important parameters of the curing process; among them are the gelation time and curing degree. In brief, the curing degree represents the extent of polymerization or cross-linking that has occurred, while the gelation time is the point in time at which a material starts to transition from a liquid or gel to a solid. Both parameters are significant in various industries where the precise control of material properties is essential ,57.The curing process of a thermoset involves a complex series of chemical reactions. Primarily, both gelation and vitrification play pivotal roles . This prIt is worth mentioning that it is also possible to monitor the curing process of a composite material using a multi-channel dielectric analysis (DEA) and potentially correlate it with the thickness of the composite. The thickness of a composite material can influence the curing process. Thicker sections may cure differently than thinner ones due to variations in heat distribution, mass, and heat dissipation. Monitoring multiple channels allows for a more comprehensive understanding of how thickness impacts the curing process. Variations in thickness can lead to non-uniform curing. A multi-channel DEA can detect inhomogeneities in the curing process, providing valuable insights into how different parts of the composite are curing ,60.When modified with various substances, the properties of the polymer matrix (intermolecular interactions) change, affecting the kinetics and mechanisms of molecular processes, which significantly affect the technological and electrical properties of epoxy compounds.2O3 powder of three different sizes was introduced into the mixture of an epoxy compound ) without chemical modifications of the filler surface, as well as a combination of micro- and nano-sized fillers without changing the total percentage of the filler, the λ values of the epoxy compound increased when moving from the nano to the micro-sized filler. When half of the Al2O3 particles with a size of 100 μm in the epoxy compound are replaced by particles with a size of 25 nm, there is a significant decrease in the effective thermal conductivity. This may be due to a decrease in the number of large particles of the highly thermally conductive filler necessary to create a heat-conducting cluster [The works ,62 descr cluster .2 concentration. Initially, the electric breakdown strength of nano-SiO2-enhanced RIP (resin-impregnated insulation paper) experiences an ascent with rising content, reaching its zenith at 2 wt%. Subsequently, it diminishes for 3 and 4 wt%. In comparison to unmodified RIP, the maximum DC breakdown strength saw an increment of 10.6% [of 10.6% .Moreover, if we follow the arrow in 2O3, TiO2, AlN, BN, or a combination thereof. Preference is given to particles with an average size of 500 µm or less.There is a patent that describes a method for obtaining an electrically insulating material with excellent insulating properties . The eleThe patent  describeCarbon–polymer composites are widely used in the creation of new structural materials for conductive, heat-absorbing, and shielding coatings. In recent years, special attention has been paid to the study of polymer composite materials based on electrically conductive nanosized fillers, such as carbon nanotubes (CNTs) and nanofibers (CNFs) ,69.In , the repIn , the resDuring the curing of the epoxy oligomer, its phase state changes and the material initially passes from a liquid to a gel-like state and then to a solid ,73,74. T2O3 and iridium orthosilicate IrSiO4 (constituting 72.1% of the composition), both in the presence and absence of a modifier, tetrabutoxytitanium (TBT) (see The study  examinedTBT) see .The incorporation of fillers or modifiers into the polymer has a discernible impact on thermal conductivity. The numerical value λ of the composite material is influenced not only by the quantity of the added component but also by its interaction with the polymer phase.2O3 significantly augments the thermal conductivity of the composite material, exhibiting a threefold increase across the entire temperature range (40–190 °C) while maintaining a consistent curve profile. Similarly, the use of iridium orthosilicate IrSiO4 as a filler doubles the thermal conductivity of the cured epoxy composition within the specified temperature range (40–180 °C). On the other hand, the introduction of tetrabutoxytitanium as a modifier in the composite material composition does not notably alter the temperature-dependent behavior of thermal conductivity.The results demonstrate that the inclusion of aluminum oxide Alk) could represent a significant hindrance to heat transfer within PNCs.According to , the sliThe authors of  experimeThe investigation of , in whicThe incorporation of nano-fillers has been widely suggested as a means to improve the dielectric properties of high voltage polymeric insulation, although there are conflicting reports in the literature. According to , the potThis study, based on , revealsThe purpose of this work  was the To create polymer composites that reduce the impact of electromagnetic fields on electronic components of computer technology and biological objects, it is necessary to obtain materials with specified values of dielectric permittivity, a dielectric loss tangent, and electrical conductivity, which are determined by the operating frequency range of the nanocomposites.Epoxy binders have the advantage of low shrinkage and high strength characteristics. However, scientific and technological progress constantly increases operational requirements, so polymers must be modified. The most promising are composite materials with nanosized fillers—nanocomposites ,46,47,84The research of  aimed toThe characteristics of the composite depend on the particle size of the filler. Large filler particles (315–500 microns) are isolated by a dielectric layer, so they have poor contact with each other. The maximum value of the dielectric constant is observed with the introduction of particles of a minimum size of 63–80 µm .In , the autComposites containing SWCNTs exhibit their lowest electrical conductivity when operating in the region above the percolation threshold. The rationale behind this observation lies in the fact that SWCNTs, being the smallest in size, consequently offer the highest number of contact regions .In a different study documented in , the resThe incorporation of carbon fillers into the polymer matrix opens up avenues for obtaining materials with diverse properties. Parameters such as the particle shape, aspect ratio, and the evenness of their dispersion within the polymer matrix play pivotal roles in determining both the percolation threshold and the electrical conductivity of the resultant composites. Hence, carbon particles hold significant promise as fillers for crafting composite materials with tailored permittivity values, influenced by the operational frequency range of these nanocomposites .The research of  explored2/g, 0.05 m2/g, and 0.025 m2/g, respectively.The study of  delved iThe authors of  investigThe flexural properties of composites composed of multi-walled carbon nanotubes (MWCNTs) and epoxy resin were found to be closely linked to two key factors: the dispersion of the MWCNTs within the matrix and the interactions occurring at the interface between the MWCNTs and the resin matrix . Figure The flexural strength and modulus of the pristine resin were measured at 122 MPa and 2.6 GPa, respectively. In comparison, the MWCNT-NH2 reinforced nanocomposites exhibited improved flexural properties, with a strength reaching 135 MPa and a modulus of 3.2 GPa, representing an increase of 11.0% and 23.1% compared to the neat resin.Conversely, the MWCNT/epoxy nanocomposites treated with surface sizing demonstrated superior flexural characteristics. This enhancement is attributed to the improved dispersion and increased wettability achieved by using epoxy-sizing MWCNTs, as opposed to MWCNT-NH2. The flexural strength and modulus of the MWCNT-BeGE/epoxy nanocomposites could reach 150 MPa and 3.6 GPa, respectively, marking a significant improvement of 22.9% and 37.8% compared to the neat epoxy. Furthermore, when compared with the MWCNT-BuGE/epoxy nanocomposites featuring the same MWCNT content, the MWCNT-BeGE/epoxy nanocomposites displayed a 7.3% increase in strength and a 7.7% increase in modulus, demonstrating that the presence of benzene rings in the surface sizing offered a more effective local load-transfer mechanism between the MWCNTs and the epoxy matrix.Epoxy polymers are one of the most commonly used polymeric materials in the production of composites. This is due to the properties of epoxy materials, such as high strength, rigidity, chemical resistance, low weight, and a low residual stress in epoxy products due to the low degree of the shrinkage of materials during curing ,94. Epox6 ohm∙m to 109 ohm∙m) and insulating (with a resistance of >109 ohm∙m). Another important field in the application of polymer composites is for protection against electromagnetic radiation [However, for application in some areas, composites based on polymeric materials must have electrical conductivity. One of the important areas for the application of polymer composite materials is the creation of coatings that prevent the accumulation of electrostatic charge (antistatic coatings). In accordance with the international standard IEC 61340-5-1 , coatingadiation . To impradiation .The use of nanosized additives makes it possible to achieve the required conductivity of the polymer composite with much lower amounts of the introduced additive. For these purposes, carbon nanotubes are used: multi-walled , single-The introduction of graphene particles into the epoxy matrix has little effect on the electrical conductivity and mechanical properties of the composites. The addition of graphene particles to composites containing carbon nanotubes improves their electromagnetic shielding efficiency without significantly affecting their strength .In the study of , it was The objective of the study described in reference  was to fIn the study  a range As one of the ways to increase the strength of epoxy resins, the addition of carbon nanomaterials (graphenes and carbon nanotubes) is considered ,109. CNTScientists from Rice University  have devThe complex of the unique physicomechanical and physicochemical properties of epoxy resin allows products based on them to cover a wide range of applications in various fields of electrical and radio engineering. Scientific and technical research that focuses on the development of the most specialized coatings (epoxy fills) that are resistant to highly aggressive environments, improving the properties of epoxy resin as a dielectric , and satisfying certain operating conditions is steadily growing.In conclusion, the resonance of epoxies as vital materials across industries is unmistakable. Their adaptability, versatility, and responsiveness to chemical and electrical factors render them as more than mere compounds—they are dynamic components that shape our technological landscape. By embracing their multifunctionality, researchers and practitioners stand poised to unlock the potential of epoxies in domains ranging from electronics to aerospace, ushering in a future where these remarkable materials continue to be at the forefront of innovation and progress.


In this editorial, we offer a comprehensive overview of the themes and findings from the Research Topic, emphasizing the significance of addressing the needs of vulnerable and marginalized populations in social and educational contexts. We also explore the research included in the Research Topic, which delves into the unique challenges faced by individuals from diverse backgrounds. This interdisciplinary Research Topic provides evidence-based studies on these groups, focusing on various areas such as education, psychology, emotional wellbeing, social work, health, and welfare issues. We believe that this Research Topic of 26 published articles serves as a valuable resource for cutting-edge research and policy development for a wide range of professionals, including scholars, policymakers, psychologists, educators, sociologists, advocates, and practitioners. We are especially proud that the research and policy articles span diverse cultural, ethnic, and linguistic backgrounds in both developing and developed countries.Lovett delved into two equity-related concerns regarding educational accommodations, underscoring the necessity of inclusive practices within educational institutions. It was evident that creating inclusive environments required proactive measures to ensure equitable access to educational resources. Another study by Madaus et al. explored the experiences of postsecondary students with disabilities during the COVID-19 pandemic and the subsequent academic year, revealing significant challenges related to accessibility, instruction, and mental health support. In a study by Gelbar et al., the perceptions of accessibility service providers regarding college students with autism spectrum disorder (ASD) were explored, highlighting the critical role of self-advocacy, independent decision-making, self-regulation, and coping strategies in facilitating the success of college students with ASD. These skills empowered students to navigate the academic environment effectively and advocate for their needs. Additionally, a study by Mohamed and Elhoweris focused on preschool teachers' perceptions of gifted learners in Abu Dhabi, emphasizing the need for educational systems to invest in resources and professional development to cater to the diverse learning needs of all students, including those with exceptional abilities. In summary, these studies collectively underscored the pressing need for equitable educational accommodations and support services. They also highlighted the persistence of accessibility challenges, the importance of skill development for students with disabilities, and the significance of early identification and support for gifted learners.The first theme explored in this Research Topic revolved around educational accommodations and the pursuit of inclusion, as students with disabilities often encounter numerous hurdles in accessing quality education Shuayb, . A studyGoodrich et al., the impact of the pandemic on elementary school teachers' practices and perceptions was examined across two critical semesters. The study highlighted the challenges faced by teachers as they adapted to rapidly changing circumstances. In another study, Mitwalli et al. investigated the double burden of COVID-19 and Israeli military rule on persons with disabilities in the West Bank of the occupied Palestinian territory. Their findings illuminated the importance of understanding the unique challenges faced by these populations during times of crisis. A separate study, conducted by Shuayb and Doueiry, focused on the impact of the COVID-19 pandemic on the education and healthcare services of persons with disabilities in Lebanon. In this study, the negative effects of the COVID-19 pandemic were found to bring new challenges to the lives of persons with disabilities. The study identified five overarching themes that hindered persons with disabilities during the COVID-19 pandemic, including accessing education and healthcare, both at the policy and decision levels and in academic and healthcare services.The global COVID-19 pandemic had far-reaching consequences, disproportionately affecting vulnerable and marginalized populations  in Arab countries. Understanding the unique stressors and support needs of these families was essential for promoting the wellbeing of both children with ASD and their caregivers. The COVID-19 pandemic disrupted education worldwide, but a study by Brigandi et al. provided a biological systems theory approach to understanding the challenges faced by educators during this crisis. Recognizing the complexities of teaching in a pandemic could inform more effective strategies for remote and hybrid learning, especially for marginalized students. Xiong and Xu shed light on the experiences of Chinese migrant children and their struggles with relative deprivation and loneliness. Their research underscored the importance of addressing the social and emotional wellbeing of marginalized children who faced unique challenges related to migration. The resilience of Palestinian refugees in Shatila camp, Lebanon, was explored in Al Beainy and El Hassan's study. Their research highlighted the coping strategies employed by this marginalized population and their potential for personal growth even in the face of adversity. These studies collectively remind us of the pressing need for compassion, support, and research that amplifies the voices and experiences of marginalized populations, including refugees.The impact of conflict and displacement on vulnerable populations, particularly children and adolescents, cannot be understated (Al-Hroub et al., Stamp et al. highlighted the importance of considering seasonal and developmental timing in school mobility and high school dropout rates. The study emphasized the need for comprehensive strategies to support mobile students during critical transitions in their educational journeys. In another study, Ching et al. examined the transition experiences of community college transfer students within an Asian educational context. Their findings shed light on the challenges and opportunities faced by these students as they navigated the “2 + 2” pathway. These studies underscored the significance of timing and support for mobile students during critical transitions, offering insights into the challenges and opportunities they encounter along their educational journeys.Another critical theme explored in this Research Topic was the impact of transition and mobility on educational outcomes. For example, Taylor and Zaghi explored the interplay of ADHD characteristics and executive functioning with the GPA and divergent thinking of engineering students. This study underscored the importance of considering individual differences in educational contexts and providing appropriate support. Cody et al. investigated teachers' beliefs about giftedness, with a focus on twice exceptional and culturally, linguistically, and economically diverse populations. This study highlighted the need for culturally sensitive and inclusive approaches to identifying and nurturing gifted students, challenging stereotypes, and recognizing potential in all corners of society. Antoun's study took place in Lebanon, where she explored the framing of education for gifted Lebanese and gifted refugee students. The research provided a critical perspective on the challenges faced by these exceptional students and the importance of fostering their potential in a context marked by adversity and displacement. Jaber and Al-Hroub's qualitative study delved into school counselors' perceptions of virtual counseling in Lebanon. Their findings shed light on the evolving landscape of mental health support in education, particularly in times when virtual platforms play a vital role. Finally, environmental education emerged as a crucial component of responsible citizenship. A study conducted by GAO and Jiang focused on the development and validation of China's Environmental Citizenship Questionnaire among junior high school students. This study highlighted the importance of nurturing environmental awareness and responsibility among future generations. These studies within this thematic area provided educators, policymakers, and researchers with essential insights to navigate the intricate web of social, psychological, and environmental factors that shaped the educational experiences of students in diverse contexts.Education is not solely about curriculum; it is also profoundly influenced by social and psychological factors, and In conclusion, the research presented in this Research Topic underscores the critical importance of serving vulnerable and marginalized populations in social and educational contexts. These populations face unique challenges, and addressing their needs requires a concerted effort from educators, institutions, and policymakers. As we navigate the ever-changing landscape of education, it is imperative that we continue to advocate for equitable and inclusive practices that empower all individuals to reach their full potential. The studies in this Research Topic provide valuable insights and serve as a catalyst for continued research, policy development, and advocacy in support of vulnerable and marginalized populations in education. It is our collective responsibility to ensure that no one is left behind in the pursuit of knowledge and opportunity.AA-H: Conceptualization, Writing—original draft, Writing—review & editing. SR: Writing—review & editing. JM: Writing—review & editing. IS: Writing—review & editing.


Advanced diagnostic imaging techniques, such as CT, can provide helpful information on the specific structures of the head, such as the ocular bulb, due to their high spatial resolution, avoidance of overlapping structures, and fast imaging acquisition. An adequate knowledge of the eye bird anatomy is essential for clinicians, biologists, and researchers to understand many aspects concerning its biology.(Fratercula arctica) using advanced imaging techniques such as CT.Imaging diagnosis plays a fundamental role in avian medicine. However, there are few publications regarding its use in ophthalmology. Seabirds, in particular, present a peculiar ecology since their lives take place in very diverse environments: the aquatic, the terrestrial, and the aerial. This fact implies a series of adaptations at a visual level that are necessary for adequate interaction with the environment. Therefore, knowledge of eye particularities is of great importance for the scientific community since it allows us to deepen our understanding of the ocular anatomy and biology of these animals, which are increasingly present in veterinary and wildlife centers. In our study, we performed a morphometric analysis of the ocular bulb and its internal structures in the puffin  Fratercula arctica) is a member of the Alcidae family and one of three species in the Fratercula genus, alongside the horned puffin (Fratercula corniculata) and the tufted puffin (Fratercula cirrhata), which are typically found in the North Pacific [The Atlantic puffin , hake , or sand eel . Adult puffins are also piscivorous, with varying amounts of polychaetes and crustaceans in their diet [The Atlantic puffin has a wide distribution, inhabiting the entire northern Atlantic Ocean region, from northwestern Greenland, Newfoundland, and Maine (USA) in the west to northwestern Russia and the Canary Islands (Spain) in the east ,7. Theseeir diet ,15.The Atlantic puffin is currently listed as a threatened species on the International Union for Conservation of Nature (IUCN) Red List, categorized as vulnerable, due to a significant population decline over most of its range . ClimateNumerous studies have emphasized the importance of vision in the interaction of these animals with their environment and their overall survival ,23,24. BStudying internal animal anatomy can be highly intricate. While dissection has traditionally been the conventional approach, contemporary diagnostic imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) offer minimally invasive and efficient means to obtain precise anatomical information . AlthougIchthyosaur order [In the case of puffins, the existing literature predominantly focuses on various aspects of their biology and ecology ,14,21,32ur order  and non-ur order . Similarur order ,37,38.Therefore, the objective of this study was to employ non-invasive examinations, such as computed tomography, to measure the size and characteristics of the puffin’s eye and its associated structures.In order to conduct this study, a total of 29 Atlantic puffin carcasses were obtained by the Consejeria de Área de Medio Ambiente, Clima, Energía y Conocimiento of the Cabildo de Gran Canaria . The weight of the animals ranged from 0.185 kg to 0.251 kg, with a mean weight of 0.251 kg. Since the physical examination alone did not provide sufficient information to determine the precise cause of the stranded individuals, modern non-invasive imaging techniques were employed to assess their appendicular skeleton, identify potential metabolic bone diseases, and exclude the presence of foreign bodies and internal organ injuries. Prior consent was obtained from the responsible person at the Cabildo de Gran Canaria to include the puffins in this study. The scanning procedures were carried out at the Veterinary Hospital of Las Palmas de Gran Canaria University.®, Tokyo, Japan). The animals were positioned symmetrically in a prone position on the stretcher, employing a craniocaudal entry. A standard clinical protocol was employed, utilizing parameters of 120 kVp, 80 mA, a 512 × 512 acquisition matrix, an 1809 × 858 field of view, a pitch of 0.94, and a gantry rotation of 1.5 s. The resulting images had a thickness of 0.6 mm. CT scans were obtained in the dorsal, transverse, and sagittal planes with both bone and soft tissue windows. Subsequently, all the acquired images were imported into an image viewer  to facilitate data manipulation and measurements of the puffin ocular bulb and its associated structures.CT examinations of the skull were conducted on the thawed carcasses of these specimens after a 12-h defrosting period at room temperature. Sequential slices were acquired using a 16-slice helical CT scanner  were analyzed by two observers using oblique sagittal, transverse, and dorsal CT images obtained from all the skulls. A soft tissue attenuation window was utilized for image analysis. The measurement methodology followed a protocol previously described in studies on the loggerhead turtle [(A)-Lens diameter: This parameter refers to the maximum distance between the lateral and medial edges of the lens, also known as the equatorial diameter A;-Internal diameter of the sclerotic ring, which represents the maximum distance between the inner lateromedial edges of the ring close to the cornea A;-External diameter of the sclerotic ring, which corresponds to the maximum distance between the outer lateromedial edges of the ring close to the sclera A;-Thickness of the sclerotic ring, defined as the distance between the internal diameter of the sclerotic ring and the external diameter, measured in the dorsal arch .Measurements in the transverse plane relative to the ocular bulb:(B)Transverse plane concerning the puffin’s bodyWe conducted measurements on the head length, width, and orbit depth. Additionally, measurements of both eyes -os lacrimale to the inner face of the os frontale -prominentia cerebellaris, providing the length of the head . Descriptive statistics, including the mean, median, range, and standard deviation (SD), were calculated for each measurement. The Shapiro-Wilk test was used to assess the normal distribution of quantitative data. The Mann-Whitney U test was employed to compare measurements between the right and left eyes. Furthermore, Spearman correlation was utilized to analyze the relationship between different ocular bulb variables and head length, as well as other quantitative variables. The statistical significance level was set at In the computed tomography images, the sclerotic rings are visible from the anterior view of the respective eyes as circular structures with continuous morphology, distinct from the surrounding elements of the skull. The ellipsoid-shaped ocular bulbs exhibit well-defined soft tissue margins that likely correspond to the sclera. Various components of the eye, including the lens, vitreous and aqueous humors, and the anterior and posterior chambers, are also well distinguished in the images . From thp < 0.001), indicating a substantial relationship between these variables. Additionally, moderate correlations were observed between ocular bulb height and length , as well as between ocular bulb width and length , suggesting meaningful associations between these measurements. Moreover, a good correlation was found between the external and internal diameters of the sclerotic ring , indicating a relationship between these variables.The Spearman correlation analysis conducted to examine the relationship between eye measurements and head length did not reveal any statistically significant findings. However, significant correlations were observed in other aspects. There was a strong correlation between ocular bulb height and width , length , but not with width . In a similar way, the external diameter of the sclerotic ring exhibited significant correlations with ocular bulb height  and width , while in this case no significant correlation was found with ocular bulb length . Significant correlations were observed when comparing the orbit depth with ocular bulb measurements: height  and width . However, no significant correlation was observed with ocular bulb length .Correlations involving the internal diameter of the sclerotic ring showed statistical significance with ocular bulb height  for measuring the attenuations of the sclerotic ring, vitreous humor, and lens were indicated by the green, yellow, and purple circles, respectively . It is nIn this study, we conducted computed tomography to assess the ocular bulb and associated hard tissues of the Atlantic puffin. To the best of the authors’ knowledge, this is the first report describing measurements of Atlantic puffin eyes using a CT scan. This technique has proven quite useful in the evaluation of the morphological knowledge of the normal eye and associated structures in different species, such as dogs ,37, catsThe morphometric analysis of the internal diameter of the sclerotic ring provides valuable insights into the relative size of the dilated pupil and the cornea, as this bone correlates well with the cornea. This relationship enables the estimation of the light-capturing capacity of the eye and consequently deduces the behavior pattern, whether diurnal or nocturnal ,35. HoweOur CT studies have also revealed a significant and positive statistical correlation between the internal and external diameters of the sclerotic ring and the width, height, and length of the ocular bulb. These findings suggest a potential relationship between these parameters, visual acuity, and the diurnal pattern observed in the Atlantic puffin. Similar associations have been documented in extinct and extant bird species  and sea Ichthyosaurus and Ophtalmosaurus with large eyes and similar feeding habits to Atlantic puffins [The assessment of orbit depth, from the midpoint of the orbital diameter to the optic foramen, has been previously investigated by other researchers in extinct and extant birds . In thos puffins , which s puffins ,2. Howev puffins ,38.The quality of the acquired tomographic images presented here could be influenced primarily by two factors: the utilization of conventional CT instead of micro-CT and the small size of the birds included in the study. Previous studies have demonstrated that micro-CT offers high contrast and superior image quality for small animals and tissues . HoweverIn this study, the CT images obtained in different planes provided relevant information about the morphometric characteristics of the ocular bulb and the sclerotic ring in the Atlantic puffin. The reference values established included the presumed normal diameters of the ocular bulb and lens, as well as various measurements of the sclerotic ring, which may be associated with the visual capabilities and activity patterns of these seabird species. However, it is essential to note that further investigations involving live animals are necessary to evaluate potential differences compared to data obtained from carcasses. Additionally, it is essential to consider the inherent operational error associated with the manual contouring of computed tomography images.


Mental health disorders are treated with all the available advanced health techniques. The pioneers of Indian philosophy, sages, saints, and yogis, through their experiences and rational explanations, expressed the importance of yoga, and their treatment effects. Yoga-Nidra (YN), one of a particular forms of yoga, is described as a simple and precise way of dealing with mental disorders. The use of YN as an intervention has been reported to reduce anxiety, anger, depression, post-traumatic stress disorder (PTSD), and other different kinds of psycho-physiological abnormalities. In addition to the role of Yoga-Nidra as an intervention tool, it also brings relaxation to the mind and brain, mental catharsis, a positive attitude, self-improvement, and personality refinement. At the same time, YN contributes to boost concentration, memory, and other cognitive capacities, including attention, and thoughts.Because of its important therapeutic contribution to psychological well-being and mental health, it is currently used as a therapy and medical intervention. Yoga-Nidra and other yogic practices will play an important role in treating mental, physical, and psychological problems and improving cognitive abilities, and will help to connect with oneself. These objectives encompass proficient leadership and governance, mental health initiatives at the community level, promotion and prevention of mental health, utilization of information technology systems, and research pertaining to mental health.The worldwide disease burden is believed to be influenced by neuropsychiatric disorders, which are responsible for approximately 14 % of its prevalence [The purpose of this narrative review is to evaluate and consolidate therapeutic effects of Yoga Nidra (YN). The review explains Yoga Nidra effects on mental health, and and concludes with possibilities for future research. This review helps experts find new research areas that can improve mental health.2The present narrative overview employed a comprehensive literature search to identify relevant scholarly literature pertaining to the connection between yoga nidra and mental health. The search undertaken in this article encompassed the utilization of well-established databases like PubMed, Scopus, and Google Scholar. The aim was to ascertain scholarly articles that underwent peer review and were published in the last 25 years. The process of selecting search terms and keywords has been carried out with careful attention to include all aspects of the subject matter, including synonymous phrases, variants, and related concepts. The incorporation of Boolean operators, specifically AND enabled the establishment of logical relationships between search words. The approach utilized for conducting the search is meticulously documented and published in adherence to established protocols, assuring transparency, and facilitating the replication of the process.The search terms employed in the PubMed search encompassed "yoga nidra" AND "mental health." The search yielded a total of 16 publications, out of which 11 were considered relevant to the specified keywords. A Scopus search using identical terms yielded a total of 13 articles, of which 11 articles were found to be directly relevant to the keywords employed. Of the 29 papers that were discovered, only 17 articles were deemed suitable for inclusion in the synthesis of this current narrative review article. This present review will exclusively consider journal articles written in the English language that directly focus on yoga nidra as an intervention. These selected articles were synthesized to generate the content for the review. The publications considered in this study encompass various types of Yogas that incorporate yoga-nidra while excluding those articles solely focused on yoga without the inclusion of yoga-nidra. This narrative review encompasses a comprehensive compilation of 35 studies. In addition to the total articles, 17 were included in the PubMed and Scopus databases for indexing purposes. The remaining 18 papers were sourced from grey research databases, specifically Google Scholar, as they were predominantly referenced in the primary publications. All study studies were thoroughly examined, regardless of their methodological variations, as this present narrative review aims to explore the significance of yoga-nidra in addressing mental health concerns. All the papers that were searched underwent a thorough evaluation process, which involved assessing their titles and abstracts to determine their suitability for inclusion in the final synthesis for the present study. The publications underwent a comprehensive evaluation, comparison, and synthesis to ascertain the significance of yoga-nidra meditation in enhancing mental well-being.2.1This narrative review encompassed a total of 35 studies, of which 17 were specifically examined to assess the impact of yoga nidra on mental health. Out of the total of 17 research analyzed, there were 5 reviews, 4 randomized controlled trials, 1 study utilizing mixed methods, 1 clinical trial, and 9 studies employing pre- and post-intervention assessments of yoga nidra practice. Among the 17 papers analyzed, a subset of 5 studies encompassed patients, with 3 of these studies specifically focusing on female participants exhibiting menstrual abnormalities, while the remaining 2 studies concentrated on persons diagnosed with post-traumatic stress disorder (PTSD). The remaining 12 trials encompassed a sample of persons who were in good health and ranged in age from 13 to 66 years. This study encompasses a comprehensive analysis of research conducted between 1998 and 2023, with a specific focus on articles pertaining to yoga nidra from 2008 to 2023. The research conducted assessed many psychological variables, including stress, anxiety, sadness, well-being, sleeplessness, somatoform symptoms, and other factors that are linked to aberrant somatic disorders. All these measurable variables have the capacity to serve as direct or indirect indicators of human mental health.3Yoga-Nidra, often referred to as yogic sleep, conscious sleep, restless sleep, dynamic sleep, psychic sleep, or profound relaxation, is a remarkable mental condition that exists between wakefulness and sleep . People Yoga Nidra helps individuals relax and meditate to maintain a high level of awareness. This practice promotes physical relaxation, mental clarity, and inner peace via body assessment, breath awareness, and visualizations. This groundbreaking technology fell into disuse over the course of time, but it is making a comeback now that it is being used by people all over the world. This practice is being used as a treatment for important mental illnesses such as stress, depression, post-traumatic stress disorder, and various other psychophysiological abnormalities ,2, and o4Over the course of the past few years, it has been observed that the frequency of mental diseases among adults in a variety of regions across the globe has been progressively rising. A variety of psychological and physiological anomalies can each give rise to a particular type of mental disorder. The current treatments employed for addressing these conditions encompass both psychotherapy and pharmacological interventions . There aThis review only focused on the meditative practice of YN and its impact on addressing mental health concerns. Yoga-Nidra is a form of guided meditation wherein a proficient practitioner facilitates individuals in attaining a meditative state through the utilization of images, music, and several other techniques. The efficacy of this remarkable meditation practice has been demonstrated in alleviating several psycho-physiological abnormalities, including stress, anxiety, rage, well-being, and post-traumatic stress disorder ,23,24,25The presence of mental loads within the academic environment has been noted. One of the studies examined the mental health status of faculty members and identified that academic stress can be alleviated with YN practice. Nevertheless, upon analyzing the demographic data, it was determined that there were no statistically significant disparities identified among the categories, apart from variations in the level of educational attainment. One study recruited individuals who were in good health, as well as individuals who were taking medication for diabetes, hypertension, and heart disease . SimilarMost investigations on yogic interventions have focused on evaluating enhancements in psycho-physiological behavior. But the specific neurological response to the yoga nidra intervention at the level of the brain remains unclear and has not been extensively investigated. A newly published study revealed notable alterations in brain activity after using yoga nidra. The investigators observed a decrease in the alpha and beta frequencies among the participants in the therapy group during their study. The discovery suggests that the inhibition of alpha waves offers a significant understanding of the cognitive mechanisms involved in the brain's preparation for integrating sensory information in a coordinated manner, hence promoting heightened attention . A notabIn recent times, the global population has been confronted with the widespread COVID-19 epidemic, resulting in a multitude of mental health challenges including stress, melancholy, anxiety, and sleep disturbances. During the global crisis, a comprehensive lockdown and other limitations were implemented worldwide. Consequently, the management and alleviation of mental health disorders through pharmaceutical interventions have been shown to be challenging, necessitating the exploration and implementation of non-pharmaceutical approaches. Extensive research has been conducted to address these challenges through the utilization of yogic practice. However, it is worth noting that just a single study has examined the impact of yoga nidra and relaxation music in alleviating feelings of sadness, anxiety, depression, and insomnia among frontline health professionals . The resBecause YN is an excellent, easy, and cost-effective interventional approach that is also easily implementable, it may be used for the prevention of many psychosomatic diseases of the body. This is one of the reasons why Yoga Nidra is one of the most popular forms of alternative medicine today.5The development of Yoga-Nidra is attributed to Swami Sri Satyananda Saraswati of the Yoga School of Munger in Bihar, who has provided a concise and accessible explanation of this practice. According to Swami Satyananda (1998), YN is a yogic technique that involves the internalization of one's awareness. During this practice, the individual steadily withdraws from external stimuli, ultimately reaching a condition when only the aural sensory channel is active . Yoga-NiThe practice of Yoga-Nidra encompasses eight stages, depicted in Sankalpa, which refers to a constructive resolution, serves to initiate a process of profound change inside the subconscious mind. The utilization of guided visualization enhances the engagement of the world of imagination and creativity. Sensory awareness entails the process of seeing emotions and sensations without any form of connection or judgment. Ultimately, the procedure culminates in a re-establishment of consciousness, delicately guiding individuals back to the current instant and their environment [The practice of Yoga Nidra commences by engaging in preparatory measures, which involve assuming a comfortable supine posture and establishing a constructive intention. Shifting focus towards bodily awareness, deliberate attention is methodically focused on individual body parts with the aim of alleviating tension and fostering a state of relaxation. The practice of breath awareness enables individuals to study their innate breathing patterns, resulting in a state of mental tranquility. The act of establishing a ironment ,2. Yoga 6The limitations observed in the examined studies include a very small sample size, the absence of a suitable sampling methodology, and a lack of blinding in treatment grouping . The expMost studies investigating the effects of YN interventions have been focused on individuals who are in good health. The implementation of yoga nidra intervention in individuals experiencing clinical distress has the potential to facilitate the utilization of therapy modalities that are accessible, affordable, and efficacious. Conducting comprehensive and extensive research on this efficacious intervention is of paramount importance. This necessitates incorporating many time points , a bigger sample size, and the inclusion of control groups, treatment groups, and clinical groups. The process of upgrading and confirming the results is crucial to ensure their accuracy and reliability. The following two major future implications could be best to understand the mechanism of yoga nidra meditation.6.1In the field of Yoga Nidra research, a fundamental strategy for enhancing the dependability and practicality of findings involves increasing the size of the sample. To improve the precision of Yoga Nidra studies, it is imperative that forthcoming research places a high priority on incorporating a diverse variety of demographic characteristics among participants. This encompasses a variety of criteria, such as age, gender, cultural heritage, and health-related concerns. To enhance the broader applicability of the study's results to a more heterogeneous population, it would be beneficial to broaden the inclusion criteria for participant selection. The utilization of longitudinal research, coupled with a larger sample size, has the potential to yield significant insights into the long-term effects of consistent Yoga Nidra practice. The acquisition of data from research endeavors with larger sample sizes will serve as the fundamental basis for conducting comprehensive meta-analyses and systematic reviews. These endeavors possess the ability to amalgamate data from multiple research studies, discern trends, and yield more precise estimations of effects. Consequently, our findings may provide a stronger foundation for formulating policy recommendations and guiding therapeutic approaches. Partnerships across research organizations can facilitate the conduct of multicenter experiments with large sample sizes. These studies possess the potential to investigate the replicability of findings across many contexts and individuals, thereby bolstering the reliability of outcomes and contributing to the validation of the efficacy of Yoga Nidra.6.2In the dynamic field of Yoga Nidra research, there exists a promising avenue for further exploration that entails doing a thorough examination of the electrophysiological aspects. The investigation of the neurological and physiological mechanisms behind Yoga Nidra holds promise for advancing our understanding of its effects on the mind-body connection.The opportunity to uncover the complex cerebral mechanisms underlying the practice of Yoga Nidra exists with the application of advanced neuroimaging techniques including functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG). These techniques will facilitate the monitoring and analysis of dynamic changes in neural activity, enabling researchers to identify with precision the specific brain areas and circuits that are impacted by the practice of Yoga Nidra.An additional intriguing viewpoint pertains to the significance of brain connectivity among distinct cerebral regions, a phenomenon that has the potential for enhanced comprehension through the practice of Yoga Nidra. The investigation of neural network coherence and synchronization enables researchers to get insights into the collective functioning of brain regions during the process of skill acquisition. Gaining insight into these patterns of connectivity will serve to elucidate the coherence of psychological, cognitive, and autonomic processes.A thorough electroencephalogram (EEG) investigation has the potential to unveil the mechanisms underlying the control of brain wave activity during the practice of Yoga Nidra. The impacts on awareness can potentially be discerned by the examination of different brain wave patterns, such as alpha, beta, theta, and delta waves. This information will elucidate the concepts of relaxation, meditation, and introspection in the context of Yoga Nidra. It is imperative to comprehend the electrophysiological markers associated with states of tranquility and alleviation of tension. Researchers have the potential to establish measurable parameters for assessing the impact of Yoga Nidra on the body's stress response mechanisms through the examination of alterations in brain oscillations, hormone levels, and autonomic responses.The potential for future research inquiries on Yoga Nidra appears highly promising in shedding light on the electrophysiological mechanisms underlying its transformative advantages. Researchers can enhance their understanding of the intricate mind-body connections facilitated by Yoga Nidra through the utilization of advanced neuroimaging techniques. By investigating the complexities of neural connectivity within the brain, analyzing brain wave patterns, and identifying biomarkers associated with relaxation, researchers can make significant progress in comprehending this phenomenon.7In most of the research, the Yoga Nidra practice was discovered to be beneficial. However, there is also clinical heterogeneity in the sample groups, treatment session lengths, times, and durations in most of the research. Because of this, it can be tough to generalize on YN intervention based simply on the data obtained in the reviewed studies. The current paper was analyzed to have a better understanding of the effects that yoga nidra has on a variety of mental health disorders. In general, there is a need to conduct a greater quantity of research, particularly studies that have larger sample sizes and more rigorous experimental designs. Specifically, this opportunity exists for studies like these. The practice of YN shows promise as an effective, non-invasive, and pharmacologically-free therapy or adjuvant for a wide range of health concerns, especially those related to the mind. Yoga Nidra also has the added benefit of being able to alleviate stress.


The cornea is an important refractive structure in the human eye. The corneal segmentation technique provides valuable information for clinical diagnoses, such as corneal thickness. Non-contact anterior segment optical coherence tomography (AS-OCT) is a prevalent ophthalmic imaging technique that can visualize the anterior and posterior surfaces of the cornea. Nonetheless, during the imaging process, saturation artifacts are commonly generated due to the tangent of the corneal surface at that point, which is normal to the incident light source. This stripe-shaped saturation artifact covers the corneal surface, causing blurring of the corneal edge, reducing the accuracy of corneal segmentation. To settle this matter, an inpainting method that introduces structural similarity and frequency loss is proposed to remove the saturation artifact in AS-OCT images. Specifically, the structural similarity loss reconstructs the corneal structure and restores corneal textural details. The frequency loss combines the spatial domain with the frequency domain to ensure the overall consistency of the image in both domains. Furthermore, the performance of the proposed method in corneal segmentation tasks is evaluated, and the results indicate a significant benefit for subsequent clinical analysis. The cornea is an important refractive medium in the human eye, participating in the transmission and processing of visual information. The corneal segmentation technique provides support for the diagnosis and treatment of corneal diseases. Accurate segmentation is crucial, as a few micrometers of corneal segmentation errors can lead to significant changes in the derived clinical parameters . ThroughRecently, deep learning technology  has showNowadays, many methods have been proposed for OCT image restoration. In order to avoid the problem of inaccurate quantification of the choroidal vascular system caused by retinal vascular shadows, Zhang et al.  proposedTo solve the issues of artifacts and speckle noise patterns and precisely segment the shallowest tissue interface in an AS-OCT image, Ouyang et al.  proposedThe dual-domain transformation capability of DualGAN  is desigA frequency loss that combines the spatial and frequency domains is introduced to ensure the overall consistency of the images in both domains;The repair experiments on both synthetic and real artifacts are devised. The results indicate that the proposed methods can restore artifacts in different situations. To confirm the clinical value of saturation artifact inpainting, segmentation experiments are designed on the three corneal boundaries of real artifact-inpainted images, including the anterior surface of the epithelium (EP), the posterior surface of Bowman’s layer (BL), and the posterior surface of the endothelium (EN). The experimental results demonstrate that the method significantly enhances the precision of corneal segmentation, proving to be more accurate than other repair techniques.In this paper, we treat saturation artifact inpainting as converting the artifact image into an artifact-free image. A new generative model is proposed to inpaint the corneal structure and texture obscured by saturation artifacts, as well as maintaining the overall consistency of the image. The main novelties and contributions are as follows:The remainder of the paper is organized as follows: We introduce our approach in S and W, the forward task of the network is to learn the generator S → W that maps the images W → S. The generated image and ground_truth image are constrained using four different loss functions, including In this work, AS-OCT image inpainting is regarded as a translation task from artifact images to artifact-free data. As shown in S-domain and W-domain images, and the two discriminators are used to distinguish the generated image and real data. Generator W-domain and data generated from the S-domain, while The network consists of two generators  [SSIM for two images, x and y , is defined as follows:µ and σ represent the standard deviation and covariance of images, respectively. y (SSIM)  is a powy (SSIM) , semantiy (SSIM) , and dehy (SSIM)  since itFrequency Loss: In AS-OCT images, non-tissue structure saturation artifact is usually positioned at high frequencies, which could overshadow or interfere with other frequency components. There are gaps between the real and generated images, especially in the frequency domain [y domain ,29, as sF represents the fast Fourier transform, transforming the image from the spatial distribution to the frequency domain via FFT.To minimize the disparities, the frequency loss is introduced, which is the main idea of obtaining frequency domain characteristics of the real and generated images by performing a fast Fourier transform (FFT); in other words, make Loss: we use Adversarial Loss: the adversarial loss acts between two pairs of generators–discriminators . Using the RMSprop optimizer, the learning rates of the generator and discriminator are 0.0005, and 0.0001, respectively, and the batch size is 4.To validate the proposed method, the model is applied for a comparison with existing deep-learning inpainting methods, including MADF , CTSDG , AOT-GANSynthetic Saturation Artifacts’ Qualitative Comparison: the comparative experiments on synthetic artifact restoration are conducted in three different situations:The repair effects of different methods on corneal tissue images with different tilt degrees under the same mask conditions are shown in The inpainting results of different methods on corneal tissue images with the same inclination combined with different masks are shown in The results of adding different masks into the corneal tissue images with different degrees of inclination using different methods are shown in As shown in these renderings, the MADF method can achieve non-tilted corneal tissue image restoration, but there may be some structural defects for wide shadows and tilted corneal tissue images. For CTSDG, AOT-GAN, and G&L, these methods can repair the corneal structure, but they retain blurry or overly smooth textures in shaded areas, especially in wide-shaded images. The RFR approach may effectively rectify backdrop pixels, yet manifests a limited capacity when addressing the corneal structure and texture. The PICNet method has a certain repair effect on the mask area, but its processing ability of the narrow-band artifact’s edge is significantly weak, resulting in incomplete restoration. Significate repair marks occur with the DualGAN method, which can distort the corneal structure and texture. The proposed method can successfully rectify artifacts across varying widths and positions, irrespective of the degree of inclination of the corneal tissue.Synthetic Saturation Artifacts’ Quantitative Comparison: To quantitatively evaluate the inpainting quality, the means of the peak signal-to-noise ratio (PSNR), SSIM, and learned perceptual image patch similarity (LPIPS) [ (LPIPS)  are calc (LPIPS) . TherefoReal Saturation Artifact Qualitative Comparison: DSC), pixel accuracy (PA), F1-score, and Jaccard value of the segmentation results. The calculation formulas for DSC, PA, F1-score, and Jaccard are shown in Equations (11)–(14).X and Y represent the generated image and the ground_truth image, respectively, and TP is the number of true positives, TN is the number of true negatives, FN is the number of false negatives, and FP is the number of false positives.To further evaluate the inpainting performance of different methods on machine analysis, experiments on a corneal segmentation task are conducted. Concretely, the widely used U-Net segmentation model was trained using the labelled AS-OCT image; 31 AS-OCT images are randomly selected from the real repaired saturation artifact to test the segmentation effect. The inpainting and segmentation results of each method are shown in As shown in In this section, two sets of experiments are conducted to verify the contribution. Here, the impact of structural similarity loss and frequency loss on the repair of saturation artifacts are studied. Specifically, the structural similarity and frequency losses are removed, respectively, and their impact on the experiment is observed. From the results in In this study, a novel deep generative method is proposed to remove saturation artifacts generated during AS-OCT imaging. The proposed model is a bilateral network and introduces two loss terms, namely structural similarity loss and frequency loss. The structural similarity loss reconstructs structural and textural details while ensuring the overall image consistency. In the frequency domain, the saturated artifact is located in the high-frequency component, and frequency loss is designed to eliminate image distortion in the high-frequency region. Moreover, frequency loss combines the spatial domain with the frequency domain to reduce the gap between the generated image and the real image. The repair comparison experiment and ablation experiment demonstrate the effectiveness of the innovative points. The results show that this method can successfully remove saturation artifacts and restore the structure and texture information of the cornea. The corneal boundary segmentation experiment further verifies that the proposed method effectively improves the quality of AS-OCT images and significantly improves the accuracy of corneal segmentation.Although this method has achieved satisfactory results, there are still some limitations to the framework. Specific device data are adopted to obtain these valuable results, while the image restoration performance of other OCT devices is not determined in this study.In summary, an inpainting method was proposed to remove AS-OCT saturation artifact while preserving the surroundings. The proposed network is of great significance for the improvement of corneal segmentation accuracy.


This systematic review investigated the effectiveness, efficiency and apical extrusion of the debris of two rotary and two reciprocating single-file systems used for the removal of filling material from straight root canals. A literature search was performed in the Medline, ISI Web of Science, and Scopus databases for relevant articles matching the keyword search strategy. Effectiveness was determined with studies dealing with the ability of the instruments to remove filling material from root canals. Efficiency was assessed with studies dealing with the time needed to completely remove the root canal filling, and apical extrusion was determined with studies that measured the amount of filling material extruded through the apex. From the 424 articles initially found, 406 were excluded for being non-relevant or not fulfilling the selection criteria. Another 9 articles were excluded after methodology evaluation. Finally, 9 studies were included in the systematic review.None of the reviewed systems is effective to completely remove the filling materials from straight root canals, and all systems appear to be equally time-efficient, although this variable shows different results. In terms of apical extrusion, the analyzed reciprocating systems extrude more material toward the periapical tissues than the continuous rotation systems. Key words:Systematic review, rotary files, reciprocating files, apical extrusion, endodontic retreatment. Endodontic retreatment could be challenging within the endodontic practice, mainly due to difficulties for the removal of contaminated materials from the root canal system without extruding them to the periapical tissues. Therefore, several studies have been addressed to analyze the effectiveness and efficiency of endodontic instruments to achieve this purpose; as well as the periapical extrusion of debris and filling materials .It is highly relevant to combine the three aforementioned variables  and analyze them in studies dealing with the removal of filling materials. Effectiveness is defined as the ability of an instrument to remove the filling material from the root canal system; efficiency refers to the patients’ chair-time required to perform the complete removal of the material, and apical extrusion of debris deals with the amount of material pushed by the endodontic instruments through the apical foramen into the periapical tissues during endodontic retreatment -4.The main purpose of endodontic retreatment is to alleviate signs and symptoms related to infectious processes by completely removing the intra-canal filling materials from the involved root, and reduce the intra-canal bacterial load after performing an adequate protocol of cleaning and disinfection of the canal to reestablish healthy periapical tissues . HoweverTo perform a more effective, efficient, and less invasive procedure in terms of apical extrusion of debris and materials, engine-driven rotatory techniques specially designed for endodontic retreatments such as Protaper Universal Retreatment system and Mtwo retreatment system have been proposed.Recently, single-file nickel-titanium (Ni-Ti) reciprocating systems like WaveOne  and Reciproc  have been used for endodontic retreatment, even though they were not designed for such purpose. However, they have shown positive results in terms of effectiveness and efficiency during these types of procedures .These system´s philosophy proposes a single-file endodontic treatment, which renders the endodontic retreatment to be time reduced. However, it has been shown that these files, are incapable of completely remove the filling material from the root canals. Moreover, it has been demonstrated that they cause greater extrusion of materials toward the periapical tissues than continuous rotation file systems ,7.Considering all the above, a systematic review of the literature was conducted following AMSTAR, PRISMA and Faggion guidelines -10, anal-Information sources and search strategy:Several keywords were used for each one of the elements of interest.1): .2): ;3): (Reciprocating systems OR reciprocating instruments OR Reciproc OR WaveOne).The electronic search of the literature has been conducted in the following databases: MEDLINE, ISI WEB OF SCIENCE and SCOPUS; using the following keyword combinations: 1 AND 2 and, 1 AND 3, and the following filters: AND humans, AND English AND 2010/01/01-2022/07/25 without filtering by journal. An additional manual search was also performed, searching for.a) Titles in the bibliographic references of the selected articles, unidentified by the method described above and.b) In-press articles in 4 high-impact Endodontic Journals .-Extraction of the information:From the selected studies, the following criteria were extracted: Authors, name, and ranking of the journal where the study was published, title, year of publication, type of study, sample size and characteristics, randomization, biases, endodontic filling removal technique, variables, units of measurement, evaluation method, statistical analysis, level of significance and results  cont.-3.Results-Selection of the studies:The electronic search Fig.  was perfRemoving duplicates for searches 1 AND 2 and 1 AND 3, a total of 412 articles were obtained. Additionally, 12 articles from the manual search were included for a total of 424 studies. Three reviewers  independently reviewed the titles, abstracts, and full-texts (in cases where there was no abstract) considering the established selection criteria . This prin vitro articles  compared to two reciprocating systems (Reciproc and WaveOne), for removing gutta-percha from straight root canals. These systems were selected because there are not enough studies published from other retreatment systems to analyze the data under similar conditions.In vivo human use is an important issue of modern dentistry since this type of studies can be conducted under controlled conditions; therefore, In vitro studies conducted on natural human teeth were established as essential inclusion criteria, although in vitro studies cannot reproduce a dynamic clinical setting  were analyzed only under the instruments used criteria and were not influenced by root morphology. Inclusion of studies with curved canals would difficult to reach valid conclusions, as they were not performed in similar conditions, following the quality standards guidelines from Faggion, PRISMA, and AMSTAR for selecting studies to be included in a systematic review -10.The working length has also been taken into consideration as it may influence the amount of apically extruded debris. It has been previously shown that a working length of −1 mm from the apical foramen significantly reduces debris extrusion , and thaAnother criterion to consider is the tooth crown sectioning in the selected studies, to standardize the working length and the approximate amount of filling material within the samples, and to rule out the influence of variables such as the crown anatomy and the access to the root canal, thus resulting in more reliable studies -34.The irrigant solutions used during the removing filling material procedure in the selected studies were distilled water  and sodiRegarding the inclusion criteria, only studies using gutta-percha as filling material have been selected, as it has been widely demonstrated that besides being the most used root canal filling material, it is ideal to accomplish a three-dimensional seal of the root canal space, preventing bacterial re-infection by blocking the passage of microorganisms and toxins to the periapical tissues. Gutta-percha has been proven to be a highly biocompatible material, with desirable physical and mechanical properties such as dimensional stability and easy insertion and removal from the root canal system .Exclusion criteria were applied to studies using solvent agents during the process of the filling material removal. Although solvent-softened gutta-percha greatly simplifies the removal of filling materials, it may also produce a residual film of softened material along the dentinal walls of the canal, which could affect the procedure´s efficacy ,32,38. AOne of the techniques with the highest levels of scientific evidence to quantify the residual filling material is the micro-computed tomography (micro-CT). The micro-CT imaging offers a noninvasive and reproducible high-resolution technique for a 3-dimensional (3D) quantitative evaluation of filling materials (in mm3) before and after instrumentation, allowing a highly accurate calculation of the percentage of residual filling material left inside the root canals after retreatment .Longitudinal sectioning of samples before stereomicroscope analysis to evaluate the presence of root canals filling material remnants has also been proposed ,40. ThisCone-Beam computed tomography (CBCT) is an easily applicable noninvasive clinical tool that provides 3D imaging and quantitative evaluation that could be another eligible method for retreatment evaluation. However, root filling materials are usually radiopaque and may cause artifacts on the CBCT images, although these artifacts can be reduced with proper machine settings and parameters. Smaller voxel sizes and small FOV scans are preferable to minimize the presence of artifacts . These aThis systematic review did not consider studies that evaluate effectiveness through radiographic images, since radiographic images provide only two-dimensional information of a three-dimensional structure, and may be subjected to distortions, which could affect the veracity of the studies .Regarding apical extrusion, the rotary systems still extrude a quantity of material and debris toward the periapical tissues, even though it has been proposed that continuous rotation movement allows the filling material to be dragged coronally . AlthougAnother important inclusion criteria for study selection was the use of the Myers & Montgomery technique or the dry-freezing technique for measuring the amount of extruded filling material. However, the Myers & Montgomery technique has more advantages than the second one as it allows a separate quantification of the amount of extruded material and the quantity of irrigant .Considering the results of the included studies, it is concluded that none of the systems is capable of completely removing the filling material from root canals. This finding is reported in the literature as the impossibility of removing 100% of the total filling material regardless of the applied technique ,45. HoweNone of the reviewed systems is effective to completely remove the filling materials from straight root canals, and all systems appear to be equally time-efficient, although this variable shows different results. In terms of apical extrusion, the analyzed reciprocating systems extrude more material toward the periapical tissues than the continuous rotation systems.