This study investigated how children's drawings can provide insights into their cognitive development. It can be challenging to quantify the diversity of children's drawings across their developmental stages as well as between individuals. This study observed children's representational drawing ability by conducting a completion task where children could freely draw on partially drawn objects, and quantitatively analyzed differences in children's drawing tendencies across age and between individuals. First, we conducted preregistered analyses, based on crowd-sourced adult ratings, to investigate the differences of drawing style with the age and autistic traits of the children, where the latter was inspired by reports of atypical drawing among children with autism spectrum disorder (ASD). Additionally, the drawings were quantified using feature representations extracted with a deep convolutional neural network (CNN), which allowed an analysis of the drawings at different perceptual levels . Findings revealed a decrease in scribbling and an increase in completion behavior with increasing age. However, no correlation between drawing behavior and autistic traits was found. The network analysis demonstrated that older children adapted to the presented stimuli in a more adult-like manner than younger children. Furthermore, ways to quantify individual differences in how children adapt to the presented stimuli are explored. Based on the predictive coding theory as a unified theory of how perception and behavior might emerge from integrating sensations and predictions, we suggest that our analyses may open up new possibilities for investigating children's cognitive development. A way to naturally gain insight into children's cognitive development is by observing their spontaneous drawings  with their priors (top-down information). Priors may include knowledge about concepts, which are needed to successfully complete a drawing, but can also include personal preferences. For example, a child might prefer to draw a specific object, regardless of the presented shape, indicating an influence mainly by top-down information. In contrast, if bottom-up information had a stronger affect, they would keep close to the presented drawing. Successful completion of the drawing can be expected only if top-down and bottom-up information are adequately integrated.Unlike general drawing tasks, drawing completion is also useful for a systematic analysis since the task limits the potential behaviors that the child might show. Another advantage is that it does not require instructions, thus, drawing completion makes it possible to investigate the drawing ability of very young children or children with linguistic deficits, for instance, in the context of developmental disorders.Therefore, in this study, an extended version of the drawing completion task of Saito et al.  was desiIn order to examine individual differences, we measure children's autistic traits  compared to previous studies, and by applying an objective data analysis process. Specifically, the analysis entailed two approaches for evaluating children's drawing data, that could be easily scaled to large datasets. First, a crowdsourcing study was performed to collect ratings from adults about features that are visible in the drawings. Second, the drawings were evaluated based on a computational technique that used visual features extracted from deep convolutional neural networks (CNNs). This technique was recently proposed by Long et al.  for examThe results presented in this paper are an extension of a previously published study  between October 2019 and February 2020, in a separate area where children with their parents could enter free of charge. Participants were recruited on the day, or could register in advance. The parents were informed of the content of the experiment, and informed consent was obtained from all participants. The experiment was reviewed and approved in advance by the research ethics committee of the Office for Life Science Research Ethics and Safety at The University of Tokyo to confirmed that the study conforms to recognized standards.outline condition, the outline of the object was shown without any detailed features. Sketching the outline could be the most typical way of getting started when drawing an object  In the scrambled inner feature condition, the features from condition (ii) were presented in a scrambled configuration, such that the typical completion of the object was not possible. Without a straightforward solution, this condition is more difficult than (i) and (ii), as the presented objects had to be reinterpreted or combined to achieve proper completion. In addition, this condition may elucidate individual differences related to autistic traits (see the hypotheses listed in the Section 1).The experiment was designed as a completion task .Each child drew up to six of the available stimuli; specifically, the child was assigned  to one of four previously prepared drawing sets that contained six drawings each .Children drew directly on a tablet PC to allow for an automated analysis.The experiment was performed in a separate area and children sat with the back to the entrance to keep distractions to a minimum; however, since it was located in an open space connected to the rest of the museum, ambient noise could not be avoided. Whenever possible, children performed the task alone, guided only by the experimenter; younger children could sit on their caretaker's lap while drawing. The children were presented with pictures on a tablet PC (IPad Pro 11 inch) and were told to draw freely on the stimuli. A blue stylus pen was provided for drawing. The original drawing was shown in black on the tablet PC. The children's drawings were displayed in blue to enable differentiation from the original drawing.The experimental setup is shown in During or immediately after the experiment, parents were asked to complete the child version of the AQ score questionnaire  were excluded because they ran away from the experiment before drawing on at least one picture per condition. Two children (5 and 6 years old) were excluded because they only drew something on the free trial drawing in the beginning but did not draw anything on any of the stimuli. Three children had to be excluded due to technical issues with the iPad (4 and 5 years old) or due to problems with handling the iPad (4 years old). One child (4 years old) was excluded because the caregiver helped the child by verbally hinting at what she should draw albeit instructed otherwise.The remaining 104 children  produced a total of 621 completion drawings that were included in the analysis. The average age of these children was 4 years and 9 months , with a standard deviation of 16 monthsAs participation was spontaneous, not all participants were able to stay long enough to complete the AQ score questionnaire. In addition, the AQ score questionnaire is designed for children of ages 4 years and above, thus posing some difficulties for parents of younger children to accurately respond. In total, only 65 questionnaires among the 104 children were filled completely; however, in most cases, only a few questions remained unanswered. Therefore, the AQ score was used for analysis if the parents filled in at least 80% of the AQ score questionnaire, that is, if they answered a minimum of 40 of the 50 questions. If less than 50 questions were answered, the resulting score was scaled accordingly to be equivalent to a fully filled questionnaire. Thus, the AQ scores of 94 children could be included in the analysis. While the age and AQ score of the children were well-distributed, approximately 60% of the children had an AQ score between 10 and 20. Only six children had an AQ score of above 32, which is usually applied as a cut-off indicating strong autistic tendencies  to investigate the drawing tendencies found in the collected data set. This analysis aimed to categorize children's drawing behavior with greater reliability than that achievable by current computational methods. For instance, in order to decide whether a drawing was completed or not, it is important to use contextual knowledge of what the drawing should represent and whether the child's drawing is meaningful within the context of the presented stimulus. Additionally, the human rating provides a baseline that can be used to confirm the validity of the subsequent computational analysis.Second, the data was evaluated based on visual features extracted from the raw drawings following the methodology proposed by Long et al. . In contThe adult rating study was conducted using Amazon Mechanical Turk, and was designed to verify our hypotheses about differences in the drawing style of the children (see Section 2.5). Recruited participants were presented with one of the children's drawings and asked to rate whether statements about the particular drawing were false or true, using a continuous scale ranging from 0  to 100 (true).drawing style to refer to the broad features of drawings; specifically, we consider “completion,” “scribbling,” “coloring in” of shapes, and the “tracing” of existing lines, inspired by drawing behaviors that were reported in Saito et al.  the drawing.”Finally, a general question that could provide a hint of whether the drawings of the children were semantically linked to the presented part was added:“What the child drew (in blue) is related to the original drawing (black).”In the instructions, examples of the intended drawing behavior were shown to ensure that the participants understood the intended meaning of the statements. These examples were selected from images that were rated with the maximum score in the corresponding question, from a pilot rating which contained the drawings of the first 27 children.The ratings for a total of 570 pictures were obtained online. Five independent ratings were obtained for each of the drawings. Raters could rate as many different drawings as they liked. A total of 417 raters participated in the study, each of whom rated an average of six drawings. For four children, the parents did not provide consent for anonymous use of their children's drawings on online platforms. Therefore, the 24 drawings of these children were separately rated offline by four adults who were not involved in this research project. Children's drawings in which nothing was drawn (27 out of the 621 obtained drawings) were automatically assigned 0 for all statements.As a known-answer question, rating study participants were additionally asked what they thought the black part of the drawing represented . The ratings provided by a participant were included in the subsequent analysis only if the participant answered correctly in more than 70% of the ratings.For statistically testing the hypotheses, we use linear mixed-effect models for regression modeling and the chi-squared test (likelihood-ratio test) to compare the goodness of fit of a model with vs. without a variable in question  to determine statistical significance of that variable.The human rating study conducted here is based on predefined rating statements. Therefore, analyzing the drawings based on computational image analysis techniques could be useful to provide an efficient and objective analysis at either the local or global level. For the analysis of children's drawings, Long et al. , 2019 prrelative differences between drawing styles, for instance, for comparing the drawings of adults and of children, or the drawings created for different conditions.Note that in the study of Long et al. , the CNNHere, the VGG19 network architecture proposed by Simonyan and Zisserman  was usedThe procedure in Long et al.  was follAs a measure of dissimilarity between different feature vectors, the Pearson correlation was utilized in accordance with Kriegeskorte et al.  and Longi and j as inputs.where Five preregistered hypothesesWith increasing age, children exhibit more representational drawings .With increasing age, children exhibit less scribbling.Children draw in a similar manner, regardless of whether the outline [condition (i)] or the inner parts are presented [condition (ii)].Furthermore, different tendencies in developmental improvement were expected in children with stronger autistic traits. Differences in drawing related to autistic traits may arise from various factors. For example, a local processing bias has been found in individuals with ASD ] and the scrambled inner features conditions [condition (iii)].As described in Section 2.4.1, adult ratings for the drawings were obtained to investigate which drawing styles children showed at different ages. First, how the scribbling and completion scores changed with the children's age was tested. It was found that children scribbled less . Nevertheless, the score reveals additional variability that is not fully explained by the completion score. For example, the 59-month-old child at the top of The RDM score correlated with the completion score [However, in its current form, this score has a number of limitations. While contextual information sometimes seemed to be reflected in the score cf. , it cannImprovements can be made either at the level of task design or at a computational level. For example, modifying the set of stimuli that children are presented with could help improve RDM comparability between children, enabling better interpretation of individual differences, as presented in In this study, children's representational drawing ability was investigated based on an extended completion task, in which incomplete drawings of four different objects were presented to the children across three different presentation conditions. A two-fold analysis was performed on the collected dataset. First, human ratings collected via a crowdsourcing study provided information on the types of drawing styles. With a larger sample size and diverse stimulus set, the preregistered analysis confirmed developmental changes with age that has been found in previous studies  can be found at: The studies involving human participants were reviewed and approved by Office for Life Science Research Ethics and Safety (The University of Tokyo). Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin. Written informed consent was obtained from the minor(s)' legal guardian/next of kin for the publication of any potentially identifiable images or data included in this article.YN, ST, and AP conceived the experiments and analyzed and interpreted the results. AP and ST conducted the psychological experiments. AP implemented and conducted the computational experiments and drafted the manuscript. YN and ST reviewed the manuscript. All authors read and approved the final manuscript.This work was supported by JST CREST Cognitive Mirroring, Japan (Grant Number: JPMJCR16E2), the JST CREST Cognitive Feelings, Japan (Grant Number: JPMJCR21P4), the JSPS KAKENHI (Grant Number: 21H05053), the Institute for AI and Beyond, the University of Tokyo, Japan, and by the World Premier International Research Center Initiative (WPI), MEXT, Japan.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Adverse Childhood Experiences (ACEs) are defined as traumatic events occurring before age 18, such as maltreatment, life-threatening accidents, harsh migration experiences, or violence. Screening for ACEs includes asking questions about an individual's early exposure to these types of events. ACEs screenings have potential value in identifying children exposed to chronic and significant stress that produces elevated cortisol levels , and its associated physical and mental health conditions, such as heart disease, diabetes, depression, asthma, ADHD, anxiety, and substance dependence. However, ACEs screenings are seldom used in primary care settings. The Surgeon General of California has addressed this care gap by introducing ACEs Aware, an ACEs screening fee-for-service healthcare policy signed into law by Gov. Gavin Newsom. Since January 2020, Medi-Cal, California's Medicaid health care program, has reimbursed primary care providers for using the Pediatric ACEs and Related Life-events Screener (PEARLS) tool to screen children and adults for ACEs during wellness visits. To achieve the goals set by the ACEs Aware state policy, it is essential to develop and test implementation strategies that are informed by the values, priorities, and resources of clinical settings, healthcare professionals, and end-users. To address this need, we partnered with a system of federally qualified health centers in Southern California on a pilot study to facilitate the implementation of ACEs screenings in five community-based clinics. The health centers had broad ideas for an implementation strategy, as well as best practices to improve adoption of screenings, such as focusing on staff training to improve clinic workflow. This knowledge was incorporated into the development of an implementation strategy template, used at the outset of this study. We used the Exploration, Preparation, Implementation and Sustainment (EPIS) framework to guide the study and inform a participatory planning process called Implementation Mapping. In this paper, we describe how Implementation Mapping was used to engage diverse stakeholders and guide them through a systematic process that resulted in the development of the implementation strategy. We also detail how the EPIS framework informed each Implementation Mapping Task and provide recommendations for developing implementation strategies using EPIS and Implementation Mapping in health-care settings. Adverse Childhood Experiences (ACEs) are defined as traumatic events occurring before age 18, such as maltreatment, neglect, life-threatening accidents, harsh migration experiences or exposure to violence , 3. ScreThe ACEs Aware policy in California is a valuable pilot for the country. The economic and humanistic benefits of ACEs screenings remain debatable because it is important not only that screenings are completed in primary care settings, but that the information is used to engage families effectively with the goal of improving health. In order to be valuable, ACEs screenings must lead to timely, evidence-based interventions. Policymakers should consider how ACEs screenings are used, within a larger process of supporting families that have experienced traumatic events. Without the training necessary to implement trauma-informed care in healthcare settings, ACEs screening could re-traumatizing families; similarly, appropriate training is necessary for healthcare professionals to prevent compassion fatigue or burnout related to the process of discussing trauma with patients and caregivers on a daily basis.The growing interest in ACEs screenings in primary care settings to address social determinants of health has been informed by research showing the benefits of this practice. Felitti et al.  stated tRariden and colleagues  conducteTo achieve the goals set by the ACEs Aware state policy, it is essential to develop and test implementation strategies informed by the values, priorities, needs and resources of clinical settings, professionals, and end-users –22. ImplThe purpose of this paper is to describe how the IM process and collaborations between the research team and diverse stakeholders representing healthcare leadership, clinic management, quality department, providers, staff, and caregivers contributed to the creation of a multi-faceted implementation strategy for ACEs screening implementation in five clinics. We report on the first four IM Tasks – Task 1: Conduct a needs and assets assessment and identify adopters and implementers; Task 2: Identify adoption and implementation outcomes, performance objectives, and determinants; Task 3: Identify and create implementation strategies; and Task 4: Produce implementation protocols and materials . We alsoThis study represents a partnership with five clinical sites that are part of a large FQHC system serving largely Hispanic/Latinx patients in frontier, rural, semi-urban, and urban regions in California. In late 2019, the partner healthcare system decided to adopt the ACEs Aware policy and reached out to the first author to support implementation efforts. An overarching implementation strategy template, designed to address identified challenges to implementing innovations in clinical settings and at the partner healthcare system –31, was The methods presented in this paper are novel in two ways. First, IM is a relatively new approach in terms of implementing practice change in community health centers to identify and/or design implementation strategies. In this case, IM was used to build on strategies that were identified during the development of the grant proposal, in which researchers collaborated with FQHC clinical partners  and a Trauma-Informed Care (TIC) workgroup (which included the researchers) to develop a multi-faceted implementation strategy  to suppoSecond, this project is novel because we used the EPIS framework to provide the conceptual framework for researchers to consider the context in which the ACEs screenings were going to be implemented and to help address IM questions designed to guide planning efforts . In sum, IM provided a structure for planning the implementation strategies and the EPIS framework provided specific processes and constructs to help answer those questions. Both EPIS and IM informed group decision-making and identification of key determinants of change. This approach exemplifies how IM can be used with implementation frameworks to plan implementation strategies and advance the field of Implementation Science.Central to the integration of IM and EPIS is engagement of stakeholders across all IM Tasks. The project started in May 2020 with an implementation team from the partner healthcare system: Director of Research, Data Manager, and Director of Pediatric Programs. Due to turnover during the COVID-19 pandemic in late 2020, the first two individuals left the organization. The Director of Pediatric Programs (DPP co-lead hereafter) remained, and a new data coordinator (data co-lead hereafter) joined the project. These two individuals are referred to as internal project co-leads, or champions. The initial implementation team was comprised of researchers, healthcare leadership and implementers, and end-users . The team held two brainstorming sessions to identify initial stakeholders to be invited to the IM process based on the needs and characteristics of each of the implementation strategy activities. These individuals were identified based on their roles within the healthcare system and previous experience collaborating in various research projects with the first author since 2017. An email was sent to these 25 stakeholders, who represented key areas in the FQHC system that would support ACEs screenings and that were described in the previous section . Stakeholders were invited to an initial Zoom meeting, which was held 30 days after the study funding started. Based on this discussion, which touched on the specific IM tasks that would need to be accomplished throughout the project, attendees identified other colleagues whose expertise and enthusiasm for new programs would contribute to the planning and implementation process. Conversations in the initial meeting made it clear that stakeholders preferred to be involved in their area of expertise, and that administrative time was in short supply. As a result, stakeholders suggested the creation of subgroups based on selected strategy activities, and on areas of expertise/interest to improve the fit of the ACEs screenings for the participating clinics, and for FQHC system. Those areas included the use of technology to improve workflow, the transfer of data from EMR system for evaluation, training, caregiver (end-user) experience, and workflow , outer context , capacity to attend meetings and individual interest. Each group met two to three times throughout the IM process. This iterative process fostered the creation of tailored protocols to facilitate activities across the EPIS phases of preparation, implementation, and sustainment. Caregivers of pediatric patients provided feedback on ways to improve families' ACEs screening experiences. The IM planning meetings were structured to identify objectives and potential challenges, brainstorm ideas to overcome those challenges, and assign responsibilities to participants. Meetings with professionals were conducted in English, using the Microsoft Teams online platform, and each meeting was recorded and professionally transcribed to aid in analysis and identify ideas or tasks that would benefit from further discussion in later meetings or sub-groups. Meetings with caregivers were held mostly in Spanish on a conference phone call by the first author and a community health specialist. Due to the low quality of the call recordings with caregivers, two note takers were used to integrate and compare notes for accuracy. Caregivers received a gift card, delivered to their phones through text or n = 23) of meeting attendees who provided demographic data reported their race or ethnicity as Hispanic , Middle Eastern , Asian , Black , and White . Professional roles included medical doctors, clinic managers, medical assistants, medical scribes, nurses, and technology managers. Separately, we included a group of end-users (13 caregivers), who provided feedback on the screening process. All caregivers identified their ethnicity as Hispanic and their gender as female; the average age was 27 years old. Just over half of the caregivers preferred to participate in the IM conversations in Spanish, rather than English.Consistent with the principals of IM, the planning process was carried out using a collaborative group process with a diverse group of stakeholders who shared responsibility for knowledge building and direction of the ACEs screening implementation. Forty-four stakeholders  participated in 12 IM meetings. The 52%  , 31 Fig.This approach allowed us to account for the dynamic nature of the healthcare system due to inner and outer context characteristics and events in general and during the COVID-19 pandemic in particular, the nature of the ACEs screenings , and the need to approach planning through a lens of equity and inclusion . The maiIn 2020, the TIC workgroup conducted anonymous organizational surveys to assess training needs among service providers, awareness of the ACEs Aware policy, perceived ability to successfully screen for ACEs in their clinic after taking the state training, leadership support, and workforce morale. The survey was open online from 17 July to 4 August 2020, and a total of 162 individuals were invited to participate, with 52 individuals completing the survey (36% response rate). Of those, 32 (61%) were clinical providers (MDs and DOs), 17 (33%) were nurse practitioners, and 3 (6%) did not report. More than half of survey participants found the ACEs training relevant (52%) to their clinical practice, and most (74%) said they had the training and information needed to screen patients based on completing the state's required 2-h ACEs Aware training. Some participants were not clear on how the workflow would accommodate this new screening and suggested including nurses, medical assistants and case managers in the screening process and training. Results from a separate leadership survey conducted in early 2021 identified internal factors related to the partner healthcare system that could challenge the implementation of the ACEs screenings. Those factors included high levels of burnout at the FQHC and a need for leadership to improve self-care among employees and promote TIC across the organization.The exploration and preparation phases of the EPIS framework informed this task by providing additional guidance on what to consider when examining needs, assets, and challenges based on organizational characteristics  and their potential impact or fit on the implementation phase see . The mapThis preliminary information informed the priorities for future planning, such as discussions about who would be leading and conducting the ACEs screenings. This was critical given the high staff turnover and shortages in clinic personnel at the time of these discussions because of the COVID-19 pandemic. With that agenda in mind, the first planning meeting was held using Zoom, for 60-min, with all stakeholders involved to introduce the new ACEs screenings initiative. The agenda included a description of the broad implementation strategy proposed in the funding proposal and the logic model behind it.  We folloOne example of the benefits of including end-users during the IM process, and early on during the EPIS preparation phase, was the fact that caregivers who participated in our project shared a need to add strength-based questions to the ACEs screenings to showcase families' resilience. It was also deemed important to clarify that all caregivers of children ages 0–5 years were being asked the ACEs questions to avoid caregivers feeling singled out. The team added these strategies to the implementation protocol with the goal of improving families' experiences during ACEs screenings in primary care settings, and to address potential unintended consequences such as further stigmatization.Given the barriers and opportunities that had been identified in Task 1, the team continued to describe targets for change and desired outcomes. For this Task, the research team shared with stakeholders the original implementation strategy template and broadly defined intended outcomes  as a starting point for stakeholder discussions. The IM process allowed the team to refine the template by identifying concrete performance objectives (implementation sub-tasks/behaviors) that would lead to those outcomes and to confirm with stakeholders that those intended outcomes were relevant and valued. One example of this feedback was that stakeholders identified a need to support efficient workflows and clinical care team procedures during the planning and implementation of the ACEs screenings, to increase likelihood of sustainment. The overall goal of this step was to focus on identifying the appropriate “implementers” and concrete activities (or Implementation Tasks) for them to overcome key challenges identified during the needs assessment . The performance objectives were framed in terms of specific Tasks and who would complete the Tasks to integrate ACEs screenings into existing organizational and clinic workflows and procedures. Identifying performance objectives for implementation and sustainment through the use of several IM Matrices of Change allowed us to identify key determinants  for each specific performance objective. In this project, we organized the activities in this step according to EPIS phases.The performance objectives and outcome discussions during this Task were integrated into a table framed around each of the phases of the EPIS framework  These questions were asked based on the inner and outer context characteristics of the FQHC system. Even though it was at times difficult for stakeholders to plan too much ahead , they appreciated the systematic and sequential approach of this step. See During this Task, having the voices of professional stakeholders with diverse backgrounds as well as the voices of caregivers allowed for sometimes difficult but needed conversations about the balance between the potential benefit of ACEs screenings  and potential unintended consequences. Those potential consequences included stigmatization, given the high prevalence of ACEs among US youth, and among minority communities –3, and iActions to address these concerns included adding two strength-based questions to the ACEs screenings; informing caregivers in advance that these screenings were happening as “usual care” at their clinic; providing a comprehensive introduction to the ACEs screenings that explained that all caregivers were being asked these questions to avoid caregivers feeling singled out; explaining that the screenings were voluntary; and having concrete resources and services available to support caregivers after the screenings were completed, based on the child's needs. Champions were identified to carry out suggestions to overcome these concerns as reflected in One example of the benefits of this participatory and co-creation planning process became clear when the two initial implementation champions at the partner healthcare system  left the organization within the first 2 months of the study. Instead of causing a major disruption to the IM process, there was a relatively smooth transition, which was likely due to clearly articulated goals and planning processes. The Director of Pediatric Programs or DPP stepped in to assume a leadership role as a co-lead, and a new data manager project co-lead was promptly identified because these two individuals had participated in Task 1 of the IM process.Given the dynamic nature and inter-dependence across the five mapping sub-groups, we are reporting the main activities of the last two Tasks together. The mapping sub-groups started by reviewing the list of factors that could serve as barriers to the ACEs screenings and strategy activities and by adding new stakeholders  and selecting the determinants that were a priority for the groups. These conversations informed the final linkage of who was doing what (agents), their performance objectives, relevant determinants of success, change methods, and practical applications in clinical settings and at the healthcare organizational levels. These linkages were built to expand and refine the implementation protocol for program use that was initiated in Task 2.Given the characteristics of the ACEs innovation involving a pediatric screening procedure that requires coordinated actions from multiple implementers , and within a dynamic organizational setting, we focused on inner context areas such as workflow, training, information technology, and electronic healthcare records systems. See The lens of identifying determinants at the outer context during the planning group process also allowed the groups to identify the impact of new challenges that emerged during this phase of the process. One of those new challenges include the state of California, as a result of the COVID-19 pandemic, instituting a new policy requiring healthcare workers to show proof of vaccination by 7 October 2021 to remain in their jobs. As a result, our clinical partner lost clinic personnel , and the project's timeline for the implementation phase had to be postponed.For Task 5  we willThrough a seven-month IM collaborative process, researchers convened and collaborated with healthcare managers, clinic personnel, and caregivers of child patients to co-create implementation protocols through an IM process, guided by the EPIS framework. A need to identify and report implementation science engagement in research has been identified as a gap in the literature . We utilWe faced challenges during this process. A few stakeholders, mostly representing the Information Technology department, shared concerns about already having a plan in place; they had worries about their time and about not being part of the initial grant proposal conversations. The first author explained that having all stakeholders available for grant writing was not feasible and that the initial work was done with members of the research department and TIC workgroup at the FQHC. In addition, through IM, we were able to engage in a participatory process that helped develop the specific activities that were suitable for stakeholders and each clinic's workflow. This information seemed satisfactory for stakeholders to move forward. In addition, we held 15 follow-up meetings with smaller groups of stakeholders ; and separately with those with less perceived power  to make those individuals feel safer and more comfortable in speaking directly.Despite these challenges, including those posed by COVID-19 and its impact on the partner healthcare system and workforce, we were able to convene diverse groups of stakeholders and gather important information using a participatory approach. This approach increased buy-in among stakeholders. This support is reflected in the fact that the partner healthcare system reduced its collaborations with academic partners in 2020, and our study was one of only three studies approved to move forward despite the organizational stress brought about by the pandemic. Having a template of an implementation strategy to begin with was helpful to move the mapping process conversations along in a structured manner, while allowing changes on the strategy activities (forms) and preserving its goals (functions) . LessonsWe acknowledge limitations in this study. The project started during the COVID-19 pandemic in May of 2021, which strained the FQHC system even more in terms of financial losses and workforce shortages. Related to this challenge, we relied on online meetings and clinic personnel often had technical difficulties accessing the meetings, and several of the stakeholders did not have video capacity. Despite these challenges, we were able to complete the IM planning process by having a flexible timeline, close communication within and across IM subgroups, and by having back up meeting times.There are many commitment strategies that we have used with the most important that we used to overcome the obstacles and barriers related to ACEs screenings was linking with and supporting initiatives focused on trauma-informed care that can be used within health systems and practices. It is also important to understand that health systems are not static and if ACEs screenings as a routine practice in primary care settings are to be sustained, there should be sufficient attention to institutionalizing screenings, the incorporation of ACEs in the mission and vision of organizations as well as in the policies and procedures needed to communicate to all providers and staff that this is something that is expected, supported, and rewarded in the organization. It is also essential to increase the capacity of healthcare systems to link families to services as a result of these screenings, while addressing the limited capacity of local communities, especially rural and under-resourced areas , to absoThis study can inform other efforts, as projects seldom start from a blank slate. Often, there are implementation strategies already planned or discussed during the early phases of the implementation process. However, tailoring and adaptation are almost always needed, and collaboration can help to support and manage these processes . IM can Overall, the IM process that was informed by the EPIS framework facilitated consideration of outer system and inner organizational contexts as well as bridging factors that linked them. Our collaborative process allowed for a suitable approach for the inclusion of diverse stakeholders to co-engage in planning and pre-implementation of a complex health intervention. These interventions are delivered in dynamic and interdependent systems and require coordinated actions from multiple actors –42. For This study presented an example of how the team engaged diverse stakeholders across all IM Tasks. We also present how to integrate the IM process within a complex health system, while being guided by an implementation framework. The EPIS framework embodies process, determinants, and potential mechanisms in the implementation process. The synergy between IM and EPIS helped to frame conversations and discussions and to provide a conceptual starting point for this collaborative process. Integrating such an implementation theory with IM activities has the potential to advance implementation science while improving public health.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.MP is the principal investigator (PI) and had the main idea for this study. She was the lead for the IM process and meeting facilitator, wrote the first draft of this manuscript, and was responsible for all revisions. MF consulted with the PI on the use of the IM process in this project and attended IM sessions. GJ attended some of the IM sessions and coordinated the IM sub-groups' communication and logistics. JD attended an IM session and contributed to the literature review. GA has been involved with the project since conception, has supported the use of the EPIS framework in general and during the IM process and attended IM sessions. All authors have read, edited, and approved the final manuscript.This work was partially supported by the National Institute of Mental Health (R21MH123835).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Biodiesel can be produced from vegetable oils, animal fats, frying oils, and from microorganism-synthesized oils. These sources render biodiesel an easily biodegradable fuel. The aim of this work was to perform an advanced bibliometric analysis of primary studies relating to biodiesel production worldwide by identifying the key countries and regions that have shown a strong engagement in this area, and by understanding the dynamics of their collaboration and research outputs. Additionally, an assessment of the main primary feedstocks employed in this research was carried out, along with an analysis of the current and future trends that are expected to define new paths and methodologies to be used in the manufacture of biodegradable and renewable fuels. A total of 4586 academic outputs were selected, including peer-reviewed research articles, conference papers, and literature reviews related to biodiesel production, in the time period spanning from 2010 to 2021. Articles that focused on feedstocks for the production of biodiesel were also included, with a search that returned 330 papers. Lastly, 60 articles relating to biodiesel production via sewage were specifically included to allow for an analysis of this source as a promising feedstock in the future of the biofuel market. Via the geocoding and the document analyses performed, we concluded that China, Malaysia, and India are the largest writers of articles in this area, revealing a great interest in biofuels in Asia. Additionally, it was noted that environmental concerns have caused authors to conduct research on feedstocks that can address the sustainability challenges in the production of biodiesel. The process of deescalating the use of conventional fuels faces several hurdles worldwide, and despite the growing scientific evidence of the viability of other biofuel production routes, governmental and regulatory limitations accentuate these difficulties and forestalls further progress ,4,5,6,7.Bibliometric analyses are a well-known and rigorous method for the analysis of large amounts of scientific information . It allohttps://www-webofscience.ez373.periodicos.capes.gov.br/wos/woscc/basic-search, accessed on 8 August 2022). The articles selected were specifically related to feedstocks employed in the manufacture of biodiesel .This article aimed to critically evaluate, from a qualitative and quantitative standpoint, academic papers published on themes related to the specific aforementioned area via the creation of a highly specific database. Articles in this database included those related to biodiesel production and those that were published between 2010 and 2021. Quantitative and qualitative conditions were set and entered within the search tool available on the Web of Science Core Collection website .Some search parameters were previously set on the Web of Science Core Collection website when using programs to collect the data to compose our advanced bibliometric analysis. The database files were accessed and downloaded via the login credentials provided by the CAPES PERIODICOS platform , CiteSpace was developed by Dr. Chaomei Chen from Drexel University, USA. VOSviewer , VOSviewer software, developed at Leiden University’s Centre for Science and Technology Studies (CWTS), Leiden University, the Netherlands. ArcGIS , ArcGIS is a product suite developed by Environmental Systems Research Institute (Esri), Redlands, California, United States. ArcGIS 10.5 was used to analyze the geographical distribution of publications, while VOSviewer was used for data visualization . CiteSpaBiodiesel production from microalgae, in which the use of microalgae in the manufacture of different energy sources, such as oil and biofuels, including biodiesel, were discussed [The initial search on the Web of Science Database Core Collection website resulted in 4586 research outputs from 2010 to 2021, the most relevant of which was published in March 2012. The title of this specific article is iscussed . FurtherMicroalgae, however, as well as other feedstocks, still face a cost–benefit challenge. Nevertheless, great advances are expected to be achieved in the areas of cultivation, harvesting, lipid extraction, transesterification, and biomass-processing technologies that could render biodiesel production from microalgae more viable and more easily commercialized in the near future . OptimizFrom the reference database created, we observed that the manuscripts relating to raw materials for biodiesel were published across 154 journals, with an average of approximately 2.1 publications per journal. This indicates that a great interest in this research theme is shared by several areas, but the number of relevant publications can still be considered low. Judging by the vast number of journals analyzed, it is possible to note that distinct groups of researchers have explored this topic via different methodologies of scientific analysis.Renewable & Sustainable Energy Reviews, which ranks first on this list, has an impact factor of 14.982 and a total of 33 articles published in the area. These account for 9.9% of the total number of documents, and the articles published in this periodical have amassed 8250 citations over the years. The second journal on the list is Bioresource Technology, with an impact factor of 9.642 and 16 articles published  that gathered 1785 citations. The ranking list is mostly composed of European journals, with Renewable & Sustainable Energy Reviews being the only American journal. Nevertheless, it has the highest impact factor of all the journals listed and the highest number of citations and publications, with an average of 250 citations per article. This shows a high concentration of articles in the area of feedstocks for biodiesel production in a single scientific journal.Analyses made from the country information declared by the authors across the articles in our database allowed us to verify that the ten countries that published most articles on biodiesel feedstocks contributed 64.5% of the total amount of publications from the 56 countries identified .It is noteworthy that, although there is a great demand and interest for this research area, the resulting publications are concentrated within just a few regions of the world. China is responsible for 12.8% of the published articles (53 articles), thus occupying first place on the list. It is followed by Malaysia, with 11.6% (48 articles), and India, with 11.6% (48 articles).To evaluate the relevance and impact of the published articles, it is necessary to also consider the number of citations. Malaysia has the highest number of citations (3715) across its 48 published papers, followed by Portugal, with 10 published papers that have amassed 3323 citations, and China, with 53 published papers and 2555 citations. It can also be noted that the articles published were the result of the work of 481 organizations across 56 different countries, which also confirms the high interest in research in this area. Nevertheless, the number of academic outputs is concentrated primarily in only ten countries, which produced two-thirds of the total number of documents. Among them are China, India, the United States, and Brazil, which indicates that there is a strong interest for this area especially in countries with large economies and a notable involvement in socio-environmental policies.Microalgae for biodiesel production and other applications: A review [Another point worthy of note was that more than 50% of the organizations identified had only one publication in the field. In addition, only a small number of organizations were perceived to conduct consistent research and constantly publish in the area. Among the identified papers, there is a peculiarity related to the Polytechnic Institute of Porto (IPP). This organization has published only one article, A review , but thiA review ,29,30 thIt is clear that many of the collaboration links are geographically related. However, there are some countries that have overcome the regional barrier and sought extracontinental academic cooperation, which is the case of (and between) the United States, China, and Malaysia. Brazil, for example, is a country that cooperates strongly with European countries such as Portugal and Spain. This is likely to happen due to their linguistic proximities and the fact that the country has a great relevance for world agribusiness, apart from showing high interest in using sustainable and renewable raw materials for the manufacture of various chemicals .A network map representation was built to enable a better visualization of the links between organizations, and it is shown in In addition to the analyses performed by studying the above clusters, geocoding was also used by transforming locations into points on the map. This allowed for a deeper observation of the geographical reference of the institutions identified in the collated database. Microalgae for biodiesel production and other applications: A review [Patent landscape review on biodiesel production: Technology updates [A total of 1304 different authors were identified across the 332 documents in the database, indicating a wide range of scientific collaboration among the researchers with the most significant influence in this area. A review , with 31The ten most cited articles on raw materials for biodiesel production have gained a collective number of 7219 citations, with the document occupying first place in this ranking amassing 3160 (43.7%) of these. As mentioned earlier, Mata’s work discussed the current status of biodiesel production by microalgae, focusing on the cultivation, harvesting, and processing techniques of the main microalgae species, along with the advantages and disadvantages of their use . This arNon-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance, and emissions production [Jatropha curcas, Pongamia pinnata (Karanja), Moringa oleifera, and Aleurites moluccanas.The second most cited article on the list is oduction , which wThe visualization and analysis done on the keywords of the articles from our database, illustrated in It is important to highlight that the journals that occupy the first and second positions in the ranking shown in The article entitled Patent landscape review on biodiesel production: Technology updates , despiteFrom the database compiled, we could observe that the 330 selected documents belonged to 25 research areas related to feedstocks for biodiesel production, from 2010 to 2021. When analyzing the database keywords, which totaled 1536 occurrences, it was possible to observe that the most used terms were “biodiesel” (225 occurrences), followed by “transesterification” (145 occurrences), and “waste cooking oil” (91 occurrences). This shows that this raw material is the most significant in the studies related to biodiesel production, given its prominence in the documents. In There seem to not yet exist highly relevant studies on feedstocks that have great potential for the future of the market, as is the case of sewage sludge. From the search carried out on the Web of Science Core Collection site, there are only 60 documents that mention this material. The article with the most relevance is entitled Recent development on sustainable biodiesel production using sewage sludge , which gIt is essential to point out that a refinement was made in the database search by discarding the works that are not of interest for the visualization of trends in the proposed theme. Therefore, the limitation of inclusion to only research articles, conference papers, and review articles enabled us to obtain more precise and relevant conclusions. Furthermore, the search for documents related to feedstocks in general and for sewage sludge as a raw material made it necessary for us to search for these terms specifically, i.e., the terms “Sewage Sludge” and “Feedstock” were entered in the search field “All fields”.The feedstocks used for biodiesel production are varied and can be classified into the four following categories: edible oils, inedible oils , oils from microorganisms, and animal fats . The figOrbignya sp.), mahua (Madhuca indica), castor oil plant (Ricinus communis), jatropha (Jatropha curcas L.), macaúba (Acrocomia aculeata), andiroba (Carapa guianensis), karanja (Pongamia pinnata), seed oil from Pistacia chinensis bge and crambe (Crambe abyssinica Hochst), pinnai , rubber tree seed (Hevea brasiliensis), and coconut (Cocos nucifera) oil [The rapid growth of the world population and the extensive human consumption of edible oils can cause serious problems, such as starvation, in developing countries. Therefore, a category that becomes very promising as an alternative material for biodiesel production is non-edible oils. Due to the high demand for edible oils in the food industry, their prices are higher than fossil fuels, and this fact alone highlights the importance of the lower cost of cultivation of non-edible vegetable oils . Oils clera) oil .4/Fe-Al-TiO(2) solid acid catalyst for biodiesel production from waste cooking oil [Among the raw materials reported, microalgae and waste cooking oil are highly relevant. Among the 332 publications in the database, 20 and 19 publications present the terms “waste cooking oil” or “microalgae” in their title, respectively. Together, they represent 11.7% of the documents. Accordingly, it is important to highlight that the evaluation criteria in this case maintained the same refinements of the initial search, but with the added logical operator “AND” with the following text: “waste cooking oil” or “microalgae”. The articles reporting research that employ microalgae as the main object of study can be seen in king oil . It presPerforming the same analysis on sewage sludge, it was possible to identify only two documents that present this raw material in their title—Biodiesel Production from Sewage Sludge: New Paradigm for Mining Energy from Municipal Hazardous Material , with 83Studies involving biodiesel production through sewage sludge are scarce due to there being currently little interest in this research. However, according to the publications collected for this analysis, there are many advantages to using this raw material for manufacturing biofuels. Feedstocks that fall into the edible group  show low cultivation costs and land use requirements, while recyclable waste feedstocks (such as cooking oils and yellow grease) have limited availability. Thus, interest in using sewage sludge as a feedstock for biodiesel production has grown significantly  due to iIn Europe, the country with the highest annual production of sewage sludge is Germany (1.85 million tons of dry solids), followed by the UK (1.14 million tons), and Spain (1.03 million tons). It can also be mentioned that more sewage sludge is produced in Japan than in the member countries in the EU. Despite scarce data on the USA, it is believed that its sludge production is the second largest in the world. China, being the country with the largest population (about 1.3 billion), has been experiencing a considerable continuous increase in its sewage sludge generation since 2011, and it surpassed the 12-million-ton mark in 2017. In that year, 45 million tons of this waste were produced worldwide . TherefoSince about 85% of the total biodiesel production value is linked to feedstock, lipid-rich sewage sludge is also highly interesting for biodiesel production from an economic standpoint . As statSewage sludge comprises organic materials  and inorganic materials  from alternative waste treatment processes. It is an unavoidable waste, its production is constantly increasing, and it causes great concern regarding the risks imposed to human health and its significant potential for environmental damage. For this reason, strict regulations have limited the disposal of sewage sludge, causing alternative methods to be sought, including technological processes that employ principles of thermochemistry, such as gasification, pyrolysis, and direct combustion . Using sOther advantages of sewage sludge are the fact that it is abundant and can deliver a continuous yield. The higher the value of food commodities in the future, the more competitive sewage sludge is set to become as a biodiesel feedstock . ConsideAs discussed earlier in this article, microalgae are an extremely important raw material in most of the articles analyzed, given the fact they are the main subject of articles with very large numbers of citations. Again, the most cited article is entitled Microalgae for biodiesel production and other applications: A review , which hMicroalgae cultivation can be carried out in environments considered unsuitable for the cultivation of other plants, such as in saltwater, brackish water, fresh water, or non-arable land that is unsuitable for conventional farming methods. In addition, cultivation can also be done in farms or even in bioreactors. Due to their non-selective, per hectare growth and development, microalgae can deliver higher production yields with better ecological performance . HarvestThree main problems in algae-based biofuel production have been highlighted: supporting algae cultivation in different climates, the high water demand, and the technology deficit for commercialization. Nevertheless, the market is predicted to create future local and regional partnerships and collaborations with a view to maximize adoption and enable technologies for manufacturing them at a larger scale . We can The potential of microalgae through high lipid productivity using small land areas, as well as the ability to use unproductive lands to this end, justify the recent investments in their culturing for fuels . TherefoAfter performing occurrence and relevance analyses, we also identify waste cooking oil as a feedstock of high interest in the research on biofuel production. Among the documents collected on this area from 2010 to 2021, waste cooking oil occupies the second place in the ranking of occurrences of articles with this specific feedstock in their title, with 221 documents . Moreover, according to Waste cooking oil is obtained from edible oils that have been used for frying food . These tBesides these raw materials, several others can be highlighted, especially in the non-edible group of materials. An example is beef tallow, which in Brazil is the second main raw material used in the production of biofuels after soybean oil. Biodiesel that is produced from tallow only generates between 17% and 35% of the total impact caused by low-sulfur diesel, thus showing an environmental advantage of using the former . AnotherThis work reveals several aspects of the biodiesel research that are clearly present across previously published review articles, such as the interest in researching feedstocks for biodiesel production in Asia, in view of the needs and economic specificities of this region. Additionally, new emerging trends are evidenced from the subsequent analysis of the articles published within the years delimited in this research, which also shows a constant search for sustainability approaches that are coupled with the maintenance of economic viability. These research trends are directed towards raw materials that do not create market competition with other industries, which is the case of the food sector, which in many cases utilizes a range of raw materials that can also be used for biodiesel production. Feedstocks such as sewage sludge, waste oils, and non-edible vegetable oils are the research foci in many of the papers reviewed earlier in this work.To better understand the development of the research on a specific area, it is necessary to carry out an analysis of the keywords in the published documents, as they reveal essential information about the topic, such as applications, trends, relevance of documents, discussions, and other general research characteristics. The CiteSpace software was used to organize the collated database and to analyze the emerging trends in the area. As mentioned earlier in this article, CiteSpace allows the visualization of knowledge development in a given area of research . AnalyziCluster #0 has “oleaginous yeast” as its main keyword. These yeasts have gained significant prominence worldwide in metabolic engineering due to the fact they offer facilitated pathway manipulation, fatty acid- or oleochemical-derived metabolite enhancements, and simplified cultivation strategies . The artCluster #1 is represented by the keyword “ionic liquid”. Ionic liquids are chemical compounds with one cation and one anion, defined by melting points of below 100 °C. Each of the above ions allows for the insertion of a unique property or function into a molecule . Mansir Cluster #2 shows the process designs involved in the various methodologies for producing biodiesel from feedstocks. One work  reviewedHevea brasiliensis (HB) and Ricinus communis (RC) as potential feedstocks. An esterification–neutralization–transesterification (ENT) process was used for biodiesel production. [Calophyllum inophyllumas for biodiesel production. The author assessed many crucial aspects of this process, such as the chemical and physical properties of the Calophyllum inophyllum crude oil and methyl ester, the mixture and engine performances, fatty acid composition, and the emissions of the Calophyllum inophyllum methyl ester.Cluster #3 depicts oil extraction processes, listing the studies covering different methodologies to this end.  carried duction.  investigIn cluster #4, the focus is on the production of enzymatic biodiesel. Adachi  attempteIn cluster #5, calcium oxide is emphasized. CaO is an inexpensive material that can be found in abundant quantities in the Earth’s lower mantle and a material that does not cause harm to the environment . The proOne issue with systematic reviews is that they may present data and conclusions within a confidence level that does not always reflect the reality, or that is feasible. One example is when systematic reviews for a particular emerging field of study do not yet exist. In addition, reviews that have been conducted within a certain time period may be out of date or may not have included all the scientific advances as comprehensively as it should. The CiteSpace tool was created to provide a potential solution to these challenges by enabling the use of customized datasets to answer questions about a field of knowledge that is changing rapidly . It can Node size is one of the key analysis points verified by CiteSpace. In The first perspective pertains to studies related to the feedstocks used for biodiesel production. The selection of raw materials is a significant point dictating the quality and cost of the biodiesel produced . There iThe second important insight from this work regards the production of biodiesel from sewage sludge, which can certainly provide a more sustainable angle to such processes, given the environmental need for this. Using sewage sludge as a feedstock for biodiesel production and therefore offering options to the resolution of the food–fuel debate can also help solve some of the difficulties in treating sludge . BiodiesOne of the key raw materials highlighted in this work, sewage sludge, has received little attention in the literature, considering that the number of cited articles is still small and despite the economic and sustainability advantages cited above. This is mostly due to the fact it is still a recent research theme and that raw materials that have been explored for longer are more attractive owing to the vast knowledge repertoire.Waste cooking oil and microalgae are the raw materials of most significant presence in the academic outputs analyzed. These are feedstocks that have been extensively reported on in the literature, mainly due to their long-standing reputation in the area. However, there has been a noticeable reduction in the volume of cited articles over the years.China, Malaysia, and India are the countries with the greatest research outputs relating to feedstocks for biodiesel production. It can be concluded, therefore, that Asia shows a great interest in this area. One factor that can explain this interest may be the sheer number of people concentrated in this region, since China, India, and Malaysia account for more than 35% of the world’s total population.For a more specific analysis of this research, keywords collected by the CiteSpace program were used. From a systematic verification of the terms, it was possible to observe that the main research topics in this area include oleaginous yeasts, ionic liquids, process design, oil extraction, enzymatic biodiesel production, and calcium oxide.Two broad perspectives related to this research area have been emphasized. The first is the generalized view of the articles that engage in the topic of feedstocks for biodiesel production. It is concluded that there is a great deal of discussion regarding the economy versus sustainability dilemma, and researchers have sought practical solutions to the problems that arise from this. The second perspective concerns the recent emergence of academic interest in studying sewage sludge for biodiesel production. It is understood that this area will be further explored in the near future due to the solution that this raw material represents to the conundrum above.This article provided a comprehensive view into the literature related to feedstocks for biodiesel production, the emerging trends that are the focus of current work, and the promising alternatives to be explored in the future. In this work, a search methodology was devised to refine the search for, and the selection of, a set of articles, which started with a database of 4586 documents. From this initial database, two more targeted databases of 330 and 60 articles were created, respectively, in order to assess the direction of travel in this research area. The period analyzed (2010 to 2021) reveals a particular emergence of meaningful research relationships and collaborations, demonstrating a more sustainable vision among researchers for developing their work. Important conclusions from this review include:Future development prospects in the biofuel market are mostly linked to a vision of sustainable change, as it was possible to observe with the analysis of the growth in publication numbers on the topic. Importantly, there is a clear concern from the countries that are active contributors to the global environmental degradation observed over the years to seek to reduce the impacts caused by them. The most influential researchers in this area are those who seek to fly the sustainability flag, as exemplified by Ahmad’s article and also by the research topics underlying hundreds of papers in our database. In addition, a great economic interest and concern was observed in most of the above works, where authors described processes on the basis of financial costs and time or productivity. This was the case for works that had sewage sludge as their main theme, for example, which categorically sought to explain the advantages and productivity hurdles of this raw material and ways in which it could become a key trend within the biodiesel market.The direction of the literature concerning the research topic under study is constantly being shaped due to the worldwide need for sustainability and a more environmentally centered economy. A very pertinent problem is the alleged competition between the biodiesel and the food industries for edible raw materials, in which, due to scale reasons, the latter industry will always have a competitive advantage over the former. The solution to this is in the exploitation of raw materials that are derived from non-edible oils. The environmental concern of researchers has shaped the methodological advances for using these oils in a way that can reconcile sustainability with the cost of manufacture, given that, even if a feedstock is exceptionally sustainable, it can be economically unviable.The research contained in this review proposed to elucidate and explore the directions of travel of the research that will define the future approach to biodiesel production, highlighting the concerns regarding environmental degradation. Nevertheless, there are some limitations in this work, a major one being the fact that the Web of Science was the only database used to create our own databases. Apart from the refinements made (language and type of documents), other articles were certainly inadvertently excluded by not being in this specific database.Furthermore, it is necessary to emphasize that the evaluation methodology used in this work was developed from the individual vision of the research described throughout the text. This should be considered, since several ways of approaching this research area have led to significantly different results. It could also be highlighted that the research domain encompassing feedstocks for biodiesel production is highly diverse due to the wide variety of research approaches undertaken on the topic. There is a clear evolving trend towards linking academic work and social compliance for sustainability. Some aspects of collaborative work were verified, showing that some countries still opt for internalized cooperation in their research development, in which authors mostly collaborate with others of the same nationality. The scientific literature on feedstocks for biodiesel production is extremely vast and can be analyzed further to allow for a comprehensive understanding of its specific characteristics that are of interest to researchers, driven mainly by a pressing, worldwide need for studies in this area.


Neuropathic pain (NP) is a chronic health condition that presents a significant burden on patients, society, and even healthcare systems. However, in recent years, an emerging field in the treatment of neuropathic pain – optogenetic technology has dawned, heralding a new era in the field of medicine, and which has brought with it unlimited possibilities for studying the mechanism of NP and the treatment of research. Optogenetics is a new and growing field that uses the combination of light and molecular genetics for the first time ever. This rare combination is used to control the activity of living cells by expressing photosensitive proteins to visualize signaling events and manipulate cell activity. The treatments for NP are limited and have hardly achieved the desirable efficacy. NP differs from other types of pain, such as nociceptive pain, in that the treatments for NP are far more complex and highly challenging for clinical practice. This review presents the background of optogenetics, current applications in various fields, and the findings of optogenetics in NP. It also elaborates on the basic concepts of neuropathy, therapeutic applications, and the potential of optogenetics from the bench to the bedside in the near future. Neuropathic pain (NP) is defined by the International Association for the Study of Pain (IASP) as the “pain caused by a lesion or disease of the somatosensory nervous system” , 2. The Furthermore, the treatment of NP that is being given to these NP patients still presents a great challenge for clinical practice, as the clinicians have to face a plethora of problems while engaging and handling such patients. Pharmacotherapy is the main and important treatment method to bring about a drastic cure in these patients, but the current treatment only produces limited remission (30–50%) that too only for a portion of patients . PharmacThe results of many research works corroborate the role of optogenetics and have also put forth a certain affirmation of the role of optogenetics. In this review, we provide an overview of the basic concepts of optogenetics and the active application of optogenetic techniques in the treatment of NP in recent years.Neuropathic pain (NP), which is triggered by the impaired somatosensory system, attributes its origin to various health-related causes. These causes are diverse, arising from a wide gamut of diseases, such as diabetes, metabolic diseases, tumors, spinal cord injury, etc. After a nerve injury takes place, the nerve fibers change at multiple levels, resulting in disturbances during transmission to the brain and spinal cord, and involves issues such as altered pain thresholds and signal effects . There aChanges in nerve fiber secretions are closely associated with pain. As regards to neurons, a popular view was held to express the fact that nociceptive afferents inhibit the flow of harmful information from the spinal cord into the brain by activating spinal inhibitory neurons and that the imbalance between excitatory and inhibitory neurotransmission serves as the source of ectopic pain . The hypTransient receptor potential (TRP) family of ion channels and other ion channels, such as acid-sensing ion channels adenosine triphosphate (ATP)-gated purine channel [ATP-PRX (peroxiredoxin)], has highly specific involvement in various types of nociceptive stimulations. At this time, different types of sodium channels play a significant role, by magnifying the point of the receptor, so as to trigger the depolarization of the action potential. Notably, these ion channels are all not only strongly regulated by post-translational modifications and transcriptional levels, but can also be deregulated upon nerve damage. However, the present study does not prove the main connection of TRP channels with NP syndrome, but pharmacologically related studies prove that blocking TRP channels in rodent models relieves neuropathic allergy . StudiesHere, we focus on some of the most recent studies related to NP. T cells in immune cells have a very important role to play, and studies have shown that mice lacking T cells completely lack the ability to produce neuropathic abnormal pain after a nerve injury . FurtherNotably, the dysfunction of mitochondrial function in peripheral neurons can manifest in various NP types in different animal models , 20, andWe describe several neural mechanisms associated with NP that are currently well recognized. Actually, the neuromechanisms underlying NP remain unexplored, because of its diverse etiology and numerous systems involved. Moreover, the transmission of pain signals is regulated by complex large neural networks, making it more difficult to carry out research on neural mechanisms. Of course, the views discussed previously also bring a direction toward new therapy in the treatment of NP, because optogenetics can also help with research into NP pathways.At present, the treatment approach of NP is mainly divided into pharmacotherapy and non-pharmacotherapy types, and both the treatment methods have their own inherent advantages and disadvantages. A broad consensus has been reached on the drug treatment to be administered to the patient , as thisAs we all know, optogenetics has become a new technology in recent years, which is helpful to explore the mechanism of most diseases. We notice that this technology still has huge untapped potential and offers scope for utilizing the unlimited prospects in the application of neurological diseases and other diseases in the future.Optogenetics is an emerging field, which boasts of a hitherto unknown, amazing combination of optics and genetics. Optogenetics mainly acts on the corresponding proteins by currents that are generated by transfer to photosensitive proteins , 42. OptOptogenetics includes three main optogenetic tools, including (1) photoactivated proteins; (2) light; (3) delivery mode, virus-mediated gene delivery system is currently one of the most commonly used methods. When applying optogenetic techniques, we benefit from a number of advantages. A significant advantage one can derive from optogenetics is that rapid activation and silencing of expressed proteins can be achieved without the use of chemicals , 49. Optin vitro during light exposure. Kaur et al.  in the CA1 region of the dorsal side of the hippocampus  stimulates the nucleus accumbens (NAc) to drive reward seeking  channel of the yellow photosensitive third-generation chloride pump successfully prevented pain  and circuits. Optogenetics involves inducing neuronal expression of light-activated membrane proteins, the activation of which can directly turn on or off neurons by depolarization  or hyperpolarization , respectively, and opening a cascade of G protein-coupled receptor (GPCR) signals . TherefoAll in all, optogenetics presents both an opportunity and a challenge. For example, optogenetics is currently restricted to experiments on animals only, so how can it be extended to experiments conducted on human beings? Optogenetic technology can be effectively implemented in rodents most of the time, but it has been difficult to effectively implement this optogenetic technology in primates for many years now. The reason for this difficulty is attributed to the all-time flexibility of primates, which makes it even more difficult to translate experiments into clinical practice. There are also limitations regarding the way photosensitive proteins are entered and the length of optogenetics to be maintained. Is there a way to make the effect longer or even permanent? There is no denying the fact that addressing these questions presents great challenges, and this also requires further in-depth investigation of optogenetics. It is worth noting that optogenetic techniques are crucial in terms of both the pathways, mechanisms, and treatment of NP. Identifying pain nociceptors through the spatiotemporality of optogenetic techniques and identifying damaged neurons is a breakthrough step in understanding the mechanism by which God carries out pain, and provides a crucial role for later treatment.Neuropathic pain is a complex, comprehensive disorder that is extremely challenging to treat clinically, owing to the complexities that surface during NP treatment. The treatments of NP are a major challenge for effective clinical practice. Pharmacotherapy is a common clinical method to relieve pain in patients, but we cannot ignore the side effects of the drug treatment, and its efficacy has not achieved the ideal effect. Non-pharmacological treatments have small side effects, but most of their efficacy lacks reliable clinical evidence. The combination of treatment methods may be a good way to improve the efficacy, as the patients stand to benefit from the cumulative effect of both these treatment methods. It has been clinically confirmed that drug treatment with some traditional treatments can not only increase the efficacy, but also reduce the side effects. It can be further explored in the combination of multiple treatment methods.In summary, there are uncertainties in both pharmacological and non-pharmacological treatments, and although the efficacy of some treatment methods is clinically affirmed, further research is still needed. Optogenetics, as an emerging field of NP, has unlimited potential in terms of the mechanism pathways and treatment of NP. Through the spatiotemporality of optogenetic techniques, the identification and localization of pain receptors, damaged neurons, which helps us to further explore pain transmission pathways. In addition, optogenetic techniques are now widely used in various fields, including the treatment of NP. According to the previous description, optogenetic techniques have been affirmed for their efficacy in relieving pain, but there are still issues that need to be further explored. For example, optogenetics is currently limited to animal experiments, so how can it be applied to human beings? How is the light-sensitive protein entered? The length of optogenetics to be maintained is also a limitation. Is there a way to make the effect longer or even permanent? There is no denying the fact that addressing these questions presents great challenges, and this also requires further investigation of optogenetics.Generally, before performing clinical experiments on human beings, we usually conduct experiments first on non-human primates that bear closeness to humans both in evolution and in development. The implementation of optogenetic technology is good and successful in rodents, but we face tough challenges while applying this technology to primates, which also signifies the application of optogenetic technology to clinical practice. Second, optogenetic techniques may be used in combination with other fields (such as slice electrophysiology ), to invIn a word, optogenetics brings with it a reliable promise for the treatment of NP. After analyzing the various advantages of optogenetics for the treatment of NP, we can emphatically state that the therapeutic prospects of optogenetic technology for NP are certain and deserve promotion and exploration for extensive experimental research.SL, XF, and HB have participated sufficiently to accept responsibility for the content of the manuscript. SL wrote the draft of the article. XF and HB played a critical role in article revision. All authors contributed to the article and approved the submitted version.This work was supported by the Kunming Medical Joint Project-Key Project (202101AY070001-001), Kunming Medical University 100 Young and Middle-Aged Academic and Technical Backbone Training Program (J13326055), and Yunnan Province Ten Thousand Talents Program Young Top Talent Special Project (YUWR-QNBJ-2019-043).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.