Decades of neuroimaging research in attention/deficit-hyperactivity disorder (ADHD) have yielded a few apparently firm findings and many open questions. The long-term objective of these efforts is to uncover the underlying brain pathophysiology of the disorder, to reveal reliable biomarkers of prognosis and treatment response, striving for personalized medicine. Unfortunately, neuroimaging research in ADHD and other psychiatric disorders is still unable to inform clinical practice. This presentation will provide an up-to-date overview of neuroimaging in ADHD, highlighting the most promising results and current challenges of structural and functional research with magnetic resonance imaging (MRI). Evidence from large, multicentric studies and from highly-sophisticated resting-state functional MRI techniques will be presented; methodological and reproducibility limitations in current literature will be introduced, and the way forward to bring this area of research closer to clinical practice with patients with ADHD will be discused. Dr. Pereira-Sanchez is conducting original research using resting-state functional MRI to study potential correlates of treatment response to stimulants in children and adolescents with ADHD; he has also recently published two literature reviews of MRI studies in ADHD.No significant relationships.


There are several conditions that lead to female infertility, where traditional or conventional treatments have limited efficacy. In these challenging scenarios, stem cell (SC) therapies have been investigated as alternative treatment strategies. Human umbilical cord (hUC) mesenchymal stem cells (hUC-MSC), along with their secreted paracrine factors, extracts, and biomolecules, have emerged as promising therapeutic alternatives in regenerative medicine, due to their remarkable potential to promote anti-inflammatory and regenerative processes more efficiently than other autologous treatments. Similarly, hUC blood derivatives, such as platelet-rich plasma (PRP), or isolated plasma elements, such as growth factors, have also demonstrated potential. This literature review aims to summarize the recent therapeutic advances based on hUC-MSCs, hUC blood, and/or other plasma derivatives  in the context of female reproductive medicine. We present an in-depth analysis of the principal molecules mediating tissue regeneration, compiling the application of these therapies in preclinical and clinical studies, within the context of the human reproductive tract. Despite the recent advances in bioengineering strategies that sustain delivery and amplify the scope of the therapeutic benefits, further clinical trials are required prior to the wide implementation of these alternative therapies in reproductive medicine. Infertility is a disease of the male or female reproductive system, defined by the World Health Organization as the failure to achieve a pregnancy, after at least 12 months of regular unprotected sexual intercourse . S. S110]. Advances in bioengineering offer new methodologies to sustain delivery of cells and paracrine factors, boosting efficiency and maintaining long-term efficacy . Thus faRemarkably, the US Food and Drug Administration (FDA) states the products used in regenerative medicine must be regulated prior to their implementation in the industry and into patients. Specifically, the safety, purity, potency, and identity of the hUC blood or their derivatives, as well as their testing in clinical trials, are mandatory .Due to the lack of studies comparing cellular and acellular therapies, it is difficult to evaluate which of the therapies described herein is superior. Nevertheless, the ongoing clinical trials assessing the application of hUC-PRP in the endometrium , and hUCNotably, treatments based on hUC blood components are also emerging as alternatives to treat male infertility. Preclinical models have already been used to demonstrate the ability of hUC-MSCs to differentiate into germ cells, in the lumen of the seminiferous tubules ,255, andIn conclusion, regenerative medicine targeting female reproduction has generated promising outcomes through the use of hUC-MSCs and blood derivatives, such as hUC-MSCs, hUC-PRP, and EVs, in the treatment of multiple gynecological disorders . These treatments enhanced tissue regeneration by upregulating the secretion of GFs and cytokines and through their immunomodulatory actions. Further studies are required to establish a clinical benefit, and to determine whether cellular or acellular therapy is superior.


Low Birth Weight (LBW) continues to be a prominent universal cause of various short- and long-term health hazards throughout infancy and adulthood. However, no study has revealed the socioeconomic inequalities in LBW among South Asian countries. This study assesses the socioeconomic inequalities among under-five South Asian children with LBW.Secondary data were derived from six  nationally representative South Asian Demographic and Health Surveys conducted between 2015 and 2021, and included 170,547 under-five years of age children. The study employed the concentration curve and concentration index to assess the socioeconomic inequalities of those with LBW. Additionally, mixed-effect logistic regression was applied to determine the factors associated with LBW.A significant negative concentration index indicates the wealth-related and education-related inequalities of LBW among under-five South Asian children. LBW is highly concentrated in the socio-economically poor section of the society. Our study found statistically significant negative concentration index in all South Asian countries: Afghanistan (Education: -0.108), Bangladesh , India , Nepal , and Pakistan . Findings from the mixed-effects logistic regression model also show that children from the poorest quintiles  and illiterate mothers  had higher odds of being afflicted with LBW compared to the wealthiest quintiles and educated mothers respectively. Women's pregnancy assessments, such as antenatal care utilisation, iron supplementation intake, and normal delivery mode, are significantly correlated with decreased odds of children's LBW.There exists a strong association between LBW cases and socioeconomic inequalities among South-Asian children below five years of age. This indicates the urgent need for health education and prenatal care services for women from Afghanistan, Bangladesh, India, Nepal, and Pakistan, especially those with lower socioeconomic status. •Wealth- and education-related inequalities in low birth weight (LBW) are evident in South Asia.•Afghanistan, Bangladesh, India, Nepal, and Pakistan have contributed significantly to the socioeconomic disparities in LBW in South Asia.•Socioeconomic inequalities in LBW are higher in India compared to other countries in South Asia. The birSocioeconomic Status (SES) is one of the contemporary measures that affect the number of LBW cases for each country. The well-being of children is directly related to maternal SES, as revealed by multiple studies conducted in several global settings . It was A wide range of studies on LBW and its associated factors from the South Asian context were observed in the literature . These iTo address this gap in the literature, this article focuses on measuring SES inequalities in South Asia using a large-scale, nationally representative dataset. The study hypothesizes that children born into lower SES households are more prone to LBW than those born in higher SES households. The study also determines the prevalence and associated factors of LBW among under-five children in South Asia, with inconsistent output for several variables documented in studies from South Asian regions . Hence, 22.1This study was based on the secondary data sources driven from the most recent Demographic and Health Surveys (DHSs) from six (6) South Asian countries, including Afghanistan (2015), Bangladesh (2017–2018), India (2019–2021), Maldives (2016–2017), Nepal (2016), and Pakistan (2017–18). These datasets were merged to evaluate SES inequalities and investigate the most significant factors of LBW across the region. This nationally representative DHS program collected data on various health indicators, focusing on mother and child health. The survey programs followed a standardised sampling technique, ensuring that the survey design was identical across the countries . Bhutan The DHS selected study participants in two stages using a stratified sampling technique. The survey methodology and sampling techniques used to collect the data have been described in detail elsewhere . The DHS2.22.2.1Low Birth Weight was the main response variable used in this study. Women who gave birth during the last five years before the recent survey were eligible to provide weight data for each country in South Asia. They reported birth weights for their children based on record assessment or reminiscence. The study then eliminated observations that had not documented birth weight information. Following conventional definition, LWB was defined as a birth weight of less than 2500 g (g). In contrast, normal or above-normal birth weights were classified as 2500 g or above . Therefo2.2.2Existing literature greatly helped in the inclusion of probable LBW factors for the current study . The stu2.3This study analysed the available data using various statistical techniques. Prior to that, sampling weights, primary sampling units, and strata were evaluated to adjust the complex survey design. At the outset, cross-tabulation was deployed to depict the distribution of baseline characteristics through STATA version 16 software. A fixed-effect meta-analysis showed LBW cases' prevalence in South Asia and its sub-regions. A forest plot highlighted the prevalence with 95% confidence intervals.Standard logistics and mixed-effect logistic regression models were used in the multivariate stage. Statistical parameters were reported to find the best-fitted model, including log-likelihood, Akaike information criterion (AIC), and Bayesian information criterion (BIC). The lowest magnitude of the AIC and BIC was selected to identify the associated factors of LBW cases. The suitable model for the dataset was the mixed-effect logistic regression model. The underlying explanation was that observations were nested within clusters due to the hierarchical structure of DHS data. This hierarchical nature violates the observations' independence and equal variance assumption of the traditional logistics model. The random part of the mixed-effect logistic regression model was appended in the main findings: Likelihood Ratio (LR) test, cluster variance, Intra-class Correlation Coefficient (ICC), and Median Odds Ratio (MOR). The estimated value of MOR is greater than one, implying a cluster effect on the outcome. In contrast, an estimated value of MOR equals one means an absence of cluster disparities . AdjusteIn addition, both Concentration Index (CI) and Concentration Curve (CC) were applied to assess SES inequalities according to wealth and education levels. The cumulative share of LBW cases was plotted against the cumulative percentage of children, ranked according to wealth index (poorest to richest) and educational attainment (lowest to highest) . The CC Decomposition technique (both Wagstaff and Blinder Oaxaca) utilised ordinary least squares regression methods to reveal the contribution of different explanatory variables while explaining SES inequalities . The out33.1Children from the lowest wealth quintiles (20.69%) and mothers with primary education (20.11%) had a greater probability of being afflicted with LWB. Female children (19.08%) and children from multiple births (63.18%), caesarean deliveries (17.60%), and rural residents (17.91%) reported a higher instance of LBW across the subcontinent. Additionally, mothers who did not take ANC services (20.60%) and iron tablets (19.58%) during the gestational period were accountable for higher LBW incidence among South Asian children.3.23.3Inverse and statistically significant index values are discovered for pooled cases from all six countries shown in , Table 3All three measurements have negative magnitudes for significant index values; Erreygers CI has the highest index value, followed by Standard CI and Wagstaff CI . HoweverThe CCs of LBW by wealth index and education level following the Standard Concentration Index (SCI) are depicted in 3.4MOR of +2.01 implies that clustering has an impact on LBW cases, which supports conducting the analysis using mixed-effects logistics regression.The variation in the intercept-only model (Model 0) was reduced by 11.86% after incorporating individual-level variables in Model 1. The full model (Model 4) explained 3.85% variations by including individual-level and community-level variables compared to Model 1. The model shifting indicates the variation across the clusters dropped from 15.21% (Model 0) to 13.20% (Model 3).Women from the poorest quintile have 1.53 times  higher odds to deliver LBW babies than women from the wealthiest quintile. Uneducated women had a 39%  higher odds of giving birth to LBW-afflicted babies than educated women. The number of increased ANC visits during pregnancy reduced the odds of being LBW among children by 0.83 folds (≥4 visits). Women who did not take iron supplements during pregnancy had a 14%  higher odds of having LBW children than those who took supplements.Further, the findings illustrate that female children had 25%  higher odds of being LBW than male children. Besides, multiple births increased the odds of LBW by 11.89 folds  among children compared to singleton birth. The caesarean section increases the odds of LBW by 14%  compared to normal delivery.In the community-level variable, residential status significantly impacted instances of LBW. Women from urban areas have 1.10 times higher odds  to have LBW children than women from rural areas.4Upon checking the currently available literature, this is the first study to investigate and measure SES inequalities in LBW among under-five children in South Asia, using the most contemporary nationally representative population-based data. The analysis provides a strong association between LBW and SES, showing women with lower SES having increased rates of LBW-afflicted children than women with higher SES across the South Asian subcontinent. The findings were corroborated by income and education-related inequalities in cases of LBW, arguing that poorer and less-educated women were more likely to have LBW babies. This coincides with the South Asian inequities policy report, which posits that South Asian countries have failed to achieve regional economic progress that benefits the poor and reduces pervasive inequality .The results also illustrate how the magnitude and patterns of SES inequalities in LBW instances vary across South Asian countries. Both wealth and education-related inequalities in LBW were highly considerable in India, echoing a previous Indian study which revealed a significant association between SES inequalities and LBW . In contThe current investigations of regional data demonstrate that maternal determinants have a significant role in LBWs. Maternal indicators, such as maternal age and education, considerably influenced LBW likelihood among South Asian children. Reduced maternal age and lower levels of education were associated with a substantial rise in LBWs, which lie consistent with prior studies . Early cPregnancy-related maternal health-seeking behaviours, such as increased ANC visits and iron supplementation, are associated with a significant reduction of LBW cases among South Asian children. These coincide with previous research conducted in the South Asian and Sub-Saharan African subcontinents, which suggested that one or more ANC visits were related to a decreased risk of LBW, compared to individuals who did not receive follow-ups . ANC visA comprehensive review established a strong link between iron supplementation and a decreased risk of LBW , which cThe current outcomes reveal that multiple birth or female gender has a significant adverse effect on birth weight; these findings are consistent with those of other studies . MultiplThe study also illustrates that women who gave birth through caesarean section also have an increased risk of LBW compared to normal delivery. This coincides with WHO's LBW policy report stating how early inducement of labour or caesarean birth is a significant cause of LBW . The decWHO recommendation for ANC service utilisation during the prenatal period should be broadened to control the LBW prevalence (The study's key novelty is the discovery of SES inequalities in LBW among South Asian children. Children afflicted with LBW are common among impoverished and illiterate women, particularly in Afghanistan, Bangladesh, India, Nepal, and Pakistan. To reduce the disparities in LBW, sophisticated initiatives based on knowledge of health education and poverty alleviation might be launched in South Asia, particularly in all the regions that are prone to SES inequalities. The evalence . This stThe current study utilised a nationally representative population-based sample in South Asia to assess LBW on an aggregate level. Estimating LBW inequities will assist health organisations and stakeholders in developing interventions to address this issue. The study's main strength is that it adopted three concentration indexes to assure the validity and precision of the estimates. The study also identified different South Asian countries' contributions to the overall SES inequalities in LBW. This study uses pooled effects to address associated factors, which might aid in generalising the impact.The casual relationship cannot be drawn due to the cross-sectional design. The respondents' weight status was collected and subjected to recall bias. There is a lack of information on genetic factors, maternal clinical indicators, and consumption status of nutrition/dietary. The Body Mass Index was not included in the study because it was not accessible in the Afghanistan dataset.5i.e. those from the poorest households and with less education, are more likely to have LBW children. Governments and NGOs of South Asia might need to focus on health education and knowledge of poverty alleviation to decrease SES inequalities in LBW. Factors such as maternal age and education, wealth status, sex of the child, birth status, number of ANC visits, iron supplementation, mode of birth, and residential status were all significant indicators of LBW children in South Asia. Public health initiatives targeting maternal health should address these significant indicators to minimise the occurrence of LBWs, with a particular emphasis on women from Afghanistan, Bangladesh, India, Nepal, and Pakistan and those with lower SES levels. Expanding the coverage and raising public awareness of the ANC program and iron supplement requirements during pregnancy are also essential. Increasing awareness of health education concerning delivery complications, including LBW, is required to reduce the LBW prevalence. These recommendations will aid in reaching the WHO's nutrition targets by ensuring the normal birth weight of children, directly assisting in attaining the connected SDGs in the future.The study depicts the SES inequalities in LBW cases among children under five in South Asia. In many countries in the subcontinent, most notably Afghanistan, Bangladesh, India, Nepal, and Pakistan, women of lower SES, http://www.dhsprogram.com and does not contain any personally identifiable information. The authors obtain access to data after procuring authorisation via an online application. Each parent or guardian was supplied with an informed consent statement prior to the interview. It guarantees the legal participation and secrecy of each child.The data is freely available at Not applicable.http://www.dhsprogram.com. Any subsequent requests for additional inquiries can be referred to the corresponding author.The data utilised in the study was acquired through the program Demographic and Health Survey. Data are available at This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.NJS, BA, and SAK initiated the study, and conducted the data analysis. NJS, BA, and SAK drafted the manuscript. KA, RH, and KYL offered advice, critical comments and edited the draft manuscript. All the authors read and approved the final manuscript.We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed.We further confirm that the order of authors listed in the manuscript has been approved by all of us.We confirm that we have given due consideration to the protection of intellectual property associated with this work and that there are no impediments to publication, including the timing of publication, with respect to intellectual property. In so doing we confirm that we have followed the regulations of our institutions concerning intellectual property.We further confirm that any aspect of the work covered in this manuscript that has involved either experimental animals or human patients has been conducted with the ethical approval of all relevant bodies and that such approvals are acknowledged within the manuscript.The authors have no conﬂicts of interest to declare.


This systematic review and meta-analysis was conducted to synthesize the findings of randomized controlled trials of mindfulness-based interventions for children with ADHD. (2) Methods: A systematic review and meta-analysis of studies published in PsycINFO, PubMed, and Google Scholar was completed from the earliest available date until August 2022. (3) Results: The systematic review included 12 studies that met the inclusion criteria, and the meta-analysis included 11 studies. The overall effect sizes were  Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent neurodevelopmental disorders, affecting more than 5% children worldwide ,2. InattStimulant medication is the first-line treatment for ADHD and is effective for reducing ADHD symptoms. However, children with ADHD who are treated with medication still have poorer prognosis than those without ADHD . In addiBehavioral intervention has better outcomes as rated by those who are aware of treatment status, but is less effective for those rated by someone blinded to the intervention status . TraditiMindfulness-based interventions are a promising approach and have received increasing attention in the field of mental health . MindfulMindfulness-based interventions are one of the best options to address the deficits associated with ADHD. Mindfulness focuses on the present moment with attention and emotion regulation, the very regulatory capacities that are impaired in ADHD . ADHD anDespite the potential benefits of mindfulness-based interventions in the management of ADHD, previous systematic reviews cannot offer definitive conclusions about the effectiveness of mindfulness-based interventions for children with ADHD because the methodological quality of the studies reviewed is low . To overThe PubMed, PsycINFO, CINAHL, Web of Science, Google Scholar, and Scopus databases were searched for studies published from 1970 to 2022. The search strategy comprised the following Medical Subject Heading terms: yoga or mindfulness or mindful awareness or meditation and child or children or adolescent or adolescence and ADHD or inattention or hyperactivity/impulsivity. Studies were organized in the references list to assist the reviewers to perform study selection. We first identified studies by title and abstract to assess whether they met the inclusion criteria, and we also searched the reference lists of relevant systematic reviews for additional articles.Studies were included in this systematic review if they randomized participants to the intervention or control group; if they included interventions with a focus on yoga, meditation, and/or mindfulness-based techniques such as mindful eating, mindful walking, or Taichi; if study participants had a diagnosis of ADHD; and if study participants were children/adolescents aged between 5 and 18 years. Yoga and/or mindfulness interventions that were combined with other approaches, such as parent training and non-specified relaxation techniques, were included.We used the Physiotherapy Evidence Database (PEDro) Scale to assess the methodological quality of the included studies. The PEDro scale has 11 items. The PEDro scale criteria are: (1) if eligibility criteria are specified; (2) if participants are randomly allocated; (3) if allocation is concealed; (4) if the baseline comparison is similar between groups; (5) if participants are blinded; (6) if therapists are blinded; (7) if assessors are blinded; (8) if there is greater than 85% follow-up for at least one key outcome; (9) if intention-to-treat analysis is applied; (10) if there is between-group statistical comparison for at least one key outcome; and (11) if there are point estimates and measures of variability for at least one key outcome. A study will receive a point when the criterion of the item is met. Item 1 is not given a point. The total score of the PEDro is the sum of the points of items 2 to 11, for a maximum score of 10. A PEDro total score of 9 to 10 is considered as excellent, 6 to 8 as good, 4 to 5 as fair, and a score of less than 4 is considered as poor . The firData extracted from each study included study design, participant characteristics, intervention characteristics, and outcome measures. The first author extracted and tabulated the relevant data from the studies, and the second author double-checked the information.g. Based on the guidelines suggested by Cohen [Comprehensive Meta-analysis version 3 was used to calculate effect size estimates of the differences in performance scores (mean and standard deviations) . Relevanby Cohen , effect Q statistics were used to test the presence or absence of heterogeneity. I2 was calculated to determine the proportion of observed variance that reflects a real difference in effect size [I2 values of 25%, 50%, and 75% are interpreted as low, moderate, and high proportions of real differences in effect size, respectively [The effect sizes of the studies might vary by chance . A heterect size . I2 valuectively .To estimate the effect of categorical  and continuous variables  on the effect of mindfulness-based intervention, we performed sub-group analysis and meta-regression analyses, respectively. The possibility of publication bias was examined. Funnel plot, the Begg and Mazumdar test, and Duval and Tweedle’s trim and fill method were adopted to impute the value of missing studies.We identified 936 articles from the databases See . Two addStudy authors spanned a number of countries or regions, including Iran ,29, SpaiAs detailed in Three types of mindfulness-based intervention were identified: yoga intervention ,36, mindIn addition to experiential intervention in groups, most programs emphasized the importance of the implementation of home programs ,33,34,36Lengths of individual sessions ranged from 20 to 90 min, with most sessions lasting 90 min ,32. The All of the reviewed studies randomized participants to an intervention or control group, although some studies provided no information regarding the randomization procedures ,31,35,36This review targeted five primary outcomes, namely, children’s ADHD symptoms, children’s internalizing problems, externalizing problems, mindfulness, and parental stress. Seven studies measured the symptoms of ADHD ,36,38,39Children’s internalizing problems and externalizing problems were measured in nine studies with the Child Behavior Checklist ,38, the Children’s mindfulness was measured in four studies with the Mindful Attention Awareness Scale ,35 and tTwelve studies scored between 4 and 7 points from a possible total of 10 points on the PEDro Scale , with ang = 0.77 , suggesting that mindfulness-based interventions had a significant effect on the reduction of ADHD symptoms . The I2 with 81.75% suggested high heterogeneity as a result of the high variability across the studies. The Begg and Mazumdar test revealed possible publication bias . There were two articles trimmed to the right mean using a random model according to the Duval and Tweedie’s trim and fill for ADHD symptoms. The Begg funnel plot showed the basically symmetric distribution  .Two studies measured the follow-up effect of ADHD symptoms. The overall effect size was calculated at  = 0.38) . The hetg = 0.03 , as presented in Q = 1.28  and I2 = 0%. The Begg and Mazumdar test revealed no publication bias . There were no missing articles to the right mean using a random model according to the Duval and Tweedie’s trim and fill for externalizing behavioral problem. The Begg funnel plot showed the basically symmetric distribution . The heterogeneity test of effect size was not significant .Two studies measured the follow-up effect of externalizing behavioral problem. The overall effect size was calculated at g = 0.13 , as presented in Q = 19.12  and I2 = 68.63%. The Begg and Mazumdar test revealed no publication bias . There were no missing articles to the right mean using a random model according to the Duval and Tweedie’s trim and fill for internalizing behavioral problem. The Begg funnel plot showed the basically symmetric distribution . The heterogeneity test results showed significant heterogeneity within results with Q = 7.55  and I2 = 86.76%.The follow-up effect on internalizing behavioral problem was g = 0.43   and I2 = 84.45%. The follow-up effect on child’s mindfulness was g = −0.17 . The Begg and Mazumdar test revealed possible publication bias . There was one article trimmed to the right mean using a random model according to the Duval and Tweedie’s trim and fill for child’s mindfulness. The Begg funnel plot showed the basically symmetric distribution  . The hetribution .g = 0.40   and I2 = 75.18%.Based on two studies, the combined effect size for parental stress was .34) see . The hetZ = 2.36, p = 0.02), and the effect size for the active control group was moderate to large . In addition, high heterogeneity was observed in the no intervention control groups  for ADHD symptoms.In the subgroup analysis of no intervention or an active control group for ADHD symptoms, the effect size for a no intervention control group was in the large range , and the effect size for an active control group was close to zero .In the subgroup analysis of no intervention or active control groups for internalizing behavioral problem, the effect size for a no intervention control group was in the small range (p = 0.03), suggesting a larger mindfulness-based intervention effect was associated positively with older children. In addition, the meta-regression results showed that overall effect size was significantly moderated by the child’s sex  but with a very small coefficient. We found that the methodological rating had a small and negative association with effect sizes of ADHD symptoms .The meta-regression results showed that the effect size of ADHD symptoms was significantly moderated by the child’s age . In addition, the meta-regression results showed that overall effect size was moderated by the child’s sex  but with a very small coefficient. We found that the methodological rating had a small and negative association with the effect sizes of internalizing behavioral problem .The meta-regression results showed that the effect size of internalizing behavioral problem was moderated by the child’s age (β = 0.05, SE = 0.10, g was altered during this procedure from 0.77 to 0.44 for ADHD symptoms, and from 0.43 to −0.02 for mindfulness, when the study of Abdolahzad and colleagues [g values did not alter and presented the stability of the findings in this meta-analysis.We performed a sensitivity analysis by removing included articles one at a time to determine the impact of every single included study on the obtained results. The corresponding Hedge’s lleagues  was remolleagues  was an oThis is the first meta-analysis of randomized controlled trials to examine the effects of mindfulness-based interventions on improving ADHD symptoms, externalizing behavioral problem, internalizing behavioral problem, mindfulness, and parental stress in children with ADHD. Using a control group for comparison with a mindfulness-based intervention means that the influence of maturational changes in children was excluded because these will be common between the mindfulness-based intervention and comparative conditions. In addition, we used a randomized design to exclude the influence of systematic differences between groups.This meta-analysis synthesized seven studies of mindfulness-based interventions and revealed a moderate-to-large effect size for ADHD symptoms in children with ADHD. The findings are similar with a previous meta-analysis  that exaTo the best of our knowledge, this is the first meta-analysis to examine the effect of mindfulness-based interventions on externalizing behavioral problem and internalizing behavioral problem in children with ADHD. Our results are consistent with a previous systematic review  that theThis meta-analysis found improvement that is small to moderate in magnitude for mindfulness after mindfulness-based interventions compared with control conditions. It is assumed that ADHD and mindfulness go through similar processes, with mindfulness focusing on the present moment with attention and emotion regulation, the prevalent deficits in children with ADHD . In thisLarger effects on ADHD symptoms were associated with older children. It is possible that this was influenced by the symptoms of ADHD that change over developmental periods. When children with ADHD get older, inattentive symptoms become more obvious, and hyperactivity and impulsivity tend to decrease. Current research supports that mindfulness-based interventions increase attention capacity more than hyperactivity and impulsivity . AdolescThere was very little influence of the mindfulness-based intervention at the follow ups, which were 1 to 6 months after the interventions. Although home practice was an important part of the mindfulness-based intervention programs, participants might not have continued practicing mindfulness exercises when the intervention was over. The effect might have diminished with time after the interventions ended. Future studies may need to explore the reasons and possible solutions for the reduced retention of intervention effects.There were significant methodological limitations in the studies included in this meta-analysis. Several studies did not report the method of randomization or concealment of allocation before assignment. Most of the studies reported rates of attrition but did not report using statistical techniques to address incomplete data. Some studies did not blind the assessors who evaluated the outcomes. Although most studies allowed participants to remain on medication throughout the course of the studies, one study  did not This systematic review and meta-analysis included 12 randomized controlled trials that investigated mindfulness-based interventions for children with ADHD. The results show that mindfulness-based interventions are an effective intervention for reducing ADHD symptoms in children with ADHD. A large effect on ADHD symptoms is noted for older children or adolescents with ADHD. Further research is needed to study the effects of different types of mindfulness for different groups of age and sex.


The prevalent, neuropsychiatric, deficit perspective on children and youth diagnosed with ADHD prohibits a multidimensional approach where socio-economic status, family stress and relationships within the families are relevant factors to examine. Assessments of ADHD through the use of rating scales and short-term interventions may lead not only to overdiagnosis but also to a reductionistic approach in the psychiatric field. This literature review aims to address research outside the prevailing discourse on ADHD as an organic brain dysfunction and broaden the perspectives on children's behavioral difficulties.ADHD in children and youth related to Attachment styles and relationships.The articles included in this applied, mixed-method, systematic review includes 26 peer-reviewed articles, both English and French, with a search focus on In the studies reported, researchers approached correlations between ADHD and attachment in different ways, and in most cases, there was a caution to address causality. The role of parents was found to be both buffering and aggravating for the appearance of ADHD. In the French case studies, the diagnosis was conceptualized as a relational phenomenon where the child's behavior was inseparable from family member's suffering.This review article illustrates how children's difficulties in terms of ADHD symptoms can be addressed through a paradigm where emotional and cognitive dysregulation is understood through psychosocial factors rather than as a neurological condition. In our view, to avoid an overly reductionistic and medicalized approach to children's behavioral difficulties, it is time to reiterate the value of the biopsychosocial perspective.Professionals and researchers need to acknowledge that becoming diagnosed with ADHD has a strong connection to economic disadvantage, social status, and familial care. The academic discourse of addressing brain dysfunctions might serve the unintended purpose of masking emotional stress and social disadvantage that manifests across generations. A biopsychosocial approach to ADHD including family, emotional history, and socio-economic issues could imply a lesser focus on medical treatment as a first choice. In the relatively short history of psychiatry and mental health care, there are numerous examples of diagnoses, interventions, and explanations of human suffering that later has been questioned . Today, It has been proven difficult to differentiate ADHD from normal variation . Since sIn modern times, some authors [e.g., –16 have rd, 2022, on ADHD and the relationship to genetics, genes or hereditary or inherited, resulted in a total of 46.994 articles published between 1990 and 2022. Research on adverse psychosocial circumstances and the presence of high stress in families where these children grow up is sparse in comparison with the organic/synaptic discourse. This regime of biased knowledge production also manifests in clinical practice where, as Singh , , based oth (APA Psychinfo), April 1st (Psychlitt.), April 21st (Cairn) and May 4th (Psychlitt. and Psychinfo). Thesis, short, descriptive studies, and articles in other languages than English and French were initially removed from the records. Criteria for inclusion were empirical studies, systematic review studies published in peer-reviewed journals and studies that were eligible for ADHD in children and youth. The results of the searches were organized and specified as the following profile:For the search of articles according to the research question, the following databases was used: Psychlitt., Psychinfo, and Cairn. The searches were performed on March 24ADHD or attention deficit hyperactivity disorder, Children or kids or youth or child, Attachment styles and relationships, or attachment styles in child development. Peer-reviewed articles (French-spoken) with the search terms: hyperactivité (hyperactivity), TDAH (ADHD), enfant (children), adolescent, famille (family).Peer-reviewed articles (English-spoken) with the search terms: n = 72). In total, 26 articles were found eligible for being included. The procedural steps taken throughout the review process are shown in The total records identified after the initial database searches were 492. Removal of duplicates left 483 articles. The vast majority of articles written in French referred to a biomedical or neurodevelopmental perspective on ADHD. Articles that did not focus on psychosocial factors associated with child and family, such as opinion and theoretical articles, were excluded. Furthermore, some articles were excluded due to irrelevant content, i.e., focusing on other diagnoses or on treatment evaluation. Full-text articles assessed for eligibility amounted to 72 articles. In order to decide on eligibility the authors examined the full-text articles . The next step implied to characterize the content by searching for common denominators, i.e., themes describing those denominators, a process undertaken by the first author (SIE). Searching for themes was guided by Braun and Clarke  who declThe main focus of the results in the review is how ADHD relate to attachment, including the family environment. Included articles had varying research methods and focuses see , and wer• ADHD, attachment, and the family environmentCompeting discourses about the interaction between ADHD and attachmentADHD, early development, and interactions with environmental stimuliNarratives of family bonds in parents of children with ADHDIn focus of this review, attachment difficulties were associated with ADHD symptoms in a different number of ways . ChildreCompeting discourses about the interaction between ADHD and attachmentdevelopmental precursor for ADHD and adjustment problems in school. Eyuboglu and Eyuboglu . Having to pay continuous attention, the parents are deprived of their own thoughts and feelings in their relationship to the child, and can hardly be involved personally in the interaction, as they most of the time only react to his lack of self-regulation. Petot .There is a noticeable risk of over-diagnosis when the treatment paradigm primarily targets the child's individual traits and overlooks contextual factors such as economic hardships and complications in family life. This review article has given examples of how the later are important variables in the understanding of ADHD symptoms. Several of the case studies based on psychotherapy explore the relationships between the parents' stress and their children's behavior , 53, 60.Being recognized as someone who have ADHD is not seldom felt as a relief and a sense of social belonging , 71. Thewhich reflect the outer lived experiences on an inner level” [ develop in harmony with the social environment. At the same time, it is important not to land in a simplified either/or approach to “organic” syndromes such as ADHD vs. “learned” behaviors such as attachment difficulties since research illustrates how these  are tightly interwoven . Such a paradigm shift includes more resources for the humanities and social sciences in studies of hyperactivity, concentration and emotional regulation. Otherwise, there is a risk of another 40 years with a continuing, rising curve of even younger children who are medicalized and defined as having a disease/disorder. To perceive children as subjects whose development is dependent on a secure and trustful social context can raise parents' (and society's) sensitivity to children's needs of sharing their feelings of frustration. The child psychiatrist Sami Timimi has offered a treatment option “The Rational Awareness Program” for parents and their children struggling with challenging behavior . This faThis review article has investigated and discussed how children's behavioral difficulties labeled as ADHD can be understood through factors such as attachment, family relations and emotional history . Such a focus does not deny that individuals have differing genetic vulnerabilities for developing psychiatric symptoms, but rather strives to re-establish a biopsychosocial model that has become vaguer in a neo-Kraepelinian era. Even though Anna Freud  wrote heSE wrote the first draft and was responsible for guidance in the process of writing the paper. The search for publications was done by SE, CH, and ND. All authors participated in reading and summarizing the review articles and writing the result section. All authors contributed to manuscript revision, read, and approved the submitted version.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.


Here, we hypothesized that the efficient delivery of menahydroquinone-4 (MKH), an active form of MK-4, could exert a supporting effect. We verified the effects of MKH delivery on mitochondrial dysfunction by using MK-4 and MKH ester derivatives in NIH/3T3 mouse fibroblast cells treated with mitochondrial inhibitors. MK-4 and MKH derivatives suppressed cell death, the decline in mitochondrial membrane potential (MMP), excessive reactive oxygen species (ROS) production, and a decrease in intrinsic coenzyme Q9 (CoQ9) induced by rotenone . MK-4 and MKH derivatives delivered MKH to NIH/3T3 cells, acting as an effective MKH prodrug, proving that the delivered MKH may reflect the mitigation effects on ROT-induced mitochondrial dysfunction. MKH prodrugs are also effective against 3-nitropropionic acid  and carbonyl cyanide-m-chlorophenylhydrazone -induced cell death. In conclusion, MKH delivery may mitigate mitochondrial dysfunction by maintaining MMP, ROS, and CoQ9, indicating that MKH prodrugs may be good candidates for treating mitochondrial disorders.Mitochondria generate energy through the action of the electron transport chain (ETC) and ATP synthase. Mitochondrial malfunction can lead to various disorders, including neurodegenerative diseases. Several reports have shown that menaquinone-4 (MK-4, vitamin K Therefore, focusing on mitochondrial function is necessary to elucidate the etiology of diseases for which there are still no effective treatment strategies and advance effective drug development.Mitochondria are integral for normal cell functioning as they generate the ATP required to maintain vital cell function in the respiratory chain behaving as “powerhouses of the cell.” Mitochondrial quality control and dysfunction are also implicated in the production of reactive oxygen species (ROS), regulation of cell death, and etiology of neurological disorders such as Huntington's disease, Parkinson's disease, and Alzheimer's disease4. The concentration gradient of protons creates a mitochondrial membrane potential (MMP), which is used by complex V (ATP synthase) , known as a representative antioxidant in the ETC, protects against mitochondrial damage caused by ROS as a part of homeostasis mechanism. However, the production of excess ROS over the defense system in problematic situations causes oxidative stress and decreases membrane potential, resulting in an inability to produce energy and mitochondrial dysfunction6. Rotenone (ROT), a major complex I inhibitor, interferes with the conversion of CoQ to reduced CoQ (CoQH2) by binding to NADH dehydrogenase, which is part of complex I8. As a result, electrons flow back, and ROS are generated, leading to cell death10. Therefore, ROT has been widely used in experimental models to explore drug effectiveness against mitochondrial dysfunction12.Mitochondria are organelles with a double-membrane structure containing five complexes in the inner membrane. In complexes I–IV (electron transport chain: ETC), protons are pumped into the intermembrane space during electron transportse) Fig. . During 2(20)) has been clinically used as a therapeutic agent for osteoporosis in Japan, and its long-term safety has been confirmed13. It has been reported that MK-4 suppresses neuronal cell death mediated by ROT-induced microglial activation14. However, a recent study showed that vitamin K2 is not a substitute for CoQ1015. Other studies have reported that MK-4 can act as a mitochondrial electron transporter17. Thus, whether MK-4 is effective in mitochondrial dysfunction remains controversial. MK-4 cannot act as a cofactor for γ-glutamyl carboxylase (GGCX) for the post-translational modification of vitamin K-dependent proteins (VKDP) until MK-4 is reduced to menahydroquinone-4 (MKH)18. MKH is stoichiometrically converted to MK-4 epoxide (MKO) when it acts as a cofactor for GGCX  and MKH 1,4-bis-hemi-succinate (MKH-SUC), which overcome the shortcomings of MK-4. In the present study, we aimed to verify whether MKH delivered by MKH prodrugs affected ROT-induced mitochondrial dysfunction and cell death. We have previously reported that MKH-DMG and MKH-SUC can act as effective MKH prodrugs in vitro and in vivo22. We have also shown that their MKH delivery via intracellular hydrolysis activation is independent of the reductive activation pathway for MK-424. In this study, we evaluated the influence of MKH prodrugs on cell death, decrease in MMP, and intracellular CoQ levels following exposure to mitochondrial inhibitors, mainly ROT, in NIH/3T3 cells.In our laboratory, we synthesized two MKH ester derivatives, MKH 1,4-bis-To verify whether MK-4 and MKH derivatives affect ROT (complex I inhibitor)-induced cell death in NIH/3T3 cells, cell viability was assessed using the CellTiter-Blue®  reagent. As preliminary tests, the cytotoxicity of ROT, MK-4, or MKH derivatives to NIH/3T3 cells was evaluated. ROT treatment  induced a dose-dependent decrease in cell survival rate. The maximum reduction rate in cell viability was approximately 40% of the vehicle group (0.1% dimethylsulfoxide: DMSO) at the highest dose in the 0.01–10 µM dose range , as shown in Fig. ROT is believed to induce ROS in the mitochondria by blocking complex I in the respiratory chain. Therefore, to confirm the influence of MK-4 and MKH derivatives on ROT-induced ROS production, intracellular ROS levels were measured using 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) reagent. The intracellular ROS levels were standardized by the number of living cells, as indicated in Fig. Heme oxygenase-1 (HO-1) is induced by such as ROS and inflammatory cytokines. To evaluate the effect of ROT-induced ROS on the amount of HO-1 expression, real-time PCR and western blotting were performed. HO-1 gene expression increased eightfold in response to ROT compared to vehicle treatment Fig. a. In con9 (CoQ9)/reduced coenzyme Q9 (CoQ9H2) balance, we measured intracellular MK-4, MKO, CoQ9, and CoQ9H2 levels using LC–MS/MS. MKH cannot be measured directly because it is easily oxidized to MK-4 in presence of air. The MKO level reflects the amount of MKH delivered due to the conversion of MKH to MKO, which acts as a cofactor for the post-translational modification of VKDP by GGCX. In the vehicle group, neither MK-4 nor MKO was detected. Intracellular MKO was observed in the drug-treated groups, indicating that both the MK-4 and MKH derivatives functioned as MKH prodrugs. After 6 and 24 h of drug treatment, intracellular MKO levels were higher than intracellular MK-4 levels at every time point. The maximum intracellular drug level of MK-4 was approximately 0.05 nmol/mg protein, and that of MKO was approximately 0.4 nmol/mg protein , antimycin A , oligomycin A , and carbonyl cyanide m-chlorophenyl hydrazone  were used. Cell viability was measured using CTB reagent, and the concentrations of all inhibitors used in the experiment were determined by preliminary experiments . It has been revealed that MKH (hydroquinone form of MK-4) is supplied not only by the reduction of exogenous MK-4 but also by biosynthesizing from vitamin K26. We employed NIH/3T3 cells to evaluate the essential effects of MKH derivatives on mitochondria. In his study, MK-4 and MKH derivatives showed a partial suppressive effect on NIH/3T3 cell death and mitochondrial dysfunction induced by mitochondrial inhibitors of complex I, II  and uncoupler (CCCP). Moreover, MK-4 and MKH derivatives acted as MKH prodrugs in NIH/3T3 cells and suppressed excessive ROS production and loss of endogenous CoQ9 induced by ROT. Based on these results, it is speculated that MKH is a key player in mitigating mitochondrial dysfunction induced by mitochondrial inhibitors.NIH/3T3 cells are derived from mouse fibroblasts and are widely used for assessing basic biological effects such as cytotoxicity and elucidation of molecular mechanisms24. If MKH delivery is important for its suppressive effect on mitochondrial dysfunction, it can be expected that the efficacy of MKH-DMG at low therapeutic concentrations will be lower than those of MK-4 and MKH-SUC. Therefore, it seems reasonable that the suppressive effects of MKH-DMG on the increase in cell death induced by mitochondrial inhibitors were lower than those of MK-4 and MKH-SUC  and CoQ9H2 (two-electron reduced form) are electron transporters in the mitochondria, and CoQ9 is more abundant than CoQ10 in rodents. NADH dehydrogenase in complex I activate the ETC by reducing CoQ9–CoQ9H2. The MK-4 and MKH derivatives maintained endogenous CoQ9 even in the presence of ROT  ROS quenching or (ii) electron transport in complex I instead of CoQ. Menke et al. reported the protective effect of CoQ10 on ROT-induced apoptosis in SH-SY5Y neuroblast cells, suggesting that excessive exogenous CoQ10 may overcome ROT inhibition via a bypass mechanism for the ETC38.CoQROT Fig. c,d. The low Fig. c,e. To o41, particularly in complex I42. AA inhibits the reduction of CoQ in respiratory chain complex III and induces ROS production43. However, it has also been reported that ROS are generated not only in ETCs I and III but also in ETCs II and IV44, 3-NP, which irreversibly inhibits succinate dehydrogenase, generates ROS and promotes mitochondrial damage45. Furthermore, studies with CCCP, which reduces MMP and inhibits oxidative phosphorylation, and OA, which binds to the proton pump of complex V and inhibits ATP synthesis, confirm ROS generation47. Regarding the inhibitory effect of MK-4 and MKH derivatives on cell death induced by 3-NP and CCCP, it is necessary to further investigate whether the effects of MKH prodrug are due to the normalization of ROS levels and ROT. However, it is unclear why MK-4 and MKH derivatives have no effect on OA- and AA-induced cell death. Although Cerqua et al. showed that MK-4 does not function as a substitute for CoQ by using CoQ-depleted cells, the ROT used in our study did not block CoQ biosynthesis and did not lead to CoQ depletion in the mitochondria15. Therefore, MKH may be able to assist or substitute for CoQ to drive the ETC. Another possibility is that the increased MKO levels by MKH prodrugs reflect the production of VKDP, and induced VKDP may affect mitochondrial rescue. Further clarification of the mechanisms underlying the suppressive effects of MKH prodrugs on mitochondrial dysfunction, including the mechanism by which MKH prodrugs maintain ROS at normal levels, is required.It has been reported that the main sites of ROS generation in mitochondria are in complex I and IIIIn this study, we present the basic effects of MKH derivatives on mitochondrial dysfunction and confirmed reproducibility. MK-4 and MKH derivatives have a partial inhibitory effect on cell death induced by respiratory chain complex I and II inhibitors and uncouplers and suppress ROS generation in mitochondria. These compounds functioned as prodrugs of MKH in NIH/3T3 cells, and it was considered that MKH delivery exerts a suppressive effect on cell death and ROS production. It is believed that the evaluation of the effect of MKH prodrugs on mitochondrial dysfunction and elucidation of the detailed mechanism using NIH/3T3 cells will become a foundation for further developmental research using cells derived from various organs.N,N-dimethylglycinate hydrochloride (MKH-DMG), and menahydroquinone-4 1,4-bis-hemi-succinate (MKH-SUC) were synthesized in our laboratory using previously reported methods48. The following chemicals were obtained commercially: rotenone (R8875), 3-nitropropionic acid (N5636), and antimycin A from Streptomyces sp. (A8674) from Sigma-Aldrich ; oligomycin A (AG-CN2-0517) from AdipoGen Life Sciences, Inc. ; carbonyl cyanide m-chlorophenylhydrazone  from FUJIFILM Wako Pure Chemical Corporation ; and coenzyme Q9 (CoQ9) from Cayman Chemical . The following antibodies were used: heme oxygenase 1 (HO-1) from Cell Signaling Technology  and monoclonal mouse anti-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Sigma-Aldrich.Menaquinone-4 (MK-4) was purchased from Seebio Biotech Inc. . Menahydroquinone-4 1,4-bis-2 atmosphere.The mouse fibroblast-like cell line NIH/3T3 (RCB2767) was obtained from the RIKEN BioResource Research Center . Cells were maintained in Dulbecco's Modified Eagle Medium/Nutrient Mixture F-12  containing 10% fetal bovine serum  and 1% penicillin/streptomycin (Thermo Fisher Scientific) at 37 °C under humidified 5% CO4 cells per well in 96-well black plates and allowed to attach for 24 h. Then, drug media, including 10 µM of ROT and 0.03‒3 µM of MK-4, MKH-DMG, or MKH-SUC at the different concentrations indicated in the related result section, were exposed for 24 h. Fluorescence signals as cell viability were measured using a microplate reader  according to the manufacturer’s instructions.Cell viability was assessed using the CellTiter-Blue®  by the following cell viability assay method. NIH/3T3 cells were plated at a density of 1.0 × 104 cells/well or in a collagen-I-coated glass dish  at a density of 2.5 × 105 cells/dish. The cells were allowed to adhere for 24 h. The cells were then treated with MK-4, MKH-DMG, or MKH-SUC in the presence of ROT for 6 h. Then, the cells were stained with JC-1 (1 mg/mL in DMSO) and incubated at 37 °C for 30 min in the dark. The cells were washed twice with serum-free media, visualized under a fluorescence microscope , and quantified using a microplate reader (Infinite M200 PRO) .MMP in cells was assessed using the JC-1 MitoMP Detection Kit  according to the manufacturer’s instructions. JC-1 accumulated in mitochondria forms red fluorescent aggregates at high membrane potentials, whereas JC-1 monomers show green fluorescence, indicating low membrane potentials. For the analysis of MMP, NIH/3T3 cells were cultured in a collagen-I-coated 96-well black plate at a density of 1.0 × 104 cells/well in a collagen-I-coated 96-well black plate and allowed to adhere for 24 h. The cells were treated with MK-4, MKH-DMG, or MKH-SUC in the presence of ROT for 6 h. The cells were washed once with serum-free media and incubated in 100 µL of 10 µM DCFH-DA for 30 min in the dark at 37 °C. After incubation, intracellular fluorescence was measured at excitation and emission wavelengths of 485 and 530 nm, respectively, using a microplate reader (Infinite M200 PRO). The obtained ROS levels were standardized by cell viability using the CTB reagent, as described in the Cell Viability Assay section.Intracellular ROS levels were examined using DCFH-DA (Thermo Fisher Scientific). The DCFH-DA probe is rapidly oxidized by ROS and converted into fluorescent 2′,7′-dichlorodihydrofluorescein (DCF). The DCF fluorescence intensity is proportional to the ROS level in the cytoplasm. Briefly, NIH/3T3 cells were seeded at a density of 1.0 × 10Total RNA was extracted from cultured cells using a High Pure RNA Isolation Kit . cDNA was reverse-transcribed using the ReverTra Ace-a-reverse transcription kit , and quantification was performed using LightCycler® 480 SYBR Green I Master (Roche Diagnostics K.K.). The sequences of the primers used were as follows: heme oxygenase-1 (HO-1), forward primer: 5′-CACTCTGGAGATGACACCTGAG-3′; reverse primer: 5′- GTGTTCCTCTGTCAGCATCACC-3′; beta-2 microglobulin (B2M), forward primer: 5′- ACGTAGCAGTTCAGTATGTTCG-3′; reverse primer: 5′- GGTCTTTCTGGTGCTTGTCT-3′. B2M was used as an internal control.5 cells/dish in a collagen-I coated 60 mm dish and treated with 10 µM ROT with or without 3 µM MK-4, MKH-DMG, or MKH-SUC for 6 h. Cultured cells were washed with ice-cold PBS and lysed in RIPA buffer  containing a protease inhibitor cocktail  on ice. A plastic cell scraper was used to scrape the adherent cells. Cell lysates were then clarified by centrifugation at 20,600 × g at 4 °C for 15 min, and the supernatant was collected. The total protein concentration was determined using the Pierce™ BCA protein assay kit (Thermo Fisher Scientific). Proteins (every 10 μg) were separated by SDS-PAGE using Super Sep ™ Ace 15% 13-well gels (FUJIFILM Wako) and transferred onto PVDF membranes . The membrane was blocked using Blocking One solution  and incubated with anti-HO-1  and anti-GAPDH antibodies , respectively, at 25 °C for 1 h. After washing, the membranes were treated with the appropriate secondary antibodies and visualized using Immunostar LD (FUJIFILM Wako). Protein expression was analyzed using the ImageJ software (version 1.53 k).NIH/3T3 cells were seeded at a density of 4.0 × 105 cells/well in 6-well plates and allowed to attach for 24 h. Next, the cells were cultured in a medium with or without 3 µM MK-4, MKH-DMG, or MKH-SUC in the presence of 10 µM ROT. The medium was then removed, and the cells were washed twice with PBS. The cells were collected in 1 mL PBS and sonicated on ice. Cell homogenates were combined with an equal volume of ethanol and three times the volume of n-hexane, vortexed for 2 min, and centrifuged at 1750 × g for 10 min. The organic layer was evaporated using N2 gas. The residue was reconstituted with 200 µL of ethanol and analyzed using LC–MS/MS, as described below. The protein concentration in the cell homogenate was determined using a BCA protein assay kit (Thermo Fisher Scientific).NIH/3T3 cells were seeded at 3.0 × 10+ MKO adduct; m/z 445.0 → 187.0, for the [M + H]+ MK-4 adduct; m/z 815.2 → 197.0, for the [M + NH4]+ CoQ9H2 adduct; and m/z 796.2 → 197.0, for the [M + H]+ CoQ9 adduct. Retention times were as follows: MKO, 3.5 min; MK-4, 3.9 min; CoQ9H2, 5.5 min; and CoQ9, 7.4 min.LC–MS/MS was performed using an LC–MS-8060 liquid chromatography-mass spectrometer  and a Shimadzu UFLC System . Separations were performed on a Shim-pack XR-C8 column  using a mobile phase comprising 10 mM ammonium acetate and 0.1% acetic acid in methanol (pump A) and ethanol (pump B) under gradient elution, at a flow rate of 0.2 mL/min. A binary gradient was established as follows: (A) 10 mM ammonium acetate and 0.1% acetic acid in methanol and (B) 10 mM ammonium acetate and 0.1% acetic acid in ethanol; 30% B at 0 min, 30% B at 2.00 min, 70% B at 10.00 min, 70% B at 10.01 min, and 70% B at 12.00 min. The column temperature was maintained at 40 °C. The mass spectrometer was equipped with an electrospray ionizer and operated in the positive ion mode. Identification and quantitation were performed under the MS/MS-multiple reaction monitoring (MRM) mode, using the following transition ions: m/z 461.0 → 81.0 for the [M + H]Comparisons among groups were performed by one-way ANOVA with Tukey’s test, and the analyses were carried out using GraphPad Prism 6 ; results with p < 0.05 were considered significant.Supplementary Information.


COP) of this ideal cycle represents the theoretical upper bound of ERC, and it does not contain any information about the properties of working fluids, which is a key cause of the large energy efficiency gap between the actual cycle and the ideal cycle. In this paper, the limiting COP and thermodynamics perfection of subcritical ERC is derived to evaluate the ERC efficiency limit under the constraint of pure working fluids. 15 pure fluids are employed to demonstrate the effects of working fluids on limiting COP and limiting thermodynamics perfection. The limiting COP is expressed as the function of the working fluid thermophysical parameters and the operating temperatures. The thermophysical parameters are the specific entropy increase in the generating process and the slope of the saturated liquid, and the limiting COP increases with these two parameters. The result shows R152a, R141b, and R123 have the best performance, and the limiting thermodynamic perfections at the referenced state are 86.8%, 84.90%, and 83.67%, respectively.An ejector refrigeration system is a promising heat-driven refrigeration technology for energy consumption. The ideal cycle of an ejector refrigeration cycle (ERC) is a compound cycle with an inverse Carnot cycle driven by a Carnot cycle. The coefficient of performance ( Refrigeration has become a very important part of modern society, and refrigeration consumes more than 20% of the overall electricity used worldwide . TherefoAn ERC is driven by a heat source. It consists of an ejector, a condenser, a pump, a generator, an expansion valve, and an evaporator, as shown in COP) is only related to the temperatures of the heat source, heat sink, and cold media. While for an actual ERC, there are different kinds of irreversible losses in it, most of which are related to working fluids. Moreover, its COP is not only related to the working conditions, but also to the working fluid properties. Since French engineer Maurice Leblanc introduced the steam ejector refrigeration system in 1910 [For the ideal cycle, all the processes are reversible. Its coefficient of performance  is o in 1910 , R123 [5 in 1910 , R141b [ in 1910 , and R24 in 1910 , ammonia in 1910 , R600 [1 in 1910 , R600a [ in 1910 , etc. αvp)// represents the maximum COP that can be achieved by the actual ERC when only considering the effect of working fluids, and the calculation method of LimitCOP is proposed. Moreover, the limiting performance of ERC with different working fluids is analyzed. This paper is organized as follows: in COPlimit methodology are presented. In In this paper, to evaluate the cycle performance upper limit under the constraint of pure working fluids, a limiting ejector refrigeration cycle (LERC) is developed. It is the closest cycle to the ideal cycle that can be achieved by the practical cycle, only taking the influence of working fluid thermophysical properties into account. The T-s diagram, the working fluids are divided into three categories: dry working fluids  and (1), there isα is the thermal expansion coefficientT-s diagram of the working fluid can be expressed as:β of 15 pure fluids is shown in Tr (Tr= Ts/ Tcr) increases from 0.555 to 0.995. They all get a minimal value as Tr is about 0.82. For isentropic fluids and dry fluids, there are two pole points. The slope decreases first and then increases as Tr increases between these two points, but it decreases as Tr increases when it is outside this range.In this research, the slope of the working fluid in a saturated state is obtained by the following method. According to the basic thermodynamic equations, there isTo quantify the influence of the fluid thermophysical properties on the cycle performance, the following assumptions are made in this paper:(1)The heat exchange processes are idealized. The temperature of the heat source and heat sink is constant. In the generator, the highest temperature of the working fluid is equal to the heat source temperature. The condensing temperature is equal to the heat sink temperature, and the evaporating temperature is equal to the cold media temperature.(2)Irreversibility in other processes of the cycle is ignored, such as the compression process in the pump, and the expansion, mixing, and diffusion process in the ejector are all regarded as isentropic processes, etc.Under the above assumptions, it can be concluded that the gap between the ideal ERC and actual ERC is caused by the property of the working fluid, as shown in COP is obtained.To evaluate the upper limit of the cycle with actual pure fluid, a cycle that is defined as a limiting ejector refrigeration cycle (LERC) is proposed in this paper. For dry fluids, the irreversible loss in the non-isothermal condensation process is ignored, when it is cooled from superheated gas to saturated vapor. For wet fluids, part of the irreversible loss in the non-isothermal generating process is neglected, when it is heated from saturated vapor to superheated gas. The diagram of LERC for different fluids is shown in COP can be expressed as:μ is the entrainment ratio, the flow rate ratio between the secondary fluid and the primary:For ERC, the COP can be expressed as an expression of the geometric area as shown in COP can be expressed asβ is the slope of the tangent line at state 1 and it can be calculated by formula (5). Although the tangent line does not completely coincide with the saturated liquid line, the difference is very small and neglected. According to the thermodynamic geometric analysis method, the limiting qco, ev is the specific condensation heat from the refrigeration part, and qco, ge is the specific condensation heat from the generation part.In the LERC, the condensation heat comes from two parts: one part is carried by the flow from the generator and the other part is carried by the flow from the evaporator. There isCOP of wetting fluids can be expressed asSubstituting Equations (8), (10), and (20) into (6), the limiting COPlimit for wet working fluid, isentropic working fluid, and dry working fluid are the same. Therefore, the limiting COP of ERC be expressed as:COPlimit is a function of TH, TM, TL, and β. The greater the slope β and COPlimit.Comparing (26) and (19), it is found that the expressions of COP isidealCOP and limitCOP:ηLTP can be an index that reflects its distance to “perfection” in the ERC. It can also evaluate the influence of the working fluid itself on the cycle performance upper limit.For the ideal ERC, the T-s diagram is infinite. Some fluids are approximately regarded as isentropic fluids [COPlimit and ηLTP are investigated. The referenced operating conditions of TH, TL, and TM are 363.15 K, 303.1 K, and 273.15 K, respectively. Based on the above method, the performance of LERC with 15 refrigerants is researched and compared. These fluids are divided into three groups: wet fluids , isentropic fluids , and dry fluids . As mentioned above, there is no perfect isentropic fluid whose slope of saturated vapor in the c fluids . In thisCOPlimit at different high temperatures for these fluids. As can be seen, when TH increases from 343.15 to 400.15 K, COPlimit increases. This is because when TH increases, the temperature difference between the middle temperature and high temperature rises. According to Equation (22), the limiting COP increases.COPlimit of R152a is significantly higher than that of R134a and R290. When TH increases from 343.15 to 383.15 K, its COPlimit increases from 0.941 to 1.479. This is because, for R152a, its Δsa-b is much larger than that of R134a. Although smaller than R290, its slope β is greater. For the isentropic fluid group, the COPlimit of R141b is the largest, and it is the smallest for R1234yf. This is because the slope and entropy increase Δsa-b of R141b is the largest in this group.As shown in COPlimit of R123 is higher than the others, while it is the lowest for R227ea. When TH increases, COPlimit increases from 0.87 to 1.15 for R227ea. For R123, it increases from 0.95 to 2.02, and for R601, COPlimit increases from 0.95 to 2.119. The order of COPlimit for these eight selected dry fluids is R123>R601>R365mfc>R600>R245fa>R600a>R236fa>R227ea. Among these dry fluids, the slope of R123 is the largest, but Δsa-b of R601 is the largest. The slope of R227ea is only smaller than R123, but its Δsa-b is the smallest. The COPlimit differences between these dry fluids are small at low temperatures, and they increase gradually as TH increases. It can be seen from Equation (27) that COPlimit is a function of high temperature TH, the slope of the saturated liquid line β, and entropy increase Δsa-b. For wet fluids and isentropic fluids, β and Δsa-b are constant when TH varies. The COPlimit is influenced by TH. However, for dry fluids, both TH and Δsa-b change when TH varies. This results in different COPlimit variations for wet fluids, isentropic fluids, and dry fluids.For the dry fluid group, as shown in ηLTP varies with high temperatures for the selected pure fluids. It is found when the TH increases, ηLTP keeps decreasing for all fluids. This is because when TH increases, as the slope remains the same, the loss caused by the subcooling section increases. This means that the higher the heat source temperature, the larger the gap between the limiting cycle and the ideal cycle. This also indicates that working fluid has a greater negative effect on cycle performance in higher generating temperatures.ηLTP remains the same compared with that of COPlimit for all fluids. The difference in ηLTP is caused by that of COPlimit. Therefore, ηLTP has similar variation law of COPlimit. For the wet fluid group, the order of ηLTP is R152a>R134a>R290. For the isentropic fluid group, the order is R141b>R142b>R1234ze>R1234yf. For the dry fluid group, the order is R123>R601>R365mfc>R600>R245fa>R600a>R236fa>R227ea. R152a, R141b, and R123 perform best in each group, respectively. The order of ηLTP is R141b>R123>R152a, with the value of 86.8%, 84.90%, and 83.67%, separately.The order of TM on the limiting performance of ERC. It can be seen from TH increases from 298.15 to 308.15 K, COPlimit decreases for all fluids. When TM increases, the temperature difference between middle temperature and low temperature increases. Consequently, the efficiency of the refrigeration part decreases according to Equation (27). At the same time, the temperature difference between the middle temperature and high temperature is reduced, which leads to a reduction in the efficiency of the cycle driving part. Therefore, the efficiency of the entire refrigeration cycle decreases.TM increases, the temperature difference between high temperature and middle temperature decreases. As a result, the irreversibility in the subcooling section of the working fluid decreases accordingly.As shown in COP that is expressed by the fluid thermophysical properties and working conditions is derived. And the limiting performance of dry fluids, wet fluids, and isentropic fluids is researched and compared. The key thermophysical parameters of the working fluid that affect COPlimit are β and Δsa-b. COPlimit is a function of TH, TM, TL, β, and Δsa-b, and COPlimit increases with the increase in TH and TM for all fluids; however, ηLTP decreases as TH increases. For the wet fluid group, the COPlimit and ηLTP of R152a are the largest. For the dry fluid group, R123 is better than the others, and ηLTP of R141b, R152a, and R123 at the referenced state is 86.8%, 84.90%, and 83.67%, respectively.To evaluate the performance upper limit of ERC with pure fluids quantitatively, a LERC is proposed in this research. Combined with a thermodynamic graphical analysis method, the limiting


To advance understanding of the heterogeneity in the course of ADHD, joint symptom trajectories of inattention and hyperactivity-impulsivity from childhood to young adulthood were modelled and associated with genetic, demographic, and clinical characteristics. Data were obtained from the NeuroIMAGE cohort which includes 485 individuals with ADHD, their 665 siblings, and 399 typically developing children. Trajectories were based on scores of the Conners Parent Rating Scale Revised and estimated over seven homogeneous age bins (from 5 to 28 years) using parallel process latent class growth analysis on data collected across 2–4 time points. Multilevel multinomial logistic regression was used to identify characteristics that differentiated between the derived classes. A seven-class solution revealed “severe combined stable” (4.8%), “severe combined decreasing” (13%), “severe inattentive stable” (4.8%), “moderate combined increasing” (7.5%), “moderate combined decreasing” (12.7%), “stable mild” (12.9%), and “stable low” (44.3%) classes. Polygenic risk for depression, ADHD diagnosis, ADHD medication use, IQ, comorbid symptom levels , and functional impairment levels differentiated classes with similar ADHD symptom levels in childhood but a diverging course thereafter. The course of ADHD is highly heterogeneous, with stable, decreasing, and increasing trajectories. Overall, severe symptom levels in childhood are associated with elevated-to-severe symptom levels in adolescence and young adulthood, despite substantial symptom reductions. Beyond symptom severity in childhood, genetic, demographic, and clinical characteristics distinguish the heterogeneous course.The online version contains supplementary material available at 10.1007/s00787-021-01764-z. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental psychiatric disorder which is common in both children and adults. Diagnostic criteria are based on two core symptom domains: inattention and hyperactivity-impulsivity. The presence and severity of ADHD symptoms differ considerably between children with ADHD , 2. FollThe longitudinal studies covering adolescence that have been conducted so far have yielded important insights. Several developmental subgroups have been identified, often including a group with a remitting course in addition to a group with a persisting and/or even deteriorating course –9. StudiThe first aim of the current study was to describe the heterogeneous course of ADHD. Data were obtained from the longitudinal NeuroIMAGE study which includes 485 individuals with ADHD, their 665 siblings with an increased vulnerability to ADHD, and 399 typically developing controls. The course of ADHD was based on scores of the cognitive problems/inattention and hyperactivity scales from the Conners Parent Rating Scale Revised and estimated over seven homogeneous age bins (between 5 and 28 years) using parallel process latent class growth analysis on data collected across 2–4 time points. Using homogeneous age bins in a heterogeneous age cohort is novel and makes our study particularly suited to disentangle momentaneous heterogeneity from developmental heterogeneity . The advThe data of the multi-wave NeuroIMAGE cohort originate from the Dutch part of the International Multicentre ADHD Genetics (IMAGE) study run by the Radboud University Medical Centre Nijmegen, Vrije Universiteit Amsterdam, and University Medical Centre Groningen , 21. TheTo assess symptom severity, the Conners Parent Rating Scale Revised long (CPRS-RL) was used at wave one, three, and four . The CPRAt wave one, participants were assessed for ADHD by the Parental Account of Children's Symptoms (PACS) and at wave three and four by the present and lifetime version of the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS) , 24. TheFunctional impairment in daily life was assessed at wave one, three, and four by the impact supplement of the Strengths and Difficulties Questionnaire (SDQ) . A parenN = 18,988), antisocial behaviour (370 cases and 5850 controls), and major depressive disorder  were available online  [P < 1. This threshold was chosen to maximally capture phenotypic variance. Polygenic risk for aggression, major depressive disorder, and antisocial behaviour were chosen in line with the comorbid problems studied based on clinical relevance, i.e., externalizing, internalizing, and social problems.PRS-analyses were performed using PRSice2-software . GWAS sutistics) –31. SNPsAdditional information on variables is provided in Online Resource 2.To ensure that homogenous developmental groups were studied the data were divided in seven age bins based on the participants’ age for each observation . This creates an optimal form of a cross-sequential design , see Online Resource 3.N = 1064; see Online Resource 1), and full information maximum likelihood was used as the estimation method. To avoid ending up with estimates at local maxima, models were run with numerous sets of initial stage random starting values (1000) and final stage optimizations (500). For each developmental subgroup, the percentage of individuals with a clinical ADHD diagnosis, comorbid symptom levels, and functional impairment levels were subsequently plotted per age bin to illustrate developmental trends.First, developmental subgroups were identified by means of parallel processes latent class growth analysis, which is a multivariate extension of latent class growth analysis. A latent class growth analysis estimates an unique intercept and slope for a given number of latent classes, with the within class variance and covariance of the intercept and slope restricted to zero . In the Second, differences between the developmental subgroups in age, gender, presence of a clinical ADHD diagnosis, medication use, intelligence quotient (IQ), educational attainment, socio-economic status (SES), comorbid symptoms, functional impairment, and polygenic risk for ADHD, aggression, antisocial behaviour, and depression were examined. To make sure that potential group differences on these variables not merely reflected symptom severity differences already present in childhood, we defined our contrasts of interest as the differences between classes with a similar severity in childhood but a diverging course during adolescence and young adulthood. Class membership was predicted by each aforementioned variable separately using the three-step approach and multilevel multinomial logistic regression . VariablBased on both fit statistics and inspection of the clinical relevance of trajectories, model estimation yielded a seven-class solution that optimally described the data. Further information on the model fit is provided in Online Resource 4.The inattention and hyperactivity-impulsivity symptom trajectories for all classes are displayed in Fig. The clinical ADHD diagnosis rates approximately followed the symptom course of the different classes. This also held for comorbid externalizing and emotion dysregulation problems. Comorbid internalizing symptom levels were generally low. While most participants reported substantial functional impairment both comorbid symptoms and functional impairment decreased over time. For more information see Online Resources 5–7.z scores given per class. Visual inspection of Table Means and standard deviations of the demographic and clinical factors are listed per class in Table The seven trajectories yielded four contrasts of interest with similar severity levels in childhood: (1) the severe combined stable was compared with severe inattentive stable class, 2) the severe combined stable was compared with the severe combined decreasing class, (3) the severe inattentive stable was compared with severe combined decreasing class, and (4) the moderate combined increasing class was compared with the moderate combined decreasing class. The odds ratios and p-values for the contrasts of interest for genetic, demographic, and clinical factors are provided in Table  the seveThe severe combined stable class differed from the severe inattentive stable class by a lower IQ, higher comorbid oppositional behaviour, emotional instability , anxious behaviour, perfectionism, and social problem symptom levels.The severe combined stable and severe inattentive stable classes had both higher clinical ADHD rates, lifetime medication use, and functional impairment levels compared to the severe combined decreasing class. The severe combined stable class additionally differed from the severe combined decreasing class by higher comorbid oppositional behaviour, emotional instability, anxious behaviour, perfectionism, and social problem symptom levels. The severe inattentive stable class additionally differed from the severe combined decreasing class by higher comorbid oppositional behaviour symptom levels.The moderate combined increasing class differed from the moderate combined decreasing class by a lower polygenic risk for depression and higher comorbid oppositional behaviour symptom levels.The remaining variables  did not significantly differ between the classes with similar childhood ADHD symptom levels.The current study examined (1) the heterogeneity in the joint course of inattention and hyperactivity-impulsivity from childhood to young adulthood and (2) the factors that differentiated trajectories with similar symptom severity in childhood but a diverging course thereafter. The study delivered several key findings. With respect to aim (1) we showed that the course of inattention and hyperactivity-impulsivity during adolescence was very heterogeneous. Among the identified trajectories were groups of individuals with stable high, decreasing, and increasing symptom levels over time. In our sample, 9.6% had persistently high levels of both inattention and hyperactivity-impulsivity, or attention problems only. For around 26% symptom levels decreased, although the clinical ADHD diagnosis still applied in most cases (52.2%). Among those with an increasing symptom course, 18.6% had an adolescent-onset of clinical ADHD. This late-onset resulted from a gradually progressing ADHD symptom severity during adolescence and was unrelated to an onset of comorbid conditions. With respect to aim (2) it was found that most demographic and clinical factors, which are known to associate with the course of ADHD, correlated in a ‘dose–response’ relationship with the symptom severity of the identified trajectories. Beyond this general pattern aligned with ADHD symptom severity, polygenic risk for depression, ADHD diagnosis, ADHD medication use, IQ, comorbid symptom levels , and functional impairment levels differentiated classes with similar ADHD symptom levels in childhood but a diverging course thereafter.Within the increasing trajectory, a fourth of the patients had an adolescent-onset of ADHD. This is in line with recent research suggesting that ADHD can manifest beyond childhood –16. In aGenetic, demographic, and clinical correlates of the course of ADHD generally followed the overall symptom severity of the identified classes in a ‘dose–response’ relationship. This is consistent with existing literature focussed on the presence or absence of ADHD, showing that persons with persistent ADHD symptoms had the most comorbid problems and functional impairment , 14, 38.Genetic and environmental risk factors that did not follow the ADHD symptom course were polygenic risk for ADHD, aggression, antisocial behaviour, and depression, IQ, and SES. First, in the severe inattentive stable class the polygenic risk for ADHD was remarkably low and the polygenic risk for depression relatively high. Possibly, the ADHD symptoms of the individuals that belong to this “inattentive only” class have a different etiological background than both remitting (both hyperactivity-impulsivity and inattention become less severe over time) and persistent ADHD . The particularly high polygenic risk for depression in persons of whom the ADHD symptoms remitted, indicates that this might be a subgroup of persons with genetic vulnerability to both ADHD and depression that are at risk of future comorbid depression, in line with the high genetic correlation between ADHD and depression .N = 47) was permitted. Yet, this decreased statistical power to detect differentiating factors, which was the second focus of our study. Even larger samples would be needed to further characterize the less common trajectories. Last, we cannot exclude the possibility of reporting false positive differences, as we did not correct for multiple testing, to keep statistical power high. Despite these limitations, the value of using the (few) existing longitudinal cohorts that reach adulthood to enhance understanding of the heterogeneity of ADHD beyond childhood cannot be overstated and we pursued this, in our view, in the best possible way.We are among the very first to do this kind of detailed developmental work. While this is an asset, our study had several limitations. The current study was longitudinal, but the age at entry, age when data contribution ended, and the number of data points differed between participants. This was handled by creating an optimal form of a cross-sequential design using same age bins. While this gave the opportunity to examine homogenous developmental groups and model trajectories over a much longer developmental period, some caution is necessary when interpreting data in terms of longitudinal stability and change. This, because not all participants were followed from below nine years old to above twenty years old as is inherent to the cross-sequential design. In addition, the cross-sequential design includes probands with an older age at entry, which might have led to an overestimation of the number of persons in the severe combined stable class when compared to a longitudinal design of same aged individuals. This, since adolescents who still have inattention and/or hyperactivity-impulsivity symptoms are, by definition, not among the subgroup that remits during this age. The primary focus of this paper was to comprehensively chart and describe the heterogeneous course of ADHD. To be able to identify relatively rare symptom trajectories  the identification of small classes  ADHD symptoms show different symptom trajectories with partly disjoint changes of inattention and hyperactivity-impulsivity over time. Individuals following a progressive symptom trajectory, part of whom had an adolescent-onset ADHD diagnosis, already had subthreshold levels of ADHD. In addition to childhood symptom severity of ADHD, polygenic risk for depression, ADHD diagnosis, ADHD medication use, IQ, comorbid problems, and functional impairment differentiated classes with similar ADHD symptom levels in childhood but a diverging course thereafter. Environmental factors, such as parental scaffolding, were currently not studied but may also explain part of the ADHD course. The heterogeneity in the course of ADHD identified in this study underlines the necessity of monitoring and tailored care for individuals with subthreshold as well as clinical ADHD.Supplementary file1 (PDF 485 kb)Below is the link to the electronic supplementary material.